Epidemiology of extended-spectrum beta-lactamase-producing Enterobacteriaceae in a UK district hospital; an observational study

• Published in: The Journal of hospital infection Vol. 81; no. 4; pp. 270 - 277
• Main Authors: Enoch, D.A, Brown, F, Sismey, A.W, Mlangeni, D.A, Curran, M.D, Karas, J.A, Cone, D.B, Aliyu, S.H, Dhanji, H, Doumith, M, Maharjan, S, Meunier, D, Woodford, N
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2012
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; beta-Lactamases - genetics; beta-Lactamases - secretion; Child; Child, Preschool; Cluster Analysis; CTX-M; DNA, Bacterial - genetics; Enterobacteriaceae - classification; Enterobacteriaceae - enzymology; Enterobacteriaceae - genetics; Enterobacteriaceae - isolation & purification; Epidemiology; Escherichia coli; Escherichia coli Infections - epidemiology; Escherichia coli Infections - microbiology; Extended spectrum β-lactamase; Female; Genotype; Hospitals, District; Humans; Infant; Infectious Disease; Klebsiella Infections - epidemiology; Klebsiella Infections - microbiology; Male; Microbial Sensitivity Tests; Middle Aged; Molecular Epidemiology; Molecular Typing; Phylogroup D; Polymerase Chain Reaction; Prevalence; Risk factors; ST131; Surveys and Questionnaires; United Kingdom - epidemiology; Young Adult; CTX-M; Escherichia coli; ST131; Extended spectrum β-lactamase; Epidemiology; Phylogroup D; Risk factors
• ISSN: 0195-6701; 1532-2939
• DOI: 10.1016/j.jhin.2012.05.006

Summary Background Extended-spectrum beta-lactamases (ESBLs) are an increasingly important cause of resistance in Gram-negative bacteria throughout the world. Aim We investigated the clinical and molecular epidemiology of infections caused by ESBL-producing Enterobacteriaceae in a UK hospital, to identify the types of ESBL produced and risk factors for acquisition. Methods Between July 2008 and June 2009, all patients yielding ESBL-producing Enterobacteriaceae from any clinical specimen were prospectively investigated using a questionnaire. API20E was used for bacterial identification; susceptibility testing and ESBL production were assessed by BSAC disc diffusion and cefpodoxime–clavulanate synergy tests, respectively. Polymerase chain reaction was used to screen a subset of isolates for blaCTX-M genes, to assign Escherichia coli isolates to their phylogenetic groups, and to identify members of the uropathogenic ST131 lineage. Results The overall prevalence of ESBL producers among clinical samples yielding Enterobacteriaceae was 1%; ESBL producers, obtained from 124 patients, were E. coli ( N  = 105), Klebsiella pneumoniae ( N  = 12), and others ( N  = 7). The main risk factors identified include recent antibiotic use (93%) and presence of a urinary catheter (24%). CTX-M group 1 ESBLs dominated (in 59 of 78, 76%, isolates studied). Most E. coli (35 of 56 tested) were phylogroup B2; of these, 23 belonged to the ST131 clone, 12 were phylogroup D, and four each belonged to phylogroups A and B1. Conclusion ESBLs are an uncommon but significant problem in north-west Cambridgeshire. CTX-M-type enzymes were found in 75% of ESBL-positive isolates. All but two patients had at least one recognized risk factor. This study supports the requirement for interventions to reduce inappropriate urinary catheterization and antibiotic prescribing.