Do patients need advice and information to prevent infections - results of a single centre structured survey

Background

Healthcare-associated infections are a major burden for hospitals, leading to morbidity and mortality and unnecessary medical costs. They can probably be reduced through what is known as patient empowerment. This study aims to address the question of whether patients are interested in receiving infection prevention and control information.

Methods

Patients were asked in structured interviews whether they would like more information on infection prevention and control. Inclusion criteria comprised 2 groups of patients. Group 1 were patients undergoing elective total endoprosthesis (TEP) and Group 2 were patients tested positive for meticillin-resistant Staphylococcus aureus (MRSA).

Results

The response rate was 38.4 % (163/425 patients). Approximately 75 % of the patients were interested in information on infection prevention and control. The topics of interest differed between the two patient groups: MRSA patients had a higher need for infection prevention and control information. TEP patients showed a high acceptance of antiseptic body wash and a willingness to pay for it themselves. Information given to patients should be group-specific and timely.

Conclusion

Our data suggest a lack of information on infection prevention and control among patients and underline the importance of patient empowerment. The willingness of patients to pay personally for antiseptic wash should be assessed further.

[First Results of the German consulting center for infection control outbreak registry]

BACKGROUND

Outbreaks of infectious diseases and / or colonization pose an increasing burden on hospitals and the health system in general and can be a threat to patient safety.

METHODS

At the end of 2013 we implemented a quality assurance registry of outbreak investigations performed by the Deutsches Beratungszentrum für Hygiene (German Consulting Center for Infection Control and prevention) in Freiburg. Now we analyzed the registered outbreaks until January 2015.

RESULTS

Norovirus was the leading causative organism and gram negative bacteria dominated the group of bacterial outbreaks. Outbreaks lasted between 6 and 185 days. 24 % of outbreaks were related to colonization only. Within 29 outbreaks we had 187 infected patients, 50 colonized patients und 92 infected health care workers (64 x norovirus, 20 x influenza, 8 x scabies). No deaths were recorded. Several risk factors and improvement potentials for future outbreaks could be identified.

CONCLUSION

Lack of staff compliance with vaccination or prophylactic therapy, misuse of personal protective equipment and lapses in absence from work for the required time can play an important role for prolonged outbreak situations esp. with viral outbreaks and scabies. A structured and goal directed outbreak management especially in the initial phase of an outbreak seems to be important for an efficient and fast termination of an outbreak.

Activity of the investigational fluoroquinolone finafloxacin and seven other antimicrobial agents against 114 obligately anaerobic bacteria

The activity of finafloxacin against 73 strains of the Bacteroides fragilis group, 10 other Gram-negative anaerobic rods and 31 Clostridium difficile strains was determined by the broth microdilution technique. The activity was compared with that of moxifloxacin, levofloxacin, ciprofloxacin, clindamycin, imipenem, piperacillin/tazobactam and metronidazole. MIC(50/90) values (minimum inhibitory concentration, in μg/mL, at which 50% and 90% of the isolates tested are inhibited, respectively) for finafloxacin for the different species were determined: B. fragilis group, 0.5/2; other Gram-negative rods, 0.06/0.25; and C. difficile, 4/16. Furthermore, the MICs against 11 selected B. fragilis strains were determined under acidic conditions and resulted in MIC(50/90) values for finafloxacin of 0.25/4 μg/mL. Thus, finafloxacin shows promising activity against several pathogenic species of anaerobes. Furthermore, finafloxacin has increased activity against selected B. fragilis strains under acidic conditions compared with activity at neutral pH.

