Pasteurella Multocida Isolates Research Articles

Comparative Minimum Inhibitory and Mutant Prevention Drug Concentrations for Pradofloxacin and Seven Other Antimicrobial Agents Tested against Bovine Isolates of Mannheimia haemolytica and Pasteurella multocida.

Pradofloxacin-a dual-targeting fluoroquinolone-is the most recent approved for use in food animals. Minimum inhibitory and mutant prevention concentration values were determined for pradofloxacin, ceftiofur, enrofloxacin, florfenicol, marbofloxacin, tildipirosin, tilmicosin, and tulathromycin. For M. haemolytica strains, MIC50/90/100 values were ≤0.016/≤0.016/≤0.016 and MPC50/90/100 values were 0.031/0.063/0.063; for P. multocida strains, the MIC50/90/100 values ≤0.016/≤0.016/0.031 and MPC50/90/100 ≤ 0.016/0.031/0.063 for pradofloxacin. The pradofloxacin Cmax/MIC90 and Cmax/MPC90 values for M. haemolytica and P. multocida strains, respectively, were 212.5 and 53.9 and 212.5 and 109.7. Similarly, AUC24/MIC90 and AUC24/MPC90 for M. haemolytica were 825 and 209.5, and for P. multocida, they were 825 and 425.8. Pradofloxacin would exceed the mutant selection window for >12-16 h. Pradofloxacin appears to have a low likelihood for resistance selection against key bovine respiratory disease bacterial pathogens based on low MIC and MPC values.

Isolation and Identification of Pasteurella multocida and Mannheimia haemolytica from Pneumonic Small Ruminants and Their Antibiotic Susceptibility in Haramaya District, Eastern Ethiopia.

Pasteurella species are frequently encountered as serious diseases in small ruminants. It is the main cause of respiratory pasteurellosis in sheep and goats of all age groups. The cross-sectional study was conducted from December 2022 to April 2023 in Haramaya district, eastern Ethiopia, to isolate and identify Pasteurella multocida and Mannheimia haemolytica and estimate their prevalence, associated risk factors, and antimicrobial sensitivity of isolates in small ruminants using a purposive sampling method. A total of 384 samples (156 nasal swabs from clinic cases and 228 lung swabs from abattoir cases) were collected. STATA 14 software was used to analyze the data. In addition, multivariable logistic regression analysis was performed to assess an association of risk factors. Out of the 384 samples examined, 164 were positive for pasteurellosis, resulting in a 42.70% prevalence. Similarly, 63 (38.4%) of the 164 positive results were from nasal swabs, while 101 (61.6%) came from lung samples. M. haemolytica accounted for 126 (76.82%) of the isolates, while P. multocida accounted for 38 (23.17%). Of the 63 nasal swab isolates, 33 (37%) were from goats and 30 (42.8%) were from sheep. And 17 (10.89%) and 46 (29.58%), respectively, were P. multocida and M. haemolytica. Of the 46 (40%) of the 101 (44.3%) isolates of the pneumonic lung, samples were from goats, while 55 (48.47%) were from sheep. In this study, the risk factors (species, age, and body condition score) were found to be significant (p < 0.05). Pasteurella isolates evaluated for antibiotic susceptibility were highly resistant to oxacillin (90.90%), followed by gentamycin (72.72%), and penicillin (63.63%). However, the isolates were highly sensitive to chloramphenicol (90.90%), followed by tetracycline (63.63%), and ampicillin (54.54%). This study showed that M. haemolytica and P. multocida are the common causes of mannheimiosis and pasteurellosis in small ruminants, respectively, and isolates were resistant to commonly used antibiotics in the study area. Thus, an integrated vaccination strategy, antimicrobial resistance monitoring, and avoidance of stress-inducing factors are recommended.

Properties of Pasteurella multocida isolated from animals during the seasonal migration of saigas.

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.

