Surveillance of Antibiotic Use and Resistance in Intensive Care Units (SARI)

Empirical carbapenems or piperacillin/tazobactam for infections in intensive care: An international retrospective cohort study

BACKGROUND

Critically ill patients in intensive care units (ICU) are frequently administered broad-spectrum antibiotics (e.g., carbapenems or piperacillin/tazobactam) for suspected or confirmed infections. This retrospective cohort study aimed to describe the use of carbapenems and piperacillin/tazobactam in two international, prospectively collected datasets.

METHODS

We conducted a post hoc analysis of data from the "Adjunctive Glucocorticoid Therapy in Patients with Septic Shock" (ADRENAL) trial (n = 3713) and the "Antimicrobial de-escalation in the critically ill patient and assessment of clinical cure" (DIANA) study (n = 1488). The primary outcome was the proportion of patients receiving initial antibiotic treatment with carbapenems and piperacillin/tazobactam. Secondary outcomes included mortality, days alive and out of ICU and ICU length of stay at 28 days.

RESULTS

In the ADRENAL trial, carbapenems were used in 648 out of 3713 (17%), whereas piperacillin/tazobactam was used in 1804 out of 3713 (49%) participants. In the DIANA study, carbapenems were used in 380 out of 1480 (26%), while piperacillin/tazobactam was used in 433 out of 1488 (29%) participants. Mortality at 28 days was 23% for patients receiving carbapenems and 24% for those receiving piperacillin/tazobactam in ADRENAL and 23% and 19%, respectively, in DIANA. We noted variations in secondary outcomes; in DIANA, patients receiving carbapenems had a median of 13 days alive and out of ICU compared with 18 days among those receiving piperacillin/tazobactam. In ADRENAL, the median hospital length of stay was 27 days for patients receiving carbapenems and 21 days for those receiving piperacillin/tazobactam.

CONCLUSIONS

In this post hoc analysis of ICU patients with infections, we found widespread initial use of carbapenems and piperacillin/tazobactam in international ICUs, with the latter being more frequently used. Randomized clinical trials are needed to assess if the observed variations in outcomes may be drug-related effects or due to confounders.

Next Generation Sequencing Outperforms Cultivation-Based Methods for Detection of Bacterial Genera in Bile After Liver Transplantation

BACKGROUND AND AIMS

Bacterial cholangitis is a common complication in patients with ischemic type biliary lesions and/or anastomotic strictures after liver transplantation (LTX). Patients frequently need antibiotics and endoscopic retrograde cholangiography (ERC) to improve the bile flow. Antibiotic treatment is based on findings in standard microbiological cultivation (SMC) of bile. However, the cultivation techniques are limited to a subset of bacteria easy-to-cultivate. Therefore, the aim of our study was to evaluate the value of next generation sequencing as an additional diagnostic tool to SMC in ischemic type biliary lesions and/or anastomotic strictures.

METHODS

We sequenced the V1-V2 region of the 16S rRNA gene in 242 stored bile samples in patients after LTX and compared the results with findings of SMC. SMC was performed in n = 135 (56%) fresh bile samples in addition to NGS. SMC was part of the clinical routine in these patients.

RESULTS

NGS detected bacterial genera in bile samples more often than SMC (P = 5.42 × 10-74). SMC showed insufficient discovery of bacterial genera compared to NGS with better performance in patients receiving antibiotics prior to ERC. SMC missed many bacterial genera detected by NGS.

CONCLUSIONS

NGS was more sensitive in detecting bacteria in bile than SMC, no clinical parameters could be used to improve discovery rates in SMC and many genera were missed by SMC. Therefore, NGS should be used in a combined approach with SMC for improved diagnostics to achieve more specific and targeted antibiotic treatments.

Vancomycin-resistant enterococci (VRE) in hospital settings across European borders: a scoping review comparing the epidemiology in the Netherlands and Germany

The rising prevalence of vancomycin-resistant enterococci (VRE) is a matter of concern in hospital settings across Europe without a distinct geographical pattern. In this scoping review, we compared the epidemiology of vancomycin-resistant Enterococcus spp. in hospitals in the Netherlands and Germany, between 1991 and 2022. We searched PubMed and summarized the national antibiotic resistance surveillance data of the two countries. We included 46 studies and summarized national surveillance data from the NethMap in the Netherlands, the National Antimicrobial Resistance Surveillance database in Germany, and the EARS-Net data. In total, 12 studies were conducted in hospitals in the Netherlands, 32 were conducted in German hospitals, and an additional two studies were conducted in a cross-border setting. The most significant difference between the two countries was that studies in Germany showed an increasing trend in the prevalence of VRE in hospitals, and no such trend was observed in studies in the Netherlands. Furthermore, in both Dutch and German hospitals, it has been revealed that the molecular epidemiology of VREfm has shifted from a predominance of vanA towards vanB over the years. According to national surveillance reports, vancomycin resistance in Enterococcus faecium clinical isolates fluctuates below 1% in Dutch hospitals, whereas it follows an increasing trend in German hospitals (above 20%), as supported by individual studies. This review demonstrates that VRE is more frequently encountered in German than in Dutch hospitals and discusses the underlying factors for the difference in VRE occurrence in these two neighboring countries by comparing differences in healthcare systems, infection prevention control (IPC) guidelines, and antibiotic use in the Netherlands and Germany.

Previous antibiotic therapy as independent risk factor for the presence of vancomycin-resistant enterococci in surgical inpatients. Results from a matched case-control study

BACKGROUND

Investigation of risk factors for the presence of vancomycin-resistant enterococci (VRE) in inpatients on surgical wards and associated intensive care units of a German tertiary care hospital.

METHODS

A single-centre retrospective matched case-control study was performed with surgical inpatients admitted between July 2013 and December 2016. Patients with in-hospital detection of VRE later than 48 h after admission were included and comprised 116 VRE-positive cases and 116 VRE-negative matched controls. VRE isolates of cases were typed by multi-locus sequence typing.

RESULTS

ST117 was identified as the dominant VRE sequence type. Next to length of stay in hospital or on an intensive care unit and previous dialysis the case-control study revealed previous antibiotic therapy as a risk factor for the in-hospital detection of VRE. The antibiotics piperacillin/tazobactam, meropenem, and vancomycin were associated with the highest risks. After taking into account length of stay in hospital as possible confounder other potential contact-related risk factors such as previous sonography, radiology, central venous catheter, and endoscopy were not significant.

CONCLUSIONS

Previous dialysis and previous antibiotic therapy were identified as independent risk factors for the presence of VRE in surgical inpatients.

Incremental costs of hospital-acquired infections in COVID-19 patients in an adult intensive care unit of a tertiary hospital from a low-resource setting

BACKGROUND

Hospital-acquired infections (HAIs) are a global public health problem and put patients at risk of complications, including death. HAIs increase treatment costs, but their financial impact on Serbia's healthcare system is unknown. Our goal was to assess incremental costs of HAIs in a tertiary care adult intensive care unit (ICU) that managed COVID-19 patients.

