BACKGROUND: Mycoplasmosis is an infectious disease of poultry and a major cause of economic losses due to decline in growth, egg production, reduction in egg hatching and exacerbation of viral and bacterial respiratory diseases. Objectives: The purpose of this study was detection of serological prevalence of Mycoplasma gallisepticum infection in broiler breeders of Mazandaran province and to suggest control strategies against mycoplasmosis. Methods: All breeder farms that were in production period in Mazandaran province were sampled (74 farms in 14 cities); blood samples were collected from 45 birds in each farm. Sera samples were examined by RSPA and ELISA tests based on the instructions of OIE. Results: In this study, by the RSPA test, 3 out of 74 farms (4%), 15 out of 553 houses (2/7%) were positive. From 5626 collected sera samples, 139 samples (2.5%) were positive in RSPA and 124 samples (2.2%) in ELISA. Conclusions: Seroprevalence of MG infection was 4% during the selected period and zone of study.  Statistical analysis showed that biosecurity situations were significantly better in negative farms (p=0.04). There are some deficiencies in quality of biosecurity situations despite  implementing biosecurity principles in farms. Establishing of farms near villages or the development  of villages, keeping backyard birds close to the farms and employees living in villages are some of the  biosecurity principles that were not followed in infected farms.

Ornithobacterium rhinotracheale (ORT) causes significant economic losses to the poultry industry around the world. The bacterium often affects poultry as part of multiple infections causing very serious clinical signs that are usually not limited only to the respiratory system. This study’s main objective was the retrospective detection and identification of ORT in turkey flocks. ORT identification was performed in 6,225 samples taken from 133 different flocks between 2015 and 2020. Molecular methods were used, specifically real-time PCR and traditional PCR. We focused on partial 16S rRNA gene sequences of isolates, which were compared with sequences obtained from GenBank. The reaction products were analysed phylogenetically. Molecular methods indicating secondary infections was carried out, and the bacterial composition of the upper respiratory tract was 16S metasequenced for selected flocks to identify any other pathogens. The presence of ORT was detected in 30.83% of samples by real-time PCR and 28.57% by PCR. Phylogenetic analysis of the PCR products from the turkeys samples showed that their sequences resolved into two main genetic groups. Tests for the occurrence of secondary infections showed the presence of Mycoplasma gallisepticum and M. synoviae in some samples but the total absence of Bordetella avium. The upper respiratory tract in turkeys was dominated by two major phyla Firmicutes and Proteobacteria. At the genus level, the genera Ornithobacterium, Mycoplasma, Gallibacterium, Avibacterium, and Escherichia-Shigella were found which may include pathogenic bacteria that can cause clinical symptoms. The results of the analysis of multiple infection carried out in flocks with respiratory signs are probably associated with outbreaks of ornithobacteriosis in turkey flocks in Poland.

Introduction:Mycoplasma gallisepticum is considered the most pathogenic and economically significant avian Mycoplasma spp. for the worldwide poultry industry. The aim of this study was to develop a novel and sensitive real-time loop-mediated isothermal amplification (LAMP) assay based on the amplification of its mgc2 gene sequence for its rapid molecular detection in poultry.

Mycoplasma gallisepticum (MG) continues to persist in many commercial layer farms in Korea, resulting in losses in egg production. Bacterins and live attenuated vaccines have been used for the prevention of losses caused by MG. One of these attenuated vaccines, MG 6/85 vaccine has been reported to be safe and efficacious in layers. However, MG 6/85 vaccine has not been evaluated for its safety and its efficacy in any commercial layer in Korea. Six-week-old specific pathogen-free (SPF) chickens were vaccinated with MG 6/85 vaccine by aerosol and were challenged with virulent MG R strain at 4 weeks after vaccination.

A panel of monoclonal antibodies (MAb) developed against Mycoplasma gallisepticum strain PG31 was used to probe the antigenic profiles of 5 recognized strains (PG31, R, S6, F, A5969) and 6 field isolates of M gallisepticum. Monoclonal antibody G9 predominantly recognized antigens at apparent molecular mass positions of 90 to 98 kDA. The MAb reacted with all strains and isolates, but the molecular mass position of the antigens varied among some mycoplasmas. Monoclonal antibody G12 reacted with all strains and isolates of M gallisepticum and had an identical banding pattern. However, MAb G10 and G11 reacted selectively only with a limited number of strains and/or isolates. Surface distribution of the MAb-recognized antigens was revealed by immunoelectron microscopy. Partial physicochemical characterization of MAb G9-recognized antigens identified glycopeptide characteristics. Monoclonal antibody G9 reacted with surface antigens and, hence, participated in agglutination of M gallisepticum. However, the degree of agglutination varied among the various strains and isolates, indicating a quantitative or conformational limitation or an alteration in the anomeric expression of the epitopes. Antigenic variation in M gallisepticum may be mediated by immunologic selective pressures, or a proclivity for habit niche in the host.

