BACKGROUND Increasing incidence rates of invasive Streptococcus dysgalactiae subspecies equisimilis (iSDSE) have been detected worldwide. AIM We aimed to investigate iSDSE infection incidence rates in Denmark during 2014–2024, and characterise the genomic population structure of a subset of iSDSE isolates and their antimicrobial resistance (AMR). METHODS Using national register data, we estimated overall and sex-/age-stratified iSDSE incidences during 2014–2024, by retrospectively identifying cases of invasive infections with group C and G streptococci or S. dysgalactiae (including specified as subspecies equisimilis). From the voluntary national beta-haemolytic streptococci laboratory surveillance system, whole-genome-sequenced isolates from August 2020−September 2022 were used to investigate the iSDSE genomic population structure. Susceptibility to penicillin, erythromycin and clindamycin was determined and AMR genes identified. RESULTS During 2014–2024, iSDSE incidence rates increased significantly (linear trend analysis p < 0.001) with mean annual incidence ranging between 10.3 and 16.4 per 100,000, peaking in 2023. Incidence was higher in males, increasing with older age. Nearly 75% of the 1,223 iSDSE isolates belonged to four of 14 genetic clusters. Sequence types (STs) ST20 and ST17 were most prevalent, while emm-type stG62647, a variant associated internationally with higher virulence, dominated. All isolates were phenotypically susceptible to penicillin but approximately 10% were respectively erythromycin and clindamycin resistant. High erythromycin resistance prevalence (57%; 39/68), coinciding with gene ermA, occurred in one genetic cluster. CONCLUSION The findings illustrate the need for national registry-based surveillance to detect epidemiological changes and potential outbreaks. Further, continuous genomic surveillance can monitor the occurrence and expansion of genetic clades and AMR genes.

Implementation of molecular detection methodology of Shiga toxin-producing Escherichia coli (STEC) in Danish patients began in 1997. Since then, changes in molecular detection methods and diagnostic criteria have led to the present situation, in which almost all diarrhoeal stool specimens are examined for STEC. Whole genome sequencing (WGS) of STEC isolates referred to the national reference laboratory has increased the detailed characterisation, and revealed a large spectrum, of STEC types, including cross-over pathotypes typically associated with extraintestinal disease or traveller’s diarrhoea. Association of subtype stx2a (and stx2d) with the risk of developing haemolytic uraemic syndrome (HUS) was confirmed. These changes have resulted in an increase in the number of diagnosed STEC cases from 31 cases in 1997 to 1432 in 2023. Similar increases in Europe have also been recorded. Culture of STEC is, on the other hand, declining, which poses a challenge to the identification of multiple STEC infections and outbreaks. Syndromic (PCR) test panels have also resulted in an increase in the detection of multiple microorganisms. Double or triple infections have increased the role of clinical microbiologists in interpreting and assessing the significance of diagnostic results and have also increased the need for high-quality curation of surveillance data.

OBJECTIVES:We aimed to identify specific anaerobic bacteria causing bacteraemia and a subsequent diagnosis of colorectal cancer. METHODS:A nationwide population-based cohort study, which included all episodes of defined specific anaerobic bacteraemia from 2010 (5,534,738 inhabitants) through 2020 (5,822,763 inhabitants) and all cases of colorectal cancer diagnosed from 2010 through 2021 in Denmark. We calculated the incidence and risk of colorectal cancer after bacteraemia with specific anaerobic bacteria using Escherichia coli bacteraemia as reference. RESULTS:Nationwide data on colorectal cancer and specific anaerobic bacteraemia (100% complete, representing 11,124 episodes). The frequencies of colorectal cancer within one year following anaerobic bacteraemia were higher for species, which almost exclusively reside in the colon, such as Phocaeicola vulgatus/dorei (5.5%), Clostridium septicum (24.2%), and Ruminococcus gnavus (4.6%) compared to 0.6% in 50,650 E. coli bacteraemia episodes. Bacteroides spp. had a subhazard ratio for colorectal cancer of 3.9 (95% confidence interval [CI], 3.0 to 5.1) and for Clostridium spp. it was 8.9 (95% CI, 6.7 to 11.8, with C. septicum 50.0 [95% CI, 36.0 to 69.5]) compared to E. coli (reference). CONCLUSION:This nationwide study identified specific colorectal cancer-associated anaerobic bacteria, which almost exclusively reside in the colon. Bacteraemia with these bacteria could be an indicator of colorectal cancer.

