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Biomedical subjects

M Gacs

Publications and source records attributed to M Gacs.

15 recordsLinked to original sources

Occurrence and regional distribution of SHV-type extended-spectrum beta-lactamases in Hungary.

In order to determine the presence and geographical distribution of SHV-type extended-spectrum beta-lactamase genes among Enterobacteriaceae strains in Hungary, isolates from 25 microbiology laboratories throughout the country were collected between January 2002 and August 2003 and examined. Sequencing of the genes showed that SHV-5 and SHV-2a are the dominant SHV-types in extended-spectrum beta-lactamase-producing Enterobacteriaceae strains in this country. The SHV-2 gene, which is prevalent in many European countries, was not detected, but one isolate carried the SHV-12 gene. The results show that these genes are circulating among Enterobacteriaceae strains in Hungary and indicate that strict infection control measures are warranted in order to prevent their spread.

Cross Infection↗

Diagnostic value of certain mastitis markers in following up the clinical and bacteriological changes in pharmacotherapeutic studies.

Trends of certain mastitis markers were studied in udder quarters (n = 201) showing clinical symptoms of acute mastitis. Besides the clinical examination, before the first treatment (baseline sample), and about 3 weeks later, 17 to 24 days following the last treatment (control sample) milk samples were collected for bacteriological identification of the mastitis pathogens and for the determination of certain inflammatory markers: somatic cell count (SCC), N-acetyl-beta-D-glucosaminidase (NAGase) and alpha 1-antitrypsin (ATR) activities, as well as bovine serum albumin (BSA) and chloride (Cl-) concentrations. Based upon the clinical and bacteriological status as well as the SCC recorded at the control investigations, 6 groups were established (recovered, latently infected, subclinical mastitis: bacteriologically positive and negative, as well as clinical mastitis: bacteriologically positive and negative). As compared to the baseline samples, all parameters decreased in the case of recovered udder quarters, as well as in those with abated latent infection or subclinical mastitis at the time of control examination. Comparing the control samples of the different categories, characteristic differences were found in NAGase activity, indicating the grade of cytodamaging effect of mastitis. Of the other markers, ATR and Cl- proved to be more adequate for the differentiation than BSA. It can be concluded that, in addition to SCC, first of all NAGase can be recommended for use as an inflammatory parameter in pharmacodynamic studies. Besides these two parameters, ATR and Cl- can also be chosen as a possible third marker.

Acetylglucosaminidase↗

Antibiotic susceptibility of Bacteroides fragilis group strains in Hungary.

Resistance rates to different antibiotics of 495 Bacteroides fragilis group strains were followed between 1987 and 1994 in Hungary. In 1992 the strains were collected in three different laboratories, whereas during the other periods strains were isolated in one centre. Metronidazole, chloramphenicol, imipenem and amoxicillin/clavulanic acid were the most active drugs. A high level of resistance was observed in 1987 for ampicillin (88% at > 4 mg/L), erythromycin (51% at > 4 mg/L), tetracyclin (53% at > 8 mg/L) and clindamycin (27% at > 4 mg/L). The same level of resistance was seen during the further years for clindamycin and ampicillin. Resistance to cefoxitin increased from 6% to 11% between 1987 and 1993/1994. No differences in resistance rates were observed between the strains collected in the three centers. For 100 strains, the results of the E test were compared with those of the micro-broth dilution test, both being used routinely for testing the antibiotic susceptibility of Bacteroides fragilis group strains in this period.

Journal Article↗

Resistance to beta-lactam antibiotics and beta-lactamase production of Bacteroides, Porphyromonas and Prevotella strains.

Resistance to beta-lactam antibiotics of 183 clinical isolates belonging to Bacteroides, Porphyromonas and Prevotella was tested by a micro-broth dilution MIC method. Beta-lactamase production was screened by using nitrocefin sticks. Prevalence of resistance to different beta-lactam antibiotics was higher among the Bacteroides strains other than B. fragilis parallel with a beta-lactamase production (88% and 96%, respectively). Resistance was observed less frequently among Porphyromonas and Prevotella strains. Cefoxitin resistance was 11.5% and amoxicillin/clavulanic acid 3.5% among Bacteroides isolates, whereas no resistance was found to these antibiotics among the Porphyromonas and Prevotella strains. All strains tested were susceptible for imipenem. Beta-lactamase production of selected isolates was tested quantitatively. Beta-lactamase of B. fragilis 1 and B. levii differed in their isoelectric points, substrate profiles and inhibition by clavulanic acid, sulbactam and tazobactam.

Anti-Bacterial Agents↗

[Correlation of slime production and pathogenicity of coagulase-negative staphylococci].

Coagulase-negative staphylococci have been increasingly recognized as pathogens in patients with indwelling medical devices. Slime production may be an important virulence factor. Slime production and antibiotic susceptibility were studied of 117 coagulase-negative staphylococci isolated from clinical specimens. The frequency of slime production among 26 coagulase-negative staphylococci was about three times higher than among 91 isolates regarded as contaminants. The former strains were isolated from 10 patients, 8 of which had device related infections. Multiply resistant cultures occurred in 22.2%, but all strains were susceptible to vancomycin.

Coagulase↗