Roles of EvpP in Edwardsiella piscicida-Macrophage Interactions
In this study, the roles of EvpP in E. piscicida-macrophage interactions were characterized. Here, we constructed the deletion mutants of evpP (ΔevpP) and complementation (ΔevpP-C) by the allelic exchange method. Compared to wild type strain (WT), ΔevpP was found to be attenuated for growth within macrophages. In line with this observation, we found its survival capacity was lower than WT under oxidative and acid stress in vitro, which simulate conditions encountered in host macrophages. Attenuation of ΔevpP also correlated with enhanced activation of macrophages, as reflected by augmented NO produc...
Source: Frontiers in cellular and infection microbiology - February 14, 2020 Category: Microbiology Source Type: research

Disruption of Intracellular Calcium Homeostasis as a Therapeutic Target Against Trypanosoma cruzi
There is no effective cure for Chagas disease, which is caused by infection with the arthropod-borne parasite, Trypanosoma cruzi. In the search for new drugs to treat Chagas disease, potential therapeutic targets have been identified by exploiting the differences between the mechanisms involved in intracellular Ca2+ homeostasis, both in humans and in trypanosomatids. In the trypanosomatid, intracellular Ca2+ regulation requires the concerted action of three intracellular organelles, the endoplasmic reticulum, the single unique mitochondrion, and the acidocalcisomes. The single unique mitochondrion and the acidocalcisomes a...
Source: Frontiers in cellular and infection microbiology - February 14, 2020 Category: Microbiology Source Type: research

Reviewing the Pathogenic Potential of the Otitis-Associated Bacteria Alloiococcus otitidis and Turicella otitidis
Alloiococcus otitidis and Turicella otitidis are common bacteria of the human ear. They have frequently been isolated from the middle ear of children with otitis media (OM), though their potential role in this disease remains unclear and confounded due to their presence as commensal inhabitants of the external auditory canal. In this review, we summarize the current literature on these organisms with an emphasis on their role in OM. Much of the literature focuses on the presence and abundance of these organisms, and little work has been done to explore their activity in the middle ear. We find there is currently insufficie...
Source: Frontiers in cellular and infection microbiology - February 14, 2020 Category: Microbiology Source Type: research

Novel Approaches for Systems Biology of Metabolism-Oriented Pathogen-Human Interactions: A Mini-Review
Pathogenic microorganisms exploit host metabolism for sustained survival by rewiring its metabolic interactions. Therefore, several metabolic changes are induced in both pathogen and host cells in the course of infection. A systems-based approach to elucidate those changes includes the integrative use of genome-scale metabolic networks and molecular omics data, with the overall goal of better characterizing infection mechanisms for novel treatment strategies. This review focuses on novel aspects of metabolism-oriented systems-based investigation of pathogen-human interactions. The reviewed approaches are the generation of ...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

Characterizing the Dysfunctional NK Cell: Assessing the Clinical Relevance of Exhaustion, Anergy, and Senescence
There is a growing body of literature demonstrating the importance of T cell exhaustion in regulating and shaping immune responses to pathogens and cancer. Simultaneously, the parallel development of therapeutic antibodies targeting inhibitory molecules associated with immune exhaustion (such as PD-1, but also TIGIT, and LAG-3) has led to a revolution in oncology with dramatic benefits in a growing list of solid and hematologic malignancies. Given this success in reinvigorating exhausted T cells and the related anti-tumor effects, there are increasing efforts to apply immune checkpoint blockade to other exhausted immune ce...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

Memantine Displays Antimicrobial Activity by Enhancing Escherichia coli Pathogen-Induced Formation of Neutrophil Extracellular Traps
In this study, we demonstrated that MEM is able to significantly suppress E. coli infection by enhancing E. coli-induced formation and release of NETs in vitro and in vivo. MEM could promote the trapping and bactericidal activities of the polymorphonuclear neutrophils (PMNs) in a manner dependent on α7 nAChR, since knockdown of this receptor noticeably reduces the survival ability of bacteria in PMNs while MEM no longer affects the survival of bacteria in PMNs. Our results also showed that when the expression of S100A9, an antiseptic protein, is inhibited, pathogen survival rates in PMNs increase significantly. MEM r...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

