Iranian Journal of Veterinary Medicine
Year:2016 | Volume:10 | Issue:2|Papers Count:12

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: 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: 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.

BACKGROUND: Although Escherichia coli (E. coli) is a part of intestinal normal microflora of warm-blooded animals, including poultry, outbreaks occur in poultry raised below standard sanitation and during the course of respiratory or immunosuppressive diseases. Avian pathogenicE. coli (APEC) harbors several genes associated with virulence and pathogenicity.APEC strains are responsible for some diseases in poultry including colibacillosis, swollen head syndrome, yolk sac infection, omphalitis and coli granuloma.OBJECTIVES: The aim of this study was examination of the presence and frequency of three important virulence genes in intestinal and extra-intestinal (liver)E. coli isolates from chicken of Khuzestan province in the southwest of Iran.METHODS: Totally 120 (60 intestinal and 60 liver)E. coli isolates were examined by polymerase chain reaction (PCR) for the presence of aerobactin (iutA), temperature sensitive hemagglutinin (tsh) and fimbriae type 1 (fimH) genes.RESULTS: The results showed that tsh, iutA and fimH are respectively present in 78.3%, 70% and 61.7% of liver isolates while in intestinal ones the frequency of these genes was 21.7%, 41.7% and 41.7% respectively. The most prevalent genotypes in extra intestinal and intestinal isolates were tsh+fimH+iutA+ and tsh-fimH-iutA-respectively.CONCLUSIONS: It seems that these sets of virulence genes are significantly more prevalent (P<0.05) in extra intestinal isolates and probably these genes play an important role in the pathogenesis of APEC isolates in the southwest of Iran. Although these virulence genes were not present in all APEC isolates their frequencies were high and using the products of these genes in vaccines may be effective in protecting against infections caused by this bacterium.

BACKGROUND: Foodborne outbreaks associated with shiga toxin-producingEscherichia coli (STEC) have been well documented worldwide. STECs are major causative agents of gastroenteritis in humans that may be complicated by hemorrhagic colitis (HC), hemolytic uremic syndrome (HUS), and thrombotic thrombocytopenia purpura (TTP).OBJECTIVES: The aim of this study was to investigate the presence of virulence-associated genes including eaeA, hlyA, stx1 and stx2 inEscherichia coli strains isolated from broiler’s Colibacillosis in the northeast of Iran.METHODS: From a total of 78 E.colistrains isolated from yolk sac infection, hepatitis and pericarditis, that were referred to educational veterinary clinic during 2011-2014, subculturing of the isolates was performed using selective media and a typical colony from each sample was subjected to multiplex PCR assay for identification of the presence of STEC important virulence-associated genes (eaeA, hlyA, stx1 and stx2) causing shiga toxin-mediated diseases.RESULTS: Of 78 E.coli isolates, one isolate was positive for both eaeA and hlyA genes while negative for stx1 and stx2 genes.CONCLUSIONS: The results showed low prevalence of STEC virulence genes associated with human infections in avian pathogenicE.coli (APEC) strains isolated from different flocks of broilers affected with colibacillosis.

BACKGROUND: Most leptospiral infections in sheep and goat are asymptomatic but may result in high fever, abortion, stillbirth, agalactiae. There is a different foraging behavior between sheep and goat that may cause the different prevalence of Leptospira interrogans infection in sheep and goats.OBJECTIVES: The purpose of the present study was to compare the prevalence ofL. interrogans antibodies in sheep and goats.METHODS: Blood samples were taken from 246 sheep and 210 goats in 12 herds from 8 areas of Ahvaz where the animals were kept together. Sera were initially screened at dilution of 1: 100 against 8 live serovars of L. intrrogans: pomana, canicola, hardjo, ballom, ictrohaemorrhagiae, grippotyphosa, tarasovi and australis using the microscopic agglutination test (MAT).RESULTS: The prevalence of leptospiral infection was 8.53% in sheep and 10.95% in goats. The highest reacting leptospira in both species wasL.i. Pomona with a reactor rate of 68.18% in sheep and 56% in goats, followed in descending order by ictrohaemorrhagiae (18.8%), canicula, hardjo and grippotyphosa (each of them 4.54%), in sheep and ictrohaemorrhagiae (28%), canicula (16%) in goats. Statistical analysis showed that were no significant differences between sheep and goat (P=0.428).There were no significant differences among age groups in sheep (p=0.301) and goats (p=0.363), but there was a tendency in adults sheep and goats (³3years) to be more seropositive than young sheep and goats. Seroprevalence of leptospiral infection among various areas in sheep (p=0.464) and goats (p= 0.710) was also not significantly different.CONCLUSIONS: It is concluded that there is no difference between sheep and goats in terms of leptospiral infection when they are kept together in the same herd and husbandry condition.

