Effects of Selected Adjuvants on Immunogenicity and Protectivity of Pasteurella multocida Bacterin Vaccine in Chickens.

Avian pasteurellosis (fowl cholera) is an important disease affecting domestic and wild birds all over the world. Although the capsular type A of Pasteurella multocida is mostly involved, other capsular types are occasionally incriminated. The present study aimed at investigating the effect of some adjuvants on immunogenicity and protectivity of P. multocida bacterin in chickens, compared to an Iranian commercial vaccine. Eight-week-old chicken pullets were double vaccinated with an interval of three weeks. Vaccine immunogenicity testing was conducted using an in-house indirect enzyme-linked immunosorbent assay and assessing serum antibody titers at 7, 14, and 21 days post-primary and 14 days post-secondary immunization. The possible adverse effects were recorded by a poultry-disease expert. For evaluating the vaccine protection rate, chickens were subjected to 2×Lethal Dose 50%of a virulent P. multocida strain two weeks post-secondary immunization. The rate of live and normal animals was regarded as protection rate 7days after the exposure. The findings showed that oil adjuvants Montanide ISA 70-and Montanide ISA 71-containingvaccines (with or without saponin) caused a powerful immune reaction than the aluminum adjuvanted vaccine and commercial vaccine (P<0.05). Significant protection against challenge was merely induced by the oil adjuvanted vaccines (P<0.05). The majority of the studied chickens showed inflammation at the injection site (yellow) throughout the trial. Vaccines made by Montanide ISA 70 and Montanide ISA 71 are novel and effective inactivated vaccines that are able to cause significant protection to fowl cholera disease.

Restriction Fragment Length Polymorphism Typing of Staphylococcus aureus Strains Isolated from Bovine Mastitis and Dairy Products in Ahvaz, Iran, Using of Digested Coagulase Gene.

Staphylococcus aureus is a major pathogen in the transmission of diseases from animals to humans and vice-versa.Various infections, such as mastitis in cattle, sheep and goats, as well as gastroenteritis due to food poisoning in humans are the most frequent problems caused by S. aureus. The bacteria also lead to severe economic losses in dairy industry. A major virulence factor for the organism is encoded by the coagulase (coa) gene. This study aimed to assess the polymorphisms of the coa gene in S. aureus strains isolated from bovine mastitis and dairy product samples in Ahvaz, Iran. The results showed that out of 91 S. aureus, 80 (87.91%) isolates were positive for coa gene(s). In total, nine different polymerase chain reaction (PCR) products were obtained for coa-positive isolates. A single band was detected in coa PCR with a size ranges from 370 to 830 bp in most isolates (n=77, 96.25%). For three isolates (3.75%), two amplification products were obtained. A PCR product of an estimated size of 590 bp was most frequent, as obtained for 48 (60.00%) isolates. Whereas, 370 and 830 bp PCR products were the least presented, for two (2.50%) and one (1.25%) isolate, respectively. Subsequently, for restriction fragment length polymorphism (RFLP), typing of coa gene and AluI restriction enzyme were used for the digestion of the products. AluI for most of PCR products generated a unique pattern; however, four PCR products (the sizes ranged 750, 670, 590, and 510 bp) generated three or more patterns. Based on AluI RFLP of coa gene, the isolates were classified into 23 groups. Two groups of isolates were dominant, making 45% of the total. According to the findings, one or two types of coa RFLP were dominant among samples that were infected with more S. aureus isolates belonging to different coa RFLP types.

Molecular Detection of Chlamydia felis in Cats in Ahvaz, Iran.

Chlamydiae are obligate generally Gram-negative intracellular parasites with bacterial characteristics, including a cell wall, DNA, and RNA. They have a worldwide distribution in different animal species. Chlamydia felis (C. felis) is an important agent with zoonotic susceptibility often isolated from cats with chronic conjunctivitis. The aim of the present survey aimed to determine the molecular occurrence of C. felis in cats in Ahvaz, Iran. In this regard, a total of 152 cats (126 households and 26 feral) were included in the current study. After recording their history information, two swabs were taken from the oropharyngeal cavity and eye conjunctiva of the investigated cats. The extraction of DNA was followed by PCR targeting the pmp gene of C. Felis. In the next step, the positive samples were sequenced based on the Gene Bank. Out of 152 samples, 35 (23.03%) were positive using polymerase chain reaction technique (95% CI: 16.30-29.70). Regarding infection with Chlamydiosis, the obtained results showed a significant difference between cats suffering from ocular or respiratory diseases (44.64%; 25 out of 56) and the healthy ones (10.42%; 10 out of 96; P=0.01). The prevalence of infection was significantly higher in cats younger than 1 year (34.12%; 29 out of 85), compared to those older than 1 year (8.96%; 6 out of 67; P=0.02). No significant difference was noted in terms of gender (25.45% in males and 21.65% in females), breed (23.81% in DSH and 19.23% in Persian), and lifestyle (22.22% companions [28 out of 126] and 26.92% ferals [7 out of 26]; P&gt;0.05). It can be concluded that a significant number of cats are infected with C. felis in Ahvaz. The use of molecular tests, such as PCR, has revolutionized the diagnosis of chlamydial infections.

