Staphylococcus jettensis sp nov., a coagulase-negative staphylococcal species isolated from human clinical specimens

Eight coagulase-negative, novobiocin-susceptible staphylococcal strains were isolated from human clinical specimens at two different Belgian medical facilities. All strains were non-motile, Gram-stain-positive, catalase-positive cocci. DNA G+C content, peptidoglycan type, menaquinone pattern, the presence of teichoic acid and cellular fatty acid composition were in agreement with the characteristics of species of the genus Staphylococcus. Sequencing of the 16S rRNA gene and four housekeeping genes (dnaJ, tuf, gap and rpoB) demonstrated that these strains constitute a separate taxon within the genus Staphylococcus. Less than 41 % DNA-DNA hybridization with the most closely related species of the genus Staphylococcus (Staphylococcus haemolyticus, Staphylococcus hominis and Staphlococcus lugdunensis) was observed. Key biochemical characteristics that allowed these bacteria to be distinguished from their nearest phylogenetic neighbours are arginine dihydrolase positivity, ornithine decarboxylase negativity and inability to produce acid aerobically from D-mannose, a-lactose and turanose. Acid is produced aerobically from trehalose. Based on these results, a novel species of the genus Staphylococcus is described and named Staphylococcus jettensis sp. nov. The type strain is SE0110(T) (=LMG 26879(T)=CCUG 62657(T)=DSM 26618(T))

Occurrence of macrolides resistance in Legionella pneumophila ST188: results of the Belgian epidemiology and resistome investigation of clinical isolates

Objectives The incidence of Legionnaires’ disease steadily increases worldwide. Although Legionella pneumophila is known as pathogenic, systematic investigations into antibiotic resistance are scarce, and reports of resistance in isolates are recently emerging. Methods Clinical cases and metadata reported to the Belgian National Reference Centre between 2011 and 2022 were retrospectively analyzed. A total of 283 clinical isolates were typed by core genome multi-locus sequence typing (cgMLST). Acquired genes or mutations triggering resistance were extracted from all of them. Results The number of Legionnaires’ disease cases has increased in Belgium. Urinary antigen testing remains the main used test, but polymerase chain reaction and serology allow the diagnostic in 14.8% and 2.4% of cases, respectively. cgMLST showed a good discrimination between sequence typing (ST) and minimal variation for ST47 isolates, whereas ST1s were more diverse. Genotypic screening identified a 23S ribosomal RNA mutation linked to a high-level macrolide resistance in one isolate of ST188, which is genetically closed to resistant isolates from France. Conclusion The increase in incidence is of concern and likely an under-estimate due to the reliance on urine antigen testing. Routine typing by cgMLST allows good discrimination and the first clinical isolate reported as resistant for macrolides was cultured, underscoring the need to define resistance breakpoints and incorporate antimicrobial susceptibility testing as routine clinical investigation practice

Genomics of an endemic cystic fibrosis Burkholderia multivorans strain reveals low within-patient evolution but high between-patient diversity

In many countries, Burkholderia multivorans is the most prevalent species within the Burkholderia cepacia complex (Bcc) found infecting the lungs of patients with cystic fibrosis (CF). Its positive identification is of immediate concern to the health of the patient as it is notoriously hard to eradicate using antibiotics and can cause necrosis of the lung tissues (cepacia syndrome). Infection control measures reduced the prevalence of B. cenocepacia in CF wards, but patients continue to acquire infections by B. multivorans from environmental sources. In most reported cases, the infecting strains are unique except in rare cases in which cross-infection is observed between patients. We report here an endemic strain of B. multivorans with sequence type ST-742 that has been infecting multiple patients, without evidence for cross-infection. We investigated the epidemiology and genomics of this ST-742 strain and show that it is microdiverse, as isolates between-patients exhibit numerous genomic differences, at scales that have not been observed previously when looking at evolutionary trajectories within-patients. Additionally, we found that the specific genomic background of a given strain may dictate the strategy of adaptation within the CF lung. Burkholderia multivorans is a member of the Burkholderia cepacia complex (Bcc), notorious for its pathogenicity in persons with cystic fibrosis. Epidemiological surveillance suggests that patients predominantly acquire B. multivorans from environmental sources, with rare cases of patient-to-patient transmission. Here we report on the genomic analysis of thirteen isolates from an endemic B. multivorans strain infecting four cystic fibrosis patients treated in different pediatric cystic fibrosis centers in Belgium, with no evidence of cross-infection. All isolates share an identical sequence type (ST-742) but whole genome analysis shows that they exhibit peculiar patterns of genomic diversity between patients. By combining short and long reads sequencing technologies, we highlight key differences in terms of small nucleotide polymorphisms indicative of low rates of adaptive evolution within patient, and well-defined, hundred Kbps-long segments of high enrichment in mutations between patients. In addition, we observed large structural genomic variations amongst the isolates which revealed different plasmid contents, active roles for transposase IS3 and IS5 in the deactivation of genes, and mobile prophage elements. Our study shows limited within-patient B. multivorans evolution and high between-patient strain diversity, indicating that an environmental microdiverse reservoir must be present for this endemic strain, in which active diversification is taking place. Furthermore, our analysis also reveals a set of 30 parallel adaptations across multiple patients, indicating that the specific genomic background of a given strain may dictate the route of adaptation within the cystic fibrosis lung

