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Biomedical subjects

C Kamme

Publications and source records attributed to C Kamme.

At least 37 records · Page 2Linked to original sources
PubMed1993

In vitro effect on group A streptococci of loracarbef versus cefadroxil, cefaclor and penicillin V.

The in vitro activity of loracarbef, penicillin V, cefaclor and cefadroxil against log and stationary phase cultures of group A streptococci was compared. MICs and MBCs were determined with the broth dilution method and by a modified agar plate dilution technique where the beta-lactams were inactivated after the MICs were determined allowing inhibited but not killed organisms to grow on further incubation. The MICs of loracarbef and the two cephalosporins were 16-32 times higher than those of penicillin V. In plate dilution the MBC/MIC ratios of all agents were < or = 2 for log phase cultures. With stationary phase cultures, especially in the broth dilution test, the MBC/MIC ratios of loracarbef and the two cephalosporins were > or = 32 for a large number of strains. The phenotype response of stationary phase cultures to beta-lactam antibiotics may not only be related to the physiological status of the streptococci, to the culture conditions and to the beta-lactam under test. The present investigation indicated that the phenotypic response was also an intrinsic property of certain strains.

Anti-Bacterial Agents↗
PubMed1992

Characterization of cell-bound papain-soluble beta-lactamases in BRO-1 and BRO-2 producing strains of Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens.

In Moraxella (Branhamella) catarrhalis and Moraxella nonliquefaciens strains isolated from clinical specimens in the south of Sweden two variants of beta-lactamase were distinguished by isoelectric focusing (IEF). The BRO-1 (Ravasio type) enzyme was the most common in Branhamella catarrhalis, constituting about 90% of the beta-lactamase found in this species, while the BRO-2 enzyme (1908 type) was as common as BRO-1 in Moraxella nonliquefaciens. The determinants mediating the production of BRO-1 and BRO-2 were both transferable by conjugation. Cell-bound beta-lactamase from reference strains producing BRO-1 and BRO-2 could be solubilized by papain digestion. The isoelectric point of the solubilized enzymes differed distinctly between BRO-1 (pI 6.5) and BRO-2 (pI 6.9). The molecular species of BRO-1 and BRO-2 released by papain digestion were purified by affinity chromatography with phenylboronic acid agarose gel. They had identical molecular weights of approximately 28,000. Their kinetic constants were indistinguishable for a number of substrates and beta-lactamase inhibitors.

Anti-Bacterial Agents↗
PubMed1992

Acute laryngitis in adults: results of erythromycin treatment.

Previous studies of acute laryngitis in adults have shown high nasopharyngeal isolation rates of B. catarrhalis and H. influenzae. Phenoxymethylpenicillin had no effect on the clinical course. In the present study, 106 patients with acute laryngitis were treated with erythromycin 0.5 g x 2 V or placebo. During the first week the isolation rate of B. catarrhalis was reduced from 60 to 10% in the erythromycin group compared to 34 to 27% in the placebo group (p less than 0.01). The elimination of H. influenzae, isolated in 19% at the acute visit, did not differ between the two groups. As compared to controls, erythromycin treated patients reported significantly lower scores of subjective voice disturbance after 1 week and cough after 2 weeks. Laryngological examination and voice evaluation failed to reveal any differences between the groups.

Acute Disease↗
PubMed1992

Penicillin tolerance in group A streptococci and treatment failure in streptococcal tonsillitis.

Penicillin tolerance in Streptococcus pyogenes has been suggested as a possible cause of therapeutic failure in streptococcal phryngitis treated with penicillin. In 144 patients with acute group A streptococcal tonsillitis treated with phenoxymethyl penicillin 12.5 mg per kg body weight b.i.d. for 10 days the same T-type was recovered after treatment in 21%. The recovery rate was higher for non-tolerant strains, 23%, than for tolerant strains, 10% (p greater than 0.05). Of patients with a non-tolerant strain 17% had both clinical and bacterial treatment failure in comparison with 5% infected with a tolerant strain (p greater than 0.05). Reinfection with a new serotype occurred in altogether 3%. The present data did not indicate that penicillin tolerance in group A streptococci is of significance in acute tonsillitis treated with phenoxymethylpenicillin for 10 days.

Acute Disease↗
PubMed1992

Production of betalactamase by respiratory tract bacteria in children: relationship to antibiotic use.

