Antimicrobial Resistance and Molecular Epidemiological Characteristics of Methicillin-Resistant and Susceptible Staphylococcal Isolates from Oral Cavity of Dental Patients and Staff in Northern Japan.

Mina Hirose,Nobumichi Kobayashi,Noriko Urushibara,Yusuke Fujita,Masato Saitoh,Yukito Hirose,Atsushi Fukuda,Shoko Yahata,Meiji Soe Aung

doi:10.3390/antibiotics10111316

Mina Hirose, Nobumichi Kobayashi + Show 7 more

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https://doi.org/10.3390/antibiotics10111316

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Abstract

The acquisition of drug resistance and virulence by staphylococcal species colonizing humans is a growing public health concern. The present study was conducted to investigate the prevalence, antimicrobial resistance and genetic characteristics of Staphylococcus isolates from the oral cavity and skin (hand) of systemically healthy subjects with dental disease and dental staff in northern Japan. Among a total of 133 subjects (91 patients and 42 staff), 87 coagulase-positive Staphylococcus (83 S. aureus/4 S. argenteus) and 162 coagulase-negative Staphylococcus (CoNS) isolates were recovered from 59 (44.4%) and 95 (71.4%) subjects, respectively. Three oral isolates were methicillin-resistant S. aureus (MRSA) (3.6%, 3/83) that were genotyped as ST8-SCCmec-IVl, ST4775(CC1)-SCCmec-IVa and ST6562(CC8)-SCCmec-IVa. Remarkably, the ST6562 isolate harbored PVL genes on ΦSa2usa and type I ACME (arginine catabolic mobile element). Four methicillin-susceptible isolates were identified as S. argenteus belonging to ST1223 and ST2250, which harbored enterotoxin genes egc-2 and sey, respectively. Among the fourteen CoNS species identified, methicillin-resistant (MR) isolates were detected in five species (11 isolates, 13.3% of CoNS), with S. saprophyticus and S. haemolyticus being the most common. ACME was prevalent in only S. epidermidis and S. capitis. These findings indicated the potential distribution of USA300 clone-like MRSA, toxigenic S. argenteus and MR-CoNS in the oral cavity of dental patients.

Highlights

Staphylococcus is well-known commensal bacteria in humans and most mammals and forms the normal flora of the skin and mucous membrane
The prevalence of S. aureus and methicillin-resistant S. aureus (MRSA) in an oral cavity reported to date varies depending on the study design having different subjects [33]
The oral carriage rates of MRSA in healthy subjects were 1.9% [22] and 4.1% [38], with MRSA accounting for 9–21% of colonizing S. aureus

Summary

Introduction

Staphylococcus is well-known commensal bacteria in humans and most mammals and forms the normal flora of the skin and mucous membrane. This genus has been divided into coagulase-positive and -negative groups that include more than forty species [1]. Human-associated coagulase-positive Staphylococcus (CoPS) represents more pathogenic groups of Staphylococcus, comprising at least three species, among which S. aureus is the most common cause of a wide variety of diseases including skin and soft tissue infections, pneumonia, bacteremia, septic shock, food poisoning and toxic shock syndrome [2]. While coagulase-negative Staphylococcus (CoNS) is regarded as a less virulent group, some CoNS species are common opportunistic pathogens that pose a significant health burden [2]. Nosocomial infections with some CoNS species become difficult to treat, due to the ability of biofilm to form on indwelling medical devices [7]

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