Disinfection, Sterilization, and Control of Hospital Waste

Presence and Causes of Sterilization Equipment Failures with Biological Indicators in Dental Offices in Mexico: A Longitudinal Cohort

Background/Objectives: Sterilization in dental practice is crucial for infection prevention. The aim of this study was to identify the presence and causes of bacterial growth using biological indicators in dental sterilization equipment in San Luis Potosí, S.L.P., Mexico, with different consecutive measurements over a year. Methods: This longitudinal cohort, conducted from January 2022 to January 2024 in San Luis Potosí, Mexico, aimed to identify the presence and causes of bacterial growth in dental sterilization equipment using biological indicators. A total of 207 dental offices were approached, and 175 participated, providing data through questionnaires and monitoring sterilization cycles with BIs. The checks were bimonthly for one year, with a total of six checks. Results: (a) An 11% (n = 1188) incidence of bacterial growth was observed, with a higher percentage in dry heat equipment (13%). (b) Upon analyzing the six consecutive verifications over a year, no statistically significant differences were observed in the failures of the sterilization cycles when comparing the two pieces of equipment. (c) Error in temperature and time of the equipment (OR = 4.0, 95% CI = 1.6-3.9, p = 0.0001) was significantly associated with the presence of bacterial growth during the one-year period. Conclusions: Monitoring sterilization cycles and identifying the causes of bacterial growth with different consecutive verifications decreased the presence of bacterial growth (failures) during the one-year period.

Compliance and determinants of infection prevention and control practices among sanitary workers in public hospitals, Eastern Ethiopia: A cross-sectional study

Background

Best practice of infection prevention and control (IPC) is a hallmark for the patient care in health care settings, but it is a major problem in developing countries like Ethiopia where resources are limited. Ethiopia Federal Ministry of Health working to strengthen its IPC program, but still it there is no organized study conducted on assessment of performance gaps and implementation challenges of IPC practice faced by hospital staffs particularly among sanitary workers (SWs) at public hospitals inline to national and international guidelines.

Aim

This study focuses on compliance and determinants of IPC among sanitary worker in public hospitals in eastern Ethiopia: A cross sectional study design.

Method

A cross-sectional study was conducted among 809 SWs and eight IPC experts in public hospitals, eastern Ethiopia, from May to August 2023. A standard questionnaire was used to collect data. Face-to-face interview was conducted. Ten (10) question pursued to answer YES/NO were prepared. The cut point for categories of IPC practice was 1: Good (16-20 scores), 2: Fair (10-15 scores), and 3: Poor (<10 scores). The cut point for compliance and noncompliance of IPC practice among hospitals was mean (500.1). Multi-level ordinal logistic regression models was applied to explore the association of dependent and independent variables at individual level (Model 1), hospital level (Model 2) and at both (Model 3). Crude odds ratio (COR) and adjusted odds ratio (AOR) at 95% confidence interval (CI) were used to report the result.

Result

The compliance of IPC practice among SWs was 36.21% (32.72, 39.82%). The Multilevel ordinal logistic regression model shows that SWs who have good knowledge of IPC trend (AOR: 4.70, 95% CI: 2.11-10.46), SWs who are not addictive with alcohol (AOR: 2.35, 95% CI: 1.15,4.78) and chew Khat (AOR: 1.62, 95% CI: 1.06,2.46) and smoke cigarette (AOR: 3.15, 95% CI: 2.35-5.41), and SWs without job stress (AOR: 1.46, 95% CI: 0.86-2.48) were more compliant to IPC practice. Similarly, those who do not have workload (AOR: 2.74, 95% CI: 1.56-4.82), work <8 h/day (AOR: 1.46, 95% CI: 0.92-2.30), and those who have good social recognition in hospitals (AOR: 6.08, 95% CI: 4.24-8.71) were more likely to increase the compliance of IPC practice among SWs. The multilevel random-effect model revealed 93.71% of the variability of compliance of IPC practice explained by both individual and hospital level factors.

Conclusion

The overall study found that inadequate IPC practice was reported among SWs as well as by IPC experts due to poor knowledge of IPC trend and individual behaviors and working environment. Thus, the study advised that hospitals have to develop and establish IPC implementation guidelines in order to solve the concerns among these groups; national IPC office should follow its implementation across health care settings particularly at public hospitals.

Using Bio-inline Reactor to Evaluate Sanitizer Efficacy in Removing Dual-species Biofilms Formed by Escherichia coli O157:H7 and Listeria monocytogenes

The efficacy of a sanitizer in biofilm removal may be influenced by a combination of factors such as sanitizer exposure time and concentration, bacterial species, surface topography, and shear stresses. We employed an inline biofilm reactor to investigate the interactions of these variables on biofilm removal with chlorine. The CDC bioreactor was used to grow E. coli O157:H7 and L. monocytogenes biofilms as a single species or with Ralstonia insidiosa as a dual-species biofilm on stainless steel, PTFE, and EPDM coupons at shear stresses 0.368 and 2.462 N/m2 for 48 hours. Coupons were retrieved from a CDC bioreactor and placed in an inline biofilm reactor and 100, 200, or 500 ppm of chlorine was supplied for 1- and 4 min. Bacterial populations in the biofilms were quantified pre- and posttreatment by plating on selective media. After chlorine treatment, reduction (Log CFU/cm2) in pathogen populations obtained from three replicates was analyzed for statistical significance. A 1-min chlorine treatment (500 ppm), on dual-species E. coli O157:H7 biofilms grown at high shear stress of 2.462 N/m2 resulted in significant E. coli O157:H7 reductions on SS 316L (2.79 log CFU/cm2) and PTFE (1.76 log CFU/cm2). Similar trend was also observed for biofilm removal after a 4-min chlorine treatment. Single species E. coli O157:H7 biofilms exhibited higher resistance to chlorine when biofilms were developed at high shear stress. The effect of chlorine in L. monocytogenes removal from dual-species biofilms was dependent primarily on the shear stress at which they were formed rather than the surface topography of materials. Besides surface topography, shear stresses at which biofilms were formed also influenced the effect of sanitizer. The removal of E. coli O157:H7 biofilms from EPDM material may require critical interventions due to difficulty in removing this pathogen. The inline biofilm reactor is a novel tool to evaluate the efficacy of a sanitizer in bacterial biofilm removal.

