- Publikační typ
- abstrakt z konference MeSH
The results of the antimicrobial susceptibility testing of clinical isolates Streptococcus suis to amoxicillin and marbofloxacin obtained by the agar dilution method and broth microdilution method with the results obtained by the commercially available E-test were compared. Comparisons between the methods based on the determination of the minimal inhibitory concentration (MIC) of the antimicrobials were assessed based on the degree and frequency of the categorical agreement (Agar dilution method as a reference system) and the percentage of the categorical agreement and error rate. A statistical evaluation was determined using the Bland-Atman method. The presented MIC values, determined for the isolates in the E-test, were slightly different from the MIC values determined by the dilution tests, mainly due to the different defined testing concentrations. For the E-test as the test system and agar-dilution method as the reference system, no error of any class was detected (very major, major and minor error) and a complete categorical agreement was obtained between the evaluated methods for amoxicillin. For amoxicillin, the regression and correlation analysis show linear relationships between the E-test and the two dilution methods with significant coefficients of determination (0.62 and 0.75). The slopes of the equality and regression lines were not significantly different. However, the E-test tends to slightly overestimate the MIC values when compared to the microdilution. The reverse is true when compared with the agar dilution. There was good agreement between the E-test and the dilution methods with a low bias (0.001 3 and −0.005 0), all the experimental data were within the computed limits of agreement. For marbofloxacin, the same trends were observed with lower coefficients of determination (0.42 and 0.73) and a less favourable agreement. The E-test constantly underestimated the MIC values when compared to the two dilution methods. No significant difference between the microdilution and agar dilution was obtained.
Enterotoxigenic Staphylococcus aureus in raw milk poses a potential health hazard to consumers, and the identification of such strains should be used as part of a risk analysis of milk and milk products. The primary purpose of this study was to investigate the occurrence of enterotoxigenic S. aureus strains in raw milk supplied for dairy processing in the Czech Republic. A further aim was to compare the production of staphylococcal enterotoxins (SEs) with the presence of the corresponding genes. This was undertaken using multiplex polymerase chain reaction (PCR) and reversed passive latex agglutination (RPLA). Out of 440 bulk tank milk samples from 298 dairy herds, 70 proved positive for S. aureus (15.9%). Staphylococcal enterotoxin genes (ses) were detected in 39 (55.7%) isolates. The genes most commonly detected were sei (38.6%), seg (31.4%) and sea (27.1%). Genes seb, seh, sed, sej and sec were observed in 10%, 4.3%, 2.9%, 2.9% and 1.4% of strains respectively. Genes see and sel did not occur. The most frequently detected genotypes were seg, sei at 11.4%; sea at 10.0%; and sea, seg, sei at 8.6%. Toxin production was observed in nine (12.9%) S. aureus isolates. Seven strains were detected as SEB- (10%) and two as SED- (2.9%) producing. A relatively high number (32%) of discrepancies between the results with multiplex PCR and RPLA assays was obtained, particularly on account of SEA. Nineteen strains were sea positive by PCR but SEA negative by RPLA, and one strain was sec positive and SEC negative. The results of both methods were identical concerning SEB and SED. It was concluded that detection of ses by PCR was a useful additional tool to support identification of enterotoxigenic strains.
- MeSH
- amplifikace genu MeSH
- antigeny bakteriální analýza genetika MeSH
- DNA bakterií genetika chemie MeSH
- enterotoxiny analýza genetika MeSH
- genotyp MeSH
- kontaminace potravin analýza MeSH
- latex fixační testy MeSH
- lidé MeSH
- mléko MeSH
- počet mikrobiálních kolonií MeSH
- polymerázová řetězová reakce metody MeSH
- potravinářská mikrobiologie MeSH
- prevalence MeSH
- sekvence nukleotidů MeSH
- skot MeSH
- spotřebitelská bezpečnost produktů MeSH
- Staphylococcus aureus izolace a purifikace metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Geografické názvy
- Česká republika MeSH
