Environmental Disinfection Research Articles

ПРЕДПОСЫЛКИ К РАЗРАБОТКЕ СИСТЕМ ОБЕЗЗАРАЖИВАНИЯ ВОЗДУХА СВИНОВОДЧЕСКИХ ПОМЕЩЕНИЙ С ПОМОЩЬЮ ЭЛЕКТРОФИЛЬТРОВ

Studies of microclimate parameters have shown the influence of microbial contamination on the productivity, growth and development of young pigs. It is known from the literature that exceeding the level of microbial contamination by 5 percent led to a decrease in the growth of piglets at weaning by 13.3 percent, in fattening pigs - to a decrease in live weight at slaughter by 3.7 percent. In addition, infectious diseases caused by pathogenic microorganisms affect the productivity of animals. For example, pneumogastroenteritis, transmitted aerogenically, affects from 30 to 95 percent of suckling piglets and weaning piglets. The damage caused by animal disease takes form of loss in productivity, death of sick animals and forced slaughter, as well as treatment costs. One of the promising and effective ways to clean the ventilation air in pig-breeding premises is the use of electrofiltration, including a wet electrofilter. There is little information in the scientific literature on the issues of disinfection of the air environment of pig-breeding premises from microbial contamination using electrofilters, which necessitates a more thorough consideration of this issue. (Research purpose) The research purpose is substantiating the prerequisites for the development of a methodology for determining the effectiveness of air disinfection with wet electrostatic filtering. (Materials and methods). The available studies on supply and exhaust ventilation systems and methods for determining the effectiveness of air purification by electrofilters from microorganisms were reviewed. Cited their shortcomings. (Results and discussion). It was found that wet electrostatic precipitators in the process of air purification generate ozone into the air, which is capable of destroying up to 95-99 percent of the population of dangerous microorganisms. It has been shown that by modernizing the air purification system in terms of improving the mechanisms for controlling ozone generation with a wet electrostatic precipitator, it is possible to improve the quality of the air environment by disinfecting the air with ozone. (Conclusions) It was determined that the effectiveness of cleaning the air of pig-breeding premises from microorganisms using wet electrostatic precipitators is relevant, further theoretical and experimental studies are needed.

Ultralong-lasting plasma-activated water: production and control mechanisms

Despite the rapidly growing interest stemming from the broad-spectrum, high inactivation capacity, and environmental friendliness of the plasma-activated water (PAW), practical applications are limited because of the PAW’s short lifetime. While low-temperature storage can extend the lifetime, but the freezing and thawing processes are energy- and labor-intense and are generally not suitable for large-scale applications such as environmental and biomedical disinfection. This work addresses this issue by developing the ultra-long-life PAW at room temperature. The innovative approach is based on using DC needle-water discharges, wherein the gaseous products are blown out and absorbed separately by a gas flow. By simply adjusting the voltage and gas flow rates, two distinctive types of PAW with acidic hydrogen peroxide and nitrite as the main products are produced and separated in the discharge chamber and gas bubbling chamber. Intentional mixing of these two PAWs causes a chain chemical reaction dominated by peroxynitrite (ONOOH). This reaction can generate a variety of short-lived reactive species, thereby achieving the ultralong-lasting PAW with very stable bactericidal ability. This study further demonstrates the ability to effectively control the reaction products in both chambers and provides insights into the secondary activation mechanism of short-lived reactive species stimulated by ONOOH.

In vitro susceptibility testing of phytochemicals from essential oils against Prototheca species.

Phytochemicals isolated from essential oils are effective alternatives for inhibiting microbial pathogens. Bovine protothecal mastitis is the cause of a reduction in milk production and the secretion of thin, watery milk with white flakes. In the present study, we performed in vitro susceptibility testing of the phytochemicals carvacrol, citral, and thymol in Prototheca strains isolated from cases of protothecosis in small animals and cow feces. The susceptibility of the algae to carvacrol, citral, and thymol was assessed using the modified CLSI M27-A3 broth microdilution method. The ranges of the minimum inhibitory concentrations (MIC%) of the phytochemicals in all isolates were 0.03% to 0.125% for carvacrol, 0.03% to 0.25% for citral, and 0.06% to 0.25% for thymol. Based on these results, carvacrol, citral, and thymol appear effective against Prototheca species at the tested concentrations, and may thus be useful for environmental disinfection in barns.

