Resuscitation of 20-year starved Salmonella in seawater and soil

Dhiaf, Amel; Abdallah, Fethi Ben; Bakhrouf, Amina

doi:10.1007/s13213-010-0020-9

Cited by 8 publications

(6 citation statements)

References 13 publications

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“…that antibiotic-resistant strains of S. enterica serovar Newport persisted for longer periods of time than their nonresistant counterparts in manure-amended soils. A fourth explanation may be that organisms enter a viable but not cultivable (VBNC) state, resulting in the appearance of an initial rapid decay, until stressed cells alter their physiology, followed by slower decay of more resilient organisms that remain cultivable, or as cells transition into and out of the VBNC state (8,12,14,27). Other potential sources of this behavior may include predation, biofilm formation, or the acquisition of genetic materials by a subpopulation of fecal bacteria from the native soil microbial community that favor their survival over counterparts that do not similarly adapt.…”

Section: Discussionmentioning

confidence: 99%

“…These genetic markers may also detect viable but nonculturable (VBNC) cells that are not detected by conventional cultivation approaches but may still pose a public health risk (38). Salmonella enterica serovar Typhimurium and E. coli O157:H7 are two examples of bacterial pathogens that may enter VBNC states (8,62). In addition, host-associated qPCR genetic markers are available and are reported to discriminate between human, cattle, swine, and other animal sources (4,23,25,32,35,(43)(44)(45), providing fecal pollution source information that may lead to better-informed remedial actions to improve water quality.…”

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confidence: 99%

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Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Rogers

Donnelly

Peed

et al. 2011

Appl Environ Microbiol

101

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This study examined persistence and decay of bacterial pathogens, fecal indicator bacteria (FIB), and emerging real-time quantitative PCR (qPCR) genetic markers for rapid detection of fecal pollution in manureamended agricultural soils. Known concentrations of transformed green fluorescent protein-expressing Escherichia coli O157:H7/pZs and red fluorescent protein-expressing Salmonella enterica serovar Typhimurium/pDs were added to laboratory-scale manure-amended soil microcosms with moisture contents of 60% or 80% field capacity and incubated at temperatures of ؊20°C, 10°C, or 25°C for 120 days. A two-stage first-order decay model was used to determine stage 1 and stage 2 first-order decay rate coefficients and transition times for each organism and qPCR genetic marker in each treatment. Genetic markers for FIB (Enterococcus spp., E. coli, and Bacteroidales) exhibited decay rate coefficients similar to that of E. coli O157:H7/pZs but not of S. enterica serovar Typhimurium/pDs and persisted at detectable levels longer than both pathogens. Concentrations of these two bacterial pathogens, their counterpart qPCR genetic markers (stx1 and ttrRSBCA, respectively), and FIB genetic markers were also correlated (r ‫؍‬ 0.528 to 0.745). This suggests that these qPCR genetic markers may be reliable conservative surrogates for monitoring fecal pollution from manure-amended land. Hostassociated qPCR genetic markers for microbial source tracking decayed rapidly to nondetectable concentrations, long before FIB, Salmonella enterica serovar Typhimurium/pDs, and E. coli O157:H7/pZs. Although good indicators of point source or recent nonpoint source fecal contamination events, these host-associated qPCR genetic markers may not be reliable indicators of nonpoint source fecal contamination events that occur weeks following manure application on land.Cultivation-based methods for fecal indicator bacteria (FIB) such as Escherichia coli and Enterococcus spp. have long been used to indicate potential public health risks associated with water impacted by human and other animal feces (53). FIB cultivation methods are simple to perform and inexpensive. However, these methods require 18 to 24 h following sampling to generate test results; this allows potential exposure of the public to fecal pathogens in the interim. Regulatory agencies, business owners, and other stakeholders have expressed interest in more rapid and specific methods to identify water quality impairment.Emerging real-time quantitative PCR (qPCR) methods designed to estimate the concentration of fecal pollution by targeting genomic DNA (gDNA) from FIB such as Bacteroidales, Enterococcus spp., and E. coli are now available and can generate test results in just a few hours after sampling (10,16,48). Some of these genetic markers can be correlated to public health risk and may soon be incorporated by the U.S. Environmental Protection Agency into water quality standards in the United States (16,59). These genetic markers may also detect viable but nonculturable (VBNC) cells tha...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Rogers

