Interactions of <i>Escherichia coli</i> and <i>Streptococcus bovis</i> with soil clay surfaces as revealed by scanning electron microscopy

Guy, Esme M.; Theng, B. K. G.; Walker, Graham D.

doi:10.1002/jpln.19801430208

Cited by 5 publications

(4 citation statements)

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“…This result surprised us, as microscopic examination of samples from environments as diverse as the large intestine (26), leaf surfaces (27), soil (21), and freshwater and marine systems (14,23,29) indicate that bacteria readily form large clumps. The lack of clumping observed in samples eroded from cowpats may be due to the energy impact of the raindrops being high enough to break up the clumps prior to transport.…”

Section: Discussionmentioning

confidence: 98%

Erosion and Subsequent Transport State of Escherichia coli from Cowpats

Muirhead

Collins

Bremer

2005

Appl Environ Microbiol

105

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Processes by which fecal bacteria enter overland flow and their transportation state to surface waters are poorly understood, making the effectiveness of measures designed to intercept this pathway, such as vegetated buffer strips, difficult to predict. Freshly made and aged (up to 30 days) cowpats were exposed to simulated rainfall, and samples of the cowpat material and runoff were collected. Escherichia coli in the runoff samples were separated into attached (to particles) and unattached fractions, and the unattached fraction was analyzed to determine if the cells were clumped. Within cowpats, E. coli grew for 6 to 14 days, rather than following a typical logarithmic die-off curve. E. coli numbers in the runoff correlated with numbers inside the cowpat. Most of the E. coli organisms eroded from the cowpats were transported as single cells, and only a small percentage (about 8%) attached to particles. The erosion of E. coli from cowpats and the state in which the cells were transported did not vary with time within a single rainfall event or over time as the cowpats aged and dried out. These findings indicate that cowpats can remain a significant source of E. coli in overland flow for more than 30 days. As well, most of the E. coli organisms eroded from cowpats will occur as readily transportable single cells.

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Section: Discussionmentioning

confidence: 98%

Erosion and Subsequent Transport State of Escherichia coli from Cowpats

Muirhead

Collins

Bremer

2005

Appl Environ Microbiol

105

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“…The prevalence in the GIT of animals and humans facilitates transmission between animals and humans via feces and saliva (Dumke et al, 2015 , 2017 ). Over a duration of 4 weeks, SB counts of an estimated 10 7 CFU/g broiler feed and 10 8 CFU/g wheat straw were only reduced by one log unit indicating high transmission possibility (Guy et al, 1980 ; Mackey and Hinton, 1990 ). Furthermore, soil clay adhesion of SB from bovine feces is very strong and cannot be desorbed after 24 h whereas long-term persistence seems weak but possibly sufficient to establish transmission within shorter time frames as observed among poultry flocks, surrounding environment and workers.…”

Section: Transmission and Niche Adaption Of Sbsec Membersmentioning

confidence: 99%

“…Furthermore, soil clay adhesion of SB from bovine feces is very strong and cannot be desorbed after 24 h whereas long-term persistence seems weak but possibly sufficient to establish transmission within shorter time frames as observed among poultry flocks, surrounding environment and workers. In laying hens, colonization of non-carrier birds introduced into an SGG -positive flock took approximately 35 weeks and occurred likely via feed and feces (Guy et al, 1980 ; Dumke et al, 2015 ; Schulz et al, 2015 ). SGG isolates of identical sequence types where thereby causing infection in one worker and contributing to in-flock and old-young transmission in hens (Dumke et al, 2015 ).…”

Section: Transmission and Niche Adaption Of Sbsec Membersmentioning

confidence: 99%

The Road to Infection: Host-Microbe Interactions Defining the Pathogenicity of Streptococcus bovis/Streptococcus equinus Complex Members

Jans¹,

Boleij²

2018

Front. Microbiol.

