Phenotypical assays and partial sequencing of the hsp60 gene for identification of Streptococcus equi.
Strangles is an acute and contagious disease characterized by inflammation of the upper respiratory tract of horses. The etiological agent of strangles is the bacteria S. equi subsp. equi, which belongs to the Lancefield group C. Opportunistic agents from the same group are frequently isolated from horses with strangles and may induce mistaken diagnoses. Among the subspecies of S. equi, the phenotypic features are almost undistinguishable; however, the pathogenic potential is widely differentiated. The aim of this study was to characterize S. equi isolates obtained from clinical samples of strangles by phenotypic tests and to analyze the partial sequences obtained from fragments of the hsp60 gene. In this work, 26 strains of Streptococcus spp. isolated from horse clinical samples were analyzed. By phenotypical assays, 18 were characterized as S. equi subsp. equi, five as S. equi subsp. zooepidemicus, two as S. dysgalactiae subsp. equisimilis, and one as Streptococcus sp. However 21 isolates were identified as S. equi subsp. equi and five as S. equi subsp. zooepidemicus by DNA sequencing. The sequencing of the partial hsp60 gene was demonstrated to be an alternative method to analyze and differentiate strains of Streptococcus spp. In addition, this method can be useful as a discriminatory tool for characterization of atypical isolates.
Sá e Silva
Mariana
M
Universidade Federal de Santa Maria, Departamento de Medicina Veterinária Preventiva, Laboratório de Bacteriologia, Santa Maria, RS, Brazil.
da Costa
Mateus Matiuzzi
MM
de Avila Botton
Sônia
S
Barretta
Clarissa
C
Groff
Ana Cláudia Mello
AC
de Vargas
Agueda Castagna
AC
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D018834:Chaperonin 60 / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D006734:Horse Diseases / Q000382:microbiology; D006736:Horses; D008969:Molecular Sequence Data; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary; D018502:Streptococcus equi / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
D001426:Bacterial Proteins; D018834:Chaperonin 60; D004269:DNA, Bacterial