Kader Yildiz

Seroprevalence of Neospora caninum in dairy cattle ranches with high abortion rate: special emphasis to serologic co-existence with Toxoplasma gondii, Brucella abortus and Listeria monocytogenes.

The aim of this study was to determine seroprevalence of Neospora caninum in dairy cattle ranches with higher abortion rates and co-existence of Neospora caninum, Toxoplasma gondii, Brucella abortus, and Listeria monocytogenes antibodies. The blood samples were collected from dairy cows with history of abortion (n=234) as well as from pregnant cows that were (n=323) kept in the same ranches. N. caninum seroprevalence was 10.77% (60/557). The co-existence rate of N. caninum seropositivity with T. gondii, B. abortus and L. monocytogenes was 24.77% (138/557), 13.82% (77/557) and 42.85% (162/378), respectively. Only one animal had significant antibody titers for all analyzed infectious agents. The seroprevalence of N. caninum and T. gondii were significantly higher in pregnant cows than aborted cows (p<0.05 and p<0.001, respectively). As a result, the comprehensive data generated through this study can significantly contribute to understanding of serologic association of N. caninum with T. gondii, B. abortus and L. monocytogenes in pregnant and aborted dairy cows.

Neospora caninum associated with epidemic abortions in dairy cattle: The first clinical neosporosis report in Turkey

Neospora caninum, a protozoan parasite, has been considered as one of the most important etiological agents responsible for abortion in dairy cattle throughout the world since it was first identified in dogs in 1988. In this report, characteristics of neosporosis, detected in a dairy cow ranch having epidemic abortions as high as 18.4%, were described. Blood samples were collected from 25 infertile or aborted dairy cattle, 6 calves born in 2006 and 40 heifers that were born in 2005 and raised in the same ranch. Necropsy was conducted in a 20-day-old Simmental calf that exhibited neurological signs including incoordination, head shaking, hyperextension in forelimbs and hindlimbs and tremor. The seroprevalance in aborted or infertile dairy cattle, heifers, and calves was 60%, 40%, and 33.3%, respectively. The mothers of seropositive two calves including clinically affected calf and its dam were N. caninum seropositive. In immunoperoxidase examinations, N. caninum antigen immunopositivity was observed in the degenerative and necrotic neurons in the brain, cerebellum as well as neurons in dorsal root ganglia of the cervical and thoracic regions of the spinal cord. In the heart, myocytes and Purkinje cells exhibited granular and linear patterns of immunoreactivity. Striated myofibers around the eyeball also showed immunolocalization for N. caninum antigen. Ultrastructurally, tachyzoites with typical apical complex, rhoptries and double-layered parasitic membrane were detected in the brain and heart sections. In conclusion, this report described clinical neosporosis for the first time in Turkey with tissue localization of the causative agents. This scientific communication also discusses the possible impact of cattle neosporosis by clinical, serologic and pathologic evidences collected from the survey of calves born in two successive generations in a ranch.

In-vivo efficacy of toltrazuril on experimentally induced Toxoplasma gondii tissue cysts in lambs: A novel strategy for prevention of human exposure to meat-borne toxoplasmosis

The aim of the present study was to investigate in vivo efficacy of toltrazuril on Toxoplasma gondii tissue cysts following induction of chronic toxoplasmosis in 4-week-old lambs (n=27) by inoculation of 1×10(5) T. gondii ME 49 strain oocysts (day 0). Beginning at the 15th day after inoculation, lambs in Group T20 and Group T40 were given toltrazuril orally 2 times, once every week (Baycox 5%, Bayer Animal Health) at a dose of 20 mg/kg and 40 mg/kg, respectively. Positive control (PC) lambs were not given any therapy, and 2 clinically healthy non-infected lambs were used as negative controls (Group NC). Two out of 9 lambs in PC group (oocyst inoculated but non-treated) were killed on toltrazuril treatment days (day 15 and 22) to evaluate the tissue cyst presence in their muscles. On day 90, the remaining 25 lambs were necropsied, and samples from the brain and 11 different muscle groups were collected. The tissues were examined for the presence of tissue cysts by histopathology, immunohistochemistry, nested-PCR and percoll gradient centrifugation. Anti-T. gondii antibodies were screened by IFAT throughout the experiment. The increased T. gondii seropositivity beginning from the 15th day of inoculation remained steady at Day 45 and Day 90 in Groups PC while it was significantly lower at Day 90 in toltrazuril receiving groups. In toltrazuril treated groups, histopathological findings included degenerative changes in the cyst wall, complete macrophage invasion to the cysts, and reduction or removal of the cysts in toto. Four out of 9 lambs (44.4%) in both toltrazuril treated group (Group T20 and T40) did not contain tissue cyst in any examined tissues while all positive control animals had T. gondii tissue cysts at least in one muscle group. The toltrazuril treatment efficacy on the cyst presence was determined as 44.4%. The number of the cysts in the musculature was significantly different between non-treated and toltrazuril treated lambs (X(2)=6.613; p=0.037). For the total number of cysts, the positive control lambs had higher number of cysts compared to both toltrazuril treated lambs (T20 and T40) (X(2)=5.629; p=0.018 and X(2)=5.629; p=0.018, respectively) while there were no differences between Group T20 and Group T40 (X(2)=0.000; p=1.000). According to PCR results, the brain and M. semitendinosus were positive in all 7 control lambs while 12 out of 18 lambs were positive in toltrazuril treated lambs. In conclusion, the results are promising as the toltrazuril treated lambs had markedly less parasite counts compared to those of untreated lambs. Further research should be conducted to reveal if toltrazuril treatment in sheep could be used as a strategy to minimize the cyst exposure of humans through consumption of raw or undercooked mutton.

