Fowl Cholera Research Articles

Genotypic evaluation of Pasteurella multocida isolated from cattle and sheep by pulsed-field gel electrophoresis.

Pasteurella multocida a Gram-negative bacterium exists as a commensal in the upper respiratory tracts of livestock, and poultry. It is causative agent of a range of diseases in mammals and birds including fowl cholera in poultry, atrophic rhinitis in pigs and bovine hemorrhagic septicemia in cattle and buffalo. This study aimed to isolate P. multocida from sheep and cattle lungs sampled and assessed by bacteriological procedures and pulse field gel electrophoresis (PFGE) characterization. In this study 52 isolated of P. multocida were obtained (2016-2017) from clinically healthy and diseased animals (sheep and cattle) evaluated by PFGE for determining the relationship between them. According to the results of this study 12 sheep isolates had similarities above 94.00% and two cattle isolates showed similarities above 94.00%. When compared between sheep and cattle, most isolates showed a similarity of less than 50.00% indicating the great differences between isolates. It is noteworthy that in the present study, performed by PFGE to determine the type of P. multocida isolates, a very high distinction was made to determine the type of isolates and the relationship between isolates based on fragments in their genome using enzymes.

Pasteurella multocida toxin - lessons learned from a mitogenic toxin.

The gram-negative, zoonotic bacterium Pasteurella multocida was discovered in 1880 and found to be the causative pathogen of fowl cholera. Pasteurella-related diseases can be found in domestic and wild life animals such as buffalo, sheep, goat, deer and antelope, cats, dogs and tigers and cause hemorrhagic septicemia in cattle, rhinitis or pneumonia in rabbits or fowl cholera in poultry and birds. Pasteurella multocida does not play a major role in the immune-competent human host, but can be found after animal bites or in people with close contact to animals. Toxigenic strains are most commonly found in pigs and express a phage-encoded 146 kDa protein, the Pasteurella multocida toxin (PMT). Toxin-expressing strains cause atrophic rhinitis where nasal turbinate bones are destroyed through the inhibition of bone building osteoblasts and the activation of bone resorbing osteoclasts. After its uptake through receptor-mediated endocytosis, PMT specifically targets the alpha subunit of several heterotrimeric G proteins and constitutively activates them through deamidation of a glutamine residue to glutamate in the alpha subunit. This results in cytoskeletal rearrangement, proliferation, differentiation and survival of cells. Because of the toxin's mitogenic effects, it was suggested that it might have carcinogenic properties, however, no link between Pasteurella infections and cell transformation could be established, neither in tissue culture models nor through epidemiological data. In the recent years it was shown that the toxin not only affects bone, but also the heart as well as basically all cells of innate and adaptive immunity. During the last decade the focus of research shifted from signal transduction processes to understanding how the bacteria might benefit from a bone-destroying toxin. The primary function of PMT seems to be the modulation of immune cell activation which at the same time creates an environment permissive for osteoclast formation. While the disease is restricted to pigs, the implications of the findings from PMT research can be used to explore human diseases and have a high translational potential. In this review our current knowledge will be summarized and it will be discussed what can be learned from using PMT as a tool to understand human pathologies.

Hanging out at the club: Breeding status and territoriality affect individual space use, multi‐species overlap and pathogen transmission risk at a seabird colony

