Explore the vast range of titles available.

Pasteurella multocida is incriminated in fowl cholera in poultry and snuffles in rabbits, causing significant economic losses in the poultry industry worldwide. This study investigated the prevalence, kmt 1 gene sequencing, antibiogram, pathogenicity, and PCR detection of the virulence and resistance genes of P. multocida recovered from chickens, ducks, and rabbits. Approximately 150 samples were collected from diseased chickens, ducks, and rabbits (50 for each) from commercial farms in Ismailia government, Egypt. The collected samples were bacteriologically examined, and the recovered isolates were subsequently subjected to kmt 1 gene sequencing, antibiogram, pathogenicity test, and PCR-based detection of virulence and antibiotic resistance genes. The overall prevalence of P. multocida was 20% (30/150). The highest prevalence was recorded in rabbits (24%; 12/50), followed by ducks (20%; 10/50) and chickens (16%; 8/50). The lung was the most predominant infected organ. Moreover, the kmt 1 phylogenetic analysis emphasized that the tested P. multocida strains presented remarkable genetic identity with other P. multocida strains from the USA, Denmark, China, India, and Iran. Chloramphenicol and ciprofloxacin exhibited promising results in treating P. multocida . Moreover, the prevalence of oma 87, ptf A, lux S, tad G, and nan B virulence genes was 100%, 86.7%, 76.6%, 73.3%, and 56.7% respectively. Herein, 13.3% of the tested strains were multidrug-resistant (MDR) to 5 antibiotic classes and carried bla ROB−1 and tet H genes. Besides, 10% of the tested P. multocida strains were extensively drug resistant (XDR) to 7 antibiotic classes and harbored the bla ROB−1 , tet H, and erm X genes. Moreover, 10% of the recovered P. multocida strains were MDR to 5 antibiotic classes and had tet H and erm X genes. Pathogenicity test revealed that the mortality rate was 20% at 1 day post-infection, reaching its highest point (100%) at 2 days post-infection. Briefly, this study highlights the occurrence of MDR and XDR P. multocida in domestic birds and rabbits, revealing a public health threat. The oma 87, ptf A, luxS , and tad G virulence genes and the bla ROB−1 , tet H, and erm X antibiotic resistance genes are usually associated with emerging MDR P . multocida strains.

Background Hemorrhagic septicemia is a highly fatal disease of cattle caused by the bacteria; Pasteurella multocida serotypes B and E in Asia and Africa respectively. Even though the capsular serotype E is considered to be the common cause of Hemorrhagic septicemia in Africa, there is not enough evidence that other serotypes are not involved. Furthermore, the serotypes currently circulating in South West Ethiopia have not been identified. This study was carried out to identify circulating capsular serotypes of Pasteurella multocida and assess its antimicrobial resistance on hemorrhagic Septicemic cattle through bacterial isolation, molecular identifications, and antimicrobial susceptibility tests in Keffa and Bench Sheko Zones of South West Ethiopia Peoples’ Regional State. Results The bacteriological analysis from 45 purposively collected nasopharyngeal swab samples of hemorrhagic Septicemic cattle revealed that 12 (26.7%) isolates were identified as Pasteurella multocida. Similarly, the molecular analysis of these isolates revealed all twelve (12) isolates were confirmed to be Pasteurella multocida. On further capsular typing, serotype B ( n  = 5, 41.6%) and E ( n  = 5, 41.6%) were the confirmed circulating strains in the area while two ( n  = 2, 16.6%) isolates formed non-specific bands. All the Pasteurella multocida isolates were susceptible to Gentamicin (100%), Chloramphenicol (100%), Oxytetracycline (91.7%), and Streptomycin (75%). However, all the isolates showed multidrug resistance (100%), to four antibiotics “Ampicillin, Clindamycin, Penicillin-G, and Vancomycin”. Conclusions Molecular analysis of the study isolates confirmed serotypes B and E as the etiology for Hemorrhagic septicemia in cattle in the study area. A multivalent vaccine comprising serotypes B and E is recommended to prevent outbreaks along with early treatment of suspected cases during the pyretic stage using antibiotics that are effective against the strains.

