Decrease in vancomycin MICs and prevalence of hGISA in MRSA and MSSA isolates from a German pediatric tertiary care center.

PURPOSE: Resistance of Staphylococcus aureus to vancomycin includes a general increase of minimal inhibitory concentrations (MIC) within the susceptible range over time (Vancomycin MIC Creep) and the presence of a subset of the bacterial population that expresses resistance (heterogeneous glycopeptide-intermediate S. aureus; hGISA). Increased MICs have been associated with adverse clinical outcomes. However, the vancomycin MIC creep is not a uniform trend suggesting the importance of regional surveys. METHODS: We performed a retrospective analysis at a German pediatric tertiary care hospital. Isolates from 2002 to 2017 were selected which were newly identified methicillin-resistant S. aureus (MRSA) or samples from invasive methicillin-susceptible S. aureus (MSSA) or MRSA infections. Vancomycin and oxacillin MICs as well as GISA/hGISA were measured using MIC test strips and resistance was evaluated over time. RESULTS: A total of 540 samples were tested, 200 from the early (2002-2009) and 340 from the later period (2010-2017). All samples were vancomycin susceptible, but the MIC was higher for the earlier samples as compared to the later ones (1.11 vs 0.99; p < 0.001). 14% of the samples were hGISA, GISA strains were not detected. Again, vancomycin resistance decreased over time with 28 vs. 6% hGISA (p < 0.001). There was no significant difference between MRSA and MSSA samples with respect to vancomycin MIC and hGISA prevalence. CONCLUSION: This study shows a decreasing trend for both MIC values and presence of hGISA strains highlighting the importance of monitoring local susceptibilities. Vancomycin remains a first-line treatment option for suspected severe infection with Gram-positive cocci and proven infection with MRSA.

Epidemiological and genetic characteristics of vancomycin-resistant Enterococcus faecium isolates in a University Children's Hospital in Germany: 2019 to 2020.

BACKGROUND: Vancomycin-resistant Enterococcus faecium (VREfm) strains are one of the most important pathogens causing nosocomial infections in Germany. Due to limited treatment options and an increased risk for acquisition in immunocompromised children, surveillance to monitor occurrence of VREfm in paediatric clinical facilities is of critical importance. Following an unusual accumulation of VREfm positive patients between April 2019 and August 2020 at Dr. von Hauner Children's Hospital in Munich, Germany, our study aimed to identify dynamics and routes of transmission, and analyse the affected population in view of previously described host risk factors for VREfm colonisation or infection. METHODS: The hospital database was used to collect epidemiological and clinical data of VREfm cases. Descriptive statistical analyses were conducted to outline patient characteristics and depict possible differences between VREfm-colonised and -infected children. An outbreak investigation determining genetic relatedness among VREfm isolates was performed by core genome multilocus sequence typing (cgMLST). To examine potential transmission pathways, results of genome analysis were compared with epidemiological and clinical data of VREfm positive patients. RESULTS: VREfm acquisition was documented in a total of 33 children (< 18 years). Seven VREfm-colonised patients (21.2%), especially those with a haemato-oncological disease (4/7; p = 0.011), showed signs of clinical infection. cgMLST analysis revealed seven distinct clusters, demonstrating a possible connection within each clonal lineage. Additional eight singletons were identified. Comparison with epidemiological and clinical data provided strong evidence for a link between several VREfm positive patients within the hospital. CONCLUSIONS: A nosocomial spread-at least in part-was the most likely reason for the unusual accumulation of VREfm cases. The study highlights that there is a constant need to increase efforts in hygiene measures, infection control and antibiotic stewardship to combat VREfm transmission events within German paediatric hospitals. Continuous monitoring of adherence to respective policies might reduce the occurrence of clustered cases and prevent future outbreaks.

The rising of old foes: impact of lockdown periods on "non-SARS-CoV-2" viral respiratory and gastrointestinal infections.

