Mouse lethal cardiovascular disease: induction by human leucocyte intracellular Mollicutes.

Plant pathologists have known for several years that intracellular Mollicutes (M), i.e. cell wall deficient bacteria, are plant vascular pathogens, but because those M are non-cultivatable, they can only be studied by Transmission Electron Microscopy (TEM). Only recently have similar M been shown to be human and animal pathogens. Those human ocular Vasculitis (V) and mouse chronic ocular and lethal systemic V producing M parasitize vitreous polymorphonuclear leucocytes, lymphocytes, and monocytes as 'viral-like' 0.005-0.010 micron elemental particles which grow within the leucocyte into 0.01-0.03 micron diameter tubules, 0.3-1.5 micron spherules, and distinctive 0.5-0.7 micron cocci with spore-like cell walls. This report describes the 48 arteriolar and capillary sized V, Aschoff nodules, valvulitis, and myocytolytic lesions in the heart and great vessels in 18 of 100 human vitreous VM containing eyelid inoculated mice versus 0 of 200 controls (P less than 0.05) plus VM within parasitized leucocytes in 15 of 15 of those lesions by TEM. The results indicate dissemination of VM from the eyelid to produce a significant incidence of distinctive multifocal VM directly induced cardiovascular micro-V lesions that probably contributed to their excessive mortality. Because several human idiopathic diseases develop similar cardiovascular lesions a TEM search for VM parasitized leucocytes in those human diseases seems justified.

Isolation and pathogenicity of mycoplasmas from geese.

Several mycoplasma isolation trials were performed on infertile goose eggs and goose embryos which died during incubation, as well as on geese of different ages. A total of 43 out of 110 goose eggs proved to be contaminated by mycoplasmas. Upon autopsy of birds which laid positive eggs, lesions were observed in the airsacs. Mycoplasmas could be isolated from their air sacs and oviduct. Four out of 15 strains examined biochemically and serologically with antisera prepared against all known avian mycoplasma species were identified as Acholeplasma laidlawii and A. axanthum, respectively. Two strains proved to be glucose-positive and arginine-negative and 9 were glucose-negative but arginine-positive. Some strains caused 50-80% mortality among embryos inoculated intra-yolk-sac at 12 days. In goslings inoculated at the age of 3 days with these strains, we observed fibrinous airsacculitis and peritonitis. By inoculating laying geese with one of the strains, we demonstrated decreasing egg production, increasing early-embryo mortality and egg transmission of mycoplasmas.

Phylogenetic classification of phytopathogenic mollicutes by sequence analysis of 16S ribosomal DNA.

The phylogenetic relationships of 17 phytopathogenic mycoplasmalike organisms (MLOs) representing seven major taxonomic groups established on the basis of MLO 16S ribosomal DNA (rDNA) restriction patterns were examined by performing a sequence analysis of the 16S rDNA gene. The sequence data showed that the MLOs which we examined are members of a relatively homogeneous group that evolved monophyletically from a common ancestor. In agreement with results obtained previously with other MLOs, our results also revealed that the organisms are more closely related to Acholeplasma laidlawii and other members of the anaeroplasma clade than to any other mollicutes. A phylogenetic tree based on 16S rDNAs showed that the MLOs which we examined can be divided into the following five primary clusters: (i) the aster yellows strain cluster; (ii) the apple proliferation strain cluster; (iii) the western-X disease strain cluster; (iv) the sugarcane white leaf strain cluster; and (v) the elm yellows strain cluster. The aster yellows, western-X disease, and elm yellows strain clusters were divided into two subgroups each. MLOs whose 16S rDNA sequences have been determined previously by other workers can be placed in one of the five groups. In addition to the overall division based on 16S rDNA sequence homology data, the primary clusters and subgroups could be further defined by a number of positions in the 16S rDNAs that exhibited characteristic compositions, especially in the variable regions of the gene.