High carriage rate of extended-spectrum beta-lactamase-producing Enterobacteriaceae among patients admitted for surgery in Tanzanian hospitals with a low rate of endogenous surgical site infections.

INTRODUCTION: Despite the high reported rates of surgical site infections (SSIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (EPE) in low-income countries, including Tanzania, the role of EPE carriage in subsequent occurrence of SSIs is not known. This study investigated the rates of EPE carriage among surgical patients at the time of admission and discharge, and linked EPE genotype with SSIs. METHODS: EPE were confirmed among isolates from rectal and wound/pus swabs using VITEK-2. Polymerase chain reaction and sequencing were performed to detect beta-lactamase genes. Multi-locus sequence typing was used to determine the genotypes of EPE isolates. RESULTS: Among 930 patients enrolled, EPE carriage was significantly higher on discharge than admission (36.4% vs 23.7%, P<0.001). Of 272 patients who tested negative on admission, 78 (28.7%) acquired EPE during hospitalization. History of hospital stay within the previous three months was an independent predictor of EPE acquisition [hazard ratio 2, 95% confidence interval (CI) 1.04-3.98, P=0.038]. Of the 536 patients who were successfully followed-up after surgery, 78 (14.6%, 95% CI 11.6-17.5) developed SSIs. Of 57 SSIs investigated, 33 (58%) were caused by enteric Gram-negative bacteria, of which 63.6% (21/33) were EPE. Escherichia coli sequence type (ST)131 pandemic clone and Klebsiella pneumoniae ST391 predominated among wound isolates. The blaCTX-M-15 gene was detected in 37 (97.3%) of 38 ESBL isolates. Male sex was an independent predictor of SSI (odds ratio 2.92, 95% CI 1.73-4.91, P<0.001). CONCLUSION: These findings warrant implementation of strict infection control measures, antimicrobial stewardship and exploration of the transmission dynamics of EPE in surgical wards.

Preliminary insights into the occurrence of similar clones of extended-spectrum beta-lactamase-producing bacteria in humans, animals and the environment in Tanzania: A systematic review and meta-analysis between 2005 and 2016.

The emergence and spread of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) are complex and of the public health concern across the globe. This review aimed at assessing the ESBL-PE clones circulating in humans, animals and the environment to provide evidence-based insights for combating ESBL-PE using One Health approach. Systematic search from Medline/PubMed, Google Scholar and African Journals Online was carried out and retrieved nine eligible articles (of 131) based on phenotypic and genotypic detection of ESBL-PE between 2005 and 2016 in Tanzania. Analysis was performed using STATA 11.0 software to delineate the prevalence of ESBL-PE, phenotypic resistance profiles and clones circulating in the three interfaces. The overall prevalence of ESBL-PE in the three interfaces was 22.6% (95% CI: 21.1-24.2) with the predominance of Escherichia coli (E. coli) strains (51.6%). The majority of ESBL-PE were resistant to the commonly used antimicrobials such as trimethoprim-sulfamethoxazole and tetracycline/doxycycline, 38%-55% were resistant to ciprofloxacin and all were sensitive to meropenem/imipenem. ESBL-PE infections were more associated with deaths compared to non-ESBL-PE infections. Strikingly, E. coli ST38, ST131 and ST2852 were found to intersect variably across the three interfaces. The predominant allele, blaCTX-M-15, was found mostly in the conjugative IncF plasmids connoting transmission potential. The high prevalence of ESBL-PE and shared clones across the three interfaces, including the global E. coli ST131 clone, indicates wide and inter-compartmental spread that calls for One Health genomic-driven studies to track the resistome flow.