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Biomedical subjects

W Brumfitt

Publications and source records attributed to W Brumfitt.

At least 181 records · Page 10Linked to original sources

Diminished effect of gentamicin under anaerobic or hypercapnic conditions.

The in-vitro activity of gentamicin, judged by M.I.C. determinations, was much reduced when a normal aerobic atmosphere was replaced either by air +4% CO2 or by anaerobic conditions. The phenomenon was greatest for Staphylococcus aureus, where a decrease in activity of up to 20-fold was found. For Escherichia coli, Klebsiella aerogenes, Enterobacter spp., and Proteus spp. the factor of decrease was between 15-fold and 2-5-fold. Changes in medium pH, as a result of bacterial growth, can explain these findings for some, but not all, the species tested.

Anaerobiosis↗

Microbiological studies on some bladder irrigation fluids.

A 1.5% glycine solution has recently been introduced as a bladder irrigation fluid. In this study, glycine solution was compared with two other recognised bladder irrigants (chlorhexidine and noxythiolin) for its inhibitory activity against common urinary tract pathogens. Glycine solution supported the growth of nearly 50% of the bacterial strains tested whereas chlorhexidine and noxythiolin were completely inhibitory. In quantitative studies with selected strains it was found that growth could be initiated from as few as 200 organisms/ml. It was concluded that glycine solution was capable of supporting bacterial growth and thus, from a microbiological viewpoint, was unsuitable as a bladder irrigant.

Bacteria↗

Amikacin in treatment of infections caused by gram-negative bacteria resistant to gentamicin and other aminoglycosides: clinical and bacteriologic results.

Amikacin (250 or 500 mg) was administered intramuscularly twice daily at 12-hr intervals to 34 patients with infections due to various gram-negative bacteria. Usually one or more aggravating factors were present, such as serious underlying pathology or therapy with steroids or immunosuppressants. Clinical isolates from most patients were resistant to gentamicin and other aminoglycosides. The overall response to therapy was excellent in 20 patients; in eight patients clinical response was good, but the organism persisted. Six patients showed some improvement without complete resolution of the infection or eradication of the causative organism. There were no complete clinical or bacteriologic failures. Ototoxicity was not observed in any patient. Levels of blood urea nitrogen and serum creatinine increased in two patients but returned to pretreatment levels within two weeks after therapy. No other adverse reactions were noted. Amikacin may replace gentamicin as initial therapy in serious gram-negative bacillary infections, particularly when resistance to gentamicin is a problem.

Adolescent↗

In vitro activity of amikacin and ten other aminoglycoside antibiotics against gentamicin-resistant bacterial strains.

Sixty-nine strains of gentamicin-resistant gram-negative bacilli obtained from different geographical sources were tested for susceptibility to 11 aminoglycoside antibiotics. From the results of determinations of minimal inhibitory concentrations, patterns of resistance were established for 45 strains of Enterobacteriaceae and 24 strains of Pseudomonas aeruginosa. Overall, 81% of the strains were sensitive to amikacin and 33% of the strains were sensitive to butirosin, the next most active compound. Results indicated that 54% of the P. aeruginosa strains were sensitive to amikacin and 33% were sensitive to tobramycin. From resistance patterns, enzymes responsible for inactivation of the antibiotics were deduced. The most common enzyme was aminoglycoside nucleotidyltransferase(2''), either alone or combined with either aminoglycoside phosphotransferase(3')-I or aminoglycoside phosphotransferase(3')-II. Aminoglycoside acetyltransferase(2) was identified exclusively in strains of Providencia stuartii. Specific enzymes could not be identified for 30 strains, 21 of which were P. aeruginosa.

Amikacin↗

Cephamycins: a review, prospects and some original observations.

