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Similar Strains (similar + strain)
Selected AbstractsMolecular epidemiological studies show that hepatitis A virus is endemic among active homosexual men in EuropeJOURNAL OF MEDICAL VIROLOGY, Issue 4 2007Kathrine Stene-Johansen Abstract Large outbreaks of hepatitis A have occurred in Denmark, Germany, the Netherlands, Norway, Spain, Sweden, and the United Kingdom during the period 1997,2005 affecting homosexual men. A collaborative study was undertaken between these countries to determine if the strains involved in these hepatitis A outbreaks were related genetically. The N-terminal region of VP1 and the VP1/P2A region of the strains were sequenced and compared. The majority of the strains found among homosexual men from the different European countries formed a closely related cluster, named MSM1, belonging to genotype IA. Different HAV strains circulated among other risk groups in these countries during the same period, indicating that specific strains were circulating among homosexual men exclusively. Similar strains found among homosexual men from 1997 to 2005 indicate that these HAV strains have been circulating among homosexual men for a long time. The homosexual communities are probably too small within the individual countries to maintain HAV in their population over time, whereas the homosexual communities across Europe are probably sufficiently large to sustain continued circulation of homologous HAV strains for years resulting in an endemic situation among homosexual men. J. Med. Virol. 79:356,365, 2007. © 2007 Wiley-Liss, Inc. [source] The first documented case of Aspergillus cardiac surgical site infection in Sweden: an epidemiology study using arbitrarily primed PCRAPMIS, Issue 8 2009ANNA BERGMAN Bergman A, Lignell A, Melhus Å. The first documented case of Aspergillus cardiac surgical site infection in Sweden: an epidemiology study using arbitrarily primed PCR. APMIS 2009; 117: 568,74. Here we report two rare cases of severe thoracic Aspergillus fumigatus infections after lung and heart surgery at the same thoracic intensive care unit at the same time. The main objective was to identify a possible source of transmission. With arbitrarily primed polymerase chain reaction a patient-to-patient transmission could rapidly be ruled out as the cause of the first documented case of aspergillosis after open-heart surgery in Sweden. Although no definitive source was identified, a genetically similar strain was found in a contaminated supply room. [source] Detection of spirochaetal microorganisms by focus floating microscopy in necrobiosis lipoidica in patients from central EuropeHISTOPATHOLOGY, Issue 7 2008K Eisendle Aims:, Necrobiosis lipoidica (NL) is a chronic inflammatory skin disease with unknown aetiology. The aim was to determine the presence of spirochaetal microorganisms in NL. Methods and results:, Focus-floating microscopy (FFM) is a modified immunohistochemical technique that was developed to detect borrelial spirochaetes within tissue sections. It has proven to be more sensitive for the detection of spirochaetes than polymerase chain reaction (PCR). Fifty-six cases of NL as well as 44 negative and 33 positive controls were investigated for the presence of Borrelia within tissue specimens. Using FFM, Borrelia could be detected in 42 cases (75.0%) and were seen significantly more often in histologically active inflammatory-rich (38/41, 92.7%) than in inflammatory-poor (4/15, 26.7%) cases of NL (P < 0.001). Seven cases investigated with a Borrelia- specific PCR (23s-RNA) remained negative. In contrast, FFM was positive in 30 of 33 (90.9%) positive controls of acrodermatitis chronica atrophicans and 15 of the positive controls (45.5%) were also positive with PCR, whereas no negative controls revealed any microorganisms. Conclusions:, Detection of spirochaetes in NL points to a specific involvement of B. burgdorferi or other similar strains in the development of or trigger for this disease. [source] Characterization of lactic acid bacteria strains on the basis of neutral volatile compounds produced in wheyJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2001G. Mauriello G. MAURIELLO, L. MOIO, G. MOSCHETTI, P. PIOMBINO, F. ADDEO AND S. COPPOLA. 2001. Aims: Seventy-eight strains of lactic acid bacteria belonging to five genera and showing six different phenotype combinations of Lac (lactose fermentation), Prt (proteolytic activity) and Cit (citrate degradation) characters were investigated for their main flavouring properties with the aim to detect variability among and within the groups. Methods and Results: High resolution gas chromatography,mass spectrometry analysis of neutral volatile compounds produced in whey showed that, considering both neo-formation compounds and substances quantified in the whey cultures at different concentrations in comparison to the extract from sterile whey, the groups of lactococci, enterococci, thermophilic streptococci and mesophilic lactobacilli produced a higher number of volatiles than thermophilic lactobacilli and leuconostocs. Applying principal component analysis (PCA) to the results, enterococci, mesophilic lactobacilli and thermophilic streptococci showed a broad diversity, while lactococci included rather similar strains as well as strains