Ventilation-Associated Particulate Matter Is a Potential Reservoir of Multidrug-Resistant Organisms in Health Facilities

Abstract

Most healthcare-associated infections (HCAIs) develop due to the colonisation of patients and healthcare workers by multidrug-resistant organisms (MDRO). Here, we investigated whether the particulate matter from the ventilation systems (Vent-PM) of health facilities can harbour MDRO and other microbes, thereby acting as a potential reservoir of HCAIs. Dust samples collected in the ventilation grilles and adjacent air ducts underwent a detailed analysis of physicochemical properties and biodiversity. All Vent-PM samples included ultrafine PM capable of reaching the alveoli. Strikingly, >70% of Vent-PM samples were contaminated, mostly by viruses (>15%) or multidrug-resistant and biofilm-producing bacterial strains (60% and 48% of all bacteria-contaminated specimens, respectively). Total viable count at 1 m from the ventilation grilles was significantly increased after opening doors and windows, indicating an association between air flow and bacterial contamination. Both chemical and microbial compositions of Vent-PM considerably differed across surgical vs. non-surgical and intensive vs. elective care units and between health facilities located in coal and chemical districts. Reduced diversity among MDRO and increased prevalence ratio in multidrug-resistant to the total Enterococcus spp. in Vent-PM testified to the evolving antibiotic resistance. In conclusion, we suggest Vent-PM as a previously underestimated reservoir of HCAI-causing pathogens in the hospital environment.

Compositional Data Analysis of 16S rRNA Gene Sequencing Results from Hospital Airborne Microbiome Samples

“…Sphingomonas may be responsible for some nosocomial infections from environmental exposure [ 62 ]. The genus Staphylococcus includes more than 45 species, mostly commensals of the skin and mucous surfaces of humans and other mammals, and it is responsible for infections especially in patients undergoing prolonged hospitalization and/or antibiotic therapy, or with comorbidities (e.g., [ 63 ]). Ribeiro et al [ 58 ] used some deep-sequencing analyses to examine and compare the structure of bacterial communities in the intensive care units (ICU) and neonatal intensive care units (NICU) of The Medical School Clinics Hospital in Brazil.…”

Simultaneous monitoring of SARS-CoV-2 and bacterial profiles from the air of hospital environments with COVID-19-affected patients

“…It is widespread in the environment and was detected in all indoor and outdoor samples of this study at RAs% on average higher than few percent. It is responsible for infections especially in patients with prolonged hospitalization, comorbidities, and in patients undergoing prolonged antibiotic therapy (Chezganova et al, 2021 ; Ribeiro et al, 2019 ). Staphylococcus , Corynebacterium , Streptococcus , and Acinetobacter are considered as the dominant genera in hospital wards (Lax et al, 2017 ; Zhang et al, 2021 ), in reasonable accordance with the results of this study.…”

“…CoNS species are among the most commonly isolated bacterial species in clinical microbiology laboratories, undoubtedly mostly as skin contaminants, as mentioned in the previous section. They are of increasing importance as nosocomial pathogens, since they infect especially immunocompromised patients (Chezganova et al, 2021 ; Ribeiro et al, 2019 ; Zhang et al, 2021 ). In addition to Staphylococcus pettenkoferi , Staphylococcus cohnii (mean RA% = 0.87%), Staphylococcus devriesei (mean RA% = 0.52%), and Staphylococcus hominis (mean RA% = 0.30%) have also been detected among the 21 most abundant species.…”

“…Kowalski and Bahnfleth ( 1998 ) provided a list of the primarily nosocomial respiratory bacterial pathogens. Nosocomial infections or HCAIs represent a challenging health problem around the world (Chezganova et al, 2021 ), since they affect 3–15% of patients within inpatient health-facilities according to recent estimates (Zingg et al, 2019 ) and may reach 30% of the patients in intensive care units (Magill et al, 2018 ). HCAIs increase deaths (morbidity and mortality) and antimicrobial resistance, prolong the duration of hospital stays and, consequently, raise healthcare costs (Ribeiro et al, 2019 ).…”

Reduction of airborne and surface-borne bacteria in a medical center burn intensive care unit using active, upper-room, germicidal ultraviolet (GUV) disinfection

“…The COVID-19 pandemic, a resurgence of endemic respiratory viruses [eg, respiratory syncytial virus (RSV), influenza, and rhinoviruses], and the increase in healthcare-associated infections (HAI) have highlighted the need for air disinfection in indoor environments. HAIs and multidrug-resistant organisms (MDROs) 1 are also persistent indoor air problems that may be treated with germicidal ultraviolet (GUV) disinfection technologies, including upper-level, in-room UV and surface treatment systems. [2][3][4][5] GUV disinfection technology has a long history of successful applications in both air and surface disinfection in hospitals, schools, government facilities, and commercial office buildings.…”