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F P Tally

Publications and source records attributed to F P Tally.

At least 37 records · Page 2Linked to original sources
PubMed1990

R-plasmid mediated transfer of beta-lactam resistance in Bacteroides fragilis.

We described plasmid mediated transfer of resistance to beta-lactam antibiotics between Bacteroides fragilis strains. Ampicillin-resistance was transferred from B. fragilis strain GAI-10150 to a B. fragilis strain JC-101 with a frequency of 10(-6)/input donor by a filter mating technique. A common plasmid band, named pBFKW1, was found in both the donor and the transconjugants. The plasmid was purified by an ethidium bromide-CsCl ultracentrifugation. The molecular size of the plasmid pBFKW1 which seemed to encode the beta-lactam resistance and beta-lactamase production was estimated ca. 40 kb by the analysis of endonuclease digest. Substrate profile of the enzymes derived from the donor and a transconjugant were of cephalosporinase character.

Ampicillin Resistance↗
PubMed1989

In-vitro susceptibility of the Bacteroides fragilis group and the inoculum effect of newer beta-lactam antibiotics on this group of organisms.

The susceptibility and inoculum effect of 190 selected Bacteroides fragilis group isolates were determined with six beta-lactam antibiotics by two different methods: agar dilution and broth microdilution. The results were analysed by species within this group of pathogens. The evaluation showed that imipenem had superior activity and was very stable to increased inoculum concentration. Cefoxitin and piperacillin exhibited very good activity and very small inoculum effect; latamoxef showed stability to changes in the inoculum concentration but only intermediate activity; while ceftizoxime and cefoperazone exhibited a marked inoculum effect and relatively poor activity. Resistance among the species was as follows: B. distasonis greater than B. thetaiotaomicron greater than B. ovatus greater than B. fragilis. The inoculum effect was higher when tests were performed in broth rather than in agar. In general, the effect was more pronounced among B. ovatus and less among B. distasonis isolates.

Anti-Bacterial Agents↗
PubMed1989

Recurrent tonsillitis: histologic and bacteriologic evaluation.

Histologic and bacteriologic evaluations of tonsils removed at surgery from ten patients with a diagnosis of recurrent tonsillitis were performed. The bacteriology was complex, with an average of 6.3 aerobic bacteria and 3.3 anaerobic bacteria isolated from each patient. Histologic sections revealed chronic cryptitis, with intact tonsillar architecture. These findings provide a possible explanation for the failure of commonly used antibiotic regimens to eradicate recurrent infection from this site.

Adolescent↗
PubMed1988

Prospective study comparing imipenem-cilastatin with clindamycin and gentamicin for the treatment of serious surgical infections.

Surgical infection remains a leading cause of hospital morbidity and mortality. We compared the efficacy and toxicity of imipenem-cilastatin sodium in 32 patients with that of clindamycin phosphate and gentamicin sulfate in 25 patients. In the imipenem-cilastatin group, 87.5% had a favorable outcome, with a 12.5% failure rate and 13 adverse reactions. In the clindamycin-gentamicin group, 80% had a favorable outcome, with a 20% failure rate and ten adverse reactions. Two significant superinfections with Pseudomonas and Candida were noted in patients treated with impenem-cilastatin. Each group had one case of Clostridium difficile-associated colitis. Cost analysis showed no differences between treatment arms, except in the appendicitis subgroup. For serious surgical infections, single-agent therapy with imipenem-cilastatin appears to be as efficacious as combination therapy with clindamycin and gentamicin.

Adolescent↗
PubMed1988

A prospective double-blind evaluation of penicillin versus clindamycin in the treatment of odontogenic infections.

In a prospective, double-blind trial, penicillin and clindamycin were compared in treatment of moderate to severe orofacial infections of odontogenic origin, which yielded pus on aspiration. Among 27 patients randomized to receive penicillin, 22 (81%) had a successful outcome, and five (19%) were improved. In the 28 clindamycin-treated patients, 23 (82%) had a successful outcome, and five (18%) were improved. No failures were noted in either group. One patient who was receiving penicillin and two who were receiving clindamycin developed diarrhea. Bacteriologic results showed an average of 6.1 organisms per culture (2.5 aerobes and 3.6 anaerobes). Resistance rates for anaerobic isolates were 8.9% to penicillin and 1.9% to clindamycin. It was concluded that penicillin and clindamycin produce similar good results in treating odontogenic infection when the rate of penicillin resistance among oral anaerobic bacteria is at a relatively low level.

Adult↗
PubMed1988

Permeability to beta-lactams in Bacteroides fragilis.