BACKGROUND: During COVID-19-related public health non-pharmaceutical prevention measures, such as social distancing, lockdown periods and use of face masks, a decrease in viral respiratory and gastroenterological infections was observed worldwide. Following discontinuation of preventative measures, a potential increase of respective infections outside of their usual seasons was a matter of concern. METHOD: We aimed to illustrate annual distribution of confirmed viral infections between 2017 and 2021 based on 32,506 clinical samples in a German pediatric tertiary care center and to explore the impact of the COVID-19 pandemic on the epidemiology of these infections in children. RESULTS: While a decrease in overall viral infections was observed during the first and second lockdown period, an extraordinary increase in the number of viral respiratory infections, predominantly caused by human Rhino-/Enterovirus and respiratory syncytial virus (RSV), was observed after relaxation of preventive measures. Notably, Rhino-/Enterovirus infections increased 4-fold (2020 vs. 2019) and 16-fold (2021 vs. 2019). The occurrence of RSV was observed beginning from June to August 2021 and reached an all-time record with a 25- to 50-fold increase in numbers in September and October 2021 in relation to previous pre-pandemic years (2017-2019). In contrast, for non-respiratory viruses (i.e. Rota-/Norovirus), the effect on respective seasonal patterns was only minimal compared to previous years. CONCLUSION: The observed increase in respiratory infections in children is worrying and is already causing hospitals to become overburdened. Enhanced vigilance will be key to face clinical challenges due to these epidemiological changes in viral disease patterns in the months to come.

Feasibility and Diagnostic Accuracy of Saliva-Based SARS-CoV-2 Screening in Educational Settings and Children Aged <12 Years.

Children have been disproportionately affected during the COVID-19 pandemic. We aimed to assess a saliva-based algorithm for SARS-CoV-2 testing to be used in schools and childcare institutions under pandemic conditions. A weekly SARS-CoV-2 sentinel study in primary schools, kindergartens, and childcare facilities was conducted over a 12-week-period. In a sub-study covering 7 weeks, 1895 paired oropharyngeal and saliva samples were processed for SARS-CoV-2 rRT-PCR testing in both asymptomatic children (n = 1243) and staff (n = 652). Forty-nine additional concurrent swab and saliva samples were collected from SARS-CoV-2 infected patients (patient cohort). The Salivette® system was used for saliva collection and assessed for feasibility and diagnostic performance. For children, a mean of 1.18 mL saliva could be obtained. Based on results from both cohorts, the Salivette® testing algorithm demonstrated the specificity of 100% (95% CI 99.7-100) and sensitivity of 94.9% (95% CI 81.4-99.1) with oropharyngeal swabs as reference. Agreement between sampling systems was 100% for moderate to high viral load situations (defined as Ct-values <33 from oropharyngeal swabs). Comparative analysis of Ct-values derived from saliva vs. oropharyngeal swabs demonstrated a significant difference (mean 4.23; 95% CI 2.48-6.00). In conclusion, the Salivette® system proved to be an easy-to-use, safe and feasible saliva collection method and a more pleasant alternative to oropharyngeal swabs for SARS-CoV-2 testing in children aged 3 years and above.

Blood culture sampling rate in hospitalised children as a quality indicator for diagnostic stewardship.

PURPOSE: Recommendations regarding the optimal number of blood cultures in children are not available. The aim of this article is to describe the correlation between blood culture (BC) rates and laboratory-confirmed bloodstream infection (LCBSI) rates, on different paediatric wards of a tertiary-care centre in Germany. METHODS: We conducted a retrospective cohort study in a paediatric university hospital, from 1st January to 31st December 2018. All blood cultures collected from neonatal (NICU) and paediatric intensive-care units (PICU), haematology/oncology, and general paediatric wards were included. There were no exclusion criteria. BC taken/1000 patients-days (BC rates/BCR) and LCBSI/1000 patient-days at risk (LCBSI rates) were calculated for each unit. RESULTS: A total of 6040 patients were admitted to the hospital with 3114 of them into wards studied. Of the 3072 BCs collected, 200 (6.5%) were positive. Collection of BCs was performed in 51/77 (66.2%) of admitted patients on NICU, in 151/399 (37.8%) of PICU patients, in 163/755 (21.6%) of haematology/oncology patients, and in 281/1883 (14.9%) of children on general paediatric wards. Gram-positive bacteria were the most commonly detected organisms in blood cultures from all wards with exception of NICU. The BCR in NICU, PICU, haematology/oncology wards, and general wards were 61.6, 196.2, 358.4, and 52.3, respectively. Excluding commensal pathogens and possible contaminations, the LCBSI rates in the same units were 2.4, 5.6, 4.4, and 1.0, respectively. CONCLUSION: We found different BCR values according the ward studied, being higher in patients with high risk of bloodstream infection such as haematology/oncology patients.