From Investigating a Case of Cellulitis to Exploring Nosocomial Infection Control of ST1 Legionella pneumophila Using Genomic Approaches.

peer reviewedLegionella pneumophila can cause a large panel of symptoms besides the classic pneumonia presentation. Here we present a case of fatal nosocomial cellulitis in an immunocompromised patient followed, a year later, by a second case of Legionnaires' disease in the same ward. While the first case was easily assumed as nosocomial based on the date of symptom onset, the second case required clear typing results to be assigned either as nosocomial and related to the same environmental source as the first case, or community acquired. To untangle this specific question, we applied core-genome multilocus typing (MLST), whole-genome single nucleotide polymorphism and whole-genome MLST methods to a collection of 36 Belgian and 41 international sequence-type 1 (ST1) isolates using both thresholds recommended in the literature and tailored threshold based on local epidemiological data. Based on the thresholds applied to cluster isolates together, the three methods gave different results and no firm conclusion about the nosocomial setting of the second case could been drawn. Our data highlight that despite promising results in the study of outbreaks and for large-scale epidemiological investigations, next-generation sequencing typing methods applied to ST1 outbreak investigation still need standardization regarding both wet-lab protocols and bioinformatics. A deeper evaluation of the L. pneumophila evolutionary clock is also required to increase our understanding of genomic differences between isolates sampled during a clinical infection and in the environment

Uncovering Gaps in Knowledge: A Survey of Belgian General Practitioners' Awareness of Legionnaires' Disease Diagnostic Testing.

peer reviewedBackground: The incidence of Legionnaires' disease (LD) is increasing steadily in Europe. Its early diagnosis by general practitioners (GPs) is crucial for better patient outcomes. Study objectives: This study assessed Belgian GPs' knowledge about LD and the accessibility of diagnostic tests in their practices. Methods: A specifically designed questionnaire was distributed to actively practicing GPs, including primary care trainees, between 31 January 2022 and 13 March 2022. This survey targeted approximately 4200 GPs with an estimated population catchment of 30% of the actively working Belgian GPs. Results: The response rate was estimated at 3%. Over 70% of the GPs correctly identified the LD occurrence peak, major risk factors, and clinical manifestations. While 62% of participants preferred the Legionella pneumophila urinary antigen test (UAT) as a primary diagnostic method, 75% were unsure about its availability within their laboratories and 82% had not prescribed it in the last year. Finally, 76% expressed a desire for additional information on this topic. Conclusions: Belgian GPs should evaluate the possibility of conducting UAT testing in their laboratories to enhance LD case management and improve their preparedness. Furthermore, initiatives should be implemented to improve communication between specialists and GPs and develop educational programs directed at Belgian GPs

Insulin resistance, adiponectin and adverse outcomes following elective cardiac surgery: a prospective follow-up study

