A comparison using gel electrophoresis of cell proteins of campylobacters (vibrios) associated with infertility, abortion and swine dysentery

Bacillus paraflexus sp. nov., isolated from compost

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium capable of growing at 15–42 °C (optimum 30 °C) and at pH 5–11 (optimum pH 7) was isolated from compost. Its taxonomic position was deduced using a polyphasic approach and the strain was designated RC2T. 16S rRNA gene sequence analysis showed that the isolate belongs to the division Firmicutes , forming a clade within the cluster containing Bacillus flexus IFO 15715T, and showed highest similarity to B. flexus IFO 15715T (98.1 %). The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The major cellular fatty acids of the novel strain were iso-C15:0 (36.83 %), anteiso-C15:0 (49.19 %) and C16:0 (5.19 %). DNA–DNA hybridization between strain RC2T and B. flexus DSM 1320T showed a level of relatedness of 54.5 %. The polar lipid profile of strain RC2T showed the presence of phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine. The predominant isoprenoid quinone was MK-7 and the G+C content of strain RC2T was 37.6 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and the results of biochemical and physiological tests, strain RC2T was clearly distinguished from closely related members of the genus, and the strain is assigned to a novel species, for which the name Bacillus paraflexus sp. nov. is proposed. The type strain is RC2T ( = MTCC 9831T = MCC 2100T = KCTC 13724T = CCM 7754T).

Sample processing effect on polymerase chain reaction used for identification ofCampylobacter jejuni

Model samples of Campylobacter jejuni for polymerase chain reaction (PCR) were prepared by rapid and simple procedures consisting of centrifugation, proteinase K treatment, Chelex 100 treatment, and boiling lyses. A PCR based on specific amplification of the variable sequence of 16S rRNA gene was performed using Tth DNA polymerase and the PCR products were visualized by agarose gel electrophoresis. The assay allowed the detection of 10 CFU/mL C. jejuni in the physiological saline and 100 CFU/mL in the basic Park and Sanders broth.

Identification methods for campylobacters, helicobacters, and related organisms

The organisms which are referred to as campylobacteria are associated with a diverse range of diseases and habitats and are important from both clinical and economic perspectives. Accurate identification of these organisms is desirable for deciding upon appropriate therapeutic measures, and also for furthering our understanding of their pathology and epidemiology. However, the identification process is made difficult because of the complex and rapidly evolving taxonomy, fastidious nature, and biochemical inertness of these bacteria. These problems have resulted in a proliferation of phenotypic and genotypic methods for identifying members of this group. The purpose of this review is to summarize the problems associated with identifying campylobacteria, critically appraise the methods that have been used for this purpose, and discuss prospects for improvements in this field.

Polyphasic taxonomy, a consensus approach to bacterial systematics

Over the last 25 years, a much broader range of taxonomic studies of bacteria has gradually replaced the former reliance upon morphological, physiological, and biochemical characterization. This polyphasic taxonomy takes into account all available phenotypic and genotypic data and integrates them in a consensus type of classification, framed in a general phylogeny derived from 16S rRNA sequence analysis. In some cases, the consensus classification is a compromise containing a minimum of contradictions. It is thought that the more parameters that will become available in the future, the more polyphasic classification will gain stability. In this review, the practice of polyphasic taxonomy is discussed for four groups of bacteria chosen for their relevance, complexity, or both: the genera Xanthomonas and Campylobacter, the lactic acid bacteria, and the family Comamonadaceae. An evaluation of our present insights, the conclusions derived from it, and the perspectives of polyphasic taxonomy are discussed, emphasizing the keystone role of the species. Taxonomists did not succeed in standardizing species delimitation by using percent DNA hybridization values. Together with the absence of another "gold standard" for species definition, this has an enormous repercussion on bacterial taxonomy. This problem is faced in polyphasic taxonomy, which does not depend on a theory, a hypothesis, or a set of rules, presenting a pragmatic approach to a consensus type of taxonomy, integrating all available data maximally. In the future, polyphasic taxonomy will have to cope with (i) enormous amounts of data, (ii) large numbers of strains, and (iii) data fusion (data aggregation), which will demand efficient and centralized data storage. In the future, taxonomic studies will require collaborative efforts by specialized laboratories even more than now is the case. Whether these future developments will guarantee a more stable consensus classification remains an open question.

