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A C Rodloff

Publications and source records attributed to A C Rodloff.

At least 37 records · Page 2Linked to original sources
PubMed2001

Electroporation of DNA sequences from the pathogenicity locus (PaLoc) of toxigenic Clostridium difficile into a non-toxigenic strain.

Toxigenic Clostridium difficile is the etiologic agent of C. difficile-associated diarrhoea (CDAD), the most common cause of hospital-acquired infectious diarrhoea. The genes tcdA and tcdB, which encode for the toxin A and B proteins, are part of the pathogenicity locus (PaLoc) of toxigenic C. difficile. Genetic and virulence studies at the molecular level in C. difficile have been hindered by the lack of techniques for DNA manipulation in this species. We describe the electroporation of DNA fragments from a toxigenic isolate into a non-toxigenic strain of C. difficile. Using previously described methods of electroporation into Clostridium spp., the complete toxin B gene and polymerase chain reaction (PCR) fragments of the PaLoc were cloned and electroporated into a non-toxigenic strain of C. difficile. The resulting transformed clones were screened for the introduced gene fragments by PCR, which confirmed their presence. This is the first description of introduction of DNA into C. difficile by electroporation.

Bacterial Proteins↗
PubMed2001

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.

Adult↗
PubMed2001

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.

Adrenal Cortex Hormones↗
PubMed2001

Isolation of Clostridium innocuum from cases of recurrent diarrhea in patients with prior Clostridium difficile associated diarrhea.

Clostridium innocuum isolates resistant to vancomycin (MIC values of 16-24 microg/mL) were isolated from three patients with recurrent Clostridium difficile -associated diarrhea (CDAD). We discuss the clinical significance and problems associated with the identification and differentiation of these two clostridial species, which may result in misdiagnosis of patients.

Clostridioides difficile↗
PubMed2001

Interpretive criteria of ceftibuten disk diffusion susceptibility tests according to the DIN 58 940 method.

OBJECTIVE: This study aimed to establish interpretive criteria for agar diffusion tests with ceftibuten disks according to DIN standards. METHODS: Minimal inhibitory concentrations (MICs) and inhibition zones produced by ceftibuten in the disk diffusion test were determined for 275 recent bacterial isolates, including 11 species with 25 strains each. Regression analysis was performed for two disk loads (10 microg and 30 microg). RESULTS: Correlation of MICs and zone diameters was good, with correlation coefficients of r = - 0.97 for both tested disk loads. Evaluation of the calculated zone size criteria for all species showed no very major discrepancies or no major discrepancies. The 30-microg disks, however, produced unacceptably large inhibition zones for very susceptible strains, so that usage of 10-microg disks must be recommended when testing according to DIN standards. CONCLUSION: Based on the MIC breakpoints recommended by the DIN (> or =8 mg/L and < or = 1 mg/L), the following interpretive breakpoints for disk diffusion susceptibility tests with 10-microg ceftibuten disks were calculated using regression line analysis: < or =19 mm for resistance and > or = 27 mm for susceptiblity. Proposed inhibition zone diameters for the reference strain Escherichia coli ATCC 25922 are between 31 and 36 mm.

Bacteria↗
PubMed2001

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.

Anti-Bacterial Agents↗
PubMed2001

Resistance to moxifloxacin in toxigenic Clostridium difficile isolates is associated with mutations in gyrA.

Clostridium difficile is the etiological agent of antibiotic-associated colitis and the most common cause of hospital-acquired infectious diarrhea. Fluoroquinolones such as ciprofloxacin are associated with lower risks of C. difficile-associated diarrhea. In this study, we have analyzed 72 C. difficile isolates obtained from patients with different clinical courses of disease, such as toxic megacolon and relapses; the hospital environment; public places; and horses. They were investigated for their susceptibilities to moxifloxacin (MXF), metronidazole (MEO), and vancomycin (VAN). Mutants highly resistant to fluoroquinolones were selected in vitro by stepwise exposure to increasing concentrations of MXF. The resulting mutants were analyzed for the presence of mutations in the quinolone resistance-determining regions of DNA gyrase (gyrA), the production of toxins A and B, and the epidemiological relationship of these isolates. These factors were also investigated using PCR-based methods. All strains tested were susceptible to MEO and VAN. Twenty-six percent of the clinical isolates (19 of 72) were highly resistant to MXF (MIC > or = 16 microg/ml). Fourteen of these 19 strains contained nucleotide changes resulting in amino acid substitutions at position 83 in the gyrA protein. Resistant strains selected in vitro did not contain mutations at that position. These findings indicate that resistance to MXF in a majority of cases may be due to amino acid substitution in the gyrA gene.

