Evaluation of polymerase chain reaction for detection of Mycoplasma meleagridis infection in turkeys

Molecular cloning of a Mycoplasma meleagridis-specific antigenic domain endowed with a serodiagnostic potential

A recombinant phage library harbouring Mycoplasma meleagridis (MM) genomic DNA fragments was generated in the bacteriophage lambda gt11 expression vector. The library was screened for expression of MM specific antigens with a polyclonal antiserum that had been preadsorbed with antigens of the most common unrelated avian mycoplasma species. A 49-amino acid antigenic domain unique to MM was isolated, expressed in Escherichia coli, and its serodiagnostic potential was demonstrated. An antiserum raised against this MM-specific antigenic domain recognized a cluster of seven membrane-associated MM proteins with molecular masses ranging from 34 to 75 kDa. Overall, this study resulted in the identification of a potent serodiagnostic tool and revealed the complex antigenic nature of MM.

Development of a blocking enzyme-linked immunosorbent assay for detection of turkey antibodies to Mycoplasma meleagridis

A blocking enzyme-linked immunosorbent assay (B-ELISA) was developed to detect antibodies to Mycoplasma meleagridis (MM) in turkey sera. This assay was based on two mouse monoclonal antibodies recognising all MM strains tested but none of seven avian mycoplasmal species tested. Furthermore, their binding to the Tween 20 antigen was inhibited by serum from MM-infected birds. The B-ELISA test format was optimized. The cut-off was determined using a set of sera from MM-free turkeys. This B-ELISA was then compared with a commercial indirect ELISA (I-ELISA). Specificities of the two ELISA tests were not significantly different (100 or 99%, respectively). The sensitivity of B-ELISA was significantly higher than the I-ELISA when I-ELISA suspicious results were considered as negative. Testing sera from experimentally MM-infected animals showed that serum plate agglutination (SPA) test detected positive birds before both ELISA methods. Samples were collected in MM-infected commercial flocks and analyzed by SPA, ELISAs, MM-PCR or culture. Results showed that the sensitivity of the B-ELISA appeared superior to the I-ELISA. Moreover, the ability to detect maternal antibodies makes it a useful tool for eradication or control of MM infections.

Respiratory diseases of rodents and rabbits

This article is written to provide differential diagnostic help for the practitioner who suspects respiratory disease in rodents or rabbits. The authors are laboratory animal veterinarians who work with rodents and rabbits on a herd health basis but also have considerable experience dealing with individual mice, rats, guinea pigs, hamsters, gerbils, and rabbits. The article presents descriptions of the presentation, pathology, treatment, and control of the primary respiratory pathogens of these species, along with an explanation of conditions that may confuse the diagnostic efforts. The article also mentions reported pathogens of secondary importance and provides extensive references.