Occurrence of Dermacentor reticulatus in central-southern Poland, and potential threats to human and animal health.

INTRODUCTION AND OBJECTIVE: Dermacentor reticulatus is one of the tick species of the greatest epidemiological importance in Europe. To date, the Eastern European and Western European populations of this tick species have been separated by an area located in Poland where the species has never been found. In this study, newly discovered D. reticulatus localities in areas transformed by human activities in central-southern Poland are described. MATERIAL AND METHODS: The specimens of the ornate dog tick were identified among ticks collected from companion animals in 2010, 2012, 2013, and 2014. They were examined using PCR methods to detect Borrelia burgdorferi s.l., Rickettsia spp., Anaplasma phagocytophilum, Bartonella spp., Babesia spp., and Toxoplasma gondii. In the case of the positive results, the amplicons were sequenced and examined by a BLAST search. RESULTS: In total, 6 specimens of D. reticulatus were collected (3 females and 3 males). As declared by the owners, animal hosts stayed in the same area throughout the study period and had never travelled outside their place of residence. As many as 3/6 (50%) of D. reticulatus adults removed from dogs were infected with Rickettsia raoultii. CONCLUSIONS: The results expand the available data on the spread of the ornate dog tick and indicate that, since 2010, this tick species and Rickettsia raoultii transmitted by this tick species have probably been present in this area, which has a strongly transformed agricultural structure and and had previously been regarded as a D. reticulatus-free zone. The presence of the ornate dog tick in urban and suburban habitats in central-southern Poland poses new threats to the health of companion animals and humans associated with the transmission of pathogens by this species.

Copulation of Ixodes ricinus males and females on the host and its potential impact on pathogen transmission.

INTRODUCTION AND OBJECTIVE: The common tick Ixodes ricinus is one of Europe's most important vectors of tick-borne diseases. The increased risk of attacks by this tick suggests the need for identification of factors contributing to the transmission of tick-borne pathogens, and the routes of pathogen circulation in nature. MATERIAL AND METHODS: Polymerase chain reaction was used to investigate the prevalence of four pathogens, i.e. Borrelia burgdorferi s.l. (Bb), Anaplasma phagocytophilum (Ap), Babesia spp. (Bs), and Bartonella spp. (Ba) in I. ricinus females and males mating on dogs in south-central Poland. RESULTS: The study revealed the presence of three pathogens: Bb, Ap, and Bs in 9.4%, 5.4%, and 5.4% of all I. ricinus adults in copula, respectively. Co-infection with two pathogens was detected in one tick specimen. Borrelia burgdorferi spirochetes were isolated in two females and two males in copula, but the sexual transfer of the spirochetes between these specimens could not be clearly confirmed. CONCLUSIONS: By increasing the feeding dynamics in females, the copulation of I. ricinus males with females attached to the host's skin may stimulate pathogen replication in tick tissues and migration from the gut to the salivary glands. Further investigations of the I. ricinus copulation on the host on female feeding and pathogen transmission may contribute to the elucidation of the eco-epidemiology of tick-borne diseases transmitted by this tick species.

Pediculosis capitis and scabies in nurses from Eastern Poland - occupational risk and environmental determinants.

INTRODUCTION AND OBJECTIVE: Nurses are a group of healthcare professionals particularly vulnerable to infestations by Pediculus humanus capitis and Sarcoptes scabiei var. hominis contracted from patients under their medical care. MATERIAL AND METHODS: The cross-sectional study included 322 professionally active nurses within public healthcare units in eastern Poland. The research tool was a questionnaire collecting anonymized data on the occurrence of pediculosis capitis and scabies in nurses, and their patients, concerning the environmental determinants in the period 2001-2013. The study was retrospective and participation of nurses was voluntary. RESULTS: The obtained results indicated that 24.8% and 9.9% of the 322 respondents were infested by head lice and scabies mites, respectively. During their professional work, most nurses contracted head lice once (76.2%) while others (23.8%) were infested twice or more. The respondents did not declare repeated occupational scabies. The risk of contracting pediculosis capitis and scabies was not related to the length of service, but increased with the rise in the number of patients provided with nursing care. In the head lice-infested patients, the majority were aged 6-10 years (31.3%), while in the case of scabietic patients, children aged 0-5 years prevailed (26.4%). CONCLUSIONS: In medical care facilities, regular hygienic checks of both patients and medical staff, covering the condition of the skin and scalp, should be mandatory. The spread of pediculosis capitis and scabies among nurses can be reduced by the implementation not only of protective procedures mitigating occupational risk, but also the improvement of working conditions in medical facilities.

