Pasteurella multocida activates apoptosis via the FAK-AKT-FOXO1 axis to cause pulmonary integrity loss, bacteremia, and eventually a cytokine storm.

Pasteurella multocida is an important zoonotic respiratory pathogen capable of infecting a diverse range of hosts, including humans, farm animals, and wild animals. However, the precise mechanisms by which P. multocida compromises the pulmonary integrity of mammals and subsequently induces systemic infection remain largely unexplored. In this study, based on mouse and rabbit models, we found that P. multocida causes not only lung damage but also bacteremia due to the loss of lung integrity. Furthermore, we demonstrated that bacteremia is an important aspect of P. multocida pathogenesis, as evidenced by the observed multiorgan damage and systemic inflammation, and ultimately found that this systemic infection leads to a cytokine storm that can be mitigated by IL-6-neutralizing antibodies. As a result, we divided the pathogenesis of P. multocida into two phases: the pulmonary infection phase and the systemic infection phase. Based on unbiased RNA-seq data, we discovered that P. multocida-induced apoptosis leads to the loss of pulmonary epithelial integrity. These findings have been validated in both TC-1 murine lung epithelial cells and the lungs of model mice. Conversely, the administration of Ac-DEVD-CHO, an apoptosis inhibitor, effectively restored pulmonary epithelial integrity, significantly mitigated lung damage, inhibited bacteremia, attenuated the cytokine storm, and reduced mortality in mouse models. At the molecular level, we demonstrated that the FAK-AKT-FOXO1 axis is involved in P. multocida-induced lung epithelial cell apoptosis in both cells and animals. Thus, our research provides crucial information with regard to the pathogenesis of P. multocida as well as potential treatment options for this and other respiratory bacterial diseases.

Dendritic cell targeting peptide plus Salmonella FliCd flagellin fused outer membrane protein H (OmpH) demonstrated increased efficacy against infections caused by different Pasteurella multocida serogroups in mouse models.

As the major outer membrane protein (OMP) presents in the Pasteurella multocida envelope, OmpH was frequently expressed for laboratory assessments of its immunogenicity against P. multocida infections, but the results are not good. In this study, we modified OmpH with dendritic cell targeting peptide (Depeps) and/or Salmonella FliCd flagellin, and expressed three types of recombinant proteins with the MBP tag (rDepeps-FliC-OmpH-MBP, rDepeps-OmpH-MBP, rFliC-OmpH-MBP). Assessments in mouse models revealed that vaccination with rDepeps-FliC-OmpH-MBP, rDepeps-OmpH-MBP, or rFliC-OmpH-MBP induced significant higher level of antibodies as well as IFN-γ and IL-4 in murine sera than vaccination with rOmpH-MBP (P < 0.5). Vaccination with the three modified proteins also provided increased protection (rDepeps-FliC-OmpH-MBP, 70 %; rDepeps-OmpH-MBP, 50 %; rFliC-OmpH-MBP, 60 %) against P. multocida serotype D compared to vaccination with rOmpH-MBP (30 %). In mice vaccinated with different types of modified OmpHs, a significantly decreased bacterial strains were recovered from bloods, lungs, and spleens compared to rOmpH-MBP-vaccinated mice (P < 0.5). Notably, our assessments also demonstrated that vaccination with rDepeps-FliC-OmpH-MBP provided good protection against infections caused by a heterogeneous group of P. multocida serotypes (A, B, D). Our above findings indicate that modification with DCpep and Salmonella flagellin could be used as a promising strategy to improve vaccine effectiveness.

Pharmacokinetic/pharmacodynamic evaluation of gamithromycin against rabbit pasteurellosis.

