Colonization and infection associated with Malassezia and Candida species in a neonatal unit.

The objectives of this study were to determine, in neonates of < 1250 g birthweight (N = 57), the initial time of skin colonization by Malassezia furfur, rate of colonization by Candida spp., and whether skin colonization by these yeasts was predictive of central line colonization or fungaemia. By age two weeks, 51% of neonates were culture-positive for M.

Comparison of spiral gradient endpoint and agar dilution methods for susceptibility testing of anaerobic bacteria: a multilaboratory collaborative evaluation.

A multilaboratory collaborative study was carried out to assess the utility of the spiral gradient endpoint (SGE) method for the determination of the antimicrobial susceptibilities of anaerobes and to evaluate the equivalence of the MICs obtained by the SGE method with those obtained by the reference agar dilution method of the National Committee for Clinical Laboratory Standards. The standard deviation of the MIC obtained by the SGE method for the five participating laboratories was +/- 0.26 of a twofold dilution, whereas it was +/- 1 twofold dilution by the reference method.

Detection of vancomycin resistance in enterococci by the Alamar MIC system.

The ability of the Alamar microdilution MIC system to detect vancomycin resistance in enterococci was evaluated by comparing the results with an agar dilution screen method. Of 100 strains tested, 41 were resistant and 47 were susceptible by both tests. Five strains were intermediate and one was resistant by the Alamar MIC system but susceptible by the agar screen.

Detection of vancomycin resistance in enterococci by the Vitek AMS system.

The ability of the Vitek AMS system to detect vancomycin resistance in enterococci was evaluated by comparing the results to an agar dilution screen method. Of 100 strains tested, 43 were resistant and 51 were susceptible by both tests. Two strains were intermediate by Vitek but susceptible by agar screen, one was intermediate by Vitek but resistant by agar screen, and four were susceptible by Vitek but resistant by agar screen.

Development of a standardized screening method for detection of vancomycin-resistant enterococci.

The incidence of vancomycin resistance among enterococci is increasing in the United States and elsewhere in the world, but automated susceptibility testing methods have difficulty detecting resistance expressed by certain strains. The agar screening method described by Willey et al. (B.

Collaborative evaluation of the Radiometer Sensititre AP80 for identification of gram-negative bacilli.

A multicenter trial of the Sensititre AP80 panel read on the Sensititre AutoReader (Radiometer America, Westlake, Ohio) for the automated identification of gram-negative bacilli was conducted with 1,023 clinical isolates (879 members of the family Enterobacteriaceae plus 144 nonenteric organisms). Assignment of taxa was based on the computer-assisted interpretation of the results of a series of reactions with fluorogenic enzyme substrates after 5 h of incubation, with an incubation interval of approximately 18 h used when indicated. Accuracy was determined initially by comparison with the results obtained with the API 20E or Rapid NFT system (Analytab Products, Plainview, N.

Review of methods for susceptibility testing of anaerobes.

In the USA, the National Committee for Clinical Laboratory Standards has studied and published a reference agar dilution method for the susceptibility testing of anaerobic bacteria. While numerous investigators both in Europe and the USA have evaluated a variety of methods with a variety of modifications, only the broth microdilution method appears to be appropriate for routine use. The problems of the choice of breakpoint, inoculum size, media, media additives, endpoint recognition and other parameters affecting test performance and interpretation, while troublesome for anaerobes, are not unique to this group of organisms.

Quality control criteria for testing the susceptibility of anaerobic bacteria to meropenem.

Reference values for quality control of in vitro susceptibility tests with meropenem against anaerobic bacteria were determined in a multilaboratory study by the approved National Committee for Clinical Laboratory Standards agar dilution method for the four quality control strains. The study protocol also included the evaluation of microdilution testing, medium additives, and multiple lots of media. The recommended MIC control ranges for three of the control organisms are as follows: Bacteroides fragilis ATCC 25285, 0.

Eubacterium lentum ATCC 43055, a new reference strain for quality control of anaerobic susceptibility tests.

A strain of Eubacterium lentum (ATCC 43055) was selected for quality control of anaerobic susceptibility tests. Multilaboratory collaborative studies with 13 different antimicrobial agents were reviewed, and MIC control limits were proposed for agar dilution tests with the new control strain.

Group C streptococcal pleurisy and pneumonia: a fulminant case and review of the literature.

A 30-year-old, previously healthy patient developed a pleurisy and pneumonia due to group C streptococcus, with multiple medical complications, including bilateral empyemas. Eight other reported cases of group C streptococcal pneumonia are reviewed.

Quality control guidelines for testing cefotetan in the reference agar dilution procedure for susceptibility testing of anaerobic bacteria.

