Abstract
BackgroundEpidemiological data of cephalosporin-resistant Enterobacterales in Sub-Saharan Africa is still restricted, and in particular in Mozambique. The aim of this study was to detect and characterize extended-spectrum β-lactamase (ESBL) - and plasmid-mediated AmpC (pAmpC)-producing clinical strains of Escherichia coli at Maputo Central Hospital (MCH), a 1000-bed reference hospital in Maputo, Mozambique.MethodsA total of 230 clinical isolates of E. coli from urine (n = 199) and blood cultures (n = 31) were collected at MCH during August–November 2015. Antimicrobial susceptibility testing was performed by the disc diffusion method and interpreted according to EUCAST guidelines. Isolates with reduced susceptibility to 3rd generation cephalosporins were examined further; phenotypically for an ESBL−/AmpC-phenotype by combined disc methods and genetically for ESBL- and pAmpC-encoding genes by PCR and partial amplicon sequencing as well as genetic relatedness by ERIC-PCR.ResultsA total of 75 isolates with reduced susceptibility to cefotaxime and/or ceftazidime (n = 75) from urine (n = 58/199; 29%) and blood (n = 17/31; 55%) were detected. All 75 isolates were phenotypically ESBL-positive and 25/75 (33%) of those also expressed an AmpC-phenotype. ESBL-PCR and amplicon sequencing revealed a majority of blaCTX-M (n = 58/75; 77%) dominated by blaCTX-M-15. All AmpC-phenotype positive isolates (n = 25/75; 33%) scored positive for one or more pAmpC-genes dominated by blaMOX/FOX. Multidrug resistance (resistance ≥ three antibiotic classes) was observed in all the 75 ESBL-positive isolates dominated by resistance to trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin. ERIC-PCR revealed genetic diversity among strains with minor clusters indicating intra-hospital spread.ConclusionWe have observed a high prevalence of MDR pAmpC- and/or ESBL-producing clinical E. coli isolates with FOX/MOX and CTX-Ms as the major β-lactamase types, respectively. ERIC-PCR analyses revealed genetic diversity and some clusters indicating within-hospital spread. The overall findings strongly support the urgent need for accurate and rapid diagnostic services to guide antibiotic treatment and improved infection control measures.
Highlights
Epidemiological data of cephalosporin-resistant Enterobacterales in Sub-Saharan Africa is still restricted, and in particular in Mozambique
We have observed a high prevalence of MDR plasmid-mediated AmpC (pAmpC)- and/or ESBL-producing clinical E. coli isolates with FOX/MOX and CTX-Ms as the major β-lactamase types, respectively
Identification and Antimicrobial Susceptibility Testing (AST) E. coli isolates were recovered from a total number of urinary (n = 199/823; 24.1%) and blood (n = 31/255; 12.1%) culture samples
Summary
Epidemiological data of cephalosporin-resistant Enterobacterales in Sub-Saharan Africa is still restricted, and in particular in Mozambique. The dissemination of multidrug-resistant (MDR), extended-spectrum β-lactamase (ESBL)-producing Enterobacterales is of particular concern limiting treatment options for invasive infections to last line antibiotics [3,4,5]. ESBLs are enzymes that hydrolyze an extended spectrum of β-lactam antibiotics including penicillins and oxyimino-cephalosporins, but not cephamycins [6]. Plasmid-mediated AmpC β-lactamases (pAmpCs) are an important cause of broad spectrum β-lactam resistance in Gram-negative bacteria [8]. AmpC β-lactamases confer resistance to a wide range of β-lactam drugs including penicillins, cephamycin, 1st – 3rd generation cephalosporins as well as classical β-lactamase inhibitors like clavulanic acid and tazobactam to which ESBLs are sensitive [6]. Co-presence of ESBLs and pAmpCs may occur [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
