The ability of Group A streptococcus to adhere to immortalized human skin versus throat cell lines does not reflect their predicted tissue tropism.
OBJECTIVE
To determine if emm pattern-inferred tissue tropisms of Group A streptococcus strains is reflected in their ability to adhere to immortalized human HaCat (keratinocyte) and Detroit 562 (pharyngeal) cell lines.


METHODS
Human epithelial cell line monolayers were inoculated with Group A streptococcus, and the percentage of adhered bacteria after a 1-h incubation period was calculated.


RESULTS
Of the 21/69 inferred-skin-tropic, and the 25/69 inferred-throat-tropic isolates no preferential adherence was observed to a particular cell line. The 23/69 strains classified as 'generalists', however, showed an overall greater ability to adhere to both cell lines.


CONCLUSIONS
Predicted tissue-tropism based on emm patterns is not reflected by preferential adherence to a specific cell line, suggesting that early adhesion events may not be as important in establishing infection at a particular ecological niche than originally expected.
Department of Molecular Medicine & Pathology, School of Medical Sciences, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, New Zealand. Electronic address: mj.loh@auckland.ac.nz.
J M S
JMS
Loh
Department of Molecular Medicine & Pathology, School of Medical Sciences, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, New Zealand.
J-Y C
JC
Tsai
Department of Molecular Medicine & Pathology, School of Medical Sciences, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, New Zealand.
T
T
Proft
D000942:Antigens, Bacterial; D001422:Bacterial Adhesion / Q000502:physiology*; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology / Q000382:microbiology; D006801:Humans; D010614:Pharynx / Q000166:cytology; D012867:Skin / Q000166:cytology; D013297:Streptococcus pyogenes / Q000472:pathogenicity* / Q000502:physiology*; D056189:Viral Tropism / Q000502:physiology*
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein
Adherence; Group A streptococcus; Streptococcus pyogenes; Tissue tropism; emm pattern