[Epidemiology, diagnosis and treatment of adult patients with nosocomial pneumonia. S-3 Guideline of the German Society for Anaesthesiology and Intensive Care Medicine, the German Society for Infectious Diseases, the German Society for Hygiene and Microbiology, the German Respiratory Society and the Paul-Ehrlich-Society for Chemotherapy]

Nosocomial pneumonia (HAP) is a frequent complication of hospital care. Most data are available on ventilator-associated pneumonia. However infections on general wards are also increasing. A central issue are infections with multi drug resistant (MDR) pathogens which are difficult to treat particularly in the empirical setting potentially leading to inappropriate use of antimicrobial therapy. This guideline was compiled by an interdisciplinary group on the basis of a systematic literature review. Recommendations are made according to GRADE giving guidance for the diagnosis and therapy of HAP on the basis of quality of evidence and benefit/risk ratio. The guideline has two parts. First an update on epidemiology, spectrum of pathogens and antiinfectives is provided. In the second part recommendations for the management of diagnosis and treatment are given. Proper microbiologic work up is emphasized for knowledge of the local patterns of microbiology and drug susceptibility. Moreover this is the optimal basis for deescalation in the individual patient. The intensity of antimicrobial therapy is guided by the risk of infections with MDR. Structured deescalation concepts and strict limitation of treatment duration should lead to reduced selection pressure.

Epidemiology and antifungal resistance in invasive candidiasis

The epidemiology of Candida infections has changed over the last two decades: The number of patients suffering from such infections has increased dramatically and the Candida species involved have become more numerous as Candida albicans is replaced as an infecting agent by various non-C. albicans species (NAC). At the same time, additional antifungal agents have become available. The different Candida species may vary in their susceptibility for these various antifungals. This draws more attention to in vitro susceptibility testing. Unfortunately, several different test methods exist that may deliver different results. Moreover, clinical breakpoints (CBP) that classify test results into susceptible, intermediate and resistant are controver- sial between CLSI and EUCAST. Therefore, clinicians should be aware that interpretations may vary with the test system being followed by the microbiological laboratory. Thus, knowledge of actual MIC values and pharmacokinetic properties of individual antifungal agents is important in delivering appropriate therapy to patients

Evaluation of three rapid assays for detection of Clostridium difficile toxin A and toxin B in stool specimens

Diagnosis of Clostridium difficile-associated disease continues to be difficult for clinical microbiology laboratories. The aim of this study was to evaluate the performance of three enzyme immunoassays for detection of C. difficile toxins A and B: the recently marketed rapid enzyme immunoassay Ridascreen Clostridium difficile Toxin A/B (R-Biopharm, Darmstadt, Germany) and two established enzyme immunoassays, the C. difficile Tox A/B II Assay (TechLab, Blacksburg, VA, USA) and the ProSpecT C. difficile Toxin A/B Microplate Assay (Remel, Lenexa, KS, USA). Stool specimens (n = 383) from patients with a clinical diagnosis of antibiotic-associated diarrhea were examined by these three enzyme immunoassays and were additionally cultured for C. difficile on selective agar. Samples giving discordant enzyme immunoassay results underwent confirmatory testing by tissue culture cytotoxin B assay and by PCR for toxin A (tcdA) and toxin B (tcdB) genes from C. difficile. Using the criteria adopted for this study, 60 (15.7%) samples tested positive for toxins A and/or B. Sensitivity and specificity of the enzyme immunoassays were, respectively, 88.3 and 100% for the TechLab enzyme immunoassay, 91.7 and 100% for the R-Biopharm enzyme immunoassay, and 93.3 and 100% for the Remel enzyme immunoassay. The differences between these results are statistically not significant (p > 0.05). The results show that all three enzyme immunoassays are acceptable tests for the detection of C. difficile toxins A and B directly in fecal specimens or in toxigenic cultures.

Toxisches Streptokokken Schock Syndrom in Verbindung mit serologisch nachgewiesenen Autoantikörpern - Streptococcal Toxic Shock-like Syndrome Associated with Detectable Autoantibodies

We report on the severe course of a Streptococcal Toxic Shocklike Syndrome (STSLS). The initial diagnosis as well as the causal therapeutic approaches were complicated and prolongated definitely by the serological detection of auto-antibodies. Besides the presentation of clinical and paraclinical findings the report responds to relevant differential diagnoses and the corresponding strategies of therapeutic intervention.

