Autotransporters are secreted bacterial proteins exhibiting diverse virulence functions. Various autotransporters have been identified among Escherichia coli associated with intestinal or extraintestinal infections; however, the specific distribution of autotransporter sequences among a diversity of E. coli strains has not been investigated. We have validated the use of a multiplex PCR assay to screen for the presence of autotransporter sequences. Herein, we determined the presence of 13 autotransporter sequences and five allelic variants of antigen 43 (Ag43) among 491 E. coli isolates from human urinary tract infections, diarrheagenic E. coli, and avian pathogenic E. coli (APEC) and E. coli reference strains belonging to the ECOR collection. Clinical isolates were also classified into established phylogenetic groups. The results indicated that Ag43 alleles were significantly associated with clinical isolates (93%) compared to commensal isolates (56%) and that agn43K12 was the most common and widely distributed allele. agn43 allelic variants were also phylogenetically distributed. Sequences encoding espC, espP, and sepA and agn43 alleles EDL933 and RS218 were significantly associated with diarrheagenic E. coli strains compared to other groups. tsh was highly associated with APEC strains, whereas sat was absent from APEC. vat, sat, and pic were associated with urinary tract isolates and were identified predominantly in isolates belonging to either group B2 or D of the phylogenetic groups based on the ECOR strain collection. Overall, the results indicate that specific autotransporter sequences are associated with the source and/or phylogenetic background of strains and suggest that, in some cases, autotransporter gene profiles may be useful for comparative analysis of E. coli strains from clinical, food, and environmental sources.

Treatment of trypanosomiasis before 1951 may have caused iatrogenic HCV transmission. Population-wide half-yearly intramuscular pentamidine for trypanosomiasis chemoprophylaxis in 1947-1953 may have caused iatrogenic HTLV-1 transmission. These and other interventions against tropical diseases could have iatrogenically transmitted SIV(cpz), jump-starting the HIV-1 epidemic. The excess mortality among patients with trypanosomiasis treated before 1951 supports this hypothesis.

We compared the germ tube test for the direct identification of Candida albicans from positive blood culture bottles, with results obtained from subcultured colonies. The direct germ tube test was 87.1% sensitive and 100% specific for the identification of C. albicans when the results obtained from fungal colonies were compared.Recent evidence has suggested that early institution of appropriate antifungal therapy is a critical factor in improving outcomes during bloodstream infections with Candida species (2, 4, 5). Given that most bloodstream isolates of C. albicans remain susceptible to azoles such as fluconazole (7, 9), the rapid identification of C. albicans is a key step in the diagnostic and treatment algorithm for bloodstream Candida infection to guide targeted and cost-effective antifungal strategy (6).Traditionally, the preliminary identification of C. albicans is made through the use of a germ tube test (GTT) performed on a subcultured colony grown on solid agar. Although the test itself is rapid, growth of sufficient colonies on solid agar requires a delay of a minimum of 24 h and up to 72 h before identification can be performed. In a preliminary report, Terlecka et al. performed the GTT directly from 31 BacTAlert blood culture bottles positive for yeast on Gram stain, thirteen of which were C. albicans (10). Although the numbers were limited, they observed 100% concordance between the direct GTT and a GTT performed with subcultured organisms grown on solid medium. We report here a 2-year prospective study from two sites investigating the possibility that the GTT could be performed directly from blood culture bottles that had been flagged positive. In addition, to extend these results, 67 yeast isolates previously recovered from candidemic patients were tested in blood culture bottles inoculated with human blood.Over a 2-year period, all positive blood cultures in which yeast were visualized by Gram staining were identified at two large teaching hospitals in Montreal, Canada. To maximize strain diversity, only the first positive blood culture was tested for each episode of fungemia. At Maisonneuve-Rosemont Hospital, all blood cultures were inoculated into BacTAlert blood culture bottles (bioMérieux, Inc., Marcy l'Etoile, France), while the Bactec system (BD Diagnostics, Oakville, Ontario, Canada) was used at the Royal Victoria Hospital. All positive cultures were subcultured on Sabouraud dextrose agar, and a direct GTT performed. To perform the direct GTT, 10 to 20 l of the blood culture bottle contents was removed and incubated with 0.5 of rabbit serum for 3 h at 37°C. The presence or absence of germ tubes was recorded. When sufficient growth was obtained on solid agar, a standard GTT was performed by inoculating 0.5 ml of citrated rabbit serum with a loopful of the test strain, followed by incubation at 37°C for 3 h. All isolates were then completely identified using the API20C AUX, the Vitek YBC (bioMérieux), or the Auxacolor 2 (Bio-Rad, Marnes-la Coquette, France) system.To complement these data,...