Recent results 2017

Insecticides with embryotoxic potential

Neonicotinoids are new generation of widely used insecticides and they act as agonists to the nicotinic acetylcholine receptors (nAChRs) of insect in the central nervous system with greater affinity than to mammals.
The potential toxicity of neonicotinoids (thiacloprid, acetamiprid, thiamethoxam and clothianidin) as well as related commercial products Calypso 480SC (thiacloprid mixture), Mospilan 20SP (acetamiprid mixture) and Agita 10WG (thiamethoxam mixture) on developmental capacities and quality of preimplantation embryos was evaluated. During in vitro tests, isolated 2-cell stage mice embryos were cultured in media with various concentrations of active compounds or commercial products until blastocysts formation. Stereomicroscopic examination showed that all neonicotinoids at highest (100 µM) concentration negatively affected embryonic development (P<0.001). Fluorescence staining revealed that obtained blastocysts displayed lower number of blastomeres and elevated incidence of cell death. Thiacloprid and acetamiprid decreased quality of blastocysts also at 10 µM concentration. From the tested products only Calypso 480SC containing 10µM of thiacloprid showed harmful impact on embryo quality. In experiment using rabbit, similar negative effect of thiacloprid was recorded. In vivo test proved that blastocysts collected from thiacloprid-treated female mice displayed lower total cell counts than blastocysts from control females. Despite the declared minimal danger for mammalian cells and organs, our study has clearly demonstrated that neonicotinoids could adversely affect embryonic cells. The sensitivity of embryonic cells to neonicotinoids is in an order of thiacloprid > acetamiprid, thiomethoxam > clothianidin. Thiacloprid impaired development and quality of both mouse and rabbit preimplantation embryos, and shows embryotoxicity even at acute reference dose.
BABEĽOVÁ, Janka – ŠEFČÍKOVÁ, Zuzana – ČIKOŠ, Štefan – ŠPIRKOVÁ, Alexandra – KOVAŘÍKOVÁ, Veronika – KOPPEL, Juraj – MAKAREVICH, A.V. – CHRENEK, P. – FABIAN, Dušan. Exposure to neonicotinoid insecticides induces embryotoxicity in mice and rabbits. In Toxicology, 2017, 392C, p. 71-80. (3.582 – IF2016). https://doi.org/10.1016/j.tox.2017.10.011

Campylobacters and enterocins

Campylobacters represent bacteria threating poultry. They are transmitted throughout broiler sheds by the feaecal-oral route. Broiler chicken but also the others poultry species are food-producing animals; it means bred for direct consumption or products originated from them. Therefore, the interest of breeders is to maintain healthy husbandry; it is in close relation with healthy food and healthy food is the interest of consumers. A promising startegy to reduce Campylobacter spp. or campylobacteriosis in poultry could be done due to the beneficial properties of probiotic bacteria and their bacteriocins. Altogether 102 faecal samples from 237 different poultry were examined. Based on Maldi-Tof mass spectrometry and genotypization, 23 isolated strains were taxonomically allotted to the species Campylobacter jejuni (19) and C. coli (4). Identified strains were mostly resistant to antibiotics; however, they were sensitive to enterocins; at least to one Ent from 9 used (produced by enterococci, characterized at our laboratory). The most active was Ent A (P) (produced by E. faecium EK13/CCM7419); 52% tested campylobacters were sensitive to this Ent. After Enterocin M-producing strain E. faecium AL41 application, reduced counts of Campylobacter spp. in chickens infected with C. jejuni CCM6191 were noted; AL41 can modulate TLR expression and modify activation of MIF, IFN-beta, MD-2 and CD14 molecules in caecum of infected chickens. Results achieved create promising base for further applicationss of enterocins/their producer strains.
ŠČERBOVÁ, Jana – LAUKOVÁ, Andrea. Sensitivity to enterocins of Thermophilic Campylobacter spp. from different poultry species. In Foodborne pathogens and disease, 2016, vol. 13, no. 12, p. 668-673, (2.12-IF2016 ), https://doi.org/10.1089/fpd.2016.2158

Analysis of ruminant methane emission

In cooperation with the international project METHAGENE, which is focused on the breeding of ruminants with a lower environmental burden, experiments were carried out at the Institute of Agricultural Sciences (ETH Zürich, Switzerland). Utility of ruminal fluid from slaughtered cattle in studying differences in methane emissions between different animal breeds were examined. The published results showed differences within and between breeds in the methane emission potential and methane mitigating potential. The rumen fluid could be useful for determining age-dependent changes in the ruminal environment as far as methane formation. Information from slaughterhouse databases, farm and animal diet are necessary. Rumen fluid from slaughtered animals may be useful to study variations in methane emission from different cattle breeds.
WANG, S. – PISARČÍKOVÁ, Jana – KREUZER, M. – SCHWARM, A. Utility of an in vitro test with rumen fluid from slaughtered cattle for capturing variation in methane emission potential between cattle types and with age. In Canadian Journal of Animal Science, 2017, (0.827-IF2016), https://doi.org/10.1139/cjas-2016-0238


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