Molecular characterizaton of mycoplasma gallisepticum isolated from chicken and turkey

Mycoplasma gallisepticum [MG] infection in chicken and turkey is still one of the important reasons causing economic losses in poultry. The current study concerned with rapid detection and molecular characterization of MG isolates. The all samples positive by culture were positive by PCR and rt- PCR. Five isolated [four from chicken and one from turkey] were sequenced for mgc2 gene. The present molecular study proved that four wild-type MG strains. [Eis 3- C-10, Eis 4- C-10, Eis 5- C-10 were recovered from chicken and one [Eis 6-T-10] was recovered from turkey. While Eis 7-C-10 [vaccinal F-strain] was isolated from commercial layer flock vaccinated with F- strain vaccine. We concluded that mgc2 gene was able to distinguish between MG wild - type and vaccinal strains

Advanced studies on Mycoplasma mastitis in Egyptian cattle and buffaloes

Mycoplasma mastitis has been seen in Egypt which is characterized by abnormal secretion followed by marked agalactiae which did not respond to treatment with antibiotics. Therefore, this study concerned with detection of mycoplasma mastitis in dairy cattle and buffaloes in six governorates using culture and molecular characterization. The highest prevalence was detected in cattle suffered from clinical mastitis at Menofia [73%], followed by Behera [50%], while Ismailia was the least [28.6%]. In the buffaloes isolation was from Menofia [100%] and Behera [60%]. The isolation rate from subclinical mastitis in cattle ranged from [0-12.4%] and from buffaloes [0-54.5%]. One hundred and twelve out of 151 isolates were identified as M. bovis, while only seven strains were M. bovirhinis and six M. arginini. On the other hand, 26 isolates were Acholeplasma species. The polymerase chain reaction [PCR] technique was used for the detection of M. bovis variable surface protein A gene [Vsp A gene] in dairy cattle and buffaloes suffered from mastitis. All positive samples by culture were positive by PCR. Sequencing of 16S rRNA gene of M. arginini isolate gave 99% homology with the reference strain [G 230]. Comparing of M. bovis isolates [Vsp gene] with the reference strain [PG 45] cleared the identity of 96-98% while the identity was 94-100% when compared with the Italian M. bovis field strain [Sar I]

Preparation of mycoplasma gallisepticum subunit vaccine and its evaluation in chickens

A 64 kilodalton [KD] lipoprotein was isolated from Mycoplasma gallisepticum membrane and used for preparation of subunit vaccine. Evaluation of the prepared vaccine against colonization of M. gallisepticum [MG] in chicken trachea was studied. lmmunoblot of 64 KD protein of M. gallisepticum separated by high performance liquid chromatography [HPLC] and Triton X -114 extraction, against anti - MG chicken serum proved that it is highly immunogenic protein. Sixty oneday old mycoplasma free Hubbard chicks were used. The chicks were divided into 5 groups each of tweleve chicks. Three groups were given 0.25, 0.5 and 0.75 mg of MG vaccine then challenged one month later with 15000 CFU/0.1 ml /bird/ intratracheally. The remaining two groups were kept as negative and positive controls. Chickens vaccinated with subunit vaccine [0.5 and 0.75 mg/ bird] resulted in 100% protection against tracheal M. gallisepticum colonization. Birds of the group was vaccinated with 0.25 mg / bird [group No. 1]were positive for mycoplasma isolation up to 4 weeks post-challenge. Vaccinated groups No [2 and 3] were positive by serum plate agglutination test and ELISA along the duration of experiment. While chickens of group No [1] that vaccinated with 0.25 mg / bird gave suspected results by SPA and ELISA in the first week postchallenge, then gave positive results. Vaccination of the chickens with M. gallisepticum subunit vaccine resulted in high antibody response to 64 KD protein at 2 weeks after the booster dose