agar and Cystic-Fibrosis

The transepithelial nasal potential difference (NPD) is used to assess cystic fibrosis transmembrane conductance regulator (CFTR) activity. Unreliability, excessive artifacts, and lack of standardization of current testing systems can compromise its use as a diagnostic test and outcome measure for clinical trials.. To determine whether a nonperfusing (agar gel) nasal catheter for NPD measurement is more reliable and less susceptible to artifacts than a continuously perfusing nasal catheter, we performed a multicenter, randomized, crossover trial comparing a standardized NPD protocol using an agar nasal catheter with the same protocol using a continuously perfusing catheter. The data capture technique was identical in both protocols. A total of 26 normal adult subjects underwent NPD testing at six different centers.. Artifact frequency was reduced by 75% (P < .001), and duration was less pronounced using the agar catheter. The measurement of sodium conductance was similar between the two catheter methods, but the agar catheter demonstrated significantly greater CFTR-dependent hyperpolarization, because Δ zero Cl- + isoproterenol measurements were significantly more hyperpolarized with the agar catheter (224.2 ± 12.9 mV with agar vs 18.2 ± 9.1 mV with perfusion, P < .05).. The agar nasal catheter approach demonstrates superior reliability compared with the perfusion nasal catheter method for measurement of NPD. This nonperfusion catheter method should be considered for adoption as a standardized protocol to monitor CFTR activity in clinical trials.

Topics: Adult; Agar; Analysis of Variance; Artifacts; Catheterization; Cross-Over Studies; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Female; Gels; Humans; Male; Membrane Potentials; Nasal Mucosa

A modified chocolate blood agar medium incorporating cefsulodin, a semi-synthetic cephalosporin, was developed and compared with non-selective chocolate blood agar and selective haemin-bacitracin blood agar for the routine isolation of Haemophilus influenzae from the respiratory secretions of patients with cystic fibrosis. The results showed that cefsulodin chocolate blood agar improved the recovery rate of H. influenzae in this group of patients. The medium was stable on storage for 10 days at 4 degrees C.

Topics: Agar; Bacitracin; Blood; Cacao; Cefsulodin; Cephalosporins; Culture Media; Cystic Fibrosis; Haemophilus Infections; Haemophilus influenzae; Hemin; Humans; Inhalation; Respiratory Tract Infections; Sputum

Topics: Agar; Animals; Anti-Bacterial Agents; Coinfection; Cystic Fibrosis; Phenotype; Sheep; Staphylococcal Infections; Staphylococcus aureus

Traditional culture of non-tuberculous mycobacteria (NTMs) has involved egg-based formulations (Lowenstein-Jensen medium, Ogawa Egg medium) or defined media (Middlebrook formulations), which have disadvatages of composition complexity, availability and cost. Previously, the commercial agar formulation, Standard Plate Count (SPC) agar [Yeast extract 2.5 g/L, pancreatic digest of casein 5.0 g/L, glucose 1.0 g/L, agar 15.0 g/L, pH 7.0 ± 0.2 at 25 °C] has been shown to be an effective solid medium for the enumeration and laboratory manipulation of Mycobacterium abscessus complex organisms. Given its relative simplicity, commercial availability and inexpensive cost, we wished to evaluate its utility for the medium- to longterm maintenance/storage of these organisms. M. abscessus complex organisms (n = 33), were inoculated onto SPCA slopes and stored undistubed in the dark at ambient temperature for six months. Following this, slopes were broken out and culture of the NTM attempted. All slopes maintained NTM culture viability and were able to initiate growth six months later. We therefore advocate the cost-effective employment of SPCA slopes for the medium- to longterm maintenance of M. abscessus organisms, without the need for complex media, availability of sterile blood and requirements for continuous -80 °C freezing.

