Salmonella enterica serovar Typhimurium is one of the most important bacterial pathogens causing diarrhea. The resistance of S. typhimurium to antimicrobial agents, which has recently been isolated from patients, is causing serious problems. We investigated the effects of salicylic acid (Sal) and acetyl salicylate (AcSal) on the susceptibility of S. typhimurium to cephalosporin antibiotics, which are known to increase resistance to cephalosporin and quinolone antibiotics. The MIC of cephalosporin antibiotics was higher than that of the media without Sal. The rate of accumulation of ethidium bromide (EtBr) in the bacteria by the outer membrane protein (Omp) was not different from that of the bacteria cultured in the medium containing Sal. However, Carbonyl cyanide-m-chlorophenylhydrazone (CCCP), an inhibitor of bacterial efflux pumps, significantly reduced the rate of accumulation of EtBr in bacteria cultured on Sal containing medium. In the medium containing CCCP, the MIC of the antimicrobial agent tended to decrease as compared with the control. In addition, the MIC of the bacteria treated with CCCP and Sal was higher than that of the antimicrobial agent against the CCCP treated experimental bacteria. These results suggest that Sal decreases the expression of OmpF in the Omp of S. typhimurium and reduces the permeability of cephalosporin antibiotics to bacteria, which may induce tolerance to cephalosporin antibiotics.
Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; Carbonyl Cyanide m-Chlorophenyl Hydrazone ; Cephalosporin Resistance ; Cephalosporins ; Diarrhea ; Ethidium ; Humans ; Membrane Proteins ; Permeability ; Salicylic Acid ; Salmonella enterica ; Salmonella typhimurium ; Salmonella ; Serogroup

Staphylococcus aureus induces chronic infection in form of biofilm that exists in the host cells and arthroplastic prosthesis surface. In this study, the biofilm formation ability of S. aureus clinically isolated from bacteremia patients, biofilm processing and relationship of resistance to antibiotics, and difference of biofilm formation ability on different prosthetic material surfaces were studied. All of them formed biofilm and especially 6 strains of S. aureus had high ability of biofilm formation. In addition, it was found that some strains with higher biofilm formation ability make more higher polysaccharide layer production. When S. aureus ATCC 25923 forms biofilm, minimal bactericidal concentration (MBC) of biofilm bacteria is more increased than that of the planktonic state bacteria about one thousand folds. Especially, after 6 hours from starting on biofilm formation, the resistance to antibiotics was increased by more than 256 microgram/ml of MBC to every antibiotics and after 8 hours prominent increase (more than 4096 microgram/ml) was noted. Biofilm formation after bacterial adherence to plastic cover-slip was increased with time-dependent manner. Microcolonies were formed after 5 hours from a point that bacteria adhere to plastic cover-slip surface and after 6 hours biofilm was diffusely formed on entire surface, and then after 8 hours very thick biofilm was formed. Thicker biofilm was found on cobalt-chromium than titanium surface. These results suggest that titanium alloy materials are better than cobalt-chromium to minimize S. aureus biofilm formation on the arthroplastic material surface. Also, when microcolonies are formed after adherence of S. aureus to the arthroplastic material surface, resistance to antibiotics is starting.
Alloys ; Anti-Bacterial Agents ; Bacteremia ; Bacteria ; Biofilms ; Humans ; Plankton ; Plastics ; Prostheses and Implants ; Staphylococcus ; Staphylococcus aureus ; Titanium

Lipoprotein plays a role in the host defense against bacterial infection, and its serum level has been demonstrated to be an important prognosis factor of survival. We have previously demonstrated that LDL directly inactivates the hemolytic activity of Vibrio vulnificus cytolysin (VVC) in vitro. The object of this study was therefore to examine whether the LDL-mediated inactivation of VVC leads to protection against lethal infection of V. vulnificus in vivo, using wild and VVC-deficient V. vulnificus strains. Unexpectedly, we found that LDL protects mouse lethality induced by VVC-deficient as well as wild V. vulnificus strain. We also demonstrated that LDL blocks V. vulnificus LPS-induced lethality in mice. These results suggest that LDL preferentially act on endotoxin rather than exotoxin in the protection against V. vulnificus-induced mice lethality.
Animals ; Disease Models, Animal ; Female ; Humans ; Lipopolysaccharides/*antagonists & inhibitors ; Lipoproteins, LDL/*pharmacology ; Mice ; Mice, Inbred ICR ; Perforin/antagonists & inhibitors/genetics ; Vibrio Infections/prevention & control ; Vibrio vulnificus/*drug effects/genetics/*pathogenicity ; Virulence/drug effects/genetics/physiology

