Emergence and spread of a mupirocin-resistant variant of the European epidemic fusidic acid-resistant impetigo clone of Staphylococcus aureus, Belgium, 2013 to 2023.

BackgroundAntimicrobial resistance to mupirocin and fusidic acid, which are used for treatment of skin infections caused by Staphylococcus aureus, is of concern.AimTo investigate resistance to fusidic acid and mupirocin in meticillin-susceptible S. aureus (MSSA) from community-acquired skin and soft tissue infections (SSTIs) in Belgium.MethodsWe collected 2013-2023 data on fusidic acid and mupirocin resistance in SSTI-associated MSSA from two large Belgian laboratories. Resistant MSSA isolates sent to the Belgian Staphylococci Reference Centre were spa-typed and analysed for the presence of the eta and etb virulence genes and the mupA resistance gene. In addition, we whole genome sequenced MSSA isolates collected between October 2021 and September 2023.ResultsMupirocin resistance increased between 2013 and 2023 from 0.5-1.5% to 1.7-5.6%. Between 2018 and 2023, 91.4% (64/70) of mupirocin-resistant isolates were co-resistant to fusidic acid. By September 2023, between 8.9% (15/168) and 10.1% (11/109) of children isolates from the two laboratories were co-resistant. Of the 33 sequenced isolates, 29 were sequence type 121, clonal and more distantly related to the European epidemic fusidic acid-resistant impetigo clone (EEFIC) observed in Belgium in 2020. These isolates carried the mupA and fusB genes conferring resistance to mupirocin and fusidic acid, respectively, and the eta and etb virulence genes.ConclusionWe highlight the spread of a mupirocin-resistant EEFIC in children, with a seasonal trend for the third quarter of the year. This is of concern because this variant is resistant to the two main topical antibiotics used to treat impetigo in Belgium.

Helicobacter pylori Infections in Children.

In the context of epidemiology, host response, disease presentation, diagnosis, and treatment management, the manifestation of Helicobacter pylori (H. pylori) infection diverges between children and adults. H. pylori infection stands out as one of the most prevalent bacterial infections globally, and its prevalence in both children and adults is decreasing in many developing countries but some still struggle with a high prevalence of pediatric H. pylori infection and its consequences. The majority of infected children are asymptomatic and pediatric studies do not support the involvement of H. pylori in functional disorders such as recurrent abdominal pain. The pathophysiology of H. pylori infection relies on complex bacterial virulence mechanisms and their interaction with the host immune system and environmental factors. This interaction gives rise to diverse gastritis phenotypes, which subsequently influence the potential development of various gastroduodenal pathologies. In clinical settings, the diagnosis of this infection in childhood requires an upper gastrointestinal endoscopic exam with mucosal biopsy samples for histology and culture, or Polymerase Chain Reaction (PCR) at the very least. When warranted, eradication treatment should be given when good compliance is expected, and there should be systematic use of a treatment adapted to the antimicrobial susceptibility profile. To combat the burgeoning threat of multidrug resistance, vigilant surveillance of resistance patterns and strategic antibiotic management are paramount.

Antibiotic resistance, heteroresistance, and eradication success of Helicobacter pylori infection in children.

