• Tuberculosis and Respiratory Diseases
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• v.53 no.1
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• pp.5-16
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• 2002

Background : Though mononuclear phagocytes serve as the final effectors in killing intracellular Mycobacterium tuberculosis, the bacilli readily survive in the intracellular environment of resting cells. The mechanisms through which cellular activation results in the intracellular killing is unclear. In this study, we sought to explore an in vitro model of a low-level infection of human mononuclear phagocytes with MAC and $H_{37}Ra$ and determine the extent of the lymphocyte dependent cytotoxicity of human monocytes and alveolar macrophages. Materials and Methods : The peripheral monocytes were prepared using the Ficoll gradient method from PPD positive healthy people and tuberculosis patients. The alveolar macrophages were prepared from PPD positive healthy people via a bronchoalveolar lavage. The human mononuclear phagocytes were infected at a low infection rate (bacilli:phagocyte 1:10) with MAC(Mycobacterium avium) and Mycobacterium tuberculosis $H_{37}Ra$. Non-adherent cells(lymphocyte) were added at a 10:1 ratio. After 1,4, and 7 days culture in $37^{\circ}C$, 5% CO2 incubator, the cells were harvested and inoculated in a 7H10/OADC agar plate for the CFU assay. The bacilli were calculated with the CFU/$1{\times}10^6$ of the cells and the cytotoxicity was expressed as the log killing ratio. Results : The intracellular killing of MAC and $H_{37}Ra$ within the monocyte was greater in patients with tuberculosis compared to the PPD positive controls (p<0.05). Intracellular killing of MAC and $H_{37}Ra$ within the alveolar macrophage appeared to be greater than that within the monocytes of the PPD positive controls. There was significant lymphocyte dependent inhibition of intracellular growth of the mycobacteria within the monocytes in both the controls and tuberculosis patients and within the macrophages in the controls(p<0.05). There was no specific difference in the virulence between the MAC and the $H_{37}Ra$. Conclusion : This study is an in vitro model of a low-level infection with MAC and $H_{37}Ra$ of human mononuclear phagocytes. The intracellular cytotoxicity of the mycobacteria within the phagocytic cells was significantly lymphocyte dependent. During the 7 days culture after the intracellular phagocytosis, the actual confinement of the mycobacteria was observed within the monocytes of tuberculosis patients and the alveolar macrophages of the controls as in the case of adding lymphocytes.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.667-676
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• 2008

This experiment was conducted to investigate the effects of dietary supplementation of various Lactobacilli strains on growth performance, intestinal microflora, ileal villi development and ileal mucosal surface of broiler chickens. Six hundred 1-d-old male chicks(Avian) were randomly divided into five groups of four replicates, each replicates containing 30 birds and fed corn-soybean meal diets containing Latobaillus were isolated from cecum of chichens at 107cfu/g diet for five weeks. The treatments were control(antibiotics-free diet), Lactobacillus crispatus avibro1(LCB), Lactobacillus reuteri avibro2(LRB), Lactobacillus crispatus avihen1(LCH) or Lactobacillus vaginalis avihen2(LVH). The body weight gain in groups fed Lactobacillus significantly improved as compared to those of control(P<0.05). Feed intake was not statistically different among the groups. The number of Lactobacillus in ileum and cecum of chicks fed various Lactobacillus tended to be increased or significantly increased as compared to those of the control(P<0.05), but there was difference by age of chicks and species of Lactobacillus. The number of yeast was significantly increased in cecum and ileum at three weeks old chicks fed Lactobacilli compared with the control(P<0.05). The anaerobes’ number of ileum and cecum tended to increase or significantly increased in Lactobacillus treatments compared with the control(P<0.05). The ileal villi length extended greatly at three weeks of age in groups fed Lactobacillus compared with the control(P<0.05). The length of ileal villi in chicks fed Lactobacillus was continuously increased up to five weeks of age, but did not increased in the control(P<0.05). Lactobacillus was found on ileal mucosal surface. And ileal mucosal surface was maintained better with Latobacillus feeding. These results suggest the possibility that cecal Lactobacillus of chickens could be used as probiotics by improving the growth performance and promoting development of ileal villi in broiler chicks.