[Wound botulism in heroin addicts in Germany]

HISTORY AND ADMISSION FINDINGS

5 heroin addicts (aged 31-44 years; 1 female, 4 men) presented with a history of blurred vision and diplopia followed by dysarthria. 3 of the patients also developed respiratory failure requiring long-term ventilatory support. Physical examination revealed cranial nerve deficits and abscesses at injection sites in 3 of them.

DIAGNOSIS

In 4 patients wound botulism was diagnosed on the basis of symptoms, course of the illness and response to specific treatment. Clostridium botulinum was grown from wound swab in one patient.

TREATMENT AND COURSE

Two of the patients, having been injected with antitoxin immediately after admission, were discharged almost symptom-free after only a few days. Adjuvant antibiotics and, in 3 patients, surgical débridement of the abscesses were needed.

CONCLUSIONS

Progressive cranial nerve pareses in addicts who inject drugs intravenously or intramuscularly should raise the suspicion of wound botulism and require hospitalization. While indirect demonstration of toxin supports the diagnosis, false-negative results are common.

Inducible metronidazole resistance in nim-positive and nim-negative bacteroides fragilis group strains after several passages metronidazole containing columbia agar plates

BACKGROUND

Recent data show an emergence of resistance in the Bacteroides fragilis group against several antimicrobial agents and inducible resistance against metronidazole in nim-positive strains. The aim of the present study was to investigate inducible metronidazole resistance in nim-positive as well as in nim-negative B. fragilis group strains.

MATERIALS AND METHODS

Of 18 B. fragilis strains (including four nim-positive reference strains and one ATCC strain), two Bacteroides ovatus strains, and one Bacteroides thetaiotaomicron DSM strain minimum inhibitory concentration (MIC) values for metronidazole were determined by Etest and analyzed for nim genes (nimA to -G) by PCR. For this purpose bacterial suspensions were incubated on supplemented Columbia agar plates containing metronidazole at twice the MIC value of the specific strain and incubated under anaerobic conditions for 48 hours. After incubation, growing bacteria were harvested and thereafter incubated at four times the original MIC. This procedure was repeated with increasing antibiotic concentrations. The resulting MIC values were confirmed by Etest.

RESULTS

The MIC values for metronidazole of the four nim-positive reference strains ranged from 3 to 8 mg/l. The B. fragilis ATCC 25285 strain and the B. thetaiotaomicron DSM 2255 strain were nim negative with MIC values of 0.19 mg/l and 0.75 mg/l, respectively. Three clinical isolates of B. fragilis strains showed MIC values of > 256 mg/l. In all three strains, nim genes were detected by PCR. The other clinical isolates were nim negative. In these strains, MIC values ranged from 0.19 to 0.75 mg/l. After several passages on metronidazole containing agar, all B. fragilis group strains exhibited MIC values of > 256 mg/l determined by Etest.

CONCLUSION

Metronidazole resistance can be selected not only in nim-positive strains but also in nim-negative strains, suggesting that mechanisms other than nim genes are involved. These findings and the emerging resistance of the B. fragilis group against several antimicrobial agents underscore the importance of susceptibility testing of anaerobes even in routine laboratories.

[Appropriate microbiological diagnostics]

In the industrialized world the threat of infectious diseases is mainly due to nosocomial infections and multi-resistant agents. In this context, microbiological evaluations have not only a benefit for the individual patient, but also allow to evaluate the local epidemiologic situation. However, quality and benefits are often compromised by incorrect specimen collection. This review attempts to summarize diagnostic procedures, collection and transport of appropriate specimens and relevant causative agents for prominent clinical manifestations of infectious diseases.

Antecedent use of fluoroquinolones is associated with resistance to moxifloxacin in Clostridium difficile

OBJECTIVE

Moxifloxacin is characterized by high activity against Gram-positive cocci and some Gram-positive and -negative anaerobes, including Clostridium difficile. This study investigates the role of prior quinolone use in relation to patterns of susceptibility of C. difficile to moxifloxacin.

