Pasteurella Multocida Strains Research Articles

Comparative In Vitro Killing by Pradofloxacin in Comparison to Ceftiofur, Enrofloxacin, Florfenicol, Marbofloxacin, Tildipirosin, Tilmicosin and Tulathromycin against Bovine Respiratory Bacterial Pathogens

Pradofloxacin is the newest of the veterinary fluoroquinolones to be approved for use in animals—initially companion animals and most recently food animals. It has a broad spectrum of in vitro activity, working actively against Gram-positive/negative, atypical and some anaerobic microorganisms. It simultaneously targets DNA gyrase (topoisomerase type II) and topoisomerase type IV, suggesting a lower propensity to select for antimicrobial resistance. The purpose of this study was to determine the rate and extent of bacterial killing by pradofloxacin against bovine strains of Mannheimia haemolytica and Pasteurella multocida, in comparison with several other agents (ceftiofur, enrofloxacin, florfenicol, marbofloxacin, tildipirosin, tilmicosin and tulathromycin) using four clinically relevant drug concentrations: minimum inhibitory and mutant prevention drug concentration, maximum serum and maximum tissue drug concentrations. At the maximum serum and tissue drug concentrations, pradofloxacin killed 99.99% of M. haemolytica cells following 5 min of drug exposure (versus growth to 76% kill rate for the other agents) and 94.1–98.6% of P. multocida following 60–120 min of drug exposure (versus growth to 98.6% kill rate for the other agents). Statistically significant differences in kill rates were seen between the various drugs tested depending on drug concentration and time of sampling after drug exposure.

Discovery of the tigecycline resistance gene cluster tmexCD3-toprJ1 in Pasteurella multocida strains isolated from pigs in China

Pasteurella multocida is a leading cause of respiratory disorders in pigs. However, the genotypes and antimicrobial resistance characteristics of P. multocida from pigs in China have not been reported frequently. In this study, we investigated 381 porcine strains of P. multocida collected in China between 2013 and 2022. These strains were assigned to capsular genotypes A (69.55%, n = 265), D (27.82%, n =106), and F (2.62%, n = 10); or lipopolysaccharide genotypes L1 (1.31%, n = 5), L3 (24.41%, n = 93), and L6 (74.28%, n = 283). Overall, P. multocida genotype A:L6 (46.46%) was the most-commonly identified type, followed by D:L6 (27.82%), A:L3 (21.78%), F:L3 (2.62%), and A:L1 (1.31%). Antimicrobial susceptibility testing showed that a relatively high proportion of strains were resistant to tetracycline (66.67%, n = 254), and florfenicol (35.17%, n = 134), while a small proportion of strains showed resistance phenotypes to enrofloxacin (10.76%, n = 41), ampicillin (8.40%, n = 32), tilmicosin (7.09%, n = 27), and ceftiofur (2.89%, n = 11). Notably, Illumina short-read and Nanopore long-read sequencing identified a chromosome-borne tigecycline-resistance gene cluster tmexCD3-toprJ1 in P. multocida. The structure of this cluster was highly similar to the respective structures found in several members of Proteus or Pseudomonas. It is assumed that the current study identified the tmexCD3-toprJ1 cluster for the first time in P. multocida.

Pathogenomic analysis and characterization of Pasteurella multocida strains recovered from human infections.

