agar and Streptococcal-Infections

Group B streptococci (GBS) are bacteria that can cause preterm birth and invasive neonatal disease. Heterogeneous expression of virulence factors enables GBS to exist as both commensal bacteria and to become highly invasive. A molecular epidemiological study comparing GBS bacterial traits, genotype and host characteristics may indicate whether it is possible to predict the risk of perinatal invasive GBS disease and more accurately target intrapartum antibiotic prophylaxis. A total of 229 invasive GBS isolates from Swedish pregnant women or neonates were assessed for virulence and phenotypic traits: hemolysis zone, hemolytic pigment (Granada agar), Streptococcus B Carrot Broth (SBCB) assay, CAMP factor, and hyaluronidase activity. Genes regulating hemolytic pigment synthesis (covR/covS, abx1, stk1, stp1) were sequenced. Of the virulence factors and phenotypes assessed, a Granada pigment or SBCB score ≥ 2 captured more than 90% of EOD isolates with excellent inter-rater reliability. High enzyme activity of hyaluronidase was observed in 16% (36/229) of the invasive GBS isolates and notably, in one case of stillbirth. Hyaluronidase activity was also significantly higher in GBS isolates obtained from pregnant/postpartum individuals versus the stillbirth or neonatal invasive isolates (p < 0.001). Sequencing analysis found that abx1 (g.T106I), stk1 (g.T211N), stp1 (g.K469R) and covS (g.V343M) variants were present significantly more often in the higher (Granada pigment score ≥ 2) versus lower pigmented isolates (p < 0.001, each variant). Among the 203 higher Granada pigment scoring isolates, 22 (10.8%) isolates had 3 of the four sequence variants and 10 (4.9%) had 2 of the four sequence variants. Although heterogeneity in GBS virulence factor expression was observed, the vast majority were more highly pigmented and contained several common sequence variants in genes regulating pigment synthesis. High activity of hyaluronidase may increase risk for stillbirth and invasive disease in pregnant or postpartum individuals. Our findings suggest that testing for GBS pigmentation and hyaluronidase may, albeit imperfectly, identify pregnant people at risk for invasive disease and represent a step towards a personalized medical approach for the administration of intrapartum antibiotic prophylaxis.

Topics: Agar; Anti-Bacterial Agents; Female; Genotype; Humans; Hyaluronoglucosaminidase; Infant, Newborn; Phenotype; Pregnancy; Pregnant Women; Premature Birth; Reproducibility of Results; Stillbirth; Streptococcal Infections; Streptococcus agalactiae; Sweden; Virulence; Virulence Factors

Topics: Agar; Culture Media; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Streptococcal Infections; Streptococcus agalactiae

Topics: Agar; Artificial Intelligence; Automation, Laboratory; Bacteriological Techniques; Child; Chromogenic Compounds; Humans; Pharyngitis; Pharynx; Sensitivity and Specificity; Software; Streptococcal Infections; Streptococcus pyogenes

Topics: Agar; Disease Outbreaks; Health Personnel; Humans; Streptococcal Infections; Streptococcus pyogenes

Topics: Agar; Bacteriological Techniques; Carrier State; Culture Media; Female; Humans; Rectum; Streptococcal Infections; Streptococcus agalactiae; Vagina

Topics: Agar; Disease Outbreaks; Health Personnel; Humans; Pharynx; Streptococcal Infections; Streptococcus pyogenes

Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a major cause of chorioamnionitis and neonatal sepsis. This study evaluates Raman spectroscopy (RS) to identify spectral characteristics of infection and differentiate GBS from Escherichia coli and Staphylococcus aureus during ex vivo infection of human fetal membrane tissues. Unique spectral features were identified from colonies grown on agar and infected fetal membrane tissues. Multinomial logistic regression analysis accurately identified GBS infected tissues with 100.0% sensitivity and 88.9% specificity. Together, these findings support further investigation into the use of RS as an emerging microbiologic diagnostic tool and intrapartum screening test for GBS carriage.

Topics: Agar; Algorithms; Anti-Bacterial Agents; Chorioamnionitis; Escherichia coli; Escherichia coli Infections; Extraembryonic Membranes; Female; Humans; Logistic Models; Microbiological Techniques; Pregnancy; Regression Analysis; Spectrum Analysis, Raman; Staphylococcal Infections; Staphylococcus aureus; Streptococcal Infections; Streptococcus agalactiae

Streptococcus milleri group (SMG) is a group of three streptococcal species (S. anginosus, intermedius and constellatus) that act as opportunist pathogens, among others in cystic fibrosis. Due to their fastidious character, they are both difficult to cultivate and to differentiate from less pathogenic streptococcal species, therefore being most probably underdiagnosed. Semi-selective McKay agar and NAS agar were developed to facilitate SMG recovery from clinical samples; however, direct comparison of recovery rates has not been published yet. We tested the performance of both media on 123 patient samples and demonstrated general superiority of NAS agar for SMG recovery during primary cultivation convincingly. This observation was also confirmed by quantitative drop tests during subculture. Despite the undisputed overall superiority of NAS agar over McKay agar, a smaller fraction of strains grew better on McKay agar. Inter-strain differences were the most probable explanation. Therefore, when economic conditions are not limiting and maximum recovery rate is desirable, both plates are advised to be used in parallel for primary cultivation of clinical samples.

Topics: Agar; Bacteriological Techniques; Culture Media; Humans; Streptococcal Infections; Streptococcus milleri Group

Bacteriological examination of milk samples is a prerequisite for pathogen-specific therapy and aids in limiting antimicrobial resistance. The aims of this study were to establish a standardized scheme for reliable Streptococcus uberis identification in routine diagnosis and to evaluate the accuracy of conventional tests and growing patterns of Strep. uberis on a selective medium (modified Rambach agar medium, MRAM) using 16S rRNA gene sequencing analysis as a reference method. We obtained isolates of presumptive Strep. uberis (n = 336) from quarter milk samples of dairy cows with intramammary infections and classified the isolates into 2 clusters using biochemical characterization. In cluster 1 (n = 280), cocci grew as non-hemolytic colonies, hydrolyzing esculin, carrying no Lancefield antigen (A/B/C/D/G) or Christie Atkins Munch-Petersen factor, and their growth was inhibited on an Enterococcus agar. Production of β-d-galactosidase on MRAM was shown by 257 of the cluster 1 isolates (91.79%), and 16S rRNA gene sequencing verified 271 (96.79%) of the isolates to be Strep. uberis. In 264 isolates (94.29%), MRAM agreed with the sequencing results. In cluster 2 (n = 56), isolates showed different characteristics: 37 (66.07%) were β-d-galactosidase-positive, and based on 16S sequencing results, 36 (64.29%) were identified correctly as Strep. uberis using biochemical methods. Identification success in this group differed significantly between routine diagnosis and MRAM application: MRAM agreed with sequencing results in 47 isolates (83.93%). To identify Strep. uberis and differentiate it from other lactic acid bacteria in routine diagnosis, we suggest using catalase reaction, hemolysis, esculin hydrolysis, and growth on enterococci agar. Isolates that show a typical biochemical profile can be identified satisfactorily with these tests. For Strep. uberis isolates with divergent patterns, application of MRAM as a follow-up test increased the diagnostic accuracy to 94.64%.

Topics: Agar; Animals; Cattle; Female; Mastitis, Bovine; Milk; RNA, Ribosomal, 16S; Streptococcal Infections; Streptococcus

We evaluated the feasibility and efficacy of a commercially available methicillin-resistant Staphylococcus aureus (MRSA)-selective agar, chromID(™) MRSA, to detect group B streptococci with reduced penicillin susceptibility (PRGBS) in this study. The results showed 72.4% (21/29) sensitivity and 98.4% (60/61) specificity to detect PRGBS using this method.