BACKGROUND: Antibiotic resistance is a well-known factor of Helicobacter pylori eradication failure. Heteroresistance indicates the coexistence of resistant and susceptible strains and might lead to underestimating antimicrobial resistance. This study aims to evaluate the susceptibility profile, the frequency of heteroresistance of H. pylori strains, and their effect on eradication success in a pediatric population. MATERIALS AND METHODS: Children aged 2-17 years who underwent an upper gastrointestinal endoscopy from 2011 to 2019 with positive H. pylori status were included. Susceptibility was measured by disk diffusion and E-test. The difference in susceptibility profiles between isolates from the antrum and the corpus was used to detect heteroresistance. For those who received eradication treatment, we evaluated eradication rate and factors affecting treatment success. RESULTS: Inclusion criteria were met by 565 children. Strains susceptible to all antibiotics were detected in 64.2%. Primary resistance rates for clarithromycin (CLA), metronidazole (MET), levofloxacin (LEV), tetracyclin (TET), and amoxicillin (AMO) were 11%, 22.9%, 6.9%, 0.4%, and 0% and secondary resistance rates were 20.4%, 29.4%, 9.3%, 0%, and 0%. Heteroresistance was present in untreated children in 2%, 7.1%, 0.7%, 0.7%, and 0% for CLA, MET, LEV, TET, and AMO. First-line eradication rates were 78.5% in intention-to-treat (ITT), 88.3% in full-analysis-set (FAS), and 94.1% in per-protocol (PP). Factors affecting eradication success were the duration of treatment when the triple-tailored treatment was used, the number of daily doses of amoxicillin administered, and the patient's adherence to treatment. CONCLUSIONS: This study shows the presence of relatively low primary resistance rates for H. pylori isolates but demonstrates the presence of heteroresistance in our population. Routine biopsies from the antrum and corpus must be considered for susceptibility testing to allow tailored treatments and increase eradication rates. Treatment success is affected by treatment choice, correct dosing of medications, and adherence. All these factors should be considered when evaluating the efficacy of an eradication regimen.

Incidence and clinical and microbiological features of invasive and probable invasive streptococcal group A infections in children and adults in the Brussels-Capital Region, 2005-2020.

Assess the incidence, risk factors, clinical and microbiological features, and outcome of both probable invasive and invasive group A Streptococcus (GAS) infections in children and adults in the BrusselsCapital Region between 2005 and 2020. A retrospective, multicentric study was performed in three university hospitals in Brussels. Patients were identified through the centralized laboratory information system. Epidemiological and clinical data were collected from patients' hospital records. A total of 467 cases were identified. Incidence has increased from 2.1 to 10.9/100,000 inhabitants between 2009 and 2019 in non-homeless adults while it was above 100/100,000 on homeless in years with available denominators. Most of GAS were isolated from blood (43.6%), and the most common clinical presentation was skin and soft tissue infections (42.8%). A third of all the patients needed surgery, a quarter was admitted to the intensive care unit, and 10% of the adult patients died. Wounds and chickenpox disease were the main risk factors for children. Tobacco, alcohol abuse, wounds or chronic skin lesion, being homeless, and diabetes were identified as major predisposing factors for adults. The most common emm clusters were D4, E4, and AC3; 64% of the isolates were theoretically covered by the 30-valent M-protein vaccine. The burden of invasive and probable invasive GAS infections is on the rise in the studied adult population. We identified potential interventions that could contribute to decrease this burden: appropriate care of wounds, specifically among homeless and patients with risk factors such as diabetes and systematic chickenpox vaccination for children.

Primary Helicobacter pylori resistance to antimicrobials in the Brussels area in 2021.

This manuscript summarizes current primary resistance of Helicobacter pylori to antibiotics in Brussels in 2021. Resistance rates were estimated at 18% for clarithromycin, 24% for levofloxacin, 52% for metronidazole, and 0% for amoxicillin and tetracycline. When compared to 2016, resistance rates remain stable, except an increase of 30% for metronidazole.

Characterization of hypervirulent Klebsiella pneumoniae isolates in Belgium.

Hypervirulent Klebsiella pneumoniae (hvKp) raised concern worldwide. We studied 22 hvKp clinical invasive isolates referred to the Belgian national reference laboratory between 2014 and 2020. Sixty-four percent of the isolates expressed K2 capsular serotype and belonged to 7 different MLST lineages, while 32% expressed K1 (all belonging to ST23) and were associated with liver abscesses. Primary extra-hepatic infections were reported in 36% and sepsis for 95% of the patients with 30% of deaths. Improved clinical and microbiological diagnostics are required as hvKp may represent an underestimated cause of community-acquired invasive infections in Belgium.

Primary antibiotic resistance of Helicobacter pylori isolates is twofold more frequent in HIV-positive than HIV-negative individuals: A descriptive observational study.

