Lack of antimicrobial effect on periodontopathic bacteria by ultrasonic and sonic scalers in vitro.

BACKGROUND: The purpose of this study was to assess the antimicrobial effects of a sonic and ultrasonic scaler generally used for subgingival scaling on gram-negative and gram-positive periodontopathic bacteria. METHOD: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, or Peptostreptococcus micros were suspended in Schaedler's broth medium and treated by a sonic or a magnetostrictive ultrasonic scaler for 30 s and 150 s in vitro. Bacterial suspensions treated by an ultrasonic cell disruptor served as a positive control and untreated bacterial suspensions served as a negative control. Following sonication, samples were serially diluted, streaked on blood agar plates and incubated for 2-5 days at 37 degrees C. RESULTS: Treatment by the sonic or ultrasonic scaler for up to 150 s did not reduce the viability of any of the tested periodontal pathogens. Compared to untreated controls, the viability of A. actinomycetemcomitans and P. gingivalis was significantly (p<0.05) reduced only following ultrasonication with the cell disruptor after 30 s (0.72 and 0.54 log CFU/ml, respectively) and of A. actinomycetemcomitans, P. gingivalis, C. rectus, and P. micros after 150 s (1.98, 1.34, 1.95 and 1.98 log CFU/ml, respectively). CONCLUSION: The data of the study may indicate that the assessed sonic and ultrasonic scaler used for subgingival debridement do not result in killing of the tested periodontal pathogens.

The in-vitro activity of moxifloxacin against Legionella species and the effects of medium on susceptibility test results.

The in-vitro activities of moxifloxacin, ciprofloxacin, erythromycin and rifampicin against 49 Legionella spp. isolates were determined by an agar dilution method with buffered charcoal yeast extract agar containing alpha-ketoglutarate. Because the inhibitory effects of charcoal in the test media were pronounced (92% for quinolones, 90.5% for rifampicin and 92.5% for erythromycin), the MICs were corrected for the charcoal-bound fraction of the antibiotics. The corrected geometric mean MICs were 0.018 mg/L for moxifloxacin, 0.02 mg/L for ciprofloxacin, 0.27 mg/L for erythromycin and 0.005 mg/L for rifampicin.

A four-year review of fatal Aspergillosis.

To investigate the incidence, underlying diseases, and macropathological and microbiological features of invasive aspergillosis in a university hospital, the protocols of 1187 autopsies performed during the 4-year period 1993-1996 were reviewed. Invasive aspergillosis was diagnosed as the cause of death in 48 (4%) cases, four (8%) of which did not involve severe primary immunosuppression. In seven (15%) cases no pulmonary involvement was found; in six of these cases the portal of infection could not be established, whereas in one case invasive aspergillosis originated from Aspergillus peritonitis. Aspergillus grew in 42% of the samples obtained from the respiratory tracts of 32 patients with pulmonary aspergillosis and submitted within 10 days antemortem; at least one positive culture was obtained from 20 (63%) of these patients. It is concluded that the diagnosis of aspergillosis by means of culture has an appreciable sensitivity. Fatal invasive aspergillosis was rare among patients without severe immunosuppression, whereas invasive aspergillosis without pulmonary involvement was unexpectedly frequent.

Elimination of fecal Enterobacteriaceae by intravenous ciprofloxacin is not inhibited by concomitant sucralfate--a microbiological and pharmacokinetic study in patients.

Intravenously administered ciprofloxacin is partially secreted into the intestinal lumen and thereby eliminates fecal Enterobacteriaceae. Sucralfate inhibits the antimicrobial activity of ciprofloxacin by chelate binding. In a prospective study, we investigated the impact of intravenous ciprofloxacin on the intestinal microflora during oral administration of sucralfate. A total of 45 stool specimens were analyzed in 20 hospitalized patients who were treated with 200 mg of ciprofloxacin i.v. bid. Ten patients concomitantly received 1 g sucralfate p.o. tid (group A). After more than 3 days of i.v. ciprofloxacin, the mean fecal ciprofloxacin concentration was 185.3 +/- 158.7 micrograms/g in patients of group A and 108.7 +/- 76.9 micrograms/g in patients without concurrent sucralfate (group B). There was no significant difference in mean fecal ciprofloxacin levels between both groups (Wilcoxon's test). Enterobacteriaceae were below the threshold of detection (10(2) cfu/g) in all patients of group B after 3 days of treatment whereas small numbers were found in only 2 samples of patients of group A (10(4) cfu/g). Intravenous ciprofloxacin eliminates or largely reduces intestinal Enterobacteriaceae irrespective of concurrent administration of sucralfate.