Topics: Agar; Bacteriological Techniques; beta-Lactam Resistance; Culture Media; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

Penicillins remain first-line agents for treatment of group B Streptococcus (Streptococcus agalactiae; GBS) infections; however, several reports have confirmed the existence of GBS with reduced penicillin susceptibility (PRGBS). Because no selective agar plates for detection of PRGBS are available to date, in this investigation, we developed the selective agar plate for detection of PRGBS. We used 19 genetically well-confirmed PRGBS isolates and 38 penicillin-susceptible GBS isolates identified in Japan. For preparation of trial PRGBS-selective agar plates, we added 1 of antimicrobial agents (among oxacillin, ceftizoxime, and ceftibuten) to a well-established GBS-selective agar plate. Among 12 trial PRGBS-selective agar plates, Muller-Hinton agar containing 128 μg/mL ceftibuten with 5% sheep blood, 8 μg/mL gentamicin, and 12 μg/mL nalidixic acid was the most appropriate selective agar for PRGBS, showing 100% sensitivity and 81.6% specificity. In cases of potential nosocomial spread of PRGBS, the selective agar plate could be useful and reliable.

Topics: Agar; Anti-Bacterial Agents; Bacteriological Techniques; Ceftibuten; Cephalosporins; Culture Media; Drug Resistance, Bacterial; Gentamicins; Humans; Japan; Nalidixic Acid; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

We isolated and characterized three multidrug-resistant clinical isolates of group B streptococci with reduced penicillin susceptibility (PRGBS) that formed small non-beta-hemolytic colonies on sheep blood agar plates but grew well on chocolate agar plates. They can be overlooked in the bacterial identification step, leading to clinical misdiagnosis and treatment failure.

Topics: Agar; Aged, 80 and over; beta-Lactam Resistance; Blood; Culture Media; Drug Resistance, Multiple, Bacterial; Hemolysis; Humans; Male; Microbial Sensitivity Tests; Penicillins; Streptococcal Infections; Streptococcus agalactiae

Group B Streptococcus (GBS) is a known leading causative pathogen of neonatal infection. Efficient screening and identification of women colonized with GBS is important for the prevention of invasive neonatal infections.. A total of 628 vaginal/rectal specimens were collected from pregnant women in Beijing, China. The chromogenic medium chromID Strepto B agar (STRB) was evaluated for its reliability in screening GBS from the vaginal/rectal swabs; results were compared to those of blood agar plates (BAP). Furthermore, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to confirm the colonies suspected of being GBS on STRB.. STRB showed excellent performance for GBS detection and outperformed BAP due to its higher sensitivity. Furthermore, MALDI-TOF MS could reliably differentiate the putative GBS isolates on STRB.. This study demonstrated that STRB combined with MALDI-TOF MS is a fast, sensitive, and accurate method for the identification of GBS-colonized pregnant women.

Topics: Adult; Agar; Bacteriological Techniques; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcal Infections; Streptococcus agalactiae; Vagina; Young Adult

Group B Streptococcus (GBS) are normal flora of the vagina and intestinal, but if the pregnant woman was infected with GBS in the vagina, miscarriage or premature would occur or the newborn would be developed to severe GBS infection. It is recommended that the inspection of GBS on all pregnant women by Japan Society of Obstetrics and Gynecology (JSOG) and Center for Disease Control and Prevention (CDC). We examined the comparison of detection rate between Pourmedia GBS agar (Eiken Chemical Co., Ltd.) and Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium (Nissui Pharmaceutical Co., Ltd.) on 112 sample. The positive rate of Pourmedia GBS agar was 21.4% (24/112 samples), Whereas Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium was 17.8% (20/112 samples). It was found that the detection rate was improved by using Pourmedia GBS agar on GBS screening test of vaginal swab.

Topics: Agar; Colony Count, Microbial; Culture Media; Female; Humans; Microbial Viability; Pregnancy; Pregnancy Complications, Infectious; Streptococcal Infections; Vaginal Smears

In the industrial world, the agar diffusion test is a standard procedure for the susceptibility testing of bacteria isolates. Beta-hemolytic Streptococcus spp. are tested with Müller-Hinton agar supplemented with 5 % blood, a so-called blood agar. The results are interpreted using standardized tables, which only exist for this type of nutrient matrix. Because of a number difficulties, both with respect to technical issues and to manual skills, blood agar is not a feasible option in many developing countries. Beta-hemolytic Streptococcus spp. also grow on Standard Nutrient Agar 1 (StNA1). This suggests using that type of nutrient medium for running agar diffusion tests. However, there are no standardized tables that can be used for interpreting the diameters of the zones of inhibition on StNA1 1. Using the existing standardized tables for blood agar to interpret cultures on StNA1 1 would be of great benefit under such circumstances where blood agar is not available. With this in mind, we conducted comparative tests to evaluate the growth characteristics of beta-hemolytic Streptococcus spp. on StNA1 1 compared to Müller-Hinton agar supplemented with 5 % sheep blood. In this study, we were able to show that beta-hemolytic Streptococcus spp. develop similar zones of inhibition on blood agar and on StNA1 1. Therefore, it is suggested that, for the interpretation of antibiograms of beta-hemolytic Streptococcus spp. performed on StNA1 1, the standard tables for blood agar can be used.

Topics: Agar; Culture Media; Developing Countries; Humans; Microbial Sensitivity Tests; Streptococcal Infections; Streptococcus

An aerobic chromogenic medium, CHROMagar™ StrepB agar, designed for isolation of group B Streptococci, was evaluated on 285 prepartum vaginal/rectal swabs from pregnant women. After overnight enrichment in Todd-Hewitt broth containing 15μg/ml nalidixic acid and 10μg/ml colistin, sensitivities were respectively 79% on day 1 and 92% on day 2, and significantly higher than those achieved by blood agar (40% and 58%) and colimycin-nalidixic-acid agar (82% on day 2).

Topics: Agar; Bacteriological Techniques; Culture Media; Female; Humans; Mass Screening; Pregnancy; Rectum; Streptococcal Infections; Streptococcus agalactiae; Vagina

The aim of the study was to assess the reliability of human blood agar media (HuBA) in identifying Streptococcus pyogenes by hemolysis analysis. We analyze several factors that might affect the accuracy of HuBA media for microbial analysis, including incubation time, blood group, Rh factor and presence of antistreptolysin-o.

Topics: Agar; Culture Media; Hemolysin Proteins; Hemolysis; Humans; Streptococcal Infections; Streptococcus pyogenes

The 'Streptococcus milleri' group (SMG) has recently been recognized as a contributor to bronchopulmonary disease in cystic fibrosis (CF). Routine detection and quantification is limited by current CF microbiology protocols. McKay agar was developed previously for the semi-selective isolation of this group. Here, McKay agar was validated against a panel of clinical SMG isolates, which revealed improved SMG recovery compared with Columbia blood agar. The effectiveness of this medium was evaluated by appending it to the standard CF sputum microbiology protocols in a clinical laboratory for a 6-month period. All unique colony types were isolated and identified by 16S rRNA gene sequencing. Whilst a wide variety of organisms were isolated, members of the SMG were the most prevalent bacteria cultured, and McKay agar allowed routine quantification of the SMG from 10(3) to >10(8) c.f.u. ml(-1) directly from sputum. All members of the SMG were detected [Streptococcus anginosus (40.7 %), Streptococcus intermedius (34.3 %) and Streptococcus constellatus (25 %)] with an overall prevalence rate of 40.6 % in our adult CF population. Without exception, samples where SMG isolates were cultured at 10(7) c.f.u. ml(-1) or greater were associated with pulmonary exacerbations. This study demonstrates that McKay agar can be used routinely to quantify the SMG from complex clinical samples.

