• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.2
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• pp.93-100
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• 2009

This research was performed to figure out the optimal mixing ratio of food- to livestock wastewater for the best degradation of organic matter in the anaerobic digestion. The presence of various microorganisms, such as Escherichia coli and Staphylococcus aureus, was also investigated in both wastewater in this process. Enteric bacteria were only found in livestock wastewater, whereas pathogenic bacteria like S. aureus were detected in both wastewater. The optimal mixing ratio of food- to livestock wastewater for the best mineralization was found to fifty to fifty, with reduction ratios of $BOD_5$, CODcr SS as 23.2%, 24.7%, 19.7%, respectively. Hygiene of the digested sludge was also analyzed by counting the number of total colonies and various pathogens. Enterobacteriaceae including E. coli were barely detected in 10 days after reaction. Meanwhile, S. aureus was gradually reduced during reaction, even showing 1,000~5,000 CFU/mL in final days.

• The Journal of the Korean Society for Microbiology
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• v.15 no.1
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• pp.19-32
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• 1980

Besides the benefits of antimicrobial agents in the control of various infectious diseases, widespread and prolonged use of particular antimicrobial agents has brought about the increase of drug-resistant strains in a community and the profound changes in the pattern of infectious diseases. In Korea, there are some remote villages where no clinics and drug stores are available and the residents in those areas are assumed to have fewer chances to contact with antimicrobial agents. In the present study, the differences in susceptibilities to 14 antimicrobial agents between the isolates from rural areas(R) and Seoul National University Hospital(SNUH, H) were studied. The isolates and their numbers were Staphylococcus aureus, R;55, H;68), Enterococci(R;28, H;30), Escherichia coli(R;40, H;40), Enterobacter aerogenes(R;25, H;21) and Klebsiella pneunoniae(R;58, H;67). Minimal inhibitory concentrations(MIC's) of penicillin, ampicillin, carbenicillin, cephalexin, tetracycline, oxytetracyline, doxycycline, minocycline, gentamicin, kanamycin, streptomycin, erythromycin, troleandomycin and co-trimoxazole were determined by agar dilution method. I. Comparison of MIC's and resistant strain proportions between isolates from SNUH and rural areas. MIC's and/or resistant strain proportions of the isolates from SNUH were significantly higher than those of the isolates from rural areas in the cases of 1. S. aureus to doxycycline, streptomycin and kanamycin. 2. E. coli to penicillin, ampicillin, carbenicillin, tetracycline, oxytetracycline, doxycycline, minocycline, streptomycin, kanamycin, erythromycin and co-trimoxazole. 3. E. aerogences to carbenicillin, tetracycline, oxytetracycline, doxycycline, minocycline, streptomycin, kanamycin, genaamicin and co-trimoxazole. 4. K pneunoniae to penicillin, ampicillin, tetracycline, oxytetracycline, doxycycline, monocycline, streptomycin, kanamycine, gentamicin and co-trimoxazole. However, the mean MIC and resistant strain proportion of S. aureus to tetracycline were higher in isolates from rural areas than in those from SNUH and Enterococci showed no differences in susceptibilities to the antimicrobial agents between isolates from rural areas and from SNUH. Therefore, in general, differenes in susceptibility to these antimicrobial agents between the isolates from rural areas and SNUH were remarkably greater and broader in gram negative enteric bacteria. II. Multiple drug resistance pattern. Patterns and incidences of multiple drug resistance were studied with penicillin, ampicillin, tetracycline, cephalexin, gentamicin, streptomcin, kanamycin and co-trimoxazole in Enterococci, E. coli, E. aeroges and K. pneumoniae. There appeared significant differences in the incidence of multiply drug-resistant strains and multiple drug resistance patterns between the isolates from SNUH and rural areas in Enterococci, E. coli, E. aerogenes and K. pneumoniae. However, there was no difference in the incidence of multiply drug-resistant strains between isolates of S. aureus from SNUH and rural areas but the pattern of multiple resistance of the SNUH strains of S. aureus was diverse, while that of the rural strains was predominantly confined to penicillin-tetracycline combination. The incidence of multigly drug-resistant strains and diversity of their patterns were the highest in E. coli strains isolated from SNUH and there were no multiply drug resistant strrains in Enterococci and K. pneumoniae strains isolated from rural areas. The number of drug-resistance determinants was also different between the isolates from rural areas and SNUH. Most of the multiply drug-resistant strains of E. coli, E. aerogenes and K. pneumoniae isolated from SNUH were resistant to more than 3 kinds of antimicrobial agents, most frequently to ampicillin, tetracycline and streptomycin, while multiply drug-resistant strains from rural areas were resistant to 2 kinds of antimicrobial agents among ampicillin, tetracycline and streptomycin. With drug-resistant E. coli strains, resistance to tetracycline which was used most widely since 1951 was most frequently involved as a part of mutliple drug-resistance, followed by resistance to ampicillin and streptomycin. This strongly suggests that emergence of drug-restant strains in a community is directly dependent on the selective pressure exerted by the antimicrobial agent used. III. Cross resistance. Cross resistance of bacteria was studied among tetracycline penicillin, aminoglycoside and macrolide derivatives by analyzing correlation coefficients of sucseptibilities using the least square method. In this study, there were high correlations among the susceptibilities to related derivatives. It appears that the relatively low correlations in susceptibilities present in some cases are due to intrinsic resistance of E. aerogenes to penicillin, Enterococci to aminoglycoside and E. coli E. aerogenes and K. pneumoniae to macrolide derivatives.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.118-126
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• 1986

