From the Guidelines
Klebsiella oxytoca is a gram-negative, rod-shaped bacterium belonging to the Enterobacteriaceae family. It is an opportunistic pathogen commonly found in the environment (soil, water) and as part of the normal flora in the human intestinal tract, mouth, and skin. K. oxytoca is facultatively anaerobic, meaning it can grow with or without oxygen, and is non-motile. This bacterium is closely related to Klebsiella pneumoniae but can be distinguished by its ability to produce indole. K. oxytoca can cause various infections, particularly in immunocompromised individuals, including urinary tract infections, pneumonia, bacteremia, and wound infections. It's notable for its natural resistance to certain antibiotics due to chromosomally encoded beta-lactamases, making infections sometimes challenging to treat. When infections occur, treatment typically involves antibiotics such as carbapenems, fluoroquinolones, or aminoglycosides, though susceptibility testing is important as resistance patterns can vary 1. Some key points to consider in the management of infections caused by K. oxytoca include:
- The use of carbapenems should be limited to preserve their activity against multidrug-resistant infections 1.
- New antibiotics such as ceftolozane/tazobactam and ceftazidime/avibactam have shown promise in treating infections caused by gram-negative multidrug-resistant organisms, including K. oxytoca 1.
- Infections caused by K. oxytoca can be challenging to treat due to its natural resistance to certain antibiotics, and susceptibility testing is essential to guide treatment decisions 1.
- The emergence of carbapenem-resistant K. oxytoca is a significant concern, and aggressive detection and control strategies are needed to prevent its spread 1.
From the FDA Drug Label
Gram-negative bacteria ... Klebsiella oxytoca ... The type of bacteria Klebsiella oxytoca is a Gram-negative bacterium 2, 3.
- Key points:
- Gram-negative
- Bacterium
- Type: Enterobacteriaceae family No further information is provided in the drug labels regarding the specific characteristics of Klebsiella oxytoca.
From the Research
Characteristics of Klebsiella oxytoca
- Klebsiella oxytoca is a facultative aerobic, gram-negative, rod-shaped bacterium 4
- It is capable of causing nosocomial infections, particularly catheter-associated urinary tract infections (CAUTIs) 4
- The bacterium has a genome comprising 6,232,464 bp, with a G+C content of 55.60% and an L50 of 7 4
- A total of 6246 putative protein-encoding genes were predicted, including genes responsible for adhesion, invasion, drug resistance, iron acquisition, and other genes relevant for virulence 4
Taxonomy and Antimicrobial Resistance
- Klebsiella oxytoca is part of a complex of nine species, including Klebsiella grimontii, Klebsiella huaxiensis, Klebsiella michiganensis, K. oxytoca, Klebsiella pasteurii, Klebsiella spallanzanii, and three unnamed novel species 5
- The K. oxytoca complex is a human commensal but also an opportunistic pathogen causing various infections, such as antibiotic-associated hemorrhagic colitis (AAHC), urinary tract infection, and bacteremia 5
- The rates of nonsusceptibility to carbapenems, ceftriaxone, ciprofloxacin, colistin, and tigecycline were 1.8%, 12.5%, 7.1%, 0.8%, and 0.1%, respectively, among 5,724 K. oxytoca clinical isolates 5
Virulence and Infections
- Klebsiella oxytoca acts as a pathobiont in the dysbiotic human intestinal microbiota, causing antibiotic-associated hemorrhagic colitis (AAHC), but it also infects other organs, resulting in pneumonia and urinary tract and skin infections 6
- The production of a specific cytotoxin has been linked to AAHC pathogenesis 6
- MLST analysis yielded 60 sequence types, 12 of which were represented by more than one isolate, and distinguished clusters of K. oxytoca isolates between patients with AAHC and those with respiratory infections 6
Antibiotic Susceptibility
- All strains of Klebsiella species, including K. oxytoca, exhibited ampicillin resistance 7
- Ampicillin/sulbactam, gentamicin, and ofloxacin showed effectiveness in 63.1%, 67.7%, and 71.5% of the Klebsiella isolates, respectively 7
- The majority of Klebsiella strains (93.9%) were susceptible to cefuroxime 7