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K Machka

Publications and source records attributed to K Machka.

At least 19 recordsLinked to original sources
PubMed1992

[Incidence, frequency and resistance characteristics of methicillin-oxacillin resistant Staphylococcus aureus strains in Germany].

In a multicentre study, the methicillin-resistant Staphylococcus aureus (MRSA) isolates in 19 large clinics in Germany were recorded, and the resistance characteristics of these strains were studied. Oxacillin-mannitol-salt agar plates were distributed to all participants to ensure uniformity of screening, and each laboratory used these plates to investigate 200 consecutive Staphylococcus aureus isolates for oxacillin-methicillin resistance. Of the 3,794 evaluable Staphylococcus aureus isolates, 71.5% were penicillin and 3.7% (142) oxacillin resistant; four study centres reported methicillin-oxacillin resistance rates of more than 5%. Of the MRSA isolates, 75% were also resistant to ciprofloxacin, 61% to fosfomycin, 52% to imipenem, 50% to trimethoprim/sulfamethoxazole and 36% to clindamycin. All isolates were sensitive to vancomycin and teicoplanin. Of the Staphylococcus aureus strains isolated from patients in intensive therapy units, 10.4% were methicillin-oxacillin resistant. Drains and catheter tips (9.8% and 5.2% respectively) were the materials with the highest proportions of MRSA. Of the MRSA isolates in this study, 58.2% belonged to lysis group II.

Ciprofloxacin↗
PubMed1992

[Evaluation of the so-called basic cephalosporins using the serum bactericidal test].

The serum bactericidal activity (SBA) was studied one hour and four hours after intravenous administration of 1 g and 2 g cefotiam, 1.5 g cefuroxime and 2 g cefazolin to six volunteers. The 136 clinical isolates tested included Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Haemophilus influenzae. One hour after administration no significant differences in the activity against staphylococci were noted in the antibiotics tested. Four hours after administration of cefazolin 96% of the Staphylococcus aureus strains were killed at a serum dilution of 1:8, whereas only one strain was killed by cefuroxime and none by cefotiam under the same conditions. The highest SBA-titers against Haemophilus influenzae were achieved with cefotiam at a dosage of 2 g. SBA-titers against Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were higher after administration of 1 g cefotiam than after administration of 1.5 g cefuroxime and 2 g cefazolin, respectively.

Blood Bactericidal Activity↗
PubMed1989

[Prospective, comparative study of a infrared spectroscopic blood culture system (Bactec NR-660)].

The automatic Bactec NR-660 system was compared with a conventional blood culture system - Septi-Check, La Roche (RSC). Out of a total of 962 blood cultures 157 isolates were detected: 123 in RSC and 104 in Bactec 6A. If only clinical relevant strains were considered the isolation rate was nearly equal in both systems, being 75% in RSC and 77% in Bactec 6A, respectively. The RSC-system was more frequently contaminated (3.3% vs 1.0%). Positive blood cultures were detected 12 hrs earlier by the Bactec system.

Automation↗
PubMed1988

Distribution and resistance patterns of Haemophilus influenzae: a European cooperative study.

The first European survey of the prevalence of antibiotic resistance in Haemophilus influenzae was conducted between February and October 1986. Eighty laboratories in nine countries participated (Austria, Belgium, France, FRG, The Netherlands, Spain, Sweden, Switzerland and the UK). A total of 1,961 clinical isolates was examined for type b encapsulation, beta-lactamase production and susceptibility to ampicillin, chloramphenicol, cefaclor, erythromycin and tetracycline, using a unique microdilution method. The proportion of isolates resistant to these antibiotics varied considerably between individual countries. The highest prevalence of ampicillin resistance was found in Spain (30.6%), and the lowest in the FRG (1.6%), with a mean value of 10% for all countries. Chloramphenicol resistance was highest in Spain (24.9%) and Belgium (10.9%) and lowest in The Netherlands (0.6%) and Austria (0.5%), with a mean value of 4.7%. Resistance to erythromycin ranged from 27% of the isolates in The Netherlands to 1.1% in Austria. For tetracycline, values ranged from 1.5% in the UK to 17.8% in Belgium and 25.4% in Spain. The lowest mean prevalence of resistance was observed for cefaclor (breakpoint 8 mg/l): 5% or less in all countries. These inter-country differences could only partially be explained by variations in the proportion of type b strains, the source of the isolates and the mode of collection.

Ampicillin Resistance↗
PubMed1988

In vitro activity of new antibiotics against Haemophilus influenzae.

The activity of sulbactam/ampicillin, aztreonam, cefetamet, cefixime, ciprofloxacin, enoxacin, fleroxacin and ofloxacin was determined against 160 Haemophilus influenzae strains using a standardized microdilution method. The strains were categorized into four groups according to beta-lactamase production and their resistance to ampicillin, chloramphenicol, erythromycin, tetracycline and cotrimoxazole. All isolates tested, regardless of their beta-lactamase production or resistance to the above mentioned drugs, were susceptible to the nine antibiotics. The most active antimicrobial agents were aztreonam, cefixime, and the two quinolone derivatives ciprofloxacin and ofloxacin.