Topics: Adult; Agar; Colony Count, Microbial; Culture Media; Cystic Fibrosis; Female; Humans; Male; Sensitivity and Specificity; Sputum; Streptococcal Infections; Streptococcus anginosus; Streptococcus constellatus; Streptococcus intermedius

We compared ChromID Strepto B agar (STRB; bioMérieux, Inc.), a selective and differential medium for group B streptococcus, with culture using neomycin-nalidixic acid agar (NNA) and LIM broth. STRB alone was more sensitive (87.7%) than NNA alone (79.0%), while each had a sensitivity of 100% when used in conjunction with LIM broth.

Topics: Agar; Bacteriological Techniques; Chromogenic Compounds; Culture Media; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

Topics: Agar; Bacteriological Techniques; Culture Media; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Streptococcal Infections; Streptococcus agalactiae

The classic method for H(2)O(2) detection involving Prussian blue formation was adapted to formulate a novel agar medium that makes possible in situ detection of H(2)O(2) produced by bacteria. Using this medium, colonies of H(2)O(2)-producing species including Streptococcus pyogenes were easily identified by the appearance of blue halos. The utility of the medium was further illustrated by its successful application to the isolation of H(2)O(2)-producing mutants from a non-H(2)O(2)-producing stain of S. pyogenes.

Topics: Agar; Bacteriological Techniques; Chromogenic Compounds; Culture Media; Humans; Hydrogen Peroxide; Prussian Blue Reaction; Streptococcal Infections; Streptococcus pyogenes

An evaluation on the applicability of Mitis Salivarius agar (MS) medium, commonly used for the detection of oral streptococci in human and animals, to dog specimens and the development of a new selective medium for isolating streptococci from the canine oral cavity are described. Oral samples from dogs were cultured on MS medium under anaerobic conditions. The predominant facultative anaerobic bacteria on MS plates were gram-negative rods. Selectivity of streptococci on MS medium was 21.2%. A new selective medium, designated MS-CAN-AE, was developed for the isolation of streptococci from the canine oral cavity. The average growth recovery of laboratory and clinically isolated strains of streptococci on MS-CAN-AE medium was 84.1% of that on MS medium. Gram-positive rods and gram-negative rods and cocci rarely grew on the MS-CAN-AE. The selectivity of MS-CAN-AE was 95.0% for clinical samples. MS-CAN-AE medium will be helpful for investigations of streptococci in the canine oral cavity.

Topics: Agar; Animals; Bacteriological Techniques; Culture Media; Dog Diseases; Dogs; Female; Male; Mouth Diseases; Streptococcal Infections; Streptococcus

This study compared several traditional culture-based media and chairside cultural assays for ability to recover mutans streptococci (MS) from pure cultures and from saliva samples.. When pure cultures were used with traditional culture-based media, mitis-salivarius bacitracin (MSB) agar demonstrated less support for bacterial recovery than trypticase-yeast extract-cysteine sucrose-bacitracin (TYCSB) agar and the modified medium of Ritz (HLR-S). One species of MS, Streptococcus ferus (c), was not recovered on MSB medium. Chairside cultural tests displayed considerable disparity between tests in recovering bacteria from pure cultures. On the glass adherence assay (Mucount), S. ferus was not detected and Streptococcus criceti was not detected on the dipslide assay (Cariescreen SM) or on the plastic adherence assay (Dentocult SM Strip mutans). The frequency of isolation of pure strains of bacteria other than MS was common. From saliva samples, the frequency of isolation of MS on HLR-S and TYCSB media and the glass adherence assay was 91-97%. The frequency of isolation on MSB medium and on the dip-slide and plastic adherence assays was significantly decreased (37, 47 and 69%, respectively). Recovery scores varied considerably among the culture methods studied and tended to be highest on the HLR-S medium and on the glass adherence assay.. Growth and recovery profiles of pure bacterial cultures and of saliva samples for the MS varied according to different media.. Caution should be exercised in comparing results between studies that employ different cultural methods for MS enumeration.

Topics: Adolescent; Adult; Agar; Bacitracin; Bacteriology; Colony Count, Microbial; Culture Media; Female; Humans; Male; Middle Aged; Reagent Kits, Diagnostic; Saliva; Streptococcal Infections; Streptococcus mutans

To evaluate a new chromogenic agar as a screening medium for the isolation of Group B streptococci from high vaginal swabs from pregnant women.. The medium was evaluated with 195 high vaginal swabs referred for antenatal screening and compared with blood agar and Granada medium. The new chromogenic medium showed 100% sensitivity for the detection of Group B streptococci, and also showed a positive predictive value of 100%. Granada medium also showed excellent sensitivity and specificity and both media were superior to blood agar.. The new chromogenic medium showed excellent performance for the detection of Group B streptococci from clinical samples.. This is the first chromogenic medium described for the detection of Group B streptococci. The medium offers an effective and convenient alternative to conventional media, currently used in clinical laboratories.

Topics: Agar; Bacterial Typing Techniques; Chromogenic Compounds; Colony Count, Microbial; Culture Media; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Streptococcal Infections; Streptococcus agalactiae; Vagina

In total, 320 vaginal or rectal swabs were cultured on Granada medium (GM) or Group B Streptococcus Differential Agar (GBSDA), and were also inoculated into LIM broth (Todd-Hewitt broth supplemented with selective antibiotics), for detection of group B Streptococcus (GBS). Overall, GBS isolates were detected on 53 of the 320 swabs; 47 of these isolates grew on both GM and GBSDA, five only on GBSDA, and one only following subculture from LIM broth. GBSDA appears to be a valid alternative to GM for the growth of GBS isolates from pregnant women.

Topics: Agar; Bacteriological Techniques; Culture Media; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Rectum; Specimen Handling; Streptococcal Infections; Streptococcus agalactiae; Vagina

The Granada agar plate (GAP; Biomedics SL, Madrid, Spain) was evaluated for the detection of group B streptococci (GBS) in urine specimens from pregnant women submitted for testing for asymptomatic bacteriuria and was compared with blood agar (BA [Columbia agar with 5% sheep blood]; bioMérieux, Marcy l'Etoile, France). The GAP detected 103 out of 105 GBS, whereas BA detected only 50. Use of the GAP could be a good method for the detection of GBS in urine specimens from pregnant women.

Topics: Agar; Bacteriological Techniques; Bacteriuria; Culture Media; Female; Humans; Infant, Newborn; Pregnancy; Streptococcal Infections; Streptococcus agalactiae; Urine

To compare the microbiologic yield of cultures obtained by direct inoculation of blood agar plates (BAP) from corneal ulcer swabbings versus indirect inoculation via transport media in a rabbit model of Streptococcus pneumoniae bacterial keratitis.. The corneas of 12 rabbits were inoculated with S. pneumoniae. Keratitis was confirmed 18 hours later. Sampling was performed at four 2.5-hour intervals. At each interval, corneal swabs were directly applied to BAP and placed into transport medium: thioglycollate and Amies medium without charcoal. Swabbings were then subcultured onto BAP at two time points: 2 and 24 hours after collection in transport medium. Plates were evaluated 48 hours later. Organism recovery rates were measured in terms of the number of positive culture plates observed and the bacterial colony counts on each plate.. The rate of positive cultures overall was 69%. The recovery rates were similar for direct inoculation, inoculation via Amies held for 2 hours, and inoculation via Amies held for 24 hours. Direct inoculation yielded fewer colonies than indirect inoculation via Amies held for 24 hours (p = 0.008). Direct inoculation yielded a higher rate of positive cultures than did thioglycollate held for 2 hours (p = 0.004) or 24 hours (p < 0.001). The rate of nonpneumococcal contaminants ranged from 6% of BAP subcultured from thioglycollate held for 24 hours to 28% of directly inoculated BAP.. Amies medium without charcoal may be used as a transport medium for up to 24 hours in the recovery of S. pneumoniae from corneal ulcers in this rabbit model. Thioglycollate appears to be less effective as a transport medium. Results of this study may justify studies of other transport media and/or other corneal pathogens. Altogether, such studies may provide justification for human clinical trials.

