Multidrug-resistant Acinetobacter baumannii outbreak: an investigation of the possible routes of transmission

Stenotrophomonas maltophilia Outbreak in an ICU: Investigation of Possible Routes of Transmission and Implementation of Infection Control Measures

Stenotrophomonas maltophilia, a non-fermentative, ubiquitous, gram-negative aerobic bacterium, is associated with high mortality rates, particularly in immunocompromised or debilitated patients. The prevalence rate of ICU-acquired pneumonia episodes caused by this microorganism has been found to be 2%. S. maltophilia has been identified as one of the top 10 microorganisms responsible for such infections in EU/EEA countries. This study describes an outbreak of S. maltophilia in an intensive care unit of a hospital in northern Italy. This includes an epidemiological investigation of the cases, the environmental microbiological controls carried out, a comparison of the strains by multilocus sequence typing (MLST), and the measures taken to prevent and control the outbreak. Among the seven clinical isolates of S. maltophilia analyzed herein, six demonstrated susceptibilities to trimethoprim-sulfamethoxazole. Conversely, one isolate of S. maltophilia exhibited resistance to first-line antibiotics. ST was found to be identical for six patients (ST 4), as well as in the environmental feedback on the trolley of Box 2. The analysis of the temporal and spatial progression of the outbreak has suggested that the transmission of S. maltophilia may have occurred through cross-transmission during care practices.

Bacterial Infections: Surveillance, Prevention and Control

Bacteria play a vital role in maintaining human health, but they may also be responsible for many different serious infections and diseases [...].

Microbiological surveillance post-reprocessing of flexible endoscopes used in digestive endoscopy: a national study

INTRODUCTION

Microbiological surveillance of endoscopes is a safety measure for verifying the quality of reprocessing procedures and identifying contaminated devices, but duodenoscope-related outbreaks are still reported.

AIM

To assess the effectiveness of duodenoscope reprocessing procedures in Italy.

METHODS

Between December 2019 and April 2020, data obtained from microbiological surveillance post-reprocessing in 15 Italian endoscopy units were collected. Sampling was carried out after reprocessing or during storage in a cabinet. In keeping with international guidelines and the Italian position paper, the micro-organisms were classified as high-concern organisms (HCOs) and low-concern organisms (LCOs).

FINDINGS

In total, 144 samples were collected from 51 duodenoscopes. Of these, 36.81% were contaminated: 22.92% were contaminated with HCOs and 13.89% were contaminated with LCOs [2.08% with an LCO load of 11-100 colony-forming units (CFU)/device and 0.69% with an LCO load of >100 CFU/device]. The contamination rate was 27.5% in samples collected after reprocessing, 40% in samples collected during storage in a cabinet that was compliant with EN 16442:2015 (C-I), and 100% in samples collected during storage in a cabinet that was not compliant with EN 16442:2015 (NC-I). The respective HCO rates were 15.00%, 27.27% and 66.67%. Correlation between LCO contamination and storage time was demonstrated (Spearman's rho=0.3701; P=0.0026). The Olympus duodenoscope TJFQ180V demonstrated the lowest rate of contamination (29.82%), although the contamination rate was 100% for duodenoscopes stored in an NC-I cabinet.

CONCLUSION

Microbiological surveillance, along with strict adherence to reprocessing protocols, may help to detect endoscope contamination at an early stage, and reduce the risk of duodenoscope-associated infections.

The management of healthcare-related infections through lean methodology: systematic review and meta-analysis of observational studies

INTRODUCTION

Lean is largely applied to the health sector and on the healthcare-associated infections (HAI). However, a few results on the improvement of the outcome have been reported in literature. The purpose of this study is to analyze if the lean application can reduce the HAI rate.

METHODS

A comprehensive search was performed on PubMed/Medline, Scopus, CINAHL, Cochrane, Embase, and Google Scholar databases using various combinations of the following keywords: "lean" and "infection". Inclusion criteria were: 1) research articles with quantitative data and relevant information on lean methodology and its impact on healthcare infections; 2) prospective studies. The risk of bias and the study quality was independently assessed by two researchers using the "The National Institutes of Health (NIH) quality assessment tool for before-after (Pre-Post) study with no control group". The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines has been used. 22 studies were included in the present meta-analysis.

