Biomedical subjects

C Wendt

Publications and source records attributed to C Wendt.

At least 19 recordsLinked to original sources

PubMed2007

[Prevention and control of the spread of vancomycin-resistant enterococci: results of a workshop held by the German Society for Hygiene and Microbiology].

The incidence of vancomycin-resistant enterococci (VRE), especially E. faecium, is increasing in several German hospitals and some facilities have experienced VRE outbreaks. The German National Nosocomial Infection Surveillance System has also noticed a sharp increase in the incidence of nosocomial VRE infections per 10,000 patients from 0.5 in 2003 to 11.0 in 2005 accompanied by a rise in VRE-associated mortality. However, the reasons of this increase remain unknown. As VRE may cause severe nosocomial infections, transmission must be restricted. This article provides the guidelines as defined by the workshop of the German Society for Hygiene and Microbiology for the prevention of VRE transmission in both, endemic and epidemic, settings. The following topics are discussed: indication for VRE screening, microbiological diagnostics, general infection control measures (isolation precautions and use of protective clothing) and additional hygiene measures in the nosocomial VRE outbreak setting.

Cross Infection↗

PubMed2006

[Control of methicillin-resistant S. aureus by active surveillance. Results of a workshop held by the Deutsche Gesellschaft für Hygiene und Mikrobiologie].

In Germany, methicillin-resistant S. aureus (MRSA) is increasing continuously. To control the spread of MRSA, active surveillance and admission screening are recommended. In most cases, screening cultures of patients at risk for MRSA will be sufficient. Screening of all patients admitted to an ICU is cost-effective when the incidence of MRSA and nosocomial MRSA infections is high (>2 cases/100 patients and 0.3 MRSA infections/100 patients, respectively): Under these circumstances, a decrease in the incidence of nosocomial MRSA infections of 50% leads to cost-effectiveness at costs of 16 Euro/sample (including subsequent costs). If the incidence of nosocomial MRSA infections decreases by 75%, costs of 24 Euro/sample (including subsequent costs) are cost-effective. If the incidence of MRSA is high, screening by PCR may be cost-effective for patients at high risk for MRSA, especially if they are isolated prophylactically. Recently, PCR methods have been developed which allow the specific identification of MRSA even from nasal swabs.

Cost-Benefit Analysis↗

PubMed2006

Evaluation of a single-locus real-time polymerase chain reaction as a screening test for specific detection of methicillin-resistant Staphylococcus aureus in ICU patients.

The aim of the present study was to determine the diagnostic value of a single-locus real-time polymerase chain reaction (PCR) recently proposed for rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) from clinical samples (IDI-MRSA; Infectio Diagnostic, Sainte-Foy, Québec, Canada). This test, which was developed on the basis of studies of the sequence analysis of the mecA gene carried by staphylococcal cassette chromosome mec (SCCmec), was used to screen nasal swabs of 320 intensive care unit (ICU) patients at admission. The results were compared with those of conventional culture of swabs from several body sites. When compared with culture of swabs from the nose, throat, and wounds, the diagnostic values of the real-time PCR test from nasal swabs were as follows: 92.3% sensitivity, 98.6% specificity, 75.0% positive predictive value, and 99.6% negative predictive value. Fifteen (4.7%) samples could not be evaluated because the PCR reaction was inhibited, even after the samples were frozen and thawed for retesting. Culture of nasal swabs showed that 78 of the patients were colonized with methicillin-susceptible S. aureus. Unexpectedly, 4 (5.1%) of these samples gave false-positive results in the IDI-MRSA. These isolates were all single clones, as shown by pulsed-field gel electrophoresis and spa typing. Reliable results were obtained with the IDI-MRSA assay, even in a patient population with a low prevalence (approximately 4%) of MRSA and even when compared with swabs of different body sites. Nevertheless, further work is needed to reduce the inhibition rate of the PCR and to explain why false-positive results were obtained with methicillin-susceptible S. aureus.

