Determination of antiseptic efficacy of rubs on the forearm and consequences for surgical hand disinfection

S2k-Guideline hand antisepsis and hand hygiene

The consensus-based guideline "hand antisepsis and hand hygiene" for Germany has the following sections: Prevention of nosocomial infections by hygienic hand antisepsis, prevention of surgical site infections by surgical hand antisepsis, infection prevention in the community by hand antisepsis in epidemic or pandemic situations, hand washing, selection of alcohol-based hand rubs and wash lotions, medical gloves and protective gloves, preconditions for hand hygiene, skin protection and skin care, quality assurance of the implementation of hand hygiene measures and legal aspects. The guideline was developed by the German Society for Hospital Hygiene in cooperation with 22 professional societies, 2 professional organizations, the German Care Council, the Federal Working Group for Self-Help of People with Disabilities and Chronic Illness and their Family Members, the General Accident Insurance Institution Austria and the German-speaking Interest Group of Infection Prevention Experts and Hospital Hygiene Consultants.

Clinical investigation of use of an antimicrobial peptide hydrogel wound dressing on intact skin

A material with the ability to rapidly eradicate bacteria via a contact-killing mechanism has the benefit of a more localised treatment that is easy to implement when needed to prevent or treat a bacterial infection. Here, we present an antimicrobial material based on covalently attached antimicrobial peptides (AMPs) to a soft amphiphilic hydrogel. This results in a material that exhibits an antimicrobial effect based on contact-killing. In this study, the antimicrobial efficacy of the AMP-hydrogel was investigated by observing the changes in total bioburden on the intact skin of healthy human volunteers when the AMP-hydrogel dressing was placed on the forearm for three hours. The AMP-hydrogel significantly reduced the bioburden on the skin from a mean value of 1200CFU/cm² for the untreated skin to 23CFU/cm². Biocompatibility evaluations of the AMP-hydrogel showed no sign of cytotoxicity, acute systemic toxicity, irritation or sensitisation, demonstrating the safety of the AMP-hydrogel as a potential wound dressing. Leachability studies confirmed no release of AMPs and that the antimicrobial effect was localised to the surface of the hydrogels, demonstrating a pure contact-killing mode of action.

Effect of Long-Term Use of Alcohol-Containing Handwashing Gels on the Biofilm-Forming Capacity of Staphylococcus epidermidis

The spread of coronavirus disease 2019 (COVID-19) has promoted the use of hand sanitizers among the general population as recommended by health authorities. Alcohols, which are used in many hand sanitizers, have been shown to promotes the formation of biofilms by certain bacteria and to increase bacterial resistance to disinfection. We investigated the effect of continued use of alcohol-based gel hand sanitizer on biofilm formation by the Staphylococcus epidermidis resident strain isolated from the hands of health science students. Hand microbes were counted before and after handwashing, and the ability to produce biofilms was investigated. We found that 179 (84.8%) strains of S. epidermidis isolated from hands had the ability to form biofilm (biofilm-positive strains) in an alcohol-free culture medium. Furthermore, the presence of alcohol in the culture medium induced biofilm formation in 13 (40.6%) of the biofilm-negative strains and increased biofilm production in 111 (76.6%) strains, which were classified as low-grade biofilm-producing. Based on our findings, there is no clear evidence that the continued use of alcohol-based gels results in the selection of strains with the capacity to form biofilms. However, other disinfectant formulations that are more commonly used in clinical settings, such as alcohol-based hand-rub solutions, should be tested for their long-term effects.

Comparison of the antimicrobial efficacy of povidone-iodine-alcohol versus chlorhexidine-alcohol for surgical skin preparation on the aerobic and anaerobic skin flora of the shoulder region

Background

Cutibacterium acnes is part of the anaerobic skin microbiome and resides in deeper skin layers. The organism is an agent of surgical site infections (SSI) in shoulder surgery. We hypothesized that prolonged skin preparation with an agent that penetrates deeply into the skin would be beneficial. Thus, we compared two classes of antiseptics, each combined with alcohol, each applied with two different contact times.

Methods

Using a cross-over arrangement, shoulders of 16 healthy volunteers were treated for 2.5 min (standard) or 30 min (prolonged) with alcohol-based chlorhexidine (CHG-ALC) or alcohol-based povidone-iodine (PVP-I-ALC). Skin sites were sampled before, immediately after, and 3 h after treatment, using a standardized cup-scrub technique.