Prevalence of pathogens in sympatric Ixodes ricinus and Dermacentor reticulatus ticks in Eastern Poland and their potential impact on oral-anal contacts between ticks.

INTRODUCTION AND OBJECTIVE: Little is known about interspecific contacts between ticks. Therefore, this study focused on the investigation of factors that may influence interspecific contacts between Ixodes ricinus and Dermacentor reticulatus ticks. MATERIAL AND METHODS: Ixodes ricinus males and D. reticulatus females involved in oral-anal contacts (group I) and questing specimens with no such behaviour (group II) collected in eastern Poland were examined using molecular techniques to detect Borrelia burgdorferi s.l. (Bb), Rickettsia spp. (Rs), Anaplasma phagocytophilum, Babesia microti, and Toxoplasma gondii. RESULTS: An extremely high infection rate of Bb and Rs was determined in I. ricinus males (in groups I: 100% and 46.15% and group II: 90% and 40%, respectively) and D. reticulatus females (in group I: 84.61% and 61.53% and in group II: 90% and 20%, respectively). The prevalence of other pathogens in these ticks was substantially lower. Co-infection with pathogens was detected in approximately 53% of ticks. CONCLUSIONS: The study suggests that tick-borne pathogens may have influenced the sexual behaviour of their vectors. The oral-anal contacts between I. ricinus and D. reticulatus ticks are probably stimulated by Bb and/or Rs. The presence of five pathogens and numerous co-infections in the analysed ticks indicates a risk of various human infectious diseases in the study region. Further studies are required to clarify the implications of oral-anal interspecific tick interactions.

Risk of Attacks by Blackflies (Diptera: Simuliidae) and Occurrence of Severe Skin Symptoms in Bitten Patients along the Eastern Border of the European Union.

The components of blackfly (Diptera: Simuliidae) saliva secreted during feeding on humans and animals induce various pathological reactions manifested by skin lesions and systemic symptoms. In this study, we describe 43 cases of severe skin lesions induced by blackfly bites and analyze their potential causes. Based on the results of a survey of 418 patients, we identified periods with risk of blackfly attacks and their environmental determinants in the eastern part of the European Union. Especially strong inflammatory reactions after blackfly bites were reported in patients with concomitant cardiovascular diseases (mainly with venous insufficiency), metabolic diseases, and bacterial infections. Enhanced symptoms of simuliosis were also observed in other patients attacked by these insects only once or repeatedly. The greatest number of blackfly attacks in the study area is recorded from May to July, with a peak in June (38.73%) in the afternoon (37.10%) and evening (33.03%), when patients are in fields, forests, or their households. The case analysis indicates interactions of various factors in the development of severe inflammatory reactions in patients bitten by blackflies. Therefore, it is recommended that subjects exposed to the presence of blackflies during their work or rest should limit the length of their stay in a vulnerable environment during the highest seasonal and daily activity of these insects. It is also necessary to take measures to reduce the number of blackflies and popularize methods for prophylaxis of their attacks.

Food-Borne Transmission of Tick-Borne Encephalitis Virus-Spread, Consequences, and Prophylaxis.

