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BackgroundThe worldwide increase of food-borne infections with antibiotic resistant pathogens constitutes a major public health problem. Therefore, this study aimed to determine the prevalence, antibiogram, virulence genes profiles and integron characteristics of non-typhoidal Salmonella spp. isolated from poultry meat and diarrhoeic patients in Egypt.MethodsA total of 150 samples comprising (100 poultry meat and 50 diarrhoeic patients’ stool) were examined for the presence of Salmonella spp. using culture methods followed by biochemical and serological identification of the isolates. All Salmonella strains were tested for their susceptibility to the antibiotics using disk diffusion method and screened for the presence of virulence genes and class I integrons using PCR.ResultsThe overall prevalence of Salmonella spp. in poultry meat samples was 10 % compared to 4 % in diarrhoeic patients. All the isolates were serologically identified into Salmonella Typhimurium (seven isolates), S. Derby, S. Kiel, S. Rubislaw (one isolate, each) and untypable strains (two isolates). Antibiotic susceptibility testing showed a higher resistance of the total isolates to erythromycin and tetracycline (100 %, each), followed by amoxicillin-clavulanic acid (91.7 %), trimethoprim-sulfamethoxazole (83.3 %), streptomycin, nalidixic acid, ampicillin-sulbactam (75 %, each), gentamycin, ampicillin (66.7 %, each), chloramphenicol (58.3 %), ciprofloxacin (25 %) and ceftriaxone (16.7 %). Virulence genes profiles revealed the presence of sopB gene in five Salmonella strains isolated from poultry meat (n = 3) and humans (n = 2). Moreover, pefA was only identified in three isolates from poultry meat. On the other hand, S. Kiel and S. Typhimurium (one isolate, each) were harboring hilA and stn genes, respectively. Class 1 integrons were detected in all Salmonella spp. with variable amplicon sizes ranged from 650–3000 bp. Sequencing of these amplicons revealed the presence of gene cassettes harboring aac(3)-Id, aadA2, aadA4, aadA7, sat, dfrA15, lnuF and estX resistance genes. Nucleotide sequence analysis showed point mutations in the aac(3)-Id of S. Derby, aadA2, estX-sat genes of S. Typhimurium. Meanwhile, frame shift mutation was observed in aadA7 genes of S. Typhimurium.ConclusionsIncreasing rate of antimicrobial resistance and class 1 integrons among multidrug resistant Salmonella spp. has prompted calls for the reduction of antimicrobial use in livestock to prevent future emergence of resistance.

Quail meat is an emerging source of high-quality animal protein. Quails are exposed to a wide range of xenobiotics such as heavy metals. In this study, residual concentrations of four toxic metals, of significant public health importance, including cadmium (Cd), lead (Pb), arsenic (As), and nickel (Ni), were determined in edible tissues of quails. In addition, metal loads were measured in water, feed, and litter samples collected from same quail farms as possible sources for quail exposure to heavy metals. The possible use of metallothionein (MT) and heat shock protein 70 (Hsp70) as molecular biomarkers of exposure to heavy metals was further investigated. Furthermore, the dietary intake and the potential risk assessment of the examined heavy metals among children and adults were calculated. The edible tissues of quails contained high concentrations of four heavy metals (contents (ppm/ww) ranging from 0.02 to 0.32 in Cd, 0.05 to 1.96 in Pb, 0.002 to 0.32 in As, and 1.17 to 3.94 in Ni), which corresponded to the high contents of these metals in the feeds, water, and litter. MT and Hsp70 mRNA expressions showed positive correlations with the concentrations of heavy metals in tissues indicating the possibility to use these proteins as biomarkers for quail's exposure to toxic metals. Dietary intake of quail meat and risk assessment revealed potential risks especially for children after prolonged exposure to the examined metals. Thus, legislations should be established and continuous screening of metal residues should be adopted in order to reduce the toxic metal concentrations in feeds and drinking water for quails. Reduction of exposure to heavy metals subsequently would lead to minimization of exposure of such toxicants through consumption of quail meat.

Aims This study aimed to determine the toxin genotypes, virulence determinants and antibiogram of Clostridium perfringens isolated from poultry, animals and humans. Biofilm formation and the efficacy of disinfectants on C. perfringens biofilms were studied. Methods and Results Thirty C. perfringens isolates (20 clinical and 10 from chicken carcasses) were genotyped by PCR and all isolates were genotype A (cpa+). The overall prevalence of cpe, cpb2, netB and tpeL virulence genes was 6·7, 56·7, 56·7 and 36·7% respectively. Twenty‐one isolates (70%) were multidrug‐resistant, 8 (26·7%) were extensive drug‐resistant and one isolate (3·3%) was pan drug‐resistant. The average multiple antibiotic resistance index was 0·7. Biofilms were produced by 63·3% of C. perfringens isolates and categorized as weak (36·7%), moderate (16·7%) and strong (10%). Sodium hypochlorite caused significant reduction in C. perfringens biofilms (P < 0·0001). Conclusions All C. perfringens strains in this study were type A, resistant to multiple antibiotics and most of them were biofilm producers. Sodium hypochlorite showed higher efficacy in reducing C. perfringens biofilms. Significance and Impact of the Study This study reported the efficacy of disinfectants in reducing C. perfringens biofilms of economic and public health concern and recommends application on surfaces in farms, food processing plants and slaughterhouses.

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