Diarrheal diseases caused by enteric pathogens are a significant public health concern. It is widely considered that close contact between persons, poor hygiene, and consumption of contaminated food are the primary causes of gastroenteritis. Clinical microbiology laboratory observations indicate that the incidence of enteropathogenic microorganisms may have been reduced in Denmark during the COVID-19 pandemic. All Departments of Clinical Microbiology in Denmark provided data on the monthly incidence of Salmonella spp., Escherichia coli, Campylobacter spp., Clostridioides difficile, Norovirus GI+GII, Giardia duodenalis, and Cryptosporidium from March 2018 to February 2021. The data were divided into three periods as follows: Control Period 1 (March 2018 to February 2019); Control Period 2 (March 2019 to February 2020); and the Restriction (pandemic) Period (March 2020 to February 2021). The incidences of pathogenic Salmonella spp.-, Escherichia coli-, and Campylobacter spp.-positive samples decreased by 57.3%, 48.1%, and 32.9%, respectively, during the restriction period. No decrease in C. difficile was observed. Norovirus GI+GII-positive samples decreased by 85.6%. Giardia duodenalis-positive samples decreased by 66.2%. Cryptosporidium species decreased by 59.6%. This study demonstrates a clear decrease in the incidence of enteropathogenic bacteria (except for C. difficile), viruses, and parasites during the SARS-CoV-2 restriction period in Denmark.

Background. In the POET (Partial Oral Endocarditis Treatment) trial, oral step-down therapy was noninferior to full-length intravenous antibiotic administration. The aim of the present study was to perform pharmacokinetic/pharmacodynamic analyses for oral treatments of infective endocarditis to assess the probabilities of target attainment (PTAs). Methods. Plasma concentrations of oral antibiotics were measured at day 1 and 5. Minimal inhibitory concentrations (MICs) were determined for the bacteria causing infective endocarditis (streptococci, staphylococci, or enterococci). Pharmacokinetic/pharmacodynamic targets were predefined according to literature using time above MIC or the ratio of area under the curve to MIC. Population pharmacokinetic modeling and pharmacokinetic/pharmacodynamic analyses were done for amoxicillin, dicloxacillin, linezolid, moxifloxacin, and rifampicin, and PTAs were calculated. Results. A total of 236 patients participated in this POET substudy. For amoxicillin and linezolid, the PTAs were 88%-100%. For moxifloxacin and rifampicin, the PTAs were 71%-100%. Using a clinical breakpoint for staphylococci, the PTAs for dicloxacillin were 9%-17%. Seventy-four patients at day 1 and 65 patients at day 5 had available pharmacokinetic and MIC data for 2 oral antibiotics. Of those, 13 patients at day 1 and 14 patients at day 5 did only reach the target for 1 antibiotic. One patient did not reach target for any of the 2 antibiotics. Conclusions. For the individual orally administered antibiotic, the majority reached the target level. Patients with sub-target levels were compensated by the administration of 2 different antibiotics. The findings support the efficacy of oral step-down antibiotic treatment in patients with infective endocarditis.

Between November and December 2021, the first ever recorded outbreak of enteroinvasive Escherichia coli in Denmark occurred at national scale. We describe the investigation of this outbreak, which was initially recognised in early December 2021. A total of 88 cases (58 female; 30 male) with a median age of 52 years (range: 0-91) were detected by PCR-based diagnostic methods. Case ascertainment was complicated by current culture-free diagnostic procedures, with only 34 cases confirmed by culture, serotyping and whole genome sequencing. Isolates from cases grouped into two serotypes (O136:H7 and O96:H19), which was supported by whole-genome-sequence-phylogeny, also yielding two clusters. Interviews of 42 cases and traceback investigation pointed towards consumption of ready-to-eat salads as the outbreak cause. While the ready-to-eat salads comprised different vegetables, imported spring onions were the only common ingredient and thus the likely source. Environmental investigations failed to recover outbreak strains. This report highlights the value of fast typing (here O-typing) to confirm cases in an outbreak situation. Timely communication and data sharing are also important, and were facilitated by the national collaboration between relevant laboratories, the public health institute and the veterinary and food administration. High hygiene standards for imported fresh vegetables intended for ready-to-eat products are essential.