METHODS

A retrospective study from March 6th to December 31st, 2020 included patients with microbiologically confirmed COVID-19 (positive rapid antigen test or real-time polymerase chain reaction) treated in the ICU of the Teaching Hospital for Infectious and Tropical Diseases, University Clinical Centre of Serbia. Demographic and HAI-specific data acquired in our ICU were collected, including total and stratified medical costs (services, materials, laboratory testing, medicines, occupancy costs). Median total and stratified costs were compared in relation to HAI acquisition. Linear regression modelling was used to assess incremental costs of HAIs, adjusted for age, biological sex, prior hospitalisation, Charlson Comorbidity Index (CCI), and Glasgow Coma Scale (GCS) on admission. Outcome variables were length of stay (LOS) in days and mortality.

RESULTS

During the study period, 299 patients were treated for COVID-19, of which 214 were included. HAIs were diagnosed in 56 (26.2%) patients. Acinetobacter spp. was the main pathogen in respiratory (38, 45.8%) and bloodstream infections (35, 42.2%), the two main HAI types. Median total costs were significantly greater in patients with HAIs (€1650.4 vs. €4203.2, p < 0.001). Longer LOS (10.0 vs. 18.5 days, p < 0.001) and higher ICU mortality (51.3% vs. 89.3%, p < 0.001) were seen if HAIs were acquired. Patients with ≥ 2 HAIs had the highest median total costs compared to those without HAIs or with a single HAI (€1650.4 vs. €3343.4 vs. €7336.9, p < 0.001). Incremental costs in patients with 1 and ≥ 2 HAIs were €1837.8 (95% CI 1257.8-2417.7, p < 0.001) and €5142.5 (95% CI 4262.3-6022.7, p < 0.001), respectively.

CONCLUSIONS

This is the first economic evaluation of HAIs in Serbia, showing significant additional costs to our healthcare system. HAIs prolong LOS and influence ICU mortality rates. Larger economic assessments are needed to enhance infection control practices.

Monitoring COVID-19 and Influenza: The Added Value of a Severe Acute Respiratory Infection Surveillance System in Portugal

Background

Severe acute respiratory infections (SARI) surveillance is recommended to assess the severity of respiratory infections disease. In 2021, the National Institute of Health Doutor Ricardo Jorge, in collaboration with two general hospitals, implemented a SARI sentinel surveillance system based on electronic health registries. We describe its application in the 2021/2022 season and compare the evolution of SARI cases with the COVID-19 and influenza activity in two regions of Portugal.

Methods

The main outcome of interest was the weekly incidence of patients hospitalized due to SARI, reported within the surveillance system. SARI cases were defined as patients containing ICD-10 codes for influenza-like illness, cardiovascular diagnosis, respiratory diagnosis, and respiratory infection in their primary admission diagnosis. Independent variables included weekly COVID-19 and influenza incidence in the North and Lisbon and Tagus Valley regions. Pearson and cross-correlations between SARI cases, COVID-19 incidence and influenza incidence were estimated.

Results

A high correlation between SARI cases or hospitalizations due to respiratory infection and COVID-19 incidence was obtained (ρ = 0.78 and ρ = 0.82, respectively). SARI cases detected the COVID-19 epidemic peak a week earlier. A weak correlation was observed between SARI and influenza cases (ρ = -0.20). However, if restricted to hospitalizations due to cardiovascular diagnosis, a moderate correlation was observed (ρ = 0.37). Moreover, hospitalizations due to cardiovascular diagnosis detected the increase of influenza epidemic activity a week earlier.

Conclusion

In the 2021/2022 season, the Portuguese SARI sentinel surveillance system pilot was able to early detect the COVID-19 epidemic peak and the increase of influenza activity. Although cardiovascular manifestations associated with influenza infection are known, more seasons of surveillance are needed, to confirm the potential use of cardiovascular hospitalizations as an indicator of influenza activity.

Genomic Analysis of Klebsiella pneumoniae ST258 Strain Coproducing KPC-2 and CTX-M-14 Isolated from Poultry in the Brazilian Amazon Region

This study aimed to characterize a Klebsiella pneumoniae strain (KP411) recovered from the stool samples of poultry (Gallus gallus) in the Brazilian Amazon Region. The whole-genome sequencing of KP411 revealed the presence of an important arsenal of antimicrobial resistance genes to β-lactams (bla_CTX-M-14, bla_TEM-1B, bla_KPC-2, bla_SVH-11), aminoglycosides [aph(3″)- Ib, aph(6)-Id, aph(3')-Ia], sulfonamides (sul1, sul2), quinolones (oqxAB), fosfomycin (fosA^KP), and macrolides [mph(A)]. Furthermore, our analyses revealed that the KP411 strain belongs to the ST258 clonal lineage, which is one of the main epidemic clones responsible for the dissemination of KPC-2 worldwide. Our data suggest that food-producing animals may act as reservoirs of multidrug-resistant K. pneumoniae belonging to the ST258 clone, and, consequently, contribute to their dissemination to humans and the environment.

Evaluating the usefulness of the estimated glomerular filtration rate for determination of imipenem dosage in critically ill patients

Background. Antibiotic dosing in critically ill patients is complicated by variations in the pharmacokinetics of antibiotics in this group. The dosing of imipenem/cilastatin is usually determined by severity of illness and renal function.Objectives. To determine the correlation between estimated glomerular filtration rates (eGFRs) calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and imipenem trough levels in critically ill patients.Methods. This prospective observational study was done in the surgical intensive care unit (ICU) at Steve Biko Academic Hospital, Pretoria, South Africa. Imipenem trough levels were measured by high-performance liquid chromatography and compared with eGFRs calculated with the CKD-EPI equation. Correlation was evaluated by the Pearson product-moment correlation coefficient.Results. The study population consisted of 68 critically ill patients aged between 18 and 81 years; 43 (63%) were male, and the mean weight was 78 kg (range 40 - 140). On admission, 30 patients (44%) had sepsis, 16 (24%) were admitted for trauma, and 22 (32%) were admitted for miscellaneous surgical conditions. Acute Physiology and Chronic Health Evaluation II (APACHE II) scores ranged from 4 to 39 (mean 18). The 28-day mortality rate was 29%. The mean albumin level was 16 g/L (range 7 - 25), the mean creatinine level 142 μmol/L (range 33 - 840), and the mean eGFR 91 mL/min/1.73 m2 (range 6 - 180). Imipenem trough levels ranged between 3.6 and 92.2 mg/L (mean 11.5). The unadjusted Pearson product-moment correlation coefficient between eGFR and imipenem trough level was –0.04 (p=0.761).Conclusion. Considering the high mortality rate of sepsis in ICUs and the rapid global increase in antimicrobial resistance, it is crucial to dose antibiotics appropriately. Owing to the variability of antibiotic pharmacokinetics in critically ill patients, this task becomes almost impossible when relying on conventional dosing guidelines. This study found that eGFRs do not correlate with imipenem blood levels in critically ill patients and should not be used to determine the dose of imipenem/cilastatin. Instead, the dose should be individualised for patients through routine therapeutic drug monitoring.

Ecological effects of selective oral decontamination on multidrug-resistance bacteria acquired in the intensive care unit: a case-control study over 5 years

Purpose

This case–control study investigated the long-term evolution of multidrug-resistant bacteria (MDRB) over a 5-year period associated with the use of selective oropharyngeal decontamination (SOD) in the intensive care unit (ICU). In addition, effects on health care-associated infections and ICU mortality were analysed.

