Genetic and antigenic structural characterization for resistance of echovirus 11 to pleconaril in an immunocompromised patient.

Pleconaril is a capsid inhibitor used previously to treat enterovirus infections. A pleconaril-resistant echovirus 11 (E11) strain was identified before pleconaril treatment was given in an immunocompromised patient. The patient was also treated with intravenous Ig (IVIg) for a long period but remained unresponsive. The pleconaril-resistant strains could not be neutralized in vitro, confirming IVIg treatment failure. To identify the basis of pleconaril resistance, genetic and structural analyses were conducted. Analysis of a modelled viral capsid indicated conformational changes in the hydrophobic pocket that could prevent pleconaril docking. Substitutions (V117I, V119M and I188L) in the pleconaril-resistant viruses were found in the pocket region of VP1. Modelling suggested that V119M could confer resistance, most probably due to the protruding sulfate side chain of methionine. Although pleconaril resistance induced in vitro in a susceptible E11 clinical isolate was characterized by a different substitution (I183M), resistance was suggested to also result from a similar mechanism, i.e. due to a protruding sulfate side chain of methionine. Our results showed that resistant strains that arise in vivo display different markers from those identified in vitro and suggest that multiple factors may play a role in pleconaril resistance in patient strains. Based on IVIg treatment failure, we predict that one of these factors could be immune related. Thus, both IVIg and capsid inhibitors target the viral capsid and can induce mutations that can be cross-reactive, enabling escape from both IVIg and the drug. This could limit treatment options and should be investigated further.

A tool to assess knowledge, attitude and behavior of Indonesian health care workers regarding infection control.

AIM: to investigate knowledge, attitude and behaviour toward infection control in two teaching hospitals on the island of Java by means of a questionnaire and to evaluate the use of the questionnaire as a tool. METHODS: we investigated knowledge, attitude and behaviour toward infection control in two teaching hospitals on the island of Java by means of a questionnaire to identify problem areas, barriers and facilitators. The target was to include at least 50% of all health care workers (physicians, nurses, assistant nurses and infection control nurses) in each hospital, department and profession. Differences between demographic variables and scores for individual questions and groups of questions were compared using the chi-square statistic and analysis of variance and Spearman's rho was used to test for correlations between knowledge, attitude, self-reported behaviour and perceived obstacles. RESULTS: more than half of the health care workers of the participating departments completed the questionnaire. Of the 1036 respondents (44% nurses, 37% physicians and 19% assistant nurses), 34% were vaccinated against hepatitis B, 77% had experienced needle stick accidents and 93% had been instructed about infection control. The mean of the correct answers to the knowledge questions was 44%; of the answers to the attitude questions 67% were in agreement with the correct attitude; obstacles to compliance with infection control guidelines were perceived in 30% of the questions and the mean self-reported compliance was 63%. Safe handling of sharps, hand hygiene and the use of personal protective equipment were identified as the most important aspects for interventions. Significant positive correlations were found between knowledge, attitude, self-reported behaviour and perceived obstacles. CONCLUSION: the questionnaire in conjunction with site visits and interviews was a valuable strategy to identify trouble spots in the hospitals and to determine barriers to facilitators of change that should be taken into account when planning interventions. Successful interventions should cover hospital management, the infection control team, as well as the health care workers on the wards.

Emergence of MRSA of unknown origin in the Netherlands.

The Netherlands is known for its low methicillin-resistant Staphylococcus aureus (MRSA) prevalence. Yet MRSA with no link to established Dutch risk factors for acquisition, MRSA of unknown origin (MUO), has now emerged and hampers early detection and control by active screening upon hospital admittance. We assessed the magnitude of the problem and determined the differences between MUO and MRSA of known origin (MKO) for CC398 and non-CC398. National MRSA Surveillance data (2008-2009) were analysed for epidemiological determinants and genotypic characteristics (Panton-Valentine leukocidin, spa). A quarter (24%) of the 5545 MRSA isolates registered were MUO, i.e. not from defined risk groups. There are two genotypic MUO groups: CC398 MUO (352; 26%) and non-CC398 MUO (998; 74%). CC398 MUO needs further investigation because it could suggest spread, not by direct contact with livestock (pigs, veal calves), but through the community. Non-CC398 MUO is less likely to be from a nursing home than non-CC398 MKO (relative risk 0.55; 95% CI 0.42-0.72) and Panton-Valentine leukocidin positivity was more frequent in non-CC398 MUO than MKO (relative risk 1.19; 95% CI 1.11-1.29). Exact transmission routes and risk factors for non-CC398 as CC398 MUO remain undefined.

