ANTIMICROBIAL RESISTANCE AND MOLECULAR CHARACTERIZATION OF AVIAN PATHOGENIC ESCHERICHIA COLI ISOLATES RECOVERED FROM BROILERS’ FARMS IN NORTHERN PALESTINE

Bzour, Mahmoud

ANTIMICROBIAL RESISTANCE AND MOLECULAR CHARACTERIZATION OF AVIAN PATHOGENIC ESCHERICHIA COLI ISOLATES RECOVERED FROM BROILERS’ FARMS IN NORTHERN PALESTINE

Date

2024-10-31

Authors

Bzour, Mahmoud

Publisher

An-Najah National University

Abstract

Background: Colibacillosis is a disease caused by a certain type of Escherichia coli called the avian pathogenic Escherichia coli (APEC), which leads to significant losses for the poultry sector and shows zoonotic potential and acts as a source of antibiotic resistance and virulence factors for other E. coli. Objectives: This work aimed to assess resistance phenotype, virulence genes, and phylogenetic groups in APEC isolates recovered from broilers’ farms in northern Palestine. As well as to clarify whether the virulence factors are directly associated with antibiotic resistance or, instead, dependent on a phylogenetic group distribution. Methodology: A total of the 65 APEC isolates were recovered from diseased chicken with typical colibacillosis symptoms from broilers’ farms located in the northern region of Palestine, during the period from May to July 2024. Classical and molecular techniques were used to identify these strains. The disk diffusion method was used to detect antibiotic resistance. Phylotyping and virulence genotyping of these APEC isolates were carried out by polymerase chain reaction. Results: This study revealed a high detection rate of APEC strains (100%) in chicken. The most APEC strains 56/65 (86.2%) assigned to group D. Other strains were related to groups B2 (5/65, 7.7%), B1 (3/65, 4.6%) and A (1/65, 1.5%). Antibiotic resistance ranged from 27.7% for PolymyxinsE (Colistin) to 100% for Amoxicillin. Polymyxins E (Colistin) and Fosfomycin were the most effective drugs. It was found that the most common virulence factor was iroN which was tested in 61 isolates (93.8%). While, 56 (86.2%), 42 (64.6%), 40 (61.5%), 37 (56.9%), 24 (36.9%), 23 (35.4%),16 (24.6%), 13 (20.0%), 0 (0.0%) and 0 (0.0%) isolates were positive for hlyF, iutA, Tsh, ColV, papGII, Iss, papGI, papC, papGIII and ompT genes, respectively. The APEC strains in Palestine exhibit a wide variety of resistance patterns and genetic variation. Conclusion: These results serve as an outline for development of efficient intervention plans for the management of APEC in broiler breeders and broiler farms. Controlling APEC infections is essential for public health, especially when APEC isolates can pass on virulence and resistance factors to other pathogenic bacteria such as E. coli that are particular to humans.