BACKGROUND: Gamithromycin is an effective therapy for bovine and swine respiratory diseases but not utilized for rabbits. Given its potent activity against respiratory pathogens, we sought to determine the pharmacokinetic profiles, antimicrobial activity and target pharmacokinetic/pharmacodynamic (PK/PD) exposures associated with therapeutic effect of gamithromycin against Pasteurella multocida in rabbits. RESULTS: Gamithromycin showed favorable PK properties in rabbits, including high subcutaneous bioavailability (86.7 ± 10.7%) and low plasma protein binding (18.5-31.9%). PK analysis identified a mean plasma peak concentration (Cmax) of 1.64 ± 0.86 mg/L and terminal half-life (T1/2) of 31.5 ± 5.74 h after subcutaneous injection. For P. multocida, short post-antibiotic effects (PAE) (1.1-5.3 h) and post-antibiotic sub-inhibitory concentration effects (PA-SME) (6.6-9.1 h) were observed after exposure to gamithromycin at 1 to 4× minimal inhibitory concentration (MIC). Gamithromycin demonstrated concentration-dependent bactericidal activity and the PK/PD index area under the concentration-time curve over 24 h (AUC24h)/MIC correlated well with efficacy (R2 > 0.99). The plasma AUC24h/MIC ratios of gamithromycin associated with the bacteriostatic, bactericidal and bacterial eradication against P. multocida were 15.4, 24.9 and 27.8 h in rabbits, respectively. CONCLUSIONS: Subcutaneous administration of 6 mg/kg gamithromycin reached therapeutic concentrations in rabbit plasma against P. multocida. The PK/PD ratios determined herein in combination with ex vivo activity and favorable rabbit PK indicate that gamithromycin may be used for the treatment of rabbit pasteurellosis.

Rare case of septic shock combined with meningitis caused by Pasteurella multocida without a history of cat and dog bites.

BACKGROUND: Pasteurella multocida is a zoonotic pathogen that mainly causes local skin and soft tissue infections in the human body through cat and dog bites. It rarely causes bacteraemia (or sepsis) and meningitis. We reported a case of septic shock and meningitis caused by P. multocida in a patient without a history of cat and dog bites. CASE PRESENTATION: An 84-year-old male patient was urgently sent to the emergency department after he was found with unclear consciousness for 8 h, accompanied by limb tremors and urinary incontinence. In the subsequent examination, P. multocida was detected in the blood culture and wound secretion samples of the patient. However, it was not detected in the cerebrospinal fluid culture, but its DNA sequence was detected. Therefore, the patient was clearly diagnosed with septic shock and meningitis caused by P. multocida. The patient had no history of cat or dog contact or bite. The patient was subsequently treated with a combination of penicillin G, doxycycline, and ceftriaxone, and he was discharged after 35 days of hospitalisation. CONCLUSION: This report presented a rare case of septic shock and meningitis caused by P. multocida, which was not related to a cat or dog bite. Clinical doctors should consider P. multocida as a possible cause of sepsis or meningitis and should be aware of its potential seriousness even in the absence of animal bites.

Molecular characterization of Pasteurella multocida from cats and antibiotic sensitivity of the isolates.

BACKGROUND: Companion animals, including dogs and cats, are frequently identified as sources of Pasteurella multocida, a bacterium that can be transmitted to humans and cause infections. OBJECTIVES: This survey defines the prevalence, antibiotic sensitivity, capsular types, lipopolysaccharide (LPS) types and virulence factors of P. multocida isolated from cats. METHODS: A total of 100 specimens from various cat breeds were collected. P. multocida was characterized using both biochemical tests and PCR. Genotypes of isolates were determined using capsular and LPS typing methods. Additionally, virulotyping was performed by detecting the presence of 12 virulence-associated genes. Disk diffusion was used to determine the antibiotic sensitivity of the isolates. RESULTS: The prevalence of P. multocida in cats was 29%. Among the isolates, the majority were capsular type A (96.5%) and type D (3.4%), with a predominant presence of type A. Twenty-six of the isolates (89.66%) belonged to LPS genotype L6, whereas three isolates (10.3%) belonged to genotype L3. Among the 12 virulence genes examined, sodC, oma87, ptfA, nanB and ompH showed remarkable prevalence (100%). The toxA gene was detected in four isolates (13.8%). Variations were observed in other virulence genes. The nanH gene was present in 93.1% of the isolates, whereas the pfhA gene was detected in 58.6% of the isolates. The exbD-tonB, hgbB, sodA and hgbA genes showed prevalence rates of 96.5%, 96.5%, 96.5% and 82.8%, respectively. Additionally, particular capsule and LPS types were associated with specific virulence genes. Specifically, the toxA and pfhA genes were found to be more prevalent in isolates with capsular type A and LPS genotype L6. Most isolates were resistant to ampicillin, clindamycin, lincomycin, streptomycin and penicillin. CONCLUSIONS: According to this epidemiological and molecular data, P. multocida from cats possess several virulence-associated genes and are resistant to antimicrobial medicines commonly used in humans and animals. Thus, it is crucial to consider the public health concerns of P. multocida in humans.