The cephamycins are a group with great potential. The first member of the group intended for therapeutic use offers the following advantages over existing cephalosporins: 1. Stability to various beta-lactamases; in an environment increasingly threatened by R-factors, this property may be of increasing value as time passes. 2. Possible lack of cross-allergenicity with other beta-lactam antibiotics. 3. Activity against anaerobic strains. Cefoxitin is only the first semi-synthetic derivative; presumably there are other compounds awaiting assessment which have even more favourable properties.

Animals↗

Ampicillin, carbenicillin indanyl ester, and nifuratel in the treatment of urinary infection in domiciliary practice.

A total of 120 patients, including 53 pregnant women with significant bacteriuria, received 163 7-day courses of oral antimicrobial agents allocated in a randomised manner. The cure rates after 6 weeks' follow-up ranged from 73% to 86%, and there was no statistical difference between preparations of ampicillin, carbenicillin indanyl easter, and 2 different formulations of nifuratel. Side-effects occurred in 30% to 40% of the courses of penicillin drugs, but in under 15% of the course of nifuratel. It is concluded that the new oral preparation of carbenicillin is a useful addition to the list of antimicrobial agents which are effective in the treatment of urinary infections in domiciliary patients. Furthermore, nifuratel has been confirmed as a highly active non-toxic drug which is valuable in the treatment of urinary infections.

Administration, Oral↗

Antibodies to Escherichia coli in chronic liver diseases.

Patients with chronic active hepatitis or alcoholic cirrhosis have serum antibodies to many more serotypes of Escherichia coli than do patients with primary biliary cirrhosis or cryptogenic cirrhosis, or normal controls. They also have antibodies against more serotypes than cirrhotic patients with a portacaval shunt. These observations suggest that factors other than shunting of blood away from the liver are responsible for the increased range of antibodies. These factors are discussed. There was no correlation between the number of serotypes to which antibodies were present and the serum immunoglobulin concentration. In three patients, each with chronic active hepatitis, the antibodies were predominantly of the IgM class, while the elevation of globulin in general was mainly due to increased IgG and IgA levels. Antibodies to Escherichia coli, therefore, probably contribute only a small part of the increased globulin levels found in patients with chronic liver disease.

Adolescent↗

A comparison of the in vitro activity of metronidazole, tinidazole, and nimorazole against Gram-negative anaerobic bacilli.

The in vitro activities of metronidazole, nimorazole, and tinidazole were compared against 69 strains of obligately anaerobic Gram-negative bacilli. Geometric mean MICs were 0-34, 1-05, and 0-28 mug/ml respectively. Thirty-six strains were also tested by the disk method. Correlation between MIC and diameter of the zones of inhibition was poor.

Gram-Negative Anaerobic Bacteria↗

Newer aminoglycosides--amikacin and tobramycin: an in-vitro comparison with kanamycin and gentamicin.

Tobramycin and amikacin are new aminoglycoside antibiotics which resemble gentamicin and kanamycin respectively in pharmacokinetic, toxicological, and some microbiological respects. Minimum inhibitory concentrations for these four antibiotics have been determined against 393 bacterial strains (13 species from eight genera) isolated from clinical materialKanamycin was the least active, 89% of the Pseudomonas aeruginosa strains being resistant. Resistance was also found in 21% of the Klebsiella aerogenes, 16% of the indoleproducing Proteus species, 4% of the E. coli and 3% of the Enterobacter spp. tested. Providenca stuartii strains were often resistant to gentamicin and tobramycin.Apart from these exceptions, however, all the organisms tested were sensitive to all four compounds, gentamicin and tobramycin usually showing the highest intrinsic activity.Amikacin was the most active compound against a selection of strains chosen because of their resistance to one or more of the aminoglycosides. Thus, amikacin represents a significant advance over kanamycin and seems to be superior to gentamicin in terms of its in-vitro properties. This is especially the case in those unusual circumstances when gentamicin-resistant strains are a problem. We suggest that amikacin warrants further investigation since it may prove to be a valuable alternative to gentamicin in the treatment of life-threatening infections.

Aminobutyrates↗