Tick-borne encephalitis (TBE) is the most common viral neurological disease in Eurasia. It is usually transmitted via tick bites but can also occur through ingestion of TBEV-infected milk and dairy products. The present paper summarises the knowledge of the food-borne TBEV transmission and presents methods for the prevention of its spread. The incidence of milk-borne TBE outbreaks is recorded in central, eastern, and north-eastern Europe, where Ixodes ricinus, Ixodes persulcatus, and/or Dermacentor reticulatus ticks, i.e., the main vectors of TBEV, occur abundantly. The growing occurrence range and population size of these ticks increases the risk of infection of dairy animals, i.e., goats, sheep, and cows, with viruses transmitted by these ticks. Consumers of unpasteurised milk and dairy products purchased from local farms located in TBE endemic areas are the most vulnerable to alimentary TBEV infections. Familial infections with these viruses are frequently recorded, mainly in children. Food-transmitted TBE can be monophasic or biphasic, and some of its neurological and psychiatric symptoms may persist in patients for a long time. Alimentary TBEV infections can be effectively prevented by consumption of pasteurised milk and the use of TBEV vaccines. It is recommended that milk and dairy products should be checked for the presence of TBE viruses prior to distribution. Protection of dairy animals against tick attacks and education of humans regarding the epidemiology and prophylaxis of TBE are equally important.

Proteomic Approaches to Study Cysteine Oxidation: Applications in Neurodegenerative Diseases.

Oxidative stress appears to be a key feature of many neurodegenerative diseases either as a cause or consequence of disease. A range of molecules are subject to oxidation, but in particular, proteins are an important target and measure of oxidative stress. Proteins are subject to a range of oxidative modifications at reactive cysteine residues, and depending on the level of oxidative stress, these modifications may be reversible or irreversible. A range of experimental approaches has been developed to characterize cysteine oxidation of proteins. In particular, mass spectrometry-based proteomic methods have emerged as a powerful means to identify and quantify cysteine oxidation sites on a proteome scale; however, their application to study neurodegenerative diseases is limited to date. Here we provide a guide to these approaches and highlight the under-exploited utility of these methods to measure oxidative stress in neurodegenerative diseases for biomarker discovery, target engagement and to understand disease mechanisms.

Ixodiphagus hookeri wasps (Hymenoptera: Encyrtidae) in two sympatric tick species Ixodes ricinus and Haemaphysalis concinna (Ixodida: Ixodidae) in the Slovak Karst (Slovakia): ecological and biological considerations.

Ixodiphagus endoparasitoid wasps are natural tick enemies that can reduce their abundance. In this study, we investigated the presence of Ixodiphagus hookeri in Haemaphysalis concinna and Ixodes ricinus ticks in the Slovak Karst (southern Slovakia) and analysed the ecological and physiological relationships in the parasitoid-host system. Unfed H. concinna and I. ricinus nymphs harvested from vegetation were fed on rabbits. The engorged specimens were kept at 25 °C and 75% RH until the emergence of the adult wasps. For the first time in Europe, we found the presence of I. hookeri in two species of ticks collected in the same locality and compared their development in these tick species. The prevalence of wasps in H. concinna and I. ricinus during their spring activity was estimated at 10.64% and 27.78%, respectively. The presence of the wasps did not affect the duration of nymph feeding. Engorged wasp-infected ticks achieved higher body mass than non-infected specimens. In both tick species, there were no differences in the length of the development period and the number and sex ratio of adult I. hookeri. The analysed indicators and characteristics of the I. hookeri wasp-tick system can be used in research on tick control.

Skin Lesions and Systemic Reactions in Humans Infested by Blackflies (Diptera: Simullidae) in Recreational Areas in Southeastern Poland.

Due to their mass occurrence in some environments and high aggressiveness, blackflies (Simulium spp.) represent the most bothersome arthropods attacking humans. In this study, we describe the medical effects of blackfly infestations in humans in southeastern Poland. Local and systemic reactions to blackfly bites were monitored in 418 patients (61.24% of females and 38.76% of males) of medical centers. Only skin lesions at the site of the bites were found in 88.52% of the patients, whereas accompanying systemic reactions were diagnosed in 11.48%. The most common signs observed in the area of the bites were pruritus (94.74%), burning (55.02%), edema (44.02%), and erythema (40.91%). The skin lesions, which were most often grouped small papules and papular and purpuric lesions with a varied range, typically persisted for several days, or for several weeks in some patients. Statistical analyses confirmed that the persistence of the skin lesions did not depend on the sex of the patients and the number of blackfly infestations. The systemic reactions to the components of the blackfly saliva were manifested by headache, increased body temperature, arthralgia, lymphadenopathy, and menstrual disorders in the females. The patients were most often attacked simultaneously by many blackflies on exposed parts of the body, mainly the upper limb, lower limb, head, and neck areas. The investigations indicate that blackflies are an important etiological factor of dermatitis and other symptoms in humans; hence, they should be considered in clinical diagnosis.

Spotted fever group rickettsiae transmitted by Dermacentor ticks and determinants of their spread in Europe.

Rickettsiae from the spotted fever group, i.e. the etiological agents of tick-borne lymphadenopathy/Dermacentor-borne necrotic erythema and lymphadenopathy (TIBOLA /DEBONEL) syndrome, are associated with ticks, including Dermacentor marginatus and Dermacentor reticulatus. The expansion of these ticks into new areas increases the risk of infection of their hosts with tick-borne pathogens. The study summarises the importance of 2 species from the genus Dermacentor, i.e. D. marginatus and D. reticulatus, in the spread of spotted fever group rickettsiae in various regions of Europe. The study also focuses on the determinants of the presence of vectors and transmission of rickettsiae, as well as the effects of human infections with these pathogens. The climate changes observed nowadays affect vectors and increase the incidence and spread of tick-borne diseases worldwide. Due to the existing risk of exposure to an increasing number of people, knowledge about the course of these serious diseases and their etiological factors should be disseminated among healthcare professionals as well as in society. There is a great challenge for epidemiological services to provide access to medical and veterinary facilities in order to diagnose and treat rickettsioses. Therefore, the development of a strategy for tick control and the popularisation of knowledge concerning prophylaxis of tick-borne diseases is indispensable.

Importation of Ticks on Companion Animals and the Risk of Spread of Tick-Borne Diseases to Non-Endemic Regions in Europe.

Increased human mobility elevates the risk of exposure of companion animals travelling with their owners or imported from other regions to tick attacks. In this study, we highlight the potential role of dogs and cats taken for tourist trips or imported animals in the spread of ticks and tick-borne pathogens. The Rhipicephalus sanguineus tick, which is a vector of numerous pathogens causing diseases in animals and humans, is imported most frequently from endemic areas to many European countries. Additionally, alien tick species with high epizootic and epidemiological importance can be imported on dogs from other continents. Companion animals play an even greater role in the spread of autochthonous tick species and transmission of tick pathogens to other animals and humans. Although the veterinary and medical effects of the parasitism of ticks carried by companion animals travelling with owners or imported animals are poorly assessed, these animals seem to play a role in the rapid spread of tick-borne diseases. Development of strategies for protection of the health of companion animals in different geographic regions should take into account the potential emergence of unknown animal tick-borne diseases that can be transmitted by imported ticks.

Tick Preventive Behaviors and Practices Adopted by Medical Students from Poland, Germany, and Thailand in Relation to Socio-Demographic Conditions and Their Knowledge of Ticks and Tick-Borne Diseases.

Given the high medical importance of ticks, we analyzed the most common preventive behaviors and practices adopted by medical students from Poland, Germany, and Thailand, and the level of their knowledge of ticks and tick-borne diseases. A survey consisting of 19 questions was conducted among 636 randomly selected students. The study showed that the Polish and German students preferred inspection of the body on their return home (86.9% and 63.5%, respectively) and wearing protective clothes (79.8% and 32.3%, respectively) as part of prophylaxis. The Thai students most often chose wearing protective clothes (54.7%) and preventive behavior in tick habitats (42.7%). Approximately 7% of the Polish medical students and as many as 22% of the German and Thai respondents did not use any means of prevention. Our analyses suggest that the use of preventive methods and respondents' behaviors depend on socio-demographic factors and the level of health education. The insufficient practical implementation of tick prevention measures by the medical students suggests a need for verification of health education programs in schools as well as effective popularization and educational activities. It is also necessary to develop a public health protection strategy against the effects of tick bites.