Antiparasitic efficiency of Artemisia absinthium on Toxocara cati in naturally infected cats.

OBJECTIVE The first aim of the present study was to determine the efficiency of A. absinthium extract on cats naturally infected with Toxocara cati. The second aim was to determine the efficiency of the extract on the embryonic development of T. cati eggs in vitro. METHODS Artemisia absinthium extract was orally administrated to cats at the doses of 300 mg/kg and 600 mg/kg body weight in Group 1 and 2, respectively. It was given only once a day and the treatment continued 7 consecutive days. The faeces of the cats were examined both macroscopically and microscopically by flotation procedure with saturated salt solution pre-, during and post- treatment period. The faecal analysis was maintained during 8 days after completing the extract administration. The alteration of faecal egg numbers was performed by using the McMaster technique. RESULTS The faecal egg numbers per gram were decreased gradually in cats in the trial groups. In the treatment period, the activities of ALT, AST, ALP, urea and creatinine were located within the physiological ranges in cats. In in vitro trials with A. absinthium extract, the embryonic development of T. cati eggs was identical in all groups (treatment and control). A. absinthium extract did not inhibit larval development in eggs in in vitro trials. CONCLUSION This plant extract may be an alternative choice in the treatment of parasitic diseases in future.

Multivesicular cysts in cattle: Characterisation of unusual hydatid cyst morphology caused by Echinococcus granulosus

Echinococcus granulosus, the causative agent of cystic echinococcosis, not only often causes unilocular cysts in intermediate hosts, but also in rare cases induces formation of multivesicular cysts which have similar morphology to alveolar cysts. The aim of the present study was to characterise multivesicular and unilocular hydatid cysts in cattle using morphologic and molecular diagnostic tools. Multivesicular cysts were detected in 4 out of 1255 slaughtered cows. Four unilocular cysts were also included in the study to compare with multivesicular cyst morphology. For histopathological evaluation, tissues were fixed in 10% neutral formalin. Following a routine histological tissue-processing procedure, samples were embedded in paraffin blocks and serial sections were cut at a thickness of 4-5 microm. For polymerase chain reaction (PCR), cyst walls and/or protoscolices recovered from six materials were preserved in 70% alcohol. Histopathologically, severity of calcification, fibrous capsule formation and giant cell layer were similar for multivesicular and unilocular cysts. However, the severity of subcapsular inflammation, inflammatory cell infiltration into adjacent organ parenchyma and eosinophil leucocyte infiltration into the cyst lumen was higher in multivesicular cysts. PCR analyses revealed that all unilocular hydatid cysts as well as two out of four multivesicular cysts were G1 genotype of E. granulosus. Molecular diagnosis of the other two multivesicular structures remained inconclusive as DNAs obtained from paraffin-embedded cyst walls were fragmented to small parts, as short as 100 bp, which were not suitable for PCR analyses. In conclusion, molecular analysis concomitant to histopathological examinations is useful in differential diagnosis of multivesicular echinococcosis.

Prevalence of Intestinal Parasites in Hamsters and Rabbits in Some Pet Shops of Turkey

OBJECTIVE In this study, we aimed to determine the parasite species carried by hamsters and rabbits purchased from some commercial pet shops in Turkey. METHODS For this purpose, the fecal samples of clinically healthy Syrian hamsters, dwarf hamsters, and crossbred rabbits were collected from 22 pet shops randomly selected in Ankara and Kirikkale provinces, located in Central Anatolia Region of Turkey. The fecal samples were examined with centrifuge flotation technique using saturated salt solution. RESULTS Parasitic infection rate was 57.5% in dwarf hamsters, 54.9% in Syrian hamsters, and 56.3% in crossbreed rabbits. Trichurid eggs were the most prevalent parasite in the feces of Syrians hamsters (28.1%). The other parasites of Syrian hamsters were as follows: Eimeria spp. oocysts (15.4%) and the eggs of H. nana (11.2%), Syphacia spp. (11%). and Aspiculuris spp. (5.6 %). Only trichurid eggs were observed in the fecal samples of dwarf hamsters (51.5%). Oocysts of Eimeria spp. (52.7%) and the eggs of P. ambiguus (3.6%) were detected in the feces of rabbits. CONCLUSION Within the scope of this study, the detection of H. nana eggs, a zoonotic parasite, in the feces of Syrian hamster was quite remarkable for public health.

