Lynn Steele-Moore

Antimicrobial Susceptibility Testing Protocols

An Overview of the Clinical and Laboratory Standards Institute and its Impact on Antimicrobial Susceptibility Testing, A. L. Barry Antimicrobial Classifications: Drugs for Bugs, C.B. Calderon, and B. Perdue Sabundayo Disk Diffusion Tests and Gradient Methodologies, A. Wanger Macro and Microdilution Methods of Antimicrobial Susceptibility Testing, S. Qaiyumi Automated Systems: An Overview, S. Stuckey Agar Dilution Susceptibility Testing, A. Hanlon, M. Taylor, and J. Dick Antibiograms/Preventive Surveillance: A Continuum of Data Collection, Analysis, and Presentation, J. Thomas and N.T. Rector Anaerobe Susceptibility Testing, D. E. Roe-Carpenter Antifungal Susceptibility Testing of Yeasts, A. Espinel-Ingroff and E. Canton Antifungal Susceptibility Testing of Filamentous Fungi, A. Espinel-Ingroff and E. Canton Susceptibility Testing of Mycobacteria, B. A. Brown-Elliott, S. Cohen, and R.J. Wallace, Jr. Methods for Determining Bactericidal Activity and Antimicrobial Interactions: Synergy Testing/Time-Kill Curves/Population Analysis, P. Verma Serum Bactericidal Testing, H. Nadler and M. Dowzicky Bioassay Methods for Antimicrobial and Antifungal Agents, D.H. Pitkin and E. Martin-Mazuelos Molecular Methods for Bacterial Strain Typing, S. Michaud and D. Berg Pharmacy and Microbiology: Interactive Synergy, B. Perdue Sabundayo and C.B. Calderon Interactions Between Clinicians and the Microbiology Laboratory, J.H. Powers Clinical Microbiology in the Development of New Antimicrobial Agents, C.D.Webb and B.G. Painter

Evolution of Antifungal Susceptibility among Candida Species Isolates Recovered from Human Immunodeficiency Virus—Infected Women Receiving Fluconazole Prophylaxis

The effect of fluconazole on the susceptibility of Candida isolates recovered from women infected with human immunodeficiency virus (HIV) was evaluated in a randomized, double-blind, placebo-controlled trial. Women with CD4(+) cell counts of < or =300 cells/mm(3) received either fluconazole (200 mg/week) or placebo as prophylaxis. The antifungal susceptibility of specimens was evaluated. One patient who received fluconazole and 2 patients assigned to placebo had Candida albicans isolates recovered that were resistant to fluconazole (MIC, > or =64 microg/mL). Eleven patients assigned fluconazole and 4 patients assigned placebo had non-albicans Candida strains (all Candida glabrata) recovered that were resistant to fluconazole. There was significant azole cross-resistance among the non-albicans Candida species isolates. Although the rate of azole resistance did not significantly increase after fluconazole prophylaxis, there was a trend toward more in vitro azole resistance in C. glabrata isolates from patients assigned fluconazole. Moreover, the majority of resistant vaginal isolates of Candida species were recovered after initiation of open-label fluconazole use.

Genotypic analysis of Staphylococcus aureus from milk of dairy cows with mastitis in Argentina

Staphylococcus aureus is the most prevalent pathogen causing mastitis of dairy ruminants. This study was developed to ascertain the genotypes and genealogical relationship among strains isolated from milk of bovines with mastitis in Argentina. Molecular epidemiological analysis of S. aureus was performed on 112 isolates from 21 districts. Clonality was assessed by SmaI pulsed-field gel electrophoresis (PFGE) typing, automated EcoRI ribotyping and restriction enzyme analysis of plasmid (REAP) DNA profiles. A total of 22 band patterns distributed in four clusters were found by SmaI PFGE analysis. The similarity of clusters 2, 3 and 4 with cluster 1 was 0.73, 0.69 and 0.33, respectively, and 101 of 112 isolates belonged in cluster 1. PFGE band patterns from 42 isolates within cluster I were indistinguishable from each other (type A). The second largest group of isolates with indistinguishable PFGE band patterns was subtype A11, which was composed of 19 isolates. Automated ribotyping assigned the 112 isolates into 13 ribotypes. Among these, the most prevalent ribotypes I and VI were composed of 49 and 35 isolates respectively. Although there was certain correspondence between PFGE genotypes and ribotypes, further discrimination was achieved by combining both methods. REAP DNA profile analysis was useful to provide even further discrimination between isolates with identical PFGE genotype and ribotype. The most prevalent S. aureus strains A/I and A11/VI were widely distributed in the country and were not restricted to individual nearby locations. Prevalence of these two strains varied consecutively within a period of 8 years. Whether the shift in type prevalence was due to selection of a phenotypic trait remains undisclosed.

