agar and Bacterial-Infections

The subject to assessment were hydrogel dressings (in 42 patients) compared with the classical gauze dressing with an addition of various pharmaceuticals (in 65 patients). We found out that the gauze dressings get dry 24 hours after they have been applied, their replacement being very painful. The hydrogel dressings, on the other hand, do not cause any pain when replaced after the 24 hours. The hygroscopic properties of hydrogel dressings allow a quick cleaning of the wound from microorganisms. Permitting an easy absorption of antibiotics and other drugs, they contribute to an acceleration of the healing process and epidermis development.

Topics: Acrylamides; Acrylic Resins; Adult; Agar; Anti-Bacterial Agents; Bacterial Infections; Burns; Child; Humans; Hydrogel, Polyethylene Glycol Dimethacrylate; Occlusive Dressings; Poland; Polyethylene Glycols; Time Factors; Wound Healing; Wound Infection

Bacterial infection is one of the most critical obstacles in wound healing, and severe bacterial infections can lead to inflammatory conditions and delay the healing process. Herein, a novel hydrogel based on polyvinyl alcohol (PVA), agar, and silk-AgNPs was prepared using a straightforward one-pot physical cross-linking method. The in situ synthesis of AgNPs in hydrogels exploited the reducibility of tyrosine (Tyr tyrosine) in silk fibroin, which endowed the hydrogels with outstanding antibacterial qualities. In addition, the strong hydrogen bond cross-linked networks of agar and the crystallites formed by PVA as the physical cross-linked double network of the hydrogel gave it excellent mechanical stability. The PVA/agar/SF-AgNPs (PASA) hydrogels exhibited excellent water absorption, porosity, and significant antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Furthermore, in vivo experimental results confirmed that the PASA hydrogel significantly promoted wound repair and skin tissue reconstruction by reducing inflammation and promoting collagen deposition. Immunofluorescence staining showed that the PASA hydrogel enhanced CD31 expression to promote angiogenesis while decreasing CD68 expression to reduce inflammation. Overall, the novel PASA hydrogel showed great potential for bacterial infection wound management.

Topics: Agar; Anti-Bacterial Agents; Bacterial Infections; Escherichia coli; Humans; Hydrogels; Inflammation; Polyvinyl Alcohol; Staphylococcus aureus; Wound Healing

We aimed to identify the enterotoxigenic Bacteroides fragilis (ETBF) and bft subtypes among patients with diarrhea. In addition, we assessed whether DNA gyrase subunit B (gyrB) and neuraminidase (nanH) genes are useful determinants for identification of B. fragilis compared to 16S rRNA sequencing as a reference method.. The 530 fecal specimens were cultured on BBE agar. The colonies which supposed to be a member of B. fragilis group were subjected to 16S rRNA gene sequencing and PCR assays targeting the Bacteroides fragilis group (BFG), gyrB and nanH. The B. fragilis toxin (bft) gene and its subtype was detected by PCR. The specificity of PCR assays was calculated considering the 16S rRNA gene sequencing as the reference method.. A total of 111 Gram-negative anaerobic coccobacilli were isolated from 530 fecal specimens using BBE agar. Of the 111 isolates, 100 (90.09%) were assumed to be a member of Bacteroides fragilis group as they yielded an amplicon through PCR using the group-specific primers (Bfra-F/g-Bfra-R). However, only 28 isolates out of 100 were definitively identified as species of Bacteroides using16S rRNA gene sequencing; of which 15 isolates were B. fragilis and the remaining 13 isolates were identified as B. thetaiotaomicron (n = 6), Parabacteroides distasonis (n = 3), B. vulgatus (Phocaeicola vulgatus) (n = 1), B. ovatus (n = 1), B. congonensis (n = 1) and B. nordii (n = 1). Among the 15 isolates of B. fragilis, 4 were found to be ETBF. Compared to the reference method, the specificity and accuracy of the PCR targeting gyrB gene (64.7% and 65%) was higher than of nanH (36.4% and 46%, respectively.. This study demonstrated that more than one-fourth of B. fragilis isolates harbored bft gene and less than 1% of patients with diarrhea harbored ETBF. The slight agreement between the PCR assays -already used for identification of B. fragilis which targeting gyrB or nanH - and 16S rRNA gene sequencing as the reference method was noted.

Topics: Agar; Bacterial Infections; Bacteroides fragilis; Bacteroides Infections; Diarrhea; Humans; Neuraminidase; RNA, Ribosomal, 16S

The continued rise of Klebsiella pneumoniae resistance to antibiotics is precipitating a medical crisis. Bacteriophages have been hailed as one possible therapeutic option to enhance the efficacy of antibiotics. This study describes the genomic characterization and biological property of a new bacteriophage vB_1086 and its potential for phage therapy application against Klebsiella pneumoniae.. In our study, the double-layer agar plate method isolated a lytic bacteriophage named vB_1086. Besides, we analyzed its biological characteristics and genetic background. Then the antibacterial ability of the bacteriophage vB_1086 combined with antibiotics were analyzed by the combined checkerboard method. The impact on the formation of biofilms was analyzed by crystal violet staining method.. vB_1086 is a lytic bacteriophage with stable biological characteristics and clear genetic background, showing good antibacterial activity in combination with ceftriaxone, and the combination of phage and meropenem can effectively inhibit the formation of biofilm. Besides, the combination of bacteriophage and antimicrobials can effectively alleviate the generation of bacterial resistance and reduce the dosage of antimicrobials.. vB_1086 is a novel phage. To some extent, these results provide valuable information that phage vB_1086 can be combined with antibiotics to reduce the dosage of antimicrobials and alleviate the generation of bacterial resistance.