Evaluasi Efektivitas Antibiotik Komersil Terhadap Agen Penyebab Gejala Snot pada Ayam Broiler di Kabupaten Kupang

Snot is a symptom of upper respiratory system infections in poultry, characterized by exudate production from the nasal cavity, swelling of infraorbital sinuses, snoring, sneezing, and dyspnoea. The aetiology of snot that have been isolated are Avibaterium paragallinarum, Pasteurella multocida, Ornithobacterium rhinotracheale, and Mycoplasma sp. Snot symptom can be eradicated with antibiotic treatment; however, antibiotic resistance makes antibiotic treatment ineffective. This study is aimed to evaluate the effectiveness of some commercial antibiotics against bacteria isolated from broiler chicken with snot symptom in Kupang Regency. Amoxycillin, ampicillin, tetracycline, cefoxitin, and ciprofloxacin were tested using the Kirby Bauer method with McFarland Turbidity Standard against Avibacterium paragallinarum, Ornithobacterium rhinotracheale, Pasteurella multocida, and Mycoplasma sp isolates. Inhibition zones were measured and compared to the standard of the Clinical Laboratory Standard Institute (CLSI) to determine the sensitivity or resistance percentage. The result showed that Avibacterium paragallinarum, Ornithobacterium rhinotracheale, Pasteurella multocida, and Mycoplasma sp were highly resistant to amoxycillin and ampicillin, yet most sensitif to ciprofloxacin. This suggests commercial antibiotics that are productive to eradicate snot symptom and implies some antibiotics that are ineffective to overcome snot symptom and hence should not be used in the field.

Isolation and Molecular Detection of Mannheimia haemolytica and Pasteurella multocida from Clinically Pneumonic Pasteurellosis Cases of Bonga Sheep Breed and Their Antibiotic Susceptibility Tests in Selected Areas of Southwest Ethiopian Peoples Regional State, Ethiopia.

Pneumonic pasteurellosis is a respiratory system disease of sheep caused by Mannheimia haemolytica, Pasteurella multocida, and Bibersteinia trehalosi responsible for the low productivity and economic loss resulting from death and treatment costs. This study was conducted to isolate and molecularly detect causative agents and antibiotic susceptibility tests from a nasal swab sample of the Bonga sheep breed that was suspected to have pneumonic pasteurellosis in selected areas of Southwest Ethiopian Peoples Regional State. A cross-sectional study design was used along with purposive sampling of nasal swab samples from sheep that were brought to veterinary clinics during the study period. Bacterial isolation and phenotypic characterization were carried out using microbiological and biochemical tests that followed standard microbiological techniques. To molecularly confirm the isolates, PHSSA and KMT1, species-specific PCR primer genes were used. Using the disc diffusion method, molecularly confirmed isolates were subjected to an in vitro antibiotic susceptibility test. The 85 samples that were scrutinized had an overall isolation rate of 31.76%, whereas the isolates of Pasteurella multocida and Mannheimia haemolytica had species compositions of 40.7% and 59.25%, respectively. Overall, 12.5% of the Mannheimia haemolytica and 18.18% of the Pasteurella multocida species were verified from phenotypical isolates using the species-specific PCR primer genes PHSSA and KMT1, respectively. An in vitro antibiotic susceptibility test was carried out on all four PCR-confirmed isolates for seven commonly used antibiotics used to treat ovine pasteurellosis in the study area. It was found that both bacterial species were resistant to chloramphenicol and penicillin G. Using phenotypic and molecular diagnostic techniques, the results of our current inquiry revealed that Pasteurella multocida and Mannheimia haemolytica are the causative agents of ovine pneumonic pasteurellosis in the study area.

Complete genomes of Pasteurella multocida isolates from porcine, bovine, and cervine samples found in New Zealand farms.

Here, we present complete genome assemblies of Pasteurella multocida strains isolated from porcine, bovine, and cervine farms as part of bacteriology incursion investigations to identify pathogens that might present a sanitary risk to New Zealand.

Susceptibility trends of swine respiratory pathogens from 2019 to 2022 to antimicrobials commonly used in Spain