Topics: Agar; Animals; Bacteriological Techniques; Culture Media; Disease Models, Animal; Eye Infections, Bacterial; Keratitis; Rabbits; Specimen Handling; Streptococcal Infections; Streptococcus pneumoniae

Maternal prenatal screening for group B streptococci (GBS) followed by offering of intrapartum chemoprophylaxis to carriers is one of the strategies used to reduce the incidence of neonatal early-onset GBS infections. Culturing of vaginal and anorectal swab specimens in selective broth is the screening procedure recommended by the Centers for Disease Control and Prevention. This technique is sensitive; it does not, however, allow either evaluation of the degree of colonization or detection of cocolonization with several GBS clones. We have examined the carriage rate and population dynamics of GBS in a group of Danish women during pregnancy and 1 year after delivery using a new detection method. In the present paper we describe a mixed blood agar medium (MB agar) that identifies GBS in the primary cultures by detection of a double hemolysis pattern consisting of characteristic, large zones of partial hemolysis ("CAMP zones") and of narrow zones of complete hemolysis. The MB agar was at least as sensitive as culturing in selective broth for detection of GBS in vaginal and anorectal swab specimens, and GBS strains could be identified directly on the primary plate due to the CAMP zones without the need for subculturing. The carriage rate of GBS in a group of Danish women was found to be more than 30%, a figure considerably higher than the rate that was reported previously.

Topics: Agar; Bacterial Proteins; Bacterial Typing Techniques; Blood; Carrier State; Culture Media; Female; Hemolysin Proteins; Hemolysis; Humans; Pregnancy; Pregnancy Complications, Infectious; Rectum; Streptococcal Infections; Streptococcus agalactiae; Vagina

Group B streptococcus (GBS) is the most common cause of early-onset neonatal sepsis in developed countries, and determination of the GBS colonization status in pregnant patients near term is essential for the provision of prophylactic measures to prevent early-onset disease.. To determine if GBS recovery rates and/or result turnaround times for vaginal or combined vaginal/rectal swab specimens from pregnant patients near term are enhanced if swabs are inoculated initially onto selective versus nonselective agar media, in addition to the standard Centers for Disease Control and Prevention method.. Prospective laboratory analysis.. Urban health region/centralized diagnostic microbiology laboratory.. Pregnant women presenting for routine obstetrical care and collection of vaginal or combined vaginal/rectal swab specimens for GBS testing at 35 to 37 weeks' gestation.. Culture of specimens directly onto selective (5% sheep blood with colistin and nalidixic acid) or nonselective (5% sheep blood) agar media, in addition to LIM broth enrichment and terminal subculture.. Group B streptococcus recovery rate and culture result turnaround time.. A total of 639 specimens were tested, with 128 (20%) positive for GBS. Sixty-three isolates were recovered on direct agar media at 24 hours, of which 16 (12.5%) were isolated on selective plates only. An additional 38 isolates were recovered at 48 hours from direct plates. Twenty-seven (21.1%) isolates that failed to grow on direct plates were recovered from the LIM broth subculture only. Three (2.3%) isolates not recovered from LIM broths were detected at 48 hours on the direct selective (2 isolates) and nonselective (1 isolate) agar plates. A 24-hour result turnaround time was achieved for 63 (49.2%) and 47 (36.7%) of the 128 culture-positive specimens for direct selective and nonselective plates, respectively (chi2 = 76.63, P <.001).. Use of direct selective agar media, in addition to LIM broth enrichment, for the determination of the GBS colonization status in pregnant patients near term results in decreased turnaround time for reporting positive results.

Topics: Agar; Animals; Centralized Hospital Services; Colistin; Culture Media; Female; Humans; Mass Screening; Microbiological Techniques; Nalidixic Acid; Pregnancy; Pregnancy Complications, Infectious; Prospective Studies; Rectal Diseases; Specimen Handling; Streptococcal Infections; Streptococcus agalactiae; Urban Health Services; Vaginal Diseases; Women's Health

It has been previously well defined that selective vagino-anorectal culture is required for detection of group B streptococcal (GBS) carriage. We interestingly observed that in 5.74% of carriers, GBS were recovered only from cervico-vaginal samples inoculated onto nonselective human blood agar, without recovery from vagino-anorectal samples inoculated to four selective media.

Topics: Adult; Agar; Anti-Bacterial Agents; Carrier State; Cohort Studies; Culture Media, Conditioned; Female; Gestational Age; Humans; Microbial Sensitivity Tests; Pregnancy; Pregnancy Complications, Infectious; Prenatal Care; Rectum; Sensitivity and Specificity; Specimen Handling; Streptococcal Infections; Streptococcus agalactiae; Vaginal Smears

Topics: Agar; Culture Media; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

The purpose of the study presented here was to confirm the high yield of group B streptococci (GBS) on Granada medium for the detection of pregnant GBS carriers and to compare the results with those obtained using standard Columbia blood agar at two participating centers in Belgium. Culture results of the vaginorectal swabs obtained at the two centers were also compared. A total of 1,142 samples (838 in Leuven and 304 in Bonheiden) obtained from consecutive pregnant women were cultured onto both media. Of all GBS carriers 84.7% were detected on Columbia blood agar and 93.4% on Granada agar ( P<0.01, McNemar test). The addition of Granada agar was responsible for a 15% higher rate of detection of GBS carriers. As a result of this study, both participating hospitals will use a combination of Granada agar with Columbia blood agar for optimal GBS screening in the future.

Topics: Adult; Agar; Bacteriological Techniques; Belgium; Carrier State; Culture Media; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Infectious Disease Transmission, Vertical; Mass Screening; Pregnancy; Pregnancy Complications, Infectious; Prenatal Care; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

To evaluate group B streptococcus (GBS) detection in an in vitro setting, using a low and controlled inoculum from swabs directly inoculated into a selective medium, as compared to delayed inoculation following a period in a commercial Amies transport medium with charcoal (Venturi Transystem Copan, Italy).. Clinical isolates of GBS (n = 103), were inoculated into the Amies transport medium with charcoal in a concentration of 100 colony-forming units (cfu)/ml (10 cfu/swab). Swabs were then transferred to an enrichment broth (NPC) at time intervals of 0, 2, 4, 6 and 24 hours. Broths were then incubated for 18-24 hours at 35 degrees C in air, before being transferred to New Granada Medium Modified (NGM) for GBS detection and incubated for a further 18-24 hours at 35 degrees C in air. If the characteristic orange pigmented colonies were observed after this period, the specimen was recorded as + (1-10 colonies) or + + (more than 10 colonies).. Overall 92.2% (95/103) of isolates were detected in all tubes and at all times. An additional two isolates were non-hemolytic, non-pigment forming GBS. Of note, 3.9% (4/103) were negative until 2 hours delayed inoculation and 1.9% (2/103) gave inconsistent results, likely due to the low inoculum used.. Delayed inoculation into selective enrichment broth following a period in transport medium, even with a low inoculum, gave a similar and acceptable GBS detection rate to direct inoculation. Hence, Amies transport medium with charcoal is an appropriate transport medium to use, where it is not practical for clinical specimens to be directly inoculated into selective enrichment broth and as endorsed in the Centers for Diseases Control (CDC) Guidelines, 2002.

Topics: Agar; Bacteriological Techniques; Charcoal; Colony Count, Microbial; Culture Media, Conditioned; Female; Humans; Mass Screening; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

Direct culture of rectovaginal specimens on Granada agar was compared to culture on sheep blood agar plate (SBAP) and AccuProbe detection of group B streptococcus from overnight LIM broth enhancement cultures (LIM-SBAP). Both broth-enhanced methods demonstrated excellent sensitivity (97.5% for LIM-SBAP and 93.5% for AccuProbe), while Granada agar demonstrated a sensitivity of only 40.3%.

