From the Guidelines
The most common causative pathogens in acute cholecystitis are gram-negative aerobes, such as Escherichia coli and Klebsiella pneumoniae, and anaerobes, especially Bacteroides fragilis. These pathogens are the primary cause of infection in acute cholecystitis, and their identification is crucial for guiding empiric antibiotic therapy 1.
Key Pathogens
- Escherichia coli
- Klebsiella pneumoniae
- Bacteroides fragilis
Empiric Antibiotic Therapy
The choice of empiric antibiotic regimen should be based on the most frequently isolated germs, taking into consideration local trends of antibiotic resistance 1. In patients with complicated acute cholecystitis, initial empiric antibiotic therapy is necessary, and the decision for empiric antimicrobial management depends mainly on the presumed pathogens involved and risk factors for major resistance patterns and disease severity 1.
Clinical Considerations
Elderly patients, especially those from institutions such as nursing homes or geriatric hospitals, can be colonized by multidrug-resistant organisms, posing a particular challenge 1. In these patients, intraoperative cultures should be performed to reassess the antibiotic regimen, and complex regimens with broader spectra may be recommended 1. Early correct empirical antimicrobial therapy has a significant impact on the outcome in patients with sepsis, and recent international guidelines recommend intravenous antibiotics within the first hour after severe sepsis and septic shock are recognized 1.
From the Research
Causative Pathogens in Acute Cholecystitis
The most common causative pathogens in acute cholecystitis include:
- Escherichia coli 2, 3, 4, 5
- Klebsiella spp. 2, 3, 5
- Streptococcus spp. 2, 5, 6
- Enterococcus spp. 2, 3, 4, 5
- Clostridium spp. 2
- Enterobacter 3
- Bacteroides fragilis and clostridia (anaerobes) 5
- Streptococcus gallolyticus subsp. pasteurianus (rare) 6
Bile Bacterial Colonization
Bile bacterial colonization rates in patients with acute cholecystitis range from 33.6% to 60% 2, 4, 5. The presence of bactibilia is particularly prevalent in the elderly and in cases of recurrent cholecystitis 5.
Antibiotic Susceptibilities
Antibiotic susceptibilities vary among the different microorganisms, with: