• Journal of the East Asian Society of Dietary Life
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• v.9 no.2
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• pp.214-222
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• 1999

Prunus mume has been used for the folk medicine by many old civilizations to treat food-borne diseases or enteric disorders. The purpose of this study was to investigate the antimicrobial activity of beverages containing Prunus mume extracts against Staphylococcus aureus, Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Escherichia coli and Pseudomonas aeruginosa. Seven different types of Prunus mume extracts containing beverages have been prepared for the test in which minimum inhibitory concentration for each microorganism has been determined by serial dilution method using either TSA or TSB medium. Pseudomonas aeruginosa showed least resistance and 0.3g/$m\ell$ concentrations of 5% Prunus mume extracts containing beverage had antimicrobial property against the organism. Beverages containing more than 15% of Prunus mume extracts showed antimicrobial activity against all tested microorganisms at the MIC value of less than 0.25g/$m\ell$. The effect of Prunus mume on the growth of food-borne pathogens has been also studied using a spectrophotometer. In the growth assay, each of the Prunus mume extracts containing beverage was added to the medium at the concentration of 25% (v/v). Beverage containing 20% Prunus mume extracts showed inhibitory effect on the growth of all tested microorganisms.

• Journal of Microbiology
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• v.45 no.4
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• pp.326-332
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• 2007

In order to understand the functional role of CPRl in Saccharomyces cerevisiae KNU5377 with regard to its multi-tolerance characteristics against high temperatures, inorganic acids, and oxidative stress conditions, whole cellular proteins were analyzed via liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). This procedure was followed by two-dimensional (2-D) gel electrophoresis. Under menadione stress conditions, the 23 upregulated proteins were clearly identified only in the wild- type strain of KNU5377. Among the proteins, Sodl1p Tsa1p, Ahp1, Cpr1p, Cpr3, Ssb2p, and Hsp12p were identified as components of antioxidant systems or protein-folding related systems. The CPR1 protein could not be completely detected in the $cpr1{\Delta}$ mutant of KNU5377 and the other upregulated proteins in the wild-type strain evidenced a clear correlation with the results of immunoblot analysis. Moreover, a reduction in growth patterns (about 50%) could be observed in the $cpr1{\Delta}$ mutant, as compared with that of the wild-type strain under mild MD stress conditions. These results indicate that the upregulation of CPR1 may contribute to tolerance against MD as an inducer of oxidative stress.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.317-322
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• 2019

Gastroenteritis with diarrhea is one of the most infectious diseases in the world following respiratory infections. Notably, diarrhea-causing viruses (DVs) cause more than 70% of such cases. In this study, 3,065 stool specimens from patients with diarrhea (median age, 1.1 years; range, 0.0-91.1 years), who were admitted to the DanKook University Hospital, were examined using multiplex reverse transcription PCR (mRT-PCR). The target viruses were astrovirus (AstV), enteric adenovirus (EAdV), group A rotavirus (RotV), norovirus GI (NoV-GI), and norovirus GII (NoV-GII). The mRT-PCR results were analyzed based on various factors such as seasonality, age, presence of co-infection, and analyzed trends. The detection rate of the DVs during the study period was found to be 30.8% (n = 943/3,065). When the detection rate was analyzed monthly, the DV detection rate was found to be highest between December to January. Of the detected DVs, NoV-GII was the most common, accounting for 45.5% of the detected viruses (n = 446/980). Notably, 86.5% (n = 848/980) of the pathogens were detected in individuals who were less than 5 years of age. During the study period, NoV-GII and RotV showed alternating trends. In addition, both the number and rate of co-infections increased.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.388-396
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• 2023

