Pneumocystis species in Brown Leghorn laying hens--a hint for an extra-mammalian reservoir.

Abstract

The fungus Pneumocystis spp. causes Pneumocystis pneumonia in immunocompromised mammals including humans, whereas healthy individuals are often colonized and can transmit it to others. There is little evidence that Pneumocystis spp. is also present outside mammalian species. We describe the first detection of Pneumocystis DNA from the lungs and air sacs of laying hens from deep litter and floor husbandry systems. The DNA from chickens' lungs and air sacs was amplified with a Pneumocystis-specific mtLSU rRNA gene nested PCR and sequenced. Pneumocystis DNA was detected in 20 of 111 (18.0%) hens. The DNA sequences showed specific differences to all known Pneumocystis mtLSU sequences. In induced sputum samples of 2 of 7 farm workers at this poultry farm, human Pneumocystis jirovecii strains without these mutations were detected; therefore, a transmission between chickens and farm workers appears implausible.