Fowl Cholera Research Articles

Characterization and Potential Application of Phage vB_PmuM_CFP3 for Phage Therapy Against Avian Pasteurella multocida.

The rise of antibiotic-resistant bacterial infections necessitates alternative therapeutic strategies, such as phage therapy. This study investigates the potential of phage vB_PmuM_CFP3 (CFP3) as a therapeutic agent against avian cholera caused by Pasteurella multocida (P. multocida). Phage CFP3 was isolated from the feces and wastewater of a laying hen farm and underwent comprehensive biological characterization, including host range, lytic activity, and environmental stability. Transmission electron microscopy revealed CFP3's typical myovirus morphology, with a head diameter of approximately 60 nm and a tail length of about 120 nm. CFP3 demonstrated high stability across a pH range of 4-10 and temperatures of 30-40 °C, making it suitable for oral administration in poultry. The phage exhibited a latent period of about 90 min and an optimal multiplicity of infection (MOI) of 1. Despite its narrow host range, with a lysis rate of 28.2% against avian-derived type A P. multocida, CFP3's specificity minimizes impact on non-target bacteria. Whole-genome sequencing revealed a 32,696 bp linear double-stranded DNA genome with 46 predicted open reading frames (ORFs) and no tRNA or antibiotic resistance genes, enhancing its safety profile. Phylogenetic analysis indicated a close evolutionary relationship with Haemophilus phages HP1, HP2, and Pasteurella phage F108. While CFP3 shows promise as a precision therapeutic tool, further in vivo studies are required to evaluate its efficacy and safety. Future research should focus on expanding the phage library, optimizing phage mixtures, and exploring synergistic effects with other antimicrobial strategies. This study provides foundational data supporting the development of CFP3 as a viable alternative to antibiotics for controlling avian cholera.

Complete genome sequences of eight Pasteurella multocida isolates representing all lipopolysaccharide outer core loci.

Pasteurella multocida (PM) is a major bacterial pathogen that causes fowl cholera disease in both domestic poultry and wild birds. Here, we report the complete genome sequences of eight PM isolates representing all known lipopolysaccharide outer core loci, which are phenotypically expressed as 16 known PM serotypes.

Comparative evaluation of PCR and loop-mediated isothermal amplification (LAMP) assays for detecting Pasteurella multocida in poultry

ABSTRACT Aims To develop a colourimetric loop-mediated isothermal amplification (LAMP) assay for the detection of Pasteurella multocida in clinical poultry samples and compare the performance of this assay with PCR. A secondary aim was to evaluate a simple DNA extraction method that could enable LAMP-based testing in the field without the need for specialised laboratory equipment. Methods Primer sets for both LAMP and PCR were designed to amplify the KMT1 gene of P. multocida. DNA was extracted from 12 P. multocida isolates using a commercial extraction kit, and subjected to analysis using both LAMP and PCR. The analytical specificity of the LAMP assay was evaluated by testing it against a panel of 12 unrelated bacterial species, and the analytical sensitivity (limit of detection) was determined through testing of serial dilutions of the target DNA and compared to that of PCR. Subsequently, cloacal swabs (n = 40) from a commercial turkey flock were subjected to analysis using both LAMP and PCR assays, using a rapid DNA extraction method and a commercial extraction kit. Clinical sensitivity and specificity of the LAMP assay were calculated in comparison to PCR. Results A single DNA fragment of the expected size (∼ 200 base pairs), was amplified by PCR from 12 P. multocida isolates, which were also all positive by the LAMP assay. The identity of all PCR amplicons was confirmed by sequencing. Both PCR and LAMP showed similar analytical sensitivity, with a LOD of 20 pg of target DNA. As neither PCR nor LAMP assays produced positive results with 12 non-related bacterial species, the analytical specificity was assessed as 100%. However, LAMP demonstrated lower clinical specificity (94.74%) compared to PCR (100%) when 40 clinical samples were tested. None of the DNA samples extracted using the simplified DNA extraction method were amplified by either LAMP or PCR. Conclusion The LAMP assay developed in this study exhibits comparable performance to PCR in detecting P. multocida. Clinical relevance The use of a rapid and portable DNA extraction method, in conjunction with LAMP assays, could create opportunities for point-of-care testing for fowl cholera in field settings.