Topics: Agar; Bacteriological Techniques; Culture Media; DNA Probes; DNA, Ribosomal; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Reagent Kits, Diagnostic; Rectum; RNA, Ribosomal; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae; Time Factors; Vagina

A new selective medium (CNA-P) that reduces or eliminates the inhibitory activity of bacteriocin-producing Streptococcus salivarius against beta-hemolytic streptococci has been developed and compared with sheep blood agar (SBA) for the sensitive detection of small numbers of beta-hemolytic streptococci in clinical specimens. CNA-P has as its basis a commercial medium (Difco Columbia CNA agar) supplemented with 5% (vol/vol) sheep blood, and the CNA is further modified by addition of 100 mM PIPES buffer [piperazine-N,N'-bis(2-ethanesulfonic acid)] (pH 7.5) to maintain cultures at an alkaline pH during incubation. CNA-P was shown to inhibit the production and/or release of four different types of S. salivarius bacteriocins or bacteriocin-like inhibitory molecules. The efficacies of CNA-P and SBA for detection of beta-hemolytic streptococci in 1,352 pharyngeal samples from 376 children were compared. The beta-hemolytic streptococcal isolates recovered from the samples included 314 group A (S. pyogenes), 61 group G, 33 group B, and 5 group C streptococci. Of 314 samples that yielded S. pyogenes, 300 were positive on CNA-P (96%) and 264 (86%) were positive on SBA. A significantly greater number of S. pyogenes isolates from these samples were recovered only on CNA-P (50 of 314) compared with the number of isolates recovered only on SBA (14 of 314). In addition, the degree of positivity, a measure of the total numbers of S. pyogenes isolates on the plate, was significantly higher on CNA-P than on SBA (2.40 versus 2.07; P < 0.001). Interestingly, CNA-P was also found to enhance the hemolytic activity of streptolysin O, allowing detection of streptolysin S-deficient S. pyogenes strains which might otherwise go undetected on SBA and other isolation media.

Topics: Agar; Antibiosis; Bacteriological Techniques; Blood; Buffers; Child; Child, Preschool; Culture Media; Humans; Hydrogen-Ion Concentration; Pharyngitis; Pharynx; Streptococcal Infections; Streptococcus; Streptococcus pyogenes; Tongue

Granada medium was evaluated for the detection of group B streptococci (GBS) in vaginal and rectal swabs compared with selective Columbia blood agar and selective Lim broth. From May 1996 to March 1998, 702 pregnant women (35 to 37 weeks of gestation) participated in this three-phase study; 103 (14.7%) of these women carried GBS. In the first phase of the experiment (n = 273 women), vaginorectal specimens were collected on the same swab; the sensitivities of Granada tube, selective Columbia blood agar, and Lim broth were 31.4, 94.3, and 74.3%, respectively. In the second and third phases (n = 429 women), vaginal and rectal specimens were collected separately; the sensitivities of Granada plate, selective Columbia blood agar, and Lim broth (subcultured at 4 h on selective Columbia agar in the second phase and at 18 to 24 h in Granada plate in the third phase) were 91.1, 83.9, and 75%, respectively, in the second phase and 88.5, 90.4, and 63.5%, respectively, in the third phase. There were no statistically significant differences in GBS recovery between the Granada agar plate and selective Columbia blood agar, but the Granada plate provided a clear advantage; the characteristic red-orange colonies produced overnight by GBS can be identified by the naked eye and is so specific that further identification is unnecessary. The use of the Granada tube and Lim broth did not result in increased isolation of GBS. In conclusion, the Granada agar plate is highly sensitive for detecting GBS in vaginal and rectal swabs from pregnant women and can provide results in 18 to 24 h.

Topics: Agar; Bacterial Typing Techniques; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Rectum; Streptococcal Infections; Streptococcus; Vagina

The combination of neomycin-nalidixic acid (NNA) agar and a selective broth medium (SBM) has recently been shown to improve the sensitivity of screening cultures for group B streptococcal (GBS) carriage in women. Because of the relatively high cost of NNA agar, a study was initiated to determine whether Columbia colistin-nalidixic acid (CNA) agar would be an equally sensitive, more economical alternative. A total of 580 cervical-vaginal and/or rectal specimens submitted for detection of GBS were included in the study. Each was plated onto NNA and CNA agar and then inoculated into SBM. GBS were recovered from 95 of 580 (16.4%) specimens, including 61 isolates from CNA, 74 from NNA, 73 from the CNA-SMB combination, and 86 from the NNA-SMB tandem. Of those, 22 isolates were recovered on NNA but not CNA, 9 were cultured on CNA but not NNA, 52 were isolated on both media, and 12 were recovered from subcultures of SBM only. The overall sensitivity of CNA alone (64. 2%) was statistically significantly less than that of NNA agar (77. 9%), as was the sensitivity of combination of CNA plus SBM (76.8%) compared to that of NNA plus SBM (90.5%). Based on these findings, CNA should not be considered an acceptable alternative to NNA for the detection of GBS colonization in women despite potential cost savings.

Topics: Agar; Bacteriological Techniques; Carrier State; Colistin; Culture Media; Evaluation Studies as Topic; Female; Humans; Infant, Newborn; Infectious Disease Transmission, Vertical; Nalidixic Acid; Neomycin; Pregnancy; Pregnancy Complications, Infectious; Sensitivity and Specificity; Streptococcal Infections; Streptococcus agalactiae

Topics: Agar; Bacteriological Techniques; Blood; Child; Culture Media; Evaluation Studies as Topic; Humans; Pharyngitis; Pharynx; Sensitivity and Specificity; Sodium Chloride; Streptococcal Infections; Streptococcus; Streptococcus pyogenes

The medium of Rambach was modified to permit differentiation of mastitis streptococci. A total of 377 streptococci isolated from bovine IMI was used in the study. Of the 159 strains identified as Streptococcus uberis, 151 strains (94.9%) were beta-galactosidase-positive and yielded blue colonies on modified Rambach agar. In comparison, Streptococcus agalactiae, Streptococcus dysgalactiae, Enterococcus saccharolyticus, or Enterococcus faecalis strains were negative for propylene glycol utilization (red colonies) or beta-galactosidase production; all strains yielded colorless colonies on modified Rambach agar. However, 5 of 35 (14.3%) Streptococcus equinus strains were also positive for beta-galactosidase. Results indicate that modified Rambach agar is a convenient medium for the differentiation of the Strep. uberis from the other mastitis streptococci. Furthermore, modified Rambach agar could be easily incorporated as a screening medium for Strep. uberis in mastitis bacteriology laboratories.

Topics: Agar; Animals; beta-Galactosidase; Cattle; Female; Mastitis, Bovine; Propylene Glycol; Propylene Glycols; Streptococcal Infections; Streptococcus

In a study on acute pharyngitis in general practice, we compared a selective group A streptococcal agar (ssA) for the recovery of group A beta-hemolytic streptococci (GABHS) with sheep blood agar. All plates were incubated at 36 degrees C in an atmosphere reinforced with 5% CO2 for 48 h with a first reading after 24 h. A total of 197 GABHS isolates were obtained from 721 throat cultures on both media. The recovery of GABHS was significantly higher after 48 h of incubation for both media. With the ssA plate, we detected significantly more GABHS after 24 h as well as after 48 h of incubation. The ssA plate reduced normal flora qualitatively and quantitatively. In conclusion, ssA is more sensitive and specific for the detection of GABHS than sheep blood agar and moreover easier to read. We recommend incubation for 48 h.

