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Developmental Cell Oct 2016When bacteria infect a cell, the bacterial membrane partially shields microbial structures from the immune system, preventing detection and clearance. In a recent issue...
When bacteria infect a cell, the bacterial membrane partially shields microbial structures from the immune system, preventing detection and clearance. In a recent issue of Cell, Man et al. (2016) show that the interferon-inducible protein IRGB10 liberates bacterial ligands for sensing by both the AIM2 and the non-canonical NLRP3 inflammasomes.
Topics: Bacteria; Inflammasomes
PubMed: 27728782
DOI: 10.1016/j.devcel.2016.09.026 -
The Science of the Total Environment Feb 2021The discovery of complete ammonia oxidizer (comammox) was a breakthrough in the study of nitrification. However, slow growth of comammox bacteria makes it challenging to...
The discovery of complete ammonia oxidizer (comammox) was a breakthrough in the study of nitrification. However, slow growth of comammox bacteria makes it challenging to distinguish them from traditional ammonia oxidizing microorganisms. Genomic data indicated that comammox bacteria encoded genes that can metabolize urea and had higher nitrite tolerance, which could only be found in several ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). This implies that using nitrite and urea as nitrogen sources may accelerate comammox bacteria's enrichment efficiency. In this study, two reactors using nitrite and urea as substrates, respectively, were operated for 390 days. At the end of cultivation, the reactor fed with urea exhibited higher nitrification potential than the reactor fed with nitrite. Comammox bacteria outcompeted AOA and AOB, regardless of whether they were cultured with nitrite or urea. Using nitrite can improve the proportion of comammox amoA to total amoA of 92%, while using urea may increase the proportion of comammox bacteria among total bacteria to 14.2%. Metagenomic results implied that nitrite was converted to ammonia by nitrate reduction and absorbed by comammox bacteria. On the other hand, urea may be directly utilized as substrate. These results demonstrated that using different nitrogen sources caused niche differentiation of comammox bacteria, AOA, and AOB. Using nitrite can increase the relative abundance of comammox amoA to total amoA, while using urea can increase the quantity of comammox amoA. Comammox bacteria were dominant among ammonia oxidizing microorganisms for both nitrite and urea cultures.
Topics: Ammonia; Archaea; Bacteria; Nitrification; Nitrites; Oxidation-Reduction; Phylogeny; Soil Microbiology; Urea
PubMed: 33059137
DOI: 10.1016/j.scitotenv.2020.142580 -
Scientific American Jan 2015
Topics: Bacteria; Bacterial Outer Membrane Proteins; Bacterial Physiological Phenomena; Biological Evolution; Drug Resistance, Bacterial; Receptors, Cell Surface
PubMed: 25597108
DOI: 10.1038/scientificamerican0115-40 -
ACS Applied Bio Materials Feb 2022Infectious bacteria evolve fast into resistance to conventional antimicrobial agents, whereas treatments for drug resistance bacteria progress more slowly. Here, we...
Infectious bacteria evolve fast into resistance to conventional antimicrobial agents, whereas treatments for drug resistance bacteria progress more slowly. Here, we report a universally applicable photoactivated antimicrobial modality through light-responsive carbon dot-embedding soft hyaluronic acid hydrogel (CDgel). Because of the innate nature of the infectious bacteria that produce hyaluronidase, applied hyaluronic acid-based CDgel breaks down via bacteria and releases carbon dots (CDs) into the infectious sites. The released CDs possess photodynamic capabilities under light irradiation, inducing O generation and growth inhibition of the infectious bacteria, and (∼99% and ∼97%, respectively), in vitro. In particular, these photodynamic effects of CDs from CDgel have been shown to accelerate the healing of infected wounds in vivo, showing a higher wound regeneration rate as compared to that of untreated wounds. Our work demonstrates that the biocompatible and shape-controllable CDgel possesses therapeutic potential as a treatment modality for the light-driven control of drug-resistant bacterial infections.
