Air dispersal of multi-drug-resistant organisms including meticillin-resistant Staphylococcus aureus, carbapenem-resistant Acinetobacter baumannii and carbapenemase-producing Enterobacterales in general wards: surveillance culture of air grilles

BACKGROUND

The environmental surveillance of air grilles in clinical areas has not been systematically analysed.

METHODS

Samples were collected from frequently touched items (N = 529), air supply (N = 295) and exhaust (N = 184) grilles in six medical and 11 surgical wards for the cultures of multi-drug-resistant organisms (MDROs): meticillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenemase-producing Enterobacterales (CPE), and isolates were selected for whole-genome sequencing (WGS). The contamination rates were correlated with the colonization pressures of the respective MDROs.

RESULTS

From 3rd October to 21st November 2023, 9.8% (99/1008) of the samples tested positive, with MRSA (24.2%, 24/99), CRAB (59.6%, 59/99) and CPE (2.0%, 2/99), being the only detected MDROs. The contamination rate in air exhaust grilles (26.6%, 49/184) was significantly higher than in air supply grilles (5.8%, 17/295; P<0.001). The contamination rate of air exhaust grilles with any MDRO in acute medical wards (73.7%, 14/19) was significantly higher than in surgical wards (12.5%, 4/32; P<0.001). However, there was no difference in the contamination rate of air exhaust grilles between those located inside and outside the cohort cubicles for MDROs (27.1%, 13/48 vs 28.8%, 30/104; P=0.823). Nevertheless, the weekly CRAB colonization pressure showed a significant correlation with the overall environmental contamination rate (r = 0.878; 95% confidence interval (CI): 0.136-0.986; P=0.004), as well as with the contamination rate in air supply grilles (r = 0.960; 95% CI: 0.375-0.999; P<0.001) and air exhaust grilles (r = 0.850; 95% CI: 0.401-0.980; P=0.008). WGS demonstrated clonal relatedness of isolates collected from patients and air exhaust grilles.

CONCLUSIONS

Air grilles may serve as MDRO reservoirs. Cohort nursing in open cubicles may not completely prevent MDRO transmission through air dispersal, prompting the consideration of future hospital design.

Nosocomial transmission of multi-drug-resistant organisms in Ukrainian hospitals: results of a multi-centre study (2019-2021)

BACKGROUND

The increasing emergence and spread of multi-drug-resistant organisms (MDROs) in hospitals is a public health problem and continues to challenge infection control and hospital epidemiology practice worldwide.

AIM

The aim of this study was to characterize the epidemiology of transmission of MDROs via healthcare workers (HCWs) and the environment in the hospital wards/patient rooms.

METHODS

A multi-centre prospective observational study was conducted in 17 hospitals in Ukraine. Species identification was performed with standard microbial methods. β-Lactamase genes were investigated by polymerase chain reaction. Pulsed-field gel electrophoresis (PFGE) was used to determine the genetic similarity between isolates.

FINDINGS

Among 51,656 isolates, 19.5% were MDROs. The proportions of MDROs among isolates from patients with healthcare-associated infections, environmental surfaces and HCWs (hands, gown/gloves) were 29.2%, 16.3% and 24.2%, respectively. In 51.9% of the tested isolates, identical MDROs were found in clinical isolates, environmental samples and HCWs' hands. Meticillin resistance was found in 32.4% of Staphylococcus aureus (MRSA) isolates, and vancomycin resistance was found in 28.9% of enterococci (VRE). Resistance to third-generation cephalosporins was detected in 48.4% of Enterobacterales, and carbapenem resistance in 19.1%. Overall, 37.4% of MDROs had broad-spectrum β-lactamase genes, including extended-spectrum β-lactamase (35.8%), OXA-type (29.7%), AmpC-type (25.1%), KPC-type (25.7%) and metallo-β-lactamases, including IMP-type (5.7%), VIM-type (31.7%) and NDM-1 (21.3%).

CONCLUSIONS

In Ukrainian hospitals the prevalence of healthcare-associated infections caused by MDROs continues to increase, while infection control gaps in healthcare settings facilitate their transmission between patients.

How dirty are the pens in health-care environment? An easily overlooked detail of hand hygiene

Pens, common in hospitals, may be a potential vehicle for cross-infection. In this study, the number of pathogens on different pens and the positive rates of several common multi-drug-resistant bacteria were calculated and compared according to the nature of use and material. In addition, the effect of pens on bacterial transmission was explored through simulation experiments. High levels of bacteria were found on pens and the simulations demonstrated transmission of bacteria.

Spread of ESBL-producing Escherichia coli in nursing home residents in Ireland and the Netherlands may reflect infrastructural differences

A prevalence study in two nursing homes (one each in the Netherlands and Ireland) found four (11%) Dutch and six (9%) Irish residents colonized with 11 extended-spectrum beta-lactamase-producing Escherichia coli, 10 of which contained CTX-M-15. Four Dutch isolates, from three residents of the same ward, belonged to E. coli O25:H4, sequence type (ST) 131 and were part of the same cluster type by whole-genome sequencing. Four Irish residents on three different wards were colonized with an identical E. coli O89:H9, ST131, complex type 1478. Cross-transmission between three Irish wards may reflect differences in nursing home infrastructure, specifically communal areas and multi-bedded resident rooms.

