A survey of avian Mycoplasma species for neuraminidase enzymatic activity
Rebeka Lucijana Bercic1, Brigita Slavec, Miha Lavric
1Department of Animal Science, University of Ljubljana, Biotechnical Faculty, Groblje 3, Domzale, Slovenia.
Abstract:
Among 23 currently recognized avian Mycoplasma (AM) species only Mycoplasma gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis and Mycoplasma iowae cause disease and loss of production in chickens and/or turkeys. Because neuraminidases are considered virulence factors in many pathogenic microorganisms the aim of our study was to determine which AM species possess neuraminidase enzymatic activity (NEAC). Small samples of AM cells were assayed for NEAC using the chromogenic substrate 5-bromo-4-chloro-3-indolyl-alpha-d-N-acetylneuraminic acid. In the case of positive NEAC reaction the substrate gave the insoluble indigoblue product what enabled simple test and easy estimation of NEAC. M. gallisepticum and M. synoviae which share sequences of the gene encoding neuraminidase (sialidase NanH) exhibited considerable levels of NEAC. However, NEAC levels differed among their strains, as well as among cultures of different strains. Only certain cultures of the type strain of M. meleagridis showed NEAC, whereas among six serovars of M. iowae only serovar I (type strain 695) showed NEAC. Weak NEAC was detectable in M. anseris, M. cloacale and M. pullorum, whereas the type strain of M. corogypsi (BV1) showed strong NEAC. Our study provides novel informations about NEAC in AM species and suggests that higher invasiveness and possibly, the pathological processes might be associated with their NEAC.
Insights
Avian Mycoplasma species were tested for neuraminidase enzymatic activity (NEAC). Mycoplasma gallisepticum and Mycoplasma synoviae showed significant NEAC, suggesting a role in avian disease pathogenesis.
Area of Science:
- Veterinary Microbiology
- Enzymology
Background:
- Avian Mycoplasma (AM) species are significant pathogens in poultry.
- Neuraminidases are recognized virulence factors in various microorganisms.
Purpose of the Study:
- To determine which avian Mycoplasma species possess neuraminidase enzymatic activity (NEAC).
- To investigate the potential link between NEAC and pathogenicity in AM species.
Main Methods:
- Assay of AM cell samples for NEAC using a chromogenic substrate (5-bromo-4-chloro-3-indolyl-alpha-d-N-acetylneuraminic acid).
- Visual estimation of NEAC based on the insoluble indigoblue product formation.
Main Results:
- Mycoplasma gallisepticum and Mycoplasma synoviae exhibited considerable NEAC levels, varying among strains and cultures.
- Mycoplasma meleagridis and Mycoplasma iowae showed limited or strain-specific NEAC.
- Weak NEAC was detected in Mycoplasma anseris, M. cloacale, and M. pullorum; strong NEAC was found in Mycoplasma corogypsi.
Conclusions:
- This study provides new insights into NEAC presence across AM species.
- NEAC may be associated with increased invasiveness and pathological processes in avian Mycoplasma infections.
