Cristian Magdaş

Contribution of the IL-17/IL-23 axis to the pathogenesis of inflammatory bowel disease

Inflammatory bowel diseases (IBDs) are chronic disorders of modern society, requiring management strategies aimed at prolonging an active life and establishing the exact etiology and pathogenesis. These idiopathic diseases have environmental, genetic, immunologic, inflammatory, and oxidative stress components. On the one hand, recent advances have shown that abnormal immune reactions against the microorganisms of the intestinal flora are responsible for the inflammation in genetically susceptible individuals. On the other hand, in addition to T helper cell-type (Th) 1 and Th2 immune responses, other subsets of T cells, namely regulatory T cells and Th17 maintained by IL-23 are likely to develop IBD. IL-23 acts on innate immune system members and also facilitates the expansion and maintenance of Th17 cells. The IL-17/IL-23 axis is relevant in IBD pathogenesis both in human and experimental studies. Novel biomarkers of IBD could be calprotectin, microRNAs, and serum proinflammatory cytokines. An efficient strategy for IBD therapy is represented by the combination of IL-17A and IL-17F in acute IL-17A knockout TNBS-induced colitis, and also definite decrease of the inflammatory process in IL-17F knockout, DSS-induced colitis have been observed. Studying the correlation between innate and adaptive immune systems, we hope to obtain a focused review in order to facilitate future approaches aimed at elucidating the immunological mechanisms that control gut inflammation.

Synopsis of the hard ticks (Acari: Ixodidae) of Romania with update on host associations and geographical distribution

The current paper is a synoptic review of the distribution and host associations of the 25 species of hard tick fauna (family Ixodidae) in Romania. In addition to a full literature survey, original data is presented, based on eight years of occasional or targeted sample collection. The literature data on geographical distribution was transposed digitally to the decimal degree coordinate system. For each species, an updated distribution map is given together with all historical data and new host associations. Overall, our paper records 58 new tick-host associations for Romania: 20 for Ixodes ricinus, 1 for I. apronophorus, 6 for I. arboricola, 2 for I. hexagonus, 9 for I. redikorzevi, 1 for I. trianguliceps, 2 for I. vespertilionis, 2 for Haemaphysalis punctata, 1 for H. sulcata, 2 for H. concinna, 1 for D. marginatus, 4 for Rhipicephalus sanguineus sensu lato, 1 for R. bursa and 6 for Hyalomma marginatum.

Tick parasites of rodents in Romania: host preferences, community structure and geographical distribution

BackgroundTicks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania.MethodsRodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of <0.05 was considered statistically significant.ResultsWe examined 423 rodents (12 species) collected from six counties in Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus.ConclusionsOur study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents was I. ricinus, followed by I. redikorzevi. Certain rodents seem to host a significantly higher number of tick species than others, the most important within this view being Apodemus flavicollis and Microtus arvalis. The same applies for the overall prevalence of tick parasitism, with some species more commonly infected (M. arvalis, A. uralensis, A. flavicollis and M. glareolus) than others. Two rodent species (Mus musculus, Rattus norvegicus) did not harbour ticks at all. Based on our results we may assert that rodents generally can act as good indicators for assessing the distribution of certain tick species.

Geographical distribution and prevalence of Borrelia burgdorferi genospecies in questing Ixodes ricinus from Romania: a countrywide study.

The paper reports the prevalence and geographical distribution of Borrelia burgdorferi sensu lato (s.l.) and its genospecies in 12,221 questing Ixodes ricinus ticks collected at 183 locations from all the 41 counties of Romania. The unfed ticks were examined for the presence of B. burgdorferi s.l. by PCR targeting the intergenic spacer 5S-23S. Reverse line blot hybridization (RLB) and restriction fragment length polymorphism (RFLP) analysis were performed for identification of B. burgdorferi genospecies. The overall prevalence of infection was 1.4%, with an average local prevalence between 0.75% and 18.8%. B. burgdorferi s.l. was found in ticks of 55 of the 183 localities. The overall prevalence B. burgdorferi s.l. in ticks in the infected localities was 3.8%. The total infection prevalence was higher in female ticks than in other developmental stages. Three Borrelia genospecies were detected. The most widely distributed genospecies was B. afzelii, followed by B. garinii and B. burgdorferi sensu stricto (s.s.). The study is the first countrywide study and the first report of B. burgdorferi s.s. in Romania. The distribution maps show that higher prevalences were recorded in hilly areas, but Lyme borreliosis spirochetes were also present in forested lowlands, albeit with a lower prevalence.

Transstadial Transmission of Borrelia turcica in Hyalomma aegyptium Ticks

Borrelia turcica comprises the third major group of arthropod-transmitted borreliae and is phylogenetically divergent from other Borrelia groups. The novel group of Borrelia was initially isolated from Hyalomma aegyptium ticks in Turkey and it was recently found in blood and multiple organs of tortoises exported from Jordan to Japan. However, the ecology of these spirochetes and their development in ticks or the vertebrate hosts were not investigated in detail; our aims were to isolate the pathogen and to evaluate the possibility of transstadial transmission of Borrelia turcica by H. aegyptium ticks. Ticks were collected from Testudo graeca tortoises during the summer of 2013 from southeastern Romania. Engorged nymphs were successfully molted to the adult stage. Alive B. turcica was isolated from molted ticks by using Barbour-Stoenner-Kelly (BSK) II medium. Four pure cultures of spirochetes were obtained and analyzed by PCR and sequencing. Sequence analysis of glpQ, gyrB and flaB revealed 98%–100% similarities with B. turcica. H. aegyptium ticks collected from T. graeca tortoises were able to pass the infection with B. turcica via transstadial route, suggesting its vectorial capacity.