Topics: Agar; Bacteriological Techniques; Culture Media; Evaluation Studies as Topic; Humans; Pharyngitis; Streptococcal Infections; Streptococcus pyogenes

Group A streptococcal strains (three T-type 1, two T-type 2 and three T-type 4), freshly isolated from throat cultures, were subjected to 25 serial passages on blood agar. All strains changed their M protein production and/or opacity factor (OF)-activity during the passages. The capacity of each strain to adhere to a pool of buccal cells from six healthy individuals was studied both before and after passage. Five of six strains with decreased OF-activity/M protein production diminished significantly in adherence capacity, whereas one of two strains with increasing OF-activity adhered better to the epithelial cells. The results are discussed in relation to the clinical view of asymptomatic carriers of group A streptococci.

Topics: Agar; Antigens, Bacterial; Bacterial Adhesion; Bacterial Outer Membrane Proteins; Bacterial Proteins; Bacteriological Techniques; Carrier Proteins; Carrier State; Humans; Peptide Hydrolases; Streptococcal Infections; Streptococcus pyogenes

Topics: Agar; Child; Diagnostic Errors; Fluorescent Antibody Technique; Humans; Pharyngitis; Pharynx; Reagent Kits, Diagnostic; Streptococcal Infections; Streptococcus pyogenes; Time Factors

During recent years, it has become more and more common among general practitioners and pediatricians to inoculate and read agar plates for diagnosis of beta-hemolytic streptococci so that an accurate etiological diagnosis in cases of suspected tonsillitis can be made. As a control of the diagnostic quality, "unknown" streptococcal strains were distributed from the bacteriological laboratory to the practitioners performing this type of diagnostic procedure. The results show that the ability to correctly classify these strains varied greatly. Technical problems such as inadequate temperature control of relatively simple incubators were also found. Continuous education and information on beta-hemolytic streptococcal diagnostic procedures are important to ensure sufficient quality.

Topics: Agar; Bacteriological Techniques; Blood; Culture Media; Family Practice; Humans; Pediatrics; Pharyngitis; Streptococcal Infections; Streptococcus

We compared the selective blood agar medium of Gunn et al. (J. Clin. Microbiol. 5:650-655, 1977) which contains sulfamethoxazole plus trimethoprim (SXT-BA) to the conventional blood agar surface plate (SBA) and a modified blood agar pour plate plus broth method for the recovery of group A streptococci from throat swabs. The influence of CO(2) and ambient air incubation of the SXT-BA and SBA plates was also evaluated. A total of 696 throat swabs from symptomatic children were cultured simultaneously by the five methods and observed after overnight incubation; 204 positive cultures were detected overall. Recovery rates of each individual method were: SXT-BA (CO(2)), 90.7%; SXT-BA (air), 87.7%; pour plate plus broth, 83.3%; SBA (CO(2)), 79.4%; and SBA (air) 77%. Approximately one-half of the false-negative cultures in the SXT-BA (CO(2)) and SXT-BA (air) methods had colony counts of >/=10 to 100 colonies per plate. In contrast, for the SBA (CO(2)), SBA (air), and pour plate plus broth methods, approximately 70% of the false-negative cultures had colony counts of >/=10 to 100/plate. False-positive cultures obtained by the SXT-BA (CO(2)) and SXT-BA (air) methods were 11 and 12.7%, respectively-one-half as high as the rates obtained by the remaining methods. Beta-hemolytic streptococci, groups C, F, and G, are inhibited on the SXT-BA plates and were the primary cause of the higher false-positive rates on SBA and pour plate plus broth methods. An additional 3% positive cultures were obtained by incubating SXT-BA (CO(2)) plates up to 48 h before discarding as negative. We recommend either the SXT-BA (CO(2)) or the SXT-BA (air) method with up to 48 h of incubation for routine use in throat cultures.

Topics: Adolescent; Agar; Blood; Child; Child, Preschool; Diagnosis, Differential; Humans; Pharynx; Streptococcal Infections; Streptococcus pyogenes; Sulfamethoxazole; Trimethoprim

Detection of group A streptococci in primary throat cultures was compared by using aerobic and anerobic incubation with selective nonselective media. Sheep blood agar plates incubated anaerobically detected 98% of the group A streptococci, whereas aerobically incubated blood agar plates which had been stabbed at the time of inoculation detected only 63%. Blood agar plates containing sulfamethoxazole and trimethoprim (23.75 and 1.25 mirograms per ml, respectively) detected only 70% of group A streptocci when incubated aerobically and 84% when incubated anaerobically.

Topics: Aerobiosis; Agar; Anaerobiosis; Blood; Diagnosis, Differential; Humans; Pharynx; Streptococcal Infections; Streptococcus pyogenes; Sulfamethoxazole; Trimethoprim

Several presumptive tests were evaluated for their effectiveness in differentiating streptococci. When the tests were combined into a battery and the resulting reactions were interpreted as patterns, the overall presumptive identification rate was at least 97%. We used the hemolytic reaction, susceptibility to bacitracin and sulfamethoxazole plus trimethoprim (1.25 micrograms plus 23.75 micrograms), and standard CAMP reactions on sheep blood Trypticase soy agar, and bile-esculin and 6.5% NaCl agar tolerance tests with incubation in candle extinction jars. Subsequently, 98.9% of the group A; 95.3% of the group B; 100% of the beta-hemolytic non-group A, B, or D; 92.3% of group D enterococcal; 100% of the group D non-enterococcal; and 92.8% of the viridans streptococci were presumptively identified. We then used the hemolytic reactions, susceptibility of bacitracin and sulfamethoxazole-plus-trimethoprim disks, CAMP disk reactions on sheep blood Trypticase soy agar and bile-esculin and 6.5% NaCl agar tolerance tests with incubation in normal atmosphere. Subsequently, 98.1% of the group A; 98.6% of the group B; 99.2% of the beta hemolytic non-group A, B, or D; 97.5% of the group D entercoccal; 97.6% of the group D non-entercoccal; and 92.4% of the viridans strains were presumptively identified.

Topics: Aerobiosis; Agar; Anaerobiosis; Bacteriological Techniques; Drug Resistance, Microbial; Humans; Sodium Chloride; Streptococcal Infections; Streptococcus; Streptococcus agalactiae; Streptococcus pyogenes

One hundred strains of group B streptococci isolated from human infections were tested for growth on dip-slides available for the culture of urine. All grew on CLED agar, and none grew on MacConkey agar. The colonies were barely or not at all visible to the naked eye after overnight incubation (diameter, around 0.1 mm). The colony size increased eith prolonged incubation, but not if the inoculum density exceeded 10(6)/ml. Differences were found between lots of dip-slides. Poor growth on dip-slides may explain why group B streptococci have received little attention as pathogens of the urinary tract. The dip-slide screening personnel of one laboratory were informed of the experimental findings, and they started the practice of frequent subculture and prolonged incubation. The proportion of group B streptococci in significant bacteriuria increased from 0 to about 2% of positive cultures, whereas there was no conmitant increase of group B streptococci in dip-slides screened in several other laboratories serving as controls.

Topics: Agar; Bacteriological Techniques; Humans; Streptococcal Infections; Streptococcus agalactiae; Urinary Tract Infections; Urine

Sulfamethoxazole-trimethoprim blood agar (SXT-BA), neomycin blood agar (NEO-BA) and plain sheep blood agar plates (SBA) were compared for isolating group A streptococci in 1,954 throat cultures. SBA and SXT-BA had similar isolation rates (approximately 75% of all positive isolates). NEO-BA was significantly better (87% recovery). A combination of any two media gave 92-95% recovery of group A streptococci from throat specimens.