Attenuated vaccine PmCQ2Δ4555-4580 effectively protects mice against Pasteurella multocida infection.

Pasteurella multocida type A (PmA) mainly causes respiratory diseases such as pneumonia in bovines, leading to great economic losses to the breeding industry. At present, there is still no effective commercial vaccine against PmA infection. In this study, a mutant strain (PmCQ2Δ4555-4580) with brand-new phenotypes was obtained after serially passaging at 42 °C. Whole genome resequencing and PCR analysis showed that PmCQ2Δ4555-4580 missed six genes, including PmCQ2_004555, PmCQ2_004560, PmCQ2_004565, PmCQ2_004570, PmCQ2_004575, and PmCQ2_004580. Importantly, the virulence of PmCQ2Δ4555-4580 was reduced by approximately 2.8 × 109 times in mice. Notably, live PmCQ2Δ4555-4580 could provide 100%, 100% and 40% protection against PmA, PmB and PmF, respectively; and inactivated PmCQ2Δ4555-4580 could provide 100% and 87.5% protection against PmA and PmB. Interestingly, immune protection-related proteins were significantly upregulated in PmCQ2Δ4555-4580 based on RNA-seq and bioinformatics analysis. Meaningfully, by in vitro expression, purification and in vivo immunization, 12 proteins had different degrees of immune protective effects. Among them, PmCQ2_008205, PmCQ2_010435, PmCQ2_008190, and PmCQ2_004170 had the best protective effect, the protection rates against PmA were 50%, 40%, 30%, and 30%, respectively, and the protective rates against PmB were 62.5%, 42.9%, 37.5%, and 28.6%, respectively. Collectively, PmCQ2Δ4555-4580 is a potential vaccine candidate for the prevention of Pasteurellosis involving in high expression of immune protective related proteins.

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.

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.

Pathogenic and genomic characterization of rabbit-sourced Pasteurella multocida serogroup F isolates recovered from dead rabbits with respiratory disease.

Pasteurella multocida serogroup F can infect a number of animals. However, the pathogenicity and genomic features of this serogroup are still largely unknown. In the present study, the pathogenicity and genomic sequences of 19 rabbit-sourced P. multocida serogroup F isolates were determined. The 19 isolates were highly pathogenic for rabbits causing severe pathologic lesions and high mortality in inoculated rabbits. Nevertheless, the pathologic lesions in rabbits caused by the 19 isolates were distinct from those caused by the previously reported high-virulent serogroup F strains J-4103 (rabbit), P-4218 (turkey), and C21724H3km7 (chicken). Moreover, the 19 isolates were avirulent to white feather broilers. The genomes of the 19 isolates were determined to understand the pathogenicity of these isolates. The finding of a number of functional genes in the 19 isolates by comparison with the low-virulent rabbit-sourced serogroup F strain s4 might contribute to the high virulence of these isolates. Notably, polymorphisms were determined in the lipopolysaccharide outer core biosynthetic genes natC and gatF among the serogroup F strains of different hosts. However, the sequences of natC and gatF from rabbit-sourced strains (except for SD11) were identical, which might be responsible for the host specific of the 19 isolates. The observations and findings in this study would be helpful for the understanding of the pathogenicity variation and host predilection of P. multocida. IMPORTANCE: The 19 rabbit-sourced Pasteurella multocida serogroup F isolates showing high virulence to rabbits were avirulent to the broilers. Notably, polymorphisms were determined in the lipopolysaccharide outer core biosynthetic genes natC and gatF among all serogroup F strains of different hosts. However, the sequences of natC and gatF from rabbit-sourced strains (except for SD11) were identical, which might be responsible for the host specific of the 19 isolates.

