1.
Olsson-Liljequist, B, et al.
(författare)
Antimicrobial susceptibility testing in Sweden. III. Methodology for susceptibility testing
1997
Ingår i: Scandinavian Journal of Infectious Diseases. Supplementum. - 0300-8878. ; 105, s. 13-23
Tidskriftsartikel (refereegranskat) abstract
A subcommittee of the Swedish Reference Group for Antibiotics, SRGA-M, has worked with standardization of methodology for susceptibility testing. In vitro data obtained with the disk diffusion procedure were collected from 5 clinical laboratories, compiled and presented as histograms of inhibition zones, and compared with data [minimum inhibitory concentrations (MICs) and inhibition zones] obtained from the reference laboratory at the Swedish Institute for Infectious Disease Control on a collection of clinically relevant bacterial species. Results from the reference collection of strains were presented as MIC histograms, and their corresponding inhibition zones were inserted in the compiled zone histograms as identifiable bars. These distributions formed the basis for decisions of breakpoints. Special tests were recommended for the detection of certain resistance mechanisms. A beta-lactamase test should be used for Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae and enterococci. Screening for beta-lactam resistance caused by altered penicillin binding proteins should be done by using oxacillin 1 microgram for Streptococcus pneumoniae and Staphylococcus aureus (MRSA), and by phenoxymethylpenicillin 10 micrograms for H, influenzae. The standardized disk diffusion procedure was helpful in detecting enterobacteria carrying beta-lactamases with extended spectra. Registration of inhibition zones will provide a powerful tool for the epidemiological surveillance of antibiotic resistance.
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5.
Abate, Getahun, et al.
(författare)
Direct colorimetric assay for rapid detection of rifampin-resistant Mycobacterium tuberculosis
2004
Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 42:2, s. 871-871
Tidskriftsartikel (refereegranskat) abstract
The colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was standardized for direct detection of rifampin-resistant Mycobacterium tuberculosis in sputum samples. The sensitivity and specificity of the direct MTT assay matched those of the standard indirect susceptibility assay on 7H10 medium, and interpretable results were obtained for 98.5% of the samples within 2 weeks. Traditional methods of in vitro drug susceptibility testing are time consuming and laborious. Susceptibility tests on clinical isolates require 6 to 9 weeks, and tests conducted directly on smear-positive samples take about 3 weeks (International Union Against Tuberculosis and Lung Disease, The public health service national tuberculosis reference laboratory and the national laboratory network. Minimum requirements, role and operation in a low-income country, Paris, France, 1998, and P. T. Kent and G. P. Kubica, Public health mycobacteriology. A guide for the level III laboratory, Centers for Disease Control and Prevention, Atlanta, Ga., 1985). More-rapid methods are available but are very expensive for routine use under program conditions in countries with high levels of tuberculosis endemicity.
6.
7.
Brimnes, J, et al.
(författare)
Reactions of N-N and N-O compounds with horseradish peroxidase and peroxidases from Mycobacterium tuberculosis
1999
Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - 1600-0463. ; 107:6, s. 555-565
Tidskriftsartikel (refereegranskat) abstract
Several N-N-and N-O-containing compounds were analysed for their ability to act as substrates for horseradish peroxidase and peroxidases in Mycobacterium tuberculosis extracts. Aminoguanidine, diaminoguanidine, isoniazid, hydroxylamine and hydrazine were found to be weak substrates for horseradish peroxidase in reaction I and to inhibit the reaction of horseradish peroxidase with hydrogen peroxide. The same compounds inhibited the reaction of Mycobacterium tuberculosis peroxidase-catalase with hydrogen peroxide, and hydroxylamine was found to be a weak substrate for this enzyme. In growth inhibition experiments, diaminoguanidine inhibited the growth of M. tuberculosis H37Rv at 50 microg/mL, but not the growth of two isoniazid-resistant strains. Isonicotinic acid hydroxamate inhibited the reaction of the peroxidases with hydrogen peroxide, but was not itself a substrate and had no growth-inhibitory effects. On the basis of these results we suggest that the effect of isoniazid on growth of M. tuberculosis results from increased oxidative stress due to inhibition of catalase-peroxidase as well as from generation of toxic radicals with the structure [structure in text].
8.
Gebre, Negussie, et al.
(författare)
Improved microscopical diagnosis of pulmonary tuberculosis in developing countries
1995
Ingår i: Transactions of the Royal Society of Tropical Medicine and Hygiene. - : Oxford University Press (OUP). - 1878-3503 .- 0035-9203. ; 89:2, s. 191-193
Tidskriftsartikel (refereegranskat) abstract
The diagnosis of pulmonary tuberculosis (TB) relies on the bacteriological examination of sputum. However, microscopy of smears made directly from sputum has a low sensitivity and there is an urgent need for improved methods. We have compared microscopy of smears made directly from sputum with microscopy after liquefaction of sputum with household bleach (NaOCl) and concentration of bacteria by centrifugation. In 3 studies performed in Ethiopia and India, the use of the NaOCl method increased the number of samples positive for acid-fast bacilli by more than 100%. The technique is appropriate for developing countries and its application would increase the efficiency of TB control programmes. As a potent disinfectant, NaOCl also has the advantage of lowering the risk of laboratory infection.
9.
Holst, Elisabet, et al.
(författare)
In vitro activities of cefcanel and some other cephalosporins against Pasteurella multocida
1989
Ingår i: Antimicrobial Agents and Chemotherapy. - 1098-6596. ; 33:12, s. 2142-2143
Tidskriftsartikel (refereegranskat) abstract
Thirty-five strains of Pasteurella multocida from humans and animals were tested for susceptibility to five cephalosporins by a broth dilution method. Cefcanel showed high activity against all isolates (MIC and MBC, less than or equal to 0.64 micrograms/ml). The corresponding figure for cefaclor and cefuroxime was 2.56 micrograms/ml. Cefadroxil and cephalexin were the least active compounds tested.
10.
Larsson, Inger, et al.
(författare)
Interferon production in glia and glioma cell lines
1978
Ingår i: Infection and Immunity. - 1098-5522. ; 22:3, s. 786-789
Tidskriftsartikel (refereegranskat) abstract
Interferon (IF) was produced in glia and glioma cell lines in titers comparable to those produced by human fibroblasts. It was inducible by both Sendai virus and polyriboinosinic:polyribocytidylic acid. "Superinduction" resulted in up to 500-fold-higher titers of IF. The IF appeared to be of the fibroblast type, as revealed by experiments using heat treatment, assay of antiviral activity in heterologous cell lines, and neutralization with specific antisera. Since large amounts of IF may easily be produced with glioma cell lines, such cells may be suitable for mass production of IF.
