Biomedical subjects

G Kampf

Publications and source records attributed to G Kampf.

At least 55 records · Page 3Linked to original sources

PubMed1998

Limited effectiveness of chlorhexidine based hand disinfectants against methicillin-resistant Staphylococcus aureus (MRSA).

Hand disinfectants containing chlorhexidine are thought to be less bactericidal against methicillin-resistant Staphylococcus aureus (MRSA) than methicillin-susceptible Staphylococcus aureus (MSSA). We report an in vitro comparison between three distinct MRSA strains and three MSSA strains. The bactericidal efficacy of chlorhexidine digluconate, 'Hibiscrub' and 'Hibisol' against Staphylococcus aureus was determined in a quantitative suspension test. Logarithmic reduction factors (RF) were calculated for each of six parallel experiments. Chlorhexidine digluconate and 'Hibisol' showed RF > 5 at most concentrations and reaction times but 'Hibiscrub' did not. MRSA was found to be significantly less susceptible than MSSA to chlorhexidine digluconate, 'Hibiscrub' and 'Hibisol' (P < 0.05; two-tailed t-test for independent samples). 'Hibisol' was significantly more effective against MRSA than 'Hibiscrub' (P < 0.05). Hand disinfectants containing both alcohol and chlorhexidine (e.g., 'Hibisol') are more effective against MRSA than scrubs based only on chlorhexidine ('Hibiscrub') and should be used in clinical practice.

Chlorhexidine↗

PubMed1998

Prevalence of nosocomial infections in representative German hospitals.

The nosocomial infection (NI) rate in German hospitals was studied in order to create reference data for comparison in hospitals where ongoing surveillance is impossible. The study was designed as a one-day prevalence study. Patients in 72 selected hospitals (inclusion criteria: acute care hospitals with departments for general medicine, surgery, obstetrics/gynaecology) were examined by four external investigators (physicians trained and validated in the diagnosis of NI). A total of 14,996 patients were studied. The overall prevalence rate was 3.5% (CI 3.1-3.9) with a variation of 0-8.9% between hospitals. The commonest NI were: urinary tract infection (42.1%), lower respiratory tract infection (20.6%), surgical site infections (15.8%) and primary sepsis (8.3%). The highest prevalence rate (15.3%) was found in intensive care ward patients, followed by surgery (3.8%), general medicine (3.0%) and gynaecology/obstetrics (1.4%). The infection rate varied significantly with hospital size. A microbiology laboratory report was only available for 56.5% of patients thought to have an NI, and there were remarkable differences between hospitals with and without an on-site microbiology laboratory. Because of this and other methodological reasons the NI prevalence rates reported here may represent the absolute minimum of nosocomially infected patients in Germany.

Cross Infection↗

PubMed1998

Prevalence and risk factors for nosocomial lower respiratory tract infections in German hospitals.

The prevalence and risk factors for nosocomial lower respiratory tract infections (LRTI) in Germany were determined as part of a national survey on nosocomial infections. The study included 14,966 patients in 72 representatively selected hospitals with departments of general medicine, surgery, obstetrics, gynecology, and intensive care units (ICU). Surveillance was carried out by four previously validated medical doctors who strictly applied the CDC-criteria for diagnosis of nosocomial infections. The overall prevalence of hospital-acquired LRTI was 0.72% with the highest rate in hospitals with more than 600 beds (1.08%) and among the patients on intensive care units (9.00%). Ventilator-associated pneumonia rates were highest in patients on ICUs (13.27). Polytrauma, impaired consciousness, chronic airway disease, prior surgery, and cardiovascular disease were significantly related to the occurrence of nosocomial LRTI. P. aeruginosa was the predominant organism causing nosocomial LRTI. Nosocomial LRTI remain a problem mainly on ICUs. Patients at risk should be monitored with extra care.

Cross Infection↗

PubMed1998

Prevalence of primary bloodstream infections in representative German hospitals and their association with central and peripheral vascular catheters.

