Are histopathological findings of diagnostic value in native valve endocarditis?

BACKGROUND: Optimal management of infective endocarditis (IE) depends on the early detection of IE-causing pathogens and on appropriate antimicrobial and surgical therapy. The current guidelines of the European Society of Cardiology (ESC) recommend histopathological examination as the gold standard for diagnosing IE Habib et al. (Eur Heart J 30:2369-2413, 2005). We hypothesize that histopathological findings do not provide additional information relevant to clinical decision-making. METHODS: We retrospectively reviewed a cohort of patients who had undergone surgery for native valve endocarditis (NVE) at the University Hospital Regensburg between September 1994 and February 2005. All episodes of intraoperatively confirmed endocarditis during this period were included in the study. Data were retrieved from surgical records, microbiological and histopathological reports, and medical files of the treating as well as admitting hospital. Pathogens were correlated with the site of manifestation of the affected heart valve and with clinical and histopathological findings. RESULTS: A total of 163 episodes of NVE were recorded and entered into our study for analysis. The valves affected were the aortic valve (45 %), the mitral valve (28 %), the aortic and mitral valve (22 %), and other valves (5 %). IE-causing pathogens were Staphylococcus aureus (22 %), viridans streptococci (18 %), enterococci (10 %), streptococci other than Streptococcus viridans (9 %), coagulase-negative staphylococci (5 %), miscellaneous pathogens (4 %), and culture-negative endocarditis (33 %). Infection with S. aureus was associated with high rates of sepsis, septic foci, and embolic events, while patients with enterococcal IE showed the highest rate of abscesses. Mortality rate in all subgroups was low without significant differences. However, histopathological findings correlated poorly with the pathogen involved and showed only few significant associations that were without clinical relevance. CONCLUSIONS: The clinical presentation of IE depends on the pathogen involved. Among the episodes of NVE examined, the histopathological examination of resected heart valves did not show any pathogen-specific morphological patterns and therefore did not provide any additional information of clinical value. Based on our findings, we recommend complementary cultures of the resected materials (valve tissue, thrombotic material, pacer wire) and implementation of molecular diagnostic methods (e.g., broad-range PCR amplification techniques) instead of histopathological analyses of resected valve tissue.

Splanchnic sympathectomy prevents translocation and spreading of E coli but not S aureus in liver cirrhosis.

INTRODUCTION: Spontaneous bacterial peritonitis (SBP) is mainly caused by bacterial translocation of enteric Gram-negative bacteria, predominantly Escherichia coli. The sympathetic nervous system (SNS) is activated in advanced cirrhosis, particularly in the splanchic circulation, and exerts potent immunosuppressive actions. However, the role of splanchnic SNS activity in bacterial translocation and bacterial spreading in cirrhosis remains unclear. METHODS: E coli or Stapylococcus aureus (10(6) CFU) were given intraperitoneally. After 6 h, mesenteric lymph nodes (MLN), liver, spleen, lung and peripheral blood were harvested from ascitic cirrhotic rats (LC) and healthy controls with and without splanchnic sympathectomy (SE). The bacterial tissue burden was determined by standard microbiological culture techniques. In vitro phagocytic activity of peritoneal polymorphonuclear leucocytes was assessed by FACS analysis. RESULTS: Under basal conditions SE reduced bacterial translocation to MLN in LC rats from 45% to 17%. LC rats had a marked increase in bacteraemia after E coli and S aureus challenge and an increased incidence and degree of E coli translocation to MLN, liver, spleen and lung compared with control rats. SE prevented bacteraemia in LC rats after E coli but not after S aureus challenge. Prior SE abolished the difference in incidence as well as the bacterial tissue burden in each organ after E coli application in LC rats, being no longer significantly different from control rats with or without SE. The protective effects of SE against E coli were associated with a greater influx of mononuclear cells into the peritoneal cavity and increased phagocytic activity of peritoneal polymorphonuclear leucocytes. CONCLUSIONS: In cirrhosis with bacterial peritonitis, hyperactivity of the splanchnic sympathetic nervous system contributes to the translocation of E coli but not S aureus to MLN and extraintestinal sites. This indicates a key role for sympathetic drive in the impairment in host defence against Gram-negative bacteria in cirrhosis.

