Haemolysin and Shigella Toxin Production in Multidrug Resistant Escherichia Coli Pathotypes from Clinical Specimens

Authors: Iliyasu MY*, Salisu A, Mustapha I, Shuaibu SM, Lawan GM, Umar AF, Agbo EB, Uba A and Deeni YY

DOI: 10.23880/oajmb-16000188

Volume 6, Issue 1

Abstract

The acquisition and dissemination of virulent traits represent a survival advantage to bacterial pathogens. Drug resistance is on the rise among E. coli strains that cause human infections. Proper selection of antimicrobial treatment depends on the susceptibility test outcomes. A total of 178 bacterial isolates were phenotypically screened for Haemolysin and Shigatoxin production, then to obtain Multidrug Resistant (MDR) E. coli. Twelve isolates were identified and selected based on the ability to grow on Luria-Bertani (LB) agar medium containing 100μg/ml Ampicillin. The isolates, coded as; U01, U02, U03, U04, U08, U10 and U11 were from urine specimens, S05, S06, S07 and S12 from stool, while B09 was from blood. The isolates were screened for multidrug resistant pattern according to Kirby-Bauer disc diffusion method. Genes hlyA and stx1 encoding the virulence factors; Haemolysin A and Shigatoxin1 was PCR amplified and sequenced. All the isolates were resistant to Ampicillin, Cephalothin, Erythromycin, Fusidic acid, Novobiocin and Oxacillin, but sensitive to Colistin sulphate and Imipenem. Nine isolates (75%) are sensitive to Augmentin. All the virulence genes (hlyA and stx1) are present in isolates S07 and U08. The isolates (75%) produced 2 to 4 of each of the genes indicating a strong relationship in determining multidrug resistance. Haemolysin (hlyA) was the most common (66.7%) gene in urine, stool and blood isolates. Most of the virulence genes sequence (61.8%) in this study had significant alignment (95 to 100% homology) with E.coli genome in the NCBI database. This study revealed the interplay of drug resistance and virulence at genetic levels, so advocate for further identification of the mechanisms regulating the expression of these traits, to improve the management of bacterial infections.

Keywords: Multidrug Resistance; Virulence; Haemolysin A; Shigatoxin 1; Colistin Sulphate; Imipenem

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