BACKGROUND: Green iguana (Iguana iguana) is one of the newly imported exotic pets which has been observed with increasing regularity in veterinary clinics in Iran. Despite their popularity, information about their diseases is scarce.OBJECTIVES: The aim of this study was to assess the pathogenic agents in green iguanas with skin disorders.METHODS: The animals were brought to Small Animal Hospital, Faculty of Veterinary Medicine, Tehran, Iran, with chronic pruritic dermatitis, scabs, loss of spines and deep ulcerative dermatitis located over the body. During physical exam, deposits of dry seborrhea were taken and processed for diagnosis. The clinical specimens were cultured on sabouraud dextrose agar containing chloramphenicol and cycloheximide and mycosel agar.RESULTS: Microscopic examination revealed fungal elements as Trichophyton mentagrophytesvar. mentagrophytes and psoroptid mites as Geckobiella donnae. CONCLUSIONS: This was the first report of the presence of fungal and parasitic agents as the etiological agents of dermatological disorders in green iguanas.

BACKGROUND: Heart valve diseases are considered a common disease in human and animals, and valve replacement is an option for treatment of valvular diseases.OBJECTIVES: In this study efficacy of a tissue engineered valve in thoracic aorta was evaluated with transthoracic echocardiography.METHODS: This study was undertaken on 6 male sheep. Echocardiography was performed on all sheep 24 hours before surgery and repeated 24 hours (D1), 2 weeks (W2) and 4 weeks (W4) after surgery. Right parasternal long axis view of left ventricular outflow tract (LVOT) was used to assess hemodynamic across new valve.RESULTS: Velocity time integral (VTI) significantly decreased from 18.98±2.88 before surgery to 12.55±2.48 one day after surgery (D1) (p<0.05). Mean Velocity (Vmean) decreased significantly from 52.56±12.01 to 39.72±12.30 at D1 (p<0.05). But maximum velocity (Vmax) was constant during study. There was not any statistical difference between mean Pressure gradient (Pgmean) or maximum pressure gradient (Pgmax) in comparison with pre-surgery and D1, W2 and W4.At D1, W2 and W4, time to peak (TTP) differed significantly from previous time.CONCLUSIONS: Our results demonstrated that this tissue engineered aortic valve (TEAV) could change some hemodynamic parameters, but heart could compensate some of them. Valve movement remained normal but the major complication was aneurism which seems to be the result of poor scaffold.

BACKGROUND: Ghrelin, an endogenous ligand for the growth secretagogue receptor is predominantly produced in the stomach and an expression of ghrelin has recently been identified in placenta and ovary.OBJECTIVES: Therefore, we decited to measure ovarian ghrelin as quantitative and evaluate the correlation between ghrelin and estrogen during second half of ovine pregnancy.METHODS: The ovarian samples were collected from 40 pregnant sheep in 3, 3.5, 4, 4.5 and 5 months of pregnancy in a local abattoir. Follicles and active corpora lutea (CL) were dissected from surrounding tissues, separately. The samples were homogenized with phosphate buffer (0.1 M, pH=7.4) on liquid nitrogen to provide fluid samples. Ghrelin and estrogen concentrations were measured by ELISA method and expressed as milligram (mg) and picogram (pg) per mg of tissue protein, respectively.RESULTS: There was a linear correlation between ghrelin and estrogen in ovarian follicles (r=0.97 and p=0.004), but not in CL. Follicular ghrelin significantly increased in 4, 4.5 and 5 months (p<0.001) but CL ghrelin significantly decreased in the 4.5 month of ovine pregnancy (p<0.01). Estrogen concentration was also significantly higher in 4-5 months of pregnancy in ovarian follicles (p<0.001) but potent CL indicated higher estrogen level only in the 5th month of pregnancy (p<0.001).CONCLUSIONS: These results emphasize the role of ghrelin in the reproductive system and open a new window to future studies.

Caudal duplication is an abnormality which usually affects the digestive, urogenital and even respiratory systems. It forms a graded series from slight duplication to near separation of two fetuses caudocranially. In some conjoined twins, duplication process may cranially proceed up to the head region. This kind of developed conjoined monocephalus twin has been reported in many domestic species and is classified as thoracopagus or omphalopagus twins according to the presence of one or two hearts, respectively. A male dead conjoined monocephalus twin lamb attached from neck to thorax was used for this study.Lateral and dorso-ventral digital radiography and anatomic dissection were performed on the case. The results showed that duplication process of the gastrointestinal tract interestingly prevented cranial to the midgut, while more cranial organs such as heart, lungs and even brain were seen duplicated. Duplication anomaly has been mostly reported cranially in cattle and caudally in sheep. Nevertheless, if duplication process does not occur completely, some body organs of the resulting conjoined twin will remain unduplicated. Duplication process of this case is thought to strengthen Spencer’s spherical theory.