Genetic diversity of Yersinia pestis in Brazil

Abstract

ABSTRACT. Plague outbreaks are occasionally reported in Brazil. Unfortunately, due to great genetic similarity, molecular subtyping of Yersinia pestis strains is difficult. Analysis of multiple-locus variable number of tandem repeats (VNTR), also known as MLVA, has been found to be a valuable tool to discriminate among strains. To check for genetic differences, strains obtained from two different ecological complexes in Brazil collected during two different epidemiological events, an epizootic in Sítio Alagoinha in 1967 and an outbreak in Planalto da Borborema in 1986, were subtyped through MLVA using 12 VNTR loci. Three clusters (A, B and C) were observed. Of the 20 strains from the epizootic, 18 fit into cluster A. Cluster A was divided into two subgroups: A 1 (15 strains) and A 2 (3 strains). Of the 17 strains from the outbreak, 15 fit into cluster B. Cluster B was divided into three subgroups: B 1 (4 strains), B 2 (4 strains) and B 3 (7 strains). Cluster C is a singleton with one epizootic strain. The external standards, Y. pestis CO92 and Y. pseudotuberculosis IP32953, formed two clusters of singletons. The stability of 12 VNTR loci of three unrelated cultures ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 11 (3): 3414-3424 (2012) Brazilian Yersinia pestis diversity 3415 included in this study was assessed. The 12 VNTR loci were stable through multiple serial subcultures in the laboratory. MLVA revealed that Y. pestis populations in Brazil are not monomorphic, and that there is intraspecific genetic diversity among Brazilian plague strains. We conclude that there is some correlation among genetic groups of this species, related to the temporal and geographic origin of isolates.

Dynamics of CRISPR Loci in Microevolutionary Process of Yersinia pestis Strains

“…The molecular data supported the historical evidence of the spread of an ancestral lineage, reinforcing the hypothesis of a single clonal entry into Brazil [10] , [24] . The other genotypes showed distinct subpopulations of Y. pestis that demonstrated bacterial microevolution in these environments.…”

“…Genomic DNA was extracted using the method described by Keim et al [9] , and adapted by Oliveira et al [10] . PCR reactions were performed as described by Le Flèche et al [11] , and 3 CRISPR loci (YPa, YPb, YPc) were amplified with primer pairs described by Pourcel et al [3] .…”

Subtyping Brazilian Yersinia pestis strains by pulsed-field gel electrophoresis

“…This analysis establishes a relative correlation among genetic groups, which is related to the temporal and geographic origin of the isolates (Oliveira et al, 2012).…”

A single introduction of Yersinia pestis to Brazil during the 3rd plague pandemic

“…In contrast, an analysis of 20 Y . pestis strains from an epizootic event in Sítio Alagoinha in 1967 and 17 strains from an outbreak in Planalto da Borborema in 1986 using 12 variable-number tandem repeat (VNTR) loci provided 100% discrimination and identified three genetic groups, which revealed some association with the geographic/temporal origin of the strains [11]. Here, we expand upon these previous analyses using whole genome sequencing.…”