Systematic review and meta-analysis of antibiotic prophylaxis to prevent infections from chest drains in blunt and penetrating thoracic injuries.

BACKGROUND: No consensus exists as to whether antibiotic prophylaxis in tube thoracostomy as primary treatment for traumatic chest injuries reduces the incidence of surgical-site and pleural cavity infections. METHODS: A systematic literature search was performed according to PRISMA guidelines to identify randomized clinical trials on antibiotic prophylaxis in tube thoracostomy for traumatic chest injuries. Data were extracted by two reviewers using piloted forms. Mantel-Haenszel pooled odds ratios (ORs) were calculated with 95 per cent confidence intervals (c.i.). RESULTS: Eleven articles were included, encompassing 1241 chest drains in 1234 patients. Most patients (84·7 per cent) were men, and a penetrating injury mechanism was most common (856, 69·4 per cent). A favourable effect of antibiotic prophylaxis on the incidence of pulmonary infection was found, with an OR for the overall infectious complication rate of 0·24 (95 per cent c.i. 0·12 to 0·49). Patients who received antibiotic prophylaxis had an almost three times lower risk of empyema than those who did not receive antibiotic treatment (OR 0·32, 0·17 to 0·61). A subgroup analysis in patients with penetrating chest injuries showed that antibiotic prophylaxis in these patients reduced the risk of infection after tube thoracostomy (OR 0·28, 0·14 to 0·57), whereas in a relatively small blunt trauma subgroup no effect of antibiotic prophylaxis after blunt thoracic injury was found. CONCLUSION: Infectious complications are less likely to develop when antibiotic prophylaxis is administered to patients with thoracic injuries requiring chest drains after penetrating injury.

Endemic and epidemic acinetobacter species in a university hospital: an 8-year survey.

The prevalence of the currently known Acinetobacter species and related trends of antimicrobial resistance in a Dutch university hospital were studied. Between 1999 and 2006, Acinetobacter isolates from clinical samples were collected prospectively. Isolates were analyzed by amplified fragment length polymorphism fingerprinting. For species identification, a profile similarity cutoff level of 50% was used, and for strain identification, a cutoff level of 90% was used. Susceptibility for antimicrobial agents was tested by disk diffusion by following the CLSI guideline. The incidences of Acinetobacter isolates ranged from 1.7 to 3.7 per 10,000 patients per year, without a trend of increase, during the study years. Twenty different species were distinguished. Acinetobacter baumannii (27%) and Acinetobacter genomic species (gen. sp.) 3 (26%) were the most prevalent. Other species seen relatively frequently were Acinetobacter lwoffii (11%), Acinetobacter ursingii (4%), Acinetobacter johnsonii (4%), and Acinetobacter junii (3%). One large cluster of A. baumannii, involving 31 patients, and 16 smaller clusters of various species, involving in total 39 patients, with at most 5 patients in 1 cluster, occurred. Overall, 37% of the A. baumannii isolates were fully susceptible to the tested antibiotics. There was a borderline significant (P = 0.059) trend of decreasing susceptibility. A. baumannii was the Acinetobacter species causing the largest burden of multiple-antibiotic resistance and transmissions in the hospital.

Transient and constitutive repression of cytoplasmic translation signaling in cells with mtDNA mutation.