Impact of veterinary pharmaceuticals on environment and their mitigation through microbial bioremediation

Veterinary medications are constantly being used for the diagnosis, treatment, and prevention of diseases in livestock. However, untreated veterinary drug active compounds are interminably discharged into numerous water bodies and terrestrial ecosystems, during production procedures, improper disposal of empty containers, unused medication or animal feed, and treatment procedures. This exhaustive review describes the different pathways through which veterinary medications enter the environment, discussing the role of agricultural practices and improper disposal methods. The detrimental effects of veterinary drug compounds on aquatic and terrestrial ecosystems are elaborated with examples of specific veterinary drugs and their known impacts. This review also aims to detail the mechanisms by which microbes degrade veterinary drug compounds as well as highlighting successful case studies and recent advancements in microbe-based bioremediation. It also elaborates on microbial electrochemical technologies as an eco-friendly solution for removing pharmaceutical pollutants from wastewater. Lastly, we have summarized potential innovations and challenges in implementing bioremediation on a large scale under the section prospects and advancements in this field.

Clinical Issues - July 2024

Cleaning surgical instruments after use in a procedure involving chemotherapeutic medications Key words: deactivation, decontamination, cleaning, disinfection, chemotherapeutic medication. Paper count sheets sterilized inside instrument sets Key words: count sheets, instrument sets, printer ink, toner, toxicity. Off-label use of dental devices during direct laryngoscopy Key words: mouth guard, dental injury, direct laryngoscopy, anesthesia, intubation. Using intermittent pneumatic compression devices on patients in lithotomy position Key words: mechanical compression devices, compartment syndrome, lithotomy, venous thromboembolism, thromboprophylaxis.

The novel sterilization device: the prototype testing

Currently, there are numerous methods that can be used to neutralize pathogens (i.e., devices, tools, or protective clothing), but the sterilizing agent must be selected so that it does not damage or change the properties of the material to which it is applied. Dry sterilization with hydrogen peroxide gas (VHP) in combination with UV-C radiation is well described and effective method of sterilization. This paper presents the design, construction, and analysis of a novel model of sterilization device. Verification of the sterilization process was performed, using classical microbiological methods and flow cytometry, on samples containing Geobacillus stearothermophilus spores, Bacillus subtilis spores, Escherichia coli, and Candida albicans. Flow cytometry results were in line with the standardized microbiological tests and confirmed the effectiveness of the sterilization process. It was also determined that mobile sterilization stations represent a valuable solution when dedicated to public institutions and businesses in the tourism sector, sports & fitness industry, or other types of services, e.g., cosmetic services. A key feature of this solution is the ability to adapt the device within specific constraints to the user's needs.

From Prevention to Management: Understanding Postoperative Infections in Gynaecology

This narrative review examines the multifaceted realm of postoperative infections in gynaecology, addressing their significance, types, risk factors, prevention, management, and emerging trends. Postoperative infections, encompassing surgical site infections, urinary tract infections, and pelvic inflammatory disease, pose considerable challenges in patient care, warranting comprehensive exploration. Strategies for prevention include preoperative patient assessment, antimicrobial prophylaxis, and aseptic techniques. Intraoperative measures encompass infection control and instrument sterilization, while postoperative care involves wound management and early infection detection. Diagnostic tools, including blood tests, imaging, and microbiological cultures, aid in timely identification. Management strategies encompass antibiotic therapy, surgical interventions, supportive care, and addressing complications. The review underscores the necessity of personalized approaches, multidisciplinary collaboration, and innovative technologies in future infection management. It calls for ongoing research, heightened awareness, and meticulous care to minimize the impact of postoperative infections and optimize patient outcomes.

Prevention of horizontal transfer of laboratory plasmids to environmental bacteria: comparison of the effectiveness of a few disinfection approaches to degrade DNA

The routine work of any molecular biology laboratory includes the daily use of microorganisms, including strains of E. coli, transformed with a variety of plasmids expressing at least one antibiotic resistance gene (ARG). Therefore, to avoid the accidental release of ARGs into environmental water, methods for disinfection of liquid laboratory waste must be effective in destroying nucleic acids. In support of this recommendation, the origin of replication of Enterobacteriaceae plasmids has been detected in strains of non-Enterobacteriaceae bacteria isolated from wastewater from laboratories and research institutes, suggesting that interspecific transfer of laboratory plasmids had occurred. Using quantitative polymerase chain reaction, we determined the decimal reduction value (D value, expressed as concentration of disinfectant or length of physical treatment) of several decontamination methods for their DNA degradation effect on cultures of E. coli Top10 transformed with a kanamycin resistant plasmid (pET28A + or pEGFP-C2). The estimated D values were 0.7 M for sulfuric acid, 6.3% for a commercial P3 disinfectant, 25 min for steam sterilization at 121 °C, and 49 min for disinfection by UVC. A 20-min treatment of bacteria cultures with a final concentration of 1-10% sodium hypochlorite was found to be ineffective in completely destroying a bacteria plasmid gene marker (coding for the pBR322 origin of replication). Residual DNA from NaClO-treated cells was 60%, while it decreased under 10% using the commercial disinfectant P3 diluted at 5%. As the degradation was incomplete in both cases, we recommend avoiding discharge of disinfected liquid waste to wastewater (even after chemical neutralization) without additional plasmid destruction treatment, to prevent horizontal transfer of laboratory ARGs to environmental bacteria.

Carbon footprints in minimally invasive surgery: Good patient outcomes, but costly for the environment

Advancements in technology and surgical training programs have increased the adaptability of minimally invasive surgery (MIS). Gastrointestinal MIS is superior to its open counterparts regarding post-operative morbidity and mortality. MIS has become the first-line surgical intervention for some types of gastrointestinal surgery, such as laparoscopic cholecystectomy and appendicectomy. Carbon dioxide (CO2) is the main gas used for insufflation in MIS. CO2 contributes 9%-26% of the greenhouse effect, resulting in global warming. The rise in global CO2 concentration since 2000 is about 20 ppm per decade, up to 10 times faster than any sustained rise in CO2 during the past 800000 years. Since 1970, there has been a steady yet worrying increase in average global temperature by 1.7 °C per century. A recent systematic review of the carbon footprint in MIS showed a range of 6-814 kg of CO2 emission per surgery, with higher CO2 emission following robotic compared to laparoscopic surgery. However, with superior benefits of MIS over open surgery, this poses an ethical dilemma to surgeons. A recent survey in the United Kingdom of 130 surgeons showed that the majority (94%) were concerned with climate change but felt that the lack of leadership was a barrier to improving environmental sustainability. Given the deleterious environmental effects of MIS, this study aims to summarize the trends of MIS and its carbon footprint, awareness and attitudes towards this issue, and efforts and challenges to ensuring environmental sustainability.