Bacterial Proteins↗

PubMed2006

[International comparison of health care systems. Overview of state of research].

The article provides an overview on the state of research with regard to a comparative analysis of health care systems. The focus is on the financing, provision, and regulation of health care systems. Finally, some concepts are discussed which aim at the development of a typology of health care systems. It is demonstrated that existing models (for instance, a Beveridge versus a Bismarck type of system or a National Health Service type versus a Social Insurance type) are not sufficient to capture the accelerating change of health care systems in a systematic way. The development of a health care system typology, based on concepts which are discussed in this article, is a promising objective of future research.

Europe, Eastern↗

PubMed2005

Emergence of methicillin-resistant Staphylococcus aureus with Panton-Valentine leukocidin genes in central Europe.

The aim of the present study was to investigate strains of methicillin-resistant Staphylococcus aureus (MRSA) for the presence of the lukS-lukF determinant of Panton-Valentine leukocidin and to further characterize strains found to contain the genes. During the past 2 years, MRSA containing the lukS-lukF genes for Panton-Valentine leukocidin, particularly those emerging outside of hospitals, have become of interest. MRSA strains sent to the national reference center in Germany were investigated for lukS-lukF by polymerase chain reaction (PCR). If the presence of lukS-lukF was demonstrated, strains were further characterized by molecular typing (determination of SmaI pattern, spa sequence, and multilocus sequence type), PCR demonstration of resistance genes, and characterization of the SCCmec element. Since the end of 2002, MRSA containing Panton-Valentine leukocidin genes have been demonstrated as the causative agent of 28 cases of infection (9 community-acquired cases, 19 sporadic nosocomial cases) in different areas of Germany. Twenty-seven of these 28 isolates exhibited a unique pattern of genomic typing: all exhibited multilocus sequence type 80, spa sequence type 44, and a SmaI macrorestriction pattern that corresponds to a community-acquired strain of MRSA from France and Switzerland. In addition to resistance to oxacillin, the strains exhibited resistance to ciprofloxacin, tetracycline (tetM), and fusidic acid, the last of which is encoded by the far-1 gene. The far-1 gene was shown to be located on the plasmid. One isolate corresponded to community MRSA (cMRSA) of multilocus sequence type 1 from the USA.

Anti-Bacterial Agents↗

PubMed2005

Risk factors for colonization with third-generation cephalosporin-resistant enterobacteriaceae.

BACKGROUND AND METHOD: Colonization and infections caused by Enterobacteriaceae resistant to third-generation cephalosporins (CRE) have been observed with increasing frequency in intensive care unit (ICU) patients. In contrast to outbreak investigations, information about risk factors for colonization in an endemic situation are rare. We studied risk factors for colonization with CRE in a case control study including 1,706 patients, admitted to any of the 15 ICUs of Heidelberg University Hospitals. RESULTS: 163 patients carried CRE with Enterobacter spp. representing the predominant species. Independent risk factors for CRE carriage in the multivariate logistic regression analysis were an age of under 2.5 years (OR 4.034), an indwelling central venous catheter (CVC) for more than 3 days (OR 2.640), treatment with second- or third generation cephalosporin for longer than 3 days (OR 2.260) and any antibiotic therapy before admission to the ICU. CONCLUSION: Apart from the well-recognized risk factor previous antibiotic treatment, the risk factors age and presence of a CVC might suggest that bacterial overgrowth of the gut either due to an increased susceptibility in younger age or as a consequence of parenteral nutrition is a relevant mechanism for acquiring carriage of CRE in a non-outbreak situation.

Adolescent↗

PubMed2005

Antibiotic-resistant bloodstream infections in hospitalized patients: specific risk factors in a high-risk population?

