First detection of multidrug-resistant and toxigenic Pasteurella aerogenes in sow vaginal discharge: a novel threat to swine health in Thailand.

Pasteurella aerogenes has been implicated in reproductive disorders in sows, yet its prevalence and characteristics in vaginal discharge are not well understood. This study aimed to detect P. aerogenes in sow vaginal discharge samples and investigate its antibiotic resistance profile, toxin genes, and toxicity. P. aerogenes was isolated from 40% (8/20) of samples. Antimicrobial susceptibility testing revealed universal resistance to amoxicillin-clavulanate (4:1), with 87.5% of isolates also resistant to oxytetracycline, amoxicillin, ceftriaxone, and enrofloxacin. The colistin resistance gene mcr-2 was detected in 75% of isolates, while class 1 integron (int1) was found in 12.5%. The pax toxin gene cluster was present in 75% of isolates. Toxicity assays using Panagrellus redivivus demonstrated dose-dependent effects of P. aerogenes supernatant containing pax toxins. This study represents the first report of P. aerogenes isolation from sow vaginal discharge in Thailand. The high prevalence of antibiotic resistance, presence of the mcr-2 gene, and toxicity of pax toxin-positive isolates suggest that P. aerogenes may be an underestimated factor in swine reproductive health. These findings highlight the need for further investigation into the role of P. aerogenes in sow reproductive disorders and its potential impact on swine production.

Pasteurella Infections in South Korea and Systematic Review and Meta-analysis of Pasteurella Bacteremia.

Pasteurella spp. can cause fatal zoonotic infections in humans. We performed a multicenter study to investigate the prevalence and clinical features of Pasteurella infections in South Korea during 2018‒2022. We also conducted a collaborative systematic review and meta-analysis of the global burden of Pasteurella bacteremia. The study included 283 cases found an increasing trend in Pasteurella infections. Blood cultures were positive in 8/35 (22.9%) cases sampled, for overall bacteremia-associated rate of 2.8% (8/283). Aging was a significant risk factor for bacteremia (odds ratio 1.05 [95% CI 1.01-1.10]), according to multivariate analyses. For the meta-analysis, we included a total of 2,012 cases from 10 studies. The pooled prevalence of bacteremia was 12.4% (95% CI 7.3%-18.6%) and of mortality 8.4% (95% CI 2.7%-16.5%). Our findings reflect the need for greater understanding of the increase in Pasteurella infections and the global burden of Pasteurella bacteremia to determine appropriate case management.

Prosthetic Valve Endocarditis Caused by Pasteurella dagmatis, Germany.

An 81-year-old male patient in Germany had prosthetic valve endocarditis caused by Pasteurella dagmatis after a domestic cat bite. We surgically treated a paravalvular abscess and administered definitive antibiotic therapy consisting of penicillin G and levofloxacin. The patient was discharged from the intensive care unit in good condition 21 days after the surgery.

Pasteurella bettyae Infections in Men Who Have Sex with Men, France.

Pasteurella bettyae is a gram-negative bacillus sporadically involved in human infections; its main reservoirs are cats and dogs. A recent publication suggests the possibility of sexual transmission leading to genital infections in men who have sex with men. We report 9 cases in France of genital infection among this population.

Rodentibacter caecimuris comb. nov., arising from the heterotypic synonymy between Pasteurella caecimuris Lagkouvardos et al. 2016 and Rodentibacter heylii Adhikary et al. 2017.

The misclassification of the species Pasteurella caecimuris Lagkouvardos et al. 2016 along with the heterotypic synonymy between P. caecimuris and Rodentibacter heylii Adhikary et al. 2017 has long been recognized. However, no formal assignment of P. caecimuris to its correct taxonomic position has been made accordingly and therefore the nomenclatural consequences have not been implemented. In the present study, the author first re-evaluates the taxonomic relationships of P. caecimuris using genome-based approaches, confirming the need of reclassification to the genus Rodentibacter and presenting evidence of the synonymy between R. heylii and P. caecimuris. Next, the author proposes a new name Rodentibacter caecimuris comb. nov. and, based on the priority of their specific epithets, treats Rodentibacter heylii as a later heterotypic synonym of Rodentibacter caecimuris.

To Lick One's Wounds: A Case of Pasteurella canis oralis Osteomyelitis and Neisseria animaloris Infection from Canine Saliva.

