A case of cervical subcutaneous abscess due to Bordetella hinzii

Uncovering the Unseen: Bordetella hinzii Emerges in a Lung Transplant Recipient

Bordetella hinzii (B. hinzii), a Gram-negative bacillus commonly associated with respiratory infections in animals, has garnered attention for its sporadic cases in humans, particularly in immunocompromised individuals. Despite its opportunistic nature, there remains limited understanding regarding its pathogenicity, diagnostic challenges, and optimal treatment strategies, especially in the context of immunosuppression. Herein, we present the first documented case of acute bronchitis caused by B. hinzii in an immunocompromised patient following double-lung transplantation. The patient, a former smoker with sarcoidosis stage IV, underwent transplant surgery and subsequently developed a febrile episode, leading to the identification of B. hinzii in broncho-alveolar lavage samples. Antimicrobial susceptibility testing revealed resistance to multiple antibiotics, necessitating tailored treatment adjustments. Our case underscores the importance of heightened awareness among clinicians regarding B. hinzii infections and the imperative for further research to elucidate its epidemiology and optimal management strategies, particularly in immunocompromised populations.

Bordetella bronchiseptica and Bordetella pertussis: Similarities and Differences in Infection, Immuno-Modulation, and Vaccine Considerations

Bordetella pertussis and Bordetella bronchiseptica belong to the genus Bordetella, which comprises 14 other species. B. pertussis is responsible for whooping cough in humans, a severe infection in children and less severe or chronic in adults. These infections are restricted to humans and currently increasing worldwide. B. bronchiseptica is involved in diverse respiratory infections in a wide range of mammals. For instance, the canine infectious respiratory disease complex (CIRDC), characterized by a chronic cough in dogs. At the same time, it is increasingly implicated in human infections, while remaining an important pathogen in the veterinary field. Both Bordetella can evade and modulate host immune responses to support their persistence, although it is more pronounced in B. bronchiseptica infection. The protective immune responses elicited by both pathogens are comparable, while there are important characteristics in the mechanisms that differ. However, B. pertussis pathogenesis is more difficult to decipher in animal models than those of B. bronchiseptica because of its restriction to humans. Nevertheless, the licensed vaccines for each Bordetella are different in terms of formulation, route of administration and immune responses induced, with no known cross-reaction between them. Moreover, the target of the mucosal tissues and the induction of long-lasting cellular and humoral responses are required to control and eliminate Bordetella. In addition, the interaction between both veterinary and human fields are essential for the control of this genus, by preventing the infections in animals and the subsequent zoonotic transmission to humans.

Detection and characterisation of Bordetella hinzii in line-related bacteraemia and respiratory tract infection in Australia

Bordetella hinzii has emerged as an unusual cause of infection in immunocompromised patients, previously linked to zoonotic transmission. Antimicrobial susceptibility and genetic diversity of B. hinzii are poorly understood. This study reports phenotypic and genomic characteristics of the first four Australian isolates of B. hinzii obtained from elderly immunocompromised patients. Bordetella hinzii isolates were identified by MALDI-TOF and whole genome sequencing (WGS). Antibiotic susceptibility testing was performed using disk diffusion or E-test. Genomes of B. hinzii were analysed in global context. A phylogenetic tree was constructed of all isolates using Roary and a maximum-likelihood tree was generated from the core-snp alignment. Bordetella hinzii minimum inhibitory concentrations (MICs) were largely uniform with high MICs to ampicillin, ceftriaxone and ciprofloxacin and low MICs to meropenem and piperacillin-tazobactam. Genomic analysis of isolate sequences divided strains analysed into two phylogenetically distinct groups, with one Australian B. hinzii isolate (AUS-4) assigned to Group 1, and the remaining isolates (AUS1-AUS3 and AUS-5) to Group 2. Single nucleotide polymorphism (SNP) analysis revealed two isolates, AUS-1 and AUS-2, were closely related with 14 SNP differences between them. All other Australian isolates were unrelated to each and all other isolates from the international dataset. Bordetella hinzii appears to pose a risk to immunocompromised individuals but remains susceptible to extended spectrum β-lactam and carbapenem antibiotics. Genomic analysis suggested a dissemination of genetically distinct strains.

Bordetella hinzii Pneumonia and Bacteremia in a Patient with SARS-CoV-2 Infection

Patients with severe acute respiratory syndrome coronavirus 2 infection may have bacterial co-infections, including pneumonia and bacteremia. Bordetella hinzii infections are rare, may be associated with exposure to poultry, and have been reported mostly among immunocompromised patients. We describe B. hinzii pneumonia and bacteremia in a severe acute respiratory syndrome coronavirus 2 patient.

Bordetella hinzii Meningitis in Patient with History of Kidney Transplant, Virginia, USA

A patient in Virginia, USA, who had previously undergone multiple kidney transplantations showed signs of Bordetella hinzii bacteremia and meningitis. This emerging pathogen has been increasingly identified as a clinically significant pathogen in immunosuppressed and, less frequently, immunocompetent patients. This patient was treated and recovered without further issue.

In vivo evolution of an emerging zoonotic bacterial pathogen in an immunocompromised human host

Zoonotic transfer of animal pathogens to human hosts can generate novel agents, but the genetic events following such host jumps are not well studied. Here we characterize the mechanisms driving adaptive evolution of the emerging zoonotic pathogen Bordetella hinzii in a patient with interleukin-12 receptor β1 deficiency. Genomic sequencing of 24 B. hinzii isolates cultured from blood and stool over 45 months revealed a clonal lineage that had undergone extensive within-host genetic and phenotypic diversification. Twenty of 24 isolates shared an E9G substitution in the DNA polymerase III ε-subunit active site, resulting in a proofreading deficiency. Within this proofreading-deficient clade, multiple lineages with mutations in DNA repair genes and altered mutational spectra emerged and dominated clinical cultures for more than 12 months. Multiple enzymes of the tricarboxylic acid cycle and gluconeogenesis pathways were repeatedly mutated, suggesting rapid metabolic adaptation to the human environment. Furthermore, an excess of G:C > T:A transversions suggested that oxidative stress shaped genetic diversification during adaptation. We propose that inactivation of DNA proofreading activity in combination with prolonged, but sub-lethal, oxidative attack resulting from the underlying host immunodeficiency facilitated rapid genomic adaptation. These findings suggest a fundamental role for host immune phenotype in shaping pathogen evolution following zoonotic infection.

Bordetella hinzii is an emerging pathogen with zoonotic risk to humans, known to be able to cause respiratory tract infection, bacteremia and endocarditis. Here, applying whole genome sequencing to bacterial isolates, the authors characterize the mechanisms driving adaptive evolution in B. hinzii in a patient with interleukin-12 receptor β1 deficiency, suggesting a role for host immune phenotype in shaping within-host pathogen evolution following zoonotic infection.

Peripancreatic abscess supported by Bordetella hinzii

We report a novel case of an infection with Bordetella hinzii, a pathogen usually detected in poultry, supporting a peripancreatic abscess formation as a complication of an acute necrotizing pancreatitis.