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Biomedical subjects

V Hájek

Publications and source records attributed to V Hájek.

At least 19 recordsLinked to original sources
PubMed1998

[Personal experience with classification of yeast microorganisms. I. The combined biotyping method of Mencl and Otcenásek and typing using the "killer" phenomenon].

Using a group of 150 isolates of Candida albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis a C. kefyr the differentiating capacity of two biotyping systems was tested-the combined method according to Mencl and Otcenásek, and typing using the so-called killer phenomenon. With the combined method comparable results with the original work of the authors were obtained. This applies to the number of biotypes as well as to the ratio of the dominant biotype. As regards the differentiating characteristics of different biotypes the two studies differed fundamentally. As to typing, using the "killer" phenomenon, its practical usefulness was tested, the differentiating capacity of the method was, however, very much influenced by the small number of available killer-positive yeast strains.

Candida↗
PubMed1998

[Occurrence of gram-negative non-fermenting rods in hemocultures and their sensitivity to antimicrobial agents].

In the period from January 1993 to June 1996 were at the Department of Microbiology of the University Hospital in Olomouc 122 strains of Gram-negative nonfermentative rod-shaped bacteria isolated from haemocultures. The majority represented the group of 51 strains of the genus Acinetobacter (41.8%), complex A. calcoaceticus-baumannii (Acb complex). The second largest group were 21 strains (17.2%) of Pseudomonas aeruginosa. These were followed by 17 strains (13.9%) of Stenotrophomonas maltophilia, 8 strains (6.6%) of non-Acb complex acinetobacters, 6 strains (4.9%) of Pseudomonas putida and 5 strains (4.1%) of Alcaligenes xylosoxidans. The remaining species were represented only by 1-2 strains. In three isolations was the identification impossible. The majority of strains (24.6%) were from the Department of Haematology of the University Hospital in Olomouc. The most frequent diagnoses in patients with positive haemocultures were leukemias and lymphomas (24.6%). The most effective tested antimicrobial agents were ceftazidime (93.4% of sensitive strains) and ofloxacin (91.7%). From the total number of 80 strains detected using the equipment BacT/Alert 120, 22 (27.5%) were isolated repeatedly confirming their role in the etiology of bacteriemic or septic episodes. Because only one blood sample was obtained in 34 cases (58.6%) of the remaining 58 only once detected strains, it was impossible to confirm their etiologic role by repeated isolation. (Tab. 6, Ref. 22.)

Blood↗
PubMed1996

Borreliae in immature Ixodes ricinus (Acari:Ixodidae) ticks parasitizing birds in the Czech Republic.

Of 411 forest birds of 33 species examined near Valtice, Czech Republic, 29% were infested with Ixodes ricinus (L.); 2.2% were parasitized by Haemaphysalis concinna Koch. Borreliae were detected in 5.1 and 11.7% of larval and nymphal I. ricinus, respectively. None of the 13 H. concinna tested was infected. In total, 3.2% of the birds examined were parasitized by I. ricinus immatures infected by borreliae. Borreliae-containing ticks parasitized European robin, Erithacus rubecula (L.); Eurasian blackbird, Turdus merula L.; Blackcap, Sylvia atricapilla (L.); Eurasian chiffchaff, Phylloscopus collybita (Vieillot); Great tit, Parus major L.; and Eurasian jay, Garrulus glandarius (L.). The isolate BR-34 from a nymphal I. ricinus off a Eurasian blackbird had a sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein pattern, reactions to monoclonal antibodies, and fragments of HindIII digested DNA probed with fla and ospA genes that suggested to us that it belongs to the genospecies Borrelia garinii. Free-living birds may be involved in the circulation of B. burgdorferi sensu lato principally as disseminators of infected ixodid ticks to new area.

Animals↗
PubMed1996

Staphylococcus saprophyticus subsp. bovis subsp. nov., isolated from bovine nostrils.