with special flavouring properties. Applying PCA to thermophilic streptococci and enterococci, to lactococci and enterococci, to lactococci and thermophilic streptococci, or to mesophilic and thermophilic lactobacilli, the strains gathered consistently with their systematic position. Conclusions: The study evidenced strains producing some volatile compounds responsible for food flavouring. Flavouring properties were variable among the systematic groups and in some cases different within the same bacterial group. Significance and Impact of the Study: The potential of the findings is discussed with reference to the development of flavouring adjuncts for the dairy industry. [source] Discrepancies between the phenotypic and genotypic characterization of Lactococcus lactis cheese isolatesLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2006M. De La Plaza Abstract Aims:, The use of randomly amplified polymorphic DNA (RAPD)-PCR fingerprinting and plasmid profiles to determine at the strain level, the similarity of Lactococcus lactis isolates obtained during sampling of traditional cheeses and to verify its correspondence to the selected phenotypic characteristics. Methods and Results:, A total of 45 L. lactis isolates were genotypically analysed by RAPD-PCR fingerprinting and plasmid patterns. Phenotypic traits used to compare strains were proteolytic, acidifying, aminotransferase (aromatic and branched chain aminotransferase) and , -ketoisovalerate decarboxylase (Kivd) activities. The results show that 23 isolates could be grouped in clusters that exhibited 100% identity in both their RAPD and plasmid patterns, indicating the probable isolation of dominant strains during the cheese sampling process. However, there were phenotypic differences between isolates within the same cluster that included the loss of relevant technological properties such as proteinase activity and acidifying capacity or high variation in their amino acid converting enzyme activities. Likewise, the analysis of a specific attribute, Kivd activity, indicated that 7 of 15 isolates showed no detectable activity despite the presence of the encoding (kivd) gene. Conclusion:, Phenotypic differences found between genotypically similar strains of L. lactis strains could be linked to differences in enzymatic expression. Significance and Impact of the Study:, Phenotypic analysis of L. lactis isolates should be considered when selecting strains with new cheese flavour forming capabilities. [source] Drug resistance and genotypic analysis of Mycobacterium tuberculosis strains from Thai tuberculosis patientsAPMIS, Issue 4 2009WATTANA CHEUNOY The aim of this study was the molecular characterization of primary drug-resistant Mycobacterium tuberculosis strains in Thailand. We examined a group of M. tuberculosis isolates from newly registered tuberculosis (TB) cases, collected at the largest university hospital, the Siriraj Hospital, in Thailand. Of 76 selected drug-resistant M. tuberculosis strains recovered from previously untreated pulmonary TB patients whose sputum samples were sent to this hospital, 29 (38%) were single-drug resistant, 26 (34%) multidrug resistant and two (2.6%) extensively drug resistant. Fifty (66%) strains belonged to Beijing genotype. The study demonstrate a severe problem of drug resistance among recently detected TB patients, and two large clusters of genetically similar strains indicated ongoing transmission of drug-resistant TB. [source] The emergence of Beijing family genotypes of Mycobacterium tuberculosis and low-level protection by bacille Calmette,Guérin (BCG) vaccines: is there a link?CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2006F. Abebe Summary The world is confronted with major tuberculosis (TB) outbreaks at a time when the protection of bacillus Calmette,Guérin (BCG) vaccine has become inconsistent and controversial. Major TB outbreaks are caused by a group of genetically similar strains of Mycobacterium tuberculosis (Mtb) strains, including the Beijing family genotypes. The Beijing family genotypes exhibit important pathogenic features such high virulence, multi-drug resistance and exogenous reinfection. These family strains have developed mechanisms that modulate/suppress immune responses by the host, such as inhibition of apoptosis of infected macrophages, diminished production of interleukin (IL)-2, interferon (IFN)-,, tumour necrosis factor (TNF)-, and elevated levels of IL-10 and IL-18. They demonstrate distinct expression of proteins, such as several species of ,-crystallin (a known Mtb virulence factor), but decreased expression of some antigens such as heat shock protein of 65 kDa, phosphate transport subunit S and a 47-kDa protein. In addition, the Beijing family strains specifically produce a highly bioactive lipid (a polyketide synthase)-derived phenolic glycolipid. This altered expression of proteins/glycolipids may be important factors underlying the success of the Beijing family strains. The Beijing family strains are speculated to have originated from South-east Asia, where BCG vaccination has been used for more than 60 years. The hypothesis that mass BCG vaccination may have been a selective factor that favoured genotypic and phenotypic characteristic acquired by the Beijing family strains is discussed. [source] | |||||||||||||