title: Seroprevalence of Mycoplasma gallisepticum antibody by ELISA and serum plate agglutination test of laying chicken.
abstract: OBJECTIVE
  Mycoplasma gallisepticum (MG) is important avian pathogens responsible for chronic respiratory diseases of chicken and turkeys, which result in large economic loss for the poultry industry. The objectives of this study were determination of seroprevalence of MG antibody of commercial layer chicken at laying period in selected areas of Bangladesh.
  
  
  METHODS
  A total of 563 blood samples were collected randomly from selected commercial layer chickens at laying period during the period from July to December, 2013. Indirect enzyme linked immunosorbent assay (iELISA) and serum plate agglutination (SPA) test were performed to detect the presence of antibodies against MG.
  
  
  RESULTS
  Of 563 samples, 64.47% and 56.13% showed an overall prevalence of MG antibodies in iELISA and SPA test respectively. Prevalence of MG was recorded the highest (69.63%) at 50-55 weeks of age compared with lowest (53.26%) at 56-61 weeks of age (p<0.05). Significant (p<0.05) effect of breed were observed in the seroprevalence of MG infection in layer birds in the present study. The overall, 68.77%, 63.74% and 59.37% prevalence were found respectively in sonali, ISA Brown and White leg horn. The prevalence of MG antibodies was the highest (70.13%) in December followed by November (68%), October (65.67%), August (63.46%), September (58.54%) and July (51.78%) month. The seroprevalence of MG antibodies was higher (69.63%) in most of the large flocks and lower (56.82%) in small flocks.
  
  
  CONCLUSIONS
  Therefore, might be suggested that the commercial layer farms should be routinely checked to monitor MG infection and the reactor birds should be culled since MG organism has the potential to transmit vertically. The correlation between MG antibody in month and flock size was not significant (p=0.359 and p=0.868, respectively).
authors.affiliation: Department of Microbiology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh.
authors.forename: Md Zulfekar
authors.initials: MZ
authors.lastname: Ali
authors.affiliation: Department of Microbiology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh.
authors.forename: Md Mostafizer
authors.initials: MM
authors.lastname: Rahman
authors.affiliation: Department of Pathology and Parasitology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh.
authors.forename: Shirin
authors.initials: S
authors.lastname: Sultana
keywords: Mycoplasma gallisepticum; antibodies; layer chickens; seroprevalence