Risk factors associated with long-term prognosis of patients with Staphylococcus aureus bacteremia.

OBJECTIVE: To estimate risk factors associated with long-term outcome (i.e., 1-year survival) in patients with Staphylococcus aureus bacteremia (SAB). METHODS AND MATERIALS: This was a retrospective study in which the microbiological laboratory data records of patients admitted to the University Hospital of Regensburg between January 2004 and June 2005 were examined to identify those patients with blood cultures positive for S. aureus. Corresponding clinical records for all patients were reviewed using a standardized questionnaire. Of the 119 patients identified with SAB, 80 were available for the >1-year follow-up. RESULTS: Crude 1-year mortality was 47.5; 30- and 90-day mortality was 28.8 and 37.5%, respectively. In-hospital mortality was 28.8%. There were no significant differences in 1-year survival in terms of age, gender, antibiotic resistance, and mode of acquisition (nosocomial vs. community-acquired). A significantly better survival was observed with an identifiable focus present, if the chosen empiric antibiotic therapy was adequate or if the body mass index of the patient was >24. CONCLUSION: In summary, in this patient cohort, considerable additional mortality due to SAB beyond 30 or 90 days was present. Our results suggest that long-term survival data should be taken into account in outcome studies involving patients with S. aureus bacteremia.

Single-nucleotide polymorphism in the SCCmec-orfX junction distinguishes between livestock-associated MRSA CC398 and human epidemic MRSA strains.

A number of real-time PCR assays for direct detection of methicillinresistant (MRSA) in clinical specimens are targeting staphylococcal cassette chromosome mec (SCCmec) right extremity sequences and the S. aureus chromosomal orfX gene sequences located to the right of the SCCmec integration site. When testing 184 MRSA strains of human and animal origin from geographically distinct locations, we identified several characteristic single-nucleotide polymorphisms (SNPs) within the SCCmec-orfX junction of livestock-associated (LA) MRSA CC398 which serve as suitable strain markers for screening purposes. Within an assay time of 60 minutes and an additional 10 minutes for the melting curve analysis, all MRSA CC398 isolates were correctly identified by their characteristic T(m) value in the commercial LightCycler MRSA Advanced test. Studies to confirm the diagnostic accuracy of the SNP-based strain identification assay with a larger collection of clinical and LA-MRSA strains are ongoing.

The effect of changes in core body temperature on the QT interval in beagle dogs: a previously ignored phenomenon, with a method for correction.

BACKGROUND AND PURPOSE: Body core temperature (Tc) changes affect the QT interval, but correction for this has not been systematically investigated. It may be important to correct QT intervals for drug-induced changes in Tc. EXPERIMENTAL APPROACH: Anaesthetized beagle dogs were artificially cooled (34.2 degrees C) or warmed (42.1 degrees C). The relationship between corrected QT intervals (QTcV; QT interval corrected according to the Van de Water formula) and Tc was analysed. This relationship was also examined in conscious dogs where Tc was increased by exercise. KEY RESULTS: When QTcV intervals were plotted against changes in Tc, linear correlations were observed in all individual dogs. The slopes did not significantly differ between cooling (-14.85+/-2.08) or heating (-13.12+/-3.46) protocols. We propose a correction formula to compensate for the influence of Tc changes and standardize the QTcV duration to 37.5 degrees C: QTcVcT (QTcV corrected for changes in core temperature)=QTcV-14 (37.5 - Tc). Furthermore, cooled dogs were re-warmed (from 34.2 to 40.0 degrees C) and marked QTcV shortening (-29%) was induced. After Tc correction, using the above formula, this decrease was abolished. In these re-warmed dogs, we observed significant increases in T-wave amplitude and in serum [K(+)] levels. No arrhythmias or increase in pro-arrhythmic biomarkers were observed. In exercising dogs, the above formula completely compensated QTcV for the temperature increase. CONCLUSIONS AND IMPLICATIONS: This study shows the importance of correcting QTcV intervals for changes in Tc, to avoid misleading interpretations of apparent QTcV interval changes. We recommend that all ICH S7A, conscious animal safety studies should routinely measure core body temperature and correct QTcV appropriately, if body temperature and heart rate changes are observed.

