Multicenter Prevalence Study Comparing Molecular and Toxin Assays for Clostridioides difficile Surveillance, Switzerland.

Public health authorities in the United States and Europe recommend surveillance for Clostridioides difficile infections among hospitalized patients, but differing diagnostic algorithms can hamper comparisons between institutions and countries. We compared surveillance based on detection of C. difficile by PCR or enzyme immunoassay (EIA) in a nationwide C. difficile prevalence study in Switzerland. We included all routinely collected stool samples from hospitalized patients with diarrhea in 76 hospitals in Switzerland on 2 days, 1 in winter and 1 in summer, in 2015. EIA C. difficile detection rates were 6.4 cases/10,000 patient bed-days in winter and 5.7 cases/10,000 patient bed-days in summer. PCR detection rates were 11.4 cases/10,000 patient bed-days in winter and 7.1 cases/10,000 patient bed-days in summer. We found PCR used alone increased reported C. difficile prevalence rates by <80% compared with a 2-stage EIA-based algorithm.

Simplifying the World Health Organization Protocol: 3 Steps Versus 6 Steps for Performance of Hand Hygiene in a Cluster-randomized Trial.

BACKGROUND: In an experimental setting, a simplified, 3-step hand hygiene technique for applying alcohol-based hand rub was non inferior in terms of reduction of bacterial counts, as compared to the conventional World Health Organization 6-step technique. We therefore compared compliance and microbiological efficacy between both hand hygiene techniques in routine clinical practice. METHODS: We performed a cluster-randomized trial from October-November 2015 at the University Hospital Basel, Switzerland: a tertiary, academic care center (ISRCTN45923734). We randomly assigned 12 wards to either the 3-step technique or the conventional 6-step technique of hand rubbing. The primary endpoints were compliance with the assigned technique and reduction of bacterial counts on the hands of health-care workers. RESULTS: Overall, 2923 hand hygiene indications were observed, and compliance was 70.7% (2066/2923). Compliance with technique and indications was 51.7% (595/1151) and 75.9% (1151/1516) on wards assigned to the 3-step technique, respectively, as compared to 12.7% (116/915) and 65.0% (915/1407) on wards assigned to the 6-step technique (P < .001). The reduction factor (RF) of bacterial colony counts did not differ between techniques (median RF 0.97 log10 colony-forming units [CFU] [interquartile range 0.39-1.59] for the 3-step technique vs median RF 1.04 log10 CFU [interquartile range 0.49-1.52] for the 6-step technique; P = .629). CONCLUSIONS: In a clinical setting, the simpler hand hygiene technique, consisting of 3 steps, resulted in higher compliance with both hand hygiene indications and technique, as compared to the 6 steps. As the results of the microbiological analyses exclude inferiority, the conventional 6 steps could be safely replaced by a simpler hand hygiene technique. CLINICAL TRIALS REGISTRATION: ISRCTN45923734.

Transmissibility of Clostridium difficile Without Contact Isolation: Results From a Prospective Observational Study With 451 Patients.

Background: Contact precautions are recommended by health authorities in Europe and the United States for patients with Clostridium difficile infection (CDI). Recently, the significance of nosocomial transmission has been challenged by screening on admission studies and whole-genome sequencing, providing evidence for an endogenous source of C. difficile. We discontinued contact precautions for patients with CDI, except for patients infected with hypervirulent ribotypes or with stool incontinence, to determine the rate of transmission. Methods: From January 2004 to December 2013, contacts of each index case with CDI were screened for toxigenic C. difficile by culturing rectal swabs. Transmission was defined as possible if toxigenic C. difficile was detected in contacts, as probable if the identical polymerase chain reaction ribotype was identified in index­contact pairs, and as confirmed if next-generation sequencing (NGS) revealed clonality of strains. Results: Four hundred fifty-one contacts were exposed to 279 index patients nursed in 2-to 4-bed rooms. Toxigenic C. difficile was detected in 6.0% (27/451) after a median contact time of 5 days. Identical ribotypes were identified in 6 index­contact pairs, accounting for probable transmission in 1.3% (6/451). NGS was performed for 4 of 6 pairs with identical strains, and confirmed transmission in 2 contact patients. Conclusions: The rate of transmission of toxigenic, predominantly nonhypervirulent C. difficile, was low and no outbreaks were recorded over a 10-year period after discontinuing contact precautions for patients with CDI who were not severely incontinent and who used dedicated toilets. As contact precautions may lead to lower levels of care, their implementation needs to be balanced against the risk of nosocomial transmission.

