Karol Račka

Dr. Karol Račka


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2016 in Journal of Wildlife Diseases
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CKCornelia Konicek
Cornelia Konicek
PVPavel Vodrážka
Pavel Vodrážka
PBPavel Barták
Pavel Barták
ZKZdenek Knotek
Zdenek Knotek
CHClaudia Hess
Claudia Hess
STSalome Troxler
Salome Troxler
To assess the importance of wild birds as a reservoir of zoonotic pathogens in Austria and the Czech Republic, we sampled 1,325 wild birds representing 13 orders, 32 families, and 81 species. The majority belonged to orders Columbiformes (43%), Passeriformes (25%), and to birds of prey: Accipitriformes, Strigiformes, and Falconiformes (15%). We collected cloacal swabs from 1,191 birds for bacterial culture and 1,214 triple swabs (conjunctiva, choana, cloaca) for DNA and RNA isolation. The cloacal swabs were processed by classical bacteriologic methods for isolation of Escherichia coli, Salmonella spp., methicillin-resistant Staphylococcus aureus (MRSA), and thermophilic Campylobacter spp. Nucleic acids isolated from triple swabs were investigated by PCR for West Nile virus, avian influenza viruses, and Chlamydia spp. We also tested tissue samples from 110 fresh carcasses for Mycobacterium spp. by PCR and we cultured fresh droppings from 114 birds for Cryptococcus spp. The most-frequently detected...

10 December 2014 in Parasites & Vectors
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Journal Article
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BHBožena Haklová-Kočíková
Božena Haklová-Kočíková
AHAdriana Hižňanová
Adriana Hižňanová
IMIgor Majláth
Igor Majláth
KRKarol Račka
Karol Račka
DHD. James Harris
D. James Harris
VMViktoria Majláthová
Viktoria Majláthová
Blood parasites of the genus Karyolysus Labbé, 1894 (Apicomplexa: Adeleida: Karyolysidae) represent the protozoan haemogregarines found in various genera of lizards, including Lacerta, Podarcis, Darevskia (Lacertidae) and Mabouia (Scincidae). The vectors of parasites are gamasid mites from the genus Ophionyssus. A total of 557 individuals of lacertid lizards were captured in four different localities in Europe (Hungary, Poland, Romania and Slovakia) and blood was collected. Samples were examined using both microscopic and molecular methods, and phylogenetic relationships of all isolates of Karyolysus sp. were assessed for the first time. Karyolysus sp. 18S rRNA isolates were evaluated using Bayesian and Maximum Likelihood analyses. A total of 520 blood smears were examined microscopically and unicellular protozoan parasites were found in 116 samples (22.3% prevalence). The presence of two Karyolysus species, K. latus and K. lacazei was identified. In total, of 210 samples tested by polymerase chain reaction (PCR), the presence of parasites was observed in 64 individuals (prevalence 30.5%). Results of phylogenetic analyses revealed the existence of four haplotypes, all part of the same lineage, with other parasites identified as belonging to the genus Hepatozoon. Classification of these parasites using current taxonomy is complex - they were identified in both mites and ticks that typically are considered to host Karyolysus and Hepatozoon respectively. Furthermore although distortions to the intermediate host erythrocyte nuclei were observed, the defining characteristic of Karyolysus, the haplotypes were nearly identical to those reported from lizards in the Iberian Peninsula, where such distortions were not reported and which were thus identified as Hepatozoon. Based on the phylogenetic analyses, neither vertebrate host, nor geographical patterns of the studied blood parasites could be established.

11 May 2015 in Annals of Agricultural and Environmental Medicine
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Journal Article
Open access
KRKarol Račka
Karol Račka
EBEva Bártová
Eva Bártová
MBMarie Budíková
Marie Budíková
PVPavel Vodrážka
Pavel Vodrážka
The aims of the study were: 1) to detect antibodies against Toxoplasma gondii from wild boar meat; 1) establish seroprevalence of toxoplasmosis in the wild boar population; 3) establish risk factors concerned in higher possible seroprevalence; 4) to estimate the usefulness of meat juice for detection of T. gondii antibodies in wild boar. Diaphragm meat juice samples from 656 wild boar (Sus scrofa) were collected during the hunting seasons between September 2008 - October 2010 from 9 districts of the Czech Republic. The samples were stratified per age category into 2 groups: piglets (n = 279) and yearlings together with adults (n = 377). The in-house ELISA test was used for the detection of antibodies against T. gondii from the meat juice samples. Antibodies against T. gondii were detected by in-house ELISA in 260 of 656 wild boars (40%) with 26% prevalence in piglets (72/279) and 50% prevalence in yearlings and adults (188/377). The district total seroprevalences ranged between 32% - 59%, with a significantly higher prevalence in the district of Havlíčkův Brod (59%). Statistically significant differences (p-value < 0.05) were found between 2 age categories, and between 9 districts, with a significant variability in the district of Havlíčkův Brod. Seroprevalence correlated positively with farm density, but without any statistical significance. The obtained results indicate that consumption of raw or undercooked meat from wild boars can carry an important risk of toxoplasma infection. Post mortem detection of antibodies in meat juice samples using ELISA is a useful alternative to blood serum examination. In addition, a diaphragm sample has been well-proven as a matrix sample for the contemporaneous diagnostics of trichinellosis and toxoplasmosis.