Abstract Wildlife movement ecology often focuses on breeders, whose territorial attachments facilitate trapping and following individuals over time. This leads to incomplete understanding of movements of individuals not actively breeding due to age, breeding failure, subordinance, and other factors. These individuals are often present in breeding populations and contribute to processes such as competition and pathogen spread. Therefore, excluding them from movement ecology studies could bias or mask important spatial dynamics. Loafing areas offer an alternative to breeding sites for capturing and tracking individuals. Such sites may allow for sampling individuals regardless of breeding status, while also avoiding disturbance of sensitive breeding areas. However, little is known about the breeding status of individuals attending loafing sites, or how their movements compare to those of breeders captured at nests. We captured a seabird, the brown skua, attending either nests or loafing areas (‘clubs’) at a multi‐species seabird breeding site on Amsterdam Island (southern Indian Ocean). We outfitted skuas with GPS‐UHF transmitters and inferred breeding statuses of individuals captured at clubs using movement patterns of breeders captured at nests. We then compared space use and activity patterns between breeders and nonbreeders. Both breeding and nonbreeding skuas attended clubs. Nonbreeders ranged more widely, were more active, and overlapped more with other seabirds and marine mammals than did breeders. Moreover, some nonbreeders occupied fixed territories and displayed more restricted movements than those without territories. Nonbreeders became less active over the breeding season, while activity of breeders remained stable. Nonbreeding skuas were exposed to the agent of avian cholera at similar rates to breeders but were more likely to forage in breeding areas of the endangered endemic Amsterdam albatross, increasing opportunities for interspecific pathogen transmission. Our results show that inference based only on breeders fails to capture important aspects of population‐wide movement patterns. Capturing nonbreeders as well as breeders would help to improve population‐level representation of movement patterns, elucidate and predict effects of external changes and conservation interventions (e.g. rat eradication) on movement patterns and pathogen spread, and develop strategies to manage outbreaks of diseases such as highly pathogenic avian influenza. Read the free Plain Language Summary for this article on the Journal blog.

Pasteur and the veterinarians.

Pasteur's work on fermentations has variously influenced the conception that veterinarians had of the origin of virulent diseases. Jean-Baptiste Chauveau asserted as early as 1866 the specificity of contagious diseases and their exogenous origin. Henri Bouley was initially a supporter of the spontaneity of these diseases. He became an advocate of the germ theory when Pasteur unambiguously demonstrated the causal role of anthrax bacteridia in 1877. Pasteur then had a fruitful collaboration with veterinarians during his work on chicken cholera, swine erysipelas, contagious pleuropneumonia and rabies. After Pasteur's experience at Pouilly-le-Fort, Henri Bouley and Edmond Nocard, a disciple of Pasteur, were strong advocates for the adoption of vaccinations by veterinarians and farmers. Nocard's work on various contagious animal diseases greatly contributed to the foundation of veterinary microbiology.

Modern approaches to the production of inactivated vaccines against chicken cholera

Introduction. Chicken cholera is one of the most dangerous avian infectious diseases, causing significant economic damage to the industrial poultry production. Chicken cholera usually occurs in septic form, and causes high morbidity and mortality (60–80%), but recently it has become chronic, subclinical and associated. Inactivated emulsion vaccines are used worldwide to prevent chicken cholera and provide high and long-term immunity. However, there is a problem with residual reactogenicity of inactivated vaccines, particularly of the bacterial variants. This problem can be solved by using safer, next-generation adjuvants. The aim of the article is to study the physical and biological properties and determine the optimal inoculation volume and method of administration of inactivated vaccines against chicken cholera , based on different adjuvants.Materials and methods. Formaldehyde inactivated culture of P. multocida st. 115and a number of adjuvants (“Montanide GEL-02” and oil adjuvants “Montanide ISA 70 VG” and “Montanide ISA 78 VG”) were used for vaccine production. The vaccine samples were tested for sterility, stability and viscosity by conventional methods. Determination of reactogenicity and antigenic activity of the vaccines was carried out on young 30-days old chickensof egg-laying type.Results. The vaccine sample based on the adjuvant “Montanide ISA 70 VG” containing 1.5 billion P. Multocida microbial cells in a single immunizing dose of 0.3 cm3 was found to be the best among the tested preparations. When assessing the reactogenicity, it was obvious that all samples, regardless of the type of adjuvant, showed more pronounced residual reactogenic properties when injected intramuscularly into the chest muscle than when injected subcutaneously into the middle third of the neck.

