Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

The effect of free and encapsulated cisplatin into long-circulating and pH-sensitive liposomes on IEC-6 cells during wound healing in the presence of host-microbiota

OBJECTIVES

To circumvent cisplatin (CDDP) toxic effects and improve the antitumoural effect, our research group developed long-circulating and pH-sensitive liposomes containing CDDP (SpHL-CDDP). This study aimed to evaluate whether SpHL-CDDP is associated with intestinal protection under in-vitro conditions in the presence of host-microbiota, compared with free CDDP.

METHODS

The cytotoxicity of CDDP and SpHL-CDDP were evaluated by colorimetric MTT and sulforhodamine B (SRB) assays. Epithelial proliferation was assessed by using an in-vitro wounding model in the presence of host-microbiota with intestinal epithelial cell line 6 (IEC-6) monolayers. Cytokines were determined by ELISA.

KEY FINDINGS

Reduced cytotoxicity of SpHL-CDDP in IEC-6 cells (minimum of 1.3-fold according to the IC50 values) was observed when compared with CDDP. The presence of microbiota or CDDP reduced the wound healing. The association of microbiota and SpHL-CDDP improved the wound healing and cell number in IEC-6 cells when compared with control. These beneficial results can be associated with increased IL-6 and IL-10 levels induced by SpHL-CDDP which were affected by the presence of microbiota.

CONCLUSIONS

These results indicate that the presence of microbiota associated with SpHL-CDDP provided less intestinal cellular damages compared with CDDP and constitutes a promising candidate for clinical use.

Virulence-Related Genes and Coenteropathogens Associated with Clinical Outcomes of Enteropathogenic Escherichia coli Infections in Children from the Brazilian Semiarid Region: a Case-Control Study of Diarrhea

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in children from developing countries and presents high genetic variability. We aimed to characterize the EPEC virulence-related gene (VRG) distribution and copathogens associated with diarrhea and nutrition-related outcomes in children from the low-income Brazilian semiarid region. A cross-sectional case-control study of diarrhea was conducted in 1,191 children aged 2 to 36 months from the northeast region of Brazil. Stool samples were collected and clinical, epidemiological, and anthropometric data were identified from each child. A broad molecular evaluation of enteropathogens was performed, and EPEC-positive samples were further investigated for 18 VRGs using five multiplex PCRs. EPEC was detected in 28.2% of the study population, with similar proportions among cases and controls. Typical EPEC (tEPEC) infections were more often associated with diarrhea than atypical EPEC (aEPEC) infections, while aEPEC infections presented a higher prevalence. The VRG ler, a negative regulator of the locus of enterocyte effacement, was associated with the absence of diarrhea in aEPEC-positive children; espB, a major component of the type 3 secretion system, was associated with diarrhea in tEPEC-positive children; the presence of procolonization VRGs-the combination of cesT positivity, espP negativity, and the presence of the map gene-was associated with undernutrition; and Campylobacter spp., norovirus, and enteroaggregative E. coli (EAEC) coinfections were associated with increased clinical severity in EPEC-infected children. These data identified tEPEC strains associated with diarrhea and specific VRGs of EPEC (ler, espB, cesT, and map genes) and Campylobacter spp., norovirus, and EAEC to be major contributors to diarrhea and undernutrition in children from a low-income Brazilian region.