Entamoeba histolytica is an enteric tissue-invasive protozoan parasite causing amoebic colitis and liver abscesses in humans. Amoebic contact with host cells activates intracellular signaling pathways that lead to host cell death via generation of caspase-3, calpain, Ca²⁺ elevation, and reactive oxygen species (ROS). We previously reported that various NADPH oxidases (NOXs) are responsible for ROS-dependent death of various host cells induced by amoeba. In the present study, we investigated the specific NOX isoform involved in ROS-dependent death of hepatocytes induced by amoebas. Co-incubation of hepatoma HepG2 cells with live amoebic trophozoites resulted in remarkably increased DNA fragmentation compared to cells incubated with medium alone. HepG2 cells that adhered to amoebic trophozoites showed strong dichlorodihydrofluorescein diacetate (DCF-DA) fluorescence, suggesting intracellular ROS accumulation within host cells stimulated by amoebic trophozoites. Pretreatment of HepG2 cells with the general NOX inhibitor DPI or NOX2-specific inhibitor GSK 2795039 reduced Entamoeba-induced ROS generation. Similarly, Entamoeba-induced LDH release from HepG2 cells was effectively inhibited by pretreatment with DPI or GSK 2795039. In NOX2-silenced HepG2 cells, Entamoeba-induced LDH release was also significantly inhibited compared with controls. Taken together, the results support an important role of NOX2-derived ROS in hepatocyte death induced by E. histolytica.

• Tuberculosis and Respiratory Diseases
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• v.71 no.6
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• pp.476-479
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• 2011

The Streptococcus milleri group, which also includes S. anginosus, S. intermedius and S. constellatus, is found in the oropharynx, upper respiratory tract, gastrointestinal tract, and urogenital tract mucosa. Bacteria in the Streptococcus milleri group are associated with bacteremia and abscess formation. Most of the reports of of Streptococcus milleri group (SMG) infection occur in patients with underlying medical conditions. Predisposing factors that have been associated with S. milleri group empyema include mucosal disturbances (sinusitis, periodontal disease, enteric disease), preceding to pneumonia, thoracic surgery, malignancy, neurological disease, alcohol abuse, and also diabetes mellitus. We report on a 42-year-old man with mental retardation. He who suffered from dyspnea and a fever that he had developed for over 14 days. S. constellatus and anaerobic bacterias (Prevotella buccae and Micromonas micros) were cultured. The patient was treated with the drainage of pleural effusion and clindamycin and levofloxacin.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.145-150
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• 2016

In order to perform an epidemiological characterization of opportunistic mycosis infections, we collected health insurance data between the years 2006 and 2010 from the Health Insurance Corporation and analyzed the data to determine the prevalence of opportunistic mycoses and treatment management of opportunistic mycoses. The prevalence within the study increased consecutively by 0.02% to 0.12% every year. The annual prevalence of opportunistic mycoses increased from 2.437% in 2006 to 2.709% in 2010. The average annual prevalence was 2.605%. Candidiasis occurred the most frequently, followed by aspergillosis, zygomycosis, and cryptococcosis. The regions with the highest incidences were the capital areas, Gyeonggi and Seoul. By sex, the prevalence in females (4.851%) was 14 times higher than that in males (0.352%). Interestingly, the adults from the 20- to 49-year-old age group showed higher prevalence than children and the elderly. The average duration of hospitalized treatment was 17.31 days and of outpatient treatment was 2.21 days; 3,577 hundred million won was used in total for medical expenses. This study provides useful data to study trends of opportunistic mycoses.

• Journal of Microbiology and Biotechnology
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• v.25 no.12
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• pp.2043-2048
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• 2015

Bacillus thuringiensis microbial insecticide products have been applied worldwide. Although a few cases of B. thuringiensis foodborne illness have been reported, little is known about the toxigenic properties of B. thuringiensis isolates. The aims of this study were to estimate the pathogenic potential of B. thuringiensis selected from microbial insecticide products, based on its possession of toxin genes and production of enterotoxins. Fifty-two B. thuringiensis strains selected from four kinds of microbial insecticide products were analyzed. PCR assay for detection of toxin genes and immunoassay for detection of enterotoxins were performed. The hemolysin BL complex as a major enterotoxin was produced by 17 (32.7%), whereas the non-hemolytic enterotoxin complex was detected in 1 (1.9%) of 52 B. thuringiensis strains. However, cytK, entFM, and ces genes were not detected in any of the tested B. thuringiensis strains. The potential risk of food poisoning by B. thuringiensis along with concerns over B. thuringiensis microbial insecticide products has gained attention recently. Thus, microbial insecticide products based on B. thuringiensis should be carefully controlled.

