Hafnia alvei pneumonia: a rare cause of infection in the multimorbid or immunocompromised

Isolation of Hafnia alvei from bronchoalveolar lavage of an immunocompetent host presenting with cavitating pneumonia: Contaminant or Causative?

Introduction

Hafnia alvei is a Gram-negative, facultative anaerobic bacillus that is most often found as an enteric commensal. It is seldom considered to be pathogenic in immunocompetent individuals.

Case report

We describe a case of a 23-year-old, previously healthy male, who presented to the emergency department with a two-day history of hemoptysis, mild dyspnea, pleuritic chest pain, fevers, and chills. Bloods revealed leukocytosis and elevated C-reactive protein. Chest X-ray and CT of the thorax revealed a cavitating lesion in the right upper lobe. He was commenced on empiric antibiotic treatment with amoxicillin/clavulanate and clarithromycin for community-acquired pneumonia in accordance with local guidelines. He subsequently underwent a bronchoscopy, and the bronchoalveolar lavage sample revealed a heavy growth of H. alvei. Despite the widely documented natural resistance of H. alvei to penicillin, the patient demonstrated complete resolution of his symptoms and initial raised inflammatory markers.

Conclusions

We present a case of community-acquired cavitary pneumonia in a previously healthy young adult with H. alvei isolated from bronchoalveolar lavage samples. Parallels are drawn between our case and other cases of H. alvei respiratory isolates in our discussion of its clinical significance.

An In-Silico Investigation to Design a Multi-Epitopes Vaccine against Multi-Drug Resistant Hafnia alvei

Antimicrobial resistance has become a significant health issue because of the misuse of antibiotics in our daily lives, resulting in high rates of morbidity and mortality. Hafnia alvei is a rod-shaped, Gram-negative and facultative anaerobic bacteria. The medical community has emphasized H. alvei’s possible association with gastroenteritis. As of now, there is no licensed vaccine for H. alvei, and as such, computer aided vaccine design approaches could be an ideal approach to highlight the potential vaccine epitopes against this bacteria. By using bacterial pan-genome analysis (BPGA), we were able to study the entire proteomes of H. alvei with the aim of developing a vaccine. Based on the analysis, 20,370 proteins were identified as core proteins, which were further used in identifying potential vaccine targets based on several vaccine candidacy parameters. The prioritized vaccine targets against the bacteria are; type 1 fimbrial protein, flagellar hook length control protein (FliK), flagellar hook associated protein (FlgK), curli production assembly/transport protein (CsgF), fimbria/pilus outer membrane usher protein, fimbria/pilus outer membrane usher protein, molecular chaperone, flagellar filament capping protein (FliD), TonB-dependent hemoglobin /transferrin/lactoferrin family receptor, Porin (OmpA), flagellar basal body rod protein (FlgF) and flagellar hook-basal body complex protein (FliE). During the epitope prediction phase, different antigenic, immunogenic, non-Allergenic, and non-Toxic epitopes were predicted for the above-mentioned proteins. The selected epitopes were combined to generate a multi-epitope vaccine construct and a cholera toxin B subunit (adjuvant) was added to enhance the vaccine’s antigenicity. Downward analyses of vaccines were performed using a vaccine three-dimensional model. Docking studies have confirmed that the vaccine strongly binds with MHC-I, MHC-II, and TLR-4 immune cell receptors. Additionally, molecular dynamics simulations confirmed that the vaccine epitopes were exposed to nature and to the host immune system and interpreted strong intermolecular binding between the vaccine and receptors. Based on the results of the study, the model vaccine construct seems to have the capacity to produce protective immune responses in the host, making it an attractive candidate for further in vitro and in vivo studies.

Complete Genome Sequence of a Novel Hafnia alvei Bacteriophage

A bacteriophage that is able to infect Hafnia alvei and can also infect two other hosts, Klebsiella pneumoniae and Salmonella enterica, was isolated from wastewater. The complete genome sequence was determined by long-read PacBio sequencing. Based on sequence similarity, the bacteriophage is assigned to the viral genus Kolesnikvirus within the family Myoviridae.

[Rare Cause of Lung Tumour - Pulmonary Infection with Hafnia alvei: A Case Report]

If a malignant disease is suspected, rapid diagnosis of suspicious pulmonary masses is required. In the presented case, malignancy was repeatedly not proven. Only the test-appropriate antibiotic treatment of an intestinal germ that was initially assessed as an impurity brought the therapeutic success with total remission. In our case the treatment with broad-spectrum penicillin piperacillin/tazobactam was ineffective and only the gyrase inhibitors ciprofloxacin and levofloxacin brought therapeutic success.

Hafnia alvei Pneumonia: A Rare Cause of Infection in a Patient with COVID-19

Herein, we describe a case report of a critically ill patient, a 48-year-old man without comorbidities admitted to the hospital with a serious type 1 (hypoxemic) respiratory insufficiency and confirmed diagnosis of COVID-19. After 5 days with invasive mechanical ventilation, the patient developed a bacterial co-infection, namely a pneumonia by Hafnia alvei, requiring the last line of respiratory support: extracorporeal membrane oxygenation (ECMO). Subsequently, his clinical situation gradually stabilized, until he was discharged from the hospital on day 61, being accompanied in ambulatory consultation by the physical medicine and pulmonology department during the post-COVID-19 recovery. H. alvei is a Gram-negative bacterium that is rarely isolated from human specimens and is rarely considered to be pathogenic. However, COVID-19 disease can cause substantial organ dysfunction and can be associated with bacterial secondary infections which can favor the emergence of rare infectious diseases by uncommon microorganisms.