A host metabolite promotes Salmonella survival

Science ◽  
2021 ◽  
Vol 371 (6527) ◽  
pp. 344-345
Author(s):  
Jason P. Lynch ◽  
Cammie F. Lesser
Keyword(s):  
Salmonella Survival

scholarly journals Salmonella stimulate macrophage macropinocytosis and persist within spacious phagosomes.

1994 ◽  
Vol 179 (2) ◽  
pp. 601-608 ◽  
Author(s):  
C M Alpuche-Aranda ◽  
E L Racoosin ◽  
J A Swanson ◽  
S I Miller
Keyword(s):  
Bone Marrow ◽  
Plasma Membrane ◽  
Time Lapse ◽  
Membrane Ruffling ◽  
Mouse Macrophages ◽  
Constitutive Mutation ◽  
Microscopic Studies ◽  
Specific Igg ◽  
Salmonella Survival ◽  
Time Lapse Video

Light microscopic studies of phagocytosis showed that Salmonella typhimurium entered mouse macrophages enclosed in spacious phagosomes (SP). Viewed by time-lapse video microscopy, bone marrow-derived macrophages exposed to S. typhimurium displayed generalized plasma membrane ruffling and macropinocytosis. Phagosomes containing Salmonella were morphologically indistinguishable from macropinosomes. SP formation was observed after several methods of bacterial opsonization, although bacteria opsonized with specific IgG appeared initially in small phagosomes that later enlarged. In contrast to macropinosomes induced by growth factors, which shrink completely within 15 min, SP persisted in the cytoplasm, enlarging often by fusion with macropinosomes or other SP. A Salmonella strain containing a constitutive mutation in the phoP virulence regulatory locus (PhoPc) induced significantly fewer SP. Similar to Yersinia enterocolitica, PhoPc bacteria entered macrophages in close-fitting phagosomes, consistent with that expected for conventional receptor-mediated phagocytosis. These results suggest that formation of SP contributes to Salmonella survival and virulence.

scholarly journals Salmonella SipA mimics a cognate SNARE for host Syntaxin8 to promote fusion with early endosomes

2018 ◽  
Vol 217 (12) ◽  
pp. 4199-4214 ◽  
Author(s):  
Pawan Kishor Singh ◽  
Anjali Kapoor ◽  
Richa Madan Lomash ◽  
Kamal Kumar ◽  
Sukrut C. Kamerkar ◽  
...  
Keyword(s):  
Actin Polymerization ◽  
Enteric Fever ◽  
Caspase 3 ◽  
Arginine Residue ◽  
Terminal Domain ◽  
Trafficking Pathway ◽  
Early Endosomes ◽  
N Terminus ◽  
Snare Motif ◽  
Salmonella Survival

SipA is a major effector of Salmonella, which causes gastroenteritis and enteric fever. Caspase-3 cleaves SipA into two domains: the C-terminal domain regulates actin polymerization, whereas the function of the N terminus is unknown. We show that the cleaved SipA N terminus binds and recruits host Syntaxin8 (Syn8) to Salmonella-containing vacuoles (SCVs). The SipA N terminus contains a SNARE motif with a conserved arginine residue like mammalian R-SNAREs. SipAR204Q and SipA1–435R204Q do not bind Syn8, demonstrating that SipA mimics a cognate R-SNARE for Syn8. Consequently, Salmonella lacking SipA or that express the SipA1–435R204Q SNARE mutant are unable to recruit Syn8 to SCVs. Finally, we show that SipA mimicking an R-SNARE recruits Syn8, Syn13, and Syn7 to the SCV and promotes its fusion with early endosomes to potentially arrest its maturation. Our results reveal that SipA functionally substitutes endogenous SNAREs in order to hijack the host trafficking pathway and promote Salmonella survival.

Salmonella Survival in Soil and Transfer Onto Produce via Splash Events

2019 ◽  
Vol 82 (12) ◽  
pp. 2023-2037 ◽  
Author(s):  
DEBBIE LEE ◽  
MOUKARAM TERTULIANO ◽  
CASEY HARRIS ◽  
GEORGE VELLIDIS ◽  
KAREN LEVY ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Geometric Mean ◽  
The United States ◽  
Mean Difference ◽  
Antecedent Soil Moisture ◽  
Produce Safety ◽  
Produce Contamination ◽  
Salmonella Survival