Scabies and Pediculosis in Penitentiary Institutions in Poland-A Study of Ectoparasitoses in Confinement Conditions.

BACKGROUND: Scabies (caused by Sarcoptes scabiei var. hominis) and pediculosis (caused by Pediculus humanus) are infectious diseases common in educational institutions and long-term care centres. The aim of the study was to assess the scale of the phenomenon in confinement conditions favouring the spread of these parasitoses. METHODS: Data on the prevalence of scabies (2001-2015) and pediculosis (2008-2015) in Polish prisoners were provided by the Central Board of Prison Service. The information for the period between 2010 and 2015 in the Lublin Province was obtained from the District Inspectorate of the Prison Service in Lublin. Correlations between the prevalence of scabies and pediculosis and the number of prisoners were analysed, as well as correlations between the number of passes granted to prisoners and the prevalence of scabies and pediculosis in incarcerated individuals. RESULTS: The prevalence of scabies and pediculosis in Polish prisoners has been estimated at 2.3% and 1.9%, respectively. CONCLUSIONS: Pediculosis and scabies are still current issues in Polish prisons. Convicts returning from passes and new prisoners should be carefully examined and monitored for the presence of S. scabiei var. hominis and P. humanus invasion. Education of prisoners could be a promising tool in prevention of scabies and pediculosis in correctional settings.

Comparison of Skin Lesions Caused by Ixodes ricinus Ticks and Lipoptena cervi Deer Keds Infesting Humans in the Natural Environment.

Background: The territorial expansion and increased population size of haematophagous arthropods (i.e., the castor bean tick Ixodes ricinus (Ixodida: Ixodidae) and the deer ked Lipoptena cervi (Diptera: Hippoboscidae)) has enhanced the risk of human infestations in Europe. The aim of our study was to present skin lesions induced by tick and deer ked bites in patients from recreational forest regions in southeastern Poland and pay attention to features of skin changes that may be useful in differential diagnosis. Methods: We compare the skin lesions after I. ricinus and L. cervi bite and draw attention to the biological and ecological traits of both ectoparasites, which may be diagnostically relevant for determination of the cause of skin symptoms reported by patients. Results: I. ricinus bites lead to development of erythematous-infiltrative poorly demarcated lesions with a centrally located bite mark, which usually disappears within one to several days. In turn, L. cervi bites leave irregularly shaped scattered erythematous papules. The papules may persist for up to one year and are accompanied by itching. Conclusions: Correct assessment of the clinical picture and its association with an arthropod bite (e.g., tick or deer ked) is highly important for further diagnostic procedures (i.e., differentiation of skin lesions developing in tick-borne diseases and, consequently, correct choice of pharmacological therapy). I. ricinus and L. cervi differ in their developmental cycles and rhythms of activity, which indicates that both species should be considered potential causative agents in the differential diagnosis of skin lesions when the patient has been bitten by an arthropod in autumn and winter months.

EFTUD2 missense variants disrupt protein function and splicing in mandibulofacial dysostosis Guion-Almeida type.

