Evaluation of PhenoMATRIX and PhenoMATRIX PLUS for the screening of MRSA from nasal and inguinal/perineal swabs using chromogenic media.

The objective of this study was to assess the clinical performances of PhenoMATRIX and PhenoMATRIX PLUS for the screening of methicillin-resistant Staphylococcus aureus (MRSA) from nasal and inguinal/perineal ESwabs using chromogenic media. The automated performances were compared to the manual reading. Additionally, we evaluated PhenoMATRIX PLUS for the automatic release of the negative results to the Laboratory Information System (LIS) and the automatic discharge of the negative plates from the incubators. A total of 6,771 non-duplicate specimens were used by PhenoMATRIX as a machine learning model. The validation of these settings was performed on 17,223 non-duplicate specimens. The MRSA positivity rate was 5% (866/17,223). Validated settings were then used by PhenoMATRIX PLUS on another 1,409 non-duplicate specimens. The sensitivities of PhenoMATRIX and PhenoMATRIX PLUS were 99.8% [95% confidence interval (CI), 99.2%-99.9%] and 100% (95% CI, 92.1%-100%), respectively. The specificities of PhenoMATRIX and PhenoMATRIX PLUS were 99.1% (95% CI, 99.0%-99.2%) and 95.2% (95% CI, 93.8%-96.1%), respectively. All the 1,297 MRSA-negative specimens analyzed by PhenoMATRIX PLUS were automatically released and sent to the LIS immediately after availability of the culture image on the WASPLab (100% accuracy). All negative media plates were automatically discarded. PhenoMATRIX PLUS decreases the time spent by technologists on negative plates and ensures optimal usage of the incubators' capacity.

Performance of the HiberGene Group B Streptococcus kit, a loop-mediated isothermal amplification-based assay for GBS screening during pregnancy.

Timely and accurate detection of Group B Streptococcus (GBS) carriage in pregnant women allows for targeted peripartum prophylaxis. Replacing culture-based screening by molecular biology assays enables faster results obtention, better targeted antibiotic prophylaxis, and reduces the laboratory workload. Here, we present a comparative analysis between a Loop Mediated Isothermal Amplification assay (HiberGene GBS kit) and culture (gold-standard). The HiberGene GBS kit showed a sensitivity of 97.9% and a specificity of 96.8% compared with culture. The limit of detection was estimated at 103 cfu/ml and results were obtained within 30 min. HiberGene GBS assay can be used for peripartum GBS screening and targeted antibiotic prophylaxis provided sample processing can be swiftly performed around the clock.

Diagnostic test accuracy of an automated device for the MALDI target preparation for microbial identification.

The objective of this study was to evaluate the performance of the Copan Colibrí™ against the manual preparation of the MALDI targets. We analyzed 416 (31 different species) non-duplicate strains covering the most important species identified in clinical routine. We also assessed the intra-strain repeatability between the comparable methods. We then analyzed the performance of this new method after implementation in routine on 12,253 aerobic bacterial isolates and yeasts, encompassing a total of 42 different species. Among the 416 strains analyzed, 6.3% (26/416) and 10.8% (45/416) had a score value < 2 when processed by the Colibri™ and manual method, respectively. Only 5.9% (9/152) of the Gram positive rods and cocci had a score values < 2 by the Colibri™ versus 20.4% (31/152) by the manual method. We confirmed that this relative superiority observed for the Colibri™ was due primarily in the use of the formic acid protocol. For the Gram-negative bacteria, the results of both methods were comparable; 6.6% (17/256) and 4.7% (12/256) had a score value < 2 by the Colibri™ and the manual method, respectively. After implementation in routine, the results according to the Biotyper score cut-off values were distributed as follows: < 1.70: 2.5% (304/12,253), 1.70-1.79: 1.9% (227/12,253), 1.80-1.89: 3.1% (377/12,253), 1.90-1.99: 6.7% (825/12,253), and ≥ 2: 85.9% (10,520/12,253). The Colibrí™ coupled to MALDI-TOF/MS revealed good performances and higher intra-strain repeatability as compared to the manual preparation of the MALDI targets.