Reference values for quality control of in vitro susceptibility tests with cefotetan against anaerobic bacteria were determined in two independent multilaboratory studies with the approved National Committee for Clinical Laboratory Standards agar dilution method and three control strains (Bacteroides fragilis ATCC 25285, Bacteroides thetaiotaomicron ATCC 29741, and Clostridium perfringens ATCC 13124). The results of the two studies were in agreement. The recommended MIC control limits for B.

A multicenter study of the in vitro antianaerobic activity of cefotetan compared with other antimicrobial agents.

The in vitro antianaerobic activity of cefotetan was compared with that of chloramphenicol, clindamycin, cefoxitin, and penicillin in a multicenter study. Both agar dilution and broth microdilution testing procedures, as described by the National Committee for Clinical Laboratory Standards (NCCLS), were employed; a total of 1,377 strains were examined. Results were interpreted using the U.

Gardnerella vaginalis in the urinary tract: incidence and significance in a hospital population.

The significance of Gardnerella vaginalis in urine was studied by comparing urine culture results, urinalysis data, and clinical findings. Over a two-year period, G vaginalis was reported in 2.3% of all urine cultures.

Determination of synergy by two methods with eight antimicrobial combinations against tobramycin-susceptible and tobramycin-resistant strains of Pseudomonas.

Eleven strains of tobramycin-susceptible Pseudomonas aeruginosa, 12 strains of tobramycin-resistant P. aeruginosa, and 11 strains of P. maltophilia were tested against tobramycin in combination with azlocillin, piperacillin, ceftazidime, and imipenem and against colistin in combination with azlocillin, piperacillin, ceftazidime, and imipenem by microdilution checkerboard and time-kill curve techniques.

Comparative activity of several beta-lactam antibiotics against anaerobes determined by two methods.

The susceptibility of 120 strains of several species of anaerobes to a number of second and third generation beta-lactam antibiotics was determined by the National Committee for Clinical Laboratory Standards reference agar dilution and microdilution methods. The antibiotics tested were cefoperazone, cefotaxime, cefotetan, ceftizoxime, cefoxitin, and imipenem. The MIC50s ranged from 0.

Predicting the susceptibility of anaerobes to cefoperazone, cefotaxime, and cefoxitin with the thioglycolate broth disk procedure.

A variety of clinical anaerobic isolates were tested against cefoperazone (216 strains), cefoxitin (120 strains), and cefotaxime (120 strains) by the thioglycolate anaerobic broth disk method, and the results were compared with the National Committee for Clinical Laboratory Standards reference agar dilution method. The broth disk and reference breakpoint concentrations were as follows: cefoperazone, 60 and 64 or 30 and 32 micrograms/ml; cefotaxime, 30 and 32 micrograms/ml; cefoxitin, 18 and 16 micrograms/ml, respectively. Discrepant results were retested to obtain a mode.

Propionibacterium avidum as the etiologic agent of splenic abscess.

Propionibacterium avidum was isolated from an intrasplenic abscess in a patient recovering from coronary artery bypass surgery. This organism has not previously been reported as an etiologic agent of splenic abscess nor has splenic abscess been described as a complication of coronary bypass surgery. This report emphasizes the potential pathogenicity of normal microbial flora following surgical manipulation.

Evaluation of the 10-micrograms clindamycin disk for susceptibility testing of anaerobes by the aerobically incubated thioglycolate broth disk method.

The reliability of the 10-micrograms clindamycin disk was evaluated for susceptibility testing of anaerobes by the aerobic thioglycolate broth disk method. A good correlation between the aerobic thioglycolate broth disk method and the reference agar dilution procedure of the National Committee for Clinical Laboratory Standards was obtained by using a 4-microgram/ml breakpoint. Improved correlation was obtained when the medium of the National Committee for Clinical Laboratory Standards was buffered.

The comparative in vitro susceptibility of cefazolin-resistant organisms to six cephalosporins, four penicillins, and three aminoglycosides.

One thousand thirty-seven cefazolin-resistant, gram-negative clinical isolates including members of the family Enterobacteriaceae, pseudomonads, and other nonfermenters were tested against a variety of newer antimicrobial agents by microdilution. Most of the Enterobacteriaceae were resistant to the second-generation cephalosporins, but highly susceptible to the third-generation agents and the broad-spectrum penicillins, 90% of the strains being inhibited at attainable serum concentrations. Cefoperazone and the penicillins had good activity against the Pseudomonas species, but the aminoglycosides remained the most active agents against all the gram-negative bacilli tested except Pseudomonas maltophilia.

Establishment of MICs of moxalactam for control and reference anaerobic organisms in agar dilution and microdilution techniques.

The MICs of moxalactam were determined for eight National Committee for Clinical Laboratory Standards control and reference strains and for Fusobacterium nucleatum ATCC 10953 by agar and microdilution techniques. The recommended MIC for the control strain Bacteroides fragilis in both agar and microdilution tests is 0.5 micrograms/ml.