In Vitro Study to Assess Effective Cleaning Techniques for Removing Staphylococcus aureus from Menstrual Cups

Abstract

Background: We sought to determine the effectiveness of common cleaning procedures in eliminating S. aureus from silicone menstrual cups. Methods: In this in vitro study, we tested four cleaning techniques: (1) cold water; (2) cold water and liquid soap; (3) cold water followed by steeping the cup in boiled water for 5 min in a ceramic mug covered with a small plate; and (4) cold water and soap followed by steeping the cup in boiled water as in (3). Human blood was coated to the inner and outer surface of each cup, dried, and incubated with 106 S. aureus colony-forming units (CFU/mL). All tests were performed in triplicate. Viable bacterial abundance was measured with decadic dilution and drop plate or surface plating. Results: Bacteria were most effectively eliminated by cleaning cups with soap and water and then steeping in boiled water (0 CFU/cup vs. 2.075 × 108/cup no cleaning, p = 0.005). This was not statistically significantly different from washing cups with water only and steeping 5 min in boiled water (14 CFU/cup). Raised lettering on the outer surface of the menstrual cups resulted in more bacterial recovery from pieces with lettering than without lettering. Conclusions: These results advance knowledge of between-period menstrual cup cleaning recommendations, suggesting that the logistical challenges of continuous boiling may be eliminated with steeping at least 5 min.

Development of in vitro methods to model the impact of vaginal lactobacilli on Staphylococcus aureus biofilm formation on menstrual cups as well as validation of recommended cleaning directions

“…When all these co-factors are met, almost all medical device surfaces are susceptible to colonization by adherent bacteria during human use ( 99 , 113 ). Nevertheless, the results presented from our experiments do not support Nonfoux, et al ( 39 ), regarding S. aureus biofilm formation on MC or Wunch et al ( 40 ), regarding cleaning the MC. No visual identification of any biofilm formation by S. aureus using cryo-SEM was observed a well-accepted methodology for visualizing microbes and their modality of growth.…”

“…Cleaning is a necessary step prior to subjecting devices to boiling. The methodology described herein utilizes slightly different design parameters than described by Wunsch ( 40 ) to understand cleaning effectiveness including use of an artificial menstrual fluid, meant to represent the complex nature of menses ( Supplementary Table S–4 ). The data described herein have demonstrated that, when the cleaning protocol was initiated, the soiled MC with added bacteria using model gram positive and gram negative organisms, had at least a 3 log reduction (99.9%) when S. aureus and E. coli were inoculated on the MC compared to study initiation at t = 0 h. Less than 200 cfu/ml from the MC were identified as part of the sonication protocol.…”

“…The same publication suggested that current cleaning protocols are not sufficient to remove biofilm ( 39 ). Subsequently, a publication by Wunsch et al ( 40 ), investigated various cleaning techniques noting that cleaning with cold tap water (with or without soap) followed by steeping in boiled water for 5 min was most effective at reducing viable bacteria. Thus, the objectives of this research report centered on whether S. aureus biofilms would form on the MC in the presence of lactic acid bacteria (keystone species) and if the instructions on the current package of the Tampax MC were sufficient manage the cleaning (both effectively and easily) of the MC in between uses.…”

Insight about Menstrual Cups on Student of the Faculty of Pharmacy and Health Science, Abdurrab University

“…The majority of respondents fell into the Good knowledge category with a total of 175 people (67.3%). The research results are in line with research Wunsch N, et al (2022) conducted in India, namely 65.75% of respondents have good knowledge about menstrual cups and their use.…”