Thermoresistant Newcastle disease vaccine effectively protects SPF, native, and commercial chickens in challenge with virulent virus.

BACKGROUND: Due to the more stability and a better homogenecity in immune response, the use of thermoresistant vaccines in different chicken types has been increased. OBJECTIVE: This study aimed to evaluate the efficacy of a newly developed Newcastle disease vaccine (ND.TR.IR) originating from I-2 strain in specific pathogen-free (SPF) and native and broiler chickens. METHODS: Following determination of pathogenicity indices on the candidate seed, three efficacy examinations were conducted. In the first experiment, 120 1-day-old SPF chickens were randomly allocated to six groups and either vaccinated with ND.TR.IR via eye drop at 1, 7, and 21 days of age (V1 , V7 , and V21 ), or considered as non-vaccinated control groups (C1 , C7 , and C21 ). At 20th post-vaccination day, sera hemagglutination inhibition (HI) antibody titres against ND virus (NDV) were measured and then the chickens were challenged by virulent NDV (vNDV). In the second and third experiments, the efficacy of ND.TR.IR vaccine was compared to routine vaccination program (B1 and LaSota) in native and broiler chickens that were vaccinated at 10 and 20 days of age, respectively. The HI antibody titres were measured on 10, 20, 30, and 40 days of age, and also challenge efficacy test with vNDV was conducted on 30 days of age. RESULTS: The studied virus, as a vaccinal seed, complied with the pathogenicity indices of avirulent NDV and molecular identity of I-2 strain. In the efficacy evaluation trials, the vaccinated chickens had higher HI antibody titres against NDV compared with their corresponding control chickens (p < 0.05). Results of the challenge tests indicated 95% and 100% protection against vNDV in native, SPF, and broiler-vaccinated chickens, respectively. CONCLUSIONS: The present findings indicated that administration of ND.TR.IR induced appropriate HI antibody titres against NDV in SPF, native, and broiler chickens associated with good protection in efficacy test.

High frequency of Mycoplasma pneumoniae among patients with atypical pneumonia in Tehran, Iran.

INTRODUCTION: Mycoplasma pneumoniae is a major cause of atypical community-acquired pneumonia (CAP) with a prevalence range of 15-20% and up to 40% in adults and children, respectively. In Iran, the recorded frequency ranges between 1-6.15%. We aimed to investigate the frequency of M. pneumoniae among patients with atypical pneumonia acquired from the community. METHODS: Over a period of 5 months between January and June 2017, 520 patients with suspected CAP, who had been to the hospital outpatient clinics of Tehran University, were enrolled in this study. Throat swab specimens were obtained from 110 outpatients who presented with symptoms of atypical pneumonia. M. pneumoniae was identified via culture and biochemical tests, such as fermentation of glucose and arginine, hemolysis, and hemadsorption. For confirmation, PCR was performed to amplify the gene fragment coding for p1 adhesin. RESULTS: The major and minor clinical signs of the patients were dyspnea (67.3%) and nausea (15.5%), respectively. Out of 110 specimens, 25 (22.7%) and 29 (26.4%) isolates were identified to be M. pneumoniae via culture and molecular assay, respectively. Comparing the results of the two methods, the PCR showed better sensitivity and rapidity for the detection of M. pneumoniae. There was a high congruence between culture and the PCR assay; kappa level was 'almost perfect' (κ=0.90). CONCLUSION: This is the first report of high frequency of M. pneumoniae in our region. This finding can serve as baseline information for further investigation and confirmation of the potential epidemics of M. pneumoniae pneumonia in our community.