ABSTRACT Nearly one-half of foodborne illnesses in the United States can be attributed to fresh produce consumption. The preharvest stage of production presents a critical opportunity to prevent produce contamination in the field from contaminating postharvest operations and exposing consumers to foodborne pathogens. One produce-contamination route that is not often explored is the transfer of pathogens in the soil to edible portions of crops via splash water. We report here on the results from multiple field and microcosm experiments examining the potential for Salmonella contamination of produce crops via splash water, and the effect of soil moisture content on Salmonella survival in soil and concentration in splash water. In field and microcosm experiments, we detected Salmonella for up to 8 to 10 days after inoculation in soil and on produce. Salmonella and suspended solids were detected in splash water at heights of up to 80 cm from the soil surface. Soil-moisture conditions before the splash event influenced the detection of Salmonella on crops after the splash events—Salmonella concentrations on produce after rainfall were significantly higher in wet plots than in dry plots (geometric mean difference = 0.43 CFU/g; P = 0.03). Similarly, concentrations of Salmonella in splash water in wet plots trended higher than concentrations from dry plots (geometric mean difference = 0.67 CFU/100 mL; P = 0.04). These results indicate that splash transfer of Salmonella from soil onto crops can occur and that antecedent soil-moisture content may mediate the efficiency of microbial transfer. Splash transfer of Salmonella may, therefore, pose a hazard to produce safety. The potential for the risk of splash should be further explored in agricultural regions in which Salmonella and other pathogens are present in soil. These results will help inform the assessment of produce safety risk and the development of management practices for the mitigation of produce contamination. HIGHLIGHTS

Salmonella survival after exposure to heat in a model meat juice system

2021 ◽  
Vol 94 ◽  
pp. 103628
Author(s):  
Amreeta Sarjit ◽  
Joshua T. Ravensdale ◽  
Ranil Coorey ◽  
Narelle Fegan ◽  
Gary A. Dykes
Keyword(s):  
Meat Juice ◽  
Salmonella Survival

Growth and Heat Resistance of Salmonella enteritidisin Refrigerated and Abused Eggs

1993 ◽  
Vol 56 (11) ◽  
pp. 927-931 ◽  
Author(s):  
A. MAHDI SAEED ◽  
CAROL W. KOONS
Keyword(s):  
Heat Resistance ◽  
Salmonella Enteritidis ◽  
Room Temperature ◽  
Storage Temperature ◽  
Phase 1 ◽  
Shell Eggs ◽  
Growth Inhibitory ◽  
Significant Barrier ◽  
The Common ◽  
Salmonella Survival

The effect of storage temperature on the growth and heat resistance of Salmonella enteritidis (SE) in eggs artificially inoculated with 20 CFU per egg has been investigated. SE organisms grew to a stationary phase (1 × 109 CFU/ml of egg) within 2–3 d after storing the eggs at room temperature (23°C), while minimal or no growth occurred in similarly inoculated eggs that were refrigerated at 4°C. None of the common methods of egg cooking was found totally effective in eliminating SE organisms in massively contaminated eggs. SE organisms survived in significantly higher proportions of the eggs that were stored at 23°C than in refrigerated eggs after cooking by different methods (P < 0.05). Higher rates of Salmonella survival after cooking were detected in the eggs that were stored at room temperature for 5 d or longer than in eggs stored for shorter time (P < 0.05). Data from this study indicated: i) storage abuse of eggs can be a major factor in increasing the prevalence of eggborne SE infections by increasing the infectious load and heat resistance of the SE organisms in the contaminated eggs, and ii) that breaking and pooling of eggs immediately before cooking can minimize the substantial multiplication of SE organisms from slightly contaminated eggs. Refrigeration, therefore, can be a significant barrier against SE infections through its growth inhibitory and heat resistance-reducing effects on the SE organisms in contaminated shell eggs as well as in large volumes of liquid eggs intended for pasteurization.

scholarly journals Quantification of Salmonella Survival and Infection in an In vitro Model of the Human Intestinal Tract as Proxy for Foodborne Pathogens

2017 ◽  
Vol 8 ◽  
Author(s):  
Lucas M. Wijnands ◽  
Peter F. M. Teunis ◽  
Angelina F. A. Kuijpers ◽  
Ellen H. M. Delfgou-Van Asch ◽  
Annemarie Pielaat
Keyword(s):  
Foodborne Pathogens ◽  
Intestinal Tract ◽  
In Vitro Model ◽  
Vitro Model ◽  
Salmonella Survival ◽  
Human Intestinal Tract

Survival of Salmonella during Apple Dehydration as Affected by Apple Cultivar and Antimicrobial Pretreatment

2020 ◽  
Vol 83 (5) ◽  
pp. 902-909
Author(s):  
JOSHUA B. GURTLER ◽  
SUSANNE E. KELLER ◽  
XUETONG FAN ◽  
O. MODESTO OLANYA ◽  
TONY JIN ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Lactic Acid ◽  
Citric Acid ◽  
Fumaric Acid ◽  
Potassium Sorbate ◽  
Apple Cultivar ◽  
Sodium Bisulfate ◽  
Apple Slices ◽  
Apple Cultivars ◽  
Salmonella Survival

