A search strategy for detecting duodenoscope-associated infections: a retrospective observational study.

BACKGROUND: Duodenoscope-associated infections (DAIs) are exogenous infections resulting from the use of contaminated duodenoscopes. Though numerous outbreaks of DAI have involved multidrug-resistant micro-organisms (MDROs), outbreaks involving non-MDROs are also likely to occur. Detection challenges arise as these infections often resolve before culture or because causative strains are not retained for comparison with duodenoscope strains. AIM: To identify and analyse DAIs spanning a seven-year period in a tertiary care medical centre. METHODS: This was a retrospective observational study. Duodenoscope cultures positive for gastrointestinal flora between March 2015 and September 2022 were paired with duodenoscope usage data to identify patients exposed to contaminated duodenoscopes. Analysis encompassed patients treated after a positive duodenoscope culture and those treated within the interval from a negative to a positive culture. Patient identification numbers were cross-referenced with a clinical culture database to identify patients developing infections with matching micro-organisms within one year of their procedure. A 'pair' was established upon a species-level match between duodenoscope and patient cultures. Pairs were further analysed via antibiogram comparison, and by whole-genome sequencing (WGS) to determine genetic relatedness. FINDINGS: Sixty-eight pairs were identified; of these, 21 exhibited matching antibiograms which underwent WGS, uncovering two genetically closely related pairs categorized as DAIs. Infection onset occurred up to two months post procedure. Both causative agents were non-MDROs. CONCLUSION: This study provides crucial insights into DAIs caused by non-MDROs and it highlights the challenge of DAI recognition in daily practice. Importantly, the delayed manifestation of the described DAIs suggests a current underestimation of DAI risk.

Proposal for a screening protocol for Candida auris colonization.

BACKGROUND: Candida auris is an emerging multidrug-resistant yeast which can cause severe infection in hospitalized patients. Since its first detection in 2009, C. auris has spread globally. The control and elimination of this pathogen in a hospital setting is particularly challenging because of its ability to form biofilms, allowing for long-term patient colonization and persistence in the environment. Identification of C. auris from cultures is difficult due to the morphologic similarities to other yeasts, its slow growth, and the low culture sensitivity when using standard agars and temperatures. AIM: We have developed a screening protocol for C. auris colonization using an in-house-developed polymerase chain reaction (PCR), combined with confirmatory culture in optimized conditions. METHODS: C. auris-specific primers and probe were developed, targeting the internal transcribed spacer (ITS) region, and specificity was confirmed in silico using the BLAST tool. The PCR was validated using a panel of 12 C. auris isolates and 103 isolates from 22 other Candida species and was shown to be 100% accurate. The limit of detection of the assay was determined at approximately four cells per PCR. FINDINGS: C. auris screening was introduced on February 15th, 2023, and was used for patients who had been admitted to a healthcare facility abroad in the two months prior to admission to our hospital. The screening protocol included swabs from nose, throat, rectum, axilla, and groin. In the first eight months, 199 patients were screened and seven were found positive (4%). CONCLUSION: Our proposed screening protocol may contribute to control C. auris in hospitals.

Vermamoeba vermiformis resides in water-based heater-cooler units and can enhance Mycobacterium chimaera survival after chlorine exposure.

BACKGROUND: Mycobacterium chimaera colonizes water-based heater-cooler units (HCUs), from which it can spread to patients during surgery. Vermamoeba vermiformis is a free-living waterborne amoeba, which was consistently present within HCUs. AIM: To determine whether these amoebae can be involved in the persistent presence of M. chimaera. METHODS: An in-vitro disinfection model. FINDINGS: Increased survival of M. chimaera was observed after chlorine exposure in the presence of V. vermiformis. Confocal microscopy demonstrated the intracellular presence of M. chimaera in V. vermiformis. CONCLUSION: In this way, V. vermiformis can contribute to the persistent presence of M. chimaera in HCUs. Cleaning and disinfection protocols should take this phenomenon into account.

