• Food Science and Preservation
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• v.13 no.2
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• pp.246-251
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• 2006

Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm produce because most of the compose are originated from excrementitious matters of domestic animals. Irradiation was performed to improve microbiological safety of organic compost and the effectiveness of gamma-irradiation for inactivating Salmonella typhimurium and E. coli was investigated. Total aerobic bacteria and coliform bacteria in 16 produce or commercial compose were ranged from $10^5\;to\;10^7\;CFU/mL\;and\;0\;to\;10^3\;CFU/mL$, respectively. All coliform bacteria in the composts were eliminated by irradiation at 5 kGy, while about $10^2\;CFU/mL$ of total aerobic bacteria survived up to 10 kGy of irradiation. In the inoculation test the test organisms (inoculated at $10^7\;CFU/mL$) were eliminated by irradiation at 3 kGy. $D_{10}$ values of inoculated Salmonella typhimurium and E. coli in the compost were $0.4{\pm}0.05\;and\;0.39{\pm}0.03kGy$. It was considered that $3{\sim}5kGy$ of gamma irradiation was effective for radicidation (radiation sterilization of pathogenic microbes) of organic fertilizer.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.856-861
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• 2002

Surface-modified powders were produced by hybridization system using core freeze-dried lactic acid bacteria (Lactobacillus acidophilus ATCC 43121) and enteric coating materials. Scanning electron microscopy showed that the surface of freeze-dried lactic acid bacteria changed to smooth round shape during surface reforming process, although no significant physical damages affecting the activity of the lactic acid bacteria were observed based on viability and salt-tolerance tests. Signigicant difference was not found in acid tolerance test probably due to the inherent acid tolerance of L. acidophilus ATCC 43121. Significantly improved heat tolerance was obtained by surface modification process. Among the tested coating materials, Sureteric showed a higher surface- reforming ability than Eudragit S100 and L100-55. Core : coating ratio agent of 9 : 1 (w/w) with rotor speed of 15,000 rpm for 3 min were determined to be optimum conditions for the process.

• The Journal of the Korean Society for Microbiology
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• v.14 no.1
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• pp.17-25
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• 1979

Bacteriologic diagnosis of enteric infection remains to be an important role of clinical laboratory because of the prevalence of the infection. Often the determination of etiologic agent and its susceptibility to antibiotics are of vital importance for a proper management of the infection. In our previous paper, an analysis of the isolation of enteric pathogens for the years 1969-73 was reported to clarify the status of those years. The present analysis was made based on the data obtained during the years 1974-78, to see if any change of the status was rendered. 1. During the 5-year period, from the cultures of 7,308 stool or rectal specimens 833 patients yielded enteric pathogens: 468 Shigella, 295 Salmonella, 30 Vibrio parahaemolyticus and 40 enteropathogenic Escherichia coli(EPEC). 2. Of the 295 Salmonella, 271 were S. typhi Isolation of 12 S.paratyphi-A, 1 Salmonella group B, 4 group C, 5 group D and 2 group E meant a definite increase of these sero-groups, S. typhi was most frequently isolated in August and in December, and from 30- to 39-year-old patients. 3. Of the 468 Shigella, 10 were subgroup A, 338 subgroup B, 3 subgroup C and 117 subgroup D. Most of the subgroup B belonged to type 1,2, or 3. The proportion of S. sonnei decreased from 31.3% in 1974 to 18.2% in 1978. In foreign patients, S. sonnei remained to be the frequntly isolated species. Shigella isolation was frequent in August and in 2- to 5-year-old patients. 4. V. parahaemolyticus was isolated from 30 and EPEC from 40 patients. 5. Ninty-nine per cent and 99.5% of the S. typhi isolates were susceptible to chloramphenicol and to ampicillin respectively. 92.8% of S sonnei were susceptible to ampicillin. S. flexneri type 2 was notable for their markedely decreased proportion being susceptible to ampicillin: 84.4% in 1974 and 25.6% in 1978.

• The Journal of the Korean Society for Microbiology
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• v.19 no.1
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• pp.41-48
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• 1984

The present study was undertaken to elucidate the antibacterial spectrum of L. casei phage type $J_1$ strain isolated from a fermented milk product against pathogenic enteric bacteria. Growth inhibitory effects and minimum inhibitory concentration(MIC) of culture supernatants of L. casei grown in MRS broth were measured by both plate culture method and microplate broth dilution technique against Salmonella typhi, Salmonella typhimurium, Shigella flexneri, Shigella dysenteriae, enterpathogenic E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The results are summarized as follows: 1. The MRS broth culture of L. casei gave a similar extent of growth inhibitory effects against S. typhi, S. typhimurium, S. flexneri, S. dysenteriae, E. coli, K. pneumoniae and P. aeruginosa, respectively. 2. The inhibitory effects of L. casei culture were observed either in whole broth culture or in culture supernatant, but neither the bacterial suspension nor the neutralized culture supernatant showed such as antibacterial activities. 3. The MIC titres of the culture supernatants were ${\log_2}5$ to ${\log_2}6$, whereas those of the neutralized culture supernatant dropped markdely to ${\log_2}2$ to ${\log_2}3$. These results indicated that major portion of growth inhibitory effects of MRS broth culture of L. casei against enteric bacterial pathogens was possibly due to the acids produced, and minor portion to other antibacterial substances.