NK Cells Regulate CD8+ T Cell Mediated Autoimmunity
Elucidating key factors that regulate immune-mediated pathology in vivo is critical for developing improved strategies to treat autoimmune disease and cancer. NK cells can exhibit regulatory functions against CD8+ T cells following viral infection. Here we show that while low doses of lymphocytic choriomeningitis virus (LCMV-WE) can readily induce strong CD8+ T cell responses and diabetes in mice expressing the LCMV glycoprotein on β-islet cells (RIP-GP mice), hyperglycemia does not occur after infection with higher doses of LCMV. High-dose LCMV infection induced an impaired CD8+ T cell response, which coincided with ...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

Monocytes and the Host Response to Fungal Pathogens
Monocytes and their derivatives, including macrophages and dendritic cells, play diverse roles in the response to fungal pathogens. Sensing of fungi by monocytes triggers signaling pathways that mediate direct effects like phagocytosis and cytokine production. Monocytes can also present fungal antigens to elicit adaptive immune responses. These monocyte-mediated pathways may be either beneficial or harmful to the host. In some instances, fungi have developed mechanisms to evade the consequences of monocyte activation and subvert these cells to promote disease. Thus, monocytes are critically involved in mediating the outcom...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

In vitro Evaluation of Mannosylated Paromomycin-Loaded Solid Lipid Nanoparticles on Acute Toxoplasmosis
This study aimed to synthesize mannosylated paromomycin-loaded solid lipid nanoparticles (PM-SLN-M) and to evaluate them on acute toxoplasmosis. SLN was synthesized and then loaded by 7 mg/mL paromomycin sodium. Mannose coating was performed, and after washing, the size, zeta potential, and loading percentage were calculated. To evaluate the cell toxicity, an MTT assay was performed on Vero cells by different concentrations (log 10−1) of SLN, PM-SLN-M, and PM-SLN. In addition, the anti-Toxoplasma effects were also evaluated using trypan-blue staining and scanning electron microscopy (SEM). An MTT assay was also emplo...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

The Heparin-Binding Hemagglutinin of Nocardia cyriacigeorgica GUH-2 Stimulates Inflammatory Cytokine Secretion Through Activation of Nuclear Factor κB and Mitogen-Activated Protein Kinase Pathways via TLR4
Heparin-binding hemagglutinin (HBHA) from mycobacteria is involved in the dissemination of infection and the activation of the host immune response. However, the interaction of Nocardia cyriacigeorgica HBHA with the host cells remains unknown. In the present study, we describe N. cyriacigeorgica HBHA interactions with epithelial cells and organ colonization. We then investigate the mechanisms by which HBHA induces the production of inflammatory cytokines in macrophages. Immunofluorescent microscopy showed that HBHA adhered to A549 cells and HeLa cells and that the C-terminal fragment, which contains a Pro-Ala-Lys–ric...
Source: Frontiers in cellular and infection microbiology - February 13, 2020 Category: Microbiology Source Type: research

How the Cervical Microbiota Contributes to Cervical Cancer Risk in Sub-Saharan Africa
Despite ongoing efforts, sub-Saharan Africa faces a higher cervical cancer burden than anywhere else in the world. Besides HPV infection, definitive factors of cervical cancer are still unclear. Particular states of the cervicovaginal microbiota and viral infections are associated with increased cervical cancer risk. Notably, HIV infection, which is prevalent in sub-Saharan Africa, greatly increases risk of cervicovaginal dysbiosis and cervical cancer. To better understand and address cervical cancer in sub-Saharan Africa, a better knowledge of the regional cervicovaginal microbiome is required This review establishes curr...
Source: Frontiers in cellular and infection microbiology - February 12, 2020 Category: Microbiology Source Type: research

Gastrointestinal (GI) Tract Microbiome-Derived Neurotoxins —Potent Neuro-Inflammatory Signals From the GI Tract via the Systemic Circulation Into the Brain
The microbiome of the human gastrointestinal (GI)-tract is a rich and dynamic source of microorganisms that together possess a staggering complexity and diversity. Collectively these microbes are capable of secreting what are amongst the most neurotoxic and pro-inflammatory biopolymers known. These include lipopolysaccharide (LPS), enterotoxins, microbial-derived amyloids and small non-coding RNA (sncRNA). One of the major microbial species in the human GI-tract microbiome, about ~100-fold more abundant than Escherichia coli, is Bacteroides fragilis, an anaerobic, rod-shaped Gram-negative bacterium that secretes: (i) a par...
Source: Frontiers in cellular and infection microbiology - February 12, 2020 Category: Microbiology Source Type: research