BACKGROUND: The aim of this study was to explore characteristics that are associated with bloodstream infections due to specific multiresistant microorganisms (methicillinresitant Staphylococcus aureus, MRSA; vancomycin-resistant enterococci, VRE; third-generation cephalosporin-resistant Enterobacteriaceae) or Candida spp. in hospitalized patients. PATIENTS AND METHODS: All patients who experienced a bloodstream infection with one of the aforementioned pathogens between September 1999 and October 2001 were included into a statistical analysis of independent risk factors. The possible impact of previous antibiotic and antifungal therapies was evaluated. RESULTS: Of the study population, 22% had two or more episodes with different pathogens. In the 314 patients with a single bloodstream infection MRSA was isolated in 189 patients, VRE in 31, Enterobacteriaceae in 13, and Candida spp. in 80 patients. Crude mortality was high in the study population (overall 40%) and varied between 33% (MRSA bacteremia only) and 58% (VRE bacteremia only). Patients who yielded more than one of the pathogens under surveillance had crude mortalities ranging from 41% to 83% (all four pathogens). In this group of high-risk patients, the following factors were independently associated with the individual pathogen: prior chemotherapy (OR 4.88 CI(95) 1.50-15.87) and bronchoscopy (OR 3.17 CI(95) 1.05-9.52) for VRE patients; burns (OR 4.50 CI(95) 0.90-22.73), presence of a tracheostomy (OR 4.22 CI(95) 1.15-15.38) and acute dialysis (OR 3.62 CI(95) 0.99-13.16) for patients with Enterobacteriaceae; and an underlying malignant disease (OR 1.98 CI95 0.99-3.97), performance of a bowel endoscopy (OR 2.80 CI(95) 1.27-6.13) and presence of a central venous catheter (CVC) (OR 12.34 CI(95) 1.63-90.91) for patients with candidemia. CONCLUSION: Patients with bacteremia due to VRE, Enterobacteriaceae or Candida spp. had more severe risk factors associated with the respective pathogen than patients with MRSA bacteremia.

Adult↗

PubMed2005

[The changing role of the state in health care systems in OECD countries--research questions, research design and first results].

In the framework of the DFG-Research-Unit 597 "Transformation of the State" is Project C3 investigating the change of the role of the state in health care systems in OECD-countries between 1970 and 2000. The primary research hypothesis is, that a tendency of convergence exists regarding the role of the state for the three main dimensions of health care systems, namely service provision, financing and regulation. This is carried out firstly based on a quantitative oriented analysis for 23 OECD-countries, utilising the data set "OECD Health Data 2002", and secondly with qualitative oriented country-studies for England, Germany and the U.S. Findings for the qualitative country-studies give some hints of convergence regarding the "private-public-mix" between the health system types "social insurance" (Germany), "national health system" (England), and "market oriented health system" (USA). First quantitative results concerning the changing role of the state in relation to the health care systems in OECD-countries provide evidence for a convergence process between these states in the financing dimension. For the dependent variable "total health care costs in % of gross domestic product" a trend of convergence is observed for the members states of the European Union (n = 12), while in the remaining Non-EU countries (n = 11) a trend of divergence is identified. For the same parameter we found a convergence for OECD-countries of the type "national health system" (n = 14). For OECD-countries of the type "social insurance" (n = 8) this convergence process is observed only for the time period 1970 - 1980. Some results confirm the hypothesis of the "growth to limits" (Flora). But it appears to us that in future other significant factors like globalisation processes, the increasing potentials of the medical technology and demographic changes may play an important role for the overall health budget and specific needs of the population in the OECD-states.

Financing, Government↗

PubMed2005

Characteristics that promote transmission of Staphylococcus aureus nursing homes in German nursing homes.

