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K Tunér

Publications and source records attributed to K Tunér.

At least 19 recordsLinked to original sources
PubMed1993

Antibiotic susceptibility of anaerobic bacteria in Europe.

Twenty-two laboratories in 15 European countries determined the MICs of 12 antibiotics for 1,289 isolates of the B. fragilis group by a microdilution method. There was no resistance to metronidazole (breakpoint, 8 mg/L), and only one isolate was found to be resistant to chloramphenicol (breakpoint, 8 mg/L). Resistance was uncommon to imipenem (0.3% at concentrations > 4 mg/L), amoxicillin/clavulanate (1% at concentrations > 8 mg/L), cefoxitin (3% at concentrations > 32 mg/L), mezlocillin (6% at concentrations > 64 mg/L), and clindamycin (9% at concentrations > 4 mg/L). The majority of the isolates were resistant to ampicillin (93% at concentrations > 4 mg/L), ciprofloxacin (56% at concentrations > 4 mg/L), and tetracycline (64% at concentrations > 4 mg/L). Bacteroides fragilis was the most susceptible species of the group, and the most striking regional differences in susceptibility were found in association with clindamycin and tetracycline; more resistance was noted in isolates from the southern part of Europe (Greece, Italy, Portugal, and Spain). It has been reported that Fusobacterium species and Clostridium species occasionally produce beta-lactamases. A few metronidazole-resistant Clostridium perfringens strains but no metronidazole-resistant fusobacteria have been isolated.

Bacteria, Anaerobic↗
PubMed1992

Effect of beta-lactamase inhibitors on beta-lactamases from anaerobic bacteria.

Three beta-lactamase inhibitors in clinical use--clavulanic acid, sulbactam and tazobactam--were investigated for their activity on beta-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum. Purification of the beta-lactamases was carried out by anion-exchange chromatography, gel filtration and FPLC. The inactivation of beta-lactamase activity was determined spectrophotometrically with nitrocefin as substrate. Various concentrations of the inhibitors were preincubated at 30 degrees C together with the enzyme for different periods of time before determination of the beta-lactamase activity. The three beta-lactamases tested were more susceptible to tazobactam than to clavulanic acid and sulbactam. Clavulanic acid and sulbactam reduced the enzyme activity of the Bacteroides uniformis beta-lactamase more effectively than the Clostridium butyricum and Fusobacterium nucleatum beta-lactamases.

Bacteria, Anaerobic↗
PubMed1992

Effect of clavulanic acid, sulbactam and tazobactam on three different beta-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum.

The effect of three beta-lactamase inhibitors, clavulanic acid, sulbactam and tazobactam used in clinical practice were compared for their activity against purified beta-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum. The enzymes from B. uniformis and C. butyricum were produced in fermenters under controlled growth conditions and the enzyme from F. nucleatum was produced in batch cultures. Purification of the beta-lactamases was achieved by anion-exchange chromatography, gel filtration and FPLC-technique. The degree of inactivation of beta-lactamase activity was determined spectrophotometrically with nitrocefin as the substrate. The inhibitors in various concentrations were preincubated at 30 degrees C together with the enzyme for different time periods (0.5-120 min) before determination of the remaining beta-lactamase activity. The inhibitors all decreased the activity of the beta-lactamases investigated. Clavulanic acid and sulbactam were capable of reducing the enzyme activity of the B. uniformis beta-lactamase more effectively than the C. butyricum and F. nucleatum beta-lactamases. All beta-lactamases tested were more susceptible to tazobactam than to clavulanic acid and sulbactam.

Bacteroides↗
PubMed1992

Cellular fatty acids in Fusobacterium species as a tool for identification.

Identification of fusobacteria from clinical specimens currently requires analysis of metabolic end products by gas-liquid chromatography in addition to certain biochemical and enzymatic tests because of the relative biochemical inactivity of these bacteria. Even the finding of pointed, thin gram-negative cells on Gram-stained slides can no longer be relied on for identification of Fusobacterium nucleatum, since at least four other species of fusobacteria have been seen to exhibit similar morphology. We examined 46 clinical isolates and six American Type Culture Collection type strains of fusobacteria by conventional methods and by the Microbial ID Systems MIDI software package for analyzing cellular fatty acid patterns measured by capillary column gas-liquid chromatography. Distinctive patterns of major fatty acids could be used to reliably identify most clinical isolates to the species level. The MIDI system identified 89% of the isolates correctly and provides an alternative to conventional methods.

Bacterial Typing Techniques↗
PubMed1992

Bilophila wadsworthia isolates from clinical specimens.

Bilophila wadsworthia is an anaerobic, gram-negative, asaccharolytic, bile-resistant, catalase-positive bacillus that is usually urease positive and was originally recognized in specimens of peritoneal fluid and tissue from patients with appendicitis. Additional isolations from clinical specimens, including a scrotal abscess, mandibular osteomyelitis, axillary hidradenitis suppurativa, pleural fluid, joint fluid, and blood, are described here.