Cytoplasmic translation is under sophisticated control but how cells adapt its rate to constitutive loss of mitochondrial oxidative phosphorylation is unknown. Here we show that translation is repressed in cells with the pathogenic A3243G mtDNA mutation or in mtDNA-less rho(0) cells by at least two distinct pathways, one transiently targeting elongation factor eEF-2 and the other initiation factor eIF-2alpha constitutively. Under conditions of exponential cell growth and mammalian target of rapamycin (mTOR) activation, eEF-2 becomes transiently phosphorylated by an AMP-activated protein kinase (AMPK)-dependent pathway, especially high in mutant cells. Independent of AMPK and mTOR, eIF-2alpha is constitutively phosphorylated in mutant cells, likely a signature of endoplasmic reticulum (ER)-stress response induced by the loss of oxidative phosphorylation. While the AMPK/eEF-2K/eEF-2 pathway appears to function in adaptation to physiological fluctuations in ATP levels in the mutant cells, the ER stress signified by constitutive protein synthesis inhibition through eIF-2alpha-mediated repression of translation initiation may have pathobiochemical consequences.

Can Escherichia coli be used as an indicator organism for transmission events in hospitals?

Can Escherichia coli be used as an indicator organism for transmission events in hospitals? Perineal and pharyngeal swabs were obtained from patients admitted to a medical or surgical intensive care unit within 24 h of admission and then twice per week. Escherichia coli isolates were typed by random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) typing. Based on the typing results, transmission rates for RAPD and AFLP typing were 8.5 and 6.6 per 100 patient-days. Requiring in addition to similarity in genotype parity in time and place for a transmission event, the incidence dropped to 3.8 (RAPD) and 1.7 (AFLP) per 100 patient-days. The two typing methods not only differed with respect to numbers of transmissions identified, but also to individuals involved in transmissions. This study identified a number of problems regarding the use of Escherichia coli as indicator organism for transmission events. The use of Escherichia coli for this purpose cannot be recommended at the moment.

Infection control measures to limit the spread of Clostridium difficile.

Clostridium difficile-associated diarrhoea (CDAD) presents mainly as a nosocomial infection, usually after antimicrobial therapy. Many outbreaks have been attributed to C. difficile, some due to a new hyper-virulent strain that may cause more severe disease and a worse patient outcome. As a result of CDAD, large numbers of C. difficile spores may be excreted by affected patients. Spores then survive for months in the environment; they cannot be destroyed by standard alcohol-based hand disinfection, and persist despite usual environmental cleaning agents. All these factors increase the risk of C. difficile transmission. Once CDAD is diagnosed in a patient, immediate implementation of appropriate infection control measures is mandatory in order to prevent further spread within the hospital. The quality and quantity of antibiotic prescribing should be reviewed to minimise the selective pressure for CDAD. This article provides a review of the literature that can be used for evidence-based guidelines to limit the spread of C. difficile. These include early diagnosis of CDAD, surveillance of CDAD cases, education of staff, appropriate use of isolation precautions, hand hygiene, protective clothing, environmental cleaning and cleaning of medical equipment, good antibiotic stewardship, and specific measures during outbreaks. Existing local protocols and practices for the control of C. difficile should be carefully reviewed and modified if necessary.

Multifactorial origin of high incidence of Serratia marcescens in a cardio-thoracic ICU: analysis of risk factors and epidemiological characteristics.