Pathogenic variants in the core spliceosome U5 small nuclear ribonucleoprotein gene EFTUD2/SNU114 cause the craniofacial disorder mandibulofacial dysostosis Guion-Almeida type (MFDGA). MFDGA-associated variants in EFTUD2 comprise large deletions encompassing EFTUD2, intragenic deletions and single nucleotide truncating or missense variants. These variants are predicted to result in haploinsufficiency by loss-of-function of the variant allele. While the contribution of deletions within EFTUD2 to allele loss-of-function are self-evident, the mechanisms by which missense variants are disease-causing have not been characterized functionally. Combining bioinformatics software prediction, yeast functional growth assays, and a minigene (MG) splicing assay, we have characterized how MFDGA missense variants result in EFTUD2 loss-of-function. Only four of 19 assessed missense variants cause EFTUD2 loss-of-function through altered protein function when modeled in yeast. Of the remaining 15 missense variants, five altered the normal splicing pattern of EFTUD2 pre-messenger RNA predominantly through exon skipping or cryptic splice site activation, leading to the introduction of a premature termination codon. Comparison of bioinformatic predictors for each missense variant revealed a disparity amongst different software packages and, in many cases, an inability to correctly predict changes in splicing subsequently determined by MG interrogation. This study highlights the need for laboratory-based validation of bioinformatic predictions for EFTUD2 missense variants.

The Potential Role of Migratory Birds in the Rapid Spread of Ticks and Tick-Borne Pathogens in the Changing Climatic and Environmental Conditions in Europe.

This opinion piece highlights the role of migratory birds in the spread of ticks and their role in the circulation and dissemination of pathogens in Europe. Birds with different lifestyles, i.e., non-migrants residing in a specific area, or short-, medium-, and long-distance migrants, migrating within one or several distant geographical regions are carriers of a number of ticks and tick-borne pathogens. During seasonal migrations, birds that cover long distances over a short time and stay temporarily in different habitats can introduce tick and pathogen species in areas where they have never occurred. An increase in the geographical range of ticks as well as the global climate changes affecting the pathogens, vectors, and their hosts increase the incidence and the spread of emerging tick-borne diseases worldwide. Tick infestations of birds varied between regions depends on the rhythms of tick seasonal activity and the bird migration rhythms determined by for example, climatic and environmental factors. In areas north of latitude ca. 58°N, immature Ixodes ricinus ticks are collected from birds most frequently, whereas ticks from the Hyalomma marginatum group dominate in areas below 42°N. We concluded that the prognosis of hazards posed by tick-borne pathogens should take into account changes in the migration of birds, hosts of many epidemiologically important tick species.

Conspecific hyperparasitism in the Hyalomma excavatum tick and considerations on the biological and epidemiological implications of this phenomenon.

INTRODUCTION: This study presents for the first time a case of Hyalomma excavatum hyperparasitism and an analysis of this phenomenon in terms of its potential role in the biology of ticks and epidemiology of tick-borne diseases. MATERIAL AND METHODS: Two partially engorged H. excavatum females, one fully engorged female, and 5 males were collected from a naïve rabbit and placed together in a rearing chamber at a temperature of 25°C and 75% humidity. RESULTS: 3-4 days after tick detachment from the host's skin, one partially engorged H. excavatum female was observed attached to the idiosoma of the fully engorged conspecific female. CONCLUSIONS: This study and observations of other authors confirm that partially engorged ixodid ticks can re-infest the host, and even co-feeding fully engorged ticks in order to collect the blood meal that is indispensable for important physiological processes. However, inefficient feeding of a partially engorged female on another conspecific female may reduce its reproductive performance and disturb the development of eggs and larvae. It seems that parasitism of a tick on another conspecific specimen, when at least one of them is infected by a microorganism, may be a yet poorly explored route of transmission of pathogens or symbionts between the ticks. Initiation of feeding by a hungry or partially engorged tick on a fully engorged specimen is an attempt to obtain food in the drastic conditions of the absence of a target host. Tick hyperparasitism with concurrent pathogen transmission can contribute to the genospecific diversity of pathogens in vectors and hosts.

Disease modeling of core pre-mRNA splicing factor haploinsufficiency.

