Molecular epidemiology of β-lactamase production in penicillin-susceptible Staphylococcus aureus under high-susceptibility conditions. Issue 2 (February 2018)

• Record Type: Journal Article
• Authors: Matono, Takashi; Nagashima, Maki; Mezaki, Kazuhisa; Motohashi, Ayano; Kutsuna, Satoshi; Hayakawa, Kayoko; Ohmagari, Norio; Kaku, Mitsuo
• Is Part Of: Journal of infection and chemotherapy. Volume 24:Issue 2(2018:Feb.)
• Page Start: 153
• Page End: 155
• Publication Date: 2018-02
• Subjects: Staphylococcus aureus -- β-lactamase -- Zone edge -- blaZ gene; Chemotherapy -- Periodicals; Infection -- Periodicals; Communicable diseases -- Chemotherapy -- Periodicals; 615.5805
• DOI: 10.1016/j.jiac.2017.10.014
• Languages: English
• ISSNs: 1341-321X

Abstract

Abstract: Little is known about the prevalence of β-lactamase production in penicillin-susceptible Staphylococcus aureus isolates under high-susceptibility conditions. We analyzed S. aureus isolates with penicillin G minimum inhibitory concentration (MIC) ≤ 0.12 μg/ml that were recovered from in-/outpatients (n = 108) between 2016 and 2017 in Japan. β-Lactamase production was detected by nitrocefin-based and Clinical and Laboratory Standards Institute penicillin zone edge testing and blaZ PCR. All isolates were categorized as having penicillin G MIC ≤0.03 μg/ml using an automated system; MICs determined based on the microdilution method were 0.016 μg/ml (2%), 0.03 μg/ml (44%), and 0.06 μg/ml (54%). Notably, no isolates harbored the blaZ gene. The results from the nitrocefin-based and zone edge tests were consistent with those obtained by PCR. S. aureus isolates with penicillin G MIC ≤0.03 μg/ml exhibited a low frequency of β-lactamase production. Thus, screening for β-lactamase production may be unnecessary for isolates showing such high susceptibility.