Bacterial Distribution and Community Structure in Beef Cattle Liver and Bile at Slaughter
| Autor: | Yoshimasa Sasaki, Yumiko Okada, Ken Shiroma, Hiroshi Asakura, Ayako Kiyoshima, Chie Hisamoto, Akiko Fujimori, Yutaka Shiraki, Kanako Munakata, Shiori Yamamoto, Jun Kawase, Sachiko Katabami, Yasuyo Ojima, Hisashi Nishibu |
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| Rok vydání: | 2022 |
| Předmět: |
Veterinary medicine
Meat Firmicutes Colony Count Microbial Indicator bacteria Food Contamination Beef cattle medicine.disease_cause Microbiology Enterobacteriaceae RNA Ribosomal 16S Parenchyma medicine Animals Bile Microecosystem Escherichia coli Feces biology biology.organism_classification Liver Food Microbiology Cattle Proteobacteria Abattoirs Food Science |
| Zdroj: | Journal of Food Protection. 85:424-434 |
| ISSN: | 0362-028X |
| Popis: | In this study, the distribution of hygienic indicator bacteria in cattle livers and bile was examined at slaughterhouses. One hundred twenty-seven cattle livers with gallbladders were carefully eviscerated from carcasses at 10 slaughterhouses. Microbiological examination revealed that nine bile samples (7.1% prevalence) and 19 liver parenchyma samples (15.0% prevalence) were positive for Enterobacteriaceae (EB) with means ± standard deviations of 3.68 ± 4.63 log CFU/mL and 1.59 ± 2.47 log CFU/g, respectively; thus, bacterial contamination was apparent even at the postevisceration stage. Subsequently, 70 cattle livers were obtained at the postprocessing and storage stage from 7 of the 10 slaughterhouses. Microbiological analysis revealed significantly higher levels of EB in the liver parenchyma (3.00 ± 3.89 log CFU/g, P = 0.011) than those at the postevisceration stage, suggesting that bacterial dissemination and/or replication occurred in the liver parenchyma during processing and storage. According to 16S rRNA ion semiconductor sequencing analysis of representative samples from 12 cattle, Proteobacteria, Firmicutes, and Actinobacteria were dominant in both the parenchyma and bile in which EB and Escherichia coli were predominant among livers with higher EB levels. These results suggest that bile plays a role as a vehicle for bacterial transmission to the liver parenchyma. This study is the first to evaluate bacterial distribution and community structure in the liver and biliary microecosystem of cattle at slaughter. Our data support the use of EB testing of bile to screen cattle livers contaminated with high levels of fecal indicator bacteria. |
| Databáze: | OpenAIRE |
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