Summary
Objectives and hypothesis: This thesis concerns the study of plasmids of vancomycin-
resistant enterococci isolated from feces of American crows in the years 2012 - 2013 period.
The hypothesis is that, in various environments, there is one or more types of
epidemiologically significant vanA gene-carrying plasmids that are capable of horizontally
spread.
Methods: Based on PFGE method the number and size of plasmids were detected in selected
isolates of vancomycin-resistant E. faecium. Using PCR method the isolates were subjected
to detection of genes of replicases, relaxases and toxin-antitoxin system of plasmid-bound
resistance genes. Using 19 primers were characterized types of Tn1546.
Results: Of the 12 tested vancomycin-resistant isolates of E. faecium the following number
and size of plasmids was proven using PFGE method: 2 isolates contained two plasmids
(17%), 3 isolates contained three plasmids (25 %), 5 isolates contained four plasmids (42 %)
and 2 isolates contained five plasmids (17 %).
All isolates (n = 12) were then subjected to the detection of genes of replicases, relaxases and
toxin-antitoxin system for typing of plasmids from each plasmid families.
RepA_N family of plasmids:
genes characterizing plasmids related to pRUM: rep17 in 11 isolates (92 %),
gene Axe-Txe was detected in 5 isolates (42 %)
genes characterizing plasmids related to pLG1: rep20 in 7 isolates (58 %)
genes characterizing plasmids related to pAD1: relpAD1 gene was detected in one isolate (8 %)
Inc18 family of plasmids:
genes characterizing plasmids related to pIL501: rep1 gene detected in one case (8 %)
genes characterizing plasmids related to pRES25: rep2 gene in 2 isolates (17 %)
genes characterizing plasmids related to pEF1: relpEF1 detected in 11 isolates (92 %)
pHTB family of plasmids:
genes characterizing plasmids related to pHTB: rep22 gene was detected in 4 isolates (33%) and in 2 isolates gene relpHTB was detected (17%)
RCR family of plasmids:
genes characterizing plasmids related to pRI: positive detection of Rep14 gene in 8 isolates (67%) and in 4 isolates relpRI gene was detected
Small theta-replicating plasmids:
genes characterizing plasmids related to pEF418 plasmids: rep18a gene in 2 isolates (17%)
genes characterizing plasmids related to pB82: rep18b gene was detected in one isolate (8%)
genes characterizing plasmids related to pCIZ2: relpCIZ2 gene was detected in 9 isolates tested (75%)
Types of transposon Tn1546
Using the PCR method types of Tn1546 were characterized. In 4 isolates (n = 12; 33 %)
Tn1546 was characterized as a F3 type. In one isolate (8 %) Tn1546 was characterized as a
type F5, in one isolate (8 %) as a type PP-16. In 6 isolates Tn1546 was untypeable. Most
likely these are new, yet unknown types.
Conclusion: This is the first study of plasmids of vancomycin-resistant isolates E. faecium
isolated from feces of American crows. These results emphasize not only a high proportion of
plasmids in individual isolates, but also a high proportion of genes with horizontal transfer.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:257670 |
| Date | January 2016 |
| Creators | Bubeníček, Karel |
| Contributors | Rada, Vojtěch, Igor, Igor |
| Publisher | Česká zemědělská univerzita v Praze |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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