Genome Sequences of Mycoplasma alligatoris A21JP2T and Mycoplasma crocodyli MP145T▿

Mycoplasma alligatoris and Mycoplasma crocodyli are closely related siblings, one being highly virulent and the other relatively attenuated. We compared their genomes to better understand the mechanisms and origins of M. alligatoris' remarkable virulence amid a clade of harmless or much less virulent species. Although its chromosome was refractory to closure, M. alligatoris differed most notably by its complement of sialidases and other genes of the N-acetylneuraminate scavenging and catabolism pathway

Extensive Horizontal Gene Transfer in Ureaplasmas from Humans Questions the Utility of Serotyping for Diagnostic Purposes ▿ †

Ureaplasma parvum and Ureaplasma urealyticum are sexually transmitted, opportunistic pathogens of the human urogenital tract. There are 14 known serovars distributed between the two species. For decades, it has been postulated based upon limited data that virulence is related to serotype specificity. The results were often inconclusive due to the small sample size and extensive cross-reactivity between certain serovars. We developed real-time quantitative PCRs that allow reliable differentiation of the two species and type strains of each of the 14 serovars. To investigate species and serovar distributions, we typed 1,061 clinical isolates of human ureaplasmas from diverse patient populations. There was only a tenuous association between individual Ureaplasma serovars and certain patient populations. This may in part be explained by the fact that almost 40% of the isolates were genetic mosaics, apparently arising from the recombination of multiple serovars. This explains the extensive cross-reactivity based upon serotyping and the lack of consistent association of given serotypes with disease