Donnelly

Peed

et al. 2011

Appl Environ Microbiol

101

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“…VBNC forms of salmonellae may undergo morphological transition in response to stress, as they form a shorter rods shape (Roszak et al, 1984). Resuscetation of VBNC Salmonella cells may be possible (Roszak et al, 1984;Smith et al, 2002;Dhiaf et al, 2010), yet these resuscitated cells may lose their virulence or ability to cause infection (Caro et al, 1999) as serovar Typhimurium in VBNC forms and active but nonculturable (ABNC) (i.e. resuscitated cells) were unable to infect, nor colonize laboratory animals (Smith et al, 2002).…”

Section: Survival In Naturementioning

confidence: 99%

Salmonellae in the Environment

Abulreesh¹

2012

Salmonella - Distribution, Adaptation, Control Measures and Molecular Technologies

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“…Typhimurium is characterized by an efficient adaptive response controlled by a set of genes when exposed to extend starvation in salty condition. Previously, Dhiaf and collaborators reported that S. Typhimurium was recovered after incubation for 20 years in seawater [8].…”

Section: Discussionmentioning

confidence: 99%

“…Frequently, osmotic conditions are used for food preservation and to control hazardous bacteria such as Salmonella [6]. However, S. Typhimurium can be isolated from shellfish [7], and can even persist and survive for long periods in hyperosmotic environments such as seawater [8].…”

Section: Introductionmentioning

confidence: 99%

Molecular analysis of the adaptive response in Salmonella Typhimurium after starvation in salty conditions

Elabed

Merghni

Hamza

et al. 2016

J Infect Dev Ctries

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Introduction: The pathogenic bacterium Salmonella enterica serovar Typhimurium elicits a variety of genetic programs to adapt to stress conditions encountered within hostile environments such as host phagocytes and preserved food. Methodology: In this work, differential display (DD) methodology was used to investigate the effect of one month starvation in a salty microcosm (0.5 M NaCl) on transcript profiling in a Salmonella Typhimurium LT2 strain. cDNA fragments resulting from differentially expressed mRNA were eluted from the gel, re-amplified, cloned, and then sequenced. Results: A total of 21 differentially expressed bands were detected by DD reverse transcription-polymerase chain reaction (RT-PCR). However, only 12 of them were successfully identified as upregulated genes in stressed cells. Based on the sequencing data and BLAST analysis, these genes were sopA, ssaD, yhhK, gmK, cspC, uspA, ompR, phoP, stcC, fimA, acrA,and yehZ. As a confirmation of the differential expression, RT-PCR was carried out using a set of specific primers. Remarkably, the expression levels of these genes were significantly increased in starved bacteria compared to standard laboratory conditions. Conclusions: Our results indicate that the starvation of Salmonella Typhimurium over one month in a salty microcosm changes the expression of stress proteins, response regulator in a two-component system, outer membrane proteins, effector proteins translocated by Salmonella pathogenicity island SPI1 and SPI2 type III secretion systems (TTSS), several metabolic enzymes, efflux pumps, and transport proteins. This suggests that the expression of the identified genes is important for the response of this pathogen to starvation in salt.

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Resuscitation of 20-year starved Salmonella in seawater and soil

Cited by 8 publications

References 13 publications

Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Decay of Bacterial Pathogens, Fecal Indicators, and Real-Time Quantitative PCR Genetic Markers in Manure-Amended Soils

Salmonellae in the Environment

Molecular analysis of the adaptive response in Salmonella Typhimurium after starvation in salty conditions

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