What is the significance of Alcaligenes xylosoxidans?

From the Guidelines

Alcaligenes xylosoxidans is a rare cause of infection in patients with bronchiectasis, and its management should be guided by antibiotic susceptibility testing, with consideration of combination therapy using agents such as carbapenems, trimethoprim-sulfamethoxazole, or piperacillin-tazobactam. When managing exacerbations of bronchiectasis, it is essential to consider the potential for colonization with various microorganisms, including H. influenzae, Pseudomonas spp., and other Gram-negative bacilli 1. In the case of Alcaligenes xylosoxidans, which is rarely encountered in bronchiectasis patients 1, treatment should prioritize agents with effective coverage against this organism. Key considerations in managing Alcaligenes xylosoxidans infections include:

• The use of antibiotic susceptibility testing to guide specific treatment 1
• The potential need for combination antibiotic therapy due to multidrug resistance 1
• The importance of proper infection control measures to prevent transmission in healthcare settings 1 Given the rarity of Alcaligenes xylosoxidans as a cause of infection in bronchiectasis and the lack of specific guidance in the provided evidence, treatment should be individualized based on clinical presentation, antibiotic susceptibility testing, and consideration of the patient's overall health status. In general, the management of bronchiectasis exacerbations should follow a structured approach, including:
• Obtaining sputum cultures to guide antibiotic therapy 1
• Using antibiotics with good bronchial penetration and the ability to decrease bacterial burden 1
• Considering the potential for antibiotic resistance and adjusting treatment accordingly 1

From the Research

Alcalingenes xylosoxidans Overview

• Alcaligenes xylosoxidans is a non-fermenting gram-negative bacterium that can cause opportunistic infections in humans, particularly in immunocompromised individuals 2, 3.
• The bacterium is often found in aqueous environments and can be resistant to multiple antibiotics, making treatment challenging 4, 5.

Clinical Features and Infections

• Alcaligenes xylosoxidans can cause a range of infections, including bacteremia, pneumonia, urinary tract infections, and skin and soft tissue infections 4, 3.
• The clinical presentation of A. xylosoxidans infections can vary, but primary bacteremia and pneumonia are common manifestations 3.
• The mortality rate for A. xylosoxidans infections can be high, particularly in immunocompromised hosts and those with underlying diseases 6, 3.

Antimicrobial Susceptibility

• A. xylosoxidans isolates have been shown to be susceptible to certain antibiotics, including imipenem, meropenem, and piperacillin-tazobactam 4, 5.
• However, the bacterium can also be resistant to multiple antibiotics, including aminoglycosides, ciprofloxacin, and cefepime 4, 5.
• The use of combination antibiotic therapy may be effective in treating A. xylosoxidans infections, but the optimal treatment regimen is not well established 5.

Epidemiology and Prevention

• A. xylosoxidans infections can be nosocomially acquired, and outbreaks have been reported in healthcare settings 4, 3.
• Strict infection control measures, including the use of sterile equipment and proper hand hygiene, are essential to prevent the spread of A. xylosoxidans infections 4, 2.
• The removal of central venous catheters and other invasive devices can also help to prevent A. xylosoxidans infections in high-risk patients 2.