Explorative Study on Isolation and Characterization of a Microviridae G4 Bacteriophage, EMCL318, against Multi-Drug-resistant Escherichia coli 15-318

Bacteriophages screened and isolated from sewage water samples exhibited antibacterial activities against multi-drug-resistant Escherichia coli strains. Five different water samples from Canadian habitats such as Kamloops Wastewater Treatment Center, Domtar, the Pacific Ocean, Bisaro Anima Cave, and alkali ponds, were used in this study. Four Enterobacteriaceae strains including one non-resistant and three clinical multi-drug Escherichia coli strains (E. coli 15-102, E. coli 15-124, and E. coli 15-318) were selected as target bacteria to screen for the bacteriophages from these collected water samples. Seeded agar assay technique was implemented for the screening. It was found that only sewage water sample exhibited a significant number of plaques count with the E. coli 15-318 (1.82 × 10² plaques/plate) cells in comparison to E. coli non-resistant strain K12 (8 plaques/plate). The phage did not produce plaques in the E. coli 15-124 and E. coli 15-102 strains. The bacteriophage, designated EMCL318, was isolated, purified, characterized, and identified to belong to the G4 species of the Family Microviridae, GenBank accession number MG563770. This is an explorative study conducted in order to reveal the viruses as alternative potentials to fight against emerging and existing multi-drug-resistant infectious diseases.

Adherence to contact precautions by different types of healthcare workers through video monitoring in a tertiary hospital

BACKGROUND

Contact precautions are required to prevent transmission of multi-drug-resistant organisms; however, reports on adherence rates vary. This study used video monitoring to evaluate adherence to the use of personal protective equipment (PPE) by different types of healthcare workers.

METHODS

This observational study was conducted in a 781-bed tertiary hospital from July 2016 to March 2017. Cameras were installed in areas where staff don PPE. Infection control teams observed the videos and assessed adherence rates.

RESULTS

In total, 1097 opportunities for donning PPE were observed. Most staff observed were nurses and nursing assistants (Ns/Nsas) (880/1097, 80.2%). Overall, the adherence rate to appropriate PPE use was 34.0%. The adherence rate among Ns/Nsas was lower (239/858, 27.9%) compared with infectious disease doctors (18/18, 100%) and cleaning staff (42/49, 85.7%). The adherence rate for PPE use for Clostridium difficile infection (CDI) with toxin detection was significantly higher than that for CDI without toxin detection and multi-drug-resistant organisms (P<0.001 for both). The adherence rate for patients with an independent functional status was higher than that for patients with a dependent functional status (P=0.018). The adherence rate was lower in the intensive care unit (ICU) than in non-ICU wards (27.6% vs 36.5%; P=0.006).

CONCLUSION

Video monitoring is a useful tool for monitoring adherence to PPE use, facilitating observation of more PPE opportunities than direct observation. Adherence to contact precautions varied by occupation; however, overall adherence was insufficient. The lower adherence rate in nurses might be due to more frequent care visits.

Deconstructing the relative benefits of a universal glove and gown intervention on MRSA acquisition

BACKGROUND

The 20-site Benefits of Universal Glove and Gown (BUGG) study found that wearing gloves and gowns for all patient contacts in the intensive care unit (ICU) reduced acquisition rates of meticillin-resistant Staphylococcus aureus (MRSA). The relative importance of gloves and gowns as a barrier, improved hand hygiene, and reduced healthcare worker (HCW)-patient contact rates is unknown.

AIM

To determine what proportion of the reduction in acquisition rates observed in the BUGG study was due to improved hand hygiene, reduced contact rates, and universal glove and gown use using agent-based simulation modelling.

METHODS

An existing agent-based model to simulate MRSA transmission dynamics in an ICU was modified, and the model was calibrated using site-specific data. Model validation was completed using data collected in the BUGG study. A full 2^k factorial design was conducted to quantify the relative benefits of improving each of the aforementioned factors with respect to MRSA acquisition rates.

FINDINGS

Across 40 simulated replications for each factorial design point and intervention site, approximately 44% of the decrease in MRSA acquisition rates was due to universal glove and gown use, 38.1% of the decrease was due to improvement in hand hygiene compliance on exiting patient rooms, and 14.5% of the decrease was due to the reduction in HCW-patient contact rates.

CONCLUSION

Using mathematical modelling, the decrease in MRSA acquisition in the BUGG study was found to be due primarily to the barrier effects of gowns and gloves, followed by improved hand hygiene and lower HCW-patient contact rates.

Ertapenem in outpatient parenteral antimicrobial therapy for complicated urinary tract infections

BACKGROUND

Ertapenem is a broad-spectrum antibiotic that is increasingly being utilized. Its dosing convenience renders it suitable for outpatient therapy, and its pharmacokinetic characteristics favour its use against complicated urinary tract infections (cUTIs). Despite this, sufficient clinical data are lacking for its use against cUTIs in the outpatient setting. We assessed the microbiological and clinical cure rates associated with ertapenem treatment for cUTIs in two outpatient parenteral antimicrobial therapy (OPAT) departments.

METHODS

We undertook a prospective observational study of adult patients who received ertapenem for cUTIs between August 2010 and August 2014. Data on patient characteristics, clinical progress and microbiological results were collected and analysed.

RESULTS

Sixty-one patients were enrolled. The median age was 59 years (range 24, 83) and 61% were male. The most common diagnoses were pyelonephritis (39%) and prostatitis (15%). The most common causative organism was Escherichia coli (67%). Extended-spectrum β-lactamase (ESBL)-producing organisms were detected in 72% of infections. Microbiological cure was achieved in 67% overall, and was less likely in those with Klebsiella pneumoniae infection (OR = 0.21 [95%CI: 0.05 to 0.85] p = 0.029). Clinical cure was observed in 92% of patients.

CONCLUSION

In this study of treating cUTIs with ertapenem, we have demonstrated good clinical outcomes. A lower than expected microbiological cure rate was observed in those with Klebsiella pneumoniae infection.