• Childhood Kidney Diseases
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• v.17 no.1
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• pp.19-24
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• 2013

Purpose: Recently, enterococcus spp. have become one of the most common nosocomial pathogens with increasing rates of multi-drug resistance. However, study on enterococcal urinary tract infections (UTIs) in children is very limited, especially community acquired UTIs. We studied the clinical characteristics of enterococcus spp. in community acquired UTIs and antibiotic resistance within our urban area. Methods: All children with first episode of community acquired UTIs due to enterococcus spp. and Echerichia coli who were admitted in Pusan National University Children's Hospital between January 2010 and January 2013 were included in our study. We retrospectively reviewed their medical records. Results: During the study period, 201 patients were identified to have first episode of community acquired UTIs. 154 cases were E.coli UTIs (76.6%) and 11 cases were enterococcal UTIs (5.5%) and all enterococcus spp. were Enterococcus feacalis. In enterococcal UTI group, voiding cystourethrogram(VCUG) was performed in 7/11 patients and demonstrated 4 vesicoureteral refluxes (VURs) with renal scar and 3 patients underwent corrective surgery. In E.coli UTI group, VCUG was performed in 121/154 patients and demonstrated 23 VURs and 11 patients underwent corrective surgery. Enterococcal group had significant high rate of underlying urinary abnormalities and surgical corrections compared with E. coli group. All enterococcus spp. were susceptible to ampicillin, vancomycin and linezolid, but all were resistant to tetracycline. They also showed 71.4% resistance to trimethoprim-sulfamethoxazole and 20% resistance to ciprofloxacin. Conclusion: Community acquired enterococcal UTIs in children were rare within our urban area. However, they could be indicative of severe underlying urinary tract abnormalities.

• Food Science and Preservation
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• v.22 no.6
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• pp.920-925
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• 2015

The microbial composition in Nuruk, a Korean cereal fermentation starter, is a critical factor for the quality and organoleptic properties of traditional alcoholic beverages. This study was aimed at monitoring the compositional change and enzyme activity of culturable lactic acid bacteria (LAB) in two types of Nuruk fermented at different temperatures. All culturable LAB were isolated at various time points (0, 3, 6, 10, 20, and 30 days) and identified by 16S rRNA sequencing. In traditional Nuruk type A (TN-A), which was fermented at $36^{\circ}C$, the population of total culturable LAB during the fermentation period was between $10^4$ and $10^5$ log CFU/mL. On the other hand, the LAB population in traditional Nuruk type B (TN-B) fermented at $45^{\circ}C$ (primary fermentation for 10 days) and $35^{\circ}C$ (secondary fermentation for 20 days) was $10^2$ log CFU/mL; however, these bacteria could not be detected after 6 days. Major LAB strains were identified in both Nuruk types: (1) from the MRS-culture of TN-A, Pediococcus pentosaceus at 3-30 days; (2) from MRS-culture of TN-B, P. pentosaceus at 3 days and Enterococcus hirae at 6 days. The protease activities of the dominant LAB isolated from the TN-A and TN-B cultures were within the ranges of 0.64~1.03 mg/mL and 0.74~0.81 mg/mL (tyrosine content), respectively, whereas the ${\alpha}$-amylase activities were 0.75~0.98 mg/mL and 0.78~0.79 mg/mL (amylose content), respectively.