Vibrio vulnificus is a recently recognized halophilic organism that nay cause serious human infections. Patients infected with V. vulnificus often have a history of exposure to the sea, suggesting that the organism may be common inhabitant of marine environment. The purpose of this experiment is to investigate the distribution and bacteriological characteristics of V. vulnificus. The strain used in this experiment was isolated from sea water and sea products such as common octopus (Octopus variabilis), ark shell (Anadara broughtonii), blue crab (Ericheir japonica), and sea squirt (Synthia roretzi) collected in Pusan area from July to October in 1985. V. vulnificus was frequently isolated in August when temperature of sea water was around $26^{\circ}C$ and rarely isolated in October when temperature of sea water was around $18.5^{\circ}C$. The distinctive biochemical characteristics of V. vulnificus were ONPG hydrolysis positive and fermented lactose and not grown in peptone water contained $8\%$ NaCl. The optical density at 660 nm of the growth of V. vulnificus was reached maximum level after 8 hours of culture at $35^{\circ}C$ in brain heart infusion broth but that of V. vulnificus was little increased at $15^{\circ}C$ for 14 hours. Optimum temperature and pH for the growth of V. vulnificus were around $35^{\circ}C$ and 8.0. The specific growth rate and the generation time of V. vulnificus isolated from the samples were $1.21\;hr^{-1}$, 34 min at $35^{\circ}C$ and $0.61\;hr^{-1}$, 69 min at $25^{\circ}C$, respectively. V. vulnificus did not grow on eosin-methylene-blue agar, salmonella-shigella agar, deoxycholate agar but grew well on Endo agar, xylose-lysine-deoxycholate agar and hektoen enteric agar. On Endo agar, the colonies of V. vulnificus were red and achieved a diameter of 2 to 4 mm as a feature enabling differentiation of V. vulnificus from other Vibrio spp. V. vulnificus grow well on TCBS agar forming green colonies. V. vulnificus refrigerated at $4^{\circ}C$ exhibited a linear decline of its viablity as 1 log cycle in every 16 hours storage, while V. vulnificus freezed at $-18^{\circ}C$ almost became extinct.

• Pediatric Infection and Vaccine
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• v.21 no.1
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• pp.43-52
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• 2014

Purpose: This study aimed to evaluate the disease severity of children suffering from gastroenteritis using different scales. The results are compared and subsequently classified on the basis of the type of virus causing the disease in order to investigate the differences in clinical characteristics and disease severity according to pathogen. Method: This study was conducted prospectively with patients under 5 years of age diagnosed with acute gastroenteritis and hospitalized at 9 medical institutions in 8 regions across the Republic of Korea. Disease severity was evaluated using the Vesikari Scale, the Clark Scale, and the modified Flores Scale. Fecal samples collected from patients were used to detect rotavirus and enteric adenovirus by enzyme immunoassay, and for RT-PCR of norovirus, astrovirus, and sapovirus. Results: There were a total of 214 patients with a male : female ratio of 1.58 : 1, of which 35 were under the age of 6 months (16.4%), 105 were aged 6-23 months (49.1%), and 74 were aged 24-59 months (34.5%). The rate of concordance between the Vesikari and Clark Scales was 0.521 (P<0.001) and, in severe cases, the Vesikari Scale was 60.7% and Clark Scale was 2.3%, indicating that the Clark Scale was stricter in the evaluation of severe cases. Conclusions: In children with gastroenteritis, there were differences in disease severity based on the scale used. Therefore, to achieve consistent results among researchers, either only a single scale or a measure of all scales should be used to determine disease severity.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.8-13
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• 2017

This study was conducted to develop an agent-based computing platform enabling simulation of on-farm produce contamination by enteric foodborne pathogens, which is herein called PPMCS (Preharvest Produce Microbial Contamination Simulator). Also, fecal contamination of preharvest produce was simulated using PPMCS. Although Agent-based Modeling and Simulation, the tool applied in this study, is rather popular in where socio-economical human behaviors or ecological fate of animals in their niche are to be predicted, the incidence of on-farm produce contamination which are thought to be sporadic has never been simulated using this tool. The agents in PPMCS including crop, animal as a source of fecal contamination, and fly as a vector spreading the fecal contamination are given their intrinsic behaviors that are set to be executed at certain probability. Once all these agents are on-set following the intrinsic behavioral rules, consequences as the sum of all the behaviors in the system can be monitored real-time. When fecal contamination of preharvest produce was simulated in PPMCS as numbers of animals, flies, and initially contaminated plants change, the number of animals intruding cropping area affected most on the number of contaminated plants at harvest. For further application, the behaviors and variables of the agents are adjustable depending on user's own scenario of interest. This feature allows PPMCS to be utilized in where different simulating conditions are tested.

