title: Subspecies variation in Greek strains of Chlamydophila abortus.
abstract: The Greek chlamydial strains FAS, FAG, VPG and LLG, isolated from aborted sheep or goat foetuses, had been previously characterized as divergent on the basis of mouse cross-protection experiments, with LLG and its homologous POS significantly different from the rest in inclusion morphology, polypeptide profiles and reactivity with monoclonal antibodies. To determine the genetic basis of their divergence the 16S-23S ribosomal intergenic spacer was analysed by RFLP analysis of PCR 16SF2/23R amplicons. Using the restriction enzymes BfaI, SfcI, HpaI, BclI, DdeI and AclI, the strains were classified as Chlamydophila abortus. However, digestion with RsaI made it possible to differentiate strains FAS, FAG and VPG from strains LLG and POS, generating DNA fragments of 530/55 and 585bp, respectively. By subsequent sequence analysis of the 23S domain I rRNA gene only strain FAS was identical to reference strain A22 of C. abortus. Strains FAG and VPG presented an identical nucleotide deviation at position 593 of signature sequences. Strains LLG and POS presented three identical nucleotide deviations at positions 156, 186 and 307. Variation within the domain I signature sequences for the examined abortion strains was < or =0.69%. In conclusion, substantial genetic and biological diversity among strains of C. abortus was demonstrated, suggesting that subspecies variation status for certain strains may be applicable. Our findings suggest that differentiation may be possible at a subspecies level by RFLP analysis.
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Aristotle University, 540 06, Thessaloniki, Greece. vickysi@vet.auth.gr
authors.forename: Victoria
authors.initials: V
authors.lastname: Siarkou
authors.forename: Alexandros F
authors.initials: AF
authors.lastname: Lambropoulos
authors.forename: Sofia
authors.initials: S
authors.lastname: Chrisafi
authors.forename: Alexandros
authors.initials: A
authors.lastname: Kotsis
authors.forename: Orestis
authors.initials: O
authors.lastname: Papadopoulos
mesh_terms: D000034:Abortion, Veterinary / Q000382:microbiology*; D000818:Animals; D001483:Base Sequence; D023501:Chlamydophila / Q000145:classification* / Q000235:genetics; D023521:Chlamydophila Infections / Q000382:microbiology / Q000662:veterinary*; D004275:DNA, Ribosomal / Q000235:genetics; D021903:DNA, Ribosomal Spacer; D005784:Gene Amplification; D014644:Genetic Variation / Q000235:genetics*; D015511:Goat Diseases / Q000382:microbiology*; D006041:Goats; D006115:Greece; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D015183:Restriction Mapping / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*
chemical_list: D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S