A new coagulase-negative subspecies, Staphylococcus saprophyticus subsp. bovis, is described on the basis of a study of five strains isolated from the anterior nares of cows. This subspecies is differentiated from the other novobiocin-resistant staphylococci by its phenotypic properties, cell wall composition, and levels of genetic relatedness. The type strain of the new subspecies is KV 12 (=CCM 4410).

Animals↗
PubMed1996

[Comparison of the results of antibiotics sensitivity tests using the standard microdilution method on isolated bacteria and the direct disc method on positive hemocultures from the automatic BacT/Alert system].

During a six-month period 2,221 haemocultures obtained from patients hospitalized in the Faculty Hospital Olomouc were examined. In all 304 isolated bacteria the sensitivity was assessed by the standard dilution micromethod and moreover all positive haemocultures were examined the "direct" disc method. Agreement between the results of the two methods was proved in 84% of pairs of tests and within a range from 67 to 100%, depending on the type of antimicrobial preparation. Based on these findings it may be stated that assessment of the sensitivity by the "direct" method agrees significantly with assessment of the sensitivity according to minimal inhibitory concentrations (MIC). In patients with septicaemia this procedure makes it possible to change empirical antibiotherapy by 24 hours sooner to aimed therapy.

Bacteremia↗
PubMed1996

[Characteristics of multiresistant gram-negative bacteria and their occurrence at the Medical School Hospital in Olomouc].

Currently, a persistent growth of bacterial resistance to antibiotics takes place. Multiresistant bacterial strains thus represent a serious danger for therapy in practice. The aim of the study was to characterize the multiresistant Gram-negative bacteria and to judge their antibiograms by using the minimum inhibition concentrations (MIC). At the same time the study evaluates the relations to the most frequent diagnoses and epidemiologic data concerning the occurrence of these strains in different clinical cases treated at individual departments of the Faculty Hospital in Olomouc. Out of the total of 4.988 strains of Gram-negative rods, the number of isolated multiresistant strains reached 316 (6.3%). Individual bacterial species were isolated in the following order: Pseudomonas aeruginosa (28.8%), Enterobacter cloacae (23.4%) and Acinetobacter Baumannii complex (Acb complex) (18.7%). The most frequent occurrence of investigated bacteria was registered at the departments in the following order: urology (45.9%), internal medicine (18%), paediatrics (13.6%), and surgery (11.1%). The most frequent diagnoses based on positive cultivation of these bacteria were the infections of the urogenital tract (53.8%), postoperative infections (16.8%), and the infections of the upper respiratory ducts (7.3%). 64.2% of strains were cultivated from urine, 16.1% from pus, and 6.9% from swabs taken from the upper respiratory ducts. (Tab. 8, Ref. 18.).

Drug Resistance, Multiple↗
PubMed1995

[Occurrence of Klebsiella pneumonia strains resistant to third-generation cephalosporins at the Pediatric Clinic of the Medical School Hospital in Olomouc].

The authors describe the high incidence of strains of Klebsiella pneumoniae resistant to cephalosporins of the IIIrd generation at the department of pathological neonates of the Paediatric Clinic of the Faculty Hospital in Olomouc. They discuss possible reasons for this adverse situation and the way how to resolve it. They emphasize the necessity of rational administration of antibiotics and continuous monitoring of resistance in the most frequent causal agents of bacterial infections.

Cephalosporin Resistance↗
PubMed1995

Resistance to antibiotics in gram-negative rods from clinical material of hospital and community origin.

The authors examined the resistance to 13 antibiotics and chemotherapeutic agents by the diluting micromethod and the routine disk method in the group of 5375 gram-negative strains of 7 genera which prevailed in clinical material of an hospital (FN Olomouc) and in material of community (OHS Olomouc) provenance during the years 1992 and 1993. In the majority of cases, the resistance was more frequent in the strains isolated from the hospital material. The most remarkable differences were found in A cinetobacter sp. (9-76%), Enterobacter sp. (10-60%) and Citrobacter sp. (18-58%). In other examined species, the differences varied in the ranges 3-40% in E.coli, 2-33% in Klebsiella sp., 0-28% in P. vulgaris, 2-28% in P.mirabilis, 0-16% in M.morganii, and 0-13% in P. aeruginosa.

