title: Genetic variability and limited clonality of Mycoplasma hyorhinis in pig herds.
abstract: Mycoplasma hyorhinis is a common inhabitant of the upper respiratory tract and tonsils of pigs. Its role as a possible pathogen remains controversial. In order to gain more insight into the epidemiology and population structure of M. hyorhinis we genetically characterized 60 isolates by multi locus sequence typing (MLST). The M. hyorhinis strains originated from Swiss and German pig herds with knowledge on the clinical background. The MLST scheme of Tocqueville et al. (J. Clin. Microbiol. 2014) was optimized, primers for the six MLST gene fragments were newly designed to allow amplification and sequencing with a single protocol. A total of 27 ST were observed with the 60 strains, 26 of those were previously unknown types. Generally identical genotypes were observed within a farm but they differed between farms. The identical genotype was also observed in three different Swiss farms. On the other hand different genotypes within a farm were found with three German farms. The Swiss isolates formed a distinct cluster but otherwise there was no geographical nor a clinical association with specific clusters observed. Data shows a high variability of M. hyorhinis comparable to what is observed for Mycoplasma hyopneumoniae. Similar to this pathogen the population structure of M. hyorhinis also shows some limited clonality with predominant genotypes within an animal and a single farm but different ones between farms. The comparable population structure of M. hyopneumoniae and M. hyorhinis could indicate a similar evolution of the two species in the common pig host.
authors.affiliation: Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstr, 122, 3001 Bern, Switzerland.
authors.forename: Bettina
authors.initials: B
authors.lastname: Trüeb
authors.affiliation: Department of Veterinary Science, University of Parma, Via del Taglio 8, 43126 Parma, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Catelli
authors.affiliation: Field Station for Epidemiology, University of Veterinary Medicine Hannover, Foundation, Bueschelerstr, 9, 49456 Bakum, Germany.
authors.forename: Adrian
authors.initials: A
authors.lastname: Luehrs
authors.affiliation: Clinic for Swine, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bremgartenstr, 109a, 3001 Bern, Switzerland.
authors.forename: Heiko
authors.initials: H
authors.lastname: Nathues
authors.affiliation: Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Laenggassstr, 122, 3001 Bern, Switzerland. Electronic address: peter.kuhnert@vetsuisse.unibe.ch.
authors.forename: Peter
authors.initials: P
authors.lastname: Kuhnert
mesh_terms: D000818:Animals; D002999:Clone Cells; D014644:Genetic Variation; D005838:Genotype; D005858:Germany / Q000453:epidemiology; D058885:Multilocus Sequence Typing; D045790:Mycoplasma hyorhinis / Q000235:genetics*; D010802:Phylogeny; D045729:Pneumonia of Swine, Mycoplasmal / Q000453:epidemiology / Q000382:microbiology*; D013552:Swine; D013557:Switzerland / Q000453:epidemiology
keywords: Coughing; Enzootic pneumonia; Genotyping; MLST; Pig disease