• Korean Journal of Veterinary Service
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• v.46 no.2
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• pp.137-145
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• 2023

From November 2021 to October 2022, 151 pigs were discarded due to the suspected salmonellosis, when assessed by antemortem inspection at slaughterhouses in Gwangju. Among them, 85 cases shown with the rectal stricture were confirmed to be infected with Salmonella spp, when assessed by postmortem inspection and Salmonella-oriented culture in the laboratory, accounting for 56.3% of the carcass discard cases. Salmonella spp. were isolated in 58 cases (68.2%) out of 85 total discard cases. As for serotyping of the Salmonella isolates, 28 cases (48.3%) belonged to serogroup B and 28 cases (48.3%) belonged to serogroup C, those were the most frequent isolates, and 2 cases (3.4%) belonged to serogroup E. The most prevalent serotype was Rissen (39.7%), followed by I4,[5],12:i:-(37.9%), Derby (8.6%), Bareilly (5.2%), Infantis (3.4%), Give (3.4%), and Typhimurium (1.7%). The 58 isolates of salmonellae showed resistance to tetracycline (63.8%), chloramphenicol (56.9%), ampicillin (53.4%), and ampicillin-sulbactam (51.7%). S. Rissen showed resistance to chloramphenicol (82.6%), ampicillin (52.2%), ampicillin-sulbactam (52.2%), and tetracyclin (47.8%). S. I4,[5],12:i:-was resistant to tetracycline (90.9%), ampicillin (81.8%), ampicillin-sulbactam (77.3%), and chloramphenicol (59.1%). Among the isoates, S. Bareilly (3 strains), S. Infantis (2 strains), S. Give (2 strains), S. Rissen (3 strains), and S. I4,[5],12:i:- (1 strain) showed no resistance to the tested antimicrobials. As for the prevalence of the antibiotic resistance pattern, AM-SAM-TE-C was the most common, which was shown in 15.5% of S. Rissen. At second, the resistance pattern was occurred as AM-SAM-TE (12.1%) and AM-SAM-CF-CZ-FOX-CTX-NA-TE-C (12.1%), respectively in the case of S. I4,[5],12:i:-.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.45-54
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• 2009

Contamination levels of aerobic colony counts, coliforms and pathogenic bacteria were tested in fried rice dishes to monitor quality for risk management. The prevalence of Bacillus cereus in dishes from 8 Chinese-style restaurants and 2 institutional foodservices was 10%, and the bacteria's contamination levels was 3.47 log CFU/g. Echerichia coli, Staphylococcus aureus, and Salmonella were not detected in any of the 10 samples. However, for their aerobic colony counts and numbers of isolated coliforms, the samples were 30% and 70% over the microbial criteria, respectively, for ready-to-eat foods presented in the Korean Food Code. This suggests that fried rice dishes, although cooked with oil at high temperature, require special care. For the prediction of the growth curve of B. cereus spp. in the fried rice samples, an experiment design of 3 storage temperatures ($7^{\circ}C$, $35^{\circ}C$, $57^{\circ}C$) x 5 storage times (0 h, 2 h, 4 h, 6 h, 24 h) was applied. The sample exposed to $35^{\circ}C$ showed no B. cereus spp. at 0 h; however, there was a tendency of slow growth (1.0 log CFU/g) after 4 hours of storage and then faster growth at 6 h (3.7 log CFU/g) and 12 h (4.7 log CFU/g), showing a growth rate of 0.56 log CFU/g/hr. These results indicate that fried rice, despite being heat-treated, can become heavily contaminated with B. cereus spp. when held over 2 hours at room temperature. However, the samples stored at $7^{\circ}C$ and $57^{\circ}C$ over 24 hours were not contaminated with B. cereus. Based on these results, management guidelines for controlling B. cereus are suggested.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.81-86
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• 2011

In grower pigs, enteric diseases are major economic problem in swine industries. Enteric diseases are attributed to numerous bacterial agents, such as Lawsonia (L.) intracellularis, Brachyspira (B.) hyodysenteriae, B. pilosicoli and Salmonella spp. Therefore we investigated the prevalence of enteric pathogens and found out the correlation of infectious agents in enteric diseases of grower pigs in Jeju-do using polymerase chain reaction (PCR) method. A total of 509 fecal samples of grower pigs from 49 pig farms of Jeju-do were collected from May 2006 to June 2007. Diagnostic confirmation was performed based on the detection of bacterial DNA from fecal samples. Based on the PCR methods, B. pilosicoli, B. hyodysenteriae, L. intracellularis and Salmonella spp. were detected in 82 (16.1%), 38 (7.5%), 15 (2.9%), and 12 (2.4%) fecal samples from grower pigs in Jeju-do, respectively. Single infection of enteric pathogen and mixed infection with more than 2 pathogens were detected in 110 (86.6%) and 17 (13.4%) grower pigs, respectively. These results suggest that B. pilosicoli and B. hyodysenteriae are main pathogens of diarrheal disease among grower pigs in Jeju-do. Therefore, accurate control strategy for enteric pathogens should be warranted in Jeju-do.