Prospective Validation of Cessation of Contact Precautions for Extended-Spectrum ß-Lactamase-Producing Escherichia coli(1).

After contact precautions were discontinued, we determined nosocomial transmission of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli by screening hospital patients who shared rooms with ESBL-producing E. coli-infected or -colonized patients. Transmission rates were 2.6% and 8.8% at an acute-care and a geriatric/rehabilitation hospital, respectively. Prolonged contact was associated with increased transmission.

Association of Novel Nonsynonymous Single Nucleotide Polymorphisms in ampD with Cephalosporin Resistance and Phylogenetic Variations in ampC, ampR, ompF, and ompC in Enterobacter cloacae Isolates That Are Highly Resistant to Carbapenems.

InEnterobacter cloacae, the genetic lesions associated with derepression of the AmpC ß-lactamase include diverse single nucleotide polymorphisms (SNPs) and/or indels in theampDandampRgenes and SNPs inampC, while diverse SNPs in the promoter region or SNPs/indels within the coding sequence of outer membrane proteins have been described to alter porin production leading to carbapenem resistance. We sought to define the underlying mechanisms conferring cephalosporin and carbapenem resistance in a collection ofE. cloacaeisolates with unusually high carbapenem resistance and no known carbapenemase and, in contrast to many previous studies, considered the SNPs we detected in relation to the multilocus sequence type (MLST)-based phylogeny of our collection. Whole-genome sequencing was applied on the most resistant isolates to seek novel carbapenemases, expression ofampCwas measured by reverse transcriptase PCR, and porin translation was detected by SDS-PAGE. SNPs occurring inampC,ampR,ompF, andompCgenes (and their promoter regions) were mostly phylogenetic variations, relating to the isolates' sequence types, whereas nonsynonymous SNPs inampDwere associated with derepression of AmpC and cephalosporin resistance. The additional loss of porins resulted in high-level carbapenem resistance, underlining the clinical importance of chromosomal mutations among carbapenem-resistantE. cloacae.

Standard Genotyping Overestimates Transmission of Mycobacterium tuberculosis among Immigrants in a Low-Incidence Country.

Immigrants from regions with a high incidence of tuberculosis (TB) are a risk group for TB in low-incidence countries such as Switzerland. In a previous analysis of a nationwide collection of 520 Mycobacterium tuberculosis isolates from 2000 to 2008, we identified 35 clusters comprising 90 patients based on standard genotyping (24-locus mycobacterial interspersed repetitive-unit-variable-number tandem-repeat [MIRU-VNTR] typing and spoligotyping). Here, we used whole-genome sequencing (WGS) to revisit these transmission clusters. Genome-based transmission clusters were defined as isolate pairs separated by ≤12 single nucleotide polymorphisms (SNPs). WGS confirmed 17/35 (49%) MIRU-VNTR typing clusters; the other 18 clusters contained pairs separated by >12 SNPs. Most transmission clusters (3/4) of Swiss-born patients were confirmed by WGS, as opposed to 25% (4/16) of the clusters involving only foreign-born patients. The overall clustering proportion was 17% (90 patients; 95% confidence interval [CI], 14 to 21%) by standard genotyping but only 8% (43 patients; 95% CI, 6 to 11%) by WGS. The clustering proportion was 17% (67/401; 95% CI, 13 to 21%) by standard genotyping and 7% (26/401; 95% CI, 4 to 9%) by WGS among foreign-born patients and 19% (23/119; 95% CI, 13 to 28%) and 14% (17/119; 95% CI, 9 to 22%), respectively, among Swiss-born patients. Using weighted logistic regression, we found weak evidence of an association between birth origin and transmission (adjusted odds ratio of 2.2 and 95% CI of 0.9 to 5.5 comparing Swiss-born patients to others). In conclusion, standard genotyping overestimated recent TB transmission in Switzerland compared to WGS, particularly among immigrants from regions with a high TB incidence, where genetically closely related strains often predominate. We recommend the use of WGS to identify transmission clusters in settings with a low incidence of TB.