Topics: Agar; Bacteriological Techniques; Cost-Benefit Analysis; Culture Media; Cystic Fibrosis; Humans; Mycobacterium abscessus; Nontuberculous Mycobacteria

A novel method is described for the laboratory storage of the filamentous fungi, Aspergillus fumigatus and Scedosporium apiospermum. These fungi were isolated directly from the sputum of patients with cystic fibrosis (CF) on previously described Medium B+ fungal selective agar. Medium B+ plates containing heavy growths of filamentous fungi were air dried to completeness and the resulting dehydrated agar containing fungi were hermetically sealed within A4 plastic lamination sheets using a domestic paper laminator. Fungi were successfully recovered and recultured post lamination. This method is simple, inexpensive, versatile and widely adaptable and requires minimum preparation/handling/processing, thereby encouraging the routine archiving of fungal isolates. Laminated fungal sheets may be catalogued and stored safely and securely in fireproof lockable filing cabinets in laboratories, thereby saving valuable bench- or freezer space.

Topics: Agar; Aspergillus fumigatus; Bacteriological Techniques; Culture Media; Cystic Fibrosis; Fungi; Humans; Scedosporium; Sputum

Topics: Agar; Burkholderia cenocepacia; Burkholderia Infections; Cell Culture Techniques; Culture Media; Cystic Fibrosis; Humans; Pseudomonas aeruginosa; Pseudomonas Infections; Sputum

A novel selective agar (RGM medium) has been advocated for the isolation of rapidly growing mycobacteria from the sputa of cystic fibrosis (CF) patients. The aim of this study was to compare RGM medium to

Topics: Agar; Culture Media; Cystic Fibrosis; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sputum; United States

We evaluated the use of a chromogenic selective medium (MRSA ID) as a useful tool for the detection of methicillin-resistant Staphylococcus aureus (MRSA) in cystic fibrosis (CF) patient samples. Fifty-four MRSA isolates were detected by MRSA ID, while only 24/54 (44%) (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.63 to 4.76) were detected by conventional methods. A chromogenic selective medium for MRSA detection may improve its surveillance in CF patients.

Topics: Agar; Bacteriological Techniques; Chromogenic Compounds; Culture Media; Cystic Fibrosis; Humans; Methicillin-Resistant Staphylococcus aureus; Sensitivity and Specificity; Staphylococcal Infections

Topics: Agar; Culture Media; Cystic Fibrosis; Diagnosis, Differential; Humans; Influenza, Human; Reagent Kits, Diagnostic; Respiratory Tract Infections

We implemented a selective medium for improved detection of Stenotrophomonas maltophilia in sputum samples from CF patients. We also performed antimicrobial susceptibility testing with eight antibiotics.. A total of 623 consecutive sputum samples from 165 CF patients in a German CF center were cultured onto conventional media and onto Steno medium agar (SMA). All isolates confirmed as S. maltophilia by biochemical and molecular methods were subjected to antimicrobial susceptibility testing. The following agents were tested by Etest: ceftazidime, levofloxacin, moxifloxacin, tigecycline, trimethoprim-sulfamethoxazole, fosfomycin, colistin, and ticarcillin-clavulanate acid.. Conventional media supported the growth of S. maltophilia in 7.1% of samples, whereas SMA supported its growth in 11.6%, increasing the detection rate to 64%. Trimethoprim-sulfamethoxazole and tigecycline exhibited the highest in vitro activity, whereas ceftazidime, colistin, and ticarcillin-clavulanate acid exhibited higher resistance rates.. SMA is a promising medium allowing improved isolation of S. maltophilia from sputum samples from CF patients. Trimethoprim-sulfamethoxazole and tigecycline demonstrated excellent inhibitory effects against S. maltophilia, which may suggest a potential clinical effect.

