title: Serological versus molecular typing of surface-associated immune evading polysaccharide antigens-based phenotypes of Staphylococcus aureus.
abstract: The aim of this study was to compare the performance of serological versus molecular typing methods to detect capsular polysaccharide (CP) and surface-associated polysaccharide antigen 336 phenotypes of Staphylococcus aureus isolates. Molecular typing of CP types 1, 5 and 8 was carried out using PCR, whereas serological typing of CP1, 2, 5, 8 and antigen 336 was carried out by slide agglutination using specific antisera. By genotyping, 14/31 strains were CP8 positive, 12/31 strains were CP5 and the remaining 6/31 isolates were non-typable (NT). One isolate was positive for both CP5 and CP8 by PCR, but was confirmed as CP8 type serologically. Detection of CP2 and type 336 by PCR was not possible because specific primers were either not available or non-specific. Using serotyping, 14/31 strains were CP8 positive, 11/31 CP5 positive and 2/31 positive for antigen 336. The remaining four S. aureus isolates were serologically NT. However, three of four NT and two 336-positive S. aureus isolates were encapsulated as determined by light microscopy after capsular staining. This discovery was surprising and warrants further investigations on the identification and characterization of additional capsular phenotypes prevalent among S. aureus clinical isolates. It was concluded that serological typing was a better method than molecular typing for use in epidemiological investigations based upon the distribution of surface-associated polysaccharide antigens-based phenotypes.
authors.affiliation: School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia 6102, Australia.
authors.forename: Charlene B
authors.initials: CB
authors.lastname: Waryah
authors.affiliation: School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia 6102, Australia.
authors.forename: Jully
authors.initials: J
authors.lastname: Gogoi-Tiwari
authors.affiliation: School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia 6102, Australia.
authors.forename: Kelsi
authors.initials: K
authors.lastname: Wells
authors.affiliation: School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia 6102, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Costantino
authors.affiliation: School of Pharmacy, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia 6102, Australia.
authors.forename: Hani
authors.initials: H
authors.lastname: Al-Salami
authors.affiliation: Department of Veterinary Microbiology, Karnataka Veterinary, Animal and Fisheries Sciences University, Hebbal, Bengaluru 560024, Karnataka, India.
authors.forename: Raju
authors.initials: R
authors.lastname: Sunagar
authors.affiliation: Department of Veterinary Microbiology, Karnataka Veterinary, Animal and Fisheries Sciences University, Hebbal, Bengaluru 560024, Karnataka, India.
authors.forename: Shrikrishna
authors.initials: S
authors.lastname: Isloor
authors.affiliation: Ella Foundation, Genome Valley, Turkapally, Shameerpet Mandal, Hyderabad 500078, Andhra Pradesh, India.
authors.forename: Nagendra
authors.initials: N
authors.lastname: Hegde
authors.affiliation: School of Paediatrics and Child Health, University of Western Australia, Crawley, Western Australia 6009, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Richmond
authors.affiliation: School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia 6102, Australia.
authors.forename: Trilochan
authors.initials: T
authors.lastname: Mukkur
mesh_terms: D005838:Genotype; D006801:Humans; D057131:Immune Evasion / Q000502:physiology; D058889:Molecular Typing / Q000379:methods*; D011135:Polysaccharides, Bacterial / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012698:Serologic Tests / Q000379:methods*; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014904:Western Australia
chemical_list: D011135:Polysaccharides, Bacterial