Fully Automated EUCAST Rapid Antimicrobial Susceptibility Testing (RAST) from Positive Blood Cultures: Diagnostic Accuracy and Implementation.

The objective of this study was to evaluate the accuracy and robustness of a fully automated EUCAST RAST (rapid antimicrobial susceptibility test) directly from positive blood culture and to appreciate its implementation constraints. This study was conducted in two phases: (i) spiked blood culture bottles (BCs) using 779 non-duplicate clinical isolates and (ii) a prospective clinical trial including 534 positive BCs sequentially processed in routine at the Bacteriology Laboratory of Geneva University Hospitals. The RAST results were assessed against EUCAST standardized disk diffusion testing results. Our first finding was that the results of the spiked BCs precisely predicted the clinical trial results. The overall categorical agreements for all species analyzed were greater than 95% at the different time points. RAST for Pseudomonas aeruginosa, however, raised several challenges. The categorical agreement for imipenem was lower than 95% at 6 h and was not improved with longer incubation times. Additionally, piperacillin-tazobactam, ceftazidime, and cefepime cannot be released at 6 h due to suboptimal performances, but the categorical agreement substantially improved at 8 h. Our results establish that the performance of fully automated EUCAST RAST directly from positive blood culture bottles is consistently robust, even for the detection of extended-spectrum ß-lactamase (ESBL), carbapenemase-producing bacteria, and methicillin-resistant Staphylococcus aureus (MRSA). The automation markedly enhanced the percentage of readable inhibition zones and reduced the percentage of isolates categorized in the area of technical uncertainty (ATU). In summary, a fully automated EUCAST RAST can substantially improve laboratory workflow by reducing hands-on time and removing the strong constraints linked to manual read-outs at precisely defined times.

Missed pertussis diagnosis during co-infection with Bordetella holmesii.

The purpose of this study is to identify predictive factors associated with missed diagnosis of B. pertussis-B. holmesii co-infection by assessing the analytical performance of a commercially available multiplexed PCR assay and by building a prediction model based on clinical signs and symptoms for detecting co-infections. This is a retrospective study on the electronic health records of all clinical samples that tested positive to either B. pertussis or B. holmesii from January 2015 to January 2018 at Geneva University Hospitals. Multivariate logistic regression was used to build a model for co-infection prediction based on the electronic health record chart review. Limit of detection was determined for all targets of the commercial multiplexed PCR assay used on respiratory samples. A regression model, developed from clinical symptoms and signs, predicted B. pertussis and B. holmesii co-infection with an accuracy of 82.9% (95% CI 67.9-92.8%, p value = .012), for respiratory samples positive with any of the two tested Bordetella species. We found that the LOD of the PCR reaction targeting ptxS1 is higher than that reported by the manufacturer by a factor 10. The current testing strategy misses B. pertussis and B. holmesii co-infections by reporting only B. holmesii infections. Thus, we advocate to perform serological testing for detecting a response against pertussis toxin whenever a sample is found positive for B. holmesii. These findings are important, both from a clinical and epidemiological point of view, as the former impacts the choice of antimicrobial drugs and the latter biases surveillance data, by underestimating B. pertussis infections during co-infections.

An interventional quasi-experimental study to evaluate the impact of a rapid screening strategy in improving control of nosocomial extended-spectrum beta-lactamase-producing Enterobacterales and carbapenemase-producing organisms in critically ill patients.

