Outbreak of pulmonary Pseudomonas aeruginosa and Stenotrophomonas maltophilia infections related to contaminated bronchoscope suction valves, Lyon, France, 2014

Upraising Stenotrophomonas maltophilia in Critically Ill Patients: A New Enemy?

Stenotrophomonas maltophilia (S. maltophilia), an important pathogen in immuno-compromised patients, has recently gained attention in patients admitted in intensive care units (ICU). We sought to investigate clinical features of infections caused by S. maltophilia in ICU patients and identify risk factors for mortality. We conducted a retrospective study in two multivalent non-COVID-19 ICUs of tertiary-teaching hospitals in Greece and Spain, including patients with isolated S. maltophilia from at least one clinical specimen along with clinical signs of infection. A total of 103 patients (66% male) were analyzed. Median age was 65.5 (54–73.3) years and mean APACHE II and SOFA scores upon ICU admission were 18.36 (±7.22) and 18.17 (±6.95), respectively. Pneumonia was the predominant clinical syndrome (72.8%), while 22% of cases were among hemato/oncology patients. Crude 28-day mortality rate was 54.8%, even though, 14-day clinical and microbiological response was 96%. Age, APACHE II on ICU admission, hemato-oncologic disease, and multi-organ failure were initially identified as potential predictors of mortality. In the multivariable analysis, only increasing age and hemato-oncologic disease were shown to be independent risk factors for 28-day mortality. High all-cause mortality was observed in critically ill patients with predominantly respiratory infections by S. maltophilia, despite initial clinical and laboratory response after targeted treatment. The study elucidates a potentially worrisome emerging pathogen in the ICU.

Correlation Between the Number of Fiberoptic Bronchoscopies and Nosocomial Infection/Colonization of Carbapenem-Resistant Enterobacteriaceae

Objective

The present study aims to explore the effects of different numbers of fiberoptic bronchoscopic examinations on the nosocomial infection/colonization of carbapenem-resistant Enterobacteriaceae (CRE).

Methods

The data of 129 patients admitted to the intensive care unit of a grade 3A hospital were retrospectively analyzed, and CRE nosocomial infection/colonization situations in patients with fiberoptic bronchoscope application times of 1, 2, 3, and ≥4 were statistically analyzed.

Results

The incidence of nosocomial infection/colonization of CRE increased significantly when the number of fiberoptic bronchoscopic examinations was ≥3.

Conclusion

Nosocomial infection/colonization of CRE is highly correlated with an increased number of fiberoptic bronchoscopic examinations.

Clinical challenges treating Stenotrophomonas maltophilia infections: an update

Stenotrophomonas maltophilia is a non-fermenting, Gram-negative bacillus that has emerged as an opportunistic nosocomial pathogen. Its intrinsic multidrug resistance makes treating infections caused by S. maltophilia a great clinical challenge. Clinical management is further complicated by its molecular heterogeneity that is reflected in the uneven distribution of antibiotic resistance and virulence determinants among different strains, the shortcomings of available antimicrobial susceptibility tests and the lack of standardized breakpoints for the handful of antibiotics with in vitro activity against this microorganism. Herein, we provide an update on the most recent literature concerning these issues, emphasizing the impact they have on clinical management of S. maltophilia infections.

Comparative Genomic Analysis and Phenotypic Characterization of Bronchoscope-Associated Klebsiella aerogenes

Bronchoscopes have been linked to outbreaks of nosocomial infections. The phenotypic and genomic profiles of bronchoscope-associated Klebsiella aerogenes isolates are largely unknown. In this work, a total of 358 isolates and 13 isolates were recovered from samples after clinical procedures and samples after decontamination procedures, respectively, over the five months. Antimicrobial susceptibility testing found seven K. aerogenes isolates exhibiting a low-level resistance to antimicrobial agents. Among seven K. aerogenes isolates, we found five sequence types (STs) clustered into three main clades. Collectively, this study described for the first time the phenotypic and genomic characteristics of bronchoscope-associated K. aerogenes.

A pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, United Kingdom

Outbreaks of fungal infections due to emerging and rare species are increasingly reported in healthcare settings. We investigated a pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, UK. We aimed to determine route of healthcare-associated transmission and prevent additional infections. From July 2018 through February 2019, we detected a pseudo-outbreak of R. similis isolated from bronchoalveolar lavage (BAL) fluid samples collected from nine patients who had undergone bronchoscopy in a multispecialty teaching hospital, during a period of 8 months. Isolates were identified by MALDI-TOF mass spectrometry. Antifungal susceptibility testing was performed by EUCAST broth microdilution. To determine genetic relatedness among R. similis isolates, we undertook amplified fragment length polymorphism analysis. To determine the potential source of contamination, an epidemiological investigation was carried out. We reviewed patient records retrospectively and audited steps taken during bronchoscopy as well as the subsequent cleaning and decontamination procedures. Fungal cultures were performed on samples collected from bronchoscopes and automated endoscope washer-disinfector systems. No patient was found to have an infection due to R. similis either before or after bronchoscopy. One bronchoscope was identified to be used among all affected patients with positive fungal cultures. Physical damage was found in the index bronchoscope; however, no fungus was recovered after sampling of the affected scope or the rinse water of automated endoscope washer-disinfectors. Use of the scope was halted, and, during the following 12-month period, Rhinocladiella species were not isolated from any BAL specimen. All pseudo-outbreak isolates were identified as R. similis with high genetic relatedness (>90% similarity) on ALFP analysis. The study emphasises the emergence of a rare and uncommon black yeast R. similis, with reduced susceptibility to echinocandins, in a bronchoscope-related pseudo-outbreak with a potential water-related reservoir. Our findings highlight the importance of prolonged fungal culture and species-level identification of melanised yeasts isolated from bronchoscopy samples. Possibility of healthcare-associated transmission should be considered when R. similis is involved in clinical microbiology samples.

Stenotrophomonas maltophilia: An Emerging Pathogen of the Respiratory Tract

Patient: Female, 70-year-old

Final Diagnosis:Stenotrophomonas maltophilia

Symptoms: Difficult to breath, patient could not wean from oxygen/premature

Medication: —

Clinical Procedure: —

Specialty: General and Internal Medicine

Challenges in achieving effective high-level disinfection in endoscope reprocessing

Endoscope reprocessing is often ineffective, and microbes frequently remain on endoscopes after the use of high-level disinfectants (HLDs). Several factors impact reprocessing effectiveness, including non-adherence to guidelines, use of damaged endoscopes, use of insoluble products during endoscopy, insufficient cleaning, contaminated rinse water, and inadequate drying before storage. Our team suspected that issues with HLD chemistries and monitoring could also contribute to reprocessing failures. We conducted a mixed-methods analysis of published literature, our interviews with frontline personnel, and evidence from our previous studies. The evidence showed that reusable HLDs commonly failed tests for minimum effective concentration (MEC) before their maximum usage periods. MEC tests also detected failures associated with single-use HLDs that did not fully deploy. These failures were due to product issues, process complexities, and personnel non-adherence with guidelines and manufacturer instructions. HLDs will likely continue to be used for the foreseeable future. More research is needed to assess real-world practice patterns related to the high-level disinfection step and MEC testing and to establish more realistic usage periods for reusable HLD chemistries. Manufacturers and researchers should evaluate the ability of technological solutions and engineered safeguards to overcome human error. Recognition of the need for quality improvement is growing, and infection preventionists should take action to build on this momentum and collaborate with manufacturers, endoscopists, and reprocessing personnel to improve the effectiveness of high-level disinfection.

An outbreak of Pseudomonas aeruginosa urinary tract infections following outpatient flexible cystoscopy

The investigation of an outbreak of Pseudomonas aeruginosa urinary tract infections after ambulatory cystoscopies identified a damaged cystoscope contaminated by P aeruginosa and acting as a relay object. This outbreak urges us not to trivialize urinary tract infections occurring after an elective cystoscopy. Patients should be advised to signal the occurrence of urologic symptoms after urologic exploration.