OBJECTIVE: To determine factors that influence transmission of Staphylococcus aureus in nursing homes in the Rhine-Neckar region of southern Germany. DESIGN: Ecologic study. SETTING: Forty-seven nursing homes in the region. PARTICIPANTS: Residents of the approached nursing homes who agreed to participate. METHODS: Personal data and swabs of the nares were collected from participants. Swabs were examined for growth of S. aureus. All S. aureus isolates were typed using pulsed-field gel electrophoresis (PFGE). Transmission rates were calculated by dividing the number of transmissions (ie, cases in which two inhabitants shared the same PFGE type) by the number of S. aureus carriers. Characteristics of the nursing homes were correlated with a home's transmission rate. RESULTS: In each nursing home, 12% to 54% of the residents were colonized with S. aureus. The transmission rates for the 47 nursing homes ranged from 0% to 70%. A linear regression model revealed that a stay in the nursing home of longer than 6 months and accommodation in a room with 3 or more beds were positively associated with the transmission rate. Receipt of antibiotics during the 4 weeks preceding the study was negatively associated with transmission. CONCLUSIONS: Stays beyond 6 months and accommodation in rooms with multiple beds are important for the transmission of S. aureus. One way to reduce transmission would be to design facilities with single and double rooms. However, the social needs of the residents must be evaluated and respected.

Cross Infection↗

PubMed2004

[Compliance with infection control guidelines].

Compliance is the degree to which advice is adhered to. It can be assumed that compliance rates are considerably less than 100% for nearly all infection control guidelines. Factors that may influence compliance rates can be found on different levels of the health care system. Health care workers may adhere to guidelines because they believe that a measure is effective, they receive positive or negative feedback, or because they follow role models. The institution is responsible for providing the structural conditions that allow easy adherence. Incentives for the institution are regulations that have been made mandatory by law or financial considerations. Finally, guidelines must be accepted by society to be widely adhered to. Compliance can be measured by direct or indirect surveillance. If it is found to be under the expected value, it should be improved using interventional programs. Long-lasting effects on compliance rates can be achieved by using a multifactorial approach that considers all levels of the health care system. The goal of the program should be clearly defined and accepted by all parties. Especially the institution should highly value the goal. Strategies that may be used to improve compliance include educational programs for health care workers, provision of better structures by the institution, e. g., administrative sanction or rewarding, or education of patients to influence the expectations of society. As long as there are no striking new interventions to protect the patients, the improvement of compliance with existing guidelines remains the most important measure to reduce rates of nosocomial infection.

Germany↗

PubMed2004

Prevalence of colonisation with third-generation cephalosporin-resistant Enterobacteriaceae in ICU patients of Heidelberg University Hospitals.

The aim of this study was to assess colonisation and transmission of third-generation cephalosporin-resistant Enterobacteriaceae (CRE) from patients in 16 intensive care units. A prospective, repetitive point prevalence survey was performed over 6 months, involving samples from 1851 patients. CRE were isolated from 186 (10%) patients, with Enterobacter spp. being the most common. Mean point prevalence rates were significantly higher for paediatric wards (22.5%) compared to surgical (8.1%) and medical (5.5%) units. All CRE isolates were typed by pulsed-field gel electrophoresis. Non-outbreak nosocomial transmission rates of these pathogens were calculated as 12.8% for paediatric patients, compared to 6.8% for adult patients, which may reflect differences in sensitivity to overgrowth with resistant bacteria and contact with health care workers.

Adolescent↗

PubMed2001

Polyclonal bacteremia due to gram-negative rods.

The frequency of, risk factors for, and outcome of polyclonal gram-negative bacteremia are still unknown. We investigated them in a prospective cohort study of patients for whom a blood culture yielded >/=1 species of gram-negative aerobic rod. For each patient, pulsed field gel electrophoresis (PFGE) was performed on 4 colonies of each morphologic type. Episodes of bacteremia were considered polyclonal if caused by >1 PFGE type of the same species. Ten (6.5%) of 153 investigated patients had polyclonal bacteremia. Bacteremia due to nonfermenting rods was the single significant risk factor for polyclonal bacteremia. Complications were equally frequent in all patient groups. However, patients with polyclonal bacteremia received more extensive antibiotic therapy than did patients with monoclonal bacteremia. Nearly 20% of episodes of bacteremia due to nonfermenting rods were polyclonal, but it remains unclear why nonfermenting rods were more likely to cause polyclonal bacteremia than were other gram-negative rods.