Sales of antibiotics have increased in Sweden during the past decade. This has been paralleled by an increase in the frequency of beta-lactamase-producing respiratory tract bacteria. To investigate the effects of regional differences in use of antibiotics on beta-lactamase production in respiratory tract bacteria, we collected nasopharyngeal specimens and information about antibiotic use from 1133 children attending day-care centres in four rural municipalities with low use, and one urban municipality with high use of antibiotics, use being assessed from pharmacy sales. The frequency of beta-lactamase production among isolates of Branhamella catarrhalis and Moraxella nonliquefaciens was significantly higher in the urban municipality. This appeared to be a long-term ecological effect of differences in the level of use of antibiotics between the urban and rural populations, rather than an effect of recent antibiotic treatment of individual patients.

Anti-Bacterial Agents↗
PubMed1990

Emergence and persistence of beta-lactamase-producing bacteria in the upper respiratory tract in children treated with beta-lactam antibiotics.

PURPOSE: To assess the ecologic impact, in terms of selection of beta-lactamase-producing respiratory tract bacteria, of a single course of peroral beta-lactam antibiotics. PATIENTS AND METHODS: One-hundred fifty consecutive children with clinical signs of bacterial respiratory tract infection were randomly assigned to a seven-day course of treatment with either penicillin V, amoxicillin, or cefaclor. Bacteriologic specimens were collected before treatment, at its termination, and at follow-up four weeks later. RESULTS: All three drugs investigated caused a similar increase in beta-lactamase-producing bacteria, both in absolute and relative terms, an increase that persisted over a period of at least one month after completion of treatment. CONCLUSION: Penicillin V, amoxicillin, and cefaclor all act as selective agents for beta-lactamase-producing bacteria in the upper respiratory tract. Treatment with a peroral beta-lactam antibiotic puts patients at risk of becoming persistent carriers of beta-lactamase-producing bacteria.

Amoxicillin↗
PubMed1989

Evaluation of four qualitative methods for detection of beta-lactamase production in Staphylococcus and Micrococcus species.

Four qualitative methods for the detection of beta-lactamase production in Staphylococcus and Micrococcus species were evaluated and compared with a quantitative macroiodometric reference method. The disc diffusion test with penicillin G and the cloverleaf method could not separate beta-lactamase-positive from beta-lactamase-negative strains. Two applications of the chromogenic cephalosporin test, using uninduced strains and strains grown on blood agar plates, gave a large number of false negative and false positive results. False negative reactions were most common among uninduced strains, while the false positive reactions were most often recorded for Staphylococcus saprophyticus. A high degree of efficiency was recorded for the nitrocefin spot test, using induced strains grown on antibiotic susceptibility agar, and for the starch-iodine plate method. The starch-iodine plate with methicillin as inducer gave the most reliable results.

Bacteriological Techniques↗
PubMed1989

Levels of toxic shock syndrome toxin-1 production among Staphylococcus aureus strains and clinical implications.

Among 250 S. aureus clinical isolates, the incidence of TSST-1 production was 18.0%. S. aureus var. hominis strains were predominant (95.6%), producing high levels of toxin in vitro, within the range of 0.6 to 4.3 micrograms/ml and exhibiting crystal violet binding with C/D pattern. No correlation was found between the level of TSST-1 production in vitro and the clinical course. Two (3.4%) of the var. bovis strains produced toxin in amounts less than 0.6 micrograms/ml and did not bind crystal violet. None of the 24 var. canis isolates produced TSST-1. Fifty five per cent of the isolates of phage group I produced TSST-1 and corresponded to 57.8% of the toxigenic strains. Two of the 250 patients developed toxic shock syndrome.

Adolescent↗
PubMed1989

Infections and antibiotic prophylaxis in reconstructive vascular surgery.

In 98 patients undergoing elective vascular surgery, specimens for bacterial cultures were obtained from urine, ischaemic ulcers, incisional wounds and the implanted grafts. Wound and graft infections were registered and compared with the results of these cultures and suspected risk factors in an attempt to find the source of infections. Antibiotic prophylaxis with cefuroxime was given for 24 h beginning at the start of surgery. Patients with ischaemic ulcers also received "spread prophylaxis", directed against isolated bacteria, for ten days. Three cases of graft infection and twelve cases of wound infection occurred. Positive postoperative cultures from wounds did not correlate with pre- or peroperative cultures. Peroperative cultures revealed small numbers of staphylococcus epidermidis in eleven patients, and none of them developed graft infection. Ischaemic ulcers, diabetes or re-do procedures were not accompanied by a significantly increased frequency of wound or graft infection, although each of three patients with graft infection had one of these risk factors. Bacteria, sensitive to cefuroxime, were found in one graft infection, six wound infections, and in two patients with urosepsis, whereas cefuroxime resistant organisms were isolated from one graft infection and three infected wounds. One of the three graft infections was probably caused by bacteria originating from the patient's ischaemic ulcer. In the other two patients the source of bacteria could not be determined. Cefuroxime seems to be an adequate alternative for prophylaxis of vascular graft infection, but in some patients with bacteriuria or indwelling catheters, a one day regimen may be too short.