Advances in Cyclosporiasis Diagnosis and Therapeutic Intervention
Cyclosporiasis is caused by the coccidian parasite Cyclospora cayetanensis and is associated with large and complex food-borne outbreaks worldwide. Associated symptoms include severe watery diarrhea, particularly in infants, and immune dysfunction. With the globalization of human food supply, the occurrence of cyclosporiasis has been increasing in both food growing and importing countries. As well as being a burden on the health of individual humans, cyclosporiasis is a global public health concern. Currently, no vaccine is available but early detection and treatment could result in a favorable clinical outcome. Clinical d...
Source: Frontiers in cellular and infection microbiology - February 11, 2020 Category: Microbiology Source Type: research

Amplification of Replication Competent HIV-1 by Adoptive Transfer of Human Cells From Infected Humanized Mice
Detection of latent human immunodeficiency virus type 1 (HIV-1) in “putative” infectious reservoirs is required for determining treatment efficiency and for viral elimination strategies. Such tests require induction of replication competent provirus and quantitative testing of viral load for validation. Recently, humanized mice were employed in the development of such tests by employing a murine viral outgrowth assay (mVOA). Here blood cells were recovered from virus infected antiretroviral therapy suppressed patients. These cells were adoptively transferred to uninfected humanized mice where replication compet...
Source: Frontiers in cellular and infection microbiology - February 11, 2020 Category: Microbiology Source Type: research

Pulmonary Macrophage and Dendritic Cell Responses to Cryptococcus neoformans
The fungal pathogen Cryptococcus neoformans can cause life-threatening infections in immune compromised individuals. This pathogen is typically acquired via inhalation, and enters the respiratory tract. Innate immune cells such as macrophages and dendritic cells (DCs) are the first host cells that encounter C. neoformans, and the interactions between Cryptococcus and innate immune cells play a critical role in the progression of disease. Cryptococcus possesses several virulence factors and evasion strategies to prevent its killing and destruction by pulmonary phagocytes, but these phagocytic cells can also contribute to an...
Source: Frontiers in cellular and infection microbiology - February 11, 2020 Category: Microbiology Source Type: research

Discovery of Multitarget-Directed Ligands Against Influenza A Virus From Compound Yizhihao Through a Predictive System for Compound-Protein Interactions
In conclusion, a compound-protein interaction-prediction system was an efficient tool for the discovery of novel compounds against influenza, and the findings from CYZH provide important information for its usage and development. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - February 11, 2020 Category: Microbiology Source Type: research

Mycobacterium tuberculosis PE31 (Rv3477) Attenuates Host Cell Apoptosis and Promotes Recombinant M. smegmatis Intracellular Survival via Up-regulating GTPase Guanylate Binding Protein-1
The Mycobacterium (M.) tuberculosis comprising proline–glutamic acid (PE) subfamily proteins associate with virulence, pathogenesis, and host-immune modulations. While the functions of most of this family members are not yet explored. Here, we explore the functions of “PE only” subfamily member PE31 (Rv3477) in virulence and host-pathogen interactions. We have expressed the M. tuberculosis PE31 in non-pathogenic Mycobacterium smegmatis strain (Ms_PE31) and demonstrated that PE31 significantly altered the cell facet features including colony morphology and biofilm formation. PE31 expressing M. smegmatis sh...
Source: Frontiers in cellular and infection microbiology - February 7, 2020 Category: Microbiology Source Type: research

Endocytosis and Exocytosis in Leishmania amazonensis Are Modulated by Bromoenol Lactone
In the protozoan pathogen Leishmania, endocytosis, and exocytosis occur mainly in the small area of the flagellar pocket membrane, which makes this parasite an interesting model of strikingly polarized internalization and secretion. Moreover, little is known about vesicle recognition and fusion mechanisms, which are essential for both endo/exocytosis in this parasite. In other cell types, vesicle fusion events require the activity of phospholipase A2 (PLA2), including Ca2+-independent iPLA2 and soluble, Ca2+-dependent sPLA2. Here, we studied the role of bromoenol lactone (BEL) inhibition of endo/exocytosis in promastigotes...
Source: Frontiers in cellular and infection microbiology - February 7, 2020 Category: Microbiology Source Type: research

Murine and Human Cathelicidins Contribute Differently to Hallmarks of Mastitis Induced by Pathogenic Prototheca bovis Algae
In conclusion, cathelicidins were involved in protothecosis pathogenesis, with unique roles among the diverse peptide family. Whereas, endogenous cathelicidin (Camp) was key in mammary gland innate defense against P. bovis, human LL-37 had algicidal and immunomodulatory functions. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - February 7, 2020 Category: Microbiology Source Type: research