Pasteurella multocida bacteraemia with liver abscess.

A previously healthy woman in her mid-70s presented with right upper quadrant abdominal pain, fever, intermittent chills and malaise for 1 week. She was clinically septic with raised inflammatory markers. Her blood culture revealed Pasteurella multocida, which was susceptible to penicillin and amoxicillin-clavulanic acid. CT of liver revealed an abscess of 8.0×7.9×8.5 cm at the left lobe of the liver. However, the abscess was not amenable for surgical or radiological drainage. She was a farmer and had close contact with her pet cats. She was occasionally scratched by her cats when caring for them. The liver abscess resolved completely without drainage after prolonged antimicrobial therapy of 109 days. She commenced on 63 days of intravenous antimicrobials and 46 days of oral amoxicillin-clavulanic acid. This case illustrated P. multocida bacteraemia with a large liver abscess in an immunocompetent adult after non-bite exposure.

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

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

Genomic analysis reveals the population structure and antimicrobial resistance of avian Pasteurella multocida in China.

OBJECTIVES: To investigate the population structure and antimicrobial resistance (AMR) of avian Pasteurella multocida in China. METHODS: Utilizing WGS analysis, we explored the phylogeny using a dataset of 546 genomes, comprising avian P. multocida isolates from China (n = 121), the USA (n = 165), Australia(n = 153), Bangladesh (n = 3) and isolates of other hosts from China (n = 104). We examined the integrative and conjugative element (ICE) structures and the distribution of their components carrying resistance genes, and reconstructed the evolutionary history of A:L1:ST129 (n = 110). RESULTS: The population structure of avian P. multocida in China was dominated by the A:L1:ST129 clone with limited genetic diversity. A:L1:ST129 isolates possessed a broader spectrum of resistance genes at comparatively higher frequencies than those from other hosts and countries. The novel putative ICEs harboured complex resistant clusters that were prevalent in A:L1:ST129. Bayesian analysis predicted that the A:L1:ST129 clone emerged around 1923, and evolved slowly. CONCLUSIONS: A:L1:ST129 appears to possess a host predilection towards avian species in China, posing a potential health threat to other animals. The complex AMR determinants coupled with high frequencies may strengthen the population dominance of A:L1:ST129. The extensive antimicrobial utilization in poultry farming and the mixed rearing practices could have accelerated AMR accumulation in A:L1:ST129. ICEs, together with their resistant clusters, significantly contribute to resistance gene transfer and facilitate the adaptation of A:L1:ST129 to ecological niches. Despite the genetic stability and slow evolution rate, A:L1:ST129 deserves continued monitoring due to its propensity to retain resistance genes, warranting global attention to preclude substantial economic losses.

Comparative genome analysis of Pasteurella multocida strains of porcine origin.

Pasteurella multocida causes acute/chronic pasteurellosis in porcine, resulting in considerable economic losses globally. The draft genomes of two Indian strains NIVEDIPm17 (serogroup D) and NIVEDIPm36 (serogroup A) were sequenced. A total of 2182-2284 coding sequences (CDSs) were predicted along with 5-6 rRNA and 45-46 tRNA genes in the genomes. Multilocus sequence analysis and LPS genotyping showed the presence of ST50: genotype 07 and ST74: genotype 06 in NIVEDIPm17 and NIVEDIPm36, respectively. Pangenome analysis of 61 strains showed the presence of 1653 core genes, 167 soft core genes, 750 shell genes, and 1820 cloud genes. Analysis of virulence-associated genes in 61 genomes indicated the presence of nanB, exbB, exbD, ptfA, ompA, ompH, fur, plpB, fimA, sodA, sodC, tonB, and omp87 in all strains. The 61 genomes contained genes encoding tetracycline (54%), streptomycin (48%), sulphonamide (28%), tigecycline (25%), chloramphenicol (21%), amikacin (7%), cephalosporin (5%), and trimethoprim (5%) resistance. Multilocus sequence type revealed that ST50 was the most common (34%), followed by ST74 (26%), ST13 (24%), ST287 (5%), ST09 (5%), ST122 (3%), and ST07 (2%). Single-nucleotide polymorphism and core genome-based phylogenetic analysis clustered the strains into three major clusters. In conclusion, we described the various virulence factors, mobile genetic elements, and antimicrobial resistance genes in the pangenome of P. multocida of porcine origin, besides the rare presence of LPS genotype 7 in serogroup D.