Anti-Bacterial Agents↗
PubMed1987

Comparative in vitro activity of RO 23-6240 (fleroxacin), a new 4-quinolone derivative.

The in vitro activity of RO 23-6240 was compared with that of norfloxacin, ofloxacin and ciprofloxacin as well as four other antimicrobial agents against 345 recent clinical isolates. The MICs of RO 23-6240 against Enterobacteriaceae and Acinetobacter anitratum was less than or equal to 0.5 mg/l. At the same concentration of the compound 90% of staphylococci were inhibited. Against Enterococcus faecalis and Pseudomonas aeruginosa RO 23-6240 proved less active, having MIC90 values of 4.0 mg/l and 8.0 mg/l, respectively. Enterobacteriaceae and staphylococci strains that were resistant to piperacillin, cefotaxime or tobramycin were susceptible to the compound. In general the activity of RO 23-6240 was comparable to those of norfloxacin and ofloxacin, but less than that of ciprofloxacin.

Anti-Bacterial Agents↗
PubMed1987

Serum bactericidal activity of ciprofloxacin and ofloxacin in volunteers.

The serum bactericidal activity of two newer quinolones, ciprofloxacin and ofloxacin, against 206 clinical bacterial isolates was determined in six male volunteers after oral administration of either 500 mg of ciprofloxacin or 200 mg of ofloxacin respectively. The highest bactericidal titers were achieved against Enterobacteriaceae 1 h after ciprofloxacin administration, ranging from 1:121 for indole-positive Proteus species to 1:30 for Serratia spp. Ofloxacin generated lower titers, ranging from 1:14 for indole-positive Proteus spp. to 1:2.5 for Enterobacter spp. Only low serum bactericidal titers were found for Pseudomonas aeruginosa, Acinetobacter spp. and gram-positive cocci. It is concluded that the activity of orally administered ciprofloxacin is superior to that of orally administered ofloxacin in the serum bactericidal test.

Administration, Oral↗
PubMed1987

Comparative in vitro activity of LY146032 (daptomycin) against gram-positive cocci.

The in vitro activity of LY146032 was compared with those of seven other antimicrobial agents against gram-positive cocci. MICs of LY146032 were lowest for Streptococcus pneumoniae and methicillin-susceptible Staphylococcus epidermidis (0.25 mg/l). For methicillin-resistant Staphylococcus epidermidis and Staphylococcus aureus the MICs were 1 mg/l, for Enterococcus faecalis 2 mg/l and for Enterococcus faecium 4 mg/l. The activity of LY146032 was in general higher than that of vancomycin. Time-kill studies showed LY146032 had higher bactericidal activity than vancomycin against a methicillin-resistant Staphylococcus aureus strain, and bactericidal activity against Enterococcus faecalis and Enterococcus faecium.

Aminocoumarins↗
PubMed1986

Comparison of the serum bactericidal activity of ceftriaxone/piperacillin and ceftriaxone/netilmicin.

The serum bactericidal activities of ceftriaxone, netilmicin, piperacillin and the combinations of ceftriaxone with each of the two other antibiotics were compared 1, 4 and 24 h after i.v. infusion in six volunteers. One hundred and one clinical isolates were used, including Staphylococcus aureus, Pseudomonas aeruginosa and various Enterobacteriaceae. The highest bactericidal titers were found against the Enterobacteriaceae, geometric means of 1:741 and 1:851 being obtained for ceftriaxone/netilmicin and ceftriaxone/piperacillin respectively. Against Staphylococcus aureus the geometric mean bactericidal titers of ceftriaxone/piperacillin (1:105) were markedly higher than ceftriaxone/netilmicin (1:35). Low bactericidal activity was exhibited by all drugs and combinations tested against Pseudomonas aeruginosa; a geometric mean bactericidal titer of 1:4.6 was achieved. The serum bactericidal activity of the double beta-lactam combinations was found to be at least equal to that of the combination containing a cephalosporin and an aminoglycoside.

Ceftriaxone↗
PubMed1986

Evaluation of novel antipseudomonal drugs using the serum bactericidal activity test.

Serum bactericidal activity against Pseudomonas aeruginosa was determined in six volunteers 1 and 4 h after administration of 2 g ceftazidime, 4 g piperacillin, 500 mg imipenem, 80 mg tobramycin and four combinations of these agents. Ceftazidime produced the highest serum bactericidal titers, killing 100% and 86% of the 50 Pseudomonas aeruginosa strains tested after 1 and 4 h respectively at a serum dilution of 1:8. Imipenem had lower serum bactericidal titers than ceftazidime, killing 88% of the isolates after 1 h at a serum dilution of 1:8. The combination showed only slightly higher titers. Killing curves were determined for nine strains of Pseudomonas aeruginosa using undiluted volunteer serum drawn 1 h after administration of the antibiotics. The combinations ceftazidime/tobramycin and piperacillin/tobramycin exhibited higher killing activity than the single drugs. As the activity of the aminoglycosides could be underestimated on the basis of their low serum bactericidal titers, it is concluded that determination of these titers is inappropriate for evaluating the efficacy of the aminoglycosides.

