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R Auckenthaler

Publications and source records attributed to R Auckenthaler.

At least 19 recordsLinked to original sources
PubMed1992

[Typing and sensitivity of meningococci isolated in Switzerland 1988-1990].

Since 1906 severe infections due to Neisseria meningitidis have been reported in Switzerland. The clinical application of antimicrobial agents reduced the mortality rate due to meningococcal infections from 82% before 1939 to 22% after 1942. However, the annual incidence remained at about 1.5 cases per 100,000 inhabitants. During the years 1988 to 1990, 177 strains isolated in Switzerland have been typed with a dot ELISA using 15 different monoclonal antibodies. The distribution of serogroups was as follows: A (0.6%), B (70.6%), C (22.6%), and W135 (0.6%), while 5.6% could not be assigned to a serogroup. The most common associations of serogroup, serotype and subtype were: B:15:P1.16 (15.3%), B:4:P1.15 (13.6%), and C:2a:P1.2 (9.0%). The susceptibility of 174 strains was determined by an agar-dilution procedure. All strains were susceptible to cefuroxime, ceftriaxone, ciprofloxacin, minocycline and spiramycin. One strain showed reduced sensitivity to penicillin (MIC = 0.25 mg/l), while another strain was resistant to rifampicin, 3% were resistant of erythromycin and 75% to sulfadiazine.

Drug Resistance, Microbial↗
PubMed1992

Comparative in-vitro activity of new quinolones against clinical isolates and resistant mutants.

The in-vitro activity of five new fluoroquinolones, WIN 57273, sparfloxacin, fleroxacin, temafloxacin and ciprofloxacin was determined against 543 recent clinical isolates and eight quinolone resistant strains derived by mutation and their five parent strains. WIN 57273 was the most active compound against Gram-positive bacteria, sparfloxacin had a broad spectrum which was similar to that of ciprofloxacin. Ciprofloxacin showed the greatest activity against Gram-negative bacteria. Temafloxacin showing some activity against Gram-positive organisms and Acinetobacter spp. Fleroxacin was the least active compound studied. Compared to wild type parent strains, the mutated strains produced the following results. In Enterobacter cloacae OmpF deficiency increased the MICs of all quinolones by 8-32-fold. In Pseudomonas aeruginosa OmpF deficiency had a limited effect, Omp D2 deficiency combined with an increased lipopolysaccharide content produced greater resistance, i.e. 4-16-fold; mutations in gyrase were associated with variously increased MICs, depending on the strain and compound tested.

4-Quinolones↗
PubMed1992

In-vitro and in-vivo evaluation of the antistaphylococcal activity of S-5556, a new 16-membered macrolide.

During recent years, a resurgence of interest in the macrolides had led to the discovery of new derivatives of erythromycin with improved antibacterial activity and pharmacokinetic properties. In this study the in-vitro and in-vivo antistaphylococcal activity of S-5556, a 16-membered macrolide, was evaluated. In vitro, S-5556 was slightly less active than erythromycin against methicillin-susceptible Staphylococcus aureus. In contrast, it had superior activity for methicillin-resistant S. aureus (MRSA); several of these strains with inducible resistance to the macrolides-lincosamides-streptogramins group were susceptible to S-5556 whereas erythromycin was inactive. The combination of S-5556 with oxacillin was synergic for most MRSA strains tested. In vivo, a single prophylactic dose of S-5556 prevented 75%-100% of the cases of acute staphylococcal subcutaneous foreign body infection in a guinea pig-model. In a rat-model of chronic implant infection due to a methicillin- and erythromycin-resistant S. aureus strain, S-5556 significantly decreased the bacterial concentration around the foreign material, however resistant mutants emerged.

Animals↗
PubMed1992

Evaluation of the Wellcolex Colour Salmonella Test for detection of Salmonella spp. in enrichment broths.

The Wellcolex Colour Salmonella Test was evaluated for detection of Salmonella spp. in enrichment broths of 1,010 stool samples. In 39 specimens, Salmonella spp. could be isolated from the selenite F broth (SF). Wellcolex agglutination indicative of the presence of Salmonella spp. was noted with the SF in 36 cases, 34 of which were in agreement with the subculture results. Therefore, relative to subculture, the sensitivity and specificity of the Wellcolex-selenite F procedure were 87 and 99%, respectively. Five false-negative results were noted. The gram-negative broth (GN) subculture revealed only 23 Salmonella spp. (59% sensitivity). The Wellcolex agglutination procedure applied to the GN indicated Salmonella spp. for 21 samples; its sensitivity was 70% and its specificity was 99% compared with GN subcultures. The Wellcolex agglutination procedure applied to the SF performed better than the agglutination of GN or direct plating procedures and detected 17 of the 39 Salmonella spp. at least 24 h earlier than did culture.