Pasteurella multocida is an upper respiratory tract commensal in several mammal and bird species but can also cause severe disease in humans and in production animals such as poultry, cattle, and pigs. In this study, we performed whole-genome sequencing of P. multocida isolates recovered from a range of human infections, from the mouths of cats, and from wounds on dogs. Together with publicly available P. multocida genome sequences, we performed phylogenetic and comparative genomic analyses. While isolates from cats and dogs were spread across the phylogenetic tree, human infections were caused almost exclusively by subsp. septica strains. Most of the human isolates were capsule type A and LPS type L1 and L3; however, some strains lacked a capsule biosynthesis locus, and some strains contained a novel LPS outer-core locus, distinct from the eight LPS loci that can currently be identified using an LPS multiplex PCR. In addition, the P. multocida strains isolated from human infections contained novel mobile genetic elements. We compiled a curated database of known P. multocida virulence factor and antibiotic resistance genes (PastyVRDB) allowing for detailed characterization of isolates. The majority of human P. multocida isolates encoded a reduced range of iron receptors and contained only one filamentous hemagglutinin gene. Finally, gene-trait analysis identified a putative L-fucose uptake and utilization pathway that was over-represented in subsp. septica strains and may represent a novel host predilection mechanism in this subspecies. Together, these analyses have identified pathogenic mechanisms likely important for P. multocida zoonotic infections.IMPORTANCEPasteurella multocida can cause serious infections in humans, including skin and wound infections, pneumonia, peritonitis, meningitis, and bacteraemia. Cats and dogs are known vectors of human pasteurellosis, transmitting P. multocida via bite wounds or contact with animal saliva. The mechanisms that underpin P. multocida human predilection and pathogenesis are poorly understood. With increasing identification of antibiotic-resistant P. multocida strains, understanding these mechanisms is vital for developing novel treatments and control strategies to combat P. multocida human infection. Here, we show that a narrow range of P. multocida strains cause disease in humans, while cats and dogs, common vectors for zoonotic infections, can harbor a wide range of P. multocida strains. We also present a curated P. multocida-specific database, allowing quick and detailed characterization of newly sequenced P. multocida isolates.

Pasteurella multocida strains of a novel capsular serotype and lethal to Marmota himalayana on Qinghai-Tibet plateau in China

Pasteurella multocida is a zoonotic pathogen causing serious diseases in humans and animals. Here, we report P. multocida from wildlife on China's Qinghai-Tibet plateau with a novel capsular serotype, forming a single branch on the core-genome phylogenetic tree: four strains isolated from dead Himalayan marmot (Marmota himalayana) and one genome assembled from metagenomic sequencing of a dead Woolly hare (Lepus oiostolus). Four of the strains were identified as subspecies multocida and one was septica. The mouse model showed that the challenge strain killed mice within 24 h at an infectious dose of less than 300 bacteria. The short disease course is comparable to septicemic plague: the host has died before more severe pathological changes could take place. Though pathological changes were relatively mild, cytokine storm was obvious with a significant rise of IL-12p70, IL-6, TNF-αand IL-10 (P < 0.05). Our findings suggested P. multocida is a lethal pathogen for wildlife on Qinghai-Tibet plateau, in addition to Yersinia pestis. Individuals residing within the M. himalayana plague focus are at risk for P. multocida infection, and public health warnings are necessitated.

Emergence of multidrug resistant strains of Pasteurella multocida isolated from cattle and buffaloes in India during the period 2000-2016

Emergence of multidrug resistant strains of Pasteurella multocida isolated from cattle and buffaloes in India during the period 2000-2016

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.

Draft genome sequence of Pasteurella multocida strain BD1769 with untypable capsular serotype isolated from a layer chicken.

We report the draft genome sequence of Pasteurella multocida strain BD1769 (GenBank accession numbers JARFTQ010000001-JARFTQ010000021) isolated in 2021 from a layer chicken in Japan. No gene locus for capsular biosynthesis was annotated in the genome of this strain.

Identification of Aztreonam as a potential antibacterial agent against Pasteurella multocida sialic acid binding protein: A combined in silico and in-vitro analysis

Pasteurella multocida, a Gram-negative zoonotic bacterial pathogen, interacts with the host environment, immune response, and infection through outer membrane proteins, adhesins, and sialic acid binding proteins. Sialic acids provide nutrition and mask bacterial identity, hindering the complement system, facilitates tissue access and biofilm formation. Sialic acid binding protein (SAB) enable adhesion to host cells, immune evasion, and nutrient acquisition, making them potential targets for preventing Pasteurella multocida infections. In this study, in silico molecular docking assessed 11 antibiotics targeting SAB (4MMP) comparing their docking scores to Amoxicillin. As SAB (4MMP) exhibits a highly conserved sequence in various Pasteurella multocida strains, including the specific strain PMR212 studied in this article, with a 96.09% similarity score. Aztreonam and Gentamicin displayed the highest docking scores (−6.025 and −5.718), followed by a 100ns molecular dynamics simulation. Aztreonam exhibited stable simulation with protein RMSD fluctuations of 1.8–2.2 Å. The ligand initially had an RMSD of 1.6 Å, stabilizing at 4.8 Å. Antibiotic sensitivity testing confirmed Aztreonam's efficacy with the largest inhibition zone of 42 mm, while Amoxicillin and Gentamicin had inhibition zones of 32 mm and 25 mm, respectively. According to CLSI guidelines, all three antibiotics were effective against Pasteurella multocida. Aztreonam's superior efficacy positions it as a promising candidate for further investigation in targeting Pasteurella multocida.

