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Pasturella multocida (P. multocida), a gram-negative bacterium, has long been a focus of interest in animal health because of its capacity to cause different infections, including hemorrhagic septicemia. Yaks, primarily found in high-altitude environments, are among the several livestock animals affected by these bacteria. Yaks are essential to the socioeconomic life of the people who depend on them since they are adapted to the cold and hypoxic conditions of highland environments. Nevertheless, these terrains exhibit a greater incidence of P. multocida despite the severe environmental complications. This predominance has been linked to the possible attenuation of the yak's immunological responses in such circumstances and the evolution of some bacterial strains to favor survival in the respiratory passages of the animals. Moreover, these particular strains threaten other cattle populations that interact with yaks, which might result in unanticipated outbreaks in areas previously thought to be low risk. Considering these findings, designing and executing preventative and control strategies suited explicitly for these distinct biological environments is imperative. Through such strategies, yaks' health will be guaranteed, and a larger bovine population will be safeguarded against unanticipated epidemics. The current review provides thorough insights that were previously dispersed among several investigations. Its distinct method of connecting the ecology of yaks with the dynamics of infection offers substantial background information for further studies and livestock management plans., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Pasteurella multocida is a bacterial pathogen that causes a variety of infections across diverse animal species, with one of the most devastating associated diseases being hemorrhagic septicemia. Outbreaks of hemorrhagic septicemia in cattle and buffaloes are marked by rapid progression and high mortality. These infections have particularly harmful socio-economic impacts on small holder farmers in Africa and Asia who are heavily reliant on a small number of animals kept as a means of subsistence for milk and draft power purposes. A novel vaccine target, PmSLP-3, has been identified on the surface of hemorrhagic septicemia-associated strains of P. multocida and was previously shown to elicit robust protection in cattle against lethal challenge with a serogroup B strain., Methods: Here, we further investigate the protective efficacy of this surface lipoprotein, including evaluating the immunogenicity and protection upon formulation with a variety of adjuvants in both mice and cattle., Results: PmSLP-3 formulated with Montanide ISA 61 elicited the highest level of serum and mucosal IgG, elicited long-lasting serum antibodies, and was fully protective against serogroup B challenge. Studies were then performed to identify the minimum number of doses required and the needed protein quantity to maintain protection. Duration studies were performed in cattle, demonstrating sustained serum IgG titres for 3 years after two doses of vaccine and full protection against lethal serogroup B challenge at 7 months after a single vaccine dose. Finally, a serogroup E challenge study was performed, demonstrating that PmSLP-3 vaccine can provide protection against challenge by the two serogroups responsible for hemorrhagic septicemia., Conclusion: Together, these data indicate that PmSLP-3 formulated with Montanide ISA 61 is an immunogenic and protective vaccine against hemorrhagic septicemia-causing P. multocida strains in cattle., Competing Interests: TM, AS, and SG-O are co-authors on a patent, “Slam polynucleotides and polypeptides and uses thereof” - Patent Number: WO2017136947A1. EI, JF, AS, SG-O, and TM are coauthors on a provisional patent, “Veterinary vaccines and methods for the treatment of Pasteurella multocida infections in food production animals” - United States Provisional Application No. 63/332,966 or WO/2023/201434 and PCT/CA2023/050537., (Copyright © 2024 Fegan, Waeckerlin, Tesfaw, Islam, Deresse, Dufera, Assefa, Woldemedhin, Legesse, Akalu, Bayissa, Nguyen, Ng, Ahn, Schryvers, Tefera, Moraes and Gray-Owen.)

Background: Pasteurella multocida is the etiological agent responsible for several diseases in a wide range of hosts around the world and thus, causes serious economic losses. Acute septicemia associated with capsular type B P. multocida has recently emerged in Europe and continuous outbreaks of these acute processes have been described in Spain since they were first detected in pigs in 2009 and cattle in 2015. The scarcity of studies on the antimicrobial susceptibility of this capsular type of P. multocida and growing concern about the general increase of antimicrobial resistance mean that studies related to the performance of type B P. multocida against antibiotics are necessary to establish accurate treatments and to monitor antimicrobial resistances., Results: Seventy-six isolates of P. multocida type B from pigs and cattle with acute septicemia were tested for susceptibility to 10 different antimicrobials. Bovine isolates were susceptible to all the antibiotics we tested except for lincomycin (94.4% of isolates were resistant). However, the antimicrobials we tested were less effective against swine isolates, of which none were susceptible to lincomycin. Furthermore, 29.3% swine isolates were resistant to tetracycline, 27.6% to penicillin, 20.7% to oxytetracycline, 17.3% to chloramphenicol, 15.5% to gentamicin, and 3.4% to enrofloxacin; no resistance to ceftiofur was detected. No multidrug resistant isolates were detected from cattle, while 25.86% of swine isolates were resistant to three or more antibiotic classes., Conclusions: In this study, the lower resistance rates and multidrug resistant isolates reported for P. multocida type B derived from cattle compared to those isolated from pigs may be related to the increased use of antibiotics in the porcine industry in Spain. Lincomycin is not recommended for the treatment of acute septicemia in pigs or cattle, rather, the use of ceftiofur, enrofloxacin, or gentamicin is indicated as an emergency treatment in the early stages of disease; once the susceptibility results are known, the use of tetracyclines, penicillin, or chloramphenicol should be prioritized. The increase in multidrug resistant isolates and antimicrobial resistance rates indicates that more attention should be paid to prevention as well as the responsible use of antibiotics.

