Background: Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) are increasingly reported as pathogens in urinary tract infections (UTIs). However, in Sri Lanka, the clinical and molecular epidemiology of ESBL-PE implicated in UTIs has not been well described.
Materials and methods: We conducted prospective, laboratory-based surveillance from October to December 2013 at a tertiary care hospital in southern Sri Lanka and enrolled patients ≥1 year of age with clinically relevant UTIs due to ESBL-PE. Isolate identity, antimicrobial drug susceptibility, and ESBL production were determined. Presence of ß-lactamase genes, bla(SHV), bla(TEM), and bla(CTX-M), was identified by polymerase chain reaction.
Results: During the study period, Enterobacteriaceae were detected in 184 urine samples, with 74 (40.2%) being ESBL producers. Among 47 patients with ESBL-PE who had medical records available, 38 (80.9%) had clinically significant UTIs. Most UTIs (63.2%) were community acquired and 34.2% were in patients with diabetes. Among 36 cultured ESBL-PE isolates, significant susceptibility (>80%) was only retained to amikacin and the carbapenems. The group 1 bla(CTX-M) gene was present in 90.0% of Escherichia coli isolates and all Klebsiella pneumoniae and Enterobacter cloacae isolates. The bla(SHV) and bla(TEM) genes were more common in K. pneumoniae (75% and 50%) and E. cloacae (50% and 50%) isolates than in E. coli (10% and 20%) isolates, respectively.
Conclusion: The majority of UTIs caused by ESBL-PE were acquired in the community and due to organisms carrying the group 1 CTX-M ß-lactamase. Further epidemiologic studies of infections due to ESBL-PE are urgently needed to better prevent and treat these infections in South Asia.
Keywords: Community-acquired urinary tract infections; Enterobacteriaceae; Extended-spectrum ß-lactamases; Sri Lanka.