• Title/Summary/Keyword: Infections

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Molecular Characterization of Regulatory Genes Associated with Biofilm Variation in a Staphylococcus aureus Strain

  • Kim, Jong-Hyun;Kim, Cheorl-Ho;Hacker, Jorg;Ziebuhr, Wilma;Lee, Bok-Kwon;Cho, Seung-Hak
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.28-34
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    • 2008
  • Biofilm formation in association with the intercellular adhesion (icaADBC) gene cluster is a serious problem in nosocomial infections of Staphylococcus aureus. In all 112 S. aureus strains tested, the ica genes were present, and none of these strains formed biofilms. The biofilm formation is known to be changeable by environmental factors. We have found about 30% of phase variation in these strains with treatment of tetracycline, pristinamycin, and natrium chloride. However, this phenotype disappeared without these substances. Therefore, we have constructed stable biofilm-producing variants through a passage culture method. To explain the mechanism of this variation, nucleotide changes of ica genes were tested in strain S. aureus 483 and the biofilm-producing variants. No differences of DNA sequence in ica genes were found between the strains. Additionally, molecular analysis of three regulatory genes, the accessory gene regulator (agr) and the staphylococcal accessory regulator (sarA), and in addition, alternative transcription factor ${\sigma}^B$ (sigB), was performed. The data of Northern blot and complementation showed that SigB plays an important role for this biofilm variation in S. aureus 483 and the biofilm-producing variants. Sequence analysis of the sigB operon indicated three point mutations in the rsbU gene, especially in the stop codon, and two point mutations in the rsbW gene. This study shows that this variation of biofilm formation in S. aureus is deduced by the role of sigB, not agr and sarA.

Clinical manifestations of CNS infections caused by enterovirus type 71

  • Choi, Cheol-Soon;Choi, Yun-Jung;Choi, Ui-Yoon;Han, Ji-Whan;Jeong, Dae-Chul;Kim, Hyun-Hee;Kim, Jong-Hyun;Kang, Jin-Han
    • Clinical and Experimental Pediatrics
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    • v.54 no.1
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    • pp.11-16
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    • 2011
  • Purpose: Enterovirus 71, one of the enteroviruses that are responsible for both hand-foot-and-mouth disease and herpangina, can cause neural injury. During periods of endemic spread of hand-foot-andmouth disease caused by enterovirus 71, CNS infections are also frequently diagnosed and may lead to increased complications from neural injury, as well as death. We present the results of our epidemiologic research on the clinical manifestations of children with CNS infections caused by enterovirus 71. Methods: The study group consisted of 42 patients admitted for CNS infection by enterovirus 71 between April 2009 and October 2009 at the Department of Pediatrics of 5 major hospitals affiliated with the Catholic University of Korea. We retrospectively reviewed initial symptoms and laboratory findings on admission, the specimen from which enterovirus 71 was isolated, fever duration, admission period, treatment and progress, and complications. We compared aseptic meningitis patients with encephalitis patients. Results: Of the 42 patients (23 men, 19 women), hand-foot-and-mouth disease was most prevalent (n=39), followed by herpangina (n=3), upon initial clinical diagnosis. Among the 42 patients, 15 (35.7%) were classified as severe, while 27 (64.3%) were classified as mild. Factors such as age, fever duration, presence of seizure, and use of intravenous immunoglobulin (IVIG) were statistically different between the 2 groups. Conclusion: Our results indicate that patients with severe infection caused by enterovirus 71 tended to be less than 3 years old, presented with at least 3 days of fever as well as seizure activity, and received IVIG treatment.

Parasitic infections in HIV-infected patients who visited Seoul National University Hospital during the period 1995-2003