Virus-induced airway hyperresponsiveness in guinea pigs is related to a deficiency in nitric oxide.

Intratracheal inoculation of parainfluenza type 3 virus to guinea pigs induces a marked increase in airway responsiveness in vivo and in vitro. In spontaneously breathing anesthetized guinea pigs inhalation of an aerosol containing the nitric oxide (NO) precursor L-arginine (2.0 mM) completely prevented the virus-induced airway hyperresponsiveness to histamine. In addition, perfusion of L-arginine (200 microM) or the direct NO-donor S-nitroso-N-acetyl-penicillamine (SNAP, 1 microM) through the lumen of tracheal tubes from infected animals prevented the increase in airway responsiveness to histamine or the cholinoceptor agonist methacholine. The NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME, 120 microM) did not further increase the virus-induced airway hyperresponsiveness. In additional experiments, NO was measured with an Iso-NO nitric oxide meter and sensor. Stimulation of control tissues in vitro with histamine (10(-3) M) resulted in a contraction with a simultaneous release of NO (44.5 +/- 5.4 nM). The release of NO was markedly reduced by 75% (P < 0.01, 11.4 +/- 3.1 nM) in tracheas from virus-infected animals that demonstrated enhanced contractile responses. Preincubation of tissues from virus-treated guinea pigs with L-arginine (200 microM) completely prevented the enhanced contraction and simultaneously returned the NO production to control values (51.2 +/- 3.4 nM). An NO deficiency might be causally related to the development of airway hyperresponsiveness after a viral respiratory infection.

Comparative genomics and DNA array-based genotyping of pandemic Staphylococcus aureus strains encoding Panton-Valentine leukocidin.

Within the last few years, methicillin-resistant Staphylococcus aureus (MRSA) strains encoding Panton-Valentine leukocidin (PVL) have emerged and spread worldwide. This epidemic can be attributed to a small number of distinct clones. The present study used a novel assay, based on multiplex linear DNA amplification and subsequent microarray hybridisation, to simultaneously detect all relevant exotoxins, antimicrobial resistance determinants and the allelic variants of agr. The genes of the staphylococcal exotoxin-like (set) locus were also included for typing purposes. This assay, together with multilocus sequence typing (MLST) and spa typing, was applied to 56 clinical isolates and reference strains representing all major pandemic PVL-MRSA lineages, as well as to phylogenetically-related strains and putative ancestors. Array hybridisation results allowed the assignment of isolates to clonal groups, which were in accordance with MLST and spa typing data. Ten distinct clonal groups of PVL-MRSA (ST1, ST5, ST8, ST22, ST30, ST59/359, ST80/583, ST88, ST93 and ST152), including 12 MLST types, were identified and analysed with regard to resistance determinants and genes coding for exotoxins. The array hybridisation data confirmed that pandemic PVL-positive strains originate from very diverse genetic backgrounds, and provided insights into the evolution of some lineages. The DNA microarray technique provides a valuable epidemiological tool for the detailed characterisation of clinical isolates and comparison of strains at a global level.

Management of a large healthcare-associated outbreak of Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus in Germany.

