Maciej Grzybek

Medical University of Gdansk | MUG · Department of Tropical Parasitology

Parasites are considered to be an important selective force in host evolution but ecological studies of host-parasite systems are usually short-term providing only snap-shots of what may be dynamic systems. We have conducted four surveys of helminths of bank voles at three ecologically similar woodland sites in NE Poland, spaced over a period of 11...

Rodents are known to play a significant role as reservoir hosts for TBEV. During three sequential expeditions at four year intervals to three ecologically similar study sites in NE Poland, we trapped bank voles (Myodes glareolus) and then tested their blood for the presence of specific antiviral antibodies to TBEV. The strongest effects on seroprev...

SARS-CoV-2 is the aetiological agent of COVID-19 disease and has been spreading worldwide since December 2019. The virus has been shown to infect different animal species under experimental conditions. Also, minks have been found to be susceptible to SARS-CoV-2 infection in fur farms in Europe and the USA. Here we investigated 91 individual minks f...

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of coronavirus disease and has been spreading worldwide since December 2019. The virus can infect different animal species under experimental conditions, and mink on fur farms in Europe and other areas are susceptible to SARS-CoV-2 infection. We investigated SARS-Co...

In this study we screened for the presence of antibodies against hantavirus, arenavirus and cowpox virus in Polish bank voles over a 9 year period. Cowpox virus was most prevalent and its prevalence was affected by both extrinsic and intrinsic factors.

The increasing frequency and cost of zoonotic disease emergence due to global change have led to calls for the primary surveillance of wildlife. This should be facilitated by the ready availability of remotely sensed environmental data, given the importance of the environment in determining infectious disease dynamics. However, there has been littl...

In June 2023, a fatal disease outbreak in cats occurred in Poland. Most cases tested in Poland (29 of 47) were positive for highly pathogenic avian influenza (HPAI) A (H5N1) virus. Genetic analyses revealed clade 2.3.4.4b with point mutations indicative of initial mammalian hosts adaptations. Cat viral sequences were highly similar (n = 21), sugges...

Rodents are known to be reservoirs of Toxoplasma gondii and keep the parasite circula-tion in the environment. We conducted biomonitoring to assess the role of sylvatic rodents in maintaining T. gondii and to analyse the prevalence and seroprevalence of the parasite in seven wild rodent species. Rodents were collected in our open grassland study si...

Swine is a common model organism for biomedical research. Epigenetic reprogramming in somatic cell nuclear transfer (SCNT) embryos does not fully recapitulate the natural DNA demethylation events at fertilisation. This study aimed to conduct genome-wide methylation profiling to detect differentially methylated regions (DMRs) responsible for epigene...

The family Trombiculidae encompasses numerous and widespread mites, the larvae of which are obligatory parasites of vertebrates. Our research objective was to assess how trombiculid burdens on rodents inhabiting three forested and one open area in NE Poland vary in relation to host identity, sex and body size, and how they are influenced by qualiti...

Rodents are known to be reservoirs of Toxoplasma gondii and keep the parasite circulation in the environment. We conducted biomonitoring to assess the role of sylvatic rodents in maintaining T. gondii and to analyse the prevalence and seroprevalence of the parasite in seven wild rodent species. Rodents were collected in our study sites (woodland an...

Candidatus Neoehrlichia mikurensis (CNM) and Hepatozoon spp. are important vector-borne parasites of humans and animals. CNM is a relatively recently discovered pathogen of humans. Hepatozoon are parasites of reptiles, amphibians and mammals, commonly found in rodents and carnivores worldwide. The present study aimed to determine the prevalence of...

Small mammals are suspected of contributing to the dissemination of Toxocara canis and helping with the parasite survival during periods when there is a temporary absence of suitable definitive hosts. While the primary aim of the current study was the assessment of seroprevalence of Toxocara spp. infections in wild rodents in Poland, we also explor...

We report results from serologic surveillance for exposure to SARS-CoV-2 among 1,237 wild rodents and small mammals across Europe. All samples were negative, with the possible exception of 1. Despite suspected potential for human-to-rodent spillover, no evidence of widespread SARS-CoV-2 circulation in rodent populations has been reported to date. E...

