Characterization of Amino Acid Substitutions in the Two-Component Regulatory System AdeRS Identified in Multidrug-Resistant Acinetobacter baumannii.

In Acinetobacter baumannii, resistance-nodulation-cell division (RND)-type efflux is a resistance mechanism of great importance since it contributes to reduced susceptibility to multiple antimicrobial compounds. Some mutations within the genes encoding the two-component regulatory system AdeRS appear to play a major role in increased expression of the RND efflux pump AdeABC and, consequently, in reduced antimicrobial susceptibility, as they are commonly observed in multidrug-resistant (MDR) A. baumannii. In the present study, the impact of frequently identified amino acid substitutions, namely, D21V and D26N in AdeR and T156M in AdeS, on adeB expression, efflux activity, and antimicrobial susceptibility was investigated. Reverse transcription-quantitative PCR (qRT-PCR) studies revealed significantly increased adeB expression caused by D26N (AdeR) and T156M (AdeS). In addition, accumulation assays have shown that these mutations induce increased efflux activity. Subsequently, antimicrobial susceptibility testing via agar dilution and broth microdilution confirmed the importance of these substitutions for the MDR phenotype, as the MICs for various antimicrobials of different classes were increased. In contrast, the amino acid substitution D21V in AdeR did not lead to increased adeB expression and did not reduce antimicrobial susceptibility. This study demonstrates the impact of the D26N (AdeR) and T156M (AdeS) amino acid substitutions, highlighting that these regulators represent promising targets for interfering with efflux activity to restore antimicrobial susceptibility. IMPORTANCE The active efflux of antimicrobials by bacteria can lead to antimicrobial resistance and persistence and can affect multiple different classes of antimicrobials. Efflux pumps are tightly regulated, and their overexpression can be mediated by changes in their regulators. Identifying these changes is one step in the direction of resistance prediction, but it also opens the possibility of targeting efflux pump regulation as a strategy to overcome antimicrobial resistance. Here, we have investigated commonly found changes in the regulators of the main efflux pumps in Acinetobacter baumannii.

Comparison of the Acinetobacter baumannii Reference Strains ATCC 17978 and ATCC 19606 in Antimicrobial Resistance Mediated by the AdeABC Efflux Pump.

The Acinetobacter baumannii RND efflux pump AdeABC is regulated by the 2-component regulator AdeRS. In this study, we compared the regulation and expression of AdeABC of the reference strains ATCC 17978 and ATCC 19606. A clearly stronger efflux activity was demonstrated for ATCC 19606. An amino acid substitution at residue 172 of adeS was identified as a potential cause for differential expression of the pump. Therefore, we recommend caution with exclusively using single reference strains for research.

[Elderly patients with an abdominal aortic aneurysm; preoperative frailty-screening and a multidisciplinary approach]. / Ouderen met een aneurysma van de abdominale aorta.

Aneurysm of the abdominal aorta is common and can be treated with endovascular repair, open surgical repair or conservative treatment. Risk-stratification and treatment decision-making can be complex in frail patients and depends largely on anatomy, life-expectancy and functional capacity. Currently, risk-stratification in the Netherlands is primarily based on comorbidities and age. Insight in a patient's resilience could provide important additional information. For this reason, St. Antonius hospital has implemented an Anaesthesia Geriatric Evaluation (AGE) to screen for frailty in high risk vascular surgery patients. Results of frailty-screening are discussed in a multi-disciplinary team (MDT) to assess perioperative risk and compose a personal treatment plan. This paper presents a case-series of three patients to illustrate the additional value of MDT care and frailty-screening in a high-risk vascular surgery population.

Trends in prevalence of healthcare-associated infections and antimicrobial use in hospitals in the Netherlands: 10 years of national point-prevalence surveys.