Identification and Antibiotic Resistance of Pasteurella multocida Isolated from Infected Layer Chickens in West Java, Indonesia

Bacterial infections, such as those caused by Pasteurella multocida serotype A, pose significant threats to poultry farming. The use of antibiotics to treat these infections can lead to antibiotic resistance. The present study aimed to identify Pasteurella multocida from 14 Hisex Brown layer chicken hen farms, with chikens aged 25-55 weeks, in West Java, Indonesia, and to evaluate their resistance to various antibiotics. Three samples from each farm were collected from dead chickens having symptoms of fowl cholera. Initially, the study involved isolating and identifying isolates from liver, heart, and lung organs via polymerase chain reaction. The colony was then tested for antibiotic resistance using the disk diffusion method. The results showed that 13 samples were Pasteurella multocida and nine were serotype A. The test results also indicated that all isolates were resistant to colistin (10 µg) and sensitive to tetracycline (30 µg), amoxicillin (25 µg), enrofloxacin (5 µg), sulfamethoxazole (25 µg), lincomycin (109 µg), and ciprofloxacin (5 µg). The study concluded that none of the Pasteurella multocida type A isolates were any longer sensitive to colistin, with some isolates still sensitive to tetracycline, amoxicillin, enrofloxacin, sulfamethoxazole, lincomycin, and ciprofloxacin, and two isolates showing multidrug resistance patterns. Keywords: Antibiotic, Fowl cholera, Pasteurella multocida, Layer chicken

Use of MONTANIDE ISA 78 VG as adjuvant for the manufacture of antibacterial vaccines for chickens

Relevance. The use of antimicrobial agents and vaccine prophylaxis are the main ways to prevent and control most diseases of bacterial etiology. At the same time, uncontrolled use of antimicrobial agents without determining the sensitivity of microorganisms, as a rule, does not give the opportunity to obtain a positive therapeutic result. At the same time, a competently designed scheme of inactivated vaccine administration, taking into account the epizootic situation, is an effective and safe tool for controlling bacterial diseases.In this regard, the results of testing of vaccine samples against bacterial diseases of birds based on the modernized oil adjuvant Montanide ISA 78 VG presented in this article are interesting and modern.Methods. Four vaccine samples were manufactured for research based on the oil adjuvant Montanide ISA 78 VG. The first sample of the vaccine is against avian salmonellosis, the second — against avian pasteurellosis, the third — against avian respiratory mycoplasmosis, the fourth — against avian hemophilosis. All manufactured vaccine samples were investigated for sterility, stability and viscosity of the emulsion according to generally accepted methods. To determine the reactogenicity and antigenic activity of the vaccine samples, young egg-laying hens aged 25–40 days were used.Results. Analysis of the obtained results of physical and biological properties of tested inactivated vaccines against bacterial diseases of birds allows us to conclude that the vaccine against respiratory mycoplasmosis of birds made on the basis of adjuvant Montanide ISA 78 VG is a safe and effective immunobiological preparation.

Louis Pasteur: A Legacy Unmasked.

Louis Pasteur is perhaps the most globally recognized French scientist. His groundbreaking discoveries in molecular chirality and advancements in fermentation greatly benefited brewers and winemakers. Pasteur introduced the process of pasteurization to sterilize wines and significantly contributed to the development of germ theory, which made Joseph Lister's antiseptic surgical techniques possible. Despite initially disproving Antoine Béchamp's theory that silkworm disease was caused by a microbial infection, Pasteur tackled this issue effectively. Building on the work of Henri Toussaint and Pierre Victor Galtier, he developed vaccines for pig erysipelas, chicken cholera, anthrax, and rabies. Pasteur also coined the term "vaccination," which Richard Dunning had used before Edward Jenner expanded upon it. Although Robert Koch criticized Pasteur's vaccination methods as ambiguous, historians have clarified many of the myths surrounding Pasteur. This review explores Pasteur's career, his undeniable achievements, and the realities behind the legendary figure who strove to make a significant impact on science and medicine.