Impact of sink design on bacterial transmission from hospital sink drains to the surrounding sink environment tested using a fluorescent marker.

In hospitals, sinks act as reservoirs for bacterial pathogens. To assess the extent of splashing, fluorescein dye was added to four hospital sinks previously involved in pathogen dispersal to the environment and/or transmission to patients, and one sink that was not. Applying dye to the p-trap or tailpiece did not result in any fluorescent droplets outside of the drain. When applied to the drain, droplets were found in all but one wash basin, and this was more common in the absence of a drain plug. Sink design considerations to install drain plugs, reduce dripping and offset the tap may help to prevent transmission from drains.

Use of a smartphone app to inform healthcare workers of hospital policy during a pandemic such as COVID-19: A mixed methods observational study.

OBJECTIVE: To evaluate the use of a COVID-19 app containing relevant information for healthcare workers (HCWs) in hospitals and to determine user experience. METHODS: A smartphone app (Firstline) was adapted to exclusively contain local COVID-19 policy documents and treatment protocols. This COVID-19 app was offered to all HCWs of a 900-bed tertiary care hospital. App use was evaluated with user analytics and user experience in an online questionnaire. RESULTS: A total number of 1168 HCWs subscribed to the COVID-19 app which was used 3903 times with an average of 1 minute and 20 seconds per session during a three-month period. The number of active users peaked in April 2020 with 1017 users. Users included medical specialists (22.3%), residents (16.5%), nurses (22.2%), management (6.2%) and other (26.5%). Information for HCWs such as when to test for SARS-CoV-2 (1214), latest updates (1181), the COVID-19 telephone list (418) and the SARS-CoV-2 / COVID-19 guideline (280) were the most frequently accessed advice. Seventy-one users with a mean age of 46.1 years from 19 different departments completed the questionnaire. Respondents considered the COVID-19 app clear (54/59; 92%), easy-to-use (46/55; 84%), fast (46/52; 88%), useful (52/56; 93%), and had faith in the information (58/70; 83%). The COVID-19 app was used to quickly look up something (43/68; 63%), when no computer was available (15/68; 22%), look up / dial COVID-related phone numbers (15/68; 22%) or when walking from A to B (11/68; 16%). Few respondents felt app use cost time (5/68; 7%). CONCLUSIONS: Our COVID-19 app proved to be a relatively simple yet innovative tool that was used by HCWs from all disciplines involved in taking care of COVID-19 patients. The up-to-date app was used for different topics and had high user satisfaction amongst questionnaire respondents. An app with local hospital policy could be an invaluable tool during a pandemic.

The daily direct costs of isolating patients identified with highly resistant micro-organisms in a non-outbreak setting.

BACKGROUND: Isolation precautions are recommended when caring for patients identified with highly resistant micro-organisms (HRMOs). However, the direct costs of patients in isolation are largely unknown. AIM: To obtain detailed information on the daily direct costs associated with isolating patients identified with HRMOs. METHODS: This study was performed from November until December 2017 on a 12-bed surgical ward. This ward contained solely isolation rooms with anterooms. The daily direct costs of isolation were based on three cost items: (1) additional personal protective equipment (PPE), measured by counting the consumption of empty packaging materials; (2) cleaning and disinfection of the isolation room, based on the costs of an outsourced cleaning company; and (3) additional workload for healthcare workers, based on literature and multiplied by the average gross hourly salary of nurses. A distinction was made between the costs for strict isolation, contact-plus isolation, and contact isolation. FINDINGS: During the study period, 26 patients were nursed in isolation because of HRMO carriage. Time for donning and doffing of PPE was 31 min per day. The average daily direct costs of isolation were the least expensive for contact isolation (gown, gloves), €28/$31, and the most expensive for strict isolation (surgical mask, gloves, gown, cap), €41/$47. CONCLUSION: Using a novel, easy method to estimate consumption of PPE, we conclude that the daily direct costs of isolating a patient differ per type of isolation. Insight into the direct costs of isolation is of utmost importance when developing or updating infection prevention policies.

