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() is considered to be one of the most important mycoplasmas causing respiratory disease in small ruminants. Most epidemiologic and characterisation studies have been conducted on strains collected from sheep. Information on the presence and characteristics of in healthy and pneumonic goats is limited. Phenotypic or genotypic differences between sheep and goat isolates have never been studied. The objective of our study was to characterise and compare the similarities and differences between caprine and ovine strains isolated from affected and asymptomatic animals in order to elucidate phenotypic and genotypic variability. Four different techniques were used on a set of 23 isolates. These included SDS-PAGE, Western blotting, random amplified polymorphic DNA and the heat shock protein 70 gene sequence-based method. A high degree of phenotypic and genotypic heterogeneity among strains was demonstrated in this study. Our results demonstrated differences between goat and sheep strains, revealing not only a link between strains and host ruminant species, but by geographical origin as well. However, the finding of immunodominant antigens of molecular masses 36, 38, 40 and 70 kDa (±3 kDa) in isolates from sheep and goats foretells their potential use in the development of serological diagnostic tests and vaccines.

Mycoplasmas are the smallest and simplest organisms known. They form a large group of bacteria that can infect humans, animals, and plants. Even though several techniques have been proposed to enumerate mycoplasmas in broth medium, the determination of mycoplasma growth still remains a difficult task. The potential of using flow cytometry (FC) for rapidly estimating several species of mycoplasmas, M. agalactiae (Ma), M. putrefaciens (Mp), M. capricolum subsp. capricolum (Mcc), M. bovis (Mb), M. capricolum subsp. capripneumoniae (Mccp) and M. hyopneumoniae (Mh) in broth medium was examined. The FC analysis was performed by staining the mycoplasma cells with a fluorescent dye, SYBR green-I (SYBR), and the results were compared with plate count (Colony Forming Units--CFU) or Colour Changing Units (CCU) methods, depending on the mycoplasma species. There was a good correlation between mycoplasma counts determined by FC (cells ml(-1)) and by traditional plate count (CFU) or CCU methods. A correlation of 0.841, 0.981, 0.960, 0.913, 0.954, and 0.844 was obtained for Ma, Mp, Mcc, Mb, Mccp and Mh, respectively. FC method allowed results in 20-30 min, while 24-72 h was necessary for plate count method and 15 days for CCU method. FC was found to be a very useful, practical and fast technique to count mycoplasmas. These findings suggest that FC can be a good alternative to replace other time-consuming techniques that are currently used to enumerate mycoplasmas in broth medium.

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