Low-Dose Acetylsalicylic Acid Treatment and Impact on Short-Term Mortality in Staphylococcus aureus Bloodstream Infection: A Propensity Score-Matched Cohort Study.

OBJECTIVES: Staphylococcus aureus bloodstream infection is associated with considerable mortality. Experimental models suggest a direct antistaphylococcal effect of acetylsalicylic acid, but evidence from human studies is scarce. We aimed to estimate the effect of low-dose acetylsalicylic acid therapy on mortality in bloodstream infections caused by S. aureus compared with Escherichia coli. DESIGN: Retrospective cohort study based on observational data from 838 and 602 episodes of S. aureus and E. coli bloodstream infection, respectively. SETTING: Swiss tertiary referral center. PATIENTS: Adult patients with S. aureus and E. coli bloodstream infection, respectively, categorized according to low-dose acetylsalicylic acid therapy as outpatient or inpatient before bacteremia. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirty-day all-cause mortality was analyzed in a total of 314 propensity score-matched S. aureus bloodstream infection and in 268 E. coli bloodstream infection patients, respectively (1:1 match of low-dose acetylsalicylic acid users and nonusers). S. aureus bloodstream infection cases and controls were equally matched for relevant confounders except treatment with statins, which was strongly associated with a low-dose acetylsalicylic acid use (p < 0.001). At day 30, 12.1% of cases and 27.4% of controls had died (hazard ratio, 0.40; p < 0.001). Low-dose acetylsalicylic acid use was associated with a reduced 30-day all-cause mortality in multivariate analysis (hazard ratio, 0.38; 95% CI, 0.21-0.69; p = 0.001) of matched patients and also of the entire cohort (n = 689) after adjustment for the propensity score (hazard ratio, 0.58, 95% CI, 0.34-0.98; p = 0.04). In contrast, low-dose acetylsalicylic acid use was not associated with the primary endpoint in patients with E. coli bloodstream infection (hazard ratio, 0.78; 95% CI, 0.40-1.55; p = 0.8). CONCLUSIONS: Low-dose acetylsalicylic acid at the time of bloodstream infection was strongly associated with a reduced short-term mortality in patients with S. aureus bloodstream infection. Future studies are required to investigate if early low-dose acetylsalicylic acid is a suitable treatment in patients with S. aureus bloodstream infection.

A case report of a cystic fibrosis patient with repeated isolation of Trichosporon mycotoxinivorans identified by a novel short-extraction method.

BACKGROUND: Trichosporon mycotoxinivorans is a recently described yeast-like fungal organism and its association as a pathogen for patients with cystic fibrosis (CF) was reported previously. We show the clinical course of a CF patient over 9 years as well as the applications of modern molecular and proteomic identification techniques of this rare fungus. CASE PRESENTATION: We present the case of a 32-year-old male CF patient with sputum cultures continuously positive with the anamorphic yeast T. mycotoxinivorans during 9 years. Furthermore, susceptibility testing of T. mycotoxinivorans to different antifungals were performed. In addition, a rapid identification method of this novel fungal pathogen with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was applied using a simple extraction protocol. CONCLUSIONS: Our case presentation confirms T. mycotoxinivorans as a potential emerging pathogen in patients with CF. However, our CF patient showed mild symptoms over a very long time period of 9 years. A short MALDI-TOF MS procedure allows reliable and rapid identification of T. mycotoxinivorans and therefore should facilitate further study on the clinical relevance and epidemiology of this unusual fungal organism.

HIV infection disrupts the sympatric host-pathogen relationship in human tuberculosis.