The activity of hyaD contributed to the virulence of avian Pasteurella multocida

Fowl cholera is an infectious disease that affects both poultry and wild birds, characterized by hemorrhagic and septicemic symptoms, caused by Pasteurella multocida (P. multocida), and leading to substantial economic losses in the poultry sector. The development of genetic engineering vaccines against avian P. multocida encountered early-stage challenges due to the limited availability of effective gene editing tools. Presently, NgAgoDM-enhanced homologous recombination stands as a potent technique for achieving efficient gene knockout in avian P. multocida. Hence, this study employed NgAgoDM-enhanced homologous recombination to target and knockout hyaE (239-359aa), hyaD, hexABC, and hexD, denoted as ΔhyaE (239-359aa), ΔhyaD, ΔhexABC, and ΔhexD, respectively. Additionally, we generated a hyaD recovery strain with two point mutations, designated as mhyaD. Thus, this study systematically examined the impact of capsular synthetic gene clusters on the pathogenicity of P. multocida. Moreover, the study demonstrated the critical role of hyaD activity in the virulence of avian P. multocida. This study offers novel insights for enhancing attenuated vaccines further.

Flagellin Enhances the Immunogenicity of Pasteurella multocida Lipoprotein E Subunit Vaccine.

Fowl cholera, caused by Pasteurella multocida infection, poses challenges for prevention because of its many serotypes. Bacterins are currently widely used for vaccination against fowl cholera, but protection is limited to homologous strains. Live attenuated vaccines of P. multocida provide some heterologous protection, but side effects are considerable. More recently, protein-based antigens are promising subunit vaccines when their low immunogenicity has been addressed with effective adjuvants. Bacterial flagellin has been widely considered a promising adjuvant for vaccines. In this study, we tested the adjutancy of flagellin in a subunit vaccine against P. multocida in a mice and chicken models. For vaccine formulation, the antigen fPlpE (P. multocida liporotein E) was combined with fFliC (Salmonella Typhimurium flagellin). The recombinant proteins of fPlpE and fFliC were successfully expressed using the Escherichia coli system as the expected sizes of 55 kDa and 70 kDa, respectively. The fFliC elicited strong expression levels of proinflammatory cytokine (IL-1β, IL-8, and IL-6) when stimulated in native chicken peripheral blood mononuclear cells. Immunization of mice and chickens with the subunit vaccines containing fFliC accelerated the antibody response. In the challenge tests, fFliC increased vaccine protective efficacy against the heterologous strain P. multocida A1 and highly virulent strain Chu01 in mice and chickens, respectively. These data indicated potential possibilities of using fFliC as an immunostimulant adjuvant in developing a subunit vaccine against fowl cholera.

Cranial osteomyelitis associated with Pasteurella canis in broiler chickens

Species of the Pasteurella genus are part of the oropharyngeal microbiota of many animal species. In poultry, Pasteurella multocida causes fowl cholera, the chronic manifestation of which can include neurological symptoms. Pasteurella canis causes osteomyelitis and other infections in humans. To the best of our knowledge, this is the first report of cranial osteomyelitis associated with Pasteurella canis in broiler chickens in Chile.

Erysipelothrix amsterdamensis sp. nov., associated with mortalities among endangered seabirds.