Vaccinia virus viability under different environmental conditions and different disinfectants treatment

Monkeypox (mpox) outbreak in 2022 has caused more than 91,000 cases, has spread to 115 countries, regions, and territories, and has thus attracted much attention. The stability of poxvirus particles in the environment is recognized as an important factor in determining their transmission. However, few studies have investigated the persistence of poxviruses on material surfaces under various environmental conditions, and their sensitivity to biocides. Here, we systematically measured the stability of vaccinia virus (VACV) under different environmental conditions and sensitivity to inactivation methods via plaque assay, quantitative real-time polymerase chain reaction (qPCR), and Gaussia luciferase (G-luciferase) reporter system. The results show that VACV is stable on the surface of stainless steel, glass, clothing, plastic, towel, A4 paper, and tissue and persists much longer at 4 °C and −20 °C, but is effectively inactivated by ultraviolet (UV) irradiation, heat treatment, and chemical reagents. Our study raises the awareness of long persistence of poxviruses in the environment and provides a simple solution to inactivate poxviruses using common disinfectants, which is expected to help the control and prevention of mpox virus and future poxvirus outbreaks.

МОДЕЛЮВАННЯ ПРОЦЕСІВ СТВОРЕННЯ СВІТЛОВОГО ПРОСТОРУ У БАКТЕРИЦИДНИХ УЛЬТРАФІОЛЕТОВИХ СВІТЛОДІОДНИХ УСТАНОВКАХ

The pandemic continues, as does the issue of preventing environmental pollution with harmful substances, viruses and bacteria. In these conditions, lighting technology and disinfection technologies based on the use of radiation in the ultraviolet spectral range open up wide opportunities. The relevance of the topic lies in the fact that modern events, namely pandemics, earthquakes, volcanic eruptions, tsunamis and wars, cause a large amount of environmental pollution with harmful substances, various viruses and bacteria. Unfortunately, these problems have affected the entire population of our planet, and in the future, without solving the issue of high-quality disinfection of various environments, they may lead to new, larger-scale disasters. The research was carried out in O.M. Beketov National University of Urban Economy in Kharkiv was allowed to establish the possibility of using ultraviolet LEDs for the treatment of various environments infected with harmful microorganisms and Covid-19, to develop a method for modeling the curve of light intensity of a light device and an algorithm for calculating LED installations, which will provide the possibility of calculating and designing such installations for the disinfection of various environments, in particular, water environments and environments infected with Covid-19. Thus, studies have confirmed the possibility of using ultraviolet LEDs to disinfect the environment from particles of the Covid-19 virus, harmful microorganisms in 193various environments and to establish requirements for bactericidal installations in these conditions. And the developed method can be applied to any arbitrarily selected observation points, bases of LEDs and their environment, which makes the algorithm suitable for calculating light distribution from LED systems for bactericidal disinfection of various environments, including water or infected with Covid-19, from harmful microorganisms.

Autonomous Fever Detection, Medicine Delivery, and Environmental Disinfection for Pandemic Prevention

In facing the outbreak of the pandemic, robots are highly appealing for their non-contact nature. Among them, we have selected the mobile robot manipulator to develop an autonomous system for pandemic prevention, as it possesses both mobility and manipulability. The robot was used as a platform for performing autonomous fever detection, medicine delivery, and environmental disinfection system for the fever station and isolation ward, which are the two primary units that deal with the pandemic in a hospital. The proposed novel algorithms aim to ensure both human safety and comfort by automating fever detection and recognizing medicine taking. Additionally, they address environmental disinfection by effectively covering blind spots. We conducted a series of experiments to evaluate their performance in a hospital-like setting, which was designed specifically for the testing of intelligent medical systems developed in our university. Quantitative assessment was administered to analyze how the introduction of the proposed autonomous system reduced the risk of infection, and feedback was also collected from participants through questionnaires.

Investigation of two norovirus outbreaks linked to drinking water contaminated with multiple GII strains in a rural county-Chongqing, China, 2021.