Bacteriological Techniques↗
PubMed1992

Rapid diagnosis of gram negative pneumonia by assay of endotoxin in bronchoalveolar lavage fluid.

BACKGROUND: Diagnosis of ventilator associated pneumonia can be made by quantitative cultures of bronchoalveolar lavage fluid or of protected specimen brushings, though cultures require 24-48 hours to provide results. In 80% of cases aerobic Gram negative bacteria are the cause. METHODS: A rapid diagnostic method of assessing the endotoxin content of lavage fluid by Limulus assay is described. Forty samples of lavage fluid were obtained from patients with multiple trauma requiring mechanical ventilation for a prolonged period. Pneumonia was diagnosed on the basis of clinical, radiological, and bacteriological findings, including quantitative cultures of lavage fluid. RESULTS: A relation was observed between the concentration of endotoxin in lavage fluid and the quantity of Gram negative bacteria. The median endotoxin content of lavage fluid in Gram negative bacterial pneumonia was 15 endotoxin units (EU)/ml; the range observed in individual patients was 6 to > 150 EU/ml. In patients with pneumonia due to Gram positive cocci and in non-infected patients the median endotoxin level was 0.17 (range < or = 0.06 to 2) EU/ml. An endotoxin level greater than or equal to 6 EU/ml distinguished patients with Gram negative bacterial pneumonia from colonised patients and from those with pneumonia due to Gram positive cocci. CONCLUSION: The measurement of endotoxin in lavage fluid is a rapid (less than two hours) and accurate diagnostic method. It should allow specific and early treatment of Gram negative bacterial pneumonia.

Bronchoalveolar Lavage Fluid↗
PubMed1992

[Common cold: diagnostic steps? Antibiotics?].

The common cold is caused by more than 100 virus types. However, the clinical manifestation is always similar with rhinorrhea, stuffiness, sneezing, pharyngitis, laryngitis and cough. The local inflammatory reactions are not due to the presence of virus but caused by locally produced inflammatory mediators. Bacterial superinfections may cause otitis or sinusitis. Bacterial nasopharyngitis has been described in children. This entity possibly exists also in adults. Traditional viral cultures are rarely positive and are not recommended in the daily routine. In children, antigen detection for adenovirus, respiratory syncytial virus, parainfluenza and influenza virus are recommended to confirm the viral etiology or for epidemiological surveillance. The presence of group-A streptococci must be proven by culture or antigen detection before treatment with penicillin. Antiviral treatment is limited to interferon or ribavirin. New antiviral substances are in development. Today, treatment of common cold is limited to symptomatic measures, and antibiotic treatment is not justified.

Adult↗
PubMed1991

Contour-clamped homogeneous electric field gel electrophoresis as a powerful epidemiologic tool in yeast infections.

To examine the longitudinal and cross-sectional patterns of yeast colonization in critically ill patients using genotypic characteristics defined by contour-clamped homogeneous electric field (CHEF) gel electrophoresis, 322 clinical isolates of Candida species were prospectively collected from 29 critically ill patients under routine surveillance over a 6-month period. All isolates, recovered from multiple anatomic sites and from the same sites on different days, were characterized by several identification methods (germ tube test), phenotyping (API system), and genotyping (electrophoretic karyotyping). Electrophoretic karyotype (EK) was determined using pulsed field electrophoresis with the CHEF technique. We used a karyotyping system for Candida albicans (EK code) that facilitated intraspecies delineation. C. albicans colonized 83% of the 29 patients. Candida sp. strains isolated from an individual patient had an identical EK pattern, even when isolated from different body sites, and remained the same over a prolonged period, up to 140 days. EK delineated not only the different Candida species, but also different strains of C. albicans. Strains of C. albicans isolated from different patients were distinguished using the EK pattern, but not API system. Minor variations in EK pattern could be demonstrated in a minority of strains recovered from four patients and were interpreted as chromosomal rearrangements between parent strains. Severe candidal infections, including eight episodes of fungemia, occurred in 11 of 29 patients (38%). All patients had been previously colonized with strains with identical EK patterns. Infection occurred a mean of 25 days after initial surveillance cultures grew yeast. No horizontal transmission could be demonstrated during the study period. In conclusion, EK is a reproducible, stable marker allowing inter-, as well as, intraspecies Candida strain delineation. EK strain delineation is a useful tool in candidal epidemiologic and pathogenic studies. Yeast colonization with the same strain preceded infection in critically ill patients.