The complications of wound infections caused by animal related trauma are well known and explored. Of the numerous polymicrobial etiologies, Neisseria animaloris and Pasteurella canis oralis have been reported only in a limited number of cases. This manuscript explores the rare finding of these species in the case of an 83-year-old male with a diabetic foot wound complicated by infection from the saliva of his pet dog. The case highlights the first instance of P. canis oralis without the setting of a penetrating animal bite, emphasizing the vulnerability of open lesions in patients whose comorbidities impair proper wound healing. These bacteria are susceptible to beta-lactams with beta-lactamase inhibitors and can be treated once identified. It is crucial to recognize rare pathogens and initiate appropriate treatment early, and to emphasize proper wound care, especially in the context of pet interactions.

Pasteurella sp. associated with fatal septicaemia in six African elephants.

The sudden mortality of African elephants (Loxodonta africana) in Botswana and Zimbabwe in 2020 provoked considerable public interest and speculation. Poaching and malicious poisoning were excluded early on in the investigation. Other potential causes included environmental intoxication, infectious diseases, and increased habitat stress due to ongoing drought. Here we show evidence of the mortalities in Zimbabwe as fatal septicaemia associated with Bisgaard taxon 45, an unnamed close relative of Pasteurella multocida. We analyse elephant carcasses and environmental samples, and fail to find evidence of cyanobacterial or other intoxication. Post-mortem and histological findings suggest a bacterial septicaemia similar to haemorrhagic septicaemia caused by P. multocida. Biochemical tests and 16S rDNA analysis of six samples and genomic analysis of one sample confirm the presence of Bisgaard taxon 45. The genome sequence contains many of the canonical P. multocida virulence factors associated with a range of human and animal diseases, including the pmHAS gene for hyaluronidase associated with bovine haemorrhagic septicaemia. Our results demonstrate that Bisgaard taxon 45 is associated with a generalised, lethal infection and that African elephants are susceptible to opportunistically pathogenic Pasteurella species. This represents an important conservation concern for elephants in the largest remaining metapopulation of this endangered species.

Recombinant-attenuated Salmonella enterica serovar Choleraesuis vector expressing the PlpE protein of Pasteurella multocida protects mice from lethal challenge.

BACKGROUND: Bacterial surface proteins play key roles in pathogenicity and often contribute to microbial adhesion and invasion. Pasteurella lipoprotein E (PlpE), a Pasteurella multocida (P. multocida) surface protein, has recently been identified as a potential vaccine candidate. Live attenuated Salmonella strains have a number of potential advantages as vaccine vectors, including immunization with live vector can mimic natural infections by organisms, lead to the induction of mucosal, humoral, and cellular immune responses. In this study, a previously constructed recombinant attenuated Salmonella Choleraesuis (S. Choleraesuis) vector rSC0016 was used to synthesize and secrete the surface protein PlpE of P. multocida to form the vaccine candidate rSC0016(pS-PlpE). Subsequently, the immunogenicity of S. Choleraesuis rSC0016(pS-PlpE) as an oral vaccine to induce protective immunity against P. multocida in mice was evaluated. RESULTS: After immunization, the recombinant attenuated S. Choleraesuis vector can efficiently delivered P. multocida PlpE protein in vivo and induced a specific immune response against this heterologous antigen in mice. In addition, compared with the inactivated vaccine, empty vector (rSC0016(pYA3493)) and PBS immunized groups, the rSC0016(pS-PlpE) vaccine candidate group induced higher antigen-specific mucosal, humoral and mixed Th1/Th2 cellular immune responses. After intraperitoneal challenge, the rSC0016(pS-PlpE) immunized group had a markedly enhanced survival rate (80%), a better protection efficiency than 60% of the inactivated vaccine group, and significantly reduced tissue damage. CONCLUSIONS: In conclusion, our study found that the rSC0016(pS-PlpE) vaccine candidate provided good protection against challenge with wild-type P. multocida serotype A in a mouse infection model, and may potentially be considered for use as a universal vaccine against multiple serotypes of P. multocida in livestock, including pigs.

Lower respiratory infection in humans caused by pasteurella multocida.

