scholarly journals Microbiome pattern of Lucilia sericata (Meigen) (Diptera: Calliphoridae) and feeding substrate in the presence of the foodborne pathogen Salmonella enterica

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lavinia Iancu ◽  
Iulia Roxana Angelescu ◽  
Victoria Ioana Paun ◽  
Carlos Henríquez-Castillo ◽  
Paris Lavin ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Foodborne Pathogen ◽  
Pathogen Transmission ◽  
Lucilia Sericata ◽  
Microbiome Composition ◽  
Interval Estimators ◽  
Feeding Substrate ◽  
The Impact

AbstractThe microbial diversity and quantitative dynamics during the insect’s development stages constitute recently developed putative tools in forensic and medical studies. Meanwhile, little is known on the role of insects in spreading foodborne pathogenic bacteria and on the impact of these pathogens on the overall insects and feeding substrate microbiome composition. Here, we provide the first characterization of the bacterial communities harbored in adult and immature stages of Lucilia sericata, one of the first colonizers of decomposed human remains, in the presence of the foodborne pathogen Salmonella enterica using 16S rRNA Illumina sequencing and qPCR. The pathogen transmission from the wild adults to the second generation was observed, with a 101.25× quantitative increase. The microbial patterns from both insect and liver samples were not influenced by the artificial introduction of this pathogenic foodborne bacteria, being dominated by Firmicutes and Proteobacteria. Overall, our results provided a first detailed overview of the insect and decomposed substrate microbiome in the presence of a human pathogen, advancing the knowledge on the role of microbes as postmortem interval estimators and the transmission of pathogenic bacteria.

scholarly journals Role of infection in wound healing

2020 ◽  
Vol 19 (4) ◽  
pp. 598-602
Author(s):  
Malik Asif Hussain ◽  
Flavia Huygens
Keyword(s):  
Wound Healing ◽  
Pathogenic Bacteria ◽  
Chronic Wounds ◽  
Medical Science ◽  
Vascular Diseases ◽  
Research Papers ◽  
Patients With Diabetes ◽  
Research Findings ◽  
The Impact

Chronic wounds, particularly infected wounds are clinically very important due to their significant impact on health budgets as well as patients` health worldwide. Patients with diabetes mellitus, vascular diseases especially peripheral vascular disease and pressure ulcers are major categories of patients presenting with chronic wounds. It is known that there are multiple factors determining chronic wound prognosis. The presence of multiple types of pathogenic bacteria, with specific virulence and adherent (biofilm) properties, contribute a significant role to the development of chronic wounds. This review article is based on the research project entitled” An investigation of the impact of bacterial diversity, pathogenic determinants and biofilms on chronic wounds”. The research findings have been published in form of research papers as well as conference posters. The aim of this article is to highlight various important aspects of bacterial impact on wound healing. Bangladesh Journal of Medical Science Vol.19(4) 2020 p.598-602

scholarly journals Think zinc: Role of zinc poisoning in the intraphagosomal killing of bacteria by the amoeba Dictyostelium

2018 ◽  
Author(s):  
Caroline Barisch ◽  
Vera Kalinina ◽  
Louise H. Lefrançois ◽  
Joddy Appiah ◽  
Thierry Soldati
Keyword(s):  
Pathogenic Bacteria ◽  
Spatial Dynamics ◽  
Zinc Homeostasis ◽  
Particle Uptake ◽  
Metal Poisoning ◽  
Summary Statement ◽  
Soil Amoeba ◽  
The Impact ◽  
Role Of Zn

