Distinctive features of surface-anchored proteins of Streptococcus agalactiae strains from Zimbabwe revealed by PCR and dot blotting.
The distribution of capsular polysaccharide (CPS) types and subtypes (serovariants) among 121 group B streptococcus (GBS) strains from Zimbabwe was examined. PCR was used for the detection of both CPS types and the surface-anchored and strain-variable proteins Calpha, Cbeta, Alp1, Alp2, Alp3, R4/Rib, and Alp4. The R3 protein was detected by an antibody-based method using monoclonal anti-R3 antibody in dot blotting. The CPS types detected, Ia (15.7% of strains), Ib (11.6%), II (8.3%), III (38.8%), V (24.0%), and nontypeable (1.7%), were essentially as expected on the basis of data from Western countries. The type V strains showed distinctive features with respect to protein markers in that Alp3 was detected in only 6.9% of the isolates while R3 occurred in 75.9% and R4/Rib occurred in 37.9% of the isolates. R3 occurred nearly always in combination with one of the alpha-like (Alp) proteins, and it was the third most common of the proteins studied. These results show that type V GBS strains from Zimbabwe differed from type V strains from other geographical areas and also emphasize the importance of the R3 protein in GBS serotyping and its potential importance in the immunobiology of GBS, including a potential role in a future GBS vaccine.
Mavenyengwa
Rooyen T
RT
Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, Mount Pleasant, Harare, Zimbabwe.
Maeland
Johan A
JA
Moyo
Sylvester R
SR
D001426:Bacterial Proteins / Q000235:genetics*; D002353:Carrier State / Q000382:microbiology*; D005260:Female; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D008565:Membrane Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011135:Polysaccharides, Bacterial / Q000235:genetics; D037841:Pregnant People; D012703:Serotyping; D013292:Streptococcus agalactiae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015030:Zimbabwe
D001426:Bacterial Proteins; D008565:Membrane Proteins; D011135:Polysaccharides, Bacterial