The antimicrobial susceptibility of Helicobacter pylori strains isolated from HIV-positive individuals is not well characterized. This study aimed to measure the prevalence and long-term trends associated with primary H. pylori antibiotic resistance, evaluate correlations with antibiotic consumption, and compare predictors for H. pylori antibiotic resistance between HIV-positive and HIV-negative individuals. In this longitudinal registry study, we evaluated consecutive adults with and without HIV infection, naïve to H. pylori treatment, who underwent upper gastrointestinal endoscopy and had a positive H. pylori culture, with susceptibility testing available, between 2004 and 2015. Outpatient antibiotic consumption data were based on nationwide aggregated numbers. H. pylori was isolated from gastric biopsies of 3008/8321 patients, 181/477 (37.9%) were HIV-positive and 2827/7844 (36.0%) HIV-negative. Overall cohort mean prevalence of H. pylori primary antibiotic resistance was 11.1% for clarithromycin, 17.8% levofloxacin, and 39.4% metronidazole. The prevalence of H. pylori primary resistance was significantly higher for these three drugs in HIV-positive individuals across the study period. Linear regression showed that the prevalence of clarithromycin and levofloxacin resistance correlated with the country aggregate daily dose consumption of macrolides and quinolones, respectively. Multivariable regression analysis showed that HIV infection is a strong independent risk factor for multiple H. pylori antibiotic resistance. In summary, HIV infection is a risk factor for carrying multi-resistant H. pylori strains and this is correlated with antibiotic consumption. Empirical therapies should be avoided in HIV-positive individuals. These data highlight the need to implement ongoing monitoring of H. pylori antimicrobial susceptibility among HIV-positive individuals. The study is registered at ISRCTN registry, number 13466428: https://www.isrctn.com/ISRCTN13466428.

Efficacy and safety of bismuth-based quadruple therapy for Helicobacter pylori eradication in children.

OBJECTIVES: To evaluate the efficacy and safety of a 10-day quadruple therapy containing colloidal bismuth sub-citrate (CBS), esomeprazole (ESO), amoxicillin (AMO), and metronidazole (MET) for Helicobacter pylori (H. pylori) eradication in children. METHODS: Monocentric, open-label, prospective, single-arm clinical trial in children aged 6-17 years with H. pylori infection. The study was carried out on consecutive patients with upper gastrointestinal symptoms and H. pylori infection confirmed by histology and culture of gastric biopsies. The outcome was evaluated using a 13 C-urea breath test 8-10 weeks post-therapy. Adverse events and compliance were evaluated by daily journal and pill counting. RESULTS: A total of 36 children fulfilling the inclusion criteria were enrolled. Eight (22.2%) of them had a prior H. pylori eradication treatment. Thirteen (36.1%) patients were infected by a strain resistant to MET and 8 (22.2%) by a strain resistant to both MET and Clarithromycin (CLA). In the intention-to-treat population (ITT), eradication was achieved in 35/36 patients (95%CI: 85%-99%). Twenty-three children reported at least one adverse event (63.8%), mostly mild (nausea, vomiting, abdominal pain, diarrhea, dark stool, metallic taste, headache, and rash). The compliance rate was high, with 30 (83.3%) patients taking >90% of the treatment. CONCLUSION: 10-day quadruple therapy containing CBS, ESO, AMO, and MET for H. pylori eradication in children is a safe and very effective solution, especially for previously treated patients and those infected with double resistant strains.

Update of primary Helicobacter pylori resistance to antimicrobials in Brussels, Belgium.

This study aimed to follow the trend of primary antimicrobial resistance in Helicobacter pylori isolates obtained from several centers in Brussels. We observed increasing rates of primary resistance to macrolides (10.5% to 18%) to nitro-imidazoles (28% to 40%) and to fluoroquinolones (12.4% to 22.8%), respectively, from 2008/2009 to 2016.

Evolution of Helicobacter pylori associated with gastroduodenal ulcers or erosions in children over the past 23 years: Decline or steady state?

BACKGROUND: Recent data suggest that in children, the proportion of gastroduodenal ulcers/erosions associated with Helicobacter pylori infection is currently lower than expected. In this study, we trace this proportion over two decades. METHODS: We reviewed the reports of all upper gastrointestinal endoscopies with biopsies for histology and culture over the past 23 years. H pylori status was assessed using several invasive methods. The infection rate during different time periods was compared between children with lesions and controls. RESULTS: A total of 7849 endoscopies were performed in 5983 children (2874 F/3109 M, median age 7.6 years, range 0.1-17.9 years). The endoscopy report was missing in 316 patients. At the first upper gastrointestinal endoscopy, 12.1% of the children presented with gastric and/or duodenal ulcers or erosions with an H pylori infection rate of 35.4%, whereas no such lesions were observed in 87.9% of children in whom the H pylori infection rate was 21.3%. The risk factors associated with such lesions were older age (P < 0.001), male sex (P = 0.002), and H pylori infection (P < 0.0001). Gastric ulcers were not significantly associated with H pylori (24% infected), whereas 52% of duodenal ulcers, 33% of gastric erosions, and 38% of duodenal erosions were associated with H pylori. The proportion of gastroduodenal lesions associated with H pylori remained stable over time. Children with H pylori infection and ulcers were older than those with H pylori infection without ulcers (P < 0.001). CONCLUSIONS: Our study indicates that in our pediatric population, the proportion of ulcers without H pylori infection is higher than previously suggested, and this prevalence has not changed over the past two decades.

Streptococcus pyogenes infections with limited emm-type diversity in the homeless population of Brussels, 2016-2018.

OBJECTIVES: The aim was to characterize the clinical features, outcomes, and strain diversity of laboratory-confirmed Streptococcus pyogenes (group A Streptococcus, GAS) infections among inpatients hospitalized at a tertiary level hospital in Brussels, Belgium, according to the patients' housing status (homeless vs. not homeless). METHODS: Between August 2016 and January 2018, all patients hospitalized with a laboratory-confirmed GAS infection were prospectively enrolled and risk factors were recorded. GAS strains were characterized using emm-typing and emm-clustering in both inpatients and outpatients. Analyses were performed according to homelessness status. RESULTS: During the study period, 48% (28/58) of adults hospitalized with a GAS infection at the tertiary hospital were homeless. The estimated incidence rate was 100 times higher for homeless persons. Skin abscesses were more frequent in the homeless group (21.4% vs. 3.3%) and mortality was high (10.7%). Limited emm-type diversity was found in this group, with four emm-types (64, 77, 83, and 101) accounting for 76.1% of the infections, and the majority of these emm-types belonged to the D4 emm-cluster. Pooled analyses of inpatient and outpatient strains indicated lower diversity in the homeless group. CONCLUSIONS: The homeless are disproportionately affected by GAS and have a higher rate of abscesses and high mortality. The lower emm-type diversity and preferential infection with four emm-types likely reflects endemic circulation of GAS in this population. Preventive strategies are warranted in this fragile population.

Eradication rate of Helicobacter Pylori infection is directly influenced by adherence to therapy in children.

BACKGROUND: Current commonly accepted strategies to eradicate Helicobacter pylori in children are a 10-day sequential treatment or a triple therapy for 7-14 days. To avoid further expensive and possibly risky investigations as well as induction of secondary antimicrobial resistance, a success rate of elimination strategies over 90% in a per-protocol analysis is the target goal but rates observed in clinical trials are lower. Antimicrobial resistance is a well-recognized risk factor for treatment failure; therefore, only a treatment tailored to susceptibility testing should be recommended. Adherence to therapy is also a risk factor for treatment failure but that has been poorly studied. The purpose of this study was to evaluate the influence of adherence to therapy on the elimination rates obtained with different treatment regimens. METHODS: Cohort study analysis of children, aged 2-17 years, treated for Helicobacter pylori infection between October 2011 and December 2013. As a routine clinical practice, children infected with a strain susceptible to clarithromycin and to metronidazole received either a sequential regimen or a 10-day triple therapy while children infected with a strain resistant to clarithromycin or metronidazole received a 10-day triple regimen tailored to antimicrobial susceptibility. The eradication rate was assessed by a negative 13 C-urea breath test performed at least 8 weeks after the end of the treatment and adherence evaluated using a diary. RESULTS: One hundred forty-five children (67 girls/78 boys, median age 9.7 years) fulfilled the inclusion criteria, 118 being infected with a strain susceptible to both clarithromycin and metronidazole, 10 with a clarithromycin resistant, and 17 with a metronidazole resistant strain. A sequential regimen was prescribed in 44, a triple therapy containing clarithromycin in 84 and containing metronidazole in 17. Follow-up data were available for 130/145 and clearance of the infection observed in 105 of them. A concordance of more than 90% between the prescribed and the ingested drugs was observed in 109 children, between 50 and 90% in eight, less than 50% in 11 while these data were unknown for 2/130. A successful eradication was achieved for 89.9% of patients that received at least 90% of the prescribed drugs, whereas the eradication rate for nonadherent patients was 36.6%. Adherence above 90% was significantly higher in the absence of chronic concomitant disease, in the absence of adverse event and results in a significantly higher eradication rate. With the proposed strategy and an adherence higher than 90%, eradication was obtained in 98/109 children, the rate being only significantly superior to 90% with the sequential regimen. CONCLUSION: Adherence to therapy is a very important factor for the outcome and has to be assessed when evaluating the outcome of an H. pylori eradication regimen in order to understand the reasons of treatment failure. As we treated only after evaluation of the resistance of the H. Pylori strains, we were expecting to reach the given objective of 90% successful treatment. Children with adherence to treatment above 90% had a successful outcome of 89,9%, whereas nonadherent had a successful outcome of 36,8%. This is the first time that adherence has been assessed accurately.

