Tick-borne pathogens in questing adults Dermacentor reticulatus from the Eastern European population (north-eastern Poland)

Dermacentor reticulatus is tick species with an expanding geographical range in Europe, which creates the possibility of spreading microorganisms of significant veterinary and medical importance. The study aimed to investigate the prevalence and genetic diversity of Rickettsia spp., Babesia spp., Borrelia spp. and Anaplasma phagocytophilum in adult D. reticulatus ticks from the Eastern European population in the urban and the natural biotopes of north-eastern Poland. Microorganisms were detected by PCR and identified by DNA sequencing. The overall infection rate of at least one of the pathogens was 29.6%. The predominantly was Rickettsia spp. (27.1%) (with R. raoultii-9.1%) followed by Babesia spp. (2.4%) with B. canis (1.5%) as the most frequent. Based on 18S rRNA gene sequence, three B. canis genotypes were revealed. The prevalence of R. raoultii and B. canis was significantly higher in ticks from natural biotopes. The infection rates of B. afzelii and A. phagocytophilum were determined at 0.9% and 0.3%, respectively. Co-infections were detected in 3.8% of infected ticks. In diagnosing tick-borne diseases in humans, tick-borne lymphadenopathy should not be excluded. The prevalence of different genotypes of B. canis suggests differences in the clinical picture of canine babesiosis in the area.

The Relationship between Complement Components C1R and C5 Gene Polymorphism and the Values of Blood Indices in Suckling Piglets

The main mechanism of innate immunity is the complement system. Its components include the protein products of the C1R and C5 genes, which are involved in the classical activation pathway as well as the inflammatory and cytolytic immune responses, respectively. The aim of this study was to determine the relationship between PCR-restriction fragment length polymorphism in C1R (726T > C) and C5 (1044A > C) genes, and the values of hematological and biochemical blood indices in suckling crossbred (Polish Large White × Polish Landrace × Duroc × Pietrain) piglets (n = 473), considering their age (younger, 21 ± 3 days, n = 274; older, 35 ± 3 days, n = 199) and health status. The frequencies of the C5 genotypes deviated from the Hardy-Weinberg expectations. Younger piglets, healthy piglets, piglets that deviated from physiological norms and older piglets with the C1R TT genotype all had lower white and red blood cell indices. In piglets with the C5 CC genotype, younger piglets, piglets that deviated from physiological norms and older piglets, a greater number and/or percentage of monocytes were recorded in the blood. Older piglets also showed an increase in the number of leukocytes and granulocytes, along with a tendency for a decrease in the percentage of lymphocytes in their blood. We concluded that a polymorphism in the C1R gene may exhibit a functional association or genetic linkage with other genes involved in the process of erythropoiesis. Furthermore the relationship between the C5 gene polymorphism and the number and/or percentage of monocytes in the blood may modify the body's defense abilities. Piglets with the CC genotype, having an increased number/proportion of these cells in their blood, probably display a weakened immune response to pathogens or a chronic stimulation of the immune system.

Abundance of Ixodes ricinus Ticks (Acari: Ixodidae) and the Diversity of Borrelia Species in Northeastern Poland

Monitoring the abundance of ticks and the prevalence of pathogens in ticks is an important activity in assessing the risk of tick-borne diseases and helps to develop preventive measures. This study aimed to estimate the density of Ixodes ricinus, the prevalence of Borrelia species, and their diversity in northeastern Poland. The overall mean I. ricinus density was 9.7 ticks/100 m². There were no differences between years, subregions, or habitats of study. The Borrelia infection rate was higher in females (22.6%) and males (14.3%) than in nymphs 5.5% (MIR). The most infected ticks came from the eastern subregion (10.1%) where the incidence of borreliosis among the inhabitants was over 20% higher than in the other subregions. In the infected ticks, B. afzelii (38.3%) and B. garinii (34.5%) were predominant. B. bavariensis was confirmed in I. ricinus in Poland for the first time. The most polymorphic was B. garinii. B. miyamotoi (belonged to the European type) was identified as a mono-infection in 0.9% of ticks and in 1.5% as a co-infection with B. afzelii and with B. garinii. Besides the risk of borreliosis and co-infections with different Borrelia species, physicians should also be aware of B. miyamotoi infections among patients.

