Shiga toxin producing Escherichia coli (STEC) strains vary in acid resistance; however, little is known about the underlying mechanisms that result in strain specific differences. Among 25 STEC O157:H7 strains tested, 7 strains flocculated when grown statically for 18 h in minimal salts medium at 37°C, while 18 strains did not. Interestingly, the flocculation phenotype (cells came out of suspen...

Lactose-sensitive fimbriae were identified as the only fimbriae present on Actinomyces naeslundii WVU45 (ATCC 12104). A single antigen reactive with antiserum against WVU45 cells was detected by cross immunoelectrophoresis of isolated fimbriae, and a monospecific antiserum against this antigen reacted with all fimbriae observed on the bacterial surface by immunoelectron microscopy. Moreover, th...

Klebsiella pneumoniae causes significant morbidity and mortality worldwide, particularly amongst hospitalized individuals. The principle mechanism for pathogenesis in hospital environments involves the formation of biofilms, primarily on implanted medical devices. In this study, we constructed a transposon mutant library in a clinical isolate, K. pneumoniae AJ218, to identify the genes and path...

Two types of fimbriae, designated aggregative adherence fimbria I and II (AAF/I and AAF/II) have been described in enteroaggregative Escherichia coli (EAEC) strains. These fimbriae mediate the aggregative pattern of adherence (AA) to epithelial cells. The genes encoding the structural subunit of each fimbria have been designated aggA and aafA, respectively. The prevalence of these genes was inv...

The Klebsiella pneumoniae type 3 fimbriae are mainly composed of MrkA pilins that assemble into a helixlike filament. This study determined the biomechanical properties of the fimbriae and analyzed 11 site-directed MrkA mutants to identify domains that are critical for the properties. Escherichia coli strains expressing type 3 fimbriae with an Ala substitution at either F34, V45, C87, G189, T19...

A pap+ Escherichia coli isolate from a turkey with colisepticemia expressed P fimbriae with a major subunit of an apparent molecular mass of 18 kDa which reacted with anti-F11 serum. This fimbriae was purified and polyclonal antiserum was produced in rabbits. The N-terminal amino acid sequence of the major fimbrial subunit of the avian P fimbriae was identical to that of F11. On immunoblotting,...

Motility and adherence are two integral aspects of bacterial pathogenesis. Adherence, often mediated by fimbriae, permits bacteria to attach to host cells and establish infection, whereas flagellum-driven motility allows bacteria to disseminate to sites more advantageous for colonization. Both fimbriae and flagella have been proven important for virulence of uropathogenic Escherichia coli (UPEC...

Adhesins (P-fimbriae, S-fimbriae, type 1 fimbriae and afimbrial adhesin), toxins (alpha-hemolysin and cytotoxic necrotizing factor type 1), iron acquisition systems (aerobactin) and host defense avoidance mechanisms (capsule or lipopolysaccharide) have been shown to be prevalent in Escherichia coli strains associated with urinary tract infections. In this work, 162 Uropathogenic Escherichia col...

Porphyromonas gingivalis is a predominant periodontal pathogen that expresses a number of potential virulence factors involved in the pathogenesis of periodontitis. Gingival epithelial cells are spontaneously exposed to bacterial attacks and function to prevent invasion by bacteria into deeper tissues. P. gingivalis fimbriae are a critical factor for mediation of interaction of the organism wit...