The inhibitory effect of colloidal bismuth hydroxide gel on Escherichia coli O157:H7 and on the activity of Shiga toxins

Abstract

BackgroundShiga toxin-producing Escherichia coli (STEC) is the causative agent of hemolytic uremic syndrome (HUS). Colloidal bismuth hydroxide gel (CBHG) is an anti-diarrheal and antisecretory compound, which does not inhibit gastrointestinal motility and reaches an in vivo gut concentration of 10.8 mg/ml of bismuth. Its action on bacteria has not been studied. We analyzed its inhibitory effects on STEC, as well as the deactivation of the Shiga toxin (Stx) and its ability to block the spread of genes encoding Stx. We determined a minimum inhibitory concentration and bactericidal concentration for the STEC O157:H7 strain (EDL933), with CBHG and Chobet® bismuth cream with pectin (CBCHP). We analyzed its effect on Stx by means of cytotoxicity assay and ELISA, as well as its effect on the free 933 W Stx phage.ResultsEffect on the EDL933 strain: CBHG: MIC 10 mg/ml of bismuth. CBCHP: MIC 6 mg/ml and MBC 15 mg/ml of bismuth. Effect on EDL933 virulence factors: significant decrease in active Stx and 933 W Stx phage titer. ELISA did not find significant differences with treatment.ConclusionsThe results obtained may be useful in the development of new therapeutic strategies based on the use of CBHG to prevent or improve the prognosis of HUS, as it can be used to control STEC infections.

Effect of bismuth hydroxide gel on shiga toxin-producing escherichia coli

“…Bismuth hydroxide gel is effective against pathogens as STEC that produce severe disease in children. 7 The effect of bismuth hydroxide gel has been demonstrated in vitro in STEC O157 decreasing the Stx phage titer 7 and it has been studied the action direct of protection of colonic mucosa and inactivation of the bacterial factors responsible for producing Stx. 8 However, there are not studies in STEC non-O157 serotypes O26, O103 and O91.…”

Food Poisoning Caused by Bacteria (Food Toxins)

“…A large number of research papers have been looking for substances that may inhibit the effect of bacterial toxins in human tissue; for example, the use of Bi3 + ion to prevent or treat the hemolytic uremic syndrome caused by E. coli producing shiga toxin; this ion can be applied to animals and humans. Due to the importance of toxins in the food area, with clinical and pathological consequences, these mechanisms of action and the nature of toxins should be thoroughly investigated, in order to design strategies to prevent and manage effectively toxicoinfections [117].…”

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“…Subils et al [14] focused their research conducted at the Department of Bacteriology of the Faculty of Pharmacy and Biochemistry at the National University of Rosario (Argentina) on determining the effects of BHG on the replication of Stx933 phage encoded by Stx. The results reported by the researchers show a statistically significant decrease (p<0.05) in the amount of phage title when exposed to BHG compared to untreated title.…”