Carbohydrate patterns, cellular lipoquinones, fatty acids and phospholipids of the genus Pasteurella sensu stricto

Investigation of taxa of the family Pasteurellaceae isolated from Syrian and European hamsters and proposal of Mesocricetibacter intestinalis gen. nov., sp. nov. and Cricetibacter osteomyelitidis gen. nov., sp. nov

Eleven strains from hamster of Bisgaard taxa 23 and 24, also referred to as Krause’s groups 2 and 1, respectively, were investigated by a polyphasic approach including data published previously. Strains showed small, regular and circular colonies with smooth and shiny appearance, typical of members of the family Pasteurellaceae . The strains formed two monophyletic groups based on 16S rRNA gene sequence comparison to other members of the family Pasteurellaceae . Partial rpoB sequencing as well as published data on DNA–DNA hybridization showed high genotypic relationships within both groups. Menaquinone 7 (MK7) was found in strains of both groups as well as an unknown ubiquinone with shorter chain length than previously reported for any other member of the family Pasteurellaceae . A new genus with one species, Mesocricetibacter intestinalis gen. nov., sp. nov., is proposed to accommodate members of taxon 24 of Bisgaard whereas members of taxon 23 of Bisgaard are proposed to represent Cricetibacter osteomyelitidis gen. nov., sp. nov. Major fatty acids of type strains of type species of both genera are C14 : 0, C14 : 0 3-OH/iso-C16 : 1 I, C16 : 1ω7c and C16 : 0. The two genera are clearly separated by phenotype from each other and from existing genera of the family Pasteurellaceae . The type strain of Mesocricetibacter intestinalis is HIM 933/7T ( = Kunstyr 246/85T = CCUG 28030T = DSM 28403T) while the type strain of Cricetibacter osteomyelitidis is HIM943/7T ( = Kunstyr 507/85T = CCUG 36451T = DSM 28404T).

Classification of Pasteurella species B as Pasteurella oralis sp. nov

Pasteurella species B has so far only been reported from the oral cavity of dogs, cats and a ferret. In the present study, information from 15 recent isolates from different sources, including African hedgehogs (Atelerix albiventris), banded mongoose (Mungos mungo), Moholi bushbabies (Galago moholi) and pneumonia of a cat, were compared to five strains investigated previously from bite wounds in humans inflicted by a cat and dog and from gingiva of a cat. rpoB gene sequence comparison showed that 17 isolates, including the reference strain (CCUG 19794(T)), had identical sequences, whereas two were closely related and demonstrated 97.9 and 99.6 % similarity to strain CCUG 19794(T), respectively; the type strain of Pasteurella stomatis was the most closely related strain, with 92.3 % similarity. This is within the mean range (76-100 %) of rpoB gene sequence similarity between species of the same genus within the family Pasteurellaceae. 16S rRNA gene sequencing of four strains selected based on rpoB sequence comparison showed at least 99.7 % similarity between strains of Pasteurella species B, with 96.2 % similarity to the type strain of the closest related species (Pasteurella canis), indicating that Pasteurella species B should have separate species status. Separate species status was also documented when recN sequence comparisons were converted to a genome similarity of 93.7 % within Pasteurella species B and 59.0 % to the type strain of the closest related species (P. canis). Based on analysis of the phylogenetic and phenotypic data, and since most isolates originate from the oral cavities of a diverse group of animals, it is suggested that these bacteria be classified as Pasteurella oralis sp. nov.; the type strain is P683(T) ( = CCUG 19794(T) = CCM 7950(T) = strain 23193(T) = MCCM 00102(T)), obtained from a cat. Previous reports of the type strain have shown ubiquinone-8, demethylmenaquinone-8 and menaquinone-8 as the major quinones. Polyamines in the type strain were reported as diaminopropane, putrescine, cadaverine, sym-norspermidine, spermidine and spermine in a previous investigation, and the major fatty acids of the type strain were reported to be C(16:0), C(16:1)ω7c and C(14:0), with minor amounts of C(18:0) and C(18:1)ω9c. The DNA G+C content of the type strain has been reported to be 40.0 mol%.