Comparison of antibiotic and acyclovir usage before and after the implementation of an on-site FilmArray meningitis/encephalitis panel in an academic tertiary pediatric hospital: a retrospective observational study.

BACKGROUND: Prompt initiation of empiric therapy is common practice in case of suspected meningitis or encephalitis. However, in children the most common pathogens are viruses that usually do not require and are not covered by the applied anti-infective treatment. Novel multiplex PCR (mPCR) panels provide rapid on-site diagnostic testing for a variety of pathogens. This study compared empiric antibiotic and acyclovir usage before and after the introduction of an on-site FilmArray Meningitis/Encephalitis Panel (FA ME Panel). METHODS: We retrospectively compared data for empiric antibiotic and acyclovir usage between pediatric patients with suspected central nervous system (CNS) infection receiving mPCR testing and a matched historical control group. Patients were matched by age and suspected CNS infection. We included all patients for whom empiric antibiotics and/or acyclovir were prescribed. RESULTS: Each study group consisted of 46 patients with 29 (63.0%) infants and 17 (37.0%) older children. A viral pathogen was diagnosed in 5/46 (10.9%) patients in the control group (all enteroviruses) and in 14/46 (30.4%) patients in the mPCR group (enterovirus n = 9; human herpesvirus 6 (HHV-6) n = 5), (p = 0.038)). Length of Therapy (LoT) and Days of Therapy (DoT) for antibiotics were significantly lower for infants (4.0 vs. 3.0, p = 0.038 and 8.0 vs. 6.0, p = 0.015, respectively). Acyclovir therapy was significantly shorter for both, infants and older children (3.0 vs. 1.0 day, p < 0.001 for both age groups). CONCLUSION: The findings of our study suggest that the introduction of a FA ME Panel into clinical routine procedures is associated with a significantly reduced LoT and DoT of empiric anti-infective treatment in children with suspected meningoencephalitis. The largest effect was observed in infants.

Patterns of antimicrobial consumption in neonatal and pediatric intensive care units in Germany and Brazil.

Antibiotic consumption (AC) is a key component of antimicrobial stewardship programs to recognize local patterns of antibiotic use. Our aim was to measure AC in neonatal units, including neonatal (NICU)/paediatric (PICU) intensive care units in different countries. We conducted a multicenter, retrospective, cohort study in three NICUs, one neonatal ward, and three PICUs with a total of 84 beds. Global and individual AC in days of therapy (DOT) and DOT per 1000 patient-days were assessed. During the study period, 2567 patients were admitted, corresponding to 4961 patient-days in neonatal units and 9243 patient-days in PICUs. Multidrug-resistant Gram-negative bacteria and methicillin-resistant Staphylococcus aureus were more frequent in Brazil than in Germany. Average AC was 386.5 and 1335.5 DOT/1000PD in German and Brazilian neonatal units, respectively. Aminopenicillins plus 3rd generation cephalosporins were the most commonly prescribed antibiotics in German neonatal units, while aminopenicillins plus aminoglycosides were the class most commonly used in Brazilian NICU. Average AC was 888.1 and 1440.7 DOT/1000PD in German and Brazilian PICUs, respectively. Antipseudomonal penicillins were most commonly used in the German PICU, and glycopeptides were the most frequently prescribed in Brazilian PICUs. Carbapenems represented 2.3-14% of total DOTs in German neonatal units and 4% in the Brazilian NICU and 13.0% in the German PICU and 6-12.2% in Brazilian PICUs. We concluded that different patterns of most commonly prescribed antibiotics were observed in neonatal units and PICUs in these two countries, probably related to different local patterns of antibiotic resistance, with a higher antibiotic consumption in Brazilian study units.

Evaluation of the multiplex PCR based assay Unyvero implant and tissue infection application for pathogen and antibiotic resistance gene detection in children and neonates.