Topics: Adolescent; Agar; Animals; Child; Child, Preschool; Humans; Neomycin; Pharyngitis; Sheep; Streptococcal Infections; Streptococcus; Sulfamethoxazole

Topics: Agar; Child; Culture Media; Glomerulonephritis; Humans; L Forms; Pyelonephritis; Streptococcal Infections; Streptococcus

Topics: Agar; Agglutination Tests; Bacteriological Techniques; Blood; Counterimmunoelectrophoresis; Culture Media; Epitopes; Fluorescent Antibody Technique; Humans; Pharynx; Serotyping; Specimen Handling; Streptococcal Infections; Streptococcus

Streptococci from clinical isolates were studied for their ability to produce pigment in stab cultures in Columbia agar. Serological grouping of these organisms was done by counterimmunoelectrophoresis using Burroughs-Wellcome antisera. In this group of isolates, 66 of the 68 organisms grouped as B by serological testing produced pigment in the Columbia agar stab cultures. Pigment was not produced by any of the other 36 streptococci studied (11 group A, 9 group C, 4 group D, and 12 nongroupable). The use of the Columbia agar stab culture is recommended as a rapid and simple test for recognition of group B streptococci. The counterimmunoelectrophoresis test is also suggested as a convenient, rapid, and sensitive method for grouping the streptococci.

Topics: Adult; Agar; Antigens, Bacterial; Bacitracin; Counterimmunoelectrophoresis; Drug Resistance, Microbial; Hippurates; Humans; Hydrolysis; Infant; Infant, Newborn; Pigments, Biological; Streptococcal Infections; Streptococcus agalactiae

It is well known that long transport diminishes the chances of isolating causative micro- organisms, especially from swabs. In a trial, in which beta-haemolytic streptococci were kept for 24-hours at room temperature, culturing failed even if more than one million bacteria had been placed on the swab. Culture medium consisting of agar with 0.5% human albumin made it possible to isolate beta-haemolytic streptococci even after transport and with a count of less than a hundred micro-organisms per swab. The use of selective nutrient media may be necessary because of the sometimes marked multiplication during transport when there are mixed organisms. The nutrient medium was used during six small epidemics of scarlet fever in Freiburg and proved superior to the usual dry swab. In parallel studies of patients and contacts the causative beta-haemolytic streptococcus was isolated three times as often.

Topics: Agar; Bacteriological Techniques; Culture Media; Humans; Methods; Scarlet Fever; Serum Albumin; Streptococcal Infections; Streptococcus; Temperature; Time Factors

Primary cultures of clinical material were screened for the presence of colonies suspected of being Streptococcus agalactiae (Lancefield group B). Sixty-three such cultures and 108 other isolates of beta-hemolytic streptococci (groups A, C, and G), encountered during the first 3 months of the investigation, were studied by Lancefield grouping, sodium hippurate hydrolysis, and a standardized CAMP test. All streptococci were inoculated perpendicularly to streaks of a beta-toxin-producing staphylococcus on sheep blood agar plates and incubated aerobically in a candle jar and anaerobically at 37 C. Plates were examined after 5 to 6 and 18 h of incubation. The production of a distinct "arrowhead" of hemolysis was indicative of a positive CAMP reaction. All group B streptococci produced a positive CAMP reaction in the candle jar or anaerobically, usually within 5 to 6 h, and aerobically after 18 h of incubation. All group A streptococci produced a positive reaction only under anaerobic conditions. Groups C and G streptococci were negative under all atmospheres. The CAMP reaction is a prompt and reliable procedure for the presumptive identification of group B streptococci when a candle jar atmosphere is used during incubation.

Topics: Aerobiosis; Agar; Anaerobiosis; Animals; Bacteriological Techniques; Blood; Classification; Evaluation Studies as Topic; Female; Hemolysis; Hippurates; Humans; Hydrolysis; Infant, Newborn; Infant, Newborn, Diseases; Sheep; Staphylococcus; Streptococcal Infections; Streptococcus agalactiae; Toxins, Biological

Normal skin sites in children from a population in which streptococcal impetigo is endemic were examined for the presence of beta-haemolytic streptococci by a direct agar-contact technique. Ninety-eight of 554 samples (18%) were positive for these organisms. Penicillin prophylaxis reduced the frequency of isolation of streptococci from the normal skin for a period of 3 weeks, perhaps accounting in part for the lower isolation rate in this than in earlier studies. Numbers of streptococcal colony-forming units in positive samples were generally low, both in terms of absolute numbers isolated from the surface area sampled and in comparison with numbers of other aerobic flora recovered. The presence of streptococcal pyoderma at the time of agar contact was not necessarily associated with the presence of or with increased numbers of streptococci on samples obtained from normal skin sites. Low counts were consistently found in early summer and higher counts in some samples in late summer. In a simultaneous comparison of paired samples taken from adjacent sites, the frequency of detection of streptococci by direct agar contact compared favourably with that obtained with a moist-swab method. The increased frequency of detection by the agar-contact method appeared to be related to an increased sensitivity for the detection of low numbers of streptococcal colony-forming units on the normal skin.

Topics: Adolescent; Agar; Bacteriological Techniques; Child; Child, Preschool; Humans; Impetigo; Infant; Minnesota; Penicillins; Seasons; Skin; Streptococcal Infections; Streptococcus; Streptococcus pyogenes

Topics: Administration, Oral; Agar; Animals; Bacillus subtilis; Bacteria; Chemical Phenomena; Chemistry; Dicloxacillin; Dogs; Drug Stability; Hydrogen-Ion Concentration; Immunodiffusion; Injections, Intravenous; Mice; Oxacillin; Penicillin G; Penicillin Resistance; Penicillinase; Penicillins; Pyrazoles; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Streptococcus pyogenes

Topics: Agar; Agglutination Tests; Animals; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Proteins; Cattle; Electrophoresis; Epitopes; Gels; Humans; Immunization; Immunodiffusion; Injections, Intravenous; Injections, Subcutaneous; Latex Fixation Tests; Rabbits; Streptococcal Infections; Streptococcus pyogenes

Viable counts of beta-haemolytic streptococci per ml. of saliva were made in the following groups: (1) children with acute streptococcal sore throat, (2) children with acute non-streptococcal sore throat, (3) children who had no sore throat but were streptococcal throat carriers, (4) children who neither had a sore throat nor were streptococcal throat carriers.The mean counts from cases of streptococcal sore throat and from streptococcal carriers were respectively 1.4 x 10(6) and 2.5 x 10(5) per ml.In a comparison of the efficiency of the throat swab, sublingual swab and specimen of saliva in isolating beta-haemolytic streptococci from the upper respiratory tract, culture of saliva produced the best results.

Topics: Agar; Bacteriological Techniques; Blood; Carrier State; Child; Gentian Violet; Humans; Pharyngitis; Saliva; Serotyping; Streptococcal Infections; Streptococcus; Streptococcus pyogenes

Incorporating neomycin and nalidixic acid into a blood-agar base resulted in a medium highly selective for beta-hemolytic streptococci under conditions in which detection of streptococcal colonies by conventional means would have been very difficult.