Genomic fingerprints, ARDRA profiles and quinone systems for classification of Pasteurella sensu stricto

In order to investigate the relationships between species of the genus Pasteurella sensu stricto such as Pasteurella multocida, Pasteurella canis, Pasteurella stomatis, Pasteurella dagmatis, Pasteurella avium, Pasteurella volantium, Pasteurella gallinarum, Pasteurella species A, Pasteurella species B and "Pasteurella leonis" MCCM 00659 their genomic fingerprints and ARDRA profiles were compared and their quinone systems were analysed. Visual comparison of band patterns from rep-PCR (ERIC-, REP- and BOX-PCR) and the analyses of the combined band patterns by UPGMA (unweighted pair group method with averages) dendrogram derived from the combined fingerprint profiles demonstrated that each strain displays a distinct genomic fingerprint. In members of the same species several similarities in the band patterns were observed. Combined ARDRA profiles, obtained after digestion of amplified 23S rRNA coding genes with the enzymes DdeI, MseI and RsaI, revealed a dissection of the members of the genus Pasteurella sensu stricto into two groups which was in agreement with the two groups obtained from our analyses of the quinone systems. These two groups corresponded with the two phylogenetically determined subclusters 3A and 3B described previously. The species of subcluster 3A displayed a quinone system with ubiquinone Q-7 (32-56%) and ubiquinone Q-8 (44-63%) as major compounds. Members of subcluster 3B had a quinone system with ubiquinone Q-8 (86-97%) as the major compound. Based on these results it can be suggested that the genus Pasteurella sensu stricto should be restricted to the species of subcluster 3B including the species Pasteurella multocida, Pasteurella canis, Pasteurella stomatis, Pasteurella dagmatis and Pasteurella species B. In addition, evidence was found which would indicate that: 1) Pasteurella canis MCCM 00927 is misnamed and should be reclassified with Pasteurella multocida; 2) Pasteurella multocida subsp. septica may be classified as a separate species; and 3) "Pasteurella leonis" MCCM 00659 represents a separate species within subcluster 3B and thus could be described as a species of Pasteurella sensu stricto (also in a redefined genus) when more strains become available.

Growth medium affects the cellular fatty acid composition of Pasteurellaceae

We studied the cellular fatty acid composition of 10 Actinobacillus (A.) and Pasteurella (P.) reference strains grown on 2 types of agar by the MIDI Microbial Identification System (MIS). A. capsulatus, A. equuli, A. lignieresii, A. ureae, A. dagmatis, P. gallinarum, P. haemolytica, P. multocida, P. pneumotropica biotypes Heyl and Jawetz were grown on GC agar supplemented with ascitic fluid and X and V factor (Levinthal's agar = LA agar) or GC agar supplemented with vitox and hemoglobin (VH agar) on 3 to 7 and 7 to 16 occasions respectively and fatty acid methylester (FAME) profiles were submitted to principal component analysis (PCA). All Pasteurellaceae strains showed FAME profiles typical for the family. Maximum coefficients of variation of the percentage of the 3 major FAMEs 14:0, 16:0, and 16:1 cis were 0.03, 0.03 and 0.03 for Pasteurellaceae strains grown on VH agar and 0.09, 0.17 and 0.09 respectively for strains grown on LA agar. PCA of FAME profiles obtained with growth from LA agar generally did not allow species separation of the Pasteurellaceae but most species were clearly discriminated by PCA when they were grown on VH agar. Our findings indicate that the growth medium had a significant effect on the reproducibility of fatty acid profiling in Pasteurellaceae and that PCA of fatty acid data obtained under standardized growth conditions may discriminate Pasteurellaceae species.

Rapid differentiation of avian Haemophilus-like strains by their whole-cell carbohydrate patterns

The whole-cell carbohydrate patterns of 14 Haemophilus-like strains isolated from diseased birds were examined by capillary gas chromatography/mass spectrometry. The analysis of the peracetylated aldononitrile and O-methyloxime derivatives allowed the differentiation between the phenotypically and genetically different isolates. Starting from a pure culture the procedure needs only 5 hours for the preparation of the samples and 30 minutes for subsequent analysis and is of special value for rapid diagnosis.