Methods

We investigated patients undergoing mechanical ventilation > 48 h in 11 adult ICUs located at 3 campuses of a university hospital. Administrative, clinical, and microbiological data which were routinely recorded electronically served as the basis. We analysed differences in the rates and incidence densities (ID, cases per 1000 patient-days) of MDRB associated with SOD use in all patients and stratified by patient origin (outpatient or inpatient). After propensity score matching, health-care infections and ICU mortality were compared.

Results

5034 patients were eligible for the study. 1694 patients were not given SOD. There were no differences in the incidence density of MDRB when SOD was used, except for more vancomycin-resistant Enterococcus faecium (0.72/1000 days vs. 0.31/1000 days, p < 0.01), and fewer ESBL-producing Klebsiella pneumoniae (0.22/1000 days vs. 0.56/1000 days, p < 0.01). After propensity score matching, SOD was associated with lower incidence rates of ventilator-associated pneumonia and death in the ICU but not with ICU-acquired bacteremia or urinary tract infection.

Conclusions

Comparisons of the ICU-acquired MDRB over a 5-year period revealed no differences in incidence density, except for lower rate of ESBL-producing Klebsiella pneumoniae and higher rate of vancomycin-resistant Enterococcus faecium with SOD. Incidence rates of ventilator-associated pneumonia and death in the ICU were lower in patients receiving SOD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06826-7.

An Integral Pharmacokinetic Analysis of Piperacillin and Tazobactam in Plasma and Urine in Critically Ill Patients

BACKGROUND AND OBJECTIVES

Although dose optimization studies have been performed for piperacillin and tazobactam separately, a combined integral analysis is not yet reported. As piperacillin and tazobactam pharmacokinetics are likely to show correlation, a combined pharmacokinetic model should be preferred to account for this correlation when predicting the exposure. Therefore, the aim of this study was to describe the pharmacokinetics and evaluate different dosing regimens of piperacillin and tazobactam in critically ill patients using an integral population pharmacokinetic model in plasma and urine.

METHODS

In this observational study, a total of 39 adult intensive care unit patients receiving piperacillin-tazobactam as part of routine clinical care were included. Piperacillin and tazobactam concentrations in plasma and urine were measured and analyzed using non-linear mixed-effects modeling. Monte Carlo simulations were performed to predict the concentrations for different dosing strategies and different categories of renal function.

RESULTS

A combined two-compartment linear pharmacokinetic model for both piperacillin and tazobactam was developed, with an output compartment for the renally excreted fraction. The addition of 24-h urine creatinine clearance significantly improved the model fit. A dose of 12/1.5 g/24 h as a continuous infusion is sufficient to reach a tazobactam concentration above the target (2.89 mg/L) and a piperacillin concentration above the target of 100% f T_>1×MIC (minimum inhibitory concentration [MIC] ≤ 16 mg/L). To reach a target of 100% f T_>5×MIC with an MIC of 16 mg/L, piperacillin doses of up to 20 g/24 h are inadequate. Potential toxic piperacillin levels were reached in 19.6% and 47.8% of the population with a dose of 12 g/24 h and 20 g/24 h, respectively.

CONCLUSIONS

A regular dose of 12/1.5 g/24 h is sufficient in > 90% of the critically ill population to treat infections caused by Escherichia coli and Klebsiella pneumoniae with MICs ≤ 8 mg/L. In case of infections caused by Pseudomonas aeruginosa with an MIC of 16 mg/L, there is a fine line between therapeutic and toxic exposure. Dosing guided by renal function and therapeutic drug monitoring could enhance target attainment in such cases.

CLINICALTRIALS

GOV IDENTIFIER

NCT03738683.

Antimicrobial resistance and antibiotic consumption in intensive care units, Switzerland, 2009 to 2018

Background

Intensive care units (ICU) constitute a high-risk setting for antimicrobial resistance (AMR).

Aim

We aimed to describe secular AMR trends including meticillin-resistant Staphylococcus aureus (MRSA), glycopeptide-resistant enterococci (GRE), extended-spectrum cephalosporin-resistant Escherichia coli (ESCR-EC) and Klebsiella pneumoniae (ESCR-KP), carbapenem-resistant Enterobacterales (CRE) and Pseudomonas aeruginosa (CRPA) from Swiss ICU. We assessed time trends of antibiotic consumption and identified factors associated with CRE and CRPA.

Methods

We analysed patient isolate and antibiotic consumption data of Swiss ICU sent to the Swiss Centre for Antibiotic Resistance (2009–2018). Time trends were assessed using linear logistic regression; a mixed-effects logistic regression was used to identify factors associated with CRE and CRPA.

Results

Among 52 ICU, MRSA decreased from 14% to 6% (p = 0.005; n = 6,465); GRE increased from 1% to 3% (p = 0.011; n = 4,776). ESCR-EC and ESCR-KP increased from 7% to 15% (p < 0.001, n = 10,648) and 5% to 11% (p = 0.002; n = 4,052), respectively. CRE, mostly Enterobacter spp., increased from 1% to 5% (p = 0.008; n = 17,987); CRPA remained stable at 27% (p = 0.759; n = 4,185). Antibiotic consumption in 58 ICU increased from 2009 to 2013 (82.5 to 97.4 defined daily doses (DDD)/100 bed-days) and declined until 2018 (78.3 DDD/100 bed-days). Total institutional antibiotic consumption was associated with detection of CRE in multivariable analysis (odds ratio per DDD: 1.01; 95% confidence interval: 1.0–1.02; p = 0.004).

Discussion

In Swiss ICU, antibiotic-resistant Enterobacterales have been steadily increasing over the last decade. The emergence of CRE, associated with institutional antibiotic consumption, is of particular concern and calls for reinforced surveillance and antibiotic stewardship in this setting.

Problems associated with the use of the term "antibiotics"

The term “antibiotics” is a broadly used misnomer to designate antibacterial drugs. In a recent article, we have proposed to replace, e.g., the term “antibiotics” by “antibacterial drugs”, “antibiosis” by “antibacterial therapy”, “antibiogram” by “antibacteriogram”, and “antibiotic stewardship” by “antibacterial stewardship” (Seifert and Schirmer Trends Microbiol, 2021). In the present article, we show that many traditional terms related to antibiotics are used much more widely in the biomedical literature than the respective scientifically precise terms. This practice should be stopped. Moreover, we provide arguments to end the use of other broadly used terms in the biomedical literature such as “narrow-spectrum antibiotics” and “reserve antibiotics”, “chemotherapeutics”, and “tuberculostatics”. Finally, we provide several examples showing that antibacterial drugs are used for non-antibacterial indications and that some non-antibacterial drugs are used for antibacterial indications now. Thus, the increasing importance of drug repurposing renders it important to drop short designations of drug classes such as “antibiotics”. Rather, the term “drug” should be explicitly used, facilitating the inclusion of newly emerging indications such as antipsychotic and anti-inflammatory. This article is part of an effort to implement a new rational nomenclature of drug classes across the entire field of pharmacology.

[Antibiotics Stewardship Team Recommendations - An Analysis under Routine Conditions in a University Hospital]

AIM

To evaluate recommendations of an antibiotic stewardship (ABS) team during routine weekly visits and to analyse their implementation and reasons for non-implementation by the ward physicians.