Bacteroides fragilis strains TAL2480 and TAL3636 were used to assess outer membrane permeability to various beta-lactam compounds. These strains were chosen because they possess beta-lactamases capable of hydrolysing all commonly employed beta-lactams except monobactams. The beta-lactamases are located in the periplasmic space and could be released by sonication and osmotic shock. Permeability was calculated by the method of Zimmerman & Rosselet (1977, Antimicrobial Agents and Chemotherapy 12, 368-72). The rank order of permeative ability (from fastest to slowest) was as follows: cephaloridine, imipenem, cefotaxime, cefoxitin, cefoperazone, nitrocefin, cephalothin, and latamoxef. Our results showed that ionic charge, hydrophobicity, and molecular weight influenced beta-lactam drug uptake by B. fragilis. These results are similar to findings for Escherichia coli, where increased negative charge and increased molecular weight are associated with decreased drug uptake. However, unlike E. coli, increased drug hydrophobicity, for a given charge and molecular weight of the drug, was associated with increased uptake by B. fragilis.

Anti-Bacterial Agents↗
PubMed1988

Antibiotic resistance in anaerobic bacteria.

An improved understanding of the mechanisms of resistance and transfer in Bacteroides fragilis has been gained over the past decade. B. fragilis resistance to most penicillins is largely due to production of chromosomal beta-lactamases, although recent findings indicate these micro-organisms can acquire novel beta-lactamases, which can even inactivate imipenem. Several of the beta-lactamases of B. fragilis are transferable. Most of our understanding of transferable antimicrobial resistance in Bacteroides spp. has been gained through studies of the clindamycin-erythromycin resistance determinant found on pBFTM10. This resistance is encoded on a transposon and is widely distributed among the naturally occurring clindamycin-resistant isolates. Recent studies have shown that DNA can be transferred from Escherichia coli to B. fragilis, from one B. fragilis to another, and from B. fragilis back to E. coli. Data from a large survey in the United States indicate that susceptibility patterns of B. fragilis differ in each of the eight participating centres. Overall, piperacillin and cefoxitin have been found to be the most active beta-lactam agents.

Anti-Bacterial Agents↗
PubMed1988

Factors affecting the choice of antibiotics in mixed infections.

Mixed infections can occur anywhere in the body and, on the basis of the location of the infection, involve predictable species of anaerobic bacteria. Most of our knowledge of anaerobic mixed infection has come from the study of intra-abdominal infections. The mortality associated with intra-abdominal abscesses in a recent study was lower than in earlier studies, perhaps because of improvements in radiographic techniques for better localization of abscess and early drainage, improved management of nutrition, and the selection of appropriate antimicrobial agents. The efficacy of an antimicrobial agent depends on its ability to penetrate into an abscess and function under conditions of low pH, low Eh and in the presence of beta-lactamases. Some effective antibiotics include clindamycin/gentamicin, metronidazole/gentamicin, latamoxef, cefoxitin, piperacillin and imipenem.

Abscess↗
PubMed1988

Activity of trospectomycin against Bacteroides fragilis and other Bacteroides species.

The in vitro activity of trospectomycin (U-63366; 6'-n-propyl spectinomycin pentahydrate sulfate) was evaluated against 189 clinical isolates of the Bacteroides fragilis group and 65 Bacteroides species isolates. At less than or equal to 8 micrograms/ml, the activity of trospectomycin compared favorably with those of clindamycin and cefoxitin against B. fragilis, Bacteroides distasonis, and Bacteroides vulgatus, and there was no cross resistance to these three drugs among the strains of the B. fragilis group. All the Bacteroides species were susceptible to trospectomycin. The results of this in vitro study indicate that trospectomycin possesses excellent activity against Bacteroides species.

Anti-Bacterial Agents↗
PubMed1988

Susceptibility of the Bacteroides fragilis group in the United States: analysis by site of isolation.

An ongoing survey of the susceptibility of the Bacteroides fragilis group of bacteria was continued at New England Medical Center in 1984 and 1985. A total of 1,229 strains were obtained from eight centers in the United States. These results were compared with those for 1,847 isolates tested in 1981 through 1983. The most active beta-lactam drugs were imipenem and ticarcillin-clavulanic acid (Timentin), which had a less than 1% resistance rate. No metronidazole- or chloramphenicol-resistant isolates were found during the 5 years of the study. Isolates obtained from blood, perinatal, and bone sites of infection were more resistant to a variety of antimicrobial agents. Susceptibility patterns of the members of the B. fragilis group varied at the eight hospitals and among species. These data indicate the need for determining the susceptibility patterns for the B. fragilis group of organisms at each hospital.

Anti-Bacterial Agents↗
PubMed1988

Antimicrobial resistance in oral and colonic bacteroides.

Antimicrobial resistance in Bacteroides from oral and colonic flora influences the selection of antimicrobial therapy to treat infections involving these organisms. An antimicrobial susceptibility study of 49 clinical isolates of oral bacteroides to 9 drugs revealed high resistance rates for penicillin 53%, for cefaclor 45%, and for tetracycline 27%, while there were low rates (less than 10%) with cefoxitin, piperacillin, clindamycin, chloramphenicol and metronidazole. Review of our U.S. nationwide survey of the susceptibility of colonic bacteroides (Bacteroides fragilis group) reveals low resistance to clindamycin, cefoxitin, piperacillin, imipenem, chloramphenicol and metronidazole. However, the identification of clindamycin, clindamycin, cefoxitin, piperacillin, imipenem and chloramphenicol resistant isolates is worrisome. The mechanism of resistance and the resistant transfer mechanism to the different classes of drugs in the oral and colonic bacteroides are reviewed.

