Array-Based Genomic Comparative Hybridization Analysis of Field Strains ofMycoplasma hyopneumoniae

Abstract

Mycoplasma hyopneumoniae is the causative agent of porcine enzootic pneumonia and a major factor in the porcine respiratory disease complex. A clear understanding of the mechanisms of pathogenesis does not exist, although it is clear that M. hyopneumoniae adheres to porcine ciliated epithelium by action of a protein called P97. Previous studies have shown variation in the gene encoding the P97 cilium adhesin in different strains of M. hyopneumoniae, but the extent of genetic variation among field strains across the genome is not known. Since M. hyopneumoniae is a worldwide problem, it is reasonable to expect that a wide range of genetic variability may exist given all of the different breeds and housing conditions. This variation may impact the overall virulence of a single strain. Using microarray technology, this study examined the potential variation of 14 field strains compared to strain 232, on which the array was based. Genomic DNA was obtained, amplified with TempliPhi, and labeled indirectly with Alexa dyes. After genomic hybridization, the arrays were scanned and data were analyzed using a linear statistical model. The results indicated that genetic variation could be detected in all 14 field strains but across different loci, suggesting that variation occurs throughout the genome. Fifty-nine percent of the variable loci were hypothetical genes. Twenty-two percent of the lipoprotein genes showed variation in at least one field strain. A permutation test identified a location in the M. hyopneumoniae genome where there is spatial clustering of variability between the field strains and strain 232.

Mhp107 Is a Member of the Multifunctional Adhesin Family of Mycoplasma hyopneumoniae

“…M. hyopneumoniae strain 232 (26) was used throughout this study unless stated otherwise. Additional strains of M. hyopneumoniae were isolated from various locations, including the laboratory-adapted strain J (25) and field strains OMZ407 (25), Hillcrest (isolated from New South Wales, Australia in 2003 and provided by Graeme Eamens at the Elizabeth Macarthur Agricultural Institute, New South Wales, Australia), 95MP1509 (27), 00MP1301 (27), C1735/2 (25), and 2-22421 (provided by J. Forbes-Faulkner, Oonoonba Veterinary Laboratory, Queensland, Australia). Escherichia coli TOP10 or BL21 star (DE3) (Invitrogen) were grown on LuriaBertani agar plates or cultured in Luria-Bertani medium with shaking at 200 rpm.…”

Real-Time PCR Assays To Address Genetic Diversity among Strains ofMycoplasma hyopneumoniae

“…One recent study has shown a considerable amount of genetic diversity among field isolates (12). To improve the diagnostic ability to detect field isolates of M. hyopneumoniae, the two real-time PCR assays developed for mhp165 and mhp183 were multiplexed.…”

“…A number of PCR assays have been developed and reported to be both sensitive and specific for M. hyopneumoniae (4,6,11,19,20,22,24,26). As a result, this technique is now among the most widely used for detection of M. hyopneumoniae in pigs.While the development of PCR assays has greatly enhanced our ability to detect M. hyopneumoniae, the genetic variability of the organism (1,5,12,14,15,21) can affect detection by PCR. It is not known what effect this heterogeneity has on the sensitivities of the different assays.…”

“…While the development of PCR assays has greatly enhanced our ability to detect M. hyopneumoniae, the genetic variability of the organism (1,5,12,14,15,21) can affect detection by PCR. It is not known what effect this heterogeneity has on the sensitivities of the different assays.…”

Impact of diversity of Mycoplasma hyopneumoniae strains on lung lesions in slaughter pigs

“…Mycoplasmas have small genomes (580–1300 kb) [3, 4], and genetic diversity might be one solution to adapt to the adverse environment of the host [5, 6]. Many regions in the genome of M. hyopneumoniae related to adherence in the host contain variable number of tandem repeats (VNTRs).…”