Evaluation of immunopathologic effects of aqueous extract of Echinacea purpurea in mice after experimental challenge with Pasteurella multocida serotype A.

In order to assess the immunopathological effects of aqueous Echinacea purpurea extract (EPE) on mice experimentally challenged with Pasteurella multocida serotype A, forty female BALB/c mice were randomly divided into four groups. The groups included a control group (received sterile distilled water 2 times/week for 2 weeks, intraperitoneally and then 100 µl sterile saline intranasally), a PMA group (received sterile distilled water as the control group and after 2 weeks, 5.6 × 10(3) CFU/ml of P. multocida serotype A, intranasally), an EPE+PMA group (received E. purpurea extract intraperitoneally 2 times/week for 2 weeks and then challenged as the PMA group) and an EPE group (received E. purpurea extract as EPE+PMA group and then 100 µl sterile saline intranasally). After 24 and 48 h post challenge, half of the animals in each group were sacrificed and analyzed for bacterial counts in their lungs and livers, TNFα serum levels and histapathological changes. The results showed significant differences in lung bacterial counts between PMA and EPE+PMA groups. TNFα serum level was significantly higher in the PMA group. Histopathological examination revealed infiltration of neutrophils in alveolar septa and hyperemia in the PMA group. In addition, the criteria of bronchopneumonia were partially recovered in the EPE+PMA compared to the PMA group. According to the results, it seems that E. purpurea extract has an immunomodulatory effect and can be used to prevent or control of pneumonia caused by Pasteurella.

Effect of dietary garlic on immune response of broiler chicks to live Newcastle Disease vaccine.

This study was designed to determine the effect of garlic powder on humoral immune response of broilers against NDV (Newcastle Disease Virus) vaccine. Two hundred and forty, two-day-old, Ross chicks were randomly assigned into 4 groups of 60 birds each. Chicks in groups 1 and 2 were given control mash diet during the experiment (6 week), but those in groups 3 and 4 were fed on control diet supplemented with 1 and 3% garlic powder, respectively. All groups except number 1 were vaccinated by eye-drop with B1 strain (Pestikal, Croatia) at 9 and 18 days of age. Ten blood samples were taken from each group on days 0, 14, 24 and 34 after first vaccination. The serum antibody level against NDV was measured by both HI and ELISA tests. The EDTA-mixed blood samples were examined for total and differential leukocyte count. The results showed that antibody titers in vaccinated chicks were significantly more than in non-vaccinated chicks (p < 0.05), but not influenced by the diet (p > 0.05). A significant increase of total leukocyte and percentage of lymphocytes was observed in vaccinated chicks 14 days after vaccination, but there were no difference (p > 0.05) among vaccinated groups. It is concluded that inclusion of garlic powder to the diet of broilers don't have any beneficial effect on humoral immune response to live NDV vaccine.

Detection of specific hydatid antigens and antibodies in serum and urine of experimentally infected sheep.

Immunodiagnostic confirmation of cystic human hydatidosis is frequently required before surgical intervention or of chemotherapy. However, it remains inadequate to detect specific antibodies or antigens in some confirmed cases of echinococcosis. This study was carried out to investigate the accuracy of three different immunodiagnostic tests for detection of specific circulating antigens or antibodies in the serum and urine of 13 experimentally infected sheep. For this purpose, Echinococcus granulosus were collected from small intestine of experimentally infected dogs, and 2000 taenid eggs were orally administered to each of the 13 sheep. There were six other sheep, which were kept as the control group. Biweekly serum and urine samples were collected from all the sheep for 4 months after infection. The sera were subjected to indirect hemagglutination test and the concentrated urine samples were subjected to coagglutination and counter immunoelectrophoresis tests. The results revealed that the sensitivity of these tests in detecting the hydatid antigens in the urine or antihydatid antibodies in the serum of the infected sheep reached their maximum in 12th and 13th week after infection; then it decreased in the following weeks. Examination of the non-infected sheep samples throughout the experiment showed that the aforesaid findings were specific only to the infected sheep. It seems that the appearance of specific hydatid antigen in urine and its antibodies in the serum were simultaneous. Although these tests are highly specific, false negative outcomes were encountered in their detection of cystic echinococcosis. In general, it seems rational to establish some series of diagnostic procedures in order to reveal antibodies and antigen of metacestode in serum and urine of the patients.