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The present study gives a detailed phenotypic and genotypic characterization of three Trueperella abortisuis strains isolated from a ten year old male Hovawart dog with an abscess of anal sac, from urine of an eight year old European shorthair cat with urolithiasis and nephrolithiasis and from a 14year old Maine Coon cat with a perianal abscess, respectively. All three strains could be identified phenotypically, by MALDI-TOF MS analysis and genotypically by sequencing the 16S rDNA and the molecular target genes gap and tuf. The present study gives a first description of T. abortisuis of this origin.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causal agent of Johne's disease in dairy cattle. Genotyping of MAP is useful to gain a better understanding of the origin of infection, to evaluate regional control programs, to improve diagnostics, and to develop vaccines. In this study 91 MAP isolates mainly from symptomatic dairy cattle in Rhineland-Palatinate (RP, Germany), its neighbor federal states, and Luxembourg were genotyped using Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeat (MIRU-VNTR) and Multilocus Short Sequence Repeats (MLSSR). MIRU-VNTR and MLSSR produced 11 and 6 different genotypes among the 91 isolates, respectively. The combined analysis of both methods produced 25 genotypes with an index of discrimination (D) of 0.93 (95% CI: 0.91-0.95). The results revealed the genetic diversity of MAP and the dominance of two MAP genotypes commonly found in Europe, showed the usefulness of MAP genotyping in studies at a regional scale, and provided useful information for control initiatives in RP.

The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi subsp. equi strains was amplified by polymerase chain reaction and subsequently digested with the restriction enzyme Hinc II. A restriction profile with two fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains indicating a sequence variation within the V2 region of the 16S rRNA gene of the remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA gene including the hypervariable V2 region of 11 S. equi subsp. zooepidemicus and two S. equi subsp. equi could be amplified by PCR and sequenced. The sequence of the V2 region of eight S. equi subsp. zooepidemicus strains appeared to be identical or almost identical to the sequence of the two S. equi subsp. equi strains. The sequence of the remaining three S equi subsp. zooepidemicus strains differed significantly from the sequence of S. equi subsp. equi. These differences allowed a division of S. equi subsp. zooepidemicus strains into two 16S rRNA types and might possibly have consequences for the taxonomic position of these phenotypically indistinguishable strains of one subspecies. A molecular typing could additionally be performed by amplification of the gene encoding the 16S-23S rRNA spacer region. A single amplicon of the spacer gene of 1100 bp could be observed for one S. equi subsp. zooepidemicus, an amplicon of 950 bp for two S. equi subsp. equi strains and 10 S. equi subsp. zooepidemicus strains, a amplicon of 780 bp for 27 S. equi subsp. zooepidemicus strains and a single amplicon of 600 bp for one S. equi subsp. zooepidemicus strain. The variations of the V2 region of the 16S rRNA gene and the size variations of the 16S-23S rRNA spacer gene were not related to each other. Both variations could be used for molecular typing of this species, possibly useful in epidemiological aspects.

Hyaluronic acid is thought to be one of the critical virulence factors of Streptococcus equi subsp. zooepidemicus. The present study was designed to study the role of hyaluronic acid capsular material in mediating adherence and to resist the phagocytosis of the host's immune defence. The studies were performed with two encapsulated S. equi subsp. zooepidemicus and two unencapsulated phase variants. The bacteria had been previously isolated from diseased pigs and monkeys in Indonesia. The presence of capsular material was determined using the hyaluronic acid decapsulation test and by electron microscopic studies. Both encapsulated bacteria showed mucoid colonies after cultivation on blood agar, grew with diffuse colonies in soft agar media and reacted negatively in the salt aggregation test. The unencapsulated bacteria grew with small colonies on blood agar, formed compact colonies in soft agar media and reacted positively in the salt aggregation test. Adherence and phagocytosis studies revealed that the encapsulated bacteria adhered significantly more to HeLa cells and were less phagocytosed by murine macrophages compared to unencapsulated bacteria. Pretreatment of the HeLa cells using hyaluronic acid or pretreatment of the bacteria by hyaluronidase decreased the adherence value of encapsulated bacteria. Pretreatment of bacteria with pronase had no effect. The presented results strongly indicate that the hyaluronic acid capsular material contributes to adherence properties of S. equi subsp. zooepidemicus and might help the bacteria to resist phagocytosis by macrophages.

The 16S r RNA gene of 49 streptococci of serological group B isolated from various origins was amplified by polymerase chain reaction (PCR) and subsequently digested with the restriction enzymes Rsa I and Msp I. The restriction profiles of all group B streptococci appeared to be identical indicating no intraspecies sequence variations of this gene. A fragment of the gene of two group B-streptococcal reference strains, including the hypervariable V2 region, could be amplified by PCR and sequenced. The sequence appeared to be identical and allowed the design of species-specific oligonucleotide primers. The primer pair used produced an amplicon with a size of 1250 bp and correctly identified all 49 group B-streptococci investigated but none of the control strains of various species and serogroups. This primer could be used in a multiplex PCR and allowed a rapid identification of bacteria of this species.

Streptococcus porcinus reference strains and routine isolates belonging to Lancefield's serogroup E, P, U and V and to various serotypes of serogroup E were examined for their 16S ribosomal DNA fingerprint pattern. Oligonucleotide primers complementary to 16S rRNA genes were used to amplify gene fragments by polymerase chain reaction from genomic DNA. The amplified 1450 bp fragment was subsequently digested with the restriction enzyme BpiI resulting in two fragments with a size of approximately 1250 by and 200 bp. All 45 S porcinus investigated in the present study could be identified on the basis of this characteristic 16S rDNA fingerprint pattern and clearly differentiated from 16 control strains of various species and serogroups of genus Streptococcus. The present results demonstrate the potential application of 16S rDNA analysis for identification of S porcinus, a species which might express various group- and type-specific antigens.