Topics: Adolescent; Adult; Agar; Aged; Algorithms; Anti-Infective Agents; Child; Child, Preschool; Culture Media; Cystic Fibrosis; Drug Resistance, Bacterial; Female; Humans; Infant; Male; Microbial Sensitivity Tests; Middle Aged; Prospective Studies; Stenotrophomonas maltophilia; Young Adult

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

The objective of this prospective study was to assess the prevalence of Exophiala dermatitidis in respiratory secretions of patients with cystic fibrosis (CF) and to identify risk factors for its presence. The results of all cultures performed over a 2-year period in non lung-transplant patients in our CF clinic were included in the study. Samples consisted of sputum (whenever possible) or deep pharyngeal aspirate after a session of physiotherapy. Specimens were inoculated onto Sabouraud gentamicin-chloramphenicol agar (SGCA) medium (Becton-Dickinson) and incubated at 35°C for 2 days and then at ambient temperature (15-25°C) for 3 weeks. The whole study group included 154 patients (mean age ± SD: 18.5 y ± 11.69). E. dermatitidis was isolated from 58 specimens (2.8%) of nine patients (5.8%) out of total of 2065 cultures prepared during the study period. All E. dermatitidis culture-positive patients were pancreatic insufficient and ≥12 y of age. Almost all (8/9) were homozygous for the F508 del mutation. Aspergillus fumigatus colonization and genotype seemed to be predisposing factors. No other significant characteristic was identified in this group, either in terms of predominant bacterial pathogen or treatment. A distinct comparative study performed over 3 months in our laboratory revealed that the use of SGCA yielded identical isolation rates of E. dermatitidis as erythritol-chloramphenicol agar (ECA).

Topics: Adolescent; Adult; Agar; Child; Child, Preschool; Culture Media; Cystic Fibrosis; Exophiala; Female; Humans; Infant; Lung Diseases, Fungal; Male; Microbiological Techniques; Middle Aged; Mycoses; Prevalence; Risk Factors; Sputum; Young Adult

A novel chromogenic medium for isolation and identification of Pseudomonas aeruginosa from sputa of cystic fibrosis (CF) patients was evaluated and compared with standard laboratory methods.. One hundred sputum samples from distinct CF patients were cultured onto blood agar (BA), Pseudomonas CN selective agar (CN) and a Pseudomonas chromogenic medium (PS-ID). All Gram-negative morphological variants from each medium were subjected to antimicrobial susceptibility testing, and identification using a combination of biochemical and molecular methods.. P. aeruginosa was isolated from 62 samples after 72 h incubation. Blood agar recovered P. aeruginosa from 56 samples (90.3%) compared with 59 samples (95.2%) using either CN or PS-ID. The positive predictive value of PS-ID (98.3%) was significantly higher than growth on CN (88.5%) for identification of P. aeruginosa (P<0.05).. PS-ID is a promising medium allowing for the isolation and simultaneous identification of P. aeruginosa from sputa of CF patients.

Topics: Adolescent; Adult; Agar; Bacteriological Techniques; Child; Child, Preschool; Chromogenic Compounds; Culture Media; Cystic Fibrosis; Humans; Middle Aged; Predictive Value of Tests; Pseudomonas aeruginosa; Sputum; Young Adult