There are well known infectious diarrheal disease including viral disease such as HuCVs (Human caliciviruses), rotaviruses, enteric adenoviruses and astroviruses. We performed surveillance of infectious diarrheal disease in this study for providing the information for regional prevalence of infectious diarrheal disease and establish basement of diagnostic scheme for these infectious diarrheal disease. For the study, 3,400 stool specimens collected from 10 hospitals in Gwangju from April 2000 to March 2002 were used in investigation for the detection of infectious diarrheal disease. For group A rotaviruses, enteric adenoviruses and astrovirus, we carried out antigen capturing ELISA and RT-PCR with specific primers reacting RNA dependent RNA polymerase gene of HuCVs is used for the detection of RNA of HuCVs. As a results, we detected viral antigen or genome from 537 out of 3,400 specimens (15.8%). 443 out of 537 (82.5%) were confirmed as rotaviruses antigen positively, and 14 (2.6%) and 3 (0.8%) samples were antigen positive to enteric adenoviruses and astroviruses, respectively. We detected HuCV genome from 73 (13.6%) samples by specific amplification. We found that predominantly causative virus is rotavirus in Gwangju but HuCVs take major portion of viral agents causing diarrhea considering the age and seasonal distribution of specimens. Prevalence of adenoviruses and astroviruses are very low compared with worldwide situation. While the infection of rotavirus is limited to young infant under 2 years old, infection of HuCV has wide age distribution. These results suggest that existence of various strains of HuCVs and low rate of cross-protection among distinct antigenic group make it difficult to form immunity in older age. This epidemiological information relating to various diarrheic viruses is first reported in Gwangju, therefore it could provide present prevalence of viral agents causing gastroenteritis and backgrounds to establishment of protection viral diarrhea and development.
Adenoviridae ; Age Distribution ; Child, Preschool ; Diarrhea* ; Dysentery ; Enzyme-Linked Immunosorbent Assay ; Epidemiologic Studies* ; Epidemiology ; Gastroenteritis ; Genome ; Gwangju* ; Humans ; Infant ; Prevalence ; RNA ; RNA Replicase ; Rotavirus ; Seasons ; Virus Diseases

Enteropathogenic Escherichia coli (EPEC) have been implicated in human diarrhea in several countries. Central to EPEC-mediated disease is its ability to cause intestinal lesions, known as attaching and effacing (A/E) lesion. We investigated 92 EPEC strains isolated from patients with diarrhea in Gwangju for their genotypic and phenotypic characteristics. Sixteen (17.4%) of all strains were found to be typical EPEC because they were bfpA gene positive by PCR. The most of typical EPEC isolates (87.5%) showed a localized adhesion (LA) pattern in Hep-2 cell adherence assay, whereas, only 11 atypical EPEC isolates (14.5%) were adhered to Hep-2 cells in a localized manner. Thirteen of the EPEC strains studied belonged to classical O-serogroups of EPEC and 7 isolates were classified as nonclassical EPEC serogroup and the other isolates could not be serotyped with our antisera. The subtypes of eae, tir, espA and espB genes which are major virulence genes concerned of A/E lesion on chromosome were analyzed by multiplex PCR for finding the original resource. The results showed that the composition of these genes subtypes was homogenous and heterogenous in 12 and 26 isolates, respectively. The others were non-determined type in terms of the gene subtype because of genetic diversity of intimin-coding eae genes. Our findings indicated that EPEC isolates from patients with diarrhea were diverse genetically and phenotypically, which require further study in regard to their virulence and epidemiological significance.
Diarrhea ; Enteropathogenic Escherichia coli* ; Genetic Variation ; Gwangju* ; Humans ; Immune Sera ; Multiplex Polymerase Chain Reaction ; Polymerase Chain Reaction ; Virulence