The enigmatical manipulators in the capsule synthesis of Pasteurella multocida: Iron acquisition proteins

Aim: Spontaneous capsular loss or capsular changes in Pasteurella multocida can result from repeated laboratory passages, positive or negative regulatory genes, or an unknown gene. This study, it was aimed to compare the properties of phenotypic, genotypic, and biotypic of each non-typical, and typical Pasteu-rella multocida strain, to determine the dominant genes on capsule synthesis. Materials and Methods: Fifty-six strains, which capsular type was determined, and thirty -six, which capsular type was not determined, were used in this study. Multiple linear regression analysis was used based on the presence of dominant genes (serogroup, serotype, toxin, adhesin, iron acquisition, and protectin) in the isolates. Results: When colony morphologies of strains were evaluated of these strains by culture methods, mucoid colony formation was commonly detected in typical strains (87.5%), in contrast to non-typical strains (27.7%). In typical strains, the highest percentages of ptfA, ompA, and tadD genes were 78.57%, 75%, and 69.64%, respectively. In non-typical strains, the highest rates of ompA, ptfA, and tadD genes were 61.1%, 52.78%, and 52.78%, respectively. According to multiple linear regression analysis results, the together hgbA with hgbB genes caused the increase of capsule synthesis in these strains. The presence of the ompA gene in these strains was secondly a induction on these strains. Other genes were not effective in capsule synthesis in these strains. Conclusion: It was determined that the most significant effect in the forming of non-typical P. multocida strains was related to not enough HgbA and HgbB genes. It was supposed that P. multocida may not be heavily encapsulated under iron-restricted conditions. Consequently, P. multocida may change its capsule or lose its capsule related to iron acquisition proteins.

Mannheimia cairinae sp. nov., a novel species of Mannheimia obtained from Muscovy ducks (Cairina moschata) and reclassification of Mannheimia ovis as heterotypic synonym of Mannheimia pernigra.

During a screening study for Pasteurella multocida in two unrelated flocks of Muscovy ducks pharyngeal and cloacal swabs were collected. A total of 59 Pasteurellaceae-like isolates sharing the same colony morphology were subcultured and subsequently characterized. Colonies on bovine blood agar were nonhaemolytic, regular, circular, slightly raised, shiny, intransparent with an entire margin, greyish and had an unguent-like consistency. Isolate AT1T was characterized by 16S rRNA gene sequencing and showed the highest similarity of 96.1 % to the type strain of Mannheimia caviae and 96.0 % to the type strain of Mannheimia bovis, respectively. In addition, rpoB and recN gene sequences also showed the highest similarity to the genus Mannheimia. The phylogenetic comparison of concatenated conserved protein sequences also showed a unique position of AT1T compared to other species of Mannheimia. Full phenotypic characterization of the isolates showed that between two (Mannheimia ruminalis) and 10 (Mannheimia glucosida) phenotypic characteristics separate the taxon isolated from Muscovy ducks from the accepted species of Mannheimia. Whole genomic sequences of two strains analysed by the type strain genome server showed the highest similarity of 24.9 % to the genome of the type strain of Pasteurella multocida and 23.0 % to the genome of the type strain of Mannheimia haemolytica. The species Mannheimia cairinae sp. nov. is proposed based on the phenotypic and genotypic similarity to Mannheimia as well as differences to the other validly published species of the genus. The leukotoxin protein was not predicted in the genome of AT1T. The G+C content of the type strain of M. cairinae sp. nov., AT1T (=CCUG 76754T=DSM 115341T) is 37.99 mol%, calculated from the whole genome. The investigation further proposes that Mannheimia ovis is reclassified as a later heterotypic synonym of Mannheimia pernigra, since M. ovis and M. pernigra are closely genetically related, and M. pernigra was validly published before M. ovis.