METHODS

Sixty-three clinical isolates of C. difficile were investigated for toxigenicity, susceptibility to moxifloxacin, and mutations in the DNA gyrase gene. The medical histories for 50 of these patients were available and used to identify previous fluoroquinolone use.

RESULTS

Thirty-three (52.4%) strains showed resistance to moxifloxacin (MICs > or = 16 mg/L). All moxifloxacin-resistant strains harbored a mutation at amino acid codon Ser-83 of gyrA. Forty-five isolates (71.4%) were toxigenic; all moxifloxacin-resistant strains were in this group. Resistance to moxifloxacin was associated with prior use of fluoroquinolones (P-value 0.009, chi-square).

CONCLUSIONS

Although the use of moxifloxacin to treat C. difficile-associated diarrhea is not likely to be common, these data show a relationship between antecedent fluoroquinolone use and resistance to moxifloxacin in C. difficile isolates, and raise questions regarding selection pressure for resistance placed on colonizing bacteria exposed to fluoroquinolones. Mutations in gyrA are involved in moxifloxacin resistance.

Nosocomial infections in internal medicine, University of Frankfurt, Germany--a prospective surveillance study

Nosocomial infections (NI) are serious complications associated with high morbidity and mortality. In the present study, NI were analyzed prospectively at the Center of Internal Medicine (CIM) (300 beds) of the J. W. Goethe-University -a 1380-bed major tertiary care teaching hospital- during a study period of six month. During the study period a single physician evaluated all patients with signs and symptoms of an infection during his daily rounds. NI was defined as body temperature >38 degrees C and evidence of an infection not before the third day of admission to the hospital. NI was diagnosed in 127 patients (3.5%) of the 3605 patients studied. The data of 126 patients with NI could be collected and analyzed completely. Of the 126 patients 34 patients died. The mean length of hospitalization before the diagnosis of NI was 12.0 days (standard-deviation: +/-13.1 days; median: 7 days). Compared to all patients with NI significantly more patients of the Internal Intensive care unit (11.3%), of the HIV-ward (10.3%), and of the hematology / oncology ward (5.8%) acquired a NI (p<0.05). With respect to other groups of patients the frequency of NI ranged from 0.5 to 4.6 per 100 admitted inpatients. The lower rate was in patients admitted for invasive diagnostic procedures who were hospitalized only for 3 days or less.

Rapidly growing tumor-like brain lesion

Listeria monocytogenes accounts for 8-11% of the cases of bacterial meningitis which is associated with high mortality in patients with serious underlying diseases or those receiving immunosuppressive treatment. Brain abscess due to L. monocytogenes is a very rare occurrence. The case reported here concerns a 54-year-old female patient with a rapidly growing tumor-like brain lesion. L. monocytogenes type 4b could be cultured from blood and brain biopsy. Despite antimicrobial therapy with ampicillin and gentamicin, the patient died 11 days after admission to the hospital. The growing numbers of elderly and immunocompromised patients will increasingly confront physicians with patients with listeriosis. Delayed therapy in patients treated with corticosteroids may result in a fatal outcome.

Comparative in vitro activities of gemifloxacin, other quinolones, and nonquinolone antimicrobials against obligately anaerobic bacteria

The in vitro activity of gemifloxacin was compared to that of other quinolone and nonquinolone antimicrobials against 204 anaerobes by the agar dilution technique. The data indicate that gemifloxacin has a rather selective anaerobic activity. Most Peptostreptococcus, Porphyromonas, and Fusobacterium species are susceptible, while gemifloxacin's activity against other gram-negative anaerobes appears to be variable.

Infections caused by Stenotrophomonas maltophilia--a prospective study

BACKGROUND

Stenotrophomonas maltophilia is an opportunistic microorganism, often highly resistant to routinely tested antibiotics. This microorganism is isolated in specimens from patients with nosocomial infections with increasing frequency.