RESULTS

Lean application demonstrated a significant protective role on healthcare-associated infections rate (RR 0.50; 95% C.I.: 0.38-0.66) with significant impact on central line-associated bloodstream infections (CLABSIs) (RR 0.47; 95% C.I.: 0.28-0.82).

CONCLUSIONS

Lean has a positive impact on the decreasing of HAIs and on the improvement of compliance and satisfaction of the staff.

Epidemiology and Prevention of Healthcare-Associated Infections in Geriatric Patients: A Narrative Review

Demographic studies show that life expectancy is increasing in developed countries; increased longevity has also increased the share of the older population with often concomitant chronic conditions. An ageing population and increased comorbidities lead to more complex pharmacological therapies (polypharmacy). The particular picture provided by chronic conditions and polypharmacy can lead to longer hospital stays and a greater need for healthcare. Elderly patients are identified as being in the high-risk group for the development of healthcare-associated infections (HAIs) due to the age-related decline of the immune system, known as immunosenescence. Comorbid conditions can often complicate infections, diminishing our ability to treat them effectively. Respiratory tract infections are the most common healthcare-associated infections, followed by urinary tract infections. HAIs in geriatric patients are responsible for longer hospital stays, extended antibiotic therapy, significant mortality, and higher healthcare costs. This is because the microorganisms involved are multidrug-resistant and, therefore, more difficult to eliminate. Moreover, geriatric patients are frequently transferred from one facility (nursing homes, skilled nursing facilities, home care, and other specialty clinics) to another or from one hospital ward to another; these transitions cause care fragmentation, which can undermine the effectiveness of treatment and allow pathogens to be transferred from one setting to another and from one person to another. Multifactorial efforts such as early recognition of infections, restricted use of invasive devices, and effective infection control measures (surveillance, isolation practices, hand hygiene, etc.) can contribute to significant reduction of HAIs in geriatric patients.

The Great ESKAPE: Exploring the Crossroads of Bile and Antibiotic Resistance in Bacterial Pathogens

Throughout the course of infection, many pathogens encounter bactericidal conditions that threaten the viability of the bacteria and impede the establishment of infection. Bile is one of the most innately bactericidal compounds present in humans, functioning to reduce the bacterial burden in the gastrointestinal tract while also aiding in digestion. It is becoming increasingly apparent that pathogens successfully resist the bactericidal conditions of bile, including bacteria that do not normally cause gastrointestinal infections. This review highlights the ability of Enterococcus, Staphylococcus, Klebsiella, Acinetobacter, Pseudomonas, Enterobacter (ESKAPE), and other enteric pathogens to resist bile and how these interactions can impact the sensitivity of bacteria to various antimicrobial agents. Given that pathogen exposure to bile is an essential component to gastrointestinal transit that cannot be avoided, understanding how bile resistance mechanisms align with antimicrobial resistance is vital to our ability to develop new, successful therapeutics in an age of widespread and increasing antimicrobial resistance.

Is Post-Reprocessing Microbiological Surveillance of Duodenoscopes Effective in Reducing the Potential Risk in Transmitting Pathogens?

Background: The use of a contaminated endoscope may lead to infections due to the transmission of potential pathogens from patient to patient. Methods: Post-reprocessing microbiological surveillance of four duodenoscopes was carried out over a three-year period in the Digestive Endoscopy Unit of an Italian hospital. Sampling of duodenoscopes was performed after the devices have been reprocessed. The initial phase of surveillance involved the contemporary evaluation of the four duodenoscopes; afterwards, microbiological surveillance proceeded at monthly intervals. Results: The initial phase of surveillance revealed that three duodenoscopes presented a high level of contamination with “high-concern” micro-organisms, some of which were multi-drug-resistant. The highest values of contamination regarded the species P. aeruginosa (2500 CFU/duodenoscope), K. pneumoniae (2580 CFU/duodenoscope), and A. baumannii (2600 CFU/duodenoscope). Since the cultures were repeatedly positive on three successive occasions, the contaminated devices were sent to the manufacturer for evaluation. Audits were carried out with the personnel responsible for reprocessing, which was aimed to optimize the procedures used, and subsequently, only one case of non-conformity was found. Conclusions: Our study highlighted both the potential risk of transmitting pathogens through the use of duodenoscopes and the importance of implementing a well-structured system of microbiological surveillance and training programs, in order to reduce the risk of spreading retrograde cholangiopancreatography (ERCP)-associated infections.