The ELISA is recognized as an efficient diagnostic tool for antibody detection, but there is no standard ELISA assay for detection of antibodies against hemorrhagic septicemia (HS) in cattle. The present study reports on an indirect ELISA assay for antibody detection of HS in dairy cows, and evaluates the sensitivity (Se) and specificity (Sp) of the method using a Bayesian approach. An indirect ELISA was developed with two types of heat extract antigens, Pasteurella multocida strains P-1256 and M-1404, as coating antigens. A checkerboard titration was employed using dairy cow sera immunized with P. multocida bacterin and colostrum-deprived calf sera. The concentrations of heat extract antigen (160μg/mL), sample serum (1:100) and goat anti-bovine immunoglobulin G labeled with horseradish peroxidase (1:2000) were optimal for the assay. The cut-off values were 0.147 and 0.128 for P-1256 and M-1404 coating antigens, and there were no differences in the results of tests with positive and negative sera (p<0.05). The characteristics of three diagnostic tests were evaluated using a one-population Bayesian model, assuming conditional dependence between two types of coating antigen-based ELISAs and indirect hemagglutination assay (IHA). A total of 415 sera samples from dairy cows without HS vaccination and no history of disease were tested. The Se and Sp of the P-1256 and M-1404 ELISAs were higher than those of the IHA. The Se and Sp of the P-1256 ELISA were 90.3% and 90.1%, while the Se and Sp of the M-1404 ELISA were 92.1% and 71.9%. The median values of Se and Sp from the IHA were 36.0% and 58.2%., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Hemorrhagic septicemia is a fatal disease of cattle and buffaloes caused by P. multocida. Although the pathogenesis of the bacteria has been well established in literature, there is a paucity of information on the possible role of the bacteria and its immunogens; lipopolysaccharide (LPS) and outer membrane proteins (OMPs) on the reproductive capacity of buffalo heifers., Methods: In this study, twenty one healthy prepubertal female buffaloes aged 8 months were divided into seven groups of 3 buffaloes each (G1-G7). Group 1 (G1) served as the negative control group and were inoculated orally with 10 mL sterile Phosphate Buffer Saline (PBS), groups 2 (G2) and 3 (G3) were inoculated orally and subcutaneously with 10 mL of 10 12 colony forming unit (cfu) of P.multocida type B: 2, while groups 4 (G4) and 5 (G5) received 10 mL of bacterial LPS orally and intravenously, respectively. Lastly, groups 6 (G6) and 7 (G7) were orally and subcutaneously inoculated with 10 mL of bacterial OMPs. Whole blood was collected in EDTA vials at stipulated time points (0, 2, 4, 6, 8, 10, 12, 24, 36, 48, 72, 120, 168, 216, 264, 312, 360, 408, 456 and 504 h), while tissue sections of the pituitary glands were collected and transported to the histopathology laboratory in 10% buffered formalin for processing and Hematoxylin and eosin staining. Plasma levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (PG), estradiol (EST) and gonadotrophin releasing hormone (GnRH) were determined., Results: The histopathological lesions observed in the pituitary gland included hemorrhage, congestion, inflammatory cell infiltration, hydropic degeneration, necrosis and edema. These changes were higher (p < 0.05) in distribution and severity in G3, G6 and G7. Hormonal concentrations of LH, FSH, PG, EST and GnRH declined in all inoculation groups as time elapsed and were lower (p < 0.05) than that of the control group., Conclusion: Based on these findings, P.multocida B: 2 and its immunogens can be said to negatively affect the hypothalamic-pituitary-gonadal axis, resulting in decreased levels of reproductive hormones which may predispose to infertility in buffalo heifers.

In this study, Pasteurella multocida-loaded alginate microparticles (MPs) for subcutaneous vaccination was developed by emulsification-cross-linking technique. Formulation parameter was varied as a ratio of polymer and bacterin. Optical microscopy revealed spherical particles with uniformly distribution. A mean particle size of approximately 6 µm has been successfully constructed using simple mixer and ultrasonic probe. The zeta potential of the MPs showed negatively charge of approximately -23 mV determined by Zeta Pals® analyzer. The entrapment efficiency and the in vitro bacterin released profile could be controlled by varying the amount of alginate. The high entrapment efficiency up to 69% was achieved with low concentration of alginate. The MPs possessed a slow bacterin release profile, up to 30 days. In vivo safety and potency tests were proved that the alginate MPs were safe and induced protective immunity in mice. In addition, after storage for 6 months at either 4 °C or room temperature, the protective immunity in mice was maintained.

BackgroundPasteurella multocida is a bacterial pathogen that causes a variety of infections across diverse animal species, with one of the most devastating associated diseases being hemorrhagic septicemia. Outbreaks of hemorrhagic septicemia in cattle and buffaloes are marked by rapid progression and high mortality. These infections have particularly harmful socio-economic impacts on small holder farmers in Africa and Asia who are heavily reliant on a small number of animals kept as a means of subsistence for milk and draft power purposes. A novel vaccine target, PmSLP-3, has been identified on the surface of hemorrhagic septicemia–associated strains of P. multocida and was previously shown to elicit robust protection in cattle against lethal challenge with a serogroup B strain.MethodsHere, we further investigate the protective efficacy of this surface lipoprotein, including evaluating the immunogenicity and protection upon formulation with a variety of adjuvants in both mice and cattle.ResultsPmSLP-3 formulated with Montanide ISA 61 elicited the highest level of serum and mucosal IgG, elicited long-lasting serum antibodies, and was fully protective against serogroup B challenge. Studies were then performed to identify the minimum number of doses required and the needed protein quantity to maintain protection. Duration studies were performed in cattle, demonstrating sustained serum IgG titres for 3 years after two doses of vaccine and full protection against lethal serogroup B challenge at 7 months after a single vaccine dose. Finally, a serogroup E challenge study was performed, demonstrating that PmSLP-3 vaccine can provide protection against challenge by the two serogroups responsible for hemorrhagic septicemia.ConclusionTogether, these data indicate that PmSLP-3 formulated with Montanide ISA 61 is an immunogenic and protective vaccine against hemorrhagic septicemia-causing P. multocida strains in cattle.

Outer membrane proteins (OMPs) of Pasteurella multocida play an important role in virulence and are important for vaccine development due to immunogenicity. Here, we evaluated immunoprotection in mice, immunized with native OmpH, recombinant OmpH and HS alum precipitated vaccine of P. multocida P52 against P. multocida challenge. Protection studies were performed in mice of groups I (OmpH); II (recombinant OmpH); and III (HS alum precipitated vaccine). Group IV was control group administered with sterile PBS. The protection percentage was recorded as 83.33% protection in Gr. I & III, and 66.66% in Gr. II. The control group (Gr. IV) showed 100% mortality. The mean antibodies titers were detected at day 7, 14, 21 and 28 postimmunization, and compared with the control group. All immunized groups showed significantly high immune protection compared to the control group. [ABSTRACT FROM AUTHOR]

