Proteomic and metabolomic profiling of extracellular vesicles produced by human gut archaea.

Gastrointestinal bacteria interact with the host and each other through various mechanisms, including the production of extracellular vesicles (EVs). However, the composition and potential roles of EVs released by gut archaea are poorly understood. Here, we study EVs produced by four strains of human gut-derived methanogenic archaea: Methanobrevibacter smithii ALI, M.

Expanding the cultivable human archaeome: sp. nov. and strain 'GRAZ-2' from human faeces.

Two mesophilic, hydrogenotrophic methanogens, WWM1085 and GRAZ-2, were isolated from human faecal samples. WWM1085 was isolated from an individual in the United States and represents a novel species within the genus GRAZ-2 (=DSM 116045) was retrieved from a faecal sample of a European, healthy woman and represents a novel strain within this species. Both representatives form non-flagellated, short rods with variable morphologies and the capacity to form filaments.

Age-related dynamics of predominant methanogenic archaea in the human gut microbiome.

Background: The reciprocal relationship between aging and alterations in the gut microbiota is a subject of ongoing research. While the role of bacteria in the gut microbiome is well-documented, specific changes in the composition of methanogens during extreme aging and the impact of high methane production in general on health remain unclear. This study was designed to explore the association of predominant methanogenic archaea within the human gut and aging.

Reevaluation of the gastrointestinal methanogenic archaeome in multiple sclerosis and its association with treatment.

The role of the gut archaeal microbiome (archaeome) in health and disease remains poorly understood. Methanogenic archaea have been linked to multiple sclerosis (MS), but prior studies were limited by small cohorts and inconsistent methodologies. To address this, we re-evaluated the association between methanogenic archaea and MS using metagenomic data from the International Multiple Sclerosis Microbiome Study.

First-year dynamics of the anaerobic microbiome and archaeome in infants' oral and gastrointestinal systems.

Unlabelled: Recent research provides new insights into the early establishment of the infant gut microbiome, emphasizing the influence of breastfeeding on the development of gastrointestinal microbiomes. In our study, we longitudinally examined the taxonomic and functional dynamics of the oral and gastrointestinal tract (GIT) microbiomes of healthy infants ( = 30) in their first year, focusing on the often-over-looked aspects, the development of archaeal and anaerobic microbiomes. Breastfed (BF) infants exhibit a more defined transitional phase in their oral microbiome compared to non-breastfed (NBF) infants, marked by a decrease in and the emergence of anaerobic genera such as .

Targeted isolation of Methanobrevibacter strains from fecal samples expands the cultivated human archaeome.

Archaea are vital components of the human microbiome, yet their study within the gastrointestinal tract (GIT) is limited by the scarcity of cultured representatives. Our study presents a method for the targeted enrichment and isolation of methanogenic archaea from human fecal samples. The procedure combines methane breath testing, in silico metabolic modeling, media optimization, FACS, dilution series, and genomic sequencing through Nanopore technology.

Exploring the human archaeome: its relevance for health and disease, and its complex interplay with the human immune system.

This Review aims to coalesce existing knowledge on the human archaeome, a less-studied yet critical non-bacterial component of the human microbiome, with a focus on its interaction with the immune system. Despite a largely bacteria-centric focus in microbiome research, archaea present unique challenges and opportunities for understanding human health. We examine the archaeal distribution across different human body sites, such as the lower gastrointestinal tract (LGT), upper aerodigestive tract (UAT), urogenital tract (UGT), and skin.

Archaeal key-residents within the human microbiome: characteristics, interactions and involvement in health and disease.

Since the introduction of Archaea as new domain of life more than 40 years ago, they are no longer regarded as eccentric inhabitants of extreme ecosystems. These microorganisms are widespread in various moderate ecosystems, including eukaryotic hosts such as humans. Indeed, members of the archaeal community are now recognized as paramount constituents of human microbiome, while their definite role in disease or health is not fully elucidated and no archaeal pathogen has been reported.

Evaluation of the genetic relatedness of isolates by TRs analysis.

Objectives: Human gastrointestinal tract harbors a variety of bacteria with vital roles in human health. is considered one of the dominant constituents of gut microflora which can act as an opportunistic pathogen leading to various diseases, including colon cancer, diarrhea, uterine and intrathecal abscesses, septicemia, and pelvic inflammation. In this study, multiple locus variable number of tandem repeats analysis (MLVA) was performed to genetically differentiate 50 isolates.

Overview of the current promising approaches for the development of an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine.

Coronavirus disease 2019 (COVID-19) is a pandemic infectious disease caused by the novel coronavirus called SARS-CoV-2. There is a gap in our understanding regarding the immunopathogenesis of COVID-19. However, many clinical trials are underway across the world for screening effective drugs against COVID-19.

Bacterial co-infections with SARS-CoV-2.

The pandemic coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected millions of people worldwide. To date, there are no proven effective therapies for this virus. Efforts made to develop antiviral strategies for the treatment of COVID-19 are underway.

The importance of intracellular bacterial biofilm in infectious diseases.