Topics: Agar; Anti-Bacterial Agents; Bacterial Infections; Bacteriophages; Ceftriaxone; Gentian Violet; Humans; Klebsiella pneumoniae; Meropenem

Short incubation of positive blood cultures on solid media is now increasingly applied to speed up species identification by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Although Columbia blood agar (CBA) and chocolate agar (Choc) are widely used, a direct comparison of standard agars is lacking. We therefore compared the time to species identification of blood cultures incubated on CBA, Choc, and MacConkey agar (MAC, for Gram-negative rods). Positive aerobic/anaerobic blood cultures (2 drops = 50 μl) were incubated on CBA, Choc, MAC, and the required time of incubation to low-confidence identification (score of ≥1.7 to <2) and high-confidence identification (score of ≥2) by MALDI-TOF MS was measured. Exclusion criteria were (i) false-positive blood cultures, (ii) mixed cultures with different species, (iii) growth of anaerobes/fungi, and (iv) a total number of isolates of one group (i.e., Gram-positive/-negative cocci/rods) of <30. A total of 187 blood cultures with Gram-positive cocci (

Topics: Agar; Bacteria; Bacterial Infections; Bacterial Typing Techniques; Blood Culture; Culture Media; Humans; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Time Factors

Rapid and accurate identification of pathogens involved in urinary tract infections helps to guide antimicrobial therapy. Chromogenic agars provide presumptive identification directly from primary isolation media. They have been intended to make the bacterial isolation and identification process easier and faster. Our study aimed to compare the performance and the cost of the CPS ID3® and the Uriselect4® chromogenic agars with the conventional method for the isolation and identification of urinary tract infections bacteria. We included 301 urinary samples in a prospective study conducted in May 2018 in the clinical laboratory of the National institute of nutrition and food technology of Tunis. Isolates from routine media were identified using API® system while isolates from chromogenic media were directly identified by colony color with reference to the manufacturer's recommendations. Chromogenic media yielded more pure positive cultures and allowed better isolation of Escherichia coli, Klebsiella pneumoniae, Citrobacter koseri, Morganella morganii and Streptococcus agalactiae. Sensitivity and specificity of the presumptive identification of most commonly isolated uropathogens were higher with the Uriselect4® medium than with the CPS ID3® medium. Chromogenic media yielded the identification of pathogenic organisms 24 hours sooner than the conventional method in approximately 63 % of cases with the CPS ID3® medium and in 77.7% of cases with the Uriselect4® medium. Chromogenic media allowed a much better isolation of bacteria commonly involved in urinary tract infections with a quick, easy and accurate presumptive identification especially with the Uriselect4® medium.

Topics: Agar; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Bacteriological Techniques; Chromogenic Compounds; Culture Media; Diagnostic Tests, Routine; Female; Humans; Male; Microbial Sensitivity Tests; Sensitivity and Specificity; Urinalysis; Urinary Tract Infections

The aim of this study was to evaluate the usefulness of chromogenic media for isolation of bacteria from urine and direct identification of UTI pathogens. A total of 100 urine specimens were inoculated on blood agar and MacConkey agar as a reference method and on the following media to be tested: chromID® CPS® Elite (CPSE, bioMérieux), CHROMagarTM Orientation (BioMaxima), BD CHROMagar Orientation Medium (ORI, Becton Dickinson), CHROMagarTM Orientation (ORIE, Graso) and Brillance UTI Clarity Agar (UTI C, Oxoid). After a 24-hour incubation period, 47 Gram-positive cocci and 62 Gram-negative rods were observed. The specificity and sensitivity of all chromogenic media was 97.3% and 93.5% respectively for qualitative diagnostic; and 81.9% and 81.3% respectively for semi-quantitative diagnostic. The mean PPV and NPV of the chromogenic media were 98.7% and 87.7% for qualitative UTI diagnostic, and 90.9% and 71.9% respectively for semi-quantitative diagnostic.

Topics: Agar; Bacteria; Bacterial Infections; Chromogenic Compounds; Colony Count, Microbial; Culture Media; Escherichia coli; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Sensitivity and Specificity; Urinary Tract Infections

The FDA Bacteriological Analytical Manual (BAM) Chapter 4a recommends several agars for isolating non-O157 Shiga toxin-producing Escherichia coli (STEC); not all have been thoroughly tested for recovering STECs from food. Using E. coli strains representing ten clinically relevant O serogroups (O26, O45, O91, O103, O104, O111, O113, O121, O128, O145) in artificially-contaminated fresh produce--bagged baby spinach, alfalfa sprouts, cilantro, and raw milk--we evaluated the performance of 8 different agars. Performance was highly dependent upon strain used and the presence of inhibitors, but not necessarily dependent on food matrix. Tellurite resistant-negative strains, O91:-, O103:H6, O104:H21, O113:H21, and O128, grew poorly on CHROMagar STEC, Rainbow agar O157, and a modified Rainbow O157 (mRB) agar. Although adding washed sheep's blood to CHROMagar STEC and mRB agars improved overall performance; however, this also reversed the inhibition of non-target bacteria provided by original formulations. Variable colony coloration made selecting colonies from Rainbow agar O157 and mRB agars difficult. Study results support a strategy using inclusive agars (e.g. L-EMB, SHIBAM) in combination with selective agars (R & F E. coli O157:H7, CHROMagar STEC) to allow for recovery of the most STECs while increasing the probability of recovering STEC in high bacterial count matrices.

Topics: Agar; Animals; Bacterial Infections; Cattle; Colony Count, Microbial; Coriandrum; Culture Media; Medicago sativa; Milk; Shiga-Toxigenic Escherichia coli; Spinacia oleracea

Rapid identification of the causative microorganism is important for appropriate antimicrobial therapy of bloodstream infections. Bacteria from positive blood culture (BC) bottles are not readily available for identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Lysis and centrifugation procedures suggested for direct MALDI-TOF MS from positive BCs without previous culture are associated with additional hands-on processing time and costs. Here, we describe an alternative approach applying MALDI-TOF MS from bacterial cultures incubated very briefly on solid medium. After plating of positive BC broth on Columbia blood agar (n = 165), MALDI-TOF MS was performed after 1.5, 2, 3, 4, 5, 6, 7, 8, 12 and (for control) 24 h of incubation until reliable identification to the species level was achieved (score ≥2.0). Mean incubation time needed to achieve species-level identification was 5.9 and 2.0 h for Gram-positive aerobic cocci (GPC, n = 86) and Gram-negative aerobic rods (GNR, n = 42), respectively. Short agar cultures with incubation times ≤2, ≤4, ≤6, ≤8 and ≤12 h yielded species identification in 1.2%, 18.6%, 64.0%, 96.5%, 98.8% of GPC, and in 76.2%, 95.2%, 97.6%, 97.6%, 97.6% of GNR, respectively. Control species identification at 24 h was achieved in 100% of GPC and 97.6% of GNR. Ethanol/formic acid protein extraction performed for an additional 34 GPC isolates cultivated from positive BCs showed further reduction in time to species identification (3.1 h). MALDI-TOF MS using biomass subsequent to very short-term incubation on solid medium allows very early and reliable bacterial identification from positive BCs without additional time and cost expenditure.