Outer membrane proteins (OMPs), usually found in Gram-negative bacteria, have long been shown to elicit immune responses in infected hosts. This tendency of OMPs to generate immune reactions makes them ideal candidates for vaccine development against pathogenic bacteria. Pasteurella multocida is a Gram-negative pathogen responsible for the economically significant veterinary disease, hemorrhagic septicemia (HS). HS is an endemic and highly fatal disease affecting buffaloes and cattle. In Malaysia, outbreaks of this disease cost about half a million USD each year. Thus, despite current treatment and prevention measures, HS is a prevalent issue that needs to be overcome. Pasteurella multocida subsp. multocida PMTB2.1, a Malaysian strain of the pathogen, has recently had its entire genome sequenced after being isolated from HS outbreaks in the region. Antigenic OMPs from this strain have since been identified and published for further characterisation. LptD, Wza, and TbpA are integral membrane proteins, while Pal is a peripheral membrane protein that has not been characterised in-depth. This study, therefore, aims to analyse these OMPs through in silico methods. First, protein homology modelling was performed using SWISS-MODEL, whereafter, the structures generated were validated using the SWISS-MODEL structure assessment page, PROCHECK, ERRAT, and PROSA programs. The Pal, Wza, and TbpA structures were good models, while the LptD structure was found to be a near-good model based on the validation performed. Analyses using BCPREDS, NetMHCpan4.1, and NetBoLAIIpan1.0 revealed that these four OMPs could potentially elicit humoral and cellular immune responses. [ABSTRACT FROM AUTHOR]

Abstract Background Pasteurella multocida is the etiological agent responsible for several diseases in a wide range of hosts around the world and thus, causes serious economic losses. Acute septicemia associated with capsular type B P. multocida has recently emerged in Europe and continuous outbreaks of these acute processes have been described in Spain since they were first detected in pigs in 2009 and cattle in 2015. The scarcity of studies on the antimicrobial susceptibility of this capsular type of P. multocida and growing concern about the general increase of antimicrobial resistance mean that studies related to the performance of type B P. multocida against antibiotics are necessary to establish accurate treatments and to monitor antimicrobial resistances. Results Seventy-six isolates of P. multocida type B from pigs and cattle with acute septicemia were tested for susceptibility to 10 different antimicrobials. Bovine isolates were susceptible to all the antibiotics we tested except for lincomycin (94.4% of isolates were resistant). However, the antimicrobials we tested were less effective against swine isolates, of which none were susceptible to lincomycin. Furthermore, 29.3% swine isolates were resistant to tetracycline, 27.6% to penicillin, 20.7% to oxytetracycline, 17.3% to chloramphenicol, 15.5% to gentamicin, and 3.4% to enrofloxacin; no resistance to ceftiofur was detected. No multidrug resistant isolates were detected from cattle, while 25.86% of swine isolates were resistant to three or more antibiotic classes. Conclusions In this study, the lower resistance rates and multidrug resistant isolates reported for P. multocida type B derived from cattle compared to those isolated from pigs may be related to the increased use of antibiotics in the porcine industry in Spain. Lincomycin is not recommended for the treatment of acute septicemia in pigs or cattle, rather, the use of ceftiofur, enrofloxacin, or gentamicin is indicated as an emergency treatment in the early stages of disease; once the susceptibility results are known, the use of tetracyclines, penicillin, or chloramphenicol should be prioritized. The increase in multidrug resistant isolates and antimicrobial resistance rates indicates that more attention should be paid to prevention as well as the responsible use of antibiotics.

Buffaloes and other bovines suffer from a fatal disease, "Hemorrhagic septicemia" (HS), which is produced by a gram-negative bacterium "Pasteurella multocida." Existing literature has established bacteria's pathogenesis, but still, the literature about the role of bacteria and its immunogens on the demonstration of clinical signs, hematology and serum biochemistry in Nili Ravi buffaloes under subtropics is lacking. This study was designed to fulfill this gap by analyzing the effects of exposure to the bacterial culture of Pasturella multocida (P. multocida) type B:2 and its immunogens, i.e., lipopolysaccharide (LPS) and outer membrane protein (OMP) on Nili Ravi buffaloes. Prepubertal Nili Ravi female buffaloes (N=18) of 10-12 months age in good health condition were divided into five treatment groups (n=3 each) and a control group (n=3). Treatment groups' animals were exposed to P. multocida bacterial culture and its immunogens, i.e., LPS (oral and intravenous) and OMP (oral and subcutaneous). Animals were analyzed for the development of clinical signs, hematology and serum biochemistry. All treatment groups exhibited clinical signs (ranging from mild to acute) like increased temperature, variation in rumen motility, mucous membrane, salivation, edema, dullness, depression, nasal discharge, respiratory distress and recumbence or death. A significant change in complete blood count (CBC) including packed cell volume (PCV), hemoglobin (Hgb) concentration, red blood cells (RBCs) count, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) platelets count, mean platelet volume (MPV), white blood cells (WBCs) count, monocytes count, lymphocytes count and granulocytes count. Serum biochemistry profiles (total protein, Albumin and creatinine) of treatment group animals were also changed significantly. Cumulatively it was revealed that P. multocida B: 2 and its Immunogens (LPS and OMP) affect the hematology and serum biochemistry profiles of Neeli-Ravi buffaloes. These findings prove that OMP and LPS from P. multocida B: 2 may be considered for vaccine development. [ABSTRACT FROM AUTHOR]

Pasteurella multocida causes hemorrhagic septicemia (HS), an acute, often fatal, septicaemic disease in ruminants. It is commonly observed in the world's tropical regions, especially in Asian and African countries. In the present study, eleven blackbucks (Antilope cervicapra) were diagnosed positive for hemorrhagic septicemia by using Leishman stain of blood smear showing bipolar organisms. The blackbucks were treated with bolus sulphadimidine @ 5 gm, powder uniselit @ 5 gm and liquid ostovet @ 25 mL per animal/day for seven days and after that bolus sulphadimidine @ 2.5 gm was given for the next three days. Following treatment eight blackbucks recovered and became normal. A post-mortem examination was performed on three blackbucks one died on first day and two blackbucks on the third day, which confirmed the changes typical of HS in lungs, liver and kidneys. [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate sensitivity (Se) and specificity (Sp) of a novel enzyme-linked immunosorbent assay (ELISA) test (using a coating antigen from Pasteurella multocida M-1404 via heat extraction) and an indirect hemagglutination (IHA) test for detection of Hemorrhagic septicemia (HS) in dairy cows, under Thai conditions, using a Bayesian approach. Dairy cow sera with a total of 1236 samples from 44 farms were tested with the two tests to detect immune responses against the HS. Percentages of positive samples for the ELISA and IHA tests were 73% (901/1236) and 70% (860/1236), respectively. Estimated sensitivity and estimated specificity of the ELISA test were 90.5% (95% posterior probability interval (PPI) = 83.2-95.4%) and 70.8% (95% PPI = 60.8-79.8%), respectively. Additionally, estimates for the Se and Sp values of the IHA test were 77.0% (95% PPI = 70.8-84.1%) and 51.1% (PPI = 36.8-66.3%), respectively. The estimated prevalence of the disease was 71.7% (95% PPI = 62.7-82.6%). These results demonstrate that the ELISA test can be a useful tool for the detection of the presence of an antibody against the HS in dairy cows. Notably, the cows in this area indicated a high percentage of exposure to Pasteurella multocida. [ABSTRACT FROM AUTHOR]