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1701-1708
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• 2021

Food safety is the most important global health issue due to foodborne pathogens after consumption of contaminated food. Foodborne bacteria such as Escherichia coli, Salmonella enterica, Staphylococcus aureus, Campylobacter spp., Bacillus cereus, Vibrio spp., Yersinia enterocolitica and Clostridium perfringens are leading causes of the majority of foodborne illnesses and deaths. These foodborne pathogens often come from the livestock feces, thus, we analyzed fecal microbial communities of three different livestock species to investigate the prevalence of foodborne pathogens in livestock feces using metagenomics analysis. Our data showed that alpha diversities of microbial communities were different according to livestock species. The microbial diversity of cattle feces was higher than that of chicken or pig feces. Moreover, microbial communities were significantly different among these three livestock species (cattle, chicken, and pig). At the genus level, Staphylococcus and Clostridium were found in all livestock feces, with chicken feces having higher relative abundances of Staphylococcus and Clostridium than cattle and pig feces. Genera Bacillus, Campylobacter, and Vibrio were detected in cattle feces. Chicken samples contained Bacillus, Listeria, and Salmonella with low relative abundance. Other genera such as Corynebacterium, Streptococcus, Neisseria, Helicobacter, Enterobacter, Klebsiella, and Pseudomonas known to be opportunistic pathogens were also detected in cattle, chicken, and pig feces. Results of this study might be useful for controlling the spread of foodborne pathogens in farm environments known to provide natural sources of these microorganisms.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.1-16
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• 2008

Salmonella infections cause the disease in pigs but also some zoonotic Salmonella serotypes can be transmitted to human through swine products, resulting in food poisoning. The objective of this study was to investigate the bacteriological prevalence and detection of invA gene using Salmonella specific polymerase chain reaction (PCR), the epidemiological characteristics related to Salmonella strains cultured from pig samples in Gangwon areas using serotyping, random amplified polymorphic DNA (RAPD) and pulsed field gel electrophoresis (PFGE) methods. During the period of November 2001 through April 2002, 1,174 ileocecal lymph node were collected from the slaughtered pigs raised in 38 farms located in Gangwon province. The samples were submerged in boiling water and macerated in saline and lymph node homogenates were inoculated into Tetrathionate broth with iodine (TTB, Difco, 0.5% iodine was added) for enrichment growth. Then additional tests were performed using several mediums, and suspects were identified by API 20E kit (BioMerieux) and PCR. Of total 1,174 samples from 38 farms, 44 (3.7%) were isolated as Salmonella spp from 13 farms (34.2%). Of 44 isolates, 31 were in Yangyang region, followed by 9 in Goseong, 2 in both Gangneung and Sokcho. However, there was no difference in regional isolation frequency. All isolates have a 521bp amplified product in Salmonella specific PCR with primer invA which encodes in proteins for invasion of epithelial cells. Of 44 recovered serotypes, 23 (52.3%) were S Eingedi, 10 (22.7%) S Schwarzengrund, 9 (20.5%) S Typhimurium, and 2 (4.5%) S Mbandaka. In RAPD analysis, there appeared to be unique bands distinguishing each serotype, although similarities exist between the different serotypes. Four serotypes of 44 Salmonella isolates appeared to fall into 14 different RAPD types. In PFGE analysis, 9 S Typhimurium were tested with XbaI enzyme and SpeI enzyme. The combination of results obtained with two enzymes subdivided the 9 S Typhimurium into 4 PFGE types.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• Korean Journal of Veterinary Service
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• v.26 no.4
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• pp.313-321
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• 2003

