Karyotypes of Pneumocystis carinii derived from several mammals

Abstract

Pneumocystis carinii is the most important opportunistic pathogen of humans in the world. Pneumocystis carinii is experimentally detected in the lungs of rats, mice, rabbits, and monkeys, however, the organisms from different mammals are identical in microscopic morphology. The present study tried to find out more mammalian hosts of P. carinii and also to differentiate the organisms from different mammals by karyotyping. Rats, mice, hamsters, rabbits, cats, and dogs were successfully infected by P. carinii, but guinea pigs and pigs were not. Karyotype of P. carinii from rabbits showed similar size range of chromosomes with that of the prototype, but in different pattern. The patterns from cats and dogs were also different from that of rats. The present study confirms that cats and dogs are infected by P. carinii and at least total three karyotype strains of P. carinii are proven in Korea.

Fig. 1

Pneumocystis carinii discovered from the lungs of an infected cat, Diff-Quik stained, original magnification ×1,500. A. One octanucleate cystic form (arrow) and a few trophic forms (arrow heads) are shown. B. One developing cystic form (arrow) began to divide the nucleus (arrow).

Fig. 2

Karyotype patterns of Pneumocystis carinii from rats, cats, dogs and rabbits in a 1% agarose CHEF gel in 0.5× TBE buffer. Running conditions were 50 sec initial and 200 sec final, 1:1 A/B ratio, and 6 V/cm for 40 hr. Lane 1, size marker of Saccharomyces cerevisiae AB 972; 2, W37, P. carinii from Wistar rats, 3, C2-3 P. carinii from cats; 4, D2-2 P. carinii from dogs; 5-7, P. carinii from rabbits; 8, same size marker of lane 1.

Fig. 3

Karyotype patterns of Pneumocystis carinii from different animals in a 1% agarose gel of FIGE. Running parameters were 50 sec forward and 25 sec backwards, and 105 V for 120 hr. 1, size marker from Saccharomyces cerevisiae AB 972; 2, W26 P. carinii from wistar rats; 3, C2-3 P. carinii from cats; 4-6, D2-1, D2-2, D4 P. carinii from dogs; 7-9, Rb2, Rb9, Rb6-1 P. carinii from rabbits; 10, size marker from S. cerevisiae AB 972.