Norovirus is leading cause of non-bacterial gastroenteritis outbreaks globally, characterized by different strains prevalent in different countries and regions. Cases were defined as individuals experiencing diarrhea ≥3 times/24 h, and/or vomiting ≥2 times/24 h in two villages between January 28 and February 9, 2021. Investigations were conducted to identify causes. Cases were interviewed using a standardized in-person form to collect data on potential risk factors. A retrospective cohort study was conducted to investigate the role of the spring water supply as the outbreak source. Residents from neighboring villages with different water sources served as the unexposed population. Stool specimens, rectal swabs, and water samples were tested using quantitative real-time Polymerase Chain Reaction, with subsequent sequencing performed on pathogen-positive specimens. Village-specific attack rates were 21.93% (123/561) and 26.99% (88/326), respectively. Evidence from both epidemiological and laboratory tests was consistent. Drinking spring water was statistically associated with the two outbreaks (RR = 41.8 and 79.2, respectively). In both outbreaks, stool specimens, rectal swabs, and water samples tested positive for norovirus. Specifically, GII.2 (P16) and GII.17 (P17) were identified in outbreak A, and GII.4 Sydney (P16) and GII.1 (P16) in outbreak B. These two independent gastroenteritis outbreaks share similarities, both being linked to norovirus GII strains. The contaminated spring drinking water was identified as the probable source and was promptly closed and subjected to disinfection procedures. These findings reinforce the importance of implementing sanitation and environmental disinfection measures in rural areas, especially during the periods of increased rainfall.

Rapid Environmental Contamination With Candida auris and Multidrug-Resistant Bacterial Pathogens Near Colonized Patients.

Environmental contamination is suspected to play an important role in Candida auris transmission. Understanding speed and risks of contamination after room disinfection could inform environmental cleaning recommendations. We conducted a prospective multicenter study of environmental contamination associated with C. auris colonization at 6 ventilator-capable skilled nursing facilities and 1 acute care hospital in Illinois and California. Known C. auris carriers were sampled at 5 body sites followed by sampling of nearby room surfaces before disinfection and at 0, 4, 8, and 12 hours after disinfection. Samples were cultured for C. auris and bacterial multidrug-resistant organisms (MDROs). Odds of surface contamination after disinfection were analyzed using multilevel generalized estimating equations. Among 41 known C. auris carriers, colonization was detected most frequently on palms/fingertips (76%) and nares (71%). C. auris contamination was detected on 32.2% (66/205) of room surfaces before disinfection and 20.5% (39/190) of room surfaces by 4 hours after disinfection. A higher number of C. auris-colonized body sites was associated with higher odds of environmental contamination at every time point following disinfection, adjusting for facility of residence. In the rooms of 38 (93%) C. auris carriers co-colonized with a bacterial MDRO, 2%-24% of surfaces were additionally contaminated with the same MDRO by 4 hours after disinfection. C. auris can contaminate the healthcare environment rapidly after disinfection, highlighting the challenges associated with environmental disinfection. Future research should investigate long-acting disinfectants, antimicrobial surfaces, and more effective patient skin antisepsis to reduce the environmental reservoir of C. auris and bacterial MDROs in healthcare settings.

Scabies in French Guiana: Quantitative and qualitative factors associated with therapeutic failure.

Strategies for the control of scabies should be adapted to local settings. Traditional communities in French Guiana have non-Western conceptions of disease and health. The objectives for this study were to explore knowledge, attitudes and practices to identify potential factors associated with the failure of scabies treatment in these communities. Patients with a clinical diagnosis of scabies, seen at either the Cayenne Hospital or one of 13 health centres between 01 April 2021 and 31 August 2021, were included as participants, and were seen again after 6 weeks to check for persistence of lesions. Factors associated with treatment failure were looked for both at inclusion and at 6 weeks. Semi-structured interviews were conducted with a diversified subsample of participants. In total, 164 participants were included in the quantitative component, and 21 were interviewed for the qualitative component. Declaring that the second treatment dose had been taken was associated with therapeutic success. Western treatments were not always affordable. Better adherence was observed with topical treatments than with oral ivermectin, whereas permethrin monotherapy was associated with failure. Scabies-associated stigma was high among Amerindians and Haitians but absent in Ndjuka Maroons. Participants reported environmental disinfection as being very complex. The treatment of scabies in traditional Guianan communities may vary depending on local perceptions of galenic formulations, disease-associated stigma and differences in access to health care. These factors should be taken into account when devising strategies for the control of scabies aimed at traditional communities living in remote areas, and migrant populations.

