Long-term control of hospital-wide, endemic multidrug-resistant Acinetobacter baumannii through a comprehensive "bundle" approach.

BACKGROUND: Acinetobacter baumannii (Ab) is emerging as a multidrug-resistant (MDR) nosocomial pathogen of considerable clinical importance. Data on the efficacy of infection control measures in endemic situations are lacking. Here, we investigated the impact of a long-term multifaceted "bundle" approach in controlling endemic MDR Ab in a 950-bed tertiary care center. METHODS: Ongoing staff education, promotion of hand hygiene, strict Contact and Isolation Precautions, environmental cleaning, and targeted active surveillance in high-risk areas during periods of likely transmission and contamination were initiated in this program. To assess the efficacy of our interventions, we recorded (before and after the intervention) the epidemiologic and clinical features of MDR Ab infections and determined the clonal relationship among MDR Ab bloodstream isolates by pulsed-field gel electrophoresis. RESULTS: Before the "bundle" was instituted, the rate of colonization/infection was 0.82 cases per 100 admissions (1994-1995). Colonization/infection rates showed a sustained decrease after implementation of the control program in 1995 to 0.46 in 1996-1997 and to 0.21 in 1998-2003 (P < .001). Coincident with the institution of this program, the rate of bacteremia because of MDR Ab decreased 6-fold during the 8-year observation period. A notable change in the clonal distribution of the MDR Ab isolates was also demonstrated. CONCLUSION: The implementation of a comprehensive and multifaceted infection control program ("bundle") in a tertiary care center effectively controlled the spread and clinical impact of MDR Ab.

[Activity of fosfomycin against extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae]. / Actividad de fosfomicina sobre cepas de Escherichia coli y Klebsiella pneumoniae productoras de betalactamasas de espectro extendido.

INTRODUCTION: Infection due to extended-spectrum beta-lactamase (ESBL)-producing microorganisms is an emerging problem in the community; a high proportion of these microorganisms have been isolated from urine samples of women with uncomplicated urinary tract infections (UTI). The options for oral treatment of uncomplicated UTI are limited because of the multiple drug resistance typical of ESBL-producing strains. METHODS: The in vitro activity of fosfomycin (FOS) was determined against 428 ESBL-producing strains, including 290 (68%) E. coli and 138 (32%) K. pneumoniae. Activity of fosfomycin was compared with that of amoxicillin-clavulanate (AMC), ciprofloxacin (CIP) and cotrimoxazole (SxT). MICs of AMC, CIP, and SxT, and detection of ESBL production were tested by the broth microdilution method, whereas FOS MICs were determined by the agar dilution method. ESBLs were characterized by isoelectric focusing, polymerase chain reaction (PCR) and direct sequencing of encoding genes. The genetic relationship among the isolates was determined by REP-PCR. RESULTS: Among the 428 ESBL-producing isolates studied, 417 (97.4%) were susceptible to FOS (MIC < or = 64 microg/mL). The resistance rate of E. coli to FOS was 0.3%, and was lower than resistance to AMC (11.7%), whereas the resistance rate of K. pneumoniae was 7.2% and was equal to resistance to AMC. SxT and CIP were the least active antibiotic agents against ESBL-producing isolates (sensitivity < 50%). There were no differences in fosfomycin activity against strains expressing different types of ESBLs. CONCLUSION: Fosfomycin showed maintained activity against ESBL-producing strains and did not present co-resistance with other antimicrobial groups.

Actividad de fosfomicina sobre cepas de Escherichia coli y Klebsiella pneumoniae productoras de betalactamasas de espectro extendido / Activity of fosfomycin against extended-spectrum â-lactamase producing Escherichia coli and Klebsiella pneumoniae

Introducción. Las infecciones por enterobacterias productoras de betalactamasas de espectro extendido (BLEE) son un problema emergente en la comunidad y un alto porcentaje de estos aislamientos son causa de infección no complicada del tracto urinario (ITU). El perfil de multirresistencia que expresan estas cepas limita las alternativas para el tratamiento oral de las ITU comunitarias. Material y métodos. Se determinó la actividad de fosfomicina (FOS) frente a 428 cepas productoras de BLEE, 290 (68%) Escherichia coli y 138 (32%) Klebsiella pneumoniae, comparándola con la de amoxicilina-ácido clavulánico (AMC), ciprofloxacino (CIP) y cotrimoxazol (SxT). Las concentraciones inhibitorias mínimas (CIM) de AMC, CIP, SxT y la detección de BLEE se determinaron mediante técnica de microdilución y la CIM de fosfomicina mediante técnica de dilución en agar. Las BLEE fueron caracterizadas mediante isoelectroenfoque, reacción en cadena de la polimerasa (PCR) y secuenciación de los genes codificantes, y la relación genética de los aislamientos fue determinada mediante secuencias extragénicas palindrómicas repetidas (REP)-PCR. Resultados. Entre las 428 cepas estudiadas, 417 (97,4%) resultaron sensibles a fosfomicina (CIM ≤ 64 ìg/ml). La tasa de resistencia de E. coli fue del 0,3%, muy inferior a la de AMC (11,7%); mientras que en K. pneumoniae la tasa de resistencia a FOS fue del 7,2%, igual que a AMC. Las tasas de resistencia a CIP y SxT fueron en ambos casos próximas al 50%. No se encontraron diferencias en la actividad de fosfomicina frente a cepas que expresaban diferentes familias y tipos de BLEE. Conclusión. Fosfomicina mantiene su actividad frente a cepas productoras de BLEE y no presenta resistencia cruzada con otros grupos de antimicrobianos (AU)

Introduction. Infection due to extended-spectrum â -lactamase (ESBL)-producing microorganisms is an emerging problem in the community; a high proportion of these microorganisms have been isolated from urine samples of women with uncomplicated urinary tract infections (UTI). The options for oral treatment of uncomplicated UTI are limited because of the multiple drug resistance typical of ESBL-producing strains. Methods. The in vitro activity of fosfomycin (FOS) was determined against 428 ESBL-producing strains, including 290 (68%) E. coli and 138 (32%) K. pneumoniae. Activity of fosfomycin was compared with that of amoxicillin-clavulanate (AMC), ciprofloxacin (CIP) and cotrimoxazole (SxT). MICs of AMC, CIP, and SxT, and detection of ESBL production were tested by the broth microdilution method, whereas FOS MICs were determined by the agar dilution method. ESBLs were characterized by isoelectric focusing, polymerase chain reaction (PCR) and direct sequencing of encoding genes. The genetic relationship among the isolates was determined by REP-PCR. Results. Among the 428 ESBL-producing isolates studied, 417 (97.4%) were susceptible to FOS (MIC ≤ 64 ìg/mL). The resistance rate of E. coli to FOS was 0.3%, and was lower than resistance to AMC (11.7%), whereas the resistance rate of K. pneumoniae was 7.2% and was equal to resistance to AMC. SxT and CIP were the least active antibiotic agents against ESBL-producing isolates (sensitivity < 50%). There were no differences in fosfomycin activity against strains expressing different types of ESBLs. Conclusion. Fosfomycin showed maintained activity against ESBL-producing strains and did not present co-resistance with other antimicrobial groups (AU)