Adolescent↗
PubMed1991

Evaluation of the new improved BHI-lysis blood culture medium for the BCB Roche system.

The new BHI-lysis blood culture medium for the BCB system (BCB release, Hoffmann-La Roche), which lyses blood cells, was compared with the BHI-S broth of the same BCB system and the Signal system (Oxoid). A total of 2394 sets consisting of three bottles were each inoculated with 7 ml of blood at the bedside. In the laboratory agar-coated paddles were attached to the BHI-lysis and the BHI-S bottles, and the Signal device was mounted onto the Oxoid bottle. All systems were incubated at 35 degrees C for seven days. Of the 309 (13%) positive sets, 73 (3%) were contaminated and in 242 (10%) sets a total of 250 pathogenic microorganisms were isolated. These could be grown significantly more often from the BHI-lysis bottle (n = 213) than from either the BHI-S (n = 189) or Signal bottle (n = 176). No significant differences in the time needed to achieve a positive result was noted between the BHI-lysis and BHI-S bottles, but comparison of the BHI-lysis and Signal bottles revealed that overall pathogens were detected earlier significantly more often with the BHI-lysis bottle. In view of the good performance of blood culture broths containing lysing agents, their wider use is warranted in future.

Adult↗
PubMed1991

Osteoarticular infections due to Kingella kingae in children.

By the description of two cases of osteoarticular infections due to Kingella kingae in two young children we wish to draw the attention of clinicians to invasive infections due to this micro-organism. Since its biological characterization in 1976, K. kingae has been increasingly reported as a human pathogen. Most common presentations are endocarditis, bacteraemia, septic arthritis, osteomyelitis and spondylodiscitis. Interestingly, osteorticular involvement is largely predominant in previously healthy children. From the literature, we reviewed 51 cases of K. kingae bone and joint infections, representing 23 cases of septic arthritis, 17 of osteomyelitis and 11 spondylodiscitis. Of the cases 88% occurred in children below 5 years of age and in all cases only one bone or joint was involved. An underlying disorder could be found in only 4 patients. Since these infections have a favourable outcome with intravenous antibiotic treatment, proper isolation and identification of K. kingae is essential.

Arthritis, Infectious↗
PubMed1991

Diagnosis of ventilator-associated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic "blind" bronchoalveolar lavage fluid.

Substantial efforts have been devoted to improving the means for early and accurate diagnosis of ventilator-associated (VA) pneumonia in intensive care unit (ICU) patients because of its high incidence and mortality. A good diagnostic yield has been reported from quantitative cultures of bronchoalveolar lavage (BAL) fluid or a protected specimen brush, both obtained by fiberoptic bronchoscopy. As bronchoscopy requires specific skills and is costly, we evaluated a simpler method to obtain BAL fluid, that is, by a catheter introduced blindly into the bronchial tree. Quantitative cultures from bronchoscopically sampled BAL (B-BAL) and blindly nonbronchoscopically collected BAL (NB-BAL) were assessed for sensitivity, specificity, and predictive value for the diagnosis of VA pneumonia. A total of 40 pairs of samples were examined in 28 patients requiring prolonged mechanical ventilation and presenting a high risk of developing pneumonia. For comparison with bacteriologic data we defined a clinical score for pneumonia ranging from zero to 12 using the following variables: body temperature, leukocyte count, volume and character of tracheal secretions, arterial oxygenation, chest X-ray, Gram stain, and culture of tracheal aspirate. To quantify the bacteria in BAL the bacterial index (BI) was used, defined as the sum of the logarithm of the number of bacteria cultured per milliliter of BAL fluid. A good correlation between clinical score and quantitative bacteriology was observed (r = 0.84 for B-BAL and 0.76 for NB-BAL; p less than 0.0001). Similar to studies in baboons, patients with pulmonary infection could be distinguished by a BI greater than or equal to 5 with a sensitivity of 93% and a specificity of 100% (B-BAL).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Mode of presentation and diagnosis of bacterial pneumonia in human immunodeficiency virus-infected patients.

