Persistent bovine viral diarrhea virus (BVDV) infection in cattle herds.

Bovine viral diarrhea virus (BVDV) is a significant pathogen associated with gastrointestinal, respiratory, and reproductive diseases of cattle worldwide. It causes continuous economic losses to the cattle industry primarily due to decreased reproductive performance. The ability of virus to cross the placenta during early pregnancy can result in the birth of persistently infected (PI) calves. Persistently infected animals are generally much more efficient transmitters of BVDV than transiently or acutely infected animals because they are capable of shedding large quantities of virus throughout their lives and are considered the primary reservoirs for BVDV. Due to the nature of viral infections, there is no treatment to fully cure an animal of a viral infection. All control programs which are in use in many countries of the world, mainly depend upon the detection of PI animals, eliminating them and preventing their return into the herds. Detection of PI animals at early stage, particularly soon after birth is of significant benefit to implement BVDV control programs. Available diagnostic tests such as virus isolation (VI), immunohistochemistry (IHC), Antigen-Capture ELISA (ACE), and reverse transcriptase polymerase chain reaction (RT-PCR) are used for detection of PI cattle. Each method to detect BVDV has advantages, disadvantages, and applicability for different diagnostic situations. The reliability of diagnostic tests is optimized by choosing the appropriate sampling strategy on the basis of animal age.

Genetic and pathologic characteristics of infectious bursal disease viruses isolated from broiler chickens in Iran during 2014-2015.

Infectious bursal disease (IBD) virus causes a highly contagious immunosuppressive disease in chickens. A total number of 12 pooled bursal samples were collected during 2014-2015 from broiler farms in different regions of Iran. Typical macroscopical and histopathological lesions of the bursa of Fabricius were found similar to reports by other researchers. A 474-bp part of hypervariable region of VP2 (hvVP2) was sequenced and analyzed. Ten isolates had the characteristic amino acid residues of very virulent IBD (vvIBD) viruses and the other two were identified as attenuated (vaccine) strains. The vvIBD isolates had a unique G to S mutation at position 254, compared to other Iranian vvIBD isolates. Two attenuated isolates had the mutation 253Q, not found in D78 strain, creating virulent variant of vaccine strains. Degree of similarity among the studied vvIBD isolates was relatively high (97.6-100%), proposing a common ancestor for them. However, they were partly different from previous Iranian and neighbor countries' isolates (96.2-97.3% similarity to Shiraz isolate and 95.7-96.7% to Iraq and Turkey isolates). In phylogenetic analysis, the studied vvIBD isolates classified as a separate subgroup in the group of isolates from Iran and neighbor countries. More studies on genetic and antigenic characteristics of these isolates as well as probable modifications in their pathogenicity are needed to evaluate the significance of the mentioned differences.

Morphological and molecular analyses of the spiruroid nematode, Falcaustra araxiana Massino, 1924 (= Spironoura araxiana) from the European pond turtle (Emys orbicularis).

There is little information on the phylogenetic position and life cycle of family Kathlaniidae. Falcaustra araxiana is a member of this family which infects the large intestine of the European pond turtle (Emys orbicularis). In the present study, morphological data and molecular analyses based on the 18S rDNA were performed on different types of F. araxiana originating from the large intestine and gastric nodules in the turtle. Morphological data revealed both larvae and adult stages in the gastric nodules. In addition, all nematodes recovered in the large intestine were adult worms. GenBank accession numbers KM200715 and KM200716 were provided for adult F. araxiana located in the intestine and stomach, respectively, of E. orbicularis. The results of sequencing proved that these two types are completely similar. Accordingly, it can be hypothesized that nodule formation is a part of the life cycle of the parasite or a survival strategy. Furthermore, F. araxiana develops to the adult stage in the gastric mucosa prior to migrating to the large intestine. Phylogenetic analysis revealed that F. araxiana unexpectedly branched away from other members of the superfamily Seuratoidea (Truttaedacnitis truttae, Cucullanus robustus and C. baylisi) and showed a closer relationship with Paraquimperia africana, a member of the Ascaridoidea. It seems that phylogenetic reconstruction for the present parasite needs more detailed morphology, life cycle and molecular studies.

Diffuse type testicular seminoma in a stallion.

A 7-year-old stallion with progressive left testicular enlargement was presented. Grossly, the excised testicle measured 25 × 15 × 12 cm and weighed 3.7 kg. It was multinodular with a gray-white surface; however, the right testis was normal. Histologically, the neoplastic cells were disseminated diffusely in the tumoral stroma with a minimal fibrovascular stroma. Neoplastic cells were round to polygonal with abundant eosinophilic cytoplasm and large round to oval vesicular or hyperchromatic nucleous with a single prominent nucleolus. Immunohistochemically, the neoplastic cells were positive nuclear immunostaining for C-KIT and negative for OCT3/4. According to gross, histopathological, and immunohistochemical characteristics, the diffuse type of seminoma was diagnosed. Nine months later, the follow-up observation of the case showed that the tumor had no recurrence and metastasis.

Prevalence and morphopathological characteristics of linguatulosis in one-humped camel (Camelus dromedarius) in Yazd, Iran.

Linguatula serrata is a cosmopolitan zoonotic parasite. Its adult form inhabit the nasal and respiratory passages of canids as the definitive hosts while its immature stages localize in the mesenteric lymph nodes or in other organs of herbivorous intermediate hosts. We examined the liver, mesenteric, and mediastinal lymph nodes of 272 camels slaughtered at the slaughterhouse of Yazd, Iran. Forty-one out of 272 camels (15.1 %) were infected with nymphs of L. serrata. Twenty-four out of 166 males (14.45 %) and 17 out of 106 females (16 %) were positive. The livers of five camels, which also had nymphs in their lymph nodes, were infected with the larval stage of this parasite. The infection rate increased with age and was highly significant, while sex did not play a significant role in the prevalence of this parasitic infection. The infected lymph nodes were grossly enlarged, edematous, and consisted of hemorrhagic and necrotic lesions. Histopathologically, the architecture of the infected lymph nodes was degraded, necrotic, and sectioned migrating stages of L. serrata were clearly visible. In some lymph nodes, parasitic granulomatous lymphadenitis with necrosis and in some cases, degenerated parasite in central area was observed. High prevalence of infection in camels suggests possibility of similar high rate of infection in other animals of this region. In view of the consumption of raw or undercooked visceral organs of camel by humans of this region, the importance of careful inspection at slaughterhouse needs to be emphasized.