Calcaneal osteomyelitis due to Achromobacter xylosoxidans: a case report

Chronic otorrhea and osteomyelitis of the external auditory canal by Achromobacter xylosoxidans: an uncommon diagnosis

PURPOSE

Achromobacter xylosoxidans is an emerging pathogen mainly associated with resistant nosocomial infections. This bacteria had been isolated in the ear together with other pathogens in cultures from patients with chronic otitis media, but it had never been reported as a cause of osteomyelitis of the external auditory canal.

CASE PRESENTATION

We present a unique case of a healthy 81-year-old woman who presented with left chronic otorrhea refractory to topical and oral antibiotic treatment. Otomicroscopy revealed an erythematous and exudative external auditory canal (EAC) with scant otorrhea. The tympanic membrane was intact, but an area of bone remodeling with a small cavity anterior and inferior to the bony tympanic frame was observed. Otic culture isolated multi-drug-resistant A. xylosoxidans, only sensitive to meropenem and cotrimoxazole. Temporal bone computed tomography showed an excavation of the floor of the EAC compatible with osteomyelitis. Targeted antibiotherapy for 12 weeks was conducted, with subsequent resolution of symptoms and no progression of the bone erosion.

CONCLUSIONS

Atypical pathogens such as A. xylosoxidans can be the cause of chronic otitis externa. Early diagnosis and specific antibiotherapy can prevent the development of further complications, such as osteomyelitis. In these cases, otic cultures play an essential role to identify the causal germ. This is the first case of EAC osteomyelitis due to A. xylosoxidans reported to date.

Opportunistic Pathogens in Cystic Fibrosis: Epidemiology and Pathogenesis of Lung Infection

Cystic fibrosis (CF) is one of the most common life-shortening genetic diseases in Caucasians. Due to abnormal accumulation of mucus, respiratory failure caused by chronic infections is the leading cause of mortality in this patient population. The microbiology of these respiratory infections includes a distinct set of opportunistic pathogens, including Pseudomonas aeruginosa, Burkholderia spp., Achromobacter spp., Stenotrophomonas maltophilia, anaerobes, nontuberculous mycobacteria, and fungi. In recent years, culture-independent methods have shown the polymicrobial nature of lung infections, and the dynamics of microbial communities. The unique environment of the CF airway predisposes to infections caused by opportunistic pathogens. In this review, we will highlight how the epidemiology and role in disease of these pathogens in CF differ from that in individuals with other medical conditions. Infectious diseases (ID) physicians should be aware of these differences and the specific characteristics of infections associated with CF.

A case of meningitis due to Achromobacter xylosoxidans in a child with a polymalformative syndrome: a case report

Achromobacter xylosoxidans (AX), also called alcaligenes xylosoxidans, is an aerobic, non-fermenting mobile, gram-negative bacillus which was first isolated in an otorrhea samples in 1971. Infections with these species are quite rare and have often been described in immunocompromised and in premature infants. However, very few cases of meningitis related to AX have been reported in the literature. The authors report a new case of meningitis due to AX in a 45-day-old female infant with polymarformative syndrome meningitis was confirmed by a cyto-biochemical analysis and culture of the cerebrospinal fluid and was treated by antibiotherapy. Hydrocephalus was managed initially with external ventricular drainage followed by a ventriculoperitoneal shunt after rigorous cerebrospinal fluid (CSF) sterilization, with good clinical and radiological outcomes. The prompt and adequate antibiotic adjustment following bacterial isolation has been shown to rapidly modify the clinical outcomes.

Chronic osteomyelitis caused by Achromobacter xylosoxidans following orthopaedic trauma: A case report and review of the literature

Background

Achromobacter xylosoxidans is an opportunistic environmental aerobe. In cases where A. xylosoxidans infects humans, it most commonly manifests as bacteraemia in the immunosuppressed. A. xylosoxidans causing chronic osteomyelitis is rare, particularly in the immunocompetent and young.

Case

We present the case of a 23-year-old man with chronic osteomyelitis of the right femur caused by co-infection of A. xylosoxidans and Staphylococcus aureus. Five years earlier, he had sustained a right femur fracture and was treated with intramedullary fixation at a peripheral hospital in a developing nation. Past medical history was otherwise unremarkable. Management comprised of surgical debridement and culture-directed antibiotic therapy, resulting in clinical cure.