Bacterial pneumonia (BP) has recently been reported to be more frequent in human immunodeficiency virus (HIV)-infected patients than in normal hosts. This study reviews the clinical and radiologic manifestations of BP in 132 consecutive pulmonary episodes over a 15-month period. BP was defined on a clinical basis as a pulmonary infiltrate accompanied by fever and improving in a few days with conventional antibiotics (trimethoprim-sulfamethoxazole excluded). In patients undergoing bronchoscopy (97 procedures), semiquantitative cultures and cell differentials of bronchoalveolar lavage (BAL) were performed, in addition to conventional staining and cultures for opportunistic infections. BP were frequent (45%), and the usual community-acquired pathogens were found. The radiologic manifestations of BP were often unusual, however, and 47% were indistinguishable from the typical appearance of Pneumocystis carinii pneumonia. BAL cultures had a sensitivity of 83 or 23%, depending on whether antibiotics were administered before bronchoscopy, using a cutoff value of greater than or equal to 10(4) bacteria/ml. The specificity of BAL culture was of 80.5% if patients with P. carinii pneumonia were taken as a control group. We conclude that BP is frequently encountered in HIV-infected patients. The clinical and radiologic presentation of BP may be indistinguishable from that of opportunistic infections. Semiquantitative cultures of BAL appear a valuable diagnostic tool to avoid unnecessary invasive diagnostic procedures or treatments.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Resistance of Staphylococcus aureus recovered from infected foreign body in vivo to killing by antimicrobials.

Because persistence of infections associated with prosthetic material despite the use of appropriate antibiotics is a major clinical problem, the antimicrobial susceptibility of bacteria responsible for a chronic subcutaneous tissue cage infection in rat was investigated ex vivo. Three to 6 weeks after the initiation of infection, suspensions of two strains of Staphylococcus aureus recovered from the foreign body surface and surrounding fluid were exposed to either oxacillin, vancomycin, fleroxacin, gentamicin, or rifampin. The MBCs of these bacteria were markedly elevated, in most cases 128 to greater than 256 times higher than the MBC of batch culture S. aureus in either logarithmic or stationary phase. Kinetic studies showed the bacteria did not grow when incubated for 2 h in Mueller-Hinton broth, possibly reflecting dormancy. Their killing was slow and incomplete by all antibiotics at greater than 8 times their MIC. These data provide direct evidence of a decreased susceptibility of S. aureus to the killing effect of antimicrobials during chronic foreign body infections in vivo.

Animals↗
PubMed1990

A comparison of ceftriaxone and cefuroxime for the treatment of bacterial meningitis in children.

To compare ceftriaxone with cefuroxime for the treatment of meningitis, we conducted a study in which 106 children with acute bacterial meningitis were randomly assigned to receive either ceftriaxone (100 mg per kilogram of body weight per day, administered intravenously once daily; n = 53) or cefuroxime (240 mg per kilogram per day, administered intravenously in four equal doses; n = 53). The mean age of the children was 3 years (range, 42 days to 16 years), and the characteristics of the two treatment groups were comparable at admission. Excluded from the study were eight other children who died within 48 hours of admission. After 18 to 36 hours of therapy, cultures of cerebrospinal fluid remained positive for 1 of the 52 children (2 percent) receiving ceftriaxone for whom cultures were available and 6 of 52 (12 percent) receiving cefuroxime (P = 0.11). In both groups the mean duration of antibiotic therapy was 10 days. The clinical responses to therapy were similar in the two treatment groups, and all 106 children were cured. Reversible biliary pseudolithiasis was detected by serial abdominal ultrasonography only in the children treated with ceftriaxone (16 of 35 vs. 0 of 35; P less than 0.001). The treatment of three children was switched from ceftriaxone to alternative antibiotics because these children had upper abdominal pain. Other side effects were infrequent in both groups. At follow-up examination two months later, moderate-to-profound hearing loss was present in two children (4 percent) treated with ceftriaxone and in nine (17 percent) treated with cefuroxime (P = 0.05); other neurologic abnormalities were similar in the two treatment groups. We conclude that ceftriaxone is superior to cefuroxime for the treatment of acute bacterial meningitis in children and that the benefits of milder hearing impairment and more rapid sterilization of the cerebrospinal fluid with ceftriaxone outweigh the problem of reversible biliary pseudolithiasis with this drug.

Adolescent↗
PubMed1990

Evaluation of two ELISA tests for the rapid detection of group A streptococci.

We examined 579 oropharyngeal swab specimens from children presenting with pharyngitis in order to compare two rapid diagnostic ELISA tests for group A streptococcal antigen: the TestPack Strep A (TPSA), and the Direct Strep A EIA (DSAE), with an anaerobically incubated sheep blood agar culture. The sensitivities of the methods were respectively 60.8% (TPSA) and 64.4% (DSAE), the specificities 98.3% (TPSA) and 93.2% (DSAE), the positive predictive values 88.6% (TPSA) and 70.3% (DSAE) and the negative predictive values 92.0% (TPSA) and 91.2% (DSAE). We conclude that the TPSA is easy to interpret and is sufficiently specific to initiate treatment in patients with a positive test. It is not sufficiently sensitive to ensure negative or intermediate results. The performance of the DSAE test is similar but the specificity is slightly lower and more false positive results occur.