BACKGROUND: Prevalence of healthcare-associated infections (HCAIs) and antimicrobial use in hospitals in the Netherlands has been measured using voluntary biannual national point-prevalence surveys (PPSs). AIM: To describe trends in the prevalence of patients with HCAI, risk factors, and antimicrobial use in 2007-2016. METHODS: In the PPS, patient characteristics, use of medical devices and antimicrobials, and presence of HCAI on the survey day are reported for all hospitalized patients, excluding patients in the day-care unit and psychiatric wards. Analyses were performed using linear and (multivariate) logistic regression, accounting for clustering of patients within hospitals. FINDINGS: PPS data were reported for 171,116 patients. Annual prevalence of patients with HCAI with onset during hospitalization decreased from 6.1% in 2007 to 3.6% in 2016. The adjusted odds ratio (OR) for trend was 0.97 (95% confidence interval: 0.96-0.98). Most prominent trends were seen for surgical site infections (1.6%-0.8%; OR: 0.91 (0.90-0.93)) and urinary tract infections (2.1%-0.6%; OR: 0.85 (0.83-0.87)). From 2014 on, HCAIs at admission were also registered with a stable prevalence of approximately 1.5%. The mean length of stay decreased from 10 to 7 days. The percentage of patients treated with antibiotics increased from 31% to 36% (OR: 1.03 (1.02-1.03)). CONCLUSION: Repeated PPS data from 2007 to 2016 show a decrease in the prevalence of patients with HCAI with onset during hospitalization, and a stable prevalence of patients with HCAI at admission. The adjusted OR of 0.97 for HCAI during hospitalization indicates a true reduction in prevalence of approximately 3% per year.

Laser-induced vapor nanobubbles improve diffusion in biofilms of antimicrobial agents for wound care.

Being responsible for delayed wound healing, the presence of biofilms in infected wounds leads to chronic, and difficult to treat infections. One of the reasons why antimicrobial treatment often fails to cure biofilm infections is the reduced penetration rate of antibiotics through dense biofilms. Strategies that have the ability to somehow interfere with the integrity of biofilms and allowing a better penetration of drugs are highly sought after. A promising new approach is the use of laser-induced vapor nanobubbles (VNB), of which it was recently demonstrated that it can substantially enhance the penetration of antibiotics into biofilms, resulting in a marked improvement of the killing efficiency. In this study, we examined if treatment of biofilms with laser-induced vapor nanobubbles (VNB) can enhance the potency of antimicrobials which are commonly used to treat wound infections, including povidone-iodine, chlorhexidine, benzalkonium chloride, cetrimonium bromide and mupirocin. Our investigations were performed on Pseudomonas aeruginosa and Staphylococcus aureus biofilms, which are often implicated in chronic wound infections. Pre-treatment of biofilms with laser-induced VNB did enhance the killing efficiency of those antimicrobials which experience a diffusion barrier in the biofilms, while this was not the case for those compounds for which there is no diffusion barrier. The magnitude of the enhanced potency was in most cases similar to the enhancement that was obtained when the biofilms were completely disrupted by vortexing and sonication. These results show that laser-induced VNB are indeed a very efficient way to enhance drug penetration deep into biofilms, and pave the way towards clinical translation of this novel approach for treatment of wound infections.

Correction to: Percutaneous Deep Venous Arterialization for Severe Critical Limb Ischemia in Patients With No Option of Revascularization: Early Experience From Two European Centers.

The fifth author's name was incorrectly published as "M. Messas". The correct name is "E. Messas". The original article has been corrected.

Percutaneous Deep Venous Arterialization for Severe Critical Limb Ischemia in Patients With No Option of Revascularization: Early Experience From Two European Centers.