Topics: Agar; Bacteria; Bacterial Infections; Bacteriological Techniques; Blood; Culture Media; Humans; Sensitivity and Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Time Factors

This study compared Neo-Sensitabs with Oxoid paper disks using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) disk diffusion antimicrobial susceptibility test on Mueller-Hinton agar. The EUCAST-recommended quality control strains (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212) (Part I) and clinical isolates (Part II) were investigated. In Part I of the study, 27 combinations of antimicrobial agents were tested on four quality control strains repeatedly up to 60 times and zone diameters of tablets and disks were compared. In Part II of the study, 351 clinical isolates were included to cover a broad range of species, as well as resistance mechanisms. In Part I, four major deviations (>1 mm outside quality control ranges) were observed with Neo-Sensitabs. In one case with P. aeruginosa ATCC 27853 (meropenem), there was a corresponding major deviation (2 mm) with the Oxoid disk. The three remaining major deviations with Neo-Sensitabs were observed with meropenem (2 mm) in E. coli ATCC 25922 and with ciprofloxacin (2 mm) and gentamicin (3 mm) in P. aeruginosa ATCC 27853. For Oxoid disks, there were only minor deviations (=1 mm outside quality control ranges) in these three cases. In Part II, there were six discrepancies, susceptible versus resistant, in 3,533 comparisons between the two methods with the clinical isolates. The Rosco Neo-Sensitabs appear to be a possible alternative to Oxoid paper disks for EUCAST disk diffusion antimicrobial susceptibility testing on Mueller-Hinton agar.

Topics: Agar; Anti-Infective Agents; Bacteria; Bacterial Infections; Culture Media; Disk Diffusion Antimicrobial Tests; Humans

This study investigated the effect of different Mueller-Hinton agars and media age on tigecycline MICs, obtained by Etest. Variations in MIC values on different Mueller-Hinton were noted, which may result in changes in categoric susceptibility. The use of stored Mueller-Hinton media had minimal effect on MIC values.

Topics: Acinetobacter; Agar; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Culture Media; Enterobacteriaceae; Humans; Microbial Sensitivity Tests; Minocycline; Staphylococcus aureus; Tigecycline; Time Factors

Community-associated methicillin-resistant Staphylococcus aureus outbreaks have occurred in individuals engaged in athletic activities such as wrestling and football. Potential disease reduction interventions include the reduction or elimination of bacteria on common use items such as equipment. Chlorine dioxide has a long history of use as a disinfectant. The purpose of this investigation was to evaluate the ability of novel portable chlorine dioxide generation devices to eliminate bacteria contamination of helmets and pads used by individuals engaged in football.. In field studies, the number of bacteria associated with heavily used football helmets and shoulder pads was determined before and after overnight treatment with chlorine dioxide gas. Bacteria were recovered using cotton swabs and plated onto trypticase soy agar plates. In laboratory studies, Staphylococcus aureus was applied directly to pads. The penetration of bacteria into the pads was determined by inoculating agar plates with portions of the pads taken from the different layers of padding. The ability to eliminate bacteria on the pad surface and underlying foam layers after treatment with chlorine dioxide was also determined.. Rates of recovery of bacteria after treatment clearly demonstrated that chlorine dioxide significantly (p < 0.001) reduce and eliminated bacteria found on the surface of pads. For example, the soft surface of shoulder pads from a university averaged 2.7 x 10(3) recoverable bacteria colonies before chlorine dioxide treatment and 1.3 x 102 recoverable colonies after treatment. In addition, the gas was capable of penetrating the mesh surface layer and killing bacteria in the underlying foam pad layers. Here, 7 x 10(3) to 4.5 x 10(3) laboratory applied S. aureus colonies were recovered from underlying layers before treatment and 0 colonies were present after treatment. Both naturally occurring bacteria and S. aureus were susceptible to the treatment process.. Results of this study have shown that chlorine dioxide can easily and safely be used to eliminate bacteria contamination of protective pads used by football players. This could serve to reduce exposure to potential pathogens such as the methicillin-resistant Staphylococcus aureus among this group of individuals.

Topics: Agar; Bacterial Infections; Caseins; Chemical Industry; Chlorine Compounds; Cotton Fiber; Disinfection; Football; Head Protective Devices; Humans; Oxides; Protein Hydrolysates; Staphylococcus aureus

A total of 60 anaerobic strains were isolated from 322 clinical specimens. These isolates were tested for susceptibility to seven antibiotics (penicillin G, amoxicillin/clavulanic acid, cefoxitin, imipenem, chloramphenicol, metronidazole, clindamycin) by using ATB-ANA and Epsilometer test (E-test) strips and the results were compared with the gold standard agar dilution method. Imipenem was found as the most effective agent in vitro among the agents tested (100%). Susceptibility to penicillin G, amoxicillin/clavulanic acid, cefoxitin, chloramphenicol, metronidazole and clindamycin are 36.7%, 83.3%, 88.3%, 96.6%, 85% and 90%, respectively. E-test has showed a good correlation (r=0.62, p=0.001) statistically with the results of agar dilution (total agreement for all antibiotics changing between 90.01% and 98.45%) and a moderate correlation (r=0.45, p=0.048) with the results of ATB-ANA method (total agreement for all antibiotics changing between 75.46% and 98.76%). However, the routine use of agar dilution procedure is concluded to be cumbersome, whereas E-test method offers a reliable alternative.

Topics: Agar; Anti-Bacterial Agents; Bacteria, Anaerobic; Bacterial Infections; Culture Media; Humans; Microbial Sensitivity Tests; Reference Standards

Increasing antibiotic resistance in gram-negative bacteria has recently renewed interest in colistin as a therapeutic option. The increasing use of colistin necessitates the availability of rapid and reliable methods for colistin susceptibility testing. We compared seven methods of colistin susceptibility testing (disk diffusion, agar dilution on Mueller-Hinton [MH] and Isosensitest agar, Etest on MH and Isosensitest agar, broth microdilution, and VITEK 2) on 102 clinical isolates collected from patient materials during a selective digestive decontamination or selective oral decontamination trial in an intensive-care unit. Disk diffusion is an unreliable method to measure susceptibility to colistin. High error rates and low levels of reproducibility were observed in the disk diffusion test. The colistin Etest, agar dilution, and the VITEK 2 showed a high level of agreement with the broth microdilution reference method. Heteroresistance for colistin was observed in six Enterobacter cloacae isolates and in one Acinetobacter baumannii isolate. This is the first report of heteroresistance to colistin in E. cloacae isolates. Resistance to colistin in these isolates seemed to be induced upon exposure to colistin rather than being caused by stable mutations. Heteroresistant isolates could be detected in the broth microdilution, agar dilution, Etest, or disk diffusion test. The VITEK 2 displayed low sensitivity in the detection of heteroresistant subpopulations of E. cloacae. The VITEK 2 colistin susceptibility test can therefore be considered to be a reliable tool to determine susceptibility to colistin in isolates of genera that are known not to exhibit resistant subpopulations. In isolates of genera known to (occasionally) exhibit heteroresistance, an alternative susceptibility testing method capable of detecting heteroresistance should be used.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Agar; Anti-Bacterial Agents; Bacterial Infections; Colistin; Cross Infection; Culture Media; Drug Resistance, Multiple, Bacterial; Enterobacter cloacae; Enterobacteriaceae Infections; Humans; Intensive Care Units; Microbial Sensitivity Tests; Polymyxin B

