BACKGROUND: In developed countries, food-born diseases have decreased and hospital laboratory have taken more simple method rather than complex enrichment-selective methods. But detection rate of pathogenic bacteria in stool culture was not so high. METHODS: We mixed 4 pathogenic bacteria (S. typhi, S. flexneri, V. cholerae and Y. enterocolitica) with 3 stool specimens from healthy persons (for Y. enterocolitica, 5 specimens) and innoculated directly or after enrichment (105 bacteria/plate). After proper incubation, we counted suspected colonies and calculated true positive rate after identification of each colonies. RESULTS: For S. typhi, in the case of direct innoculation on the MacConkey, XLD and SS agar, positive rate of selected colonies were below 36.6%. After enrichment in SF broth for 8 hours, the rate were 80.0%, 83.0% and 70.0% respectively. For S. flexneri, the rates were 86.7%, 100%, 93.3% in direct innoculation, and were highest after enrichment in GN broth for two hours (93.3% in MacConkey and 100.0% in both XLD and SS agar). For V. cholerae, inspite of screening by catalase and oxidase tests, positive rate of selected colonies were 0% (0/7 colonies) in direct innoculation on the MacConkey. After enrichment in APW about 1 day and on TCBS agar, the rate were 100%. For Y. enterocolitica, after incubation at room temperature for 2 days, most selected colonies were Y. enterocolitica on CIN media. CONCLUSION: For more efficient detection of pathogenic bacteria in stool culture, combination of direct innoculation on MacConkey agar and on one or two selective media after proper enrichment process, should be considered.
Agar ; Bacteria ; Catalase ; Cholera ; Developed Countries ; Humans ; Laboratories, Hospital ; Mass Screening ; Oxidoreductases ; Salmonella ; Shigella ; Vibrio ; Yersinia

BACKGROUND: In the year 1996, there were some outbreaks of Salmonella typhi infection in Pusan and therefore, the incidence of S. typhi infection was markedly increased in comparison with the previous year. To differentiate the isolates epidemiologically, a random amplified polymorphic DNA(RAPD) fingerprinting method has been developed. METHODS: A total of 9 arbitrary primers were screened with S. typhi strains isolated in Pusan, 1996. This allowed selection of a panel of primers capable of detecting DNA polymorphisms among S. typhi isolates. This panel was used to examine 54 strains of S. typhi, which had been isolated in Pusan including the cases of outbreaks that was previously characterized by phage typing. RESULTS: Four single primers and one combination of two primers were selected to discriminate the S. typhi isolates. RAPD analysis resolved the 54 strains into 20 different subtypes. At least two outbreaks were found by RAPD analysis. The isolates of E1 phage type, which are the most common in Korea, were perfectly differentiated with each other, except the strains isolated within the outbreaks. CONCLUSION: The RAPD approach is the useful epidemiologic tool to S. typhi subtyping, which is providing high discriminatory power. There were at least two outbreaks when the epidemic Salmonella infections of Pusan in 1996 had been occurred. The primers or their comb ination capable to discriminate the S. typhi isolates were described.
Animals ; Bacteriophage Typing ; Bacteriophages ; Busan ; Comb and Wattles ; Dermatoglyphics ; Disease Outbreaks ; DNA* ; Incidence ; Korea ; Molecular Typing* ; Salmonella Infections ; Salmonella typhi* ; Salmonella*