Yeasts and filamentous fungi are beginning to emerge as significant microbial pathogens in patients with cystic fibrosis (CF), particularly in relation to allergic-type responses, as seen in patients with allergic bronchopulmonary aspergillosis (ABPA), Aspergillus bronchitis and in invasive fungal disease in lung transplant patients. Four fungal media were compared in this study, including Sabouraud Dextrose Agar (SDA) and Medium B, with and without the addition of selective antibiotics, where antibiotic-supplemented media were designated with (+). These media were compared for their ability to suppress contaminating, mainly Gram-ve pathogens, in CF sputa (Pseudomonas aeruginosa, Burkholderia cepacia complex [BCC] organisms) and to enhance the growth of fungi present in CF sputum. Medium B consisted of glucose (16.7 g/l), agar (20 g/l), yeast extract (30 g/l) and peptone (6.8 g/l) at pH 6.3 and both SDA(+) and Medium B(+) were supplemented with cotrimethoxazole, 128 mg/l; chloramphenicol, 50 mg/l; ceftazidime, 32 mg/l; colistin, 24 mg/l). Employment of SDA(+) or Medium B(+) allowed an increase in specificity in the detection of yeasts and moulds, by 42.8% and 39.3%, respectively, over SDA when used solely. SDA(+) had a greater ability than Medium B(+) to suppress bacterial growth from predominantly Gram-ve co-colonisers. This is a significant benefit when attempting to detect and isolate fungi from the sputum of CF patients, as it largely suppressed any bacterial growth, with the exception of the BCC organisms, thus allowing for an increased opportunity to detect target fungal organisms in sputum and represented a significant improvement over the commercial medium (SDA), which is currently used. Overall, both novel selective media were superior in their ability to suppress bacteria in comparison with the commercially available SDA medium, which is routinely employed in most clinical microbiology diagnostic laboratories presently. Alternatively, Medium B(+) had a great ability to grow fungi than SDA(+) and when employed together, the specificity of combined use was 82%, with a sensitivity for yeasts, filamentous fungi, and combined overall fungi of 96.0%, 92.3% and 96.0%, respectively. Overall, when employing one fungal selective medium for the routine detection of yeasts and filamentous fungi in the sputum of CF patients, we would recommend employment of Medium B(+). However, we would recommend the combined employment of SDA(+) and Medium B(+), in order t

Topics: Adult; Agar; Anti-Bacterial Agents; Cell Culture Techniques; Culture Media; Cystic Fibrosis; Fungi; Humans; Mycology; Sensitivity and Specificity; Sputum

We demonstrate that all nine species of the Burkholderia cepacia complex can express the mucoid phenotype. A survey of clinical isolates showed that strains of B. cenocepacia, the most virulent species of the complex, are most frequently nonmucoid. Additionally, isolates from patients with chronic infections can convert from mucoid to nonmucoid.

Topics: Adolescent; Adult; Agar; Bacteriological Techniques; Burkholderia cepacia complex; Burkholderia Infections; Canada; Child; Child, Preschool; Culture Media; Cystic Fibrosis; Humans; Phenotype; Polysaccharides, Bacterial; Respiratory System

We used 200 sputum specimens from patients with cystic fibrosis to evaluate BBL CHROMagar Staph aureus medium (CSA; BD Diagnostics, Spark, MD). Samples were inoculated to CSA, trypticase soy blood agar (BA), and Mannitol Salt (MS; BD Diagnostics). After 18 hours of incubation, CSA detected 39 (78%) of 50 Staphylococcus aureus (SA) samples; BA detected 30 (60%); and MS detected 29 (58%). Sensitivity after overnight incubation (at least 18 hours) was 82% for CSA, 72% for BA, and 71% for MS. At 2 days, CSA detected 48 (96%) of the SA. There were 2 false-positive results on CSA (99% specificity). There were 4 (8%) minor and no major or very major discrepancies between minimum inhibitory concentration (MIC) results for isolates grown on CSA and those grown on BA. Even at early reading times, CSA was superior to conventional media for detection of SA in these very complex cultures. MICs from all SA samples can be reported 24 hours sooner, and an additional BA subculture is not needed.

Topics: Agar; Animals; Bacteriological Techniques; Chromogenic Compounds; Cystic Fibrosis; Humans; Mannitol; Reproducibility of Results; Sensitivity and Specificity; Sputum; Staphylococcal Infections; Staphylococcus aureus