Bacteroides↗
PubMed1987

Clinical importance of cefoxitin-resistant Bacteroides fragilis isolates.

Resistance to cefoxitin among species of the Bacteroides fragilis group of organisms has remained low (8%-10%) in a multicenter nationwide survey. However, a statistically significant increase in the percentage of B. fragilis group organisms resistant to cefoxitin was found at Tufts-New England Medical Center from 1981 to 1982. Non fragilis species accounted for most of the resistance. The presence of cefoxitin resistance in B. fragilis isolates correlated with resistance to other antibiotics. The presence of cefoxitin-resistant B. fragilis group organisms also correlated with the presence of other cefoxitin-resistant bacteria. No difference could be detected in therapeutic outcome of patients with cefoxitin-sensitive or cefoxitin-resistant B. fragilis group organisms, regardless of treatment with cefoxitin or other antibiotics.

Age Factors↗
PubMed1987

Comparative efficacy of clindamycin, erythromycin and spiramycin against Staphylococcus aureus in the rat croton oil pouch model.

Spiramycin, a macrolide antibiotic, has inferior in-vitro activity to erythromycin, but superior tissue penetration. Recent publications have suggested that the in-vivo activity of spiramycin should be re-assessed. The efficacy of clindamycin, erythromycin and spiramycin was compared against Staphylococcus aureus infections in the rat croton oil pouch model. The concentration of spiramycin in the pouch fluid was lower than the concentration of clindamycin or erythromycin after single or multiple intraperitoneal injections. In contrast, the concentration of spiramycin in the pouch wall (73.3 +/- 14.5 micrograms/g) was markedly higher than that of erythromycin (less than 7.5 micrograms/g). Multiple doses of spiramycin had no significant effect upon bacterial growth in the pouch, whereas clindamycin and erythromycin had a significant bactericidal effect. The results suggest that spiramycin is bound to tissues, diffuses poorly into tissue fluid and may therefore be ineffective against infections in large collections of tissue fluid.

Animals↗
PubMed1987

Safety profile of cefixime.

The clinical and laboratory safety of cefixime based on analysis of data from 1575 adults (1118 treated daily and 457 treated twice a day) and 615 children (299 treated daily and 316 treated twice a day) in studies of urinary tract and lower and upper respiratory tract infections (including otitis media) is reviewed. The incidence of adverse clinical experiences and occurrence of laboratory abnormalities were similar to those seen with other beta-lactam antimicrobial agents. Gastrointestinal side effects were the predominant adverse experiences seen in both daily and twice daily programs in adults and children. The incidence of gastrointestinal intolerance was not dependent upon the frequency of the dosage. Symptoms of drug hypersensitivity were infrequently reported. No serious chemical, hematologic or urologic abnormalities were noted. The data confirm the safety of cefiximine in both adults and children, whether it is administered once or twice a day.

Adult↗
PubMed1987

Cryptic tetracycline resistance determinant (class F) from Bacteroides fragilis mediates resistance in Escherichia coli by actively reducing tetracycline accumulation.

Escherichia coli bearing a cryptic tetracycline resistance determinant from Bacteroides fragilis expressed low-level constitutive resistance to tetracycline under aerobic, but not anaerobic, growth conditions and accumulated less tetracycline aerobically than did isogenic susceptible cells. This decreased uptake was energy dependent and reversible by increased concentrations of tetracycline, suggesting a saturable carrier-mediated active efflux mechanism. Decreased uptake was not seen when the cells were grown and assayed anaerobically. Other tetracycline resistance determinants (classes A to E) isolated from gram-negative enteric bacteria expressed resistance and generated active efflux of tetracycline under anaerobic as well as aerobic conditions. When the Bacteroides determinant was placed in the same cell with any of the class A to E tetracycline resistance determinants, there was an increase in resistance under aerobic conditions of as much as 48% more than was projected by adding the resistances expressed by the determinants individually. In cells bearing the class A determinant together with the Bacteroides determinant, saturation of the active efflux system required over twofold more exogenous tetracycline than did cells bearing the class A determinant alone. We have designated this new tetracycline resistance determinant class F.

Bacteroides fragilis↗
PubMed1986

Activity of cefotetan against anaerobic bacteria.

The in vitro activity of cefotetan, a new cephamycin, was compared with that of cefoxitin, cefotaxime, moxalactam, and piperacillin against 368 strains of anaerobic bacteria. Cefotetan was similar to cefoxitin, moxalactam, and piperacillin in its activity against B. fragilis, B. vulgatus, Bacteroides species, anaerobic gram-positive cocci, Fusobacterium and Clostridium species. High resistance rates for cefotetan, however, were demonstrated among B. thetaiotaomicron-ovatus group and B. distasonis. Increasing inoculum concentrations had little effect on the activity of cefotetan.

Anti-Bacterial Agents↗