Influence of intravenously administered ciprofloxacin on aerobic intestinal microflora and fecal drug levels when administered simultaneously with sucralfate.

Ciprofloxacin, when given intravenously (i.v.), is secreted in significant amounts via the mucosa into the intestinal lumen. Sucralfate inhibits the antimicrobial activity of ciprofloxacin. The effect of combined therapy on the intestinal flora was investigated in 16 healthy volunteers. They were randomly assigned to two groups. Group A received 2 g of sucralfate orally three times a day for 7 days and 400 mg of ciprofloxacin i.v. twice a day (b.i.d.) starting 3 days after the sucralfate administration began. Group B was given only 400 mg of ciprofloxacin i.v. b.i.d. for 4 days. A total of 9 stool samples were collected from each subject beginning the week before ciprofloxacin was administered and on days -1, 1, 2, 3, 4, 7, 9, and 10 or 11 after commencement of the infusion period. The aerobic fecal flora was determined by standard microbiological methods. Measurements of fecal ciprofloxacin levels were based on high-performance liquid chromatography. Counts of bacteria of the family Enterobacteriaceae decreased in all subjects and were below 10(2) CFU/g in eight of eight subjects (group A) and six of eight subjects (group B) on day 4, but they returned to normal in all but one subject (group A) 10 days after the last infusion. The decreases in levels of bacteria of the family Enterobacteriaceae were not significantly different in groups A and B (Kaplan-Meier test). Staphylococci and nonfermenters responded variably, enterococci and lactobacilli remained unchanged, and candida levels increased transiently in four subjects (two in each group). Maximum fecal drug levels ranged from 251 to 811 microg/g. No significant difference could be found between the two groups. The i.v. application of ciprofloxacin eliminates intestinal bacteria of the family Enterobacteriaceae in a rapid and selective manner. This effect is not affected by simultaneous oral application of sucralfate.

The prevention of anastomotic leakage after total gastrectomy with local decontamination. A prospective, randomized, double-blind, placebo-controlled multicenter trial.

OBJECTIVE: A prospective, randomized, double-blind, placebo controlled multicenter trial was undertaken in 205 patients treated with total gastrectomy for gastric malignancies to evaluate whether local antimicrobial measures reduce the incidence of esophagojejunal anastomotic leakage. SUMMARY BACKGROUND DATA: Anastomotic leakage of the esophagojejunostomy is always a septic complication of total gastrectomy for gastric malignancies, but it never has been attempted to prevent this complication with the administration of topical antimicrobial agents during the critical phase of anastomotic wound healing. METHODS: To evaluate the efficacy and safety of topical decontamination, the study was carried out as a prospective, randomized, double-blind and placebo-controlled clinical multicenter trial in patients with total gastrectomy for gastric cancer. Patients received either placebo or decontamination with polymyxin B (100 mg), tobramycin (80 mg), vancomycin (125 mg), and amphotericin B (500 mg) four times per day orally from the day before the operation until the seventh postoperative day. All patients received a perioperative intravenous prophylaxis with cefotaxime 2 x 2 g. Other interventions including the administration of antibiotics and fluids, were not affected by the study protocol. RESULTS: Of 260 patients who were randomized, total gastrectomy was not carried out in 55 patients. They dropped out of the study. Patients receiving an esophagojejunostomy were observed until day 42, when they were discharged from the clinic or died. An intention-to-treat analysis of the data was carried out. Among the 103 recipients of placebo, there were 11 (10.6%) with an anastomotic leakage of the esophagojejunostomy, and among the 102 recipients of decontamination, there were 3 (2.9%) with an anastomotic leakage of the esophagojejunostomy (p = 0.0492). Pulmonary infections were observed in 23 patients (22.3%) receiving placebo and in 9 patients (8.8%) who were decontaminated (p = 0.02). There were 11 deaths (10.6%) among the recipients of placebo and 5 deaths (4.9%) among the recipients of decontamination (p = 0.1). CONCLUSIONS: Decontamination with polymyxin, tobramycin, vancomycin, and amphotericin B during anastomotic wound healing is safe and effective in the prevention of esophagojejunal anastomotic leakage after total gastrectomy.

Decrease in nosocomial pneumonia in ventilated patients by selective oropharyngeal decontamination (SOD).