Antimicrobial Susceptibility of Pasteurella multocida Isolated from Sheep with Fibrinous Pneumonia

Abstract Ovine respiratory complex is a significant cause of death in sheep flocks, where Pasteurella multocida is the most frequent microorganisms isolated from animals with pneumonia. There is an urgent need to refine the use of different antimicrobials to avoid the problem of antimicrobial resistance and optimize the control of this disease in ovine livestock. The first step in approaching this problem is gaining an insight into the antimicrobial susceptibility of ovine pathogens. This study evaluated the in vitro activity of tildipirosin, gamithromycin, oxytetracycline, and danofloxacin against Pasteurella multocida strains isolated from sheep with fibrinous pneumonia. The strains were incubated following Clinical and Laboratory Standards Institute (CLSI) standard conditions and also with a modified method by 25% supplementation with sheep serum. Minimum inhibitory concentrations (MIC) were determined using the broth microdilution technique. The lowest MIC90 under standard conditions and by supplementation with sheep serum was obtained with tildipirosin. Sheep serum significantly reduced tildipirosin, gamithromycin, and danofloxacin MIC values for Pasteurella multocida strains. In brief, the potency of tildipirosine, gamithromycin, and danofloxacin against Pasteurella multocida increases when sheep serum is added to the culture media.

Draft Genome Sequence of a Pasteurella multocida Strain Isolated from a Spotted Deer (Axis axis) in India.

Here, we report the genome sequence of a Pasteurella multocida strain isolated from the heart blood of a spotted deer (Bareilly, India). The 2.44-Mbp genome has 2,227 coding sequences, with a G+C content of 40.7%.

De Novo Whole-Genome Sequencing of Two Pathogenic Pasteurella multocida Type D:6 Strains Isolated from Pigs.

Here, we report the complete genome sequences of Pasteurella multocida strains P504190 and P504188/1, which were isolated from the diseased lungs of a sow and her piglet, respectively. Despite the unusual clinical presentation, whole-genome sequence typing revealed both strains to be capsular type D and lipopolysaccharide (LPS) group 6, commonly found in pigs.

Polymeric Membranes of Chitosan/Aloe Vera Gel Fabrication With Enhanced Swelling and Antimicrobial Properties for Biomedical Applications.

Since ancient times, medicinal plants have been used as traditional medicine to treat a variety of ailments. Aloe vera (AV) gel's therapeutic potential is one of the most effective approach in the fabrication of functional materials. The current study aimed to prepare the AV and chitosan (CS) membranes using various cross-linkers that were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA), and ultraviolet-visible (UV-Visible) techniques, as well as swelling ratio and antimicrobial studies. SEM analysis revealed that the membrane is porous, with interconnected pores. The inclusion of AV contents in the membrane improved thermal stability and crystallinity. The swelling ratio of the ACPG-3 membrane with a 2:1 CS to AV ratio was 366%. The membranes showed promising antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pasteurella multocida strains. The findings revealed that polymeric CS/AV membranes have effective potential for use in the biomedical field.

Биологические свойства циркулирующих штаммов Pasteurella multocida на территории Республики Казахстан

The article presents the results of studies on the study of cultural, tinctorial, biochemical and virulence properties of Pasteurella multocida strains isolated from cattle. In order to refresh the isolated strains and increase their virulent properties, successive passages were carried out through the body of white mice. According to the results of the bioassays, a reduction in the period of death of mice after infection with Pasteurella cultures was established, which proves an increase in their virulence. When studying the cultural and morphological properties, pure cultures of Pasteurella were grown on nutrient media at 37°C for 18–24 h. A biochemical test on Hiss medium was used to fully confirm the data obtained. The test cultures isolated from pathological material (heart, lung, spleen, liver, intestines ) of cattle have cultural, biochemical and biological properties characteristic of the Pasteurella multocida species and form S-shaped colonies. Isolated cultures of Pasteurella multocida can be used to evaluate the immunogenicity of existing vaccines and use them as a basis for the development of anti-pasteurellosis polyvalent emulsion vaccines, anti-pasteurellosis hyperimmune serum and e.t.c.

