Comparison of the Serum Sensitivity and Antibiotic Susceptibility of Uropathogenie EschericMa coli Strains Isolated from Different Diagnostic Groups

Jasmina VRANES, Branka BEDENIC.

Author address: 

Zagreb U~ziversiiy Medical School, Zagreb Institute of Public Health, Zagreb, Croatia


Objectives: To determine and compare the serum sensitivity, anti genic structure, expression of adhesins and antibiotic susceptibility of uropathogenic Escherichia coli strains isolated from patients with urinary tract ilffection and asymptomatic bacteriuria Significance: The bactericidal activity of serum caused by complement system is an important defense mechanism protecting the host organism against infection. The capacity to resist bactericidal activity of normal human serum contributes to the virulence of many Gram negative pathogens. Study Design: Ex vivo study Setting: University hospital for infectious diseases Population: Patients with urinary tract infection or asymptomatic baeteriuria Methodology: The capacity of Escheriehia coli to resist the baeterici dal action of serum was examined in 85 clinical isolates obtained from patients with acute pyelonepliritis (n~3), acute cystitis (n~2), chi'onic pyelonephiitis (n 22) and asymptomatic bacteriuria (in 18). Serum sensitivity was also examined in relation to the serogroup specificity and expression of the different adhesins of the strains. Bacterial susceptibility to serum killing was measured by assessing regrowth after incubation in serum according to Schiller and Hatch method, and susceptibility to antimicrobial agents was determined by Kifw-Bauer disc diffusion method. The adhesins of E coli were detemfined by hemagglutination and inhibition of hemagglutination, and serotyping was peffm'med on glass slides and confirmed using a mechanized mieroteehnique. Results: The significant correlation between serum resistance of uropathogenic strains of E. coli and expression of P fimbriae and 06 serogroup was observed. P fimbriated strains were more frequently re sistant to tetracycline and cafoenicillin than strains in which P- fimbriae were not detected, and they all were resistant to amoxicillin, in contrast with non-P-fimbriated strains (p

abstract No: 


Full conference title: 

International Congress on Chemotherapy, 24th Meeting
    • ICC 24 th