Investigation and Analysis of Infection Status of Mycoplasma hyopneumoniae in Pigs in Selected Areas of Southern China,2022
Mycoplasma hyopneumoniae(Mhp)is the primary pathogen of endemic pneumonia(EP)in pigs,which causes coughing,shortness of breath,and wasting,resulting in higher feed conversion ratio,lower daily weight gain,longer farrowing time,and much higher farming costs,which cause significant economic losses to the pig farming industry.The aim of this study was to investigate and analyze the infection status of Mycoplasma hyopneumoniae in selected areas of southern China.A total of 21 large-scale pig farms in southern China were fixed-point sampled,and the sampling efficiency of nasal swabs and laryngeal swabs was compared through pathogen detection.Subsequently,the sample size for each farm was determined using simple random sampling combined with stratified sampling.A total of 1 478 laryngeal swab samples from sows were collected,and the surveyed pig populations were divided into"0-1 parity sows"and"≥ 2 parity sows".Pathogen detection was performed using real-time fluorescence quantitative PCR,and molecular epidemiological analysis was conducted using multi-locus sequence typing(MLST)combined with conserved p36 gene and non-conserved p97 and p 146 genes.The results showed that the detection rate of nasal swab samples was 16.67％,and the detection rate of laryngeal swab samples was 56.67％,with lower Ct values.The detection rate of Mycoplasma hyopneumoniae infection in the field was 66.67％,but the infection pressure in each field was relatively low,with detection rates ranging from 1.39％to 18.57％.Among them,the detection rate of"0-1 parity sows"was 10.05％;the detection rate of"≥2 parity sows"was 2.17％.Molecular epidemiological results showed that the prevalent strains in 7 farms were of the same sequence type(ST128),and the genetic variation of the prevalent strains among the different farms was small and highly homogeneous.For the pathogen detection of Mycoplasma hyopneumoniae,laryngeal swabs are a more sensitive and effective sample type in vivo than nasal swabs.Parity of sows and the transportation of pigs are important factors for the infection of Mycoplasma hyopneumoniae in large-scale breeding farms.This study provides a theoretical basis for the prevention and control of Mycoplasma hyopneumoniae.
国家科技期刊平台
NSTL
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