Haemolysin α (HlyA) produced by cell-detaching Escherichia coli, a putative new class of enteric pathogen, is considered to be the main factor responsible for detachment of cells cultured in vitro. HlyA is one of the few E. coli proteins actively secreted into the medium during exponential growth. In the present study 27 HlyA-positive E. coli isolates, randomly selected from stool specimens, produced a cell-bound haemolysin that was detectable during the exponential and stationary growth phases. The influence of both cell-free and cell-bound haemolysins of the selected isolates on cell-detaching activity of E. coli in vitro was determined. The results suggest that cell-bound haemolysin rather than cell-free HlyA was responsible for the cell-detaching activity of E. coli strains tested.
BeutinL.,
MontenegroM. A.,
ØrskovI.,
ØrskovF.,
PradaJ.,
ZimmermannS.,
StephanR.1989; Close association of verotoxin (Shiga-like toxin) production with enterohemolysin production in strains of Escherichia coli
. J Clin Microbiol 27:2559–2564
BlancoM.,
BlancoJ. E.,
BlancoJ.,
AlonsoM. P.,
BalsalobreC.,
MourinoM.,
MadridC.,
JuarezA.1996; Polymerase chain reaction for detection of Escherichia coli strains producing cytotoxic necrotizing factor type 1 and type 2 (CNF1 and CNF2). J Microbiol Methods 26:95–101[CrossRef]
ElliottS. J.,
SrinivasS.,
AlbertM. J.,
AlamK.,
Robins-BrowneR. M.,
GunzburgS. T.,
MeeB. J.,
ChangB. J.1998; Characterization of the roles of hemolysin and other toxins in enteropathy caused by alpha-hemolytic Escherichia coli linked to human diarrhea. Infect Immun 66:2040–2051
FábregaV. L. A.,
FerreiraA. J. P.,
Reis da Silva PatrícioF.,
BrinkleyC.,
ScaletskyI. C. A.2002; Cell-detaching Escherichia coli (CDEC) strains from children with diarrhea: identification of a protein with toxigenic activity. FEMS Microbiol Lett 217:191–197[CrossRef]
GadebergO. V.,
ØrskovI.,
RhodesJ. M.1983; Cytotoxic effect of an alpha-hemolytic Escherichia coli strain on human blood monocytes and granulocytes in vitro
. Infect Immun 41:358–364
GomesT. A.,
AbeC. M.,
MarquesL. R.1995; Detection of HeLa cell-detaching activity and alpha-hemolysin production in enteroaggregative Escherichia coli strains isolated from feces of Brazilian children. J Clin Microbiol 33:3364
GunzburgS. T.,
ChangB. J.,
ElliottS. J.,
BurkeV.,
GraceyM.1993; Diffuse and enteroaggregative patterns of adherence of enteric Escherichia coli isolated from aboriginal children from the Kimberley region of Western Australia. J Infect Dis 167:755–758[CrossRef]
HaqueM. A.,
OhkiK.,
KikuchiM.,
KohashiO.1994; Contact hemolysin production by strains of enteroaggregative Escherichia coli isolated from children with diarrhea. J Clin Microbiol 32:1109–1111
JorgensenS. E.,
ShortE. C.Jr,
KurtzH. J.,
MussenH. K.,
WuG. K.1976; Studies on the origin of the α -haemolysin produced by Escherichia coli
. J Med Microbiol 9:173–189[CrossRef]
MarquesL. R.,
AbeC. M.,
GriffinP. M.,
GomesT. A.1995; Association between alpha-hemolysin production and HeLa cell-detaching activity in fecal isolates of Escherichia coli
. J Clin Microbiol 33:2707–2709
OscarssonJ.,
WestermarkM.,
BeutinL.,
UhlinB. E.2002; The bacteriophage-associated Ehly1 and Ehly2 determinants from Escherichia coli O26 : H− strains do not encode enterohemolysins per se but cause release of the ClyA cytolysin. Int J Med Microbiol 291:625–631[CrossRef]
OsekJ.,
WeinerM.2003; Prevalence of cdt-III gene encoding cytolethal distending toxin (CDT) among Escherichia coli strains isolated from pig with diarrhea. Bull Vet Inst Pulawy 47:17–22
SansonettiP. J.,
RyterA.,
ClercP.,
MaurelliA. T.,
MounierJ.1986; Multiplication of Shigella flexneri within HeLa cells: lysis of the phagocytic vacuole and plasmid-mediated contact hemolysis. Infect Immun 51:461–469
TaneikeJ.,
ZhangH.-M.,
Wakisaka-SaitoN.,
YamamotoT.2002; Enterohemolysin operon of Shiga toxin-producing Escherichia coli : a virulence function of inflammatory cytokine production from human monocytes. FEBS Lett 524:219–224[CrossRef]