Signal sequence contributes to the immunogenicity of Pasteurella multocida lipoprotein E

Recombinant Pasterurella multocida lipoprotein E (PlpE) has been shown to protect against fowl cholera. This study aimed to determine if the signal sequence may contribute to the antigenicity and protective efficacy of recombinant PlpE. A small antigenic domain of PlpE (termed truncated PlpE, tPlpE) was constructed with (SP-tPlpE) or without (tPlpE) the signal sequence and evaluated in vitro and in vivo. In vitro, the HEK-Bule hTLR2 Cells were used to evaluate the activation of NF-kB in the test associated with the stimulation of the SP-tPlpE and tPlpE proteins. When chickens were immunized, compared to the tPlpE vaccine group, the SP-tPlpE group showed higher antibody levels and enhanced CD4+ T cell response. In a challenge test, the SP-tPlpE group showed a survival rate of 87.5% (n = 8), compared to 25% for the tPlpE group. It is confirmed that the inclusion of the native signal sequence enhanced protective efficacy against fowl cholera and may act as a vaccine adjuvant. The short SP-tPlpE construct is amenable to further vaccine engineering and has potential to be developed as a fowl cholera vaccine.

Collection, compilation and analysis of bacterial vaccines

BackgroundBacterial diseases are one of the leading causes of millions of fatalities worldwide, mainly due to antimicrobial resistance. The discovery of chicken cholera vaccine in 1879 revolutionized our fight against bacterial infections. Bacterial vaccines are proven to be highly effective in preventing many infectious diseases. Currently, various licensed vaccines are available against bacterial infections such as typhoid, diphtheria, cholera and tetanus in the market. In this study, we have attempted to compile different information regarding bacterial vaccines, their types, efficacy, mechanism of action, status, route of administration and other relevant details as a knowledgebase known as BacVacDB. MethodsBacVacDB was implemented using Linux-Apache-MySQL-PHP. HTML, PHP, CSS and Javascript have been used to develop the front end and MySQL for the back end. The data was curated from several sources, including literature, databases and relevant web resources. ResultsThis paper reviewed 371 vaccines against 30 human bacterial diseases maintained in BacVacDB, of which 167 are approved and 204 in clinical trials. This database provides the users an effortless search facility in the four modules, ‘Search,’ ‘Browse,’ ‘External Links’ and ‘General Information’. In this systematic attempt, we also included the history of vaccines, their mechanism, types, route of administration and approving agencies. ConclusionsThis knowledgebase has an intuitive interface that allows users to explore, search, and download information as well as to submit new bacterial vaccines (https://webs.iiitd.edu.in/raghava/bacvacdb/).

Simultaneous Protective Immune Responses of Ducks against Duck Plague and Fowl Cholera by Recombinant Duck Enteritis Virus Vector Expressing Pasteurella multocida OmpH Gene.

Duck enteritis virus and Pasteurella multocida are major duck pathogens that induce duck plague and fowl cholera, respectively, in ducks and other waterfowl populations, leading to high levels of morbidity and mortality. Immunization with live attenuated DEV vaccine containing P. multocida outer membrane protein H (OmpH) can provide the most effective protection against these two infectious diseases in ducks. We have recently reported the construction of recombinant DEV expressing P. multocida ompH gene using the CRISPR/Cas9 gene editing strategy with the goal of using it as a bivalent vaccine that can simultaneously protect against both infections. Here we describe the findings of our investigation into the systemic immune responses, potency and clinical protection induced by the two recombinant DEV-ompH vaccine constructs, where one copy each of the ompH gene was inserted into the DEV genome at the UL55-LORF11 and UL44-44.5 intergenic regions, respectively. Our study demonstrated that the insertion of the ompH gene exerted no adverse effect on the DEV parental virus. Moreover, ducklings immunized with the rDEV-ompH-UL55 and rDEV-ompH-UL44 vaccines induced promising levels of P. multocida OmpH-specific as well as DEV-specific antibodies and were completely protected from both diseases. Analysis of the humoral and cellular immunity confirmed the immunogenicity of both recombinant vaccines, which provided strong immune responses against DEV and P. multocida. This study not only provides insights into understanding the immune responses of ducks to recombinant DEV-ompH vaccines but also demonstrates the potential for simultaneous prevention of viral and bacterial infections using viral vectors expressing bacterial immunogens.

CRISPR/Cas9 Editing of Duck Enteritis Virus Genome for the Construction of a Recombinant Vaccine Vector Expressing ompH Gene of Pasteurella multocida in Two Novel Insertion Sites.

