Influence of oral conditions on colonization by highly toxigenic Staphylococcus aureus strains.
OBJECTIVE
As the oral cavity is regarded as a relevant site for Staphylococcus aureus colonization and interhuman transmission, this study aimed to investigate whether different oral conditions influence the rates of S. aureus oral carriage and genetic characters of S. aureus isolates.


METHODS
Staphylococcus aureus was searched in samples collected from cheek, gingival margin, and anterior nares of 45 healthy subjects, 27 periodontitis affected subjects, and 29 subjects with fixed prosthetic restorations. Isolates were screened for 17 genetic determinants, and Partial Least Square Discriminant Analysis was performed to evaluate whether specific characters correlated with oral condition or site of isolation.


RESULTS
The three subject groups showed comparable nasal carriage rates but, both the periodontitis and prosthetic restoration groups showed significantly higher oral carriage rates, as compared to healthy subjects (P = 0.01 and 0.02, respectively). Moreover, periodontitis affected subjects hosted strains possessing a distinct genotypic and phenotypic background, characterized by the presence of a larger number of exotoxins encoding genes.


CONCLUSIONS
These data confirm that the oral cavity is an important site of S. aureus colonization and demonstrate that conditions modifying the oral environment, as the presence of periodontitis and of fixed prosthetic restorations, promote S. aureus carriage and may favor the spread of more pathogenic strains.
Dipartimento di Sanità Pubblica e Malattie Infettive, Università"La Sapienza", Rome, Italy. claudio.passariello@uniroma1.it
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Passariello
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Puttini
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Iebba
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Pera
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Gigola
D000328:Adult; D016301:Alveolar Bone Loss / Q000382:microbiology; D058491:Bacterial Load; D018407:Bacterial Physiological Phenomena; D001427:Bacterial Toxins / Q000235:genetics; D002610:Cheek / Q000382:microbiology; D055113:Chronic Periodontitis / Q000382:microbiology; D003774:Dental Plaque Index; D017266:Dental Prosthesis / Q000382:microbiology; D005098:Exotoxins / Q000235:genetics; D005260:Female; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D005881:Gingiva / Q000382:microbiology; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D009061:Mouth Mucosa / Q000382:microbiology; D009666:Nose / Q000382:microbiology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000382:microbiology; D010641:Phenotype; D013211:Staphylococcus aureus / Q000235:genetics / Q000502:physiology*; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
D001427:Bacterial Toxins; D005098:Exotoxins; D037521:Virulence Factors