Molecular epidemiology of impetiginous group A streptococcal infections in aboriginal communities of northern Australia.
Group A streptococcal infections among the Aboriginal communities of the Northern Territory of Australia are endemic, with a concurrently high rate of the postinfection sequelae of rheumatic fever and acute post-streptococcal glomerulonephritis. The majority of the group A streptococcal isolates from the Northern Territory are not typeable by M typing. We recently developed a novel genotyping method, Vir typing. A preliminary study using this method discriminated all the M-nontypeable (MNT) isolates. Vir typing is based on restriction fragment length polymorphisms of the 4- to 7-kb Vir regulon of group A streptococci, which contains a number of genes, including emm (the gene for M protein). A total of 407 isolates of group A streptococci obtained from four Aboriginal communities over a 4-year period were typed by this genotyping method. Forty-two distinct genotypes were found among the isolates, including 22 among the MNT isolates. The correlation between Vir type and M type was good. This genotyping method allows the characterization of all group A streptococcal isolates from Aboriginal communities in the Northern Territory. We also propose that Vir typing be used in conjunction with M typing for epidemiological surveillance in geographical regions where the majority of isolates are MNT.
Gardiner
D L
DL
Menzies School of Health Research, Darwin, Australia.
Sriprakash
K S
KS
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002352:Carrier Proteins; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D007169:Impetigo / Q000453:epidemiology* / Q000382:microbiology*; D017720:Molecular Epidemiology; D015876:Northern Territory / Q000453:epidemiology; D012150:Polymorphism, Restriction Fragment Length; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein