Biomedical subjects

M Votava

Publications and source records attributed to M Votava.

At least 19 recordsLinked to original sources

PubMed2006

[Methods for detection of biofilm formation in routine microbiological practice].

The increasing use of catheters, artificial implants and antimicrobials as well as high numbers of immunocompromised patients are major causes for concern over biofilm infections. These infections are characterized particularly by high resistance to antimicrobials and formation of persistent foci that may complicate therapy. Therefore, detection of biofilm formation is of high relevance to the clinician and his/her approach to the treatment. Reliable and sensitive methods for detection of this pathogenicity factor in clinically important organisms, suitable for use in routine microbiological laboratories, are needed for this purpose. Currently, a wide array of techniques are available for detection of this virulence factor, such as biofilm visualization by microscopy, culture detection, detection of particular components, detection of physical and chemical differences between biofilm-positive organisms and their planktonic forms and detection of genes responsible for biofilm formation. Since each of these methods has limitations, the best results can be achieved by combining different approaches.

Biofilms↗

PubMed2006

[Detection and significance of biofilm formation in yeasts isolated from hemocultures].

BACKGROUND: Yeasts of the genus Candida are important opportunistic pathogens responsible for severe bloodstream infections in immunocompromised patients. An important virulence factor that allows them to colonize plastic implants and to survive in the blood is their ability to form biofilm. The purpose of the study was to assess, how frequently this virulence factor occurred in yeasts of the genus Candida isolated from blood cultures. MATERIALS AND METHODS: Cultures of the various strains in wells of microtitre plates were used to demonstrate the presence of biofilms. In total, we tested 72 isolates of yeasts of the genus Candida from the blood culture: C. albicans (33), C. parapsilosis (19), C. tropicalis (11), C. glabrata (4), C. krusei (3), C. lipolytica (1) and C. lusitaniae (1). RESULTS: The ability to form biofilm was demonstrated in 26 strains. The largest number of biofilm-positive strains was found in C. parapsilosis (13) and C. tropicalis (7). The formation of biofilms was far less frequent in the strains of C. albicans (4). The formation of biofilms was also demonstrated in C. krusei (2) and C. glabrata (1). CONCLUSION: The increasing frequency of fungal bloodstream infections is due to the increasing use of catheters and implants. The biofilm formation in these yeasts is the chief factor of virulence promoting such infections. The demonstration of biofilm formation in an isolated strain is indicative of the probable existence of a biofilm focus and of possible difficulties during antimycotic therapy.

Biofilms↗

PubMed2006

[Molecular detection and subtyping of Treponema pallidum subsp. pallidum in clinical specimens].

An in-house two-step nested PCR amplification targeting the tmpC gene (TP0319, encoding putative membrane lipoprotein) was used for detection of chromosomal DNA of Treponema pallidum subsp. pallidum in clinical specimens. We tested 138 blood serum samples from 111 adult patients with suspected, primary, secondary, early or late latent syphilis. T. p. pallidum DNA was not detected in any of the analyzed specimens. Out of 11 mucocutaneous swabs (7 genital and 4 pharyngeal), 6 collected from 3 patients with primary or secondary syphilis tested positive. One skin swab from a patient with early congenital syphilis was also positive as were his serum and cerebrospinal fluid samples. DNA sequencing of the genes TP0136 and TP0548 from the positive samples revealed two strains with DNA sequences identical to that of T. p. pallidum strain SS14 and two unique previously undescribed T. p. pallidum strains. The advances in molecular typing of T. p. pallidum in clinical specimens will be of relevance to the epidemiology of syphilis and will allow for clinical discrimination between reinfection and syphilitic reactivation.

Adult↗

PubMed2005

Increased sensitivity to the acute effects of MDMA ("ecstasy") in female rats.

