Treatment of Klebsiella oxytoca Infections

Introduction to Treatment Options

For Klebsiella oxytoca infections, novel β-lactam agents such as ceftazidime/avibactam and meropenem/vaborbactam should be the first-line treatment options when dealing with carbapenem-resistant strains, while carbapenems remain the treatment of choice for susceptible strains 1, 2

Ceftazidime/avibactam or meropenem/vaborbactam should be used as first-line treatment options for KPC-producing strains (STRONG recommendation, MODERATE certainty of evidence) 1, 2
Imipenem/relebactam and cefiderocol may be considered as alternatives for KPC-producing strains (CONDITIONAL recommendation, LOW certainty of evidence) 2
Ceftazidime/avibactam is the first-line treatment option for OXA-48-like producing strains (CONDITIONAL recommendation, VERY LOW certainty of evidence) 2
Ceftazidime/avibactam plus aztreonam is preferred for MBL-producing strains 3
Cefiderocol may also be considered as an alternative for MBL-producing strains 3

Meropenem/vaborbactam may be preferred for respiratory infections due to better epithelial lining fluid concentrations (intrapulmonary penetration ratios of 63% for meropenem and 65% for vaborbactam) 2
For severe infections with multidrug-resistant strains, use combination therapy with more than one in vitro active drug when limited to older agents like polymyxins, aminoglycosides, tigecycline, or fosfomycin 4
Mortality is significantly lower with newer agents like ceftazidime/avibactam compared to older regimens (18.3% vs 40.8%, p=0.005) 2
Monotherapy with an in vitro active agent may be sufficient for non-severe infections 4

Avoid extended use of cephalosporins due to selection pressure resulting in emergence of ESBL-producing strains 5
Limit fluoroquinolone use due to selective pressure leading to resistance 5
Consider de-escalation of antimicrobial therapy once culture and susceptibility results are available to reduce selection pressure 5
For community-acquired infections, narrower spectrum agents may be appropriate, but local ecology should guide ESBL coverage 5
For hospital-acquired infections, broader spectrum agents are preferred due to increased likelihood of resistant pathogens 5

Rapid molecular testing should be used to identify specific carbapenemase types to guide appropriate therapy 1
Local epidemiology and resistance patterns should be considered when selecting empiric therapy 2
Emergence of ceftazidime/avibactam resistance in KPC-producing isolates (0-12.8%) should be monitored 2
Combination therapy may be beneficial for severe infections when using older agents like polymyxins and tigecycline 4

The Centers for Disease Control and Prevention recommends obtaining susceptibility testing before finalizing therapy, as resistance patterns vary dramatically, and using modified Hodge test (MHT) for carbapenem-susceptible isolates with elevated MICs (>90% sensitivity/specificity for carbapenemase detection) 6, 7, 8

The Centers for Disease Control and Prevention recommends implementing contact precautions for all carbapenem-resistant isolates 8

The Centers for Disease Control and Prevention reports that CRKP infections are associated with increased mortality, length of stay, and cost 6, 9