Several studies reported a high prevalence of SARS-CoV-2 among white-tailed deer in North America. Monitoring cervids in all regions to better understand SARS-CoV-2 infection and circulation in other deer populations has been urged. To evaluate deer exposure and/or infection to/by SARS-CoV-2 in Poland, we sampled 90 red deer shot by hunters in five...

Several studies reported a high prevalence of SARS-CoV-2 among white-tailed deer in North America. Monitoring cervids in all regions to better understand SARS-CoV-2 infection and circulation in other deer populations has been urged. To evaluate deer exposure to SARS-CoV-2 in Poland, we sampled 90 reed deer individuals shot by hunters in five huntin...

We report serological surveillance for exposure to SARS-CoV-2 in 1,237 wild rodents and other small mammals across Europe. All samples were negative with the exception of one. Given the ongoing circulation of this virus in humans and potential host jumps, we suggest such surveillance be continued.

Swine is a common model organism for biomedical research. Epigenetic reprogramming in SCNT embryos does not fully recapitulate the natural DNA demethylation events at fertilisation. This study aimed to conduct a genome-wide methylation profiling to detect differentially methylated regions (DMRs) responsible for epigenetic differences in stem cells...

Small mammals are suspected of contributing to the dissemination of Toxocara canis and helping with the parasite's survival during periods when there is a temporary absence of suitable definitive hosts. While the primary aim of the current study was the assessment of seroprevalence of Toxocara spp. infections in wild rodents in Poland, we also expl...

Major histocompatibility complex (MHC) genes encode proteins crucial for adaptive immunity of vertebrates. Negative frequency‐dependent selection (NFDS), resulting from adaptation of parasites to common MHC types, has been hypothesized to maintain high, functionally relevant polymorphism of MHC, but demonstration of this relationship has remained e...

The proteolytic and antioxidant systems are important components of humoral immunity, and these biomarkers indicate the immune status. These compounds are synthesized in the bees' fat body and released into the hemolymph. Their functions maintain the organism's homeostasis and protect it against adverse environmental factors (including pathogens)....

Chronically hemodialyzed (HD) patients are vulnerable population during a SARS-COV-2 pandemic. They are at high risk of developing very severe forms of COVID-19 disease. In this article we describe, for the first time to our knowledge, three HD patients (all males, aged 70, 70 and 74 years) vaccinated intramuscularly with two doses of the mRNA BNT1...

Objectives This work aimed to analyse possible zoonotic spillover of SARS-CoV-2. We report the spillover of mink-adapted SARS-CoV-2 from farmed mink to humans after adaptation that lasted at least three months. Methods Next –Generation Sequencing and bioinformatic approach were applied to analyse the data. Results In an isolate obtained from an a...

Astrovirus infections pose a significant problem in the poultry industry, leading to multiple adverse effects such as a decreased egg production, breeding disorders, poor weight gain, and even increased mortality. The commonly observed chicken astrovirus (CAstV) was recently reported to be responsible for the “white chicks syndrome” associated with...

Routine genomic surveillance on samples from COVID-19 patients collected in Poland during summer 2021 revealed the emergence of a SARS-CoV-2 Delta variant with a large 872 nt deletion. This change, confirmed by Sanger and deep sequencing, causes complete loss of ORF7a , ORF7b , and ORF8 genes. The index case carrying the deletion is unknown. The st...

Toxoplasma gondii is an intracellular Apicomplexan parasite with a broad range of intermediate hosts, including humans and rodents. Rodents are considered to be reservoirs of infection for their predators, including cats, felids, pigs, and wild boars. We conducted a multi-site, long-term study on T. gondii in northeastern Poland. The study aimed to...

The COVID-19 pandemic caused by SARS-CoV-2 started in fall 2019. A range of different mammalian species, including farmed mink, have been confirmed as susceptible to infection with this virus. We report here the spillover of mink-adapted SARS-CoV-2 from farmed mink to humans after extensive adaptation that lasted at least 3 months. We found the pre...

Toxoplasma gondii is a significant pathogen affecting humans and animals. We conducted seromonitoring for T. gondii in four sylvatic rodent species in Poland. We report an overall seroprevalence of 5.5% (3.6% for Myodes glareolus and 20% for other vole species). Seroprevalence in bank voles varied significantly between host age and sex.