The phylogeographic population structure of Mycobacterium tuberculosis suggests local adaptation to sympatric human populations. We hypothesized that HIV infection, which induces immunodeficiency, will alter the sympatric relationship between M. tuberculosis and its human host. To test this hypothesis, we performed a nine-year nation-wide molecular-epidemiological study of HIV-infected and HIV-negative patients with tuberculosis (TB) between 2000 and 2008 in Switzerland. We analyzed 518 TB patients of whom 112 (21.6%) were HIV-infected and 233 (45.0%) were born in Europe. We found that among European-born TB patients, recent transmission was more likely to occur in sympatric compared to allopatric host-pathogen combinations (adjusted odds ratio [OR] 7.5, 95% confidence interval [95% CI] 1.21-infinity, p = 0.03). HIV infection was significantly associated with TB caused by an allopatric (as opposed to sympatric) M. tuberculosis lineage (OR 7.0, 95% CI 2.5-19.1, p<0.0001). This association remained when adjusting for frequent travelling, contact with foreigners, age, sex, and country of birth (adjusted OR 5.6, 95% CI 1.5-20.8, p = 0.01). Moreover, it became stronger with greater immunosuppression as defined by CD4 T-cell depletion and was not the result of increased social mixing in HIV-infected patients. Our observation was replicated in a second independent panel of 440 M. tuberculosis strains collected during a population-based study in the Canton of Bern between 1991 and 2011. In summary, these findings support a model for TB in which the stable relationship between the human host and its locally adapted M. tuberculosis is disrupted by HIV infection.

Infection of cardiovascular implantable electronic devices: detection with sonication, swab cultures, and blood cultures.

BACKGROUND: The number of patients with cardiovascular implantable electronic devices (CIEDs) is increasing. The purpose of this study was to compare three methods (sonication, swab cultures, and blood cultures) to detect bacteria in infections of CIEDs. METHODS: Patients with pocket infection of CIEDs and/or CIED-associated infective endocarditis were prospectively included. Generators and leads were sonicated together. Swab cultures of the generator pocket and blood cultures were performed. RESULTS: Between January 2009 and September 2012, 18 patients with a CIED infection were recorded, including two definite and four possible CIED-IEs. In 17 patients, blood cultures were performed and the device was analyzed by sonication. A swab culture from the device pocket was performed in 16 cases. Ten (59%) patients received antibiotic therapy before the device was removed. In 15 of 16 cases (94%), bacteria were detected by sonication, while bacteria were detected in only nine (56%) and seven (41%) cases by swab-and blood cultures, respectively. In four cases (24%), sonication was the only method that detected bacteria. The following bacteria were detected by sonication: methicillin-sensitive Staphylococcus aureus (MSSA; n = 6), coagulase-negative staphylococci (CNS; n = 3), Propionibacterium acnes (n = 2), Staphylococcus lugdunensis (n = 1), MSSA/Pseudomonas aeruginosa (n = 1),Bacillus cereus (n = 1), MSSA/P. acnes (n = 1), andP. acnes/CNS (n = 1). All positive swab cultures and all positive blood cultures but one grew the same bacteria as sonication fluid cultures. CONCLUSION: Sonication can be more sensitive than swab cultures or blood cultures in detecting bacteria in infections of CIEDs.

Prospective, cross-sectional study on MSSA and MRSA colonisation in hospitalised children.

There is a global trend for an increase in prevalence of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonisation in children. A decade ago, MRSA colonisation was studied in Swiss paediatric hospitals and revealed an extraordinarily low proportion (<1 %). The primary goal of this study was to determine if the current proportion of nasal colonisation with MRSA in hospitalised children was still favourable. We aimed to screen all children from the age of 0-16 years admitted to the paediatric and surgical wards at the University Children's Hospital Basel (UKBB) during 8 pre-defined surveillance weeks. After obtaining consent, a nasal swab was taken and analysed for growth of S. aureus. Furthermore, a standardised questionnaire was completed by interview with a parent. Of 535 eligible children, 340 (64 %) were enrolled. Mean age was 6.2 years (median 4.3, IQR 1 to 11.25), 111 (33 %) children were colonised with S. aureus but no MRSA was found. CONCLUSION: The prevalence of MRSA in children admitted to the UKBB during this surveillance period was zero. General MRSA screening in hospitalised children continues to be unjustified in our area. WHAT IS KNOWN: • The prevalence of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonisation in children is increasing in many regions worldwide. • Surveillance for MRSA colonisation in healthcare settings varies considerably. WHAT IS NEW: • Periodic and risk-factor-based surveillance for MRSA colonisation is sufficient when regional prevalence is low.