Aortic Aneurysm↗
PubMed1988

Beta-lactamase production in the upper respiratory tract flora in relation to antibiotic consumption: a study in children attending day nurseries.

The occurrence of beta-lactamase production in Haemophilus influenzae, Branhamella catarrhalis and Moraxella nonliquefaciens was compared in 191 healthy children attending day nurseries in 2 municipalities differing with regard to the prescription rate of beta-lactam antibiotics. A significantly higher frequency of beta-lactamase production was recorded in M. nonliquefaciens isolated in the municipality with the higher prescription rate. A corresponding difference was not recorded for H. influenzae or B. catarrhalis. Approximately 75% of the nasopharyngeal pathogens H. influenzae, B. catarrhalis and Streptococcus pneumoniae, as well as the commensal M. nonliquefaciens, were eliminated and often replaced by other strains of either species over a period of one month. Although none of the children were on antibiotics a substantial proportion of the acquired strains produced beta-lactamase. This suggested that the carrier rate of beta-lactamase producing strains of the respiratory tract is not only related to the effect of recent antibiotic treatment but also to the prevalence of such strains in the population.

Anti-Bacterial Agents↗
PubMed1987

Bacterial contamination in cerebrospinal fluid shunt surgery.

Infection is a major complication of cerebrospinal fluid (CSF) shunt treatment with a reported incidence of 8-27%. In the present study, comprising 64 patients operated under strictly defined preoperative and peroperative hygienic measures and without use of prophylactic antibiotics, the infection rate was 3.1%. Out of the 2 cases of shunt infection recorded, 1 was probably caused by peroperative contamination and 1 by postoperative, hematogenous spread. Bacterial cultures from the operation area before incision and during operation were negative in 95% and 78%, respectively, and when positive yielded low numbers of organisms. Specimens taken after skin closure revealed growth in 59% and high bacterial numbers in 20%, mostly of Staphylococcus epidermidis and other resident skin bacteria. In addition, cultures of irrigation solutions, kept in open bowls during operation, yielded bacterial growth in 65% with a predominance of S. epidermidis. Thus, the strict hygienic measures did not prevent bacterial recolonization of the wound during operation. It is conceivable that endogenous as well as exogenous spread may be of importance in this context. The contamination of irrigation solutions indicates that closed irrigation systems should be used in this type of surgery.

Adolescent↗
PubMed1986

Beta-lactamase production in the upper respiratory tract flora.

In order to determine the recovery rate of species of the genera Haemophilus and Moraxella (including subgenus Branhamella) from the upper respiratory tract and the incidence of beta-lactamase production within these genera, cultures were made of nose and throat swab specimens and adenoid tissue in 50 children undergoing adenoidectomy. Haemophilus influenzae was isolated from 92% of the children. All children harboured strains of Haemophilus spp. and in 46%, at least one strain produced the TEM-1 beta-lactamase. Branhamella catarrhalis and/or Moraxella nonliquefaciens were isolated from 82% of the children and strains producing the BRO-1 beta-lactamase from 34%. Overall, TEM-1 and/or BRO-1 producing strains were recovered from 60% of the investigated patients. The beta-lactamase production was found to be transferable by conjugation within the respective genera. It is suggested that the apathogenic species may be a source of transferable determinants mediating beta-lactamase production in the upper respiratory tract.

Adolescent↗
PubMed1986

Plasmid-mediated beta-lactamase in Branhamella catarrhalis.