Topics: Bacteria; Carbon; Communicable Diseases; Escherichia coli; Humans; Hyaluronic Acid; Hydrogels; Staphylococcus aureus
PubMed: 35020368
DOI: 10.1021/acsabm.1c01157 -
Revista Da Sociedade Brasileira de... 2000The resistance in staphylococci, enterococci, and pneumococci is reviewed. The author also recalls the first cases, and presents an overview of the distribution of cases... (Review)
Review
The resistance in staphylococci, enterococci, and pneumococci is reviewed. The author also recalls the first cases, and presents an overview of the distribution of cases in the world, the genetic and molecular mechanisms of resistance, the importance in Brazil and therapeutic alternatives. The factors that contribute to the dissemination of these problem bacteria and the measures for their control are emphasized.
Topics: Drug Resistance, Microbial; Enterococcus; Humans; Staphylococcus; Streptococcus pneumoniae
PubMed: 10967598
DOI: 10.1590/s0037-86822000000300008 -
Bioscience Reports Oct 1999Gram negative bacterial infection is a leading cause of fatality and is attributed, at least in part, to the bacteria's capacity to persist in the host in spite of...
Gram negative bacterial infection is a leading cause of fatality and is attributed, at least in part, to the bacteria's capacity to persist in the host in spite of appropriate antibiotic therapy. It has been suggested that bacteria evade antibiotics by hiding within host cells. We sought to investigate this important aspect of infections in mast cells, which are inflammatory cells found in close proximity to the host-environment interface and which have recently been reported to play a crucial role in the early innate immune response to bacteria. We examined mast cell interactions with FimH-expressing E. coli, one of the major opportunistic pathogens of humans. We determined that in serum free conditions, these bacteria were able to trigger mast cell uptake without loss of bacterial viability. CD48, a mannose containing GPI (glycosylphosphatidylinositol)-linked molecule was found to be the receptor of FimH-expressing E. coli in mouse mast cells. We found that the internalization via CD48 was blocked by filipin, a cholesterol binding drug known to disrupt cholesterol/glycolipid-enriched microdomains and the bacteria-encasing vacuoles were rich in cholesterol inside cells. Interestingly, we found that mast cells subsequently expelled majority of the intracellular bacteria in 24 hours. This expulsion process was blocked by lovastatin/cyclodextrin treatment, which is known to inhibit cellular trafficking of cholesterol/glycolipid-enriched microdomains. Thus, the bacterial entry into and expulsion from mast cells were critically dependent on cholesterol/glycolipid-enriched microdomains, which represents a novel mode of tussle between the pathogen and the mast cell occurring in opsonin deficient sites in the body or even at other sites in naive or immunocompromised hosts which have low systemic levels of E. coli specific antibody.
Topics: Adhesins, Bacterial; Adhesins, Escherichia coli; Animals; Antigens, CD; CD48 Antigen; Cells, Cultured; Cholesterol; Escherichia coli; Fimbriae Proteins; Glycolipids; Humans; Mast Cells; Mice; Opsonin Proteins; Phagocytosis
PubMed: 10763810
DOI: 10.1023/a:1020216323271 -
Wei Sheng Yan Jiu = Journal of Hygiene... Mar 2009Viable but nonculturable state of bacteria means the state of bacteria cannot be cultured in routine media, but is alive and metabolic active. Many bacteria including... (Review)
Review
Viable but nonculturable state of bacteria means the state of bacteria cannot be cultured in routine media, but is alive and metabolic active. Many bacteria including some pathogens can enter this state and maintain virulence or pathogenicity. In this paper, the information including character, induction factors, resuscitation, detection and hygiene significance about bacteria's viable but nonculturable state was reviewed.
Topics: Bacteria; Colony Count, Microbial; Culture Media; Humans; Microbial Viability; Virulence
PubMed: 19408675
DOI: No ID Found -
Water Environment Research : a Research... Nov 2020Akiyoshi-do Cave is one of the oldest and the largest show caves in Japan. Environmental alterations induced by tourism impacts have been suggested; however, only a few...
