The International Committee of Systematic Bacteriology Subcommittee on the taxonomy of Campylobacter and related bacteria has agreed in principle on minimum requirements for the description of new species of the genus Helicobacter. These requirements include the recommendation that the description of a putative new species or subspecies be based on examination of at least five strains in order to provide a measure of phenotypic and genotypic variation. Recommendations for required phenotypic and molecular data are presented. The requirements are consistent with the polyphasic approach to bacterial systematics.

A polyphasic taxonomic study of 15 bovine and human strains assigned to the catalase-negative, urease-positive campylobacter (CNUPC) group identified these bacteria as a novel, ureolytic biovar of Campylobacter sputorum for which w e propose the name C. sputorum bv. paraureolyticus : suitable reference strains are LMG 11764 (human isolate) and LMG 17590 (= CCUG 37579, bovine isolate). The present study confirmed previous findings showing that the salient biochemical tests used to differentiate C. sputorum bv. sputorum from C. sputorum bv. bubulus are not reproducible; and that the absolute validity of source-specific biovars of the species is questionable. A correlation between the results of numerical analysis of protein profiles and the reaction of strains in certain enzyme tests was, however, noted. Therefore, it is proposed that the infrasubspecific (biovar) divisions of C. sputorum should be revised to include bv. sputorum for catalase-negative strains; bv. fecalis for catalase-positive strains; and bv. paraureolyticus for urease-positive strains. Strains classified previously as bv. bubulus should be reclassified as bv. sputorum. The species description of C. sputorum is revised accordingly.

The use of numerical analysis of macrorestriction profiles resolved by pulsed-field gel electrophoresis (PFGE) for identifying epidemiological and clonal relationships between strains of Salmonella typhimurium was investigated. A cluster analysis based on Xba1 macrorestriction profiles of 40 strains was compared to biotype, phage-type and ribotype data on each isolate to validate the integrity and significance of the results. A significant correlation between these data was noted, suggesting that evolutionary divergence, of both recent and a more distant nature, may be detected. Moreover, two principal clonal lines of Salm. typhimurium appear to be prevalent in Denmark, of which one is comparatively stable with respect to phenotype and genotype, while the other is relatively diverse in these respects. We conclude that numerical analysis of macrorestriction profiles is a useful means of evaluating interstrain relationships between Salm. typhimurium strains and has practical applications for both short-and long-term epidermiological surveillance purposes.

A total of 21 clinical isolates of Campylobacter pylori from Peru and the United Kingdom and two reference strains (from Australia), including the type strain (NCTC 11637T), were characterized by high resolution one-dimensional SDS-polyacrylamide gel electrophoresis of cellular proteins. The protein patterns contained more than 40 discrete bands and the approximate molecular weights of the major bands were 22, 27, 46, 57, 60, 65 and 93 kD. The total patterns were used as the basis of numerical analysis. Most strains were clustered in four phenons at 91% similarity with the exception of six ungrouped strains. Overall similarity was high with all strains linked in the phenogram at greater than or equal to 81%. Variation among strains was attributable principally to qualitative and quantitative band differences in the 47 to 56 kD (hypervariable) region of the C. pylori protein profile. From the analysis, ten different electropherotypes (EP-types) were identified. We demonstrated that differences were detectable among isolates from widely separated geographical locations as well as from the same location, although multiple isolates from two Peruvian patients had the same electropherotype. Our results indicate that determination of protein profiles provides the basis of a reproducible method for characterization of C. pylori isolates.

Eighteen strains of Campylobacter sputorum bv. paraureolyticus (isolated over a 12-month period from seven dairy cows contained in a single herd) were examined by resistotyping, and macrorestriction profiling using pulsed field gel electrophoresis (PFGE). The resistotypes of these strains were identical, although repeat testing indicated resistance to metronidazole was not a reliable trait for typing purposes. Five SmaI-derived genotypes were identified among the 18 strains. In 5 of 7 cows, isolates obtained from the same animal, but from different time periods, were genotypically indistinguishable, indicating persistence of infection. Macrorestriction profiles of 5 strains representing the 5 SmaI genotypes and 8 other strains of C. sputorum from various sources, were prepared using 4 endonucleases (SmaI, SalI, BamHI and KpnI). The only other strain of C. sputorum bv. paraureolyticus examined (a Canadian isolate from human faeces), was found to have a SmaI macrorestriction profile identical with one of the five clones isolated from the cattle. Moreover, SalI and BamHI profiles of all bv. paraureolyticus strains were similar, while digestion with KpnI was not observed. By contrast, the seven strains of C. sputorum bv. sputorum yielded various macrorestriction profiles with all the enzymes used, and features distinguishing the two biovars studied could be identified. This study indicates that C. sputorum can persist in cattle for at least 12 months and exhibits a clonal population genetic structure.