The prevalence of noncentral and central lines and the prevalence of nosocomial primary bloodstream infections was investigated in 72 representative German hospitals (NIDEP Study). Data from a total of 14,966 patients were documented. On the prevalence day, it amounted to 23.9% for noncentral and 5.1% for central lines. The total prevalence of nosocomial primary bloodstream infections was 0.3%, 8.3% of all nosocomial infections recorded were primary bloodstream infections. The device utilization rate of vascular catheters was retrospectively observed for both the prevalence day and another 6 days. The device utilization rate was 27.3% for peripheral and 6.1% for central catheters with higher rates in west Germany. The associated incidence density of primary nosocomial bloodstream infections per 1000 catheter-days was 0.3 for noncentral and 0.8 for central lines. In 61.4%, the primary bloodstream infections were microbiologically confirmed. In 52.6% of cases, Gram-positive bacteria were isolated (Staphylococcus aureus: 15.8%, other coagulase negative Staphylococcus species: 34.2%) and in 47.4%, Gram-negative ones (mostly: Escherichia coli: 13.2% and Klebsiella species: 10.5%). Prevention to reduce nosocomial bloodstream infections is possible by antimicrobial establishing specially trained infusion therapy teams, using antimicrobial or antiseptic impregnated bloodstream catheters and a strict review of the indication for a vascular catheter together with a minimization of catheter days.

Bacterial Infections↗

PubMed1998

Importance of the surveillance method: national prevalence studies on nosocomial infections and the limits of comparison.

OBJECTIVE: To demonstrate the limits of comparison of national prevalence rates of nosocomial infections. DESIGN AND SETTING: Critical analysis of prevalence rates and methods of the Nosocomial Infections in Germany (NIDEP) study and other prevalence surveys with particular attention to the selection of patients, the qualification and training of the investigators, and the methods of identifying nosocomial infections. RESULTS: The lowest prevalence rate was found in Germany (3.5%), the highest in Belgium (9.3%). These differences may not be accurate, because variations in methods allow for differing explanations. CONCLUSIONS: Because of numerous methodological factors, comparison of infection rates between countries should be avoided. In contrast to other prevalence studies, the methodology of the German-NIDEP study permits registration of only certain infections, which is the main reason for the low rate.

Cross Infection↗

PubMed1998

Experience with two validation methods in a prevalence survey on nosocomial infections.

OBJECTIVE: To determine whether an investigator effect remained on the first German study on the prevalence of nosocomial infections Nosokomiale Infektionen in Deutschland Erfassung und Prävention (NIDEP), despite extensive validation efforts. DESIGN: Two validation methods were applied: bedside validation and validation by case studies. In both cases, the results of the four investigators were compared with the diagnosis of gold standard observers. SETTING: Validation measures were applied before, intermittently, during, and at the end of the surveillance period in 72 acute-care hospitals with 14,966 patients. RESULTS: The overall sensitivity in the bedside-validation periods was 89.0%; the overall specificity was 99.5%. For validation by case studies, overall sensitivity was 95.6%, and overall specificity was 92.8%. At the end of the surveillance, a remarkable investigator effect was found. CONCLUSION: Despite validation results that were assessed as satisfactory, based on available literature, an investigator effect was observed. This underlines the need for data validation and the formulation of recommendations for data validation. Clarification of the Centers for Disease Control and Prevention criteria for pneumonia and primary bloodstream infection and the inclusion of some diagnostic test results may reduce or prevent an investigator effect in future studies.

Bias↗

PubMed1998

Microbicidal activity of a new silver-containing polymer, SPI-ARGENT II.

The survival of three bacterial species and Candida albicans was studied on SPI-ARGENT II. The immediate recovery from silver-impregnated polymer and control polymer (1 cm2) was approximately 10(6) to 10(7) microorganisms. After incubation (37 degreesC) and neutralization of silver with horse serum (5%), surviving organisms were recovered. The survival of the microorganisms on the polymer was not found to be influenced by the silver implantation.

Anti-Infective Agents↗

PubMed1998

Evaluation of mannitol salt agar for detection of oxacillin resistance in Staphylococcus aureus by disk diffusion and agar screening.

Mannitol salt agar was evaluated for detection of oxacillin resistance in 136 Staphylococcus aureus isolates. All mecA-positive isolates (n = 54) were correctly categorized as oxacillin resistant by the disk diffusion test (1-microgram disk; zone diameter, < 16 mm); the specificity was 97.6%. Agar screening (2 micrograms of oxacillin per ml) revealed a sensitivity of 98.1% and a specificity of 95.1%.

Culture Media↗

PubMed1998

[Inactivation of chlorhexidine for in vitro testing of disinfectants].

An insufficient neutralization of chlorhexidine (4%), tested in vitro against Enterococcus faecium ATCC 6057, was suspected in the quantitative suspension test although the combination Tween 80, cysteine, histidine and saponine was assessed as sufficient for neutralising chlorhexidine. Bactericidal activity of each neutralising compound and their combinations was excluded. Sufficient neutralization was observed when all dilution steps and the corresponding agar plates were supplemented with the neutralising compounds. Successful neutralization in broth is not equivalent with successful neutralization in tryptic saline. We suggest to supplement at least the agar plates of the first dilution step with neutralising compounds when testing chlorhexidine.