AbstractProfessional phagocytes have developed an extensive repertoire of autonomous immunity strategies to ensure killing of bacteria. Besides phagosome acidification and the generation of reactive oxygen species, deprivation of nutrients and the lumenal accumulation of toxic metals are essential to kill ingested bacteria or inhibit growth of intracellular pathogens. We use the soil amoeba Dictyostelium discoideum, a professional phagocyte that digests bacteria for nutritional purposes, to decipher the role of zinc poisoning during phagocytosis of non-pathogenic bacteria and visualize the temporal and spatial dynamics of compartmentalized, free zinc using fluorescent probes. Immediately after particle uptake, zinc is delivered to phagosomes by fusion with “zincosomes” of endosomal origin, but also by the action of one or more zinc transporters. We localize the four Dictyostelium ZnT transporters to endosomes, the contractile vacuole and the Golgi apparatus, and study the impact of znt knockouts on zinc homeostasis. Finally, we show that zinc is delivered into the lumen of Mycobacterium smegmatis-containing vacuoles, and that Escherichia coli deficient in the zinc efflux P1B-type ATPase ZntA is killed faster than wild type bacteria.Summary statementMetal poisoning is one of the bactericidal strategies of macrophages. Here, we describe the dynamics of free Zn and the role of Zn transporters during phagocytosis in Dictyostelium.

scholarly journals The role of bone marrow microenvironment in the progression of multiple myeloma from monoclonal gammopathy of undetermined significance

2021 ◽  
Vol 16 (3) ◽  
pp. 26-32
Author(s):  
A. S. Khudovekova ◽  
Ya. A. Rudenko ◽  
A. E. Dorosevich
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Monoclonal Gammopathy ◽  
Plasma Cells ◽  
Bone Marrow Microenvironment ◽  
Genetic Mutations ◽  
Microbiome Composition ◽  
The Impact ◽  
Undetermined Significance

Multiple myeloma is a tumor of plasma cells, one of the most common malignant blood diseases. It is preceded by a stage called monoclonal gammopathy of undetermined significance, from which true multiple myeloma develops in only a small percentage of cases. It was assumed that this process is associated with the accumulation of genetic mutations, but in recent years there is increasing evidence that the bone marrow microenvironment plays a key role in progression and that it can become a target for therapy that prevents the myeloma development. The review considers the role of mesenchymal stem cells, immune system cells, endotheliocytes, fibroblasts, adipocytes, osteoclasts and osteoblasts in multiple myeloma progression, as well as the impact of the sympathetic nervous system and microbiome composition.

scholarly journals Distinct but Intertwined Evolutionary Histories of Multiple Salmonella enterica Subspecies

mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Cooper J. Park ◽  
Cheryl P. Andam
Keyword(s):  
Salmonella Enterica ◽  
Bacterial Species ◽  
Foodborne Pathogen ◽  
Disease Outbreaks ◽  
Thiamine Pyrophosphate ◽  
Data Set ◽  
Content Type ◽  
Pan Genome ◽  
Environmental Selection ◽  
The Impact

ABSTRACT Salmonella is responsible for many nontyphoidal foodborne infections and enteric (typhoid) fever in humans. Of the two Salmonella species, Salmonella enterica is highly diverse and includes 10 known subspecies and approximately 2,600 serotypes. Understanding the evolutionary processes that generate the tremendous diversity in Salmonella is important in reducing and controlling the incidence of disease outbreaks and the emergence of virulent strains. In this study, we aim to elucidate the impact of homologous recombination in the diversification of S. enterica subspecies. Using a data set of previously published 926 Salmonella genomes representing the 10 S. enterica subspecies and Salmonella bongori, we calculated a genus-wide pan-genome composed of 84,041 genes and the S. enterica pan-genome of 81,371 genes. The size of the accessory genomes varies between 12,429 genes in S. enterica subsp. arizonae (subsp. IIIa) to 33,257 genes in S. enterica subsp. enterica (subsp. I). A total of 12,136 genes in the Salmonella pan-genome show evidence of recombination, representing 14.44% of the pan-genome. We identified genomic hot spots of recombination that include genes associated with flagellin and the synthesis of methionine and thiamine pyrophosphate, which are known to influence host adaptation and virulence. Last, we uncovered within-species heterogeneity in rates of recombination and preferential genetic exchange between certain donor and recipient strains. Frequent but biased recombination within a bacterial species may suggest that lineages vary in their response to environmental selection pressure. Certain lineages, such as the more uncommon non-enterica subspecies (non-S. enterica subsp. enterica), may also act as a major reservoir of genetic diversity for the wider population. IMPORTANCE S. enterica is a major foodborne pathogen, which can be transmitted via several distinct routes from animals and environmental sources to human hosts. Multiple subspecies and serotypes of S. enterica exhibit considerable differences in virulence, host specificity, and colonization. This study provides detailed insights into the dynamics of recombination and its contributions to S. enterica subspecies evolution. Widespread recombination within the species means that new adaptations arising in one lineage can be rapidly transferred to another lineage. We therefore predict that recombination has been an important factor in the emergence of several major disease-causing strains from diverse genomic backgrounds and their ability to adapt to disparate environments.

