Growth and effects of ureaplasmas (T mycoplasmas) in bovine oviductal organ cultures

Abstract

Ureaplasmas isolated from the human genital tract and from the genital and respiratory tracts of cattle were grown in association with organ cultures of bovine oviduct (uterine tube). All strains of unreaplasmas multiplied in organ cultures, stopped ciliary activity, and caused histological lesions. Most strains grew well, and 10(8) to 10(9) color-changing units were determined 18 to 144 h after inoculation. Twenty-four to 144 h after inoculation with unreaplasmas, ciliostasis was complete. Ciliostasis was also caused by additions of nonviable cultures at pH 8.8 (or adjusted to 7.4) or washed disrupted cells (100 mug of protein/ml); it occurred in 48 to 96 h. The cilia-stopping effect of nonviable cultures was diminished by heating (56 C for 30 min) and was abolished by boiling. When added to fresh medium in amounts exceeding 25%, nonviable unreaplasmal cultures completely inhibited ureaplasmal growth. By light, scanning, and transmission electron microscopy, cilia-stopping effect was correlated with collapse and sloughing of the cilia (the initial lesion was "bent" cilia), with bulging and vacuolization of secretory and ciliated cells, and finally with disorganization of the epithelium, necrosis, and desquamation.

The mycoplasmas.

“…Tracheal organ cultures were introduced as experimental model systems for studying pathogenicity of respiratory mycoplasmas in 1969 independently by Butler (32) and by Corier et al (54). Later, the oviduct was added to study pathogenicity of genital mycoplasmas (188,309,311,319). Organ cultures present several advantages over intact animals in pathogenicity studies.…”

“…Localization of mycoplasmas in organ cultures. That mycoplasmas can grow in tracheal and oviduct organ cultures has been demonstrated by many authors (32,33,41,54,188,311,319), though a period of adaptation to the explant conditions is sometimes necessary before satisfactory growth will occur (33). The organ culture usually supports better growth than the conditioned medium from which the organ explants have been removed, probably because of the higher concentration of nutrients adsorbed onto the organ cell surfaces.…”

Virulence Effectors of Pathogenic Mycoplasmas

“…Members of the genus Ureaplasma depend principally on urea hydrolysis to synthesize ATP (Romano et al, 1986;Thirkell et al, 1989;Smith et al, 1993). Indirect evidence that the ammonia produced by urease is toxic includes a report that inoculation with ureaplasmas caused ciliostasis and cytotoxicity within 24 hr in a bovine oviduct explant model, effects that could be simulated by addition of urea and jack bean urease to the culture medium of uninoculated controls (Stalheim et al, 1976;Stalheim and Gallagher, 1977). The most direct evidence of ureaplasmal ammonia toxicity is that intraperitoneal injection of the bacterial urease inhibitor flurofamide protected mice against intravenous challenge with lethal doses of either intact U.…”

ISOLAMENTO DO Ureaplasma diversum EM MUCO VULVOVAGINAL DE VACAS LEITEIRAS REPETIDORAS DE ESTRO NO ESTADO DE ALAGOAS – BRASIL

“…Os mecanismos pelos quais o U. diversum causa infertilidade estão relacionados à interações com o sistema linforeticular, alterações na resposta imunocelular e humoral, indução e produção de substâncias citotóxicas como amônia e peroxidase, sendo que a sua habilidade de aderência à célula hospedeira é um importante fator de virulência, assim como condição essencial para o estabelecimento da infecção (MILLER et al, 1994). Este microrganismo, quando presente na tuba uterina, causa a diminuição ou o cessamento da atividade ciliar, interferindo na concepção e no desenvolvimento inicial do embrião (STALHEIM et al, 1976). Em alguns casos o U. diversum estimula a síntese de prostaglandina F 2 a, potente hormônio luteolítico.…”