Anti-Salmonella type H-t Polyclonal antibody

Ground beef contamination with Escherichia coli is usually a result of carcass faecal contamination during the slaughter process. Carcasses are contaminated when they come into contact with soiled hides or intestinal leakage content during dressing and the evisceration processes. A more recent and compelling hypothesis is that, when lymph nodes are present in manufacturing beef trimmings, they can be a potential source of Enterobacteriaceae contamination of ground beef. The aim of this study was to investigate the occurrence of E. coli in lymph nodes from beef carcasses used for ground meat production, in six slaughter plants situated in central Italy A total of 597 subiliac (precrural) lymph nodes were obtained from 597 cattle carcasses and screened for E. coli by culture. Furthermore, E. coli isolates (one per positive carcass) were tested for stx1, stx2 eaeA and hlyA genes that are commonly used to identify and characterise shiga toxin-producing E. coli (STEC). In addition, the E. coli isolates were profiled for antimicrobial susceptibility. A proportion of 34.2% (204/597) carcasses were positive for E. coli. PCR revealed that 29% (59/204) of E. coli possessed stx1 or stx2 which corresponded to 9.9% of the cattle sampled. Moreover, a combination of stx1 or stx2 and eaeA was found in in 4 isolates (2% among E. coli positive samples and 1% among cattle sampled) and a combination of stx1 or stx2 and eaeA and hly in 1 isolate (0.5% and 0.2%). More than 95% of isolates were susceptible to gentamicin, ceftriaxone, cyprofloxacin and cefotaxime while high rates of resistance were recorded for cephalotin, ampicillin, tetracycline, tripe sulfa and streptomycin. The multivariate analysis identified "age" as the factor most closely related to E. coli positivity (either generic E. coli or STEC) in bovine lymph nodes. In conclusion, subiliac lymph nodes represent a source of E. coli for ground beef. These results are of major importance for risk assessment and improving good manufacturing practices during animal slaughter and ground meat production.

The efficacy of probiotics as alternatives to antibiotics has been defined as one of the potential strategies to prevent Salmonella spp. infection in poultry. The purpose of this study was to isolate probiotic native Lactic acid bacteria (LAB) with high compatibility to intestinal tract and prevention of Salmonella typhimurium from broiler chicken feces. Thirty-seven samples of chicken feces were collected from seven broiler chicken farms in Northern Iran. The isolates identification was carried out with morphological and biochemical tests. Agar diffusion methods were used to evaluate the antimicrobial activities against Escherichia coli and S. typhimurium. The primary probiotic characteristics such as resistance to acid and bile and adhesion to Caco-2 cells were studied. Indeed, the ability of LAB isolates to inhibit adhesion of S. typhimurium to Caco-2 cells was evaluated by exclusion, competition and displacement assays. Among 42 isolates, S08, S01 and S06 isolates which showed appropriate probiotics characteristics were selected. Isolates S08 and S01 showed to be able to adhere strongly and also S06 was adhered moderately. In the exclusion assay, the isolates S08, S01 and S06 significantly hampered adhesion of S. typhimurium cell, in the competition assay, the isolates S08, S01 showed significant level of competition activity against S. typhimurium adherence to Caco-2 cells and isolate S08 showed the greatest displacement activity. The 16S rDNA sequence revealed that S08, S01, and S06 isolates were 99.00% similar to Lactobacillus salivarius, Lactobacillus johnsonii, and Pediococcus acidilactici, respectively. The result of this study suggested that LAB isolated from broiler chicken feces could be a remarkable reservoir for identification of probiotic to inhibit the pathogenic bacteria growth. (C) 2020 Urmia University. All rights reserved.