scholarly journals (p)ppGpp-dependent regulation of the nucleotide hydrolase PpnN confers complement resistance in Salmonella enterica serovar Typhimurium

2020 ◽  
Author(s):  
N. Y Elizabeth Chau ◽  
Deyanira Pérez-Morales ◽  
Wael Elhenawy ◽  
Víctor H. Bustamante ◽  
Yong E. Zhang ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Stringent Response ◽  
Metabolic Reprogramming ◽  
Bacterial Survival ◽  
Complement Resistance ◽  
Serovar Typhimurium ◽  
Bacterial Fitness ◽  
Host Infection

The stringent response is an essential mechanism of metabolic reprogramming during environmental stress that is mediated by the nucleotide alarmones, guanosine tetraphosphate and pentaphosphate ((p)ppGpp). In addition to physiological adaptations, (p)ppGpp also regulates virulence programs in pathogenic bacteria including Salmonella enterica serovar Typhimurium. S. Typhimurium is a common cause of acute gastroenteritis, but it may also spread to systemic tissues resulting in severe clinical outcomes. During infection, S. Typhimurium encounters a broad repertoire of immune defenses that it must evade for successful host infection. Here, we examined the role of the stringent response in S. Typhimurium resistance to complement-mediated killing and found that the (p)ppGpp synthetase-hydrolase, SpoT, is required for bacterial survival in human serum. We identified the nucleotide hydrolase, PpnN, as a target of the stringent response that is required to promote bacterial fitness in serum. Using chromatography and mass spectrometry, we show that PpnN hydrolyzes purine and pyrimidine monophosphates to generate free nucleobases and ribose 5′-phosphate, and that this metabolic activity is required for conferring resistance to complement killing. In addition to PpnN, we show that (p)ppGpp is required for the biosynthesis of the very long and long O-antigen in the outer membrane known to be important for complement resistance. Our results provide new insights into the role of the stringent response in mediating evasion of the innate immune system by pathogenic bacteria.

scholarly journals Horizontal Transfer of the Salmonella enterica Serovar Infantis Resistance and Virulence Plasmid pESI to the Gut Microbiota of Warm-Blooded Hosts

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Gili Aviv ◽  
Galia Rahav ◽  
Ohad Gal-Mor
Keyword(s):  
Multidrug Resistance ◽  
Gut Microbiota ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Lactobacillus Reuteri ◽  
Bacterial Species ◽  
Microbial Evolution ◽  
Virulence Plasmid ◽  
Transmission Properties