Acanthamoeba castellanii interferes with adequate chlorine disinfection of multidrug-resistant Pseudomonas aeruginosa.

Verona-Integron-encoded-Metallo-ß-lactamase-positive Pseudomonas aeruginosa (VIM-PA) is a cause of hard-to-treat nosocomial infections, and can colonize hospital water networks alongside Acanthamoeba. We developed an in-vitro disinfection model to examine whether Acanthamoeba castellanii can harbour VIM-PA intracellularly, allowing VIM-PA to evade being killed by currently used hospital disinfectants. We observed that A. castellanii presence resulted in significantly increased survival of VIM-PA after exposure to chlorine for 30 s or for 2 min. This undesirable effect was not observed after disinfection by 70% alcohol or 24% acetic acid. Confocal microscopy confirmed the presence of VIM-PA within A. castellanii pseudocysts. Our data indicate that A. castellanii contributes to persistent VIM-PA colonization of water systems after chlorine treatment.

Good performance of the SpectraCellRA system for typing of methicillin-resistant Staphylococcus aureus isolates.

Typing of methicillin-resistant Staphylococcus aureus (MRSA) remains necessary in order to assess whether transmission of MRSA occurred and to what extent infection prevention measures need to be taken. Raman spectroscopy (SpectraCellRA [SCRA]; RiverD International, Rotterdam, The Netherlands) is a recently developed tool for bacterial typing. In this study, the performance (typeability, discriminatory power, reproducibility, workflow, and costs) of the SCRA system was evaluated for typing of MRSA strains isolated from patients and patients' household members who were infected with or colonized by MRSA. We analyzed a well-documented collection of 113 MRSA strains collected from 54 households. The epidemiological relationship between the MRSA strains within one household was used as the gold standard. Pulsed-field gel electrophoresis (PFGE) was used for discrepancy analysis. The results of SCRA analysis on the strain level corresponded with epidemiological data for 108 of 113 strains, a concordance of 95.6%. When analyzed at the household level, the results of SCRA were correct for 49 out of 54 households, a concordance of 90.7%. Concordance on the strain level with epidemiological data for PFGE was 93.6% (103/110 isolates typed). Concordance on the household level with epidemiological data for PFGE was 93.5% (49/53 households analyzed). With PFGE regarded as the reference standard, the conclusions reached with Raman spectroscopy were identical to those reached with PFGE in 100 of 105 cases (95.2%). The reproducibility of SCRA was found to be 100%. We conclude that the SpectraCellRA system is a fast, easy-to-use, and highly reproducible typing platform for outbreak analysis that can compete with the currently used typing techniques.

Metallo-ß-lactamase-producing Pseudomonas aeruginosa in the Netherlands: the nationwide emergence of a single sequence type.

Recently, the first outbreak of clonally related VIM-2 metallo-ß-lactamase (MBL)-producing Pseudomonas aeruginosa in a Dutch tertiary-care centre was described. Subsequently, a nationwide surveillance study was performed in 2010-2011, which identified the presence of VIM-2 MBL-producing P. aeruginosa in 11 different hospitals. Genotyping by multiple-locus variable-number tandem-repeat analysis (MLVA) showed that the majority of the 82 MBL-producing isolates found belonged to a single MLVA type (n = 70, 85%), identified as ST111 by multilocus sequence typing (MLST). As MBL-producing isolates cause serious infections that are difficult to treat, the presence of clonally related isolates in various hospitals throughout the Netherlands is of nationwide concern.

First outbreak of VIM-2 metallo-ß-lactamase-producing Pseudomonas aeruginosa in The Netherlands: microbiology, epidemiology and clinical outcomes.

