Molecular epidemiology of Pneumocystis carinii f. sp. suis in Austrian pig herds

Pneumocystis spp. are a group of highly diversified opportunistic fungi which are adapted to the lungs of a large variety of mammals. High numbers of Pneumocystis carriers have been described in rats and humans, but also in preliminary studies of pigs prevalences between 51% in pigs with pneumonia and 73% in pigs without respiratory disorders were observed. In humans, Pneumocystis colonization has several potentially important clinical effects as development of acute pneumonia, transmission to other hosts, or involvement in the progression of certain lung diseases as cofactor. As different age classes of pigs may be kept together in a single facility and thus share the same microbiological environment, these animals are predisposed to polymicrobially caused diseases and in modern pig production systems respiratory disorders pose one of the main health problems. Preliminary data have shown that Pneumocystis can essentially contribute to polymicrobially caused respiratory diseases and in case of infections especially of young pigs the economic impact can be quite high, because developmental deficits early in life can hardly be compensated for.

Currently, the genomic landscape of Pneumocystis carinii f. sp. suis (referred as Pneumocystis suis in this proposal) is almost completely unknown. Whole genome sequencing of Pneumocystis suis will reveal its genome content and structure, and metabolic and other biological pathways, and provide insights into its unique characteristics compared to other Pneumocystis species. This work will contribute to a better understanding of the disease process and pathogenesis of Pneumocystis pneumonia in pigs, and potentially guide the development of new strategies for diagnosis, treatment and prevention. Studies of Pneumocystis jirovecii in humans have shown that fungal loads depend on the respective co-infections and as a matter of fact differ significantly between Pneumocystis jirovecii genotypes. Besides high-throughput sequencing we have planned to genotype Pneumocystis suis with single nucleotid polymorphism and multilocus sequence typing analyses. The examination of samples from different farms will provide an excellent opportunity to examine if different Pneumocystis suis genotypes exist and if they are associated with Pneumocystis suis organism loads, pig’s ages, clinical signs and co-infections and to study the Pneumocystis suis epidemiology in Austrian pig herds.

Project staff:
Univ.-Prof. Dr. Herbert Weissenböck
Priv.-Doz. Dr. Christiane Weissenbacher-Lang

Cooperation partners:
Univ.-Prof. Dr. Wolfgang Sipos, University Clinic for Swine, University of Veterinary Medicine Vienna
Prof. Dr. Liang Ma, Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA
Dr. Ousmane Cissé, Critical Care Medicine Department, NIH Clinical Center, Bethesda, Maryland, USA

Project period: 09/2018 – 08/2021

Funding:
FWF - Austrian Science Fund