Genome Sequence of Mycoplasma ovipneumoniae Strain SC01

Abstract

Mycoplasma ovipneumoniae is associated with chronic nonprogressive pneumonia in both sheep and goats. Studies concerning its molecular pathogenesis, genetic analysis, and vaccine development have been hindered due to limited genomic information. Here, we announce the first complete genome sequence of this organism.

GENOME ANNOUNCEMENT

Mycoplasma ovipneumoniae is considered to be a cause of nonprogressive pneumonia of both sheep and goats (1, 4, 7). As well as causing disease in its own right, M. ovipneumoniae predisposes animals to invasion by more serious respiratory pathogens, such as Mannheimia haemolytica, Pasteurella, and parainfluenza 3 virus (3, 5). Although M. ovipneumoniae is an important concern in the sheep and goat industry, little genomic information is available. Therefore, we sequenced the complete genome of M. ovipneumoniae to facilitate related studies in the future.

M. ovipneumoniae strain SC01 was isolated from the lung of a goat with pneumonia in Sichuan Province, China. Genomic DNA was extracted and sequenced using the Illumina GA. We constructed a 350-bp library and obtained 216.12 Mb of clean reads (97.69% paired-end reads). The reads were assembled using SOAP de novo (6). Gene prediction was performed using Glimmer3.0. rRNAs were analyzed with rRNAmmer. tRNA sequences were predicted by tRNAscan-SE. The genes were annotated through Blast searches in the databases Swiss-Prot and TrEMBL (release 2010-04), COG (version 2.0), KEGG (release 48.2), and NCBI-NR (release 2010-8-7).

The M. ovipneumoniae SC01 genome is 1,020,601 bp in length, with a GC content of 28.85%. The genome contains 864 putative coding sequences (CDSs) with an average gene length of 950 bp, and the mean coding percentage is 80.48%. There is only a single 16S-23S rRNA operon, and the 5S rRNA gene is separate from the 16S-23S rRNA operon. A total of 30 tRNA genes were identified. One prominent feature of the SC01 genome is the frequent usage of UUG as initiation codon. The number of UUG initiation codons is as high as 187, and these codons account for 21.6% of all initiation codons, which is the highest percentage among the mycoplasma genome sequences available so far.

M. ovipneumoniae strain SC01 contains several recognizable genes likely to be involved in virulence. Two proteins are highly similar to bacterial toxins, hemolysin A (hlyA) and hemolysin C (hlyC). They are also present in other mycoplasmas, such as M. hyopneumoniae, M. capricolum, and M. conjunctivae (2), although their contribution to pathogenicity in Mycoplasma species is unclear. Niang et al. (7) reported the correlation between ciliostasis induced by M. ovipneumoniae and hydrogen peroxide production. We identified three genes, glpF, glpK, and glpD, involved in glycerol import and production of H₂O₂ and reactive oxygen species. Mycoplasma infection depends on adherence to host epithelial cells. M. ovipneumoniae SC01 possesses at least 8 CDSs encoding proteins homologous to adhesin-like proteins of M. hyopneumoniae which is phylogenetically closely related to M. ovipneumoniae (8), including three homologues of P102-like protein, two homologues of adhesin like-protein P146, and one homologue to each of P97-like protein, adhesin, and P76 protein.

This is the first complete genome sequence of M. ovipneumoniae.

Nucleotide sequence accession numbers.

This Whole Genome Shotgun project has been deposited at DDBJ/EMBL/GenBank under the accession AFHO00000000. The version described in this paper is the first version, AFHO01000000.