Duck enteritis virus (DEV) and Pasteurella multocida, the causative agent of duck plague and fowl cholera, are acute contagious diseases and leading causes of morbidity and mortality in duck. The NHEJ-CRISPR/Cas9-mediated gene editing strategy, accompanied with the Cre–Lox system, have been employed in the present study to show that two new sites at UL55-LORF11 and UL44-44.5 loci in the genome of the attenuated Jansen strain of DEV can be used for the stable expression of the outer membrane protein H (ompH) gene of P. multocida that could be used as a bivalent vaccine candidate with the potential of protecting ducks simultaneously against major viral and bacterial pathogens. The two recombinant viruses, DEV-OmpH-V5-UL55-LORF11 and DEV-OmpH-V5-UL44-44.5, with the insertion of ompH-V5 gene at the UL55-LORF11 and UL44-44.5 loci respectively, showed similar growth kinetics and plaque size, compared to the wildtype virus, confirming that the insertion of the foreign gene into these did not have any detrimental effects on DEV. This is the first time the CRISPR/Cas9 system has been applied to insert a highly immunogenic gene from bacteria into the DEV genome rapidly and efficiently. This approach offers an efficient way to introduce other antigens into the DEV genome for multivalent vector.

Louis Pasteur: Between Myth and Reality.

Louis Pasteur is the most internationally known French scientist. He discovered molecular chirality, and he contributed to the understanding of the process of fermentation, helping brewers and winemakers to improve their beverages. He proposed a process, known as pasteurization, for the sterilization of wines. He established the germ theory of infectious diseases that allowed Joseph Lister to develop his antiseptic practice in surgery. He solved the problem of silkworm disease, although he had refuted the idea of Antoine Béchamp, who first considered it was a microbial infection. He created four vaccines (fowl cholera, anthrax, pig erysipelas, and rabies) in the paths of his precursors, Henri Toussaint (anthrax vaccine) and Pierre Victor Galtier (rabies vaccine). He generalized the word “vaccination” coined by Richard Dunning, Edward Jenner’s friend. Robert Koch, his most famous opponent, pointed out the great ambiguity of Pasteur’s approach to preparing his vaccines. Analysis of his laboratory notebooks has allowed historians to discern the differences between the legend built by his hagiographers and reality. In this review, we revisit his career, his undeniable achievements, and tell the truth about a hero who made every effort to build his own fame.

Genome-Wide Investigation of Pasteurella multocida Identifies the Stringent Response as a Negative Regulator of Hyaluronic Acid Capsule Production.

ABSTRACTPasteurella multocida is a Gram-negative capsulated bacterium responsible for a range of diseases that cause severe morbidity and mortality in livestock animals. The hyaluronic acid (HA) capsule produced by P. multocida serogroup A strains is a critical virulence factor. In this study, we utilized transposon-directed insertion site sequencing (TraDIS) to identify genes essential for in vitro growth of P. multocida and combined TraDIS with discontinuous density gradients (TraDISort) to identify genes required for HA capsule production and regulation in this pathogen. Analysis of mutants with a high cell density phenotype, indicative of the loss of extracellular capsule, led to the identification of 69 genes important for capsule production. These genes included all previously characterized genes in the capsule biosynthesis locus and fis and hfq, which encode known positive regulators of P. multocida capsule. Many of the other capsule-associated genes identified in this study were involved in regulation or activation of the stringent response, including spoT and relA, which encode proteins that regulate the concentration of guanosine alarmones. Disruption of the autoregulatory domains in the C-terminal half of SpoT using insertional mutagenesis resulted in reduced expression of capsule biosynthesis genes and an acapsular phenotype. Overall, these findings have greatly increased the understanding of hyaluronic acid capsule production and regulation in P. multocida.IMPORTANCE The bacterial pathogen P. multocida can cause serious disease in production animals, including fowl cholera in poultry, hemorrhagic septicemia in cattle and buffalo, atrophic rhinitis in pigs, and respiratory diseases in a range of livestock. P. multocida produces a capsule that is essential for systemic disease, but the complete mechanisms underlying synthesis and regulation of capsule production are not fully elucidated. A whole-genome analysis using TraDIS was undertaken to identify genes essential for growth in rich media and to obtain a comprehensive characterization of capsule production. Many of the capsule-associated genes identified in this study were involved in the stringent response to stress, a novel finding for this important animal pathogen.