An agar subcutaneous infection model (agar model), which simulates the rat subcutaneous infection model (rat model), was developed to assess the ability of antimicrobial catheters to resist microbial colonization. The catheters were implanted in the agar and rat models and the insertion sites were infected immediately or on day 7, 14 or 21 post-implantation. The catheters implanted in the agar model were transferred to fresh media one day before infection on day 7, 14 or 21. The efficacy of chlorhexidine and silver sulfadiazine impregnated (CS) catheters, CS catheters with higher levels of chlorhexidine (CS+ catheters), minocycline-rifampicin (MR) catheters and silver catheters against Staphylococcus aureus and rifampicin-resistant Staphylococcus epidermidis RIF-r2 was compared in the agar and rat models. No significant difference in the adherence or the drug release was found between the in vitro and in vivo models. In both models, CS+ and MR catheters were effective against S. aureus even when infected on day 14, whereas CS catheters were colonized when challenged on day 7. CS+ catheters were effective against S. epidermidis RIF-r2, whereas MR catheters showed adherence when infected on day 7. CS+ catheters prevented colonization of all the organisms including, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans in the agar model, whereas MR catheters were effective only against S. aureus and S. epidermidis strains. Silver catheters were ineffective against all the organisms. The agar model may be used to predict the in vivo efficacy of antimicrobial catheters against various pathogens.

Topics: Agar; Animals; Anti-Bacterial Agents; Anti-Infective Agents, Local; Bacterial Adhesion; Bacterial Infections; Catheterization; Catheterization, Central Venous; Chlorhexidine; Culture Media; Disinfectants; Female; Rats; Rats, Sprague-Dawley; Silver Sulfadiazine; Skin Diseases, Infectious

Extracellular bacterial pathogens such as Pseudomonas aeruginosa are able to penetrate into host tissues (given an initial breech in the outer barrier, e.g. a wound) through the action of exo-toxins and degradative exo-enzymes. A mathematical model of this process is presented which, in the absence of significant immune response, predicts the progression of the bacteria into the tissue as a travelling wave whose velocity can be determined explicitly in terms of the model parameters. Simple in vitro experiments in protein-based matrices are performed which yield results consistent with this behaviour. A complementary in vitro experimental system with distinct qualitative behaviour is also studied, giving further insight and confidence in the modelling approach.

Topics: Agar; Bacteria; Bacterial Infections; Extracellular Matrix; Gelatin; Humans; In Vitro Techniques; Mathematics; Models, Biological; Pseudomonas aeruginosa; Pseudomonas Infections; Wound Infection

The Oxyrase OxyPlate anaerobe incubation system was evaluated for its ability to support the growth of clinically significant anaerobic bacteria previously identified by the Anaerobe Reference Laboratory at the Centers for Disease Control and Prevention. The results were compared with those obtained with conventional anaerobe blood agar plates incubated in an anaerobe chamber. We tested 251 anaerobic bacterial strains. Plates were read at 24, 48, and 72 h; growth was scored by a numerical coding system that combines the degree of growth and the colony size. Organisms (number of strains tested) used in this study were Actinomyces (32), Anaerobiospirillum (8), Bacteroides (39), Campylobacter (8), Clostridium (96), Fusobacterium (12), Leptotrichia (8), Mobiluncus (8), Peptostreptococcus (16), and Propionibacterium (24). At 24 h, 101 (40.2%) of the 251 strains tested showed better growth with the anaerobe chamber than with the OxyPlate system, 10 (4.1%) showed better growth with the OxyPlate system, and the remaining 140 (55. 8%) showed equal growth with both systems. At 48 h, 173 (68.9%) showed equal growth with both systems, while 78 (31.1%) showed better growth with the anaerobe chamber. At 72 h, 176 (70.1%) showed equal growth with both systems, while 75 (29.9%) showed better growth with the anaerobe chamber. The OxyPlate system performed well for the most commonly isolated anaerobes but was inadequate for some strains. These results indicate that the Oxyrase OxyPlate system was effective in creating an anaerobic atmosphere and supporting the growth of anaerobic bacteria within 72 h. OxyPlates would be a useful addition to the clinical microbiology laboratory lacking resources for traditional anaerobic culturing techniques.

Topics: Agar; Anaerobiosis; Bacteria, Anaerobic; Bacterial Infections; Bacteriological Techniques; Blood; Centers for Disease Control and Prevention, U.S.; Culture Media; Evaluation Studies as Topic; Humans; Reagent Kits, Diagnostic; United States

In many developing countries sheep and horse blood, the recommended blood supplements in bacteriological media, are not readily available, whereas pig and goat blood are. Therefore, this study examined the use of pig and goat blood as potential substitutes for sheep blood in blood-supplemented bacteriologic media commonly used in clinical microbiology laboratories. In general, the growth characteristics and colony morphologies of a wide range of aerobic and anaerobic bacteria and Candida albicans were similar on media containing pig, goat, and sheep blood, although differences were found. Enterococcus sp. uniformly produced alpha-hemolysis when incubated in CO(2), but in anaerobic conditions the hemolysis varied. In contrast, beta-hemolytic streptococci produced identical hemolytic reactions on all three media. Synergistic hemolysis was not observed on pig blood agar in the CAMP test nor on goat blood agar in the reverse CAMP test. The preparation of chocolate agar (heated) with pig blood required heating to a higher temperature than with sheep or goat blood to yield suitable growth of Haemophilus species. In general, we conclude that pig and goat blood are suitable alternatives to sheep blood for use in bacteriological media in settings where sheep and horse blood are not readily available.