BackgroundOnly a subset of enteric pathogens is under surveillance in Denmark, and knowledge on the remaining pathogens detected in acute gastroenteritis is limited. Here, we present the one-year incidence of all enteric pathogens diagnosed in Denmark, a high-income country, in 2018 and an overview of diagnostic methods used for detection.MethodsAll 10 departments of clinical microbiology completed a questionnaire on test methods and provided 2018-data of persons with positive stool samples with Salmonella species, Campylobacter jejuni/coli, Yersinia enterocolitica, Aeromonas species, diarrheagenic Escherichia coli (Enteroinvasive (EIEC), Shiga toxin-producing (STEC), Enterotoxigenic (ETEC), Enteropathogenic (EPEC), and intimin-producing/attaching and effacing (AEEC)), Shigella species., Vibrio cholerae, norovirus, rotavirus, sapovirus, adenovirus, Giardia intestinalis, Cryptosporidium species, and Entamoeba histolytica.ResultsEnteric bacterial infections were diagnosed with an incidence of 229.9 cases/100,000 inhabitants, virus had an incidence of 86/100,000 and enteropathogenic parasites of 12.5/100,000. Viruses constituted more than half of diagnosed enteropathogens for children below 2 years and elderly above 80 years. Diagnostic methods and algorithms differed across the country and in general PCR testing resulted in higher incidences compared to culture (bacteria), antigen-test (viruses), or microscopy (parasites) for most pathogens.ConclusionsIn Denmark, the majority of detected infections are bacterial with viral agents primarily detected in the extremes of ages and with few intestinal protozoal infections. Incidence rates were affected by age, clinical setting and local test methods with PCR leading to increased detection rates. The latter needs to be taken into account when interpreting epidemiological data across the country.

Background Since 2008, Danish national surveillance of Clostridioides difficile has focused on binary toxin-positive strains in order to monitor epidemic types such as PCR ribotype (RT) 027 and 078. Additional surveillance is needed to provide a more unbiased representation of all strains from the clinical reservoir. Aim Setting up a new sentinel surveillance scheme for an improved understanding of type distribution relative to time, geography and epidemiology, here presenting data from 2016 to 2019. Methods For 2─4 weeks in spring and autumn each year between 2016 and 2019, all 10 Danish Departments of Clinical Microbiology collected faecal samples containing toxigenic C. difficile. Isolates were typed at the national reference laboratory at Statens Serum Institut. The typing method in 2016–17 used tandem-repeat-sequence typing, while the typing method in 2018–19 was whole genome sequencing. Results During the study period, the sentinel surveillance scheme included ca 14–15% of all Danish cases of C. difficile infections. Binary toxin-negative strains accounted for 75% and 16 of the 20 most prevalent types. The most common sequence types (ST) were ST2/13 (RT014/020) (19.5%), ST1 (RT027) (10.8%), ST11 (RT078) (6.7%), ST8 (RT002) (6.6%) and ST6 (RT005/117) (5.1%). The data also highlighted geographical differences, mostly related to ST1 and temporal decline of ST1 (p = 0.0008) and the increase of ST103 (p = 0.002), ST17 (p = 0.004) and ST37 (p = 0.003), the latter three binary toxin-negative. Conclusion Sentinel surveillance allowed nationwide monitoring of geographical differences and temporal changes in C. difficile infections in Denmark, including emerging types, regardless of binary toxin status.