OBJECTIVE: To determine the influence of selective oropharyngeal decontamination (SOD) on the rate of colonization and infection of the respiratory tract in intensive care patients requiring mechanical ventilation for more than 4 days. A financial assessment was also performed. DESIGN: Randomized, prospective, controlled study using amphotericin B, colistin sulfate (polymyxin E), and tobramycin applied to the oropharynx and systemic cefotaxime prophylaxis. SETTING: Anesthesiology intensive care unit (ICU) of a 1500-bed hospital. PATIENTS: A total of 88 patients admitted as emergencies and intubated within less than 24 h were enrolled. Fifty-eight patients received SOD and 30 patients served as controls. Randomization was in the proportion of 2 : 1 study patients to controls. INTERVENTIONS: Microbiological samples from the oropharynx and other infected sites were taken at the time of admission, then twice a week and after extubation. MEASUREMENTS AND RESULTS: With the use of SOD, colonization was significantly reduced. Furthermore, the infection rate decreased from 77% in the controls to 22% in the study patients. Staphylococcus aureus was the main potential pathogen causing colonization and pneumonia. Number of days in the ICU, duration of ventilation, and mortality were not significantly decreased. The total cost of antibiotics was reduced. Development of resistance was not observed. CONCLUSIONS: The use of SOD significantly reduced the colonization and pneumonia and the total charge for antibiotics. The length of stay in the ICU, duration of ventilation, and mortality were similar. No resistance was observed. Staphylococcus aureus was selected by SOD in some patients and the clinical relevance needs further observation.

Postmortem analysis of invasive aspergillosis in a tertiary care hospital.

To estimate the incidence of fatal invasive aspergillosis in a 1500-bed tertiary-care hospital and to investigate the utility of laboratory diagnostic approaches, necropsy protocols and microbiological data from 1994 and 1995 were reviewed. Among 694 necropsies from 1693 patients who died in these two years, 27 (4%) cases of invasive aspergillosis were identified. Twelve cases of invasive aspergillosis were found after transplantation of solid organs, three after bone marrow transplantation, four in patients with haematological malignancies, and five in patients with solid tumours. In 15 cases (56%) invasive aspergillosis was not suspected before death. In patients in whom serum sampling was performed seven days antemortem, the Aspergillus latex agglutination test had a sensitivity of 53% (9/17). Culture of tracheal secretions or bronchoalveolar lavage fluid from patients with pulmonary aspergillosis yielded Aspergillus fumigatus in 88% (14/16).

Typing of Candida albicans by use of a combined PCR/hybridization assay.

A modified genotyping assay for Candida albicans based on the RAPD-PCR (random amplification of polymorphic DNA) is described. Following capillary blot of RAPD-PCR products onto a nylon membrane, hybridization with a PCR-generated gene probe resulted in heterogeneous band patterns. By this method the discriminatory power of RAPD-PCR is enhanced with satisfactory reproducibility and reduced interference.

Small intestinal myoelectrical activity and bacterial flora after Roux-en-Y reconstruction.

Small bowel myoelectrical activity and intestinal microflora were examined after partial gastrectomy and Roux-en-Y reconstruction in six dogs. Bacteriological analysis revealed a predominance of faecal bacteria. The basal electrical rhythm of the Roux limb was significantly decreased, while the frequency of phase III was increased (P < 0.05). In the bypassed duodenum, activity fronts occurred in only 25 per cent of experiments. Food intake led to an increase in the mean(s.e.m.) motility index in the Roux limb (from 46.1(9.4) to 75.0(21.5), P < 0.05), but not in the bypassed intestine (from 27.0(3.6) to 27.8(4.1), P not significant). Stimulation of the hypomotile bypassed intestine with cisapride induced an increase in the motility index from 27.0(3.6) to 111.2(16.5) (P < 0.001).

Evaluation of commercial kits for quantitative identification and tests on antibiotic susceptibility of genital mycoplasmas.

In this study, commercial media and kits for identification and tests for antibiotic susceptibility of genital mycoplasmas were evaluated in comparison to standardized methods. A total of 298 specimens was routinely enrolled. Our results showed that all media corresponded for qualitative and semiquantitative identification with a specificity of 100% for both microorganisms and a sensitivity of 94% for U. urealyticum and of 88% for M. hominis. Standard methods were superior to commercial kits for qualitative and quantitative identification (sensitivity 85-97% for U. urealyticum and 79-83% for M. hominis). There were large discrepancies when testing antibiotic susceptibility.

Polymerase chain reaction versus culture for detection of Ureaplasma urealyticum and Mycoplasma hominis in the urogenital tract of adults and the respiratory tract of newborns.

The efficiency of the polymerase chain reaction (PCR) was compared with that of culture for detection of Ureaplasma urealyticum and Mycoplasma hominis in 726 clinical specimens comprising 189 gynecological samples, 362 urological samples, and 175 samples from newborn infants. The sensitivity of PCR versus culture was 95% for both organisms, while the sensitivity of culture versus PCR was 91% for Ureaplasma urealyticum and 84% for Mycoplasma hominis. Furthermore, PCR tests were faster than culture tests, allowing the time to diagnosis to be reduced from two to five days to 24 h.

