Molecular Detection of Mycoplasma gallisepticum and Mycoplasma synoviae in selected chicken breeds in South Africa

Abstract

BackgroundThe impact of chickens onmaintaining the economy and livelihood of rural communities cannot be overemphasized. In recent years, one of the diseases affecting its success has been Mycoplasma spp. Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are significant respiratory pathogens that affect chickens. The presentstudy aimed to molecularly detect and characterize the presence of MG and MS intracheal swabsand fecalsamples fromSouth African chicken breeds. Methods: Forty-five tracheal swabs from the Lohmann Brown (n=9), Rhode Island (n=9), Ovambo (n=9), Venda (n=9), and Potchefstroom Koekoek (n=9) breeds were collected.To detect MG and MS, DNA was extracted from tracheal swabsand faecal samples,and qPCR was performed with a 16S rRNA (185 bp) and vlhA (392 bp) gene fragment. Following the sequencing of all the amplicons, MG, and MS dendrograms showing the evolutionary relationships among the five South African chicken breeds and the reference population from the GenBankwere constructed. Results: The qPCR revealed the presence of MG and MS in 22% (2/9) of the tested tracheal swab samples for MS only in Rhode Island breeds;66.6% (6/9) and 33% (3/9) of the tested samples in Ovambo breeds;and 11.1% (1/9) and 44.4% (4/9) of the tested samples in Venda breeds. No MG orMS were detected in the Lohmann Brown orPotchefstroom Koekoek breed. Furthermore, qPCR revealed the presence of MG in pooled faecal samples from Lohmann Brown and Ovambo breeds. Eight different bacterial isolates were recognized from both samples. Four isolates were of the Mycoplasma gallisepticum 16sribosomal ribonucleic acid (rRNA) gene (named PT/MG51/ck/00, PT/MG48/ck/00, PT/MG41/ck/00 and PT/MG71/ck/00),and one was of the Mycoplasma Synoviae variable lipoprotein hemagglutinin A (vlhA) gene (named PT/MSA22/ck/01, PT/MS41/ck/01, PT/MS74/ck/01 and PT/MS46/ck/01). These isolateswere successfully sequenced with 95–100percentage similarity with isolates from the gene bank. Conclusion: The study revealedgreat variation in susceptibility to MG and MS amongthe chicken breeds sampled. This, therefore, poses a threat to South Africa poultry production becausethere is a need for strict biosecurity measures and constant detection of the presence of MG and MS to prevent their spread.