OBJECTIVE: A four-fold increase in the incidence of Serratia marcescens occurred in a cardio-thoracic ICU within a 13-month period. Clinical, epidemiological and molecular characteristics were analysed to elucidate the outbreak's origin. METHODS: Epidemiological data were analysed by mapping clustered cases; isolates were genotyped by AFLP analysis. A case-control study was performed to identify risk factors for the acquisition of S. marcescens. Data were obtained from files and electronic databases of the ICU and Department of Medical Microbiology. The adherence to hygiene protocols on the ICU was reviewed by a medical audit. RESULTS: Genotyping showed 16 distinct S. marcescens strains. Twenty-one cases and 39 controls were enrolled in the case-control study. Significant differences found by univariate analysis included the duration of surgery, APACHE-II-score on ICU admission, length of ICU stay, duration of mechanical ventilation, tube feeding and the sum of the number of days per invasive device. In a multivariate logistic regression model, the length of ICU stay and tube feeding were independent risk factors. Outbreak strains were not more frequently resistant to gentamicin, ciprofloxacin, meropenem or trimethoprim-sulfamethoxazole as compared to a reference group. Hygiene protocols, including hand washing, were insufficiently practiced by the ICU's medical staff. CONCLUSIONS: The heterogeneity of the strains points to transmission from various sources. This outbreak of S. marcescens was most probably caused by reduced hand washing and other breaks in infection prevention protocols in combination with the presence of the identified risk factors, which act by affecting the number and intensity of potential transmission events.

Anti-infective-treated central venous catheters for total parenteral nutrition or chemotherapy: a systematic review.

This systematic review assesses the effect of anti-infective-treated central venous catheters (CVCs) on catheter-related bloodstream infection (CRBSI) in patients who received a CVC for total parenteral nutrition (TPN) or chemotherapy. Randomised controlled trials were retrieved from Medline and the Cochrane Library up to 14 October 2007. Two reviewers independently assessed trial quality and extracted data. Data for CRBSI were combined where appropriate, using a random effects model, and subgroup meta-analysis was carried out where applicable. The impact of the risk for CRBSI in the control group on the effect of anti-infective CVCs was studied by using meta-regression based on the bivariate meta-analysis model. Nine trials were included in the review. One trial showed that antibiotic-treated CVCs reduced the risk for CRBSI in outpatients with chemotherapy and a CVC in-situ during a period of about nine weeks. Eight trials did not find an overall significant benefit in favour of antiseptic-treated CVCs in patients who had a CVC during a mean of about two weeks. No relationship could be established between the effect of anti-infective-treated CVCs and the underlying risk for CRBSI, although nearly all trials had serious methodological shortcomings. Thus, available scientific evidence to prevent CRBSI by the use of anti-infective-treated CVCs in patients receiving chemotherapy or TPN is not sufficient as a basis to recommend their use. The recommendation of the Centers for Disease Control and Prevention to use antibiotic- or antiseptic-impregnated CVCs, when the risk for CRBSI remains high despite good hygienic practice, should therefore be limited to patients in the intensive care/perioperative setting.

[Optimisation of the antibiotic policy in the Netherlands. XII. The SWAB guideline for antimicrobial eradication of MRSA in carriers]. / Optimaliseren van het antibioticabeleid in Nederland. XII. SWAB-richtlijn voor de behandeling van MRSA-dragerschap.

The 'Stichting Werkgroep Antibioticabeleid' (SWAB; Dutch Working Party on Antibiotics Policy) has developed evidence-based guidelines for the antimicrobial treatment of methicillin-resistant Staphylococcus aureus (MRSA) carriers for the eradication of MRSA. A distinction was made between uncomplicated and complicated carriage depending on the presence or absence of an active MRSA infection, skin lesions, foreign body material, mupirocin resistance and/or extranasal carriage. The indication for treatment is determined by the consequences of carriage for the carrier and his/her environment, the adverse events of treatment, and the likelihood of a successful treatment. The first choice of treatment in uncomplicated carriers is a combination of mupirocin nasal ointment and disinfectant soap for 5 days, along with hygiene advice. If treatment fails, sources in the vicinity of the patient must be sought. Complicated carriers receive a combination of 2 oral antibiotics, in addition to mupirocin nasal ointment and disinfectant soap, for at least 7 days.

Transmission of Pseudomonas aeruginosa in children with cystic fibrosis attending summer camps in The Netherlands.