• Journal of Microbiology
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• v.43 no.2
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• pp.133-143
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• 2005

Shigellosis is a global human health problem. Four species of Shigella i.e. S. dysenteriae, S. flexneri, S. boydii and S. sonnei are able to cause the disease. These species are subdivided into serotypes on the basis of O-specific polysaccharide of the LPS. Shigella dysenteriae type 1 produces severe disease and may be associated with life-threatening complications. The symptoms of shigellosis include diarrhoea and/or dysentery with frequent mucoid bloody stools, abdominal cramps and tenesmus. Shigella spp. cause dysentery by invading the colonic mucosa. Shigella bacteria multiply within colonic epithelial cells, cause cell death and spread laterally to infect and kill adjacent epithelial cells, causing mucosal ulceration, inflammation and bleeding. Transmission usually occurs via contaminated food and water or through person-to-person contact. Laboratory diagnosis is made by culturing the stool samples using selective/differential agar media. Shigella spp. are highly fragile organism and considerable care must be exercised in collecting faecal specimens, transporting them to the laboratories and in using appropriate media for isolation. Antimicrobial agents are the mainstay of therapy of all cases of shigellosis. Due to the global emergence of drug resistance, the choice of antimicrobial agents for treating shigellosis is limited. Although single dose of norfloxacin and ciprofloxacin has been shown to be effective, they are currently less effective against S. dysenteriae type 1 infection. Newer quinolones, cephalosporin derivatives, and azithromycin are the drug of choice. However, fluoroquinolone-resistant S. dysenteriae type 1 infection have been reported. Currently, no vaccines against Shigella infection exist. Both live and subunit parenteral vaccine candidates are under development. Because immunity to Shigella is serotype-specific, the priority is to develop vaccine against S. dysenteriae type 1 and S. flexneri type 2a. Shigella species are important pathogens responsible for diarrhoeal diseases and dysentery occurring all over the world. The morbidity and mortality due to shigellosis are especially high among children in developing countries. A recent review of literature (KotIoff et al.,1999) concluded that, of the estimated 165 million cases of Shigella diarrhoea that occur annually, $99\%$ occur in developing countries, and in developing countries $69\%$ of episodes occur in children under five years of age. Moreover, of the ca.1.1 million deaths attributed to Shigella infections in developing countries, $60\%$ of deaths occur in the under-five age group. Travellers from developed to developing regions and soldiers serving under field conditions are also at an increased risk to develop shigellosis.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.777-780
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• 1995

Salmonellosis is one of communicable disease and still occur in sporadic in Korea frequently. They are four main clinical manifestations in salmonellosis. They are gastrocnteritis, typhoidal or septisemia syndrome, focal manifestation and carrier state. Among them, focal manifestation is rarely seen. Saphra, et al. reported that localized salmonella infection is about 5%. Localized salmonella infection frequently occur during salmonella bacteremia, but may also occur with enteric fever or gastroenteritis. Gray, et al reported 3390 cases of minor gunshot wound infection that bacterial isolates from infected wounds consisted of Staphylococcus aureus(90%), Streptococcus sp.(6%), and mixed organisms(4%). Incresed host susceptibility to infection secondary to lowered resistance due to debilitating disease is an important determinant of Salmonella infection. Since salmonella is seldom suspected as a cause of soft tissue infections, there is usually a dangerous delay in the institution of appropriate antimicrobial therapy and isolation procedure. We experienced one case of subcutaneous salmonella abscess developed on gunshot wound area in lung cancer patient, which was confirmed by pus culture.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.323-327
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• 2011

Fecal specimens from acute gastroenteritis in Seoul from 2009 to 2010 were collected and then tested for the presence of Group A Rotavirus by ELISA. Among a total of 1,916 samples investigated, 354 samples (18.4%) were positive. The predominant genotypes of positive samples were confirmed as P6G[4] (35%), P8G[3] (28%), P8G[1] (24%), P4G[2] (10%), P8G[9] (3%), respectively. Among a total of 70 ground water samples investigated, 2 samples (2.8%) were positive. The genotypes of positive samples were confirmed as P8G[3] (100%). By this molecular investigation, genotypic distribution associated with rotavirus will be used for control and prevention of rotavirus related diseases.