We report the largest documented healthcare-associated outbreak of Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus (PVL(+) MRSA) in Europe. Six index patients from three long-term care facilities (LTCFs) were screened positive for PVL(+) MRSA in 2004 on admission to a community hospital in Germany. The purpose of this prospective study was to describe the prevalence of PVL(+) MRSA in the LTCFs before and after infection control interventions. Screening for MRSA with or without PVL was performed in all three LTCFs in 2004 [453 residents, 240 healthcare workers (HCWs)] and 2005 (440 residents, 192 HCWs). Swabs from anterior nares and wounds, if applicable, were collected. Colonised residents and staff were treated with mupirocin nasal ointment and topical antiseptics, and staff were provided with hygiene education. Total MRSA carrier rate of residents and HCWs in 2004 was 11.3% (PVL(+) MRSA 9.1%, PVL(-) MRSA 2.2%). There were comparable carrier rates between residents and HCWs in each LTCF. All PVL(+) MRSA isolates were of clonal origin (MLST 22) representing a novel spa sequence type t310. A decrease in total MRSA prevalence (from 11.3 to 5.5%) and PVL(+) MRSA (from 9.1 to 3.3%) was observed in 2005. The rate of PVL(-) MRSA remained unaffected. No symptomatic skin infections were noted among residents or HCWs. In this outbreak incomplete control of PVL(+) MRSA presumably resulted from difficult and delayed detection and decolonisation of carriers, incomplete compliance with control measures and lack of enforcement by public health authorities.

Potentiation by viral respiratory infection of ovalbumin-induced guinea-pig tracheal hyperresponsiveness: role for tachykinins.

1. We investigated whether virus-induced airway hyperresponsiveness in guinea-pigs could be modulated by pretreatment with capsaicin and whether viral respiratory infections could potentiate ovalbumin-aerosol-induced tracheal hyperresponsiveness. 2. Animals were inoculated intratracheally with bovine parainfluenza-3 virus or control medium 7 days after treatment with capsaicin (50 mg kg-1, s.c.). Four days after inoculation, tracheal contractions were measured to increasing concentrations of substance P, histamine and the cholinoceptor agonist, arecoline. 3. In tracheae from virus-infected guinea-pigs, contractions in response to substance P, histamine and arecoline were significantly enhanced (P < 0.01) by 144%, 46% and 77%, respectively. Capsaicin pretreatment inhibited the hyperresponsiveness to substance P partly (62%) and to histamine and arecoline completely. 4. In another series of experiments animals were first sensitized with ovalbumin (20 mg kg-1, i.p.). After 14 days animals were exposed to either saline or ovalbumin aerosols for 8 days. After 4 aerosol exposures (4 days) animals were inoculated with either parainfluenza-3 virus or control medium. One day after the last ovalbumin aerosol, tracheal contraction in response to increasing concentrations of substance P, histamine and arecoline was measured. 5. Tracheae from ovalbumin-aerosol-exposed control inoculated animals showed a similar degree of airway hyperresponsiveness to saline-aerosol-exposed virus-treated guinea-pigs. Virus inoculation of ovalbumin-treated animals significantly potentiated the tracheal contractions to substance P compared to either of the treatments alone. The contractions in response to histamine and arecoline were only slightly enhanced. 6. In conclusion, sensory nerves and/or tachykinins are involved in virus-induced airway hyperresponsivenessin guinea-pigs and viral respiratory infections can potentiate the increase in tracheal responsiveness to bronchoconstrictor agonists after ovalbumin exposure.

Factors that determine acetylcholine responsiveness of guinea pig tracheal tubes.

Acetylcholine administered to the inside of epithelium-denuded tracheal tubes did cause a potent contraction (2486+/-120 mg). In contrast, a response was hardly observed in tissues with an intact epithelial layer (674+/-81 mg), which was due to both the synthesis of nitric oxide and the activity of acetylcholinesterase, since the contractions to acetylcholine were significantly enhanced after preincubation with N(omega)-nitro-L-arginine methyl ester (L-NAME) or physostigmine (1374+/-65 and 1120+/-65 mg, respectively). In addition, the suppressive effect was caused by the barrier function of the epithelial layer, since preincubation of epithelium-denuded tissues with physostigmine significantly increased the pD2 value for acetylcholine (7.48+/-0.04) compared to intact tissues preincubated with physostigmine (6.32+/-0.10) and epithelium-denuded preparations without physostigmine (6.37+/-0.06). Increasing concentrations of physostigmine administered to the inside of tissues with epithelium did induce a potent spontaneous contraction (1440+/-350 mg) that was prevented by atropine. In contrast to what was expected, the contractile response was diminished in tracheal tubes without epithelium (665+/-221 mg). It is concluded that contractions of epithelium-denuded tissues are more pronounced to exogenous than to endogenous acetylcholine, and that the production and breakdown of this neurotransmitter is very rapid in intact guinea pig airways. Moreover, the release of nitric oxide and the barrier function of the epithelium did suppress the responsiveness to acetylcholine.

