مجله طب دامی ایران
سال:1395 | دوره:10 | شماره:2 |تعداد مقالات:12

BACKGROUND: Avian chlamydiosis is a zoonotic disease of birds caused by the intracellular bacteriumChlamydia psittaci.Avian chlamydiosis leads to severe respiratory disease in young turkeys and egg production losses in layers.OBJECTIVES: Due to paucity of information about the prevalence of chlamydial infection in the turkey population in Iran, this study was conducted to detect chlamydial infection in some Iranian turkey flocks in different provinces.METHODS: A total of 177 samples were taken from turkeys and first verified asChlamydiaceae by Chlamydiaceae-specific real-time polymerase chain reaction (real-time PCR) by detection of the 23S RNA gene of Chlamydiaceae (Ct values ranging from 34 to 38) and then positive samples were investigated for the presence of C. psittaci by a nested PCR.RESULTS: Seventeen of 177 samples (9.6%), corresponding to 13 farms of 48 examined farms were positive for Chlamydiaceaeby real-time PCR. None of the positive samples were found to beC. psittaci in the nested PCR.CONCLUSIONS: This study showed noC. psittaci infection in the turkey population in Iran. We recommend investigation on other farm animals and wild populations for possible chlamydial infection and for better understanding of the source and epidemiology of this agent. Due to the challenges that exist for sampling and the relevant impact on reducing positive samples, investigation by parallel and complementary techniques may be useful in showing the true prevalence of infection in the target populations.

BACKGROUND: DNA immunization is an appropriate method to produce an immunological response.Pseudomonas aeruginosa produces exotoxin A which is highly cytotoxic for eukaryotic cells. Since domains II (translocation domain) and 1b of the toxin have antigenic qualities, so they could be useful candidates to protect against pseudomonas infections.OBJECTIVES: To evaluate if recombinant plasmid containing immunogenic domain of exotoxin A might be protective against Pseudomonas aeruginosain fections. METHODS: To study the biologic and immunological effects of antigenic domains of exotoxin A, plasmid expression vector (pET28a) containing domain II and 1b of exotoxin was constructed. To evaluate the effects of intracellular recombinant gene expression, BALB/C mice were immunized with the recombinant plasmid and then subjected to third degree thermal injury and the humoral immunity responses were assayed.RESULTS: Immunization with the recombinant plasmid containing translocation and 1b domains of exotoxin A resulted in increasing antibodies production (IgA and IgG) againstPseudomonas aeruginosa. DNA immunization significantly decreased the bacterial count liver, spleen, blood and inoculated burns after challenging withP. aeruginosa and dramatically improved the survival rate of burn-injured mice.CONCLUSIONS: Finally, immunization by gene encoding antigenic products may be a good technique for protection against P. aeruginosainfections.

BACKGROUND: The Endothelial PAS domain-containing protein 1 (EPSA1) is the key transcriptional regulator of hypoxic response and Vascular Permeability Factor (VPF) is an important growth factor for vascular development and angiogenesis.OBJECTIVES: In the present study, the levels of the EPSA1 coding gene and VPF transcripts were evaluated during Larval development of Beluga, Huso huso. METHODS: Samples at 12 developmental time-points including 1, 2, 4 days before hatch (eyed eggs), fresh hatched larvae (0), and larvae 1, 3, 6, 10, 15, 20, 25 and 50 days post-hatching were collected and stored in a −80 °C freezer until RNA extraction. Changes in EPSA1 and VPF mRNA expression were studied and differences in normalized mRNA expression levels among the different developmental stages ofH. huso were analyzed by one-way analysis of variance (ANOVA).RESULTS: The transcripts of EPSA1 and VPF were detected in all developmental time-points ofH. huso from embryos to fingerling fish. Our results revealed that the mRNA expression of EPSA1 and VPF was low during embryonic development and then upregulated significantly at the time of hatch and early larval time-points, whereas in the late larval development stages they started to decline.CONCLUSIONS: This study showed that there is an association between the EPSA1 and VPF mRNA expression during larval development of H. huso. The up regulation of EPSA1 and VPF transcripts at the time of hatch and during yolk sac fry development ofH.husois likely tied to the role of them in vasculogenesis and angiogenesis.