Pilot study of Ixodes ricinus ticks preference for human ABO blood groups using a simple in vitro method

Introduction and objectives. The existence of a blood group preference for ticks is a problem widely discussed among the lay public but often neglected by the scientific community. The Ixodes ricinus tick transmits serious zoonotic diseases such as Lyme borreliosis, tick encephalitis, or anaplasmosis. The preventive strategies include vaccination (if available) and individual measures including the use of repellents and avoidance of risk areas. Materials and method. Since this topic is relatively neglected in the scientific literature, a simple in vitro method was used. Ticks used in this study were collected in the suburban region of Ruda in Brno, Czech Republic. One hundred active nymphs of the collected ticks were tested for preferences for blood groups, using Petri dishes and blood samples from volunteers. To demonstrate the threat of ticks and the diseases they transmit, the positivity of one of the most abundant zoonosis, Lyme borreliosis, was tested using dark-field microscopy. Results. The results obtained showed that the examined ticks were attracted most by blood group A, whereas the least preferred was group B, which was proved statistically (p <0.05). The mean positivity of collected ticks for the presence of spirochaetes was 9.35%. Conclusions. The results indicate that the host selection of ticks may be influenced by the physiological or biochemical profile of an individual, such as their blood group. This means that a blood group of an individual can be one of the factors that increase the risk of tick bite and the transmission of dangerous diseases and thus must not be underestimated

Seroprevalence of Antibodies against Borrelia burgdorferi s. l. and Leptospira interrogans s. l. in Cats in district of Brno and its environs, the Czech Republic

Objectives. The aim of this study is to evaluate the seroprevalence of antibodies of Borrelia burgdorferi sensu lato (Bbsl) and Leptospira interrogans sensu lato (Lisl) and their possible concurrence in domestic cats living in variable conditions in South Moravia in the district of Brno and its environs. Additional objectives were to discover possible differences in seroprevalence between groups of cats living in different living conditions, and to determine the spectrum of Leptospira serogroups in cats in the same places. Materials and method. A total of 360 blood sera from domestic cats of 3 different sets were collected during the period 2013–2015. All samples were examined using ELISA for the detection of IgM and IgG antibodies against Bbsl, and the microscopic agglutination test (MAT) for the detection of antibodies against 8 serogroups of Lisl. Results. The ELISA method determined 15.8%, 4.8% and 10.3% IgM anti-Borrelia antibodies in the patient group, shelter cats and street cats, respectively. IgG anti-Borrelia antibodies were found in 6.2%, 9.5%, 5.2%, respectively. Antibodies specific for 5 Leptospira serogroups were detected by the use of MAT in 8.8%, 9.5% and 10.3% of cats from the investigated groups. The total positivity of all examined cats for anti-Borrelia antibodies was 18.0% and for anti-Leptospira – 9.2%. Conclusions. Cats can be infected with both Bbsl and Lisl. The obtained results are exclusive to the city of Brno and its environs, and are comparable to the limited previous studies. There is a need for further studies of clinical signs of both infections and the possible transmission of Leptospira by ticks

Isolation, cultivation and identification of Borrelia burgdorferi genospecies from Ixodes ricinus from the city of Brno, Czech Republic

A total of 305 ticks (21 larvae, 243 nymphs, 19 females and 22 males) were collected by fl agging of vegetation in suburban woods of Pisárky Park (city of Brno) from July to October 2002. The midgut of each tick was dissected out and transferred individually into BSK-H medium. After cultivation, all specimens were examined by dark-fi eld microscopy (DFM) for the presence of borreliae. Out of 305 tick samples, 45 were (14.8%) DFM positive. The following polymerase chain reaction (PCR) then revealed 37 (12.1%) samples positive for the presence of Borrelia burgdorferi sensu lato DNA. All 37 samples were further analysed by restriction fragment length polymorphism (RFLP) method. PCR-RFLP analysis revealed 14 strains of B. afzelii (37.8%), 15 strains of B. garinii (40.5%) and 2 strains of B. burgdorferi sensu stricto (5.4%). Four samples (10.8%) showed a mixed population of these genospecies. Two samples produced atypical RFLP pattern which were detected by sequence analysis as B. valaisiana (5.4%). Isolation attempts resulted in 21 spirochaetal strains (including two stains of B. valaisiana). The results show the diversity of B. burgdorferi s.l. in tick population and refer the risk of infection by pathogenic borreliae in Brno

Combined theoretical and computational study of interstrand DNA guanine–guanine cross-linking bytrans-[Pt(pyridine)2] derived from the photoactivated prodrugtrans,trans,trans-[Pt(N3)2(OH)2(pyridine)2]

Molecular modeling and extensive experimental studies are used to study DNA distortions induced by binding platinum(II)-containing fragments derived from cisplatin and a new class of photoactive platinum anticancer drugs. The major photoproduct of the novel platinum(IV) prodrug trans,trans,trans-[Pt(N3)2(OH)2(py)2] (1) contains the trans-{Pt(py)2}2+ moiety. Using a tailored DNA sequence, experimental studies establish the possibility of interstrand binding of trans-{Pt(py)2}2+ (P) to guanine N7 positions on each DNA strand. Ligand field molecular mechanics (LFMM) parameters for Pt–guanine interactions are then derived and validated against a range of experimental structures from the Cambridge Structural Database, published quantum mechanics (QM)/molecular mechanics (MM) structures of model Pt–DNA systems and additional density-functional theory (DFT) studies. Ligand field molecular dynamics (LFMD) simulation protocols are developed and validated using experimentally characterized bifunctional DNA adducts involving both an intra- and an interstrand cross-link of cisplatin. We then turn to the interaction of P with the DNA duplex dodecamer, d(5′-C1C2T3C4T5C6G7T8C9T10C11C12-3′)·d(5′-G13G14A15G16A17C18G19A20G21A22G23G24-3′) which is known to form a monofunctional adduct with cis-{Pt(NH3)2(py)}. P coordinated to G7 and G19 is simulated giving a predicted bend toward the minor groove. This is widened at one end of the platinated site and deepened at the opposite end, while the P–DNA complex exhibits a global bend of 67° and an unwinding of 20°. Such cross-links offer possibilities for specific protein–DNA interactions and suggest possible mechanisms to explain the high potency of this photoactivated complex