Whole genome-based characterization of extended-spectrum β-lactamase-producing Enterobacter cloacae from orthopedic patients and environment of a tertiary referral hospital in Tanzania

We investigated the genomic epidemiology of extended-spectrum β-lactamase-producing Enterobacter cloacae (ESBL-Ec) isolates from patients and hospital environment to better understand their distribution to help devising effective strategies for infection prevention and control. We screened ESBL-Ec at Bugando Medical Center (BMC) in Mwanza, Tanzania. Rectal swabs from orthopedic patients on admission and swabs from the neighboring inanimate environment were collected. Following microbial culture, DNA was extracted from pure ESBL-Ec, and whole-genome sequencing was done. Sequence typing (ST), plasmid replicons, drug resistance, and virulence genes were deciphered using the Rapid Microbial Analysis Pipeline (rMAP). We obtained 209 ESBL isolates, of which 15 (7.2 %) were ESBL-Ec [8 (53.3 %) from patients and 7 (46.7 %) from the environment]. Seven isolates were novel and eight were diverse, each with a unique ST. All isolates harbored two to five β-lactamase genes, with the predominance of blaCTX-M-15 (15/15), blaOXA-1 (14/15), blaTEM (14/15) and blaACT (12/15). The most common non β-lactam drug resistance genes were aac(3)-IIa (14/15), aac(6′)-Ib-cr (14/15), fosA (14/15), and qnrB1 (12/15), aph(3″)-Ib (10/15) and aph(6)-Id (10/15). Eleven different types of plasmid replicons were identified in 14/15 of the isolates, harboring one to five plasmids, with the most common plasmids being IncFII (11/15) and IncFIB (10/15). All isolates harbored the outer membrane protein (ompA), and curli protein (csg) was in 14/15 isolates. Admitted orthopedic patients and the hospital environment act as a reservoir of ESBL-Ec with diverse STs and endowed with drug resistance and arsenals of virulence genes, calling for their routine screening on admission for mitigation of potential subsequent infections. •Understanding genomic epidemiology of ESBL-Ec from patients and hospital environment is crucial to inform preventive measures.•Orthopedic patients harbor genetically diverse ESBL-Ec with multiple antimicrobial resistance genes , virulence genes and plasmids.•There is a necessity to strengthen routine screening of ESBL-Ec among orthopedic patients with prolonged hospital stays.•Infection prevention and control measures to reduce dissemination of antibiotic resistance within hospitals should be reinforced.