Topics: Agar; Animals; Bacteria; Bacterial Infections; Bacteriological Techniques; Blood; Candida; Candidiasis; Culture Media; Goats; Humans; Sheep; Swine

Recently a commercial computer-controlled image analysis system (IAS) was introduced to measure automatically the diameters of inhibition zones in the agar diffusion test. However, there is little information on the precision of this method. In the present study clinical isolates of Salmonella spp. (N = 104), Escherichia coli (N = 100), Pasteurella spp. (N = 99), Actinobacillus pleuropneumoniae (N = 85), porcine streptococci (N = 100), and Staphylococcus aureus (N = 95) were tested in the agar diffusion test, using nineteen different antibiotics in tablets. All inhibition zone diameters were first measured by a laboratory technician and then by the IAS. Although the zone diameters of all bacteria-antibiotic combinations measured by the IAS and those measured by the laboratory technician showed a significant positive correlation, the size of the inhibition zone diameters measured by the technician and the IAS differed significantly in 59% of the combinations. However, these differences were very small and may have no clinical relevance. The IAS was also used to calculate minimum inhibitory concentrations (MIC values) from the zone diameters. In 82% of the bacteria-antibiotic combinations MIC values calculated by the IAS showed a significant positive correlation with MIC values obtained with the reference agar dilution test. However, in 92% of the bacteria-antibiotic combinations, the calculated MIC values differed significantly from the reference values. In some cases these differences were so large that they could be of clinical relevance. The IAS was unable to measure the diameter of inhibition zones of porcine streptococci properly, due to poor contrast. We concluded that when tablets are used as antibiotic carriers the IAS accurately measures the diameter of inhibition zones for bacteria species that give good contrast between the agar and bacterial growth. MIC values determined with the IAS were only indicative of those determined with the reference agar dilution test.

Topics: Agar; Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Image Processing, Computer-Assisted; Immunodiffusion; Microbial Sensitivity Tests; Tablets

Enriched broth medium is routinely used as a supplement for agar plate culture of cerebrospinal fluid (CSF). To assess the clinical utility of broth cultures, 151 consecutive CSF bacterial and fungal isolates obtained from 91 patients were retrospectively reviewed for the effect of results on treatment. Treatment decisions associated with individual CSF specimens for which isolates were recovered from thioglycollate broth only were compared with the treatment decisions associated with CSF specimens for which isolates were recovered by agar plate culture. Treatment was defined as initiation of or change in antimicrobial therapy based on the reporting of CSF culture isolates. Thirty-six (24%) of the 151 isolates were recovered in broth only. Three (8%) of these 36 isolates (from 34 patients) resulted in treatment with antimicrobial agents; however, 2 of the 3 treated isolates (Candida tropicalis, Proteus mirabilis) were recovered from a second CSF specimen in agar plate culture within 24 hours. Thus, only a single isolate (3%; Staphylococcus epidermidis) was treated based solely on a positive broth culture result. In contrast, 60 (52%) of the 115 isolates recovered in agar plate culture from 23 (40%) of 57 patients were treated (staphylococci, 28; gram-negative bacilli, 14; Cryptococcus neoformans, 10; Streptococcus pneumoniae, 3; Streptococcus sanguis, 1; other, 4). We conclude that treatment with antimicrobial agents based on isolates recovered from CSF specimens in broth culture alone is infrequent and infer from the data that the use of CSF broth cultures contributes little to treatment decisions.

Topics: Adolescent; Adult; Agar; Aged; Aged, 80 and over; Anti-Bacterial Agents; Anti-Infective Agents; Bacteria; Bacterial Infections; Cerebrospinal Fluid; Culture Media; Female; Fungi; Humans; Infant; Male; Microbiological Techniques; Middle Aged; Mycoses; Retrospective Studies

Spontaneous bacterial peritonitis is a life-threatening complication of cirrhotic ascites. Optimal patient management depends on the isolation of the causal organism from ascitic fluid. To evaluate culture techniques for the diagnosis of spontaneous bacterial peritonitis, we prospectively compared three blood culture system, the Isolator system, a lysis-centrifugation system, the Septi-Chek system, a biphasic culture system, and a nonvented tryptic soy broth system, all inoculated at the bedside, and our standard method of direct inoculation of specimens after transport to the laboratory onto agar plates and into thioglycolate broth. The results showed that the Septi-Chek and nonvented tryptic soy broth systems each recovered statistically significantly more pathogens than either the Isolator system (P = 0.0084) or the standard method (P = 0.00098). The Isolator system recovered more pathogens than the standard plate method, but this difference was not statistically significant. Both the Isolator system and the standard plate method recovered more contaminating microorganisms than the Septi-Chek or nonvented tryptic soy broth system. The Isolator system required the most processing time compared with the processing times required by any other method.

Topics: Adult; Agar; Aged; Aged, 80 and over; Bacterial Infections; Bacteriological Techniques; Culture Media; Evaluation Studies as Topic; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Peritonitis; Prospective Studies; Time Factors

The susceptibility of 201 anaerobes to erythromycin, azithromycin, clarithromycin, and roxithromycin was tested by agar dilution and E test methods by using a commercially available plate and dish system (OxyDish) to provide anaerobic conditions. Plates were incubated for 48 h. MICs for 50% of strains tested and MICs for 90% of strains tested by agar dilution and E test methods corresponded within 1 doubling dilution for all compounds. When all antibiotics were considered together, agar and E test MICs were within 1 and 2 doubling dilutions of each other in 84 to 91% and > 99% of cases, respectively.

Topics: Agar; Azithromycin; Bacteria, Anaerobic; Bacterial Infections; Clarithromycin; Drug Resistance, Microbial; Erythromycin; Evaluation Studies as Topic; Humans; Microbial Sensitivity Tests; Oxygenases; Roxithromycin

A total of 1510 strains from 15 genera of Gram-negative and Gram-positive bacteria were studied. More than 94% of 327 Escherichia coli strains showed beta-D-glucuronidase (BDG) activity. Seventeen serotypes from 170 E. coli O serogroup representatives were negative. Relationship between the existence of BDG positive and negative E. coli strains in the same serogroup or serotype has not been observed. The rate of BDG positivity was 42% among Salmonella arizonae strains and 42.2% among Shigella strains. Only one Citrobacter strain out of the 971 strains belonging to Citrobacter, Edwardsiella, Enterobacter, Hafnia, Klebsiella, Proteus, Serratia, Yersinia, Pseudomonas, Aeromonas, Vibrio and Listeria was BDG positive. A screening method based on only BDG activity is not sufficient for the primary diagnosis of E. coli.

Topics: Agar; Bacteria; Bacterial Infections; Glucuronidase; Humans; Serotyping

The agar-slide blood culture system BCB Roche was compared with the Oxoid Signal blood culture system using 2,266 paired blood cultures. A total of 271 (12%) paired sets were culture-positive, including 222 (9.8%) yielding pathogens associated with septicemia and 50 (2.2%) yielding likely contaminants. In the recovery of the total 235 isolates considered as pathogens, the BCB Roche system yielded 202 (85.9%), the Oxoid Signal 211 (89.8%); 178 (75.7%) were cultured by both systems. There was no statistically significant difference between the two systems in their sensitivity, contamination-rate and detection time, except for gram-positive organisms, which were detected earlier by the Oxoid Signal system. Both systems performed well and were easy to handle.

