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Strains of Mycoplasma mycoides subspecies capri (Mmc) are frequently isolated from goats with contagious agalactia, but they can also be recovered from herds that have shown no clinical signs of mycoplasmosis for several years. The present study was conducted in order to explore the potential genetic and antigenic differences existing between an Mmc strain isolated from an outbreak (septicaemic) and a strain isolated from the ear canal of a goat belonging to a herd with no recent episode of mycoplasmosis (carriage strain). The genomes of the two strains, compared by suppression subtractive hybridization, were shown to be poorly divergent. The two strains were inoculated into goats to produce specific antisera, but both induced fatal mycoplasmosis. These results indicate that septicaemic and carriage strains cannot be distinguished by their genetic background or by their pathogenic capacity under experimental conditions., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The immunogenicity of Mycoplasma mycoides subsp. mycoides small colony biotype (MmmSC) vaccines was investigated in BALB/c mice. Groups of mice were vaccinated with either (1) unconjugated capsular polysaccharide (CPS), (2) CPS covalently conjugated to ovalbumin via a carbodiimide reaction, (3) CPS non-covalently bound to latex microspheres, (4) CPS non-covalently complexed with rabbit anti-CPS IgG, and (5) whole inactivated, ultrasonically disrupted (WID) MmmSC. Only mice immunized with the CPS-ovalbumin conjugate exhibited a significant (P<0 small middle dot001) antibody response against CPS. Mice immunized with WID vaccine exhibited a high ELISA antibody titre against non-CPS (protein) antigens only. Mice given WID vaccine were immune against challenge with live MmmSC, and exhibited a significantly reduced degree of mycoplasmaemia (both in incidence and duration) as compared with non-vaccinated controls (P<0 small middle dot001). Mice immunized with the CPS-ovalbumin conjugate did not exhibit a reduction in mycoplasmaemia. The bactericidal activity of rabbit MmmSC-antiserum in an in-vitro growth inhibition test was related to the CPS antibody titre. This was not observed with antisera from the vaccinated mice. None of the mouse antisera exhibited growth inhibiting activity, irrespective of a high CPS or protein antibody titre (CPS-ovalbumin or WID vaccine groups, respectively). Thus, it would seem that protection against an MmmSC-induced mycoplasmaemia in the mouse is based upon cell-mediated rather than humoral immunity. The results suggest that conjugation to ovalbumin significantly increases the antibody response to CPS in the mouse; the lack of bactericidal activity of mouse anti-CPS as compared with rabbit anti-CPS in vitro suggests either that the titre of growth inhibiting antibodies is lower in the mouse or that the mechanism of growth inhibition differs between antibodies of the two species., (Copyright Harcourt Publishers Ltd.)

Between 1990 and 1993, 61 outbreaks of contagious bovine pleuropneumonia (CBPP) were reported in Lombardy, Northern Italy. In this study, gross pathological examination was carried out on 3129 slaughtered cattle, 716 of which (22.9%) showed typical CBPP pulmonary lesions. Single or multiple renal infarcts at different stages of development were observed in 88 (12.2%) of these 716 cattle. The kidneys of 77 cattle whose lungs showed typical CBPP lesions and were bacteriologically and immunohistochemically positive for the small colony type of Mycoplasma mycoides subspecies mycoides (M. m. mycoides SC) were selected and submitted to histological, immunohistochemical and bacteriological examination. Histologically, in chronic CBPP cases, infarcts were characterized by fibrosis, calcification of cortical tubules and tubular atrophy, accompanied by the presence of interstitial inflammatory infiltrates composed of lymphocytes, plasma cells and histiocytes. M. m. mycoides SC antigen was detected immunohistochemically in 65 (84.4%) of the 77 kidneys examined. The antigen was detected in the lumen of blood vessels and in glomerular cells. Immunolabelled interstitial cells and tubular epithelial cells were seen in chronic cases only. M. m. mycoides SC was isolated from the kidneys of 12 animals (15.6%) and more frequently in cases with renal infarcts. This study confirms previous observations that demonstrated a renal involvement in cases of CBPP. Moreover, the immunohistochemical results indicated that M. m. mycoides SC antigen was frequently detectable in different renal structures and cells in spontaneous cases of CBPP., (Copyright Harcourt Publishers Ltd.)

The gene encoding a lipoprotein of 67 kDa, named P67, was cloned from Mycoplasma sp. bovine group 7 strain PG50 and expressed in Escherichia coli K12. Analysis of the amino acid sequence derived from the DNA sequence of the P67 gene revealed a typical prokaryotic signal peptidase II membrane lipoprotein lipid attachment site and a transmembrane structure domain in the leader sequence at the amino-terminal end of the protein. Protein P67 showed 91% identical amino acid residues to the lipoprotein P72 of Mycoplasma mycoides subsp. mycoides small colony type (SC) and 53% identical amino acid residues to a peptide of an unassigned gene on the genome of Mycoplasma capricolum subsp. capricolum. Antibodies made against recombinant P67 reacted with a 67-kDa protein in all Mycoplasma sp. bovine group 7 strains tested and also, to some extent, with P72 of Mycoplasma mycoides subsp. mycoides SC. The gene encoding P67 was present in all strains of Mycoplasma sp. bovine group 7 analysed, but not in other Mycoplasma sp. of the "mycoides cluster" and not in the phylogenetically related Mycoplasma putrefaciens. PCR and restriction fragment analysis revealed that the gene of P67 is conserved in all strains of Mycoplasma sp. bovine group 7. A specific PCR reaction based on the P67 gene sequence enabled rapid identification of strains belonging to Mycoplasma sp. bovine group 7.

In a population of 700 goats, 150 died; of these, 29 were necropsied. Ten of the 29 goats had pleuropneumonia. Mycoplasma mycoides subsp. mycoides (Large Colony) (MmmLC), Mycoplasma mycoides subsp. capri (Mmc), and Pasteurella multocida were isolated from five of the pleuropneumonic goats. Gross and microscopical lesions were typical of caprine pleuropneumonia (CPP), with bronchopneumonia, fibrinopurulent or fibrinonecrotic pleuropneumonia and dilatation of the interlobular septa and pleura. Immunohistochemical examination with antisera against MmmLC and Mmc showed mycoplasma antigens in all 10 goats with CPP. In all cases, both MmmLC and Mmc antigens were detected together. Mycoplasma antigens were present in the lumina of the airways and alveoli, mainly inside the cytoplasm of neutrophils and macrophages, but extracellular antigen was demonstrated in areas of necrosis. Pasteurella antigens were detected in four of the 10 animals with CPP. From the histological, immunohistochemical and microbiological results it was concluded that the two mycoplasmas, acting together, caused the pleuropneumonia, with P. multocida playing a subsidiary synergistic role.