Encapsulated peracetic acid as a valid broad-spectrum antimicrobial alternative, leading to beneficial microbiota compositional changes and enhanced performance in broiler chickens

BACKGROUND

Antimicrobial alternatives are urgently needed, including for poultry production systems. In this study, we tested the potential broad-range antimicrobial alternative peracetic acid, delivered in feed via the hydrolysis of encapsulated precursors through a 28-day study using 375 Ross 308 broiler chickens. We tested two peracetic acid concentrations, 30 and 80 mg/kg on birds housed on re-used litter, and we evaluated the impact of both levels on gut microbial communities, bacterial concentration, antimicrobial resistance genes relative abundance and growth performance when compared to control birds housed on either clean or re-used litter.

RESULTS

Body weight gain and feed conversion ratio improved in peracetic acid fed birds. At d 28, birds given 30 mg/kg of peracetic acid had a decreased Firmicutes and an increased Proteobacteria abundance in the jejunum, accompanied by an increase in Bacillus, Flavonifractor and Rombustia in the caeca, and a decreased abundance of tetracycline resistance genes. Chicken given 80 mg/kg of peracetic acid had greater caecal abundance of macrolides lincosamides and streptogramins resistance genes. Growth performance on clean litter was reduced compared to re-used litter, which concurred with increased caecal abundance of Blautia, decreased caecal abundance of Escherichia/Shigella, Anaerostipes and Jeotgalicoccus, and greater gene abundance of vancomycin, tetracycline, and macrolides resistance genes.

CONCLUSIONS

Peracetic acid could be used as a safe broad-spectrum antimicrobial alternative in broilers. Encapsulated precursors were able to reduce the bacterial concentration in the jejunum whilst promoting the proliferation of probiotic genera in the caeca, especially at the low peracetic acid concentrations tested, and improve growth performance. Moreover, our findings offer further insights on potential benefits of rearing birds on re-used litter, suggesting that the latter could be associated with better performance and reduced antimicrobial resistance risk compared to clean litter rearing.

Optimal control for co-infection with COVID-19-Associated Pulmonary Aspergillosis in ICU patients with environmental contamination

In this paper, we propose a mathematical model for COVID-19-Associated Pulmonary Aspergillosis (CAPA) co-infection, that enables the study of relationship between prevention and treatment. The next generation matrix is employed to find the reproduction number. We enhanced the co-infection model by incorporating time-dependent controls as interventions based on Pontryagin's maximum principle in obtaining the necessary conditions for optimal control. Finally, we perform numerical experiments with different control groups to assess the elimination of infection. In numerical results, transmission prevention control, treatment controls, and environmental disinfection control provide the best chance of preventing the spread of diseases more rapidly than any other combination of controls.

Molecular co-localization of multiple drugs in a nanoscopic delivery vehicle for potential synergistic remediation of multi-drug resistant bacteria

Anti-microbial resistant infection is predicted to be alarming in upcoming years. In the present study, we proposed co-localization of two model drugs viz., rifampicin and benzothiazole used in anti-tuberculosis and anti-fungal agents respectively in a nanoscopic cationic micelle (cetyl triethyl ammonium bromide) with hydrodynamic diameter of 2.69 nm. Sterilization effect of the co-localized micellar formulation against a model multi-drug resistant bacterial strain viz., Methicillin resistant Staphylococcus aureus was also investigated. 99.88% decrease of bacterial growth in terms of colony forming unit was observed using the developed formulation. While Dynamic Light Scattering and Forsters Resonance Energy Transfer between benzothiazole and rifampicin show co-localization of the drugs in the nanoscopic micellar environment, analysis of time-resolved fluorescence decays by Infelta-Tachiya model and the probability distribution of the donor-acceptor distance fluctuations for 5 μM,10 μM and 15 μM acceptor concentrations confirm efficacy of the co-localization. Energy transfer efficiency and the donor acceptor distance are found to be 46% and 20.9 Å respectively. We have also used a detailed computational biology framework to rationalize the sterilization effect of our indigenous formulation. It has to be noted that the drugs used in our studies are not being used for their conventional indication. Rather the co-localization of the drugs in the micellar environment shows a completely different indication of their use in the remediation of multi-drug resistant bacteria revealing the re-purposing of the drugs for potential use in hospital-born multi-drug resistant bacterial infection.

An Enhanced Strategy for Daily Disinfection in Acute Care Hospital Rooms: A Randomized Clinical Trial

IMPORTANCE

Environmental contamination is a source of transmission between patients, health care practitioners, and other stakeholders in the acute care setting.

OBJECTIVE

To compare the efficacy of an enhanced daily disinfection strategy vs standard disinfection in acute care hospital rooms.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial (RCT) was conducted in acute care hospital rooms at Duke University Hospital in Durham, North Carolina, from November 2021 to March 2022. Rooms were occupied by patients with contact precautions. Room surfaces (bed rails, overbed table, and in-room sink) were divided into 2 sides (right vs left), allowing each room to serve as its own control. Each side was randomized 1:1 to the intervention group or control group.

INTERVENTIONS

The intervention was a quaternary ammonium, salt-based, 24-hour continuously active germicidal wipe. It was applied in addition to routine disinfection for the intervention group. The control group received no intervention beyond routine disinfection.

MAIN OUTCOMES AND MEASURES

The primary outcome was the total contamination, measured in colony-forming units (CFUs) on the bed rails, overbed table, and sink on study day 1. The secondary outcomes were the proportion of sample areas with positive test results for clinically important pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and carbapenem-resistant Enterobacteriaceae; the similarity in baseline contamination between sample area sides on study day 0 before application of the intervention, and the proportion of sample areas with removed UV luminescent gel on study day 1.

RESULTS

A total of 50 study rooms occupied by 50 unique patients (median [IQR] age, 61 [45-69] years; 26 men [52%]) with contact precautions were enrolled. Of these patients, 41 (82%) were actively receiving antibiotics, 39 (78%) were bedridden, and 28 (56%) had active infections with study-defined clinically important pathogens. On study day 1, the median (IQR) total CFUs for the intervention group was lower than that for the control group (3561 [1292-7602] CFUs vs 5219 [1540-12 364] CFUs; P = .002). On study day 1, the intervention side was less frequently contaminated with patient-associated clinically important pathogens compared with the control side of the room (4 [14%] vs 11 [39%]; P = .04).

CONCLUSIONS AND RELEVANCE

Results of this RCT demonstrated that a quaternary ammonium, salt-based, 24-hour continuously active germicidal wipe decreased the environmental bioburden in acute care hospital rooms compared with routine disinfection. The findings warrant large-scale RCTs to determine whether enhanced daily disinfection strategies can decrease patient acquisition and adverse patient outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05560321.

Exploration of oxygen-mediated disinfection of medical devices reveals a high sensitivity of Pseudomonas aeruginosa to elevated oxygen levels

The microbiological safety of medical devices is of paramount importance for patients and manufacturers alike. However, during usage medical devices will inevitably become contaminated with microorganisms, including opportunistic pathogens. This is a particular problem if these devices come in contact with body sites that carry high bacterial loads, such as the oral cavity. In the present study, we investigated whether high oxygen concentrations can be applied to disinfect surfaces contaminated with different Gram-positive and Gram-negative bacteria. We show that some opportunistic pathogens, exemplified by Pseudomonas aeruginosa, are particularly sensitive to oxygen concentrations above the atmospheric oxygen concentration of 21%. Our observations also show that high oxygen concentrations can be applied to reduce the load of P. aeruginosa on nebulizers that are used by cystic fibrosis patients, who are particularly susceptible to colonization and infection by this bacterium. We conclude that the efficacy of oxygen-mediated disinfection depends on the bacterial species, duration of oxygen exposure and the oxygen concentration. We consider these observations relevant, because gas mixtures with high oxygen content can be readily applied for microbial decontamination. However, the main challenge for oxygen-based disinfection approaches resides in a potentially incomplete elimination of microbial contaminants, which makes combined usage with other disinfectants like ethanol or hydrogen peroxide recommendable.

Assessment of a novel, easy-to-implement, aerosolized H2O2 decontamination method for single-use filtering facepiece respirators in case of shortage

The COVID-19 pandemic has affected the world and caused a supply shortage of personal protection equipment, especially filtering facepiece respirators (FFP). This has increased the risk of many healthcare workers contracting SARS-CoV-2. Various strategies have been assessed to tackle these supply issues. In critical shortage scenarios, reusing single-use-designed respirators may be required. Thus, an easily applicable and reliable FFP2 (or alike) respirator decontamination method, allowing safe re-use of FFP2 respirators by healthcare personnel, has been developed and is presented in this study. A potent and gentle aerosolized hydrogen peroxide (12% wt) method was applied over 4 hr to decontaminate various brands of FFP2 respirators within a small common room, followed by adequate aeration and storage overnight. The microbial efficacy was tested on unused respirator pieces using spores of Geobacillus stearothermophilus. Further, decontamination effectiveness was tested on used respirators after one 12-hr shift by swabbing before and after the decontamination. The effects of up to ten decontamination cycles on the respirators' functionality were evaluated using material properties, the structural integrity of the respirators, and fit tests with subjects. The suggested H₂O₂ decontamination procedure was proven to be (a) sufficiently potent (no microbial recovery, total inactivation of biological indicators as well as spore inoculum on critical respirator surfaces), (b) gentle as no significant damage to the respirator structural integrity and acceptable fit factors were observed, and (c) safe as no H₂O₂ residue were detected after the defined aeration and storage. Thus, this easy-to-implement and scalable method could overcome another severe respirator shortage, providing enough flexibility to draft safe, effective, and logistically simple crisis plans. However, as highlighted in this study, due to the wealth of design and material used in different models and brands of respirators, the decontamination process should be validated for each FFP respirator model before its field implementation.

Application of Pinhole Plasma Jet Activated Water against Escherichia coli, Colletotrichum gloeosporioides, and Decontamination of Pesticide Residues on Chili (Capsicum annuum L.)

Plasma activated water (PAW) generated from pinhole plasma jet using gas mixtures of argon (Ar) and 2% oxygen (O2) was evaluated for pesticide degradation and microorganism decontamination (i.e., Escherichia coli and Colletotrichum gloeosporioides) in chili (Capsicum annuum L.). A flow rate of 10 L/min produced the highest concentration of hydrogen peroxide (H2O2) at 369 mg/L. Results showed that PAW treatment for 30 min and 60 min effectively degrades carbendazim and chlorpyrifos by about 57% and 54% in solution, respectively. In chili, carbendazim and chlorpyrifos were also decreased, to a major extent, by 80% and 65% after PAW treatment for 30 min and 60 min, respectively. E. coli populations were reduced by 1.18 Log CFU/mL and 2.8 Log CFU/g with PAW treatment for 60 min in suspension and chili, respectively. Moreover, 100% of inhibition of fungal spore germination was achieved with PAW treatment. Additionally, PAW treatment demonstrated significantly higher efficiency (p < 0.05) in controlling Anthracnose in chili by about 83% compared to other treatments.

Bactericidal, protozoacidal, and algicidal efficacy of Sanodrink: a complete water sanitizer in poultry farm

Introduction and Aim: The growth in poultry industries due to increasing demand for meat and egg production has set off the establishment of various poultry farms on a commercial basis. But with an increase in demand for production from poultry farms, the need for maintenance of a healthy and clean environment has also become a necessity for disease free and quality production. As these pose a greater challenge in the production management, the development of a versatile compound that could be beneficial in overcoming all the microbial challenges faced in a poultry farm is also necessary.  Materials and Methods: Sanodrink is a complete water sanitizer that is a highly effective bactericidal, protozoacidal and algicidal agent which could be used for the drinking water storage tanks of poultry farm. It is effective in killing all the commonly encountered microbes like E. coli, Giardia spp. etc., and algae that are commonly found in the poultry farm water tank.  Results: It contains quaternary ammonium compounds which are microbicidal and potent inhibitors of both pathogenic and non-pathogenic bacterial, algal, and protozoal growth and survival. Quaternary ammoniums are also good surfactants as they lower the superficial tension of water. Furthermore, Sanodrink maintains its action in hard water also and in the presence of organic matter. Conclusion: Our present study aims at evaluating the microbicidal efficacy of Sanodrink as a water sanitizer that can be used at poultry farms.