<p>Abstract</p> <p>Background</p> <p>Insulin resistance and adiponectin are markers of cardio-metabolic disease and associated with adverse cardiovascular outcomes. The present study examined whether preoperative insulin resistance or adiponectin were associated with short- and long-term adverse outcomes in non-diabetic patients undergoing elective cardiac surgery.</p> <p>Methods</p> <p>In a prospective study, we assessed insulin resistance and adiponectin levels from preoperative fasting blood samples in 836 patients undergoing cardiac surgery. Population-based medical registries were used for postoperative follow-up. Outcomes included all-cause death, myocardial infarction or percutaneous coronary intervention, stroke, re-exploration, renal failure, and infections. The ability of insulin resistance and adiponectin to predict clinical adverse outcomes was examined using receiver operating characteristics.</p> <p>Results</p> <p>Neither insulin resistance nor adiponectin were statistically significantly associated with 30-day mortality, but adiponectin was associated with an increased 31-365-day mortality (adjusted odds ratio 2.9 [95% confidence interval 1.3-6.4]) comparing the upper quartile with the three lower quartiles. Insulin resistance was a poor predictor of adverse outcomes. In contrast, the predictive accuracy of adiponectin (area under curve 0.75 [95% confidence interval 0.65-0.85]) was similar to that of the EuroSCORE (area under curve 0.75 [95% confidence interval 0.67-0.83]) and a model including adiponectin and the EuroSCORE had an area under curve of 0.78 [95% confidence interval 0.68-0.88] concerning 31-365-day mortality.</p> <p>Conclusions</p> <p>Elevated adiponectin levels, but not insulin resistance, were associated with increased mortality and appear to be a strong predictor of long-term mortality. Additional studies are warranted to further clarify the possible clinical role of adiponectin assessment in cardiac surgery.</p> <p>Trial Registration</p> <p>The Danish Data Protection Agency; reference no. 2007-41-1514.</p

Dose dependent effect of statins on postoperative atrial fibrillation after cardiac surgery among patients treated with beta blockers

<p>Abstract</p> <p>Background</p> <p>Previous studies on the effects of Statins in preventing atrial fibrillation (AF) after cardiac surgery have shown conflicting results. Whether statins prevent AF in patients treated with postoperative beta blockers and whether the statin-effect is dose related are unknown.</p> <p>Methods</p> <p>We retrospectively studied 1936 consecutive patients who underwent coronary artery bypass graft (CABG) (n = 1493) or valve surgery (n = 443) at the Minneapolis Veterans Affairs Medical Center. All patients were in sinus rhythm before the surgery. Postoperative beta blockers were administered routinely (92% within 24 hours postoperatively).</p> <p>Results</p> <p>Mean age was 66+10 years and 68% of the patients were taking Statins. Postoperative AF occurred in 588 (30%) patients and led to longer length of stay in the intensive care unit versus those without AF (5.1+7.6 days versus 2.5+2.3 days, p < 0.0001). Patients with a past history of AF had a 5 times higher risk of postoperative AF (odds ratio 5.1; 95% confidence interval 3.4 to 7.7; p < 0.0001). AF occurred in 31% of patients taking statins versus 29% of the others (p = 0.49). In multivariable analysis, statins were not associated with AF (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.7 to 1.2; p = 0.59). However, in a subgroup analysis, the patients treated with Simvastatin >20 mg daily had a 36% reduction in the risk of postoperative AF (OR 0.64, 95% CI 0.43 to 0.6; p = 0.03) in comparison to those taking lower dosages.</p> <p>Conclusion</p> <p>Among cardiac surgery patients treated with postoperative beta blockers Statin treatment reduces the incidence of postoperative AF when used at higher dosages</p

Transmitted drug resistance, selection of resistance mutations and moderate antiretroviral efficacy in HIV-2: Analysis of the HIV-2 Belgium and Luxembourg database

BACKGROUND: Guidelines established for the treatment of HIV-1 infection and genotype interpretation do not apply for HIV-2. Data about antiretroviral (ARV) drug efficacy and resistance mutations is scarce. METHODS: Clinical data about HIV-2 infected patients in Belgium and Luxembourg were collected and the effect of ARV therapy on plasma viral load and CD4 counts were analysed. Viral RNA encoding for protease (PR) and reverse transcriptase (RT) from ARV-naive and treated patients were sequenced. RESULTS: Sixty-five HIV-2 infected patients were included in this cohort. Twenty patients were treated with 25 different ARV combinations in a total of 34 regimens and six months after the start of ARV therapy, only one third achieved viral load suppression. All of these successful regimens bar one contained protease inhibitors (PIs). Mean CD4 gains in the group of viral load suppressors and the group of patients treated with PI-containing regimens were respectively significantly higher than in the group of non-suppressors and the group of PI-sparing regimens. The most frequent mutations selected under therapy (compared to HIV-2 ROD) were V71I, L90M and I89V within PR. Within RT, they were M184V, Q151M, V111I and K65R. All of these mutations, except K65R and M184V, were also found in variable proportions in ARV-naive patients. CONCLUSION: Despite a high rate of ARV treatment failure, better virological and immunological results were achieved with PI-containing regimens. The analysis of polymorphic positions and HIV-2 specific mutations selected during therapy showed for the first time that transmission of drug resistant viruses has occurred in Belgium and Luxembourg. The high heterogeneity in ARV combinations reflects a lack of guidelines for the treatment of HIV-2 infection