Growth and Extended Survival of Escherichia coli O157:H7 in Soil Organic Matter

Enterohaemorrhagic Escherichia coli, such as serotype O157:H7, are a leading cause of food-associated outbreaks. While the primary reservoir is associated with cattle, plant foods have been associated as sources of human infection. E. coli is able to grow in the tissue of food plants such as spinach. While fecal contamination is the primary suspect, soil has been underestimated as a potential reservoir. Persistence of bacterial populations in open systems is the product of growth, death, predation, and competition. Here we report that E. coli O157:H7 can grow using the soluble compounds in soil, and characterize the effect of soil growth on the stationary phase proteome. E. coli 933D (stxII-) was cultured in Soil Extracted Soluble Organic Matter (SESOM) and the culturable count determined for 24d. The proteomes of exponential and stationary phase populations were characterized by 2D gel electrophoresis and protein spots were identified by MALDI-TOF mass spectrometry. While LB controls displayed a death phase, SESOM grown population remained culturable for 24d, indicating an altered physiological state with superior longevity. This was not due to decreased cell density on entry to stationary phase as 24 h SESOM populations concentrated 10-fold retained their longevity. Principal component analysis showed that stationary phase proteomes from SESOM and LB were different. Differences included proteins involved in stress response, motility, membrane and wall composition, nutrient uptake, translation and protein turnover, and anabolic and catabolic pathways, indicating an altered physiological state of soil-grown cells entering stationary phase. The results suggest that E. coli may be a soil commensal that, in absence of predation and competition, maintains stable populations in soil.

Medienart:

E-Artikel

Erscheinungsjahr:

2018

Erschienen:

2018

Enthalten in:

Zur Gesamtaufnahme - volume:9

Enthalten in:

Frontiers in microbiology - 9(2018) vom: 07., Seite 762

Sprache:

Englisch

Beteiligte Personen:

NandaKafle, Gitanjali [VerfasserIn]
Christie, Amy A [VerfasserIn]
Vilain, Sébastien [VerfasserIn]
Brözel, Volker S [VerfasserIn]

Links:

Volltext

Themen:

Escherichia coli O157:H7
Journal Article
Proteome
Soil organic matter
Stationary phase
Survival

Anmerkungen:

Date Revised 30.09.2020

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.3389/fmicb.2018.00762

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM283873469