BackgroundAntimicrobial resistance is one of the most important health challenges in humans and animals. Antibiotic susceptibility determination is used to select the most suitable drug to treat animals according to its success probability following the European legislation in force for these drugs. We have studied the antibiotic susceptibility pattern (ASP) of Actinobacillus pleuropneumoniae (APP) and Pasteurella multocida (PM) isolates, collected during the period 2019–2022 in Spain. ASP was measured by determining minimum inhibitory concentration using standardized laboratory methods and its temporal trend was determined by logistic regression analysis of non-susceptible/susceptible isolates using clinical breakpoints.ResultsIt was not observed any significant temporal trends for susceptibility of Actinobacillus pleuropneumoniae to ceftiofur, florfenicol, sulfamethoxazole/trimethoprim, tulathromycin and tildipirosin during the study period (p > 0.05). Contrarily, a significant temporal trend (p < 0.05) was observed for quinolones (enrofloxacin and marbofloxacin), tetracyclines (doxycycline and oxyteracycline), amoxicillin, tiamulin and tilmicosin. On the other hand, it was not observed any significant temporal trends for susceptibility of Pasteurella multocida to quinolones (enrofloxacin and marbofloxacin), amoxicillin, ceftiofur, florfenicol and macrolides (tildipirosin, tulathromycin and tilmicosin) during the study period (p > 0.05). Contrarily, a significant temporal trend (p < 0.05) was observed for tetracyclines (oxyteracycline), tiamulin and sulfamethoxazole/trimethoprim.ConclusionsIn general terms, pig pathogens (APP and PM) involved in respiratory diseases analysed herein appeared to remain susceptible or tended to increase susceptibility to antimicrobials over the study period (2019–2022), but our data clearly showed a different pattern in the evolution of antimicrobial susceptibility for each combination of drug and microorganism. Our results highlight that the evolution of antimicrobial susceptibility must be studied in a case-by-case situation where generalization for drug families and bacteria is not possible even for bacteria located in the same ecological niche.

Pathognomonic features of Pasteurella multocida isolates among various avian species in Sharkia Governorate, Egypt

The present study aimed to isolate Pasteurella multocida (P. multocida) from pulmonary cases in several avian species and then investigate the histopathological features, antimicrobial resistance determinants, virulence characteristics, and risk factors analysis of the isolates in each species in correlation with epidemiological mapping of pasteurellosis in Sharkia Governorate, Egypt. The obtained data revealed a total occurrence of 9.4% (30/317) of P. multocida among the examined birds (chickens, ducks, quails, and turkeys). The incidence rate was influenced by avian species, climate, breed, age, clinical signs, and sample type. Antimicrobial susceptibility testing revealed that all isolates were sensitive to florfenicol and enrofloxacin, while 86.6 and 73.3% of the isolates displayed resistance to amoxicillin-clavulanic acid and erythromycin, respectively. All of the P. multocida isolates showed a multiple-drug resistant pattern with an average index of 0.43. Molecular characterization revealed that the oma87, sodA, and ptfA virulence genes were detected in the all examined P. multocida isolates. The ermX (erythromycin), blaROB-1 (β-lactam), and mcr-1(colistin) resistance genes were present in 60, 46.6, and 40% of the isolates, respectively. Ducks and quails were the most virulent and harbored species of antimicrobial-resistant genes. These results were in parallel with postmortem and histopathological examinations which detected more severe interstitial pneumonia lesions in the trachea and lung, congestion, and cellular infiltration especially in ducks. Epidemiological mapping revealed that the Fakous district was the most susceptible to pasteurellosis infection. Thus, farmers are recommended to monitor their flocks for signs of respiratory disease, seek veterinary care promptly if any birds are sick, and avoid the random usage of antibiotics. In conclusion, this study presents a comprehensive picture of the risk factors in correlation to the pathognomonic characteristics of P. multocida infection in poultry sectors to help in developing more effective strategies for prevention and control.

Differentiating airway inflammation in calves based on cluster analysis of bronchoalveolar lavage fluid cytology.

Nonbronchoscopic bronchoalveolar lavage (nBAL) is routinely performed in calves, and airway cytology has great potential in airway disease diagnostics. A good reference framework for nBAL cytology is lacking. To distinguish different cytological profiles in nBAL from grouped housed calves using cluster analysis, and characterize these profiles on individual and herd levels. Three hundred thirty-eight group-housed calves from 60 herds (mainly dairy and beef ). Cross-sectional study. Differential counts of white blood cells were determined on nBAL fluid, followed by differentiation of cytological profiles by K-means-based cluster analysis. These profiles were characterized by reference values, decision tree analysis, and associations with clinical, ultrasonographic, bacteriological, and cytological features. A normal (55.9%), a neutrophilic (41.1%), and an eosinophilic profile (3.0%) were identified. The normal profile was characterized by reference values of 2.3% to 47.4% neutrophils, 35.1% to 95.1% macrophages, 0.4 to 22.9% lymphocytes, and 0.0% to 0.9% eosinophils. The neutrophilic profile was characterized by ≥44.5% neutrophils, <1.6% eosinophils, and <11.5% lymphocytes. This profile was associated with the isolation of Pasteurella multocida, the presence of neutrophils with toxic granulation, and the presence of phagocytosed bacteria in neutrophils. The eosinophilic profile was characterized by eosinophils ≥1.6% (neutrophilia present) or ≥2.4% (neutrophilia absent), and associated with the presence of mast cells. On herd level, the neutrophilic and eosinophilic profiles were present in 85.0% and 15.0% of the herds, respectively. This study provides a first step in the development of cytological guidelines, aiding the assessment of airway health and inflammation in calves through nBAL fluid cytology.