The present study was based on the reverse transcription polymerase chain reaction (RT-PCR) of the 16S ribosomal nucleic acid (rRNA) of Mycoplasma for detection of viable Mycoplasma gallisepticum. To determine the stability of M. gallisepticum 16S rRNA in vitro, three inactivation methods were used and the suspensions were stored at different temperatures. The 16S rRNA of M. gallisepticum was detected up to approximately 20–25 h at 37 °C, 22–25 h at 16 °C, and 23–27 h at 4 °C. The test, therefore, could detect viable or recently dead M. gallisepticum (< 20 h). The RT-PCR method was applied during an in vivo study of drug efficacy under experimental conditions, where commercial broiler-breeder eggs were inoculated with M. gallisepticum into the yolk. Hatched chicks that had been inoculated in ovo were treated with Macrolide 1. The method was then applied in a flock of day 0 chicks with naturally acquired vertical transmission of M. gallisepticum, treated with Macrolide 2. Swabs of the respiratory tract were obtained for PCR and RT-PCR evaluations to determine the viability of M. gallisepticum. This study proved that the combination of both PCR and RT-PCR enables detection and differentiation of viable from non-viable M. gallisepticum.

Monoclonal antibody (MAb) against Mycoplasma gallisepticum strain PG31 was produced in BALB/c mice. The MAb (designated M9) was of IgG3 isotype and reacted with an epitope in M gallisepticum antigens with molecular weights of 35, 90, 95, and 98 kilodaltons (kDa). The M9 reacted with M gallisepticum antigens in the dot-blot ELISA and in western blot assays. It agglutinated M gallisepticum strains PG31, F, R, S6, A5969, and 9 field isolates from various sources. A coagglutination assay, using Staphylococcus aureus (Cowan strain 1), was developed to enhance the agglutination of some weakly agglutinating M gallisepticum isolates. The M9 did not react with M synoviae, M iowae, M meleagridis, M gallinarum, or M gallinaceum in any of the aforementioned assays. This MAb may be useful in facilitating laboratory diagnosis of M gallisepticum infections.

This study aimed to determine the seroprevalence of Mycoplasma gallisepticum (MG) infection in the chicken population of Bhola district, Bangladesh, during the period from April 2011 to March 2012. A total of 480 blood samples from chickens were collected from different upazilas (sub-districts) of Bhola district. The sampling considered the types of chicken (backyard and commercial layer), age groups (pullet, adult and old) and seasons (summer and winter). On the basis of the serum plate agglutination test, 55.83% (n=268/480) chickens were found positive for MG. The MG infection was higher (62.5%) in backyard chickens as compared to those being reared in commercial farming systems (53.61%). With respect to age groups, the prevalence was highest in pullets (60.63%) followed by adults (55.63%) and old chickens (51.25%). Moreover, chickens reared in winter showed higher prevalence of MG (60.42%) as compared to those reared in summer (51.25%). In conclusion, MG infection is prevalent in the chicken population of Bhola district, Bangladesh. Appropriate strategies should be taken for successful prevention and control of this disease in Bangladesh.

This study aimed to determine the seroprevalence of Mycoplasma gallisepticum (MG) infection in the chicken population of Bhola district, Bangladesh, during the period from April 2011 to March 2012. A total of 480 blood samples from chickens were collected from different upazilas (sub-districts) of Bhola district. The sampling considered the types of chicken (backyard and commercial layer), age groups (pullet, adult and old) and seasons (summer and winter). On the basis of the serum plate agglutination test, 55.83% (n=268/480) chickens were found positive for MG. The MG infection was higher (62.5%) in backyard chickens as compared to those being reared in commercial farming systems (53.61%). With respect to age groups, the prevalence was highest in pullets (60.63%) followed by adults (55.63%) and old chickens (51.25%). Moreover, chickens reared in winter showed higher prevalence of MG (60.42%) as compared to those reared in summer (51.25%). In conclusion, MG infection is prevalent in the chicken population of Bhola district, Bangladesh. Appropriate strategies should be taken for successful prevention and control of this disease in Bangladesh.