We determined the presence of extended-spectrum-␤-lactamase (ESBL)-producing Escherichia coli among 3,344 study participants from the German community. Intestinal colonization was detected in 211 persons (6.3%), without significant differences among the different age groups. The majority (95.2%) of isolates harbored CTX-M-type ESBL, with CTX-M-15 (46%) and CTX-M-1 (24.2%) as the most common types. The finding of ESBL producers and one isolate additionally producing carbapenemase OXA-244 indicates a risk of dissemination of resistant bacteria outside the hospitals. Escherichia coli strains producing extended-spectrum ␤-lactamases (ESBLs) represent a major threat among the increasing number of drug-resistant Gram-negative bacteria (1). Fecal carriage of ESBL-producing E. coli has been described worldwide in hospitals and the ambulatory care setting (2-6) as well as in the community (7-9). A recent study investigating healthy infection control personnel (n ϭ 231) in Germany revealed that 3.5% are carriers of ESBL-producing E. coli (10). In the present study, we determined the fecal carriage rate of ESBL-producing E. coli in a large sample of persons from the German community, including molecular analysis of the isolates.From October 2009 to November 2012, we collected 3,344 nonreplicate fecal samples from individuals living in seven different areas of Bavaria (Upper Bavaria, 29.2%; Central Franconia, 20.8%; Upper Franconia, 15.0%; Upper Palatinate, 12.0%; Swabia, 10.8%; Lower Franconia, 9.0%; Lower Bavaria, 3.1%), Germany. The median age of the study participants was 32.0 years (range, 0 to 98 years), with a male/female ratio of 0.96. All probands had at the time of investigation a close contact to patients with bacterial gastroenteritis and were subsequently screened for fecal carriage of intestinal bacterial pathogens by 74 local health authorities. However, they did not show any symptoms related to gastroenteritis, and intestinal bacterial pathogens were not detected in any of these study participants. All 3,344 fecal samples were investigated for the presence of ESBL-producing E. coli by inoculation on MacConkey agar supplemented with cefotaxime (1 mg/liter). Identification to the species level was performed using API E strips (bioMérieux, Nürtingen, Germany), and ESBL production was confirmed by the combined disc method (Mast Diagnostica, Rheinfeld, Germany) using cefotaxime and ceftazidime with and without clavulanic acid. Susceptibility testing for 18 antimicrobial substances (ampicillin, cefotaxime, ceftriaxone, ceftazidime, cefepime, cefpodoxime, cefoxitin, ertapenem, imipenem, meropenem, aztreonam, amikacin, gentamicin, tetracycline, chloramphenicol, ciprofloxacin, nalidixic acid, and trimethoprim-sulfamethoxazole) was performed by disc diffusion (Oxoid Ltd., Basingstoke, United Kingdom), and interpretation was done according to EUCAST (http://www.eucast.org/clinical _breakpoints) and CLSI criteria (nalidixic acid, tetracycline) (11). E. coli isolates with the ESBL phenotype were investigated for the pres...

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BackgroundThe number of extended-spectrum beta-lactamase (ESBL) positive (+) Escherichia coli is increasing worldwide. In contrast with many other multidrug-resistant bacteria, it is suspected that they predominantly spread within the community. The objective of this study was to assess factors associated with community-acquired colonization of ESBL (+) E. coli.MethodsWe performed a matched case-control study at the Charité University Hospital Berlin between May 2011 and January 2012. Cases were defined as patients colonized with community-acquired ESBL (+) E. coli identified <72 h after hospital admission. Controls were patients that carried no ESBL-positive bacteria but an ESBL-negative E.coli identified <72 h after hospital admission. Two controls per case were chosen from potential controls according to admission date. Case and control patients completed a questionnaire assessing nutritional habits, travel habits, household situation and language most commonly spoken at home (mother tongue). An additional rectal swab was obtained together with the questionnaire to verify colonization status. Genotypes of ESBL (+) E. coli strains were determined by PCR and sequencing. Risk factors associated with ESBL (+) E. coli colonization were analyzed by a multivariable conditional logistic regression analysis.ResultsWe analyzed 85 cases and 170 controls, respectively. In the multivariable analysis, speaking an Asian language most commonly at home (OR = 13.4, CI 95% 3.3–53.8; p<0.001) and frequently eating pork (≥3 meals per week) showed to be independently associated with ESBL colonization (OR = 3.5, CI 95% 1.8–6.6; p<0.001). The most common ESBL genotypes were CTX-M-1 with 44% (n = 37), CTX-M-15 with 28% (n = 24) and CTX-M-14 with 13% (n = 11).ConclusionAn Asian mother tongue and frequently consuming certain types of meat like pork can be independently associated with the colonization of ESBL-positive bacteria. We found neither frequent consumption of poultry nor previous use of antibiotics to be associated with ESBL colonization.

ObjectiveWe aimed to retrospectively reconstruct the timing of transmission events and pathways in order to understand why extensive preventive measures and investigations were not sufficient to prevent new cases.MethodsWe extracted available information from patient charts to describe cases and to compare them to the normal population of the ward. We conducted a cohort study to identify risk factors for pathogen acquisition. We sequenced the available isolates to determine the phylogenetic relatedness of Klebsiella pneumoniae isolates on the basis of their genome sequences.ResultsThe investigation comprises 37 cases and the 10 cases with ESBL (extended-spectrum beta-lactamase)-producing K. pneumoniae bloodstream infection. Descriptive epidemiology indicated that a continuous transmission from person to person was most likely. Results from the cohort study showed that ‘frequent manipulation’ (a proxy for increased exposure to medical procedures) was significantly associated with being a case (RR 1.44, 95% CI 1.02 to 2.19). Genome sequences revealed that all 48 bacterial isolates available for sequencing from 31 cases were closely related (maximum genetic distance, 12 single nucleotide polymorphisms). Based on our calculation of evolutionary rate and sequence diversity, we estimate that the outbreak strain was endemic since 2008.ConclusionsEpidemiological and phylogenetic analyses consistently indicated that there were additional, undiscovered cases prior to the onset of microbiological screening and that the spread of the pathogen remained undetected over several years, driven predominantly by person-to-person transmission. Whole-genome sequencing provided valuable information on the onset, course and size of the outbreak, and on possible ways of transmission.