Evaluation of Serological and Molecular Tests Used for the Identification of Toxoplasma gondii Infection in Patients Treated in an Ophthalmology Clinic of a Public Health Service in S ão Paulo State, Brazil
Ocular toxoplasmosis is one of the most common complications caused by the infection with the parasite Toxoplasma gondii. The risk of developing eye lesions and impaired vision is considered higher in Brazil than other countries. The clinical diagnosis is difficult and the use of sensitive and specific laboratorial methods can aid to the correct diagnosis of this infection. We compared serological methods ELISA and ELFA, and molecular cPCR, Nested PCR and qPCR for the diagnosis of T. gondii infection in groups of patients clinically evaluated with ocular diseases non-toxoplasma related (G1 = 185) and with lesions caused by...
Source: Frontiers in cellular and infection microbiology - February 7, 2020 Category: Microbiology Source Type: research

What Are the Functions of Chitin Deacetylases in Aspergillus fumigatus?
In this study, the roles of chitosan and putative CDAs in cell wall structure and virulence of Aspergillus fumigatus were investigated. Low levels of chitosan were found in the conidial and cell wall of A. fumigatus. Seven putative CDA genes were identified, disrupted and the phenotype of the single mutants and the septuple mutants were investigated. No alterations in fungal cell wall chitosan levels, changes in fungal growth or alterations in virulence were detected in the single or septuple Δcda1-7 mutant strains. Collectively, these results suggest that chitosan is a minority component of the A. fumigatus cell wal...
Source: Frontiers in cellular and infection microbiology - February 6, 2020 Category: Microbiology Source Type: research

Landmarks of the Knowledge and Trypanosoma cruzi Biology in the Wild Environment
Trypanosomatids are ancient parasitic eukaryotes that still maintain prokaryotic characteristics. Trypanosoma cruzi, a primarily wild mammal parasite, infected humans already long before European colonization of the Americas. T. cruzi heterogeneity remains an unsolved question, and until now, it has still not been possible to associate T. cruzi genotypes with any biological or epidemiological feature. One of the first biochemical attempts to cluster the T. cruzi subpopulations recognized three main subpopulations (zymodemes) that have been associated with the transmission cycles in the wild (Z1; Z3) and in the domestic env...
Source: Frontiers in cellular and infection microbiology - February 6, 2020 Category: Microbiology Source Type: research

Microbes in the Era of Circadian Medicine
The organisms of most domains of life have adapted to circadian changes of the environment and regulate their behavior and physiology accordingly. A particular case of such paradigm is represented by some types of host-pathogen interaction during infection. Indeed, not only some hosts and pathogens are each endowed with their own circadian clock, but they are also influenced by the circadian changes of the other with profound consequences on the outcome of the infection. It comes that daily fluctuations in the availability of resources and the nature of the immune response, coupled with circadian changes of the pathogen, m...
Source: Frontiers in cellular and infection microbiology - February 5, 2020 Category: Microbiology Source Type: research

The Heat Stability of Hepatitis B Virus: A Chronological Review From Human Volunteers and Chimpanzees to Cell Culture Model Systems
During the World War II jaundice and hepatitis in the US army were observed after vaccination with the yellow fever vaccine containing human plasma for stabilization. This led to first heat experiments with volunteers without knowledge of the causative agents. Finally, experiments of human serum with volunteers and chimpanzees led to the conclusion that the hepatitis B virus (HBV) which had been identified as the responsible agent of the contamination of the vaccine, could not be inactivated at 98°C after 1 min, whereas 2 min in two chimpanzees were enough. Meanwhile, a cell culture system became available showing that...
Source: Frontiers in cellular and infection microbiology - February 4, 2020 Category: Microbiology Source Type: research

Screening the Drug:H+ Antiporter Family for a Role in Biofilm Formation in Candida glabrata
In this study, the 10 multidrug resistance transporters of the Drug:H+ Antiporter family of C. glabrata were screened for a role in biofilm formation. Besides previously identified players in this process, namely CgTpo1_2 and CgQdr2, two others are shown to contribute to biofilm formation: CgDtr1 and CgTpo4. The deletion of each of these genes was found to lead to lower biofilm formation, in both SDB and RPMI media, while their expression was found to increase during biofilm development and to be controlled by the transcription factor CgTec1, a predicted key regulator of biofilm formation. Additionally, the deletion of CgD...
Source: Frontiers in cellular and infection microbiology - February 4, 2020 Category: Microbiology Source Type: research