MOLECULAR CHARACTERIZATION, ANTIBIOTIC SUSCEPTIBILITY AND BIOFILM FORMING ABILITY OF PASTEURELLA MULTOCIDA ISOLATED FROM THE RESPIRATORY MICROBIOTA OF HEALTHY BOVINES

Livestock plays an important role in the economy of the country because it provides food producing animals. Pasteurella multocida which is an opportunistic pathogen of upper respiratory tract of animals and it has been known to cause many harmful diseases may survive in animal body by forming biofilm in different organs. So, the presence of this bacterium in animals may lead to transfer and threaten the human health by food chain. In the last few years, one of the major problems that alarms and evokes a major horrific threat to human being is the bacterial resistance to antimicrobial agents. Due to deficiency of antimicrobial agents in pipeline and emergence of new mechanisms of intra antimicrobial resistance, many surveillance programs have been set up for its containment. Many factors are responsible for this grave situation like high use of antibiotics in animals. So, the current study concluded that all of the 76 isolates of Pasteurella multocida out of 100 samples were confirmed through PCR and found sensitive to florfenicol (100%), gentamycin (92.11%), chloramphenicol (84.21%) and kanamycin (72.37%) respectively. For tetracycline and neomycin sensitivity were (69.73%) and (64.47%) respectively against the bacteria. Whereas tilmicosin and spectinomycin sensitivity were recorded as (30.27%) and (23.69%). Streptomycin (19.73%), sulfadiazine (7.89%), erythromycin (3.94%) and clindamycin (0.0 %) were least sensitive. It was also concluded that when all pure isolates of Pasteurella multocida were tested for Biofilm assay out of 76 isolates categorized as: non biofilm producer (7.89%), weak biofilm producer (34.21%), moderate biofilm producer (46.05%) and strong biofilm producer (11.84%). Hence, it was concluded that Pasteurella multocida isolated from cattle and buffaloes were found to form biofilm in in-vitro condition.

Genotypic Comparison of Pasteurella multocida from Healthy Animals at Entry to the Feedlots with That and from Bovine Respiratory Disease-Affected Animals during the Fattening Period.

The aim of this study was to investigate the possible genotypic differences between commensal Pasteurella multocida isolates from apparently healthy animals (AHA) at the time of entry to feedlots and those from BRD-affected animals (BRD-AA). A total of 20 batches of beef calves in seven feedlots were followed-up during the fattening period. P. multocida was isolated from 28.1% of AHA and 22.9% of BRD-AA. All isolates belonged to the A: L3 genotype. Most isolates from clinical cases (81.0%) grouped into a PFGE cluster were significantly associated with BRD cases (OR, 24.9; 95% CI, 6.4-96.2). The whole genomes of 14 isolates representative of the pulsotypes most frequently detected in BRD-AA and AHA were sequenced and compared with 53 bovine genomes belonging to the identified ST13, ST79, and ST80 genotypes for a global comparison. No differences were found in the virulence-associated gene content between sequence types (STs) globally or between BRD-AA and AHA isolates in this study. Significantly, ST79 isolates harbored ARGs, conferring resistance to different antimicrobials, including macrolides and tetracyclines, which are commonly used for the treatment of BRD. Two Spanish ST79 isolates carried an ICE highly similar to ICE Tn7407, which was recently detected in Germany, suggesting that ST79 P. multocida isolates in Europe and North America may be associated with different ICEs.

Agreement of antimicrobial susceptibility testing of Pasteurella multocida and Mannheimia haemolytica isolates from preweaned dairy calves with bovine respiratory disease.