Relationship between RNASE1, ANG and RNASE6 gene polymorphism and the values of blood indices in suckling piglets

The relationship between PcR-restriction fragment length polymorphism in RNASE1 (296 A/G), ANG (149 G/T) and RNASE6 (389 C/T) genes and the values of haematological and biochemical blood indices was analysed in crossbred suckling piglets (n = 473), aged 21 ± 3 days (younger, n = 274) and 35 ± 3 days (older, n = 199), descending from Polish Large White × Polish Landrace sows and Duroc × Pietrain boars. The observed distribution of all genotypes was consistent with the Hardy-Weinberg equilibrium. Anaemia was more common in younger piglets with RNASE1 GA genotype but in the blood of older GA piglets a higher count and percentage of granulocytes were noted. This could be related to the destruction of erythrocytes in younger piglets and enhanced host defence in older ones. ANG gene polymorphism was associated with the severity of iron deficiency in younger piglets. This is supposed to be linked with the different ability to protect immune cells against suppression and degradation during iron deficiency. in older piglets, this mutation differentiated the reactivity of the immune system. Varying levels of iron status and red blood cell indices in RNASE6 genotypes presumably resulted from the coupling of genes involved in iron metabolism and expressed in an age-dependent manner.

Questing Ixodes ricinus ticks (Acari, Ixodidae) as a vector of Borrelia burgdorferi sensu lato and Borrelia miyamotoi in an urban area of north-eastern Poland

Green areas located within large cities, as natural ecotypes, are a convenient habitat for ticks and their use as recreational areas is associated with the potential risk of acquiring tick-borne diseases. This study estimated the I. ricinus tick density, prevalence of infection with Borrelia species and the diversity of these bacteria in a green urban area (Olsztyn) of north-eastern Poland, an endemic region of tick-borne diseases. The ticks were collected during spring and autumn of 2015, at sites differing in the degree of human pressure and habitat. Borrelia species detection, typing and a molecular phylogenetic analysis were carried out based on the sequenced flaB gene. The overall mean abundance of I. ricinus was 2.0 ± 1.55 ticks per 100 m². The density of I. ricinus did not vary significantly between sites. According to semi-qualitative tick abundance categories, the collection sites were classified as 'very low' and 'low' tick abundance category. The overall infection rate of I. ricinus with Borrelia spirochaetes was 27.4%. The infection rate of adult ticks (42.0%) was three times higher than with nymphs (14.3%). Based on the restriction patterns and sequencing, B. afzelii (93.1%; 27/29), B. valaisiana 3.5% (1/29) and B. miyamotoi (3.5%; 1/29), related to the relapsing fever (RF) spirochaetes, were detected. No co-infections were found. Borrelia miyamotoi, detected for the first time in ticks in the north-eastern urban areas of Poland, was identical to isolates described as European-type. The Borrelia spirochaete infection rate of I. ricinus ticks in an urban area indicated a high risk of LB. Physicians should also be aware of B. miyamotoi infections among patients with a history of tick-bites in north-eastern Poland.

Tissue response after implantation of pure titanium and bioresorbable screws in scapula with postoperative irradiation: an experimental study on rats

OBJECTIVE

The study focuses on the comparison of tissue reaction to titanium and bioresorbable implants with and without postoperative irradiation on an animal model.

MATERIALS AND METHODS

Thirty-nine LEW/W rats were randomly assigned to experimental or control groups. One titanium and one bioresorbable screw (poly-L-lactide [PLLA] and L- and D-lactide poly-L/D-lactide [PDLLA]) were implanted into the left scapulas of 24 rats. Half of them received 30 Gy to the operation site and the other half received 42 Gy. In the control groups, 3 rats received 30 Gy, and 6 rats received 42 Gy to the scapula area without operation; and 6 rats had implants inserted as in the experimental group, but received no postoperative irradiation. The scapulas were removed 14 or 30 days after irradiation and a histologic analysis was performed.

RESULTS

The host tissue reaction to titanium and PLLA-PDLLA screws without postoperative irradiation was of similar intensity. In irradiated animals, the inflammatory tissue reaction was more evident around the titanium screws than around the bioresorbable screws, irrespective of the radiation dose and of the time that elapsed from the irradiation. The reaction was more evident on the 14th day than on the 30th day after the last radiation dose (70 and 86 days after surgery, respectively). The intensity of the inflammatory tissue reaction, irrespective of the implant type, was more intense in the group irradiated with 42 Gy.

