Aims: Antimicrobial compounds are bioactive compounds that have ability to inhibit microbial growth activities. This study aimed to screen and identify bacteria associated with Haliclona sp. sponges from Enggano Island, Indonesia that had potential to produce antimicrobial compounds against Escherichia coli, Candida albicans and Staphylococcus epidermidis. Methodology and results: The method used to screen and identify bacteria in this study including screening assay, morphological identification, Gram staining and spore staining method, biochemical tests and molecular identification based on 16S rRNA gene. This study resulted 16 isolates which were successfully isolated from Haliclona sp. According to screening assay, 5 isolates could potentially produce antimicrobial compounds coded as HEBS1, HEBS3, HEBS6, HEBB2 and HEBB3. Based on Gram staining, spore staining, biochemical test and molecular identification results, HEBS1 had proximity to Brachybacterium paraconglomeratum, HEBS3 had proximity to Kocuria palustris, HEBS6 had proximity to Psychrobacter pasificensis, HEBB2 had proximity to Bacillus aryabhattai, and HEBB3 had proximity to Bacillus toyonensis. Conclusion, significance and impact of study From 16 isolates that successfully isolated, there were 5 isolates that could potentially produce antimicrobial compounds against Escherichia coli, Staphylococcus epidermidis and Candida albicans. These isolates can be served as antimicrobial compounds producer. However, identification and purification of these antimicrobial compounds are needed to be done before applied it for medicine in the future.
Haliclona--microbiology ; Host-Pathogen Interactions

Poxvirus is one of the most serious zoonosis pathogens, which has largest genome and broadest host spectrum. With the development of molecular biology, functional genomics, and immunology-related technology, the interactions between pathogen and the host, particularly a large array of host range factors and their functions have been increasingly discovered. These findings provide references for the molecular basis of poxvirus tissue tropism and host specificity. This review focus on the introduction of host range factors in major members of Chordopoxvirinae to highlight the understanding of the mechanisms of molecular genetic evolution, the host tropism, and cross-species infection of poxviruses.
Animals ; Host Specificity ; Host-Pathogen Interactions ; Humans ; Poxviridae ; classification ; genetics ; isolation & purification ; physiology ; Poxviridae Infections ; veterinary ; virology ; Viral Proteins ; genetics ; metabolism

Periodontitis is a chronic inflammation of periodontal tissue caused by subgingival plaque-associated bacteria. Periodontitis has long been understood to be the result of an excessive host response to plaque bacteria. In addition, periodontal pathogens have been regarded as the causative agents that induce a hyperinflammatory response from the host. In this brief review, host-microbe interaction of nonperiodontopathic versus periodontopathic bacteria with innate immune components encountered in the gingival sulcus will be described. In particular, we will describe the susceptibility of these microbes to antimicrobial peptides (AMPs) and phagocytosis by neutrophils, the induction of tissue-destructive mediators from neutrophils, the induction of AMPs and interleukin (IL)-8 from gingival epithelial cells, and the pattern recognition receptors that mediate the regulation of AMPs and IL-8 in gingival epithelial cells. This review indicates that true periodontal pathogens are poor activators/suppressors of a host immune response, and they evade host defense mechanisms.
Bacteria ; Defense Mechanisms ; Epithelial Cells ; Host-Pathogen Interactions ; Immune Evasion ; Immunity, Innate ; Inflammation ; Interleukin-8 ; Interleukins ; Neutrophils ; Peptides ; Periodontitis ; Phagocytosis ; Receptors, Pattern Recognition

Animals ; Bacteria ; pathogenicity ; Biological Evolution ; Host-Pathogen Interactions ; Humans ; Symbiosis

Autophagy is an intracellular degradation process that maintains cellular homeostasis. It is essential for protecting organisms from environmental stress. Autophagy can help the host to eliminate invading pathogens, including bacteria, viruses, fungi, and parasites. However, pathogens have evolved multiple strategies to interfere with autophagic signaling pathways or inhibit the fusion of autophagosomes with lysosomes to form autolysosomes. Moreover, host cell matrix degradation by different types of autophagy can be used for the proliferation and reproduction of pathogens. Thus, determining the roles and mechanisms of autophagy during pathogen infections will promote understanding of the mechanisms of pathogen‍‒‍host interactions and provide new strategies for the treatment of infectious diseases.
Autophagy ; Bacteria ; Host-Pathogen Interactions ; Lysosomes ; Signal Transduction

The epiphytic orchid, Dendrobium aphyllum and D. devonianum are used as traditional Chinese medicine, and became locally endangered in recent years because of over-collection. We test the effect of inoculations of endophytic fungi FDaI7 (Tulasnella sp.), FDd1 (Epulorhiza sp. ) and FCb4 (Epulorhiza sp.), which isolated from D. aphyllum, D. denonianum and Cymbidium mannii, respectively, on artificial substrate in these two Dendrobium species. In the symbiotic germination experiment, FDaI7 and FDd1 were effective for protocorm formation and seedling development of D. aphyllum and D. denonianum separately. After 60 days, 14.46% of the D. aphyllum seeds grown to protocorms and 12.07% developed to seedlings inoculated only with FDaI7, while contrasted with 0 when inoculated the other two isolates and non-inoculation treatment. However, in D. denonianum, seeds only grown to protocorms and developed to seedlings when inoculated with FDd1, the percentages were 44.36% and 42.91% distinguishingly. High specificity was shown in symbiotic germination on artificial substrate of Dendrobium. Protocorms could further develop to seedlings within or without light when inoculated the compatible fungi. However, light condition (12/12 h Light/Dark) produced the normal seedlings, while dark condition (0/24 h L/D) produced the abnormal seedlings. These may suggest that the development of young seedlings require light based on the effective symbiotic fungi. These findings will aid in seedling production of simulation-forestry ecology cultivation, conservation and reintroduction of Dendrobium.
Basidiomycota ; classification ; physiology ; Darkness ; Dendrobium ; classification ; growth & development ; microbiology ; Germination ; Host-Pathogen Interactions ; Light ; Plants, Medicinal ; classification ; growth & development ; microbiology ; Seedlings ; growth & development ; microbiology ; radiation effects ; Seeds ; growth & development ; microbiology ; Species Specificity ; Symbiosis