PATIENTS AND METHODS

During a 1-year period (1998/1999) S. maltophilia was isolated from 137 specimens (0.26% of all investigated specimens) from 80 patients who were treated in a 1,500 bed major tertiary care teaching hospital in Leipzig. The data of 76 patients (133 specimens) could be collected and analyzed completely.

RESULTS

The pathogen was most frequently detected in specimens from the respiratory tract (54%). In five patients (six cases) S. maltophilia was isolated from blood cultures (0.3% of all positive blood cultures; 1.4% of all gram-negative isolates from blood cultures). 70 of the infected patients were inpatients and 32 (42%) of them were treated on the internal medicine wards. Of these 32 patients only six (19%) were pretreated with imipenem. The Length of stay at the hospital resulted in an independent increased risk of infection with S. maltophilia. In addition, this organism was detected in six infected outpatients.

CONCLUSION

S. maltophilia is not only a nosocomial pathogen. Pretreatment with a carbapenem is no longer an unequivocal risk factor for an infection with S. maltophilia.

Pericarditis after allogeneic peripheral blood stem cell transplantation caused by Legionella pneumophila (non-serogroup 1)

A case of Legionella pericarditis caused by a Legionella pneumophila isolate other than serogroup 1 is reported in a 59-year-old man after allogeneic peripheral blood stem cell transplantation. On admission a 5 mm pericardial effusion was detected on echocardiography. Antibodies were detected against L. pneumophila serogroups 7 to 14 using the antigen pool and against serogroup 12 alone. Antibodies were not detected against the serogroup 1 to 6 antigen pool. The patient's clinical condition improved dramatically after treatment with clarithromycin and an echocardiography revealed the total disappearance of the pericardial effusion.

In vitro activities of fourteen antimicrobial agents against obligately anaerobic bacteria

The in vitro activities of fourteen antimicrobial agents were tested against 292 clinical isolates of obligately anaerobic bacteria using the broth microdilution technique. Taking all strains as a group the MIC(50/90) (mg/l) values were metronidazole and imipenem 0.25/1, meropenem 0.25/0.5, trovafloxacin 0.25/1, gatifloxacin and moxifloxacin 0.5/2, levofloxacin 2/16, ciprofloxacin 4/32, clindamycin 0.5/8, amoxycillin/clavulanate 1/4, doxycycline and chloramphenicol 2/4, erythromycin 4/>32 and penicillin G 16/>32.

In vitro activity of telithromycin (HMR 3647) and seven other antimicrobial agents against anaerobic bacteria

We assessed the in vitro activity of telithromycin (HMR 3647) and seven other antimicrobials against 292 strains of obligately anaerobic bacteria. MICs were determined with the microdilution technique and Wilkins-Chalgren broth according to DIN 58940-83. MIC50/MIC90s (mg/L) for telithromycin were 4/4 for Bacteroides fragilis, Bacteroides ovatus and Bacteroides thetaiotaomicron, 2/4 for Fusobacterium spp. and Bilophila wadsworthia, 2/2 for Bacteroides caccae, 1/4 for Bacteroides vulgatus, 0.25/4 for Prevotella spp., > or =0.03/0.5 for Clostridium spp. and 0.125/4 for Peptostreptococcus spp.

Comparative activity of moxifloxacin in vitro against obligately anaerobic bacteria

The antimicrobial activity of moxifloxacin and seven other antibiotics (four of them quinolones) against 292 strains of obligately anaerobic bacteria was assessed employing a broth microdilution technique performed in Wilkens-Chalgren broth. MIC50/MIC90 values (mg/l) for moxifloxacin were as follows: Bacteroides fragilis (n = 62) 0.25/2, Bacteroides ovatus (n = 70) 1/4, Bacteroides vulgatus (n = 29) 0.25/1, Bacteroides thetaiotaomicron (n = 17) 2/2, Bacteroides caccae (n = 11) 1/2, Prevotella spp. (n = 11) 0.25/2, Fusobacterium spp. (n = 17) 1/4, Bilophila wadsworthia (n = 29) 0.5/1, and Clostridium spp. (n = 29) 0.125/0.5, respectively. MIC50 values (mg/l) for Bacteroides distasonis (n = 8) and Peptostreptococcus spp. (n = 9) were 0.25. The results indicated that moxifloxacin was almost as active as trovafloxacin, as active as gatifloxacin, and more active than levofloxacin and ciprofloxacin against the anaerobes tested.