• The Journal of the Korean Society for Microbiology
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• v.9 no.1
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• pp.7-11
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• 1974

The authors identified fifty-eight Shigella cultures among 1644 cultures and specimens of enteric pathogens collected from all over the country in 1973. Fifty-one out of fifty-eight cultures belonged to Shigella flexneri and the rest to Shigella sonnei. None of cultures belonging to either subgroup A or C was detected in 1973. Of fifty-one cultures of Shigella flexneri twenty-six cultures were $B_{2a}$, which were isolated in Seoul area and Kwangwon-Do. The rest were $B_{3a}$ which were isolated in Jeonla-bug-Do and Kangwon-Do. It would not be possible to understand that there might not have been the cases or carriers of Shigella in the areas where the organisms were not isolated in 1973 and that there might not have been any other serotypes existing in the country, although there was a quite disparity found in the distribution between different areas and in the detection of the serotypes as shown in Table 1. Concerning the biochemical properties there were only two cultures showing positive arginine decarboxylase test among $B_{2a}$, and there were three cultures of trehalose negative cultures, one of rhamnose positive culture and one of glycerol positive culture observed, which were considered to be unusual. All the Shigella cultures were sensitive to nitrofurantoin, cephalosporin and ampicillin, and resistant to colistin, bacitracin and neomycin. Majority of them showed sensitive results to gentamycin, and the majority of Shigella $B_{3a}$ appeared to be sensitive to chloramphenicol, tetracycline, oxytetracycline and doxycycline, but the majority of $B_{2a}$ and Shigella sonnei were observed resistant to those antibiotics by means of the In-Vitro tests.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.753-759
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• 2005

Purpose : This study was performed to characterize clinical features of benign convulsions with gastroenteritis(CwG) in infants. Methods : We reviewed clinical features of 67 episodes in 64 patients with afebrile seizure accompanied gastroenteritis admitted to Dept. of Pediatrics Bundang CHA hospital from January 2001 to June 2004. Patients with meningitis, encephalitis/encephalopathy or apparent history of epilepsy were excluded. Results : There were 32 boys and 35 girls. The age of onset ranged from 1 to 42 months($18.5{\pm}6.1$ months). The number of children admitted to the hospital with acute gastroenteritis was 2,887 in the same period. The percentage of patients with CwG was 2.3. Seizure type was exclusively generalized tonic or tonic-clonic seizure. The average number of seizures during a single episode was 3.1 (range, 1-13). Two or more seizures occurred in 53(79.1%) of the 67 episodes. Antiepileptic drugs were administered for 42 episodes. Seizure did not cease after the administration of one kind of antiepileptic drug in 23 episodes(54.7%). The seizures were rather refractory to initial antiepileptic treatment. There were no abnormalities in serum biochemistry test including glucose and electrolytes. Cerebrospinal fluid was normal in all 54 episodes. Stool cultures were negative in 49 episodes. Rotavirus was positive in stools in 51(82.3%) of 62 episodes. Norovirus was positive in stools in 2 episodes and astrovirus in 1 of 18 episodes. CT and/or MRI were performed in 15 cases and demonstrated no neuroradiologic abnormalities. Of 73 Interictal EEG, initial 24 cases showed occasional spike or sharp wave discharges from the mid-line area during stage I-II sleep, which were apparently differentiated from vertex sharp transient or K-complexes. The mean follow-up period was 5.7 months(1-36 months). Three patients experienced a recurrence of CwG, but all patients exhibited normal psychomotor development at the last follow-up. Conclusion : Afebrile infantile convulsions with gastroenteritis are brief generalized seizure in cluster with normal laboratory findings and good prognosis. Therefore CwG is likely to be categorized as situation-related seizure of special syndrome. Recognition of this entity should lead to assurance of the parents and long-term anticonvulsant therapy is not usually warranted.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.39-49
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• 1990

