Abstract
Background and Study Aims: Prior to endoscopic therapeutic procedures, no antibiotic prophylaxis is administered
routinely. Because of the reported incidence of infectious complications, which may
reach up to 10 %, a prospective study was undertaken to investigate the effects of
a prophylactic dose of cefuroxime on the incidence of bacteremia and clinical signs
of infection, but no significant effects could be demonstrated. In addition to this
published work, blood and bile cultures obtained in this trial were also investigated,
and the in-vitro susceptibility to several antibiotics was tested in order to recommend
the appropriate substances.
Patients and Methods: Ninety-nine consecutive patients (51 men, 48 women; mean age 61.4 ± 17 years) with
biliary obstruction who underwent an endoscopic retrograde cholangiopancreatography
(ERCP) or percutaneous transhepatic cholangiography with drainage (PTCD) were included.
Sequential blood cultures were taken before and up to 60 minutes after the endoscopic
intervention. Bile cultures were obtained in 56 patients with biliary drainage. Aerobic
and anaerobic cultures were prepared from all obtained specimens and the isolated
organisms were identified. In the case of positive cultures, an in-vitro resistance
test for 15 different antibiotics was performed.
Results: The incidence of bacteremia was 11.1 % (n = ll), and 16 bacteria were isolated. Twelve
different microorganisms were detected, with Escherichia coli found in four cases. From 41 positive out of 56 prepared bile cultures (73.2 %),
91 isolates were found with 25 different species. A single agent was detected in eight
cases (19.5 %), while a mixed growth, with pathogens ranging from two to six species,
was found in 33 cases (80.5 %). The seven most frequently isolated germs were E. coli and Enterococcus (each n = 19), Klebsiella (n = 10), Streptococcus viridans (n = 9), Staphylococcus epidermidis (n = 5), Morganella morganii (n = 4), and Bacteroides fragilis (n = 3), representing 76 % of all agents. Examination for fungal infection revealed
positive cultures of Candida albicans in 16.1 % of bile cultures (nine of 56). Interestingly, the use of proton-pump inhibitors
(PPIs), with a consequent rise in the gastric pH value, led to an increase in the
rate of bacteremia to 26.2 % (five of 19) compated to the other patients not on PPIs
(n = 80), who developed bacteremia in only six cases (7.5 %; p = 0.02). In-vitro testing
of different antibiotics was carried out in 73 isolates. Imipenem showed the best
antimicrobial activity (98.4 %), followed by trimethoprim and sulfamethoxazole (90 %),
amoxicillin plus clavulanic acid (87.3 %), vancomycin (82.4 %), and ofloxacin (76.9 %).
Conclusions:
Escherichia coli was found to be the pathogen most frequently detected in blood and bile following
endoscopic interventions in the biliary tract. Enterococci, Klebsiella and Streptococcus viridans were found in bile cultures with an incidence exceeding 10 %. In view of the in-vitro
test results, possible side effects, and contraindications, amoxicillin plus beta-lactamase
inhibitors or quinolones are considered to be suitable antibiotics for the prophylaxis
of biliary infections.