  • GUK Sang-Mee;SEO Min;PARK Yun-Kyu;OH Myoung-Don;CHOE Kang-Won;KIM Jae-Lip;CHOI Min-Ho;HONG Sung-Tae;CHAI Jong-Yil
    • Parasites, Hosts and Diseases
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    • v.43 no.1 s.133
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    • pp.1-5
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    • 2005
  • The prevalence of parasitic infections was investigated in human immunodeficiency virus (HIV)-infected patients (n = 105) who visited Seoul National University Hospital, Seoul, Korea, during the period from 1995 to 2003. Fecal samples were collected from 67 patients for intestinal parasite examinations, and sputum or bronchoalveolar lavage samples from 60 patients for examination of Pneumocystis carinii. Both samples were obtained from 22 patients. Thirty-three ($31.4\%$) of the 105 were found to have parasitic infections; Cryptosporidium parvum ($10.5\%$; 7/67), Isospora belli ($7.5\%$; 5/67), Clonorchis sinensis ($3.0\%$; 2/67), Giardia lamblia ($1.5\%$; 1/67), Gymnophalloides seoi ($1.5\%$; 1/67), and Pneumocystis carinii ($28.3\%$; 17/60). The hospital records of the 11 intestinal parasite-infected patients showed that all suffered from diarrhea. This study shows that parasitic infections are important clinical complications in HIV-infected patients in the Republic of Korea.

Human Infections with Liver and Minute Intestinal Flukes in Guangxi, China: Analysis by DNA Sequencing, Ultrasonography, and Immunoaffinity Chromatography

  • Jeon, Hyeong-Kyu;Lee, Dongmin;Park, Hansol;Min, Duk-Young;Rim, Han-Jong;Zhang, Hongman;Yang, Yichao;Li, Xueming;Eom, Keeseon S.
    • Parasites, Hosts and Diseases
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    • v.50 no.4
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    • pp.391-394
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    • 2012
  • The prevalence of liver and intestinal fluke infections was determined by surveying inhabitants of Hengxuan, Fusui, and Shanglin villages which were known to be endemic for liver flukes in Guangxi, China in May 2010. A total of 718 people were examined for helminth eggs by the Kato-Katz thick smear technique, ultrasonography, immunoaffinity chromatography, and DNA sequencing. The overall egg positive rate was found to be 59.6% (28.0-70.6%) that included mixed infections with liver and intestinal flukes. Cases showing higher than 20,000 eggs per gram of feces (EPG) were detected between 1.3% and 16.2%. Ultrasonographic findings exhibited overall 28.2% (72 of 255 cases) dilatation rate of the intrahepatic bile duct. Clonorchis sinensis infection was detected serologically in 88.3% (38 of 43 cases) among C. sinensis egg positive subjects by the immunoaffinity chromatography using a specific antigen for C. sinensis. For differential diagnosis of the liver and intestinal flukes, more precise PCR and nucleotide sequencing for copro-DNA were performed for 46 egg positive cases. Mixed infections with C. sinensis and Metagonimus yokogawai were detected in 8 of 46 egg positive cases, whereas 29 specimens were positive for Haplorchis taichui. Ultrasonographic findings and immunoaffinity chromatography results showed usefulness, even in a limited way, in figuring out of the liver fluke endemicity.

Prevalence of Helminthic Infections among Inhabitants of Lao PDR

  • Eom, Keeseon S.;Yong, Tai-Soon;Sohn, Woon-Mok;Chai, Jong-Yil;Min, Duk-Young;Rim, Han-Jong;Jeon, Hyeong-Kyu;Banouvong, Virasack;Insisiengmay, Bounnaloth;Phommasack, Bounlay
    • Parasites, Hosts and Diseases
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    • v.52 no.1
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    • pp.51-56
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    • 2014
  • The prevalence of helminthic infections was surveyed on a total of 6,178 residents (males 2,549 and females 3,629) in 102 villages of 9 provinces in Lao PDR between 2007 and 2011 under the project of Korea-Laos Collaborative Project for Control of Foodborne Trematode Infections in Lao PDR. Fecal specimens were collected and examined by the Kato-Katz thick smear and Stoll's egg counting techniques. The overall liver/intestinal helminth egg positive rate was 71.9% with a single or mixed infections with Opisthorchis viverrini and minute intestinal flukes (Ov/MIF), Ascaris lumbricoides, hookworms, Trichuris trichiura, Trichostrongylus sp., echinostomes, Taenia spp., and others. Ov/MIF revealed the highest prevalence (55.6%) followed by hookworms (27.8%) and T. trichiura (6.5%). The endemic regions with the highest prevalence of Ov/MIF were Savannakhet, Khammouane, Vientiane (Nam Ngum), Champasak (Khong Island), and Saravane Province. High prevalences of A. lumbricoides (33.8%), hookworms (47.8%), and T. trichiura (32.6%) were observed in Phongsaly, Luang Prabang, and Vientiane (Nam Ngum) areas, respectively. The results of this study highlight helminth parasites of current public health significance in different areas of Lao PDR.

Autogenous toxoid-bacterin treatment for Staphylococcus aureus subclinical mastitis in lactating cows

  • Hwang, Cheol-yong;Park, Son-il;Han, Hong-ryul
    • Korean Journal of Veterinary Research
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    • v.39 no.4
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    • pp.846-853
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    • 1999
  • To evaluate clinical effects of autogenous toxoid-bacterin treatment for Staphylococcus aureus subclinical mastitis in lactating cows, 22 cows which had at least one S aureus infected quarter were selected from one S aureus prevalent dairy farm, of which 11 cows were injected their own autogenous toxoid-bacterin and the others were maintain as noninjected control. In the toxoid-bacterin injected group, 27% of infected quarters were cured during the 12 weeks trials as compared to 5% in the control group. New intramammary infections with S aureus were only detected in three-quarters of the control group. Mean IgG antibody titers against S aureus somatic antigens and $\alpha$-toxin in serum and milk were significantly increased in the toxoid-bacterin injected group (p < 0.05) and remained higher than those of the control group which showed no significant changes (p < 0.05). From 3 weeks after second injection (at 7 week), mean S aureus CFU/ml in milk samples from previously infected quarters with S aureus of the toxoid-bacterin injected group was lower than that from preinjection state (p < 0.05). In the toxoid-bacterin injected group, significant decrease of mean SCC was detected from milk samples from previously infected quarters with S aureus from week 7 to week 10 (p < 0.05). These data suggested that autogenous toxoid-bacterin treatment aganist S aureus subclinical mastitis in lactating cows might increase the cure rate of the infections, reduce the severity of the infections and also prevent occurrence of the new infections.

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Prediction of HIV and AIDS Incidence Using a Back-calculation Model in Korea (후향연산 모형 (Back-calculation model)을 이용한 국내 HIV 감염자와 AIDS 환자의 추계)

  • Lee, Ju-Young;Goh, Un-Yeong;Kee, Mee-Kyung;Kim, Jee-Yun;Hwang, Jin-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.35 no.1
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    • pp.65-71
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    • 2002
  • Objective : To estimate the status of HIV infection and AIDS incidence using a back-calculation model in Korea. Methods : Back-calculation is a method for estimating the past infection rate using AIDS incidence data. The method has been useful for obtaining short-term projections of AIDS incidence and estimating previous HIV prevalence. If the density of the incubation periods is known, together with the AIDS incidence, we can estimate historical HIV infections and forecast AIDS incidence in any time period up to time t. In this paper, we estimated the number of HIV infections and AIDS incidence according to the distribution of various incubation periods Results : The cumulative numbers of HIV infection from 1991 to 1996 were $708{\sim}1,426$ in Weibull distribution and $918{\sim}1,980$ in Gamma distribution. The projected AIDS incidence in 1997 was $16{\sim}25$ in Weibull distribution and $13{\sim}26$ in Gamma distribution. Conclusions : The estimated cumulative HIV infections from 1991 to 1996 were $1.4{\sim}4.0$ times more than notified cumulative HIV infections. Additionally, the projected AIDS incidence in 1997 was less than the notified AIDS cases. The reason for this underestimation derives from the very low level of HIV prevalence in Korea, further research is required for the distribution of the incubation period of HIV infection in Korea, particularly for the effects of combination treatments.

Colibacillosis in domestic animals, a review (가축에서 대장균 감염증)