Infectious diseases threaten endangered species, particularly in small isolated populations. Seabird populations on the remote Amsterdam Island in the Indian Ocean have been in decline for the past three decades, with avian cholera caused by Pasteurella multocida proposed as the primary driver. However, Erysipelothrix species have also been sporadically detected from albatrosses on Amsterdam Island and may be contributing to some of the observed mortality. In this study, we genomically characterized 16 Erysipelothrix species isolates obtained from three Indian yellow-nosed albatross (Thalassarche carteri) chick carcasses in 2019. Histological analyses suggest that they died of bacterial septicaemia. Two isolates were sequenced using both Illumina short-read and MinION long-read approaches, which - following hybrid assembly - resulted in closed circular genomes. Mapping of Illumina reads from the remaining isolates to one of these new reference genomes revealed that all 16 isolates were closely related, with a maximum of 13 nucleotide differences distinguishing any pair of isolates. The nucleotide diversity of isolates obtained from the same or different carcasses was similar, suggesting all three chicks were likely infected from a common source. These genomes were compared with a global collection of genomes from Erysipelothrix rhusiopathiae and other species from the same genus. The isolates from albatrosses were phylogenetically distinct, sharing a most recent common ancestor with E. rhusiopathiae. Based on phylogenomic analysis and standard thresholds for average nucleotide identity and digital DNA-DNA hybridization, these isolates represent a novel Erysipelothrix species, for which we propose the name Erysipelothrix amsterdamensis sp. nov. The type strain is A18Y020dT (=CIP 112216T=DSM 115297T). The implications of this bacterium for albatross conservation will require further study.

Unraveling frontiers in poultry health (part 1) – Mitigating economically important viral and bacterial diseases in commercial Chicken and Turkey production

This symposium offered up-to-date perspectives on field experiences and the latest research on significant viral and bacterial diseases affecting poultry. A highlight was the discussion on the use of enteroids as advanced in vitro models for exploring disease pathogenesis. Outcomes of this symposium included identifying the urgent need to improve the prevention and control of avian influenza by focusing research on vaccine effectiveness. In this regard, efforts should focus on enhancing the relatedness of vaccine antigen to the field (challenge) virus strain and improving immunogenicity. It was also revealed that gangrenous dermatitis could be controlled through withholding or restricting the administration of ionophores during broiler life cycle, and that administration of microscopic polymer beads (gel) based-live coccidia vaccines to chicks could be used to reduce necrotic enteritis-induced mortality. It was emphasized that effective diagnosis of re-emerging Turkey diseases (such as blackhead, fowl cholera, and coccidiosis) and emerging Turkey diseases such as reoviral hepatitis, reoviral arthritis, Ornithobacterium rhinotracheale infection, and strepticemia require complementarity between investigative research approaches and production Veterinarian field approaches. Lastly, it was determined that the development of a variety of functionally-specific enteroids would expedite the delineation of enteric pathogen mechanisms and the identification of novel vaccine adjuvants.

Pasteurella multocida ST20 is widespread in Australian poultry farms and may infect wild waterbirds

The bacterial agent that causes fowl cholera, Pasteurella multocida, was isolated from two deceased wild waterbirds in Victoria, Australia, in 2013. Whole genome sequence analysis placed the isolates into ST20, a subtype described in farmed chickens from Queensland, Australia and more recently in feedlot cattle and in pigs across a broader area of the continent. This study also found ST20 between 2009 and 2022 on three chicken farms and two turkey farms located in four Australian states. The sequences of 25 of these ST20 isolates were compared to 280 P. multocida genomes from 23 countries and to 94 ST20 Illumina datasets from Queensland that have been deposited in public databases. The ST20 isolates formed a single phylogenetic clade and were clustered into four sub-groups with highly similar genomes, possessing either LPS type 1 or type 3 loci. Various repertoires of mobile genetic elements were present in isolates from farmed, but not wild birds, suggesting complex histories of spill-over between avian populations and gene acquisition within farm environments. No major antimicrobial resistance was predicted in any of the ST20 isolates by the genomic analysis. The closest relative of these isolates was a ST394 bovine respiratory tract isolate from Queensland, which differed from ST20 by only one allele and carried beta-lactam and tetracycline resistance genes. These findings underline the importance of understanding the role of wild and commercial birds in the maintenance of fowl cholera, and of implementing regular epidemiological surveillance and biosecurity management programmes in wildlife, as well as free-range poultry farms.