Conclusion

In the context of local trauma and previous surgery, osteomyelitis caused by atypical pathogens must be considered. A multidisciplinary approach commensurate with duration and severity of infection and tailored to the causative organism is paramount.

Achromobacter Infections and Treatment Options

Achromobacter is a genus of nonfermenting Gram-negative bacteria under order Burkholderiales Although primarily isolated from respiratory tract of people with cystic fibrosis, Achromobacter spp. can cause a broad range of infections in hosts with other underlying conditions. Their rare occurrence and ever-changing taxonomy hinder defining their clinical features, risk factors for acquisition and adverse outcomes, and optimal treatment. Achromobacter spp. are intrinsically resistant to several antibiotics (e.g., most cephalosporins, aztreonam, and aminoglycosides), and are increasingly acquiring resistance to carbapenems. Carbapenem resistance is mainly caused by multidrug efflux pumps and metallo-β-lactamases, which are not expected to be overcome by new β-lactamase inhibitors. Among the other new antibiotics, cefiderocol, and eravacycline were used as salvage therapy for a limited number of patients with Achromobacter infections. In this article, we aim to give an overview of the antimicrobial resistance in Achromobacter species, highlighting the possible place of new antibiotics in their treatment.

Osteomyelitis caused by Achromobacter xylosoxidans

Achromobacter xylosoxidans is an aerobic, nonfermenting gram-negative rod and described as a waterborne bacterium since it habits aquatic environments ubiquitously. It has frequently been isolated from aquatic surroundings in the hospital and from various human body sites. Although occasionally considered a non-pathogen, A. xylosoxidans has been associated with outbreaks of nosocomial infection due to contaminated fluids. Moreover, a wide variety of infectious etiologies due to A. xylosoxidans has been reported primarily in immunocompromised individuals. Heightened awareness of this bacterium and associated clinical importance is warranted for clinicians since its broad disease spectrum in humans and frequent multi-drug resistance may result in an increased mortality rate. In this report, we describe a case of osteomyelitis caused by A. xylosoxidans in a patient with a history of diabetes mellitus.

L5-S1 Achromobacter xylosoxidans infection secondary to oxygen-ozone therapy for the treatment of lumbosacral disc herniation: a case report and review of the literature

STUDY DESIGN

Case report and literature review.

OBJECTIVE

To present a unique case of Achromobacter xylosoxidans infection secondary to oxygen-ozone therapy for the treatment of L5-S1 disc herniation.

SUMMARY OF BACKGROUND DATA

Oxygen-ozone therapy is a minimally invasive technique for the treatment of lumbar disc herniations, with unproven efficacy and few reported complications. Achromobacter xylosoxidans is an opportunistic pathogen that inhabits aquatic environments and is a rare cause of osteomyelitis. To the best of our knowledge, this is the first report of A. xylosoxidans spondylodiscitis in the lumbar spine and the third report of spinal infection after intradiscal oxygen-ozone chemonucleolysis in the English literature.

METHODS

The medical records, operative reports, and radiographical imaging studies of a single patient were retrospectively reviewed.

RESULTS

A 29-year-old female patient who previously underwent oxygen-ozone therapy for L5-S1 disc herniation presented to our institution with a 5-month history of intractable back and leg pain. The patient's laboratory studies were within normal limits and did not indicate signs of an active infection. Her physical examination revealed globally decreased muscle strength (4/5) and hyperesthesia in the lower extremities. Magnetic resonance imaging and computed tomography revealed severe disc degeneration and vertebral body endplate changes at L5-S1, in addition to paravertebral soft tissue swelling consistent with a previous infection. Given the severity of symptoms, the patient underwent anterior lumbar interbody fusion and posterior segmental instrumentation at L5-S1. Histopathological evaluation of the disc material confirmed the diagnosis of chronic osteomyelitis and septic discitis at L5-S1. Intraoperative cultures grew A. xylosoxidans and Propionibacterium acnes. The patient had prompt improvement in her level of pain and was discharged on a 6-week course of piperacillin-tazobactam without complication.

CONCLUSION

This first report of A. xylosoxidans vertebral infection secondary to oxygen-ozone therapy illustrates the wide variety of environmental pathogens that can complicate the percutaneous treatment of degenerative vertebral disease.