Sonication for diagnosis of catheter-related infection is not better than traditional roll-plate culture: a prospective cohort study with 975 central venous catheters.

This prospective randomized controlled study with 975 nontunneled central venous catheters (CVCs) showed that the semiquantitative roll-plate culture technique (SQC) was as accurate as the sonication method for diagnosis of catheter-related infections. Sonication is difficult to standardize, whereas SQC is simpler, faster, and as reliable as the sonication method for culturing CVCs.

Seven hours to adequate antimicrobial therapy in urosepsis using isothermal microcalorimetry.

Urosepsis can progress toward severe sepsis, septic shock, and, ultimately, death. Rapid antimicrobial susceptibility testing is crucial to decrease mortality and morbidity. This report shows that isothermal microcalorimetry can provide an antibiogram within 7 h with a sensitivity of 95% and specificity of 91% using Vitek-2 system as a reference.

Weekly use of fluconazole as prophylaxis in haematological patients at risk for invasive candidiasis.

BACKGROUND: The goal was to determine whether one medical centres' unique antifungal prophylactic regimen for patients at high risk for invasive candidiasis because of their haematological malignancies, haematopoietic stem cell transplants, or high-dose chemotherapy might lead ultimately to a higher incidence of infection, to increasing fluconazole resistance, or to a shift in the predominant strain of Candida in invasive fungal episodes. METHODS: Data were collected retrospectively, for a ten-year period from ONKO-KISS surveillance records, and from hospital, medical, and pharmacy records and then evaluated with respect to incidence of fungal infection episodes, emergence of antifungal drug resistance, and predominance of specific Candida strains in isolate cultures. Fisher's exact test and linear regression were used to compare minimum inhibitory concentrations and to compare the incidence of different Candida isolates, respectively. RESULTS: The incidence of infection remained quite stable over 10 years with a median of 0.67 episodes/1000 bed days. Overall, Candida glabrata was the predominant species with 29% followed by C. albicans and C. krusei (14% each). No significant increment of non-albicans Candida species with decreased fluconazole susceptibility was perceived over this decade. CONCLUSIONS: Once weekly administration of 400 mg of fluconazole to prevent candidaemia appears to have no negative impact on the efficacy as a prophylaxis when compared to standard of care (400 mg of fluconazole daily).

First case of infective endocarditis caused by Helicobacter cinaedi.

BACKGROUND: Up to 20% of all infective endocarditis are blood culture-negative and therefore a diagnostic challenge. Here we present the case of an infective endocarditis due to Helicobacter cinaedi finally diagnosed using different molecular methods. This highly fastidious gram-negative spiral rod is increasingly recognized as a human pathogen, above all in immunocompromised patients. So far H. cinaedi has been associated with bacteremia, cellulitis, arthritis and meningitis. CASE PRESENTATION: A 71-year-old man presented with fever and progressive dyspnea for weeks. He was immunocompromised by long-term steroid therapy. As one major and two minor Duke's criteria (vegetation, fever and aortic valve stenosis as predisposition) were present, an infective endocarditis was suspected and an empiric therapy with amoxicillin/clavulanic acid and gentamicin was established. The persistent severe aortic regurgitation resulted in a valve replacement. Histological evaluation of the aortic valve showed a polypous-ulcerative endocarditis. Gram stain and culture remained negative. Broad-range bacterial PCR targeting the 16S rRNA gene on the biopsy of the aortic valve identified H. cinaedi as the causative agent. The antibiotic therapy was simplified accordingly to ceftriaxone and gentamicin with a recommended duration of 6 weeks. Ten days after valve replacement the patient was discharged. To complete our molecular finding, we sequenced nearly the complete 16S rRNA gene (accession number KF914917) resulting in 99.9% identity with H. cinaedi reference sequences. Based on this result, 2 species-specific PCR tests amplifying part of the ctd gene were established and applied to the valve specimen. The 2 PCRs confirmed H. cinaedi. In addition, we analyzed stool, urine and saliva from the patient using H. cinaedi PCR. The fecal and urine specimen showed a positive signal, saliva was PCR-negative. CONCLUSION: We identified H. cinaedi as causative agent of a culture-negative endocarditis in an immunocompromised patient using broad-range and specific PCR. In addition to 2 cases from Japan presented on international meetings in 2010 and 2013, our case report shows that H. cinaedi should be recognized as additional causative organism of infective endocarditis. The use of molecular diagnostic techniques proved to be a powerful complement for the detection of blood culture-negative infective endocarditis.