Drug Resistance, Microbial↗
PubMed1994

[Occurrence and characteristics of gram-negative rods with marginal sensitivity and resistance to ofloxacin].

In the submitted paper the authors focused their attention on the characteristics of Gram-negative bacteria with a marginal sensitivity and resistance to ofloxacin (MIC > or = 2 mg.l-1) isolated from clinical materials in the Olomouc Faculty Hospital. They give an account of their sensitivity (based on assessment of the minimal inhibitory concentration-MIC) to 20 other antibiotics and chemotherapeutic agents and the percentage ratio of different species according to department, clinical material and diagnosis.

Drug Resistance, Microbial↗
PubMed1993

[Hepatitis C virus antibodies in persons on dialysis].

Using the ELISA method (generation II), the authors made a single examination of 172 dialyzed patients for the presence of antibodies against the virus of hepatitis C (VHC). Antibodies were detected in 82 subjects, i. e. 47.7%. The prevalence of antibodies in the examined subjects increased with the number of dialyses, no relationship was found with the number of transfusions. Of 104 subjects where during inclusion into the dialyzation transplantation programme a rise of ALT occurred 69, i. e. 66.3%, had antibodies. Antibodies were detected in 17 of 44 subjects (38.6%) to whom so far blood was not administered. A decisive place in the prevention of VHC transmission in dialyzed subjects is held by non-specific preventive measures, transfusions are most probably not the decisive vehicle.

Adult↗
PubMed1992

Staphylococcus muscae, a new species isolated from flies.

A new coagulase-negative species of the genus Staphylococcus, Staphylococcus muscae, is described on the basis of the results of a study of four strains that were isolated from flies. 16S rRNA sequences of the type strains of S. muscae, Staphylococcus schleiferi, and Staphylococcus sciuri were determined and used, together with the corresponding sequences of Staphylococcus aureus and Staphylococcus epidermidis, for a comparative analysis. The new species is characterized taxonomically; this species is differentiated from the other novobiocin-susceptible staphylococci by its physiological and biochemical activities, cell wall composition, and levels of genetic relatedness. The type strain of this species is strain MB4 (= CCM 4175).

Animals↗
PubMed1991

Environmental genotoxicity monitoring using Salmonella typhimurium strains as indicator system.

Screening for mutagens in environmental complex mixtures is gradually accepted as a routine methodology in the monitoring processes. Examination of 70 drinking water samples showed that the variations in the degree of mutagenicity was dependent on the location of the water source and the type of drinking water tested. Analogous screening for mutagens in river and waste waters may help better assess the potential genotoxic hazard from various types of industrial technology. The recommended methods are routinely used for monitoring the mutagenicity and for checking the effectiveness of preventive measures.

Environmental Monitoring↗
PubMed1991

Characterization of coagulase-positive staphylococci isolated from free-living birds.

A total of 129 coagulase-positive staphylococcal strains were isolated from the nasopharyngeal region of free-living birds--81 (16%) from 501 birds of prey, 29 (25%) from 117 water birds, and 19 (2%) from 937 pheasants. Staphylococcus aureus and Staphylococcus intermedius were identified in 64 (79%) and 17 (21%) strains from birds of prey, in 1 (3%) and 28 (97%) strains from water birds, and in 4 (21%) and 15 (79%) strains from pheasants, respectively. Of the total number of the 69 S.aureus strains 45 (65%) could be biotyped. Biotype D prevailed in the strains from birds of prey. Among all the 60 S.intermedius strains 41 (68%) biotype 1 and 19 (32%) biotype 3 strains could be recognized. Biotype 1 predominated in strains from water birds and pheasants, while biotype 3 in strains from birds of prey. Resistance to antibiotics was recorded in 8 (12%) S.aureus and 5 (8%) S.intermedius strains only. Fifty-six (81%) of the 69 S.aureus strains could be typed with human phages, 30 (44%) with bovine and 41 (51%) with chicken phages. It is evident that the host range of Shimizu's (CH) phages involves not only S.aureus from chicken but also from any other birds. None of these strains was typable with canine phages. Out of the 60 S.intermedius strains 45 (75%) were lysed with Blouse and Meekins' canine phages. When human, bovine, and chicken phages were used, all the 60 strains were completely resistant.

