Genetic Characterization of Staphylococcus aureus, Staphylococcus argenteus, and Coagulase-Negative Staphylococci Colonizing Oral Cavity and Hand of Healthy Adults in Northern Japan

Abstract

The spread of methicillin resistance and virulence among staphylococci in the community poses a public health concern. In this study, we investigated the prevalence of Staphylococcus species colonizing the oral cavity and hand (skin) of healthy university students and their phenotypic and genetic characteristics in northern Japan. Among a total of 332 subjects, 6 and 110 methicillin-resistant and susceptible Staphylococcus aureus (MRSA and MSSA, respectively) isolates were recovered from 105 subjects. MRSA isolates were genotyped as CC5, CC8, CC45, and CC59 with SCCmec-IIa or IV, among which an isolate of ST6562 (single-locus variant of ST8) harbored SCCmec-IVa, PVL genes and ACME-I, which are the same traits as the USA300 clone. ST1223 S. argenteus was isolated from the oral cavity and hand of a single student. Coagulase-negative Staphylococcus (CoNS) was recovered from 154 subjects (172 isolates), and classified into 17 species, with S. capitis being the most common (38%), followed by S. warneri (24%) and S. epidermidis (15%), including nine mecA-positive isolates. S. capitis was differentiated into seven clusters/subclusters, and genetic factors associated with the NRCS-A clone (nsr, tarJ, ebh) were detected in 10–21% of isolates. The colonization of the USA300-like MRSA variant and S. capitis with the traits of the NRCS-A clone in healthy individuals was noteworthy.

Acute osteomyelitis/septic pulmonary embolism associated with familial infections caused by PVL-positive ST6562 MRSA-IVa, a presumptive variant of USA300 clone

“…Before the present MRSA was isolated in 2021, we first identified ST6562 in MRSA colonizing the oral cavity of a 66-year-old female in 2020 [6] and subsequently identified it in an isolate from the skin of the hand of an 18-year-old male in 2021 [7] , also in Hokkaido, Japan. These colonizing ST6562 belonged to the same genotypes ( spa -t1188/ coa -IIIa/SCC mec -IVa) as the isolates presented in this report, while having PVL genes and ACME type I as seen in the USA300 clone [2] ; moreover, the former isolate harbored resistance genes aph(3′)-IIIa and msrA .…”

Staphylococcus capitis Bloodstream Isolates: Investigation of Clonal Relationship, Resistance Profile, Virulence and Biofilm Formation

“…The present results obtained for the last 10 years revealed the presence of the mecA gene in 70.2% of the isolates. The resistance rate in this species appears to be much lower when the isolates originate from colonization of the skin of healthy individuals and healthcare-unrelated environments, ranging from 3 to 8% [47,48].…”