The plasmid-mediated beta-lactamase in Branhamella catarrhalis (BRO-1), also occurring in Moraxella nonliquefaciens, differs from other known plasmid-mediated beta-lactamases in Gram-negative bacteria regarding substrate profile and isoelectric point. B. catarrhalis strains previously reported to produce beta-lactamases deviating from BRO-1 were tested, and the beta-lactamases did not differ significantly from BRO-1 in substrate profile, isoelectric point or relative substrate affinity index (RSAI). Further investigations of strains of various geographic origin should be undertaken. RSAI seems to be a useful tool for screening of beta-lactamases in B. catarrhalis since values for a large number of strains can easily be determined. The previously reported conjugational transfer of BRO-1 production within species B. catarrhalis and from M. nonliquefaciens to B. catarrhalis was confirmed. Four bands of extrachromosomal DNA were regularly detected by agarose gel electrophoresis in beta-lactamase-producing as well as in beta-lactamase-negative strains of B. catarrhalis and M. non-liquefaciens, provided that the excessive nuclease activity in the preparations was inhibited.

DNA, Bacterial↗
PubMed1986

Upper respiratory tract infections. Ecological and therapeutic aspects of beta-lactamase production with special reference to Branhamella catarrhalis.

Available data indicate that the most common beta-lactamase produced by Branhamella catarrhalis is plasmid mediated. The same enzyme occurs in Moraxella nonliquefaciens, a commensal in the upper respiratory tract. The ability to produce the enzyme, which is known as BRO-1, can be transferred by conjugation from M. nonliquefaciens to B. catarrhalis. Since the first beta-lactamase-producing strains of B. catarrhalis appeared in 1977, the frequency of beta-lactamase production has increased rapidly; figures as high as 76% have been reported. The plasmid-mediated beta-lactamase TEM-1 occurs in several species of the genus Haemophilus. While the frequency of beta-lactamase production in H. influenzae is reported to be 10-15%, the incidence is significantly higher in non-pathogenic Haemophilus species. Both phenoxymethyl-penicillin and ampicillin promote the occurrence of beta-lactamase-producing strains, but the selective pressure exerted by ampicillin seems to be more pronounced. It may be possible to reduce the ecological effects of the penicillins by avoiding overdiagnosis of the most common bacterial infections of the respiratory tract, and by shortening the courses of antibiotic treatment.

Adolescent↗
PubMed1985

Characterization of the plasmid-mediated beta-lactamase in Branhamella catarrhalis, with special reference to substrate affinity.

The plasmid-mediated Branhamella catarrhalis beta-lactamase BRO-1, also found in Moraxella nonliquefaciens, was characterized as regards substrate profile, isoelectric point and relative substrate affinity index (RSAI) to various substrates and compared in these aspects with the TEM-1 enzyme of Haemophilus influenzae. As measured by a biological assay and with high performance liquid chromatography (HPLC), BRO-1 was found to hydrolyse carbenicillin, mecillinam, methicillin and cefaclor with a higher rate than TEM-1. The only substrates having a relative rate of hydrolysis higher for TEM-1 than for BRO-1 were ampicillin and cephaloridine. The rates of hydrolysis registered with these two methods were comparable for all but 2 of 13 tested substrates. Isoelectric focusing yielded a main band at pH 5.6 and several satellite bands consistent with those reported by other authors for Branhamella enzymes having a substrate profile similar to that of BRO-1. A tenfold or higher difference in RSAI between BRO-1 and TEM-1 was recorded for five of the 15 compounds tested. BRO-1 seems to be the most common beta-lactamase in Bran. catarrhalis, irrespective of geographic origin. Its substrate profile, isoelectric pattern and RSAI differ from those of other known plasmid-mediated beta-lactamases described, thus justifying a specific designation.

Anti-Bacterial Agents↗
PubMed1985

Phenoxymethylpenicillin and therapeutic failure in acute otitis media.

The aim of the present investigation was to determine to what extent beta-lactamase producing Haemophilus influenzae (H.i.) and Branhamella catarrhalis (B.c.) were isolated in cases of failure of treatment of acute otitis media (AOM) with phenoxymethylpenicillin. Among children with suspected therapeutic failure referred to an ENT specialist altogether 11, 15% of those referred, fulfilled the criteria of AOM. Three of them were on erythromycin, 1 on ampicillin and 7 on phenoxymethylpenicillin. In 5 of the children treated with phenoxymethylpenicillin H.i. was isolated from middle ear exudate and/or the nasopharynx. All H.i. isolates were non-capsulated and beta-lactamase negative. One beta-lactamase producing B.c. was isolated from the nasopharynx in a patient with pure culture of H.i. in the ear exudate. The present investigation did not support the suggestion that beta-lactamase producing H.i. or B.c. are major causative agents in therapeutic failures of AOM treated with phenoxymethylpenicillin and did not produce any evidence supporting a change from the recommended ampicillin esters/amoxycillin in therapeutic failures.

Acute Disease↗