Anti-Bacterial Agents↗

PubMed2001

Hand hygiene--comparison of international recommendations.

The value of hand hygiene for the prevention of cross-infection was first observed in the middle of the 19th century. Since then, which procedure is the most suitable for hand hygiene has been repeatedly discussed and several different guidelines and recommendations have been published. The aim of this review is to compare different recommendations for hand hygiene regarding technique and indication. Medline, the internet and a personal library were searched to obtain as many written recommendations as possible. In addition, a small questionnaire was sent by e-mail to 20 international colleagues. As a result, written recommendations from 10 countries could be compared. Recommended methods of hand hygiene include handwashing (washing hands with plain soap), hygienic handwash (washing hands with medicated soap) and hygienic hand-rub (use of antiseptic rubs). In most countries handwashing and hygienic handwash are the methods of choice and only in central European countries is hygienic hand-rub the preferred technique. Situations in which performance of hand hygiene is recommended are comparable. However, no single indication is recommended in all guidelines. Hand hygiene is most often recommended before performing invasive procedures and after microbial contamination. Guidelines should be clear and easy to follow for them to become standard of care. Thus, guidelines are needed that do not leave to the health care worker a decision as to whether hand hygiene is indicated.

Attitude of Health Personnel↗

PubMed2001

Survival of MRSA on sterile goods packaging.

For many years, MRSA (methicillin-resistant Staphylococcus aureus) has been a world-wide problem. Stringent infection control regimens need to be followed to prevent spread. One such measure is the disposal of unused, MRSA-contaminated single-use items, which is quite expensive. An alternative, less costly measure is to store these items temporarily, re-using them once the organism is non-viable. To establish survival times of MRSA on sterile goods packaging, paper and foil samples were contaminated with MRSA (approximately 10(8)-10(9) cfu/sample). The number of pathogens recoverable from the samples was measured at defined times. MRSA was demonstrated to survive on sterile goods packaging for more than 38 weeks. No MRSA was recoverable after 50 weeks. Temporary storage of MRSA-contaminated single-use items for such a long period of time is not an appropriate or reliable means of decontamination, but many be considered for items that would be costly to replace.

Equipment Contamination↗

PubMed2001

Genetic variability and prevalence of Bartonella henselae in cats in Berlin, Germany, and analysis of its genetic relatedness to a strain from Berlin that is pathogenic for humans.

Nineteen Bartonella henselae strains and one Bartonella clarridgeiae strain were isolated from blood samples of 97 pet cats and 96 stray cats from Berlin, Germany, indicating prevalence rates of 1 and 18.7%, respectively, for B. henselae and 0 and 1%, respectively, for B. clarridgeiae. Eighteen of 19 B. henselae isolates corresponded to 16S rRNA type II. Pulsed-field gel electrophoresis (PFGE) analysis revealed seven different PFGE types among the feline B. henselae strains. Interestingly, all feline isolates displayed low genetic relatedness to B. henselae strain Berlin-1, which is pathogenic for humans.

Animals↗

PubMed2000

Regulation of Na,K-ATPase beta 1 subunit gene transcription by low external potassium in cardiac myocytes. Role of Sp1 AND Sp3.