BACKGROUND: Pasteurella (P.) multocida commonly occurs in the upper respiratory tract of healthy domestic pets, especially cats and dogs. People become infected by biting, scratching or direct contact with the animal's saliva. Inflammation develops in the wound and limits itself to the skin and subcutaneous tissue. P. multocida may cause respiratory tract infections and severe life-threatening complications. The study aimed to identify the lower respiratory infection in humans caused by P. multocida, to determine the potential source of infection and the associated symptoms, comorbidities and applied treatment. MATERIALS AND METHODS: Between January 2010 and September 2021, 14,258 patients underwent 16,255 routine flexible video bronchoscopy (FVB), and the same number of bronchoalveolar lavage fluid (BALF) samples for microbiological examination were taken. RESULTS: Microbiological examinations of the BALF only allowed the identification of six patients with P. multocida infection. All persons reported multiple scratches or bites and licking or kissing by their pets in the past. Productive cough with expectoration of mucopurulent discharge was the predominant symptom. CONCLUSIONS: A lower respiratory infection caused by P. multocida is not common in humans. It should be considered particularly in elderly patients with underlying diseases and exposure to cats and dogs.

Identification of serotypes of Mannheimia haemolytica and Pasteurella multocida from pneumonic cases of sheep and goats and their antimicrobial sensitivity profiles in Borana and Arsi zones, Ethiopia.

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

Pediatric Pasteurella canis endophthalmitis.

We report an atypical presentation of endophthalmitis in a 2-month-old infant due to a rare infection by Pasteurella canis, small Gram-negative coccobacilli that inhabit the oral cavity and the gastrointestinal tracts of animals, including domesticated cats and dogs. Ocular infections are mainly associated with animal bites and scratches.

Spectrum of human Pasteurella species infections in tropical Australia.

BACKGROUND: Acquired zoonotic infections with Pasteurella bacterial species have a wide clinical spectrum of disease from invasive infections to localised bite-wound infections. METHODS: This study reviewed the spectrum of the demographic, clinical, temporal, and microbiological trends of laboratory confirmed Pasteurella species infections presenting to a single-centre tropical tertiary hospital over a twenty-year period. RESULTS: 195 episodes from 190 patients were included. 51.3% patients were female, and 20.5% Aboriginal or Torres Strait Islander peoples. Crude incidence of Pasteurella spp. infections increased from 1.5 per 100,000 population in 2000, to 11.4 per 100,000 population in 2021. There were 22 (11.3%) bloodstream infections, 22 (11.3%) invasive, 34 (17.4%) deep local, 98 (50.2%) superficial infections, and 19 (9.7%) other or unknown. Adults over 65 years of age accounted for the majority of bacteraemias (63.7%). More severe infections, including bacteraemia, invasive and deep local infections, were more common in lower limb infections and in those with underlying comorbidities. Animal contact with cats was more common in bloodstream infections (36.4%), but dog bites more common in invasive, deep local and superficial infections. 30-day all-cause mortality was low at 1.0%. Pasteurella multocida was most commonly identified (61.1%), but P. canis, P. dagmatis, and other Pasteurella infections were also noted. 67.7% of specimens were polymicrobial, with other significant organisms being Staphylococcus aureus, Streptococcus pyogenes, Group G Streptococcus and Pseudomonas aeruginosa. CONCLUSION: Pasteurella species remain clinically important pathogens, with the ability to cause severe and invasive infections with associated morbidity. Presentations to hospital are becoming more common, and the polymicrobial nature of bites wounds has implications for empiric antibiotic guidelines.

Emergence of a floR-carrying plasmid in extended spectrum ß-lactamase (ESBL) producing Pasteurella aerogenes, isolated from an avian species in China.

Identification and analysis of the antimicrobial resistance of Pasteurella aerogenes (P. aerogenes) isolated from poultry. For susceptibility testing in accordance with the CLSI, plasmids were extracted via alkaline lysis and transferred by CaCl2 treatment. Genomic DNA of a representative P. aerogenes isolate was subjected to whole genome sequencing. CCCP was utilized to determine whether SF190908 contains an efflux pump. The blaVEB gene was ligated with the pET-28 plasmid and transferred to Escherichia coli to verify it as an ESBL gene. SF190908 isolated from poultry was identified as P. aerogenes based upon biochemical and 16s rRNA results. The isolate showed high MIC values for eight antimicrobials. Sequencing results showed that the mobile element-mediated antimicrobial resistance gene cluster conferred antimicrobial resistance on the strain, and a single 5,105-bp plasmid, designated pRCAD0752PA-1, was isolated. Four antimicrobial resistance gene clusters were identified in the SF190908 chromosome; one antimicrobial resistance gene cluster carried the blaVEB gene, which was verified as ESBL according to the CLSI and was detected in Pasteurellaceae for the first time, to the best of our knowledge. The efflux pump may confer antimicrobial resistance to SF190908. P. aerogenes isolated from poultry showed resistance genes encoded in mobile elements that confer multi-antimicrobial resistance to SF190908. The antimicrobial-resistant plasmid pRCAD0752PA-1 was isolated in SF190908 and conferred resistance to florfenicol. This study indicates an urgent need to increase efforts to monitor the spread of P. aerogenes multi-antimicrobial-resistant strains and plasmids, especially in newly discovered at-risk species such as poultry.