Rodents are known to be reservoir hosts for a plethora of zoonotic viruses and therefore play a significant role in the dissemination of these pathogens. We trapped three vole species (Microtus arvalis, Alexandromys oeconomus and Microtus agrestis) in northeastern Poland, all of which are widely distributed species in Europe. Using immunofluorescen...

Rodents are known to be reservoir hosts for a plethora of zoonotic viruses and therefore play a significant role in the dissemination of these pathogens. We trapped three vole species (Microtus arvalis, M. oeconomus and M. agrestis) in N.E. Poland, all of which are widely distributed species in Europe, and, using immunofluorescence assays, we asses...

Blastocystis is an enteric microorganism commonly found in humans and animals worldwide. Its pathogenic role in humans and transmission patterns has not been fully explained. However, nine subtypes (ST1–8, ST12) are considered as potentially zoonotic. Studies from various regions of the world show that pigs are mainly infected with ST5. Although pi...

Safe and efficient techniques for the live capture of carnivores are limited. In this study, we identified some of the factors that could affect the success of capturing red fox cubs with live capture traps (also known as cage traps). During a three-year period, we analysed 32 captures of 25 fox cubs (1.3 captures/fox). We assessed the impact of th...

Background: Rodents constitute an important part of the diet of many carnivore species. This predator-prey food chain is exploited by helminth parasites, such as cestodes, whose larval stages develop in rodents and then mature to the adult stage in predators. The main aim of our study was to use molecular techniques for identification of cestode s...

Rodents are known to be reservoir hosts of zoonotic viruses and therefore play a significant role in the dissemination of these pathogens. Using immunofluorescence assays, we carried out the first long-term seromonitoring programme for hantavirus, arenavirus and cowpox virus infections in bank voles from three ecologically similar, but separate, si...

Rodents play a role as reservoir hosts for tick-borne encephalitis virus (TBEV). We trapped voles of the genus Microtus and tested their blood for the presence of antibodies against TBEV. We detected TBEV antibodies in three adult individuals (3.9%). Voles may play a role in the circulation of TBEV.

Lactate is produced by active skeletal muscles. H+ is produced during lactate neutralization in the Cori cycle, which leads to muscle acidosis and sores (so called Delayed Onset Muscle Soreness – DOMS) in vertebrates. The aim of the study was to determine the activities/concentrations of compounds which may be involved in the Cori cycle in bee work...

Rodents play an important role as reservoir hosts of zoonotic diseases. As a component of our long-term programme of monitoring parasitic infections in bank vole populations in three ecologically similar sites in NE Poland, we screened blood samples for signs of a serological response to the presence of Trichinella spp. The overall seroprevalence o...

Many factors, including pathogens, environmental change and breeding techniques, affect honeybee immunity/resistance, so substances and natural supplements that enhance it are desired. To eliminate the impact of unknown external factors, in 2016 a cage experiment was conducted under constant laboratory conditions (35 °C, 65% relative humidity). Bee...

The Apicystis bombi neogregarines parasitize bumblebees. Apis mellifera is its accidental host but, in the future, it might become its ultimate host. Using PCR and microscopic analysis we found A. bombi in 1 of 10 apiaries in Central Europe. The colony was queenless, with rebel workers. The parasite was detected in the hemolymph and digestive tract...

Background: Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for vertical transmission in their mammalian hosts. We aimed to determine: (i) the prevalence and diversity of Bartonella spp. in a Microtus spp. community; (ii) whether vertical...

The CRISPR/Cas9 system, a natural defence system of bacterial organisms, has recently been used to modify genomes of the most important protozoa parasites. Successful genome manipulations with the CRISPR/Cas9 system are changing the present view of genetics in parasitology. The application of this system offers a major chance to overcome the curren...

The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) fingerprinting of some selected cucurbits was performed on three types of seed extracts (alcoholic, cold-water, and hot-water) in order to elaborate a characteristic FTIR profile of their family representatives and to determine their biochemical content. Cluster analysis and pri...