• Journal of Environmental Health Sciences
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• v.48 no.3
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• pp.176-182
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• 2022

Background: The risk of imported infectious diseases has been increasing with the annual rise in the number of international travelers. Objectives: This study aims to analyze the distribution and characteristics of intestinal bacteria isolated in 2019 from residents of Chungcheongnam-do Province with experience of travelling overseas. Methods: Twenty-three former overseas travelers with diarrhea were analyzed to detect viruses and bacteria according to the Manual for Detection of Foodborne Pathogens at Outbreaks. Additionally, antibiotic susceptibility tests and 16s rRNA sequencing were performed. Results: Twenty-five strains of ten pathogens were isolated from 18 samples. Pathogenic E. coli was the most common at 57.7%, followed by Clostridium perfringens (15.4%), Campylobacter spp. (7.7%), and Salmonella spp. (7.7%). The serotype of Salmonella was confirmed as Salmonella Braenderup, II 9,46:g,[m],[s],t:[e,n,x]. Conclusions: It was confirmed that the major enteric bacterial pathogens isolated from overseas travelers in Chungcheongnam-do Province were pathogenic E. coli, as found in other studies. The study on Plesiomonas shigelloides is meaningful in that it is reported as a rare case of infection in Korea. Antibiotic resistance and 16s rRNA analysis were performed, which is expected to provide important basic data for the prevention of traveler's diarrhea.

• Korean Journal of Veterinary Service
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• v.17 no.3
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• pp.174-180
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• 1994

The disease syndrome characterized by the acute vomiting and diarrhea with high mortality had been greatly epidemic in Kyungbuk West Area since March 1990 and it was followed serologically for the classification of the agent. The agent present in feces of dogs associated with this syndrome had characteristic feature in agglutinating pig red blood cells that was specifically inhibited by anti-CPV reference dog serum. This also showed the serological identity with the reference CPV antigen in Hemagglutinating inhibition test. The result obtained were summarized as follows : 1. During 5 years(March. 1990∼September. 1994), 1,470 dogs were investigated on the actual condition of CPV infections. The Infection rate of CPV from dogs was 62.5% and mortality rate was 59.8%. 2. Among 24 fecal samples collected from the dogs with enteric disease, all showed the hemagglutinating activity to porcine erythrocyte ranging from 40 to 5,120 of HA titers. 3. Among 12 sera samples collected from the dogs with enteric disease, all showed the serological identity with the reference CPV antigen from 5 to 5,120 of HI titers. 4. Bacteriologic examination of fecal specimens resulted in the isolation of pathogeric bacteria such as Staphylococcus sp, Streptococcus sp, Escherichia coli and Bacillus. Cultures for salmonella sp and Clostridium remaind negative. 5. The prevalence and identification of internal parasites were determined by fecal examination using the floatation methods. From 20 fecal samples 12(60.0%) were isolated and their species were Toxacara canis, Toxascaris leonina, and coccidium.

• Journal of Wetlands Research
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• v.16 no.1
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• pp.33-39
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• 2014

The purpose of this study is to monitor the rainwater flowing from the roof of buildings and to maximize the effectiveness of the rainwater storage. This study also analyses the changes in rainwater characteristics before and after subsequent chlorination disinfection. The stored rainwater was disinfected by chlorine and then analyzed for COD, TN, TP, enteric bacteria, and general microbial population changes over time. There was an observed 99% reduction of enteric bacteria and common microbes within two weeks after chlorine injection. Thus, chlorine disinfection of rainwater improves water quality for long-term storage and future use.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.289-295
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• 2019

Acute diarrhea is a global health problem that causes high morbidity and mortality in children. Notably, enteric pathogen co-infections have been suggested to play an important role in gastroenteritis. In this study, we analyzed 1150 stool specimens of patients who visited the pediatric ward of Dongguk University Hospital in Gyeongju province from January 2011 to December 2017. The average isolation rate of potential stool pathogens over 7 years was 37.3% (429/1150), and coinfections were observed in 51 patients (51/429; 11.9%). In the 51 co-infection cases, the most frequent type of co-infection was found to be that of virus-bacteria (33/51). The most frequently detected bacterial pathogen among the co-infected cases was Clostridium spp. (22/51), out of which Clostridium perfringens was found to be the main pathogen (16/22; 72.7%). Escherichia coli spp. were the second most common bacterial pathogens found in 12 cases (12/51; 23.5%), with 10 cases of E. coli EPEC. Furthermore, the most frequently implicated viral pathogen among the co-infected cases was norovirus (16/51), followed by rotavirus (12/51).

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.414-422
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• 2001

Antibiotic resistance in human pathogens is a major public health issue. Some of the resistance problem can be attributed to the transfer of resistant bacteria from animals to people and the transfer of resistance genes from animal pathogens and commensal bacteria to human pathogens. Control measures include improvements in food hygiene to reduce the spread of zoonotic bacteria to people via the food chain. However, to specifically address the issue, the medical profession must control misuse and overuse of antibiotics in hospitals and community practice. In addition, the livestock industries and their advisors must reduce and refine the use of antibiotics in animal production and replace antibiotics with alternative disease control measures as much as possible.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.417-422
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• 1986

The specimens were collected from 89 diarrheal patients who had visited Pusan National University Hospital from June to September 1985. They were cultured and tested for the bacteriological identification of causative agents. In this study we identified 5 strains of Salmonella species, 5 strains of Shigella species, 2 strains of Y. enterocolitica, and 17 strains of enteric pathogenic E. coli. Enteric pathogenic E. coli were classified into enterotoxigenic E. coli, enteropathogenic E. coli, and enteroinvasive E. coli by serological type. We tried to isolate V. cholerae and V. parahaemolyticus too but we cannot find them out.