Immunogenicity and protection of a Pasteurella multocida strain with a truncated lipopolysaccharide outer core in ducks

Pasteurella multocida infection frequently causes fowl cholera outbreaks, leading to huge economic losses to the poultry industry worldwide. This study developed a novel live attenuated P. multocida vaccine strain for ducks named PMZ2 with deletion of the gatA gene and first four bases of the hptE gene, both of which are required for the synthesis of the lipopolysaccharide (LPS) outer core. PMZ2 produced a truncated LPS phenotype and was highly attenuated in ducks with a > 105-fold higher LD50 than the wild-type strain. PMZ2 colonized the blood and organs, including the spleen, liver and lung, at remarkably reduced levels, and its high dose of oral infection did not cause adverse effects on body temperatures and body weights in ducks. To evaluate the vaccine efficacy of the mutant, ducklings were inoculated orally or intranasally with PMZ2 or PBS twice and subsequently subjected to a lethal challenge. Compared with the PBS control, PMZ2 immunization stimulated significantly elevated serum IgG, bile IgA and tracheal IgA responses, especially after the boost immunization in both the oral and intranasal groups, and the induced serum had significant bactericidal effects against the wild-type strain. Furthermore, the two PMZ2 immunization groups exhibited alleviated tissue lesions and significantly decreased bacterial loads in the blood and organs compared with the PBS group post-challenge. All the ducks in the PMZ2 oral and intranasal groups survived the challenge, while 70% of ducks in the PBS group succumbed to the challenge. Thus, the P. multocida mutant with mutation of the gatA gene and part of the hptE gene proved to be an effective live attenuated vaccine candidate for prevention of fowl cholera in ducks.

Phase variation in the glycosyltransferase genes of Pasteurella multocida associated with outbreaks of fowl cholera on free-range layer farms.

Fowl cholera caused by Pasteurella multocida has re-emerged in Australian poultry production since the increasing adoption of free-range production systems. Currently, autogenous killed whole-cell vaccines prepared from the isolates previously obtained from each farm are the main preventative measures used. In this study, we use whole-genome sequencing and phylogenomic analysis to investigate outbreak dynamics, as well as monitoring and comparing the variations in the lipopolysaccharide (LPS) outer core biosynthesis loci of the outbreak and vaccine strains. In total, 73 isolates from two different free-range layer farms were included. Our genomic analysis revealed that all investigated isolates within the two farms (layer A and layer B) carried LPS type L3, albeit with a high degree of genetic diversity between them. Additionally, the isolates belonged to five different sequence types (STs), with isolates belonging to ST9 and ST20 being the most prevalent. The isolates carried ST-specific mutations within their LPS type L3 outer core biosynthesis loci, including frameshift mutations in the outer core heptosyltransferase gene (htpE) (ST7 and ST274) or galactosyltransferase gene (gatG) (ST20). The ST9 isolates could be separated into three groups based on their LPS outer core biosynthesis loci sequences, with evidence for potential phase variation mechanisms identified. The potential phase variation mechanisms included a tandem repeat insertion in natC and a single base deletion in a homopolymer region of gatG. Importantly, our results demonstrated that two of the three ST9 groups shared identical rep-PCR (repetitive extragenic palindromic PCR) patterns, while carrying differences in their LPS outer core biosynthesis loci region. In addition, we found that ST9 isolates either with or without the natC tandem repeat insertion were both associated with a single outbreak, which would indicate the importance of screening more than one isolate within an outbreak. Our results strongly suggest the need for a metagenomics culture-independent approach, as well as a genetic typing scheme for LPS, to ensure an appropriate vaccine strain with a matching predicted LPS structure is used.