Expression of Na,K-ATPase activity is up-regulated in cells incubated for extended intervals in the presence of low external K(+). Our previous data showed that exposure of cardiac myocytes to low K(+) increased the steady-state abundance of Na,K-ATPase beta1 subunit mRNA. In the present study we determined that incubation of primary cultures of neonatal rat cardiac myocytes with low K(+) augmented Na,K-ATPase beta1 gene expression at a transcriptional level and that this effect required extracellular Ca(2+). The stimulatory effect of low K(+) on Na,K-ATPase beta1 gene transcription was not dependent on increased contractile activity of cardiac myocytes. Na,K-ATPase beta1 5'-flanking region deletion plasmids used in transient transfection analysis demonstrated that the region between nucleotides -62 to -42 of the beta1 promoter contained a low K(+) response element. Site-directed mutagenesis of a potential GC box core motif GCG in the -58/-56 region of the beta1 promoter decreased basal and low K(+)-mediated transcription. Mutation of the core sequence of a putative GC box element located between nucleotides -101 and -99 further decreased the low K(+) effect on beta1 gene transcription. Electrophoretic mobility shift assays using oligonucleotides spanning the proximal and distal GC box elements of the beta1 promoter showed enhanced binding of two complexes in response to low K(+). The inclusion of a consensus GC box sequence as a competitor in gel shift analysis reduced factor binding to the low K(+) response elements. Antibodies to transcription factors Sp1 and Sp3 interacted with components of both DNA-binding complexes and binding of nuclear factors was abolished in gel shift studies using GC box mutants. Together these data indicate that enhanced binding of Sp1 and Sp3 to two GC box elements in the rat Na,K-ATPase beta1 subunit gene promoter mediates beta1 gene transcription up-regulation in neonatal rat cardiac myocytes exposed to low external K(+).

Animals↗

PubMed2000

[Antibiotic susceptibility of Neisseria gonorrhoeae isolates in Berlin].

BACKGROUND AND OBJECTIVE: Because of the increasing resistance of Neisseria gonorrhoeae, we studied the actual resistance of isolates in Berlin. PATIENTS/METHODS: 85 Neisseria gonorrhoeae isolates were collected between 1995 and 1997. Susceptibility testing was performed for penicillin G, tetracycline, spectinomycin, ceftriaxone, ciprofloxacin and azithromycin by agar dilution. RESULTS: 18.8% isolates were resistant or intermediately resistant to penicillin G (including 6 PPNG). 12.9% isolates were resistant, 43.5% intermediately resistant to tetracycline. One strain was resistant against ciprofloxacin, 4 isolates showed increased MIC values (0.06-0.5 mg/l), whereas 78 isolates were fully susceptible (< 0.007 mg/l). All isolates were susceptible to spectinomycin, ceftriaxone, and azithromycin. CONCLUSIONS: Penicillin G and tetracycline should be given only in cases of proven sensibility. Resistance against ciprofloxacin may occur, especially in isolates acquired in south-east Asia. Ceftriaxone, spectinomycin and azithromycin were active against all isolates. The actual resistance situation should be monitored.

Anti-Bacterial Agents↗

PubMed2000

An outbreak of pyodermas among neonates caused by ultrasound gel contaminated with methicillin-susceptible Staphylococcus aureus.

OBJECTIVE: To investigate an outbreak of methicillin-susceptible Staphylococcus aureus (MSSA) infections in a neonatal clinic. DESIGN: Prospective chart review, environmental sampling, and genotyping by two independent methods: pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). A case-control study was performed with 31 controls from the same clinic. SETTING: A German 1,350-bed tertiary-care teaching university hospital. RESULTS: There was a significant increase in the incidence of pyodermas with MSSA; 10 neonates in good physical condition with no infection immediately after birth developed pyodermas. A shared spatula and ultrasound gel were the only identified infection sources. The gel contained MSSA and was used for hip joint sonographies in all neonates. PFGE and RAPD-PCR patterns from 6 neonates and from the gel were indistinguishable and thus genetically related clones. The case-control study revealed no significant risk factor with the exception of cesarean section (P=.006). The attack rate by days of hip-joint sonography between April 15 and April 27, 1994, was 11.8% to 40%. CONCLUSIONS: Inappropriate hygienic measures in connection with lubricants during routine ultrasound scanning may lead to nosocomial S. aureus infections of the skin. To our knowledge this source of S. aureus infections has not previously been described.

Case-Control Studies↗