  • 송희종;채효석
    • Korean Journal of Veterinary Service
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    • v.21 no.4
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    • pp.413-429
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    • 1998
  • Escherichia coli is recovered from a wide variety of infections in many animals species. It may be a primary or secondary agent. Nursing and young animals are particularly susceptible, and urinary tract infections are frequent. The various serotypes of E coli are intestinal inhabitants of animals including humans and probably infect most mammals and birds : therefore, they have a cosmopolitan distribution. Colibacillosis refers to any totalized or systemic infection caused entirely or partly by E coli. Collibacillosis in mammals is most often a primary enteric disease, whereas collibacillosis in poultry is typically a secondary located or systemic disease occurring when host defenses have been impaired or overwhelmed. Other opportunistic bacteria, which can be identified by culture, may play a similar role to that of I coli in secondary infections. Collectively, infections caused by E coli are responsible for significant economic losses to the animal performance. From the standpoint of pathogenic mechanisms and diseases, four major categories of E coli are recognized : enterotoxigenic(ETEC), enteropathogenic (EPEC), enteroinvasive(EIEC), and enterohemorrhagic(EHEC). In addition, two less-well-defined E coli categories are recognized in animals and humans : enteroaggregative and cytotoxin necrotizing factor-positive. The aforementioned categories are represented by different serotypes. Certain serotypes show a host preference and are encountered more frequently in some disease syndromes. Of the four major categories, ETEC is the most common cause of diarrhea in calves, lambs, and pigs. Strains in the other categories cause the less-common diarrhea and other disease syndromes. Enterotoxins and pilus antigens are the two most prominent virulence factors thus far identified for ETEC. Two enterotoxins, one heat-stable(ST) and one heat-labile(LT), are produced by enterotoxigenic strains of E coli : not all culture produce both of these plasmid-based enterotoxins.

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Food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of Vibrio parahaemolyticus in Korea from 2003 to 2016: a review

  • Park, Kunbawui;Mok, Jong Soo;Kwon, Ji Young;Ryu, A Ra;Kim, Song Hee;Lee, Hee Jung
    • Fisheries and Aquatic Sciences
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    • v.21 no.2
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    • pp.3.1-3.10
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    • 2018
  • Background: Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in Korea, either directly or indirectly, by consuming infected seafood. Many studies have demonstrated the antibiotic susceptibility profile of V. parahaemolyticus. This strain has developed multiple antibiotic resistance, which has raised serious public health and economic concerns. This article reviews the food-borne outbreaks, distributions, virulence, and antibiotic resistance profiles of V. parahaemolyticus in Korea during 2003-2016. Main body: V. parahaemolyticus infections appeared to be seasonally dependent, because 69.7% of patient infections occurred in both August and September during 2003-2016. In addition, the occurrence of V. parahaemolyticus in marine environments varies seasonally but is particularly high in July, August, and September. V. parahaemolyticus isolated from aquaculture sources on the Korean coast varied in association with virulence genes, some did not possess either the tdh (thermostable direct hemolysin) or trh (tdh-related hemolysin) genes, and a few were positive for only the trh gene or both genes. The high percentage of ampicillin resistance against V. parahaemolyticus in the aquatic environment suggests that ampicillin cannot be used to effectively treat infections caused by this organism. Short conclusion: This study shows that the observed high percentage of multiple antibiotic resistance to V. parahaemolyticus is due to conventionally used antibiotics. Therefore, monitoring the antimicrobial resistance patterns at a national level and other solutions are needed to control aquaculture infections, ensure seafood safety, and avoid threats to public health caused by massive misuse of antibiotics.

Prophylactic antibiotics in intra-oral bone grafting procedures: a prospective, randomized, double-blind clinical trial

  • Lee, Jung-Woo;Lee, Jin-Yong;Kim, Soung-Min;Kim, Myung-Jin;Lee, Jong-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.38 no.2
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    • pp.90-95
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    • 2012
  • Objectives: This study was conducted in order to assess the efficacy of 1st generation cephalosporin as use as a single-dose preoperative prophylactic antibiotic for surgical wound infections resulting from intra-oral bone grafting procedures. Materials and Methods: A total of 23 patients who were to undergo intra-oral bone graft procedures participated in this study. After randomization, 2 grams of 1st generation cephalosporin was orally administered to both the experimental and placebo groups one hour prior to surgery in a double-blind fashion. Post-operatively, the experimental group (12 patients) was orally administered placebo three times a day for three days. The control group (11 patients) was orally administered 1st generation cephalosporin three times a day for three days. The postoperative course was observed for one month including the clinical parameters associated with infection. Results: Postoperative infections were noted in 1 out of 11 patients in the experimental group. No infections occurred in the control group. Conclusion: There was no significant difference in the incidence of postoperative infections between the two groups. Two grams of 1st generation cephalosporin administered orally one hour before surgery served as an effective prophylactic antibiotics therapy for intra-oral bone graft surgery.