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Respiratory diseases caused by Mannheimia haemolytica ( M . haemolytica ) and Pasteurella multocida ( P. multocida ) have been known to result in a considerable loss due to mortality and reduced production. This study aimed at isolation and identification of M. haemolytica and P. multocida associated with pneumonic pasteurellosis in sheep and goats using bacteriological and molecular techniques. Identification of serotypes of M. haemolytica and P. multocida was done using indirect haemagglutination test. The in vitro antimicrobial sensitivity profiles of the M. haemolytica were tested using standard disk diffusion method. A total of 52 and 78 nasal swabs were collected from pneumonic cases for bacterial isolation and identification in Borana and Arsi zone, respectively. Four hundred sera samples were collected for identification of serotypes. The results showed that 17 of 52 (32.69%; 95% CI 20.33, 47.11) nasal swabs collected from pneumonic animals in Borana yielded positive results for Pasteurella / Mannheimia species, 13 (25.00%; 95% CI 14.03, 38.95) of which were M. haemolytica . None of the samples yielded P. multocida . Twenty-three of 78 (29.49%; 95% CI 19.69, 40.89) nasal swabs collected at Arsi from pneumonic animals yielded positive results for M. haemolytica (17) and P. multocida (6). Secondary biochemical characterization revealed that 14 of the 17 isolates conform to M. haemolytica whereas none of the 6 isolates suspected to be P. mutocida were confirmed. Eleven (84.62%) isolates from Borana and 4 (28.57%) from Arsi were confirmed to be M. haemolytica using PCR targeting the Rpt2 genes. Assay for M. haemolytica serotype A1 revealed all belong to A1. None of the isolates with cultural and morphological features of P. multocida gave positive results by molecular assay. Serological assay identified three serotypes of M. haemolytica namely A1, A2 and A7 almost in all of the samples whereas P. multocida serotype A was detected in 78.75% of the samples. The M. haemolytica isolates tested for susceptibility to antibiotics showed resistance against Bacitracin (83.33%) and Penicillin (50.00%) while they were found susceptible to Gentamycin (100%), Chloramphenicol (100%) and Sulfamethoxazole (100%) and Tetracycline (83.33%). In conclusion, the results of the present study revealed the association of M. haemolytica with pneumonic pasteurellosis in sheep and goats and can be of use in vaccine development in Ethiopia. Nevertheless, further investigations and continuous monitoring of antimicrobial resistance and appropriate selection and prudent use of antimicrobials in livestock sector are required.

The reported incidences of co-participation of Mycoplasma capricolum capripneumoniae ( Mccp ) and Pasteurella multocida in increased severity and pathogenesis of goats with Contagious caprine pleuropneumonia (CCPP) in sub-Saharan Africa elicited the study’s purpose. Using the preferred reporting items for systematic review and meta-analysis (PRISMA) guideline, two search engines, namely Google Scholar and PubMed, were queried to systematically review all the available literature on the current epidemiological status of CCPP and Pneumonic Pasteurellosis co-concurrently detected in goats and assess the available treatment and control measures and their challenges in the Sub-Saharan region. The search was limited to papers published between 1998 and 2024, whereby only peer-reviewed English articles were included in the study. Review papers, papers displaying abstracts only, duplicated information, papers beyond the sub-Saharan Africa region and papers published in other languages were excluded from the study. Only articles with full text and focused on goats were included for further screening process and review. A total of 3311 articles were retrieved from both databases, whereas only 58 articles met the inclusion criteria and hence were included in the data analysis. Only eight countries namely, Ethiopia, Kenya, Uganda, Nigeria, Sudan, Eritrea, Zambia and Tanzania reported the occurrence of CCPP and or Pasteurellosis: Ethiopia 23/58(39%), Tanzania 18/58 (31%), 1/58(2%) Nigeria, 1/58(2%) Zambia, 1/58(2%) Eritrea, Uganda 2/58 (3%), 2/58(3%) Sudan and Kenya 10/58(16%). Only 5/58 (9%) reported the occurrence of pneumonic pasteurellosis in Nigeria and Ethiopia. Only Tanzania (75%) and Ethiopia (33%) reported Mccp and Pasteurella multocida co-isolation and/ or detection in CCPP cases. Information on the antimicrobial susceptibility profile of Mccp and Pasteurella multocida from Sub-Saharan Africa was unavailable. One vaccine against CCPP, namely F-38 inactivated, and one vaccine against pneumonic pasteurellosis were identified to be developed and used in Sub-Saharan Africa. Developing bivalent candidate vaccines for both etiological agents is highly recommended.

