Pasteurella multocida: a case report of bacteremic pneumonia and 10-year laboratory review

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.

A case of Pasteurella multocida pneumonia needed to differentiate from non-tuberculous mycobacteriosis

We report a case of Pasteurella multocida pneumonia. A 71-year old Japanese woman with pulmonary infiltration of the lingual division of left lung 3 years before, which was thought to be caused by non-tuberculous mycobacteriosis (NTM) was referred to our clinic on account of chronic cough, sputum, dyspnea, and left pulmonary infiltration. Although she owned over 10 cats, no bites or scratches were mentioned. Pasteurella multocida was confirmed by the culture of the patient’s bronchoalveolar lavage (BAL) fluid. NTM infection was ruled out by acid-fast bacillus smears, cultures, and polymerase chain reaction of three sputum specimens and BAL fluid. The infection route in this case was considered to have resulted from inhalation of contaminated aerosols or contact with her cats. Close contact with animals should be avoided, particularly for patients with chronic pulmonary diseases, as it is a risk factor for pneumonia due to Pasteurella multocida.

Clinical Features and Outcomes of Pasteurella multocida Infection

Pasteurella multocida, a zoonotic infectious organism, has most often been described in patients after an animal bite. Here, we characterize the clinical features and outcomes of P multocida infection in a large cohort of patients according to the presence or absence of an animal bite.We retrospectively searched MUSC's laboratory information system for all patients with positive P multocida cultures from 2000 to 2014. Extensive data were abstracted, including clinical and outcome data. The Charlson comorbidity index (CCI) was used to assess comorbidities among patients.We identified 44 patients with P multocida infections, including 25 with an animal bite. The average age was 64 years and the majority of patients were women (N = 30). There was no difference in age and sex distribution among those with and without a bite (P = 0.38 and 0.75, respectively). A CCI ≥1 was significantly associated with the absence of a bite (P = 0.006). Patients presenting without a bite were more frequently bacteremic (37% vs 4%, respectively, P = 0.001), and were hospitalized more often (84% vs 44%, respectively, P = 0.012). Of the 8 patients who required intensive care unit (ICU)-based care, 7 were non-bite-related. There were 4 deaths, all occurring in patients not bitten.P multocida infections not associated with an animal bite were often associated with bacteremia, severe comorbidity(ies), immune-incompetent states, the need for ICU management, and were associated with substantial mortality.

Pasteurella multocida: from zoonosis to cellular microbiology

In a world where most emerging and reemerging infectious diseases are zoonotic in nature and our contacts with both domestic and wild animals abound, there is growing awareness of the potential for human acquisition of animal diseases. Like other Pasteurellaceae, Pasteurella species are highly prevalent among animal populations, where they are often found as part of the normal microbiota of the oral, nasopharyngeal, and upper respiratory tracts. Many Pasteurella species are opportunistic pathogens that can cause endemic disease and are associated increasingly with epizootic outbreaks. Zoonotic transmission to humans usually occurs through animal bites or contact with nasal secretions, with P. multocida being the most prevalent isolate observed in human infections. Here we review recent comparative genomics and molecular pathogenesis studies that have advanced our understanding of the multiple virulence mechanisms employed by Pasteurella species to establish acute and chronic infections. We also summarize efforts being explored to enhance our ability to rapidly and accurately identify and distinguish among clinical isolates and to control pasteurellosis by improved development of new vaccines and treatment regimens.

[Unusual pneumonia by Pasteurella multocida]

Pasteurellosis is an infection caused by inoculation usually through bites or scratches. Pasteurella multocida is involved in 50 to 60% of cases. Cats are the main vectors of the pathogen. Immunodepression increases the risk of systemic disease. We report a case of Pasteurella multocida pneumonia in an 81-year-old patient who had no cutaneous portal of entry. The patient had a past medical history of rectal neoplasia and prostate neoplasia treated with brachytherapy and hormonal therapy respectively. He had an environmental risk factor (the presence of a cat at home). The diagnosis was confirmed by repeated blood cultures. Antimicrobial therapy resulted in clinical, biological and radiological improvement. This case report raises the question of a possible pathogenesis different from the commonly described "inoculation".

Pasteurella multocida involved in respiratory disease of wild chimpanzees

Pasteurella multocida can cause a variety of diseases in various species of mammals and birds throughout the world but nothing is known about its importance for wild great apes. In this study we isolated P. multocida from wild living, habituated chimpanzees from Taï National Park, Côte d'Ivoire. Isolates originated from two chimpanzees that died during a respiratory disease outbreak in 2004 as well as from one individual that developed chronic air-sacculitis following this outbreak. Four isolates were subjected to a full phenotypic and molecular characterisation. Two different clones were identified using pulsed field gel electrophoresis. Multi Locus Sequence Typing (MLST) enabled the identification of previous unknown alleles and two new sequence types, ST68 and ST69, were assigned. Phylogenetic analysis of the superoxide dismutase (sodA) gene and concatenated sequences from seven MLST-housekeeping genes showed close clustering within known P. multocida isolated from various hosts and geographic locations. Due to the clinical relevance of the strains described here, these results make an important contribution to our knowledge of pathogens involved in lethal disease outbreaks among endangered great apes.

Pig trotters lung--novel domestic transmission of Pasteurella multocida

Pasteurella multocida is a non-motile, faculatively-anaerobic, gram-negative bacillus associated with a spectrum of human disease. Direct and indirect zoonotic transmission is recognised with animal bites being most frequently encountered as a result of salivary colonisation in farm and domestic animals. Despite the prevalence of P. multocida in swine herds, the relationship between porcine colonisation and human disease is poorly established. This lesson reports a previously unrecognised mode of zoonotic transmission in respiratory pasteurellosis; domestic cooking of pig trotters.

Acute suppurative thyroiditis caused by Pasteurella multocida and associated with thyrotoxicosis

Acute suppurative thyroiditis (AST) is an uncommon condition of the thyroid gland. Organisms of the staphylococcal and streptococcal species are the most commonly reported causative agents. Rarely, AST has been associated with transient hyperthyroidism. We report a unique case of AST that was caused by Pasteurella multocida and was associated with thyrotoxicosis in a previously healthy 51-year-old woman.