BACKGROUND: Enteropathgenic Escherichia coli (EPEC) commonly causes infantile diarrhea in the developing countries. This study aims to find out the phenotypic and genotypic characteristics of EPEC in children with diarrhea in Gwangju city. METHODS: We isolated 35 strains from the stool obtained from diarrheal patients and investigated the presence of various virulence genes, adherence patterns, hemolysis, and antibiotic resistance patterns. RESULTS: All isolates were negative for the EPEC adherence factor (EAF) plasmid, and 14 isolates were bfpA-positive by PCR. The eae, tir, espA, and espB genes were analyzed by multiplex PCR. When the results of the four multiplex PCRs were analysed, we observed that the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was highest. The incidence of enteroaggregative E. coli heat-stable enterotoxin (east) was 17.1%. Analysis of Hep-2 cell adherence showed three adherence patterns:the localized adherence pattern, the diffuse adherence pattern, the localized adherence-like pattern. In hemolysin assay, four isolates produced enterohemolysin. The resistance rate of isolates against tetracycline, streptomycin, ampicillin, and rifampin was 56%, 39%, 34%, and 34%, respectively. All isolates were susceptible to ciprofloxacin and colistin. CONCLUSION: In our study, the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was the highest. Analysis of Hep-2 cell adherence showed various adherence patterns. Seventy-five percent of isolates were resistant to at least one antibiotic and 28% were resistant to four or more antibiotics.
Ampicillin ; Anti-Bacterial Agents ; Child* ; Ciprofloxacin ; Colistin ; Developing Countries ; Diarrhea* ; Diarrhea, Infantile ; Drug Resistance, Microbial ; Enteropathogenic Escherichia coli* ; Enterotoxins ; Escherichia coli ; Gwangju* ; Hemolysis ; Humans ; Incidence ; Infant ; Multiplex Polymerase Chain Reaction ; Plasmids ; Polymerase Chain Reaction ; Rifampin ; Streptomycin ; Tetracycline ; Virulence

BACKGROUND: Enteropathgenic Escherichia coli (EPEC) commonly causes infantile diarrhea in the developing countries. This study aims to find out the phenotypic and genotypic characteristics of EPEC in children with diarrhea in Gwangju city. METHODS: We isolated 35 strains from the stool obtained from diarrheal patients and investigated the presence of various virulence genes, adherence patterns, hemolysis, and antibiotic resistance patterns. RESULTS: All isolates were negative for the EPEC adherence factor (EAF) plasmid, and 14 isolates were bfpA-positive by PCR. The eae, tir, espA, and espB genes were analyzed by multiplex PCR. When the results of the four multiplex PCRs were analysed, we observed that the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was highest. The incidence of enteroaggregative E. coli heat-stable enterotoxin (east) was 17.1%. Analysis of Hep-2 cell adherence showed three adherence patterns:the localized adherence pattern, the diffuse adherence pattern, the localized adherence-like pattern. In hemolysin assay, four isolates produced enterohemolysin. The resistance rate of isolates against tetracycline, streptomycin, ampicillin, and rifampin was 56%, 39%, 34%, and 34%, respectively. All isolates were susceptible to ciprofloxacin and colistin. CONCLUSION: In our study, the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was the highest. Analysis of Hep-2 cell adherence showed various adherence patterns. Seventy-five percent of isolates were resistant to at least one antibiotic and 28% were resistant to four or more antibiotics.
Ampicillin ; Anti-Bacterial Agents ; Child* ; Ciprofloxacin ; Colistin ; Developing Countries ; Diarrhea* ; Diarrhea, Infantile ; Drug Resistance, Microbial ; Enteropathogenic Escherichia coli* ; Enterotoxins ; Escherichia coli ; Gwangju* ; Hemolysis ; Humans ; Incidence ; Infant ; Multiplex Polymerase Chain Reaction ; Plasmids ; Polymerase Chain Reaction ; Rifampin ; Streptomycin ; Tetracycline ; Virulence