Study of the antibacterial capacity of extracts of Solanum incanum L., (Solanaceae) traditionally used for the management of avian cholera in rural areas of Burkina Faso

Nowadays, thanks to the rise of microbial resistance, the lack of health care personnel and especially the high cost of synthetic molecules, phytotherapy could be a panacea in many developing countries. For this reason, the present work which aims to evaluate the phenolic compounds and to study the antibacterial capacity of extracts of roots, stems, leaves and fruits of Solanum incanum L., (Solanaceae) traditionally used for the treatment of pasteurellosis or avian cholera in Burkina Faso, was undertaken. For this purpose, we collected plant material in the commune of Dedougou. After extraction with acetone and water, colorimetric tests were carried out on the different extracts and revealed mostly the presence of tannins and coumarins. The Hydroacetone macerated extract was found to be very interesting for biological activities compared to the macerated extracts and the aqueous decoctions. Inhibition of bacterial growth on different bacterial strains was also shown for all the extracts, especially with Hydroacetone extract. These results could be mainly explained by the inhibitory effect of phenolic compounds. The Hydroacetone extract was also found to be especially very relevant for the prevention and treatment of microbial diseases from poultry.

Study of the antibacterial capacity of extracts of Solanum incanum L., (Solanaceae) traditionally used for the management of avian cholera in rural areas of Burkina Faso

Study of the antibacterial capacity of extracts of Solanum incanum L., (Solanaceae) traditionally used for the management of avian cholera in rural areas of Burkina Faso

Fowl cholera

This datasheet on fowl cholera covers Identity, Overview, Associated Diseases, Pests or Pathogens, Distribution, Hosts/Species Affected, Diagnosis, Further Information.

Qualitative Assessment of the Clinico-Pathological Features of Highly Pathogenic Avian Influenza H5N1 Outbreaks in Commercial Poultry and Peri-Domestic Birds in Northern Nigeria

The control of highly pathogenic avian influenza (HPAI) in Nigeria from inception is predicated on effective biosecurity by stamping out policy but outbreaks of the disease continued to re-occur with altered clinico-pathologic manifestations. This study undertook the qualitative assessment of the clinico-pathological features of HPAI H5N1 during the 2021/2022 outbreaks in commercial poultry and peri-domestic birds in northern Nigeria. A total of 22 commercial poultry farms with 53,932 laying chickens and 3 households with 120 backyard broiler chickens, 18 indigenous chickens, 10 peafowls and 9 geese were investigated for HPAI. The clinico-pathologic manifestations observed in commercial poultry were subtle compared to previous presentations of the disease except in the peafowls, geese, broilers and indigenous chickens. The interspecies mortality rates significantly varied from 1.6% to 19.6% for laying chickens and 33.3% to 100% for broilers, indigenous chickens, geese and peafowls. Based on the history of sudden and high mortality, clinical signs and post mortem lesions observed, three diseases; HPAI, very virulent Newcastle disease and fowl cholera were drawn out as differential diagnoses. However, a tentative diagnosis of HPAI was made and samples were sent to the National Veterinary Research Institute, Vom, Plateau State, Nigeria for confirmatory diagnosis. Results of the laboratory tests conducted on the samples using one step flu A screening and duplex real time RT-PCR, and virus isolation in embryonated chicken eggs confirmed HPAI H5N1 in twenty-five farms. It is concluded that the continuous though, irregular outbreaks of HPAI and emerging clinico-pathologic manifestations are pointers to failure of control and that the disease may become endemic. It is recommended that government should review its policy on the control of HPAI to include the adoption of zoned vaccination with close monitoring.

Gamma-Irradiated Fowl Cholera Mucosal Vaccine: Potential Vaccine Candidate for Safe and Effective Immunization of Chicken Against Fowl Cholera.

Fowl cholera (FC) caused by Pasteurella multocida is among the serious infectious diseases of poultry. Currently, formalin inactivated FC (FI-FC) vaccine is widely used in Ethiopia. However, reports of the disease complaint remain higher despite the use of the vaccine. The aim of this study was to develop and evaluate gamma-irradiated mucosal FC vaccines that can be used nationally. In a vaccination-challenge experiment, the performance of gamma-irradiated P. multocida (at 1 kGy) formulated with Montanide gel/01 PR adjuvant was evaluated at different dose rates (0.5 and 0.3 ml) and routes (intranasal, intraocular, and oral), in comparison with FI-FC vaccine in chicken. Chickens received three doses of the candidate vaccine at 3-week intervals. Sera, and trachea and crop lavage were collected to assess the antibody levels using indirect and sandwich ELISAs, respectively. Challenge exposure was conducted by inoculation at 3.5×109 CFU/ml of P. multocida biotype A intranasally 2 weeks after the last immunization. Repeated measures ANOVA test and Kaplan Meier curve analysis were used to examine for statistical significance of antibody titers and survival analysis, respectively. Sera IgG and secretory IgA titers were significantly raised after second immunization (p=0.0001). Chicken survival analysis showed that intranasal and intraocular administration of the candidate vaccine at the dose of 0.3 ml resulted in 100% protection as compared to intramuscular injection of FI-FC vaccine, which conferred 85% protection (p=0.002). In conclusion, the results of this study showed that gamma-irradiated FC mucosal vaccine is safe and protective, indicating its potential use for immunization of chicken against FC.

