Alcohol-based Hand Rub as a Prophylactic Measure against SARS-COV-‎‎2 Infection: Can it Reduce the Infection with Vancomycin-Resistant ‎Enterococcus faecalis?‎ ‎

INTRODUCTION

Enterococci are gastrointestinal (GI) commensals of healthy humans that belong to gram-positive anaerobes. Currently, there are more than 50 identified enterococcal species [1].Enterococcus faecalis is the most abundant enterococcal species within the human GI tract and exerts critical physiological functions as a part of intestinal microbiota [2]. Despite serving as a commensal organism, the Enterococcus faecalis has emerged as a prevalent cause of opportunistic nosocomial infections in critically ill patients, leading to life-threatening bacteremia and endocarditis [3]. Besides, Enterococcus faecalis infection may occur within the community, and it has been reported in urinary tract infections [4]. With the advance of antibiotic regimens, enterococcal species have demonstrated genetically-driven intrinsic resistance to a wide range of antimicrobial agents. The Enterococci also exhibit acquired, sometimes a rapid-onset, multidrug resistance determinants [5]. Since early reports of vancomycin-resistant enterococci (VRE), growing evidence has highlighted the significant impact of these species on the outcomes of critically ill patients and the healthcare system. Previous reports demonstrated that enterococcal species usually develop resistance to vancomycin through various mechanisms, including dysregulated glycopeptide synthesis and the emergence ofvan gene clusters [5,6]. Previous reports showed that nearly one-third of isolated Enterococcus faecalis were resistant to vancomycin [4].

On the other hand, alcohol-based disinfectants are one of the cornerstones for infection-control strategies in various healthcare settings. The current body of evidence demonstrated that alcohol-based hand washes have significantly reduced hospital-acquired infections with multidrug-resistant organisms [7]. Enterococcal species generally show susceptibility to alcoholic agents, even at a concentration as low as 11% [8]. Nonetheless, increased tolerance of Enterococcal species to alcohol-based disinfectants was recently reported following the alcohol hand rubbing policy, with equivocal results [7,8].

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily reported in China in December 2019, is the cause of a worldwide pandemic, infecting more than 200 million persons, with a mortality rate of 1.4-6.9% [9]. Prophylactic measures -such as social isolation, mask-wearing, and handwashing- have been widely recommended and implemented amongst the general population in combat against the COVID-19 pandemic[10]. Particularly, handwashing with alcohol-based disinfectants is prompted as an effective strategy for hand decontamination, preventing the spread of SARS-CoV-2[11,12]. However, little is known about the impact of frequent handwashing with alcohol-based disinfectants on the alcohol sensitivity of commensals presenting naturally in the environment, such as Enterococci species. To our knowledge, the current study is the first study to assess the resistance of Enterococcus faecalis to alcohol and vancomycin among frequent users of alcohol-based hand rub presenting with gastrointestinal symptoms.

MATERIALS‎ AND METHODS

Setting and patients:

The current study protocol was coordinated in concordance with the guidelines established declaration of Helsinki, and it was approved by the ethics committee at Masr University for Science and Technology (MUST) hospital. Patients were recruited from the outpatient clinic of internal medicine departments, MUST hospital. In this observational study, samples were collected from patients presenting with GI symptoms including abdominal pain, nausea, vomiting, and diarrhea. The patients were grouped into frequent alcohol users _more than 3 times per day and after any activity they do_ (group 1) and infrequent users _less than 3 times per day_ (group 2) of alcohol-based hand rub as a prophylactic measure from SARS-CoV-2 infection.

Sample collection:

We included subjects who did not receive any antibiotic therapy for the past three days to prevent any false-negative results. Anal samples were collected using sterile swabs during the visit to the outpatient clinic. Samples were washed in distilled water and transported to the laboratory for further analysis. Samples were stored on sheep blood agar culture media at 35°C. After overnight incubation, the cultured plates were assessed. Frist, slides were developed from the structured colonies. The Enterococcus faecalis were identified by the standard methods.

Alcohol and vancomycin susceptibility testing:

A suspension of 2 or 3 colonies in 0.9% saline was performed until obtaining the turbidity of 0.5 McFarland (1.5 £ 108 CFU/mL), which was measured in a Densichek Plus nephelometer (Biomerieux; Durham, NC). Tubes were prepared with 10 mL of BD Tryptic Soy Broth (BST) (Becton, Dickinson and Company; Franklin Lakes, NJ) with the following final alcohol concentrations (v/v): 36.8 mg/mL (46%), 18.4 mg/mL (23%), 9.2 mg/mL (11.5%), 4.6 mg/mL (5.75%), and 2.3 mg/mL (2.87%). In the wells, 100 mL of the BST mixture were added to each of the concentrations of isopropyl alcohol to be tested, and then 10 mL of each of the strains diluted 1:20 in saline were added. A well with 100 mL of BST, a well with isopropyl alcohol (92%), and BST plus the strain were included as controls for each strain tested. The vancomycin susceptibility was tested according to the Clinical and Laboratory Standards Institute (CLSI) standards.

Statistical analysis:

Data were analyzed using SPSS software, version 26 (Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, New York: IBM Corp). Chi-square was used for comparison between cases and controls regarding gender, alcohol resistance, and vancomycin resistance. T-test student was used for comparison between groups regarding age. P < 0.05 was considered statistically significant.

RESULTS:

During the period of this study, thirty patients were included in group 1. In group 1, the average age was 29.3 ±5.1 years old. 40% of the included patients were males, and 60% were females. In group 2, the average age was 29.1 ±4.3 years old. 46.7% of the included patients were males, and 53.3% were females (Table 1). There was no significant difference between both groups regarding age and gender distribution (P = 0.84 and P = 0.432, respectively).

Alcohol resistance was significantly higher in samples of group 1 compared to the control group (36.7% compared to 3.3% , with P = 0.01) at the first month . (Table 2)

Same findings were observed between the cases group and the control group at the second (46.7% vs. 3.3%, respectively) and third month (73.3% vs. 3.3%, respectively). Vancomycin resistance was significantly higher in group 1 (33.3%), while group 2 showed 3.3% of drug resistance (P < 0.001).

SD: Standard Deviation

Table 2. Clinical Data of the study cohorts

DISCUSSION