To develop a selective agar medium to help detect and quantify Gram-negative flora in the sputum of patients with cystic fibrosis (CF).. A novel Gram-negative Selective Agar (GNSA) medium was developed consisting of tryptone soya broth (30 g), bacteriological agar no.1 (10 g), yeast extract (5 g), crystal violet (2 mg), nisin (48 mg), novobiocin (5 mg), cycloheximide (100 mg), amphotericin (2 mg) and double distilled water (1 l), for the selective culture of all Gram-negative flora from the sputum of patients with CF. GNSA was able to support the proliferation of all 34 Gram-negative organisms examined, including 23 species most commonly associated with CF, but was unable to support the growth of the 12 Gram-positive or seven fungal organisms examined. Sensitivity studies demonstrated that the GNSA medium was able to detect not less than 1.50 x 102 CFU ml-1 sputum Pseudomonas aeruginosa, 2.38 x 102 CFU ml-1 sputum Burkholderia cepacia genomovar IIIb and 6.70 x 103 CFU ml-1 sputum Stenotrophomonas maltophilia. A comparison of the microbial flora detected in the sputa of 12 adult CF patients by employment of routine bacteriological agar media and GNSA, demonstrated that GNSA was able to detect all Gram-negative organisms cultured by routine media, but had the advantage of detecting Alcaligenes xylosoxidans in two CF patients, whom had no previous history of Gram-negative infection.. GNSA was unable to support the proliferation of any Gram-positive organism or yeast/fungi, but was successful in supporting the growth of all Gram-negative organisms challenged.. Employment of this medium coupled with semi-automated technology may aid in helping to efficiently determine Gram-negative loading of respiratory secretions, particularly in response to antibiotic intervention.

Topics: Adult; Agar; Alcaligenes; Burkholderia cepacia; Colony Count, Microbial; Culture Media; Cystic Fibrosis; Female; Gamma Rays; Humans; Male; Pseudomonas aeruginosa; Sensitivity and Specificity; Spectrophotometry; Sputum

To evaluate the sensitivity and specificity of two selective media for the isolation of Burkholderia cepacia from sputum specimens in patients with cystic fibrosis (CF).. In total, 149 expectorated sputum specimens from 113 patients with CF (32 cepacia colonised patients and 81 non-cepacia colonised patients) attending three CF centres were examined for the presence of B cepacia on two selective media: (1) MAST selective agar, a commercially available selective medium widely used in the UK and (2) BCSA (B cepacia selective agar), a new medium recently described, which is used predominantly in North America.. Burkholderia cepacia was isolated from 53 of 149 (35.6%) specimens examined, representing 32 of 113 (28.3%) patients, using both the MAST and BCSA media. Growth was most rapid on BCSA with all (53 of 53) isolates detectable after 48 hours, compared with 50 of the 53 isolates on MAST agar, with the remaining three isolates detectable at five days. Twenty eight contaminants were identified on MAST agar and 13 on BCSA agar; mainly Alcaligenes xylosoxidans and yeast on MAST agar and Flavobacterium indologenes on BCSA medium. BCSA was equivalent to MAST agar in its ability to isolate B cepacia from patients with CF with a history of B cepacia infection.. The increased selectivity and reduced time to detection of BCSA makes it an attractive alternative to MAST. However, its present limited commercial availability in the UK may delay its use in routine diagnostic laboratories because of complications with media preparation and quality control.

Topics: Adult; Agar; Bacteriological Techniques; Burkholderia cepacia; Child; Culture Media; Cystic Fibrosis; Female; Humans; Male; Polymerase Chain Reaction; Sensitivity and Specificity; Sputum; Time Factors

Pseudomonas aeruginosa is the most common pathogen infecting the lungs of patients with cystic fibrosis (CF). Improved antimicrobial chemotherapy has significantly increased the life expectancy of these patients. However, accurate susceptibility testing of P. aeruginosa isolates from CF sputum may be difficult because the organisms are often mucoid and slow growing. This study of 597 CF isolates of P. aeruginosa examined the correlation of disk diffusion and Etest (AB BIODISK, Solna, Sweden) results with a reference broth microdilution method. The rates of interpretive errors for 12 commonly used antipseudomonal antimicrobials were determined. The disk diffusion method correlated well (zone diameter versus MIC) for all of the agents tested. However, for mucoid isolates, correlation coefficients (r values) for piperacillin, piperacillin-tazobactam, and meropenem were <0.80. The Etest correlation with reference broth microdilution results (MIC versus MIC) was acceptable for all of the agents tested, for both mucoid and nonmucoid isolates. Category interpretation errors were similar for the disk diffusion and Etest methods with 0.4 and 0.1%, respectively, very major errors (false susceptibility) and 1.1 and 2.2% major errors (false resistance). Overall, both agar diffusion methods appear to be broadly acceptable for routine clinical use in susceptibility testing of CF isolates of P. aeruginosa.