Hemorrhagic septicemia (HS) caused by Pasteurella multocida B:2 and E:2 is among the fatal bacterial diseases in cattle and buffaloes that are economically valuable in Asian and African countries. The current work aims to study the prevalence of HS among buffaloes, cattle, sheep, and goats in 41 countries in 2005–2019. The data analysis revealed that 74.4% of the total infection rate in the world was distributed among cattle, followed by buffaloes (13.1%). The mortality of HS among cattle and buffaloes increased in 2017–2019 compared to the period between 2014 and 2016. The best measure to control the disease is through vaccination programs. Current commercial vaccines, including live-attenuated vaccines and inactivated vaccines, have some shortcomings and undesirable effects. Virus-like particles (VLPs) have more potential as a vaccine platform due to their unique properties to enhance immune response and the ability to use them as a platform for foreign antigens against infectious diseases. VLPs-based vaccines are among the new-generation subunit vaccine approaches that have been licensed for the human and veterinary fields. However, most studies are still in the late stages of vaccine evaluation.

Hemorrhagic septicemia is a highly fatal, acute septicemic disease in buffaloes and cattle caused by Pasteurella multocida (Shivachandra, et al., 2008). A lactating non-pregnant 2-year old Holstein-Friesian x Jersey imported cow weighing 423 kg (BCS 3/5) was observed to be exhibiting tachypnea, hyper salivation, and edema on the neck and thorax on October 9, 2017. As hypocalcemia or acidosis was suspected, medication and prescription given were according to these two metabolic disorders. On October 20, 2017, a blood sample was collected which resulted in a positive Pasteurella multocida antibody ELISA test. Long-acting oxytetracycline (200 mg/mL) was injected IM once the following day. On October 24, the patient exhibited nasal flaring with clear discharge, frothy tachypnea, pyrexia, sunken orbits, and dullness while standing. Medication and prescription given were 10% marbofloxacin (2 mg/kg) IM once daily for three days and tolfenamic acid (2mg/kg) IM once. Unfortunately, the cow died the following morning. Upon necropsy, the significant gross lesions were neck and brisket swelling, lung consolidation, pneumonia, and petechial hemorrhages on the heart. This disease could have been prevented through vaccination and strict biosecurity. [ABSTRACT FROM AUTHOR]

In piggery, septic pasteurellosis caused by Pasteurella multocida (B:2) is an issue of concern, which needs an effective vaccine. Here, we prepared a double emulsified (DE) vaccine containing 2.5 mg inactivated antigenic mass of pig field strain (B:2) (named as soron) isolated from an outbreak of septicaemic death in pigs and P. multocida P52 cattle strain (B:2) and studied their efficiency in terms of immunity to direct challenge, duration of immunity and the role of humoral and cellmediated immunity. Both of these strains showed presence of hgbB, pfhA, nanH, ptfA, and tbPA virulence genes. The sequence analysis of bands of 760 bp product using capsular primers were obtained for soron and P52 revealed 99.2% homology between these two strains, indicating differences at genetic level. nanH and pfhA genes of soron shared 99.2% and 92.7% homology with P52, respectively suggesting differences between these two strains at genetic level. SDS-PAGE analysis of cell wall of both strains showed presence of about 15 major protein bands whereas Western blot analysis with 21 day soron immunized pig serum showed 16, 33, 47, 63 and 83 kDa polypeptides in both strains. The duration of immune responses were monitored at 3, 6 and 9 months post immunization in pigs. By direct challenge, pigs showed that the vaccines were protective at 21 days and up to 270th day post immunization. Vaccines induced a serum ELISA IgG response that peaked on 60 DPI which declined gradually up to 270th DPI in both vaccines. Stimulation index measured by lymphocyte proliferation test (LTT) indicated that the vaccine, induced cell-mediated immune response and in general percent stimulation index (SI) was higher in pigs immunized with soron vaccine at 15 days post challenge infection. The results showed that pig strain (soron) would be a potential homologous strain of P. multocida for the vaccine against pasteurellosis in place of use of cattle P. multocida P52 strain. [ABSTRACT FROM AUTHOR]

Pasteurella multocida is a gram-negative, non-motile bacterial pathogen, which is associated with chronic and acute infections as snuffles, pneumonia, atrophic rhinitis, fowl cholera and hemorrhagic septicemia. These diseases affect a wide range of domestic animals, leading to significant morbidity and mortality and causing significant economic losses worldwide. Due to the interest in deciphering the genetic diversity and process adaptive between P . multocida strains, this work aimed was to perform a pan-genome analysis to evidence horizontal gene transfer and positive selection among 23 P . multocida strains isolated from distinct diseases and hosts. The results revealed an open pan-genome containing 3585 genes and an accessory genome presenting 1200 genes. The phylogenomic analysis based on the presence/absence of genes and islands exhibit high levels of plasticity, which reflects a high intraspecific diversity and a possible adaptive mechanism responsible for the specific disease manifestation between the established groups (pneumonia, fowl cholera, hemorrhagic septicemia and snuffles). Additionally, we identified differences in accessory genes among groups, which are involved in sugar metabolism and transport systems, virulence-related genes and a high concentration of hypothetical proteins. However, there was no specific indispensable functional mechanism to decisively correlate the presence of genes and their adaptation to a specific host/disease. Also, positive selection was found only for two genes from sub-group hemorrhagic septicemia, serotype B. This comprehensive comparative genome analysis will provide new insights of horizontal gene transfers that play an essential role in the diversification and adaptation mechanism into P . multocida species to a specific disease. [ABSTRACT FROM AUTHOR]

