Immunohistochemical study of Pneumocystis carini infection in pigs: evaluation of Pneumocystis pneumonia and a retrospective investigation

Abstract

Infection with Pneumocystis carinii was demonstrated immunohistochemically in the lungs of pigs 15 to 75 days of age from a herd with epidemic pneumonia due to the organism. The distribution of the organism was centered on the airways, and extended progressively with age from the alveolar ducts to the alveoli. In a retrospective immunohistochemical study of 245 newborn to adult pigs which were necropsied between 1988 and 1995, P carinii infection was found in 87 pigs (35.5 per cent) aged between 17 days to seven months. In the pigs aged between one and three months the infection rate was 63.1 per cent. Pigs from herds in which suckler and weaner pigs shared the same air space were more heavily infected than those from the herds in which they were reared separately. There were no regional or seasonal variations in the level of infection, and the infection was not associated with any single disease.

Characterizing Pneumocystis in the Lungs of Bats: Understanding Pneumocystis Evolution and the Spread of Pneumocystis Organisms in Mammal Populations

“…In human communities, infants could constitute a major reservoir for Pneumocystis organisms (67,94), and some data collected in other mammals, like domestic or wild rabbits (26,40), pigs (50), and macaques maintained in partial release (30), seem to strengthen this hypothesis. A survey scheduled just after the breeding period in a bat colony could provide data on the levels of infection of young bats and on their potential role in the transmission of Pneumocystis organisms within the colony.…”

<i>Pneumocystis carinii</i> Infection in a Domestic Goat (<i>Capra hircus domesticus</i>) with Multibacillary Paratuberculosis

“…Although most mAb react only with the subspecies used for the immunization [10,12,13], some mAb react with P. carinii from different host species. In the present study, goat derived P. carinii showed positive staining with one mAb (clone, 0921), but not with another (clone, 3F6) made against Pneumocystis jirovecii (P. jirovecii), human-specific pneumocystis species, as also observed in pigs [11]. In contrast, equine P. carinii stains positive with the latter [7].…”

Pneumocystis Infection in Goat Kids in Uganda

“…Since natural selection exerted by the innate immune system is thought to generate hypervirulent bacterial variants in streptococcal infections (Walker et al 2007), it is probable that not only sulfa drugs but also host immune responses impose selective pressure on Pneumocystis organisms. Immunocompetent human infants (Beard et al 2005), suckling piglets (Kondo et al 2000) and newborn rabbits (DeiCas et al 1998) are considered to serve as reservoirs for Pneumocystis organisms. The infection subsequently clears as the immune response matures (Beard et al 2005), and an elevation of antibody titers to the organisms in pigs after weaning (Kondo et al 2000) suggests the involvement of the acquired immune system.…”

“…Immunocompetent human infants (Beard et al 2005), suckling piglets (Kondo et al 2000) and newborn rabbits (DeiCas et al 1998) are considered to serve as reservoirs for Pneumocystis organisms. The infection subsequently clears as the immune response matures (Beard et al 2005), and an elevation of antibody titers to the organisms in pigs after weaning (Kondo et al 2000) suggests the involvement of the acquired immune system. Healthy young goat kids are presumably also a reservoir, but in the present farm and surrounding areas, many goats were infested with Haemonchus contortus, capable of causing anemia, weakness and weight loss (Kaufmann 1996).…”

“…Pneumocystosis is also found in young swine, and can occur concurrently with certain viral or bacterial infections (Kondo et al 2000). Although reports on Pneumocystis infection are extremely rare in ruminants, molecular phylogenetic analyses demonstrated a goat-specific strain from a 3-year-old doe suffering from heavy paratuberculosis (Sakakibara et al 2013).…”