Host-Pathogen Interactions ; Humans ; Immunocompromised Host ; MicroRNAs ; genetics ; immunology ; RNA, Viral ; genetics ; immunology ; Viruses ; genetics ; immunology

The primary determinant of influenza virus infectivity is the type of linkage between sialic acid and oligosaccharides on the host cells. Hemagglutinin of avian influenza viruses preferentially binds to sialic acids linked to galactose by an alpha-2,3 linkage whereas hemagglutinin of human influenza viruses binds to sialic acids with an alpha-2,6 linkage. The distribution patterns of influenza receptors in the avian respiratory tracts are of particular interest because these are important for initial viral attachment, replication, and transmission to other species. In this study, we examined the distribution patterns of influenza receptors in the respiratory tract of chickens, ducks, pheasants, and quails because these species have been known to act as intermediate hosts in interspecies transmission. Lectin histochemistry was performed to detect receptor-bearing cells. Cell-specific distribution of the receptors was determined and expression densities were compared. We observed species-, site-, and cell-specific variations in receptor expression. In general, receptor expression was the highest in quails and lowest in ducks. Pheasants and quails had abundant expression of both types of receptors throughout the respiratory tract. These results indicate that pheasants and quails may play important roles as intermediate hosts for the generation of influenza viruses with pandemic potential.
Animals ; Cell Membrane/metabolism/virology ; Hemagglutinin Glycoproteins, Influenza Virus/metabolism ; Host-Pathogen Interactions ; Influenza A virus/*metabolism ; Influenza in Birds/metabolism/transmission ; Lectins/metabolism ; Poultry/metabolism/*virology ; Poultry Diseases/metabolism ; Receptors, Cell Surface/analysis/chemistry/metabolism ; Receptors, Virus/*analysis/metabolism ; Respiratory System/*chemistry ; Sialic Acids/metabolism ; Species Specificity ; Specific Pathogen-Free Organisms

FtsH is a membrane-bound, ATP-dependent protease involved in various cellular functions. To understand its roles in Streptococcus pneumoniae and host-pathogen interactions, we inactivated the ftsH gene of D39 strain by inserting a tetracycline-resistance (tet) gene. Several recombinants containing the tet cassette within the ftsH gene were confirmed by Western immunoblotting for the absence of pneumococcal FtsH protein that could cross-react with antiserum raised against Escherichia coli FtsH. Compared with the wild-type D39 strain, the ftsH null mutants grew slowly with encapsulation and alpha-hemolysis on blood agar plates, but failed to grow in liquid media other than Todd Hewitt yeast extract broth. Even fresh cultures of ftsH null mutants appeared gram-negative. When the incubation temperature of liquid cultures was shifted from 37degrees C to 40degrees C, the mutants gradually lysed, whereas the shift to 30degrees C abolished further growth. The mutants also exhibited increased sensitivity to salt and remarkable growth inhibition by optochin. These observations suggest that no functional FtsH protein in pneumococcal cells causes a loss of cell surface integrity, resulting in impairment of cell growth under normal and stressful conditions.
Agar ; ATP-Dependent Proteases ; Blotting, Western ; Escherichia coli ; Host-Pathogen Interactions ; Streptococcus pneumoniae* ; Streptococcus* ; Yeasts

FtsH is a membrane-bound, ATP-dependent protease involved in various cellular functions. To understand its roles in Streptococcus pneumoniae and host-pathogen interactions, we inactivated the ftsH gene of D39 strain by inserting a tetracycline-resistance (tet) gene. Several recombinants containing the tet cassette within the ftsH gene were confirmed by Western immunoblotting for the absence of pneumococcal FtsH protein that could cross-react with antiserum raised against Escherichia coli FtsH. Compared with the wild-type D39 strain, the ftsH null mutants grew slowly with encapsulation and alpha-hemolysis on blood agar plates, but failed to grow in liquid media other than Todd Hewitt yeast extract broth. Even fresh cultures of ftsH null mutants appeared gram-negative. When the incubation temperature of liquid cultures was shifted from 37degrees C to 40degrees C, the mutants gradually lysed, whereas the shift to 30degrees C abolished further growth. The mutants also exhibited increased sensitivity to salt and remarkable growth inhibition by optochin. These observations suggest that no functional FtsH protein in pneumococcal cells causes a loss of cell surface integrity, resulting in impairment of cell growth under normal and stressful conditions.
Agar ; ATP-Dependent Proteases ; Blotting, Western ; Escherichia coli ; Host-Pathogen Interactions ; Streptococcus pneumoniae* ; Streptococcus* ; Yeasts