Open AccessIdentification of Campylobacter fetus Subspecies by Phenotypic Differentiation and PCR
Author(s) -
Frank Schulze,
Audrey Bagon,
Wolfgang Müller,
Helmut Hotzel
Publication year - 2006
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.02566-05
Subject(s) - fetus , campylobacter fetus , biology , cefoperazone , aborted fetus , microbiology and biotechnology , genetics , antibiotic resistance , antibiotics , pregnancy , imipenem
The speciesCampylobacter fetus is divided into the subspeciesC. fetus subsp.venerealis andC. fetus subsp.fetus , which differ in their epidemiologies and clinical importance. The differences between these subspecies make accurate distinction between the two essential. First, the value of seven key tests for the traditional differentiation ofC. fetus was investigated. Afterwards, the results of the phenotypic differentiation and PCR were compared to address the question of the reliability of this PCR assay. Altogether, 103C. fetus isolates were investigated, including the type strains ofC. fetus subsp.fetus andC. fetus subsp.venerealis . Depending on the result of the glycine tolerance test, the isolates could be separated into 81C. fetus subsp.venerealis isolates (glycine intolerant) and 22C. fetus subsp.fetus isolates (glycine tolerant). For allC. fetus subsp.venerealis strains tested, the results of the selenite reduction assay and sensitivity to metronidazole and cefoperazone completely agreed with the results of the glycine tolerance test (correspondence, 100%). Seventy-threeC. fetus subsp.venerealis isolates did not grow at 42°C (correspondence, 90.1%), but eight isolates showed a faintly discernible, flat, dark gray growth. For 22C. fetus subsp.fetus isolates, the results of additional phenotypic tests only partly agreed with the results of the glycine tolerance test. ForC. fetus subsp.fetus the results of the glycine tolerance test showed a relatively good correspondence with those of the selenite reduction assay (correspondence, 81.8%), assays for cefoperazone resistance (correspondence, 86.4%), and assays for growth at 42°C (correspondence, 81.8%). The results of the glycine tolerance test and PCR completely agreed for the 103C. fetus isolates tested. We conclude that at present the traditional phenotypic characterization ofC. fetus subspecies under strongly defined conditions remains indispensable, but this PCR assay constitutes a valuable adjunctive technique for the confirmation of phenotypic results.