Pasteurella multocida PlpE Protein Polytope as a Potential Subunit Vaccine Candidate.

Pasteurella multocida is the causative agent of a range of animal, and occasionally human, diseases. Problems with antimicrobial treatment of P. multocida highlight the need to find other possible ways, such as prophylaxis, to manage infections. Current vaccines against P. multocida include inactivated bacteria, live attenuated and nonpathogenic bacteria; they have disadvantages such as lack of immunogenicity, reactogenicity, or reversion to virulence. Using bioinformatics approaches, potentially immunogenic and protective epitopes were identified and merged to design the most optimally immunogenic triple epitope PlpE fusion protein of P. multocida as a vaccine candidate. This triple epitope (PlpE1 + 2 + 3) was cloned into the pBAD/gIII A plasmid (pBR322-derived expression vectors designed for regulated, secreted recombinant protein expression and purification in Escherichia coli), expressed in Top 10 E. coli and purified in denatured form using Ni-NTA chromatography and 8 M urea. The immunogenicity of the purified proteins in BALB/c mice was assayed by measuring immunoglobulin G (IgG) responses. The protection potential was evaluated by challenging with 10 LD50 of serotype A:1, X-73 strain of P. multocida and compared with commercially available inactivated fowl cholera vaccine and PlpE protein. IgG levels elicited by the polytope fusion protein of P. multocida PlpE were higher than both commercially available inactivated fowl cholera vaccine and PlpE protein. Surprisingly, protection was independent of IgG level; commercially available inactivated fowl cholera vaccine (100% protection) was more protective than the polytope fusion protein (69% protection) and PlpE protein (69% protection). These results also confirm that IgG level is not a reliable indicator of protection. Further studies to evaluate the other antibody classes, such as immunoglobulin A or M, are required. The role of cell-mediated immunity should also be considered as a potential protection pathway.

Retrospective study of livestock vaccine coverage and trend in Lemu and Bilbilo Woreda, Arsi Zone, Ethiopia

Vaccination is one of the most efficient tools for protection against clinical disease of livestock and reduces the rate of spread of infection. The study was conducted using secondary data that recorded at Lemu and Bilbilo Woreda veterinary clinic with the objective to assess the vaccination coverage in the study area from March to September 2021. Results revealed the most commonly practiced vaccine were bacterial and viral diseases from secondary data recorded were Lumpy skin disease, Black leg, Pasteurellosis, New castle, Gumboro disease, chicken pox, Fowl pox, and Fowl Cholera. The percentage of vaccine coverage for lumpy skin disease decreases from a year 2017 (51.1%) to 2021(24%). The majority of Goat (96.7%) was vaccinated against goat pox during 2017 and the 0% Anthrax vaccine for Goat in 2021. Only 7.3% sheep in 2017 and near 37.4% in 2021 were vaccinated with sheep pox from total population. About 87.4% of equines were vaccinated from total population in 2017. The proportion of Newcastle disease and Gumboro disease vaccine coverage were 35% and 15.4%, respectively. Dog vaccination against rabies is increases from a year 2017 (4.8%) to 2020 (11%) in except 0.5% in 2021. The vaccine trends were fluctuating and/or decreasing from year to year. However, vaccine trend for Anthrax of cattle was increasing from year to year. It is therefore, suggested that implementation of planed and regularly vaccination of animal was very important for diseases control and prevention are recommended in order to decrease disease reoccurrence in the area.