The craniofacial disorder mandibulofacial dysostosis Guion-Almeida type is caused by haploinsufficiency of the U5 snRNP gene EFTUD2/SNU114. However, it is unclear how reduced expression of this core pre-mRNA splicing factor leads to craniofacial defects. Here we use a CRISPR-Cas9 nickase strategy to generate a human EFTUD2-knockdown cell line and show that reduced expression of EFTUD2 leads to diminished proliferative ability of these cells, increased sensitivity to endoplasmic reticulum (ER) stress and the mis-expression of several genes involved in the ER stress response. RNA-Seq analysis of the EFTUD2-knockdown cell line revealed transcriptome-wide changes in gene expression, with an enrichment for genes associated with processes involved in craniofacial development. Additionally, our RNA-Seq data identified widespread mis-splicing in EFTUD2-knockdown cells. Analysis of the functional and physical characteristics of mis-spliced pre-mRNAs highlighted conserved properties, including length and splice site strengths, of retained introns and skipped exons in our disease model. We also identified enriched processes associated with the affected genes, including cell death, cell and organ morphology and embryonic development. Together, these data support a model in which EFTUD2 haploinsufficiency leads to the mis-splicing of a distinct subset of pre-mRNAs with a widespread effect on gene expression, including altering the expression of ER stress response genes and genes involved in the development of the craniofacial region. The increased burden of unfolded proteins in the ER resulting from mis-splicing would exceed the capacity of the defective ER stress response, inducing apoptosis in cranial neural crest cells that would result in craniofacial abnormalities during development.

Abnormal Development of Hyalomma Marginatum Ticks (Acari: Ixodidae) Induced by Plant Cytotoxic Substances.

The increasing application of toxic plant substances to deter and fight ticks proves the need for investigations focused on the elucidation of their impact on the developmental stages and populations of these arthropods. We examined the course of embryogenesis and egg hatch in Hyalomma marginatum ticks under the effect of cytotoxic plant substances. The investigations demonstrated that the length of embryonic development of egg batches treated with 20 µL of a 0.1875% colchicine solution did not differ significantly from that in the control group. Colchicine caused the high mortality of eggs (16.3%) and embryos (9.7%), disturbances in larval hatch (8.1%), and lower numbers of normal larval hatches (65.6%). In 0.2% of the larvae, colchicine induced anomalies in the idiosoma (67.6%) and gnathosoma (22.5%) as well as composite anomalies (8.5%). The study demonstrates that cytotoxic compounds with an effect similar to that of colchicine can reduce tick populations and cause teratological changes, which were observed in the specimens found during field studies. Since there are no data on the toxic effects of active plant substances on other organisms and the risk of development of tick resistance, a strategy for the use of such compounds in tick control and the management of plant products should be developed.

Host feeding behaviour of Dermacentor reticulatus males in relation to the transmission of pathogens.

INTRODUCTION: The three-host Dermacentor reticulatus tick transmits many pathogens, which are introduced into the host with saliva during feeding. MATERIAL AND METHODS: The aim of present study was to analyse the behaviour of males of this species on the host in homogeneous sex groups comprising 15 (group I) and 30 (group II) male specimens and in a mixed group composed of 15 males and 15 females (group III). RESULTS: Although the dynamics of attachment of the males to host skin slightly differed between these three groups, there was no statistically significant difference in the duration of the attachment process. The duration of host attachment of the males in groups I, II, and III at 18±2°C and 50 ± 2% RH was 2.43 ± 2.46, 7.75 ± 11.85, and 9.07 ± 10.97 days, respectively. After 7-9-day feeding, the male engorgement weight (MEW) was similar, regardless of the size of the group and the presence or absence of females on the host. Tick males ingest a small amount of host blood. The value of MEW in the three groups did not differ statistically from the weight of unengorged specimens. CONCLUSIONS: The host feeding behaviour of D. reticulatus males and their effective feeding suggest that they may play a role in transmission of pathogens and non-pathogenic microorganisms with tick saliva during blood meal ingestion. Clinical and laboratory diagnostics of human and animal tick-borne diseases as well as epidemiological studies should consider the possibility of pathogen transmission by males of metastriata ticks, which feed on the host for several days.