Mannheimia haemolytica is recognized as principal pathogen associated with pneumonic pasteurellosis leading to huge economic losses to small ruminant farmers. Even though the disease causes huge economic losses, epidemiology of M. haemolytica is less studied, hindering the formulation of effective control strategies. Current study aimed to highlight molecular characterisation of M. haemolytica strains isolated from ovine pneumonic infection. M. haemolytica 27 isolates with two reference strains were characterised using capsular and virulence gene typing, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) methods. M. haemolytica serotype A2 recognized as predominant serotype (74%) followed by A6 (11%) and A1 (5%) serotypes. Virulence gene profiling by PCRs showed dominance of all five virulent genes [such as adh and gcp (100% each)] followed by gs60 (88.8%), lktC (85.2%), tbpB (51.9%) and least nmaA gene (14.8%). MLST profiling delineated M. haemolytic isolates into 11 sequence types (STs) with most prevalent being ST37 (27.9%) and ST16 (23%) and nine new STs (ST37, 38, 39, 40, 41, 42, 47, 48, and 49). These new STs did not belong to any of the three clonal complexes (CC4, CC8 and CC28). ST16 was exclusively noted in A1 and A6 serotypes. Amongst 25 isolates, 22 pulsotypes (GD 0.88) recorded indicated variability of the M. haemolytica isolates in PFGE analysis. In conclusion, the study suggested dominance of M. haemolytica serotype A2 harbouring different virulent genes, diverse STs and pulsotypes responsible for pneumonic pasteurellosis frequently encountered in sheep.

Mannheimia haemolytica is the major cause of severe pneumonia in bovine respiratory disease (BRD). Early M. haemolytica bacterins were either ineffective or even enhanced disease in vaccinated cattle, which led to studies of the bacterium's virulence factors and potential immunogens to determine ways to improve vaccines. Studies have focused on the capsule, lipopolysaccharide, various adhesins, extracellular enzymes, outer membrane proteins, and leukotoxin (LKT) resulting in a strong database for understanding immune responses to the bacterium and production of more efficacious vaccines. The importance of immunity to LKT and to surface antigens in stimulating immunity led to studies of individual native or recombinant antigens, bacterial extracts, live-attenuated or mutant organisms, culture supernatants, combined bacterin-toxoids, outer membrane vesicles, and bacterial ghosts. Efficacy of several of these potential vaccines can be shown following experimental M. haemolytica challenge; however, efficacy in field trials is harder to determine due to the complexity of factors and etiologic agents involved in naturally occurring BRD. Studies of potential vaccines have led current commercial vaccines, which are composed primarily of culture supernatant, bacterin-toxoid, or live mutant bacteria. Several of those can be augmented experimentally by addition of recombinant LKT or outer membrane proteins.

Respiratory diseases in ruminants are a main cause of economic losses to farmers worldwide. Approximately 25% of ruminants experience at least one episode of respiratory disease during the first year of life. Mannheimia haemolytica is the main etiological bacterial agent in the ruminant respiratory disease complex. M. haemolytica can secrete several virulence factors, such as leukotoxin, lipopolysaccharide, and proteases, that can be targeted to treat infections. At present, little information has been reported on the secretion of M. haemolytica A2 proteases and their host protein targets. Here, we obtained evidence that M. haemolytica A2 proteases promote the degradation of hemoglobin, holo-lactoferrin, albumin, and fibrinogen. Additionally, we performed biochemical characterization for a specific 110 kDa Zn-dependent metalloprotease (110-Mh metalloprotease). This metalloprotease was purified through ion exchange chromatography and characterized using denaturing and chaotropic agents and through zymography assays. Furthermore, mass spectrometry identification and 3D modeling were performed. Then, antibodies against the 110 kDa-Mh metalloprotease were produced, which achieved great inhibition of proteolytic activity. Finally, the antibodies were used to perform immunohistochemical tests on postmortem lung samples from sheep with suggestive histology data of pneumonic mannheimiosis. Taken together, our results strongly suggest that the 110-Mh metalloprotease participates as a virulence mechanism that promotes damage to host tissues.