PURPOSE: To report our initial experience of fully percutaneous deep venous arterialization (pDVA) for the treatment of chronic critical limb ischemia (cCLI) after failed distal angioplasty. MATERIALS AND METHODS: pDVA was performed in five consecutive patients by creating an arteriovenous fistula (AVF) between a below the knee artery and its satellite deep vein. In this early experience, only patients with failed prior interventional attempts at establishing flow with no distal targets for an arterial bypass were selected. Early technical success was defined as successful AVF creation and retrograde venous perfusion of the wound site. Patient demographics, procedural details, morbidity/mortality and wound healing outcomes were assessed prospectively. Patients were followed up in wound care centers, and graft patency was documented on duplex ultrasound. RESULTS: All five consecutive patients (mean age 58 years) underwent successful pDVA without any procedural complications. There were neither 30-day major adverse limb events nor major cardiovascular complications. Three out of the five patients (60%) had clinical improvement as observed by resolution of rest pain and complete wound healing. At the 1-month FU, one patient died and one patient received a major amputation. The median wound healing time was 39 weeks. CONCLUSION: pDVA is a safe and feasible vascularization alternative in patients with end-stage/no-option CLI. The early experience highlights the need for a multidisciplinary approach including a dedicated wound care service.

Applicability of generic quality indicators for appropriate antibiotic use in daily hospital practice: a cross-sectional point-prevalence multicenter study.

The ability to monitor the appropriateness of hospital antibiotic use is a key element of an effective antibiotic stewardship program. A set of 11 generic quality indicators (QIs) was previously developed to assess the quality of antibiotic use in hospitalized adults treated for a bacterial infection. The primary aim of the current study was to assess the clinimetric properties of these QIs (nine process and two structure indicators) in daily clinical practice. In a cross-sectional point-prevalence survey, performed in 2011 and 2012, 1890 inpatients from 22 hospitals in the Netherlands treated with antibiotics for a suspected bacterial infection were included, and data were extracted from medical records. In this cohort we tested the measurability, applicability, reliability, room for improvement and case mix stability of the previously developed QIs. Low applicability (≤10% of reviewed patients) was found for the QIs 'therapeutic drug monitoring', 'adapting antibiotics to renal function' and 'discontinue empirical therapy in case of lack of clinical and/or microbiological evidence of infection'. For the latter, we also found a low inter-observer agreement (kappa <0.4). One QI showed low improvement potential. The remaining seven QIs had sound clinimetric properties. Case-mix correction was necessary for most process QIs. For all QIs, we found ample room for improvement and large variation between hospitals. Establishing the clinimetric properties was essential, as four of the 11 previously selected QIs showed unsatisfactory properties in this practice test. Since the quality of antibiotic use and the process of documenting data is changing over time and may vary per country, QIs should always be tested in practice first.

An undetected common renal arterial trunk: surgical consequences and morbidity analysis.

We present a patient with a recurrent precaval left renal artery, stemming from a right-sided common trunk renal artery. The patient was a 44-year male who presented with a post-traumatic grade IV renal injury. After 3 months without renal function improvement and repeated urinary tract infection, a laparoscopic nephrectomy of the affected right kidney was performed, without upfront identification of the vascular variation, resulting in ischemia of the remaining left kidney. An anastomosis of the common renal trunk and the distal left renal artery was created in between the abdominal aorta and the inferior vena cava. This case describes the importance of upfront detection of renal vascular variations using the appropriate imaging techniques.

Post-discharge surveillance (PDS) for surgical site infections: a good method is more important than a long duration.

Post-discharge surveillance (PDS) for surgical site infections (SSIs) normally lasts 30 days, or one year after implant surgery, causing delayed feedback to healthcare professionals. We investigated the effect of shortened PDS durations on SSI incidence to determine whether shorter PDS durations are justified. We also studied the impact of two national PDS methods (those mandatory since 2009 ('mandatory') and other methods acceptable before 2009 ('other')) on SSI incidence. From Dutch surveillance (PREZIES) data (1999-2008), four implant-free surgeries (breast amputation, Caesarean section, laparoscopic cholecystectomy and colectomy) and two implant surgeries (knee replacement and total hip replacement) were selected. We studied the impact of PDS duration and method on SSI incidences by survival and Cox regression analyses. We included 105,607 operations. Shortened PDS duration for implant surgery from one year to 90 days resulted in 6­14% of all SSIs being missed. For implant-free procedures, PDS reduction from 30 to 21 days caused similar levels of missed SSIs. In contrast, up to 62% of SSIs (for cholecystectomy) were missed if other instead of mandatory PDS methods were used. Inferior methods of PDS, rather than shortened PDS durations, may lead to greater underestimation of SSI incidence. Our data validate international recommendations to limit the maximum PDS duration (for implant surgeries) to 90 days for surveillance purposes, as this provides robust insight into trends.