Effects of Pasturella Multocida B: 2 and its immunogens (LPS and OMP) on reproductive hormones in Nili-Ravi Buffaloes / Efeitos de Pasteurella multocida B: 2 e seus imunógenos (LPS e OMP) em hormônios reprodutivos em búfalos Nili-Ravi

Abstract Livestock is a fundamental part of the agriculture industry in Pakistan and contributes more than 11.53% to GDP. Among livestock species, the buffaloes are regarded as the black gold of Pakistan. Being the highest milk producers globally, Nili-Ravi buffaloes are the most famous ones. Buffaloes are affected by many endemic diseases, and "Hemorrhagic septicemia" (HS) is one of them. This study was designed to ascertain the effects of experimental exposure ofP. multocida B:2 (oral) and its immunogens, i.e., LPS (oral and intravenous) and OMP (oral and subcutaneous) on reproductive hormonal profiles in Nili-Ravi buffaloes. Repeated serum samples were collected from the jugular vein of experimental animals for 21 days (0, 02, 04, 08, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 and 504 hours). Hormonal assays to determine the serum concentrations of Gonadotropin-releasing hormone (GnRH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Estrogen (E2) and progesterone (P4) were performed using (MyBioSource) commercial Elisa kits. The hormonal profile of all treatment groups of the buffalo heifers exhibited significant (P<0.05) variations as compared to the control group (G-1). These results indicate suppression in Nili-Ravi buffaloes' reproductive hormonal profile on exposure to P. multocida B:2 and its immunogens. This influence warrants that exposure to H.S may be a possible reason for delayed puberty and poor reproduction performance in Nili-Ravi buffaloes.

Resumo A pecuária é uma parte fundamental da indústria agrícola no Paquistão e contribui com 11,53% do PIB nacional. Entre as espécies de gado, os búfalos são considerados o ouro negro do Paquistão. Sendo os maiores produtores de leite em todo o mundo, os búfalos Nili-Ravi são os mais famosos. Os búfalos são afetados por muitas doenças endêmicas, entre as quais a "septicemia hemorrágica" (SH). Este estudo busca verificar os efeitos da exposição experimental de P. multocida B:2 (oral) e seus imunógenos, ou seja, LPS (oral e intravenoso) e OMP (oral e subcutâneo), nos perfis hormonais reprodutivos em búfalos Nili-Ravi. Amostras de soro repetidas foram coletadas da veia jugular de animais experimentais por 21 dias (0, 2, 4, 8, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 e 504 horas). Os ensaios hormonais para determinar as concentrações séricas do hormônio liberador de gonadotrofina (GnRH), hormônio foliculoestimulante (FSH), hormônio luteinizante (LH), estrogênio (E2) e progesterona (P4) foram realizados usando kits comerciais Elisa (MyBioSource). O perfil hormonal de todos os grupos de tratamento das novilhas bubalinas apresentou variações significativas (P < 0,05) em relação ao grupo controle (G-1). Esses resultados indicam supressão no perfil hormonal reprodutivo de búfalos Nili-Ravi na exposição a P. multocida B:2 e seus imunógenos. Essa influência garante que a exposição à SH possa ser uma possível razão para o atraso da puberdade e o baixo desempenho reprodutivo em búfalos Nili-Ravi.

Unusual Presentation of Lumbar Surgical Site Infection: A Case Study of Early Onset Pasteurella multocida Infection after Arthrodesis.

