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

Subils T, Casabonne C, Balagué C - BMC Res Notes (2014)

Bottom Line: Effect on EDL933 virulence factors: significant decrease in active Stx and 933 W Stx phage titer.ELISA did not find significant differences with treatment.The 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.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Biochemistry and Pharmaceutical Sciences, Department of Clinical Bacteriology, National University of Rosario, Suipacha 531, S2002LRK Rosario, Santa Fe, Argentina. tomassubils@hotmail.com.

ABSTRACT

Background: Shiga 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.

Results: Effect 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.

Conclusions: The 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.

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Microscopy of monolayers of Vero cells. A. Normal monolayer, 1/32 CBHG 3 mg/ml. B. With 20% cytotoxicity, 1/4 CBCHP 3 mg/ml. C. With 50% cytotoxicity 1/16 CBHG 3 mg/ml. D. With 80% cytotoxicity 1/2 CBHG 3 mg/ml.
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Fig1: Microscopy of monolayers of Vero cells. A. Normal monolayer, 1/32 CBHG 3 mg/ml. B. With 20% cytotoxicity, 1/4 CBCHP 3 mg/ml. C. With 50% cytotoxicity 1/16 CBHG 3 mg/ml. D. With 80% cytotoxicity 1/2 CBHG 3 mg/ml.

Mentions: We observed a significant reduction (p < 0.05) in the active Stx titer in the samples treated with a 1/5 dilution of CBHG, which corresponds to a bismuth concentration of 6 mg/ml; and with a 1/10 dilution of CBCHP, which is equivalent to a bismuth concentration of 3 mg/ml. These results show that concentrations even lower than the MIC could inhibit Stx activity. However, no significant differences were observed at lower concentrations (Table 2). The following changes were observed by means of optical microscopy (Figure 1): brightness and progressive detachment of cells from monolayer, formation of cell surface in folds with multiple blebs, and finally release of several membrane-bound apoptotic bodies. The apoptotic cells were characterized by condensed chromatin, intensive nuclear fragmentation, cytoplasmic organelle disruption, formation of apoptotic bodies and cell shrinkage[33].Table 2


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

Subils T, Casabonne C, Balagué C - BMC Res Notes (2014)

Microscopy of monolayers of Vero cells. A. Normal monolayer, 1/32 CBHG 3 mg/ml. B. With 20% cytotoxicity, 1/4 CBCHP 3 mg/ml. C. With 50% cytotoxicity 1/16 CBHG 3 mg/ml. D. With 80% cytotoxicity 1/2 CBHG 3 mg/ml.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4289334&req=5

Fig1: Microscopy of monolayers of Vero cells. A. Normal monolayer, 1/32 CBHG 3 mg/ml. B. With 20% cytotoxicity, 1/4 CBCHP 3 mg/ml. C. With 50% cytotoxicity 1/16 CBHG 3 mg/ml. D. With 80% cytotoxicity 1/2 CBHG 3 mg/ml.
Mentions: We observed a significant reduction (p < 0.05) in the active Stx titer in the samples treated with a 1/5 dilution of CBHG, which corresponds to a bismuth concentration of 6 mg/ml; and with a 1/10 dilution of CBCHP, which is equivalent to a bismuth concentration of 3 mg/ml. These results show that concentrations even lower than the MIC could inhibit Stx activity. However, no significant differences were observed at lower concentrations (Table 2). The following changes were observed by means of optical microscopy (Figure 1): brightness and progressive detachment of cells from monolayer, formation of cell surface in folds with multiple blebs, and finally release of several membrane-bound apoptotic bodies. The apoptotic cells were characterized by condensed chromatin, intensive nuclear fragmentation, cytoplasmic organelle disruption, formation of apoptotic bodies and cell shrinkage[33].Table 2

Bottom Line: Effect on EDL933 virulence factors: significant decrease in active Stx and 933 W Stx phage titer.ELISA did not find significant differences with treatment.The 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.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Biochemistry and Pharmaceutical Sciences, Department of Clinical Bacteriology, National University of Rosario, Suipacha 531, S2002LRK Rosario, Santa Fe, Argentina. tomassubils@hotmail.com.

ABSTRACT

Background: Shiga 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.

Results: Effect 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.

Conclusions: The 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.

Show MeSH
Related in: MedlinePlus