In vitro activities of gatifloxacin, two other quinolones, and five nonquinolone antimicrobials against obligately anaerobic bacteria

The activity of the new fluoroquinolone gatifloxacin was compared with those of other quinolones and antimicrobial agents of other classes against 294 anaerobes by the broth microdilution technique. For all strains tested, gatifloxacin MICs at which 50 and 90% of the isolates were inhibited were 0.5 and 2 mg/liter, respectively, and were 3 to 4 dilution steps lower than, e.g., ciprofloxacin.

Endothelial cell compatibility of clindamycin, gentamicin, ceftriaxone and teicoplanin in Bier's arterial arrest

In patients with infected diabetic foot lesions, and gangrenous, peripheral, occlusive arterial disease, it is important to achieve high concentrations of antibiotics in the tissues, as the extent of amputation is often influenced by the presence of infection. Local transvenous pressure injection of antibiotics, in Bier's arterial arrest, allows high local tissue concentrations to be attained in the extremities. Information on the endothelial compatibility of antibiotics in high concentrations combined with the effect of reperfusion injury following tissue hypoxia is lacking. To evaluate the effect of clindamycin, gentamicin, ceftriaxone and teicoplanin injected in Bier's arterial arrest, on endothelial cells, an in-vitro model using human umbilical venous endothelial cells (HUVEC) has been devised. The intracellular levels of purine nucleotides, reflecting DNA/RNA synthesis, energy production and signal transduction of these cells were measured by means of high-performance liquid chromatography. Incubation of cells with 10 mg/mL clindamycin, gentamicin, ceftriaxone and teicoplanin for 20 min resulted in no significant decline of intracellular purines. Levels of purines obtained after exposure of the cells to 0.1 mmol/L hydrogen peroxide (H2O2), to simulate reperfusion injury, were not significantly different from those obtained from cells allowed to recover after antibiotic exposure. These findings indicate that the infusion of high doses of antibiotics, during Bier's arterial arrest, is compatible with maintenance of endothelial cell function, even in the presence of increased free radical activity, provided the exposure is limited to 20 min.

Effects of imipenem and meropenem on purine content of endothelial cells

Intravenous compatibility of antibacterial agents has been tested in animal models. Use of human umbilical venous endothelial cells (HUVEC) to test antibiotic solutions for intravenous tolerance provides a valuable alternate model.

OBJECTIVE

Evaluation of the effect of imipenem and meropenem on intracellular purines reflecting viability, energy production, signal transduction, and DNA/RNA synthesis of these cells.

MATERIALS AND METHODS

Levels of intracellular adenosine 5' triphosphate (ATP), adenosine 5' diphosphate (ADP), guanosine 5' triphosphate (GTP) and guanosine 5' diphosphate (GDP) were measured by means of high performance liquid chromatography (HPLC).

RESULTS

The total amount of ATP after incubation of cells with 10.0 mg/ml imipenem and meropenem for 20 minutes (12.93 +/- 0.93 nmol/million cells and 13.27 +/- 0.89 nmol/million cells, respectively) did not result in a decrease compared to controls (12.34 +/- 0.87 nmol/million cells). In addition, ATP levels were maintained or actually increased after 60 minutes. Incubation of cells with 5.0 mg/ml and 2.5 mg/ml of imipenem or meropenem for 20 and 60 minutes showed similar results. Purine nucleotide profiles of ADP, GTP, GDP following exposure of 10.0 mg/ml, 5.0 mg/ml and 2.5 mg/ml of imipenem and meropenem did not differ markedly.