Various bacterial species, previously known as extracellular pathogens, can reside inside different host cells by adapting to intracellular modes by forming microbial aggregates with similar characteristics to bacterial biofilms. Additionally, bacterial invasion of human cells leads to failure in antibiotic therapy, as most conventional anti-bacterial agents cannot reach intracellular biofilm in normal concentrations. Various studies have shown that bacteria such as uropathogenic Escherichia coli, Pseudomonas aeruginosa, Borrelia burgdorferi,Moraxella catarrhalis, non-typeable Haemophilus influenzae, Streptococcus pneumonia, and group A Streptococci produce biofilm-like structures within the host cells.

Role of microRNAs in Staphylococcus aureus infection: Potential biomarkers and mechanism.

Staphylococcus aureus is known as a common pathogen that colonizes 30% of healthy humans. Additionally, this bacterium can cause a number of serious infections, that is, endocarditis, bacteremia, pneumonia, wound, skin infections, and tissue abscesses. A variety of cellular and molecular pathways and targets are involved in response against S.

Combination of Antibiotics-Nisin Reduces the Formation of Persister Cell in .

Persister cells are a subpopulation of bacteria with the ability of survival when exposed to lethal doses of antibiotics, and are responsible for antibiotic therapy failure and infection recurrences. In this study, we investigated persister cell formation and the role of nisin in combination with antibiotics in reducing persistence in . We also examined the expression of toxin-antitoxin (TA) systems in persister cells of to gain a better understanding of the effect of TA systems on persister cell formation.

The expression of type II TA system genes following exposure to the sub-inhibitory concentration of gentamicin and acid stress in Brucella spp.

Background: Brucellosis is one of the most common diseases that afflicts both humans and animals. Bacteria react to stress conditions using different mechanisms one of which is Toxin-Antitoxin (TA) systems. It is believed that the Toxin-Antitoxin (TA) systems have a key role in the chronicity of the disease.

The biofilm-associated bacterial infections unrelated to indwelling devices.

Biofilms are microbial communities established in the self-produced extracellular substances that include up to 80% of associated microbial infections. During biofilm formation, bacterial cells shift from the planktonic forms to aggregated forms surrounded by an extracellular polymeric substance. The bacterial biofilm shows resistance against immune reactions as well as antibiotics and is potentially able to cause disorders by both device-related and nondevice-related infections.

Evaluation of cell-penetrating peptide-peptide nucleic acid effect in the inhibition of cagA in Helicobacter pylori.

Helicobacter pylori is the most common cause of chronic infection in human and is associated with gastritis, peptic ulcer disease, and adenocarcinoma of mucosa-associated lymphoid tissue cells. Peptide nucleic acid (PNA) is a synthetic compound, which can inhibit the production of a particular gene. This study aimed to investigate the effect of PNA on inhibiting the expression of cagA.

Prevalence of vaginolysin, sialidase and phospholipase genes in isolates between bacterial vaginosis and healthy individuals.

is considered as the predominant microorganism found in bacterial vaginosis (BV). The aim of this study was to evaluate the prevalence of virulence factors in associated with BV or non-BV cases and their correlations with this disorder. A total of 102 vaginal specimens were collected from patients during their visit to Akbar Abadi hospital in Tehran, Iran.

Listeriolysin S may inhibit the anti-listerial properties of Lactobacillus plantarum.

Listeriosis is a serious infection linked to the consumption of food contaminated with Listeria monocytogenes. Outbreaks and mortality rates associated with this infection make it a significant public health concern. As biocontrol agents, probiotics such as Lactobacillus plantarum had been of interest for the promotion of antilisterial activities.

Effects of sub-inhibitory concentrations of antibiotics and oxidative stress on the expression of type II toxin-antitoxin system genes in Klebsiella pneumoniae.

Objectives: Sub-inhibitory concentrations (sub-MICs) of antibiotics reflect the conditions that bacteria encounter in tissues and the natural environment. Sub-MICs of antibiotics can induce stress and alter the expression of different bacterial genes. Bacteria react to stress conditions using different mechanisms, one of which is the toxin-antitoxin (TA) system.

Targeting Listeria monocytogenes consensus sequence of internalin genes using an antisense molecule.

As an intracellular pathogen, Listeria monocytogenes can enter host cells where it can replicate and escape detection and eradication by the host immune response making the clearance of infection very challenging. Furthermore, with the advent of antimicrobial resistance, the need for alternative targets is inevitable. Internalin proteins are crucial to this bacterium as they contribute to bacterial entry to the systemic circulation.

Time-variable expression levels of , , , and genes during biofilm formation in .

is an opportunistic pathogen causing infections related to the usage of implants and medical devices. Pathogenicity of this microorganism is mainly linked to its capability to form biofilm structures. Biofilm formation vastly depends on several factors including different proteins.

Identification of an intestinal microbiota signature associated with hospitalized patients with diarrhea.

As an important global health challenge, diarrhea kills nearly two million people each year. Postinfectious irritable bowel syndrome (IBS) usually manifests itself as the diarrhea-predominant subtype. Small intestinal bacterial overgrowth has been observed more frequently in patients with IBS compared to healthy controls.

The Human Immune System against Staphylococcus epidermidis.

Staphylococcus epidermidis is one of the major causes of nosocomial infections in humans. This organism can exist as a commensal on the skin. However, it can also lead to severe infections.