BACKGROUNDS: Helicobacter pylori infection is now recognized as a cause of chronic gastritis, peptic ulcer disease, gastric carcinoma and lymphoma. Several diagnostic methods of H. pylori infection, such as histopathology, culture, rapid urease test, urea breath test, serologic test and polymerase chain reaction(PCR) have been used. This study aimed to compared with different diagnostic methods of H. pylori infection and determined the appropriate cut-off value of IgG anti-H. pylori antibody using receiver operating characteristic(ROC) curve. METHODS: We compared sensitivities, specificities and efficiencies of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR using the ureC gene in gastric biopsy specimens from 112 H. pylori patients and 140 control group. RESULTS: The sensitivities of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR were 72%, 91%, 86%, 82% and 94%, respectively and the specificities of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR were 96%, 99%, 100%, 73% and 99%, respectively. The efficiencies of histology, CLO test, culture, IgG anti-H. pylori Ab and PCR were 88%, 96%, 89%, 77% and 97%, respectively. From the ROC curve, the cut-off value of the anti-H. pylori Ab determined 10U/mL in which sensitivity was 82% and specificity was 82%. CONCLUSIONS: These findings suggest that the PCR assay in gastric biopsy is the most sensitive and efficient diagnostic method of H. pylori infection and the cut-off value of the anti-H. pylori Ab determines 10U/mL showing highest efficiency.
Biopsy ; Breath Tests ; Diagnosis* ; Gastritis ; Helicobacter pylori* ; Helicobacter* ; Humans ; Immunoglobulin G ; Lymphoma ; Peptic Ulcer ; Polymerase Chain Reaction* ; ROC Curve ; Sensitivity and Specificity ; Serologic Tests* ; Stomach Diseases ; Urea ; Urease

In the past decades there has been a dramatic increase in the number of opportunistic fungal infections. Establishing the diagnosis of opportunistic fungal infections in compromised patients is not simple. The laboratory diagnostic tests include microscopic examination, culture and serological tests. Although the most reliable method is the histologic examination, various opportunistic fungal agents can reveal similar histologic morphology. Culture should be attempted, however, the isolation of these organisms from cultures must be interpretated with caution, because the causing agents for opportunistic fungal infections are common laboratory contaminants. Serology for fungal infections has limited value except cryptococcal antigen: the usefulness of detection of antigenemia in invasive candidiasis and invasive aspergillosis has been limited by the rapid clearance of Candida mannan and Aspergillus galactomann from serum, which results in only moderate sensitivity for the disease. Therefore, it should be appreciated that every laboratory test, for the diagnosis of opportunistic infections, has its limitations and should be interpreted with caution.
Aspergillosis ; Aspergillus ; Candida ; Candidiasis, Invasive ; Clinical Laboratory Techniques* ; Diagnosis ; Diagnostic Tests, Routine ; Fungi ; Humans ; Mannans ; Opportunistic Infections ; Serologic Tests

No abstract available.

No abstract available.
Legionella*

No abstract available.

Recently, two groups reported independently on the isolation of new positive-trand RNA viruses, designated hepatitis G virus (HGV) & GB virus C (GBV-C). Sequence analysis revealed that both genomes are different isolates of the same virus & represent a new genus of Flaviviridae. The prevalence of HGV ranges from 0.9 to 10% among blood donors throughout the world. A high prevalence of HGV RNA has been found in subjects with frequent parenteral exposure, including intravenous drug users, patients on hemodialysis, patients with hemophilia and patients with anemia. HGV is a blood borne virus that is parenterally transmitted. Vertical transmission has also been reported. HGV commonly occurs as a coinfection with another hepatitis virus such as HCV or HBV. However, HGV coinfection usually does not alter the clinical course or level of biochemical marker and the response to antiviral therapy of chronic hepatitis B or C in these patients. Acute HGV infection rarely causes acute hepatitis and is unlikely to be a major cause of chronic non-A-E hepatitis or fulminant viral hepatitis. HGV infection can be diagnosed by PCR assay to detect the viral RNA in serum. An enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to recombinant HGV putative envelope protein E2 was recently available. But antibodies to E2 appears to be a serological marker for diagnosing recovery from HGV infection. Since the role of HGV as a etiologic agent of liver disease is unclear, therapy is not recommended at this point.
Anemia ; Antibodies ; Biomarkers ; Blood Donors ; Coinfection ; Diagnosis ; Drug Users ; Enzyme-Linked Immunosorbent Assay ; Flaviviridae ; GB virus C* ; Genome ; Hemophilia A ; Hepatitis B, Chronic ; Hepatitis Viruses ; Hepatitis* ; Humans ; Liver Diseases ; Polymerase Chain Reaction ; Prevalence ; Renal Dialysis ; RNA ; RNA Viruses ; RNA, Viral ; Sequence Analysis

No abstract available.

No abstract available.
Vibrio vulnificus* ; Vibrio*