Chlamydia pneumoniae as a cause of community-acquired pneumonia in hospitalized patients in Berlin.

The incidence of community-acquired pneumonia due to Chlamydia pneumoniae was evaluated in a 1-year prospective study of 236 hospitalized patients with 237 manifestations of pneumonia. The microbiological diagnosis was based on results of cultures of blood and sputum or bronchoalveolar lavage fluid and results of complement fixation tests and indirect immunofluorescence of acute- and convalescent-phase sera for C. pneumoniae, Mycoplasma pneumoniae, Legionella species, Coxiella burnetii, and respiratory viruses. Diagnosis of acute C. pneumoniae infection was made on the basis of the results of microimmunofluorescence of paired serum samples. A microbiological diagnosis was obtained in 160 cases (67.5%). C. pneumoniae was the causative agent in 27 patients (11.4%). The following organisms were the other etiologic agents of pneumonia: Streptococcus pneumoniae, 30 cases (12.7%) (bacteremia occurred in 53.3%); Mycoplasma pneumoniae, 22 (9.3%); respiratory viruses, 22 (9.3%); and Enterobacteriaceae, 18 (7.6%). The prevalence of C. pneumoniae antibody in our study population was 47.5%. As has been increasingly reported in recent years and confirmed by this study, C. pneumoniae appears to be a common etiologic agent of community-acquired pneumonia and upper respiratory tract infection in Germany.

Cure of gastric ulcer disease after cure of Helicobacter pylori infection--German Gastric Ulcer Study.

BACKGROUND: Helicobacter pylori infection is associated with gastric ulcer disease in about 75% of cases. OBJECTIVE: The aim of this study was to determine whether H. pylori eradication reduces gastric ulcer relapse rates. DESIGN: The study was randomized, controlled, multicentric and investigator blinded, and was conducted at three university hospitals, two teaching hospitals, and by six practising gastroenterologists. METHODS: During a period of 1 year 152 patients with gastric ulcers were randomly assigned to one of two treatment regimens: omeprazole 20 mg daily in the morning for 8 weeks (74 patients), or bismuth subsalicylate 600 mg three times daily for 8 weeks combined with 500 mg amoxicillin twice daily and 1000 mg tinidazole twice daily for the first 10 days (triple therapy) (78 patients). Follow-up examinations were performed 6, 12 and 18 months after treatment and whenever ulcer symptoms occurred. RESULTS: Of the 152 randomized patients five were excluded because of gastric cancer, 10 missed follow-up examinations and seven receiving triple therapy terminated treatment because of side effects. Of the remaining 130 patients, five of 69 (7.2%) in the omeprazole and six of 61 (9.8%) in the triple group were H. pylori negative. After 8 weeks' therapy, the gastric ulcer was healed in 85.9% (omeprazole) and in 81.8% triple) in H. pylori-positive patients, and in 80% (omeprazole) and 16.7% (triple) in H. pylori-negatives. H. pylori was eradicated in 8.1% of the patients who received omeprazole monotherapy and in 78.2% receiving triple therapy, and in 8.1% and 69.4% in an intention-to-treat analysis. The subsequent relapse rates during a follow-up period of 12 months were 50% in the omeprazole group and 4% in the triple group. Gastric ulcer relapse was observed in 49% of patients who were H. pylori positive and in 2% who were H. pylori negative after treatment. CONCLUSION: The data show that the presence of H. pylori is an important predictor of gastric ulcer relapse and that eradication of H. pylori may heal gastric ulcer disease.

Methicillin-resistant Staphylococcus haemolyticus on the hands of health care workers: a route of transmission or a source?

We undertook a cross-sectional study of hand carriage and environmental contamination of methicillin-resistant coagulase-negative staphylococci on three wards of a single subspeciality surgical service. Sixteen hand cultures from 15 health care workers and 32 environmental cultures were obtained. Of 49 isolates, 35 (72%) were Staphylococcus haemolyticus. This species comprised 14 of the 16 (87%) hand isolates and 21 of the 32 (66%) environmental isolates. Using restriction length polymorphism of total DNA, we identified a single clone of S. haemolyticus on the hands of four health care workers and in the environment at seven locations on two wards. The widespread dissemination of a single clone suggests transmission of S. haemolyticus on the wards and prompts further prospective studies.

Enzyme immunoassay for detection of antibodies against isolated flagella of Legionella pneumophila.