Induction of guinea pig airway hyperresponsiveness by inactivation of guanylate cyclase.

To examine the role of cyclic 3', 5'-guanosine monophosphate (cGMP) in airway responsiveness the effects of substances known to interfere with nitric oxide (NO) or cGMP were investigated on guinea pig airways. Using a perfused organ bath system, it was possible to apply the chemicals from either the serosal or the mucosal side independently. In addition, levels of intracellular cGMP were determined in tissues after various treatments. Sodium nitroprusside (a donor of NO), zaprinast (a specific inhibitor of cGMP phosphodiesterase) and 8-bromo-cGMP (8-Br-cGMP) caused a concentration-dependent relaxation of guinea pig trachea. These results indicate that cGMP is an important second messenger mediating tracheal relaxations. The above mentioned drugs caused a more profound relaxation when applied to the serosal side compared to the mucosal side, suggesting a barrier function of the epithelial layer. Incubation on the mucosal side of the tissues with 100 microM pyrogallol (a generator of superoxide that may inactivate NO) increased the contractile response to histamine at concentrations 0.3-3.2 microM (P < 0.05). Treatment of the preparations with 1 mM cystamine (an inactivator of guanylate cyclase) caused a 5-fold increase in the sensitivity to histamine (P < 0.05), indicating the involvement of the NO/cGMP pathway in the development of airway hyperresponsiveness. Incubation of the tissues with 100 microM histamine elevated the intracellular cGMP levels 10-fold; this effect was completely prevented by incubation of the tissues with methylene blue (a potent inactivator of guanylate cyclase). Mucosal incubation of the tracheal tubes with 10 microM methylene blue induced an 8-fold increase in sensitivity to histamine (P < 0.01) and the Emax was slightly increased. 25 min after instillation of 0.4 mumol methylene blue into the airways of anaesthetized guinea pigs, the lung resistance in response to histamine was elevated up to 395 +/- 82% (P < 0.001). The present study revealed that inactivation of NO or guanylate cyclase enhances the histamine-induced contractions of guinea pig tracheas. Therefore, it is suggested that the NO/cGMP pathway may be implicated in the pathogenesis of airway hyperresponsiveness and that drugs which enhance cGMP levels in airway smooth muscle may be of significance in the treatment of airway obstruction and enhanced reactivity.

Virus-induced airway inflammation and hyperresponsiveness in the guinea-pig is inhibited by levodropropizine.

Intratracheal Parainfluenza type 3 (PI-3) virus inoculation of guinea pigs leads to a non-specific airway hyperresponsiveness in vivo and in vitro which coincides with a significant increase in the number of inflammatory cells in the broncho-alveolar lavage fluid (90% increase, 4 days after inoculation). The activity of the bronchoalveolar cells, as measured by the chemiluminescence production of infected animals is significantly diminished (34.2%, 4 days after inoculation) after renewed stimulation with PI-3 virus in vitro as compared to the chemiluminescence production by bronchoalveolar cells obtained from control guinea pigs. Pretreatment of the guinea-pigs with the antitussive agent levodropropizine, administered intra-peritoneally twice a day for five successive days at a dose of 10 mg/kg, prevents the virus-induced airway hyperresponsiveness in vivo and in vitro, and inhibits the influx of broncho-alveolar cells. Levodropropizine at a dose of 1 mg/kg did not modulate these responses. Further, the decrease in chemiluminescence production of broncho-alveolar cells obtained from virus-infected animals after PI-3 virus stimulation in vitro was inhibited by levodropropizine (10 mg/kg). These data demonstrate the ability of levodropropizine to counteract the hyperresponsiveness phenomenon and the associated inflammatory event induced by PI-3 virus, an effect which may be due to its capacity to act on the peptidergic system or may be due to the anti-allergic/bronchoconstrictor property of this compound.