Haemorrhagic septicaemia (HS) is a globally renowned disease that affects cattle and buffaloes. Its effects on the reproductive system have not been previously studied. The present study evaluated the pathological responses in pre-pubertal female buffaloes infected with immunogens; lipopolysaccharide (LPS) and outer membrane protein (OMP) derived from P. multocida type B:2. Fifteen healthy pre-pubertal female buffaloes were divided into 5 equal groups. Buffaloes in groups 1 and 2 were intravenously and orally inoculated with P. multocida LPS, while those in groups 3 and 4 were subcutaneously and orally inoculated with P. multocida OMP. Buffaloes in group 5 were inoculated with sterile phosphate buffered saline (negative control). During the post infection period, all buffaloes were examined for clinical signs throughout 21 days and surviving animals were euthanised for postmortem evaluation. Histopathological evaluation of buffaloes inoculated intravenously with LPS showed a significantly higher occurrence (P<0.05) of necrosis and degeneration in the uterine horn and supramammary glands . Following inoculation with OMP, haemorrhage and congestion was significantly higher (P<0.05) in the ovaries, cervix, vagina, mammary and supra-mammary glands of buffaloes inoculated subcutaneously, while necrosis and degeneration and inflammatory cell infiltration in different organs was also significantly increased in the same group. The findings showed that both P. multocida bacterial LPS and OMP affected the uterine horn, ovaries, cervix, mammary gland and supramammary lymph nodes of buffalo calves inoculated either intravenously or subcutaneously, as compared to those inoculated orally. [ABSTRACT FROM AUTHOR]

Haemorrhagic septicaemia (HS) an acute septicaemic disease caused by the bacteria Pasteurella multocida, is an almost neglected disease although it had been significantly caused high mortality in infected buffaloes and cattles. A great effort has been made to search for vaccine candidates for HS using different approaches and methodologies, as the vaccine that is currently available only confer short-term protection with side effects. Thus, this study was conducted to construct a recombinant protein expression system expressing Murine polyomavirus-like particles and the fimbrial protein of Pasteurella multocida for future application as vaccine for HS in livestock. Virus-like particles (VLPs) are viral subunit that mimics the conformation of authentic viruses without requirement of containing infectious genetic material. In this study, polymerase chain reaction (PCR) was used to isolate and amplify fimbrial protein gene of P. multocida B:2 strain. To introduce restriction enzyme (RE) site at the fimbrial gene sequence, PCR was employed using the upstream primer and downstream primer with NotI and XhoI site. The ~435 bp of amplified fimbrial protein gene was cloned into an expression plasmid containing Murine polyomavirus major protein 1 (VP1), pGEX-4T-1 plasmid, between XhoI and NotI site and was then transformed into E. coli JM109 strain. The putative transformants were verified by RE digestion and sequencing. The plasmid (pGEX-VP1) and recombinant plasmid (pGEX-VP1-fimbrial) were transformed into BL21 (DE3) cells for protein expression. Control (GST-VP1) and recombinant (GST-VP1-fimbrial) protein was optimized under various IPTG concentrations (0.4 mM to 1.0 mM) in order to produce the highest protein yield. The highest expression level of control protein (GST-VP1) was observed at 0.8 mM IPTG (~66 kDa), while the IPTG concentration yielded the highest expression level for GST-VP1-fimbrial protein is 0.6 mM which showed the size ~82 kDa. Further analysis will be conducted in order to produce the ultimate protein product which is the purified VP1-fimbrial protein in order to elucidate the potential of the purified protein as a vaccine candidate. [ABSTRACT FROM AUTHOR]

The efficacy of attenuated strain of gdhA derivative Pasteurella multocida B:2 mutant as a live vaccine to control haemorrhagic septicaemia (HS) disease in cattle and buffaloes has been demonstrated. In order to use P. multocida B:2 mutant as a commercial product, it is essential to optimise its formulation for high viability and stability of the live cells. The effectiveness of freeze-drying process using different protective agent formulations for improving cells viability was explored. Sugar and nitrogen compounds were used as protective agents in freeze-drying and the capability of these compounds in maintaining the viability of mutant P. multocida B:2 during subsequent storage was investigated. A complete loss in viability of freeze-dried mutant P. multocida B:2 was monthly observed until 6–12 months of storage at −30 °C, 4 °C and 27 °C when nitrogen compound or no protective agent was added. Trehalose and sucrose showed significantly high survival rate of 93–95% immediately after freeze-drying and the viability was retained during the subsequent storage at −30 °C and 4 °C. A smooth cell surface without any cell-wall damage was observed for the cells formulated with trehalose under scanning electron micrograph. This study presented a freeze-drying process generating a dried live attenuated vaccine formulation with high stability for commercial applications. [ABSTRACT FROM AUTHOR]

Background: Outbreaks of a Haemorrhagic Septicaemia (HS) like disease causing large mortalities in camels (Camelus dromedarius) in Asia and in Africa have been reported since 1890. Yet the aetiology of this condition remains elusive. This study is the first to apply state of the art molecular methods to shed light on the nasopharyngeal carrier state of Pasteurellaceae in camels. The study focused on HS causing Pasteurella multocida capsular types B and E. Other Pasteurellaceae, implicated in common respiratory infections of animals, were also investigated. Methods: In 2007 and 2008, 388 nasopharyngeal swabs were collected at 12 locations in North Kenya from 246 clinically healthy camels in 81 herds that had been affected by HS-like disease. Swabs were used to cultivate bacteria on blood agar and to extract DNA for subsequent PCR analysis targeting P. multocida and Mannheimia-specific gene sequences. Results: Forty-five samples were positive for P. multocida genes kmt and psl and for the P. multocida Haemorrhagic Septicaemia (HS) specific sequences KTSP61/KTT72 but lacked HS-associated capsular type B and E genes capB and capE. This indicates circulation of HS strains in camels that lack established capsular types. Sequence analysis of the partial 16S rRNA gene identified 17 nasal swab isolates as 99% identical with Mannheimia granulomatis, demonstrating a hitherto unrecognised active carrier state for M. granulomatis or a closely related Mannheimia sp. in camels. Conclusions: The findings of this study provide evidence for the presence of acapsular P. multocida or of hitherto unknown capsular types of P. multocida in camels, closely related to P. multocida strains causing HS in bovines. Further isolations and molecular studies of camelid P. multocida from healthy carriers and from HS-like disease in camels are necessary to provide conclusive answers. This paper is the first report on the isolation of M. granulomatis or a closely related new Mannheimia species from camelids. [ABSTRACT FROM AUTHOR]