Adult↗
PubMed1990

Detection and quantitation by lysis-filtration of bacteremia after different oral surgical procedures.

Patients with bacteremia after dental extraction, third-molar surgery, dental scaling, endodontic treatment, and bilateral tonsillectomy were studied by means of lysis-filtration of blood samples with subsequent aerobic and anaerobic incubation. Samples were obtained before, during, and 10 min after treatment. Bacteremia was observed in 100% of patients after dental extraction, 55% of patients after third-molar surgery, 70% of patients after dental scaling, 20% of patients after endodontic treatment, and 55% of patients after bilateral tonsillectomy. Anaerobic microorganisms were isolated more frequently than aerobic microorganisms were, and viridans group streptococci were the most commonly isolated bacteria. Ten minutes after treatment, the frequency as well as the magnitude of bacteremia showed pronounced reduction.

Adolescent↗
PubMed1989

Purification and characterization of a new beta-lactamase from Clostridium butyricum.

A highly penicillin-resistant beta-lactamase-producing strain of Clostridium butyricum, strain NBL 3, was isolated. The specific activity of the unpurified beta-lactamase was 0.29 U/mg of protein. The enzyme was purified 1,130-fold by QAE Zetaprep, Sephacryl S-300, and Mono Q column passages. The purified enzyme was judged homogeneous by sodium dodecyl sulfate gradient gel electrophoresis and fast protein liquid chromatography. The enzyme hydrolyzed phenoxymethylpenicillin, benzylpenicillin, ampicillin, and carbenicillin more rapidly than piperacillin and cephaloridine. Cephalothin, cephalexin, cefoxitin, moxalactam, cefotaxime, and imipenem were only slightly hydrolyzed, at less than 1% the rate for phenoxymethylpenicillin. The enzyme was inhibited by clavulanic acid, sulbactam, tazobactam, and p-chloromercuribenzoate. The molecular weight was determined by gel filtration and sodium dodecyl sulfate gradient gel electrophoresis to be 32,000. The isoelectric point was 4.4. Aspartic acid-asparagine, glutamic acid-glutamine, leucine, lysine, alanine, and serine dominated the amino acid composition.

Amino Acids↗
PubMed1988

Beta-lactamase producing anaerobic bacteria in the oropharynx and their clinical relevance.

The mechanisms of resistance to beta-lactam antibiotics in anaerobic bacteria are production of beta-lactamases, alteration of penicillin-binding proteins and blocked penetration of beta-lactam agents through the outer membranes. The most important factor in beta-lactam resistance is production of beta-lactamase. Beta-lactamases have been found in oropharyngeal strains of bacteroides and fusobacteria isolated from orofacial infections, peritonsillitis and recurrent tonsillitis. Clinical failures with penicillin therapy of these infections are reported in an increasing frequency and other antimicrobial agents such as clindamycin and metronidazole should be considered in the treatment of these failures.

Bacteria, Anaerobic↗
PubMed1986

Emergence of beta-lactamase producing anaerobic bacteria in the tonsils during penicillin treatment.

The emergence of beta-lactamase producing bacteria in the microflora in the oropharyngeal cavity was studied in ten healthy volunteers treated with 1 g phenoxymethylpenicillin b.i.d. for ten days. Beta-lactamase activity in saliva was also investigated. A significant increase in the number of beta-lactamase producing strains of Bacteroides species and Fusobacterium nucleatum was observed. One beta-lactamase producing Staphylococcus aureus strain was recovered in one of the volunteers before the penicillin administration started and three Staphylococcus aureus strains produced beta-lactamase after ten days of antibiotic treatment. Beta-lactamase-production in Haemophilus influenzae, Haemophilus parainfluenzae or Branhamella catarrhalis was not observed before, during or after the antibiotic treatment. Beta-lactamase activity was noted in the broth cultures from one volunteer colonized with a beta-lactamase producing Escherichia coli strain. Beta-lactamase activity in saliva was observed in all volunteers, the activity increasing significantly in parallel to the increase of beta-lactamase producing bacterial strains. Beta-lactamase activity in saliva was completely inhibited in vitro by clavulanic acid and p-chloromercurbenzoate and about 70-80 per cent of the activity was inhibited by cefoxitin. The increase of beta-lactamase producing bacteria in the oropharynx as a consequence of penicillin treatment raises doubt as to whether penicillin is the drug of choice in the treatment of tonsillitis caused by group A streptococci when previous treatment has failed.

Adult↗
PubMed1985

Characterization of a new beta-lactamase from Fusobacterium nucleatum by substrate profiles and chromatofocusing patterns.