The zoonotic bacterium Pasteurella multocida infects a wide range of animals worldwide. While the genetic diversity of this pathogen is well described in production animals, it remains underexplored in companion animals. In Australia, most P. multocida genomes come from commercial poultry. Here, 59 P. multocida clinical isolates obtained from Australian pets, (cats, dogs, rabbits), farm animals (birds, ruminants, porcine) and captive wildlife (Quolls, Serval) between 2006 and 2023 were sequenced and compared to 523 representative RefSeq genomes. Clustering and phylogenomic analyses placed 24/25 Australian pet isolates in a long-branched clade containing several MLST profiles (ST36, ST37, ST171, ST359, ST451 and ST527) also found in human isolates. Genotypes associated with Australian production animals (e.g., ST8, ST9 and ST20 from poultry, ST79 and ST394 from cattle) fell in the main branch of the tree. Minimum spanning tree and SNP analyses suggested several occurrences of cross-species transmission. Mobile genetic elements were found across the P. multocida population, without clustering into any specific phylogenetic, host, or geographic group. However, a 1.8 kb cryptic plasmid (Acc. U51470), previously described in Pasteurella canis strains from South Korea, was detected in 99/289 (34.3%) Australian P. multocida isolates from various hosts, while being largely absent from the rest of the world. Antimicrobial resistance was not detected in the isolates from Australian companion animals and captive wildlife. However, resistances to tetracyclines in bovine isolates (2/10) and ampicillin in avian (1/17) isolates were identified. This study greatly expands our insights on the diversity of P. multocida genomes from Australian companion animals and provides the basis for wider investigations on the molecular epidemiology and diversity of this pathogen, with potential applications to better understand the zoonotic risks associated with this pathogen.

Pasteurella multocida is an important multihost animal and zoonotic pathogen that is capable of causing respiratory and multisystemic diseases, bacteremia, and bite wound infections. The glycosaminoglycan capsule of P. multocida is an essential virulence factor that protects the bacterium from host defenses. However, chronic infections (such as swine atrophic rhinitis and the carrier state in birds and other animals) may be associated with biofilm formation, which has not been characterized in P. multocida . Biofilm formation by clinical isolates was inversely related to capsule production and was confirmed with capsule-deficient mutants of highly encapsulated strains. Capsule-deficient mutants formed biofilms with a larger biomass that was thicker and smoother than the biofilm of encapsulated strains. Passage of a highly encapsulated, poor-biofilm-forming strain under conditions that favored biofilm formation resulted in the production of less capsular polysaccharide and a more robust biofilm, as did addition of hyaluronidase to the growth medium of all of the strains tested. The matrix material of the biofilm was composed predominately of a glycogen exopolysaccharide (EPS), as determined by gas chromatography-mass spectrometry, nuclear magnetic resonance, and enzymatic digestion. However, a putative glycogen synthesis locus was not differentially regulated when the bacteria were grown as a biofilm or planktonically, as determined by quantitative reverse transcriptase PCR. Therefore, the negatively charged capsule may interfere with biofilm formation by blocking adherence to a surface or by preventing the EPS matrix from encasing large numbers of bacterial cells. This is the first detailed description of biofilm formation and a glycogen EPS by P. multocida . IMPORTANCE Pasteurella multocida is an important pathogen responsible for severe infections in food animals, domestic and wild birds, pet animals, and humans. P. multocida was first isolated by Louis Pasteur in 1880 and has been studied for over 130 years. However, aspects of its lifecycle have remained unknown. Although formation of a biofilm by P. multocida has been proposed, this report is the first to characterize biofilm formation by P. multocida . Of particular interest is that the biofilm matrix material contained a newly reported amylose-like glycogen as the exopolysaccharide component and that production of capsular polysaccharide (CPS) was inversely related to biofilm formation. However, even highly mucoid, poor-biofilm-forming strains could form abundant biofilms by loss of CPS or following in vitro passage under biofilm growth conditions. Therefore, the carrier state or subclinical chronic infections with P. multocida may result from CPS downregulation with concomitant enhanced biofilm formation. Pasteurella multocida is an important pathogen responsible for severe infections in food animals, domestic and wild birds, pet animals, and humans. P. multocida was first isolated by Louis Pasteur in 1880 and has been studied for over 130 years. However, aspects of its lifecycle have remained unknown. Although formation of a biofilm by P. multocida has been proposed, this report is the first to characterize biofilm formation by P. multocida . Of particular interest is that the biofilm matrix material contained a newly reported amylose-like glycogen as the exopolysaccharide component and that production of capsular polysaccharide (CPS) was inversely related to biofilm formation. However, even highly mucoid, poor-biofilm-forming strains could form abundant biofilms by loss of CPS or following in vitro passage under biofilm growth conditions. Therefore, the carrier state or subclinical chronic infections with P. multocida may result from CPS downregulation with concomitant enhanced biofilm formation.

