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有会员求助让我将以下这篇文献翻译出来,我现将此转到这儿让大家共同来完成他的心愿,不知大家能帮帮他吗?
文题和摘要:
Comparison of Five Genotypic Techniques for Identification of
Optochin-Resistant Pneumococcus-Like Isolates
Rita Verhelst,1* Tarja Kaijalainen,2 Thierry De Baere,1 Gerda Verschraegen,1 Geert Claeys,1
Leen Van Simaey,1 Catharine De Ganck,1 and Mario Vaneechoutte1
Department of Chemistry, Microbiology and Immunology, Ghent University Hospital, Gent, Belgium,1 and
National Reference Laboratory for Pneumococcus, National Public Health Institute, Oulu, Finland2
Received 31 December 2002/Returned for modification 3 March 2003/Accepted 8 May 2003
Three PCR techniques (amplification of the psaA, ply, and lytA genes) and a commercial kit (AccuProbe
[GenProbe, San Diego, Calif.], based on hybridization with the 16S rRNA gene), all four of which claimed to
be specific for Streptococcus pneumoniae, were used to identify 49 alpha-hemolytic streptococcal isolates suspected of being pneumococci. The definite phenotypic identification of these organisms as S. pneumoniae was
difficult when optochin susceptibility and the presence of a capsule were taken as markers. Furthermore, RsaI
digestion of the amplified 16S rRNA gene was applied. All 49 strains were optochin resistant. Eleven of these
were encapsulated and were identified as pneumococci by all tests. Twenty of the 38 unencapsulated strains
were unambiguously identified as nonpneumococci by all tests. The identities of another 18 unencapsulated
strains remained inconclusive due to highly variable reactions for all phenotypic and genotypic techniques
applied. The AccuProbe test was positive for seven strains for which the results of the other tests were inconclusive. RsaI restriction of the amplified 16S rRNA gene confirmed the AccuProbe result for all strains, while
the result of the psaA-specific PCR was in concordance with encapsulation for all strains. The results presented
here indicate that identification problems continue to exist for some strains, despite the application of
genotypic and phenotypic tests in combination. We found the psaA-specific PCR to be the genotypic technique
best suited for the identification of genuine pneumococci and optochin-resistant pneumococci.
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