Identification of Mycobacterium tuberculosis by Dot Blot Hybridization Using Digoxigenin-Iabeled Probe

Mycobacterium tuberculosis H37Rv ATCC 27294, restricted with EcoRI, was used to construct a genomic library in a bacteriophage expression vector, Lambda 9111. One 1.5-kb DNA fragment was selected by picoBlue immunoscreening kit on the basis of the ability to encode M. bovis-specific protein. Recombinant pBluescript with the 1.5-kb DNA was constructed into EcoRI site. Denatured DNA solution was blotted with BIO-DOT microfiltration apparatus(BIO-RAD) onto nylon membrane. The 1.5-kb probe, labeled with digoxigenin, reacted strongly with M. tuberculosis H37Rv, M. bovis, and 5 clinical isolates of M. tuberculosis. No hybridizations were observed with M. tuberculosis H37Ra, M. scrofulaceum, M. intracellulare, S. au reu s, S. epidennidis, S. marcescens, K. pneumoniae, E. coli, E. cloacae, P. vulgaris, and P. aeruginosa. When purified DNA from M. tuberculosis H37Rv was spotted onto nylon membrane, the 1.5-kb probe was able to detect 100 ng of DNA, which corresponds to 2 X 107 mycobacteria. This dot blot hybridization method using digoxigenin-Iabeled 1.5-kb probe may be applicable for identifying M. tuberculosis in hospital laboratories

A Case of Streptococcus gallolyticus subsp gallolyticus Infective Endocarditis with Colon Cancer: Identification by 16S Ribosomal DNA Sequencing

Although the association between Streptococcus bovis endocarditis and colon carcinoma is well known, very few cases of S. bovis infection associated with underlying malignancies have been reported in Korea The S. bovis group has been recently reclassified and renamed as Streptococcus gallolyticus and Streptococcus infantarius subspecies under a new nomenclature system. We report a case of infective endocarditis with colon cancer caused by S. gallolyticus subsp. gallolyticus (previously named S. bovis biotype 1). A 59-yr-old woman presented with a 1-month history of fever. Initial blood cultures were positive for gram-positive cocci, and echocardiography showed vegetation on mitral and aortic valves. Antibiotic treatment for infective endocarditis was started. The infecting strain was a catalase-negative and bile-esculin-positive alpha-hemolytic Streptococcus susceptible to penicillin and vancomycin. The strain was identified as S. gallolyticus subsp. gallolyticus with the use of the Vitek 2 GPI and API 20 Strep systems (bioMerieux, USA). The 16S rDNA sequences of the blood culture isolates showed 100% homology with those of S. gallolyticus subsp. gallolyticus reported in GenBank. The identification of the infecting organism, and the subsequent communication among clinical microbiologists and physicians about the changed nomenclature, led to the detection of colon cancer. The patient recovered after treatment with antibiotics, valve surgery, and operation for colon cancer. This is the first report of biochemical and genetic identification of S. gallolyticus subsp. gallolyticus causing infective endocarditis associated with underlying colon cancer in a Korean patient. (Korean J Lib Med 2010;30:160-5)Herrero IA, 2002, J CLIN MICROBIOL, V40, P3848, DOI 10.1128/JCM.40.10.3848-3850.2002Beck M, 2008, J CLIN MICROBIOL, V46, P2966, DOI 10.1128/JCM.00078-08Poyart C, 2002, INT J SYST EVOL MICR, V52, P1247, DOI 10.1099/js.0.02044-0Clarridge JE, 2001, J CLIN MICROBIOL, V39, P1549KOH DW, 2001, KOREAN J GASTROINTES, V23, P503Schlegel L, 2000, INT J SYST EVOL MICR, V50, P1425Ellmerich S, 2000, CARCINOGENESIS, V21, P753KWACK KK, 2000, KOREAN J MED, V59, P198Devriese LA, 1998, J CLIN MICROBIOL, V36, P3520COYKENDALL AL, 1989, CLIN MICROBIOL REV, V2, P315Schlegel L, 2003, INT J SYST EVOL MICR, V53, P631, DOI 10.1099/ijs.0.02361-0UH Y, 2006, KOREAN J CLIN MICROB, V9, P36RUOFF KL, 1989, J CLIN MICROBIOL, V27, P305FARROW JAE, 1984, SYST APPL MICROBIOL, V5, P467WILSON WR, 1981, JAMA-J AM MED ASSOC, V245, P360KLEIN RS, 1979, ANN INTERN MED, V91, P560KLEIN RS, 1977, NEW ENGL J MED, V297, P800MC CW, 1951, J MED ASS STATE ALA, V21, P162