CONCLUSIONS

These in vitro data show an excellent endothelial compatibility of imipenem and meropenem even in high concentrations.

Phagocytosis of Escherichia coli and Staphylococcus aureus by neutrophils of human immunodeficiency virus-infected patients

To study the influence of human immunodeficiency virus (HIV) infection on phagocytosis of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by polymorphonuclear neutrophils (PMN) from HIV-infected patients in vitro. PMN were isolated from the blood of 25 HIV-infected patients (group 1: CD subset4 </= 250/microL: 14 patients, group 2: CD subset4 >250/microL: 11 patients ) by Percoll density gradient and incubated with E. coli and S. aureus. Subculture technique was used to determine PMN function at 0, 0.5, 1, 2, 4, 6, and 24 hours. Controls were run with PMN from healthy volunteers. Phagocytosis of E.coli and S.aureus by PMN of HIV-infected patients was significantly lower in group 1 (p <0.05). Reduced phagocytosis of E. coli and S. aureus was found in HIV-infected patients with low CD subset4-cell counts. Our findings may contribute to increased susceptibility to bacterial infection in HIV-infected patients with low CD subset4-cell counts.

Endothelial cell compatibility of clarithromycin for intravenous use

OBJECTIVES

Tolerance of intravenously applied clarithromycin has been tested on marginal ear veins of rabbits. Use of human umbilical venous endothelial cells (HUVEC) for testing antibiotic solutions for intravenous compatibility provides a valuable alternate model.

DESIGN AND METHODS

In order to evaluate the effect of clarithromycin on intracellular purines, reflecting cell viability, energy production, signal transduction and DNA/RNA synthesis, intracellular adenosine 5' triphosphate (ATP), adenosine 5' diphosphate (ADP), guanosine 5' triphosphate (GTP), and guanosine 5' diphosphate (GDP) levels were measured by means of high performance liquid chromatography (HPLC).

RESULTS

Incubation of cells with 2 mg/mL clarithromycin resulted in a rapid decrease of the intracellular ATP from 12.6 +/- 1.1 to 8.87 +/- 0.82 nmol/million cells or 1.5 +/- 0.6 nmol/million cells, after 20 or 60 min, respectively. In addition, ADP was extensively depleted. Purine nucleotide profiles were markedly different following exposure to 1 mg/mL clarithromycin. There was no significant decline of intracellular high energy phosphate levels after 20 min.

CONCLUSION

These results show that clarithromycin has a better endothelial compatibility if diluted to a final concentration of 1 mg/mL. These data are in line with our clinical observations that the occurrence of phlebitis could be minimized by diluting the manufacturers' preparation of clarithromycin to 1 mg/mL.

Endothelial cell compatibility of fluoroquinolone solutions for intravenous use

One local side-effect closely related to the use of parenteral fluoroquinolones is phlebitis. The occurrence of this phenomenon is largely thought due to the damage of endothelial cells with subsequent inflammation. In order to evaluate the effect of ciprofloxacin, fleroxacin, and ofloxacin on the viability of human umbilical venous endothelial cells (HUVEC), intracellular ATP levels were measured by a luciferin-luciferase assay. Prostacyclin (PGI2) and thromboxane A2 (TXA2) were determined by means of direct radioimmunoassay. Commercially available preparations of ciprofloxacin (2 mg/ml) and fleroxacin (4 mg/ml) reduced the intracellular ATP content by 75.9 +/- 1.9% and 82.1 +/- 0.6%, respectively, within 20 minutes, indicating severe damage of endothelial cells. Incubation with ofloxacin (2 mg/ml) did not have any detrimental effect. All fluoroquinolones were tolerated well by endothelial cells at low concentrations up to 20 micrograms/ml. Concentrations between 100-200 micrograms/ml gradually led to functional alterations such as increased PGI2 release. The tolerance of intravenously applied antibiotics has been tested in animal models. Use of human venous endothelial cells for testing antibiotic solutions for intravenous application provides a valuable alternate model for tolerability.