Background: Pasteurella multocida is a Gram-negative bacterium that causes economically significant infections of a broad range of animal species. Pneumonic and septicaemic pasteurellosis caused by this bacterium remain important problems in pigs, cattle, and water buffaloes in Thailand. The aim of this study was to characterise the virulence-associated gene profiles and to develop an OmpA molecular typing scheme for classifying 191 bovine and porcine isolates of P. multocida collected between 1989 and 2012 in Thailand using polymerase chain reactions (PCRs), nucleotide sequencing, and sequence and structural bioinformatics analyses. Results: PCR screening successfully characterised the profiles of 25 virulence-associated genes in all isolates. The gene profiles separated these isolates into bovine and porcine clusters based on eight genes ( hgbB, hsf1, tadD, nanH, pfhA, plpE, pmHAS, and tbpA). Phylogenetic analyses of the nucleotide and protein sequences corresponding to the ompA gene, which encodes a major outer membrane surface protein, showed two major bovine and porcine clusters. Structural prediction and analysis of the dN/dS ratio revealed four hypervariable extracellular loops of the OmpA transmembrane domains. These four loops were used to develop an OmpA typing scheme. This scheme classified 186 isolates into five major loop sequence types (LST8, LST12, LST15, LST18, and LST19), consistent with the phylogenetic results. The loop regions of the bovine isolates were predicted to be more antigenic than those of the porcine isolates. Thus, molecular evolution of the OmpA proteins could be used to classify P. multocida isolates into different capsular types, host types, and, possibly, pathogenicity levels. Conclusions: Together with the virulence-associated gene profiles, the typing reported in this work provides a better understanding of P. multocida virulence. Effective monitoring and potential strain-specific subunit vaccines could be developed based on these loop oligopeptides. [ABSTRACT FROM AUTHOR]

Background: Pasteurella multocida B:2 causes bovine haemorrhagic septicaemia (HS), leading to rapid fatalities in cattle and buffaloes. An attenuated derivative of P. multocida B:2 GDH7, was previously constructed through mutation of the gdhA gene and proved to be an effective live attenuated vaccine for HS. Currently, only two potential live attenuated vaccine candidates for HS are being reported; P. multocida B:2 GDH7 and P. multocida B:2 JRMT12. This study primarily aims to investigate the potential of P. multocida B:2 GDH7 strain as a delivery vehicle for DNA vaccine for future multivalent applications. Results: An investigation on the adherence, invasion and intracellular survival of bacterial strains within the bovine aortic endothelial cell line (BAEC) were carried out. The potential vaccine strain, P. multocida B:2 GDH7, was significantly better (p = 0.05) at adhering to and invading BAEC compared to its parent strain and to P. multocida B: 2 JRMT12 and survived intracellularly 7 h post treatment, with a steady decline over time. A dual reporter plasmid, pSRGM, which enabled tracking of bacterial movement from the extracellular environment into the intracellular compartment of the mammalian cells, was subsequently transformed into P. multocida B:2 GDH7. Intracellular trafficking of the vaccine strain, P. multocida B:2 GDH7 was subsequently visualized by tracking the reporter proteins via confocal laser scanning microscopy (CLSM). Conclusions: The ability of P. multocida B:2 GDH7 to model bactofection represents a possibility for this vaccine strain to be used as a delivery vehicle for DNA vaccine for future multivalent protection in cattle and buffaloes. [ABSTRACT FROM AUTHOR]

Background: Hemorrhagic septicemia is a fatal disease of cattle and buffaloes caused by P. multocida. Although the pathogenesis of the bacteria has been well established in literature, there is a paucity of information on the possible role of the bacteria and its immunogens; lipopolysaccharide (LPS) and outer membrane proteins (OMPs) on the reproductive capacity of buffalo heifers. Methods: In this study, twenty one healthy prepubertal female buffaloes aged 8 months were divided into seven groups of 3 buffaloes each (G1-G7). Group 1 (G1) served as the negative control group and were inoculated orally with 10 mL sterile Phosphate Buffer Saline (PBS), groups 2 (G2) and 3 (G3) were inoculated orally and subcutaneously with 10 mL of 1012 colony forming unit (cfu) of P.multocida type B: 2, while groups 4 (G4) and 5 (G5) received 10 mL of bacterial LPS orally and intravenously, respectively. Lastly, groups 6 (G6) and 7 (G7) were orally and subcutaneously inoculated with 10 mL of bacterial OMPs. Whole blood was collected in EDTA vials at stipulated time points (0, 2, 4, 6, 8, 10, 12, 24, 36, 48, 72, 120, 168, 216, 264, 312, 360, 408, 456 and 504 h), while tissue sections of the pituitary glands were collected and transported to the histopathology laboratory in 10% buffered formalin for processing and Hematoxylin and eosin staining. Plasma levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone (PG), estradiol (EST) and gonadotrophin releasing hormone (GnRH) were determined. Results: The histopathological lesions observed in the pituitary gland included hemorrhage, congestion, inflammatory cell infiltration, hydropic degeneration, necrosis and edema. These changes were higher (p < 0.05) in distribution and severity in G3, G6 and G7. Hormonal concentrations of LH, FSH, PG, EST and GnRH declined in all inoculation groups as time elapsed and were lower (p < 0.05) than that of the control group. Conclusion: Based on these findings, P.multocida B: 2 and its immunogens can be said to negatively affect the hypothalamic-pituitary-gonadal axis, resulting in decreased levels of reproductive hormones which may predispose to infertility in buffalo heifers. [ABSTRACT FROM AUTHOR]