Anti-Infective Agents, Local↗

PubMed1998

Direct detection of Pneumocysytis carinii in outdoor air: preliminary results of a field study.

P. carinii causes pneumonia in immunocompromised patients. New studies are suggestive of the de novo infections. Although P. carinii is believed to be ubiquitous it has not been detected directly from outdoor air. Therefore, outdoor air samples (n = 20) of 5 m3 were collected onto gelatin filters (pore size: 3 microns) on a cemetery using a suction pump (Sartorius MD8). Five samples were silver-stained, five samples were stained with an indirect immunfluorescence test kit, the remaining ten samples were stained with the combinations of the two individual stains. In a total of 100 m3 outdoor air one cyst resembling P. carinii was detected by the methenamine silver stain. Other cells not resembling P. carinii were found with a silver stained cell wall and positive fluorescence. The natural reservoir of P. carinii remains unknown. The indirect immunfluoresence which is common in the clinical laboratory is probably not specific enough for environmental samples.

Air Microbiology↗

PubMed1997

Genotoxic activity of important nitrobenzenes and nitroanilines in the Ames test and their structure-activity relationship.

The most important commercially available nitro- and aminobenzenes and the explosive trinitrobenzene were tested for mutagenicity in the Salmonella typhymurium TA 98 and TA 100 both in the absence and presence of S 9. Ten of the 14 compounds tested (71%) were mutagenic. All the substances showed positive results in TA 98 and 4 substances were also mutagenic in TA 100. The three diaminobenzenes and 4-nitroaniline were mutagenic only with metabolic activation. All other compounds did not require the addition of S 9. Only nitrobenzene, 1,2-dinitrobenzene, aniline and 2-nitroaniline were negative in both strains. In summary, all substances that are derived from nitrobenzene or aniline by addition of a nitro group in the meta- or para-position were mutagenic, whereas nitrobenzene and aniline themselves and their ortho-derivates were nonmutagenic. The possible relationships between the position of the substituents and the mutagenicity are discussed.

Aniline Compounds↗

PubMed1997

Comparison of screening methods to identify methicillin-resistant Staphylococcus aureus.

Screening methods to identify methicillin-resistant Staphylococcus aureus (MRSA) were compared using 96 isolates representing 17 distinct clones. The sensitivity of four commercial agglutination tests was determined in comparison to the tube coagulation test, and the results related to the presence of the coagulase gene. The broth screening test, agar dilution test and disc diffusion test were carried out, and the results related to the presence of the mecA gene. Mannitol salt agar and Iso-Sensitest agar with varying salt supplements were used. All agglutination tests had high rates of detection of Staphylococcus aureus (95.8-99.0%). Resistance in mecA gene-positive Staphylococcus aureus isolates was correctly detected by the oxacillin broth test, the agar dilution test and the disc diffusion test on mannitol salt agar, whereas on Iso-Sensitest agar detection rates were lower (between 68.5% and 94.4%, depending on the salt supplement). Incubation of the Iso-Sensitest plates for 48 hours significantly improved the rate of detection of resistance, but increased the major error rate up to 71.4%. MecA gene-positive Staphylococcus aureus isolates not detected by the disc diffusion test on Iso-Sensitest agar had significantly lower oxacillin minimal inhibitory concentration values and were significantly less resistant to a variety of antibiotics. Thus, mannitol salt agar might be a suitable medium for use in the disc diffusion and agar dilution test to detect resistance to oxacillin in Staphylococcus aureus.

Agglutination Tests↗

PubMed1997

[Effectiveness of alcoholic hand disinfectants against methicillin resistant Staphylococcus aureus].

In order to determine the efficacy of hand disinfectants based on alcohol against three MRSA strains and 3 methicillin-susceptible S. aureus strains (MSSA), 1-propanol (60%) as well as Sterillium and Spitaderm were investigated in the quantitative suspension test at various dilutions and reactions times (15, 30 and 60s). All undiluted disinfectants revealed reduction factors > 6 against MRSA and MSSA after 30s. Diluted disinfectants (50%) were significantly less effective against MRSA at short reaction times (15 s) (p < 0.05). Sterillium in a dilution of 50% did not reach 5 reduction factors against either MRSA or MSSA after 30 s. The impact of an appropriate use of hand disinfectants in order to break chains of infections with MRSA is obvious.

1-Propanol↗

PubMed1997

Analysis of risk factors for nosocomial infections--results from the first national prevalence survey in Germany (NIDEP Study, Part 1).