Diagnosis of infectious endophthalmitis after cataract surgery by polymerase chain reaction.

PURPOSE: To ascertain whether the use of the polymerase chain reaction (PCR) technique leads to more rapid diagnosis of infectious endophthalmitis after cataract surgery. SETTING: University Eye Clinic Regensburg, Germany. METHODS: The aqueous humor and vitreous of 16 eyes with infectious endophthalmitis (10 acute, 6 delayed) were evaluated by microscopy, diagnostic culture, and PCR to detect the infectious agent. RESULTS: Microscopy of the vitreous was positive in 3 eyes and the culture media results were positive in 7 eyes, all with acute endophthalmitis. Significantly fewer positive results were obtained in the aqueous humor. Using PCR, an infectious agent was detected in the aqueous humor of all 16 eyes and in the vitreous of 14. The vitreous sample was negative in 2 eyes with delayed endophthalmitis. CONCLUSIONS: Detection of the infectious agent was more successful using PCR than using conventional microbiological tests, especially in the diagnosis of delayed endophthalmitis where the pathogen was detected in the aqueous humor in all eyes.

Depression of tumor necrosis factor-alpha, interleukin-6, and interleukin-10 production: a reaction to the initial systemic hyperactivation in septic shock.

Sepsis remains a major cause of mortality in surgical intensive care units. Patients who survive the initial shock phase but die weeks later from multiple organ dysfunction still are a challenge to basic and clinical research. We addressed whether fulminant sepsis results in rapid changes (24 h) in the cellular capacity to produce cytokines in whole blood of septic patients on further stimulation after the initial systemic inflammatory response. Interleukin (IL)-6 plasma concentrations from 279 pg/mL to 5979 pg/mL confirmed the presence of a systemic inflammatory response. Anti-inflammatory IL-10 concentrations up to 275 pg/mL were detected, but there was no biologically active tumor necrosis factor-alpha (TNFalpha) detectable (by bioassay) at the time of investigation. On stimulation with Escherichia coli ex vivo, pro-inflammatory TNFalpha (130 pg/mL), IL-6 (4061 pg/mL), and anti-inflammatory IL-10 (711 pg/mL) production were markedly depressed in all patients compared with controls (2339 pg/mL, 50,319 pg/mL, and 9654 pg/mL, respectively). Septic shock resulted in early depression of the capacity for pro- and anti-inflammatory cytokine production. Monitoring of this effect, including its relationship to outcome, may offer a target variable for therapeutic efforts to maintain or restore adequate immune reactions to improve survival.

Disciforme keratitis caused by Bartonella henselae: an unusual ocular complication in cat scratch disease.

Cat scratch disease (CSD) is a common infectious disease, however, its association with disciforme keratitis is a previously unreported ocular complication. With the use of the 16S rDNA-PCR technique with subsequent DANN sequencing on corneal material obtained by corneal scrape we were able to identify Bartonella henselae in an unusual form of disciforme keratitis.

Listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy individual: rapid PCR-diagnosis as the basis for effective treatment.

PURPOSE: Listeria monocytogenes is a rare cause of endogenous endophthalmitis. To date 15 cases have been published in the literature. All eyes showed similar clinical features and profound visual loss mainly due to delayed diagnosis. METHODS: An additional case of an otherwise healthy 73 year-old male, who was referred to our hospital because of acute iridocyclitis with secondary glaucoma, is reported. Within a few days the severity of the intraocular infection increased dramatically, resulting in the clinical picture of acute endophthalmitis. RESULTS: In contrast to most published cases, early identification of the causative pathogen in the aqueous humor after anterior chamber puncture using polymerase chain reaction (PCR) and the initiation of a specific, systemic antibiotic medication, resulted in-complete recovery of visual acuity. CONCLUSIONS: PCR is very useful for the identification of the pathogen in intraocular infections.

Uptake and killing of Candida by human peritoneal macrophages and amphotericin B.

