Environmental mycobacteria are a common cause of human infections. Recently, contaminated domestic water supplies have been suggested as potential environmental source several mycobacterial diseases. Since many these species replicate best intracellularly, hosts sought. In the present study, we examined interaction Mycobacterium avium with protozoan host, water-borne amoeba Acanthamoeba castellanii. We found that M. enters and replicates in A. addition, similar to shown for within...

Abstract Mycobacterium avium and tuberculosis are human pathogens that infect replicate within macrophages. Both organisms live in phagosomes fail to fuse with lysosomes have adapted their lifestyle accommodate the changing environment endosomal system. Among many environmental factors could influence expression of bacterial genes concentrations single elements phagosomes. We used a novel hard x-ray microprobe suboptical spatial resolution analyze characteristic fluorescence 10 inside...

Organisms belonging to the Mycobacterium avium complex (MAC) are most common bacterial pathogens in patients with AIDS but factors associated activation of cellular defense mechanisms against this atypical mycobacterium have not been defined. Peritoneal macrophages harvested from a chronic MAC infection C57 black mice able kill approximately 86% intracellular contrast 0 20% killing by unstimulated human and mouse vitro. The availability rTNF-alpha, rIFN-gamma, rIL-2 permitted evaluation role...

Although Mycobacterium tuberculosis is assumed to infect primarily alveolar macrophages after being aspirated into the lung in aerosol form, it plausible hypothesize that M. can come contact with epithelial cells upon arrival space. Therefore, as a first step toward investigation of interaction between and cells, we examined ability bind invade vitro. The H37Rv H37Ra strains were cultured mid-log phase used both adherence invasion assays. A549 human type II cell line was confluence RPMI 1640...

ABSTRACT Since Legionella pneumophila is an intracellular pathogen, entry into and replication within host cells are thought to be critical its ability cause disease. L. grown in one of environmental hosts, Acanthamoeba castellanii , phenotypically different from on standard laboratory medium (BCYE agar). Although amoeba-grown displays enhanced monocytes compared BCYE-grown bacteria, the mechanisms used effects virulence have not been examined. To explore whether differs these...

Mycobacterium tuberculosis interacts with macrophages and epithelial cells in the alveolar space of lung, where it is able to invade replicate both cell types. M. tuberculosis-associated cytotoxicity these has been well documented, but mechanisms host death are not understood. We examined induction apoptosis necrosis human (U937) type II (A549) by virulent (H37Rv) attenuated (H37Ra) strains. Apoptosis was determined enzyme-linked immunosorbent assay (ELISA) TdT-mediated dUTP nick end...

Organisms of the Mycobacterium avium complex are associated with disseminated infection in patients AIDS. The mechanisms that account for survival intracellular bacteria unknown. We document here C57BL/6 black mice M. 101 triggered interleukin-10 (IL-10) production. synthesis IL-10 peaked after 2 weeks and remained elevated throughout period infection. Treatment avium-infected peritoneal macrophages recombinant suppressed stimulatory effect tumor necrosis factor alpha granulocyte-macrophage...

Pulmonary infections caused by nontuberculous mycobacteria (NTM) are an increasing problem in individuals with chronic lung conditions and current therapies lacking. We investigated the activity of liposomal amikacin for inhalation (LAI) against NTM vitro as well a murine model respiratory infection. Macrophage monolayers were infected three strains Mycobacterium avium, two abscessus, exposed to LAI or free 4 days before enumerating bacterial survival. Respiratory infection was established...

Mycobacterium avium is an environmental organism encountered in natural and urban water sources as well soil. M. biofilm has recently been identified on sauna walls city pipes might have a role the survival of virulent strains environment host. To characterize biofilm, vitro model was adapted wherein develops PVC surface. Biofilm detected by staining with crystal violet visualization optical microscopy quantified A(570). MAC 101, 100, 104, 109, A5 5501 (all isolated from blood AIDS patients)...

ABSTRACT The mechanism(s) by which Mycobacterium tuberculosis crosses the alveolar wall to establish infection in lung is not well known. In an attempt better understand mechanism of translocation and create a model study different stages bacterial crossing through wall, we established two-layer transwell system. M. H37Rv was evaluated regarding ability cross disrupt membrane. invaded A549 type II cells with efficiency 2 3% initial inoculum, although it efficient invading endothelial cells....

Mycobacterium avium causes disseminated infection in patients with acquired immune deficieny syndrome. tuberculosis is a pathogen associated the deaths of millions people worldwide annually. Effective therapeutic regimens exist that are limited by emergence drug resistance and inability antibiotics to kill dormant organisms. The present study describes system using smegmatis an avirulent mycobacterium, deliver lytic phage TM4 where both M. reside within macrophages. These results showed...