METHODS

Multiprofessional ABS Rounds (members: infectiology, microbiology, pharmacy and hospital epidemiology) were accompanied by an observer in nine intensive and peripheral wards of a university hospital (1451 beds) for eight weeks. The recommendations of the ABS team were prospectively analysed, and when these were not implemented, ward physicians in charge were asked to give reasons for non-implementation.

RESULTS

A total of 262 patients were visited in the course of 359 ABS visits. A median of four physicians and one pharmacist (Q25/Q75: 4/6) participated in the ABS rounds. In 177/359 (49%) of visits, at least one recommendation for anti-infective therapy was given; the total number of recommendations made was 210. The most frequent (38%, 80/210) recommendations were related to the prescribed therapy duration. The more different the professional groups participating in the ABS rounds, the larger was the number of recommendations given (p=0.016; odds ratio=1.018 (1.003-1.033)). 62/210 (30%) of the ABS recommendations were not implemented by the ward physicians in charge. The most frequent reason (32%: 20/62) for this was the deliberate decision by the physicians to deviate from the recommended therapy.

CONCLUSIONS

The high recommendation rate of 50% demonstrates the need for optimizing therapy by the ABS teams in routine practice. The larger the number of different specialists participating in single visits, the larger was the number of recommendations. Reasons for the lack of implementations need to be critically examined by both the ABS team and the ward physicians in charge.

Prevalence and risk factors of colonisation with vancomycin-resistant Enterococci faecium upon admission to Germany's largest university hospital

Background: Hospital-acquired infections due to vancomycin-resistant enterococci (VRE) are emerging globally. The aims of our study were to estimate VRE colonisation prevalence in patients upon admission, to determine possible risk factors for VR E. faecium acquisition that already exist in the outpatient setting, and to monitor whether VRE-colonised patients developed a VRE infection during their current hospital stay.

Methods: In 2014 and 2015, patients admitted to non-intensive care units were screened for rectal VRE carriage. The study patients filled out a questionnaire on potential risk factors. Analyses were restricted to VR E. faecium carriage. All patients with VRE colonisation were retrospectively monitored for infections with VRE during their current hospital stay.

Results: In 4,013 enrolled patients, the VRE colonisation prevalence upon admission was 1.2% (n=48), and colonisation prevalence was 1.1% (n=45) for VR E. faecium. Only one VRE-colonised patient developed an infection with the detection of a VRE, among others. Colonisation with VR E. faecium was associated with current antibiotic use. Risk factors of VR E. faecium colonisation upon admission were increasing age, previous colonisation or infection with multidrug resistant organisms, sampling year 2015, and, within the previous six months, antibiotic exposure, a stay at a rehabilitation center, and a hospital stay.

Conclusions: We observed that antibiotic treatment which occurred prior admission influenced VR E. faecium prevalence upon admission. Thus, wise antibiotic use in outpatient settings plays a major role in the prevention of VR E. faecium acquisition.

The epidemiology of carbapenem resistance in Acinetobacter baumannii complex in Germany (2014-2018): an analysis of data from the national Antimicrobial Resistance Surveillance system

Background

Carbapenem-resistant Acinetobacter baumannii complex (CRABC) has globally emerged as a serious public health challenge. This study aimed to describe epidemiological trends and risk factors of carbapenem resistance in A. baumannii complex isolates in Germany between 2014 and 2018.

Methods

We analysed 43,948 clinical A. baumannii complex isolates using 2014 to 2018 data from the German Antimicrobial Resistance Surveillance system. We applied descriptive statistics and uni- and multivariable regression analyses to investigate carbapenem resistance in A. baumannii complex isolates.

Results

The proportion of carbapenem resistance in clinical A. baumannii complex isolates declined from 7.6% (95% confidence interval [95% CI] 4.4–12.7%) in 2014 to 3.5% (95% CI 2.5–4.7%) in 2018 (adjusted OR [aOR] 0.85 [95% CI 0.79–0.93, p ≤ 0.001]). Higher mean CRABC proportions for 2014 to 2018 were observed in secondary care hospitals (4.9% [95% CI 3.2–7.5%], aOR 3.6 [95% CI 2.4–5.3, p ≤ 0.001]) and tertiary care hospitals (5.9% [95% CI 3.0–11.2%], aOR 5.4 [95% CI 2.9–10.0, p ≤ 0.001) compared to outpatient clinics (1.3% [95% CI 1.1–1.6%]). CRABC proportions in hospitals varied between German regions and ranged between 2.4% (95% CI 1.6–3.5%) in the Southeast and 8.8% (95% CI 4.2–17.3%) in the Northwest. Lower CRABC proportions were observed in younger patients (< 1 year: 0.6% [95% CI 0.2–1.3%]; 1–19 years: 1.3% [95% CI 0.7–2.5%]) than adults (20–39 years: 7.7% [95% CI 4.4–13.0%]; 40–59 years: 6.2% [4.2–8.9%]; 60–79 years: 5.8% [95% CI 4.0–8.3%]). In the 20–39 year old patient age group, CRABC proportions were significantly higher for men than for women (14.6% [95% CI 8.6–23.6%] vs. 2.5% [95% CI 1.3–4.5%]). A. baumannii complex isolates from lower respiratory infections were more likely to be carbapenem-resistant than isolates from upper respiratory infections (11.4% [95% CI 7.9–16.2%] vs. 4.0% [95% CI 2.7–6.0%]; adjusted OR: 1.5 [95% CI 1.2–1.9, p ≤ 0.001]).

Conclusions

In contrast to many other regions worldwide, carbapenem resistance proportions among clinical A. baumannii complex isolates are relatively low in Germany and have declined in the last few years. Ongoing efforts in antibiotic stewardship and infection prevention and control are needed to prevent the spread of carbapenem-resistant A. baumannii complex in Germany.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00909-8.

The Animal-foods-environment interface of Klebsiella pneumoniae in Germany: an observational study on pathogenicity, resistance development and the current situation

Klebsiella (K.) pneumoniae as a multi-drug resistant (MDR) pathogen is an emerging challenge for clinicians worldwide. Virulence factors are capsular antigens, adherence factors, the O-lipopolysaccharide, and siderophores promoting infectivity. Mechanisms of antimicrobial resistance are inactivation of compounds via enzymes, change of membrane permeability, and alteration of the target site of the antimicrobial compound. In addition to environmental resistance, K. pneumoniae can survive increasing concentrations of disinfectants, if exposed. This review describes the temporal and spatial distribution of K. pneumoniae in the past decades in Germany, with emphases on the development of resistance in the non-human columns of the One-Health concept. In general, K. pneumoniae is a neglected pathogen in veterinary and environmental health, and the risk of human infection concerning animal contact and food consumption is barely investigated. Few reports exist (n = 26) on antibiotic resistance of isolates from non-human origin. Multi-drug resistance and extended-spectrum β-lactamase (MDR-ESBL) strains also resistant to carbapenems and antibiotics of the ß-lactam group harbor blaCTX-M, blaOXA, blaTEM, blaSHV, blaCMY, and PMQR have been found in animals, foods, and the environment. Colistin resistant strains carrying the mcr-1 gene were detected in wastewater. The blaCTX-M-15 and blaOXA-48 genes are the most frequently identified AMR genes in isolates of humans and were also the most predominant ESBL-genes in samples collected from animal hosts. Several aspects of the molecular epidemiology and resistance development of K. pneumoniae in farm animal populations, wildlife, and foods need intensive research. Environmental health has to be integrated into national research plans, as a lack of data is apparent. Increasing awareness of the fact that non-human sources can act as a reservoir for this pathogen has to be raised.

