Iron influences the expression of colonization factor CS6 of enterotoxigenic Free

Abstract

Enterotoxigenic (ETEC) is a major pathogen of acute watery diarrhoea. The pathogenicity of ETEC is linked to adherence to the small intestine by colonization factors (CFs) and secretion of heat-labile enterotoxin (LT) and/or heat-stable enterotoxin (ST). CS6 is one of the most common CFs in our region and worldwide. Iron availability functions as an environmental cue for enteropathogenic bacteria, signalling arrival within the human host. Therefore, iron could modify the expression of CS6 in the intestine. The objective of this study was to determine the effect of iron availability on CS6 expression in ETEC. This would help in understanding the importance of iron during ETEC pathogenesis. ETEC strain harbouring CS6 was cultured under increasing concentrations of iron salt to assess the effect on CS6 RNA expression by quantitative RT-PCR, protein expression by ELISA, promoter activity by β-galactosidase activity, and epithelial adhesion on HT-29 cells. RNA expression of CS6 was maximum in presence of 0.2 mM iron (II) salt. The expression increased by 50-fold, which also reduced under iron-chelation conditions and an increased iron concentration of 0.4 mM or more. The surface expression of CS6 also increased by 60-fold in presence of 0.2 mM iron. The upregulation of CS6 promoter activity by 25-fold under this experimental condition was in accordance with the induction of CS6 RNA and protein. This increased CS6 expression was independent of ETEC strains. Bacterial adhesion to HT-29 epithelial cells was also enhanced by five-fold in the presence of 0.2 mM iron salt. These findings suggest that CS6 expression is dependent on iron concentration. However, with further increases in iron concentration beyond 0.2 mM CS6 expression is decreased, suggesting that there might be a strong regulatory mechanism for CS6 expression under different iron concentrations.

Funding
This study was supported by the:
  • indian council of medical research (Award 3/1/3/JRF-2015/HRD-LS/96/40713/57)
    • Principle Award Recipient: DebjyotiBhakat
  • department of biotechnology, ministry of science and technology (Award BT/PR21476/MED/29/1135/2016)
    • Principle Award Recipient: Sekhar ChatterjeeNabendu
Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.001089
2021-09-22
2024-03-29
Loading full text...

Full text loading...

/deliver/fulltext/micro/167/9/mic001089.html?itemId=/content/journal/micro/10.1099/mic.0.001089&mimeType=html&fmt=ahah