Background Pasteurella multocida causes progressive atrophic rhinitis and suppurative bronchopneumonia in pigs, which results in severe economic losses in swine industry. This study aimed to determine the serovar, genotype and prevalence of toxA virulence gene of Pasteurella multocida isolates collected in Taiwan. A total of 164 Pasteurella multocida isolates from 161 diseased pigs were characterized by serotyping, multilocus sequence typing (MLST), antimicrobial susceptibility testing, and the presence of virulence gene ( toxA ) and antibiotic resistance gene ( floR ). Results The majority of Pasteurella multocida strains were serovar D:L6 (48.2%; 79/164) followed by A:L6 (28.7%; 47/164) and A:L3 (19.5%; 32/164). More than 80% of strains carrying toxA gene belonged to serovar A:L6 (82.6%; 19/23). The MLST data showed five sequence types (STs), where multi-host ST10 was the most dominant. Most Pasteurella multocida strains of multi-host ST10 were serovar A:L6 (93.9%; 31/33), which suggested that STs were highly associated with specific serovars. Most of the floR -carrying Pasteurella multocida strains belonged to serovar D:L6 with significantly high resistance to some antimicrobial agents, especially florfenicol. Conclusions This study demonstrated that serovar D:L6 and multi-host ST10 was the most prevalent Pasteurella multocida strain in Taiwan. A:L6 accounted for the majority of tox A-positive strains and the presence of  floR gene may be responsible for the antimicrobial resistance to florfenicol.

Haemorrhagic septicaemia (HS), an acute and highly fatal disease of bovines in tropical countries of Africa and Asia, including India, is primarily caused by Pasteurella multocida serogroup B:2 strains. Although P. multocida strains are ubiquitous and known to infect a wide range of host species with varied clinical manifestations hitherto, the molecular basis of host tropism remains unknown. In this study, we present an integrated genomic, structural, and molecular dynamics framework to investigate how P. multocida serogroup B strains selectively adhere to bovine tissues. Comparative pangenomic analysis identified 115 genes significantly enriched in serogroup B strains, among which five lineage-specific putative adhesins were predicted through a multi-layer computational pipeline. In silico adhesin-fibronectin docking and interface energetics analyses identified preferential binding of these five adhesins to bovine fibronectin FnIII 9–10 domains, with markedly weaker interactions observed for non-bovine (caprine, pig, chicken and rabbit) homologues. Molecular dynamics simulations further revealed exceptional structural stability and favourable binding energetics for three adhesins (PACFBAAN_02021, PACFBAAN_00422 and PACFBAAN_00429), whereas two adhesins (PACFBAAN_01225 and PACFBAAN_01232) exhibited substantially lower adhesive performance. Together, these adhesins represent a potential molecular signature of bovine host tropism and warrant experimental validation for diagnostics, anti-adhesion therapeutics, and subunit vaccine development.

Pasteurella multocida (P. multocida), a pathogenic bacterium known to induce duck cholera, stands as a significant contributor to bacterial diseases afflicting the duck industry, causing substantial annual economic losses on a global scale. In this study, the genes encoding the lipoproteins PlpE of P. multocida strain PMWSG-4 was cloned, inserted into the pBAD-ClyA vector, and the recombinant outer membrane vesicles (OMVs) fused with PlpE antigen of P. multocida was expressed by Escherichia coli (E. coli). Ducks immunized with OMV-PlpE had significantly (P < 0.001) increased production of antigen-specific antibodies. Moreover, at 28 days post-immunization, the expression of genes associated with immune response, including interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-γ in the spleen tissue of immunized ducks were significantly (P < 0.001) up-regulated compared to unimmunized ducks in the control group. And the active serum had significant bactericidal effects against the PMWSG-4 strain (P < 0.001). The protective efficacy of the vaccines was evaluated by leg muscle challenge with 20 LD50 doses of P. multocida, with the recombinant OMV-PlpE conferring 100 % protection. Histopathological examination and tissue bacterial load detection revealed that OMV-PlpE mitigated tissue damage and bacterial colonization to a statistically significant extent (P < 0.001). These findings serve as a valuable reference for the development of vaccines against P. multocida.