Background Monitoring of microbiological cause of infective endocarditis (IE) remains key in the understanding of IE; however, data from large, unselected cohorts are sparse. We aimed to examine temporal changes, patient characteristics, and in-hospital and long-term mortality, according to microbiological cause in patients with IE from 2010 to 2017. Methods and Results Linking Danish nationwide registries, we identified all patients with first-time IE. In-hospital and long-term mortality rates were assessed according to microbiological cause and compared using multivariable adjusted logistic regression analysis and Cox proportional hazard analysis, respectively. A total of 4123 patients were included. Staphylococcus aureus was the most frequent cause (28.1%), followed by Streptococcus species (26.0%), Enterococcus species (15.5%), coagulase-negative staphylococci (6.2%), and "other microbiological causes" (5.3%). Blood culture-negative IE was registered in 18.9%. The proportion of blood culture-negative IE declined during the study period, whereas no significant changes were seen for any microbiological cause. Patients with Enterococcus species were older and more often had a prosthetic heart valve compared with other causes. For Streptococcus species IE, in-hospital and long-term mortality (median follow-up, 2.3 years) were 11.1% and 58.5%, respectively. Compared with Streptococcus species IE, the following causes were associated with a higher in-hospital mortality: S aureus IE (odds ratio [OR], 3.48 [95% CI, 2.74-4.42]), Enterococcus species IE (OR, 1.48 [95% CI, 1.11-1.97]), coagulase-negative staphylococci IE (OR, 1.79 [95% CI, 1.21-2.65]), "other microbiological cause" (OR, 1.47 [95% CI, 0.95-2.27]), and blood culture-negative IE (OR, 1.99 [95% CI, 1.52-2.61]); and the following causes were associated with higher mortality following discharge (median follow-up, 2.9 years): S aureus IE (hazard ratio [HR], 1.39 [95% CI, 1.19-1.62]), Enterococcus species IE (HR, 1.31 [95% CI, 1.11-1.54]), coagulase-negative staphylococci IE (HR, 1.07 [95% CI, 0.85-1.36]), "other microbiological cause" (HR, 1.45 [95% CI, 1.13-1.85]), and blood culture-negative IE (HR, 1.05 [95% CI, 0.89-1.25]). Conclusions This nationwide study showed that S aureus was the most frequent microbiological cause of IE, followed by Streptococcus species and Enterococcus species. Patients with S aureus IE had the highest in-hospital mortality.

Background: Intestinal failure (IF) is defined by a need for intravenous (IV) supplementation. Patients may present with multiple morbidities, and IV treatments carry a risk for catheter-related complications. Few studies described patient characteristics and clinical outcomes according to type of IF. Methods: We consecutively included patients who were admitted to a newly established inpatient IF unit (IFU) from 2013 through 2017. We evaluated patient characteristics and clinical outcomes of all patients' first admission. Outcomes included IF classification, length of stay, central line-associated blood stream infection (CLABSI), and discharge on home parenteral support (HPS). Follow-up was conducted six months after discharge for mortality and the continued need for HPS. Results: A total of 236 patients were evaluated, including 39 (17%) with type 1 IF, 123 (52%) with type 2 IF, and 74 (31%) with type 3 IF. Of 91 who had a central venous catheter (CVC) on admission, CLABSI was present in 11 (12%). The CLABSI occurrence during admissionwas 2 (1%) of 173 patients with a CVC. Mean length of stay declined from mean 33 days (95% confidence interval (CI): 26.2-42.5) in 2013 to 15 days (95% CI: 12.2-17.7) in 2017 (p < 0.0001). Undiagnosed comorbidity was revealed in 165 patients (70%) with unchanged frequency during the study period (p = 0.8). Sixty-seven (28%) patients were discharged with HPS. Conclusions: Inpatients with IF present with multiple morbidities. CLABSI should be investigated on admission. A low inpatient CLABSI rate may be achieved through the implementation of a specialised IFU. (c) 2020 The Authors. Published by Elsevier Ltd on behalf of European Society for Clinical Nutrition and Metabolism. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Renal transplant recipients (RTRs) are highly susceptible to infections, and antimicrobial resistance is an increasing problem with limited treatment options. Faecal microbiota transplantation (FMT) is effective for recurrent Clostridium difficile infection and may be used for patients with intestinal carriage of multidrug-resistant (MDR) microorganisms. We present a RTR who suffered from recurrent urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase-producing (ESBL+) Klebsiella pneumoniae. Blood and urinary isolates revealed the same antibiotic susceptibility pattern, and whole-genome sequencing confirmed identical isolates in blood and urine. Despite several treatments with meropenem, the patient experienced recurrent infections that caused hospitalisation. ESBL+ K. pneumoniae was isolated in faeces. In an attempt to decolonise the gut, FMT was performed. A few days after nasojejunal infusion of donor faeces, the patient experienced a single relapse of UTI. During the subsequent 12 months, no further episodes of UTI occurred. Absence of ESBL+ K. pneumoniae in urine and faeces was demonstrated during follow-up. We conclude that FMT may be an effective treatment in RTRs with recurrent UTIs caused by intestinal colonisation with MDR organisms.