Is switching to an oral antibiotic regimen safe after 2 weeks of intravenous treatment for primary bacterial vertebral osteomyelitis?

BACKGROUND: Vertebral osteomyelitis (VO) may lead to disabling neurologic complications. Little evidence exists on optimal antibiotic management. METHODS: All patients with primary, non-implant VO, admitted from 2000-2010 were retrospectively analyzed. Patients with endocarditis, immunodeficiency, vertebral implants and surgical site infection following spine surgery were excluded. Persistence of clinical or laboratory signs of inflammation at 1 year were defined as treatment failure. Logistic regression was used to estimate the odds ratios (OR) of switch to an oral regimen after 2 weeks. RESULTS: Median antibiotic treatment was 8.1 weeks in 61 identified patients. Switch to oral antibiotics was performed in 72% of patients after a median intravenous therapy of 2.7 weeks. Switch to oral therapy was already performed after two weeks in 34% of the patients. A lower CRP at 2 weeks was the only independent predictor for switch to oral therapy (OR 0.7, 95% confidence interval 0.5-0.9, p = 0.041, per 10 mg/l increase). Staphylococcus aureus was the most frequently isolated microorganism (21%). Indications for surgery, other than biopsy, included debridement with drainage of epidural or paravertebral abscess (26 patients; 42%), and CT-guided drainage (3 patients).During the follow-up, no recurrences were observed but 2 patients died of other reasons than VO, i.e. the 1 year intention to treat success rate was 97%. CONCLUSIONS: Cure rates for non-implant VO were very high with partly short intravenous and overall antibiotic therapy. Switching to an oral antibiotic regimen after two weeks intravenous treatment may be safe, provided that CRP has decreased and epidural or paravertebral abscesses of significant size have been drained.

High colonization rates of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in Swiss travellers to South Asia- a prospective observational multicentre cohort study looking at epidemiology, microbiology and risk factors.

BACKGROUND: International travel contributes to the worldwide spread of multidrug resistant Gram-negative bacteria. Rates of travel-related faecal colonization with extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae vary for different destinations. Especially travellers returning from the Indian subcontinent show high colonization rates. So far, nothing is known about region-specific risk factors for becoming colonized. METHODS: An observational prospective multicentre cohort study investigated travellers to South Asia. Before and after travelling, rectal swabs were screened for third-generation cephalosporin- and carbapenem-resistant Enterobacteriaceae. Participants completed questionnaires to identify risk factors for becoming colonized. Covariates were assessed univariately, followed by a multivariate regression. RESULTS: Hundred and seventy persons were enrolled, the largest data set on travellers to the Indian subcontinent so far. The acquired colonization rate with ESBL-producing Escherichia coli overall was 69.4% (95% CI 62.1-75.9%), being highest in travellers returning from India (86.8%; 95% CI 78.5-95.0%) and lowest in travellers returning from Sri Lanka (34.7%; 95% CI 22.9-48.7%). Associated risk factors were travel destination, length of stay, visiting friends and relatives, and eating ice cream and pastry. CONCLUSIONS: High colonization rates with ESBL-producing Enterobacteriaceae were found in travellers returning from South Asia. Though risk factors were identified, a more common source, i.e. environmental, appears to better explain the high colonization rates.