Irrational use of antibiotics with representation of antimicrobial resistance patterns in Sudan: a narrative review

Background

Increasing bacterial resistance to antibiotics is a growing menace, mainly caused by the rapid genetic modification of bacterial strains and new alternations in behavior favoring their survival. There is no doubt that the irrational use of antibiotics is one of the factors contributing to the rise of this problem, whether that be in hospitals or at a community level. Although the extent of this influence is yet to be learned, it is definite that this is of great impact on the endemic disease patterns in developing areas specifically and on an expanding global issue generally.

Purpose and scope

This paper will provide a narrative review of relevant previous publications of antibiotic misuse to portray a clearer picture of its causes and consequences in Sudan.

Methodology

The PICO method was used by which evidence-based research websites were scanned for key words. Results were assessed for relevance and then critically appraised. All papers included were summarized and presented in a narrative review format.

Results

From a total of 9 research papers from Pub Med, Scopus, Cochrane and Google Scholar search engines, 7 were selected, presented, and discussed.

Conclusion

Given the facts of high bacterial resistance that has emerged worldwide catastrophically, the implementation of a meticulous surveillance system designed to restrict the irrational use of antibiotics by the public and health sectors alike with adjunct educational and training programs relevant to the regional epidemiology and economy will massively contribute to a lower resistance rate due to antibiotic misuse.

Experience of establishing severe acute respiratory surveillance in the Netherlands: Evaluation and challenges

The 2009 influenza A (H1N1) pandemic prompted the World Health Organization (WHO) to recommend countries to establish a national severe acute respiratory infections (SARI) surveillance system for preparedness and emergency response. However, setting up or maintaining a robust SARI surveillance system has been challenging. Similar to other countries, surveillance data on hospitalisations for SARI in the Netherlands are still limited, in contrast to the robust surveillance data in primary care.

The objective of this narrative review is to provide an overview, evaluation, and challenges of already available surveillance systems or datasets in the Netherlands, which might be used for near real-time surveillance of severe respiratory infections.

Seven available surveillance systems or datasets in the Netherlands were reviewed. The evaluation criteria, including data quality, timeliness, representativeness, simplicity, flexibility, acceptability and stability were based on United States Centers for Disease Control and Prevention (CDC) and European Centre for Disease Prevention and Control (ECDC) guidelines for public health surveillance. We added sustainability as additional evaluation criterion.

The best evaluated surveillance system or dataset currently available for SARI surveillance is crude mortality monitoring, although it lacks specificity. In contrast to influenza-like illness (ILI) in primary care, there is currently no gold standard for SARI surveillance in the Netherlands.

Based on our experience with sentinel SARI surveillance, a fully or semi-automated, passive surveillance system seems most suited for a sustainable SARI surveillance system. An important future challenge remains integrating SARI surveillance into existing hospital programs in order to make surveillance data valuable for public health, as well as hospital quality of care management and individual patient care.

•

Multiple surveillance systems or datasets are available in the Netherlands with potential use for SARI surveillance.

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There is currently no gold standard for SARI surveillance in the Netherlands.

•

A potential sustainable SARI surveillance system for the long-term is a fully or semi-automated, passive surveillance system.

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SARI surveillance data should be valuable for both public health and individual patient care.

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An important future challenge remains integrating SARI surveillance into existing hospital programs.

The use of antibiotics in the intensive care unit of a tertiary hospital in Malawi

BACKGROUND

Antibiotic resistance is on the rise. A contributing factor to antibiotic resistance is the misuse of antibiotics in hospitals. The current use of antibiotics in ICUs in Malawi is not well documented and there are no national guidelines for the use of antibiotics in ICUs. The aim of the study was to describe the use of antibiotics in a Malawian ICU.

METHODS

A retrospective review of medical records of all admissions to the main ICU in Queen Elizabeth Central Hospital in Blantyre, Malawi, between January 2017 and April 2019. Data were extracted from the ICU patient register on clinical parameters on admission, diagnoses, demographics and antibiotics both prescribed and given for all patients admitted to the ICU. Usage of antibiotics in the ICU and bacterial culture results from samples taken in the ICU and in the peri-ICU period, (from 5 days before ICU admission to 5 days after ICU discharge), were described.

RESULTS

Six hundred-and-forty patients had data available on prescribed and received medications and were included in the analyses. Of these, 577 (90.2%) were prescribed, and 522 (81.6%) received an antibiotic in ICU. The most commonly used antibiotics were ceftriaxone, given to 470 (73.4%) of the patients and metronidazole to 354 (55.3%). Three-hundred-and-thirty-three (52.0%) of the patients received more than one type of antibiotic concurrently - ceftriaxone and metronidazole was the most common combination, given to 317 patients. Forty five patients (7.0%) were given different antibiotics sequentially. One-hundred-and-thirty-seven patients (21.4%) had a blood culture done in the peri-ICU period, of which 70 (11.0% of the patients) were done in the ICU. Twenty-five (18.3%) of the peri-ICU cultures were positive and eleven different types of bacteria were grown in the cultures, of which 17.2% were sensitive to ceftriaxone.

CONCLUSION

We have found a substantial usage of antibiotics in an ICU in Malawi. Ceftriaxone, the last-line antibiotic in the national treatment guidelines, is commonly used, and bacteria appear to show high levels of resistance to it, although blood culture testing is infrequently used. Structured antibiotic stewardship programs may be useful in all ICUs.

Imipenem-Relebactam Susceptibility Testing of Gram-Negative Bacilli by Agar Dilution, Disk Diffusion, and Gradient Strip Methods Compared with Broth Microdilution

This study aimed to determine whether agar dilution, research-use-only disk diffusion (Mast Group Ltd., Bootle Merseyside, UK), Etest (bioMérieux, Inc., Durham, NC), and MIC test strip (MTS) (Liofilchem, Inc., Waltham, MA) methods yield equivalent results to those of broth microdilution (BMD) for imipenem-relebactam susceptibility testing using a collection of 297 Gram-negative bacilli, including members of the order Enterobacterales and Pseudomonas aeruginosa, enriched for drug resistance. MIC and disk diameter results were interpreted using United States Food and Drug Administration breakpoints. Overall, 76.8% of the isolates tested were susceptible to imipenem-relebactam by BMD. MIC values for agar dilution, Etest, and MTS were not significantly different from that for BMD, although they tended to be 1 to 2 dilutions higher. Essential agreement was 95.6% for agar dilution, 90.6% for Etest, and 85.2% for MTS. Categorical agreement was 98.0% for agar dilution, 73.1% for disk diffusion, 96.3% for Etest, and 96.6% for MTS. In conclusion, agar dilution and Etest yielded comparable results to BMD for imipenem-relebactam.

