Recent results 2013

Antibiotic resistance in the rooks

The study was focused on antibiotic resistance in the rooks, which have many behavioural and ecological aspects important from an epidemiological point of view. A total of 130 Escherichia coli strains isolated from rook faeces were investigated for antibiotic resistance and virulence. E. coli strains with a higher level of MICs of cephalosporins and fluoroquinolones were selected for detection of betalactamase genes (CTX-M, CMY), plasmid-mediated quinolone resistance qnrS, integrase 1, and for avian pathogenic E.coli virulence factors (iutA, cvaC, iss, tsh, ibeA, papC, kpsII). Genes of CTX-M1, CMY-2, integrase 1, papC, cvaC, iutA were detected in one strain of E.coli, and qnrS, integrase 1, iss, cvaC, tsh were detected in another E.coli. DNA microarray revealed the absence of verotoxin and enterotoxin genes and pathogenicity islands. The results show that rooks can serve as a reservoir of antibiotic-resistant E. coli with avian pathogenic virulence factors for the human population, and potentially transmit such E. coli over long distances.

KMEŤ, Vladimír – DRUGDOVÁ, Zuzana – KMEŤOVÁ, M. – STANKO, Michal. Virulence and antibiotic resistance of Escherichia coli isolated from rooks. In Annals of Agricultural and Environmental Medicine, 2013, vol.20, no.2, p.273-275. Contact: kmetv (at)

Isolation of Staphylococcus nepalensis from guano

Cultivated bacteria from the six years old guano sample from mixed Myotis myotis and M. blythii summer roosts colony were isolated and identified as Staphylococcus nepalensis using combination of MALDI TOF and 16S rRNA gene sequencing analysis. Several virulence factors were produced by tested isolates, mainly capsule formation and resistance to tetracycline, ampicillin and chloramphenicol antibiotics. This is the first report on the occurrence of S. nepalensis in the guano of bats and our results indicate that the guano accumulated near or directly in human dwellings and buildings may represent a significant risk for human health.

VANDŽUROVÁ, Anna – BAČKOR, Peter. – JAVORSKÝ, Peter – PRISTAŠ, Peter. Staphylococcus nepalensis in the guano of bats (Mammalia). In Veterinary Microbiology, 2013, vol., 164, p. 116-121. Contact: pristas(at)

Analysis of Polo-Like kinase 1 (Plk1)

The western blotting showed that the Plk1 protein content increased significantly during the S-phase of the one-cell stage and declined during the first mitotic division. Activation of Plk1 preceded nuclear envelope breakdown (NEBD) in both pronuclei at the entry to first embryo mitosis. Immunofluorescence revealed the presence of phosphorylated, active PLK1 (pThr210-Plk1) in both male and female pronuclei, and in the microtubule-organizing centers (MTOCs) shortly before NEBD. During the first mitotic metaphase, pThr210- Plk1 accumulated at the spindle poles and was also associated with condensed chromosomes. Inhibition of Plk1 activity with a specific Plk1 inhibitor, BI 2536, at the one-cell stage induced the formation of a bipolar spindle that displayed disordered microtubular arrangements and dislocated, condensed chromosomes. Although such embryos entered mitosis, they did not complete mitosis and arrested at metaphase. Time-lapse recording revealed progressive misalignment of condensed chromosomes during first mitotic metaphase. These data indicate that Plk1 activity is not essential for entry into first mitosis, but is required for the events leading up to metaphase-anaphase transition in the one-cell mouse embryo.

BARAN, Vladimír – ŠOLC, P. – KOVAŘÍKOVÁ, Veronika – REHÁK, Pavol – ŠUTOVSKÝ, P. Polo-like kinase 1 is essential for the first mitotic division in the mouse embryo. In Molecular Reproduction and Development, 2013, vol. 80, p. 522-534.  Contact: baran(at)