Results of reinterventions for failed endovascular aortic repair: a single-center experience.

AIM: The aim of this paper was to review technical success and clinical outcome of reinterventions to treat complications after endovascular abdominal aortic aneurysm (AAA) repair (EVAR) in a tertiary vascular center. METHODS: The study enrolled 107 patients treated for post-EVAR complications between January 2005 and March 2014. Details of reinterventions, technical success, and midterm clinical outcome were analyzed for reinterventions. Radiologic follow-up after reinterventions was performed by computed tomography scans and duplex ultrasonography. RESULTS: Indications for reinterventions in the 107 patients were predominantly endoleaks type Ia, Ib, II, and III (55.1%). Endograft obstructions were observed in 39 patients (36.4%). The initial technical success rate for the 107 reinterventions was 93.5% (N.=100). Median follow-up postreintervention was 20 months (range, 1-107 months). During follow-up, 34 of 107 patients (31.8%) needed at least one renewed reintervention. Kaplan-Meier analysis of overall survival after the primary reinterventions was 85% at 1 year, and 78% at 3 years of follow-up. AAA/EVAR-associated mortality was 4% at 3 years. Kaplan-Meier survival estimation of freedom of recurrence was 88% at 1 year post-reintervention and 78% at 3 years. Renewed reintervention-free survival dropped to 78% at 1 year and 58% at 3 years. CONCLUSION: In this series of patients, the technical success rate of reinterventions to treat post-EVAR complications was high. During a median follow-up of 20 months, AAA-associated mortality is low, but the need for renewed (endovascular) reinterventions is substantial.

CT angiography to evaluate hemodynamic changes in popliteal artery aneurysms during flexion and extension of the knee joint.

AIM: The aim of this study was to find out which characteristics of an asymptomatic popliteal artery aneurysm (PAA) will increase the risk for acute thrombosis. METHODS: This was a single-center prospective study of consecutive patients with asymptomatic PAAs presenting from January 2010 to April 2012. Computed tomography angiography was used to perform measurements of the PAA during 0º extension and 90º flexion of the knee. After semi-automated segmentation of the popliteal artery (PA) lumen, a center lumen line (CLL) was automatically constructed. RESULTS: The study included 16 asymptomatic PAAs. Median lumen area of the PA was directly proximal and distal of the PAA 57 mm2 (IQR, 44-87 mm2) and 46 mm2 (IQR, 32-66 mm2) in extension vs. 51 mm2 (IQR, 38-73 mm2) and 38 mm2 (IQR, 30-62 mm2) during 90º flexion, respectively (P=0.007) and (P=0.03). The median of the greatest decrease in lumen area after flexion and extension of the knee was 36 mm (IQR, 28-48 mm) in PAAs≥30 mm compared with 11 mm (IQR, 4-18 mm) in PAAs<30 mm (P<0.05). The proximal angulation was a median 48° in extension (IQR, 27-61º) and 75° during flexion (IQR, 46-99º; P=0.02). Distal angulation was a median of 31° (IQR, 21-42º) after extension vs. 62° (IQR, 33-81º) during flexion (P=0.03). CONCLUSION: Knee bending in patients with PAAs will lead to a reduction in the lumen area of the PAA and a change in the degree of angulation of the PAA. A significant decrease in lumen area was seen in PAAs≥30 mm compared with PAAs<30 mm after flexion of the knee.

Catheter application, insertion vein and length of ICU stay prior to insertion affect the risk of catheter-related bloodstream infection.