CONCLUSIONS

PLLA-PDLLA implants appear to cause less tissue reaction after irradiation and could be safer reconstructive devices than titanium implants for patients undergoing surgery and adjuvant radiotherapy for cancer.

Susceptibility loci and chromosomal abnormalities in radiation induced hematopoietic neoplasms in mice

Genetics of susceptibility to radiation-induced hematopoietic neoplasms and somatic chromosomal aberrations were analyzed in 305 backcross (CcS-17xCcS-2)xCcS-2 mice of two CcS/Dem recombinant congenic strains. Irradiated CcS-2 mice were previously shown to exhibit high frequency of myeloid neoplasms whereas irradiated CcS-17 mice were susceptible to T-cell lymphomas. Mice were exposed to four whole-body irradiation doses of 1.7 Gy at one week intervals, which resulted in 139 hematopoietic neoplasms. The hematopoietic neoplasms were classified according to the Bethesda proposals for classification of lymphoid and nonlymphoid hematopoietic neoplasms in mice. Genotyping of mice with 24 microsatellite markers and subsequent statistical analysis indicated linkage of the radiation induced T-lymphomas to two loci on chromosome 10 (D10Mit134) and chromosome 12 (D12Mit52). T-lymphoma susceptibility appeared to be linked to D10Mit134 in a sex dependent way. In contrast, the myeloid-granulocytic leukemias susceptibility is linked to combined effects of chromosome 5 (D5Mit179) and 16 (D16Mit34). Cytogenetic analysis was performed according to the standard G-bands procedure and confirmed using FISH method. We found non-random numerical and structural chromosomal changes in lymphoid neoplasms. Cytogenetic analysis indicated chromosomal aberrations presumably associated with lymphomagenesis, no specific cancer-related rearrangements were observed.

[Genetically engineered mice: mouse models for cancer research]

Genetically engineered mice (GEM) have been extensively used to model human cancer. Mouse models mimic the morphology, histopathology, phenotype, and genotype of the corresponding cancer in humans. GEM mice are created by random integration of a transgene into the genome, which results in gene overexpression (transgenic mice); gene deletion (knock-out mice); or targeted insertion of the transgene in a selected locus (knock-in mice). Knock-out may be constitutive, i.e. total inactivation of the gene of interest in any cell, or conditional, i.e. tissue-specific inactivation of the gene. Gene knock-down (RNAi) and humanization of the mouse are more sophisticated models of GEM mice. RNA interference (RNAi) is a mechanism in which double-stranded RNAs inhibits the respective gene expression by inducing degradation of its mRNA. Humanization is based on replacing a mouse gene by its human counterpart. The alterations in genes in GEM have to be heritable. The opportunities provided by employing GEM cancer models are: analysis of the role of specific cancer genes and modifier genes, evaluation of conventional cancer therapies and new drugs, identification of cancer markers of tumor growth, analysis of the influence of the tumor's microenvironment on tumor formation, and the definition of the pre-clinical, discrete steps of tumorigenesis. The validation of mouse models of human cancer is the task of the MMHCC (Mouse Models of Human Cancer Consortium). The GEM models of breast, pancreatic, intestinal and colon, and prostate cancer are the most actively explored. In contrast, the models of brain tumors and ovary, cervical, and skin cancer are in the early stage of investigation.

Decreased histamine content and metabolism in mammary cancer tissue from C3H mice

Histamine (HA) level and its metabolism in adenocarcinoma mammae, spontaneously growing cancer in C3H mice, were examined in relation to the type of tumor, intensity of tumor vascularization and the presence or absence of a secretory function. Histamine concentration being in mammary gland one of the highest among mammalian organs (418 nmol/g) was decreased by 90% in tumor (34 nmol/g). Similarly, histidine decarboxylase (HDC) activity dropped from approximately 7.6 pmol/min/g in normal gland to an undetectable level in adenocarcinoma mammae. Of the two main HA degrading enzymes, namely, diamine oxidase and histamine N-methyl-transferase (HMT), only HMT could be detected in mammary gland, either healthy or neoplastic, and its activity was about 5-fold lower in tumor than in the control tissue (1 nmol/g/min vs. 5.2 nmol/g/min). The pattern of changes in histaminergic parameters evoked by the tumor was similar irrespective of the morphological type it represented, characteristics of its vascular bed or whether or not it showed secretory activity.