Behavioral effects of +/-3,4-methylenedioxymethamphetamine (MDMA, ecstasy) are relatively well described in humans as well as in animals. However, little is known about gender differences to the effects of MDMA. The aim of our study was to evaluate gender differences in stimulant effects of MDMA (2.5, 5.0, and 10.0 mg/kg subcutaneously (s.c.)) in male and female Wistar rats. We have used three behavioral methods (activity cage, open field, and elevated plus-maze) each describing a different pattern of spontaneous behavior. In the activity cage, 30 min after the MDMA administration, horizontal and vertical locomotor activities were registered for a period of 3 min. In the open field test rats were placed into an arena 15 min after drug treatment and locomotor activity was registered for a period of 30 min. Finally, in the elevated plus-maze test, rats were given MDMA 30 min prior to measurements and subsequently they were tested in the maze for a period of 5 min. In our experiments we observed a dose-dependent locomotion-enhancing effect of MDMA both in male and female rats in both locomotor tests. Female rats were more sensitive to the locomotor-stimulating effect than males in both tests, suggesting higher sensitivity to the stimulatory effect of MDMA. Further on, MDMA increased thigmotaxis in female rats in the open field test and decreased "anxious-like" behavior in the elevated plus-maze in both genders. In conclusion, we observed higher sensitivity of females to the locomotor-stimulant effect of MDMA. Increased sensitivity of females to the behavioral effects of MDMA can be explained by increased reactivity of serotonergic and dopaminergic systems.

Animals↗

PubMed2005

Relation of sex and estrous phase to deficits in prepulse inhibition of the startle response induced by ecstasy (MDMA).

Sensorimotor gating is the ability of a weak sensory event to inhibit the motor response to an intense stimulus. Drugs that act as serotonin releasers, such as MDMA (3,4-methylenedioxymethamphetamine), impair sensorimotor gating, which is measured as a prepulse inhibition (PPI) of the acoustic startle response. The first objective of the present study was to compare the effect of different doses of MDMA on PPI and the acoustic startle response (ASR) in male and female Wistar rats. The second objective was to examine the effect of MDMA on PPI across the estrous cycle in female rats. MDMA was administered in doses of 2.5, 5 and 10 mg/kg s.c. 15 min before the start of the experiment. The controls received saline in equivalent volumes. MDMA dose-dependently decreased PPI in both the male and female rats and produced higher levels of ASR in the male rats compared to the females. In addition, we found that female rats in the diestrous and metestrous phases are more sensitive to MDMA and showed higher deficits in PPI than female rats in the proestrous and estrous phases. Our result showed that female rats in the proestrous and estrous phases were less sensitive to the disruption of PPI by MDMA.

Acoustic Stimulation↗

PubMed2005

[Inhibition of hemolytic activity of Staphylococcus aureus 3-hemolysin by an exosubstance produced by some Enterococcus faecalis strains].

OBJECTIVE: Accidentally, some Enterococcus faecalis strains were found to inhibit the hemolysis caused by Staphylococcus aureus beta-hemolysin. The study objectives were to define the conditions under which this phenomenon appears and to characterize the inhibitory agent. MATERIALS AND METHODS: Ninety-one wild strains and five type strains of E. faecalis and nine wild E. faecium strains were tested for antihemolytic activity on blood agar with 5% sheep erythrocytes prepared using the following agar bases: Columbia Agar Base (BBL, 211124), Columbia Agar (Bio Mérieux, 51026), Blood Agar Base (Bio-Rad, 64524), Blood Agar Base (Columbia) (Ferosa, 1-034), Columbia Blood Agar Base (HiMedia, M114), Blood Agar Base No. 4 (Imuna), Columbia Agar Base (Merck, 10455) and Columbia Agar Base (Oxoid, CM331). The exosubstance produced by E. faecalis strains was isolated by means of acetone precipitation and was exposed to elevated temperature and trypsin. RESULTS: Thirty-three (36%) out of 91 wild strains of E. faecalis produced the substance inhibiting hemolysis caused by Staphylococcus aureus beta-hemolysin. Two out of five E. faecalis type strains and none of E. faecium strains appeared to be producers of the same substance. Inhibition of the hemolysis was observed on all of the media tested, being the most pronounced with the use of Blood Agar Base No. 4 (Imuna) and Columbia Agar Base (BBL) at pH 7.0-7.5 when cultured at 37 degrees C for 24 hours. The exosubstance lost its inhibitory effect after exposure to 70 degrees C for 15 min and to 0.1% trypsin for 30 min. The inhibitory potential against staphylococcal hemolysis correlated with the ability of strains to produce protease. CONCLUSION: About one third of wild E. faecalis strains produce a protease-like substance that seems proteinaceous in nature and has an inhibitory effect on the hemolysis caused by Staphylococcus aureus beta-hemolysin.

Animals↗

PubMed2005

[Czech terms for rod-shaped bacteria].

With increasing frequency, the rod-shaped bacteria have been recently referred to in Czech as tyce (the singular is tyc) instead of the diminutive tycinky (the singular is tycinka) as used in classical Czech textbooks and handbooks of medical microbiology. This discordance might result from inadequate translation of the English term rods. Although the English-Czech dictionary gives three equivalents for the analyzed meaning of this word, i.e. tyc, tycka, tycinka, the first option, a mono-syllable as the English rod is, is often selected without further consideration. Nevertheless, such simplification is not justified; to avoid confusion it is preferable to use conventional terminology.

Bacteria↗

PubMed2004

Biofilm detection and the clinical significance of Staphylococcus epidermidis isolates.

The ability of Staphylococcus epidermidis to produce biofilm was compared in 147 clinically significant strains repeatedly isolated from blood cultures of patients with bloodstream infection and in 147 strains isolated from skin. The strains were examined for the presence of ica operone, for the ability to form biofilm by Christensen's test-tube method and for the production of slime by Congo Red agar method. The ica operone was found in 92 (62.6 %) blood isolates and in 44 (29.9) isolates from skin. Christensen's test-tube method was positive in 79 (53.7) and 33 (22.4), Congo Red agar method in 64 (43.5) and 31 (21.1) of blood and skin isolates, respectively. All three methods were more frequently positive in clinically significant isolates from blood than in strains isolated from skin. The detection of ica operone and the Christensen's test-tube method showed better correlation with the clinical significance than the Congo Red agar method.

Bacteremia↗

PubMed2004

Determination of minimal regrowth concentration (MRC) in clinical isolates of various biofilm-forming bacteria.

Based on the ability to attach to polymeric surfaces, the formation of biofilms was determined in 5 wild-type strains (Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanii, Escherichia coli, Staphylococcus warneri). Using modified Christensen method, minimum regrowth concentration (MRC) of piperacillin, piperacillin-tazobactam, cefoperazon, ceftazidim, cefepim, meronem, ciprofloxacin, netilmicin and amikacin for Gram-negative and of ampicillin-sulbactam, chloramphenicol, tetracycline, clindamycin, vancomycin and teicoplanin for Gram-positive bacteria was estimated in trypticase-soy broth medium after a 1-d growth on polystyrene microtiter plates. Adherent bacterial populations exhibited reduced antimicrobial susceptibility, which was not shown in submerged cultures. Our results indicate that MRC can predict therapeutic outcome of antibiotic treatment better than the minimum inhibitory concentration tests commonly used.

Acinetobacter baumannii↗

PubMed2004

[Differences in antibiotic sensitivity in biofilm-positive and biofilm-negative strains of Staphylococcus epidermidis isolated from blood cultures].

The adhering capability and biofilm growth facilitate staphylococcal colonization of surfaces of damaged tissues and foreign bodies. Biofilm-forming bacteria are more resistant to immune system activities, mechanical effects of blood flow and other adverse effects, e.g. those due to antibiotics. Minimal inhibitory concentrations (MICs) were compared for two groups of Staphylococcus epidermidis strains isolated from blood cultures. Group 1 included biofilm positive strains whose biofilm-forming potential was revealed by both phenotypic and genotypic methods. Group 2 included strains without biofilm-forming potential. The comparison of MICs for selected antibiotics showed higher resistance of biofilm positive compared to biofilm negative strains. The difference was evident particularly for oxacillin, tetracycline, co-trimoxazole and gentamicin.

Biofilms↗

PubMed2004

Impact of surface coating on the adherence of slime producing and nonproducing Staphylococcus epidermidis.