References

  1. Hosangadi D, Smith PG, Kaslow DC, Giersing BK. WHO consultation on ETEC and Shigella burden of disease, Geneva, 6–7th April 2017: Meeting report. Vaccine 2019; 37:7381–7390 [View Article]
    [Google Scholar]
  2. Qadri F, Svennerholm A-M, Faruque ASG, Sack RB. Enterotoxigenic Escherichia coli in developing countries: Epidemiology, microbiology, clinical features, treatment, and prevention. Clin Microbiol Rev 2005; 18:465–483 [View Article]
    [Google Scholar]
  3. Black RE. Epidemiology of travelers’ diarrhea and relative importance of various pathogens. Rev Infect Dis 1990; 12 Suppl 1:S73–9 [View Article]
    [Google Scholar]
  4. Gaastra W, Svennerholm A-M. Colonization factors of human enterotoxigenic Escherichia coli (ETEC. Trends Microbiol 1996; 4:444–452 [View Article]
    [Google Scholar]
  5. von Mentzer A, Tobias J, Wiklund G, Nordqvist S, Aslett M et al. Identification and characterization of the novel colonization factor CS30 based on whole genome sequencing in enterotoxigenic Escherichia coli (ETEC. Sci Rep 2017; 7:12514 [View Article]
    [Google Scholar]
  6. Sabui S, Dutta S, Debnath A, Ghosh A, Hamabata T et al. Real-time PCR-based mismatch amplification mutation assay for specific detection of CS6-expressing allelic variants of enterotoxigenic Escherichia coli and its application in assessing diarrheal cases and asymptomatic controls. J Clin Microbiol 2012; 50:1308–1312 [View Article]
    [Google Scholar]
  7. Begum YA, Baby NI, Faruque ASG, Jahan N, Cravioto A et al. Shift in phenotypic characteristics of enterotoxigenic Escherichia coli (ETEC) isolated from diarrheal patients in Bangladesh. PLoS Negl Trop Dis 2014; 8:e3031 [View Article]
    [Google Scholar]
  8. Bhakat D, Debnath A, Naik R, Chowdhury G, Deb AK et al. Identification of common virulence factors present in enterotoxigenic Escherichia coli isolated from diarrhoeal patients in Kolkata, India. J Appl Microbiol 2019; 126:255–265 [View Article]
    [Google Scholar]
  9. Sabui S, Debnath A, Ghosal A, Wajima T, Hamabata T et al. Characterization of oligomeric assembly of colonization factor CS6 from enterotoxigenic Escherichia coli . Microbiology (Reading) 2016; 162:72–83 [View Article]
    [Google Scholar]
  10. Andrews SC, Robinson AK, Rodríguez-Quiñones F. Bacterial iron homeostasis. FEMS Microbiol Rev 2003; 27:215–237 [View Article]
    [Google Scholar]
  11. Bullen JJ, Rogers HJ, Spalding PB, Ward CG. Iron and infection: The heart of the matter. FEMS Immunol Med Microbiol 2005; 43:325–330 [View Article]
    [Google Scholar]
  12. WHO U. Focusing on anaemia: Towards an integrated approach for effective anaemia control: Joint statement by the World Health Organization and the United Nations Children’s Fund ; 2004
  13. Sazawal S, Black RE, Ramsan M, Chwaya HM, Stoltzfus RJ et al. Effects of routine prophylactic supplementation with iron and folic acid on admission to hospital and mortality in preschool children in a high malaria transmission setting: Community-based, randomised, placebo-controlled trial. The Lancet 2006; 367:133–143 [View Article]
    [Google Scholar]
  14. Oppenheimer SJ. Iron and its relation to immunity and infectious disease. J Nutr 2001; 131:616S–635S [View Article]
    [Google Scholar]
  15. Skaar EP. The battle for iron between bacterial pathogens and their vertebrate hosts. PLoS Pathog 2010; 6:e1000949 [View Article]
    [Google Scholar]
  16. Ghosal A, Bhowmick R, Nandy RK, Ramamurthy T, Chatterjee NS. Pcr-based identification of common colonization factor antigens of enterotoxigenic Escherichia coli . J Clin Microbiol 2007; 45:3068–3071 [View Article]
    [Google Scholar]
  17. Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. Methods 2001; 25:402–408 [View Article]
    [Google Scholar]
  18. Wajima T, Sabui S, Fukumoto M, Kano S, Ramamurthy T et al. Enterotoxigenic Escherichia coli cs6 gene products and their roles in cs6 structural protein assembly and cellular adherence. Microb Pathog 2011; 51: [View Article] [PubMed]
    [Google Scholar]