Experience with imipenem in internal medicine--a postmarketing surveillance study

Imipenem was registered for clinical use in Germany in 1985. It is recommended for initial treatment in either severe nosocomial infections or infections in ICU or immunocompromised patients. In this study, we evaluated 1,215 patients who were prescribed imipenem at our Zentrum der Inneren Medizin-a major tertiary care university hospital-over a 6 year period. 650 of 1,215 patients (53.5%) had rapidly fatal disease; and the main indication for imipenem was pneumonia and fever of unknown origin. 56.2% received 500 mg imipenem t.i.d., 40.4% 500 mg b.i.d., 0.9% 1000 mg b.i.d.; and 2.5% 1000 mg t.i.d. Average duration of treatment was 11 days. Lower dose (500 mg b.i.d.) was used in patients with renal insufficiency; highest dose was used in severe infections or infections caused by moderately sensitive organisms. Imipenem was used as a single initial antibacterial agent in the majority of the patients. Success was seen in 80% of the episodes, irrespective of the dosage used; 89% at 500 mg b.i.d., 74% at 500 mg t.i.d., 77% at 1,000 mg b.i.d.; and 69% at 1,000 mg t.i.d. We observed the highest favourable response (91.5%) in the episodes treated initially with imipenem monotherapy. Overall, imipenem was well tolerated. The majority of the patients with untoward effects was on multiple-drug regimens. The most frequent untoward event observed involved the gastrointestinal tract.

Empirical monotherapy with meropenem versus imipenem/cilastatin for febrile episodes in neutropenic patients

In a nonblind, randomised, parallel-group study, initial empirical monotherapy with meropenem 1 g intravenously every 8 h was compared to an identical dosage of imipenem/cilastatin for the treatment of 66 febrile episodes in 61 adult neutropenic patients. 25/31 episodes treated with meropenem and 24/30 imipenem/cilastatin-treated episodes were still receiving unmodified therapy at 72 h (primary endpoint); this difference was not statistically significant. By the end of the treatment courses, 18/31 meropenem-treated episodes had responded clinically (cured or improved) compared with 18/30 episodes treated with imipenem/cilastatin. Another ten episodes initially treated with meropenem and six episodes treated with imipenem/cilastatia were cured after an additional antimicrobial agent had been administered (cured with modification). Satisfactory bacteriological responses (eradication plus presumed eradication) at the end of unmodified therapy was 9/11 in the meropenem group and 14/16 in the comparator group. Both regimes were well tolerated; however, there were more reports of nausea and/or vomiting in the impenem/cilastatin group (7/33 vs. 2/33 in the meropenem group). The carbapenems meropenem and imipenem/cilastatin appear to be suitable agents for empirical monotherapy of febrile episodes in neutropenic patients. Meropenem may be better tolerated than imipenem/cilastatin, allowing optimal dosing in this patient population.

Influence of free or liposomal amphotericin B on killing of Candida species by human peritoneal macrophages

The influence of free and liposomal amphotericin B at subinhibitory and inhibitory concentrations on killing of Candida albicans (ATCC 10231), Candida tropicalis (ATCC 13803) and Cryptococcus neoformans (930) by human peritoneal macrophages was investigated in vitro. Peritoneal macrophages were harvested from overnight peritoneal dialysate of 10 patients undergoing regular continuous ambulatory peritoneal dialysis and incubated with Candida species (1:2), pooled human serum, fetal calf serum, Medium 199 and Sabouraud broth (with or without amphotericin B) for 6 hours. The killing of Candida species was determined using subculture technique. The combination of amphotericin B (free or liposomal) with peritoneal macrophages enhanced the killing of the Candida species. Candidacidal activity of free and liposomal amphotericin B resulted in comparable effects; however, the killing of the yeasts by liposomal amphotericin B was slower than by free amphotericin B.