Are quinolone-resistant uropathogenic Escherichia coli less virulent?
The prevalence of hemolysin, type 1 fimbriae, P fimbriae, cytotoxic necrotizing factor-1 (CNF-1), aerobactin, and autotransporter toxin (sat) was analyzed by polymerase chain reaction and phenotypic assays of 42 epidemiologically unrelated Escherichia coli strains causing acute pyelonephritis in women (21 nalidixic acid-susceptible and 21 nalidixic acid-resistant strains) and 58 E. coli strains causing cystitis in women (29 nalidixic acid-susceptible and 29 nalidixic acid-resistant strains). Hemolysin and CNF-1 were less prevalent (P<.05) in nalidixic acid-resistant than in nalidixic acid-susceptible E. coli strains from patients with either pyelonephritis (14.3% vs. 52.4%) or cystitis (0% vs. 31.0%). Among E. coli strains causing cystitis, type 1 fimbriae expression was less prevalent (P<.05) in the nalidixic acid-resistant group (55.2%) than in the nalidixic acid-susceptible group (86.2%). None of the nalidixic acid-resistant and 20.7% of the nalidixic acid-susceptible strains causing cystitis showed the proteolytic toxin Sat (P<.05). These results suggest that resistance to quinolones may be associated with a decrease in the presence or the expression of some virulence factors in uropathogenic E. coli.
Vila
Jordi
J
Servei de Microbiologia, Instiutu Clinic Infeccions i Immunologia, Hospital Clinic-IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain. vila@medicina.ub.es
Simon
Karine
K
Ruiz
Joaquin
J
Horcajada
Juan P
JP
Velasco
Maria
M
Barranco
Margarita
M
Moreno
Antonio
A
Mensa
Josep
J
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000378:metabolism; D002939:Ciprofloxacin / Q000494:pharmacology; D003556:Cystitis / Q000382:microbiology; D003603:Cytotoxins / Q000378:metabolism; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins; D005260:Female; D010861:Fimbriae, Bacterial / Q000378:metabolism; D006460:Hemolysin Proteins / Q000378:metabolism; D006801:Humans; D009268:Nalidixic Acid / Q000494:pharmacology; D011704:Pyelonephritis / Q000382:microbiology; D014552:Urinary Tract Infections / Q000382:microbiology*; D014774:Virulence
D000890:Anti-Infective Agents; D001427:Bacterial Toxins; D003603:Cytotoxins; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C060296:cytotoxic necrotizing factor type 1; D009268:Nalidixic Acid; D002939:Ciprofloxacin