Evolution of Vaginal Candida Species Recovered from Human Immunodeficiency Virus-Infected Women Receiving Fluconazole Prophylaxis: The Emergence of Candida glabrata?

The effect of fluconazole prophylaxis on the vaginal flora of 323 human immunodeficiency virus-infected women was evaluated in a multicenter, randomized, double-blind, placebo-controlled trial. Women with CD4 cell counts of < or = 300/mm3 received either 200 mg of fluconazole per week or placebo. Vaginal surveillance cultures were performed every 3 months. After a follow-up of 29 months, Candida albicans was recovered from 53% of patients receiving fluconazole and 68% of patients assigned placebo. Fluconazole was associated with a 50% reduction in the odds of being colonized with C. albicans but with higher rates for non-albicans Candida species. Candida glabrata was recovered from 40 women assigned fluconazole and 29 assigned placebo (relative odds, 1.96; 95% confidence interval, 0.98-3.94). Fluconazole had an early and persistent effect on the vaginal mycoflora, with the emergence of C. glabrata vaginal colonization within the first 6 months. The effect of fluconazole prophylaxis can be attributed to the reduction in vaginal C. albicans colonization; however, C. glabrata colonization rapidly supervened.

Clinical applicability of antifungal susceptibility testing on non-Candida albicans species in hospitalized patients

We assessed the distribution, antifungal susceptibility, and treatment associated with 161 non-Candida albicans isolates recovered from hospitalized patients over a 6-month period. The three most prevalent species were C. glabrata (100), C. tropicalis (28), and C. krusei (15). Resistance of C. glabrata to fluconazole and itraconazole were 6% and 17% respectively; 80% of the fluconazole-resistant isolates were cross-resistant to itraconazole. Prior azole exposure significantly reduced azole susceptibility in C. glabrata and also affected its subsequent selection among colonized patients. Only 21% of the patients had clinical infections. Patients with fungemia were more likely to be treated with amphotericin versus an azole. Overall treatment success was higher in patients treated with amphotericin versus an azole (56% vs 31%). Routine susceptibility testing on all Candida species does not appear necessary except where therapy with an azole is being considered to detect resistant isolates or for epidemiologic surveillance purposes. Further studies are needed to delineate the relationship between azole MICs and treatment outcomes of invasive candidiasis due to non-C. albicans species.

Pseudomonas aeruginosa Outbreak in a Neonatal Intensive Care Unit due to Construction Related Water Line Alterations † 1485

Pseudomonas aeruginosa Outbreak in a Neonatal Intensive Care Unit due to Construction Related Water Line Alterations † 1485

Epidemiology of a Vancomycin Resistant Enterococcal Outbreak in the Neonatal Intensive Care Unit |[dagger]| 1466

Epidemiology of a Vancomycin Resistant Enterococcal Outbreak in the Neonatal Intensive Care Unit † 1466

EPIDEMIOLOGY OF CANDIDA SPECIES IN THE NEONATAL INTENSIVE CARE UNIT USING MOLECULAR TYPING OF CHROMOSOMAL DNA † 1312

EPIDEMIOLOGY OF CANDIDA SPECIES IN THE NEONATAL INTENSIVE CARE UNIT USING MOLECULAR TYPING OF CHROMOSOMAL DNA † 1312

EPIDEMIOLOGY OF COAGULASE NEGATIVE STAPHYLOCOCCI IN NEONATAL INTENSIVE CARE UNITS: THE ROLE OF PULSED FIELD GEL ELECTROPHORESIS. † 776

Coagulase negative staphylococci (CONS) are the most common cause of bacteremia in the Neonatal Intensive Care Unit (NICU). It is unclear as to whether simple colonization of infants is the source of these infections, or whether there are other endemic sources. In order to determine their epidemiology, we investigated the clinical and molecular characteristics of CONS. To determine acquisition and transmission in the NICU, 30 episodes of bacteremia in 19 neonates were evaluated over a one year period. Risk factors for infection as determined by multivariate analysis included degree of prematurity, intravenous catheters (especially central intravenous catheters), and prior antibiotics. 14 distinct strains were identified by pulsed field gelelectrophoresis of chromosomal DNA. One strain was common to four patients,two strains were found in three patients each, and four different strains were shared by two patients each. Common strains were noted almost exclusively in patients with overlapping hospital stays, and persisted less than three months before being replaced by another common strain. These data suggest nosocomial acquisition of CONS strains causing bacteremia, and supports evaluation of potential control methods, including handwashing and aseptic techniques during intravenous catheter insertion. Pulsed field gel electrophoresis is an extremely important tool in determining the epidemiology of infective agents in the NICU setting.