Search for OIE-listed ruminant mycoplasma diseases in Afghanistan

BACKGROUND

Little is known about the occurrence of important diseases of ruminants in Afghanistan because of the conflict affecting the country over the last 40 years. To address this discrepancy, ruminant herds in Afghanistan were screened for OIE-listed mycoplasma diseases, contagious bovine (CBPP) and caprine pleuropneumonias (CCPP).

RESULTS

Of the 825 samples from 24 provinces tested for serological evidence of CBPP caused by Mycoplasma mycoides subsp.mycoides, 20 (3.4%) had ELISA values greater than the positive threshold of 50% though all were less than 55%. Repeat testing of these suspect sera gave values below 50. A smaller number of sera (330) from cattle in nine provinces were also tested by the rapid latex agglutination test (LAT) for CBPP, 10 of which were considered suspect. However, no positive bands were seen when immunoblotting was carried out on all sera that gave suspect results. Serological evidence of Mycoplasma bovis was detected in half of 28 herds in eight provinces. The cause of CCPP, M. capricolum subsp. capripneumoniae was not detected in any of the 107 nasal swabs and lung tissue collected from goats in seven provinces though sample handling and storage were not optimal. However, strong serological evidence was detected in goat herds in several villages near Kabul some of which were over 50% seropositive by LAT and ELISAs for CCPP; immunoblotting confirmed positive results on a selection of these sera.

CONCLUSIONS

The data presented here provide a first assessment of the occurrence of the two OIE listed mycoplasma diseases in Afghanistan. From the results of the testing bovine sera from the majority of provinces there is no evidence of the presence of CBPP in Afghanistan. However the samples tested represented only 0.03% of the cattle population so a larger survey is required to confirm these findings. Serological, but not bacterial, evidence was produced during this investigation to show that CCPP is highly likely to be present in parts of Afghanistan.

Seroepidemiological survey of sheep flocks from Northern Japan for Mycoplasma ovipneumoniae and Mycoplasma agalactiae

Sheep flocks from Hokkaido, Iwate and Aomori, three northern prefectures of Japan, were screened for antibodies to Mycoplasma ovipneumoniae and Mycoplasma agalactiae by ELISA. Sixty four animals out of 246 (26%) were seropositive to M. ovipneumoniae, with positive results obtained from all three prefectures. None of the sera tested were serologically positive to M. agalactiae.

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.