There has been an increase in the occurrence of antibiotic resistance among Salmonella enterica,
one of the commonest causative agents of Salmonella infections. Fluoroquinolones and third
generation cephalosporins are usually the drugs of choice in the management of Salmonella
infections. Previous reports have indicated common occurrence of multi-drug resistance (MDR)
including resistance to β-lactams and fluoroquinolones among clinical Gram-negative organisms.
However, there is paucity of information on the genetic determinants of resistance to β-lactam
and fluoroquinolones from S. enterica in Southeast Nigeria. This study screened for the presence
of Extended-Spectrum Beta-Lactamases (ESBL) and mutations in gyrA and parC genes of S.
enterica from human origin in the Southeast Nigeria.
Twenty-five S. enterica isolates from stool of patients suspected to have Salmonella infection
were collected from each of four hospitals (one teaching hospital and three Federal Medical
Centres) in Southeast Nigeria between July and September, 2010. The isolates were confirmed
using Microbact identification kit®
. Antibiogram for the isolates was determined by discdiffusion based on Clinical and Laboratory Standards Institute breakpoints. Five commonly used
antibiotics (amoxicillin-clavulanic acid, cefotaxime, ceftriaxone, ciprofloxacin and levofloxacin)
in the treatment of Salmonella infections were selected for determination of Minimum Inhibitory
Concentrations (MIC) against the isolates using broth-dilution method. Isolates resistant to two
or more different classes of antibiotics were classified as MDR. Isolates resistant to
fluoroquinolones and cephalosporins were exposed to mutagens for R-plasmid curing, and ESBL
were detected phenotypically using Double-Disk Synergy Test. Genomic and plasmid DNA of
mutagen treated and untreated isolates were extracted by boiling and alkaline lysis, respectively.
Polymerase chain reaction was used to amplify blaTEM, blaSHV and blaCTX-M among the ESBL
positive isolates, and Quinolone Resistance Determining Regions (QRDR) among
fluoroquinolone resistant isolates, followed by sequencing of the QRDRs. Antibiogram data
were analysed using ANOVA at p = 0.05.
The Public Access, L (2021). Molecular Characterisation Of Some Multi-Drug Resistant Salmonella Enterica Of Human Origin In Southeast Nigeria. Afribary.com: Retrieved May 08, 2021, from https://afribary.com/works/molecular-characterisation-of-some-multi-drug-resistant-salmonella-enterica-of-human-origin-in-southeast-nigeria
Library, The Public Access. "Molecular Characterisation Of Some Multi-Drug Resistant Salmonella Enterica Of Human Origin In Southeast Nigeria" Afribary.com. Afribary.com, 05 Apr. 2021, https://afribary.com/works/molecular-characterisation-of-some-multi-drug-resistant-salmonella-enterica-of-human-origin-in-southeast-nigeria . Accessed 08 May. 2021.
Library, The Public Access. "Molecular Characterisation Of Some Multi-Drug Resistant Salmonella Enterica Of Human Origin In Southeast Nigeria". Afribary.com, Afribary.com, 05 Apr. 2021. Web. 08 May. 2021. < https://afribary.com/works/molecular-characterisation-of-some-multi-drug-resistant-salmonella-enterica-of-human-origin-in-southeast-nigeria >.
Library, The Public Access. "Molecular Characterisation Of Some Multi-Drug Resistant Salmonella Enterica Of Human Origin In Southeast Nigeria" Afribary.com (2021). Accessed May 08, 2021. https://afribary.com/works/molecular-characterisation-of-some-multi-drug-resistant-salmonella-enterica-of-human-origin-in-southeast-nigeria