Identification of EF group 22 campylobacters from gastroenteritis cases as Campylobacter concisus

EF (E. Falsen) group 22, a group of Campylobacter strains sorted out by routine immunotyping among unidentified or misidentified human nonoral clinical specimens, was characterized by numerical analysis of gel electrophoretic protein profiles and immunotyping. The protein electrophoretic and immunotyping analyses, DNA:DNA hybridizations, and the DNA base composition demonstrated unambiguously that all EF group 22 strains belong to Campylobacter concisus. EF group 22 strains have DNA binding values of at least 42% with the type strain of C. concisus, showing a considerable degree of genomic heterogeneity. The isolation from blood, esophagus, stomach, duodenum, and feces of humans in association with different gastrointestinal disorders considerably extends the clinical significance of this species. Our results indicate that sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunotyping are excellent tools for the identification of the fastidious C. concisus strains and relatives.

Numerical analysis of electrophoretic protein patterns of Campylobacter laridis and allied thermophilic campylobacters from the natural environment

Twenty-one strains comprising Campylobacter laridis (nine), nalidixic acid sensitive campylobacters (NASC) (four), and urease-positive thermophilic campylobacters (UPTC) (eight) were characterized by one-dimensional SDS-PAGE of cellular proteins. The UPTC and NASC strains included six from river water, two from mussels and four from sea water. The type strains of three other Campylobacter species were included for reference. The protein patterns, which contained 45-50 discrete bands, were highly reproducible and were used as the basis for two numerical analyses. In the first, which included all the protein bands, the 21 strains formed nine clusters at the 80% similarity (S) level. The typical C. laridis strains were restricted to two phenons (2 and 5); the atypical strains being distributed among the remaining phenons. In the second analysis, which excluded the principal protein bands (40-48.5 kD range), the 21 strains formed five clusters at the 80% S level. The typical C. laridis strains were relatively homogeneous and fell into a single phenon (2) within which two subgroups were discernable. The atypical strains were more heterogeneous with respect to background protein pattern, with representatives appearing in all five phenons. An electropherotyping scheme comprising six electropherotypes, and based on both analyses is proposed. The high within-group S level and separation from reference strains of Campylobacter in the second analysis, suggested that UPTC and NASC strains belonged within C. laridis possibly as biovars.

Microscopic agglutination and polyacrylamide gel electrophoresis analyses of oral anaerobic spirochetes

Microscopic agglutination (MA) analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine strain and species similarities and dissimilarities among three species of oral anaerobic spirochetes, Treponema denticola, Treponema pectinovorum, and Treponema vincentii. The MA analysis revealed a diversity of serologic reactivity or sharing of common antigens within each species. However, there was no cross-reactivity or sharing of common antigens among the three species. Distinct SDS-PAGE whole-cell electrophoretograms for each species were obtained. The banding patterns for 16 T. denticola strains revealed 30 distinct proteins, while the banding patterns for 5 strains of T. pectinovorum and 2 strains of T. vincentii revealed 26 and 35 distinct proteins, respectively. Analysis of the electrophoretograms showed that their respective banding patterns could be used to distinguish the three species from one another. In addition, strain differences within each species could be detected. There was a correlation between MA analysis and SDS-PAGE analysis. It is thus suggested that both MA and SDS-PAGE analysis be included in classification schemes for the identification of oral spirochetes.

Differentiation of Campylobacter species by protein banding patterns in polyacrylamide slab gels

Soluble protein extracts of 37 catalase-positive strains of Campylobacter species were examined by polyacrylamide slab gel electrophoresis (PAGE). Electrophoretic banding patterns showed good correlation with biochemical tests and with available DNA homology data in distinguishing species of Campylobacter but did not differentiate subspecies or biotypes. PAGE patterns indicated that Campylobacter coli is a distinct species. Furthermore, the PAGE patterns indicated that C. jejuni and nalidixic acid-resistant thermophilic Campylobacter species (C. laridis) are each distinct species. The protein banding patterns of C. fetus subsp. venerealis and C. fetus subsp. fetus strains were distinctly different from those of the three thermophilic species.