Recycling of plastic wastes generated from COVID-19: A comprehensive illustration of type and properties of plastics with remedial options

Plastic has contributed enormously to the healthcare sector and towards public health safety during the COVID-19 pandemic. With the frequent usage of plastic-based personal protective equipment (PPEs) (including face masks, gloves, protective body suits, aprons, gowns, face shields, surgical masks, and goggles), by frontline health workers, there has been a tremendous increase in their manufacture and distribution. Different types of plastic polymers are used in the manufacture of this equipment, depending upon their usage. However, since a majority of these plastics are still single-use plastics (SUP), they are not at all eco-friendly and end up generating large quantities of plastic waste. The overview presents the various available and practiced methods in vogue for disposal cum treatment of these highly contaminated plastic wastes. Among the current methods of plastic waste disposal, incineration and land filling are the most common ones, but both these methods have their negative impacts on the environment. Alongside, numerous methods that can be used to sterilize them before any treatment have been discussed. There are several new sorting technologies, to help produce purer polymers that can be made to undergo thermal or chemical treatments. Microbial degradation is one such novel method that is under the spotlight currently and being studied extensively, because of its ecological advantages, cost-effectiveness, ease of use, and maintenance. In addition to the deliberations on the methods, strategies have been enumerated for combination of different methods, vis-à-vis studying the life cycle assessment towards a more circular economy in handling this menace to protect mankind.

Infection Control in Dental Clinics: Prosthodontics Perspectives

AIM

The aim of this article is to discuss the infection control measures with focus on those related to prosthodontic work.

BACKGROUND

The risk of transmission of several infectious microorganisms during dental procedures and the increased awareness and knowledge of infectious diseases have led to an increased attention to the importance of infection control. Prosthodontists and dental personnel are exposed directly or indirectly to a significant risk of acquiring healthcare-associated infections.

REVIEW RESULTS

High standards of occupational safety and dental infection control must be applied by dental personnel for the safety of patients and dental healthcare workers. All reusable items (critical and semicritical instruments) that come in contact with the patient's saliva, blood, or mucous membranes must be heat-sterilized. Proper disinfectants should be used to disinfect nonsterilizable instruments (e.g., wax knifes, dental shade plastic mixing spatula, guides, fox bite plane, articulators, and facebows).

CONCLUSION

In prosthodontics, items potentially contaminated with patient's blood and saliva are transported between dental clinics and dental laboratories. Such fluids may contain microorganisms with high potential for transmission of several diseases. Therefore, sterilization and disinfection of all items used during prosthodontic work should be part of infection control protocol in dental care setting.

CLINICAL SIGNIFICANCE

In prosthodontic practice, a strict infection prevention plan should be implemented to minimalize the risk of infectious diseases transmission among prosthodontists, dental office, dental laboratory personnel, and patients.

The efficacy of commercial decontamination agents differs between standardised test settings and research laboratory usage for a variety of bacterial species

Decontamination of surfaces and items plays an important role in reducing the spread of infectious microorganisms in many settings including hospitals and research institutes. Regardless of the location, appropriate decontamination procedures are required for maintaining biosafety and biosecurity. For example, effective decontamination of microbial cultures is essential to ensure proper biocontainment and safety within microbiological laboratories. To this end, many commercial decontamination agents are available which have been tested to a prescribed standard to substantiate their efficacy. However, these standardised tests are unlikely to accurately reflect many conditions encountered in medical and biomedical research. Despite this, laboratory workers and other users of decontamination agents may assume that all decontamination agents will work in all situations. We tested commonly used commercial decontamination agents against a range of bacterial species to determine their efficacy under real-world research laboratory conditions. As each decontamination agent has a different recommended dilution for use, to compare their efficacy we calculated their 'effective ratio' which reflects the difference between the manufacturer-recommended dilution and the dilution needed to achieve decontamination under real-world research laboratory conditions. Effective ratios above one indicate that the agent was effective at a dilution more dilute than recommended whereas effective ratios lower than one indicate that the agent required a higher concentration than recommended. Our results show that the quaternary ammonium agents TriGene Advance and Chemgene HLD4L were the most effective out of the agents tested, with biocidal activity measured at up to 64 times the recommended dilution. In contrast, hypochlorite (bleach) and Prevail™ (stabilised hydrogen peroxide) had the lowest effective ratios amongst the tested agents. In conclusion, our data suggests that not all decontamination agents will work at the recommended dilutions under real-world research laboratory conditions. We recommend that the protocols for the use of decontamination agents are verified under the specific conditions required to ensure they are fit for purpose.

The environmental impact of surgery: A systematic review

BACKGROUND

Climate change is a significant public health threat. Health care comprises 10% of greenhouse gas emissions in the United States, where surgery is especially resource intensive. We did a systematic review to assess and summarize the published evidence of the environmental impact of surgery.

METHODS

We searched Medline, Embase, Web of Science, and GreenFILE databases for publications that report any environmental impact measure by all surgical subspecialties, including anesthesia. Inclusion criteria were published in English, original research, and passed peer review. Because data were heterogeneous and the aim was broad, we conducted a qualitative summary of data. Where possible, we compare impact measures.

RESULTS

In the study, 167 articles were identified by our search strategy and reviewed, of which 55 studies met criteria. Eight were about anesthesia, 27 about operating room waste, and 6 were life cycle assessments. Other topics include carbon footprint and greenhouse gas emissions. Nine papers fell into 2 or more categories. Overall, the operating room is a significant source of emissions and waste. Using anesthetic gases with low global warming potential reduces operating room emissions without compromising patient safety. Operating room waste is often disposed of improperly, often due to convenience or knowledge gaps. There are environmental benefits to replacing disposable materials with reusable equivalents, and to proper recycling. Surgeons can help implement these changes at their institution.

CONCLUSION

Although there is a clear need to lower the carbon footprint of surgery, the quality of research with which to inform protocol changes is deficient overall. Our attempt to quantify surgery's carbon footprint yielded heterogeneous data and few standardized, actionable recommendations. However, this data serves as a starting point for important future initiatives to decrease the environmental impact of surgery.

