Molecular description of alpha-hemolysin producing Escherichia coli isolates from extraintestinal source

Cite this:
[1]
D. A. C. Dr. Vishwas Saralaya, “Molecular description of alpha-hemolysin producing Escherichia coli isolates from extraintestinal source”, ijmhs, vol. 8, no. 6, Jul. 2018.
© 2022 Interactive Protocols
RIGHTS & PERMISSIONS
Article Views
320
Altmetric
1
Citations
-
LEARN ABOUT THESE METRICS
   PDF  

Abstract

Context: Alpha-hemolysin (Hly) is a common exotoxin produced by Escherichia coli, which plays an important role as a virulence factor in a number of clinical infections. There exist other virulence properties exhibited by such strains whose role in pathogenesis have not yet been clearly elucidated.

Aims: Aim of present study was to characterize those alpha-hemolysin producing isolates on the basis of their virulence factors and phylogenetic background.

Settings and Design: This descriptive study was carried out in a multi-specialty tertiary care hospital.

Methods and Material: Three hundred non-repeat E. coli isolates from in-patients were studied. Isolates were differentiated as haemolytic and non-haemolytic on the basis of both phenotypic methods such as haemolysis on sheep blood agar and genotypic detection of the hly gene. Possession of virulence and drug resistance genes was determined by multiplex polymerase chain reaction (PCR). Phylogenetic analysis was performed by triplex PCR methods. Antibiotic sensitivity testing was performed by disk diffusion method.

Results: Of the 300 isolates, it was observed that by phenotypic (haemolysis on blood agar) method, 65(22%) were hemolytic whereas the genotypic method detected 70 (23.5%) isolates possessing alpha haemolysin (hlyA+) marker. B2 phylogroup isolates were found to harbour the hlyA+ marker at a significantly higher (P < 0.05) rate.  The possession of papC and cnf1 genes was significantly higher in hlyA+ isolates.

Conclusions: Alpha-haemolysin producing isolates demonstrated higher virulence properties. The microbiology laboratory may report haemolytic characteristics of the isolates as it may alert the physician of the higher pathogenic potential of the strain and to initiate appropriate treatment.

KEYWORDS:

 Special Issue

Article Metrics Graph

Chart Graph | Range Graph

Content

Section

Source

License

All paper submissions must carry the following duly signed by all the authors:
“I certify that I have participated sufficiently in the conception and design of this work and the analysis of the data (wherever applicable), as well as the writing of the manuscript, to take public responsibility for it. I believe the manuscript represents valid work. I have reviewed the final version of the manuscript and approve it for publication. Neither has the manuscript nor one with substantially similar content under my authorship been published nor is being considered for publication elsewhere, except as described in an attachment. Furthermore I attest that I shall produce the data upon which the manuscript is based for examination by the editors or their assignees, if requested.”