Fecal Serine Protease Profiling in Inflammatory Bowel Diseases
Serine proteases are extensively known to play key roles in many physiological processes. However, their dysregulation is often associated to several diseases including inflammatory bowel diseases (IBD). Here, we used specific substrates to monitor fecal protease activities in a large cohort of healthy and IBD patients. Of interest, serine protease activity was 10-fold higher in IBD fecal samples compared to healthy controls. Moreover, functional analysis of these fecal proteolytic activities revealed that the most increased activities are trypsin-like, elastase-like and cathepsin G-like. We also show for the first time, a...
Source: Frontiers in cellular and infection microbiology - February 4, 2020 Category: Microbiology Source Type: research

Interaction of Oral and Toothbrush Microbiota Affects Oral Cavity Health
Tooth brushing is necessary to maintain oral health. Little research has been carried out to explore microbial diversity in toothbrushes and to study the potential impact of these bacteria on human health. In the present study, 20 participants were enrolled, and the microbial diversity in their oral cavity and toothbrushes was investigated using high-throughput sequencing. Our results indicate that 1,136 and 976 operational taxonomic units (OTUs) were obtained from groups CB (samples from toothbrushes of participants using traditional Chinese medicinal toothpaste) and AB (samples from toothbrushes of those using antibacter...
Source: Frontiers in cellular and infection microbiology - February 4, 2020 Category: Microbiology Source Type: research

Specific Integration of Temperate Phage Decreases the Pathogenicity of Host Bacteria
Temperate phages are considered as natural vectors for gene transmission among bacteria due to the ability to integrate their genomes into a host chromosome, therefore, affect the fitness and phenotype of host bacteria. Many virulence genes of pathogenic bacteria were identified in temperate phage genomes, supporting the concept that temperate phages play important roles in increasing the bacterial pathogenicity through delivery of the virulence genes. However, little is known about the roles of temperate phages in attenuation of bacterial virulence. Here, we report a novel Bordetella bronchiseptica temperate phage, vB_Bbr...
Source: Frontiers in cellular and infection microbiology - February 4, 2020 Category: Microbiology Source Type: research

Discovery of in vivo Virulence Genes of Obligatory Intracellular Bacteria by Random Mutagenesis
Ehrlichia spp. are emerging tick-borne obligatory intracellular bacteria that cause febrile and sometimes fatal diseases with abnormal blood cell counts and signs of hepatitis. Ehrlichia HF strain provides an excellent mouse disease model of fatal human ehrlichiosis. We recently obtained and established stable culture of Ehrlichia HF strain in DH82 canine macrophage cell line, and obtained its whole genome sequence and annotation. To identify genes required for in vivo virulence of Ehrlichia, we constructed random insertional HF strain mutants by using Himar1 transposon-based mutagenesis procedure. Of total 158 insertional...
Source: Frontiers in cellular and infection microbiology - February 4, 2020 Category: Microbiology Source Type: research

Protective Effect of Recombinant Proteins of Cronobacter Sakazakii During Pregnancy on the Offspring
This study first reported that exposure to C. sakazakii proteins during pregnancy could improve the offspring's ability to resist infection caused by this pathogen. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - February 1, 2020 Category: Microbiology Source Type: research

One-Year Old Dormant, “Non-culturable” Mycobacterium tuberculosis Preserves Significantly Diverse Protein Profile
For adaptation to stressful conditions, Mycobacterium tuberculosis (Mtb) is prone to transit to a dormant, non-replicative state, which is believed to be the basis of the latent form of tuberculosis infection. Dormant bacteria persist in the host for a long period without multiplication, cannot be detected from biological samples by microbiological methods, however, their “non-culturable” state is reversible. Mechanisms supporting very long capacity of mycobacteria for resuscitation and further multiplication after prolonged survival in a dormant phase remain unclear. Using methods of 2D electrophoresis and MAL...
Source: Frontiers in cellular and infection microbiology - January 31, 2020 Category: Microbiology Source Type: research

Structure, Properties, and Function of Glycosomes in Trypanosoma cruzi
Glycosomes are peroxisome-related organelles that have been identified in kinetoplastids and diplonemids. The hallmark of glycosomes is their harboring of the majority of the glycolytic enzymes. Our biochemical studies and proteome analysis of Trypanosoma cruzi glycosomes have located, in addition to enzymes of the glycolytic pathway, enzymes of several other metabolic processes in the organelles. These analyses revealed many aspects in common with glycosomes from other trypanosomatids as well as features that seem specific for T. cruzi. Their enzyme content indicates that T. cruzi glycosomes are multifunctional organelles...
Source: Frontiers in cellular and infection microbiology - January 31, 2020 Category: Microbiology Source Type: research

