The Role of the Respiratory Mucosal Immunity in Protection against Pasteurella Haemolytica A2 Infection in Goats

Pneumonic pasteurellosis is one of the most important and devastating diseases in sheep and goats, causing great economic losses to small ruminant industry worldwide. The disease is caused either by Pasteurella haemolytica or Pasteurella multocida and Pasteurella haemolytica A2 is the most common isolate from sheep and goats in Malaysia, comprising approximately 38 per cent of the isolates from pneumonic lung lesions. The disease is best controlled by vaccination, and systemic vaccination has been used for years with limited success. Stress, improper vaccination program and unpopularity of the vaccine among the farmers are some of the reasons that have been associated with the persistence of the disease. Since the systemic vaccination failed to give promising results, studies on the role of mucosal immunity of the respiratory tract in controlling pneumonic pasteurellosis should timely be reviewed. In this study, the bronchus-associated lymphoid tissue (SALT) in the lungs 9 been successfully stimulated by double intranasal exposures to either live or formalin-killed Pasteurella haemolytica A2 at two weeks interval. The size of SALT and number of lymphocytes in the SALT were significantly increased as early as week 2 post-exposure and remained high until week 4 post-exposure. At the same time, the level of IgA against Pasteurella haemolytica A2 increased significantly as early as week 1 post-first exposure and reached a peak level at week 6 post-exposure. The IgM appeared to be present for a short while, at week 3 post-exposure before the levels started to decline in the following week. Initially, the IgG increased gradually and insignificantly before it reached significantly high level at week 4 post-exposure, and remained high at weeks 5 and 6 at the time when the numbers of SALT continued to increase. This study also revealed that intranasal stimulation of SALT was able to protect the lungs from colonization by Pasteurella haemolytica A2 during an in vitro study, thus prevent the lung surface from being adhered and invaded by the organism. However, dexamethasone treatment which is similar to the effect of steroid released under stressful conditions, significantly reduced the number and size of the SALT, thus significantly reduced the percentage of IgA-producing cells. Vaccination trial on goat farm using the pasteurella spray vaccine intranasally showed good protection towards pneumonic pasteurellosis. Significant high levels of systemic antibody responses were also noted during the period of vaccination trial. The incidence of pneumonic pasteurellosis in the farm was markedly reduced

Efficacy of an inactivated recombinant vaccine encoding a fimbrial protein of Pasteurella multocida B:2 against hemorrhagic septicemia in goats

This study was carried out to determine the antibody responses and protective capacity of an inactivated recombinant vaccine expressing the fimbrial protein of Pasteurella multocida B:2 following intranasal vaccination against hemorrhagic septicemia in goats. Goats were vaccinated intranasal with 106 CFU/mL of the recombinant vaccine (vaccinated group) and 106 CFU/mL of pET32/LIC vector without fimbrial protein (control group). All three groups were kept separated before all goats in the three groups were challenged with 109 CFU/mL of live pathogenic P. multocida B:2. During the course of study, both serum and lung lavage fluid were collected to evaluate the antibody levels via enzyme-linked immunosorbent assay. It was found that goats immunized with the inactivated recombinant vaccine developed a strong and significantly (p < 0.05) higher specific IgA and IgG responses in both serum and lung lavage fluid samples compared to the control and unvaccinated groups. Following intratracheal challenge, the rate of isolation was 17% for the vaccinated group, 67% for the control group and 100% for the unvaccinated group. However, none of the goat from the vaccinated group had P. multocida B:2 in the liver, tonsil and heart. Therefore, the study revealed that an inactivated recombinant vaccine significantly provides significant protection against high dose challenge and enhances the stimulation of the local and systemic immunities

Effect of intranasal attenuated Pasteurella multocida B:2 on haemorrhagic septicaemia in calves

This report describes the effect of vaccination with attenuated P. multocida B:2 on wild-type P. multocida B:2 infection in calves. Calves were given 5 ml intranasal 107 CFU/mL live attenuated gdhA derivative of P. multocida B:2. Untreated calves were then mingled with the vaccinated Group. Control untreated calves were kept separate. After 6 weeks, all calves were challenged intra-tracheally with 107 CFU/mL of live wild-type P. multocida B:2. At Post-Mortem none of the vaccinated or mingled calves had lesions whereas controls revealed pulmonary petechial haemorrhages with acute pneumonia patches with neutrophils. Both exposed and commingled calves showed significantly (p<0.05) higher levels of serum IgG. P. multocida B:2 were successfully isolated only from the control calves of Group 3. These findings suggest that intranasal exposures to live attenuated P. multocida B:2 prevented infection by wild-type P. multocida B:2 and may have protected susceptible calves