Stability of mpox virus on different commonly contacted surfaces.

Mpox is still spreading globally and is mostly reported to be transmitted by skin and mucosal contact. However, transmission through contact with fomites, contaminated objects, or surfaces has been reported in general population. Evaluation of the stability of mpox virus (MPXV) on different surfaces is important to minimize mpox transmission. In the study, the stability of MPXV on different kinds of commonly contacted surfaces was determined. MPXV was observed to have a surface-dependent stability pattern. Viable virus was detected on both glass and stainless steel for up to 5 days, and on plastic surfaces for up to 3 days. In contrast, no viable MPXV was detected on wooden board and cardboard, which are porous and water-absorbent surfaces, after 1 and 2 days of incubation, respectively. In addition, MPXV nucleic acids were more stable and showed better correlation with viral titers on stainless steel, plastic, and glass. The results indicate that fomite transmission of MPXV is plausible. Moreover, the stability of MPXV was highly surface-dependent and more stable on smooth surfaces, which could provide more information for minimizing the transmission of mpox and emphasize the significance of environmental disinfection in mpox prevention and control.

1756. Takeaways from Investigation of a Large Invasive Group A Streptococcus Outbreak in a Skilled Nursing Facility, Virginia, 2022-2023

Abstract Background Group A Streptococcus (GAS) primarily infects the respiratory tract, skin, and soft tissue. Invasive GAS (iGAS), in which the bacteria infect a normally sterile body site, is severe and can be life threatening, especially in older adults. The Virginia Department of Health investigated a prolonged iGAS outbreak in a skilled nursing facility from March 2022 - April 2023. Cases continued despite multipronged outbreak response. Methods A case was defined as GAS isolated from a sterile or nonsterile body site. Cases were identified through active surveillance, retrospective chart review, colonization screening by skin/throat swab, and culture. Multiple onsite visits were conducted to assess infection control practices at the facility. Genotyping (emm type) analysis was performed on resident and staff isolates. Results From March 2022 to April 2023, 30 (71.4%) GAS cases were identified among facility residents, and 12 (28.6%) cases among staff. Ten residents (23.8%) died. GAS was isolated from throat (21, 50%), wounds (14, 33.3%), from more than one site (2, 4.8%), and invasive infections (5, 11.9%). Twenty (47.6%) cases were identified through colonization screening; the carriage rate among residents was 7% (16 positive out of 230) and 2.8% among staff (4 positives out of 142). Sequencing was conducted on 34 isolates, 33 (97%) were emm type 89 and were within < 10 single nucleotide polymorphisms (SNP) apart. Infection prevention assessments identified gaps in hand hygiene, wound care, and environmental cleaning and disinfection. Conclusion Genotyping results suggested common source exposure. GAS might have transmitted several times between colonized or infected residents and staff which caused the extended outbreak. Multiple challenges at the facility contributed to a prolonged outbreak despite aggressive interventions. Challenges included high staff turnover; use of agency staff since the beginning of the COVID-19 pandemic; change in facility ownership; suboptimal infection prevention practices including wound care; and lack of appropriate active surveillance for GAS infections. Review of epidemiological data, frequent onsite infection prevention assessments, numerous educational sessions, and active follow-up were all crucial strategies for outbreak mitigation. Disclosures All Authors: No reported disclosures

Responding to avian influenza A H5N1 detection on a hospital property in Maine-An interdisciplinary approach.

The risk of infection with avian influenza A viruses currently circulating in wild and domestic birds in the Americas is considered low for the general public; however, detections in humans have been reported and warning signs of increased zoonotic potential have been identified. In December 2022, two Canada geese residing on the grounds of an urban hospital in Maine tested positive for influenza A H5N1 clade 2.3.4.4b. Given the opportunity for exposure to staff and hospital visitors through potentially infected faeces on the property, public health authorities determined mitigation efforts were needed to prevent the spread of disease. The ensuing response relied on collaboration between the public health and animal health agencies to guide the hospital through efforts in preventing possible zoonotic transmission to humans. Mitigation efforts included staff communication and education, environmental cleaning and disinfection, enhanced illness surveillance among staff and patients, and exposure and source reduction. No human H5N1 cases were identified, and no additional detections in birds on the property occurred. Hospital staff identified barriers to preparedness resulting from a lack of understanding of avian influenza A viruses and transmission prevention methods, including avian influenza risk in resident wild bird populations and proper wildlife management methods. As this virus continues to circulate at the animal-human interface, this event and resulting response highlights the need for influenza A H5N1 risk awareness and guidance for facilities and groups not traditionally involved in avian influenza responses.