  19. Elder BL, Boraker DK, Fives-Taylor PM. Whole-bacterial cell enzyme-linked immunosorbent assay for streptococcus sanguis fimbrial antigens. J Clin Microbiol 1982; 16: [View Article] [PubMed]
    [Google Scholar]
  20. Sjöling A, Wiklund G, Savarino SJ, Cohen DI, Svennerholm A-M. Comparative analyses of phenotypic and genotypic methods for detection of enterotoxigenic Escherichia coli toxins and colonization factors. J Clin Microbiol 2007; 45:3295–3301 [View Article]
    [Google Scholar]
  21. Rocha LB, Ozaki CY, Horton DSPQ, Menezes CA, Silva A et al. Different assay conditions for detecting the production and release of heat-labile and heat-stable toxins in enterotoxigenic Escherichia coli isolates. Toxins (Basel) 2013; 5:2384–2402 [View Article]
    [Google Scholar]
  22. Miller J, Lee K. Experiments in Molecular Genetics Yi Hsien Pub. Co; 1984
    [Google Scholar]
  23. De SN, Bhattacharya K, Sarkar JK. A study of the pathogenicity of strains of Bacterium coli from acute and chronic enteritis. J Pathol Bacteriol 1956; 71:201–209 [View Article]
    [Google Scholar]
  24. Sousa Gerós A, Simmons A, Drakesmith H, Aulicino A, Frost JN. The battle for iron in enteric infections. Immunology 2020; 161:186–199 [View Article]
    [Google Scholar]
  25. Andrews S, Norton I, Salunkhe AS, Goodluck H, Aly WS et al. Control of iron metabolism in bacteria. In Metallomics and the cell Springer; 2013 pp 203–239 [View Article]
    [Google Scholar]
  26. Schaible UE, Kaufmann SHE. Iron and microbial infection. Nat Rev Microbiol 2004; 2:946–953 [View Article]
    [Google Scholar]
  27. Haines S, Arnaud-Barbe N, Poncet D, Reverchon S, Wawrzyniak J et al. ISCR regulates synthesis of colonization factor antigen I fimbriae in response to iron starvation in enterotoxigenic Escherichia coli . J Bacteriol 2015; 197:2896–2907 [View Article]
    [Google Scholar]
  28. Payne SM, Neilands I. Iron and virulence in the family Enterobacteriaceae. Crit Rev Microbiol 1988; 16:81–111 [View Article]
    [Google Scholar]
  29. Magistro G, Magistro C, Stief CG, Schubert S. The high-pathogenicity island (HPI) promotes flagellum-mediated motility in extraintestinal pathogenic Escherichia coli . PloS one 2017; 12:e0183950 [View Article]
    [Google Scholar]
  30. Alderete JF, Nguyen J, Mundodi V, Lehker MW. Heme-iron increases levels of AP65-mediated adherence by Trichomonas vaginalis . Microb Pathog 2004; 36:263–271 [View Article]
    [Google Scholar]
  31. Karjalainen TK, Evans DG, Evans DJ Jr, Graham DY, Lee C-H. Iron represses the expression of CFA/I fimbriae of enterotoxigenic E. coli . Microbial Pathogenesis 1991; 11:317–323 [View Article]
    [Google Scholar]
  32. Kortman GAM, Boleij A, Swinkels DW, Tjalsma H. Iron availability increases the pathogenic potential of Salmonella typhimurium and other enteric pathogens at the intestinal epithelial interface. PloS one 2012; 7:e29968 [View Article]
    [Google Scholar]
  33. Ochoa TJ, Cleary TG. Effect of lactoferrin on enteric pathogens. Biochimie 2009; 91:30–34 [View Article]
    [Google Scholar]
  34. Jaeggi T, Kortman GAM, Moretti D, Chassard C, Holding P et al. Iron fortification adversely affects the gut microbiome, increases pathogen abundance and induces intestinal inflammation in kenyan infants. Gut 2015; 64:731–742 [View Article]
    [Google Scholar]
  35. van Asbeck BS, Marcelis JH, Marx JJ, Struyvenberg A, van Kats JH et al. Inhibition of bacterial multiplication by the iron chelator deferoxamine: Potentiating effect of ascorbic acid. Eur J Clin Microbiol 1983; 2:426–431 [View Article]
    [Google Scholar]
  36. Carver PL. The battle for iron between humans and microbes. CMC 2018; 25:85–96 [View Article]
    [Google Scholar]
  37. Sritharan M. Iron and bacterial virulence. Indian J Med Microbiol 2006; 24:163–164 [View Article]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.001089
Loading
/content/journal/micro/10.1099/mic.0.001089
Loading

Data & Media loading...

Supplements

Supplementary material 1

PDF

Most cited Most Cited RSS feed