A rare infection of the trachea with the bacteria Achromobacter xylosoxidans deteriorated the respiratory function of an idiopathic bronchiectasis patient, a case study reports.
The U.K. case report “Achromobacter xylosoxidans in idiopathic cystic bronchiectasis,” was published in the journal BMJ Case Reports.
A. xylosoxidans is a bacterium that causes hospital-acquired infections, and is highly resistant to the action of multiple antibiotics. It is a strict aerobe, meaning it requires oxygen for growth. As a result, an infection with this bacterium puts an additional strain of increased oxygen demand on an already breathing-compromised bronchiectasis patient.
Bacterial infections contribute to the disease exacerbations seen in bronchiectasis patients. In the event of a rare, uncommon infection, timely identification is key to managing and treating the condition.
Here, researchers from the U.K. have described the case of a 66-year-old man admitted to the emergency ward with a productive cough and shortness of breath. His medical history included bronchiectasis and long-term supplemental oxygen therapy. He also had experienced recurrent ear infections since childhood.
His chest X-ray and CT (computed tomography) scans were consistent with a history of bronchiectasis.
An arterial blood gas test at admission revealed low oxygen (hypoxemia) and high carbon dioxide (hypercapnia) levels, indicating mild type II respiratory failure. A routine blood test also showed increased levels of C-reactive protein — an indicator of inflammation.
Microbiological analysis of the patient’s blood did not indicate bacterial infections.
The medical team suspected a case of infective exacerbation of bronchiectasis, and the patient was treated intravenously (through the vein) with the antibiotics co-amoxiclav and clarithromycin. He was then moved to the respiratory care unit for further treatment.
However, 24 hours later, his condition worsened, and he went into severe type II respiratory failure. Noninvasive breathing support was provided, but his health did not improve.
Blood gas test reflected respiratory failure, and the doctors explained the prognosis to the patient. A decision was made to move him to the intensive care unit. He was intubated, meaning he was given breathing support with the help of a flexible tube placed into the trachea through the mouth, and provided ventilator support.
After intubation and ventilation for seven days, the doctors performed a tracheostomy — an invasive breathing support technique in which a flexible tube is placed directly into the trachea through an incision in the throat. Despite all the breathing support provided, the oxygen levels in his blood kept dropping.
Blood work for any bacterial infection was again negative. However, laboratory testing of fluid from his trachea (tracheal aspiration) revealed the presence of A. xylosoxidans, which was absent at the time of intubation.
An antibiotic sensitivity test for A. xylosoxidans was performed, and showed that it was a very resistant strain.
The patient was then given a 14-day intravenous antimicrobial course of Tazocin, which is a combination of the two antibiotics, piperacillin and tazobactam. The patient responded well to treatment and was discharged after two months.
At a six-month follow-up, the patient had fully recovered from the A. xylosoxidans infection.
Based on this case report, the team concluded, “Given the inherent resistance of the genus [Achromobacter] to antimicrobial therapy, timely identification and appropriate treatment are especially important in the management of patients with systemic comorbidities such as bronchiectasis and immunodeficiency.”