What is Klebsiella aerogenes (Klebsiella pneumoniae subspecies aerogenes)?

From the Guidelines

Klebsiella aerogenes infections should be treated with novel β-lactam agents such as ceftazidime/avibactam or meropenem/vaborbactam as first-line options, as they have shown improved clinical outcomes and reduced mortality compared to traditional antibiotic regimens 1.

Treatment Options

• Ceftazidime/avibactam and meropenem/vaborbactam are recommended as first-line treatment options for infections caused by KPC-producing carbapenem-resistant Enterobacterales (CRE), including Klebsiella aerogenes, due to their strong efficacy and moderate certainty of evidence 1.
• Imipenem/relebactam and cefiderocol may also be considered as potential alternatives for the treatment of infections involving KPC-producing CRE, although clinical studies of their efficacy in these patients are limited 1.

Rationale

• The introduction of new antibiotics such as ceftazidime/avibactam and meropenem/vaborbactam has changed the therapeutic approach to CRE infections and improved clinical outcomes in patients with these infections 1.
• Traditional antibiotic regimens, including combinations of carbapenems, aminoglycosides, and colistin, have been associated with poor efficacy and unfavorable toxicity profiles, with approximately one in three patients dying and less than 70% achieving a clinical or microbiological response 1.
• Observational studies have shown that ceftazidime/avibactam is safer than colistin due to its lower risk of nephrotoxicity and has a higher clinical cure rate compared to other drugs in patients with CPE infections 1.
• Meropenem/vaborbactam has been associated with a higher clinical cure rate, decreased mortality, and reduced nephrotoxicity compared to the best available therapy in patients with CRE infections 1.

Considerations

• The site of infection should be considered when choosing between ceftazidime/avibactam and meropenem/vaborbactam, with meropenem/vaborbactam potentially being preferred for infections such as pneumonia due to its intrapulmonary penetration properties 1.
• Local epidemiology and the emergence of ceftazidime/avibactam resistance in KPC-producing isolates should also be taken into account when selecting a treatment option 1.

From the Research

Klebsiella Aerogenes Overview

• Klebsiella aerogenes is a type of bacteria that can cause various infections, including pneumonia, urinary tract infections, and bloodstream infections.
• The treatment of Klebsiella aerogenes infections often involves the use of antibiotics, but the emergence of antibiotic-resistant strains has become a significant concern.

Antibiotic Resistance and Treatment Options

• Studies have shown that certain antibiotics, such as ceftazidime-avibactam, meropenem-vaborbactam, and imipenem/cilastatin-relebactam, can be effective against Klebsiella pneumoniae carbapenemase-producing Enterobacterales (KPC) infections 2.
• However, the emergence of resistance to these antibiotics has been reported, highlighting the need for continued monitoring and development of new treatment options 3, 4.
• Combination therapy with aztreonam has been shown to be effective against multidrug-resistant, metallo-β-lactamase-producing Klebsiella pneumoniae 5.
• Meropenem+avibactam has been shown to have synergistic effects against MBL-producing carbapenem-resistant Klebsiella pneumoniae 6.

Genetic Determinants of Resistance

• Mutations in the OmpK36 porin have been identified as a potential determinant of resistance to imipenem/relebactam in KPC-producing Klebsiella pneumoniae 4.
• The presence of genetic variants associated with the production of beta-lactamases has also been identified in resistant strains 4.

Treatment Outcomes and Resistance Patterns

• Imipenem/relebactam has been shown to have good in vitro activity against KPC-producing Klebsiella pneumoniae, with 98% of strains susceptible to the antibiotic 4.
• Meropenem/vaborbactam and ceftazidime/avibactam have been shown to maintain good activity against imipenem/relebactam-resistant isolates 4.
• The emergence of resistance to these antibiotics highlights the need for continued monitoring and development of new treatment options 2, 3, 4.