Plasmids in Mycoplasma species isolated from goats and sheep and their preliminary typing

Abstract

One-hundred-five (105) clinical isolates of mycoplasma from caprine origin and one isolate from ovine were surveyed for plasmids, which were present in thirty-three (31%) of them. These mycoplasmas originated from 13 herds. Ten of them were symptomatic for mycoplasmal disease (mastitis, polyarthritis, septicemia) and three herds were asymptomatic, i.e., clinically normal. Twenty-eight isolates were Mycoplasma mycoides subspecies mycoides LC (large colony or caprine biotype), four were Mycoplasma capricolum subsp. capricolum and one was Mycoplasma cottewii. The isolated plasmids were linearized by EcoRI, EcoRV, EcoRI and EcoRV or BamHI and EcoRV, and were of five sizes (1.1, 1.6, 1.7, 1.8, and 1.9 Kbp). Based on restriction enzyme digestion and size of the linearized supercoiled extrachromosomal DNA, five plasmid types were recovered (p1II, p2III, p2V, p3I, and p4IV). The small size of these DNA elements probably exclude replicative forms of DNA virus, which are equal or larger than 8.0 Kbp.

Distribution and diversity of mycoplasma plasmids: lessons from cryptic genetic elements

“…This study was performed in the context of (i) conflicting reports regarding the prevalence of plasmids in mycoplasma species [3,24] and of (ii) the quest for MGE that may have served as genetic vehicles resulting in the high level of HGT reported among ruminant mycoplasmas [58]. We found a rather high prevalence of plasmids in species belonging to the M. mycoides cluster and, in contrast, a lack of plasmids in the M. bovis-M. agalactiae group.…”

“…capri (Mmc) . In contrast to the apparent scarcity of mycoplasma plasmids, other investigators have reported a much higher prevalence of strains with plasmids but these data were only based on agarose gel detection of extrachromosomal DNA, without DNA sequencing [24]. …”