The role of horizontal gene transfer in the dissemination of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates in an endemic setting.
The contribution of horizontal gene transmission (HGT) in the emergence and spread of extended-spectrum beta-lactamase (ESBL)-producing Gram-negative bacteria during periods of endemicity is unclear. Over a 12-month period, rectal colonization with SHV-5- and SHV-12-producing Escherichia coli and Klebsiella pneumoniae was quantified among a cohort of residents in a long-term care facility. Demographic and clinical data were collected on colonized residents. Transferability of SHV-encoding plasmids and pulsed-field gel electrophoresis were performed to quantify the contribution of HGT and cross-transmission, respectively. A total of 25 (12%) of 214 enrolled patients were colonized with 11 SHV-5- and 17 SVH-12-producing E. coli and K. pneumoniae. Clonally related isolates were detected among multiple residents residing on the same and different wards. Among 12 clonally distinct isolates, HGT of SHV-5- and SHV-12-encoding plasmids was identified among 6 (50%) isolates. HGT among clonally distinct strains contributes to the transmission dynamics of these ESBL-producing Gram-negative bacteria and should be considered when evaluating the spread of these pathogens.
Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Yohei
Y
Doi
Jennifer M
JM
Adams-Haduch
Anton Y
AY
Peleg
Erika M C
EM
D'Agata
D000369:Aged, 80 and over; D002353:Carrier State / Q000382:microbiology; D016000:Cluster Analysis; D015331:Cohort Studies; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D005260:Female; D022761:Gene Transfer, Horizontal; D005838:Genotype; D006268:Health Facilities; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000235:genetics; D008134:Long-Term Care; D008297:Male; D017720:Molecular Epidemiology; D058889:Molecular Typing; D010957:Plasmids; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
D001618:beta-Lactamases