Frequency and clinical implications of the isolation of rare nontuberculous mycobacteria

Background: To date, more than 125 species of nontuberculous mycobacteria (NTM) have been identified. In this study, we investigated the frequency and clinical implication of the rarely isolated NTM from respiratory specimens. Methods: Patients with NTM isolated from their respiratory specimens between July 1, 2010 and June 31, 2012 were screened for inclusion. Rare NTM were defined as those NTM not falling within the group of eight NTM species commonly identified at our institution: Mycobacterium avium, M. intracellulare, M. abscessus, M. massiliense, M. fortuitum, M. kansasii, M. gordonae, and M. peregrinum. Clinical, radiographic and microbiological data from patients with rare NTM were reviewed and analyzed. Results: During the study period, 73 rare NTM were isolated from the respiratory specimens of 68 patients. Among these, M. conceptionense was the most common (nine patients, 12.3%). The median age of the 68 patients with rare NTM was 68 years, while 39 of the patients were male. Rare NTM were isolated only once in majority of patient (64 patients, 94.1%). Among the four patients from whom rare NTM were isolated two or more times, only two showed radiographic aggravation caused by rare NTM during the follow-up period. Conclusions: Most of the rarely identified NTM species were isolated from respiratory specimens only once per patient, without concomitant clinical aggravation. Clinicians could therefore observe such patients closely without invasive work-ups or treatment, provided the patients do not have decreased host immunity towards mycobacteriaPeer Reviewe

Genetic Diversity and Exotoxin A Production of Group A Streptococci Causing Sepsis

The M protein and streptococcus pyrogenic exotoxin (SPE A) are important virulence factors in group A streptococci (GAS) infections. The emm types of GAS strains isolated from patients with sepsis were determined by sequencing the 5' N-terminus of the emm gene, encoding the M protein, and clonality analysis using pulsed-field gel electrophoresis. The presence of speA and production of SPE A were also examined. There were no predominant GAS clones. The emm genotypes were variable, and the most common genotype was emm13 (17.9%). The production prevalence of SPE A was 21.4%. The low mortality rate (7.1%) of GAS sepsis might be attributable to the low incidence of virulent strains such as emm1 (10.7%) and emm3 (7.1%), as well as to low production rate of SPE A

Real-Time PCR Method for HPV DNA Detection

Human papillomavirus (HPV) infection is an important etiologic factor in cervical carcinogenesis. Various HPV DNA detection methods have been evaluated for clinicopathological level. For the specimens with normal cytological finding, discrepancies among the detection methods were frequently found and adequate interpretation can be difficult. 6,322 clinical specimens were submitted and evaluated for real-time PCR and Hybrid Capture 2 (HC2). 573 positive or "Not Detected but Amplified" (NDBA) specimens by real-time PCR were additionally tested using genetic analyzer. For the reliability of real-time PCR, 325 retests were performed. Optimal cut-off cycle threshold ( ) value was evaluated also. 78.7% of submitted specimens showed normal or nonspecific cytological finding. The distributions of HPV types by real-time PCR were not different between positive and NDBA cases. For positive cases by fragment analysis, concordance rates with real-time PCR and HC2 were 94.2% and 84.2%. In NDBA cases, fragment analysis and real-time PCR showed identical results in 77.0% and HC2 revealed 27.6% of concordance with fragment analysis. Optimal cut-off value was different for HPV types. NDBA results in real-time PCR should be regarded as equivocal, not negative. The adjustment of cut-off value for HPV types will be helpful for the appropriate result interpretation