Results

Aerobic skin flora was reduced more effectively by PVP-I-ALC than by CHG-ALC after 2.5 min application and immediate sampling (reduction factor [RF] 2.55 ± 0.75 vs. 1.94 ± 0.91, p = 0.04), but not after prolonged contact times and 3-h sampling. Coagulase-negative staphylococci were completely eliminated after PVP-I-ALC application, but still recovered from 4 of 32 samples after CHG-ALC application. Anaerobic flora was reduced more effectively by PVP-I-ALC than CHG-ALC after standard (RF 3.96 ± 1.46 vs. 1.74 ± 1.24, p < 0.01) and prolonged (RF 3.14 ± 1.20 vs. 1.38 ± 1.16, p < 0.01) contact times and immediate sampling, but not after 3-h sampling. No adverse events were reported.

Conclusions

PVP-I-ALC showed marginal benefits concerning the aerobic flora, but more substantial benefits over CHG-ALC concerning the anaerobic flora of the shoulder. Standard and prolonged contact times showed superiority for PVP-I-ALC for anaerobic flora at all immediate sampling points, but missed significance at 3-h sampling. The results underscore the need for protection against C. acnes and coagulase-negative staphylococci in orthopaedic surgery. The clinical relevance of these findings, however, should be studied with SSI as an endpoint.

Cross-sectional survey of surgical techniques used to perform dog and cat spays in New Zealand veterinary practice

Aims: To describe the variation in surgical techniques used by veterinarians to perform routine dog and cat spays in first-opinion veterinary practice in New Zealand, and how these techniques differed with the number of years since the veterinarian graduated.Methods: A cross-sectional survey of veterinarians registered to practice in New Zealand was conducted online between 1 April and 30 May 2018. Respondents were asked their year of graduation and about the procedures, they would use to perform a routine spay of a healthy, 5 kg, young adult, female domestic shorthair cat, and a healthy, 20 kg, young adult, female mixed-breed dog. The number of years since graduation was calculated by subtracting the reported year of graduation from 2018.Results: Overall, 282 respondents provided details about dog spays, and 361 about cat spays, and the median number of years since graduation was 14 (min 0, max 50). Only 54/282 (19.1%) respondents performing dog spays and 43/361 (11.9%) performing cat spays wore a surgical cap, gown, mask, and gloves. For dog spays, 278 (98.6%) respondents used a ventral midline approach and 147 (52.1%) used manual exteriorisation of the uterus. Most used two clamps (168; 59.6%) and used two encircling ligatures (152; 53.9%) for removal of the uterus. For cat spays, 254 (70.4%) respondents used a ventral midline approach and 313 (86.7%) used a spay hook for exteriorising the uterus. Most used two clamps (250; 69.3%) with one encircling ligature (213; 59.0%) for removal of the uterus. Simple interrupted external or intradermal patterns were mostly used for skin closure for both dog and cat spays. For cat spays, the percentage of respondents using the ventral midline approach decreased with increasing years since graduation (p < 0.001). For both dog and cat spays, the percentage of respondents using two encircling ligatures and transfixation ligation of the uterus, and using a simple continuous suture pattern for the closure of the abdomen, decreased with number of years since graduation (p < 0.05).Conclusions and clinical relevance: Veterinarians responding to this survey used a wide range of techniques to perform routine dog and cat spays, some of which were associated with the number of years since graduation. It may be beneficial to provide veterinarians with resources to reflect on their current approaches for performing routine spays. However further research is needed to determine whether any surgical techniques are superior to others.

New strategies for preoperative skin antisepsis

During the past decades, encouraging progress has been made in the prevention of surgical site infections (SSI). However, as SSI still occur today, strategic prevention measures such as standardized skin antisepsis must be implemented and rigorously promoted. Recent discoveries in skin physiology necessitate the development of novel antiseptic agents and procedures in order to ameliorate their efficacy. In particular, alternate target structures in the skin need to be taken into consideration for the development of the next generation of antiseptics. Recent investigations have shown that a high number of microorganisms are located within and in the close vicinity of the hair follicles. This suggests that these structures are an important reservoir of bacterial growth and activity in human skin. To date, it has not been fully elucidated to what extent conventional liquid antiseptics sufficiently target the hair follicle-related microbial population. Modern technologies such as tissue-tolerable plasma (TTP) have been tested for their potential antiseptic efficiency by reducing the bacterial load in the skin and in the hair follicles. First experiments using liposomes to deliver antiseptics into the hair follicles have been evaluated for their potential clinical application. The present review evaluates these two innovative methods for their efficacy and applicability in preoperative skin antiseptics.

Comparison of surgical hand scrub and alcohol surgical hand rub on reducing hand microbial burden

This study was performed to compare the effects of two hand decontamination methods on the microbial burden of operating room staff hands. The surgical hand washing methods compared were a traditional surgical hand scrub using a povidone iodine solution, and a social wash using a liquid non-antibacterial soap followed by the application of an alcoholic hand rub.