Multilocus sequence typing of Mycoplasma agalactiae.

Mycoplasma agalactiae is the main cause of contagious agalactia, a serious disease of sheep and goats, which has major clinical and economic impacts. We have developed a multilocus sequence typing (MLST) scheme using the sequenced genomes of the M. agalactiae strains PG2 and 5632. An MLST scheme based on the genes gltX, metS, gyrB, tufA and dnaA was designed and in total 3468 bp of sequence were analysed for each strain. MLST offers a highly discriminatory typing method for M. agalactiae and was capable of subdividing 53 strains into 17 distinct sequence types, largely according to geographical origin. MLST detected unexpected diversity in recent isolates from Spain, identifying two novel outliers, and enabled typing of novel Mongolian isolates for the first time. Genetic diversity in the sequenced regions was largely due to mutation, with recombination playing a much smaller role. A web-accessible database has been set up for this MLST scheme for M. agalactiae: http://pubmlst.org/magalactiae/. MLST offers a robust, objective molecular epidemiological tool for M. agalactiae that that enables interlaboratory comparison of data.

Vaccines for Mycoplasma diseases in animals and man.

Vaccines for important mycoplasma diseases, including contagious bovine and caprine pleuropneumonia, have been used for centuries, consisting mainly of infected tissue or fluids which are inoculated into sites at which the risk of severe infection is slight, such as the tail and bridge of the nose. Surprisingly, little progress has been made in developing safe, defined and protective alternatives, the vaccines today still consisting of mildly attenuated strains serially passaged in eggs or in culture. Ill-defined temperature-sensitive mutants are widely used for mycoplasmoses in poultry despite uncertainty about their mode of protection. Inactivated vaccines for enzootic pneumonia appear to have improved pig health worldwide, but disease reduction has been generally modest. Ironically, attempts to develop subunit preparations have often led to exacerbation of disease, particularly in human atypical pneumonia. Promising results have been seen in DNA vaccine technology, which has been applied to the development of mycoplasma vaccines for porcine enzootic pneumonia, but field trials still seem a long way off. No commercial vaccines exist for Mycoplasma bovis, despite evidence that this is a major cause of calf pneumonia, mastitis and arthritis.

Isolation and characterization of unusual Mycoplasma spp. from captive Eurasian Griffon (Gyps fulvus) in Sicily.

Mycoplasmas have been isolated from birds of prey during clinical examinations, but their significance to the health of raptors is unclear. We report the isolation and characterization of four mycoplasmas found in the upper respiratory tract of four sick Eurasian Griffon (Gyps fulvus) that were housed in a Sicilian rehabilitation center at Ficuzza, near Palermo in Sicily, before reintroduction into the wild. These included Mycoplasma gallinarum, an unidentified mycoplasma highly similar to Mycoplasma glycophilum, and two unidentified mycoplasmas with similarities to Mycoplasma falconis and Mycoplasma gateae.

A high level of strain variation within the Mycoplasma ovipneumoniae population of the UK has implications for disease diagnosis and management.

Mycoplasma ovipneumoniae is one of only two mycoplasma species associated with small ruminant disease in Britain and has been associated with an increasing number of disease outbreaks since 2002. This investigation used well-defined techniques to assess the variability of UK M. ovipneumoniae isolates, in an attempt to identify strain clusters within the population. Strains received for routine diagnosis between 2002 and 2004 were analysed using random amplified polymorphic DNA (RAPD) and pulsed field gel electrophoresis (PFGE). Of the 43 samples screened 40 RAPD Hum-1, 41 RAPD Hum-4 and 40 PFGE profiles were observed. Composite data analysis divided strains into 10 similarity clusters with SDS-PAGE and Western blotting indicating that this DNA variability is translated into a pattern of variable protein expression. In order to assess the strains isolated within flocks two sets of samples, from diverse locations, were included in this test panel. The presence of variable isolates existing on the same farm may reflect animal movement and the introduction of asymptomatic, carrier, animals where M. ovipneumoniae is already established within a flock. These findings have significant implications regarding disease diagnosis and management.

Effect of nifedipine on total ischemic activity and circadian distribution of myocardial ischemic episodes in angina pectoris.

A randomized, double-blind, crossover study was conducted in 10 patients to assess the effect of nifedipine versus placebo on total ischemic activity and circadian distribution of ischemic episodes. After baseline exercise treadmill testing and 48-hour ambulatory electrocardiographic ST-segment monitoring, patients received either nifedipine (mean dose, 80 mg/day) or placebo administered 4 times per day, with the initial dose taken immediately upon arising in the morning. Patients were maintained on a stable dose of each study drug for 7 days, after which they underwent repeat exercise treadmill testing and 48-hour ambulatory electrocardiography. During exercise treadmill testing, greater exercise duration was achieved by patients receiving nifedipine than by those receiving placebo (421 +/- 121 vs 353 +/- 155 seconds, respectively; p less than 0.05). Time to greater than or equal to 1 mm ST depression was significantly greater with nifedipine (282 +/- 146 seconds) than at baseline (130 +/- 72 seconds, p less than 0.003) and with placebo (150 +/- 98 seconds, p less than 0.0005). During ambulatory electrocardiographic monitoring, nifedipine reduced both the total number of ischemic episodes (18 vs 54 at baseline and 63 with placebo; p less than 0.02 for both) and the total duration of ischemia (260 vs 874 at baseline and 927 minutes with placebo; p less than 0.02 for both). The surge of ischemia between 06:00 and 12:00 noted at baseline and during placebo therapy was nearly abolished during nifedipine treatment. Nifedipine at this dosage, administered in this manner, is effective in reducing total ischemic activity and may prevent morning surges of ischemic episodes.

Efficacy of ketoconazole v nystatin in prevention of fungal infections in neutropenic patients.

A prospective randomized study was undertaken in neutropenic patients to evaluate the efficacy of prophylactic ketoconazole v nystatin in reducing yeast infections. Eighteen patients received 500,000 units of nystatin suspension four times daily, and 18 patients received 200 mg of ketoconazole daily. The nystatin group experienced nine local yeast infections (four thrush, three esophagitis, and two vaginitis); three patients receiving ketoconazole had thrush. No cases of disseminated candidiasis occurred in either group. Ketoconazole was better tolerated than nystatin and neither drug caused toxic effects. In addition to being nontoxic and better tolerated, ketoconazole appeared to be slightly more effective than nystatin in reducing locally severe yeast infections.