Role of NETs in the difference in host susceptibility to Toxoplasma gondii between sheep and cattle

The main aim of this study was to compare extracellular traps (NETs) formation by polymorphonuclear neutrophils (PMNs) of cattle and sheep when exposed to T. gondii tachyzoites in vitro. The effects of parasite concentrations and different incubation periods on NETs development in cattle and sheep PMNs were studied. The effect of NET structures on host cell invasion by tachyzoites was also studied. This is the first report of NETs development by sheep and cattle PMNs against T. gondii in vitro. T. gondii-induced extracellular DNA production from PMNs was dependent on tachyzoite concentrations and incubation time in both sheep and cattle. Many nuclear and cytoplasmic changes were observed in sheep and cattle PMNs after exposure to T. gondii tachyzoites. The typical appearance of NETs, with MPO, NE and histone (H3) attached to extracellular DNA, was observed. Tachyzoites were entrapped within this structure. Myeloperoxidase (MPO) activity was higher in the cattle PMN-tachyzoite co-cultures than sheep. NETs structures released from sheep PMNs caused mechanical immobilisation of T. gondii tachyzoites, however, NET structures released from cattle PMNs may be lethal to tachyzoites. Bovine MPO may have a lethal effect on T. gondii tachyzoites in vitro during a 3h incubation. Besides other mechanisms that effect on host susceptibility to T. gondii in sheep and cattle, extracellular traps formation as a part of immunological reactions may be play a role in host susceptibility to T. gondii.

The relationship between seropositivity and tissue cysts in sheep naturally infected with Toxoplasma gondii

Skeletal muscles (tongue, masseter, leg, intercostal, and diaphragmatic muscles) and brain samples of 100 sheep at slaughter were analysed for the presence of T. gondii tissue cysts along with serum IgG titres. Two methods of isolation by percoll gradient centrifugation and tissue microarray (TMA) technique with immunoperoxidase staining were used. Seropositivity was detected in 88% (88/100) of sheep sera analysed by indirect fluorescent antibody test. Tissue cysts were observed in 46 (52.3%, 46/88) and 15 (17%, 15/88) of the seropositive sheep with the isolation technique and TMA and immunoperoxidase staining, respectively. The diameters of the tissue cysts were 25–58 × 25–62 (mean 34 × 36) µm. The relationship between the presence of tissue cysts and seropositivity in sheep was statistically significant at 1/16 (P < 0.01) and at 1/64 and 1/128 (P < 0.001) serum dilutions.

Seroprevalence of Toxoplasma gondii in sheep in Silopi district by using indirect fluorescent antibody test (IFAT)

OBJECTIVE In the present study, it was aimed to detect seropositivity of T. gondii in sheep raised in the Silopi district. METHODS For this aim, blood samples were obtained from 100 female Hamdani sheep. The serum samples were examined using indirect fluorescent antibody (IFA) with respect of T. gondii specific antibody. RESULTS Seropositivity was detected in 97 of sheep examined (97%). The seropositivity titers for the IFA test showed that 1:16 in 58 (59.7%), 1:64 in 22 (22.6%), 1:128 in 16 (16.4%) and 1:256 in 1 (%1) of sheep were found as seropositive. Seropositivity was observed as 96% in aborted sheep. Seropositivity was detected as 96% and 100% in 2-4 and 5-10 year old sheep, respectively. The relationship between age and seropositivity rate was not found significant (p > 0.05). CONCLUSION The seropositivity of T. gondii was higher in sheep grown in Silopi.

Immunohistochemical localisation of 3β-hydroxysteroid dehydrogenase in Sarcocystis spp.

Abstract3β-Hydroxysteroid-dehydrogenase (3β-HSD) is an isoenzyme that catalyses an essential step in the synthesis of all classes of active steroid hormones. The presence of steroid hormones of the vertebrate type in invertebrates is acknowledged in addition to a group of steroid-like hormones called ecdysteroids that were present in arthropods and helminths. In the present study, 3β-HSD was detected in the bradyzoites enclosed in sarcocysts of Sarcocystis spp. with immunohistochemistry. The results suggest that self-originating steroid hormones may play important roles in the development of Sarcocystis spp., and possibly in the regulation of the reciprocal immune interaction between the host and these parasites.