Topics: Agar; Bacteria; Bacterial Infections; Bacteriological Techniques; Blood; Evaluation Studies as Topic; Humans

Four different commercial brucella blood agar plating media (Anaerobe Systems, BBL Microbiology Systems, Remel, and Scott Laboratories) were compared for the abilities to recover anaerobic organisms from clinical specimens and to support the growth of American Type Culture Collection anaerobic stock cultures. Following 24 h of incubation in an anaerobe chamber, Anaerobe Systems prereduced, anaerobically sterilized brucella plates yielded 63% of the total clinical anaerobe isolates, the Scott medium yielded 51%, the Remel medium yielded 42%, and the BBL medium yielded 37%. Poor growth of Peptostreptococcus magnus, P. anaerobius, Fusobacterium necrophorum, F. nucleatum, and pigmented Bacteroides spp. was observed on brucella media obtained from BBL, Remel, and Scott. Data obtained with stock anaerobic cultures showed that Anaerobe Systems plates yielded good growth and produced a larger colony size with all of the strains tested in 1 day, whereas poor growth of Peptostreptococcus spp., B. melaninogenicus, and Fusobacterium spp. was noted on brucella media from BBL, Remel, and Scott.

Topics: Agar; Bacteria, Anaerobic; Bacterial Infections; Bacteroides; Brucella; Culture Media; Evaluation Studies as Topic; Humans

Coomassie Brilliant Blue Agar was used to quantify the frequency of the A-layer phenotype in different isolates of Aeromonas salmonicida. Hydrophilic, non-clumping isolates of A. salmonicida consisted predominantly of the A-layer minus phenotype. These bacteria were avirulent by intraperitoneal injection into susceptible brook trout (Salvelinus fontinalis) and could not be reisolated from infected fish. By contrast, hydrophobic, clumping isolates were predominantly of the A-layer positive phenotype, highly virulent in brook trout, and easily recovered from dead or moribund fish. A-layer positive and negative clones of A. salmonicida were derived by plating bacteria on Coomassie Blue Agar. The plating showed clearly that Coomassie Blue Agar could be used as a highly selective in vitro screening method to reclaim the virulence of certain isolates of A. salmonicida having a relatively low percentage of A-layer positive phenotypes.

Topics: Aeromonas; Agar; Animals; Bacterial Infections; Bacterial Proteins; Electrophoresis, Polyacrylamide Gel; Fish Diseases; Phenotype; Rosaniline Dyes; Trout; Virulence

Factors influencing pathogenicity of various microbes found in the female lower genital tract remain incompletely understood. Protease production by cervico/vaginal microorganisms may alter or inactivate a variety of proteins important in host defense and structural-functional integrity including collagen-containing chorioamniotic membranes and uterine cervix. Host tissues may be made more susceptible to other organisms' virulence factors by protease-producing members of genital tract local flora. Microorganisms themselves may also be influenced by the presence of other microbial protease. Nonspecific protease, gelatinase, collagenase, and elastase production was examined for in vitro with use of aerobic (30) and anaerobic (25) strains of microorganisms typical of those isolated from the lower genital tract of women with premature rupture of membranes, chorioamnionitis, and puerperal infection. Microorganisms including Bacteroides bivius, Bacteroides melaninogenicus, Bacteroides fragilis, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Proteus species, and Propionibacterium acnes produce various proteases. Protease production by both acknowledged pathogenic and commensal bacteria may contribute to the occurrence of reproductive tract morbidity including premature rupture of membranes and preterm labor.

Topics: Agar; Bacteria, Aerobic; Bacteria, Anaerobic; Bacterial Infections; Female; Gelatinases; Genital Diseases, Female; Humans; In Vitro Techniques; Microbial Collagenase; Pancreatic Elastase; Pepsin A; Peptide Hydrolases; Pregnancy; Pregnancy Complications; Puerperal Disorders

A number of microdilution and agar-replicating systems are currently available for the rapid, accurate identification of common bacterial pathogens. These systems can be highly automated for large clinical laboratories or used manually for small laboratories.

Topics: Agar; Bacteria; Bacterial Infections; Culture Media; Enterobacteriaceae; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Indicator Dilution Techniques

Charcoal is an effective replacement for serum in media for the isolation and culture of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fish. The medium, KDM-C, contains 10 g of peptone, 0.5 g of yeast extract, 1 g of L-cysteine hydrochloride, 1 g of activated charcoal, and 15 g of agar per liter and is adjusted to pH 6.8 with NaOH before autoclaving. Eight strains of R. salmoninarum grew from dilute inocula as well on KDM-C as on a standard serum-containing medium (KDM-2). The medium was effective for both primary isolations from fish and repeated transfers and has potential value for antigen preparation and physiological studies.

Topics: Agar; Animals; Bacterial Infections; Charcoal; Culture Media; Fish Diseases; Gram-Positive Bacteria; Kidney Diseases; Salmonidae

A total of 64 strains of gram-negative, asaccharolytic, anaerobic, agar-corroding, rod-shaped bacteria from soft-tissue infections of cats and dogs were compared with other agar-corroding, anaerobic organisms isolated from human periodontal pockets (Wolinella recta ATCC 33238T), bovine rumens (Wolinella succinogenes ATCC 29543T), and gingival crevices of humans (Bacteroides gracilis ATCC 33236T and Bacteroides ureolyticus NCTC 10941T). Campylobacter concisus ATCC 33237T (from human gingival crevices) which did not corrode agar but which biochemically resembled organisms in this group was also included in this study. Although the type strains of W. recta, W. succinogenes, and B. gracilis resembled the animal strains phenotypically and in DNA base ratios, none had bacterial protein patterns (as indicated by isoelectric focusing) identical with the animal strains studied. The animal strains could be divided into motile and nonmotile groups. The motile animal strains were similar biochemically but could be divided into three groups by isoelectric focusing of bacterial proteins. Some had cell wall ultrastructural features identical with W. recta; others had the smooth walls of conventional gram-negative organisms. One group of nonmotile animal strains closely resembled B. gracilis phenotypically, and they had the cell wall ultrastructure of conventional gram-negative bacteria as described previously (4). The other nonmotile group had cell wall ultrastructure like that of W. recta.