Severe-combined immune deficient (SCID) mice have been found to resist infection with the intracellular protozoan parasite Toxoplasma gondii via interleukin (IL)-12 stimulation of interferon (IFN)-gamma production by natural killer (NK) cells. Previously, we demonstrated presence increased levels transcripts for transforming growth factor-beta (TGF-beta) in brains and lungs SCID infected T. gondii, leading us investigate role TGF-beta mechanism resistance these mice. Stimulation splenocytes...

Transforming growth factor-beta 1 (TGF-beta 1) is a potent immunoregulatory molecule. It modulates production of cytokines, such as TNF-alpha and IL-6, cell response to cytokine stimulation. Mycobacterium avium an intracellular bacterium that multiplies within macrophages. The reason why M. can survive macrophages still unknown but probably multifactorial. Exposure avium-infected rTGF-beta before TNF stimulation significantly decreases the mycobactericidal/mycobacteriostatic activity...

Mycobacterium avium complex (MAC) is the most common bloodstream pathogen isolated from patients with AIDS. We have previously shown that TNF alone or in combination IL-2 can activate human and murine macrophages vitro to kill MAC strains disseminated infections. To determine whether treatment could effect course of infections a model infection, we infected C57BL mice 3 x 10(8) bacteria i.v. 1 wk later administered: 1) IL-2, 100 micrograms/kg; 2) TNF, 25 3) 50 micrograms/kg, 12.5 4) saline....

Invasive, disease-associated members of the Mycobacterium avium complex are facultative intracellular pathogens mammalian macrophages. The mechanism(s) by which M. is ingested mononuclear phagocytes unknown. We examined role membrane receptors on macrophages as well opsonic components serum (complement, fibronectin, C-reactive protein and fibrinogen in attachment ingestion human monocyte-derived Preincubation with antibodies against C3 contrast to preincubation complement-reactive...

Organisms of the Mycobacterium avium complex (MAC) are widely distributed in environment, form biofilms water pipes and potable tanks, cause chronic lung infections patients with obstructive pulmonary disease cystic fibrosis. Pathological studies MAC infection revealed granulomatous inflammation around bronchi bronchioles. BEAS-2B human bronchial epithelial cell line was used to study invasion. strain A5 entered polarized cells an efficiency 0.1 +/- 0.03% 2 h 11.3 4.0% 24 h. In contrast,...

SUMMARY Murine peritoneal macrophages activated with interferon-gamma (IFN-γ) produce large quantities of nitric oxide and are efficient in the killing certain intracellular pathogens. To examine role this mechanism Mycobacterium avium by murine human macrophages, we infected mouse monocyte-derived M. Listeria monocytogenes stimulated cells recombinant tumour necrosis factor (TNF), granulocyte-macrophage colony-stimulating (GM-CSF) or IFN-γ, presence absence N-monomethyl-L-arginine (NMA)...

Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that associated with biofilm-related infections of the respiratory tract and difficult to treat. In recent years, extracellular DNA (eDNA) has been found be a major component bacterial biofilms, including many pathogens involved in biofilm-associated infections. To date, eDNA not described as mycobacterial biofilms. this study, we identified characterized high biofilm-producing strain (MAH). addition, surveyed for presence...

Extracellular DNA (eDNA) is an integral biofilm matrix component of numerous pathogens, including nontuberculous mycobacteria (NTM). Cell lysis the source eDNA in certain bacteria, but remains unidentified for NTM, as well other eDNA-containing bacterial species. In this study, conditions affecting export were examined, and genes involved with mechanism identified. After a method monitoring real time undisturbed biofilms was established, different investigated. Bicarbonate positively...

PPE and PE gene families, which encode numerous proteins of unknown function, account for 10% Mycobacterium tuberculosis genome. avium genome has similar families. Using a temperature-sensitive phage phAE94 transposon mutagenesis system, M. library was created in the strain MAC109. Screening individual mutants human U937 macrophages ability to replicate intracellularly, we identified several attenuated clones. One them, 2D6 mutant, interrupting (52% homologous Rv 1787 tuberculosis)...

Abstract Organisms belonging to the Mycobacterium avium complex (MAC) are associated with life-threatening bacteremia in patients acquired immunodeficiency syndrome (AIDS). As these organisms survive within macrophages, we examined ability of recombinant human granulocyte–monocyte colony-stimulating factor (GM-CSF) activate monocyte-derived macrophages inhibit intracellular growth or kill most mouse-virulent MAC strain In our collection that belongs serotype 1. While unstimulated cells did...