BACKGROUND: During the past 10 years, there has been an increased incidence of gastrointestinal infections caused by salmonellae in Korea. In 1999, there were several outbreaks and sporadic occurrences of food borne infections due to Salmonella enterica serotype Enteritidis in Gwangju. Thus, there is a need for careful monitoring of its occurrence. METHODS: Salmonella Enteritidis were isolated from feces samples of patients with foodborne diarrhea in Gwangju, 1999. We performed antigen typing, examination of biochemical properties, anibiotic susceptibility test, plasmid typing and RAPD analysis to characterize of S. Enteritidis isolates. RESULTS: There were three Salmonella outbreaks (April, July, October), and 203 isolates of S. Enteritidis were isolated from the 286 patients. Eighteen isolates were obtained from the patients of sporadic occurrences. Antigenic types of the isolates were O antigen; D1 (1, 9, 12), H antigen phase 1; (g, m), serotype; Enteritidis. The isolates were susceptible to most of the antibiotics. We performed plasmid DNA analysis of the isolates, and the results showed 3 plasmids (8, 6, 3.8 kb) in 14 of 14 strains from outbreaks; 3 plasmids (8, 6, 3.8 kb) in 2 isolates from sporadic cases; 4 plasmids (8, 6, 3.8, 2 kb) in 10 isolates from sporadic occurrences, and 2 isolates from food specimens. However, 1 isolate from patients and 2 isolates from Ham-Yang, Kyung Nam, did not contain plasmids. RAPD analysis showed that all isolates from Gwangju in 1999 showed relatively uniform characteristics which were different from those derived from Ham-Yang, Kyung-Nam. CONCLUSION: The present data demonstrated that most food poisoning cases by S. Enteritidis in Gwangju, 1999, were originated from the same Salmonella Enteritidis strains.
Anti-Bacterial Agents ; Diarrhea ; Disease Outbreaks* ; DNA* ; Epidemiologic Studies* ; Feces ; Foodborne Diseases ; Gwangju* ; Humans ; Incidence ; Korea ; O Antigens ; Plasmids* ; Salmonella enterica* ; Salmonella enteritidis ; Salmonella*

BACKGROUND: During the past 10 years, there has been an increased incidence of gastrointestinal infections caused by salmonellae in Korea. In 1999, there were several outbreaks and sporadic occurrences of food borne infections due to Salmonella enterica serotype Enteritidis in Gwangju. Thus, there is a need for careful monitoring of its occurrence. METHODS: Salmonella Enteritidis were isolated from feces samples of patients with foodborne diarrhea in Gwangju, 1999. We performed antigen typing, examination of biochemical properties, anibiotic susceptibility test, plasmid typing and RAPD analysis to characterize of S. Enteritidis isolates. RESULTS: There were three Salmonella outbreaks (April, July, October), and 203 isolates of S. Enteritidis were isolated from the 286 patients. Eighteen isolates were obtained from the patients of sporadic occurrences. Antigenic types of the isolates were O antigen; D1 (1, 9, 12), H antigen phase 1; (g, m), serotype; Enteritidis. The isolates were susceptible to most of the antibiotics. We performed plasmid DNA analysis of the isolates, and the results showed 3 plasmids (8, 6, 3.8 kb) in 14 of 14 strains from outbreaks; 3 plasmids (8, 6, 3.8 kb) in 2 isolates from sporadic cases; 4 plasmids (8, 6, 3.8, 2 kb) in 10 isolates from sporadic occurrences, and 2 isolates from food specimens. However, 1 isolate from patients and 2 isolates from Ham-Yang, Kyung Nam, did not contain plasmids. RAPD analysis showed that all isolates from Gwangju in 1999 showed relatively uniform characteristics which were different from those derived from Ham-Yang, Kyung-Nam. CONCLUSION: The present data demonstrated that most food poisoning cases by S. Enteritidis in Gwangju, 1999, were originated from the same Salmonella Enteritidis strains.
Anti-Bacterial Agents ; Diarrhea ; Disease Outbreaks* ; DNA* ; Epidemiologic Studies* ; Feces ; Foodborne Diseases ; Gwangju* ; Humans ; Incidence ; Korea ; O Antigens ; Plasmids* ; Salmonella enterica* ; Salmonella enteritidis ; Salmonella*

Benign endobronchial tumors are rare diseases with an incidenced of between 1 and 5% of all lung tumors. An endobronchial fibroepithelial polyp is an extremely rare form of benign bronchial tumor. Clinically, an endobronchial fibroepithelial polyp causes an airway obstruction and obstructive pneumonitis as does other endobronchial tumors. Therefore, it is important to differentiate an endobronchial fibroepithelial polyp pathologically from other benign endobronchial tumors and bronchogenic carcinomas. Here, we report a case of an endobronchial fibroepithelial polyp, in a 25-year-old man who had suffered from chest discomfort upon deep breathing with a brief review of the relevant literature.
Adult ; Airway Obstruction ; Carcinoma, Bronchogenic ; Humans ; Lung ; Pneumonia ; Polyps* ; Rare Diseases ; Respiration ; Thorax