Seven beta-lactamase-producing Fusobacterium nucleatum strains were isolated from patients with recurrent tonsillitis. The isolates were highly resistant to phenoxymethylpenicillin, benzylpenicillin, ampicillin, piperacillin and cloxacillin. They were all sensitive to cefaclor, cephaloridine, cefotaxime, cefoxitin, latamoxef (moxalactam) and imipenem. Penicillinase activity was found intracellularly after 20 h incubation. Specific activity of the unpurified penicillinase varied among the strains between 0.24-9.3 U/mg protein. The enzyme hydrolysed ampicillin and benzylpenicillin more rapidly than piperacillin. Cephalothin and imipenem were hydrolysed at rates less than 1% of benzylpenicillin. Chromatofocusing experiments eluted the beta-lactamases from all strains at a single peak between pH 5.1-5.2.

Anti-Bacterial Agents↗
PubMed1985

Purification and properties of a novel beta-lactamase from Fusobacterium nucleatum.

A strain of Fusobacterium nucleatum which produced high levels of beta-lactamase was isolated. The specific activity of the unpurified beta-lactamase was 7.8 U/mg of protein. By Sephacryl S-300 and S-200 column passage and chromatofocusing, the enzyme was purified 450-fold. Sodium dodecyl sulfate-gradient gel electrophoresis revealed a single band. The enzyme hydrolyzed phenoxymethylpenicillin, benzylpenicillin, and ampicillin more rapidly than carbenicillin and piperacillin. Cephaloridine, cefaclor, cephalothin, imipenem, and SCH 34343 had hydrolysis rates of less than or equal to 1% that of phenoxymethylpenicillin. The enzyme was inhibited by clavulanic acid and RO-15-1903/001 but not by p-mercuribenzoate or cefoxitin. Molecular weight by gel filtration was determined to be 21,000 and by sodium dodecyl sulfate-gradient gel electrophoresis was determined to be 26,000. The amino acids aspartic acid-asparagine, glutamic acid-glutamine, serine, glycine, and lysine dominated the amino acid composition.

Amino Acids↗
PubMed1985

Beta-lactamases in anaerobic bacteria.

The known mechanisms of beta-lactam resistance in anaerobic bacteria involve production of beta-lactamases, alteration of penicillin-binding proteins and blocked penetration of beta-lactams through the outer membranes. The most important factor in beta-lactam resistance is production of beta-lactamase. Beta-lactamases in various Bacteroides, Fusobacterium and Clostridium species have been described. Beta-lactam resistance in Bacteroides fragilis is most commonly mediated by beta-lactamase production mainly of cephalosporinase character. Recent studies have also shown that B. fragilis can produce a penicillinase which inactivates piperacillin and carbenicillin. Enzymes inactivating cefoxitin and imipenem have also been isolated from B. fragilis. The Bacteroides non-fragilis species produce beta-lactamases of mainly penicillinase character. Recently a penicillinase from Fusobacterium nucleatum has been characterized. Among the clostridia, Clostridium butyricum, C. clostridiiformis and C. ramosum have been shown to produce penicillinases.

Bacteria, Anaerobic↗
PubMed1983

Betalactamase-producing microorganisms in recurrent tonsillitis.

In 73% of 167 patients with recurrent tonsillitis, colonization with betalactamase-producing microorganisms was found. Betastreptococci group A were recovered in 6% of the patients and group C and G streptococci in 23%. Other microorganisms found were Staphylococcus aureus in 42%, Haemophilus species in 52%, bacteroides species in 80% and fusobacteria in 40%. Ninety-eight per cent of Staph. aureus, 60% of bacteroides species and 10% of fusobacteria were betalactamase-producing. Phenoxymethylpenicillin (1 g twice a day for ten days) diminished 50% of group A, C and G streptococci. No other microorganisms were affected by this antibiotic. Clindamycin (0.15 g four times a day for ten days) eradicated Staph. aureus, group A, C and G streptococci, bacteroides and fusobacteria. Haemophilus species were not affected by clindamycin. Tinidazole (1 g once a day for 10 days) diminished bacteroides and fusobacteria. Aerobic microorganisms, Staph. aureus, streptococci and Haemophilus, were not affected by tinidazole.

Adolescent↗
PubMed1982

Battered women. A surgical problem.

In a retrospective study on 456 women hospitalized at the Departments of Surgery and Oto-rhinolaryngology of Huddinge Hospital for emergency injuries during the years 1978 and 1979, the injuries were found to have been caused by battering in 29%. The majority of the women had been physically abused by their husbands, fiancés or cohabitees. As women seldom seek social or psychiatric assistance for this problem spontaneously, it is an important task of the responsible accident surgeon both to detect battering as the cause of the injuries and to act as mediator in contacting a women's refuge or other social assistance agency.

Abdominal Injuries↗