Topics: Agar; Animals; Bacteria; Bacterial Infections; Bacteroides; Campylobacter; Cat Diseases; Cats; Dog Diseases; Dogs

Regression analyses to determine the correlation of MIC and inhibition zone produced by enoxacin discs were carried out using 300 freshly isolated cultures of infective organisms (20 strains each from 15 species). For this purpose, commercially available discs containing 10 micrograms enoxacin and locally made discs containing 5 and 10 micrograms enoxacin were used. Studies were performed simultaneously with I.C.S. and Kirby-Bauer methods on Iso-Sensitest and Mueller-Hinton agars. It was found that correlation becomes poorer with increasing disc content and when the Kirby-Bauer method was used. Based on preliminary MIC breakpoints of 1 and 4 mg/l and the zone cut-off points calculated from regression equations, no major errors were found in zone interpretations. Minor errors were observed in 3.7% with our own 5 micrograms discs used in the I.C.S. method, and in 11.0% with 10 micrograms commercial discs and the Kirby-Bauer method. For 5 micrograms enoxacin discs and the Kirby-Bauer method the following zone interpretations are recommended: resistant up to 13 mm, intermediate 14-21 mm, susceptible 22 mm or more. The respective values for the I.C.S. method are: resistant up to 14 mm, intermediate 15-22 mm, susceptible 23 mm or more.

Topics: Agar; Bacteria; Bacterial Infections; Diffusion; Enoxacin; Microbial Sensitivity Tests; Naphthyridines

Topics: Agar; Animals; Bacterial Infections; Cattle; Cattle Diseases; Keratoconjunctivitis; Moraxella; Polysorbates; Species Specificity

Ceftazidime was compared with cefotaxime, ceftizoxime, cefmenoxime, cefotiam, cefoperazone, moxalactam, piperacillin, carbenicillin, mezlocillin, cefsulodin and the aminoglycoside antibiotic gentamicin in a series of mouse protection tests. Ceftazidime, together with the other cephalosporin antibiotics and moxalactam were equally effective against infections caused by Staphylococcus aureus with ED50 values ranging from 3.5 to 25 mg/kg. Gentamicin was the most active antibiotic with ED50 values of 0.4 and 1.6 mg/kg. Ceftazidime showed excellent activity against Enterobacteriaceae with ED50 values ranging from 0.2-0.9 mg/kg for Escherichia coli strains, 1.1-13.8 mg/kg for indole positive and negative Proteus spp, and 0.1-25 for Enterobacter cloacae, Klebsiella pneumoniae and Serratia spp. Similar activity against many of the test strains of Enterobacteriaceae was found for gentamicin, cefotaxime, ceftizoxime, cefmenoxime and moxalactam, although cefotiam and cefoperazone were significantly less active than ceftazidime. Ceftazidime was significantly more active than the other beta-lactam antibiotics tested against Pseudomonas aeruginosa infections with ED50 values ranging from 02-108 mg/kg. Only the aminoglycoside antibiotic gentamicin, with ED(50,S) 0.6-6.3 mg/kg, was as effective as ceftazidime. Very poor activity was found for moxalactam, cefoperazone, piperacillin, carbenicillin and mezlocillin against the majority of the test strains of Pseudomonas. The results of these in-vivo indicate that ceftazidime is a promising potential alternative to aminoglycoside antibiotics.

Topics: Agar; Animals; Anti-Bacterial Agents; Bacterial Infections; beta-Lactams; Ceftazidime; Cephalosporins; Colony Count, Microbial; Female; Gentamicins; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Mice; Microbial Sensitivity Tests

The antiserum agar method (ASA), which is based on the formation of immunoprecipitates around bacterial growth on agar containing meningococcal hyperimmune horse serum, was evaluated for serogroup identification of Neisseria meningitidis. Four hundred meningococcal stains were serogrouped by ASA employing horse antisera to serogroups A, B, C, Y, W135, Z, and 29E and compared to serogroup identification by bacterial slide agglutination (BA) employing rabbit antisera. Overall, there was 95% agreement between the two methods. The ASA proved to be more accurate than BA since 15 strains which cross-reacted with Y and W135 rabbit antisera by BA were specifically serogrouped as either Y or W135 by ASA. In addition, 5 out of 75 strains which were ungroupable by BA were serogrouped as either B or 29E by ASA. Repeat serogroup identification of 100 meningococcal strains by ASA provided identical results thus showing the reproducibility of the method. The ASA is advantageous to BA since it is more reliable, utilizes standard antisera which do not have to be absorbed to remove cross-reactions, does not require the preparation of standardized bacterial antigen, and is simple to perform.

Topics: Agar; Agglutination Tests; Antigen-Antibody Reactions; Bacterial Infections; Humans; Neisseria meningitidis; Serotyping

The recovery of clinical anaerobic isolates on selective and nonselective agar media, as well as the time required to detect the isolates, was examined. Of a total of 235 isolates, 77, 46, and 40% were detected on Schaedler blood agar, colistinnalidixic acid blood agar, and kanamycin-vancomycin-lysed blood agar, respectively, and 94% were detected on the combination of Schaedler blood agar with kanamycin-vancomycin-lysed blood agar. A total of 19% of the anaerobes were detected after incubation for 1 day, and 70% were detected after 2 days.

Topics: Agar; Anaerobiosis; Bacteria; Bacterial Infections; Culture Media; Humans; Species Specificity

Motility and various biochemical activities of isolates of bacteria and yeasts were tested on undivided agar plates by using a simple, manually operated multipoint inoculation apparatus that allowed the analysis of 25 isolates per 9-cm-diameter petri plate. Fermentation of all 17 carbohydrates tested as well as 13 other biochemical activities commonly used for identification of bacteria were readily demonstrated by the multipoint inoculation plate method, and the results agreed very well with those of conventional tube tests. In addition to speedy inoculation and low cost of materials, the multipoint inoculation plate method offers several other advantages when compared with conventional tube tests or with some of the manufactured test kits currently available for recognizing members of the family Enterobacteriaceae.

Topics: Agar; Bacteria; Bacterial Infections; Bacterial Physiological Phenomena; Enterobacteriaceae; Humans; Microbiological Techniques; Mycoses; Yeasts

The quantitative growth, the colony size, and the rate of growth of 47 clinical anaerobic isolates were compared on five different media, namely Brucella agar, brain heart infusion agar, Columbia agar, Schaedler agar, and tryptic soy agar. There was no significant difference in the quantitative growth of the anaerobes inoculated onto the five media. Although no single medium was superior for the growth of all isolates, 12 of 22 isolates, inoculated onto media stored for 4 weeks or less, grew best on Schaedler agar. The effects of supplementation of the media with reducing agents and reduction of the media before use were also analyzed and were found to be affected by the composition and length of storage of the media, as well as the bacteria tested.