• Journal of Life Science
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• v.24 no.6
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• pp.664-670
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• 2014

In the present study, we investigate the role of V. vulnificus in promoting the inflammation of mouse ileal ephitelium and its related signaling pathways. ICR mice were infected orally with V. vulnificus ($1{\times}10^9CFU$) for 16 h as a representative model of food-borne infection. To find the major portal of entry of V. vulnificus in mouse intestine, we have measured the levels of bacterial colonization in small intestine, colon, spleen, and liver. V. vulnificus appeared to colonize in intestine and colon in the order of ileum >> jejunum> colon, but lack in the duodenum, spleen, and liver. V. vulnificus in ileum caused severe necrotizing enteritis and showed shortened villi heights accompanied by an expanded width and inflammation, compared with the control mice. V. vulnificus induced ileal epithelium inflammation by activating phosphorylation of PKC and membrane translocation of $PKC{\alpha}$. V. vulnificus induced the phosphorylation of ERK and JNK, but did not affect p38 MAPK phosphorylation. Notably, V. vulnificus stimulated the I-${\kappa}B$-dependent phosphorylation of NF-${\kappa}B$ in mouse ileal epithelium. Finally, the ileal infection of V. vulnificus resulted in a significant increase in expression of proinflammatory cytokines and Toll-like receptors, respectively, compared to the control. Collectively, our results indicate that V. vulnificus induces ileal epithelium inflammation by increasing NF-${\kappa}B$ phosphorylation via activation of PKC, ERK, and JNK, which is critical for host defense mechanism in food-borne infection by V. vulnificus.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.296-301
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• 2014

Rotavirus is a major cause of acute gastroenteritis in young children in developed and developing countries. The use of probiotics for the treatment of gastrointestinal diseases is both safe and easily accessible. In this study, we evaluated the anti-rotaviral activities of probiotic mixtures in a Sprague-Dawley rat. 24 litters with their dams were randomly assigned to four groups; placebo, phosphate buffered saline (PBS), and two probiotic mixture (PRO-1 and PRO-2) groups. All rats were inoculated with rotavirus at dose of 8 log plaque forming units per rat at 5 days old. Animals in the PRO-1 and PRO-2 groups were orally administered probiotic mixtures 1 or 2, respectively, at a dose of 8 log colony forming units daily during 4 days. For control purposes, placebo and PBS groups were orally administered the same amount of placebo (containing maltose and polydextrose) or PBS once daily for 4 days, respectively. Antiviral analysis was performed by real-time quantitative PCR (RT-qPCR) and observing intestinal villi. As a result, weights of small intestines were greater in the PRO-1, PRO-2 groups than in control groups. Villi were short and villous epithelial necrosis was exhibited in control groups, but these morphological changes were not observed in PRO-1, PRO-2 treated rats. RT-qPCR analysis showed that VP7 gene level of rotavirus in fecal samples and small intestinal epithelial cells were lower in the PRO-1 and PRO-2 groups. These findings suggest that probiotic mixtures may be useful probiotics for the treatment of or as alternative therapies for rotaviral gastroenteritis.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.817-832
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• 2011

It is said that the reason Bulgarians enjoy longevity is that they have a lot of yogurt, whose $Lactobacillus$ controls intestinal poison-producing germs. In young individuals, the number of bifidobacteria exceeds 10 billion per 1 g of intestinal content, but this number decreases for older or senile individuals, who have a larger number of harmful microorganisms such as $Clostridium$. In addition, it is well known that artificially increasing intestinal bifidobacteria can help control harmful microorganisms and thus facilitate a healthier and longer life. The microorganisms used for artificial spawn are referred to as probiotic microorganisms, and in general, lactic acid bacteria(LAB) are used. Unlike antibiotics, which kill harmful microorganisms, probiotic microorganisms coexist with and control them, while improving the health of the individual, that is, they can improve and invigorate host cells. Because probiotic microorganisms and its products based on LAB are known to help prevent and treat constipation, diarrhea, intestinal inflammation, and blood cholesterol and generally improve health through the purification of intestines, its market has been continuously expanding. Korea imports approximately 90% of spawn and uses them. It is likely that they are not appropriate for Korean's physical condition. Thus, considering this problem into account, Entecbio, a biotech firm in Korea, has produced various products by using its proprietary microorganisms. In this paper, the effects, characteristics, and kinds of products from based on proprietary microorganisms, with its prospect for market, etc., are generally examined.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.424-428
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• 2013