Akiyoshi-do Cave is one of the oldest and the largest show caves in Japan. Environmental alterations induced by tourism impacts have been suggested; however, only a few previous studies have investigated the impacts of tourism on the cave. In this study, enrichment culture procedures were applied to detect human-associated bacteria (HAB) including Escherichia coli, Staphylococcus aureus, and thermo-tolerant Bacillus spp. in cave water. Physical and bacterial parameters of water including total nitrogen, ammonia, phosphate, total number of bacteria, and total number of viable bacteria were collected as environmental factors. Escherichia coli was absent at all sites, but increased levels of total bacteria, viable bacteria, S. aureus, and thermo-tolerant Bacillus spp. were present at high-impact sites. Examination of the origin tracking of HAB suggested that cave tourists could be a source of HAB contamination, but other causes related to the surface land use could also contribute to HAB contamination. © 2020 Water Environment Federation PRACTITIONER POINTS: Detection of HAB was performed for the first time in Japanese show caves to consider tourism impacts. The greater number of HAB was detected from the tourist area than the nontourist area in the cave. It was suggested that the origin of HAB may not be limited to tourists, but may also include the surface.
Topics: Ammonia; Bacteria; Humans; Japan; Staphylococcus aureus; Water
PubMed: 32386088
DOI: 10.1002/wer.1355 -
Proceedings of the National Academy of... Jun 2010Microorganisms and zooplankton are both important components of aquatic food webs. Although both inhabit the same environment, they are often regarded as separate...
Microorganisms and zooplankton are both important components of aquatic food webs. Although both inhabit the same environment, they are often regarded as separate functional units that are indirectly connected through nutrient cycling and trophic cascade. However, research on pathogenic and nonpathogenic bacteria has shown that direct association with zooplankton has significant influences on the bacteria's physiology and ecology. We used stratified migration columns to study vertical dispersal of hitchhiking bacteria through migrating zooplankton across a density gradient that was otherwise impenetrable for bacteria in both upward and downward directions (conveyor-belt hypothesis). The strength of our experiments is to permit quantitative estimation of transport and release of associated bacteria: vertical migration of Daphnia magna yielded an average dispersal rate of 1.3 x 10(5) x cells x Daphnia(-1) x migration cycle(-1) for the lake bacterium Brevundimonas sp. Bidirectional vertical dispersal by migrating D. magna was also shown for two other bacterial species, albeit at lower rates. The prediction that diurnally migrating zooplankton acquire different attached bacterial communities from hypolimnion and epilimnion between day and night was subsequently confirmed in our field study. In mesotrophic Lake Nehmitz, D. hyalina showed pronounced diel vertical migration along with significant diurnal changes in attached bacterial community composition. These results confirm that hitchhiking on migrating animals can be an important mechanism for rapidly relocating microorganisms, including pathogens, allowing them to access otherwise inaccessible resources.
Topics: Actinomycetales; Animals; Bacterial Adhesion; Bacterial Physiological Phenomena; Caulobacteraceae; Daphnia; Ecosystem; Food Chain; Green Fluorescent Proteins; Models, Biological; Movement; Recombinant Proteins; Water Microbiology; Zooplankton
PubMed: 20547852
DOI: 10.1073/pnas.1000668107 -
Polski Merkuriusz Lekarski : Organ... Nov 2008It encounters despite solid progress in development of diagnostic methods diagnostics the diseases of upper respiratory tract and ears in children called out by atypical... (Review)
Review
UNLABELLED
It encounters despite solid progress in development of diagnostic methods diagnostics the diseases of upper respiratory tract and ears in children called out by atypical bacteria's on the ground clinical symptoms and their treatment is difficulty still.
AIM
The performance of accessible review of current literature was on the aim of work opinion of the atypical bacteria's part in evocation the infections the upper respiratory tract and ears in children, and performance of characteristic symptoms of clinical diseases these organs the bacteria's also.
CONCLUSIONS
The quoted in work results of investigations do not it let on the unambiguous opinion the atypical bacteria part in contagions of infections the upper respiratory tract and ears in children. It seems however, that Mycoplasma pneumoniae answers first of all for evocation the acute infections of upper respiratory tract; however Chlamydophila pneumoniae plays the larger part in illnesses chronic as well as co-existent pathogen in illnesses sharp. Atypical bacteria can cause upper respiratory tract infections significantly more often than previously thought. These infections often occur in patients with history of respiratory recurrences.
Topics: Atypical Bacterial Forms; Bacterial Infections; Child; Chlamydophila pneumoniae; Humans; Mycoplasma pneumoniae; Otitis; Respiratory Tract Infections
PubMed: 19177778
DOI: No ID Found