BACKGROUND: Cross-infection of Pseudomonas aeruginosa has been reported to occur at holiday camps for children with Cystic Fibrosis (CF) with varying frequency. The study aimed to establish the degree of transmission resulting in subsequent infection of P. aeruginosa among CF children (n=80) attending holiday camps in The Netherlands. METHODS: The study was performed in the summer of 2001 in four camps organised simultaneously at different locations. Sputum was collected on day 1 of the holiday, and three and six months later. Different morphotypes of P. aeruginosa from sputum were genotyped by AFLP analysis. Criteria were defined for the degree of evidence of transmission. RESULTS: There were 18 cases possible, 2 cases of probable transmission and 1 case of highly probable transmission. Two predominant types of P. aeruginosa were found (types 18 and 23). Type 18 was already prevalent on day 1 mostly in younger children and was involved in eleven cases of transmission; type 23 was involved in six cases of transmission among older children. CONCLUSIONS: There was a considerable risk of transmission of P. aeruginosa during holiday camps for CF children in The Netherlands. Two genotypes of P. aeruginosa appeared to be easily transmissible, one of which seemed common in the Dutch CF population.

Anti-infective-treated central venous catheters: a systematic review of randomized controlled trials.

OBJECTIVE: This systematic review assesses the effect of anti-infective-treated central venous catheters (CVCs) on catheter-related bloodstream infection (CRBSI) in the acute care setting. METHODS: Randomized controlled trials were retrieved from Medline and the Cochrane Library up to 15 January 2007. Two reviewers independently assessed trial quality and extracted data. Data for CRBSI were combined where appropriate, using a random effects model. The impact of the risk for CRBSI in the control group (baseline risk) on the benefit of anti-infective CVCs was studied by using meta-regression based on the binomial normal bivariate meta-analysis model. RESULTS: Twenty-one trials were included in the review. Mainly intensive care (IC) patients were studied. Eighteen trials showed that anti-infective CVCs reduced the risk of CRBSI. The number needed to treat (NNT) varied from 182 to 12, with baseline risks ranging from 1% to 10%. Nearly all trials had serious methodological shortcomings. Three trials comparing minocycline-rifampicin-treated catheters with antiseptic-treated catheters showed inconsistent results. One trial suggested that there is not any difference in CRBSI between heparin- and antiseptic-treated CVCs. CONCLUSION: Because the NNT is large when the baseline risk is low, the use of anti-infective-treated CVCs in the acute care setting should only be considered in situations in which background rates of CRBSI are high. The magnitude of benefit as calculated in this review should be interpreted with caution because of strong arguments in favor of a systematic overestimation of the effect. Which type of anti-infective catheter is most effective could not be established from the available data.

Can history and exam alone reliably predict pneumonia?

BACKGROUND: Prediction rules based on clinical information have been developed to support the diagnosis of pneumonia and help limit the use of expensive diagnostic tests. However, these prediction rules need to be validated in the primary care setting. METHODS: Adults who met our definition of lower respiratory tract infection (LRTI) were recruited for a prospective study on the causes of LRTI, between November 15, 1998 and June 1, 2001 in the Leiden region of The Netherlands. Clinical information was collected and chest radiography was performed. A literature search was also done to find prediction rules for pneumonia. RESULTS: 129 patients--26 with pneumonia and 103 without--were included, and 6 prediction rules were applied. Only the model with the addition of a test for C-reactive protein had a significant area under the curve of 0.69 (95% confidence interval [CI], 0.58-0.80), with a positive predictive value of 47% (95% CI, 23-71) and a negative predictive value of 84% (95% CI, 77-91). The pretest probabilities for the presence and absence of pneumonia were 20% and 80%, respectively. CONCLUSIONS: Models based only on clinical information do not reliably predict the presence of pneumonia. The addition of an elevated C-reactive protein level seems of little value.

Policies for endotracheal suctioning of patients receiving mechanical ventilation: a systematic review of randomized controlled trials.