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The Streptococcus bovis/Streptococcus equinus complex (SBSEC) comprises several species inhabiting the animal and human gastrointestinal tract (GIT). They match the pathobiont description, are potential zoonotic agents and technological organisms in fermented foods. SBSEC members are associated with multiple diseases in humans and animals including ruminal acidosis, infective endocarditis (IE) and colorectal cancer (CRC). Therefore, this review aims to re-evaluate adhesion and colonization abilities of SBSEC members of animal, human and food origin paired with genomic and functional host-microbe interaction data on their road from colonization to infection. SBSEC seem to be a marginal population during GIT symbiosis that can proliferate as opportunistic pathogens. Risk factors for human colonization are considered living in rural areas and animal-feces contact. Niche adaptation plays a pivotal role where Streptococcus gallolyticus subsp. gallolyticus (SGG) retained the ability to proliferate in various environments. Other SBSEC members have undergone genome reduction and niche-specific gene gain to yield important commensal, pathobiont and technological species. Selective colonization of CRC tissue is suggested for SGG, possibly related to increased adhesion to cancerous cell types featuring enhanced collagen IV accessibility. SGG can colonize, proliferate and may shape the tumor microenvironment to their benefit by tumor promotion upon initial neoplasia development. Bacteria cell surface structures including lipotheichoic acids, capsular polysaccharides and pilus loci (pil1, pil2, and pil3) govern adhesion. Only human blood-derived SGG contain complete pilus loci and other disease-associated surface proteins. Rumen or feces-derived SGG and other SBSEC members lack or harbor mutated pili. Pili also contribute to binding to fibrinogen upon invasion and translocation of cells from the GIT into the blood system, subsequent immune evasion, human contact system activation and collagen-I-binding on damaged heart valves. Only SGG carrying complete pilus loci seem to have highest IE potential in humans with significant links between SGG bacteremia/IE and underlying diseases including CRC. Other SBSEC host-microbe combinations might rely on currently unknown mechanisms. Comparative genome data of blood, commensal and food isolates are limited but required to elucidate the role of pili and other virulence factors, understand pathogenicity mechanisms, host specificity and estimate health risks for animals, humans and food alike.

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“…Because of their high water content ( > 99%) and polysaccharidic nature (Cagle, 1975), bacterial extracellular polymers, or exopolymers, are notoriously difficult to stabilize for scanning electron microscopy (SEM) observation. When prepared using conventional methods (chemical fixation followed by critical-point-drying or freezedrying), bacterial capsules and slime layers have been described alternatively as a line matrix of fibrillar material (Guy et al, 1980;Mutaftschiev et al, 1982, Shaw et al, 1985, as randomly arranged thicker fibrils (Cagle, 1974), or as a condensed layer encasing the cells (Eighmy et al, 1983;Shaw et al, 1985;McKinley et al, 1988). The fibrils sometimes contain bulbous protrusions (Cagle, 1974(Cagle, ,1975Cassity et al, 1978).…”

Section: Introductionmentioning

confidence: 99%

Improved preservation of bacterial exopolymers for scanning electron microscopy

Vandevivere

Baveye

1992

Journal of Microscopy

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SUMMARY Two methods of sample preparation, originally developed for transmission electron microscopy and better at preserving bacterial exopolymers than the traditional fixation with glutaraldehyde, were adapted for scanning electron microscopy. The first involves a glutaraldehyde‐lysine mixture as a fixative. The second, based on the use of polycationic ferritin, was modified to include a post‐fixation step with either glutaraldehyde or a glutaraldehyde‐lysine mixture. These techniques were found to improve considerably the preservation of exopolymers secreted by three bacterial strains.

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Interactions of Escherichia coli and Streptococcus bovis with soil clay surfaces as revealed by scanning electron microscopy

Cited by 5 publications

References 10 publications

Erosion and Subsequent Transport State of Escherichia coli from Cowpats

Erosion and Subsequent Transport State of Escherichia coli from Cowpats

The Road to Infection: Host-Microbe Interactions Defining the Pathogenicity of Streptococcus bovis/Streptococcus equinus Complex Members

Improved preservation of bacterial exopolymers for scanning electron microscopy

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