To identify risk factors for Legionella contamination, water quality variables routinely measured in examination of natural and city waters were meta-analyzed for significance of correlation to Legionella incidences. For evaluation of abundance of Escherichia coli as a risk factor, which is currently used as an indicator of Legionella contamination in an official guideline in Korea, odds ratio (OR) of above-cutoff total coliform counts for Legionella presence/absence was used as the effect size in the meta-analysis. The OR was estimated as 1.05 (0.36-3.12, 95% CI), and the probability of having identical odds reached 0.92. Also, ORs from individual studies showed significant heterogeneity (P=0.008), which contributed to 63% of total variance of the ORs. In the case of heterotrophic plate count (HPC), the OR for Legionella presence/absence was 2.72 (2.04-3.63) with highly significant deviation from identical odds (P<0.0001). ORs from different studies were seemingly homogeneous ($Q_{df=8}$=12.7, P=0.12). Turbidity and concentrations of chlorine, iron ion and cupper ion were other routine variables that could be considered as risk factors. However, statistical measures from different studies were not uniform enough to develop an appropriate effect size while the number of studies reporting the variables was also small (3-5). In conclusion, HPC appeared to be appropriate as indicator of Legionella contamination, rather than fecal bacteria contamination. HPC may imply abundance of habitats (amoebas and biofilms) of Legionella in water. This result warrants further studies for standardizing protocols and cutoff values to infer Legionella risks from HPC.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.542-550
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• 2019

To detect Escherichia coli from agri-food and production environments, a device based on IoT (internet of things) technology that can check test results in real time on a mobile phone has been developed. The efficiency of the developed device, which combines an incubator equipped with a UV lamp, a high-resolution camera and software to detect E. coli in the field, was evaluated by measuring the device's temperature, detection limit, and detection time. The device showed a difference between its programmed temperature setting and actual temperature of about 1.0℃. In a detection limit test performed with a single-colony inoculation, a color change to yellow and a florescent signal were detected after 12 and 15 h incubations, respectively. The incubation time also decreased along with increasing bacteria levels. When applying the developed method and device to various samples, including utensils, gloves, irrigation water, seeds, and vegetables, detection rates of E. coli using the device were higher than those of the Korean Food Code method. These results show that the developed protocol and device can efficiently detect E. coli from agri-food production environments and vegetables.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.136-140
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• 1986

The change of cell counts of Vibrio parahaemolyticus in fish muscle by the storage time and temperature was examined to get basic informations for precautionary steps against food poisoning of slices of raw fish (sashimi). There fore, we inoculated fish homogenate of oceanic bonito (Katsuwonus pelamis), yellow tail (Seriola quinqueradiata) with Kanagawa positive Vibrio parahaemolyticus and stored it at $30^{\circ}C,\;18^{\circ}C,\;4^{\circ}C\;and\;-20^{\circ}C$ for 24 hours. The number of the Vibrio parahaemolyticus upon fish homogenate stored at $30^{\circ}C\;and\;18^{\circ}C$ decreased for the first two hours and increased thereafter. When the fish homogenates inoculated with Vibrio parahaemolyticus at about $10^3$ per gram were stored at $18^{\circ}C\;and\;30^{\circ}C$ for 10 hours, the cell numbers increased about 10 times and 1,000 times initial cell numbers, respectively. The survival rate of Vibrio parahaemolyticus was about $20\%$, when the inoculated fish homogenates were stored at $-20^{\circ}C$ for 24 hours. Vibrio parahaemolyticus inoculated in fish homogenates was decreased by about $10\%$ of initial cell numbers by the storage at $4^{\circ}C$ for 4 hours and it was decreased by about $50\%$ after 24 hours storage of the samples at the same temperature. The decreasing rate of inoculated Vibrio parahaemolyticus in fresh fish muscle homogenate was higher than that in frozen fish muscle homogenate during the storage time at a refrigerator.