RESUMO
Fish is an excellent source of protein and other essential minerals and vitamins; nevertheless, several food-borne disease outbreaks have been linked to the consumption of different types of fish. Therefore, we aimed to overcome these health threats by evaluating gamma radiation as a good fish preservation method. The aerobic plate count (APC), identification of most common pathogenic bacteria, organoleptic properties, proximate composition, and other chemical evaluations were detected in both untreated and gamma-treated fish. The overall grades of organoleptic evaluations ranged from good to very good. Fortunately, the overall chemical analysis of all examined fish samples was accepted. For the untreated fish samples, the APC was within and above the permissible limit (5 × 107 CFU/g). Pathogenic bacteria were detected with a high prevalence rate, especially S. aureus, which was found in high percentages among examined untreated fish samples. Regarding the treated fish samples, APC and pathogenic bacterial counts were reduced in a dose-dependent manner, and the irradiation at dose 5 KGy resulted in complete eradication of the aerobic plate count (not detectable) with a mean reduction percentage equal to 100%. However, gamma irradiation has no significant effect on proximate composition; particularly, carbohydrates, proteins, and lipids were not significantly affected by low and medium doses of radiation. Therefore, gamma irradiation is a highly effective fish preservation method without any effect on fish quality. Additionally, gamma irradiation as a cold process is an attractive technology for solving the problem arising from fish-borne pathogens, and it has been purposed in this study as a cheap and safe method for reducing microbial contamination of fish.
RESUMO
BACKGROUND: The goal of this study was to investigate the prevalence of extended-spectrum ß-lactamase production in Enterobacterales isolated from retail sheep meat in Zagazig, Egypt. METHODS: One hundred random samples of sheep meat were collected from different retail butcher shops (n = 5) in the city of Zagazig, Egypt. Bacterial isolates were identified by MALDI-TOF MS and screened for antibiotic susceptibility by disk diffusion; further genotypic characterization of ß-lactamase-encoding genes was performed with Real-Time PCR. E. coli strains were phylotyped with the Clermont triplex PCR method. RESULTS: Of the total of 101 bacterial isolates recovered from retail sheep meat samples, 93 were E. coli, six were Enterobacter cloacae and two were Proteus mirabilis. As many as 17% of these 100 samples showed ESBL phenotypes, all were E. coli. The blaCTX-M genes were detected in seven isolates (six were blaCTX-M-15 and one was blaCTX-M-14), three isolates harboured blaTEM (all were blaTEM-one), and two carried genes of the blaSHV family (both were blaSHV-12). Eight E. coli isolates expressed ESBL phenotype but no blaTEM, blaSHV or blaCTX-M genes were detected by PCR. ESBL- positive E. coli isolates were nearly equally distributed over the commensal groups A/B1 and the virulent group D. CONCLUSION: Nearly one in five sheep meat samples was contaminated with ESBL-E. coli. This further corroborates the potential role played by contaminated meat in the increasing resistance rates that have been reported worldwide.