Monitoring Antimicrobial Resistance and Drug Usage in the Human and Livestock Sector and Foodborne Antimicrobial Resistance in Six European Countries

INTRODUCTION

Antimicrobial resistance (AMR), associated with antimicrobial use (AMU), is a major public concern. Surveillance and monitoring systems are essential to assess and control the trends in AMU and AMR. However, differences in the surveillance and monitoring systems between countries and sectors make comparisons challenging. The purpose of this article is to describe all surveillance and monitoring systems for AMU and AMR in the human and livestock sectors, as well as national surveillance and monitoring systems for AMR in food, in six European countries (Spain, Germany, France, the Netherlands, the United Kingdom and Norway) as a baseline for developing suggestions to overcome current limitations in comparing AMU and AMR data.

METHODS

A literature search in 2018 was performed to identify relevant peer-reviewed articles and national and European grey reports as well as AMU/AMR databases.

RESULTS

Comparison of AMU and AMR systems across the six countries showed a lack of standardization and harmonization with different AMU data sources (prescription vs sales data) and units of AMU and AMR being used. The AMR data varied by sample type (clinical/non-clinical), laboratory method (disk diffusion, microdilution, and VITEK, among others), data type, ie quantitative (minimum inhibition concentration (MIC) in mg/L/inhibition zone (IZ) in mm) vs qualitative data (susceptible-intermediate-resistant (SIR)), the standards used (EUCAST/CLSI among others), and/or the evaluation criteria adopted (epidemiological or clinical).

DISCUSSION

A One Health approach for AMU and AMR requires harmonization in various aspects between human, animal and food systems at national and international levels. Additionally, some overlap between systems of AMU and AMR has been encountered. Efforts should be made to improve standardization and harmonization and allow more meaningful analyses of AMR and AMU surveillance data under a One Health approach.

Impact of short-term storage on the quantity of extended-spectrum beta-lactamase-producing Escherichia coli in broiler litter under practical conditions

Applying broiler litter containing extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) to arable land poses a potential risk for humans to get colonized by contact with contaminated soil or vegetables. Therefore, an inactivation of these bacteria before land application of litter is crucial. We performed 2 short-term litter storage trials (one in summer and winter, respectively), each covering a time span of 5 D to investigate the effectiveness of this method for inactivation of ESBL-producing E. coli in chicken litter. Surface and deep litter samples were taken from a stacked, ESBL-positive chicken litter heap in triplicates in close sampling intervals at the beginning and daily for the last 3 D of the experiments. Samples were analyzed quantitatively and qualitatively for ESBL-producing E. coli, total E. coli, and enterococci. Selected isolates were further characterized by whole-genome sequencing (WGS). In the depth of the heap ESBL-producing E. coli were detected quantitatively until 72 h and qualitatively until the end of the trial in winter. In summer detection was possible quantitatively up to 36 h and qualitatively until 72 h. For surface litter samples a qualitative detection of ESBL-producing E. coli was possible in all samples taken in both trials. In the deep samples a significant decrease in the bacterial counts of over 2 Log10 was observed for total E. coli in the winter and for total E. coli and enterococci in the summer. Genetic differences of the isolates analyzed by WGS did not correlate with survival advantage. In conclusion, short-term storage of chicken litter stacked in heaps is a useful tool for the reduction of bacterial counts including ESBL-producing E. coli. However, incomplete inactivation was observed at the surface of the heap and at low ambient temperatures. Therefore, an extension of the storage period in winter as well as turning of the heap to provide aerobic composting conditions should be considered if working and storage capacities are available on the farms.

Spatio-Temporal Distribution of Acinetobacter baumannii in Germany-A Comprehensive Systematic Review of Studies on Resistance Development in Humans (2000-2018)

Acinetobacter (A.) baumannii has gained global notoriety as a significant nosocomial pathogen because it is frequently associated with multi-drug resistance and hospital-based outbreaks. There is a substantial difference in the incidence of A. baumannii infections between different countries and within Germany. However, its continuous spread within Germany is a matter of concern. A systematic literature search and analysis of the literature published between 2000 and 2018 on A. baumannii in humans was performed. Forty-four studies out of 216 articles met the criteria for inclusion, and were selected and reviewed. The number of published articles is increasing over time gradually. Case reports and outbreak investigations are representing the main body of publications. North Rhine-Westphalia, Hesse and Baden-Wuerttemberg were states with frequent reports. Hospitals in Cologne and Frankfurt were often mentioned as specialized institutions. Multiresistant strains carrying diverse resistance genes were isolated in 13 of the 16 German states. The oxacillinase blaOXA-23-like, intrinsic blaOXA-51-like, blaOXA-58 variant, blaNDM-1, blaGES-11, blaCTX-M and blaTEM are the most predominant resistance traits found in German A. baumannii isolates. Five clonal lineages IC-2, IC-7, IC-1, IC-4 and IC-6 and six sequence types ST22, ST53, ST195, ST218, ST944/ST78 and ST348/ST2 have been reported. Due to multidrug resistance, colistin, tigecycline, aminoglycosides, fosfomycin, ceftazidime/avibactam and ceftolozan/tazobactam were often reported to be the only effective antibiotics left to treat quadruple multi-resistant Gram-negative (4MRGN) A. baumannii. Dissemination and infection rates of A. baumannii are on the rise nationwide. Hence, several aspects of resistance development and pathogenesis are not fully understood yet. Increased awareness, extensive study of mechanisms of resistance and development of alternative strategies for treatment are required. One-Health genomic surveillance is needed to understand the dynamics of spread, to identify the main reservoirs and routes of transmission and to develop targeted intervention strategies.

Long-term mortality and outcome in hospital survivors of septic shock, sepsis, and severe infections: The importance of aftercare

Patients with severe infections and especially sepsis have a high in-hospital mortality, but even hospital survivors face long-term sequelae, decreased health-related quality of life, and high risk of death, suggesting a great need for specialized aftercare. However, data regarding a potential benefit of post-discharge rehabilitation in these patients are scarce. In this retrospective matched cohort study the claim data of a large German statutory health care insurer was analyzed. 83,974 hospital survivors having suffered from septic shock, sepsis, and severe infections within the years 2009–2016 were identified using an ICD abstraction strategy closely matched to the current Sepsis-3 definition. Cases were analyzed and compared with their matched pairs to determine their 5-year mortality and the impact of post-discharge rehabilitation. Five years after hospital discharge, mortality of initial hospital survivors were still increased after septic shock (HR_adj 2.03, 95%-CI 1.87 to 2.19; P<0.001), sepsis (HR_adj 1.73, 95%-CI 1.71 to 1.76; P<0.001), and also in survivors of severe infections without organ dysfunction (HR_adj 1.70, 95%-CI 1.65 to 1.74; P<0.001) compared to matched controls without infectious diseases. Strikingly, patients treated in rehabilitation facilities showed a significantly improved 5-year survival after suffering from sepsis or septic shock (HR_adj 0.81, 95%-CI 0.77 to 0.85; P<0.001) as well as severe infections without organ dysfunction (HR_adj 0.81, 95%-CI 0.73 to 0.90; P<0.001) compared to matched patients discharged to home or self-care. Long-term mortality and morbidity of hospital survivors are markedly increased after septic shock, sepsis and severe infections without organ dysfunction, but best 5-year survival was recorded in patients discharged to a rehabilitation facility in all three groups. Thus, our data suggest that specialized aftercare programs may help to improve long-term outcome in these patients and warrants more vigilance in future investigations.

