Home|Journals|Articles by Year|Audio Abstracts
 

Original Article

AJVS. 2014; 40(1): 1-15


Molecular Characterization of Listeria Species Isolated from Frozen Fish

Gaber S. Abdellrazeq, Ayman M. Kamar, Samya M. El-Houshy.




Abstract

The objective of this study was to investigate the molecular characterization of Listeria species isolated from frozen raw fish. A total of 219 samples consisting of 104 mackerel, 52 horse mackerel, 51 catfish and 12 herring were collected and analyzed by bacteriological, serological, antimicrobial and molecular methods. Overall, 29(56.9%) and 1(0.96%) of catfish samples and mackerel samples respectively were positive for Listeria spp. No Listeria was detected in herring and horse mackerel. In catfish, L. welshimeri (13.7 %) was the most commonly isolated species followed by L. monocytogenes (11.8 %), L. innocua (9.8 %), L. grayi subsp. murrayi (9.8 %), L. grayi subsp. grayi (7.8 %), and L. ivanovii (3.9 %). In mackerel, only L. monocytogenes was detected in one sample. L. monocytogenes isolates serotyped as type 1 and type 4 (3 isolates each) and one non-typeable. Antimicrobial resistance profiling showed all L. monocytogenes isolates were resistant to ampicillin and tetracycline. Two were resistant to erythromycin. However, they were susceptible to rifampicin, vancomycin, chloramphenicol and streptomycin. Four virulence-associated genes (prfA, hlyA, actA and inlA) in addition to the genus gene (prs) were investigated using multiplex PCR. All the isolates were positive for prs gene but, only L. monocytogenes isolates were positive for all tested virulence genes. Our study indicates that imported raw catfish can represent a significant source of L. monocytogenes and potential health risk for listeriosis.

Key words: Listeria monocytogenes Prevalence Antibiotic resistance Virulence genes Basa catfish






Full-text options


Share this Article


Online Article Submission
• ejmanager.com




ejPort - eJManager.com
Refer & Earn
JournalList
About BiblioMed
License Information
Terms & Conditions
Privacy Policy
Contact Us

The articles in Bibliomed are open access articles licensed under Creative Commons Attribution 4.0 International License (CC BY), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.