Chi-Square Distribution↗
PubMed1990

International collaborative evaluation of the ATB 32 staph gallery for identification of the Staphylococcus species.

This international collaborative study evaluates a new system (ATB 32 Staph) for the identification of staphylococci taking into account the new novobiocin-sensitive and -resistant species reported. This study involved eight laboratories and 792 strains were tested. The reproducibility obtained for the cumulative results of the inter- and intra-laboratory tests was more than 90%. For 713 strains relevant of a species 95.5% were correctly identified by the system. Eight strains (1.2%) were misidentified and 24 strains (3.3%) were not identified. For 79 strains initially considered as not-classified, 62% were identified at the species level by the new system. The newer ATB 32 Staph gallery is a performant and useful method for routine identification of the currently described staphylococci species from clinical and animal origin.

Animals↗
PubMed1990

Absence of significant bacteremia during urinary catheter manipulation in patients with chronic indwelling catheters.

The objective of this study was to quantify the microorganisms present in blood at urinary catheter removal and at reinsertion in patients with chronic indwelling urinary catheters. This was a prospective study during a 4-month period at a university-affiliated geriatric medical center. Our subjects were 33 patients with chronic indwelling urinary catheters and positive urinary cultures; the urinary catheter was usually changed once a month. A peripheral vein line was used for blood withdrawal and urinary cultures and quantitative blood cultures (Isolator) were performed during and shortly after urinary catheter removal and insertion. All patients had significant bacteriuria (greater than 10(5) cfu/mL) with an average of 2.3 microorganisms. Among the 46 sequential quantitative blood cultures performed, only two patients had bacteremia from the urinary source and at a very low concentration; one patient had 0.13 cfu/mL Str. faecalis in blood 5 minutes after removal of the urinary catheter, and the other 0.1 cfu/mL Proteus mirabilis 5 minutes after reinsertion of a new urinary catheter. None of the patients had any subjective or objective clinical problem during the 36 hours after the urinary manipulation. Clinical symptoms and bacteremia are rare events, and prophylactic antibiotics do not appear necessary during urinary catheter removal and reinsertion in elderly institutionalized patients. Further studies are necessary to identify risk factors in the rare instances of patients with bacteremia.

Aged↗
PubMed1990

Treatment of experimental foreign body infection caused by methicillin-resistant Staphylococcus aureus.

A novel model of experimental foreign body infection was developed in rats: four perforated Teflon tissue cages per animal were implanted subcutaneously and 3 to 4 weeks later were infected with 0.5 x 10(5) to 2 x 10(5) CFU of methicillin-resistant Staphylococcus aureus. After 2 weeks, the number of CFU in the cage fluid was determined [day 1 mean, (7.25 +/- 0.79) log10 CFU/ml], and treatment with vancomycin (50 mg/kg twice a day [BID]), fleroxacin (50 mg/kg BID), or fifampin (25 mg/kg BID), alone and in combination, was initiated for a duration of 6 days. Concentrations of antibiotics in cage fluids were in the range of those encountered in clinical conditions. Eighteen hours after the last injection (day 7), the number of CFU in the cage fluid was determined and the difference between day 1 and day 7 values was calculated. Rifampin, alone and in combination with fleroxacin or vancomycin, was the most effective regimen in reducing the bacterial counts in the tissue cage fluids [(1.87 +/- 1.44, 2.18 +/- 1.02, and 2.55 +/- 1.09 log10) CFU/ml, P less than 0.001, respectively]. After treatment, cage fluids and cages were analyzed for resistant bacteria. Resistance to rifampin occurred in 15 of 19 cages in animals treated with rifampin alone and in 4 of 25 in animals treated with rifampin plus vancomycin. We detected no development of resistance to rifampin in animals treated with rifampin plus fleroxacin or to fleroxacin in animals treated with this antimicrobial agent. In conclusion, regimens including rifampin alone or in combination with vancomycin or fleroxacin were an effective treatment of foreign body infection due to methicillin-resistant S. aureus in reducing bacteria counts, but rifampin monotherapy was compromised by significant emergence of resistance. The combined therapy of fleroxacin with rifampin prevent development of resistance to rifampin.

Animals↗