Evaluate agreement among the antimicrobial susceptibility profiles of Mannheimia haemolytica or Pasteurella multocida obtained by transtracheal wash, nasal swab, nasopharyngeal swab, and bronchoalveolar lavage. 100 Holstein and Holstein-cross bull calves with bovine respiratory disease. Calves > 30 days old with naturally occurring bovine respiratory disease were sampled sequentially by nasal swab, nasopharyngeal swab, transtracheal wash, and then bronchoalveolar lavage. Samples were cultured, and for each antimicrobial, the MIC of 50% and 90% of isolates was calculated, and isolates were categorized as susceptible or not. Categorical discrepancies were recorded. Percent positive agreement and kappa values were calculated between isolates for each of the sampling methods. Antimicrobial susceptibility varied by pathogen and resistance to enrofloxacin, florfenicol, tilmicosin, and spectinomycin was detected. Minor discrepancies were seen in up to 29% of classifications, with enrofloxacin, penicillin, and florfenicol more frequently represented than other drugs. Very major and major discrepancies were seen when comparing florfenicol (1.9%) and tulathromycin (3.8 to 4.9%) across sampling methods. Some variability was seen in agreement for enrofloxacin for several comparisons (8.3 to 18.4%). Susceptibility testing of isolates from 1 location of the respiratory tract can reliably represent susceptibility in other locations. Nevertheless, the potential for imperfect agreement between sampling methods does exist. The level of restraint available, the skill level of the person performing the sampling, the age and size of the animal, disease status, and treatment history all must be factored into which test is most appropriate for a given situation.

First study on capsular serotypes and virulence factors of Pasteurella multocida isolates from Phan Rang sheep in Vietnam.

Pasteurella multocida is considered as a main factor mediating pneumonic pasteurellosis in ruminants, including sheep. It is also a current threat to Phan Rang sheep in Vietnam. This study aimed to characterize P. multocida isolated from Phan Rang sheep, their antibiotic resistance profile, and the prevalence of some virulence-associated genes of these strains. Bacteria were isolated on brain heart infusion, 10% sheep blood agar plates, and screened by biochemical tests. The polymerase chain reaction technique was used with specific primers to identify P. multocida, the presence of virulence-associated genes, and serotypes of isolates. Antimicrobial susceptibility and biofilm formation of isolates were examined using the disk diffusion method and crystal violet-based method, respectively. A total of 41 P. multocida strains were isolated from 485 samples from clinically sick and healthy sheep. Of the isolates, 58.53% were serotype A, 9.75% were serotype B, and 31.71% were serotype D. Healthy animals were infected with serotype D only. All 15 virulence genes were identified in all strains isolated from clinically sick sheep, while strains isolated from healthy sheep carried 11/15 virulence genes tested. Among virulence-associated genes exbB, exbD, tonB, ompA, oma87, fimA, hgbA, and nanB were detected in over 90% of isolates, whereas hgbB, nanH, tbpA and pfhA were less frequent. Interestingly, pmHAS and tadD were highly prevalent in capsular type A strains, whereas the toxA gene was detected in capsular type D strains only. All of the isolated strains were fully susceptible to enrofloxacin, ciprofloxacin, neomycin, and ofloxacin. About 92.68% were susceptible to chloramphenicol and 90.24% to amikacin, but there was high resistance to erythromycin, tetracycline, and amoxicillin. Our results reveal that 53.65% of 41 isolates could produce biofilm, whereas 46.34% could not. Pasteurella multocida from Phan Rang sheep possess many virulence genes and resistance to several common antibiotics such as erythromycin, tetracycline, and amoxicillin. The results are an important warning regarding antibiotic resistance of P. multocida.

Investigation of the Effectiveness of Chromogenic Media in the Isolation of Pasteurella multocida and Mannheimia haemolytica from Calf Nasal Swab Samples

Investigation of the Effectiveness of Chromogenic Media in the Isolation of Pasteurella multocida and Mannheimia haemolytica from Calf Nasal Swab Samples

Pasteurella multocida Infection in Duck, Detection of Virulence Genes and Antimicrobial Susceptibility of the Isolates