Topics: Agar; Anti-Bacterial Agents; Child; Cystic Fibrosis; Humans; Lung; Lung Diseases; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Reproducibility of Results; Sputum

The aim of the study was to evaluate the effects of two kinds of Chinese medicinal herbs, Isatis tinctoria L (ITL) and Daphne giraldii Nitsche (DGN), on a rat model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis (CF). Compared to the control group, both drugs were able to reduce the incidence of lung abscess (p < 0.05) and to decrease the severity of the macroscopic pathology in lungs (p < 0.05). In the great majority of the rats, the herbs altered the inflammatory response in the lungs from an acute type inflammation, dominated by polymorphonuclear leukocytes (PMN), to a chronic type inflammation, dominated by mononuclear leukocytes (MN). DGN also improved the clearance of P. aeruginosa from the lungs (p < 0.03) compared with the control group. There were no significant differences between the control group and the two herbal groups with regard to serum IgG and IgA anti-P. aeruginosa sonicate antibodies. However, the IgM concentration in the ITL group was significantly lower than in the control group (p < 0.03). These results suggest that the two medicinal herbs might be helpful to CF patients with chronic P. aeruginosa lung infection, DGN being the most favorable.

Topics: Agar; Animals; Antibodies, Bacterial; Chronic Disease; Culture Media; Cystic Fibrosis; Disease Models, Animal; Drugs, Chinese Herbal; Female; Lung Diseases; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Rats; Rats, Inbred Lew

In patients with cystic fibrosis who do not produce sputum, deep throat swabs are cultured for potential respiratory pathogens. Usually these swabs are directly streaked onto selective agar media. In a study of 50 pediatric cystic fibrosis patients, we compared this traditional method using rayon swabs with two methods having quantitative modifications: calcium alginate swabs eluted in Ringer's lactate and rayon swabs eluted in normal saline. The eluates were then processed quantitatively (three-step dilution series). The yield of potential pathogens was significantly higher with the two quantitative methods. Overall, the combination of alginate with Ringer's lactate was superior to the combination of rayon with saline, although only some of these differences achieved statistical significance.

Topics: Adolescent; Adult; Agar; Alginates; Bacteria; Bacteriological Techniques; Candida albicans; Cellulose; Child; Child, Preschool; Culture Media; Cystic Fibrosis; Evaluation Studies as Topic; Glucuronic Acid; Hexuronic Acids; Humans; Infant; Mycology; Pharynx

A total of 258 respiratory tract specimens from patients with cystic fibrosis were inoculated onto nine different plated media, and the rates of recovery of potential pathogens were compared. Media included sheep blood agar, enriched chocolate agar, MacConkey agar for gram-negative bacilli, chocolate agar containing bacitracin for Haemophilus spp., bromcresol green agar for yeasts, cetrimide agar for Pseudomonas spp., sheep blood agar containing colistin and nalidixic acid for gram-positive cocci, mannitol salt agar for Staphylococcus aureus, and oxidation-fermentation agar containing 300 U of polymyxin B per ml and 2 U of bacitracin per ml (OF-PBL medium) for Pseudomonas cepacia. With two exceptions, all of these media proved useful in recovering potential pathogens from respiratory tract specimens from patients with cystic fibrosis. The two exceptions were cetrimide agar and colistin-nalidixic acid-supplemented sheep blood agar, which were found to be superfluous. In addition, the results of this study further delineated the prevalence of selected bacteria and fungi in respiratory tract secretions from patients with cystic fibrosis. In rank order of frequency of isolation, we recovered isolates of Pseudomonas aeruginosa, Haemophilus parainfluenzae, Candida albicans, S. aureus, Haemophilus influenzae, molds, members of the family Enterobacteriaceae, yeasts other than Candida albicans, miscellaneous gram-negative bacilli, beta-hemolytic streptococci, P. cepacia, and Streptococcus pneumoniae.