This study was designed to investigate the prevalence and characteristics of metallo-ß-lactamase (MBL)-producing Pseudomonas aeruginosa in a tertiary care centre in The Netherlands, a country that is considered to have a low prevalence of antibiotic-resistant bacteria. Imipenem-resistant P. aeruginosa isolates cultured from clinical specimens during 2008-2009 were analysed phenotypically and molecularly by polymerase chain reaction (PCR) with sequencing. Genotyping was performed by multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA). Clinical information was obtained by electronic chart review for all patients infected or colonised with an imipenem-resistant P. aeruginosa isolate that was included in the study. In total, 106 imipenem-resistant P. aeruginosa isolates were included. The bla(VIM-2) gene was detected in 35/106 isolates (33%) and was associated with integrons. Compared with non-MBL-producing imipenem-resistant P. aeruginosa, VIM-2 MBL-producing isolates showed higher rates of multidrug resistance. Patients with VIM-2 MBL-producing isolates were more likely to be admitted to the Intensive Care Unit (ICU) and had a higher risk of invasive infection, including development of bacteraemia. MLVA identified two separate VIM-2 MBL-producing clones, responsible for outbreaks in the ICU but also affecting 10 other departments. This is the first reported outbreak of VIM-2 MBL-producing P. aeruginosa in The Netherlands. Once introduced, VIM-2 MBL-producing P. aeruginosa cause significant infections and are easily spread within the hospital setting.

Nasal carriage of methicillin-resistant and methicillin-sensitive strains of Staphylococcus sciuri in the Indonesian population.

Staphylococcus sciuri strains were unexpectedly cultured from healthy persons and patients from Indonesia during a population-based survey on nasal Staphylococcus aureus carriage. Fifty-one S. sciuri isolates were further characterized. The S. aureus mecA gene was detected by PCR in 22 isolates (43.1%), whereas S. sciuri mecA was found in 33 isolates (64.7%). The staphylococcal cassette chromosome mec (SCCmec) regions of S. aureus mecA-positive isolates contained elements of classical S. aureus SCCmec types II and/or III.

Successful treatment for carriage of methicillin-resistant Staphylococcus aureus and importance of follow-up.

With this prospective observational follow-up study of 165 methicillin-resistant Staphylococcus aureus (MRSA)-positive individuals (23 health care workers and 142 patients), we determined that our MRSA eradication therapy protocol results in a high success rate (81%). Five or more negative culture sets give a predictive value for MRSA eradication therapy success of >90%. Furthermore, MRSA colonization, at least in the throat, and the presence of wounds just before the start of MRSA eradication therapy are associated with MRSA eradication therapy failure.

Antimicrobial resistance among commensal isolates of Escherichia coli and Staphylococcus aureus in the Indonesian population inside and outside hospitals.

The prevalence of antimicrobial resistance among the commensal microflora was examined in the Indonesian population inside and outside hospitals. A total of 3,995 individuals were screened in two major urban centers. Among Escherichia coli from rectal samples (n = 3,284) the prevalence of resistance to ciprofloxacin and other classes of antibiotics was remarkably high, especially in individuals at the time of discharge from hospital. Staphylococcus aureus isolates (n = 361) were often resistant to tetracycline (24.9%), but this was not associated with hospital stay. Two S. aureus isolates harbored the mecA gene. Regional differences in resistance rates exist, suggesting regional differences in selection pressure, i.e., antibiotic usage patterns. The results show that antimicrobial resistance among commensal E. coli and S. aureus has emerged in Indonesia.

Innate immunity in defense against Chlamydia trachomatis infections.

Innate immunity is of key importance in primary recognition of invading pathogens. Infected epithelial cells respond in similar, but not identical ways to different invading pathogens and the pathogens are capable of modifying the host cell response. Chlamydia trachomatis is a major cause of preventable blindness in underdeveloped countries and of sexually transmitted infections with sequelae such as infertility, pelvic inflammatory disease, and extrauterine gravidity throughout the world. Limited knowledge about molecular mediators and effectors, immunocompetent cells, and host response in chlamydial mucosal infections will be described. Recent findings of a differential response to invasive and noninvasive chlamydial infections are highlighted.