Pasteurella multocida is a gram negative bacterium causing respiratory diseases in many birds including ducks resulting in great morbidity and mortality rates among them. Seventy five samples were collected from air sacs, lungs, livers, hearts and spleens were collected from different duck flocks which selected randomly and hade respiratory manifestations and diarrhea. All samples subjected to bacteriological examination for the presence of Pasteurella multocida (P. multocida). The results showed that Pasteurella multocida was isolated in a prevalence rate of as 13%. All isolates were identified by vitek 2 system. The virulence genes of two random isolates of Pasteurella multocida (toxA , tbpA and pfhA ) were detected by PCR. The results of antibiotic sensitivity test proved that the isolates were resistant to Cefalexin, Cefpodoxime, Ceftiofur, Amikacin, Nitrofurantoin, Trimethoprim, Rifampicin and Tetracycline. While the isolates were sensitive to Ampicillin, Amoxicillin/clavunic acid, Piperacillin, Cefpirome, Imipenen and Trimethoprim/Sulfamethoxazle. The three examined virulence genes were detected in both samples.

Molecular evaluation of sheep and goats isolates of Pasteurella multocida and their antibiotic resistance.

Pasteurella multocida exists as a commensal in the upper respiratory tracts of livestock, and poultry, and causes a wide variety of diseases in humans and animals. This study aimed to investigate the incidence of P. multocida by bacteriological and molecular characterization in sheep and goats and screening the existence of capsule-specific genes and their antibiotic resistance pattern. Totally, 1650 nasopharyngeal swabs were collected from apparently healthy sheep and goats and 460 lung tissues were collected from slaughtered animals in Fars province, Iran. All samples were cultured and suspected colonies were examined by biochemical tests, antimicrobial assay and polymerase chain reaction (PCR). Among 165 P. multocida (104 sheep and 61 goats) isolates, the capA, capD, and capB genes were amplified in 98, 48, and 12 isolates, respectively. The occurrence of four virulence-associated genes of P. multocida isolates were determined by PCR. Most isolates harbored the toxA (79.40%) and hgbB genes (70.90%) and 59.40% of isolates had the pfhA gene. Almost half of the isolates (46.10%) contained the tbpA gene. According to the current study, P. multocida capsular type A had the most frequency followed by type D. In addition, the high frequency of tbpA, pfhA, toxA, and hgbB genes revealed that these genes are possibly important in the pathogenesis of P. multocida. Oxytetracycline, enrofloxacin, florfenicol, and tilmicosin were the most effective drugs.

The in-vitro Antibiotic Sensitivity Test of Pasteurella multocida Isolated from Layer and Breeder Chickens

The current study aimed to characterize Pasteurella multocida (P. multocida) isolates from layers and breeder chickens in Egypt regarding in-vitro antibiotic sensitivity and resistance pattern. In doing so, spleen, liver, lungs, and heart, were taken aseptically from chickens suffering from a drop in egg production, septicemia, respiratory manifestations, and mortalities between 2016 and 2017. To isolate bacteria, samples were grown on a modified Das medium. Moreover, microscopic appearance and biochemical characteristics were used to identify pure colonies of P. multocida isolates. In the next step, in-vitro antibiotic sensitivity testing was performed on the isolated P. multocida. The findings indicated that P. multocida was found in 36 isolates out of 330 investigated chicken flocks. Small glistering, mucoid, grayish, and dew drop P. multocida colonies were discovered during the culture analysis. Pasteurella multocida isolates were Gram-negative coccobacilli using the microscope. Catalase, indole generation, H2S production, nitrate reduction, and oxidase tests were all positive for the sample; however, methyl red, urease activity, Voge's proskaur, and gelatin liquefaction tests were all negative. They also fermented glucose, mannose, fructose, sucrose, mannitol, xylose, and sorbitol without producing gas but not lactose, arabinose, maltose, inositol, salicin, raffinose, or dulcitol. Isolated P. multocida strains were sensitive to tetracycline, erythromycin, trimethoprim/sulphamethoxazole, norfloxacin, ofloxacin, penicillin, chloramphenicol, and azithromycin, while resistant to ampicillin and clindamycin. Cefoperazone, gentamycin, and streptomycin all showed intermediate sensitivity.

