The objective of this study was to identify microbial pathogens associated with bacteriuria and UTI in patients with indwelling urethral catheters and determine their susceptibility patterns to commonly used antimicrobial agents in our institution. Catheter urine and catheter tip specimens of all the patients were analyzed by microscopy and culture on Blood, MacConkey and CLED agar plates. Pure colonies of isolated organism were biochemically characterized and disc diffusion antibiotic susceptibility was performed on each bacterial isolate. The commonest indication for catheterization is benign prostatic hyperplasia (BPH, 62.3%). One hundred and eight patients (88.5%) were urine culture positive for microbial pathogens with 126 microbial isolates while 14 (11.5%) were bacteriologically sterile. Ninety two of those positive (85.1%) each had one organism recovered, 14 (13.0%) had two organisms recovered and 2 (1.9%) had 3 organisms recovered.
Klebsiella
spp were the commonest pathogen isolated with 46 (36.6%), followed by
Pseudomonas
spp 34 (27.0%),
Escherichia coli
26 (20.6%),
Staphylococcus aureus
12 (9.5%),
Proteus mirabilis
4 (3.2%),
Candida albicans
4 (3.2%) and coagulase negative staphylococci 2 (1.6%). The in vitro antibiotic susceptibility pattern of the Gram negative organisms showed high resistance to commonly used antibiotics such as ampicillin (100%), gentamicin (90.9%), tetracycline (89.1%), cotrimoxazole (87.3%), cefuroxime (81.1%), nalidixic acid (87.3%), nitrofurantoin (67.3%), colistin (63.7%), perfloxacin (65.5%) and ciprofloxacin (56.4%). Staphylococcus aureus isolates were also resistant to penicillin (100%), gentamicin (100%), cotrimoxazole (100%), chloramphenicol (100%), cloxacillin (83.3%), tetracycline (83.3%), erythromycin (66.7%) and cefuroxime (66.7%). Only perfloxacin (66.7% sensitivity) and ciprofloxacin (83.3% sensitivity) appear effective. We conclude that catheter-associated UTI in our institution is caused by multi-resistant microbial pathogens which has occurred consequent on prophylactic antibiotic therapy administered after catheterization. Emphasis should be placed on good catheter management rather than the use of prophylaxis, to reduce the incidence of catheter associated UTI.