INTRODUCTION: Rapid molecular tests could accelerate the control of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) and carbapenemase-producing organisms (CPO) in intensive care units (ICUs). OBJECTIVE AND METHODS: This interventional 12-month cohort study compared a loop-mediated isothermal amplification (LAMP) assay performed directly on rectal swabs with culturing methods (control period, 6 months), during routine ICU screening. Contact precautions (CP) were implemented for CPO or non-E. coli ESBL-producing Enterobacterales (nEcESBL-PE) carriers. Using survival analysis, we compared the time intervals from admission to discontinuation of unnecessary preemptive CP among patients at-risk and the time intervals from screening to implementation of CP among newly identified carriers. We also compared diagnostic performances, and nEcESBL-PE/CPO acquisition rates. This study is registered, ISRCTN 23588440. RESULTS: We included 1043 patients. During the intervention and control phases, 92/147 (62.6%) and 47/86 (54.7%) of patients at-risk screened at admission were candidates for early discontinuation of preemptive CP. The LAMP assay had a positive predictive value (PPV) of 44.0% and a negative predictive value (NPV) of 99.9% for CPO, and 55.6% PPV and 98.2% NPV for nEcESBL-PE. Due to result notification and interpretation challenges, the median time from admission to discontinuation of preemptive CP increased during the interventional period from 80.5 (95% CI 71.5-132.1) to 88.3 (95% CI 57.7-103.7) hours (p = 0.47). Due to the poor PPV, we had to stop using the LAMP assay to implement CP. No difference was observed regarding the incidence of nEcESBL-PE and CPO acquisition. CONCLUSION: A rapid screening strategy with LAMP assays performed directly on rectal swabs had no benefit for infection control in a low-endemicity setting.

Nontuberculous Mycobacteria under Scrutiny in the Geneva Area (2015-2020).

BACKGROUND: Nontuberculous mycobacteria (NTM) are increasingly identified in industrialized countries, and their role as pathogens is more frequently recognized. The relative prevalence of NTM strains shows an important geographical variability. Thus, establishing the local relative prevalence of NTM strains is relevant and useful for clinicians. METHODS: Retrospective analysis (2015-2020) of a comprehensive database was conducted including all results of cultures for mycobacteria in a University Hospital (Geneva, Switzerland), covering a population of approximately 500,000 inhabitants. All NTM culture-positive patients were included in the analyses. Patients' characteristics, NTM strains, and time to culture positivity were reported. RESULTS: Among 38,065 samples analyzed during the study period, 411 were culture-positive for NTM, representing 236 strains, and 231 episodes of care which occurred in 222 patients. Patients in whom NTM were identified were predominantly female (55%), with a median age of 62 years, and a low BMI (median: 22.6 kg/m2). The Mycobacterium avium complex (MAC) was the most frequently identified group (37% of strains) followed by Mycobacterium gordonae (25%) and Mycobacterium xenopi (12%) among the slowly growing mycobacteria (SGM), while the Mycobacterium chelonae/abscessus group (11%) were the most frequently identified rapidly growing mycobacteria (RGM). Only 19% of all patients were treated, mostly for pulmonary infections: the MAC was the most frequently treated NTM (n = 19, 43% of cases in patients treated) followed by RGM (n = 15, 34%) and M. xenopi (n = 6, 14%). Among those treated, 23% were immunosuppressed, 12% had pulmonary comorbidities, and 5% systemic comorbidities. Cultures became positive after a median of 41 days (IQR: 23; 68) for SGM and 28 days (14; 35) for RGM. CONCLUSIONS: In Western Switzerland, M. avium and M. gordonae were the most prevalent NTM identified. Positive cultures for NTM led to a specific treatment in 19% of subjects. Patients with a positive culture for NTM were mostly female, with a median age of 62 years, a low BMI, and a low prevalence of immunosuppression or associated severe comorbidities.

Performance of Fully Automated Antimicrobial Disk Diffusion Susceptibility Testing Using Copan WASP Colibri Coupled to the Radian In-Line Carousel and Expert System.

The purpose of the present study was to assess the agreement at the categorical level between the Vitek 2 system and the Colibri coupled to the Radian under real routine laboratory conditions. The 675 nonduplicate clinical strains included in this study (249 Enterobacterales isolates, 198 Pseudomonas aeruginosa, 107 Staphylococcus aureus, 78 coagulase-negative staphylococci, 38 Enterococcus faecalis, and 5 Enterococcus faecium) were isolated from nonconsecutive clinical samples referred to our laboratory between June and November 2020. In addition, 43 carbapenemase-producing Enterobacterales (CPE) formerly identified and stored in our laboratory were added to the panel, for a total of 718 strains. The overall categorical agreements between the two compared methods were 99.3% (4,350/4,380; 95% CI 99% to 99.5%); 98.6% (2,147/2,178; 95% CI 98.0% to 99.0%); 99.4% (1,839/1,850; 95% CI 98.9% to 99.7%); and 99.4% (342/344; 95% CI 97.9% to 99.8%) for Enterobacterales, P. aeruginosa, Staphylococcus spp., and Enterococcus spp., respectively. The most important cause of the very major errors encountered on the Vitek 2 for P. aeruginosa (62%, 13/21) was related to the presence of heteroresistant populations. Among the 43 CPE included in this study, one OXA-48-like, and one OXA-181-like were missed by the Vitek 2, even by rigorously applying the CPE screening cutoffs defined by EUCAST. The Colibri coupled to the Radian provide a fully automated solution for antimicrobial disk diffusion susceptibility testing with an accuracy that is equal to or better than that of the Vitek 2 system.