Topics: Agar; Animals; Bacteriological Techniques; Blood; Culture Media; Humans; Nalidixic Acid; Neomycin; Pharynx; Sheep; Streptococcal Infections; Streptococcus

Topics: Administration, Oral; Adolescent; Adult; Agar; Aged; Candidiasis; Cephalosporins; Escherichia coli; Escherichia coli Infections; Female; Haemophilus Infections; Haemophilus influenzae; Humans; Klebsiella; Klebsiella Infections; Male; Microbial Sensitivity Tests; Middle Aged; Nausea; Proteus; Proteus Infections; Staphylococcal Infections; Streptococcal Infections; Streptococcus; Streptococcus pneumoniae; Streptococcus pyogenes; Urinary Tract Infections; Vulvovaginitis

Topics: Agar; Agglutination Tests; Animals; Antigens; Bacitracin; Drug Resistance, Microbial; Erythrocytes; Fluorescent Antibody Technique; Hemolysis; Humans; Serotyping; Sheep; Streptococcal Infections; Streptococcus

Topics: Adolescent; Adult; Agar; Cephalosporins; Child; Drug Resistance, Microbial; Electrolytes; Female; Humans; Liver; Male; Middle Aged; Otitis Externa; Otitis Media; Staphylococcal Infections; Staphylococcus; Streptococcal Infections; Tonsillitis

Topics: Agar; Animals; Anti-Bacterial Agents; Culture Media; Drug Resistance, Microbial; Drug Synergism; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli Infections; Folic Acid Antagonists; Haemophilus Infections; Meningococcal Infections; Mice; Microbial Sensitivity Tests; Pneumococcal Infections; Pyrimidines; Streptococcal Infections; Sulfamethoxazole

Topics: Agar; Animals; Bacitracin; Child; Female; Hemolysis; Humans; Male; Sheep; Streptococcal Infections; Streptococcus

Topics: Agar; Child; Child, Preschool; Costs and Cost Analysis; Culture Media; Female; Fluorescent Antibody Technique; Humans; Infant; Infant, Newborn; Male; Methods; Pediatrics; Specimen Handling; Streptococcal Infections; Streptococcus

Topics: Agar; Antistreptolysin; Aortic Valve Stenosis; Arthritis; Dextran Sulfate; Dextrans; Glomerulonephritis; Humans; Immune Sera; Mitral Valve Stenosis; Osteomyelitis; Rheumatic Fever; Staphylococcal Infections; Streptococcal Infections; Tonsillitis

Studies on the purification of group A streptococcal extracellular antigens detectable with naturally occurring human antibodies from normal individuals have been extended. It has been shown that streptococcal electrophoretic fractions intermediate between the most rapidly migrating components are quite complex. In the calcium phosphate chromatography of adjacent electrophoretic fractions, particular antigenic components desorbed at similar buffer elution steps. It is clear from the results obtained that substantially more extracellular antigens than the twelve heretofore recognized are secreted in human beings during infection, as judged by their detection with human antibodies. The precise number is not yet known, but is probably greater than 16. Of the nine components which thus far have been separated rather well from the others, four were previously identified as streptolysin "O," diphosphopyridine nucleotidase, proteinase precursor, and desoxyribonuclease B. The accumulated data substantiated these previous identifications. The identity of a fifth antigen has been made as a possible complex of C carbohydrate and protein. Tentative evidence for the relationship of a sixth component to scarlet fever toxin has been presented. It has been shown that rechromatography of crystalline proteinase precursor and desoxyribonuclease B on calcium phosphate columns resulted in elution principally at the expected stepwise increase in buffer concentration. Attempts to isolate antigens present as mixtures in some calcium phosphate chromatographic peaks, by rechromatography on DEAE or CM cellulose columns resulted in only limited further purifications.

Topics: Agar; Antigens; Bacterial Proteins; Endopeptidases; Exotoxins; Humans; Precipitins; Streptococcal Infections; Streptococcus; Streptococcus pyogenes; Streptolysins

As evidenced by precipitin analysis with pooled human gamma globulin, at least 12 distinct antigens were produced in cultures by one strain of Group A streptococcus (C203S). It was suggested on this basis, that these antigens were produced in vivo during human infections. By the combined use of continuous flow electrophoresis on paper curtains, and column chromatography with calcium phosphate gels, five of these have been isolated in a probable high state of purity. One of the components was obtained from culture filtrates of a Group C streptococcal strain. Three of the purified antigens have been tentatively identified as streptolysin "O", diphosphopyridinenucleotidase, and proteinase precursor. The latter could be very readily crystallized, and appears "identical" with that described by Elliott. The DPNase was of extremely high potency, 1 mg. being capable of destroying 12.6 gm. of DPN in 7(1/2) minutes at 37 degrees C. The identity of the other two components is uncertain as yet. They are distinct from each other and the above products immunologically, and are not related to the "C" carbohydrate. The applicability of these methods for the analysis of infectious diseases generally was discussed.

Topics: Agar; Antigens; Bacterial Proteins; Humans; Precipitins; Streptococcal Infections; Streptococcus pyogenes; Streptolysins

Using a highly concentrated and partially purified streptolysin O preparation, migrating agar precipitins have been found in 94 of 143 human sera from patients with a variety of diseases. Most of those showing no bands, had very low antistreptolysin titers. A correlation was found between the migration rates of these bands and the antistreptolysin titer. A strong trend toward a straight line relationship was apparent when the ASO titers were plotted on a logarithmic scale. In addition, a roughly positive correlation was found between the intensity of these bands and the antistreptolysin O titers. The finding of high levels of antistreptolysin O activity and slowly migrating heavy bands in normal pooled human gamma globulin supported the above observations. Very similar results were obtained with rabbit and guinea pig sera after immunization with the streptolysin O concentrates. The data strongly indicate that antistreptolysin O activity in human sera is generally due to precipitating antibody, and that non-specific inhibitors are not usually involved, even with low titered sera. Rabbit and guinea pig antisera to the oxidized inactive and to the reduced active forms of streptolysin O showed no obvious differences. Attempts to demonstrate immunological differences between the two states of streptolysin were apparently complicated by proteolysis, due to contamination of the concentrates with proteinase precursor.

Topics: Agar; Animals; Antibodies; Antigens; Antistreptolysin; Bacterial Proteins; Endopeptidases; Guinea Pigs; Humans; Hydrolases; Immune Sera; Precipitins; Proteolysis; Rabbits; Streptococcal Infections; Streptolysins; Vaccination

It has been shown by agar precipitin tests (Ouchterlony and Oakley) that human sera may contain from 0 to 5 antibodies against antigens present in a partially purified streptolysin O preparation, and from 0 to 7 antibodies against antigens in a crude ammonium sulfate concentrate of the streptococcal culture supernate used. These antigens were prepared from a Group A hemolytic streptococcus (strain C203S). Strong evidence was presented suggesting that some of the bands seen with streptolysin O concentrate represented antibody reponses to streptococcal antigens heretofore undescribed. Tests were also carried out with other streptococcal antigens, including streptokinase-desoxyribonuclease mixture from Group C streptococci (varidase-Lederle), crystalline proteinase, proteinase precursor, C carbohydrate, and sonic vibrated streptococcal cell extracts (group A, C203S). Fewer bands were seen with these preparations, and with some they were quite uncommon. The observations indicated that the predominating antibody responses in human streptococcal infections were to extracellular products of the micro-organisms, and only very slightly and infrequently to intracellular antigens. The human sera studied included sera from patients with active or convalescent rheumatic fever, and non-rheumatic subjects suffering from a variety of illnesses. As was expected, the rheumatic subjects showed antibody responses to many more of the antigens present in these preparations than did the nonrheumatic group. Pooled normal human gamma globulin was found to contain many of the antibodies found in potent human sera. This finding confirmed the antigen-antibody nature of the bands seen with individual sera. The epidemiological significance of these findings with gamma, globulin was briefly discussed. It was found that rabbit, guinea pig, and human antibody precipitin bands join quite readily in the Ouchterlony tests. This finding adds another tool for the identification of the precipitin bands found with human sera. Evidence was obtained which indicated differing immunological specificities of two samples of streptococcal desoxyribonuclease, one from Group A, the other from a Group C streptococcus. The value of these technics as representing a new approach to the study of human infectious disease was discussed.

Topics: Agar; Antibodies; Antibody Formation; Antigens; Antigens, Bacterial; Guinea Pigs; Humans; Precipitins; Streptococcal Infections; Streptococcus; Streptococcus pyogenes

Topics: Agar; Bacteria; Culture Media; Humans; Neisseria gonorrhoeae; Streptococcal Infections; Streptococcus; Streptococcus pneumoniae