Reptiles are becoming increasingly popular animals in amateur husbandry in Poland and worldwide. The world literature, however, does not provide data on the actual causes of radiological and ultrasound consultations in certain groups of animals, including reptiles. The aim of the study was the analysis of causes and results of diagnostic imaging ex...

The aim of the study was to investigate the state of parasitic invasions in flocks of carrier and fancy pigeons in south-western Poland. Coproscopic methods (flotation with saturated NaCl and saccharose, as well as the McMaster method) were used to examine 42 pigeon flocks (18 flocks of fancy pigeons and 24 flocks of carrier pigeons). A total of 21...

The aim of the study was to analyze endoparasitic fauna in roe deer of a selected area of south-western Poland using coproscopic studies and postmortem studies of internal organs (lungs, livers and digestive tracts). Microscopic methods included flotation and the McMaster method. In May and June 2015, 53 culled male roe deer were examined. Parasite...

Equine Anoplocephalosis constitute a significant problem in horses worldwide. The aim of this study was to analyse intrinsic (host age and sex) and extrinsic (management type, pasture type and moisture) factors that influence the prevalence and FEC of A. perfoliata infections. Faecal samples were collected from 994 horses managed in studs or indivi...

2017): Effect of dietary supplementation with preparation comprising the blend of essential oil from Origanum vulgare (lamiaceae) and Citrus spp. (citraceae) on coccidia invasion and lamb growth, ABSTRACT The objective of this research was to assess the effectiveness of dietary supplementation with oils extracted from Origanum vulgare (Lamiaceae) a...

Parasites are considered to be an important selective force in host evolution but ecological studies of host-parasite systems are usually short-term providing only snap-shots of what may be dynamic systems. We have performed a long term monitoring of helminths of bank voles at three ecologically similar woodland sites in NE Poland, spaced over a pe...

Small rodents represent ideal model species to investigate dynamics of parasite infections, thanks to their abundance, ease of manipulation and to the availability of a large scientific knowledge gathered through laboratory experiments. Laboratory investigations in controlled environments allow indeed to examine in depth complex biological mechani...

We examined age-related biochemical and histological changes in the fat bodies and hemolymph of Osmia rufa males and females. We analysed solitary bees during diapause, in October and in April; as well as the flying insects following diapause, in May and June. The trophocyte sizes, as well as the numbers of lipid droplets were the greatest at the b...

Background Vertical transmission is one of the transmission routes for Babesia microti, the causative agent of the zoonotic disease, babesiosis. Congenital Babesia invasions have been recorded in laboratory mice, dogs and humans. The aim of our study was to determine if vertical transmission of B. microti occurs in naturally-infected reservoir host...

The reprogramming of human induced pluripotent stem cells (hiPSCs) proceeds in a stepwise manner with reprogramming factors binding and epigenetic composition changes during transition to maintain the epigenetic landscape, important for pluripotency. There arises a question as to whether the aberrant epigenetic state after reprogramming leads to ep...

Zarażenia pasożytami są głownie kontrolowane przy użyciu syntetycznych środków przeciwpasożytniczych. Rosnąca lekooporność pasożytów jest stwierdzana u ludzi i zwierząt . Rośliny z rodziny Cucurbitaceae, a w szczególności dynia (np. Cucurbita moschata) i jej pestki zostały wskazane jako gatunki charakteryzujące się działaniem przeciwpasożytniczym u...

A significant number of studies report growing resistance in nematodes thriving in both humans and livestock. This study was conducted to evaluate the in vitro and in vivo anthelmintic efficiency of Curcubita pepo (C. pepo) L. hot water extract (HWE), cold water extract (CWE) or ethanol extract (ETE) on two model nematodes: Caenorhabditis elegans (...

Gastrointestinal parasites are responsible for high economic losses to sheep production. Infected animals show developmental problems, reduced weight and a low quality of meat and wool. This study takes into consideration two different sheep management systems, indoor (n = 50) and outdoor (n = 50) ones, and their impact on the occurrence of gastroi...

Introduction: The most prevalent cardiopulmonary nematodes in domestic cats in Europe is Aelurostrongylus abstrusus [1]. Clinical sings of diseases range from asymptomatic to severe respiratory symptoms, dependent on the intensity of invasions, co-infections, host age, conditions and immune status. Early and correct diagnosis improves the prognosis...