BACKGROUND: Skin and soft tissue infections have a high disease burden in children. The emergence of multidrug-resistant bacteria over the last decades has heavily influenced hospitalization rates, morbidity and mortality. In addition, with increased survival rates in neonatology and oncology, health-care associated infections are more frequently encountered. There is a growing need for fast and feasible diagnostic tools for the recognition of microorganisms and drug resistances. METHODS: In this prospective study, we compared results of routine culture with the multiplex PCR based Unyvero Implant and Tissue Infection (ITI) application. Specimens were obtained from different sources from neonates and children. RESULTS: We analyzed specimens from 29 patients (72.4% male) with a median age of 8.1 years (range 0.03-15.2). Concordance between Unyvero ITI and culture was reached in 16 of 29 samples (55.2%). Unyvero ITI yielded an overall sensitivity and specificity of 76.3% and 96.5%, respectively. Accuracies were best for non-fermenting bacteria, for which sensitivity was 100% and specificity 98.2%. Detection rates were lower for Gram-positive bacteria (68.8 and 95.2%, respectively). Unyvero correctly detected one blaOXA-24/40 producing Acinetobacter baumannii, while none of the six gyrA87 had a correlate in antimicrobial susceptibility testing. CONCLUSIONS: Unyvero ITI quickly provides additional information relevant for clinical decision-makers. Sensitivity of the PCR must be improved especially for Gram-positive bacteria, and further studies are needed to assess the impact on clinical decision-making and outcome.

Assessment of the multiplex PCR-based assay Unyvero pneumonia application for detection of bacterial pathogens and antibiotic resistance genes in children and neonates.

BACKGROUND: Pneumonia is a major healthcare problem. Rapid pathogen identification is critical, but often delayed due to the duration of culturing. Early, broad antibacterial therapy might lead to false-negative culture findings and eventually to the development of antibiotic resistances. We aimed to assess the accuracy of the new application Unyvero P50 based on multiplex PCR to detect bacterial pathogens in respiratory specimens from children and neonates. METHODS: In this prospective study, bronchoalveolar lavage fluids, tracheal aspirates, or pleural fluids from neonates and children were analyzed by both traditional culture methods and Unyvero multiplex PCR. RESULTS: We analyzed specimens from 79 patients with a median age of 1.8 (range 0.01-20.1). Overall, Unyvero yielded a sensitivity of 73.1% and a specificity of 97.9% compared to culture methods. Best results were observed for non-fermenting bacteria, for which sensitivity of Unyvero was 90% and specificity 97.3%, while rates were lower for Gram-positive bacteria (46.2 and 93.9%, respectively). For resistance genes, we observed a concordance with antibiogram of 75% for those specimens in which there was a cultural correlate. CONCLUSIONS: Unyvero is a fast and easy-to-use tool that might provide additional information for clinical decision making, especially in neonates and in the setting of nosocomial pneumonia. Sensitivity of the PCR for Gram-positive bacteria and important resistance genes must be improved before this application can be widely recommended.

Isolation of highly active monoclonal antibodies against multiresistant gram-positive bacteria.

Multiresistant nosocomial pathogens often cause life-threatening infections that are sometimes untreatable with currently available antibiotics. Staphylococci and enterococci are the predominant Gram-positive species associated with hospital-acquired infections. These infections often lead to extended hospital stay and excess mortality. In this study, a panel of fully human monoclonal antibodies was isolated from a healthy individual by selection of B-cells producing antibodies with high opsonic killing against E. faecalis 12030. Variable domains (VH and VL) of these immunoglobulin genes were amplified by PCR and cloned into an eukaryotic expression vector containing the constant domains of a human IgG1 molecule and the human lambda constant domain. These constructs were transfected into CHO cells and culture supernatants were collected and tested by opsonophagocytic assay against E. faecalis and S. aureus strains (including MRSA). At concentrations of 600 pg/ml, opsonic killing was between 40% and 70% against all strains tested. Monoclonal antibodies were also evaluated in a mouse sepsis model (using S. aureus LAC and E. faecium), a mouse peritonitis model (using S. aureus Newman and LAC) and a rat endocarditis model (using E. faecalis 12030) and were shown to provide protection in all models at a concentration of 4 µg/kg per animal. Here we present a method to produce fully human IgG1 monoclonal antibodies that are opsonic in vitro and protective in vivo against several multiresistant Gram-positive bacteria. The monoclonal antibodies presented in this study are significantly more effective compared to another monoclonal antibody currently in clinical trials.