Swine pasteurellosis is an acute infectious disease and is considered to be one of the most economically important diseases in Asia particularly in South and South East Asia leading to huge economic loss in livestock industry. A study was conducted to analyze the histopathological alterations caused by cytotoxins released by Pasteurella multocida serotype B, which caused Swine pasteurellosis in descript as well as nondescript pigs of Chhattisgarh, India. Affected animals exhibited pyrexia, dullness, staggering gait, anorexia, serous nasal discharge and dyspnoea. Typical lesions of oedematous swellings noted in the pharyngeal region. Case fatality rate was 95% in adult animals and 100% in piglets. The causative organism, Pasteurella multocida was isolated and characterized by biochemical tests and the detection of the KMT1, CapB, toxA, and ompH genes was performed using Polymerase Chain Reaction (PCR). Gross lesions included severe pneumonia and haemorrhages in lungs, petechial haemorrhages on serous membranes and other visceral organs. Lymph nodes were enlarged, oedematous and haemorrhagic. The histopathological lesions developed in lungs were typical fibrinous bronchopneumonia, multifocal suppuration and severe thickening of pleura. Heart showed presence of thrombi, haemorrhages and necrosis of myocardium. Hepatic architecture showed server haemorrhages and necrosis while kidneys and spleen showed degenerative and necrotic changes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To develop 2 rapid loop-mediated isothermal amplification (LAMP) assays for detection of Pasteurella multocida DNA (Pm-LAMP assay) and P multocida DNA from strains associated with hemorrhagic septicemia (HS) in cattle and buffalo (HS-LAMP assay). SAMPLE Solutions containing 16 P multocida strains and 9 other bacterial species at various concentrations. PROCEDURES: Optimal conditions were determined for running the Pm-LAMP and HSLAMP assays. The assays were then used to detect DNA of the test organisms. Results of LAMP assays were validated against conventional PCR assays designed for specific detection of P multocida and the B:2 serotype of HS-associated strains. RESULTS: Following incubation of sample reaction mixtures for 27 minutes, specificity and sensitivity of the HS-LAMP assay at template DNA amounts as low as 5 pg were 93% and 97%, respectively. When duplicates of each sample were incubated for 28 minutes (a positive result defined as positive results for both reactions of a given sample), specificity and sensitivity of the HSLAMP assay in the same conditions increased to 100%. The best specificity and sensitivity of Pm-LAMP single (93% and 91%) and duplicate (97% and 98%) reactions at template DNA amounts as low as 10 pg were achieved at 33 and 34 minutes, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: These preliminary findings suggested the developed HS-LAMP assay had high sensitivity and specificity for detection of HS-associated P multocida. Additional research is needed to determine the accuracy of the assay for use on clinical specimens obtained in HS-endemic countries such as Pakistan and Thailand. [ABSTRACT FROM AUTHOR]

Necropsy was conducted for thirty-five dead bovines during the six months duration from February to July 2016 at post-mortem facility, IVRI. Detailed post-mortem examination was done by impression smear, gross and histopathological lesions examination. Out of thirty-five cases, eight showed the septicemic changes like petechial haemorrhages on serosal surface. The necropsy examination of these cases revealed the consolidation of lungs and haemorrhages on the epicardium, spleen, and small intestine. Gross lesions were correlated with the microscopic lesions. Microscopic examination showed diffuse congestion and haemorrhages along with the neutrophilic infiltration in different organs including lung, heart, and intestine. Impression smear from heart (8 samples) showed bipolar organism under microscope by Leishman's stain. Based on the gross and microscopic examination along with further confirmation by bipolar staining in heart impression smear indicates septicaemia by Pasteurella multocida organism which leads to death of animals. [ABSTRACT FROM AUTHOR]

An outbreak of a respiratory disease occurred in the dromedary population of Greater Cholistan desert, which was quite foreign to the locale. The duration of outbreak was more than a month (from the mid of November 2010 to the mid of December 2010). Prevalence, cumulative mortality and case fatality of outbreak were 0.79, 0.018 and 0.023, respectively. The disease was characterized by pyrexia (up to 107.4ºF), severe dyspnea due to choking of nasal cavity with thick gummy material and abortion during late gestation. The disease ran a clinical course of 5-7 days. Febrile carcasses showed congestion of all visceral organs, petechial hemorrhages on the serosal surfaces, serosanguineous fluid in the thoracic and abdominal cavities and pneumonia. Postmortem findings indicated septicemia. Pasteurella multocida subsp. multocida was isolated from representative clinical and morbid specimens. Treatment trial on clinical cases indicated ciprofloxacin, ceftiofur hydrochloride, gentamicin + tylosin and thiamphenicol + tylosin to be highly efficacious.

Serotype B of Pasteurella multocida is a major agent of haemorrhagic septicaemia (HS), a form of blood poisoning widespread in cattle and buffalo from Southern Asia. The vaccines currently used against the disease are not potent enough, being effective only for a limited duration only. In an attempt to identify immunogenic components of P. multocida for use as live/subunit vaccines, the outer membrane proteins (OMPs) of B:2 and B:3,4 serotypes were isolated and their profiles compared. Three common immunogenic components; polypeptides of molecular weight (MW) 39.0, 33.5,31.0 kDa, were identified by immunoblotting.The immunogenicity of identified OMPs was also confirmed using antisera generated against them. The antigenic OMPs identified in current research could be explored in the formulation of new, safe and effective vaccines for indigenous buffalo and cattle breeds with a prolonged efficacy. [ABSTRACT FROM AUTHOR]

Pasteurella multocida represents a highly diverse group of bacteria infecting various hosts like the fowl, goat and buffalo leading to huge economic loss to the poultry and cattle industry. Previous reports indicated that the outer membrane proteins contribute significantly to the pathogenesis of Pasteurella multocida . The comparative in-silico genome wide analysis of four pathogenic Pasteurella multocida strains ( Anand1-poultry , Anand1-goat , PMTB and VTCCBAA264 ) with their respective hosts was performed. A pipeline was developed to identify the list of non-homologous proteins of Pasteurella multocida strains and their hosts. The list was further analyzed for the identification of the essential outer membrane proteins responsible for the pathogenicity. Outer membrane proteins were further selected from these antigenic proteins on the basis of their pathogenic potential. A common B-cell epitope (TDYRNRDRS, ARRSVTSKEN, and KINDQWRW) determined via sequential and structural approach from the lipopolysaccharide (LPS) assembly outer membrane complex protein was predicted from fowl, goat and buffalo. Furthermore, we identified T-cell epitopes based on the lipopolysaccharide (LPS) assembly outer membrane complex protein via docking studies which were either similar to the B-cell epitopes or were occurring in the same patch except for MHC class II M fowl. We propose that this difference in epitope sequence is due to different interacting MHC class II protein predicted from the fowl. Hence, in the current study we found that a unique epitope based on the common antigenic lipopolysaccharide (LPS) outer membrane complex protein present in fowl, goat and buffalo can be a suitable target for vaccine development against the two economic devastating diseases; fowl cholera (FC) and hemorrhagic septicemia (HS). [ABSTRACT FROM AUTHOR]

