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.

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.

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.

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.

[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.

Coupling of proadipocyte growth arrest and differentiation. II. A cell cycle model for the physiological control of cell proliferation.

Experimental evidence is presented that supports a cell cycle model showing that there are five distinct biological processes involved in proadipocyte differentiation. These include: (a) growth arrest at a distinct state in the G1 phase of the cell cycle; (b) nonterminal differentiation; (c) terminal differentiation; (d) loss of the differentiated phenotype; and (e) reinitiation of cell proliferation. Each of these events is shown to be regulated by specific human plasma components or other physiological factors. At two states designated GD and GD', coupling of growth arrest and differentiation is shown to occur. We propose that these mechanisms for the coupling of growth arrest and differentiation are physiologically significant and mimic the regulatory processes that control stem cell proliferation in vivo.

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.

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.

[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.

[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.

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.

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.

Validation of surgical site infection surveillance in the Netherlands.

OBJECTIVES: To describe how continuous validation of data on surgical site infection (SSI) is being performed in the Dutch National Nosocomial Infection Surveillance System (Preventie Ziekenhuisinfecties door Surveillance [PREZIES]), to assess the quality and accuracy of the PREZIES data, and to present the corresponding outcomes of the assessment. DESIGN: Mandatory, 1-day on-site validation visit to participating hospitals every 3 years. The process of surveillance, including the quality of the method of data collection, is validated by means of a structured interview. The use of SSI criteria is validated by review of medical records, with the judgment of the validation team as the criterion standard. SETTING: Hospitals participating in PREZIES. RESULTS: During 1999-2004, the validation team visited 40 hospitals and reviewed 859 medical charts. There was no deviation between reports of SSI by infection control professionals and findings by the PREZIES validation team at 30 hospitals and 1 deviation in each of 10 hospitals; the positive predictive value was 0.97, and the negative predictive value was 0.99. The validation team often gave advice to the hospital, aimed at perfecting the process of surveillance. On 2 occasions, data were removed from the PREZIES database after the validation visit revealed deviations from the SSI surveillance protocol that could have resulted in nonrepresentative SSI rate data. CONCLUSIONS: PREZIES is confident that the assembled Dutch SSI surveillance data are reliable and robust and are sufficiently accurate to be used as a reference for interhospital comparison. PREZIES will continue performing on-site validation visits, to improve the process of surveillance and ensure the reliability of the surveillance data.

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.

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.

Random effect modelling of patient-related risk factors in orthopaedic procedures: results from the Dutch nosocomial infection surveillance network 'PREZIES'.

In the Dutch surveillance for surgical site infections (SSIs), data from 70277 orthopaedic procedures with 1895 SSIs were collected between 1996 and 2003. The aims of this study were: (1) to analyse the trends in SSIs associated with Gram-positive and Gram-negative bacteria; (2) to estimate patient-related risk factors for deep and superficial SSIs after all orthopaedic procedures, with special attention to primary total hip arthroplasty (THA); and (3) to analyse inherent differences in infection risk between hospitals. A random effect model was used to estimate the odds ratios of patient-related risk factors for developing an SSI, and to describe the distribution of the most widespread bacterial species responsible for SSIs among hospitals. Gram-positive organisms, mainly staphylococci, were the main cause of both deep (84.0%) and superficial SSIs (69.1%) after orthopaedic procedures. The percentage of SSIs after THA caused by coagulase-negative staphylococci decreased over the surveillance period, while the contribution of Staphylococcus aureus increased. Temporary elevations in the incidence of the most widespread pathogen species were observed within hospitals. Patient-related factors such as the National Nosocomial Infections Surveillance System risk index or age had little effect on the predictive power of the random effect models. This study underlines the usefulness of a random effect model, which adjusts risk estimates for random variation between hospitals, in a multicentre study on risk factors for SSIs.

Surveillance of healthcare-associated infections in Indonesian hospitals.

A cross-sectional surveillance of healthcare-associated infections (HAIs) and exposure to risk factors was undertaken in two Indonesian teaching hospitals (Hospitals A and B). Patients from internal medicine, surgery, obstetrics and gynaecology, paediatrics, a class department and intensive care were included. Patient demographics, antibiotic use, culture results, presence of HAI [phlebitis, surgical site infection (SSI), urinary tract infection (UTI) and septicaemia] and risk factors were recorded. To check for interobserver variation, a validation study was performed in Hospital B. In Hospitals A and B, 1,334 and 888 patients were included, respectively. Exposure to invasive devices and surgery was 59%. In Hospital A, 2.8% of all patients had phlebitis, 1.7% had SSI, 0.9% had UTI and 0.8% had septicaemia. In Hospital B, 3.8% had phlebitis, 1.8% had SSI, 1.1% had UTI and 0.8% had septicaemia. In the validation study, the prevalence as recorded by the first team was 2.6% phlebitis, 1.8% SSI, 0.9% UTI and no septicaemia, and that recorded by the second team was 2.2% phlebitis, 2.6% SSI, 3.5% UTI and 0.9% septicaemia. This study is the first to report on HAI in Indonesia. Prevalence rates are comparable to those in other countries. The reliability of the surveillance was insufficient as a considerable difference in prevalence rates was found in the validation study. The surveillance method used is a feasible tool for hospitals in countries with limited healthcare resources to estimate their level of HAI and make improvements in infection control. Efficiency can be improved by restricting the surveillance to include only those patients with invasive procedures. This can help to detect 90% of all infections while screening only 60% of patients.

Neoplastic transformation and defective control of cell proliferation and differentiation.

The control of proliferation of nontransformed 3T3 t-proadipocytes in vitro can be mediated at three states in the G1 phase of the cell cycle. These states are induced by the commitment of cells to differentiate (GD); by growth factor deprivation at low density or "contact inhibition" at high density (Gs); and by nutrient deprivation (GN). To determine if neoplastic transformation of proadipocytes is associated with a selective defect in one or more of these G1 growth arrest processes, we developed and studied eight cloned and several noncloned tumorigenic proadipocyte cell lines. We report that all transformed proadipocyte cell lines are tumorigenic and all lack the ability to arrest at GD and differentiate. By contrast, or approximately 90% of transformed proadipocyte cell lines retain their ability to growth arrest at Gs at low density when deprived of growth factors, and or approximately 90% growth arrest at GN when deprived of nutrients. These observations suggest that neoplastic transformation of proadipocytes is primarily associated with abrogation of growth control mediated at GD. However, whereas most transformed proadipocytes arrest at Gs at low density when deprived of serum, all transformed proadipocyte cell lines do not efficiently arrest at Gs at high density due to "contact inhibition." This suggests that neoplastic transformation of proadipocytes results from a primary defect in growth control mediated at GD and from an additional defect at Gs. These results are discussed with respect to their possible significance for the biological mechanisms of the initiation and promotion of carcinogenesis.