Comparative susceptibilities of various animal-pathogenic mycoplasmas to fluoroquinolones.

The in vitro activities of six antimicrobial agents were tested against 162 mycoplasma strains of eight species isolated from poultry and livestock at different geographic sites. Tiamulin was most active (MICs at which 90% of the isolates were inhibited [MIC90s], 0.025 to 0.25 microg/ml); enrofloxacin and danofloxacin had near equivalent activities (MIC90s, 0.05 to 1.0 microg/ml), but were much more active than flumequine (MIC90s, 1 to 50 microg/ml). The MIC90s of tylosin and oxytetracycline were 0.25 to > 100 microg/ml and 0.25 to 100 microg/ml, respectively.

An outbreak of respiratory disease in horses associated with Mycoplasma felis infection.

Lower respiratory tract disease developed in a group of racehorses in training between two and six years of age. Disease was observed in 22 of 25 horses for which full records were available. Seroconversion to Mycoplasma felis was demonstrated by indirect haemagglutination assay in 19 of 22 paired sera and high titres (> or = 64) were found in convalescent sera from the three remaining horses. Evidence of respiratory viral infection was confined to seroconversions to equine herpesvirus-4 in two of the horses. Tracheal wash samples, taken from four horses with visibly increased tracheal mucopus, contained more than 10(4) colony forming units/ml M felis and high proportions of neutrophils. This is the first description of an outbreak of lower respiratory tract disease in horses in training associated with M felis infection.

A rapid and sensitive method for the detection of mycoplasmas in infected cell cultures using 6-methyl purine deoxyriboside.

6MPDR causes the death of cells lightly infected with mycoplasmas. This is brought about by the action of the mycoplasmal enzyme adenosine phosphorylase which converts 6MPDR to highly toxic metabolites. If the medium conditions are adjusted to favour the growth of mycoplasmas by the addition of pig serum to the medium, infections as low as 1 mycoplasma per 200,000 cells can be detected within 7 days. This finding enables mycoplasma tests to be carried out rapidly and reliably by untrained personnel.

Biological and serological comparison of two embryo-lethal mycoplasmas isolated from turkeys.

Two uncharacterised, independently isolated, embryo-lethal mycoplasmas obtained from turkeys and designated W8 and CT were compared with each other and with a third, culturally similar, embryo-lethal turkey mycoplasma, Iowa 695, by cultural and serological methods. The three mycoplasma isolates were serologically distinct and CT could be differentiated from W8 by its ability to reduce 2,3,5-triphenyltetrazolium chloride under aerobic conditions.

Method for concentrating antisera for preparing Mycoplasma growth inhibition discs.

Mycoplasma growth inhibiting antibody in rabbit anitsera was concentrated with a dry polyacrylamide gel. Discs prepared with such concentrated antisera inhibited only the homologous organism provided the antisera had been heated at 56 degrees C for 30 min, and when dried retained their potency during storage for over two years at 4 degrees C.

A solid medium for culture and identification of human T-mycoplasmas.

A solid urea-containing medium buffered to pH 6.5 with a suitable mixture of KH2PO4 and Na2HPO4 produced enlarged T-mycoplasma colonies containing a white precipitate. This was absent from M. hominis colonies. The medium can be used for the isolation and identification of T-mycoplasmas.

Haemagglutination and haemagglutination inhibition with Mycoplasma synoviae.

A haemagglutinating antigen prepared from cultures of M synoviae WVU 1853 successfully detected homologous haemagglutination inhibition (HI) in sera of fowls and turkeys inoculated with M synoviae. Nonspecific HI was encountered with normal fowl sera but this was removed by treatment with receptor destroying enzyme. It is suggested that M synoviae. HA antigen will be a useful reagent for the diagnosis of M synoviae infection.

Flat gel polyacrylamide electrophoresis of porcine mycoplasmas.

The flat gel acrylamide electrophoresis technique was standardized and applied to the comparison of four species of porcine mycoplasmas. Clear differences were observed between these species, and differences were seen among the strains of Mycoplasma hyosynoviae. The clarity of the patterns and the number of bands developed was influenced by the amount of protein in the extract and the age of the culture. The technique allows the comparison of several protein extracts in parallel without the problems associated with the rearrangement of separate gel columns.