It has been reported that bombesin induces contraction of the smooth muscle of the gastrointestinal tract. Thus, the present investigation was undertaken to see an influence of bombesin on electrical activity of the gastric smooth muscle, since electrical activity is associated with contractile activity in the smooth muscle of the stomach. Smooth muscle strips $(5\;{\times}\;1.5\;cm)$ that included the corpus and antrum were prepared from the ventral and dorsal portion of the feline stomach along the greater curvature. Circular muscle strips $(1\;{\times}\;0.3\;cm)$ of the corpus were also obtained. Electrical activity of the corpus and antrum of the muscle strip was monophasically recorded by using Ag-AgCl capillary electrodes placed on the circular muscle layer. Contractile activity of the circular muscle strip was also recorded. The recordings were performed in Krebs-Ringer solution that was continuously aerated with $O_{2}$ containing 5% $Co_{2}$, and kept at $36^{\circ}C$. Dose-related responses of electrical activity and contractility to bombesin was studied after frequency of slow waves and contraction of each strip reached to a steady state. An action of $D-leu^{13}-{\psi}\;(CH_{2}NH)-D-leu^{14}-bombesin,\;D-pro^{2}-D-trp^{7,9}-substance\;P$, tetrodotoxin, hexamethonium, atropine, phentolamine or propranolol on the effect of bombesin was also observed. 1) Bombesin increased frequency of slow waves and contractions dose-dependently at concentrations from $10^{-9}\;M\;to\;3\;{\times}\;10^{-8}\;M$. 2) The bombesin analogue at a concentration of $3\;{\times}\;10^{-7}\;M$ antagonized the effect of bombesin on frequency of slow waves. 3) The effect of bombesin on frequency of slow waves was inhibited by tetrodotoxin $(10^{-6}\;M)$ and hexamethonium $(10^{-3}\;M)$ but unaffected by atropine $(10^{-6}\;M)$, phentolamine $(10^{-5}\;M)$ and propranolol $(10^{-5}\;M)$. 4) The effect of bombesin on frequency of slow waves was blocked by the substance P analogue at a concentration of $10^{-5}\;M$. 5) Substance P at a concentration of $10^{-5}\;M$ failed to change frequency of slow waves. It is concluded from the above results that bombesin increases the frequency of slow waves as well as contractions of the smooth muscle strip from the feline stomach, and the effect of bombesin might be mediated by non-cholinergic or non-adrenergic mechanism at neuromuscular junction. However, enteric nerves that have substance P as a neurotransmitter do not appear to participate in the action of bombesin on frequency of slow waves.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.99-104
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• 2005

Corynebacterial clones which exert regulatory effects on the expression of the glyoxylate bypass genes were isolated using a reporter plasmid carrying the enteric lacZ fused to the aceB promoter of Corynebacterium glutamicum. Some clones carried common fragments as turned out by DNA mapping technique. Subcloning analysis followed by the measurement of $\beta-galactosidase$ activity in Escherichia coli identified the region responsible for the aceB-repressing activity. Sequence analysis of the DNA fragment identified two independent ORFs of ORF1 and ORF2. Among them, ORF2 was turned out to be responsible for the aceB-repressing activity. ORF1 encoded a 23,216 Da protein composed of 206 amino acids. Sequence similarity search indicated that the ORF may encode a ECF-type $\sigma$ factor and designated sigH. To identify the function of sigH, C. glutamicum sigH mutant was constructed by gene disruption technique and the sigH mutant showed growth retardation as compared to the wild type strain. In addition, the mutant strain showed sensitivity to oxidative-stress generating agent plumbagin. This result imply that sigH is probably involved in the stress response occurring during normal cell growth.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1354-1361
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• 2005

Purpose : Rotavirus is an enteric pathogen that affects millions of children globally each year. But no specific therapy is available for the management of rotavirus diarrhea. Due to the clear need to define improved modality for treatment of rotavirus diarrhea, we evaluated the efficacy of antirotavirus IgY in the treatment of infants and children with gastroenteritis. Methods : First, the amount of viral particle in the stools of thirteen patients(seven were given IgY, 6 placebo) infected by rotavirus were evaluated for 3 days with the quantitative RT-PCR method. Second, 36 children with known rotavirus infection identified by ELISA or semi-quantitative RT-PCR were evaluated. We gave 5 g anti-rotavirus egg yolk daily in two equally divided doses for 3 days to two groups(an 18 IgY group and an 18 placebo group), respectively after parenteral consent. Daily vomiting frequency, stool frequency, oral intake and urine output were monitored for 3 days, and electrolyte and blood chemistry were checked at the first and third days. Results : First, in the placebo group, the amount of virus particles increased daily, but in the IgY group it decreased daily. Second, when IgY and placebos were given to children infected with rotavirus, diarrhea on the third day decreased significantly in the IgY group, compared with the placebo group. Conclusion : Treatment with antirotavirus immunoglobulin from immunized chicken's egg resulted in a decrease in the amount of viral particles in stools and diarrhea frequency in children. These results suggest that anti-rotavirus IgY is effective in the treatment of rotavirus gastroenteritis.