Characterisation of Yersinia pestis isolates from natural foci of plague in the Republic of Georgia, and their relationship to Y. pestis isolates from other countries

Abstract

Forty Yersinia pestis isolates from endemic foci of plague in the Republic of Georgia, and six Y. pestis isolates from neighbouring former Soviet Union countries, were analysed for their biochemical and phenotypic properties, and their genetic relatedness was compared with Y. pestis strains KIM and CO92 by pulsed-field gel electrophoresis (PFGE). In addition, 11 Y. pestis isolates from the USA, together with published nucleotide sequences from Y. pestis strains KIM, CO92 and 91001, were compared with the 46 isolates in the present collection using multilocus sequence typing (MLST), based on sequence data for the 16S rRNA, hsp60, glnA, gyrB, recA, manB, thrA and tmk loci. Four virulence gene loci (caf1, lcrV, psaA and pla) were also sequenced and analysed. Two sequence types (ST1 and ST2), which differed by a single nucleotide, were identified by MLST. With the exception of a single isolate (771G), all of the Georgian Y. pestis isolates belonged to ST2. PFGE also grouped the Georgian Y. pestis isolates separately from the non-Georgian isolates. Overall, PFGE discriminated the Y. pestis isolates more effectively than MLST. The sequences of three of the four virulence genes (lcrV, psaA and pla) were identical in all Georgian and non-Georgian isolates, but the caf1 locus was represented by two allele types, with caf1 NT1 being associated with the non-Georgian isolates and caf1 NT2 being associated with the Georgian isolates. These results suggest that Georgian Y. pestis isolates are of clonal origin.

Subtyping Brazilian Yersinia pestis strains by pulsed-field gel electrophoresis

“…Although PFGE sensitivity and discriminatory ability depend on the restriction enzyme and organism studied, its high performance has become valuable for typing many bacteria and discriminating Y. pestis strains Huang et al, 2002;Revazishvili et al, 2008;Zhang et al, 2009).…”

Genetic diversity of Yersinia pestis in Brazil

“…Alternatively, the strains could be inaccurate representatives of the original isolates, and these differences could be due to handling procedures during the prolonged storage of the strains in the laboratory since their isolation (Revazishvili et al, 2008;Vogler et al, 2011). Leal et al (2000) and Leal-Balbino et al (2004, 2006 observed spontaneous changes in the genome (both plasmid and chromosomal) of Brazilian Y. pestis following prolonged storage and laboratory handling.…”

Сapsular Antigen of Yersinia Pestis

“…orientalis) мутации приве-ли к возможности синтеза только укороченных до 147 и 130 аминокислотных остатков и, веро-ятно, функционально неполноценных вариан-тов белка Caf1. Секвенирование гена caf1 из 41 штамма, выделенного на территории Грузии и Армении от полевок и их эктопаразитов, пока-зало, что для них всех характерна замена A48 → S48, а штаммы, выделенные в этом же регионе от песчанок или сусликов, обладали канониче-ской последовательностью гена caf1 [79].…”