• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.461-467
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• 1996

Four strains of lactic acid bacteria (LAB), that lower the pH of sausage $\leq$ 4.2 within 24 h of incubation at $37^{\circ}C$, were screened from 57 bacteriocin producing LAB which were isolated from kajamie shikhae and natural fermented sausages. The proteinaceous nature of the bacteriocin was confirmed by losing antimicrobial activity after pronase treatment. Inhibitory activity against pathogens, times of bacteriocin production and sensory tests were compared between 4 isolates and 3 commercial starters. Especially, strain NFS #8-1, screened from natural fermented sausage and identified as Pediococcus acidilactici, antagonized a large number of foodborne pathogens including Listeria monocytogenes, Aeromonas hydrophila, Bacillus cereus, Clostridium perfringens, Salmonella typhimurium and Staphylococcus aureus. Production of bacteriocin by strain NFS #8-1 was early in the growth phase (mid log phase) and its sensory acceptance was high. The feasibility of using strain NFS #8-1 as a starter for the production of microbiologically safe fermented sausage is envisaged.

• Journal of Veterinary Clinics
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• v.3 no.1
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• pp.277-298
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• 1986

This paper reviews the mechanisms effecting host defense in the mammary gland and assesses their possible in preventing of bovine mastitis. The streak canal is the first line of defense against invading mastitis pathogens, providing a physical barrier and antibacterial substances. The milk leukocytes are a second defense line by ingesting pathogens breached the streak canal by multiplication, physical passage, and propulsion during milking. Leukocytosis in milk and enhancement of the phagocytic defense machanisms of the udder were accomplished by inserting intramammary devices. Milk antibodies serum derived and synthesized in mamma tissue aggregate and opsonise bacteria, agglutinate and neutralise toxins, and inhibit. binding of bacteria to epitherial surfaces. Vaccination generally has been unsuccessful because protection is not absolute, but immunization is useful in controlling specific pathogens. Immunostimulant to enhance locally the protective nature of antibody-producing plasma cells concentrated in internal teat end tissue may be effective in reducing the occurrence of infection, but ineffective in preventing intramammary infections.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.709-717
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• 2015

Airborne bacteria from hog farms may have detrimental impacts on human health, particularly in terms of antibiotic resistance and pathogen zoonosis. Despite human health risks, very little is known about the composition and diversity of airborne bacteria from hog farms and hog-related spray fields. We used pyrosequencing analysis of 16S rRNA genes to compare airborne bacterial communities in a North Carolina hog farm and lagoon spray field. In addition, we isolated and identified antibiotic-resistant bacteria from both air samples. Based on 16S rRNA gene pyrosequence analysis, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla in airborne bacterial communities from both hog farm and spray field sites. Within the Firmicutes genera, Clostridium spp. were more abundant in the hog farm, whereas Staphylococcus spp. were higher in the spray field. The presence of opportunitic pathogens, including several Staphylococcus species and Propionibacterium acnes, was detected in both bioaerosol communities based on phylogenetic analysis. The isolation and identification of antibiotic-resistant bacteria from air samples also showed similar results with dominance of Actinobacteria and Proteobacteria in both hog farm and spray field air. Thus, the existence of opportunistic pathogens and antibiotic resistant bacteria in airborne communities evidences potential health risks to farmers and other residents from swine bioaerosol exposure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1268-1272
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• 2004

The 70% ethanol extract from cactus Chounnyouncho (Opuntia humifusa) was fractionated subsequently by hexan, chloroform, ethyl acetate, buthanol and water. The ethyl acetate fraction exhibited strong antimicrobial activities by paper disk diffusion method on the five strains of food born bacteria Bacillus subtilis, Staphylococcus aureus subsp. aureus, Escherichia coli, Salmonella typhimurium and Pseudomonas fluorescens. It has a heat resistance to show inhibitory effect after heat treatment at 11$0^{\circ}C$ for 1 hr. The ethyl acetate fraction showed almost perfect growth inhibition at over 700 ppm on the tested strains.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1060-1067
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• 2006

This study was undertaken to determine the effect of reservoirs on water quality and the distribution of pathogenic and indicator bacteria in a drinking water distribution system (total length 14km). Raw water, disinfected water, and water samples from the distribution system were subjected to physicochemical and microbiological analyses. Most factors encountered at each season included residual chloride, nitrate, turbidity, and phosphorus for heterotrophic bacterial distribution, and hardness, heterotrophic bacteria, sampling site, and DOC (dissolved organic carbon) for bacteria on selective media. No Salmonella or Shigella spp. were detected, but many colonies of opportunistic pathogens were found. Comparing tap water samples taken at similar distances from the water treatment plant, samples that had passed through a reservoir had a higher concentration of heterotrophic bacteria, and a higher rate of colony formation with 10 times as many bacteria on selective media. Based on the results with m-Endo agar, the water in reservoirs appeared safe; however, coliforms and opportunistic pathogenic bacteria such as Pseudomonas aeruginosa were identified on other selective media. This study illustrates that storage reservoirs in the drinking water distribution system have low microbiological water quality by opportunistic pathogens, and therefore, water quality must be controlled.

• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.77-87
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• 2017

Objectives: This study attempted to provide basic data necessary for a prevention promotion program for oral health management in college students. Methods: This study investigated general characteristics and subjective periodontal health status using a structured questionnaire and examined the distribution of bacteria related to periodontal disease in oral cavity by real-time PCR in subjects composed of 57 male and female college students. Results: It was statistically significant that P. gingivalis was detected more frequently in smokers with 25% compared to non-smokers with 6.1%, not detected in subjects that engaged in tooth brushing more than three times a day, and was detected in subjects that engaged in tooth brushing fewer than three times a day with 21.1%. Pathogens in saliva had significant correlations with each other (p<0.05, p<0.01, p<0.001). P. gingivalis showed positive correlations with T. forsythia, T. denticola, P. intermedia, and A. actinomycetemocmitans, and T. forsythia with P. intermedia, and A. actinomycetemocmitans. P. intermedia had a positive correlation with A. actinomycetemocmitans, and F. nucleatum with P. intermedia. Conclusions: Bacteria related to periodontal disease in oral cavities in college students were distributed in various ways, and smoking and the frequency of daily toothbrushing were found to be risk factors for the detection of bacteria.

• Journal of the Korean Society of Food Culture
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• v.15 no.1
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• pp.9-15
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• 2000

This study was conducted to investigate the antimicrobial activity of grapefruit extracts and polylysine mixture against food-borne pathogens. The mixture was showed a potent and quick antibacterial activity for 5 major bacteria causing food poisoning i.e. Escherichia coli, Escherichia coli O-157, Salmonella typhi, Staphylococcus aureus, Vibrio cholerae. The antibacterial effect of the mixture on the ordinary bacteria inhibiting on the surface of lettuce was lasted even 6 hrs after the treatment, however the mixture was non-effective on the color, smell and taste of lettuce. The treatment with 10% mixture solution of the foods such as fish, meat, rice and bread suppressed the growth of the bacteria and kept the foods more freshly than the untreated foods.

• Clinical and Experimental Pediatrics
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• v.64 no.6
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• pp.260-268
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• 2021

Since the 2000s, the major causes of acute gastroenteritis in children in Korea have been identified by classifying the pathogens into viruses, bacteria, and protozoa. For viruses, the detection rate is 20%-30%, and norovirus is being increasingly detected to account for the majority of viral gastroenteritis cases. In addition, despite the dissemination of the rotavirus vaccine, many rotavirus infections persist, and its seasonal distribution is changing. The detection rate of bacterial pathogens is 3%-20%, with Escherichia coli and Salmonella spp. infections being the most common, while the incidences of Bacillus cereus and Campylobacter spp. infections are gradually increasing. Owing to intermittent outbreaks of gastroenteritis caused by individual bacteria as well as the inflow of causative bacteria, such as E. coli, Vibrio spp., and Campylobacter spp., from overseas, continuous surveillance of and research into the characteristics and serotypes of each bacterium are needed.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.462-468
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• 2013

Jeotgal is a generic term given to the high-salt-fermented seafood of Korea. This study aimed at developing an overview of the bacterial community present in Ojingeo-jeotgal, a highly consumed type of jeotgal, which is made with squid. Bacteria were isolated and purified from two samples on six different kinds of media and identified by 16S rRNA gene sequence analysis. Among the 121 total isolates, the most dominant genus was Bacillus, followed by coagulase-negative staphylococci (CNS) and lactic acid bacteria (LAB). CNS were detected in both samples, but LAB were observed in only a single sample. Six strains of Bacillus species inhibiting the growth of food pathogens, Staphylococcus aureus and Vibrio parahaemolyticus, were selected from the 121 isolates. These were found to inhibit the growth of both pathogens in addition to displaying proteolytic activities on media containing 6% NaCl and 2% skim milk.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.493-504
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• 2017

Objectives: This study aimed to find out the antimicrobial activities of Ramaria botrytis (Fr.) extracts against oral pathogens. Methods: The antimicrobial activities of Ramaria botrytis (Fr.) extracts were evaluated against oral pathogens by the disc diffusion assay, and the minimum inhibitory concentrations (MICs) of ethyl acetate extracts were determined by broth dilution method. The strains used in this study were Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Streptococcus anginosus, Streptococcus ratti, Streptococcus criceti, Actinomyces israelii, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. Results: The ethyl acetate extract of Ramaria botrytis (Fr.) effectively inhibited the growth of oral bacteria compared with acetone or ethanol extract. The ethyl acetate extract exhibited MIC values ranging from 3.75 to 15.00 mg/ml, and it showed antimicrobial activity against both Gram-positive and negative oral bacteria. Conclusions: The ethyl acetate extracts from Ramaria botrytis (Fr.) showed the antimicrobial activities against ten oral bacteria. Thus, the extract of Ramaria botrytis (Fr.) may be considered as an effective natural antimicrobial agent for the prevention of oral pathogens.