Background Pneumonic pasteurellosis leads to substantial economic losses in the small ruminant Production because of high mortality and reduced productivity. A cross‐sectional study was employed with the objective to isolate and identify Mannheimia haemolytica and Pasteurella multocida from outbreak cases of small ruminants in selected districts of Afar region, Ethiopia from December 2021 to June 2023. A total of 192 nasal swab samples were collected using purposive sampling technique and bacterial isolation and identification was carried out as per the standard bacteriological methods. Descriptive statistics and Pearson's chi‐square (χ2) were employed to check the association between occurrence of the disease and associated risk factors and statistical significance was set at p < 0.05. Results In the current study, the overall bacterial isolation rate from clinical cases of ovine and caprine pneumonic pasteurellosis was found to be 24.48% (n = 47/192), of which M. haemolytica accounted for 17.19% (n = 33/192) of bacterial isolates, while P. multocida accounted for 7.29% (n = 14/192) from isolates recovered from nasal swabs. Moreover, the present study also indicated that goats were more affected by this disease with the bacterial occurrence rate of 32.86% (n = 23/70) as compared to sheep with 19.67% (n = 24/122) in the study districts. There was statistically significant difference across species (p = 0.041) of the study animals with occurrence of the ovine and caprine pasteurellosis in nasal swabs. The study further revealed significant variation in the incidence rates of presumptive Pasteurella isolates across the study areas with Asayita recording the highest rate at 19.70% (n = 13/66), followed by Dubti at 17.46% (n = 11/63), and Mille at 14.29% (n = 9/63) even though no statistical association was observed. Conclusions The present study finding indicated that M. haemolytica is the predominant bacterium associated with pneumonic pasteurellosis in ovine and caprine in the study areas. This could highlights the need for developing a polyvalent vaccine incorporating M. haemolytica strains. • The present study finding indicated that M. haemolytica is the predominant bacterium associated with pneumonic pasteurellosis in ovine and caprine in the study areas. • Goats were found to be significantly more susceptible than sheep. • This could suggest the need for developing a polyvalent vaccine incorporating M. haemolytica strains.

Abstract The paper describes data from the study of cultural, morphological, and biochemical properties and the pathogenicity and virulence of epizootic isolates of Pasteurella multocida obtained from cattle and saigas. The study aimed to investigate the properties of P. multocida isolated from saigas and cattle during their seasonal migration, with a focus on its role in the epizootic process and potential transmission to farm animals. The research was conducted in a laboratory setting at the West Kazakhstan Agrarian-Technical University. White mice, saigas, and cattle were examined, and pathological and bacteriological analyses were performed on tissues and secretions. Pathogenicity, virulence, and toxigenicity of the isolated Pasteurella cultures were determined through biological tests on white mice. The morphological, cultural, and biochemical properties of the isolates were studied using standard microbiological methods. The study found that P. multocida isolates from both saigas and cattle exhibited high pathogenicity and virulence when tested on white mice. The isolates from sick and dead animals displayed 65.3 and 83.3% pathogenicity, respectively. The isolates were toxic to white mice, with filtrate dilutions showing 100% toxigenicity. Comparative analysis showed morphological and cultural similarities between Pasteurella isolates from saigas and cattle, confirming their identity. This research demonstrates that P. multocida, isolated from both saigas and cattle, contributes to the epizootic process and poses a threat to farm animals. Saigas, in particular, play a role in disease transmission during seasonal migrations. Understanding the ecological interactions between wild and farm animals is crucial for implementing preventive measures to control the spread of infectious diseases, emphasizing the need for comprehensive monitoring and intervention strategies. Resumo O artigo descreve dados do estudo das propriedades culturais, morfológicas e bioquímicas e da patogenicidade e virulência de isolados epizoóticos de Pasteurella multocida obtidos de bovinos e saigas. A pesquisa foi conduzida em laboratório na Universidade Técnica Agrária do Cazaquistão Ocidental. Camundongos brancos, saigas e bovinos foram examinados, e análises patológicas e bacteriológicas foram realizadas em tecidos e secreções. A patogenicidade, virulência e toxigenicidade das culturas isoladas de Pasteurella multocida foram determinadas através de testes biológicos em camundongos brancos. As propriedades morfológicas, culturais e bioquímicas dos isolados foram estudadas utilizando métodos microbiológicos padrão. O estudo descobriu que isolados de P. multocida tanto de saigas quanto de gado exibiram alta patogenicidade e virulência quando testados em camundongos brancos. Os isolados de animais doentes e mortos apresentaram patogenicidade de 65,3 e 83,3%, respectivamente. Os isolados foram tóxicos para camundongos brancos, com diluições de filtrado apresentando 100% de toxigenicidade. A análise comparativa mostrou semelhanças morfológicas e culturais entre isolados de Pasteurella de saigas e bovinos, confirmando sua identidade. Esta pesquisa demonstra que P. multocida, isolado tanto de saigas quanto de gado, contribui para o processo epizoótico e representa uma ameaça para os animais de fazenda. As saigas, em particular, desempenham um papel na transmissão de doenças durante as migrações sazonais. Compreender as interações ecológicas entre animais selvagens e de criação é crucial para a implementação de medidas preventivas para controlar a propagação de doenças infecciosas, enfatizando a necessidade de estratégias abrangentes de monitorização e intervenção.