Acute Hemorrhagic Conjunctivitis caused by Coxsackievirus A24 Variant, South Korea, 2002

In summer 2002, a nationwide outbreak of acute hemorrhagic conjunctivitis occurred in South Korea. The etiologic agent was confirmed as coxsackievirus A24 variant (CA24v) by virus isolation and sequencing of a part of the VP1 gene. Phylogentic analysis, based on the protease 3C sequences, showed that the Korean isolates were clustered into a lineage distinct from the CA24v isolates reported in previous outbreaks in Asia

Outbreak of Shewanella algae and Shewanella putrefaciens infections caused by a shared measuring cup in a general surgery unit in Korea

OBJECTIVE: To control an outbreak of Shewanella algae and S. putrefaciens infections by identifying the risk factors for infection and transmission. DESIGN: Matched case-control study. SETTING: A university-affiliated tertiary acute care hospital in Seoul, Republic of Korea, with approximately 1,600 beds. PATIENTS: From June 20, 2003, to January 16, 2004, a total of 31 case patients with Shewanella colonization or infection and 62 control patients were enrolled in the study. INTERVENTIONS: Requirement to use single-use measuring cups and standard precautions (including hand washing before and after patient care and use of gloves). RESULTS: S. algae or S. putrefaciens was isolated from blood, for 9 (29.0%) of 31 patients who acquired one of the organisms; from bile, for 8 (25.8%), and from ascitic fluid, for 8 (25.8%). The attack rate of this outbreak was 5.8% (31 patients infected or colonized, of 534 potentially exposed on ward A) and the pathogenicity of the two species together was 77.4% (24 patients infected, of 31 who acquired the pathogens). The estimated incubation period for Shewanella acquisition was 3-49 days. Using logistic analysis, we identified the following risk factors: presence of external drainage catheters in the hepatobiliary system (odds ratio [OR], 20; P < .001), presence of hepatobiliary disease (OR, 6.4; P < .001), admission to the emergency department of the hospital (OR, 2.9; P = .039), wound classification of "contaminated" or "dirty or infected" (OR, 16.5; P = .012), an American Society of Anesthesiologists score of 3 or higher (OR, 8.0; P = .006), duration of stay in ward A (OR, 1.1; P < .001), and, for women, an age of 60-69 years (OR, 13.3; P = .028). A Shewanella isolate was recovered from the surface of a shared measuring cup, and 12 isolates of S. algae showed the same pulsed-field gel electrophoresis pattern. CONCLUSIONS: This Shewanella outbreak had a single-source origin and spread by contact transmission via a contaminated measuring cup. Shewanella species are emerging as potentially serious human pathogens in hospitals and could be included in hospital infection surveillance systems

Changes in Histopathological and Serological Findings of the Liver after Treatment in Rabbit Clonorchiasis

In order to elucidate the recovery course and the residual change of clonorchiasis after praziquantel treatment, the changing pattem of histopathological findings of the liver, along with the serological, biochemical and hematological parameters, were evaluated in experimental rabbit clonorchiasis. Twenty rabbits were infected each with 300 metacercariae of Clonorchis sinensis and treated with praziquantel 200 mg/kg 14 weeks after infection. Until one year after infection, a Widening of the bile ducts, proliferation of biliary epithelium, and periductal fibrosis were observed in the liver, although the lesions became much milder than those of the untreated rabbits. The levels of anti-e. sinensis IgG antibody in the sera by EUSA decreased continuously after treatment. Biochemical items and hematological parameters showed no consistent changing pattem after infection or after treatment. It can be suggested that the histopathological lesions of rabbit cionorchlais, i.e., duct dilatation, hyperplasia of biliary epithelium and periductal fibrosis, may be hardly reversible. However, the level of circulating specific IgG antibody decreased significantly according to the healing process of inflammation