Evaluation of a novel surface-coating formulation with time-extended antimicrobial activity for healthcare environment disinfection

BackgroundThe importance of environmental contamination in the transmission of pathogens among hospitalized patients is universally recognized, and disinfection of surfaces is a widely accepted modality for reducing healthcare-associated infections. Nevertheless, hospital disinfection is still suboptimal. In this study, we evaluated the sustained effects of the novel formulation OxiLast™ which extends the antimicrobial effects of chlorine-based disinfectants.MethodsIn an experimental lab phase, PVC surfaces were coated with OxiLast™ and then inoculated with representative Gram-positive and Gram-negative pathogenic bacteria. Cells were recovered at different contact times (5, 15, 30 min) to assess the reduction in bacterial counts compared to uncoated surfaces and also subject to various challenges to assess robustness. A similar methodology was then applied in an unoccupied hospital room to evaluate the sustained effect of OxiLast™ on high-touch surfaces.ResultsOxiLast™ demonstrated notable activity against the range of bacterial strains tested with ≥ 4 log10 reduction in bacterial counts observed for up to seven days following one surface application, for various strains and contact times. Similar results were observed following challenges such as simulated abrasion of coated surfaces, organic contamination or successive inoculations. The results were confirmed in a simulated patient care environment.ConclusionsThe addition of OxiLast™ to common chlorine-based disinfectants has shown a substantial and sustained reduction in bacterial pathogen counts for up to 7 days following one application. The consistent results in the laboratory and hospital are promising and should be tested in a real-life clinical scenario.

Intrahospital transmission and infection control of Candida auris originating from a severely infected COVID-19 patient transferred abroad

Intrahospital spread of Candida auris, which survives tenaciously in many environments, can cause sustained colonization and infection. A large outbreak of C.auris was experienced in the intensive care units (ICUs) at the study hospital during the coronavirus disease 2019 (COVID-19) pandemic. The index patient with severe COVID-19, who was transferred from Vietnam in January 2022, developed C.auris candidaemia 10 days after hospitalization. From mid-June 2022 to January 2023, strengthened infection prevention and control (IPC) measures were implemented in three ICUs: (1) contact precautions and isolation (CPI) for C.auris-positive cases; (2) surveillance cultures including point-prevalence (N=718) for patients or close contacts or ICU-resident healthcare workers (HCWs); (3) intensive environmental disinfection with 10-fold diluted bleach; and (4) 2% chlorhexidine bathing for all ICU patients. Environmental cultures (ECx) on surfaces and shared objects (N=276) were conducted until early September 2022, when all ECx were negative. Among 53 C.auris-positive patients between February 2022 and January 2023, invasive infections resulted in seven cases of candidaemia and one case of pneumonia. C.auris was isolated from reusable tympanic thermometers (TTMs) contaminated with earwax. The isolation rate of C.auris in ECx decreased from 6.8% in June 2022 to 2.0% in August 2022, and was no longer detected in TTMs. Colonization in HCWs was remarkably rare (0.5%). The number of C.auris-positive patients peaked in July (N=10) then decreased gradually. By January 2023, no C.auris were isolated in the ICU. Aggressive IPC measures with CPI, ECx and surveillance, decontamination of TTMs, and bathing were effective in successfully controlling this C.auris outbreak.