Does vancomycin resistance increase mortality in Enterococcus faecium bacteraemia after orthotopic liver transplantation? A retrospective study

BACKGROUND

The relevance of vancomycin resistance in enterococcal blood stream infections (BSI) is still controversial. Aim of this study was to outline the effect of vancomycin resistance of Enterococcus faecium on the outcome of patients with BSI after orthotopic liver transplantation (OLT).

METHODS

The outcome of OLT recipients developing BSI with vancomycin-resistant (VRE) versus vancomycin-susceptible Enterococcus faecium (VSE) was compared based on data extraction from medical records. Multivariate regression analyses identified risk factors for mortality and unfavourable outcomes (defined as death or prolonged intensive care stay) after 30 and 90 days.

RESULTS

Mortality was similar between VRE- (n = 39) and VSE- (n = 138) group after 30 (p = 0.44) or 90 days (p = 0.39). Comparable results occurred regarding unfavourable outcomes. Mean SOFA_Non-GCS score during the 7-day-period before BSI onset was the independent predictor for mortality at both timepoints (HR 1.32; CI 1.14-1.53; and HR 1.18; CI 1.08-1.28). Timely appropriate antibiotic therapy, recent ICU stay and vancomycin resistance did not affect outcome after adjusting for confounders.

CONCLUSION

Vancomycin resistance did not influence outcome among patients with Enterococcus faecium bacteraemia after OLT. Only underlying severity of disease predicted poor outcome among this homogenous patient population.

TRIAL REGISTRATION

This study was registered at the German clinical trials register (DRKS-ID: DRKS00013285).

Sustainable implementation of antibiotic stewardship on a surgical intensive care unit evaluated over a 10-year period

OBJECTIVE

This retrospective observational study examined the implementation of antibiotic stewardship (ABS) on the surgical intensive care unit (SICU) of a specialized academic teaching hospital.

METHODS

Application density of antimicrobial agents (ADA), substance class change, development of resistance, and clinical outcomes were investigated with reference to ABS in three intervals over a 10-year period: the pre-intervention phase (2008-2010), the intervention phase (2011-2014), and the post-intervention phase (2015-2017).

RESULTS

Following the introduction of ABS, ADA was reduced from 89.3 recommended daily doses/100 patient days (RDD/100 PD) at the pre-intervention phase to 68.0 RDD/100 PD at the post-intervention phase. The antibiotic ADA (AB-ADA) similarly showed a significant decrease from 83.3 to 62.0 RDD/100 PD (p < 0.0001). The case mix index (CMI), which describes the average case severity across patients and mortality on the SICU was not significantly different comparing intervention and post-intervention phase. It was also possible to achieve a substance class change following the introduction of ABS. There was no obvious change in bacterial resistance rates.

CONCLUSION

The study demonstrates a sustainable effect of the implementation of ABS, which was sustained through the post-intervention phase.

In Vitro Activity Of Ceftaroline And Comparators Against Staphylococcus aureus Isolates: Results From 6 Years Of The ATLAS Program (2012 To 2017)

Background

Ceftaroline is effective against methicillin-resistant Staphylococcus aureus (MRSA), but the resistance patterns still need to be defined. This study aimed to investigate the susceptibility of S. aureus to ceftaroline and comparator antimicrobial agents in patients hospitalized due to infection and to observe the patterns among different regions and over the years.

Methods

The Antimicrobial Testing Leadership And Surveillance (ATLAS) program includes medical centers located in five geographical regions (Europe, Asia-Pacific, South America, Africa-West Asia, and the United States). The isolates were collected from different specimens from patients hospitalized between 2012 and 2017 due to documented complicated skin and soft tissue infection, complicated intra-abdominal infection, complicated urinary tract infection, lower respiratory tract infection, and bloodstream infection.

Results

During the study period, 61,045 isolates were tested, including 35,837 MRSA isolates (58.7%) and 25,208 methicillin-sensitive S. aureus (MSSA) isolates (41.3%). For MRSA, the minimal inhibitory concentration (MIC)₅₀, MIC₉₀, and MIC range of ceftaroline were 0.5, 2, and 0.015–64 μg/mL. The proportion of susceptible MRSA strains was 89.3%. The proportion of resistant MRSA strains was 0.7%. The susceptibility of all S. aureus, MRSA, and MSSA strains to ceftaroline remained relatively constant from 2012 to 2017. The susceptibility to ceftaroline of S. aureus, MRSA, and MSSA strains from the United States, Europe, South America, and Africa/West Asia was high, while the susceptibility of the strains from Asia-Pacific was lower, especially for MRSA.

Conclusion

This study reveals the patterns of ceftaroline susceptibility of MRSA and MSSA around the world and over 6 years.

[Hygiene aspects of multidrug-resistant pathogens in the operating room and intensive care unit]

The major multidrug-resistant pathogens (MRE) in human medicine are methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and multidrug-resistant Gram-negative rod bacteria (MRGN). MRE are a very heterogeneous group with respect to epidemiology and therapeutic or hospital hygiene consequences. After MRSA played an important role among MREs at the beginning of the twenty-first century, VRE and MRGN have come to the fore in recent years. During work in the operating room and on the intensive care unit, there are many possibilities for transmission of MRE between the patient environment and the patient, especially via the hands, e. g. during intubation or catheterization in vessels, tissues or the urinary tract. For this reason, hand and surface hygiene is of particular relevance in the prevention of nosocomial colonization or infection, in particular with MRE.

Incidence of infections due to third generation cephalosporin-resistant Enterobacteriaceae - a prospective multicentre cohort study in six German university hospitals

Background

Infections caused by third generation cephalosporin-resistant Enterobacteriaceae (3GCREB) are an increasing healthcare problem. We aim to describe the 3GCREB infection incidence and compare it to prevalence upon admission. In addition, we aim to describe infections caused by 3GCREB, which are also carbapenem resistant (CRE).

Methods

In 2014-2015, we performed prospective 3GCREB surveillance in clinically relevant patient specimens (screening specimens excluded). Infections counted as hospital-acquired (HAI) when the 3GCREB was detected after the third day following admission, otherwise as community-acquired infection (CAI).

Results

Of 578,420 hospitalized patients under surveillance, 3367 had a 3GCREB infection (0.58%). We observed a similar 3GCREB CAI and HAI incidence (0.28 and 0.31 per 100 patients, respectively). The most frequent pathogen was 3GCR E. coli, in CAI and HAI (0.15 and 0.12 per 100 patients). We observed a CRE CAI incidence of 0.006 and a HAI incidence of 0.008 per 100 patients (0.014 per 1000 patient days).

Conclusions

Comparing the known 3GCREB admission prevalence of the participating hospitals (9.5%) with the percentage of patients with a 3GCREB infection (0.58%), we conclude the prevalence of 3GCREB in university hospitals to be about 16 times higher than suggested when only patients with 3GCREB infections are considered. Moreover, we find the HAI and CAI incidence caused by CRE in Germany to be relatively low.

One-year molecular surveillance of carbapenem-susceptible A. baumannii on a German intensive care unit: diversity or clonality

Background

A. baumannii is a common nosocomial pathogen known for its high transmission potential. A high rate of carbapenem-susceptible Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB)-complex in clinical specimens led to the implementation of a pathogen-based surveillance on a 32-bed surgical intensive care unit (SICU) in a German tertiary care centre.