Topics: Agar; Anaerobiosis; Bacteria; Bacterial Infections; Cysteine; Dithiothreitol; Humans; Palladium

Salt dependent gram-negative bacilli responsible for gastroenteritis and tissue infections are often not recovered because proper media for isolation are not used. A salt-starch XLD agar with 1.5% NaC1 and 0.5% starch medium has been found to permit the isolation of pathogenic Enterobacteriaceae, non-Enterobacteriaceae gram-negative bacilli, and salt-dependent gram-negative bacilli, among which is Vibrio parahemolyticus. As far as the Enterobacteriaceae are concerned, the selectivity and sensitivity of the medium are the same as with standard media with the added advantage of isolating salt-dependent organisms, thereby saving time and money. It can be used for routine blood cultures, investigation of sea water, seafood and tissue infections related to marine activities.

Topics: Agar; Bacteria; Bacterial Infections; Deoxycholic Acid; Diagnosis, Differential; Enterobacteriaceae; Feces; Humans; Lysine; Skin; Sodium Chloride; Species Specificity; Starch; Vibrio parahaemolyticus; Xylose

A defined agar medium (hereinafter designated caprylate-thallous [CT5 agar) containing 0.01% yeast extract, 0.1% caprylic (n-octanoic) acid, and 0.025% thallous sulfate is highly selective for all Serratia species and effectively discriminates against most non-Serratia strains likely to be in the same habitats. The selectivity of CT agar is demonstrated by the very high efficiency of colony formation (mean, 80.7% of that on a nonselective complex medium) on CT agar by known Serratia strains and the very low efficiency of colony formation (close to zero) on CT agar by bacterial strains known not to be Serratia. The utility of this medium in actual clinical laboratory practice is demonstrated by the more rapid and higher recovery of Serratia on this selective medium as compared to conventional procedures of in-tandem runs of 513 consecutive urine, feces, and sputum specimens. Pigmented and nonpigmented Serratia strains deliberately added to fecal specimens can be selectively and quantitatively recovered on CT agar. CT agar compares favorably with, or in some cases is an improvement over, other selective media which have been recommended for isolating Serratia. This selective CT agar medium could be quite useful in ecological surveys, especially those related to hospital-acquired infections.

Topics: Agar; Bacterial Infections; Caprylates; Cross Infection; Evaluation Studies as Topic; Feces; Humans; Serratia; Species Specificity; Sputum; Thallium; Urine

The diagnosis of obligately aerobic Gram-negative rods in the clinical laboratory may encounter difficulties since media used for Enterobacteriacae are only partially usable for the diagnosis of this group of bacteria (Psuedomonas, Xanthomonas, Alcaligenes, Achromobacter, Brucella, Bordetella, Flavobacterium, Moraxella, Acinetobacter, and some still unnamed taxa). We have developed a diagnostic scheme, based on recent publications in the field and representing an extension of earlier tables from this and other laboratories, which attempts to classify a maximal number of obligately aerobic Gram-negative rods with a minimal number of tests. The scheme, employed on 4051 strains, used blood agar and MacConkey Agar as isolation media. Growth characteristics on these media and microscopic morphology may be of help, but only the type of growth on Triple Sugar Iron (or Kligler's) Agar is characteristic for the group as a whole (no growth in the butt, alkalinization or no pH change on the slant). A primary identification series employs tests for oxidase (Kovacs), oxidation of glucose and xylose (in OF medium), deoxyribonuclease and indole (in DNase Test Agar with Methyl Green), nitrate reduction (in Indole Nitrite Medium), motility (hanging drop), and fluorescein production (on Flo Agar). Results of Kirby-Bauer antimicrobial sensitivity testing serve as additional (colistin) or confirmatory criteria. Incubation is at 30 degrees C for 24-48 hrs. If a diagnosis is not possible than, a secondary series, including tests for lysine decarboxylase (tablets), 4 hr urease, esculin hydrolysis, growth at 42 C and on SS Agar, gelatin liquefaction, and flagellar staining may have to be used, and read after 4-24 hrs at 30 degrees C. Five tables, drawn up according to oxidase, glucose, and xylose reactions, serve to identify the species or taxa. Biotypes cannot be differentiated. The scheme will need updating as more knowledge of these bacteria will become available.

Topics: Agar; Bacterial Infections; Culture Media; Drug Resistance, Microbial; Glucose; Gram-Negative Aerobic Bacteria; Humans; Oxidation-Reduction; Oxidoreductases; Xylose

In the Institute of Bacteriology of Allgemeines Krankenhaus St. Georg, Hamburg, all clinical specimens received (except stools, sputum, and vaginal swabs) have been studied for the presence of anaerobians since 1947. More than 25 years' experience has convinced the authors that not infrequently, non-sporogenic anaerobians occur as infectious agents. Statistical data compiled for the period 1956-1972 revealed that from a total of 71,973 specimens contaminated with bacteria, 7,047 (9.8%) were containing non-sporogenic anaerobians. Pure anaerobic cultures were obtained in 2.404 cases (3.3%) and mixed cultures of aerobic and anaerobic bacteria in 4,643 cases (6.5%). The pathogenic importance was revealed by identifications from osteomyelitis cases: 11-13.7% pure cultures and 17% mixed cultures (with aerobians). Also in cases of total endoprosthesis of complicated course they were detected in up to 23%. On account of the frequent cultures of non-sporogenic anaerobians obtained from clinical specimens, the authors demand a routine analysis of all clinical specimens for the presence of anerobians...

Topics: Agar; Anaerobiosis; Animals; Bacteria; Bacterial Infections; Bacteriological Techniques; Blood; Culture Media; Glucose; Humans; Liver; Sheep; Species Specificity

Topics: Agar; Bacteria; Bacterial Infections; Cell Wall; Cephalosporins; Cephalothin; Eye; Feces; Immunodiffusion; Microbial Sensitivity Tests; Organ Culture Techniques; Respiratory System; Urogenital System

Topics: Agar; Antigens; Bacterial Infections; Dysentery; Precipitin Tests; Research; Shigella dysenteriae

Topics: Agar; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Drug Resistance, Microbial; Humans; Microbial Sensitivity Tests

Topics: Agar; Anti-Bacterial Agents; Antibiotics, Antitubercular; Bacteria; Bacterial Infections; Coinfection; Humans; Microbial Sensitivity Tests

Topics: Agar; Anti-Bacterial Agents; Antibiotics, Antitubercular; Bacteria; Bacterial Infections; Drug Resistance, Microbial; Microbial Sensitivity Tests

Topics: Agar; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Drug Resistance, Microbial; Microbial Sensitivity Tests