Co-existence of fowl cholera and lymphoid leucosis in Desi chickens

Co-existence of fowl cholera and lymphoid leucosis in Desi chickens

Efficiency of NHEJ-CRISPR/Cas9 and Cre-LoxP Engineered Recombinant Turkey Herpesvirus Expressing Pasteurella multocida OmpH Protein for Fowl Cholera Prevention in Ducks.

Fowl cholera is caused by the bacterium Pasteurella multocida, a highly transmissible avian ailment with significant global implications, leading to substantial economic repercussions. The control of fowl cholera outbreaks primarily relies on vaccination using traditional vaccines that are still in use today despite their many limitations. In this research, we describe the development of a genetically engineered herpesvirus of turkeys (HVT) that carries the OmpH gene from P. multocida integrated into UL 45/46 intergenic region using CRISPR/Cas9-NHEJ and Cre-Lox system editing. The integration and expression of the foreign cassettes were confirmed using polymerase chain reaction (PCR), indirect immunofluorescence assays, and Western blot assays. The novel recombinant virus (rHVT-OmpH) demonstrated stable integration of the OmpH gene even after 15 consecutive in vitro passages, along with similar in vitro growth kinetics as the parent HVT virus. The protective efficacy of the rHVT-OmpH vaccine was evaluated in vaccinated ducks by examining the levels of P. multocida OmpH-specific antibodies in serum samples using ELISA. Groups of ducks that received the rHVT-OmpH vaccine or the rOmpH protein with Montanide™ (SEPPIC, Paris, France) adjuvant exhibited high levels of antibodies, in contrast to the negative control groups that received the parental HVT or PBS. The recombinant rHVT-OmpH vaccine also provided complete protection against exposure to virulent P. multocida X-73 seven days post-vaccination. This outcome not only demonstrates that the HVT vector possesses many characteristics of an ideal recombinant viral vaccine vector for protecting non-chicken hosts, such as ducks, but also represents significant research progress in identifying a modern, effective vaccine candidate for combatting ancient infectious diseases.

Pasteurella multocida causes liver injury in ducks by mediating inflammatory, apoptotic and autophagic pathways

Pasteurella multocida.(PM) infection is a major cause of avian cholera, but the pathogenesis of the disease is unknown. The purpose of this study was to further understand the host response to infection by using a duck model of PM, 20 female ducks were divided into two groups (n = 10). One group was infected with PM, while the other served as an uninfected control group. The ducks were observed after infection and samples were collected for testing. In this study, we report the mechanism of PM-induced inflammation to further mediate apoptosis and autophagic signaling pathways in liver cells. Our results demonstrated that PM infection initially induces hemorrhagic and necrotic lesions in the liver tissue of duck, promoting inflammasome assembly and release, triggering inflammation. The TLR4/NF-κB axis activated and interacted with multiple inflammation-related proteins, including TNF-α and IL-1β, which affected apoptosis and autophagy. Tumor necrosis factor induced hepatocyte apoptosis was implicated in a wide range of liver diseases; the release of TNF-α and activation with NF-κB further incite apoptotic pathways,such as Bax/BCL2/caspase to promote apoptotic genes APAF1, Bax, Caspase3, BCL-2, p53, and Cytc expression. Finally, PM-induced autophagy suppressed liver injury by promoting the Beclin-1, LC3B, p62, and mTOR. Thus, liver injury caused by PM via promoting autophagy was induced. In conclusion, we analyzed the liver injury of ducks infected with PM, and confirmed that inflammation appeared in the liver; this was followed by the intricate interplay between inflammation, apoptosis, and autophagy signaling pathways. The observed results provided a reference basis for studying pathogenic mechanisms of PM-host interactions.