The effects of amphotericin B at subinhibitory and inhibitory concentrations on ingestion and intracellular killing of C. albicans ATCC 10,231 and C. tropicalis ATCC 13,803 by human peritoneal macrophages in vitro was investigated. Peritoneal macrophages were harvested from overnight peritoneal dialysate of 26 patients undergoing regular continuous ambulatory peritoneal dialysis (CAPD) using a new simple isolation technique. Macrophages were suspended with Candida (1:2-3) together with pooled human serum and with or without amphotericin B at various concentrations. Vital staining with acridine orange at a very low concentration using the metachromatic property of the dye allowed simultaneous assessment of ingestion and intracellular viability of the yeasts. Counts of Candida in 100 macrophages were performed at 1, 2, 3, 4, 6 and 24 h under a fluorescence microscope at 1000x and the ratios of living to dead intracellular Candida were calculated. Amphotericin B was added at concentrations of 0.1, 1 and 10 times the MIC. Ingestion was rapid and complete, while intracellular killing ranged from 4-69% for C. albicans and from 9-48% for C. tropicalis. Amphotericin B at 1 MIC enhanced the killing of C. tropicalis (factor 1.32) but reduced killing of C. albicans (factor 0.6) after 6 h.

Development and characterization of a murine monoclonal antibody reactive with a 64 kDa somatic antigen of Burkholderia cepacia.

Monoclonal antibodies (MAbs) to Burkholderia cepacia were produced from mice immunized with inactivated whole-cell antigen. For screening of resulting MAbs an enzyme-linked immunosorbent assay (ELISA) was used. A stable hybridoma cell line (BC-2) producing specific antibodies to a 64 kDa somatic antigen from B. cepacia was established. In ELISA and immunoblotting analysis the MAb BC-2 recognized all tested strains of B. cepacia whereas no cross-reaction with 32 Pseudomonas aeruginosa strains was found. From a wide range of other bacteria only strains of the species Burkholderia mallei, Burkholderia pseudomallei, and Burkholderia gladioli showed cross-reactions. The MAb BC-2 will be used to develop a diagnostic assay for the identification of B. cepacia and B. gladioli, important agents of nosocomial infections in immunocompromised patients suffering especially from cystic fibrosis (CF).

[Effects of restrictions on use of vancomycin in a German university hospital]. / Erfahrungen mit der Beschränkung des Einsatzes von Vancomycin an einem deutschen Universitätsklinikum.

BACKGROUND: Recently, increasing antibiotic resistance has been observed among gram-positive bacteria. However, only few isolates were found to be resistant against glycopeptides. Therefore, internationally accepted guidelines recommend a restricted use of vancomycin and other glycopeptide antibiotics in order to prevent the development of resistance against these clinically important antibiotics. In many countries, the hospital pharmacies play a key role in control and reinforcement of antibiotic formulary restrictions. In Germany, however, the hospital pharmacies usually do not take over such control functions, and most wards keep a stock of regularly used drugs including antibiotics, which makes reinforcement of restrictions difficult. METHODS: In an attempt to achieve a restriction of vancomycin use, the pharmacy of our university hospital was advised to deliver vancomycin to the wards only on request with a special order form signed by an attending, individually for every patient who should receive vancomycin. The efficacy of this restriction measure was evaluated in 3-month periods before and after the restriction became effective. RESULTS: Hospitalwide, this led to a 20.1% reduction of i.v. vancomycin and an 85.7% reduction of oral vancomycin use per 1000 patient days. If the hematology/oncology units were not considered, the reduction of i.v. vancomycin use was 41.8%, and the total use after the restriction 24.2 g per 1000 patient days. Microbiology results which justified the use of vancomycin decreased by 8.3% (10.9% hematology/oncology units not considered) between the 2 observation periods. Assuming a 7-day mean course of i.v. vancomycin therapy, the empirical use of i.v. vancomycin decreased from 39.9% to 8% after the restriction had been instituted. CONCLUSION: Allowing only experienced physicians (attendings) to decide on the use of vancomycin therapy, proved in our experience to be an effective measure to reduce unnecessary vancomycin use.