Octenidine exposure was not associated with reduced Octenidine susceptibility of meticillin-resistant Staphylococcus aureus (MRSA) in an extended-care facility in Singapore

Ying Wei Tang; Pei Yun Hon; Joanna Tan; Bee Fong Poh; Brenda Ang; Angela Chow

doi:10.1016/j.jhin.2024.02.030

Octenidine exposure was not associated with reduced Octenidine susceptibility of meticillin-resistant Staphylococcus aureus (MRSA) in an extended-care facility in Singapore

J Hosp Infect. 2024 Apr 24:S0195-6701(24)00122-1. doi: 10.1016/j.jhin.2024.02.030. Online ahead of print.

Authors

Ying Wei Tang¹, Pei Yun Hon², Joanna Tan³, Bee Fong Poh³, Brenda Ang⁴, Angela Chow⁵

Affiliations

¹ Department of Preventive and Population Medicine, Office of Clinical Epidemiology, Analytics, and Knowledge, Tan Tock Seng Hospital, Singapore.
² Infectious Disease Research Laboratory, National Centre for Infectious Diseases, Singapore.
³ Department of Infection Prevention and Control, Tan Tock Seng Hospital, Singapore.
⁴ Department of Infection Prevention and Control, Tan Tock Seng Hospital, Singapore; Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore.
⁵ Department of Preventive and Population Medicine, Office of Clinical Epidemiology, Analytics, and Knowledge, Tan Tock Seng Hospital, Singapore; Respiratory and Infectious Disease Programme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Infectious Disease Research and Training Office, National Centre for Infectious Diseases, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore. Electronic address: Angela_Chow@ttsh.com.sg.

PMID: 38670494
DOI: 10.1016/j.jhin.2024.02.030

Abstract

Objectives: Antiseptics such as chlorhexidine gluconate (CHG) and octenidine dihydrochloride (OCT) are frequently used in hospitals to prevent and control meticillin-resistant Staphylococcus aureus (MRSA) transmission. With increasing prevalence of reduced CHG susceptibility of MRSA, concerns are raised about the possibility of reduced OCT susceptibility. Hence, we evaluated the prevalence of reduced CHG and OCT susceptibility over 3 years and assessed the association between exposure to OCT and MRSA reduced susceptibility to OCT.

Methods: MRSA isolates from inpatients who acquired MRSA in an extended-care facility from 2019 to 2021, were included for antiseptic susceptibility testing. Inpatients were exposed to universal daily CHG bathing from January to September 2019, and universal daily OCT bathing after October 2019. The minimum inhibitory concentrations (MICs) were determined by broth microdilution method. Multivariable logistic regression was used to assess if exposure to OCT bathing was independently associated with reduced OCT susceptibility.

Results: Of 186 isolates, 179 (96%) had reduced CHG susceptibility (MIC ≥4 mg/L) whilst 46 (25%) had reduced OCT susceptibility (MIC ≥2 mg/L). OCT reduced susceptibility rates were 26.9%, 13.8% and 14.3% in 2019, 2020 and 2021, respectively. CHG reduced susceptibility rates were 95.4%, 100% and 95.9% in 2019, 2020 and 2021, respectively. OCT exposure was not associated with reduced OCT susceptibility (adjusted odds ratio [aOR] 0.23, 95% confidence interval [CI] 0.08 - 0.75, p 0.014), after adjusting for age, gender, race, sample collection year, days-at-risk in facility, past hospitalisation and previous MRSA in the preceding year.

Conclusion: The prevalence of reduced OCT susceptibility has remained low, despite universal OCT bathing for extended inpatient care. However, CHG reduced susceptibility rates were high. OCT exposure was not associated with reduced OCT susceptibility in MRSA.

Keywords: Antiseptic susceptibility; Chlorhexidine; Extended-care facility; Methicillin-resistant Staphylococcus aureus (MRSA); Octenidine.