Gut Microbial Dysbiosis Is Associated With Profibrotic Factors in Liver Fibrosis Mice
Conclusion: In the case of liver fibrosis, the intestinal flora is disordered, and the disorder is related to NOX4 and RhoA. This study provides theoretical support for a better understanding of the underlying mechanisms of liver fibrosis development. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - January 31, 2020 Category: Microbiology Source Type: research

Colonization of Toxigenic Clostridium difficile Among Intensive Care Unit Patients: A Multi-Centre Cross-Sectional Study
Background:Clostridium difficile (CD) is a major cause of healthcare-associated infections and antibiotic-associated diarrhea in hospitalized patients worldwide. Carriers of toxigenic CD (tCD) have a higher risk of developing CD infections and can transmit CD to the environment and susceptible patients. However, little is known regarding the carriers and transmission of tCD in China.Methods: A multi-center cross-sectional study of tCD colonization (tCDC) was conducted from October 24 to 31, 2014, at 33 hospitals in Shanghai, China. Rectal swabs or stool samples were collected and tested, and the clinical and demographic st...
Source: Frontiers in cellular and infection microbiology - January 30, 2020 Category: Microbiology Source Type: research

Rapid and Accurate Species Identification of Mitis Group Streptococci Using the MinION Nanopore Sequencer
In this study, we established a scheme for identifying 12 species of MGS (S. pneumoniae, S. pseudopneumoniae, S. mitis, S. oralis, S. peroris, S. infantis, S. australis, S. parasanguinis, S. sinensis, S. sanguinis, S. gordonii, and S. cristatus) using the MinION nanopore sequencer (Oxford Nanopore Technologies, Oxford, UK) with the taxonomic aligner “What's in My Pot?” (WIMP; Oxford Nanopore's cloud-based analysis platform) and Kraken2 pipeline with the custom database adjusted for MGS species identification. The identities of the species in reference genomes (n = 514), clinical isolates (n = 31), and reference...
Source: Frontiers in cellular and infection microbiology - January 30, 2020 Category: Microbiology Source Type: research

New Insights Into CRASP-Mediated Complement Evasion in the Lyme Disease Enzootic Cycle
Lyme disease (LD), which is caused by genospecies of the Borrelia burgdorferi sensu lato complex, is the most common vector-borne disease in the Northern hemisphere. Spirochetes are transmitted by Ixodes ticks and maintained in diverse vertebrate animal hosts. Following tick bite, spirochetes initially establish a localized infection in the skin. However, they may also disseminate hematogenously to several distal sites, including heart, joints, or the CNS. Because they need to survive in diverse microenvironments, from tick vector to mammalian hosts, spirochetes have developed multiple strategies to combat the numerous hos...
Source: Frontiers in cellular and infection microbiology - January 30, 2020 Category: Microbiology Source Type: research

Kupffer Cells: Important Participant of Hepatic Alveolar Echinococcosis
Aims: Kupffer cells (KCs) are the liver-resident macrophages and play a leading role in the regulation of liver homeostasis in physiological conditions and in pathology. The study aims to investigate the anti-echinococcosis effect of KCs and the effects of hepatic stellate cells (HSCs) activation in the progression of liver fibrosis in hepatic alveolar echinococcosis (hepatic AE).Methods: Hematoxylin—eosin (H&E) and Masson staining were used to assess the pathological inflammatory changes and collagen deposition, respectively. Immunohistochemistry and qRT-PCR were used to detect the number of aggregates of KCs, t...
Source: Frontiers in cellular and infection microbiology - January 29, 2020 Category: Microbiology Source Type: research

Structural and Functional Characterization of the Gut Microbiota in Elderly Women With Migraine
Migraine is a very common, multifactorial, and recurrent central nervous system disorder that causes throbbing headache, photophobia, phonophobia, nausea, and disability. Migraine occurs more often in females, and its complex physiopathology is not yet fully understood. An increasing number of gastrointestinal disorders have been linked to the occurrence of migraine suggesting that gut microbiota might play a pivotal role in migraine through the gut–brain axis. In the present work, we performed a metagenome-wide association study (MWAS) to determine the relationship between gut microbiota and migraine by analyzing 10...
Source: Frontiers in cellular and infection microbiology - January 29, 2020 Category: Microbiology Source Type: research