Pasteurella multocida is a leading cause of respiratory disease in pigs worldwide. In this study, we determined the genetic characteristics of 115 P. multocida isolates from the lungs of pigs with respiratory disease in China in 2015 using capsular typing, lipopolysaccharide (LPS) genotyping, and virulence genotyping based on the detection of virulence-associated genes. The results showed that the isolates belonged to three capsular types: A (49.6%), D (46.1%), and nontypable (4.3%); and two LPS genotypes: L3 (22.6%) and L6 (77.4%). When combining the capsular types with the LPS genotypes, a genotype group D: L6 (46.1%) was the most prevalent among the strains. Among the 23 virulence-associated genes detected in this study, a small number of them displayed a certain level of “genotype-preference”. We found that pfhA, hgbA, and hgbB had a close association with P. multocida LPS genotypes, while tadD was more associated with P. multocida capsular types. In addition, multilocus sequence typing (MLST) on 40 P. multocida isolates identified four sequence types: ST3, ST10, ST11, and ST16, and the distribution of ST11 was significantly higher than the other MLST genotypes. Interestingly, all of the ST11 isolates detected in this study were genotype D: L6 strains and they were 100% positive for hgbB. Our data suggest that a capsule/LPS/MLST genotype D/L6/ST11 is likely to be strongly associated with respiratory clinical manifestation of the disease in pigs.

Pasteurella multocida is a Gram-negative bacterium that causes a range of distinct diseases in livestock animals. Different P. multocida diseases are associated with different capsule and lipopolysaccharide (LPS) types, but little else is known about what underpins this disease specificity. In this study, we utilised transposon-directed insertion site sequencing (TraDIS) to identify genes required for growth in rich media, and genes important for survival during systemic infections in BALB/c mice, for two diverse P. multocida strains; VP161 (capsule type A and LPS type L1) and M1404 (capsule type B and LPS type L2). Analysis of growth in heart infusion broth showed that both VP161 and M1404 shared 461 genes essential for growth in rich media, with 95% of these rich media-essential genes present in all publicly available closed P. multocida genomes. In vivo fitness analysis identified 63 and 94 genes important for VP161 and M1404 survival in BALB/c mice, respectively. Only 35 homologs were identified as important for survival in both strains, showing that conserved biological systems can be differentially important for different P. multocida strains. Investigation of proteins involved in the catabolite response showed that an active cyclic-adenosine monophosphate (cAMP) receptor protein (CRP) was required for maximal fitness in M1404. Furthermore, disrupting CRP or cAMP production also reduced capsule production in M1404, but increased capsule production in VP161, demonstrating that these P. multocida strains have different regulatory systems for crucial virulence factors.

Pasteurella multocida is a pathogen that causes bovine respiratory disease, and the development of an effective vaccine is important for improving animal health. Live-attenuated vaccines induce a long-lasting immune response with minimal side effects. The objective of this study was to evaluate potential live vaccine candidates from three P. multocida mutants produced by separately disrupting the genes of filamentous hemagglutinin 2 ( fhaB2 ) , hydrogenase-1 operon ( hyaE ) , and n-acylneuraminate-9-phosphatase ( nanP ) of a serogroup 3 strain (P1062, WT) by clinical testing and transcriptome analysis. Challenge with WT and the three mutants conferred protection against P. multocida , with less lung lesions (4.7–6.2%) compared to 22.4% in the sham group. Transcriptome analysis identified 807 differentially expressed protein-coding transcripts (DETs) in the blood and 6473 DETs in the liver compared to the sham, WT, and each of the mutants. In total, 15 and 64 differentially expressed microRNAs (DEmiRNAs) and 12 and 74 differentially expressed long non-coding RNAs (DElncRNAs) were identified in blood and liver, respectively. The DEmiRNAs were not significantly associated with the DETs within each comparison. DElncRNAs were associated with 12 and 170 DETs in blood and liver respectively. The greatest number of unique DETs were found between hyaE and sham groups in the liver, which agreed with the low colonization rate in the nares and palatine tonsils. For the DETs between sham and WT the under-enriched gene ontology terms in blood were all included in the liver for the DETs identified by WT vs. sham, nanP vs. sham, and hyaE vs. sham, and were related to the signaling pathway, stimulus, and sensory perceptions in biological processes with the molecular function of olfactory receptor activity. The number of identified DETs, decreased percentage of lung lesions, and colonization rates indicate that fhaB2 could be a promising vaccine candidate.