Pasteurella multocida is responsible for one of the major animal diseases with economic importance in both developed and developing countries. P. multocida B:2 causes haemorrhagic septicemia (HS) in cattle and buffaloes, which result in heavy economic losses through direct effect, resulting in high mortality rates and indirect effects through impairment of the animal productivity. It is well known that HS affects mainly the respiratory and digestive tracts of host animals. However, involvement of the reproductive system in the pathogenesis of HS has not been reported previously. This study was designed to present detailed detection and histopathological changes of the reproductive system and mammary glands of buffaloes experimentally infected with P. multocida B:2. Briefly, nine healthy buffalo calves aged 8-month-old were divided into three groups of three calves each. Calves from groups 1 and 2 were inoculated subcutaneously and orally with 10 mL of 1 × 10 cfu/mL of P. multocida B:2, respectively, while calves of group 3 were inoculated orally with 10 mL of phosphate buffer saline as a sham control. All the calves in group 1 had to be euthanized after 12 h post-infection, while calves in group 2 were euthanized after day 21 post-infection. Successful isolation and PCR confirmation of P. multocida B:2 was achieved from different parts of the reproductive system, including ovary, oviduct, uterine horn, uterine body and vagina as well as mammary glands and supramammary lymph nodes of the buffaloes in group 1 after 12 h post-infection. However, P. multocida B:2 was not detected in the reproductive organs of buffaloes in group 2 and group 3 after 21 days post-infection. Significant differences ( P < 0.05) were found in histopathological changes between the two groups, which mainly affected different anatomic regions of the reproductive system. This work provides an insight into the involvement of the female reproductive system of buffaloes during the pathogenesis of HS and shows that route of inoculation strongly affect the localization of the bacterium in the reproductive system. [ABSTRACT FROM AUTHOR]

The present study describes the gross, histopathology and ultrastructural changes in the respiratory, gastrointestinal and urinary tracts of buffalo calves experimentally inoculated with wild-type Pasteurella multocida B:2. Six 8-month old buffalo calves were divided into two groups. Calves of Group 1 were inoculated subcutaneously with 5 ml the inoculum containing 109 colony-forming unit (cfu)/mL of live wild-type P. multocida B:2 while calves of Group 2 were similarly inoculated with 5 ml of sterile phosphate buffered saline. All buffaloes were observed daily for clinical signs before surviving buffaloes were killed on day 3 post-inoculation for gross and histology examinations of the respiratory, gastrointestinal and urinary tracts. All infected calves of Group 1 were dead between 6 and 12 h post-inoculation with typical gross lesions of hemorrhagic septicemia. The respiratory, gastrointestinal and urinary tracts showed moderate to severe congestion and hemorrhages. Frothy fluid and fibrin were found in the respiratory tract while the content of gastrointestinal tract appeared soft, watery and occasionally blood-tinged. The urinary tract contained blood-tinged urine. Histologically, the organs of respiratory, gastrointestinal and urinary tracts showed varying degrees of congestion and hemorrhages with endothelial destruction. The right middle lung lobe, the small intestines and kidneys showed significantly more severe histological lesions. Ultrastructure examination revealed the presence of P. multocida B:2 on the erythrocytes and the endothelium of the respiratory, gastrointestinal and urinary tracts. Similarly, P. multocida B:2 was successfully isolated from all samples collected from these tracts, suggesting the involvement of these body systems in transmission of the disease. [ABSTRACT FROM AUTHOR]

Hemorrhagic septicemia (HS) is an acute septicemic disease principally affecting cattle and buffaloes caused by specific serotypes B:2 and E:2 of Pasteurella multocida in Asia and Africa, respectively. Despite continuing researches on pathogenesis of P. multocida for several decades, the mechanisms by which these bacteria develop the diseases are poorly understood. Although the involvement of the nervous system in the disease progress of HS is rare under natural conditions, few reports indicated the involvement of the nervous system in outbreaks of HS in cattle and buffaloes. Additionally, recent pathogenesis studies in both mouse and buffalo experimental models reported the involvement of nervous system due to P. multocida B:2, with bacteriological and histopathological evidences. In this review, we summarized and discussed the updates on the involvement of the nervous system in pathogenesis of HS focusing on clinical signs, pathological and pathophysiological changes. [ABSTRACT FROM AUTHOR]

Pasteurella multocida is the primary causative agent of a range of economically important diseases in animals, including haemorrhagic septicaemia (HS), a rapidly fatal disease of ungulates. There is limited information available on the diversity of P. multocida strains that cause HS. Therefore, we determined draft genome sequences of ten disease-causing isolates and two vaccine strains and compared these genomes using a range of bioinformatic analyses. The draft genomes of the 12 HS strains were between 2,298,035 and 2,410,300 bp in length. Comparison of these genomes with the North American HS strain, M1404, and other available P. multocida genomes (Pm70, 3480, 36950 and HN06) identified a core set of 1,824 genes. A set of 96 genes was present in all HS isolates and vaccine strains examined in this study, but absent from Pm70, 3480, 36950 and HN06. Moreover, 59 genes were shared only by the Asian B:2 strains. In two Pakistani isolates, genes with high similarity to genes in the integrative and conjugative element, ICEPmu1 from strain 36950 were identified along with a range of other antimicrobial resistance genes. Phylogenetic analysis indicated that the HS strains formed clades based on their country of isolation. Future analysis of the 96 genes unique to the HS isolates will aid the identification of HS-specific virulence attributes and facilitate the development of disease-specific diagnostic tests. [ABSTRACT FROM AUTHOR]

This study was aimed at investigating effects of biomass, adjuvant, storage, priming alone or with boosting of an inactivated Haemorrhagic Septicemia (HS) vaccine (prepared from dense growth of Pasteurella multocida) on its potency using indirect hem-agglutination (IHA) test. The vaccine containing dry mass 1.7 mg/dose or bacterial count 1014/dose was sufficient to induce protective antibody titer (GMT=log 25.2). Montanide ISA 70 based HS vaccine induced better antibody response (GMT=log 26) in buffalo calves than that of HS vaccine containing aluminum hydroxide gel (GMT=log 23.2) or no adjuvant (undetectable). The oil based HS vaccine remained potent (GMT=log 23.8) even after storage at 40C for eight months. Boosting of calves with oil based HS vaccine may help keep the calves immunized for 12 months. It was concluded that the proposed study improved quality of the vaccine and reduced the vaccine volume per dose, cost of its production and frequency of the vaccination. © 2015 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Lipopolysaccharides (LPS) were extracted from the whole cell of the causative organism (Pasteurella multocida) and quantified by using the semi-carbazide method. This quantified antigen was then inoculated subcutaneously into rabbits to stimulate antibody production. The maximum antibody titre was determined by applying indirect ELISA, and was found to have been achieved at one week post inoculation in all groups. It was concluded that with an increase in the dose of LPS antigen, the antibody titre increased and the combination of LPS of P. multocida with yeast produced more immunity when compared to LPS alone in rabbits. [ABSTRACT FROM AUTHOR]