Super Shedding in Enteric Pathogens: A Review

Kempf, Florent; Ragione, Roberto La La; Chirullo, Barbara; Schouler, Catherine; Velge, Philippe

doi:10.3390/microorganisms10112101

Cited by 10 publications

(6 citation statements)

References 132 publications

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“…A change in environment especially those eliciting stressors also affects the gut microbiome. Fecal shedding of E. coli O157 often increases in summer seasons as reviewed by Kempf et al (2022) . Placing animals in a feedlot decreased the diversity in individual animals and the similarity between animals after 2 days, but these changes diminished at 7 and 14 days after the placement, suggesting the native microbiome in a cattle tends to be robust ( Maslen et al, 2022 ).…”

Section: Carriage Of Bacteria By Animalsmentioning

confidence: 99%

Driving forces shaping the microbial ecology in meat packing plants

Yang,

Narvaez-Bravo,

Zhang

2024

Front. Microbiol.

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Meat production is a complex system, continually receiving animals, water, air, and workers, all of which serve as carriers of bacteria. Selective pressures involved in different meat processing stages such as antimicrobial interventions and low temperatures, may promote the accumulation of certain residential microbiota in meat cutting facilities. Bacteria including human pathogens from all these sources can contaminate meat surfaces. While significant advancements have been made in enhancing hygienic standards and pathogen control measures in meat plants, resulting in a notable reduction in STEC recalls and clinical cases, STEC still stands as a predominant contributor to foodborne illnesses associated with beef and occasionally with pork. The second-and third-generation sequencing technology has become popular in microbiota related studies and provided a better image of the microbial community in the meat processing environments. In this article, we reviewed the potential factors influencing the microbial ecology in commercial meat processing facilities and conducted a meta-analysis on the microbiota data published in the last 10 years. In addition, the mechanisms by which bacteria persist in meat production environments have been discussed with a focus on the significant human pathogen E. coli O157:H7 and generic E. coli, an indicator often used for the hygienic condition in food production.

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Section: Carriage Of Bacteria By Animalsmentioning

confidence: 99%

Driving forces shaping the microbial ecology in meat packing plants

Yang,

Narvaez-Bravo,

Zhang

2024

Front. Microbiol.

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“…to ampicillin and reach a "supershedder" state. The supershedder state entails the expansion of K. pneumoniae to high levels in the gut, allowing it to shed over 100-fold more than mocktreated mice [40]. No statistical difference in shedding was observed between the WT and the ΔeutC L /C S mutant, with both strains shedding at a supershedder state (S3C Fig) , suggesting that EA metabolism is dispensable with a reduced gut microbiome afforded by antibiotic treatment that likely allows K. pneumoniae access to more preferred energy sources.…”

Section: Plos Pathogensmentioning

confidence: 99%

Ethanolamine metabolism through two genetically distinct loci enables Klebsiella pneumoniae to bypass nutritional competition in the gut

Barnes,

Bennett,

Vezina

et al. 2024

PLoS Pathog

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Successful microbial colonization of the gastrointestinal (GI) tract hinges on an organism’s ability to overcome the intense competition for nutrients in the gut between the host and the resident gut microbiome. Enteric pathogens can exploit ethanolamine (EA) in the gut to bypass nutrient competition. However, Klebsiella pneumoniae (K. pneumoniae) is an asymptomatic gut colonizer and, unlike well-studied enteric pathogens, harbors two genetically distinct ethanolamine utilization (eut) loci. Our investigation uncovered unique roles for each eut locus depending on EA utilization as a carbon or nitrogen source. Murine gut colonization studies demonstrated the necessity of both eut loci in the presence of intact gut microbiota for robust GI colonization by K. pneumoniae. Additionally, while some Escherichia coli gut isolates could metabolize EA, other commensals were incapable, suggesting that EA metabolism likely provides K. pneumoniae a selective advantage in gut colonization. Molecular and bioinformatic analyses unveiled the conservation of two eut loci among K. pneumoniae and a subset of the related taxa in the K. pneumoniae species complex, with the NtrC-RpoN regulatory cascade playing a pivotal role in regulation. These findings identify EA metabolism as a critical driver of K. pneumoniae niche establishment in the gut and propose microbial metabolism as a potential therapeutic avenue to combat K. pneumoniae infections.

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“…Fecal contamination of food and water is the most common source of STEC O157 transmission [ 11 ] and it is estimated that approximately 20% of cattle shed > 10 4 CFU/g in feces [ 12 ], a condition known as super-shedding (SS). A high prevalence of STEC O157 caused by SS events is thought to be a contributing factor to persistence, survival, and infection [ 13 ]. Although successful strategies have been implemented to control STEC O157 in food processing [ 14 ], on-farm control strategies have been inconsistent [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

In Silico Analysis of Shiga Toxin-Producing Escherichia coli O157:H7 Strains from Presumptive Super- and Low-Shedder Cattle

Bumunang,

Castro,

Alexander

et al. 2024

Toxins

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Cattle are the primary reservoir for STEC O157, with some shedding >104 CFU/g in feces, a phenomenon known as super-shedding (SS). The mechanism(s) responsible for SS are not understood but have been attributed to the environment, host, and pathogen. This study aimed to compare genetic characteristics of STEC O157 strains from cattle in the same commercial feedlot pens with SS or low-shedding (LS) status. Strains from SS (n = 35) and LS (n = 28) collected from 11 pens in three feedlots were analyzed for virulence genes, Shiga toxin-carrying bacteriophage insertion sites, and phylogenetic relationships. In silico analysis showed limited variation regarding virulence gene profiles. Stx-encoding prophage insertion sites mrlA and wrbA for stx1a and stx2a, respectively, were all occupied, but two isolates had fragments of the stx-carrying phage in mrlA and wrbA loci without stx1a and stx2a. All strains screened for lineage-specific polymorphism assay (LSPA-6) were 111111, lineage I. Of the isolates, 61 and 2 were clades 1 and 8, respectively. Phylogenetic analysis revealed that pens with more than one SS had multiple distantly related clusters of SS and LS isolates. Although virulence genes and lineage were largely similar within and across feedlots, multiple genetic origins of strains within a single feedlot pen illustrate challenges for on-farm control of STEC.

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Super Shedding in Enteric Pathogens: A Review

Cited by 10 publications

References 132 publications

Driving forces shaping the microbial ecology in meat packing plants

Driving forces shaping the microbial ecology in meat packing plants

Ethanolamine metabolism through two genetically distinct loci enables Klebsiella pneumoniae to bypass nutritional competition in the gut

In Silico Analysis of Shiga Toxin-Producing Escherichia coli O157:H7 Strains from Presumptive Super- and Low-Shedder Cattle

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