Macrolides and lincomycin susceptibility of Mycoplasma hyorhinis and variable mutation of domain II and V in 23S ribosomal RNA

• Published in: Journal of Veterinary Medical Science Vol. 67; no. 8; pp. 795 - 800
• Main Authors: Kobayashi, H.(National Inst. of Animal Health, Tsukuba, Ibaraki (Japan)), Nakajima, H, Shimizu, Y, Eguchi, M, Hata, E, Yamamoto, K
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 01.08.2005; Japan Science and Technology Agency
• Subjects: 23S ribosomal RNA; Animals; Anti-Bacterial Agents - toxicity; antimicrobial susceptibility; ARN; Base Pairing; Base Sequence; CERDO; DNA Primers; DRUG RESISTANCE; Escherichia coli; GENE; GENES; Lincomycin - toxicity; macrolide resistance; Macrolides - toxicity; Microbial Sensitivity Tests; Molecular Sequence Data; MUTACION; MUTATION; Mutation - genetics; MYCOPLASMA HYORHINIS; Mycoplasma hyorhinis - drug effects; Mycoplasma hyorhinis - genetics; PORCIN; RESISTANCE AUX MEDICAMENTS; RESISTENCIA A MEDICAMENTOS; RNA; RNA, Ribosomal, 23S - genetics; Sequence Analysis, DNA; Species Specificity; Sus scrofa - microbiology; SWINE; TILOSINA; TYLOSIN; TYLOSINE
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.67.795

A total of 151 strains of Mycoplasma hyorhinis isolated from porcine lung lesions (weaned pigs, n = 71, and finishers, n = 80) were investigated for their in vitro susceptibility to 10 antimicrobial agents. Thirty-one strains (28 from weaned pigs and 3 from finishers) showed resistance to 16-membered macrolide antibiotics and lincomycin. The prevalence of the 16-membered macrolide-resistant M. hyorhinis strain in weaned pigs from Japanese herds has approximately quadrupled in the past 10 years. Several of the 31 strains were examined for mutations in the 23S ribosomal RNA (rRNA). All field strains tested showed a transition of A to G at position 2059 of 23S rRNA-rendered Escherichia coli. On the other hand, individual tylosin- and lincomycin-resistant mutants of M. hyorhinis were selected in vitro from the susceptible type strain BTS7 by 3 to 9 serial passages in subinhibitory concentrations of each antibiotic. The 23S rRNA sequences of both tylosin and lincomycin-resistant mutants were compared with that of the radical BTS7 strain. The BTS7 mutant strain selected by tylosin showed the same transition as the field-isolated strains of A2059G. However, the transition selected in lincomycin showed mutations in domains II and V of 23S rRNA, G2597U, C2611U in domain V, and the addition of an adenine at the pentameric adenine loop in domain II. The strain selected by lincomycin showed an additional point mutation of A2062G selected by tylosin.