Anti-Streptomycin 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.

Background: Ready to eat (RTE) vegetables are easily accessible healthy foods that are commonly consumed globally, including in Indonesia. However, these RTE vegetables contain potential contamination from patho- gens and multi -drug resistant bacteria. Therefore, in the present study, we examined the presence of tetracycline - resistant E. coli (TRE) isolates from RTE vegetables. Methods: Susceptibility to antimicrobial agents was determined using the Kirby -Bauer disc di ffusion method. Characterisation of antibiotic resistant genes was performed using PCR and sequencing of tetracycline resistant gene, integron and gene cassette from the TRE isolates. Results: The isolates collected in this study were resistant not only to tetracycline, but also to streptomycin. Some isolates also displayed resistance to kanamycin (77.8%), chloramphenicol (11.1%), and cipro floxacin (5.6%). All of the isolates contained integrons ( intI1 ) and the tetA gene; tetB was not detected in our study. Further analysis showed that some isolates (38.8%) contained the dfr A 7 gene cassette, which encodes dihydrofolate reductase, which is responsible for resistance to trimethoprim. Of all the isolates that presented integrons, 11 isolates (61.1%) did not carry gene cassettes. These empty integrons have the potential to convert themselves rapidly into multigraviton strains. Conclusions: TRE isolates contain the tetA gene and integron 1. Only 38.8% of the isolates that have been identi fied contain the dfrA7 gene cassette, which is responsible for trimethoprim antibiotic resistance. Further identi fication of genes conferring resistance to other antibiotics is necessary to better characterise antibiotic resistance.