Performances of automated digital imaging of Gram-stained slides with on-screen reading against manual microscopy.

The objective of this study was to evaluate the performances of the automated digital imaging of Gram-stained slides against manual microscopy. Four hundred forty-three identified Gram-stained slides were included in this study. When both methods agreed, we considered the results as correct, and no further examination was carried out. Whenever the methods gave discrepant results, we reviewed the digital images and the glass slides by manual microscopy to avoid incorrectly read smears. The final result was a consensus of multiple independent reader interpretations. Among the 443 slides analyzed in this study, 101 (22.8%) showed discrepant results between the compared methods. The rates of discrepant results according to the specimen types were 5.7% (9/157) for positive blood cultures, 42% (60/142) for respiratory tract specimens, and 22% (32/144) for sterile site specimens. After a subsequent review of the discrepant slides, the final rate of discrepancies dropped to 7.0% (31/443). The overall agreement between the compared methods and the culture results reached 78% (345/443) and 79% (349/443) for manual microscopy and automated digital imaging, respectively. According to culture results, the specificity for automated digital imaging and manual microscopy were 90.8% and 87.7% respectively. In contrast, sensitivity was 84.1% for the two compared methods. The discrepant results were mostly encountered with microorganism morphologies of rare occurrence. The results reported in this study emphasize that on-screen reading is challenging, since the recognition of morphologies on-screen can appear different as compared to routine manual microscopy. Monitoring of Gram stain errors, which is facilitated by automated digital imaging, remains crucial for the quality control of reported Gram stain results.

Rapid identification by MALDI-TOF/MS and antimicrobial disk diffusion susceptibility testing for positive blood cultures after a short incubation on the WASPLab.

The objectives of this study were to define the shortest incubation times on the WASPLab for reliable MALDI-TOF/MS-based species identification and for the preparation of a 0.5 McFarland suspension for antimicrobial disk diffusion susceptibility testing using short subcultures growing on solid culture media inoculated by positive blood cultures spiked with a wide range of pathogens associated with bloodstream infections. The 520 clinical strains (20 × 26 different species) included in this study were obtained from a collection of non-consecutive and non-duplicate pathogens identified at Geneva University Hospitals. After 4 h of incubation on the WASPLab, microorganisms' growth allowed accurate identification of 73% (380/520) (95% CI, 69.1-76.7%) of the strains included in this study. The identification rate increased to 85% (440/520) (95% CI, 81.3-87.5%) after 6-h incubation. When excluding Corynebacterium and Candida spp., the microbial growth was sufficient to permit accurate identification of all tested species (100%, 460/460) (95% CI, 99.2-100%) after 8-h incubation. With the exception of Burkholderia cepacia and Haemophilus influenzae, AST by disk diffusion could be performed for Enterobacterales and non-fermenting Gram-negative bacilli after only 4 h of growth in the WASPLab. The preparation of a 0.5 McFarland suspension for Gram-positive bacteria required incubation times ranging between 3 and 8 h according to the bacterial species. Only Corynebacterium spp. required incubation times as long as 16 h. The WASPLab enables rapid pathogen identification as well as swift comprehensive AST from positive blood cultures that can be implemented without additional costs nor hands-on time by defining optimal time points for image acquisition.

Implementation of the WASPLab™ and first year achievements within a university hospital.

