Occurrence Of Enteropathogens Research Articles

Impact of the pre-slaughter period on the contamination of bovine leather and the operational sanitary procedure for skinning on the quality and microbiological safety of the carcass

Sanitary procedures are essential in cattle slaughter processes to minimize microbiological hazards from meat consumption. This study aimed to verify the influence of the pre-slaughter period and the correct execution of the operational sanitary procedure (OSP) for skinning in the breast region on the counts of indicator microorganisms and the occurrence of enteropathogens in the hides and carcasses of cattle. Forty-eight animals were evaluated and divided into 12 clusters, half of which were allowed 13 h of preslaughter rest, while the other half were allowed 23 h of pre-slaughter rest. The presence of microbiological indicators, including Salmonella spp., Listeria spp., and Shiga toxin-producing (STEC), enteropathogenic (EPEC), and enterohemorrhagic (EHEC) Escherichia coli, were evaluated in superficial samples of leather and carcass in which the OSP for skinning of the chest was performed either correctly or incorrectly. There was no significant effect (p > 0.05) of the pre-slaughter period on the counts of total coliforms, E. coli, enterobacteria, and mesophilic aerobics in the hide or carcass, although, in the carcasses, this difference was 93.4% for mesophilic aerobics and enterobacteria in the group of animals subjected to 23 h of rest compared to those subjected to 13 h of rest. Regarding the correct execution of the skinning OSP, there was also no significant effect (p > 0.05) on the indicator quantifications, but in relation to the presence of enteropathogens, it was possible to proportionally identify more EPEC and STEC in carcasses subjected to the wrong OSP, as it was only possible to identify Salmonella spp. and EHEC in carcasses subjected to the wrong OSP. The correct execution of the OSP for skinning incision in the chest region of the animal reduced the microbiological risk of the carcasses for the presence of enteropathogens and facilitated compliance with the microbiological standards for the carcass.

An investigation of dairy calf management practices, colostrum quality, failure of transfer of passive immunity, and occurrence of enteropathogens among Australian dairy farms

Calf preweaning morbidity and mortality risks have been reported as high in several countries, with average values approximating 35 and 7%, respectively. However, limited data are available for calf morbidity and mortality risks on Australian dairy farms. The aims of this study were (1) to investigate current calf management practices on dairy farms in Australia and their association with herd-level morbidity and mortality using a questionnaire-based, cross-sectional study; and (2) to estimate the prevalence of common enteropathogens causing diarrhea, the failure of passive transfer of immunity, and poor colostrum quality in a sample of Australian dairy farms. We analyzed 106 completed questionnaires and samples from 23 farms (202 fecal, 253 calf serum, and 221 colostrum samples). Morbidity and mortality risks reported by farmers in preweaned heifers were 23.8 and 5.6%, respectively. These risks were above the Australian dairy industry targets in 75.5 and 66.7% of respondents. The zoonotic pathogens Cryptosporidium spp. and Salmonella spp. were the most prevalent enteropathogens, with a true prevalence of 40.9 and 25.2%, respectively. Salmonella O-group D was present in 67.9% of Salmonella-positive samples, followed by O-groups B (17.9%) and C (10.7%). Failure of transfer of passive immunity (IgG <10 g/L) was observed in 41.9% of calves (mean herd-level prevalence of 36.2%), and only 19.5% of colostrum samples met the standards for immunoglobulin content and microbiological quality. Collectively, these data indicate that there is still considerable room for improvement in calf-rearing practices on Australian dairy farms, particularly with regard to colostrum management and feeding hygiene.

Impact of urban contamination of the La Paz River basin on thermotolerant coliform density and occurrence of multiple antibiotic resistant enteric pathogens in river water, irrigated soil and fresh vegetables.

La Paz River in Andean highlands is heavily polluted with urban run-off and further contaminates agricultural lowlands and downstream waters at the Amazon watershed. Agricultural produce at this region is the main source of vegetables for the major Andean cities of La Paz and El Alto. We conducted a 1 year study, to evaluate microbial quality parameters and occurrence of multiple enteropathogenic bacteria (Enterohemorrhagic E. coli—EHEC, Enteroinvasive E. coli or Shigella—EIEC/Shigella, Enteroaggregative E. coli—EAEC, Enteropathogenic E. coli—EPEC Enterotoxigenic E. coli—ETEC and Salmonella) and its resistance to 11 antibiotics. Four sampling locations were selected: a fresh mountain water reservoir (un-impacted, site 1) and downstream sites receiving wastewater discharges (impacted, sites 2–4). River water (sites 1–4, N = 48), and soil and vegetable samples (site 3, N = 24) were collected during dry (April–September) and rainy seasons (October–March). Throughout the study, thermotolerant coliform density values at impacted sites greatly exceeded the guidelines for recreational and agricultural water uses. Seasonal differences were found for thermotolerant coliform density during dry season in water samples nearby a populated and hospital compound area. In contrast to the un-impacted site, where none of the tested enteropathogens were found, 100 % of surface water, 83 % of soil and 67 % of vegetable samples at impacted sites, were contaminated with at least one enteropathogen, being ETEC and Salmonella the most frequently found. ETEC isolates displayed different patterns of toxin genes among sites. The occurrence of enteropathogens was associated with the thermotolerant coliform density. At impacted sites, multiple enteropathogens were frequently found during rainy season. Among isolated enteropathogens, 50 % were resistant to at least two antibiotics, with resistance to ampicillin, nalidixic acid, trimethoprim–sulfamethoxazole and tetracycline commonly present. Moreover, some Salmonella isolates were distinguished by their multi-resistance to ≥8 antibiotics, within soil and vegetable samples. Overall, this study demonstrates that La Paz River—an affluent of the Amazon macrobasin—is heavily polluted along the year with a high density of thermotolerant coliforms and is a reservoir of multiple antibiotic resistant enteropathogens, present in river water, soil and vegetables. These data highlight health risk associated with food and waterborne diseases at the region.