Pasteurella species bloodstream infections in Queensland, Australia, 2000-2019.

Pasteurella species are infrequent but potentially severe causes of bloodstream infection (BSI). The objective of this study was to determine the incidence, risk factors, and outcomes of Pasteurella species BSI in a large Australian population. Retrospective, laboratory-based surveillance was conducted in Queensland, Australia (population ≈ 5 million) during 2000-2019, and clinical and outcome information was established by linkage to state hospital admissions and vital statistics databases. During more than 86 million person-years of surveillance, 272 incident Pasteurella species BSI occurred for an overall age- and sex-standardized annual incidence of 3.3 per million residents. The incidence of Pasteurella species BSI was highest in recent years and older individuals were at greatest risk. The median (interquartile range) Charlson Comorbidity Index was 2 (0-4) with scores of zero, 1, 2, and 3 + observed in 81 (30%), 37 (14%), 44 (16%), and 110 (40%) of cases. The 30-day all-cause case fatality was 9% (24/272) and patients who died had more comorbidities and were less likely to have community-associated disease. Although Pasteurella species are infrequent causes of BSI, older individuals and those with comorbidities are at highest risk. The burden of this disease may be expected to increase with an aging and more comorbid population.

Pasteurella Endocarditis in a Patient with Rheumatic Mitral Valve Disease.

BACKGROUND As a common member of the oral bacterial flora of cats and dogs, Pasteurella multocida can cause skin and soft tissue infection in humans after bites, licks, or scratches from animals. Uncommonly, infection due to Pasteurella can cause sepsis in humans. Even more rare is the development of infectious endocarditis from a Pasteurella infection. CASE REPORT A 76-year-old woman presented with malaise and symptoms of fluid overload. Blood cultures were positive for Pasteurella multocida, and an echocardiogram was significant for mitral valve vegetation and severe biatrial enlargement. A diagnosis of Pasteurella endocarditis was made. Surgical intervention was recommended, but owing to the risk involved, the patient elected for conservative management involving long-term treatment with intravenous antibiotics. CONCLUSIONS While exceedingly rare, Pasteurella multocida can cause infectious endocarditis in patients with predisposing factors. This patient had a known history of rheumatic heart disease, which is believed to have caused the significant findings on imaging. To the best of our knowledge, our case is the only one to depict Pasteurella endocarditis in a patient with rheumatic heart disease and severe biatrial enlargement. It is the authors' belief that the rheumatic heart disease and remodeling of the heart increased her susceptibility to severe infection from Pasteurella. The purpose of this case is to describe the pathogenicity of an otherwise low-attack bacterial infection in an elderly patient with underlying structural acquired heart damage.

Femoral artery aneurysm with large hematoma from Pasteurella: case report and literature review.

BACKGROUND: Pasteurella multocida is a well-known gram-negative facultative anaerobe well known for its ability to cause soft tissue infections following animal bite or scratch. Here we present a case with mycotic aneurysm of the superficial femoral artery due to P. multocida infection. CASE PRESENTATION: A 62 year old male patient presented with worsening right leg pain and swelling. On examination, he was found to have profound swelling and erythema of the right medial thigh and tenderness to palpation. Computerized tomography showed findings suggestive of right femoral pseudoaneurysm with a large right medial thigh hematoma. Blood cultures grew P. multocida. Patient underwent emergent open resection of the mycotic aneurysm and vascular bypass surgery. Intraoperatively, the site was noted to be grossly infected with multiple pockets of pus which were drained and pus cultures grew P. multocida. The diagnosis of P. multocida bacteremia with right femoral mycotic aneurysm and thigh abscess was made. Patient received 6 weeks of intravenous ceftriaxone and recovered. CONCLUSION: Our case is the first report on infection of peripheral vessel with Pasteurella and highlights the importance of prompt surgical intervention and effective antibiotic treatment.