UVC-PURGE: A Novel Cost-Effective Disinfection Robot for Combating COVID-19 Pandemic

During the COVID-19 pandemic, surface disinfection using prevailing chemical disinfection methods had several limitations. Due to cost-inefficiency and the inability to disinfect shaded places, static UVC lamps cannot address these limitations properly. Moreover, the average market price of the prevailing UVC robots is huge, approximately 55,165 USD. In this research firstly, a requirement elicitation study was conducted using a semi-structured interview approach to reveal the requirements to develop a cost-effective UVC robot. Secondly, a semi-autonomous robot named UVC-PURGE was developed based on the revealed requirements. Thirdly, a two-phased evaluation study was undertaken to validate the effectiveness of UVC-PURGE to inactivate the SARS-CoV-2 virus and the capability of semi-autonomous navigation in the first phase and to evaluate the usability of the system through a hybrid approach of SUPR-Q forms and subjective evaluation of the user feedback in the second phase. Pre-treatment swab testing revealed the presence of both Gram-positive and Gram-Negative bacteria at 17 out of 20 test surfaces in the conducted tests. After the UVC irradiation of the robot, the microbial load was detected in only 2 (1D and 1H) out of 17 test surfaces with significant reductions (95.33% in 1D and 90.9% in 1H) of microbial load. Moreover, the usability evaluation yields an above-average SUPR-Q score of 81.91% with significant scores in all the criteria (usability, trust, loyalty, and appearance) and the number of positive themes from the subjective evaluation using thematic analysis is twice the number of negative themes. Additionally, compared with the prevailing UVC disinfection robots in the market, UVC-PURGE is cost-effective with a price of less than 800 USD. Moreover, small form factor along with the real time camera feedback in the developed system helps the user to navigate in congested places easily. The developed robot can be used in any indoor environment in this prevailing pandemic situation and it can also provide cost-effective disinfection in medical facilities against the long-term residual effect of COVID-19 in the post-pandemic era.

Safety of 0.5% hydrogen peroxide mist used in the disinfection gateway for COVID-19

Hydrogen peroxide (H2O2) is a reactive chemical used in a wide range of applications. Most importantly, it is used for sterilization process in health care environment. In the present study, safety assessment of 0.5% of H2O2 and its mist intended to be used in the disinfection gateway for COVID-19 was evaluated. Skin irritation and repeated-dose inhalation toxicity studies were carried out in rabbits and rats, respectively. In Skin irritation study, New Zealand white rabbits were exposed topically with 0.5% H2O2 solution and observed for 24 h, 48 h, and 72 h. For repeated-dose inhalation toxicity study, Wistar rats (both male and female) were exposed (whole body exposure) to 0.5% of H2O2 mist, at a concentration of 11.022 (low dose-2-min exposure), 22.044 (medium dose-4-min exposure), and 55.11mg/kg (high dose/high dose recovery-10-min exposure) body weight, daily for 7 days. Rats in the high-dose recovery group (55.11mg/kg-10-min exposure) were kept for another 7 days without any exposure. A toxicological evaluation was done based on general health parameters, hematology, serum biochemistry, gross necropsy, and histopathological data. The results of the study indicated that there was no skin irritation potential induced on exposure of 0.5% of H2O2 to rabbits. Similarly, the inhalation toxicity of 0.5% of H2O2 mist imparts no evidence of hematological, biochemical, gross pathology, or histopathological abnormalities in rats. Further, at the laboratory condition stimulated, the NOEL was found to be 55.11mg/kg body weight. Hence, the present study concluded that 0.5% H2O2 or its mist used in the disinfection gateway for COVID-19 failed to induce any skin irritation in rabbits or inhalation toxicity in rats. Graphical abstract.

Reusability of autoclaved 3D printed polypropylene compared to a glass filled polypropylene composite

Health care waste can be a costly expenditure for facilities as specific disposal methods must be used to prevent the spread of pathogens. If more multi-use medical devices were available, it could potentially relieve some of this burden; however, sterilization between uses is important in preventing disease transmission. 3D printing has the ability to easily create custom medical devices at a low cost, but the majority of filaments utilized cannot survive steam sterilization. Polypropylene (PP) can withstand autoclave temperatures, but is difficult to print as it warps and shrinks during printing; however, a composite PP filament reduces these effects. Commercially available PP and glass filled PP (GFPP) filaments were successfully 3D printed into 30 × 30 × 30 mm cubes with no shrinking or warping and were autoclaved. The 134 °C autoclave temperature was too high as several cubes melted after two to three rounds, but both PP and GFPP cubes displayed minimal changes in mass and volume after one, four, seven, and ten rounds of autoclaving at 121 °C. GFPP cubes autoclaved zero, four, seven, and ten times had significantly smaller average compressive stress values compared to all PP groups, but the GFPP cubes autoclaved once were only less than PP cubes autoclaved zero, seven and ten times. GFPP cubes autoclaved zero, one, four, and seven times also deformed less indicating that the embedded glass fibers provided additional strength. While a single method was found that successfully printed PP and GFPP cubes that were able to survive up to ten rounds of autoclaving, future work should include further investigation into the mechanical properties and increasing the number of autoclave rounds.

Disinfectants in a Hemodialysis Setting: Antifungal Activity Against Aspergillus and Fusarium Planktonic and Biofilm Cells and the Effect of Commercial Peracetic Acid Residual in Mice

Aspergillus and Fusarium cause a broad spectrum of infections in humans, mainly in immunocompromised patients. Among these, patients undergoing hemodialysis are highly susceptible to infections, requiring a constant and adequate environmental disinfection program. Nevertheless, monitoring the residual disinfectants can contribute to the morbidity and mortality reduction in these patients. Here, we evaluated the susceptibility of Aspergillus spp. (n=19) and Fusarium spp. (n=13) environmental isolates against disinfectants (acetic acid, citric acid, peracetic acid, sodium hypochlorite, and sodium metabisulphite) at different concentrations and time exposures. Also, we investigated the in vivo toxicity of the peracetic acid residual concentration in mice. Fusarium isolates were identified by F. equiseti, F. oxysporum and F. solani while Aspergillus presented clinically relevant species (A. fumigatus, A. niger and A. terreus) and environmental ones. Against planktonic cells, only two disinfectants (acetic acid and sodium hypochlorite) showed a fungicidal effect on Fusarium spp., while only one (sodium hypochlorite) was effective against Aspergillus spp. Both fungi formed robust in vitro biofilms with large amounts of the extracellular matrix, as evidenced by electron micrographs. Exposure of fungal biofilms to disinfectants showed sensitivity to three (acetic, citric, and peracetic acids), although the concentrations and times of exposure varied according to the fungal genus. Mice exposure to the residual dose of peracetic acid during 60 weeks showed anatomopathological, hematological, and biochemical changes. The implementation of news control measures and those that already exist can help reduce infections, the second cause of death and morbidity in these patients, besides providing safety and well-being to them, a priority of any quality health program.