Review on diseases and health management of poultry and swine

Poultry and swine production play an important role in countries' socioeconomic development by providing proteins that support food and nutrition security. However, several infectious and non-infectious diseases hinder the production of swine and poultry. Therefore, this review aim to provide highlight of the common disease and health management of poultry and swine. Poultry production has suffered from different pathogenic microorganisms that cause devastating economic losses in poultry industries worldwide. Poultry can be infected with common diseases like endoparasites, ectoparasites, infectious bronchitis, Marek's disease, fowl cholera, salmonellosis, infectious coryza, fowl pox, avian encephalomyelitis, etc. Health management is a system of preventive medicine that considers the whole poultry farms and the total influences, including social, with respect to relationships with others in the flock, psychological, and environmental factors that affect health. Swine production can be destructed by the influence of infectious diseases, which include Mycoplasma Hyopneumoniae, Actinobacillus pleuropneumoniae, Porcine Reproductive and Respiratory Syndrome Virus, Trichinella spp., Toxoplasma gondii, Salmonella spp., Campylobacter, and Leprospira. This all causes respiratory problems, leg problems, reproductive disorders, gastrointestinal problems, claw and skin problems, parasitic infections, and piglet mortality. Endoparasites and ectoparasites are regarded as the most significant constraints for welfare and health, as well as economic loss, in swine production, particularly during the post-weaning period. However, health management of swine production can reduce the effect of disease and optimize their productivity. Herd health management practices include vaccination, genetic improvement, and observation for all animals’ clinical signs, record keeping, detection and treatment of injury, sanitation, disease, pest control, and animal handlers. Generally, disease has a great risk to the health of poultry and swine animals that causes a decrement in their production. Therefore, the health management on poultry and swine farms should have to be strictly measured and further studies need to be conducted to solve the major problem of economic loss of production.

Weaving Indigenous and Western ways of knowing in ecotoxicology and wildlife health: a review of Canadian studies

Western-trained, non-Indigenous researchers in Canada have an ethical responsibility to collaborate with Indigenous Peoples and to re-envision the scientific research process through the lens of reconciliation. The health of the natural environment has long been a concern to both Indigenous and non-Indigenous Peoples, and weaving different ways of knowing could provide a path forward to address critical wildlife health concerns. Here, we conducted a review of the peer-reviewed and grey literature that claims to weave Indigenous and Western ways of knowing in ecotoxicology and wildlife health in Canada, coding for background information, wildlife health stressors, research methods, Indigenous participation, and research outcomes. Seventeen studies met the inclusion criteria, the majority of which were published since 2015 and took place in Canada’s North. Research collaborations were often between First Nations or Inuit knowledge holders (most frequently, active harvesters and Elders) and Western-trained, non-Indigenous academics. Most studies were initiated by mutual agreement between community partners and researchers, but no study was “Indigenous-led” at any stage of research. Studies investigated environmental contaminants and health-related topics in a range of wildlife, usually traditional subsistence species. The most commonly studied disease was avian cholera, and the most studied class of toxicants was metals and trace elements. Indigenous knowledge was primarily collected via interviews. Studies often used multiple methodologies to braid or weave knowledge, but the most frequently used methodology was community-based participatory research. To provide a more holistic understanding of the process of weaving knowledge, we conducted an in-depth examination, applying a decolonizing lens, of two exemplar cases of collaborative research with Indigenous communities. This exploration led to the conclusion that research that weaves ways of knowing must not be approached with a “one-size-fits-all” mindset, but instead should emphasize relationship building, continuous engagement, and ethical practices. By adopting such practices, Western-trained, non-Indigenous academics can better address critical wildlife health concerns while contributing meaningfully to advancing healing and reconciliation with Indigenous Peoples.

Survey study for diseases of house chickens in villages of Kirkuk governorate

This research included (436) infected case of house chickens were diagnosed in villages of Kirkuk in the period (January 2015 to December 2015).The study showed that Newcastle Disease still the most important diseases in poultry of Iraq, with a high percentage of (35.3%) from total cases. The incidence of other diseases were as follow: Parasitic infestations manifested in chickens as Ectoparasites (15%), Fowl pox (14.4%), Internal parasites (13.3%), Bumble foot (7.3%), Fowl Typhoid and Pullorum Disease (6.9%), Necrotic enteritis (4.8%), the low incidence with Fowl cholera (3%) was recorded .

