What are the recommendations for managing the rising burden of fecal carriage of colistin and carbapenem-resistant Gram-Negative Bacteria (GNBs)?

From the Guidelines

To manage the rising burden of fecal carriage of colistin and carbapenem-resistant Gram-Negative Bacteria (GNBs), a comprehensive approach involving infection control measures, antimicrobial stewardship, and targeted decolonization strategies is recommended.

Key Recommendations

• Active surveillance through rectal swabs or stool cultures should be implemented in high-risk settings such as intensive care units and transplant wards to identify carriers 1.
• Strict contact precautions including patient isolation, dedicated equipment, and enhanced environmental cleaning are essential for preventing transmission.
• Healthcare workers should adhere to rigorous hand hygiene protocols using alcohol-based hand sanitizers or soap and water before and after patient contact.
• Antimicrobial stewardship programs should restrict the use of carbapenems and colistin to necessary cases only, with appropriate dosing and duration.
• For decolonization, selective digestive decontamination may be considered in specific situations using non-absorbable antibiotics like oral gentamicin (80mg four times daily), colistin (2 million units four times daily), or neomycin (500mg four times daily) for 5-7 days, though evidence for routine use remains limited 1.

Rationale

The intestinal tract serves as a major reservoir for resistant GNBs, facilitating both patient colonization and environmental contamination. The gut microbiome disruption caused by broad-spectrum antibiotics creates favorable conditions for resistant bacteria to proliferate, highlighting the importance of judicious antibiotic use alongside infection control measures to reduce the overall burden of these difficult-to-treat pathogens.

Infection Control Measures

• Single room isolation is preferred, and separate toilet should be provided for those infected/colonized with CRGNB 1.
• When resource is limited, priority of single room isolation should be given to those with fecal or urinary incontinence, using invasive device/equipment, or having continuous wound secretion; cohorting isolation for those infected or colonized with the same CRGNB species.
• Nursing staffs designated to care for patients with CRGNB infections or colonization should not participate in caring for other patients (Nursing staff cohorting) 1.

Antimicrobial Stewardship

• Novel β-lactam agents such as ceftazidime/avibactam and meropenem/vaborbactam should be the first-line treatment options for patients with infections caused by KPC-producing carbapenem-resistant Enterobacterales (CRE) 1.
• Imipenem/relebactam and cefiderocol may also be considered as potential alternatives for the treatment of infections involving KPC-producing CRE 1.

From the Research

Burden of Fecal Carriage of Colistin and Carbapenem-Resistant GNBs

• The spread of carbapenem-resistant Gram-negative bacteria (GNB) is a significant concern worldwide, with the rapid expansion of acquired carbapenem resistance increasingly propagated by mobile genetic elements 2.
• The risk of acquisition of carbapenem-resistant Acinetobacter baumannii increases four-fold with carbapenem exposure, and new meta-analyses have confirmed excess mortality associated with carbapenem-resistant Pseudomonas aeruginosa 2.
• Carbapenemase-producing Klebsiella pneumoniae is a major cause of high-mortality hospital-related infections and represents the most rapidly growing global threat 2.

Risk Factors for Fecal Carriage of Colistin and Carbapenem-Resistant GNBs

• History of antibiotics and nasogastric tube (NGT) use are risk factors for infection with carbapenem-resistant Gram-negative bacteria (CR-GNB) 3.
• The presence of any indwelling device and nasogastric tube are independent risk factors for acquiring gut colonization with carbapenem-resistant Enterobacteriaceae (CRE) 4.
• Prior antibiotic exposure and NGT use are risk factors for CR-GNB infections, and strict implementation of antimicrobial stewardship programs and adherence to infection prevention and control are warranted to curb CR-GNB infections 3.

Management of Fecal Carriage of Colistin and Carbapenem-Resistant GNBs

• Ceftazidime/avibactam combined with colistin is a novel attempt to treat carbapenem-resistant Gram-negative bacilli infection, with potential efficacy in patients with CR-GNB infection 5.
• Ceftazidime/avibactam and meropenem/vaborbactam are changing the management of invasive infections due to carbapenem-resistant Enterobacteriaceae (CRE), leading to higher rates of clinical cure, decreased mortality, and decreased rates of acute kidney injury compared with colistin-based regimens 6.
• The combination of CAZ/AVI and colistin has potential efficacy in patients with CR-GNB infection, but more studies are needed to determine whether it can reduce 30-day mortality rates and increase 7-day microbial clearance 5.