Anaplasma phagocytophilum in questing Ixodes ricinus ticks from Romania

Granulocytic anaplasmosis is a common vector-borne disease of humans and animals with natural transmission cycle that involves tick vectors, among which Ixodes ricinus is the most important. The present paper reports the prevalence and geographical distribution of A. phagocytophilum in 10,438 questing Ixodes ricinus ticks collected at 113 locations from 40 counties of Romania. The unfed ticks were examined for the presence of A. phagocytophilum by PCR targeting a portion of ankA gene. The overall prevalence of infection was 3.42%, with local prevalences ranging between 0.29% and 22.45%, with an average prevalence of 5.39% in the infected localities. The infection with A. phagocytophilum was detected in 72 out of 113 localities and in 34 out of 40 counties. The highest prevalence was recorded in females followed by males and nymphs. The results and the distribution model have shown a large distribution of A. phagocytophilum, covering Romanias entire territory. This study is the first large scale survey of the presence of A. phagocytophilum in questing I. ricinus ticks from Romania.

Effects of artemisinin in broiler chickens challenged with Eimeria acervulina, E. maxima and E. tenella in battery trials

Four experiments were conceived in order to test the efficacy of artemisinin, a sesquiterpene lactone derived from Artemisia annua, in single experimental infection of broiler chickens with Eimeria acervulina (1 × 10(5) oocysts), Eimeria maxima (5 × 10(4) oocysts) or Eimeria tenella (1 × 10(4) oocysts), and mixed infection with all 3 species (3.2 × 10(4) Eimeria spp. oocysts). For each experiment, three different dosages of artemisinin (5, 50 and 500 ppm) were compared with a negative control (uninfected, unmedicated), a positive control (infected, unmedicated) and a classical anticoccidial (monensin). The weight gain (WG), feed conversion ratio (FCR), oocysts shedded per gram of feces (OPG), lesion score, oocysts sporulation rates and mortality rate were recorded in all groups. The dosage of 5 ppm of artemisinin improved the WG and FCR for the chickens infected with E. acervulina. The OPG was significantly decreased in all the groups medicated with artemisinin and challenged with a mixed infection (p ≤ 0.01). The lesion score of the chickens challenged with Eimeria was reduced by different concentrations of artemisinin, depending on the species involved, but this compound did not have a positive effect on the lesions caused by E. acervulina. Histopathological analysis revealed superficial erosions of the intestinal mucosa, mixt. mononuclear and heterophilic inflammatory infiltrate in the lamina propria and intralesional presence of various developmental stages of parasite in groups infected with Eimeria spp.The sporulation rate of E. acervulina and E. maxima oocysts was significantly affected by 500 ppm of artemisinin, whilst the dosage of 5 ppm affected the sporulation of E. tenella oocysts. These data suggest that artemisinin is not effective against single eimerian infections but could be used as an alternative in mixed coccidiosis, especially if its effect on the oocysts sporulation would be fully investigated.

Comparison of two models of inflammatory bowel disease in rats.

BACKGROUND There is a need for experimental animal models for inflammatory bowel diseases (IBD), but no proposed model has been unanimously accepted. OBJECTIVES The aim of this study was to develop 2 affordable models of IBD in rats and to compare them. MATERIAL AND METHODS We produced IBD in rats using either dextran sodium sulfate (DSS) or 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). The requirements for experimental models were: a predictable clinical course, histopathology and inflammation similar to human ulcerative colitis (UC) and Crohns disease (CD). The effect of acute administration of DSS and TNBS on oxidative stress (as measured by the assessment of glutathione peroxidase - GPx) was verified. The activity of whole blood GPx was measured using a commercially available Randox kit (Crumlin, UK). RESULTS The administration of DSS increased GPx activity compared to the control and TNBS-treated groups, but not to a statistically significant degree. Histological examination of the colonic mucosa following the administration of DSS showed multifocal erosions with minimal to mild inflammatory infiltrate, mainly by polymorphonuclear cells (PMN), lymphocytes and plasma cells. For TNBS-induced colitis, the histological changes manifested as multifocal areas of ulcerative colitis with mild to severe inflammatory infiltrate. Whole blood GPx values displayed a direct dependence on the chemical agent used. Our results show a correlation between histopathology, proinflammatory state and oxidative stress. CONCLUSIONS The experimental DSSor TNBS-induced bowel inflammation used in this study corresponds to human IBD and is reproducible with characteristics indicative of acute inflammation in the case of the protocols mentioned.

Morphological, histopathological and immunofluorescence characterization of Cryptosporidium parvum natural infection in goat kids from Romania.

Few studies were conducted to investigate the pathogenesis and to characterize the histopathological alterations in the intestinal mucosa of kids with cryptosporidiosis. In our study, 58 kids were presented for necropsy, and the faeces of another 83 goat kids were studied. Animals were aged between 1 day and 3 weeks. Infection was confirmed by oocyst identification in the faeces (Ziehl-Neelsen stain modified by Henriksen). Gross examination was followed by examination of the tissue using histopathological procedures (Hematoxylin-Eosin stain), scanning electron microscopy (SEM) and immunofluorescence. Pathological changes occurred mainly in the ileum, but also jejunum and caecum of the infected animals, at the apical surface of intestinal epithelial cells. Oocysts appeared as round or oval formations, with a diameter 4.5 m, sometimes covering the atrophic and denudated free border of intestinal villi. Most histological and morphological characteristics of infection with C. parvum are common on the whole to other Cryptosporidium spp. Massive dentification of cryptospodiosis in kids indicates the possible role of these animals as disease reservoirs for other animals and for humans. This is the first study to characterize the Cryptosporidium infection by confocal technique and SEM in Romania.