BACKGROUND: The Dutch PREZIES surveillance scheme for catheter-related bloodstream infection (CR-BSI) collects data on infection rates and related risk factors. AIM: To evaluate risk factors for CR-BSI. METHODS: Hospitals collected data for intensive care units (ICU) or for the entire hospital. All short-term central venous catheters (CVC), including Swan-Ganz catheters, present for ≥48h were surveyed, except in cases when bacteraemia was present at insertion. CVCs were monitored until infection, removal or death for up to 28 days. Data were collected on 3750 CVCs and 29,003 CVC-days. FINDINGS: Of the CVCs surveyed, 1.6% [95% confidence interval (CI) 1.2-2.0] resulted in CR-BSI, representing 2.0/1000 CVC-days (95% CI 1.6-2.6). Multi-variate analysis revealed that the length of ICU stay prior to CVC insertion, insertion in the jugular or femoral vein, and use of the CVC to deliver total parenteral nutrition increased the risk of CR-BSI, whereas use of the CVC to deliver antibiotics decreased the risk of CR-BSI. CONCLUSION: Attention to these risks has the potential to reduce the incidence of CR-BSI.

Appropriateness of antimicrobial therapy: a multicentre prevalence survey in the Netherlands, 2008-2009.

A survey was carried out to determine the prevalence and appropriateness of antimicrobial therapy (AMT) in the Netherlands and to identify determinants for inappropriate AMT. Prevalence surveys of patients hospitalised in the Netherlands were performed three times in 2008 and 2009. Patients' demographic, infection-related and AMT-related data were collected from hospital wards. A total of 19 hospitals participated, consisting of a mix of university, teaching and general hospitals, which were distributed evenly across the country. The appropriateness of AMT was assessed using a standardised algorithm based on local AMT prescription guidelines. A total of 7,853 patients were included, of which 2,327 (29.6%) patients were on AMT (range: 20.8­39.5%). In 372 patients (16% of patients on AMT), treatment was considered inappropriate. In 265 (11.4%) patients on AMT, appropriateness of treatment was not judged because of insufficient information. The percentage of patients without a judgment varied considerably between the participating hospitals (range: 1.3­36.2%). Appropriate AMT use was significantly associated with a patient being in an intensive care unit, having a central venous catheter and being given beta-lactamase-sensitive penicillins. The use of fluoroquinolones was significantly associated with more frequent inappropriate use. There was considerable and significant variation between the participating hospitals in the amount of antimicrobials prescribed and the appropriateness of their use. To improve the completeness and reliability of such surveys, there is a need for intensive training of observers and medical staff in recording information.

Prevalence of nosocomial infections in The Netherlands, 2007-2008: results of the first four national studies.

The PREZIES national network for the surveillance of nosocomial infections (NI) in The Netherlands has organised a national prevalence study twice a year since 2007. This paper presents the results of the first four surveys. Of 95 hospitals in The Netherlands, 41 participated in 92 surveys and 26 937 patients were included. On the survey day 6.2% had an NI (prevalence of infections 7.2%). The prevalence of infections varied from 1.4% to 16.5% between hospitals. The prevalence of surgical site infections was 4.8%, pneumonia 1.1%, primary bloodstream infection 0.5% and symptomatic urinary tract infection 1.7%. On admission to hospital, 3.3% of patients had an NI. On the day of the survey, 30.9% of the patients were receiving antibiotics. The use of antibiotics as well as medical devices differed considerably between hospitals. Both the prevalence of NI in The Netherlands and the use of antibiotics and devices were comparable to other European countries.

Vitex agnus castus as prophylaxis for osteopenia after orchidectomy in rats compared with estradiol and testosterone supplementation.