Mannheimia haemolytica is a major bacterial pathogen associated with respiratory diseases in domestic ruminants, resulting in devastating economic losses in the global food production industry. This study aimed to isolate and assess the antibiotic resistance/sensitivity patterns of M. haemolytica associated with pneumonic pasteurellosis in sheep in the western Gojjam and Awi zones of Northwest Ethiopia. One hundred and forty nasal swabs from sheep were collected using purposive sampling and subjected to standard bacteriological and polymerase chain reaction (PCR) assays. The antibiotic susceptibility of the isolates was assessed using Kirby-Bauer's disk diffusion method. The findings of this study revealed that M. haemolytica was the primarily identified agent of pneumonic pasteurellosis in sheep. Molecular analysis confirmed 23 M. haemolytica isolates. The antibiotic susceptibility test results showed sensitivity to oxytetracycline (78.3%), streptomycin (78.3%), chloramphenicol (87%), kanamycin (100%), gentamicin (100%) and ampicillin (100%), and resistance to erythromycin (100%). Four isolates showed multidrug resistance with a MAR index greater than 0.3. The findings underscore the potential role of M. haemolytica in causing pneumonic pasteurellosis in sheep in the region. In this study, due to resource limitations, further serotype determination and characterization of antigenic relationships among the isolates were not conducted. Molecular characterization of strains using high-throughput sequencing technologies is needed to elucidate the molecular mechanisms of pathogenesis and develop more effective, widely applicable vaccines and antimicrobial drugs.

Small ruminant production plays a great role in the livelihood of smallholder farmers. But their production is constrained by pneumonic pasteurellosis. It is a high-priority issue at the national level. So, in this paper, relevant aspects of pneumonic pasteurellosis in small ruminants are reviewed. The disease is most frequent as air is the main route of transmission. They are characterized by high fever, coughing, dyspnoea and muco-purulent nasal discharge that commonly develops in immunocompromized hosts. Stressors being psychological and/or physical are associated with poor management practices. It is a multifactorial disease. But clinical infections are mainly caused by Mannheimia haemolytica, Bibersteinia trehalosi and Pasteurella multocida. Eleven of the known 17 serotypes of M. haemolytica and B. trehalosi have so far been identified in Ethiopia. Virulence factors like cell capsules, fimbriae and endotoxin play a great role in disease development. The disease causes heavy losses that deserve control. However, the presence of multiple serotypes without cross-protection and the development of drug resistance complicated its control. Moreover, the causative agents are normal commensal of the upper respiratory tract which may cause infection in immunocompromized conditions. Therefore, proper management, sound diagnostic methods and the available serotypes should be considered in vaccine preparation.

Porcine pasteurellosis is an infectious disease caused by Pasteurella multocida ( P. multocida ), which seriously endangers the healthy development of pig breeding industry. Early detection of disease transmission in animals is a crucial early warning for humans. Therefore, predicting risk areas for disease is essential for public health authorities to adopt preventive measures and control strategies against diseases. In this study, we developed a predictive model based on multi-criteria decision analysis (MCDA) and assessed risk areas for porcine pasteurellosis in the Chinese mainland. By using principal component analysis, the weights of seven spatial risk factors were determined. Fuzzy membership function was used to standardize all risk factors, and weight linear combination was used to create a risk map. The sensitivity of the risk map was analyzed by calculating the mean of absolute change rates of risk factors, as well as calculating an uncertainty map. The results showed that risk areas for porcine pasteurellosis were predicted to be locate in the south-central of the Chinese mainland, including Sichuan, Chongqing, Guangdong, and Guangxi. The maximum standard deviation of the uncertain map was less than 0.01and the ROC results showed that the prediction model has moderate predictive performance with the area under the curve (AUC) value of 0.80 (95% CI 0.75–0.84). Based on the above process, MCDA was combined with WebGIS technology to construct a system for predicting risk areas of porcine pasteurellosis. Risk factor data was directly linked to the developed model, providing decision support for disease prevention and control through monthly updates.