Numerical simulation study of indoor disinfection spray distribution based on CFD-DPM method

In today's world, environmental safety has become a top priority, with a special focus on terminal disinfection of indoor environments, which has proven to be a crucial and formidable issue in infection control. The use of hydrogen peroxide disinfection through vaporization or atomization presents a viable solution to the challenges posed by traditional wiping disinfection and ultraviolet disinfection methods that are plagued by incomplete disinfection and other factors that can significantly reduce the virus content within a room. To improve the application of hydrogen peroxide disinfection spray, the CFD-DPM (Computational Fluid Dynamics-Discrete Particle Model) method is employed to simulate the particle distribution of traditional sprays in a 30 m3 room. The study places emphasis on analyzing the impact of the placement position and bottle number of disinfection spray on the distribution of spray particles. The results demonstrate an impressive consistency between the numerical simulation method and experimental findings regarding the particle size distribution of disinfectant spray across various Schemes, validating the method's accuracy and reliability. However, the placement of a single disinfection spray source is insufficient to achieve uniformly distributed particles throughout the space when a bathroom is present within a given room. Nevertheless, by placing internal and external sources within the bathroom, the distribution of disinfectant spray particles becomes more even, thanks to a well conceived placement technique and an increased number of spray sources. Among all the schemes tested, Scheme 4 stands out for its ability to produce the greatest number of spray particles, with almost 60.71% of these particles remaining airborne for over 40 s. Therefore, it is also the most effective scheme for conducting disinfection.

Environmental Persistence and Disinfection of Lassa Virus.

Lassa fever, caused by Lassa virus (LASV), is endemic to West Africa, where ≈300,000 illnesses and ≈5,000 deaths occur annually. LASV is primarily spread by infected multimammate rats via urine and fomites, highlighting the need to understand the environmental fate of LASV. We evaluated persistence of LASV Josiah and Sauerwald strains on surfaces, in aqueous solutions, and with sodium hypochlorite disinfection. Tested strains were more stable in deionized water (first-order rate constant [k] for Josiah, 0.23 days; for Sauerwald, k = 0.34 days) than primary influent wastewater (Josiah, k=1.3 days; Sauerwald, k = 1.9 days). Both strains had similar decay rates on high-density polyethylene (Josiah, k=4.3 days; Sauerwald, k = 2.3 days) and stainless steel (Josiah, k=5.3 days; Sauerwald, k = 2.7 days). Sodium hypochlorite was highly effective at inactivating both strains. Our findings can inform future risk assessment and management efforts for Lassa fever.

Preparation and properties of modified cassava starch slow-release hydrogel with acid and alkali resistance

Slow release of chlorine dioxide is receiving increasing attention in the field of environmental disinfection. This study focuses on the binary solid dioxide rate to improve its acid and alkali resistance. Cassava starch hydrogels were prepare as the backbone and polyvinyl alcohol (PVA) as the soft segment and were modified by adding quaternized carboxymethyl cellulose and chitin to make the hydrogel acid- and alkali- resistant. Subsequently, sodium bicarbonate was introduced to make the hydrogel porous, thereby solving the problem whereby binary solid chlorine dioxide is corroded by acid and alkali during the slow-release process of chlorine dioxide, thus resulting in poor mechanical properties. The chemical structure and morphology of the cassava starch-based composite hydrogels were confirmed by solid-state nuclear magnetic resonance and other methods. Measurements of the compressive properties with different pH solutions demonstrated the acid and alkali resistance of the modified hydrogel was the strongest at pH= 3.5 and pH= 10.5 with compressive stresses of 200.47 kPa and 180.65 kPa. The cumulative chlorine dioxide release curves were in good agreement with the first-order kinetic model, and R2 values were all greater than 0.95. This research offers broad applications in environmental disinfection, fruit and vegetable preservation, and wastewater adsorption.

Long-term intensive care unit outbreak of carbapenemase-producing organisms associated with contaminated sink drains

Between 2018 and 2022, a Belgian tertiary care hospital faced a growing issue with acquiring carbapenemase-producing organisms (CPO), mainly VIM-producing P. aeruginosa (PA-VIM) and NDM-producing Enterobacterales (CPE-NDM) among hospitalized patients in the adult intensive care unit (ICU). We report the investigation of this ICU long-term CPO outbreak involving multiple species and a persistent environmental reservoir. Active case finding, environmental sampling, whole genome sequencing (WGS) analysis of patient and environmental strains and implemented control strategies were described in this study. From 2018 to 2022, 37 patients became colonised or infected with PA-VIM and/ or CPE-NDM during their ICU stay. WGS confirmed the epidemiological link between clinical and environmental strains collected from the sink drains with clonal strains dissemination and horizontal gene transfer mediated by plasmid conjugation and/or transposon jumps. Environmental disinfection by quaternary ammonium-based disinfectant and replacement of contaminated equipment failed to eradicate environmental sources. Interestingly, efflux pumps genes conferring resistance to quaternary ammonium compounds were widespread in the isolates. As removing sinks was not feasible, a combination of a foaming product degrading the biofilm and foaming disinfectant based on peracetic acid and hydrogen peroxide has been evaluated and has so far prevented re-colonisation of the proximal sink drain by CPO. The persistence in the hospital environment of antibiotic-and-disinfectant resistant bacteria with the ability to transfer mobile genetic elements poses a serious threat on ICU patients with a risk of shifting towards an endemicity scenario. Innovative strategies are needed to address persistent environmental reservoirs and prevent CPO transmission.