Challenges and strategies for effective plastic waste management during and post COVID-19 pandemic

The advent of the COVID-19 pandemic has enhanced the complexities of plastic waste management. Our improved, hyper-hygienic way of life in the fear of transmission has conveniently shifted our behavioral patterns like the use of PPE (Personal protective equipment), increased demand for plastic-packaged food and groceries, and the use of disposable utensils. The inadequacies and inefficiencies of our current waste management system to deal with the increased dependence on plastic could aggravate its mismanagement and leakage into the environment, thus triggering a new environmental crisis. Mandating scientific sterilization and the use of sealed bags for safe disposal of contaminated plastic wastes should be an immediate priority to reduce the risk of transmission to sanitation workers. Investments in circular technologies like feedstock recycling, improving the infrastructure and environmental viability of existing techniques could be the key to dealing with the plastic waste fluxes during such a crisis. Transition towards environmentally friendly materials like bioplastics and harboring new sustainable technologies would be crucial to fighting future pandemics. Although the rollbacks and relaxation of single-use plastic bans may be temporary, their likely implications on the consumer perception could hinder our long-term goals of transitioning towards a circular economy. Likewise, any delay in building international willingness and participation to curb any form of pollution through summits and agendas may also delay its implementation. Reduction in plastic pollution and at the same time promoting sustainable plastic waste management technologies can be achieved by prioritizing our policies to instill individual behavioral as well as social, institutional changes. Incentivizing measures that encourage circularity and sustainable practices, and public-private investments in research, infrastructure and marketing would help in bringing the aforementioned changes. Individual responsibility, corporate action, and government policy are all necessary to keep us from transitioning from one disaster to another.

Decontamination of microbiologically contaminated abiotic porous surfaces in an oral surgery clinic using vaporised hydrogen peroxide (VHP)

PURPOSE

The aims of the study were to identify microorganisms, including those in the VBNC state, inhabiting porous surfaces in oral surgery offices and to assess the biocidal effectiveness and impact of 300 ppm vaporised hydrogen peroxide (VHP) for 20 min on decontaminated materials.

METHODS

From the surfaces of textured armrests of dental chairs, pinewood doors and window frames and cotton medical aprons, 30 swabs were taken with moistened sponges. The identification of isolated microorganisms was performed using molecular methods with MALDI-TOF MS, DNA Sanger sequencer and Illumina MiSeq. To evaluate the impact of VHP decontamination (independent variable) on the number of microorganisms (response variable) ANOVA and LSD tests were used. After application of 10 processes of VHP decontamination, changes in the properties of the materials were assessed using FTIR spectroscopy, SEM microscopy and XPS spectrometry.

RESULTS

The concentration of microorganisms was 10¹-10⁴ CFU/100 cm² on the tested surfaces and 10² CFU/m³ in the air. Twenty species of bacteria, one yeast and 16 filamentous fungi were identified, with the predominance of Bacillus, Staphylococcus, Alternaria, Aspergillus and Penicillium. Moreover, Janthinobacterium, Acremonium, Aureobasidium, Coprinellus and Cosmospora in the VBNC state were metagenomically detected. VHP decontamination resulted in a reduction in the majority of tested microbial strains by a minimum of 3 log, and all tested mixed cultures inhabiting porous surfaces were above 98% and in the air, 100%. VHP decontamination did not affect the structural and morphological properties of cotton fibres, wood or stainless steel.

CONCLUSIONS

VHP decontamination at a concentration of 300 ppm for 20 min can be used for the holistic disinfection of air, surfaces and equipment in oral surgery offices.

Antiseptic quaternary ammonium compound tolerance by gram-negative bacteria can be rapidly detected using an impermeant fluorescent dye-based assay

Biocides such as quaternary ammonium compounds (QACs) are potentially important contributors towards bacterial antimicrobial resistance development, however, their contributions are unclear due to a lack of internationally recognized biocide testing standards. Methods to detect QAC tolerance are limited to laborious traditional antimicrobial susceptibility testing (AST) methods. Here, we developed a rapid fluorescent dye-based membrane impermeant assay (RFDMIA) to discriminate QAC susceptibility among Gram-negative Enterobacterales and Pseudomonadales species. RFDMIA uses a membrane impermeant fluorescent dye, propidium iodide, in a 30-min 96-well fluorescent microplate-based assay where cell suspensions are exposed to increasing QAC concentrations. Our results demonstrate that RFDMIA can discriminate between QAC-susceptible and QAC-adapted Escherichia coli tolerant phenotypes and predict benzalkonium and cetrimide tolerance in all species tested except for intrinsically fluorescent Pseudomonas aeruginosa. RFDMIA identified a close association to minimum inhibitory concentration values determined by broth microdilution AST and increasing fluorescent dye emission values. RFDMIA emission values and scanning electron microscopy results also suggest that CET-adapted E. coli isolates have a CET dependence, where cells require sub-inhibitory CET concentrations to maintain bacilliform cell integrity. Overall, this study generates a new, rapid, sensitive fluorescent assay capable of detecting QAC-susceptible Gram-negative bacteria phenotypes and cell membrane perturbations.

Quaternary Ammonium Compound Disinfectants Reduce Lupus-Associated Splenomegaly by Targeting Neutrophil Migration and T-Cell Fate

Hypersensitivity reactions and immune dysregulation have been reported with the use of quaternary ammonium compound disinfectants (QACs). We hypothesized that QAC exposure would exacerbate autoimmunity associated with systemic lupus erythematosus (lupus). Surprisingly, however, we found that compared to QAC-free mice, ambient exposure of lupus-prone mice to QACs led to smaller spleens with no change in circulating autoantibodies or the severity of glomerulonephritis. This suggests that QACs may have immunosuppressive effects on lupus. Using a microfluidic device, we showed that ambient exposure to QACs reduced directional migration of bone marrow-derived neutrophils toward an inflammatory chemoattractant ex vivo. Consistent with this, we found decreased infiltration of neutrophils into the spleen. While bone marrow-derived neutrophils appeared to exhibit a pro-inflammatory profile, upregulated expression of PD-L1 was observed on neutrophils that infiltrated the spleen, which in turn interacted with PD-1 on T cells and modulated their fate. Specifically, QAC exposure hindered activation of splenic T cells and increased apoptosis of effector T-cell populations. Collectively, these results suggest that ambient QAC exposure decreases lupus-associated splenomegaly likely through neutrophil-mediated toning of T-cell activation and/or apoptosis. However, our findings also indicate that even ambient exposure could alter immune cell phenotypes, functions, and their fate. Further investigations on how QACs affect immunity under steady-state conditions are warranted.