In a randomized trial of patients with rCDI, we found the combination of vancomycin and FMT to be superior to fidaxomicin or vancomycin, based on endpoints of clinical and microbiological resolution or clinical resolution alone. ClinicalTrials.gov no: NCT02743234. EudraCT j.no: 2015-003004-24.

As the use of fecal microbiota transplantation (FMT) has gained momentum, an increasing need for continuous access to healthy feces donors has developed. Blood donors constitute a healthy subset of the general population and may serve as an appropriate group for recruitment. In this study, we investigated the suitability of blood donors as feces donors. In a prospective cohort study, we recruited blood donors onsite at a public Danish blood bank. Following their consent, the blood donors underwent a stepwise screening process: First, blood donors completed an electronic pre-screening questionnaire to rule out predisposing risk factors. Second, eligible blood donors had blood and fecal samples examined. Of 155 blood donors asked to participate, 137 (88%) completed the electronic pre-screening questionnaire, 16 declined, and 2 were excluded. Of the 137 donors who completed the questionnaire, 79 (58%) were excluded mainly due to having an allergy, being overweight, or presenting gastrointestinal complaints. Among the remaining 58 (37%) donors, complete blood and feces screenings were obtained from 46 (79%). Of these 46 donors, 15 (33%) were excluded primarily due to abnormal blood results or the presence of apathogenic intestinal parasites. Overall, 31 (20%; 95% confidence interval 14-27%) of the 155 blood donors qualified as feces donors. In conclusion, blood donors constitute a suitable and motivated population for a continuous recruitment of voluntary feces donors. We found that a stepwise recruitment procedure was feasible and that 20% of the blood donors were eligible for feces donation.

BACKGROUNDThe buttonhole cannulation technique for arteriovenous fistulas is widely used, but has been associated with an increased rate of vascular access-related infections. We describe the frequency and type of bacterial colonization of the buttonhole tract over time and associated clinical infections.STUDY DESIGNA prospective observational cohort study with 9 months of follow-up.SETTING & PARTICIPANTS84 in-center hemodialysis patients using the buttonhole cannulation technique at 2 Danish dialysis centers.OUTCOMESBacterial growth from the buttonhole tract and dialysis cannula tip and clinically important infections during follow-up.MEASUREMENTSOn 3 occasions 1 month apart, cultures before dialysis (from the skin surrounding the buttonhole before disinfection and from the cannulation tract after disinfection and scab removal) and the cannula tip after dialysis. Patients with positive cultures from the buttonhole tract or cannula tip had repeat cultures within 1 week, along with blood cultures.RESULTSGrowth from the cannulation tract and/or cannula tip at each of the 3 monthly sets of cultures was found in 18%, 20%, and 17% of patients, respectively. 38% of patients had at least 1 positive culture from the buttonhole tract. Sustained growth was detected in 11% of patients, whereas asymptomatic bacteremia was seen in 30% of those with positive buttonhole cultures. Staphylococci species were the most common pathogens (Staphylococcus aureus, 25%; and Staphylococcus epidermidis, 41%). Colonization-positive buttonholes had more localized redness and slightly more tenderness. During follow-up, significantly more access-related infections were diagnosed among those with positive buttonhole cultures (P<0.001).LIMITATIONSNo comparison to area puncture cannulation technique. Blood cultures were obtained only from patients with positive buttonhole bacteriology.CONCLUSIONSTransient or sustained colonization of the buttonhole tract by staphylococci and asymptomatic bacteremia is common in hemodialysis patients, implying a substantial risk for access-related infections among patients using a buttonhole cannulation technique. These findings suggest the possible value of surveillance of buttonhole colonization.