The ability of Staphylococcus epidermidis to grow in the form of a biofilm not only facilitates its persistence in the host, but also allows it to survive at antibiotic concentrations several orders higher than the Minimum Inhibitory Concentration (MIC). We evaluated different surface treatments of hardened polystyrene in order to develop a model system for growth of S. epidermidis as a biofilm. We assayed for biofilm growth of S. epidermidis clinical isolates on unmodified polystyrene, on polystyrene modified by chemical abrasion and on polystyrene modified by sulfonation, using either Tryptic Soya Broth or Brain Heart Infusion as a growth medium. We concluded that sulfonated polystyrene and Brain Heart Infusion provided the best growth system for predicting the ability of a clinical isolate to form biofilm (Akaike value 23.680). Using this method, biofilm formation was detected in 14 (70%) of ica-positive strains and negative in 16 (80%) of ica-negative strains.

Bacterial Adhesion↗

PubMed2004

[Solitary fibrous tumor of the pleura--description of two cases with features of malignancy].

Two cases of solitary fibrous tumor of the pleura with features of malignancy are described. In the first case, the tumor macroscopically showed noncircumscribed growth. Microscopically, on low power examination, the tumor was characteristically "patternless", with alternation of cellular areas and hypocellular, prominently collagenized areas. There was an infiltrative growth present at the margins. Cytological atypias were not present. In the second case, the tumor was macroscopically circumscribed. Microscopically, on low power examination, the tumor had characteristical "patternless" appearance again. Pleomorphic cells with high mitotic activity dominated in cellular areas on high power examination. The infiltrative pattern of growth was not present at the margins. Both tumors were classified as malignant solitary fibrous tumors of the pleura, or fibrosarcomas of the pleura. The criteria of malignancy for solitary fibrous tumor are discussed.

Female↗

PubMed2003

Botryoid-type of embryonal rhabdomyosarcoma of renal pelvis in an adult. A case report and review of the literature.

A case of botryoid-type embryonal rhabdomyosarcoma of the renal pelvis in a 49-year-old woman is reported. The tumor led to hydronephrosis. The surgical resection specimen disclosed a translucent, polypoid mass attached to the wall of the renal pelvis by thin stalk. Light-microscopic examination revealed a large exophytic polypoid tumor with intact surface epithelium, which was negative for dysplasia or carcinoma in situ. There was a condensation of epithelioid to spindle cells underneath the basement membrane, forming a cambium layer. The core of the lesion contained interspersed epithelioid to spindle cells with myxoid change and edema. Cells of the cambium layer as well as interspersed cells in the core exhibited marked cytologic atypia with mitotic figures. Immunohistochemical stains for cytokeratin, S-100 and myoglobin were negative, stains for desmin and actin were positive. Although botryoid-type embryonal rhabdomyosarcomas have been reported to occur at various sites in the genital tract and lower urinary tract, to our knowledge, this is the first reported case of the tumor within the renal pelvis. Also, the occurrence of these tumors in adults is quite rare.

Female↗

PubMed2003

[Molecular diagnosis of infections].

Molecular diagnostics (detection of nucleic acids by molecular genetics techniques) become more valuable in clinical diagnosis of disease. Apart from the already long-time used genetic techniques for detection of congenital anomalies, current use of molecular techniques includes detection of microbial pathogens. The character of these techniques increases the possibility of achieving diagnosis in cases where classical cultivation is not possible, is not reliable or is not fast enough. As with every new approach, molecular diagnostics have faced encountered reactions from the scientific community. Some scientists tend to overestimate the value of molecular diagnostic techniques, while sceptics, sometimes influenced by a biased or incomplete knowledge of the technology, think it is of little value. In this work, on the basis of literature and our own data from more than 5 years of experience with these methods, we have assessed the pros and cons of the use of molecular diagnostics of infectious diseases in the light of their potential use in clinical practice.

Bacterial Infections↗

PubMed2003

Unusual course of treatment of a patient diagnosed with Pemphigus Vulgaris (case report).