A Peroxiredoxin From the Haemaphysalis longicornis Tick Affects Langat Virus Replication in a Hamster Cell Line
In this study, we established stable strains of baby hamster kidney (BHK) cells expressing two types of H2O2-scavenging Prxs from the hard tick Haemaphysalis longicornis (BHK-HlPrx and BHK-HlPrx2 cells). Although the infection of TBEV surrogate Langat virus (LGTV) did not induce H2O2 production in normal BHK cells, the mortality rate and the virus titer of LGTV infected BHK-HlPrx cells increased. In addition, HlPrx proteins in BHK cells can facilitate LGTV replication in cells, while HlPrx2 proteins in BHK cells cannot. The results also demonstrated that this facilitation of LGTV replication by the 1-Cys Prx in the BHK cel...
Source: Frontiers in cellular and infection microbiology - January 28, 2020 Category: Microbiology Source Type: research

The Influence of Recombinational Processes to Induce Dormancy in Trypanosoma cruzi
The protozoan Trypanosoma cruzi is the causative agent of Chagas disease, a neglected tropical disease that affects around 8 million people worldwide. Chagas disease can be divided into two stages: an acute stage with high parasitemia followed by a low parasitemia chronic stage. Recently, the importance of dormancy concerning drug resistance in T. cruzi amastigotes has been shown. Here, we quantify the percentage of dormant parasites from different T. cruzi DTUs during their replicative epimastigote and amastigote stages. For this study, cells of T. cruzi CL Brener (DTU TcVI); Bug (DTU TcV); Y (DTU TcII); and Dm28c (DTU Tc...
Source: Frontiers in cellular and infection microbiology - January 28, 2020 Category: Microbiology Source Type: research

Face/Off: The Interchangeable Side of Candida Albicans
Due to limited mobility, fungi, like most unicellular organisms, have evolved mechanisms to adapt to sudden chemical and/or physical variation in their environment. Candida albicans is recognized as a model organism to study eukaryotic responses to environmental changes, as this human commensal yeast but also opportunistic pathogen responds to numerous environmental cues through switching morphologies from yeast to hyphae growth. This mechanism is largely controlled by two major pathways: cAMP-PKA and MAPK, but each environmental signal is sensed by specific sensors. However, morphological switching is not the only respons...
Source: Frontiers in cellular and infection microbiology - January 28, 2020 Category: Microbiology Source Type: research

Extracellular Vesicles Released From the Skin Commensal Yeast Malassezia sympodialis Activate Human Primary Keratinocytes
In this study, we explored the host-microbe interaction between MalaEx and human keratinocytes with the hypothesis that MalaEx might be able to activate human keratinocytes to express the intercellular adhesion molecule-1 (ICAM-1, CD54). MalaEx were prepared from M. sympodialis (ATCC 42132) culture supernatants by a combination of centrifugation, filtration and serial ultracentrifugation. The MalaEx showed a size range of 70–580 nm with a mean of 154 nm using nanoparticle tracking analysis. MalaEx were found to induce a significant up-regulation of ICAM-1 expression on primary human keratinocytes isolated from human ...
Source: Frontiers in cellular and infection microbiology - January 24, 2020 Category: Microbiology Source Type: research

Determination of Causative Human Papillomavirus Type in Tissue Specimens of Common Warts Based on Estimated Viral Loads
Conclusions: CWs are mostly etiologically associated with HPV2/27/57 and only rarely with HPV1. In the majority of CWs containing multiple HPVs, a single HPV type was present in high concentration, indicating etiological association. No significant differences in VLs of lesion-causing HPV types in CWs containing single or multiple HPVs were found. (Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - January 24, 2020 Category: Microbiology Source Type: research

Inflammatory Dendritic Cells, Regulated by IL-4 Receptor Alpha Signaling, Control Replication, and Dissemination of Leishmania major in Mice
Leishmaniasis is a vector-borne disease caused by Leishmania parasites. Macrophages are considered the primary parasite host cell, but dendritic cells (DCs) play a critical role in initiating adaptive immunity and controlling Leishmania infection. Accordingly, our previous study in CD11ccreIL-4Rα−/lox mice, which have impaired IL-4 receptor alpha (IL-4Rα) expression on CD11c+ cells including DCs, confirmed a protective role for IL-4/IL-13-responsive DCs in replication and dissemination of parasites during cutaneous leishmaniasis. However, it was unclear which DC subset/s was executing this function. To in...
Source: Frontiers in cellular and infection microbiology - January 24, 2020 Category: Microbiology Source Type: research