Anti-Infective Agents↗
PubMed2000

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.

Anti-Bacterial Agents↗
PubMed2000

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.

Anti-Bacterial Agents↗
PubMed2000

Epidemiologic characterization of Pseudomonas aeruginosa in patients with cystic fibrosis.

OBJECTIVE: To determine persistence and variability of colonization with Pseudomonas aeruginosa in cystic fibrosis patients over long time periods, and to look for possible cross-colonization. METHODS: In total, 469 Pseudomonas aeruginosa isolates were obtained from 30 patients during the period from April 1994 to April 1996. The sources were mainly sputum and a few deep throat swabs. All grown strains dissimilar in macromorphology were processed separately. Typing with PFGE was carried out by contour-clamped homogeneous electric field electrophoresis. Genomic DNA was subjected to the rare-cutting restriction enzyme SpeI. For pyocin typing, the procedure described by Fyfe was applied. RESULTS: After typing with PFGE, we observed 40 restriction profiles. Eighteen different pyocin types were found. The most frequent pyocin type was type 3, followed by types 1 and 5. Twenty-two patients were persistently colonized by one clone specific and different for each patient, and four were co-colonized by a second clone also different for each of these patients. Cross-colonization had apparently been rare in the cystic fibrosis center of Leipzig. CONCLUSIONS: Typing with PFGE is well suited for detailed investigations of colonization with Pseudomonas aeruginosa in cystic fibrosis patients. Pyocin typing can provide additional information for epidemiologic purposes.

Adolescent↗
PubMed2000

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.

Anti-Bacterial Agents↗
PubMed1999

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.

Anti-Bacterial Agents↗
PubMed1998

[Comparative study of the cost-effectiveness of initial therapy with imipenem/cilastatin in secondary peritonitis].

The total costs of the hospital treatment of patients with secondary peritonitis were investigated with a prospective, randomized, multicenter study. Moreover, the cost-effectiveness of an initial therapy with Imipenem/Cilastatin was compared to selected alternative antibiotic regimens. Altogether 154 patients (77 Imipenem/Cilastatin group, 77 alternative group) that displayed Mannheim Peritonitis Scores between 16 and 26 (average 20.8) were analyzed. The average total cost of treatment was DM 11,140 per patient (range DM 2794-45,526). Patients receiving an initial therapy with Imipenem/Cilastatin incurred average costs of DM 10,455, while patients with alternative regimens caused average costs of DM 11,826. The difference between the two treatment groups was statistically significant (P = 0.037).

Adolescent↗
PubMed1998

Randomized observational studies on the economics of therapies--biometrical experience of two trials.

Economic studies in medicine are intended to investigate costs, associated with a particular problem dealing with the indication, diagnosis or therapy, for instance, whether the high costs involved in a highly intensive or innovative therapy could be balanced by the eventual savings made, due to the shorter periods of treatment. In such situations a randomized controlled trial is necessary to find out which therapy or which therapeutical strategy is least expensive in the long run. Economic studies do, however, present some specific problems. Making a list of all the cost-relevant treatment items can be very laborious, but the use of flat rates and lump sums alone cannot lead to a complete cost analysis. Often, costs between hospitals vary more than between treatment regimens. Early and sudden deaths incur low costs and may bias the results. Furthermore, costs are distributed with a long and heavy upper tail including extreme outliers. This does, in fact, complicate the estimation of the sample size. In this article, these problems are outlined and, with the help of the data obtained from two randomized economic trials in health care, solutions are proposed and discussed.

Costs and Cost Analysis↗