Methods

Between April 2017 and March 2018, ACB-complex isolates with an epidemiological link to the SICU were further assessed. Identification to the species level was carried out using a multiplex PCR targeting the gyrB gene, followed by RAPD, PFGE (ApaI) and whole genome sequencing (WGS, core genome MLST, SeqSphere+ software, Ridom). Additional infection prevention and control (IPC) measures were introduced as follows: epidemiological investigations, hand hygiene training, additional terminal cleaning and disinfection incl. UV-light, screening for carbapenem-susceptible A. baumannii and environmental sampling. Hospital-acquired infections were classified according to the CDC definitions.

Results

Fourty four patients were colonized/infected with one or two (different) carbapenem-susceptible ACB-complex isolates. Fourty three out of 48 isolates were classified as hospital-acquired (detection on or after 3rd day of admission). Nearly all isolates were identified as A. baumannii, only four as A. pittii. Twelve patients developed A. baumannii infections. Genotyping revealed two pulsotype clusters, which were confirmed to be cgMLST clonal cluster type 1770 (n = 8 patients) and type 1769 (n = 12 patients) by WGS. All other isolates were distinct from each other. Nearly all transmission events of the two clonal clusters were confirmed by conventional epidemiology. Transmissions stopped after a period of several months. Environmental sampling revealed a relevant dissemination of A. baumannii, but only a few isolates corresponded to clinical strains. Introduction of the additional screening revealed a significantly earlier detection of carbapenem-susceptible A. baumannii during hospitalization.

Conclusions

A molecular and infection surveillance of ACB-complex based on identification to the species level, classic epidemiology and genotyping revealed simultaneously occurring independent transmission events and clusters of hospital-acquired A. baumannii. This underlines the importance of such an extensive surveillance methodology in IPC programmes also for carbapenem-susceptible A. baumannii.

Antibiotic prescribing behavior among general practitioners - a questionnaire-based study in Germany

Background

This study investigates the barriers and facilitators of the use of antibiotics in acute respiratory tract infections by general practitioners (GPs) in Germany.

Methods

A multidisciplinary team designed and pre-tested a written questionnaire addressing the topics awareness of antimicrobial resistance (7 items), use of antibiotics (9 items), guidelines/sources of information (9 items) and sociodemographic factors (7 items), using a five-point-Likert-scale (“never” to “very often”). The questionnaire was mailed by postally to 987 GPs with registered practices in eastern Germany in May 2015.

Results

34% (340/987) of the GPs responded to this survey. Most of the participants assumed a multifactorial origin for the rise of multidrug resistant organisms. In addition, 70.2% (239/340) believed that their own prescribing behavior influenced the drug-resistance situation in their area. GPs with longer work experience (> 25 years) assumed less individual influence on drug resistance than their colleagues with less than 7 years experience as practicing physicians (Odds Ratio [OR] 0.32, 95% Confidence Interval [CI] 0.17–0.62; P < 0.001). 99.1% (337/340) of participants were familiar with the “delayed prescription” strategy to reduce antibiotic prescriptions. However, only 29.4% (74/340) answered that they apply it “often” or “very often”. GPs working in rural areas were less likely than those working in urban areas to apply delayed prescription.

Conclusion

The knowledge on factors causing antimicrobial resistance in bacteria is good among GPs in eastern Germany. However measures to improve rational prescription are not widely implemented yet. Further efforts have to be made in order to improve rational prescription of antibiotic among GPs. Nevertheless, there is a strong awareness of antimicrobial resistance among the participating GPs.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3120-y) contains supplementary material, which is available to authorized users.

Continuous increase of vancomycin resistance in enterococci causing nosocomial infections in Germany - 10 years of surveillance

Background

Enterococci are frequent pathogens causing nosocomial infections in Germany. Infections due to strains with vancomycin resistance are high when compared with other European states. Therefore, the study aimed to describe the recent progression of nosocomial infections due to vancomycin-resistant enterococci (VRE) in Germany.

Methods

We analyzed data from two components of the German national nosocomial infection surveillance system for the period 2007–2016. For primary bloodstream infections (BSIs) and urinary tract infections (UTIs) we used data from intensive care units and for surgical site infections (SSIs) data from surgical departments. In a sensitivity analysis, we considered only data from participants that participated continuously from 2007 to 2016 (“core group”). We calculated proportions of VRE among all nosocomial enterococcal infections with 95% confidence intervals (95% CIs) and trends over time. A multivariable logistic regression was used to compare occurrence of VRE proportions among German federal states.

Results

Enterococcal infections from 857 ICUs and 1119 surgical departments were analyzed. On ICUs, the proportion of vancomycin resistance in enterococci causing nosocomial infections significantly increased for BSIs from 5.9 to 16.7% and for UTIs from 2.9 to 9.9%; for surgical site infections, the proportion of VRE increased from 0.9 to 5.2% (P < 0.001 for all). In the core group, the increase of VRE was more pronounced in ICUs (BSIs: 5.5 to 21.6%; UTIs: 2 to 11.2%) but was not seen in surgical departments (SSIs: 1.5 to 2.8%). Compared with the most populous German federal state North Rhine Westphalia, enterococcal infections in Hesse (Odds Ratio (OR) 2.3, 95% CI 1.7–3.1), Saxony (OR 2.5, 95% CI 1.8–3.5) and Thuringia (OR 1.9, 95% CI 1.4–2.6) were more likely to be caused by vancomycin-resistant strains.

Conclusion

In Germany, the proportion of VRE in nosocomial infection due to enterococci is still increasing. It remains unclear, why a large variation in the proportion of VRE exists between German federal states.

Lactobacillus paracasei CNCM I-3689 reduces vancomycin-resistant Enterococcus persistence and promotes Bacteroidetes resilience in the gut following antibiotic challenge

Enterococci, in particular vancomycin-resistant enterococci (VRE), are a leading cause of hospital-acquired infections. Promoting intestinal resistance against enterococci could reduce the risk of VRE infections. We investigated the effects of two Lactobacillus strains to prevent intestinal VRE. We used an intestinal colonisation mouse model based on an antibiotic-induced microbiota dysbiosis to mimic enterococci overgrowth and VRE persistence. Each Lactobacillus spp. was administered daily to mice starting one week before antibiotic treatment until two weeks after antibiotic and VRE inoculation. Of the two strains, Lactobacillus paracasei CNCM I-3689 decreased significantly VRE numbers in the feces demonstrating an improvement of the reduction of VRE. Longitudinal microbiota analysis showed that supplementation with L. paracasei CNCM I-3689 was associated with a better recovery of members of the phylum Bacteroidetes. Bile salt analysis and expression analysis of selected host genes revealed increased level of lithocholate and of ileal expression of camp (human LL-37) upon L. paracasei CNCM I-3689 supplementation. Although a direct effect of L. paracasei CNCM I-3689 on the VRE reduction was not ruled out, our data provide clues to possible anti-VRE mechanisms supporting an indirect anti-VRE effect through the gut microbiota. This work sustains non-antibiotic strategies against opportunistic enterococci after antibiotic-induced dysbiosis.