19 February 2008 in Parasitology Research
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Andrei Daniel MihalcaAndrei Daniel Mihalca
Andrei Daniel Mihalca
KRKarol Račka
Karol Račka
Calin Mircea GhermanCalin Mircea Gherman
Calin Mircea Gherman
DID. T. Ionescu
D. T. Ionescu

30 January 2024 in Frontiers in Cellular and Infection Microbiology
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Journal Article
Open access
KRKarol Račka
Karol Račka
EBEva Bártová
Eva Bártová
AHAzra Hamidović
Azra Hamidović
NPNicolas Plault
Nicolas Plault
AKAlica Kočišová
Alica Kočišová
AHAli Halajian
Ali Halajian
Introduction: There have only been a few molecular studies conducted on the detection of T. gondii in tissues of carnivores in South Africa, with no data on the genetic diversity of this parasite. That is why the aim of this study was to detect and genotype T. gondii DNA in tissues of selected wild and domestic carnivores in South Africa.Methods: Samples were collected from 80 animals of 20 species (mainly road-killed) in the four provinces of Limpopo (n=57), Mpumalanga (n=21), Gauteng (n=1) and Free State (n=1) during the period 2014–2018. Samples of brain (n=31), heart (n=4), liver (n=40), spleen (n=2) and lung (n=3) were used to detect T. gondii by real-time PCR targeting a 529 bp repeating fragment of T. gondii DNA. Samples that were positive in real-time PCR were genotyped using 15 microsatellite markers.Results: T. gondii DNA was detected in 4 (5 %) samples: in the brain from a Black-backed Jackal (Canis mesomelas), in the liver from a African Wildcat (Felis silvestris lybica) and in the liver and heart of two Rusty-spotted Genets (Genetta maculata) respectively. The DNA sample from Black-backed Jackal was genotyped and characterized as belonging to the type Africa 4 lineage (equivalent to RFLP genotype ToxoDB#20), that is a widespread lineage in Africa.Discussion: This is the first genetic characterization of T. gondii isolated from a wild carnivore on the African continent and the first report of T. gondii in Black-backed Jackal. The Africa 4 lineage was also confirmed in the region of Southern Africa for the first time.

22 December 2015 in Journal of Medical Entomology
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JRJana Rádrová
Jana Rádrová
MMMarie Mračková
Marie Mračková
ZGZdeňka Galková
Zdeňka Galková
JLJiří Lamka
Jiří Lamka
KRKarol Račka
Karol Račka
JVJan Votýpka
Jan Votýpka
In the light of the emergence of bluetongue and Schmallenberg viruses in northern and central Europe, an extensive entomological survey within the framework of a bluetongue control program was undertaken from 2008 to 2013 in the Czech Republic to investigate Culicoides biting midges (Diptera: Ceratopogonidae) collected in close proximity of domestic livestock and semiwild ruminants. Insects were sampled using CDC black-light suction traps placed overnight near ruminants in farms or in forest game preserves to provide data on Culicoides fauna collected near these two groups of hosts inhabiting different environments. From almost a half million biting midge specimens collected at 41 sampling sites, 34 species were identified including three species newly recorded for the Czech Republic: Culicoides (Oecacta) clastrieri Callot, Kremer & Deduit, Culicoides (Oecacta) odiatus Austen, and Culicoides (Pontoculicoides) saevus Kieffer. The Culicoides obsoletus species group, incriminated as a bluetongue virus vector, was predominant in both domestic livestock (91%) and semiwild game (52%). A relatively high proportion (around 30%) of C. obsoletus Meigen females with pigmented abdomen (= more likely parous) was observed from spring till autumn. In contrast, adult biting midges were found to be largely absent during at least three winter months, approximately December till March, which could be considered as the biting midge vector-free period.