Distribution and histological structure of peyer's patches in the large intestine of three-month-old calves

Distribution and histological structure of aggregated lymphoid tissues (Peyer's patches) of the large intestine were evaluated in three-month-old calves. The first patch was situated in the ileocaecal entrance, second patch in the proximal colon and third in the rectum. The length ofPeyer's patches in the proximal colon varied from 4 to 8 cm. Macroscopically, the patches at ileocaecal entrance and proximal colon were clearly seen, whereas the rectal patch was inconspicuous. Histologically, the Peyer's patches of the large intestine consisted of lymphoglandular complex and lamina propria nodules. The lymphoglandular complex was located within the submucosa that contains epithelial diverticula, which extends from muscularis mucosae. The lamina propria nodules were located in the lamina propria. The propria nodules were surrounded by wide crypts, lined by distinct follicle-associated epithelium and lacked goblet cells. The lymphoglandular complexes were covered with distinct follicle-associated epithelium with numerous intraepithelial lymphocytes and lacked goblet cells. Intraepithelial lymphocytes were distributed in the epithelial layer of the large intestine and formed a unique lymphocyte population. Some Peyer's patches ofthe large intestine were similar to that of jejunal Peyer's patches as they contained broad follicles, distinct corona areas and wide interfollicular areas

Stimulating immunoglobulin response by intramuscular delivery of exopolysaccharides-adjuvanted mannheimiosis vaccine in goats

Background and Aim: Pneumonic mannheimiosis (PM) is a common respiratory bacterial disease among small ruminants. Despite numerous management methods, vaccination remains a suitable strategy to combat or reduce PM in goats and sheep. Thus, a study was conducted in Malaysia to evaluate the immunogenicity of exopolysaccharide-adjuvanted Mannheimia haemolytica A2 vaccine (EPS-MHA2) under laboratory and field conditions for its potential use as an efficient vaccine against PM. Materials and Methods: This study induced immunoglobulin (Ig) responses following intramuscular (IM) delivery of the EPS-MHA2 vaccine on 12 goats for about 7 months. Goats were divided into three groups, with three goats per group, and they were vaccinated intramuscularly as follows: Group 1 was vaccinated with an adjuvanted vaccine prepared from formalin-killed M. haemolytica serotypes A2 and EPS excipient; Group 2 was vaccinated with formalin-killed M. haemolytica seed only, whereas Group 3 was injected with phosphate-buffered saline (PBS) as the negative control. Measures of specific immunity included serum IgM, IgG, and IgA as well as bronchoalveolar lavage fluid secretory IgA and the size and number of the bronchus-associated lymphoid tissue (BALT). Results: From the 1st day of vaccination, Groups 1 and 2 showed a significant (p < 0.05) increase in serum IgM, IgG, and IgA levels. However, the antibodies started to decline 5-week post-vaccination, indicating that the booster dose was necessary. On the second exposure to the same vaccine (booster), the level of antibodies showed a significant increase (p < 0.05), particularly IgG. All groups were challenged intratracheally by virulent MHA2 2 weeks after the decline of second antibodies on the administration of booster. All goats were euthanatized and necropsied 4-week post-challenge. The number and size of the BALT in Group 1 goats significantly increased compared with those in Group 2 and the unvaccinated control. Bacteriological parameters were evaluated, in which MHA2 was reisolated successfully from lung samples in Group 3. The IgA level produced by the group vaccinated with EPS-MHA2 was significantly (p < 0.001) higher than that the MHA2 vaccine and PBS groups. All data obtained were analyzed statistically using a one-way analysis of variance. The results indicate that IM injection of EPS-MHA2 vaccine significantly enhanced the immune response against MHA2. Conclusion: Therefore, the addition of EPS to MHA2 (EPS-MHA2 vaccine) can effectively protect goats from lethal mannheimiosis infection. Factors such as the ideal concentration of EPS should be further studied to verify its application potential as a vaccine adjuvant, and the extraction of EPS from different microalgae species should be further investigated. This study showed a novel and exciting set of data and a vaccination system, in which the suppressive effects of mannheimiosis may be further investigated

