Virulence genes and antibiotic resistance in Escherichia coli strains from poultry in Western Algeria

Introduction. The widespread use of antibiotics in food animal production systems has resulted in the emergence of antibiotic resistant zoonotic bacteria that can be transmitted to humans through the food chain. The aim of this study was to evaluate virulence genes and antibiotic resistance in Escherichia coli strains isolated from healthy broiler chickens and eggs samples in Western Algeria. Materials and Methods. A total of 47 Escherichia coli strains isolated from healthy broiler chickens and eggs, collected from 7 different geographic areas of Western Algeria, were identified by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS). E. coli O157:H7 ATCC 43894 was the reference strain. Virulence associates genes of E. coli including Shiga toxins (STEC) (stx1 and stx2), O157-antigen gene (rfbE), flagellar gene (fliC), and intimin (eaeA) were detected by polymerase chain reaction. Susceptibility to 11 antibiotics agents (nalidix acid-NA, ciprofloxacin-CIP, amoxicillin-AML, AML+clavulanic acid-AUG, cefotaxime-CTX, trimethoprim-sulfamethoxazole-SXT, tetracycline-TE, chloramphenicol-C, neomycin-N, colistin-CS and imipenem-IMP) was determined by standards methods. Phenotypic extended-spectrum beta-lactamase (ESBL) detection test was performed by double disc synergy test (DDST) using AUG and CTX. Results. Among E. coli strains, only one was non STEC O-157:H7 (rfbE +), whereas another was non O-157 STEC (stx2+). The strains were resistant to some of the antibiotics most frequently used in poultry. In particular, they were resistant to NA (95.74%), N (93.61%), TE (87.23%), CIP (85.10), AUG (85.10%), SXT (76.59%), AML (70.21%), C (21.27%), CTX (17.02%). Furthermore, 8 (17%) were ESBL producer E. coli strains. Conclusions. These epidemiological data showed the low incidence of STEC strains isolated from healthy broiler chicken and eggs in Western Algeria. This territory may be considered a significant food safety area. However, it is to be highlighted the high prevalence of multidrug resistant E. coli strains that can be transmitted from poultry to humans with serious consequences on public health. Therefore, implementation of more efficient preventive measures of antibiotic resistance in broiler and layer farms should became mandatory. This work was conducted within of the "Programme and Partner Countries within the program Erasmus+/KA1 Higher Education Agreement between the University of Messina, Italy and the University of Mostaganem, Algeria.