In essence, automation can be driven by several of the following incentives: increased processing capacity of the laboratory, better costs control through processes standardization, optimized traceability, or improved workflows to reduce turnaround times (TAT). This project aims at presenting an overview of the project management and change management with a focus on the major challenges addressed by lab staff and laboratory leadership during the different phases of the implementation of the WASPLab™ in a routine clinical bacteriology laboratory. This paper reports our experience and reviews changes in the bacteriology laboratory at Geneva University Hospitals when shifting to the WASPLab™. Practically, the whole automation process was segmented into different packages (specimen type-based segmentation) allowing sequential validation, staff training, and routine implementation. Such process allowed reaching 90% of the identified "automatable" samples within 1 year, including personal training, documentation for accreditation supported by publications, without interrupting routine operations. In addition, we implemented a validated automated solution for antimicrobial disk diffusion susceptibility testing. Structured supervision and accurate monitoring of all the activities related to the automation project including key partners such as IT support, technical committee, and after-sales service guaranteed a swift and timely achievement of the project allowing the improvement of the workflow in routine bacteriology within 1 year.

Septic shock caused by Capnocytophaga canis after a cat scratch.

Capnocytophaga canis is an uncommon cause of septic shock. Only three cases have been previously reported in the literature. In this article, we describe the case of a 70-year-old male admitted to the intensive care unit for septic shock of unknown origin. On day 2, one anaerobic bottle out of the two sets taken at admission turned positive with Gram-negative bacilli. The pathogen was identified by 16S rRNA gene as C. canis. The strain was characterized and compared with other clinical isolates of Capnocytophaga spp.

Association between oropharyngeal carriage of Kingella kingae and osteoarticular infection in young children: a case-control study.

BACKGROUND: Kingella kingae has been increasingly identified in patients with osteoarticular infections. Our main objective was to evaluate the association between carriage of K. kingae in the oropharynx of preschool children and osteoarticular infections. METHODS: We conducted this prospective case-control study in 2 tertiary care pediatric hospitals (Canada and Switzerland) between 2014 and 2016. Potential cases were children aged 6 to 48 months with a presumptive diagnosis of osteoarticular infection according to the treating emergency physician. Confirmed cases were those with diagnosis of osteomyelitis or septic arthritis proven by positive findings on technetium-labelled bone scan or magnetic resonance imaging or identification of a microorganism in joint aspirate or blood. For each case, we recruited 4 age-matched controls from among children presenting to the same emergency department for trauma. The independent variable was presence of oropharyngeal K. kingae DNA identified by a specific polymerase chain reaction assay. We determined the association between oropharyngeal carriage of K. kingae and definitive osteoarticular infection. RESULTS: The parents of 77 children admitted for suspected osteoarticular infection and 286 controls were invited to participate and provided informed consent. We identified K. kingae in the oropharynx of 46 (71%) of 65 confirmed cases and 17 (6%) of 286 controls; these results yielded an odds ratio of 38.3 (95% confidence interval 18.5-79.1). INTERPRETATION: Detection of oropharyngeal K. kingae was strongly associated with osteoarticular infection among children presenting with symptoms suggestive of such infection.

Meropenem/colistin synergy testing for multidrug-resistant Acinetobacter baumannii strains by a two-dimensional gradient technique applicable in routine microbiology.

OBJECTIVES: Precise assessment of potential therapeutic synergy, antagonism or indifference between antimicrobial agents currently depends on time-consuming and hard-to-standardize in vitro chequerboard titration methods. We here present a method based on a novel two-dimensional antibiotic gradient technique named Xact™. METHODS: We used a test comprising a combination of perpendicular gradients of meropenem and colistin in a single quadrant. We compared test outcomes with those obtained with classical chequerboard microbroth dilution testing in a study involving 27 unique strains of multidrug-resistant Acinetobacter baumannii from diverse origins. RESULTS: We were able to demonstrate 92% concordance between the new technology and classical chequerboard titration using the A. baumannii collection. Two strains could not be analysed by Xact™ due to their out-of-range MIC of meropenem (>128 mg/L). CONCLUSIONS: The new test was shown to be diagnostically useful, easy to implement and less labour intensive than the classical method.

