What are the features of Klebsiella pneumoniae infection?

From the Guidelines

Klebsiella pneumoniae is a gram-negative, encapsulated, non-motile bacterium that commonly causes healthcare-associated infections, and its treatment typically requires broad-spectrum antibiotics, with combination therapy being associated with better clinical outcomes, especially in severe cases, as evidenced by a large retrospective cohort study 1.

Key Features of Klebsiella pneumoniae

• Distinctive mucoid colonies on culture media due to its thick polysaccharide capsule
• Short, plump rods under microscopy
• Facultative anaerobe that ferments lactose
• Commonly colonizes the human gastrointestinal tract and respiratory tract
• Can cause severe infections including pneumonia, urinary tract infections, bloodstream infections, and liver abscesses

Treatment and Resistance

• Naturally resistant to ampicillin and often acquires additional resistance mechanisms, including extended-spectrum beta-lactamases (ESBLs) and carbapenemases
• Treatment typically requires broad-spectrum antibiotics like carbapenems, though therapy should be guided by susceptibility testing due to increasing resistance
• Combination therapy, including more than one in vitro active antimicrobial, has been associated with lower 14-day mortality and better clinical outcomes in severe cases 1

Risk Factors and Prevention

• Risk factors for infection include hospitalization, mechanical ventilation, immunosuppression, and recent antibiotic use
• Aggressive infection control strategies, including contact precautions and active surveillance cultures, are recommended to limit the spread of carbapenem-resistant Enterobacteriaceae (CRE) in acute care facilities 1

From the Research

Klebsiella Pneumoniae Features

• Klebsiella pneumoniae is a major worldwide source and shuttle for antibiotic resistance, with a wide resistome that encompasses plentiful chromosomal and plasmid-encoded antibiotic resistance genes (ARGs) 2.
• It is an important multidrug-resistant (MDR) pathogen affecting humans and a major source for hospital infections associated with high morbidity and mortality due to limited treatment options 2.
• Klebsiella species cause infections at multiple sites, including lung, urinary tract, bloodstream, wound or surgical site, and brain, and are more likely to occur in people with preexisting health conditions 3.
• The emergence of carbapenemase-resistant Gram-negative bacteria, including Klebsiella pneumoniae, is designated as an 'urgent' priority of public health, with significant mortality associated with carbapenemase-producing Klebsiella pneumoniae (CPKP) 4.

Infection Sites and Risk Factors

• Klebsiella pneumoniae infections can occur in various sites, including:
  • Lung (pneumonia) 5, 3, 6
  • Urinary tract 3, 6
  • Bloodstream 3, 6
  • Wound or surgical site 3
  • Brain 3
  • Intra-abdominal structures 5, 6
• Risk factors for Klebsiella pneumoniae infections include preexisting health conditions, such as septic shock, neutropenia, and underlying diseases 3, 6.

Treatment and Outcomes

• Treatment of Klebsiella pneumoniae infections often involves the use of carbapenems, such as imipenem-cilastatin, meropenem-vaborbactam, and ceftazidime-avibactam, which have shown favorable outcomes in some cases 5, 4, 6.
• However, the emergence of resistance to these antibiotics is a significant concern, and novel treatments, such as cefiderocol, eravacycline, and apramycin, are being developed to combat infections caused by CPKP 4.
• The all-cause mortality rate for Klebsiella pneumoniae infections can be high, ranging from 25% to 50% in some studies 5, 6.