An analysis of risk factors for nosocomial infections (NI) was carried out using data from the first national prevalence survey on NI in Germany. Fourteen thousand, nine hundred and sixty-six patients, with a total of 543 NI, were included. Urinary tract infections (UTI), lower respiratory tract infections (LRTI), surgical site infections (SSI) and primary septicaemia (PS) were analysed. UTI were significantly associated with unconsciousness, age, prior operation, hospital size and female sex (P < 0.1). LRTI were significantly associated with chronic airway disease, intensive care units, unconsciousness, polytrauma, prior operation, cardiovascular disease, malignancy and absence of infection on admission. The department, age, diabetes mellitus, male sex and hospital size were risk factors for SSI. The department, prior operation and unconsciousness were significantly associated with PS. An investigator effect was observed for LRTI and PS. Although no final conclusions from a risk factor analysis based on prevalence data can be drawn the results support stratification of NI for routine surveillance.

Adult↗

PubMed1997

Uptake of 169Yb complexes in normal and tumour cells: influence of ligand and metabolic cell activity and stability of cellular association.

For better understanding of the accumulation of trivalent radiometal tracers in tumours, studies of uptake of different 169Yb complexes into cultured normal (V79/4) and tumour (KTCTL-2) cells were performed. Cellular uptake of 169Yb3+ is dependent on both the metabolic activity of the cells and the nature of the ligand used. Uptake of 169Yb3+ from the citrate complex is an active cellular transport process but not tumour-specific. The 169Yb-aminopolycarboxylic acid complexes are taken up via a different, unknown mechanism, and in higher amounts by the tumour cells than by the V79/4 cell line, but the general features of uptake were principally the same with the normal and the tumour cells. Uptake of the complexes studied leads to a stable association of cellular components, which is a good premise for the therapeutic use of trivalent radiometals.

Animals↗

PubMed1996

[Nosocomial infections in Germany--assessment and prevention. NIDEP Study, 1: On prevalence in surgery].

One aim of the NIDEP study (nosocomial infections in Germany: surveillance and prevention) was to determine in part 1 (surveillance) the prevalence of nosocomial infections (NI) in patients in surgical departments of 72 representatively selected hospitals in Germany. The surveillance was carried out by four previously validated physicians who applied the CDC criteria for NI. The overall rate of NI was 3.8%. Urinary tract infections (1.45%) and surgical wound infections (1.34%) were the most common NI. The highest rate of wound infections was noted after amputations (7.2%), conventional appendectomies (4.1%) or operations on the colon or rectum (3.8%). The use of perioperative antibiotics varied widely depending on the kind of operation and was not in accordance with international guidelines in all hospitals.

Adolescent↗

PubMed1996

[Postoperative wound infections in surgery--prevalence in Germany (Nosocomial Infections in Germany--Assessment and Prevention Study)].

Part of the NIDEP study was to determine the prevalence of surgical site infections in the surgical departments of 72 representatively selected hospitals. Four physicians, trained and validated in detecting nosocomial infections, carried out the surveillance, based on the CDC criteria for nosocomial infections. The prevalence of surgical site infections was 1.34% for all surgical patients (n = 5377) and 2.13% for all operated patients (n = 3383). Lower rates were found in patients with a low ASA score, clean wounds, and an average duration of the operation. Most surgical site infections were noted after amputations (7.2%), operations on colon or rectum (4.1%), and appendectomies (3.8%).

Cross Infection↗

PubMed1995

Evaluation of radioselenium labeled selenomethionine, a potential tracer for brain protein synthesis by PET.

The blood-brain transfer, protein incorporation and metabolism of L-[75Se]selenomethionine (SeMet) of relatively high specific activity (> 400 GBq mmol) were studied in male Wistar rats. The highest uptake was found in the pancreas, followed by the tumor, kidney, liver, brain and muscle. In addition, plasma and brain samples of rats were analyzed for labeled fractions of free SeMet, metabolites, and SeMet bound to t-RNA and proteins. For example, free SeMet represented more than 80% of brain radioactivity at 1.5 min while it was less than 15% at 360 min. A concomitant increase was observed for protein bound SeMet in brain. A three-compartment model was applied to calculate the blood-brain transfer constant (K1 (0.15 +/- 0.070 mL g-1 min-1) and the rate constant of SeMet incorporation into proteins (k3 = 0.026 +/- 0.008 min-1). The apparent incorporation of methionine into proteins was estimated to be about 0.73 nmol g-1 min-1. From the studies it is concluded that the use of L-[75Se]selenomethionine may be appropriate to measure brain protein incorporation in humans with PET.

Animals↗