Immobilization of Metanil yellow decolorizing mixed culture FN3 using gelling gum as matrix for bioremediation application

In this study, the Metanil Yellow (MY) decolorizing mixed culture, namely FN3, has been isolated from agriculture soil. The mixed culture was immobilized using gellan gum. In order to optimize the immobilization process for maximal dye decolorization, Response Surface Methodology (RSM) was performed. The optimal conditions for immobilization predicted by desirability function are 130 mg/L of MY dye concentration, 1.478% of gellan gum concentration, 50 beads and 0.6 cm of beads size with the percentage of decolorization of 90.378%. The correlation coefficients of the model (R2 and R2 adj) are 0.9767 and 0.9533, respectively. This indicates that the established model is suitable to predict the effectiveness of dye decolorization under the investigated condition. The immobilized beads of mixed culture FN3 were able to be reused up to 15 batches of decolorization. The immobilized cells also have high tolerance towards heavy metals. This was proven by higher dye decolorization rate by the immobilized cells even with the addition of heavy metals in the media. The decolorization potential of the mixed culture indicates that it could be useful for future bioremediation of soil contaminated sites and treatment solutions of water bodies polluted with MY dye

Histological assessments of intestinal immuno-morphology of tiger grouper juvenile, Epinephelus fuscoguttatus

Histological assessments on the intestinal morphology and immunity of tiger grouper juveniles, Epinephelus fuscoguttatus help in determining the earliest age to start an oral vaccination. This study describes the morphological development of the intestinal immunity of tiger grouper of various ages. Clinically healthy tiger groupers were selected and divided into 4 groups of 20 fish per group. Groups 1, 2, 3 and 4 consisted of juveniles of 30, 60, 90 and 120 days old, respectively. The whole intestine was collected and divided into three regions, the anterior, mid and posterior intestine and fixed in 10% buffered formalin before slides were prepared for microscopic examinations. It was found that the histological structures of the anterior intestine were for absorption of nutrient from digested food particles. The significantly (p < 0.05) higher number and length of the intestinal villi and smaller gap between villi were observed in the anterior intestine, which were structures for absorption. Structures of the posterior intestine were for immunity especially the adaptive immunity with included significantly (p < 0.05) higher numbers of the lymphoid and goblet cells, and significantly (p < 0.05) thicker lamina propria, which were structures for immunity. The mid intestine was the transition structure that involved in both absorption and innate immunity. The results also revealed that leukocytes existed in the lamina propria of 30-days old tiger groupers, an indication that the immune system was present at that particular age

Morphological study of the jejunal and ileal Peyer's patches of three-month old calves

The current study was conducted with the aim to described the light and electron microscopic features of jejunal and ileal Peyer`s patches of three-month old calves. The samples of jejunum and ileum portion of small intestine of three-month old calves were taken and processed for light microscopic, scanning electron microscopy and transmission electron microscopy examinations. Histologically, jejunal Peyer`s patches were characterized by pear-shaped lymphoid follicles with large dome and interfollicular area. Ileal Peyer`s patches were composed of long sac like follicles with poor developed interfollicular area and an inconspicuous corona. The Follicle Associated Epithelium (FAE) is composed of absorptive epithelial cells or enterocytes and intraepithelial lymphocytes but lack of goblet cells and specialized cells or membranous cells (M cell). The jejunal Peyer`s patches consist more intraepithelial lymphocytes than that of the ileal peyer`s patches. The number of intraepithelial lymphocyte was significantly higher (p<0.05) in villi than those of crypts. Most of the intraepithelial lymphocytes were found in the subnuclear position below the nuclear level of the enterocytes. Electron microscopic examination revealed that the FAE of jejunal Peyer`s patches had scattered membranous cells or microfolds (M cells). M cells of jejunal Peyer`s patches were columnar shaped with luminal surface that bulged toward the intestinal lumen. M cells of dome epithelium of small intestine in calves were covered by blunt microvilli that were irregular, short and thick. These microvilli differed from microvilli of absorptive epithelial cells (enterocytes). Membranous bound particles were found in the dome epithelium of jejunal and ileal Peyer`s patches