The case report is describing patient with an autoimmune disease, Pemphigus Vulgaris. This patient arrived to the general practitioner with Pemphigus Vulgaris after 20 days from the first manifestation of the disease. Despite intensive care, patient dies forty-seventh day after first clinical manifestation of the illness of candidemia. Candidiasis was diagnosed only in postmortem examination.

Candidiasis↗

PubMed2002

[Contradictory results of passive hemagglutination and immunoenzyme tests in the determination of specific immunoglobulin G in the serodiagnosis of lues].

BACKGROUND: With continuing automatization it comes into consideration, which tests should be a part of the syphilis screening. Trying to learn more about the correlation and comparability of passive hemaglutination and imunoenzymatic assay, which are the candidate reactions on the screening test, we analyzed results of the above mentioned reactions in 2319 serum samples sent for diagnostics of syphilis. Special attention was paid to sera with contradictory results in both tests. METHODS AND RESULTS: When results were contradictory the patient's probability of having syphilis and the intensity of the reaction were analysed. Out of 2319 sera samples examined for syphilis 141 (6.1%) specimens belonging to 125 patients were found to provide contradictory results in passive hemagglutination (TPHA) and immunoenzymatic assay for the specific immunoglobulins G (ELISA IgG). In 14 cases (children of syphilitic mothers) only the passively transferred antibodies were found and these samples were excluded from the examined group. Almost four fifths of contradictions (88 out of 111, i.e. 79.3%) were based on the positivity of TPHA with the negativity of ELISA IgG and one fifth only (23 specimens, i.e. 20.3%) concerned the positivity of ELISA IgG with the negativity of TPHA. The relation to syphilis was more obvious in the TPHA-positive patients: in 88 TPHA-positive patients the syphilitics were relatively more common (39 syphilitics, i.e. 44.3%) than in 23 ELISA-positive patients (5 syphilitics, i.e. 21.7%), the difference is statistically significant (p < 0.05). CONCLUSIONS: It is concluded that TPHA seems to be more sensitive, whereas ELISA IgG more specific.

Adult↗

PubMed2002

Effects of alprazolam and fluoxetine on morphine sensitization in mice.

Benzodiazepines seem to be frequently abused in conjunction with opioids. Fluoxetine was reported to block morphine locomotor sensitization in rats. Sensitization has been implicated in some aspects of drug abuse. We have investigated the effect of alprazolam (0.25 mg/kg) and fluoxetine (5 mg/kg) on the development and expression of sensitization to the locomotor stimulant effect of morphine (10 mg/kg) in mice. Sensitization was produced by daily injections of morphine (10 mg/kg) for 10 days. There was a clear sensitization of locomotor activity produced by morphine in photocell activity cages but co-administration of alprazolam with morphine had no effect on the degree of sensitization. Alprazolam was also without effect on the expression of the sensitized response to morphine in mice sensitized with morphine alone. Fluoxetine partly reduced both the development and expression of morphine sensitization. In conclusion, the present experiments have not yielded evidence that alprazolam may influence the development or the expression of sensitization to morphine. However, they have corroborated and extended results indicating that fluoxetine can attenuate, to a certain level, the development and expression of morphine sensitization.

Alprazolam↗

PubMed2002

[Biofilms and their significance in medical microbiology].

Microorganisms are able to adhere to various surfaces and to form there a three-dimensional structure known as biofilm. In biofilms, microbial cells show characteristics and behaviours different from those of plankton cells. Intercellular signalizations of the quorum-sensing type regulate interaction between members of the biofilm. Bacteria embedded in the biofilm can escape and form well known planktonic forms, that are obviously only a part of the bacterial life cycle. Bacteria adhere also to medically important surfaces such as catheters, either urinary or intravenous ones, artificial heart valves, orthopedic implants and so on and contribute to device-related infections like cystitis, catheter-related sepsis, endocarditis etc. Once a biofilm has been established on a surface, the bacteria harboured inside are less exposed to the host's immune response and less susceptible to antibiotics. As an important cause of nosocomial infections the biofilm must remain in the centre of the microbiologist's attention.

Biofilms↗