BACKGROUND Infection is a serious surgical complication that significantly increases morbidity rates and health care expenses. Most human Pasteurella multocida infections are soft-tissue infections caused by dog or cat bites. Pasteurella multocida (P. multocida) is present in the oral, nasopharyngeal, and upper respiratory tract microbiota among cats, dogs, and other domestic or wild animals. Here, we report a case of lumbar surgical site infection caused by this bacterium. CASE REPORT A 70-year-old diabetic and overweight woman had a Pasteurella multocida surgical site infection after lumbar arthrodesis carried out for lumbar stenosis associated with spondylolisthesis. The patient had been in contact with her cat and claimed to have simply slept with it in her bed. Multiple antibiotic therapies and 3 debridement-irrigations with change of spinal implants during the last revision were needed. CONCLUSIONS Infections caused by P. multocida are rare and most often occur as a result of animal scratches or bites, but can sometimes occur after simple contact with an animal. Surgical site infection of spinal arthrodesis due to Pasteurella multocida implies treatment difficulties. In case of Pasteurella multocida infection of lumbar spinal arthrodesis, even in the early period, implant removal seems to be useful to limit the appearance of biofilm more specific to this micro-organism.

[Septic shock originating from a pulmonary focus caused by Pasteurella multocida. Report of one case]. / Shock séptico de foco respiratorio por Pasteurella multocida en un paciente inmunocompetente. Caso Clínico.

Pasteurella multocida is a gram-negative coccobacillus bacterium found as a commensal in the oropharynx of domestic animals such as cats and dogs and some farm animals. Soft tissue infections and occasionally bacteremia in immunocompromised patients with direct contact with animals are described. We report a 61 year old male with a history of scratches and close contact with domestic cats, with a septic shock originating from a pulmonary focus, requiring mechanical ventilation and vasopressors. Blood cultures disclosed the presence of Pasteurella multocida. He responded successfully to antimicrobials.

[Pasteurella multocida Pneumonia with Hemoptysis in an Immunocompetent Case]. / Immün Kompetan Bir Olguda Hemoptizi ile Seyreden Pasteurella multocida Pnömonisi.

Pasteurella species are gram-negative bacilli found in healthy pets' oropharynx and gastrointestinal tract flora. In humans, skin and soft tissue infections develop most frequently with the bite or scratching of animals such as cats or dogs. At the same time, they cause infections in the respiratory tract, mainly in patients with chronic lung disease or immunosuppressive patients. In this case report, a rare case of pneumonia caused by P.multocida bacteria in a patient with bronchiectasis was presented. A young male patient was admitted to the emergency department of our hospital with complaints of hemoptysis, cough with phlegm, and weight loss. The patient's blood pressure was 140/82 mmHg and SO2= 94%. Rales and rhonchi were detected in the lower left lung during the examination. Standard thorax tomography revealed prominent cystic structures and pneumonic infiltrates in the left lower lobe. Laboratory findings were normal. The Coronavirus disease-2019 (COVID-19) quantitative real-time polymerase chain reaction (qRt-PCR) test was found to be negative in the nasopharyngeal swab sample taken from the patient. Fiberoptic bronchoscopy was performed on the patient to investigate the presence of endobronchial lesion or foreign body aspiration. Culture and cytological evaluation was requested from the bronchial lavage taken. Gram-negative coccobacilli were seen among dense polymorphonuclear leukocytes in the Gram stain of the sample. Acid-fast bacilli were not detected with Ehrlich Ziehl Neelsen stain. In the lavage culture evaluated after 24 hours, colonies growing in blood and chocolate media were stained and gramnegative coccobacilli were observed. The isolate was identified as 96.0% P.canis with the automated Vitek 2 (Biomerieux, France) system. It was determined that the isolate was susceptible to levofloxacin, trimethoprim-sulfamethoxazole, amoxicillin-clavulanic acid, penicillin, ciprofloxacin and cefotaxime in the antibiogram performed by disc diffusion test according to EUCAST v13.0 guideline criteria. Sequence analysis of the isolate obtained from the culture was performed on the ABI Prism 310 Genetic Analyzer (Applied Biosystems, USA). Sequence analysis of the isolate revealed 99.85% homology with P.multocida (GenBank accession no: NG_115137.1). Although Pasteurella multocida pneumonia is not commonly observed, the presence of underlying bronchiectasis in this patient facilitated the establishment of the bacteria. In order not to miss the diagnosis of pneumonia due to P.multocida, microbiological evaluation and molecular typing should be performed in the samples taken from the respiratory tract in patients with chronic respiratory diseases such as bronchiectasis.