Effect of chlorhexidine bathing on colonization or infection with Acinetobacter baumannii: a systematic review and meta-analysis

Healthcare-associated infections (HAIs) caused by multi-drug-resistant Gram-negative bacteria (MDRGNB) have increased prevalence in intensive care units (ICUs). A common strategy to prevent HAIs is bathing patients with chlorhexidine gluconate (CHG). However, the effectiveness of CHG bathing against multidrug-resistant Acinetobacter baumannii (MDRAB) is still controversial. The aim of this study was to perform a systematic review and meta-analysis of the effectiveness of CHG bathing on Acinetobacter baumannii colonization and infection in the ICU setting. A systematic literature search of PubMed, EMBASE, Web of Science and CINAHL was performed from inception through to June 2018. Randomized controlled trials (RCTs), pre-post studies, or interrupted time series (ITS) studies were included. The numbers of patients with/without colonization or infection of A. baumannii in the experimental or control groups were extracted from each study. Quality assessment was performed by the related instruments of National Institute of Health. Pooled risk ratios (RRs) were calculated using the random-effects model. One RCT and 12 pre-post or ITS studies comprising 18,217 patients were included, of which 8069 were in the CHG bathing arm and 9051 in the control arm. CHG bathing was associated with a reduced colonization of A. baumannii (RR, 0.66; 95% confidence interval: 0.57-0.77; P<0.001). Chlorhexidine at 4% showed a better effect than 2% chlorhexidine (meta-regression P=0.044). CHG bathing was associated with a non-significant reduction of infection (pooled RR 0.41, 95% CI: 0.13-1.25). This study suggests that CHG bathing significantly reduces colonization of A. baumannii in the ICU setting. However, more trials are needed to confirm whether CHG bathing can reduce infections with A. baumannii.

Asymmetric transfer efficiencies between fomites and fingers: Impact on model parameterization

BACKGROUND

Healthcare-associated infections (HAIs) affect millions of patients every year. Pathogen transmission via fomites and healthcare workers (HCWs) contribute to the persistence of HAIs in hospitals. A critical parameter needed to assess risk of environmental transmission is the pathogen transfer efficiency between fomites and fingers. Recent studies have shown that pathogen transfer is not symmetric. In this study,we evaluated how the commonly used assumption of symmetry in transfer efficiency changes the dynamics of pathogen movement between patients and rooms and the exposures to uncolonized patients.

METHODS

We developed and analyzed a deterministic compartmental model of Acinetobacter baumannii describing the contact-mediated process among HCWs, patients, and the environment. We compared a system using measured asymmetrical transfer efficiency to 2 symmetrical transfer efficiency systems.

RESULTS

Symmetric models consistently overestimated contamination levels on fomites and underestimated contamination on patients and HCWs compared to the asymmetrical model. The magnitudes of these miscalculations can exceed 100%. Regardless of the model, relative percent reductions in contamination declined after hand hygiene compliance reached approximately 60% in the large fomite scenario and 70% in the small fomite scenario.

CONCLUSIONS

This study demonstrates how healthcare facility-specific data can be used for decision-making processes. We show that the incorrect use of transfer efficiency data leads to biased effectiveness estimates for intervention strategies. More accurate exposure models are needed for more informed infection prevention strategies.

Draft Genome Sequences of Two Carbapenemase-Producing Acinetobacter baumannii Clinical Strains Isolated from Albanian and Togolese Patients

We report here the draft genome sequences of two multidrug-resistant Acinetobacter baumannii clinical strains, H31499 and H31506, which were isolated at the Lausanne University Hospital in 2015 from an Albanian and a Togolese patient, respectively.

