Strain-specific transmission in an outbreak of ESBL-producing Enterobacteriaceae in the hemato-oncology care unit: a cohort study

BMC Infectious Diseases

Research Article

Norimitsu Kadowaki¹  Shumpei Uchida¹  Hiroaki Dobashi¹  Makiko Uemura¹  Osamu Imataki¹  Tomomi Kuwahara²  Haruyuki Nakayama-Imaohji²  Yukiko Ohue³  Hatsune Mori³  Harumi Matsuka³ 

[1] Division of Hematology, Rheumatology and Respiratory Medicine, Department of Internal Medicine, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, 761-0793, Miki-cho, Kita-gun, Kagawa, Japan;Division of Molecular Microbiology, Kagawa University, Kagawa, Japan;Nursing Division, Kagawa University Hospital, Kagawa, Japan;

关键词: Extended-spectrum β-lactamase (ESBL);    Klebsiella pneumoniae;    Escherichia coli;    Non-clonal outbreak;    Multidrug resistance;   

DOI  :  10.1186/s12879-016-2144-4

 received in 2016-09-03, accepted in 2016-12-20,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundExtended-spectrum β-lactamase (ESBL)-producing bacteria are resistant to several types of antibiotics excluding carbapenems. A transmissibility of ESBL-producing Enterobacteriaceae would be depending on each bacterial property, however, that has not been elucidated in clinical setting. In this study, we attempted to identify the source of an outbreak of ESBL-producing bacteria in a medical oncology and immunology care unit.MethodsAn ESBL-producing Enterobacteriaceae (ESBL-E) outbreak observed between July 2012 and August 2012 in Kagawa University Hospital was surveyed using various molecular microbiology techniques. We used Pulsed-field gel electrophoresis (PFGE), PCR-based ESBL gene typing, and direct sequence of ESBL gene as molecular microbiology typing method to distinguish each strain.ResultsThe typical prevalence of ESBL-E isolation in the unit was 7.0 per month (1.7 per week). The prevalence of ESBL-E isolation during the target research period was 20.0 per month (5.0 per week). In total, 19 isolates (11 K. pneumoniae and 8 E. coli) were obtained from clinical samples, including four control strains (two each of both bacteria), that were physically different from those obtained from other inpatient units in our hospital. Pulsed-field gel electrophoresis (PFGE) for K. pneumoniae (digested by XbaI) produced similar patterns excluding one control strain. PCR classification of the ESBL gene for K. pneumoniae revealed that all strains other than the control strain carried SHV and CTX-M-9. This result was reconfirmed by direct DNA sequencing. Although the outbreak of K. pneumoniae was considered to be “clonal,” PFGE and PCR classification of the ESBL genes for E. coli uncovered at least six different “non-clonal” strains possessing individual ESBL gene patterns. According to the result of an antibiogram, the pattern of antimicrobial susceptibility was more variable for K. pneumoniae than for E. coli.ConclusionsTyping by PFGE and ESBL gene PCR analysis is practical for discriminating various organisms. In our cohort, two outbreaks were concomitantly spread with different transmission strategies, namely clonal and non-clonal, in the same unit. This might represent clinical evidence that transmissibility differs according to the type of strain. We speculated that patient-to-patient transmission of ESBL-E occurred according to the properties of each individual strain.

【 授权许可】

CC BY   
© The Author(s). 2017