Dr. Alonso who just graduated from her PhD at the University of Minnesota, published in collaboration with Drs. Davies, Morrison and Torremorell an article evaluating the electrostatic particle ionization (EPI) technology as a technique to reduce particle load in the air. The results showed that EPI was the most efficient when the system was close to the particle source and when the particle size was between 3.3 and 9 μm no matter what swine pathogen was evaluated. This technique could be promising in decreasing the risk of disease transmission between swine facilities.
This past month, a team of swine pathologists including Dr. Albert Rovira from the University of Minnesota identified, thanks to funds from Swine Health Information Center’s Support for Diagnostic Fees program, a new swine virus called porcine sapelovirus.
This virus is thought to induce atypical neurological signs in pigs and has previously been described in Korea. Videos of the clinical presentation can be been here.
Research is still on-going to prove Koch’s postulate and declare causality between the presence of the virus and the clinical presentation but it is a step forward in the identification and understanding of swine pathogens.
To answer this question, Drs. Mirajkar, Davies, and Gebhart from the University of Minnesota, collected a total of 124 field isolates originating from all over the country. In this study, four different Brachyspira species were evaluated for their susceptibility against the main antimicrobial medicines used in swine production. Overall the US isolates had the tendency to be less resistant to antimicrobials than were isolates from other countries. However, low susceptibility to lincomycin and to tylosin were noted in the domestic strains. Lastly, the authors raised the question of the lack of Clinical and Laboratory Standards Institute-approved clinical breakpoints for Brachyspira species which, by categorizing an isolate as sensitive, intermediate, or resistant, would be a tremendous help in determining the best treatment and control strategies at the farm level .
Abstract: Outbreaks of swine dysentery, caused by Brachyspira hyodysenteriae and the recently discovered “Brachyspira hampsonii,” have reoccurred in North American swine herds since the late 2000s. Additionally, multiple Brachyspira species have been increasingly isolated by North American diagnostic laboratories. In Europe, the reliance on antimicrobial therapy for control of swine dysentery has been followed by reports of antimicrobial resistance over time. The objectives of our study were to determine the antimicrobial susceptibility trends of four Brachyspira species originating from U.S. swine herds and to investigate their associations with the bacterial species, genotypes, and epidemiological origins of the isolates. We evaluated the susceptibility of B. hyodysenteriae, B. hampsonii, Brachyspira pilosicoli, andBrachyspira murdochii to tiamulin, valnemulin, doxycycline, lincomycin, and tylosin by broth microdilution and that to carbadox by agar dilution. In general, Brachyspira species showed high susceptibility to tiamulin, valnemulin, and carbadox, heterogeneous susceptibility to doxycycline, and low susceptibility to lincomycin and tylosin. A trend of decreasing antimicrobial susceptibility by species was observed (B. hampsonii > B. hyodysenteriae > B. murdochii > B. pilosicoli). In general, Brachyspira isolates from the United States were more susceptible to these antimicrobials than were isolates from other countries. Decreased antimicrobial susceptibility was associated with the genotype, stage of production, and production system from which the isolate originated, which highlights the roles of biosecurity and husbandry in disease prevention and control. Finally, this study also highlights the urgent need for Clinical and Laboratory Standards Institute-approved clinical breakpoints for Brachyspira species, to facilitate informed therapeutic and control strategies.