title: Do temperature-sensitive auxotrophs of Escherichia coli have special virulence?
abstract: To determine whether temperature (42 degrees C)-sensitive auxotrophs of Escherichia coli have special virulence properties (W. D. Welch, D. Kitts, H. S. Moyed, and L. D. Thrupp, J. Clin. Microbiol. 13:606-608, 1981), we examined 301 strains isolated from patients with bacteremia or acute cystitis and from the stools of healthy subjects. Of these strains, 49.5% grew at 42 degrees C without supplements, 39.2% required a nutritional supplement, and 11.3% failed to grow even with selected nutrients. Nicotinamide restored growth for 35.2% of strains at either 37 or 42 degrees C. Some of strains required methionine, glutamic, aspartic, and amino acid mixtures or NaCl for growth at 42 degrees C. Temperature-sensitive strains were significantly more abundant in isolates from blood and urine than in stool, but temperature-sensitive auxotrophs were isolated at about the same frequency from each site. There were no discernible clonal patterns, by serotype, among of the nicotinamide-requiring temperature-sensitive auxotrophs. Resistance to trimethoprim-sulfamethoxazole was associated with ability to grow at 42 degrees C. This was not observed with any other antimicrobial drug. Temperature-sensitive strains are a heterogenous group. The relationship of temperature-sensitive auxotrophy to virulence is uncertain.
authors.affiliation: Department of Internal Medicine, Ohio State University, Columbus 43210-1240.
authors.forename: C M
authors.initials: CM
authors.lastname: Kunin
authors.forename: T H
authors.initials: TH
authors.lastname: Hua
authors.forename: C
authors.initials: C
authors.lastname: Krishnan
authors.forename: L V
authors.initials: LV
authors.lastname: White
mesh_terms: D016470:Bacteremia / Q000382:microbiology; D003556:Cystitis / Q000382:microbiology; D004352:Drug Resistance, Microbial / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity*; D005260:Female; D006801:Humans; D009536:Niacinamide; D013696:Temperature; D014296:Trimethoprim Resistance / Q000502:physiology; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology; D014774:Virulence
chemical_list: D009536:Niacinamide; D015662:Trimethoprim, Sulfamethoxazole Drug Combination