Ceftazidime↗
PubMed1986

[Treatment of chronic osteomyelitis with a collagen-antibiotic compound--preliminary report].

A compound of collagen and gentamicin was used in a controlled examination on 67 patients for the treatment of posttraumatic as well as postoperative osteomyelitis and, when applying cement-free endoprostheses, for hemostasis and local prevention of infection in the bed for implantation. Even in case of relatively high doses, the gentamicin concentration measured was only at the threshold value of detectability, due to the local application of the absorbable antibiotic compound. In most of all cases (n = 63), the healing of infection is demonstrated by clinical and radiobiological investigation.

Collagen↗
PubMed1979

[Antibacterial activity of cefotaxim in comparison with seven cephalosporins].

The antibacterial activity of cefotaxim and seven cephalosporins was determined in 1,112 fresh isolates using the microdilution technique. All of the cephalosporins tested were ineffective against enterococci. Cefalotin was the most effective agent against Staphylococcus aureus. Cefaclor was superior to cephalexin against Escherichia coli and Proteus mirabilis, and thus inhibited 20% more Enterobacteriaceae. Cefazolin was as effective as cefamandole against E. coli. Cefuroxime and cefoxitin were almost equally effective against E. coli, Klebsiella and P. mirabilis; more than 95% of the strains were sensitive. Cefuroxime and also cefamandole were much more effective than cefoxitin against Citrobacter and Enterobacter. Cefoxitin on the other hand was superior against Serratia and indol-positive Proteus species. Cefotaxim was by far the most active cephalosporin against Enterobacteriaceae, only 2% of the strains being resistant. More than 90% of the strains of E. coli, Klebsiella, P. mirabilis and Serratia were sensitive to 1 mg/l, the lowest degree of activity being displayed against Enterobacter; 82% of the strains were inhibited by 16 mg/l. Cefotaxim was the only cephalosporin which showed appreciable activity against Pseudomonas.

Bacteria↗
PubMed1979

[The antibacterial efficacy of cefaclor against bacteria resistant to ampicillin, tetracycline and co-trimoxazole (author's transl)].

The antibacterial activity of the new oral cephalosporin cefaclor was investigated using 623 freshly isolated bacterial strains. A high degree of efficacy of cefaclor was noticed against Escherichia coli, Proteus mirabilis and Klebsiella. Nearly all strains which were sensitive to ampicillin, tetracycline and co-trimoxazole were also inhibited by cefaclor. Some of the strains resistant to the three above-mentioned antibiotics were also sensitive to cefaclor as follows: all of ten P. mirabilis strains resistant to co-trimoxazole, 54% of the E. coli strains resistant to ampicillin, tetracycline and co-trimoxazole, and 18% of the Klebsiella strains resistant to tetracycline and co-trimoxazole.

Cefaclor↗
PubMed1978

The influence of maternal immunoglobulin-G-antibodies on indirect haemagglutination in newborns.

High antibody titers against Escherichia coli were found in 100 randomly selected pregnant women by means of indirect haemagglutination (IHA). After birth, sera from the umbilical vein of the newborns were also tested. It was found that the indirect haemagglutination titers of the children were strongly influenced by the IgG which had been transferred via the placenta. Twenty-two sera of newborns showed an increased IHA-titer against E. coli, but only seven children displayed specific IgM antibodies, determined by indirect immunofluorescence. After chromatographic separation of the sera into IgG and IgM fractions, it was demonstrated that isolated antibodies of the IgG type alone can produce increased IHA titers. The assumption that the indirect haemagglutination is determined almost exclusively by antibodies of the IgG type is unfounded. Therefore, indirect haemagglutination is not suitable as a screening-test for newborns.

Antibodies, Bacterial↗
PubMed1978

[A method for testing susceptibility of Haemophilus influenzae to co-trimoxazole (author's transl)].

Various methods for determining the activity of co-trimoxazole against haemophilus influenzae have been compared. The results were cortically influenced by antagonistic substances in the medium. The content of p-aminobenzoeacid and thymidine in the medium should be as low as possible. The antagonistic influences are compensated by lysed horseblood, which contains thymidine-phosphorylase. Haeminchloride and nicotinamide adenine dinucleotide (NAD) are better growth-factors than other poorly defined preparations (Supplement C, Fil-des-Enrichment, Iso-VitaleX). For the determination of the minimal inhibition concentration (MIC) we propose the microtiter technique. Likewise a modified agar diffusion test can be recommended for screening purposes. Of the 143 haemophilus influenzae strains tested against co-trimoxazole 134 (94%) were sensitive.

4-Aminobenzoic Acid↗