Is airborne transmission of Acinetobacter baumannii possible: A prospective molecular epidemiologic study in a tertiary care hospital

BACKGROUND

Understanding the dynamics of aerial spread of Acinetobacter may provide useful information for production of effective control measurements. We investigated genetic relationships between air and clinical isolates of Acinetobacter baumannii in an intensive care unit (ICU) setting.

METHODS

We conducted a prospective surveillance study in a tertiary care hospital for 8 months. A total of 186 air samples were taken from 2 ICUs. Clonal characteristics of air isolates were compared with the prospective clinical strains and the previously isolated strains of ICU patients over a 23-month period.

RESULTS

Twenty-six (11.4%) air samples yielded A baumannii, of which 24 (92.3%) isolates were carbapenem-resistant. The Acinetobacter concentration was the highest in bedside sampling areas of infected patients (0.39 CFU/m³). Air isolates were clustered in 13 genotypes, and 7 genotypes (including 18 air strains) were clonally related to the clinical strains of 9 ICU patients. One clone continued to be cultured over 27 days in ICU air, and air isolates could be clonally related to 7-week retrospective and approximately 15-week prospective clinical strains.

CONCLUSIONS

The results of this study suggest that infected patients could spread significant amounts of Acinetobacter to ICU air. These strains could survive in air for some weeks and could likely still infect new patients after some months. Special control measurements may be required against the airborne spread of Acinetobacter in ICUs.

The impact of aerators on water contamination by emerging gram-negative opportunists in at-risk hospital departments

OBJECTIVE

Our aim was to evaluate the impact of aerators on water microbiological contamination in at-risk hospital departments, with a view to quantifying the possible risk of patient exposure to waterborne microorganisms.

DESIGN

We analyzed the microbiological and chemical-physical characteristics of hot and cold water in some critical hospital departments.

SETTING

Two hospitals in northern Italy.

METHODS

We took 304 water samples over a 1-year period, at 3-month intervals, from taps used by healthcare personnel for handwashing, surgical washing, and the washing of medical equipment. We analyzed heterotrophic plate counts (HPCs) at 36°C and 22°C, nonfastidious gram-negative bacteria (GNB-NE), and Legionella pneumophila.

RESULTS

The percentages of positivity and mean values of HPCs at 22°C, HPCs at 36°C, and GNB-NE loads were significantly higher at outlet points than in the plumbing system. In particular, GNB-NE positivity was higher at outlet points than in the plumbing system in both the cold water (31.58% vs 6.58% of samples were positive) and hot water (21.05% vs 3.95%) supplies. Our results also revealed contamination by L. pneumophila both in the plumbing system and at outlet points, with percentages of positive samples varying according to the serogroup examined (serogroups 1 and 2-14). The mean concentrations displayed statistically significant (P < .001) differences between the outlet points (27,382.89 ± 42,245.33 colony-forming units [cfu]/L) and the plumbing system (19,461.84 ± 29,982.11 cfu/L).

CONCLUSIONS

These results reveal a high level of contamination of aerators by various species of gram-negative opportunists that are potentially very dangerous for immunocompromised patients and, therefore, the need to improve the management of these devices.

Novel 3-arylfuran-2(5H)-one-fluoroquinolone hybrid: design, synthesis and evaluation as antibacterial agent

3-Arylfuran-2(5H)-one, a novel antibacterial pharmacophore targeting tyrosyl-tRNA synthetase (TyrRS), was hybridized with the clinically used fluoroquinolones to give a series of novel multi-target antimicrobial agents. Thus, twenty seven 3-arylfuran-2(5H)-one-fluoroquinolone hybrids were synthesized and evaluated for their antimicrobial activities. Some of the hybrids exhibited merits from both parents, displaying a broad spectrum of activity against resistant strains including both Gram-negative and Gram-positive bacteria. The most potent compound (11) in antibacterial assay shows MIC50 of 0.11μg/mL against Multiple drug resistant Escherichia coli, being about 51-fold more potent than ciprofloxacin. The enzyme assays reveal that 11 is a potent multi-target inhibitor with IC50 of 1.15±0.07μM against DNA gyrase and 0.12±0.04μM against TyrRS, respectively. Its excellent inhibitory activities against isolated enzymes and intact cells strongly suggest that 11 deserves to further research as a novel antibiotic.