Group A streptococcus colonies from a single throat swab can have heterogeneous antimicrobial susceptibility patterns.

This study describes for the first time heterogeneity of antibiotic resistance profiles among group A Streptococcus isolates originating from a single throat swab in patients with acute pharyngitis. For each throat swab, 10 group A Streptococcus colonies were randomly selected from the primary plate and subcultured to a secondary plate. These isolates were characterized by various phenotypic and genotypic methods. Our results demonstrated that differing antibiotic resistance profiles were present in 19% of pediatric patients with acute pharyngitis before antimicrobial treatment. This heterogeneity likely resulted from horizontal gene transfer among streptococcal isolates sharing the same genetic background. As only a minority of colonies displayed antibiotic resistance among these heterogeneous samples, a classical diagnostic antibiogram would have classified them in most instances as "susceptible," although therapeutic failure could be caused by the proliferation of resistant strains after initiation of antibiotic treatment.

Performance of individual Helicobacter pylori antigens in the immunoblot-based detection of H. pylori infection.

To develop a specific line blot (LB) for supporting ELISA-based serodiagnosis of Helicobacter pylori infection, individual native/recombinant H. pylori antigens were evaluated with respect to their reactivity with both serum IgG and IgA from 156 dyspeptic screening patients (67% H. pylori positive). Of 13 antigens, HP0175, p17, and p19 revealed highest positive likelihood ratios for H. pylori-specific IgG (> 5.0) and were selected as LB substrates, in addition to the established virulence markers VacA and CagA. For validation, the LB was compared to a commercial whole-cell-lysate-based ELISA by parallel (re-)analysis of 156 screening sera, 22 sera from diabetes mellitus patients and 15 sera from follow-up patients after H. pylori eradication. In screening patients, the combined use of IgG ELISA and LB revealed a sensitivity, specificity, and accuracy of 94%, 81%, and 90%, respectively, whereas IgG ELISA alone exhibited a low specificity of 75%. In diabetic and follow-up patients, IgA ELISA exhibited high accuracy of 89% and 93%, respectively, whereas IgG detection was unreliable (accuracy < 80%). In conclusion, using HP0175, p17, p19, CagA, and VacA as LB substrates significantly improves the specificity of anti-H. pylori IgG analysis, providing a reliable tool for (1) confirmation/refutation of ELISA-based screening results and (2) assessment of the CagA/VacA status.

Practical use of GenoType® HelicoDR, a molecular test for Helicobacter pylori detection and susceptibility testing.

Compared to culture-based method, the sensitivity, specificity, positive, and negative predictive values of the GenoType(®) HelicoDR for detecting Helicobacter pylori resistance were, respectively, 100, 86.2, 89.7%, and 100% to clarithromycin as well as 82.6, 95.1, 90.5%, and 90.7% to fluoroquinolones. This molecular assay detected a mixture of genotypes and could successfully analyze biopsies without transport/storage limitations.