ABSTRACT Salmonella enterica serovar Infantis is one of the prevalent salmonellae worldwide. Recently, we showed that the emergence of S . Infantis in Israel was facilitated by the acquisition of a unique megaplasmid (pESI) conferring multidrug resistance and increased virulence phenotypes. Here we elucidate the ecology, transmission properties, and regulation of pESI. We show that despite its large size (~280 kb), pESI does not impose a significant metabolic burden in vitro and that it has been recently fixed in the domestic S . Infantis population. pESI conjugation and the transcription of its pilus ( pil ) genes are inhibited at the ambient temperature (27°C) and by ≥1% bile but increased under temperatures of 37 to 41°C, oxidative stress, moderate osmolarity, and the microaerobic conditions characterizing the intestinal environment of warm-blooded animals. The pESI-encoded protein TraB and the oxygen homeostasis regulator Fnr were identified as transcriptional regulators of pESI conjugation. Using the mouse model, we show that following S . Infantis infection, pESI can be horizontally transferred to the gut microbiota, including to commensal Escherichia coli strains. Possible transfer, but not persistence, of pESI was also observed into Gram-positive mouse microbiota species, especially Lactobacillus reuteri . Moreover, pESI was demonstrated to further disseminate from gut microbiota to S. enterica serovar Typhimurium, in the context of gastrointestinal infection. These findings exhibit the ability of a selfish clinically relevant megaplasmid to distribute to and from the microbiota and suggest an overlooked role of the microbiota as a reservoir of mobile genetic elements and intermediator in the spread of resistance and virulence genes between commensals and pathogenic bacteria. IMPORTANCE Plasmid conjugation plays a key role in microbial evolution, enabling the acquisition of new phenotypes, including resistance and virulence. Salmonella enterica serovar Infantis is one of the ubiquitous salmonellae worldwide and a major cause of foodborne infections. Previously, we showed that the emergence of S . Infantis in Israel has involved the acquisition of a unique megaplasmid (pESI) conferring multidrug resistance and increased virulence phenotypes. Recently, the emergence of another S . Infantis strain carrying a pESI-like plasmid was identified in Italy, suggesting that the acquisition of pESI may be common to different emergent S . Infantis populations globally. Transmission of this plasmid to other strains or bacterial species is an alarming scenario. Understanding the ecology, regulation, and transmission properties of clinically relevant plasmids and the role of the microbiota in their spreading offers a new mechanism explaining the emergence of new pathogenic and resistant biotypes and may assist in the development of appropriate surveillance and prevention measures.

scholarly journals Endogenous Metabolites Released by Sanitized Sprouting Alfalfa Seed Inhibit the Growth of Salmonella enterica

mSystems ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Ga-Hee Ban ◽  
Yue Dai ◽  
Tao Huan ◽  
Alfred Ke ◽  
Pascal Delaquis ◽  
...  
Keyword(s):  
Food Safety ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
The United States ◽  
Antimicrobial Treatment ◽  
Human Consumption ◽  
Content Type ◽  
Alfalfa Seed ◽  
The Impact ◽  
Combinatorial Treatment

ABSTRACT Sprouts are the leading cause of foodborne disease outbreaks globally, mainly because the specialized conditions required to germinate seed sprouts for human consumption contribute to an environment that allows pathogenic bacteria to flourish. To reduce risk of illness, current food safety guidelines in the United States and Canada recommend hypochlorite treatment for seed sanitation. However, many growers and consumers have become wary of the impact of hypochlorite on human health and the environment and are actively seeking less caustic approaches. Here, we evaluated the effects of both the traditional hypochlorite treatment and a milder alternative on nontyphoidal Salmonella enterica colonization of germinating alfalfa seed. Moreover, we explored three biological factors as potential contributors for inhibition of S. enterica growth: colonization by indigenous bacteria, seed composition changes, and seed metabolite release. In this experimental setting, we found that a combinatorial treatment of heat, peroxide, and acetic acid was as effective as hypochlorite for inhibiting S. enterica growth. Notably, we pinpointed N-acetyl-spermidine as an endogenous metabolite exuded by treated seeds that strongly inhibits S. enterica growth. In doing so, we both elucidated one of the mechanisms of chemical sanitation and highlighted a potential seed-derived mode of antimicrobial treatment that may apply to modernized food safety protocols. IMPORTANCE Warm, humid, and nutrient-rich conditions that are used to produce sprouts encourage Salmonella enterica to proliferate. However, many disparate sanitation methods exist, and there is currently no single treatment that can guarantee pathogen-free seeds. Here, we compared the ability of traditional hypochlorite treatment against a combinatorial treatment of heat, peroxide, and vinegar (HPA) commonly used in organic farming practices to inhibit S. enterica colonization and growth during alfalfa germination and found HPA to be at least as effective. Furthermore, we explored seed-based changes following sanitization treatments using metabolomics and identified polyamines as strong inhibitors of Salmonella growth on germinating alfalfa. Our findings enable a better understanding of host-pathogen interactions in sprout microbial communities and promote in-depth, evidence-based research in seed sprout safety.

