Disinfection efficacy of ozone on ESKAPE bacteria biofilms: Potential use in difficult-to-access medical devices.

BACKGROUND: Medical devices can be reservoirs of multidrug-resistant bacteria that may be involved in the acquisition of infections since bacteria with the ability to form biofilms that are difficult to eradicate, mainly in mechanical ventilators. The aim of this work was to evaluate the efficacy of O3 against biofilms of bacteria ESKAPE group through disinfection studies. METHODS: The formation of biofilms of ESKAPE group bacteria was induced in vitro. O3 was injected at different exposure times at a constant dose of 600 mg/h. The recovery of surviving bacteria after O3 treatment was assessed by bacterial counts and biofilm disruption was analyzed. Finally, the viability and integrity of biofilms after O3 treatment was determined by confocal laser scanning microscopy (CLSM). RESULTS: O3 showed bactericidal activity on biofilms from 12 min/7.68 ppm for A. baumannii and C. freundii. P. aeruginosa, K. pneumoniae and S. aureus were killed after 15 min/9.60 ppm. Correlation analyses showed inversely proportional relationships between the variables "disruption versus O3". CLSM revealed that death was time-dependent of biofilms upon O3 exposure. Orthogonal plane analysis showed that bacteria located in the outer region of the biofilms were the ones that initially suffered damage from O3 exposure. CONCLUSIONS: Our findings suggest that this method could be an alternative for the disinfection in mechanical ventilators colonized by bacteria biofilm forming.

Massive sequencing of the V3-V4 hypervariable region of bronchoalveolar lavage from patients with COVID-19 and VAP reveals the collapse of the pulmonary microbiota.

Background. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is a predisposing factor for the development of healthcare-associated infections, of which ventilator-associated pneumonia (VAP) is one.Hypothesis. VAP is caused by ESKAPE bacteria and other pathogens not detected by microbiological culture.Aim. To elucidate the bacterial pathogens of severe coronavirus disease 2019 (COVID-19) and VAP patients by massive sequencing and to predict their degree of relationship with the age and sex of the patients.Methods. Analysis of ribosomal libraries of the V3-V4 hypervariable region obtained by Illumina sequencing of bronchoalveolar lavages from COVID-19 and VAP (first wave) patients from Hospital Juárez de México.Results. Acinetobacter and Pseudomonas were the main bacterial genera in the bronchoalveolar lavages (BALs) analysed. Other members of the ESKAPE group, such as Enterococcus and Klebsiella, were also identified. Taxonomic composition per patient showed that non-ESKAPE genera were present with significant relative abundances, such as Prevotella, Stenotrophomas, Enterococcus, Mycoplasma, Serratia and Corynebacterium. Kruskal-Wallis analysis proved that VAP acquisition is an adverse event that is not influenced by the sex and age of COVID-19 patients.Discussion. Metagenomic findings in COVID-19/VAP patients highlight the importance of implementing comprehensive microbiological diagnostics by including alternative tools for the detection of the causal agents of healthcare-associated infections (HAIs).Conclusions. Timely identification of bacteria 'not sought' in diagnostic bacteriology laboratories will allow specific and targeted treatments. Implications for the restricted diagnosis of VAP causative agents in COVID-19 patients and the presence of pathogens not detected by classical microbiology are analysed and discussed.

ESKAPE bacteria characterization reveals the presence of Acinetobacter baumannii and Pseudomonas aeruginosa outbreaks in COVID-19/VAP patients.

INTRODUCTION: A decrease of detection of outbreaks by multidrug-resistant bacteria in critical areas has been reduced due to COVID-19 pandemic. Therefore, molecular epidemiological surveillance should be a primary tool to reveal associations not evident by classical epidemiology. The aim of this work was to demonstrate the presence of hidden outbreaks in the first wave of the COVID-19 pandemic and to associate their possible origin. METHODS: A population of 96 COVID-19 patients was included in the study (April to June 2020) from Hospital Juárez de México. Genetic identification and antimicrobial susceptibility testing of VAP causative agents isolated from COVID-19 patients was performed. Resistance phenotypes were confirmed by PCR. Clonal association of isolates was performed by analysis of intergenic regions obtained. Finally, the association of clonal cases of VAP patients was performed by timelines. RESULTS: ESKAPE and non-ESKAPE bacteria were identified as causative agents of VAP. ESKAPE bacteria were classified as MDR and XDR. Only A. baumannii and P. aeruginosa were identified as clonally distributed in 13 COVID-19/VAP patients. Time analysis showed that cross-transmission existed between patients and care areas. CONCLUSIONS: Acinetobacter baumannii and Pseudomonas aeruginosa were involved in outbreaks non-detected in COVID-19/VAP patients in the first wave of COVID-19 pandemic.

Biocide effect against SARS-CoV-2 and ESKAPE pathogens of a noncytotoxic silver-copper nanofilm.

