Campylobacter hyoilei Alderton et al. 1995 and Campylobacter coli Veron and Chatelain 1973 Are Subjective Synonyms

Abstract

The taxonomic affiliation of Campylobacter hyoilei was reevaluated by examining a variety of phenotypic and genotypic criteria. Whole-cell protein electrophoresis and a comparison of 66 phenotypic characters revealed that reference strains of C. hyoilei were indistinguishable from Campylobacter coli strains. These data were confirmed by a DNA-DNA hybridization level of 67% between the type strains of the two species. Several species-specific assays based on PCR amplification or probe hybridization further substantiated that C. coli strains and C. hyoilei strains are indistinguishable. It is therefore concluded that C. hyoilei and C. coli represent the same species and that the former name should be regarded as a junior synonym of the latter name. The taxonomic structure and relationships of the family Campylobacteraceae have been unravelled by an integrated polyphasic approach (40,41,44,49). As in many other lineages of the class Proteobacteria, results from rRNA homology experiments formed the framework used to revise the classification and nomenclature of campylobacters (17, 31, 36, 41, 44). Assignment of taxa to the genus Campylobacter and to the related genera Arcobacter and Helicobacter is primarily based on rRNA similarity data, in accordance with the present view of classification (namely, that natural relationships between bacteria [55] should be reflected where possible). Although definitely among the most valuable taxonomic tools, rRNA sequence analysis is not the appropriate method for resolving every problem in bacterial classification. The resolution of 16s rRNA sequence analysis for closely related species (organisms sharing more than 97% of their 16s rRNA sequences) has been shown to be low (5, 11, 35). For such organisms, DNA-DNA hybridization experiments are essential for species demarcation , and guidelines have been presented by an ad hoc committee (54). However, the interpretation of DNA-DNA hybridization results is often not straightforward as the threshold values for species delimitation vary among taxa and data obtained in different laboratories or with different hybridiza-tion methods often do not correlate (46). In the present study, we evaluated the criteria used to assign 12 porcine isolates to the new species Campylobacter hyoilei (1). Remarkably, strains classified as C. hyoilei and Campy-lobactel-coli were reported to produce exactly the same band patterns in several DNA probe hybridization assays, and the phenotypic data used to differentiate C. hyoilei from C. coli were at variance with other published data (1, 3, 27). MATERIALS AND METHODS Strains used. The strains used and their sources are listed in Table 1. Bacte-riological purity was checked by plating and examining living and Gram-stained cells. Polyacrylamide gel electrophoresis of whole-cell proteins. All of the strains examined were grown on Mueller-Hinton agar (catalog no. CM 337; Oxoid, Ltd., Basingstoke, United Kingdom) supplemented with 5% (vol/vol) horse blood and were incubated at 36 to 37°C in a microaerobic atmosp...

Campylobacter

“…They demonstrated the clonality of C. sputorum bv. paraureolytics determined by macrorestricion profiling and biotyping by using the 18 isolates isolated over a 12-month period from seven dairy cows contained in a single herd [181], Their study also indicated that the organism can persist in cattle for a long-term, at least 12 months.…”

Caracterização fenotípica e diversidade de bactérias diazotróficas associativas isoladas de solos em reabilitação após a mineração de bauxita

“…O perfil protéico dos seguintes isolados não foi revelado no gel: 11,36,50,51,53,54,55,56,57,58,59,60,61,65,66,68 , 1993;Dupuy et al, 1994;Lajudie et al, 1994;Moreira et al, 2000) que empregaram este método identificaram novas espécies de rizóbio. Além disso, Vandamme et al (1990), Kampfer, (1995 e Vandamme et al (1997) demonstraram haver alta correlação entre resultados de hibridização DNA:DNA e do perfil eletroforético de proteínas. Neste contexto, a alta dissimilaridade da maioria dos isolados em relação a estirpes tipo e referência, principalmente com relação aos padrões eletroforéticos de proteína total, admite a presença de novas espécies entre esses.…”

“…Padrões eletroforéticos de proteínas totais solubilizadas por SDS (dodecil sulfato de sódio) para identificação de espécies bacterianas têm fornecido informações relevantes nos estudos de caracterização e taxonomia, pois a expressão do genoma microbiano resulta na síntese de aproximadamente 2.000 moléculas de proteínas (Jackman, 1985). A correlação entre resultados de hibridização DNA:DNA e do perfil eletroforético de proteínas (Vandamme et al, 1997) tem sido evidenciada. Este método permite, principalmente, diferenciar estirpes e espécies (Rademaker & Bruijin, 1997), sendo considerado uma ferramenta útil para o estudo da diversidade de microrganismos em geral e tem sido aplicado no estudo de diazotróficos simbióticos (Moreira et al, 1993;Dupuy, et al, 1994, Lajudie et al, 1994.…”

Recommendations of the subcommittee on the taxonomy of Campylobacter and related bacteria.

“…These data showed C. hyoilei to be indistinguishable from C. coli. Vandamme et al (1997) proposed that the two species be regarded as synonymous, with C. coli taking nomenclatural precedence. The subcommittee members agreed to discourage the use of the name C. hyoilei in favour of C. coli.…”

“…They considered the strains to represent a species closely related to Campylobacter coli and Campylobacter jejuni and proposed the name Campylobacter hyoilei (Alderton et al, 1995). The taxonomic position of C. hyoilei was reevaluated by Vandamme et al (1997) by using a range of phenotypic and genotypic methods and, crucially, a classical quantitative DNA-DNA hybridization method. These data showed C. hyoilei to be indistinguishable from C. coli.…”