Detection of CTX-M-15 beta-lactamases in Enterobacteriaceae causing hospital- and community-acquired urinary tract infections as early as 2004, in Dar es Salaam, Tanzania

Joel Manyahi,Marit Gjerde Tellevik,Faustine Ndugulile,Bjørn Blomberg,Willy Urassa,Nina Langeland,Sabrina J Moyo

doi:10.1186/s12879-017-2395-8

Abstract

BackgroundThe spread of Extended Spectrum β-lactamases (ESBLs) among Enterobacteriaceae and other Gram-Negative pathogens in the community and hospitals represents a major challenge to combat infections. We conducted a study to assess the prevalence and genetic makeup of ESBL-type resistance in bacterial isolates causing community- and hospital-acquired urinary tract infections.MethodsA total of 172 isolates of Enterobacteriaceae were collected in Dar es Salaam, Tanzania, from patients who met criteria of community and hospital-acquired urinary tract infections. We used E-test ESBL strips to test for ESBL-phenotype and PCR and sequencing for detection of ESBL genes.ResultsOverall 23.8% (41/172) of all isolates were ESBL-producers. ESBL-producers were more frequently isolated from hospital-acquired infections (32%, 27/84 than from community-acquired infections (16%, 14/88, p < 0.05). ESBL-producers showed high rate of resistance to ciprofloxacin (85.5%), doxycycline (90.2%), gentamicin (80.5%), nalidixic acid (84.5%), and trimethoprim-sulfamethoxazole (85.4%). Furthermore, 95% of ESBL-producers were multi-drug resistant compared to 69% of non-ESBL-producers (p < 0.05). The distribution of ESBL genes were as follows: 29/32 (90.6%) blaCTX-M-15, two blaSHV-12, and one had both blaCTX-M-15 and blaSHV-12. Of 29 isolates carrying blaCTX-M-15, 69% (20/29) and 31% (9/29) were hospital and community, respectively. BlaSHV-12 genotypes were only detected in hospital-acquired infections.ConclusionblaCTX-M-15 is a predominant gene conferring ESBL-production in Enterobacteriaceae causing both hospital- and community-acquired infections in Tanzania.

Highlights

The spread of Extended Spectrum β-lactamases (ESBLs) among Enterobacteriaceae and other Gram-Negative pathogens in the community and hospitals represents a major challenge to combat infections
The most frequent bacteria isolated were Escherichia coli (64%), followed by Klebsiella pneumoniae (15.7%) and other Enterobacteriaceae accounted for 20.3%
When comparing rates of resistance between HA and CA ESBL, we found that hospital-acquired E. coli and K. pneumoniae were more frequently resistant to ciprofloxacin, gentamicin and nalidixic acid than those isolated from community-acquired infections (Table 3)

Summary

Introduction

The spread of Extended Spectrum β-lactamases (ESBLs) among Enterobacteriaceae and other Gram-Negative pathogens in the community and hospitals represents a major challenge to combat infections. We conducted a study to assess the prevalence and genetic makeup of ESBL-type resistance in bacterial isolates causing community- and hospital-acquired urinary tract infections. Extended Spectrum β-lactamases (ESBLs) have been observed in virtually all species of the family Enterobacteriaceae. Spread of ESBL-producing strains from general wards to intensive care units (ICU) and into the community can contribute to the further propagation of these resistant strains [1]. ESBLs are responsible for resistance against betalactam antibiotics such as penicillins, cephalosporins, monobactams and sometimes carbapenems [2]. Spread of ESBL-producing bacterial isolates in the community has made empirical treatment of infections more difficult, and narrows the treatment options to expensive antibiotics like colistin and carbapenems.

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