Animals↗
PubMed1990

[Mutagenic activity analysis of body fluids in the first phase of clinical drug trials].

On the example of the model drugs metronidazole and ornidazole, a possible use of an analysis of mutagenic activity of blood and urine in the first stage of clinical testing of drugs is demonstrated. Mutagenicity of blood and urine after metronidazole administration in the dose of 1 and 2 g was examined in 3 experiments with 6 volunteers, the presence of mutagenic drugs in urine in the dose of 1 g was observed till 48 h, in the dose of 2 g till 72 h after administration. Besides base-substitution mutations also frameschif mutations were detected, but with considerable individual variability. Mutagenic activity in blood and urine after the administration of 1 g of ornidazole was investigated in the 1st experiment in 3, in further two experiments in 8 volunteers. It was characterized by a two-peak increase in mutagenicity in blood and urine in the intervals of 1-6 h and 48-72 h. Saturation of 1 g of ascorbic acid daily in the course of 1 week prior to the administration of ornidazole was manifested by a decrease in mutagenic activity in blood and increased excretion of mutagenic drugs in urine.

Adult↗
PubMed1988

Effect of ascorbic acid prophylaxis on the frequency of chromosome aberrations, urine mutagenicity and nucleolus test in workers occupationally exposed to cytostatic drugs.

The genetic risk of workers occupationally exposed to a series of newly developed cytostatic drugs and the presumed antimutagenic potential of ascorbic acid (AA) were studied in a group of 38 chemical laboratory personnel examined for chromosome aberrations in lymphocytes, urine mutagenicity and nucleolar RNA activity before and after a 6-month prophylactic administration of AA at daily doses of 1 g for 5 days a week. Chromosome aberration tests revealed elevated aberrant cell (AB.C) rates both prior to and after AA supplementation (3.9% and 3.65% of AB.C., respectively). These values were significantly higher than those found in 18 non-exposed matching controls (1.05% of AB.C.). Tests for mutagenic activity in the urine of drug-exposed workers revealed 64% positive urine samples prior to vitaminization and 60% positive urine specimens after it; positive urine samples in the group of controls accounted for 21% of samples. In the nucleolus test, numbers of inactivated micronuclei in the exposed were initially higher than those of controls (33.4% versus 24.3%), but dropped to 20.5% after AA supplementation. These findings show that AA prophylaxis alone cannot substantially reduce the hazards associated with exposure to anti-cancer drugs.

Antineoplastic Agents↗
PubMed1988

Phage typing coagulase-positive staphylococci from rooks and gulls.

Phage typing was performed on 86 strains of Staphylococcus aureus and 25 strains of Staphylococcus intermedius from rooks and gulls with human, bovine, chicken and canine phages. Eighty per cent of the S aureus strains and 64 per cent of the S intermedius strains were typable. The S aureus biotype D strains of rook origin were specifically lysed at routine test dilution (RTD) by chicken phages from groups I or I + IV, by human phages belonging to groups I and M, and partly by canine phage 58. The other rook and gull S aureus strains did not show characteristic phage patterns. The S intermedius strains isolated from both species of birds could be typed only with canine phages and this correlated with their classification into biotypes. All the biotype 1 strains tested but only two of 12 biotype 2 strains were lysed with canine phages at RTD.

Animals↗