Influence of environmental factors in the adherence of an atypical enteropathogenic Escherichia coli strain to epithelial cells

Romão, Fabiano T.; Hernandes, Rodrigo T.; Yamamoto, Denise; Osugui, Lika; Popi, Ana Flávia; Gomes, Tânia A. T.

doi:10.1186/s12866-014-0299-y

Cited by 9 publications

(8 citation statements)

References 29 publications

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“…Finally, we utilized quantitative RT-PCR analysis for additional data to support the transcription of adherence genes. As described in previous literature for other pathogens (39–42), glucose induced the expression of the S. flexneri 2457T genes encoding structural subunits (Figure 4). In all, the data indicate that adherence gene clusters are genomically maintained and transcriptionally regulated in S. flexneri 2457T despite the pseudogene annotations.…”

Section: Resultssupporting

confidence: 77%

Shigella flexneri adherence factor expression in in vivo-like conditions

Chanin

Nickerson

Llanos-Chea

et al. 2019

Preprint

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26The Shigella species are Gram-negative, facultative intracellular pathogens that invade the 27 colonic epithelium and cause significant diarrheal disease. Despite extensive research on the pathogen, 28 comprehensive understanding of how Shigella initiates contact with epithelial cells remains unknown. 29 Shigella maintains many of the same Escherichia coli adherence gene operons; however, at least one 30 critical gene component in each operon is currently annotated as a pseudogene in reference genomes. 31 These annotations, coupled with a lack of structures upon microscopic analysis following growth in 32 laboratory media, have led the field to hypothesize that Shigella is unable to produce fimbriae or other 33 "traditional" adherence factors. Nevertheless, our previous analyses have demonstrated that a 34 combination of bile salts and glucose induce both biofilm formation and adherence to colonic epithelial 35 cells. Through a two-part investigation, we first utilized various transcriptomic analyses to demonstrate 36 that S. flexneri strain 2457T adherence gene operons are transcribed. Subsequently, we performed 37 mutation, electron microscopy, biofilm, infection, and proteomic analyses to characterize three of the 38 structural genes. In combination, these studies demonstrate that despite the gene annotations, S. 39 flexneri 2457T uses adherence factors to initiate biofilm formation as well as epithelial cell contact. 40 Furthermore, host factors, namely glucose and bile salts in the small intestine, offer key environmental 41 stimuli required for proper adherence factor expression in S. flexneri. This research may have a 42 significant impact on vaccine development for Shigella and further highlights the importance of 43 utilizing in vivo-like conditions to study bacterial pathogenesis. 44 45 Importance 46 Bacterial pathogens have evolved to regulate virulence gene expression at critical points in the 47 colonization and infection processes to successfully cause disease. The Shigella species infect the 48 epithelial cells lining the colon to result in millions of cases of diarrhea and a significant global health 49 burden. As antibiotic resistance rates increase, understanding the mechanisms of infection are vital to 50 3 ensure successful vaccine development. Despite significant gains in our understanding of Shigella 51 infection, it remains unknown how the bacteria initiate contact with the colonic epithelium. Most 52 pathogens harbor multiple adherence factors to facilitate this process, but Shigella was thought to have 53 lost the ability to produce these factors. Interestingly, we have identified conditions that mimic some 54 features of gastrointestinal transit and enable Shigella to express adherence factors. This work 55 highlights aspects of genetic regulation for Shigella adherence factors and may have a significant 56 impact on future vaccine development. 57 58 59Shigella flexneri is a Gram-negative, facultative anaerobe that infects millions of people each 60 year by causing water...

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Section: Resultssupporting

confidence: 77%

Shigella flexneri adherence factor expression in in vivo-like conditions

Chanin

Nickerson

Llanos-Chea

et al. 2019

Preprint

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“…Finally, we utilized quantitative RT-PCR (qRT-PCR) analysis to obtain additional data to support the transcription of adherence genes. As described in previously published literature for other pathogens (43–46), glucose induced the expression of the S. flexneri 2457T genes encoding structural subunits (Fig.…”

Section: Resultssupporting

confidence: 60%

Shigella flexneri Adherence Factor Expression in In Vivo -Like Conditions

Chanin

Nickerson

Llanos-Chea

et al. 2019

mSphere

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Bacterial pathogens have evolved to regulate virulence gene expression at critical points in the colonization and infection processes to successfully cause disease. The Shigella species infect the epithelial cells lining the colon to result in millions of cases of diarrhea and a significant global health burden. As antibiotic resistance rates increase, understanding the mechanisms of infection is vital to ensure successful vaccine development. Despite significant gains in our understanding of Shigella infection, it remains unknown how the bacteria initiate contact with the colonic epithelium. Most pathogens harbor multiple adherence factors to facilitate this process, but Shigella was thought to have lost the ability to produce these factors. Interestingly, we have identified conditions that mimic some features of gastrointestinal transit and that enable Shigella to express adherence structural genes. This work highlights aspects of genetic regulation for Shigella adherence factors and may have a significant impact on future vaccine development.

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“…The data suggest that colonization factors other than fimbriae were utilized to enhance binding events in typical EPEC strains in response to bile. Conversely, enhanced adhesion was not observed with atypical EPEC strain 1551-2, which lacks the bundle-forming pilus, when grown on HeLa cells (49). A second interesting observation is that EPEC responses to bile have been demonstrated to impact host cell physiology, as described by Annaba et al in a study showing that EPEC inhibits enterocyte bile absorption in the ileum and leads to increased bile concentrations in the colon.…”

Section: Pathogenic E Colimentioning

confidence: 78%

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

et al. 2016

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SUMMARYBacterial pathogens have coevolved with humans in order to efficiently infect, replicate within, and be transmitted to new hosts to ensure survival and a continual infection cycle. For enteric pathogens, the ability to adapt to numerous host factors under the harsh conditions of the gastrointestinal tract is critical for establishing infection. One such host factor readily encountered by enteric bacteria is bile, an innately antimicrobial detergent-like compound essential for digestion and nutrient absorption. Not only have enteric pathogens evolved to resist the bactericidal conditions of bile, but these bacteria also utilize bile as a signal to enhance virulence regulation for efficient infection. This review provides a comprehensive and up-to-date analysis of bile-related research with enteric pathogens. From common responses to the unique expression of specific virulence factors, each pathogen has overcome significant challenges to establish infection in the gastrointestinal tract. Utilization of bile as a signal to modulate virulence factor expression has led to important insights for our understanding of virulence mechanisms for many pathogens. Further research on enteric pathogens exposed to thisin vivosignal will benefit therapeutic and vaccine development and ultimately enhance our success at combating such elite pathogens.

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Influence of environmental factors in the adherence of an atypical enteropathogenic Escherichia coli strain to epithelial cells

Cited by 9 publications

References 29 publications

Shigella flexneri adherence factor expression in in vivo-like conditions

Shigella flexneri adherence factor expression in in vivo-like conditions

Shigella flexneri Adherence Factor Expression in In Vivo -Like Conditions

Survival of the Fittest: How Bacterial Pathogens Utilize Bile To Enhance Infection

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