Oropharyngeal Kingella kingae carriage in children: characteristics and correlation with osteoarticular infections.

BACKGROUND: The aim of this study was to investigate changes in oropharyngeal K. kingae carriage during the first 4 y of life, including seasonal variation and comparison of asymptomatic carriage with cases of invasive osteoarticular infections (OAI). METHODS: Oropharyngeal bacterial K. kingae carriage was screened in 744 healthy children aged 7-48 mo between January 2009 and December 2012. Oropharyngeal swabs were analyzed by rt-PCR targeting the DNA of K. kingae RTX toxin, epidemiological characteristics of asymptomatic carriers and OAI case patients were recorded. RESULTS: The carriage prevalence showed no significant difference between age groups or seasons. Compared with asymptomatic carriers, OAI cases were more likely to be aged from 7 to 12 mo (OR = 2.5; 95% CI (1.2-5.0)) and 13-24 mo (OR = 2.2; 95% CI (1.2-3.9)), and less likely over 36 mo (OR = 0.2; 95% CI (0.1-0.7)). Fewer OAI cases were identified in spring compared to asymptomatic carriers (OR = 0.3; 95% CI (0.1-0.7)), while more were detected in autumn (OR = 2.5; 95% CI (1.4-4.4)). CONCLUSION: Although oropharyngeal K. kingae colonization is a prerequisite for further invasive infection, this epidemiological study emphasizes that the carriage rate variations do not correlate with the variations of OAI incidence by gender, season, or age group.

Characteristics of multidrug-resistant Acinetobacter baumannii strains isolated in Geneva during colonization or infection.

This study determined the antibiotic susceptibility profile and genetic mechanisms of ß-lactam resistance in 27 clinical strains of Acinetobacter baumannii isolated at the University Hospitals of Geneva, Switzerland. The antimicrobial susceptibility testing was performed using Etest and the disc diffusion method in accordance with CLSI guidelines. All of the strains were defined as multi-drug resistant (MDR) and were susceptible to colistin and moderately susceptible to tigecycline. Uniplex PCR assays were used to detect the following ß-lactamase genes: four class D carbapenem-hydrolysing oxacillinases (blaOXA-51, blaOXA-23, blaOXA-24 and blaOXA-58), four class B metallo-ß-lactamases genes (blaIMP, blaVIM, blaSPM and blaNDM) and two class A carbapenemases (blaKPC and blaGES). All of the strains were positive for blaOXA-51 (intrinsic resistance), 14/27 strains carried blaOXA-23, 2/27 strains carried a blaOXA-24-like gene, and 4/27 strains had a blaOXA-58 gene. blaGES-11 was found in three strains, and NDM-1-harbouring strains were identified in three patients. All of the A. baumannii isolates were typed by rep-PCR (DiversiLab) and excluded any clonality. Altogether, this analysis suggests a very high genetic diversity of imported MDR A. baumannii.

[Severe osteoarticular infections with Staphylococcus aureus producer of Panton-Valentine Leukocidine in children]. / Infections ostéo-articulaires sévères d staphylocoque doré producteur de leucocidine de Panton-Valentine chez l'enfant.

Emerging strain of Stapylococcus aureus (S. aureus) producer of the Panton-Valentine Leukocidine (PVL+) are becoming a new issue in public health. Those bacteria are accountable for serious cutaneous infection with a necrotic evolution, necrotizing pneumonia and severe osteoarticular infection. These last infections can be life-threatening and are at high risk of complications. Therefore, a multidisciplinary approach is necessary, in addition with an aggressive chirurgical treatment. We are here reporting 3 cases of osteoarticular infections by S. aureus PVL+ sensitive to methicilline, which illustrate the difficulties encountered in the management and treatment, as well as the potential for serious orthopedics complications.

Controlling the hospital aquatic reservoir of multidrug-resistant organisms: a cross-sectional study followed by a nested randomized trial of sink decontamination.