Historic methicillin-resistant Staphylococcus aureus: expanding current knowledge using molecular epidemiological characterization of a Swiss legacy collection.

BACKGROUND: Few methicillin-resistant Staphylococcus aureus (MRSA) from the early years of its global emergence have been sequenced. Knowledge about evolutionary factors promoting the success of specific MRSA multi-locus sequence types (MLSTs) remains scarce. We aimed to characterize a legacy MRSA collection isolated from 1965 to 1987 and compare it against publicly available international and local genomes. METHODS: We accessed 451 historic (1965-1987) MRSA isolates stored in the Culture Collection of Switzerland, mostly collected from the Zurich region. We determined phenotypic antimicrobial resistance (AMR) and performed whole genome sequencing (WGS) using Illumina short-read sequencing on all isolates and long-read sequencing on a selection with Oxford Nanopore Technology. For context, we included 103 publicly available international assemblies from 1960 to 1992 and sequenced 1207 modern Swiss MRSA isolates from 2007 to 2022. We analyzed the core genome (cg)MLST and predicted SCCmec cassette types, AMR, and virulence genes. RESULTS: Among the 451 historic Swiss MRSA isolates, we found 17 sequence types (STs) of which 11 have been previously described. Two STs were novel combinations of known loci and six isolates carried previously unsubmitted MLST alleles, representing five new STs (ST7843, ST7844, ST7837, ST7839, and ST7842). Most isolates (83% 376/451) represented ST247-MRSA-I isolated in the 1960s, followed by ST7844 (6% 25/451), a novel single locus variant (SLV) of ST239. Analysis by cgMLST indicated that isolates belonging to ST7844-MRSA-III cluster within the diversity of ST239-MRSA-III. Early MRSA were predominantly from clonal complex (CC)8. From 1980 to the end of the twentieth century, we observed that CC22 and CC5 as well as CC8 were present, both locally and internationally. CONCLUSIONS: The combined analysis of 1761 historic and contemporary MRSA isolates across more than 50 years uncovered novel STs and allowed us a glimpse into the lineage flux between Swiss-German and international MRSA across time.

Microbial biofilm formation and catheter-associated bacteriuria in patients with suprapubic catheterisation.

PURPOSE: Catheter-associated bacteriuria (CAB) with transurethral catheters is almost inevitable. Suprapubic catheters (SPCs) are widely considered to decrease the risk of CAB. However, SPCs are implants similarly prone to microbial biofilm formation. The spectrum of colonising pathogens has not been investigated. The aim of this prospective study was: (1) to assess the diversity of microbial suprapubic catheter colonisation (MSPCC), (2) to identify risk factors and (3) to investigate its association with CAB and catheter-associated urinary tract infection (CA-UTI). METHODS: A total of 218 SPCs from 112 patients were studied. Urine specimens were obtained after device replacement or removal. Sonication was performed to dislodge adherent microorganisms. Data of patient sex, age, indwelling time, and underlying disease were recorded. RESULTS: Sonicate-fluid culture (SFC) detected MSPCC in 95 %. Increasing indwelling time correlated with MSPCC (p < 0.05). Negative SFC was more frequent when antibiotic prophylaxis was applied at time of catheter placement (15 vs. 2 %, p < 0.05). Most commonly isolated were Enterobacteriaceae (45.8 %), followed by Enterococcus spp. (25.7 %) and Pseudomonas aeruginosa (10.3 %). CAB and CA-UTI were observed in 95 and 11 %, respectively. CONCLUSIONS: This study provides the first analysis of MSPCC. Indwelling time increases, whereas antibiotic prophylaxis decreases the risk of MSPCC. The spectrum of pathogens is comparable to the one obtained from urethral catheter biofilms. Urine specimens could not demonstrate the microbial diversity of MSPCC. SPCs are not preferable to urethral catheters to reduce CAB. Whether the risk of CA-UTI could be minimised by SPCs remains to be clarified.