Comparative evaluation of 3 selective media for primary isolation of Helicobacter pylori from gastric biopsies under routine conditions.

This study evaluates 3 selective media (Pylori agar [bioMérieux, France], BD Helicobacter agar, modified [Becton Dickinson, USA], and an in-house medium) designed for Helicobacter pylori isolation. Ninety-eight strains were isolated from 400 gastric biopsies. The media were equally efficient for Helicobacter pylori's growth. However, contaminations were only observed using commercial media.

Kytococcus schroeteri infection of a ventriculoperitoneal shunt in a child.

Kytococcus schroeteri is a newly described micrococcal species and, to date, has been associated mostly with endocarditis. Six infections attributable to this opportunistic pathogen have been described since 2002, when the first case was identified. We describe here the first pediatric case of a K. schroeteri ventriculoperitoneal shunt infection. The child was successfully treated with a combination of rifampin and vancomycin and shunt replacement. Initially identified as a Micrococcus spp. by both automated identification and conventional biochemical testing, sequencing of the 16S ribosomal RNA gene enabled accurate identification of the organism.

Diagnostic value of five commercial tests for the rapid diagnosis of Clostridium difficile-associated disease.

We compared five commercial immunoassays (Biostar OIA CdTOX AB, ImmunoCard Toxins A&B - Meridian, Xpect C. difficile toxin A/B -Remel, C. difficile toxin A test- Oxoid, and TOX A/B QUIK CHEK- Techlab) which allow a rapid diagnosis of C. difficile associated disease. The tests were performed directly on patient's stool specimen submitted for routine investigation of C. difficile infection from two University Hospitals in Brussels. The cell cytotoxicity assay was considered as the gold standard. Of the 100 stool specimens included in the study 23 were positive for C. difficile toxin. The sensitivity, specificity, positive and negative predictive values were respectively, 95.7%, 100%, 100% and 98.7% for TOX A/B QUIK CHEKTM, 91.3%, 100%, 100% and 97.5% for ImmunoCard Toxins A&B and for Xpect C. difficile toxin A/B, 87%, 100%, 100% and 96.3% for OIA CdTOX AB and 87%, 98.7%, 97.2% and 96.3% for C. difficile toxin A test. The differences were not statistically significant (p > 0.05). These data suggest that the tested immunoassays are acceptable for rapid detection of C. difficile toxin.

Differences between Belgian and Brazilian group A Streptococcus epidemiologic landscape.

BACKGROUND: Group A Streptococcus (GAS) clinical and molecular epidemiology varies with location and time. These differences are not or are poorly understood. METHODS AND FINDINGS: We prospectively studied the epidemiology of GAS infections among children in outpatient hospital clinics in Brussels (Belgium) and Brasília (Brazil). Clinical questionnaires were filled out and microbiological sampling was performed. GAS isolates were emm-typed according to the Center for Disease Control protocol. emm pattern was predicted for each isolate. 334 GAS isolates were recovered from 706 children. Skin infections were frequent in Brasília (48% of the GAS infections), whereas pharyngitis were predominant (88%) in Brussels. The mean age of children with GAS pharyngitis in Brussels was lower than in Brasília (65/92 months, p<0.001). emm-typing revealed striking differences between Brazilian and Belgian GAS isolates. While 20 distinct emm-types were identified among 200 Belgian isolates, 48 were found among 128 Brazilian isolates. Belgian isolates belong mainly to emm pattern A-C (55%) and E (42.5%) while emm pattern E (51.5%) and D (36%) were predominant in Brasília. In Brasília, emm pattern D isolates were recovered from 18.5% of the pharyngitis, although this emm pattern is supposed to have a skin tropism. By contrast, A-C pattern isolates were infrequently recovered in a region where rheumatic fever is still highly prevalent. CONCLUSIONS: Epidemiologic features of GAS from a pediatric population were very different in an industrialised country and a low incomes region, not only in term of clinical presentation, but also in terms of genetic diversity and distribution of emm patterns. These differences should be taken into account for designing treatment guidelines and vaccine strategies.