Management system and productivity of backyard poultry in Jhenidah district of Bangladesh: a survey

This study was carried out to know the current scenarios of rearing backyard poultry in Jhenidah district of Bangladesh. A total of 2832 poultry birds (deshi chicken, sonali, duck and pigeon) were selected from 170 households. The data were collected according to prepared questionnaire. The study revealed that, most of the farmers reared their poultry in semi scavenging system (97.64%). The poultry houses were commonly made of tin and bamboo (88.82%) and some of farmers kept their poultry in houses which were at unsatisfactory level (11.2%). They used polythene, sack, ash, sand, straw, papers separately or together as bedding materials (78.82%) and 21.18% of farmers did not use any bedding materials. They usually cleaned poultry house irregularly (73.53%). The rice (84.71%) as feed supplement followed by boiled rice, paddy, broken rice, wheat and commercial as well, was commonly given twice (62.9%) in a day. The farmers did not usually use feeder and waterer (44.12%) and use only 8.82% of vaccine. The supplementary feed to each deshi chicken, sonali, duck and pigeon per day were 32.77 g, 38.70 g, 82.04 g and 12.40 g gaining average body weight of 1.19 kg, 1.36 kg, 1.22 kg and 315.35 g respectively. The average egg production per deshi chicken, sonali, duck and pigeon per year were 37.27, 47.30, 84.66, and 19.90 containing average weight 35.01 g, 41.20 g, 52.68 g and 11.10 g successively. Furthermore, the mean hatchability was found 77.50% in deshi chicken, 79.25% in sonali, 78.95% in duck and 97.45% in pigeon along with 28.79% significant (P<0.05) mortality in deshi chicken, 30.35% in sonali, 14.50% in duck and 11.40% in pigeon consecutively. The prevalence of diseases were investigated as Newcastle disease, fowl cholera, duck cholera, duck plague and pigeon pox. Diseases (54.1%) are the most current constraints followed by lack of knowledge, predators for poultry rearing in backyard system. This study will support farmers by enhancing their income through improved management practice in backyard poultry. Asian J. Med. Biol. Res. 2023, 9 (1), 1-8

Modern approaches in the diagnosis of avian Pasteurellosis

Studies carried out in many countries of the world demonstrate considerable variability in the virulence properties of pasteurellosis. The variety of antigenicity and toxicity serovars of the pathogen determines a number of specific features of display of poultry pasteurellosis, especially in associated infections when several causative agents of infectious diseases of bacterial and/or viral etiology circulate in one farm. In mixed infections, birds show a variety of clinical signs, most notably a respiratory syndrome characterized by respiratory involvement (sinusitis, conjunctivitis, laryngitis, tracheitis, bronchitis, pneumonia, and aerosacculitis) and tissue swelling in the suborbital sinuses, intermandibular spaces, and ear flaps.This situation makes it difficult to timely and promptly conduct effective therapeutic and anti-epizootic measures. However, it is necessary to identify the etiology of the disease as soon as possible, methodically and comprehensively, taking into account epizootic data, clinical signs, pathological anatomical changes and with obligatory confirmation by laboratory tests.At present time laboratory methods for diagnostics of avian pasteurellosis are regulated by Methodical instructions (MI) on laboratory diagnostics of pasteurellosis of animals and birds approved by the Chief Veterinary Department on August 20, 1992 № 22-7/82.According to the approved MI, the laboratory diagnosis of avian pasteurellosis includes microscopy of smears and fingerprints, isolation of pasteurella cultures and their identification, and, if necessary, bioassaying.It should be noted that the laboratory diagnosis of pasteurellosis according to the MI is a laborious and time-consuming process.Apart from the methods described in the MI, the serological method - enzyme immunoassay (ELISA) and molecular biological method - polymerase chain reaction (PCR) are currently widely and successfully used in laboratory practice for diagnosis of avian pasteurellosis, which are not reflected in the approved MI, but allow relatively simple and rapid reliable results.