OBJECTIVE: The Dutch Working Party on Infection Prevention (Werkgroep Infectiepreventie [WIP]) aimed to determine whether certain policies on endotracheal suctioning are better than others in terms of prevention of ventilator-associated pneumonia (VAP) in patients receiving mechanical ventilation in the intensive care unit. METHODS: Publications were retrieved by a systematic search of Medline and the Cochrane Library for literature published before February 2006. Additionally, the reference lists of all identified trials were examined. All randomized trials, quasi-randomized trials, and systematic reviews or meta-analyses of randomized or quasi-randomized trials that compared different policies on endotracheal suctioning for patients receiving mechanical ventilation in the intensive care unit were selected. Two reviewers independently assessed trial quality and extracted data. Disagreements were resolved by discussion with a third reviewer. Data from the original publications were used to calculate the relative risk of VAP. Data for VAP were combined in the analysis where appropriate, by use of a random-effects model. RESULTS: Ten trials were included in the review. The quality of the trials and the way they were reported were generally unsatisfactory. Eight low-quality trials indicate that use of closed instead of open suction systems has no effect on the incidence of VAP. Two moderate-quality trials indicate that changing in-line suction catheters less frequently than every 24 hours does not increase the incidence of VAP. CONCLUSION: The WIP recommends that there be no preferential use of either open or closed endotracheal suction systems to reduce the rate of VAP, but it elucidates that the quality of the evidence is low. Considerations other than prevention of VAP should determine the choice of the suction system. When closed systems are used, the WIP recommends changing the in-line suction catheters every 48 hours. In case of mechanical failure or soiling of the suction system, they may be changed more frequently.

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.

How many infection control staff do we need in hospitals?

During a one-day workshop experienced infection control practitioners (ICPs) and medical microbiologists debated how much time was needed for the delivery of infection control activities in a model hospital. They agreed a standard of one full-time equivalent (FTE) ICP per 178 hospital beds and one FTE medical microbiologist per 806 hospital beds. This is 40% and 24% more than the usual standard, respectively. Now that official numbers of hospital beds have become an inadequate parameter for work delivered by hospitals, a new standard is proposed, with the number of admissions as the denominator. This is one FTE ICP per 5000 admissions and one medical microbiologist or epidemiologist per 25000 admissions.

[Optimisation of the antibiotic policy in the Netherlands. X. The SWAB guideline for antimicrobial treatment of complicated urinary tract infections]. / Optimaliseren van het antibioticabeleid in Nederland. X. SWAB-richtlijn voor antimicrobiële therapie bij gecompliceerde urineweginfecties.

The 'Stichting Werkgroep Antibioticabeleid' (SWAB; Dutch Working Party on Antibiotic Policy) has developed an evidence-based guideline for the empirical antimicrobial treatment of complicated urinary tract infections (UTIs) in hospitalised adult patients. The choice of treatment is based on recent Dutch data on the resistance ofuropathogens to the most frequently used antibiotics. The first choice for empirical antibiotic treatment in a patient with a complicated UTI is a 2nd or 3rd generation cephalosporin or the combination of amoxicillin and gentamicin. Amoxicillin-clavulanic-acid intravenously is the second empirical choice. The treatment duration must be at least 10 days. The treatment must be adjusted after the results of the urine culture become known and made more specific if possible. Oral treatment can be given if the patient's clinical situation allows it. There are separate recommendations for the treatment ofUTIs in the following patient categories: men, pregnant women, patients with a urinary catheter, patients with diabetes mellitus and patients with renal diseases, congenital polycystic kidney disease or pyocystis.

Genotypic diversity and antibiotic susceptibility of Acinetobacter baumannii isolates in a Bulgarian hospital.

A set of 18 Acinetobacter baumannii isolates, collected prospectively in a Bulgarian hospital during episodes of increased A. baumannii occurrence during 2000-2002, was investigated for genotypic diversity and antibiotic susceptibility. Four genotypes were identified by amplified fragment length polymorphism genomic fingerprinting, one of which (type 1) accounted for 13 isolates, indicating that a specific strain was predominant. The single isolate allocated to type 2 was identified to European clone I. All isolates were resistant to multiple antibiotics, but most retained susceptibility to tobramycin and colistin, and all except one were susceptible to imipenem.