In this recent publication in the Canadian Journal of Veterinary Research, Dr. Alyssa Betlach from the MycoLab at the University of Minnesota investigates the genetic variability of Mycoplasma hyopneumoniae within and across various production flows within a single system.
Key points
Multiple-locus variable-number tandem repeat analysis allows to detect genetic variability between M. hyopneumoniae strains.
Four production flows were sampled over a duration ranging from 4 months to 3 years.
Between 1 and 6 variable-number tandem repeat (VNTR) types were found within the four production flows.
VNTR types in growing sites seem to originate from their respective breeding herds.
This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.
This week, Dr. Mariana Kikuti from the MSHMP team is sharing results from a study using whole genome sequencing to assess PRRSv diversity within and across litters.
Key points
Viral diversity within the piglet population is generally small, but higher diversity was found in ORFs 4 and 5a.
Within animal consensus changes were observed in a period as short as 2 weeks, which means piglets might be going to the GF sites with different viruses than the ones identified closer to farrowing.
PhD candidate April Estrada, working with Drs. Gebhart and Marthaler published an open-access article on Streptococcus suis in the Journal of Clinical Microbiology. Streptococcus suis is an older pathogen but its prevalence as well as its virulence have been rising lately. This study investigates if categorizing isolates into serotypes and genotypes could help predict the severity of the disease on the farm.
This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.
Abortion cases in the study had a high rate of PCV3 positivity.
PCV3 found in association with lesions in an abortion case suggesting causality.
The study looked at 730 cases from the UMN Veterinary Diagnostic Laboratory with a positive sample for PCV3, received between Feb 2016 and Jan 2018.
Out of 22 states, 18 states were PCV3 positive. PCV3 was detected in pigs from all ages.
The positive rate among fetus, piglets, nursery and finishing pigs ranged from 15% to 20%. The PCV3 rate in adults was 35%.
PCV3/PCV2 co-infection rate was 5.2%, and PCV3/PRRSV coͲinfection rate was 7.6%.
In our data, we had 67 abortion cases, and 40% of them were PCV3 positive. In one abortion case investigation, histological lesions were observed in lung tissue of aborted fetus and PCV3 in-situ hybridization showed presence of PCV3 in the lesion.
Seven PCV3 whole genome sequences were obtained. Current PCV3 genomes in the U.S shared over 98% nucleotide identities. U.S strains did not cluster together and were grouped with PCV3 sequences obtained in other countries.
