Isolation and Progeny Transmission of Non-Temperature-Sensitive MS-H Vaccine Strains of <i>Mycoplasma synoviae</i> from Temperature-Sensitive MS-H-Vaccinated Laying Breeder Hens

Abstract

This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts + MS-H strain. At 9 weeks of age, an outbreak of infectious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were collected. RAPD was performed on the isolates at 39.5˚C, and the same ts -MS-H strains were identified in the breeder hens and their progeny. Tracheal swabs from breeder hens were negative to MS isolation at 37˚C and 39.5˚C at 24-and 39-weeks. MS isolation was recovered from tracheal swabs from 9/10 and 10/10 breeders at 48-and 70week. At 9 weeks of age in the progeny, MS was isolated from tracheal swabs of 10/10 from non-IS pullets. MS was isolated from 9/10 joints samples. The isolates from breeder hens and their progeny showed non-significant differences in five antimycoplasmic MIC100 values; otherwise, enrofloxacin presented a significant difference in MIC100 value (p < 0.05). This investigation demonstrated the reversal of the thermosensitivity, pathogenicity, and vertic-How to cite this paper