Osteoporosis research undertaken in males is rare and there are only a few therapeutic options. Phytoestrogens might be a safe alternative for prophylaxis. Sixty 3-month-old male rats were orchidectomized and divided into five groups. The groups either received soy-free food (C), estradiol (E), testosterone (T) or Vitex agnus castus in different concentrations (AC high/AC low) for 12 weeks. The tibia metaphysis was tested biomechanically and histomorphometrically. The AC high group reached 87% of the biomechanical values of the estradiol group and was significantly superior to the control group. Testosterone supplementation resulted in poor biomechanical properties. The cortical bone parameters of the AC group were similar to the control group, while supplementation with estradiol and testosterone demonstrated a reduction of cortical bone. The AC high group reached 88.4% of trabecular bone area, 80.7% of trabecular number and 66.9% of the number of trabecular nodes compared with estradiol supplementation. Vitex agnus castus demonstrated osteoprotective effects in males. It preserves the cortical as well as the trabecular bone and might be a safe alternative for HRT. Testosterone supplementation has positive effects on trabecular bone, which are concurrently counteracted by the loss of cortical bone.

[Diagnostic image (381). A man with painful, red spots on one foot]. / Diagnose in beeld (381). Een man met pijnlijke, rode vlekken op de voet.

A 49-year-old Turkish man with classic Kaposi sarcoma on his right foot, was successfully treated by irradiation.

[Diagnostic image (378). A woman with a subungual pigmentation of the left hallux]. / Diagnose in beeld (378). Een vrouw met een subunguale pigmentatie aan de linker hallux.

An 81-year-old woman presented with a subungual pigmented lesion of the left hallux, caused by a malignant acral-lentiginous melanoma.

Comparison of the National Surgical Site Infection surveillance data between The Netherlands and Germany: PREZIES versus KISS.

As there has been increasing interest in comparing surgical site infection (SSI) rates between countries, we compared the SSI surveillance data for The Netherlands ('PREZIES') and Germany ('KISS'). Both surveillance systems have comparable protocols with many similar risk factors, including SSI definitions developed by the Centers for Disease Control and Prevention and optional postdischarge surveillance. Nine surgical procedure categories from several specialities were included, the reporting of which were similar, with respect to content and with enough data for proper comparison. Differences for the SSI data were found between PREZIES and KISS for duration of surgery, wound contamination class, American Society of Anesthesiologists physical status classification and the postoperative duration of hospitalization. A significantly higher superficial SSI rate was found for seven surgical procedures according to PREZIES and a higher deep SSI rate for five procedures. When considering only deep SSI during hospitalization, the differences in SSI rates were much smaller. Differences in intensity of postdischarge surveillance led to 34% of SSI being detected after discharge for PREZIES and 21% for KISS. In conclusion, even though similar infection surveillance protocols are used in The Netherlands and Germany, differences occurred in the implementation. Comparisons between countries are most reliable if only deep SSIs during hospitalization are taken into account, since these SSI are not affected by postdischarge surveillance and the diagnostic sensitivity for deep SSI is probably more alike between countries than for superficial SSI.

Humidification policies for mechanically ventilated intensive care patients and prevention of ventilator-associated pneumonia: a systematic review of randomized controlled trials.

The Dutch Working Party on Infection Prevention (WIP) aimed to determine whether certain humidification policies are better than others in terms of prevention of ventilator-associated pneumonia (VAP) in mechanically ventilated intensive care unit (ICU) patients. Publications were retrieved by a systematic search of Medline and the Cochrane Library up to February 2006. All (quasi-) randomized trials and systematic reviews/meta-analyses comparing humidification methods in ventilated ICU patients were selected. Two reviewers independently assessed trial quality and extracted data. If the data was incomplete, clarification was sought from original authors and used to calculate the relative risk of VAP. Data for VAP were combined in the analysis, where appropriate, using a random-effects model. Ten trials were included in the review. In general, the quality of the trials and the way they were reported were unsatisfactory. The results did not show any benefit from specific humidification techniques in terms of reducing VAP. WIP do not recommend either passive or active humidifiers to prevent VAP, nor the type of passive humidifiers to be used. Regarding active humidification, WIP recommends using heated wire circuits. This is due to the theoretical consideration that less condensate reduces colonization and subsequent risk of spread throughout an ICU when condensate is removed.