Topics: Agar; Bacteria; Bacteriological Techniques; Culture Media; Cystic Fibrosis; Humans; Respiratory Tract Infections

We used selective media together with aerobic and anaerobic incubation for the quantitation of common pathogens in liquefied sputum from children with cystic fibrosis. The accuracy of the technique was verified by reconstruction studies in which laboratory strains with antibiotic-resistance markers were added to sputum from cystic fibrosis patients. Comparison of the numbers of bacteria found on quantitative culture of clinical specimens with the "predominant" organism found on routine culture yielded a poor correlation. When Pseudomonas aeruginosa was the most prevalent on routine culture, it was present in the highest numbers on quantitative culture (mean count = 10(8) cfu/g). However, large numbers of Haemophilus influenzae (mean count = 10(7) cfu/g), Staphylococcus aureus (mean count = 2 X 10(6) cfu/g), and streptococci (mean count = 2 X 10(6) cfu/g) were also present in these cultures. When S. aureus was the predominant organism, H. influenzae and P. aeruginosa were also present in similar numbers (c. 10(7) cfu/g). When H. influenzae was the predominant species on routine culture, the mean count was 7 X 10(6) cfu/g and P. aeruginosa was often completely absent. We conclude that the selective technique permits reliable enumeration of sputum bacteria, and offers a more accurate assessment of the microbial flora of sputum in cystic fibrosis than does simple plating of unhomogenised sputum.

Topics: Agar; Bacteria; Child; Culture Media; Cystic Fibrosis; Enterobacteriaceae; Haemophilus influenzae; Humans; Pseudomonas; Pseudomonas aeruginosa; Sputum; Staphylococcus aureus; Streptococcus pneumoniae

Topics: Agar; Cystic Fibrosis; Humans; Sputum; Staphylococcus aureus; Thymine

A rapid and simple screening test for detecting cystic fibrosis, described in 1956, has been used routinely for 21 years; the results during a 15-month period are compared with those using the quantitative pilocarpine iontophoresis sweat test. In the chloride agar plate test the concentration of chloride on the finger tips is evaluated accordingly to the intensity of the imprint. Readings of 2+ or less excluded cystic fibrosis in 1589 cases with only two doubtful instances, whereas 4+ readings were recorded in 198 cases of cystic fibrosis and 3+ readings in 15 cases of cystic fibrosis. In doubtful cases 4 individuals had 4+ readings and 11 had 3+ readings. This screening test does not replace the quantitative pilocarpine iontophoresis test but it does identify an individual who is likely to have the disease and who requires further tests. It is not reliable for infants aged under 2 months.

Topics: Agar; Child; Child, Preschool; Chlorides; Cystic Fibrosis; Humans; Infant; Methods; Sweat

Topics: Adult; Agar; Animals; Bacitracin; Bronchiectasis; Cattle; Culture Media; Culture Techniques; Cystic Fibrosis; Haemophilus Infections; Haemophilus influenzae; Hemin; Humans; Respiratory Tract Infections; Sputum

Topics: Agar; Child; Chlorine; Cystic Fibrosis; Humans; Iontophoresis; Methods; Sweat

Topics: Agar; Bronchi; Bronchial Diseases; Chromatography; Cystic Fibrosis; Humans; Phenylacetates; Respiratory Tract Infections; Sputum; Staphylococcal Infections; Staphylococcus