ABSTRACT Dehydrated fruits, including dried coconut (Cocos nucifera) and dried apple (Malus sp.) slices, have been the subject of manufacturer recalls due to contamination with Salmonella. A study was conducted to determine the survival of Salmonella on apple slices of six apple cultivars after dehydration and also following treatment with antimicrobial solutions (0.5%, w/w) and dehydration. Samples of six apple cultivars (Envy, Gala, Red Delicious, Fuji, Pink Lady, Granny Smith) were cored and sliced into 0.4-cm rings, halved, inoculated with a five-strain composite of desiccation-resistant Salmonella, and dehydrated at 60°C for 5 h. Subsequently, Gala apple slices were treated in 0.5% solutions of one of eight antimicrobial rinses for 2 min and then dehydrated at 60°C for 5 h. Antimicrobial solutions used were potassium sorbate, sodium benzoate, ascorbic acid, propionic acid, lactic acid, citric acid, fumaric acid, and sodium bisulfate. Reduction of Salmonella populations varied according to apple cultivar. Salmonella survival on Envy, Gala, Red Delicious, Fuji, Pink Lady, and Granny Smith was 5.92, 5.58, 4.83, 4.68, 4.45, and 3.84 log CFU, respectively. There was significantly greater (P < 0.05) Salmonella inactivation on Granny Smith, Pink Lady, and Fuji apples than on Gala and Envy. Survival of Salmonella on Gala apple slices following dehydration was 5.58 log CFU for the untreated control and 4.76, 3.90, 3.29, 3.13, 2.89, 2.83, 2.64, and 0.0 log CFU for those treated with potassium sorbate, sodium benzoate, ascorbic acid, propionic acid, lactic acid, citric acid, fumaric acid, and sodium bisulfate, respectively. Pretreatment of apple slices with either fumaric acid or sodium bisulfate before dehydration led to lower Salmonella survival than pretreatment with all other antimicrobial treatments. Lower apple pH was statistically correlated (P < 0.05) with decreasing survival of Salmonella following dehydration. These results may provide methodology applicable to the food industry for increasing the inactivation of Salmonella during the dehydration of apple slices. HIGHLIGHTS

Effect of Overhead Spray and Brush Roller Treatment on the Survival of Pectobacterium and Salmonella on Tomato Surfaces

2015 ◽  
Vol 78 (1) ◽  
pp. 51-56 ◽  
Author(s):  
ALINA N. BALAGUERO ◽  
ASWATHY SREEDHARAN ◽  
KEITH R. SCHNEIDER
Keyword(s):  
Relative Humidity ◽  
Plant Pathogen ◽  
Tomato Fruit ◽  
Soft Rot ◽  
Human Pathogen ◽  
Physical Damage ◽  
Tomato Quality ◽  
Negative Effect ◽  
Survival And Growth ◽  
Salmonella Survival

Overhead spray and brush roller (OSBR) treatment has been shown to remove significantly more Salmonella from tomato surfaces than flume treatment. However, OSBR is not widely used in tomato packing facilities compared with other commodities, and little is known about whether brushing causes microabrasions or other physical damage. Bacteria such as Pectobacterium, a soft rot–producing plant pathogen, and Salmonella, a human pathogen, show increased survival and growth on damaged tomato surfaces. This study evaluated whether OSBR treatment had a negative effect on the safety and/or marketability of tomatoes by examining its effect on Pectobacterium and Salmonella survival. Pectobacterium survival was evaluated on inoculated tomatoes that were OSBR treated with water or sanitizer (100 ppm of NaOCl, 5 ppm of ClO2, or 80 ppm of peracetic acid). A 15-s OSBR treatment using water or sanitizer achieved a 3-log CFU/ml reduction in Pectobacterium levels. Survival of Pectobacterium and Salmonella on OSBR-treated, untreated, and puncture-wounded tomatoes stored at 25°C and 75 to 85% relative humidity for 7 days was also assessed. Both Pectobacterium and Salmonella populations declined rapidly on OSBR-treated and untreated tomatoes, indicating that brushing does not damage tomato fruit to the extent of promoting better pathogen survival. In contrast, the survival of both organisms was significantly (P ≤ 0.05) higher on artificially wounded fruit. These results indicate that OSBR treatment does not increase the survival and growth of Pectobacterium or Salmonella on tomato surfaces and that it is effective in reducing Pectobacterium levels on the surface of inoculated tomatoes. These results suggest that, if used properly, an OSBR system in packinghouses is effective in removing surface contamination and does not affect tomato quality or safety.

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