A systematic review and cost effectiveness analysis of reusable vs. single-use flexible bronchoscopes

The cost effectiveness of reusable vs. single‐use flexible bronchoscopy in the peri‐operative setting has yet to be determined. We therefore aimed to determine this and hypothesised that single‐use flexible bronchoscopes are cost effective compared with reusable flexible bronchoscopes. We conducted a systematic review of the literature, seeking all reports of cross‐contamination or infection following reusable bronchoscope use in any clinical setting. We calculated the incidence of these outcomes and then determined the cost per patient of treating clinical consequences of bronchoscope‐induced infection. We also performed a micro‐costing analysis to quantify the economics of reusable flexible bronchoscopes in the peri‐operative setting from a high‐throughput tertiary centre. This produced an accurate estimate of the cost per use of reusable flexible bronchoscopes. We then performed a cost effectiveness analysis, combining the data obtained from the systematic review and micro‐costing analysis. We included 16 studies, with a reported incidence of cross‐contamination or infection of 2.8%. In the micro‐costing analysis, the total cost per use of a reusable flexible bronchoscope was calculated to be £249 sterling. The cost per use of a single‐use flexible bronchoscope was £220 sterling. The cost effectiveness analysis demonstrated that reusable flexible bronchoscopes have a cost per patient use of £511 sterling due to the costs of treatment of infection. The findings from this study suggest benefits from the use of single‐use flexible bronchoscopes in terms of cost effectiveness, cross‐contamination and resource utilisation.

Comparative In Vivo Antibacterial Activity of Human-Simulated Exposures of Cefiderocol and Ceftazidime against Stenotrophomonas maltophilia in the Murine Thigh Model

Cefiderocol is a novel siderophore cephalosporin that utilizes bacterial ferric iron transports to cross the outer membrane. Cefiderocol shows high stability against all classes of β-lactamases, rendering it extremely potent against carbapenem- and multidrug-resistant Gram-negative organisms. Using a neutropenic murine thigh model, we compared the efficacies of human-simulated exposures of cefiderocol (2 g Q8H 3 h infusion) and ceftazidime (2 g Q8H 2 h infusion) against Stenotrophomonas maltophilia, an emerging opportunistic Gram-negative organism associated with serious and often fatal nosocomial infections. Twenty-four S. maltophilia isolates were studied, including isolates resistant to ceftazidime, trimethoprim-sulfate, and/or levofloxacin. The thighs were inoculated with bacterial suspensions of 10⁸ CFU/mL and the human-simulated regimens were administered over 24 h. Efficacy was measured as the change in log₁₀CFU/thigh at 24 h compared with 0 h controls. Cefiderocol human-simulated exposure demonstrated potent bacterial killing; mean bacterial reduction at 24 h was -2.67 ± 0.68 log₁₀CFU/thigh with ≥ 2 log-reduction achieved in 21 isolates (87.5%) and ≥ 1 log-reduction achieved in the remaining three isolates (12.5%). In comparison, ceftazidime human-simulated exposure produced mean bacterial reduction of -1.38 ± 1.49 log₁₀CFU/thigh among 10 ceftazidime-susceptible isolates and mean bacterial growth of 0.64 ± 0.79 log₁₀CFU/thigh among 14 ceftazidime-non-susceptible isolates. While ceftazidime showed modest efficacy against most susceptible isolates, humanized cefiderocol exposures resulted in remarkable in vivo activity against all S. maltophilia isolates examined, inclusive of ceftazidime-non-susceptible isolates. The potent in vitro and in vivo activity of cefiderocol supports the development of this novel compound for managing S. maltophilia infections.

A Systematic Review of Disposable Sheath Use During Flexible Endoscopy

Flexible endoscopes are exposed to blood, mucus, and other secretions during procedures. Single-use sheaths are designed to prevent contact between contaminants and reusable endoscope components. This systematic review examined findings from 22 studies that assessed endoscopic sheath use during urologic, gastrointestinal, or respiratory procedures. The evidence showed that sheaths were durable and yielded faster endoscope turnover times because their reusable components did not require high-level disinfection or sterilization. After a brief learning period, health care providers successfully assembled and maneuvered sheathed endoscopes. Patients generally did not experience greater discomfort during procedures in which sheaths were used. Microbial cultures of sheathed endoscopes were negative or similar to unsheathed endoscopes. More research is needed to evaluate the potential effect of disposable sheaths on infection risks. The evidence suggests that sheaths are a viable option for reliably providing a barrier between endoscopes and patients without affecting the quality of endoscopic procedures.

