Genetic diversity of Yersinia pestis in Brazil.
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 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.
Departamento de Bioquímica, Universidade Federal de Pernambuco, Recife, PE, Brasil.
M B M
MB
Oliveira
M P S
MP
Barros
V M
VM
Silveira-Filho
M R
MR
Araújo-Nepomuceno
V Q
VQ
Balbino
N C
NC
Leal
A M P
AM
Almeida
T C
TC
Leal-Balbino
D000483:Alleles; D001938:Brazil; D016000:Cluster Analysis; D004587:Electrophoresis, Agar Gel; D056426:Genetic Loci / Q000235:genetics; D014644:Genetic Variation; D005843:Geography; D018598:Minisatellite Repeats / Q000235:genetics; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D010930:Plague / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015010:Yersinia pestis / Q000145:classification / Q000235:genetics*