Clinical characteristics of bacteraemia caused by extended-spectrum ß-lactamase-producing Enterobacteriaceae in the era of CTX-M-type and KPC-type ß-lactamases.

Clin Microbiol Infect 2012; 18: 887-893 ABSTRACT: A multicentre, case-control study was conducted to assess risk factors and patient outcomes of bacteraemia caused by Enterobacteriaceae producing extended-spectrum ß-lactamases (ESBLs) and Klebsiella pneumoniae carbapenemases (KPCs). One hundred and five and 20 patients with bacteraemia caused by ESBL-producing and KPC-producing organisms were matched to controls who had bacteraemia caused by non-ESBL/KPC-producing organisms, respectively. Independent risk factors for ESBL production included admission from a nursing home (OR 4.64; 95% CI 2.64-8.16), chronic renal failure (OR 2.09; 95% CI 1.11-3.92), the presence of a gastrostomy tube (OR 3.36; 95% CI 1.38-8.18), length of hospital stay before infection (OR 1.02; 95% CI 1.01-1.03), transplant receipt (OR 2.48; 95% CI 1.24-4.95), and receipt of antibiotics with Gram-negative activity in the preceding 30 days (OR 1.76; 95% CI 1.00-3.08). Twenty-eight-day crude mortality rates for patients infected with ESBL-producing or KPC-producing organisms and controls were 29.1% (34/117) and 19.5% (53/272), respectively (OR 1.70; 95% CI 1.04-2.80). On multivariate analysis, inadequate empirical therapy (OR 2.26; 95% CI 1.18-4.34), onset of bacteraemia while in the intensive-care unit (OR 2.74; 95% CI 1.47-5.11), Apache II score (OR 1.17; 95% CI 1.12-1.23) and malignancy (OR 2.66; 95% CI 1.31-5.41) were independent risk factors for mortality. CTX-M was the most common ESBL type in Escherichia coli, whereas SHV predominated in Klebsiella spp. and Enterobacter spp.

Extended-spectrum and CMY-type beta-lactamase-producing Escherichia coli in clinical samples and retail meat from Pittsburgh, USA and Seville, Spain.

Infections due to Escherichia coli producing extended-spectrum beta-lactamase (ESBL) or CMY-type beta-lactamase (CMY) are increasingly observed in non-hospitalized patients. The origin of these organisms is uncertain, but retail meat contaminated with E. coli may be a source. In the present study, clinical information and strains collected from patients infected or colonized with ESBL-producing and CMY-producing E. coli at hospitals in Pittsburgh, USA and Seville, Spain were investigated. Retail meat purchased in these cities was also studied for the presence of these organisms. Twenty-five and 79 clinical cases with ESBL-producing E. coli and 22 cases and one case with CMY-producing E. coli were identified in Pittsburgh and Seville, respectively. Among them all, community-acquired and healthcare-associated cases together constituted 60% of the cases in Pittsburgh and 73% in Seville. Community-acquired cases were more common in Seville than in Pittsburgh (49% vs. 13%; p <0.001). ESBL-producing and CMY-producing E. coli isolates were commonly recovered from the local retail meat. In particular, 67% (8/12) of retail chickens in Seville and 85% (17/20) of those in Pittsburgh contained ESBL-producing and CMY-producing E. coli isolates, respectively. Among the ESBL-producing isolates, CTX-M and SHV were the most common ESBL types in both clinical and meat isolates. Approximately half of the ESBL-producing and CMY-producing E. coli isolates from meat belonged to phylogenetic groups associated with virulent extra-intestinal infections in humans. Community and healthcare environments are now significant reservoirs of ESBL-producing and CMY-producing E. coli. Retail meat is a potential source of these organisms.

Faecal carriage of CTX-M-15-producing Klebsiella pneumoniae in patients with acute gastroenteritis.

BACKGROUND & OBJECTIVE: Data on extended-spectrum beta-lactamases (ESBLs) produced by Gram-negative bacteria including Klebsiella pneumoniae especially molecular types of ESBL genes from India are limited. The present study was conducted to investigate the carriage and ESBL contents of multidrug-resistant K. pneumoniae recovered from patients with gastroenteritis in a rural village in southern India. METHODS: Nine K. pneumoniae isolates obtained from 45 stool samples from patients with gastroenteritis from one rural and two urban sites, in southern India were included in the study. Antibiotic susceptibility testing, PCR analysis and sequencing were conducted to characterize the ESBL genes. Clonal relatedness was assessed by pulsed-field gel electrophoresis (PFGE). RESULTS: All the isolates were found to be resistant to at least one of the third generation cephalosporins tested. All the study isolates were confirmed to produce ESBLs. PCR and sequencing revealed the responsible gene to be bla(CTX-M-15). bla(TEM) and bla(SHV) were absent. PFGE indicated that fi ve of seven isolates from villagers were genetically closely related, and in turn were related to isolates from patients in two urban areas in this region. INTERPRETATION & CONCLUSION: Our findings showed that genetically-related isolates of K. pneumoniae producing CTX-M-15 were present in multiple areas in southern India. Larger studies need to be done in various geographical regions of the country to better define the molecular epidemiology of ESBL-producing K. pneumoniae and its clinical implications.