During the period of December 2000 to November 2001, a total of 419(10.9%) Salmonella was isolated from 3,850 slaughtered pig samples(2,732 lymph nodes and 1,118 caecal contents) in Korea. Three hundred and seventy(13.5%) and 49(4.4%) Salmonella were isolated from lymph nodes and caecal contents, respectively. In the isolation ratio of Salmonella spp originated from each class of season, summer(15.7%), autumn(11.5%), spring(10.0%) and winter(8.3%), in order. As the result of serotyping, B group(67.5%) were the most common, in order of C$_1$(14.6%), D$_1$(6.0%), C$_2$(4.1%) and E$_1$(3.3%). 32 serovars were found, the major serotypes were as follows; S typhimurium(21.7%), S schwarzengrund(16.0%), S derby(15.8%), S typhimurium variant copenhagen(9.8%), S enteritidis (6.0%) and S mbandaka(6.0%). All of the isolates were susceptible to norfloxacin and ofloxacin. The isolates were resistant in order of doxycycline(69.2%), tetracycline(68.7%), penicliin(54.9%) and streptomycin(52.5%).

• Food Science of Animal Resources
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• v.27 no.1
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• pp.127-131
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• 2007

In order to investigate the presence of pathogenic bacteria in fresh pig loin and the growth changes of microorganism in raw ham during storage at 10 and $25^{\circ}C$. These hams were manufactured according to a short-ripening procedure being completed in 4 weeks with dry-curing followed by wet-curing and ripening. The result regarding the contamination level of microorganism in the fresh raw pig loin showed that the count of total aerobes was $3.11\;log\;CFU/cm^2$, and the population of lactic acid bacteria, Pseudomonas spp., Clostridium spp., and yeast and mould had not risen over $2\;log\;CFU/cm^2$ on the storage time. However, the average count ofEnterobacteriaceae in pork loin was $3.11\;log\;CFU/cm^2$, which represented the predominant species. The pathogenic bacteria including Salmonella spp, Staphylococcus aureus, Vibrio parahaemolyticus, Clostridium perfringene, Listeria monocytogenes, and Escherichia coli O157:H7 were not detected either in fresh pork loin or in raw ham products stored at 10 and $25^{\circ}C$. The initial count of total aerobes in raw ham samples was 3.06 log CFU/g, and increased slightly after 90 days at 10 and $25^{\circ}C$ to 4.6 and 4.69 log CFU/g, respectively. The predominant species in raw ham products during storage time were lactic acid bacteria and Staphylococcus spp.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.113-116
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• 2010

To determine the prevalence of Escherichia (E.) coli O157 : H7 from pigs after the Hazard Analysis and Critical Control Point (HACCP) system has been applied to Korean swine farm since 2006, 291 fecal samples were tested between May and December in 2008. Four E. coli O157:non-H7 (1.4%) were isolated from 4 different non-HACCP-accredited farms and they didn't have virulent genes which can cause illness for human. Also, Clostridium (C.) perfringens, Salmonella spp. and E. coli enterotoxins were tested using multiplex PCR. The positive rate for these pathogens of non-HACCP-accredited farms was higher than that of HACCP-accredited farms, and especially in case of C. perfringens, E. coli enterotoxins LT and STa, it was statistically significant (p < 0.05). Thus, the early implementation of the HACCP program is expected to greatly contribute to the safety of livestock products as well as food hygiene.

• Korean Journal of Veterinary Service
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• v.28 no.3
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• pp.215-223
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• 2005

The bacteria on the surface of slaughtered meat was monitored to investigate the relationships between microbiological quality and sanitation management in slaughter process of cattle and pig. It was conducted to evaluate the microbiological quality on the surface of slaughtered beef and pork in Seoul from January to December 2004. Two hundred and thirty three beef and 233 pork carcasses were surveyed on generic E coli counts and standard plate count for microbiological quality and Salmonella spp, Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens and E coli O157: H7 as pathogenic microorganisms. The prevalence of the excellent or good grade $(10^4\;CFU/cm^2)$ in beef and pork carcasses were $100\%\; and\;99.2\%$, respectively. The frequency of beef carcasses with less than $10^2\;CFU/cm^2$ of generic I coli counts was $100\%$, while that of pork carcasses was $99.6\%$. Of 233 beef carcasses, $1(0.42\%)$ was contaminated with L monocytogenes and $6(2.58\%)$ with C perfringens. Of 233 pork carcasses, $11(4.72\%),\;2(0.86\%),\;and\;2(0.86\%)$ were contaminated with L monocytogenes, C perfringens, and S aureus, respectively, Salmonella spp and E coli O157:H7 were not detected with all of the beef and pork carcasses. In conclusion, this study emphasized the Importance of relationship between microbiological quality and sanitation management in slaughter process of cattle and pig, in abattoirs.