The use of bronchoscopy in critically ill patients: considerations and complications

INTRODUCTION

Flexible bronchoscopy has been well established for diagnostic and therapeutic purposes in critically ill patients. Areas covered: This review outlines the clinical evidence of the utility and safety of flexible bronchoscopy in the intensive care unit, as well as specific considerations, including practical points and potential complications, in critically ill patients. Expert commentary: Its ease to learn and perform and its capacity for bedside application with relatively few complications make flexible bronchoscopy an indispensable tool in the intensive care unit setting. The main indications for flexible bronchoscopy in the intensive care unit are the visualization of the airways, sampling for diagnostic purposes and management of the artificial airways. The decision to perform flexible bronchoscopy can only be made by trade-offs between potential risks and benefits because of the fragile nature of the critically ill. Flexible bronchoscopy-associated serious adverse events are inevitable in cases of a lack of expertise or appropriate precautions.

Residual moisture and waterborne pathogens inside flexible endoscopes: Evidence from a multisite study of endoscope drying effectiveness

BACKGROUND

Endoscopy-associated infection transmission is frequently linked to inadequate reprocessing. Residual organic material and moisture may foster biofilm development inside endoscopes. This study evaluated the effectiveness of endoscope drying and storage methods and assessed associations between retained moisture and contamination.

METHODS

Endoscope reprocessing, drying, and storage practices were assessed at 3 hospitals. Researchers performed visual examinations and tests to detect fluid and contamination on patient-ready endoscopes.

RESULTS

Fluid was detected in 22 of 45 (49%) endoscopes. Prevalence of moisture varied significantly by site (5%; 83%; 85%; P < .001). High adenosine triphosphate levels were found in 22% of endoscopes, and microbial growth was detected in 71% of endoscopes. Stenotrophomonas maltophilia, Citrobacter freundii, and Lecanicillium lecanii/Verticillium dahliae were found. Retained fluid was associated with significantly higher adenosine triphosphate levels (P < .01). Reprocessing and drying practices conformed with guidelines at 1 site and were substandard at 2 sites. Damaged endoscopes were in use at all sites.

CONCLUSIONS

Inadequate reprocessing and insufficient drying contributed to retained fluid and contamination found during this multisite study. More effective methods of endoscope reprocessing, drying, and maintenance are needed to prevent the retention of fluid, organic material, and bioburden that could cause patient illness or injury.

What Healthcare Workers Should Know about Environmental Bacterial Contamination in the Intensive Care Unit

Intensive care unit- (ICU-) acquired infections are a major health problem worldwide. Inanimate surfaces and equipment contamination may play a role in cross-transmission of pathogens and subsequent patient colonization or infection. Bacteria contaminate inanimate surfaces and equipment of the patient zone and healthcare area, generating a reservoir of potential pathogens, including multidrug resistant species. Traditional terminal cleaning methods have limitations. Indeed patients who receive a bed from prior patient carrying bacteria are exposed to an increased risk (odds ratio 2.13, 95% confidence intervals 1.62-2.81) of being colonized and potentially infected by the same bacterial species of the previous patient. Biofilm formation, even on dry surfaces, may play a role in reducing the efficacy of terminal cleaning procedures since it enables bacteria to survive in the environment for a long period and provides increased resistance to commonly used disinfectants. No-touch methods (e.g., UV-light, hydrogen peroxide vapour) are under investigation and further studies with patient-centred outcomes are needed, before considering them the standard of terminal cleaning in ICUs. Healthcare workers should be aware of the role of environmental contamination in the ICU and consider it in the broader perspective of infection control measures and stewardship initiatives.