Hepatitis E Virus Cysteine Protease Has Papain Like Properties Validated by in silico Modeling and Cell-Free Inhibition Assays
Hepatitis E virus (HEV) has emerged as a global health concern during the last decade. In spite of a high mortality rate in pregnant women with fulminant hepatitis, no antiviral drugs or licensed vaccine is available in India. HEV-protease is a pivotal enzyme responsible for ORF1 polyprotein processing leading to cleavage of the non-structural enzymes involved in virus replication. HEV-protease region encoding 432–592 amino acids of Genotype-1 was amplified, expressed in Sf21 cells and purified in its native form. The recombinant enzyme was biochemically characterized using SDS-PAGE, Western blotting and Immunofluore...
Source: Frontiers in cellular and infection microbiology - January 23, 2020 Category: Microbiology Source Type: research

Peptidoglycan Recognition Proteins (PGRPs) Modulates Mosquito Resistance to Fungal Entomopathogens in a Fungal-Strain Specific Manner
In this study, we investigated the role of peptidoglycan recognition receptors (PGRPs) in host resistance to fungal entomopathogens at the early stages of infection. Our study identified the induction of PGRP-LA, -LB, -LD, -LE, and -S1 during infection with two different fungal entomopathogenic strains. Furthermore, our data shows temporal differences in PGRP elicitation, with most PGRPs displaying significant upregulation at 60 h post-infection. Depletion of certain PGRPs via RNAi silencing resulted in a significant increase in fungal proliferation and a reduction in mosquito survival that was fungal strain-specific. Our ...
Source: Frontiers in cellular and infection microbiology - January 23, 2020 Category: Microbiology Source Type: research

Long Non-coding RNA LincRNA-EPS Inhibits Host Defense Against Listeria monocytogenes Infection
Long non-coding RNAs (lncRNAs) have emerged as key regulators of gene expression in several biological systems. The long intergenic RNA-erythroid pro-survival (lincRNA-EPS) has been shown to play a critical role in restraining inflammatory gene expression. However, the function of lincRNA-EPS during bacterial infections remains unknown. Here, we demonstrate that following infection with the intracellular bacterium Listeria monocytogenes, both mouse macrophages and dendritic cells lacking lincRNA-EPS exhibit an enhanced expression of proinflammatory cytokine genes, as well as an increased expression of the inducible nitric ...
Source: Frontiers in cellular and infection microbiology - January 22, 2020 Category: Microbiology Source Type: research

Hydroxycarboxylic Acid Receptor 2 Is a Zika Virus Restriction Factor That Can Be Induced by Zika Virus Infection Through the IRE1-XBP1 Pathway
Zika virus (ZIKV) is an emerging arthropod-borne virus and belongs to the Flaviviridae family. The infection of ZIKV has become the global health crisis because of its rapid spread and association with severe neurological disorders, including congenital microcephaly and Guillain-Barre Syndrome. To identify host factors contributing to ZIKV pathogenesis, transcriptomic landscape in ZIKV-infected cells was examined with mRNA microarray analysis and we observed that the expression of hydroxycarboxylic acid receptor 2 (HCAR2) could be significantly induced by ZIKV infection. By utilizing two IRE1 inhibitors and XBP1-specific s...
Source: Frontiers in cellular and infection microbiology - January 22, 2020 Category: Microbiology Source Type: research

Oral Microbiota Perturbations Are Linked to High Risk for Rheumatoid Arthritis
In this study, we aim to investigate whether and whereby the oral microbiome communities alter prior to symptoms of RA. Seventy-nine saliva samples were collected from 29 high-risk individuals, who were positive for anti-citrullinated protein antibodies (ACPA) and have no clinical arthritis, 27 RA patients and 23 healthy controls (HCs). The salivary microbiome was examined using 16S ribosomal RNA gene sequencing. Alpha and beta diversity analysis and the linear discriminant analysis were applied to examine the bacterial diversity, community structure and discriminatory taxa between three groups, respectively. The correlati...
Source: Frontiers in cellular and infection microbiology - January 22, 2020 Category: Microbiology Source Type: research

Editorial: Protein Export and Secretion Among Bacterial Pathogens
(Source: Frontiers in cellular and infection microbiology)
Source: Frontiers in cellular and infection microbiology - January 22, 2020 Category: Microbiology Source Type: research