scholarly journals Examining the Effects of an Anti-Salmonella Bacteriophage Preparation, BAFASAL®, on Ex-Vivo Human Gut Microbiome Composition and Function Using a Multi-Omics Approach

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1734
Author(s):  
Janice Mayne ◽  
Xu Zhang ◽  
James Butcher ◽  
Krystal Walker ◽  
Zhibin Ning ◽  
...  
Keyword(s):  
Food Chain ◽  
Gut Microbiome ◽  
Food Industry ◽  
Ex Vivo ◽  
Human Gut ◽  
Microbiome Composition ◽  
Human Gut Microbiome ◽  
And Function ◽  
The Impact

Salmonella infections (salmonellosis) pose serious health risks to humans, usually via food-chain contamination. This foodborne pathogen causes major food losses and human illnesses, with significant economic impacts. Overuse of antibiotics in the food industry has led to multidrug-resistant strains of bacteria, and governments are now restricting their use, leading the food industry to search for alternatives to secure food chains. Bacteriophages, viruses that infect and kill bacteria, are currently being investigated and used as replacement treatments and prophylactics due to their specificity and efficacy. They are generally regarded as safe alternatives to antibiotics, as they are natural components of the ecosystem. However, when specifically used in the industry, they can also make their way into humans through our food chain or exposure, as is the case for antibiotics. In particular, agricultural workers could be repeatedly exposed to bacteriophages supplemented to animal feeds. To our knowledge, no studies have investigated the effects of such exposure to bacteriophages on the human gut microbiome. In this study, we used a novel in-vitro assay called RapidAIM to investigate the effect of a bacteriophage mixture, BAFASAL®, used in poultry farming on five individual human gut microbiomes. Multi-omics analyses, including 16S rRNA gene sequencing and metaproteomic, revealed that ex-vivo human gut microbiota composition and function were unaffected by BAFASAL® treatment, providing an additional measure for its safety. Due to the critical role of the gut microbiome in human health and the known role of bacteriophages in regulation of microbiome composition and function, we suggest assaying the impact of bacteriophage-cocktails on the human gut microbiome as a part of their safety assessment.

scholarly journals The nature of individual heterogeneity shape outbreak dynamics

2021 ◽  
Author(s):  
Baptiste Elie ◽  
Christian Selinger ◽  
Samuel Alizon
Keyword(s):  
Transmission Rate ◽  
Sir Model ◽  
Pathogen Transmission ◽  
Main Driver ◽  
Biological Sources ◽  
Stochastic Sir ◽  
Stochastic Sir Model ◽  
The Impact ◽  
Parasite Emergence

AbstractIt is now common-place that pathogen transmission during an outbreak can be more heterogeneous than what is commonly assumed, and that it can have major consequences on their dynamics. However, previous studies did not explore the impact of the different biological sources of heterogeneity while controlling for the resulting heterogeneity in the number of secondary cases. In this study, we explore the role of individual variation in infection duration and transmission rate on parasite emergence and spread in a population. We simulate outbreaks using a custom stochastic SIR model, with and without evolution of the parasite. We show that for a given mean, the variance in the number of secondary cases is the main driver of the outbreak probability, with or without evolution, while it does not play a role on the outbreak dynamic once it emerged. On the opposite, a smaller and more realistic variance in the infection duration causes a faster outbreak. It is therefore useful to take into consideration more realistic distributions when modelling infectious diseases outbreaks.

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