Flagella of Legionella pneumophila serogroup 1, strain Philadelphia (ATCC 33152), were isolated and used as antigen to detect antibodies by enzyme immunoassay (EIA) in sera of patients with significant titers against Legionella as determined by the indirect immunofluorescence assay (IFA). Healthy blood donors served as a control group. Whereas the sera of blood donors were negative in both assays, sera of patients showed two patterns of reactivity. Sera with elevated titers against Legionella pneumophila serogroup 1 or Legionella gormanii in IFA usually demonstrated high titers in EIA. However, high IFA titers against Legionella bozemanii were associated with low titers in EIA. The data show that flagella protein of Legionella pneumophila serogroup 1 strain Philadelphia is of limited value for the detection of antibodies against Legionella other than Legionella pneumophila serogroup 1, although in vitro studies revealed genus-specific epitopes. This might be due to unpredictable variabilities in the expression of flagella in vivo.

The influence of the pH-value on the growth of Brevibacterium epidermidis in continuous culture.

Brevibacterium epidermidis is a major component of the bacterial flora of certain skin surface biotopes, characterized by a comparatively high pH-value. The presence of Brevibacterium epidermidis seems to be linked to the production of malodour. Skin surface pH has been found to be a major factor of bacterial growth on the skin. In order to find out if this might also apply to Brevibacterium epidermidis, this microorganism was grown in vitro in continuous culture using a chemostat. Specific growth rate and density of colony forming units were well correlated. While the organism grew readily from pH 5.5 to 8.5, this was not the case with a pH of 5.0. Thus pH-shifts induced by cosmetic procedures can only prevent unpleasant body odour due to abundant growth of bacteria if the pH-value is decreased to 5.0 or less.

Risk factors for systemic fungal infections in liver transplant recipients.

The risk factors for systemic fungal infections were analysed retrospectively in 186 orthotopic liver transplant procedures performed in 152 patients between June 1985 and January 1993. The total incidence of systemic fungal infections was 16.5% (25/152). The incidence of disseminated candidiasis, aspergillosis, and combined candidiasis and aspergillosis was 6.5% (n = 10), 7.2% (n = 11) and 2.6% (n = 4), respectively. Mortality associated with systemic fungal infections was 80% (20 of 25 patients). There were ten cases of disseminated candidiasis, with 4 patients surviving, and 11 cases of invasive aspergillosis, with 1 patient surviving. All patients with combined systemic fungal infection died. To identify perioperative risk factors, 39 variables were used to compare patients with systemic fungal infections versus those without fungal infections. Fourteen variables were significantly associated with systemic fungal infections by univariate analysis. A consecutive logistic regression analysis revealed that the amount of fresh frozen plasma transfused due to poor initial function of the allograft and acute renal failure requiring hemofiltration were independently significant risk factors for systemic fungal infections. There was no statistical correlation between systemic fungal infections and the underlying liver disease, previous long-term corticosteroids and the postoperative immunosuppressive therapy. Risk factors identified in this study should be considered in the postoperative care of the individual liver transplant recipient. In our study a poor initial function of the hepatic allograft substantially increased the risk of systemic fungal infection.

Two-year follow-up of duodenal ulcer patients treated with omeprazole and amoxicillin.

The present study evaluated the time in remission during a 2-year follow-up after eradication of Helicobacter pylori (HP) in patients with an HP-associated duodenal ulcer (DU). HP was eradicated by combined treatment with high-dose omeprazole (2 x 40 mg) and amoxicillin (2 x 1,000 mg; n = 27) administered for 10 days (OME + AMX); alternatively, patients were treated with omeprazole monotherapy (OME) using the same dosage (n = 25). During the 2-year follow-up period endoscopy including histological examination was performed after 1 and 2 years or whenever symptoms compatible with ulcer relapse occurred. HP eradication was achieved in 82% of the OME + AMX group, but in 0% of the OME group. The cumulative DU relapse rates were 0% after 1 year and 7% after 2 years in 22 patients who became HP-negative. Both HP-negative patients who relapsed in the 2nd year of follow-up were HP-positive again at the time of relapse. Of the 5 patients who were not eradicated after OME + AMX therapy, 2 relapsed within the 1st year (40%) and another 2 within the 2nd year (80%). In the OME group the cumulative relapse rates within 1 and 2 years of follow-up were 52 and 76%, respectively. The results further confirm that eradication of HP with combined OME + AMX treatment leads to a distinct decrease in DU relapse rates and thus may cure DU disease. Long-term eradication with combined OME + AMX treatment is possible, and the rate of reinfection with HP is low (4.5%/year).