BACKGROUND:In accordance with international guidelines, primary antifungal treatment (AFT) of candidemia with echinocandins has been nationally recommended in Denmark since 2009. Our nationwide cohort study describes the management of candidemia treatment focusing on the impact of prophylactic AFT on species distribution, the rate of adherence to the recommended national guidelines for AFT, and the effect of AFT on patient outcomes.MATERIALS AND METHODS:Incident candidemia cases from a 2-year period, 2010-2011, were included. Information on AFT was retrospectively collected from patient charts. Vital status was obtained from the Danish Civil Registration System. HRs of mortality were reported with 95% CIs using Cox regression.RESULTS:A total of 841 candidemia patients was identified. Prior to candidemia diagnosis, 19.3% of patients received AFT (162/841). The risk of non-albicans candidemia increased after prior AFT (59.3% vs 45.5% among nontreated). Echinocandins as primary AFT were given for 44.2% (302/683) of patients. Primary treatment with echinocandins resulted in adequate treatment in a higher proportion of patients (97.7% vs 72.1%) and was associated with lower 0- to 14-day mortality compared with azole treatment (adj. HR 0.76, 95% CI: 0.55-1.06). Significantly lower 0- to 14-day mortality was observed for patients with Candida glabrata and Candida krusei with echinocandin treatment compared with azole treatment (adj. HR 0.50, 95% CI: 0.28-0.89), but not for patients with Candida albicans or Candida tropicalis.CONCLUSION:The association shown between prior AFT and non-albicans species underlines the importance of treatment history when selecting treatment for candidemia. Compliance with national recommendations was low, but similar to previously reported international rates. Primary treatment of candidemia with echinocandins compared with azoles yielded both a higher proportion of adequately treated patients and improved mortality rates. This real-life setting supports guidelines recommendation, and further focus on compliance with these seems warranted.

Shared bicycles are prevailing in China but the extent to which they contribute to maintaining and transmitting pathogens and antibiotic-resistant bacteria remain largely unknown. To fill the knowledge gap, herein, swab samples (n = 963) were collected from handlebars of shared bicycles in areas of hospital, school, metro station (n = 887) and riders (n = 76) in Chengdu, China. Staphylococci (n = 241) and Enterococci (n = 69) were widely distributed across sampling locations at a frequency of 2.3%–12.9%, and 0.08%–5.5%, respectively. Bicycle or rider-borne Gram-positive bacteria were frequently resistant to clinically important antibiotics including linezolid, fosfomycin, and vancomycin, and a significant portion of these isolates (3.4%–16.6% for Staphylococci and 0.1%–13.8% for Enterococci) indicated multidrug resistance. Nineteen Staphylococcus aureus isolates were identified in this collection and 52.6% of which were considered as methicillin-resistant S. aureus. Whole genome sequencing further characterized 26 antimicrobial resistance genes (ARGs) including fosB, fusB, and lnu(G) in S. aureus and 21 ARGs including optrA in Enterococci. Leveraging a complementary approach with conventional MLST, whole genome SNP and MLST analyses, we present that genetically closely-related bacteria were found in bicycles and riders across geographical-distinct locations suggesting bacterial transmission. Further, five new ST types 5697–5701 were firstly characterized in S. aureus. ST 942 and ST 1640 are new ST types observed in E. faecalis, and E. faecium, respectively. Our results highlighted the risk of shared bicycle system in disseminating pathogens and antibiotic resistance which warrants effective disinfections.

Acute alcoholic hepatitis (AH) is a life-threatening disease and its course is often determined by infections. However, the pattern of pathogens has not been studied. We examined the microbiological pathogens that caused blood-borne infection in patients with AH. We included 32 AH patients without infection at inclusion. Patients were followed for 1 month and their infection status was recorded based on clinical records, radiologic exams and cultures of different secreta. Nine patients (28%) developed blood culture-positive infections. The agents were of heterogeneous aetiology and came from various sites of infection. Candida species accounted for three of these infections (33%). Five patients (16%) died, two of which had positive blood cultures. A high fraction was invasively infected by a heterogeneous spectrum of microbes including yeasts and commensal bacteria. This may reflect the severe immune impairment of AH and suggests thorough infection screening and an immediate broad-spectrum antibiotic approach if infection is suspected.