Transcriptomic and phenotype analysis revealed the role of rpoS in stress resistance and virulence of a novel ST3355 ESBL-producing hypervirulent Klebsiella pneumoniae isolate.

An extended-spectrum beta-lactamase (ESBL)-hypervirulent Klebsiella pneumoniae (HvKP) strain HKE9 was isolated from the blood in an outpatient. The effect of the global regulatory factor RpoS on antimicrobial resistance, pathogenicity, and environmental adaptability was elucidated. HKE9 is a novel ST3355 (K20/O2a) hypervirulent strain with a positive string test and resistant to cephems except cefotetan. It has a genome size of 5.6M, including two plasmids. CTX-M-15 was found in plasmid 2, and only ompk37 was found in the chromosome. HKE9 could produce bacterial siderophores, and genes of enterobactin, yersiniabactin, aerobactin, and salmochelin have been retrieved in the genome. As a global regulatory factor, knockout of rpoS did not change antimicrobial resistance or hemolytic phenotype while increasing the virulence to Galleria mellonella larvae and showing higher viscosity. Moreover, rpoS knockout can increase bacterial competitiveness and cell adhesion ability. Interestingly, HKE9-M-rpoS decreased resistance to acidic pH, high osmotic pressure, heat shock, and ultraviolet and became sensitive to disinfectants (H2O2, alcohol, and sodium hypochlorite). Although there were 13 Type 6 secretion system (T6SS) core genes divided into two segments with tle1 between segments in the chromosome, transcriptomic analysis showed that rpoS negatively regulated T4SS located on plasmid 2, type 1, and type 3 fimbriae and positively regulate genes responsible for acidic response, hyperosmotic pressure, heat shock, oxidative stress, alcohol and hypochlorous acid metabolism, and quorum sensing. Here, this novel ST3355 ESBL-HvKP strain HKE9 may spread via various clonal types. The important regulation effect of rpoS is the enhanced tolerance and resistance to environmental stress and disinfectants, which may be at the cost of reducing virulence and regulated by T4SS.

Methicillin-resistant Staphylococcus aureus (MRSA) clusters in neonatal intensive care units (NICUs) and other neonatal units in New York State (NYS), 2001 to 2017

New York State (NYS) mandates reporting of all hospital-associated communicable disease outbreaks. We describe trends in NYS surveillance for neonatal unit methicillin-resistant Staphylococcus aureus (MRSA) outbreaks, the evolution of national MRSA infection prevention and control (IPC) recommendations, and IPC measures taken by NYS neonatal units. We evaluated trends of reported neonatal unit MRSA outbreaks by etiology from 2001 to 2017. We reviewed all reports and the use of IPC recommendations over time. From 2001 to 2017, 124 MRSA outbreaks were reported in 47 hospital neonatal units, with a total of 1,055 laboratory-confirmed infant cases, 18 infant deaths, and 52 laboratory-confirmed staff cases. The number of outbreaks increased with the level of care. During the study period, a higher proportion of hospitals reported implementing IPC measures, including reinforcing hand hygiene compliance (increased from 79.2% to 95.1%) and enhancing environmental cleaning and disinfection (increased from 4.2% to 78.0%) as well as performing active surveillance testing (AST) on exposed neonates (increased from 4.2% to 51.2%) and molecular testing on MRSA-positive isolates (increased from 5.3% to 18.9%). From 2001 to 2017, IPC measures in neonatal units increased in parallel with expanded national IPC recommendations. However, MRSA outbreaks in neonatal units continued to be frequent occurrences in NYS.