Antimicrobial Resistance of and Genomic Insights into Pasteurella multocida Strains Isolated from Australian Pigs.

Infection with Pasteurella multocida represents a significant economic threat to Australian pig producers, yet our knowledge of its antimicrobial susceptibilities is lagging, and genomic characterization of P. multocida strains associated with porcine lower respiratory disease is internationally scarce. This study utilized high-throughput robotics to phenotypically and genetically characterize an industry-wide collection of 252 clinical P. multocida isolates that were recovered between 2014 and 2019. Overall, antimicrobial resistance was found to be low, with clinical resistance below 1% for all tested antimicrobials except those from the tetracycline class. Five dominant sequence types, representing 64.8% of all isolates, were identified; they were disseminated across farms and had previously been detected in various animal hosts and countries. P. multocida in Australian farms remain controllable via current antimicrobial therapeutic protocols. The identification of highly dominant, interspecies-infecting strains provides insight into the epidemiology of the opportunistic pathogen, and it highlights a biosecurity threat to the Australian livestock industry. IMPORTANCE Pasteurellosis is rated by the World Animal Health Organisation (OIE) as a high-impact disease in livestock. Although it is well understood in many host-disease contexts, our understanding of the organism in porcine respiratory disease is limited. Given its high frequency of involvement in porcine respiratory disease complex (PRDC), it is important that we are aware of its antimicrobial susceptibilities so that we can respond quickly and appropriately with antimicrobial therapy. Genetic insights about the organism can help us to better understand its epidemiology and inform our biosecurity practices and prophylactic management.

Antibiogram study of Pasteurella multocida strains isolated from pneumonic sheep and goats in Warangal region of Telangana

Antibiogram study of Pasteurella multocida strains isolated from pneumonic sheep and goats in Warangal region of Telangana

Characterization of Pasteurella multocida Strains Isolated from Local Flocks in Egypt by Phenotypic and Genotypic Schemes

Characterization of Pasteurella multocida Strains Isolated from Local Flocks in Egypt by Phenotypic and Genotypic Schemes

Characterization of Pasteurella multocida Strains Isolated from Local Flocks in Egypt by Phenotypic and Genotypic Schemes

Characterization of Pasteurella multocida Strains Isolated from Local Flocks in Egypt by Phenotypic and Genotypic Schemes

Examination of the horizontal gene transfer dynamics of an integrative and conjugative element encoding multidrug resistance in Histophilus somni.

Integrative and conjugative elements (ICEs) are self-transferable mobile genetic elements that play a significant role in disseminating antimicrobial resistance between bacteria via horizontal gene transfer. A recently identified ICE in a clinical isolate of Histophilus somni (ICEHs02) is 72 914 base pairs in length and harbours seven predicted antimicrobial resistance genes conferring resistance to tetracycline (tetR-tet(H)), florfenicol (floR), sulfonamide (Sul2), aminoglycosides (APH(3″)-Ib, APH(6)-Id, APH(3')-Ia), and copper (mco). This study investigatedICEHs02 host range, assessed effects of antimicrobial stressors on transfer frequency, and examined effects of ICEHs02 acquisition on hosts. Conjugation assays examined transfer frequency ofICEHs02to H. somni andPasteurella multocida strains. Polymerase chain reaction assays confirmed the presence of a circular intermediate, ICE-associated core genes, and cargo genes in recipient strains. Susceptibility testing examinedICEHs02-associated resistance phenotypes in recipient strains. Tetracycline and ciprofloxacin induction significantly increased the transfer rates ofICEHs02 in vitro. The copy numbers of the circular intermediate of ICEHs02 per chromosome exhibited significant increases of ∼37-fold after tetracycline exposure and ∼4-fold after ciprofloxacin treatment. The acquisition of ICEHs02 reduced the relative fitness of H. somni transconjugants (TG) by 28% (w=0.72±0.04) and the relative fitness of P. multocida TG was decreased by 15% (w=0.85±0.01).