ISOLATION AND MOLECULAR CHARACTERIZATION OF MYCOPLASMA SYNOVIAE FROM INFECTED CHICKENS WITH RESPIRATORY SIGNS.

Ali & Et Al

doi:10.36103/ijas.v51i5.1157

Abstract

The aim of this study was to investigate the presence of Mycoplasma synoviae in broiler and layer chickens infected with respiratory signs. A total of 80 samples were collected randomly from layer and broiler chickens with respiratory signs in Baghdad from the period between January to May 2017 from the trachea, Lung, Air sac, oviduct, tracheal swabs, conjunctiva swabs, choanal swabs, and nasal swabs and cultured in PPLO medium with supplements, then positive culture subjected to DNA extracted and Polymerase Chain Reaction assay (PCR) to detect Mycoplasma as a genus and Mycoplasma spp by using specific primers targeting16S rRNA gene. The results of culture revealed that the total rate of Mycoplasma isolates was19/80(23.75%). DNA was extracted from 19 positive isolates, all nineteen isolates were positive for Mycoplasma genus by conventional PCR assay, and a product of 270 bp was generated by amplification of the 16SrRNA gene, while a 210 bp region of 16S rRNA gene was amplified for the Mycoplasma synoviae in 19 isolates. The products of amplification of Mycoplasma synoviae16SrRNA gene was sent to MACROGEM (Korea) for sequencing, then submitted in the Gene bank database and have accession number:ID: MG846121.1. Sequencing alignment showed that local MS isolates had highly identical with standard references at gene bank, analysis the phylogenetic tree revealed the presence of 100% identity of the Iraqi isolate to the USA: West Virginia, United Kingdom, Australia, and Brazil, also had 99% identity to South Africa, China, Sweden, USA, and VitNamHatey. This result was concluded that circulation of the Mycoplasma synoviae among birds of the flock and caused respiratory signs in chickens.

Highlights

Mycoplasma synoviae(MS) is one of the important Mycoplasma species that infect avian species, has been listed as a notifiableMycoplasma by World Organization for Animal Health(28)
In the present study, a total of 80 samples were collected randomly from layer and broiler chickens with respiratory signs (10) from trachea, (10) Lungs, (10) Air sacs, (10) oviducts, (10) tracheal swabs, (10) conjunctiva swabs, (10) choanal swabs and (10) nasal swabs . percentage of positive samples revealed by culture was 23.75% as show in table (1), positive samples revealed growing typical fried egg colonies figure(1).Isolation by culture was the gold-standard method for MS detection(8) isolation may be compromised by rivalry from other pathogens" especially in the cases of chronically infected animals" which in general have relatively low MS loads (33)
Primers of the16S rRNA gene had successfully targeted the respective gene and shown the single bands of the16S RNA gene of MS at 1500 bp in the isolate of MS as showed in figure (4) It was stated that a combination of culture and polymerase chain reaction (PCR) is the most recommended method because of Mycoplasma are having very small genome size, they fail to show the many biochemical pathways as compared to bacteria to identify at species level ( 7;43)

Summary

Introduction

Mycoplasma synoviae(MS) is one of the important Mycoplasma species that infect avian species, has been listed as a notifiableMycoplasma by World Organization for Animal Health(28). Newcastle disease (ND), infectious bronchitis (IB), or both(42).The clinical signs of MS infection could not be differentiated from those caused by other avian pathogens, such as avian reovirus, Mycoplasma gallisepticum (MG), Staphylococcus aureus, Escherichia coli, Pasteurella multocida, and "Salmonella spp., which in poultry species could cause symptoms similar to MS infection (17).Transmission of MS is accomplished laterally via direct contact and respiratory aerosols, and vertically within eggs(27). The molecular characterization of MS strains may assist in epidemiological studies to determine the source of infections and relationships among strains isolated from neighbouring or related flocks Kursa (18;15) Because of the above causes and possibility of contributing of MS in distributing the respiratory disease in Iraq the current study is designed to detect the presence of MS in the broiler and layer chickens infected with respiratory signs and study the molecular characterization ,sequencing , phylogenetic tree of in Iraq

Objectives

Methods

Results