A Review of Decontamination Methods for Filtering Facepiece Respirators

During the current COVID-19 infectious disease pandemic, the demand for NIOSH-approved filtering facepiece respirators (FFR) has exceeded supplies and decontamination and reuse of FFRs has been implemented by various user groups. FFR decontamination and reuse is only intended to be implemented as a crisis capacity strategy. This paper provides a review of decontamination procedures in the published literature and calls attention to their benefits and limitations. In most cases, the data are limited to a few FFR models and a limited number of decontamination cycles. Institutions planning to implement a decontamination method must understand its limitations in terms of the degree of inactivation of the intended microorganisms and the treatment's effects on the fit and filtration of the device.

Safety Protocols for Videolaryngoscopy During the COVID-19 Pandemic: A Prospective Review of 196 Cases

To prepare safety protocols for performing videolaryngoscopy (VLS) during COVID-19 pandemic, that would be feasible for patients, hospital and the health care providers. This was a prospective study performed from March 01, 2020 to June 30, 2020. It analyzed the precautions adapted for VLS initially and subsequently describes modifications with the time. The safety protocols are developed considering the safety aspect, the feasibility aspect (due to increase in number of the VLS), and the financial aspect. The VLS was performed with the personal protective equipment (PPE), including the face shield mask and head cover. The PPE was re-used after sterilization with ethylene oxide. For local anesthesia, the oropharynx was sprayed with 15% xylocaine and nose packed with 4% xylocaine soaked pledget. Following the VLS, the scope was wiped three times with 80% alcohol and then immersed in 5.25% sodium hypochlorite and 0.55% ortho-phthalaldehyde for 10 min each. Each VLS was spaced by at least 15 min gap. The endoscopy suite maintained with laminar air flow. It can be concluded that during the COVID-19 pandemic, the VLS must be performed using PPE with proper sterilization of the scope and the endoscopy suite after the procedure. The use of face shield mask and 15% xylocaine spray into the oropharynx were also highlighted. The financial burden should be minimized by reusing the materials whenever possible.

Titanium dioxide-mediated resistive nanobiosensor for E. coli O157:H7

A titanium dioxide nanoparticle (TiO₂ NP)-mediated resistive biosensor is described for the determination of DNA fragments of Escherichia coli O157:H7 (E. coli O157:H7). The sol-gel method was used to synthesize the TiO₂ NP, and microlithography was applied to fabricate the interdigitated sensor electrodes. Conventional E. coli DNA detections are facing difficulties in long-preparation-and-detection-time (more than 3 days). Hence, electronic biosensor was introduced by measuring the current-voltage (I-V) DNA probe without amplification of DNA fragments. The detection scheme is based on the interaction between the electron flow on the sensor and the introduction of negative charges from DNA probe and target DNA. The biosensor has a sensitivity of 1.67 × 10¹³ Ω/M and a wide analytical range. The limit detection is down to 1 × 10^-11 M of DNA. The sensor possesses outstanding repeatability and reproducibility and is cabable to detect DNA within 15 min in a minute-volume sample (1 μL). Graphical abstract Fig. (a) Graphical illustration of electronic biosensor set up and (b) relationship between limit of detection (LOD) and the unaffected poultry samples on E. coli O157:H7.

Laboratories

Patient test samples are taken and examined at outpatient clinics, in bed posts and at policlinic consultations and treatment units. They are collected and transported to central laboratories or examined by smaller laboratory units, adapted to the patient group. Samples are sent in pipes or transported by defined methods to the laboratory. A large number of samples are also sent to other hospitals, laboratories or diverse private laboratories.

The following chapter is focused on laboratory safety for patients and personnel to avoid spread of infections between patients, personnel and environment.

Disinfection Room: Cleaning Room

The disinfection room is central to all operations and is a multifunctional room. Here, all contaminants and organic materials are taken care of and removed. Contaminated textiles are sorted and ordinary waste from infectious waste. Used syringes and other stabbing/cutting waste, glass, etc. are collected as hazardous waste. Used wheelchairs and other major patient aids are usually washed here. The bedpan, urine bottles, etc. are disinfected in the decontaminator. The room has a large load of dirt and microbial agents where the personnel may perform many space-demanding tasks. A large and efficient area with good separation between clean and unclean work tasks, good ventilation and negative pressure ventilation and good methods for cleaning and disinfection are necessary. The following chapter is focused on areal and outfit of the disinfection room to avoid transmittance of infections between patients, personal and environment.

Hydrogen peroxide and sodium hypochlorite disinfectants are more effective against Staphylococcus aureus and Pseudomonas aeruginosa biofilms than quaternary ammonium compounds

Background

Antimicrobial disinfectants are used as primary treatment options against pathogens on surfaces in healthcare facilities to help prevent healthcare associated infections (HAIs). On many surfaces, pathogenic microorganisms exist as biofilms and form an extracellular matrix that protects them from the antimicrobial effects of disinfectants. Disinfectants are used as all-purpose antimicrobials though very few specifically make biofilm efficacy claims. The objective of this study was to evaluate the efficacy of eight registered disinfectants (six registered by the Environmental Protection Agency and two products registered in by the European Chemical Agency) with general bactericidal claims, but currently no biofilm efficacy claims, against Staphylococcus aureus ATTC-6538 and Pseudomonas aeruginosa ATCC-15442 biofilms. We hypothesized that hydrogen peroxide and sodium hypochlorite disinfectant products would be more effective than quaternary ammonium chlorides.

Methods

This study tested the bactericidal efficacy of eight registered disinfectant products against S. aureus ATCC-6538 and P. aeruginosa ATCC-15442 grown on glass coupons using a Center for Disease Control (CDC) biofilm reactor and EPA MLB SOP MB-19. Bactericidal efficacy was determined after treating coupons with disinfectants following standard EPA MLB SOP MB-20.

Results

Overall, sodium hypochlorite and hydrogen peroxide disinfectants had significantly higher bactericidal efficacies than quaternary ammonium chloride disinfectants. We also found that all tested disinfectants except for quaternary ammonium chloride disinfectants met and exceeded the EPA standard for bactericidal efficacy against biofilms.

Conclusion

In general, bactericidal efficacy against biofilms differed by active ingredient. The efficacies of sodium hypochlorite and hydrogen peroxide disinfectants did not vary between strains, but there were significant differences between strains treated with quaternary ammonium chloride disinfectants.