Acid-happy: Survival and recovery of enteropathogenic Escherichia coli (EPEC) in simulated gastric fluid

Pienaar, Jennifer Anne; Singh, Atheesha; Barnard, T.G.

doi:10.1016/j.micpath.2019.01.022

Cited by 30 publications

(30 citation statements)

References 46 publications

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“…Benefited from the complicated AR and ATR systems, E. coli can survive without growth for several hours at pH 2.0 1,18-20 , and the acid limit for growth of E. coli is pH 4.0 in rich medium, or pH 4.5 in minimal medium 6,18,[20][21][22] . So, E. coli will experience the transition of pH from no-growth to growth conditions when passing through the stomach and entering the intestine.…”

mentioning

confidence: 99%

An acid-tolerance response system protecting exponentially growing Escherichia coli

et al. 2020

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The ability to grow at moderate acidic conditions (pH 4.0-5.0) is important to Escherichia coli colonization of the host's intestine. Several regulatory systems are known to control acid resistance in E. coli, enabling the bacteria to survive under acidic conditions without growth. Here, we characterize an acid-tolerance response (ATR) system and its regulatory circuit, required for E. coli exponential growth at pH 4.2. A two-component system CpxRA directly senses acidification through protonation of CpxA periplasmic histidine residues, and upregulates the fabA and fabB genes, leading to increased production of unsaturated fatty acids. Changes in lipid composition decrease membrane fluidity, F 0 F 1 -ATPase activity, and improve intracellular pH homeostasis. The ATR system is important for E. coli survival in the mouse intestine and for production of higher level of 3-hydroxypropionate during fermentation. Furthermore, this ATR system appears to be conserved in other Gram-negative bacteria.

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confidence: 99%

An acid-tolerance response system protecting exponentially growing Escherichia coli

et al. 2020

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“…Upon ingestion of contaminated food or water, EPEC and EHEC initially enter the stomach. Acidity of the gastric fluid not only aids the host in digestion of food but also serves as a significant barrier to enteric infection (Pienaar, Singh, & Barnard, 2019;Yasutomi et al, 2018). EPEC has the ability to withstand and recover from exposure to simulated gastric fluid (Pienaar et al, 2019).…”

Section: The Physical Landscape and Ae Pathogensmentioning

confidence: 99%

“…Acidity of the gastric fluid not only aids the host in digestion of food but also serves as a significant barrier to enteric infection (Pienaar, Singh, & Barnard, 2019;Yasutomi et al, 2018). EPEC has the ability to withstand and recover from exposure to simulated gastric fluid (Pienaar et al, 2019). However, during EHEC infection, 20-80% of ingested bacteria are estimated to die before reaching the small intestine (Takumi, de Jonge, & Havelaar, 2000).…”

Section: The Physical Landscape and Ae Pathogensmentioning

confidence: 99%

Here, there, and everywhere: How pathogenicEscherichia colisense and respond to gastrointestinal biogeography

Woodward

Krekhno

2019

Cellular Microbiology

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Gastrointestinal (GI) pathogens enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC and EHEC), and related mouse pathogen Citrobacter rodentium, are referred to as attaching and effacing (AE) pathogens for the lesions they form upon colonisation of the host epithelium. EPEC, EHEC, and C. rodentium are well known to use a type III secretion system to intimately attach to intestinal cells and secrete bacterial effectors to manipulate host cell processes. Less well known is the ability of AE pathogens to overcome significant physiological and microbial barriers and target specific gut niches for initial colonisation of the host epithelium. This review considers recent work highlighting the biogeography of the GI tract as it applies to colonisation by enteric pathogens, including environmental barriers to enteric infection, signals sensed by AE pathogens for navigation of the GI tract, and the tools AE pathogens use to respond to the changing host environment.

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“…Shifts in pH can also interfere with the proton motive force and change the protein profile of the outer membrane in Gram-negative cells. This can cause cells to fail to use proton pumps to remove H + ions from the cells (Pienaar et al, 2019). Acidification also disrupts key biochemical processes (Chung et al, 2006).…”

Section: Acid Stress Induction and Evaluation Of Cell Culture And Viamentioning

confidence: 99%

“…Oliver (2010) suggested that entering VBNC is a strategy of bacterial survival when environmental conditions are not suitable for normal growth. Although VBNC cells cannot be cultured, they can maintain metabolic activity and express toxic proteins (Ding et al, 2017), energy activity and respiratory activity (Pienaar et al, 2019), membrane integrity (Lahtinen et al, 2008), and main regulatory gene from the general stress response (Kusumoto et al, 2012). Pinto et al (2013) explained that cell populations that can be cultured when induced into VBNC conditions will experience a reduction in the number of cells that can be cultured to below the detection limit and other cell populations i.e.…”

Section: Acid Stress Induction and Evaluation Of Cell Culture And Viamentioning

confidence: 99%

Cronobacter sakazakii local isolates response to acid stress and their resuscitability

Hati¹,

Dewanti‐Hariyadi²,

Nuraida³

2019

Food Res.

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Cronobacter spp. has been reported to cause meningitis, necrotizing enterocolitis, and septicemia in a group of infants through the consumption of powder infant formula. These bacteria are reported to withstand various stress conditions such as heating, drying, low water activity, low pH, etc. A local isolate of Cronobacter sakazakii YRt2a was reportedly survived and entered Viable But Non-Culturable (VBNC) conditions during desiccation stress. This study aims to study the behavior of local isolates of Cronobacter spp. in response to acid stress and its resuscitability. C. sakazakii E2 and YRt2a were grown in TSB at pH 3.0±0.2 or 3.5±0.2. The number of culturable cells and viable cells were enumerated by the Total Plate Count and Direct Viable Count methods, respectively. Resuscitation was done by growing the stress or VBNC cells in TSB with or without sodium pyruvate, catalase, Tween 20, or Cronobacter autoinducer. The results showed that C. sakazakii E2 and YRt2a entered VBNC state after 60 mins of exposure to pH 3.0±0.2, while remained culturable after 120 minutes exposure to pH 3.5±0.2. TSB with or without sodium pyruvate, catalase, Tween 20, or Cronobacter autoinducer could resuscitate the stress or VBNC cells of C. sakazakii. Stress or VBNC state experienced by C. sakazakii in response to acid tends to be transient and can be resuscitated. C. sakazakii experiencing stress or VBNC may pose a risk for food safety.

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Acid-happy: Survival and recovery of enteropathogenic Escherichia coli (EPEC) in simulated gastric fluid

Cited by 30 publications

References 46 publications

An acid-tolerance response system protecting exponentially growing Escherichia coli

An acid-tolerance response system protecting exponentially growing Escherichia coli

Here, there, and everywhere: How pathogenicEscherichia colisense and respond to gastrointestinal biogeography

Cronobacter sakazakii local isolates response to acid stress and their resuscitability

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