OBJECTIVES: The hospital water environment is an important reservoir of multidrug-resistant organisms (MDROs) and presents a risk for patient safety. We assessed the effectiveness of thermal and chemical interventions on sinks contaminated with MDRO in the hospital setting. METHODS: We conducted a cross-sectional assessment of MDRO contamination of sinks and toilets in 26 clinical wards of a tertiary care hospital. MDRO-contaminated sink traps were then replaced and randomized (1:1:1) to receive chemical (sodium hypochlorite), thermal disinfection (steam), or no intervention. Interventions were repeated weekly for 4 weeks. Sinks were resampled 7 days after the last intervention. The primary outcome was the proportion of decontaminated sinks. MDROs of interest were extended spectrum beta-lactamase (ESBL) producing and carbapenemase-producing Enterobacterales, and non-fermentative Gram-negative bacilli. RESULTS: In the cross-sectional assessment, at least one MDRO was identified in 258 (36%) of the 748 samples and in 91 (47%) of the 192 water sources. In total, 57 (42%) of the 137 sinks and 34 (62%) of the 55 toilets were contaminated with 137 different MDROs. The most common MDRO were ESBL Enterobacterales (69%, 95/137), followed by Verona Integron-Borne Metallo-ß-Lactamase (VIM) carbapenemase producing Pseudomonas aeruginosa (9%, 12/137) and Citrobacter spp. (6%, 5/137). In the nested randomized trial, five of the 16 sinks (31%) in the chemical disinfection group were decontaminated, compared with 8 of 18 (44%) in the control group (OR 0.58; 95% CI, 0.14-2.32) and 9 of 17 (53%) in the thermal disinfection group (OR 1.40; 95% CI, 0.37-5.32). DISCUSSION: Our study failed to demonstrate an added benefit of repeated chemical or thermal disinfection, beyond changing sink traps, in the MDRO decontamination of sinks. Routine chlorine-based disinfection of sinks may need to be reconsidered.

Decolonization of intestinal carriage of extended-spectrum ß-lactamase-producing Enterobacteriaceae with oral colistin and neomycin: a randomized, double-blind, placebo-controlled trial.

OBJECTIVES: Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) are an increasingly frequent cause of infections in the community and the healthcare setting. In this study, we aimed to investigate whether intestinal carriage of ESBL-E can be eradicated. METHODS: We conducted a double-blind, randomized, placebo-controlled, single-centre trial to assess the efficacy of an oral decolonization regimen on intestinal ESBL-E carriage in adult patients with an ESBL-E-positive rectal swab. Fifty-eight patients were allocated 1 : 1 to either placebo or colistin sulphate (50 mg 4×/day) and neomycin sulphate (250 mg 4×/day) for 10 days plus nitrofurantoin (100 mg 3×/day) for 5 days in the presence of ESBL-E bacteriuria. The primary outcome was detection of ESBL-E by rectal swab 28 ± 7 days after the end of treatment. Missing primary outcome data were imputed based on the last available observation. Additional cultures (rectal, inguinal and urine) were taken on day 6 of treatment and on days 1 and 7 post-treatment. The study protocol has been registered with ClinicalTrials.gov (NCT00826670). RESULTS: Among 54 patients (27 in each group) included in the primary analysis, there was no statistically significant difference between the groups with regard to the primary outcome [14/27 (52%) versus 10/27 (37%), P = 0.27]. During treatment and shortly afterwards, there was significantly lower rectal ESBL-E carriage in the treatment group: 9/26 versus 19/22 on day 6 of treatment (P < 0.001) and 8/25 versus 20/26 on day 1 post-treatment (P = 0.001). This effect had disappeared by day 7 post-treatment (18/27 versus 17/25, P = 0.92). Liquid stools were more common in the treatment group (7/27 versus 2/29, P = 0.05). CONCLUSIONS: The regimen used in this study temporarily suppressed ESBL-E carriage, but had no long-term effect.

Draft Genome Sequence of a Mixed-Serogroup W/Y Invasive Neisseria meningitidis Strain.

We report the genome of a Neisseria meningitidis strain (GE-156) that was isolated in Switzerland from a patient diagnosed with bacteremia. The strain belongs to a rare mixed serogroup W/Y and sequence type 11847 (clonal complex 167), as revealed by both routine laboratory examination and genomic sequencing.