Nanometric materials with biocidal properties effective against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and pathogenic bacteria could be used to modify surfaces, reducing the risk of touching transmission. In this work, we showed that a nanometric layer of bimetallic AgCu can be effectively deposited on polypropylene (PP) fibers. The virucidal properties of the AgCu nanofilm were evaluated by comparing the viral loads remaining on uncoated and coated PP after contact times between 2 and 24 h. Quantification of virion numbers for different initial concentrations indicated a reduction of more than 95% after 2 h of contact. The bactericidal action of the AgCu nanofilm was also confirmed by inoculating uncoated and coated PP with a pool of pathogenic bacteria associated with pneumonia (ESKAPE). Meanwhile, no cytotoxicity was observed for human fibroblasts and keratinocyte cells, indicating that the nanofilm could be in contact with human skin without threat. The deposition of the AgCu nanofilm on the nonwoven component of reusable cloth masks might help to prevent virus and bacterial infection while reducing the pollution burden related to the disposable masks. The possible mechanism of biocide contact action was studied by quantum chemistry calculations that show that the addition of Ag and/or Cu makes the polymeric fiber a better electron acceptor. This can promote the oxidation of the phospholipids present at both the virus and bacterial membranes. The rupture at the membrane exposes and damages the genetic material of the virus. More studies are needed to determine the mechanism of action, but the results reported here indicate that Cu and Ag ions are good allies, which can help protect us from the virus that has caused this disturbing pandemic.

Impact of the modification of a cleaning and disinfection method of mechanical ventilators of COVID-19 patients and ventilator-associated pneumonia: One year of experience.

BACKGROUND: Mechanical ventilators are essential biomedical devices for the respiratory support of patients with SARS-CoV-2 infection. These devices can be transmitters of bacterial pathogens. Therefore, it is necessary to implement effective disinfection procedures. The aim of this work was to show the impact of the modification of a cleaning and disinfection method of mechanical ventilators of patients with SARS-CoV-2 and ventilator-associated pneumonia. METHODS: A total of 338 mechanical ventilators of patients infected with SARS-CoV-2 and ESKAPE bacteria were divided in two groups. Group A and B were subjected to cleaning and disinfection with superoxidation solution-Cl/enzymatic detergent and isopropyl alcohol, respectively. Both groups were cultured for the detection of ESKAPE bacteria. The isolates were subjected to tests for identification, resistance, adherence, and genomic typing. RESULTS: Contamination rates of 21.6% (n = 36) were identified in group A. The inspiratory limb was the circuit involved in most cases of postdisinfection contamination. Acinetobacter baumanni, Pseudomonas aeruginosa, and multi-resistant Klebsiella pneumoniae were the pathogens involved in the contamination cases. The pathogens were highly adherent and in the case of A. baumanni, clonal dispersion was detected in 14 ventilators. Disinfection with enzymatic detergents allows a 100% reduction in contamination rates. CONCLUSIONS: The implementation of cleaning and disinfection with enzymatic detergents/isopropyl alcohol of mechanical ventilators of patients with SARS-CoV-2 and ESKAPE bacteria had a positive impact on postdisinfection microbial contamination rates.

Clonal dispersion of Acinetobacter baumannii in an intensive care unit designed to patients COVID-19.

INTRODUCTION: SARS-CoV2 pandemic marks the need to pay attention to bacterial pathogens that can complicate the hospital stay of patients in the intensive care unit (ICU). ESKAPE bacteria which includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae are considered the most important, because of their close relationship with the development of ventilator-associated pneumonia (VAP). The aim of this work was to identify and characterize ESKAPE bacteria and to detect their possible clonal spread in medical devices, patients, and medical personnel of the ICU for COVID-19 patients of the Hospital Juarez de Mexico. METHODOLOGY: Genetic identification of ESKAPE bacteria was performed by analyzing the 16S rRNA gene. Resistance assays were performed according to the CLSI guidelines. Assembly of AdeABCRS operon and inhibition assays of pumps efflux in Acinetobacter baumannii isolates were performed. Associated gene involved in biofilm formation (icaA) was performed in isolates belonging to the Staphylococcus genus. Finally, typing by ERIC-PCR and characterization of mobile genetic element SCCmec were done. RESULTS: Heterogeneous distribution of ESKAPE and non-ESKAPE bacteria was detected in various medical devices, patients, and medical personnel. Acinetobacter baumannii and Staphylococcus aureus were the predominant ESKAPE members. The analysis of intergenic regions revealed an important clonal distribution of A. baumannii (AdeABCRS+). Genotyping of SCCmec mobile genetic elements and the icaA gene showed that there is no clonal distribution of S. aureus. CONCLUSIONS: Clonal spread of A. baumannii (AdeABCRS+) highlights the importance of adopting good practices for equipment disinfection, surfaces and management of COVID-19 patients.

Disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria using hydrogen peroxide plasma: Impact on the reutilization of disposable devices.

INTRODUCTION: One of the serious consequences of the SARS-CoV-2 pandemic is the shortage of protective equipment for health personnel. N95 masks are considered one of the essential protective equipment in the management of patients with COVID-19. The shortage of N95 masks implies potential health risks for health personnel and significant economic losses for the health institution. The objective of this work was to investigate the disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria by using hydrogen peroxide plasma. MATERIAL AND METHODS: We examined the disinfection capacity of hydrogen peroxide plasma against the SARS-CoV-2 and 2 members of the ESKAPE bacteria (Acinetobacter baumannii and Staphylococcus aureus) through a study of artificial contamination in situ of N95 masks. Amplification of specific genes by real-time reverse transcription polymerase chain reaction of SARS-CoV-2 and microbiological culture of ESKAPE bacteria was performed before and after the disinfection process. RESULTS: SARS-CoV-2 was not detected in all assays using 5 different concentrations of the virus, and A baumannii and S aureus were not cultivable with inoculums of 102 to 106 CFU after disinfection tests of N95 masks with hydrogen peroxide plasma. CONCLUSION: Disinfection of N95 masks by using the hydrogen peroxide plasma technology can be an alternative for their reuse in a shortage situation. Implications for the use of disinfection technologies of N95 masks and the safety of health personnel are discussed.