Molecular Epidemiology of Pasteurella multocida Associated with Bovine Respiratory Disease Outbreaks

Studies that characterize bovine respiratory disease (BRD)-associated Pasteurella multocida isolates are scarce compared with research on isolates from other hosts and clinical backgrounds. In the present study, 170 P. multocida isolates from 125 BRD outbreaks were characterized by capsular and LPS typing as well as by virulotyping. Three capsular types (A, B, F) and three LPS genotypes (L2, L3, L6) were identified. Capsular and LPS typing revealed a very low genetic diversity (GD = 0.02) among P. multocida, with most isolates belonging to genotype A:L3 (97.6%). Virulotyping identified seven virulence-associated gene profiles, with two profiles including 95.9% of the isolates. A subset of isolates was further characterized by MLST and PFGE. The sequence types ST79 and ST13 were the most frequently identified and were grouped into the same clonal complex (CC13), a result that supports the clonal population structure of BRD-associated P. multocida isolates. PFGE typing also revealed a low genetic diversity (GD = 0.18), detecting a single pattern in 62.5% of the outbreaks in which multiple isolates were analyzed. Overall, 85.2% of the isolates belonged to pulsotypes with at least 80% genetic similarity, consistent with a clonal population structure observed by MLST analysis and corroborating the genetic relatedness of most P. multocida isolates associated with BRD in cattle.

Studija znakova patogenosti kod Pasteurella multocida, izolirane iz životinja različitih vrsta

A significant number of microorganisms in natural and artificial environments exist in a structured formation – biofilm. This formation attaches to a certain surface, particularly the epithelium. The ability to form a similar structure has been observed in Pasteurella multocida, the causative agent of anthropozoonoses that affect domestic and wild animals, birds, companion animals and humans. The spectrum of pathogenetic action of P. multocida is wide and associated with the development of respiratory and multisystemic pathology, bacteraemia and other manifestations. Timely detection of P. multocida and treatment of the diseases it causes in farm and domestic animals is important to limit economic losses and improve social security. The main objective of this study was to determine the pathogenicity of P. multocida, its ability to form a biofilm, its resistance to antibiotics, and to identify the genes responsible for the formation of dermonecrotic toxin and biofilm formation. The paper presents the results of a study of 11 isolates of P. multocida: six isolates (54.5%) from rabbits, two isolates (18.2%) from dogs, two isolates (18.2%) from cats, and one isolate from pigs (9.2%). In all isolates, the gene ptfA was detected. This gene encodes the formation of type 4 fimbriae and participates in the formation of the biofilm, and the studied cultures in vitro formed a biofilm of different densities. The genome of eight isolates (72.7%) included the toxA gene (provides the formation of dermonecrotic toxin), while 45.4% of isolates had a complete set of the studied signs of pathogenicity, both in phenotypic (biofilm formation, mortality for laboratory animals) and genotypic (presence of toxA, ptfA) traits, and three isolates (27.3%) showed signs of multidrug resistance. The virulence of the toxA-negative isolates of P. multocida was lower than in toxA-positive isolates. The culture with the highest virulence (0.5x 101 CFU) and extreme resistance to antibiotics formed a biofilm of the highest density. The association of the gene in the biofilm-producing mechanism needs further evaluation, and further research is needed to identify the relationships between pathogens in Pasteurella multocida isolates from different species of animals and humans.

Screening and purification of NanB sialidase from Pasteurella multocida with activity in hydrolyzing sialic acid Neu5Acα(2-6)Gal and Neu5Acα(2-3)Gal.

Study on sialidases as antiviral agents has been widely performed, but many types of sialidase have not been tested for their antiviral activity. Pasteurella multocida NanB sialidase is one such sialidase that has never been isolated for further research. In this study, the activity of NanB sialidase was investigated in silico by docking the NanB sialidase of Pasteurella multocida to the Neu5Acα(2–6)Gal and Neu5Acα(2–3)Gal ligands. Additionally, some local isolates of Pasteurella multocida, which had the NanB gene were screened, and the proteins were isolated for further testing regarding their activity in hydrolyzing Neu5Acα(2–6)Gal and Neu5Acα(2–3)Gal. Silico studies showed that the NanB sialidase possesses an exceptional affinity towards forming a protein–ligand complex with Neu5Acα(2–6)Gal and Neu5Acα(2–3)Gal. NanB sialidase of Pasteurella multocida B018 at 0.129 U/mL and 0.258 U/mL doses can hydrolyze Neu5Acα(2–6)Gal and Neu5Acα(2–3)Gal better than other doses. In addition, those doses can inhibit effectively H9N2 viral binding to red blood cells. This study suggested that the NanB sialidase of Pasteurella multocida B018 has a potent antiviral activity because can hydrolyze sialic acid on red blood cells surface and inhibit the H9N2 viral binding to the cells.