Immunobiological effects of lipopolysaccharide derived from Helicobacter pylori and influence of a proton pump inhibitor lansoprazole on human polymorphonuclear leukocytes.

Helicobacter pylori colonizes the human gastric mucosa of more than half of the human population and has a unique lipopolysaccharide (LPS) structure. LPS is the most dominant and suitable pathogen-associated molecular pattern that is detected via pattern recognition receptors. Although the priming effect of H.

Tigecycline Suppresses the Virulence Factors of Multidrug-Resistant Allowing Human Neutrophils to Act.

Purpose: To determine the ability of human neutrophils to kill multidrug-resistant (MDRAB) in the presence of tigecycline (TGC).

Methods: Clinical isolates of MDRAB were cultured with human neutrophils and HO in the presence of TGC. The numbers of viable bacteria, catalase activity, gene expression at the K locus of the MDRAB, reactive oxygen species (ROS) production, and granule exocytosis in human neutrophils were determined.

Orbital metastasis of invasive lobular carcinoma of the breast.

We herein report a case of orbital metastasis from the breast cancer in a 58-year-old woman presenting with visual disturbance and bilateral periorbital swelling. She had undergone radical mastectomy for right breast cancer 9 years previously and been receiving hormone therapy for bone metastasis of breast cancer for the past 4 years. Computed tomography and magnetic resonance imaging revealed an ill-defined mass in the bilateral orbits, whereas an excisional biopsy confirmed metastasis of invasive lobular carcinoma (ILC) of the breast.

Effects of colistin and tigecycline on multidrug-resistant Acinetobacter baumannii biofilms: advantages and disadvantages of their combination.

We investigated the antimicrobial effects of colistin (CST) and tigecycline (TGC), either alone or in combination, on biofilm-dispersed and biofilm-embedded multidrug-resistant Acinetobacter baumannii (MDRAB) strains R1 and R2. The bacterial growth of biofilm-dispersed MDRAB was inhibited by CST or TGC. However, the inhibitory effects were attenuated by a combination of CST and low concentrations of TGC.

Prevalence and Relatedness of -Mediated Colistin-Resistant Isolated From Livestock and Farmers in Japan.

Colistin is used to treat infectious diseases in humans and livestock; it has also been used as a feed additive for livestock for approximately 50 years. Since the plasmid-mediated colistin resistance gene was discovered in China in 2015, it has been detected worldwide, mainly in livestock. In this study, we investigated the prevalence and characteristics of -mediated colistin-resistant in livestock and farmers in Japan.

LOS Regulate the Expression of Inflammatory Cytokine Genes and Proteins in Human Mast Cells.

Herein, we investigated the effect of bacterial lipooligosaccharides (LOS), from , on the expression of pro-inflammatory genes that play an essential role in bacterial clearance. LAD2 human mast cells were stimulated with LOS derived from two strains of -ATCC 19606 and MDRA T14. LOS exposure induced the expression of genes for pro-inflammatory mediators, including TNF-α, IL-8, LTC4S, CCL4, and TLR4.

Analysis of Immune Responses in -Infected Klotho Knockout Mice: A Mouse Model of Infection in Aged Hosts.

is an important opportunistic pathogen that primarily afflicts elderly people. To clarify the pathogenicity of in the elderly, we investigated immune responses to ATCC 19606 infection in klotho knockout (KO) mice, the mouse model of aging. Following intravenous inoculation, the mice seldom displayed severe symptoms.

Immunomodulatory gene expression analysis in LPS-stimulated human polymorphonuclear leukocytes treated with antibiotics commonly used for multidrug-resistant strains.

Conventional antibiotics used for the treatment of severe infections such as sepsis and septic shock confer immunomodulatory benefits. However, the growing problem of multidrug resistant infections has led to an increase in the administration of non-conventional last-resort antibiotics, including quinolones, aminoglycosides, and polypeptides, and the effects of these drugs on immunomodulatory gene expression in activated human polymorphonuclear leukocytes (PMNs) have not been reported. In this study, lipopolysaccharide-stimulated PMNs were incubated with piperacillin, rifampicin, fosfomycin (FOM), levofloxacin (LVFX), minocycline (MINO), colistin, tigecycline, or amikacin, and the mRNA expression levels of pattern recognition receptors (TLR2, TLR4, and CD14), inflammatory cytokines (TNFα and IL6), and chemokine receptors (IL8Rs and ITGAM) in these cells were quantitated using real-time qPCR.

Multidrug-resistant Acinetobacter baumannii resists reactive oxygen species and survives in macrophages.

We investigated the intracellular survival of multidrug-resistant Acinetobacter baumannii (MDRAB) clinical isolates in macrophages, after phagocytosis, to determine their virulence characteristics. After ATCC 19606 and 5 clinical isolates of MDRAB were phagocytosed by mouse and human macrophages, the bacterial count of MDRAB strains, R4 and R5, increased in the mouse macrophages, 24 hours after phagocytosis. Bacterial count of the strains, R1 and R2, was almost equal 4 and 24 hours after phagocytosis.

Resolvin E1, but not resolvins E2 and E3, promotes fMLF-induced ROS generation in human neutrophils.

E-series resolvins are biosynthesized from eicosapentaenoic acid during the resolution phase of acute inflammation and enhance inflammation resolution. However, the role of E-series resolvins in inflammation resolution is not yet known. Herein, we show that in human polymorphonuclear neutrophils (PMNs), resolvin E1 (RvE1) selectively enhances reactive oxygen species (ROS) generation induced by N-formylmethionyl-leucyl-phenylalanine.

Sub-minimum inhibitory concentrations of colistin and polymyxin B promote Acinetobacter baumannii biofilm formation.

We investigated the numbers of planktonic and biofilm cells and the expression levels of genes encoding efflux pumps and biofilm-related proteins in 10 clinical isolates of multi-drug resistant Acinetobacter baumannii (MDRA) as well as in its standard strain ATCC 19606 in the presence of colistin (CST), polymyxin B (PMB), minomycin (MIN), and tigecycline (TGC) at their respective sub-MICs. The number of planktonic and biofilm cells of ATCC 19606 decreased in the presence of all aforementioned antibiotics in a dose-dependent manner. Cell number also decreased in two representative MDRA strains, R2 and R3, in the presence of MIN and TGC in a dose-dependent manner.

Pathogenic Bacterium Inhibits the Formation of Neutrophil Extracellular Traps by Suppressing Neutrophil Adhesion.

Hospital-acquired infections caused by have become problematic because of high rates of drug resistance. is usually harmless, but it may cause infectious diseases in an immunocompromised host. Although neutrophils are the key players of the initial immune response against bacterial infection, their interactions with remain largely unknown.

The TNF-α of mast cells induces pro-inflammatory responses during infection with Acinetobacter baumannii.

Mast cells serve important roles as sentinels against bacterial infection by secreting mediators stored in granules. Much of their effectiveness depends upon recruiting and/or modulating other immune cells. The location of mast cells implies that they recognize pathogens invading tissues or mucosal tissues.

Spontaneous formation of neutrophil extracellular traps in serum-free culture conditions.

Neutrophils play a critical role in the innate immune response. Recently, a new neutrophilic biological defense mechanism, termed neutrophil extracellular traps (NETs), has been attracting attention. Neutrophils have been observed to release both lysosomal enzymes and their nuclear contents, including unfolded chromatin, which together trap and inactivate bacteria.

Virulence characteristics of Acinetobacter baumannii clinical isolates vary with the expression levels of omps.

Purpose: We investigated the expression levels of virulence factors (ompA, omp33-36 and carO) in five clinical isolates and in a standard ATCC 19606 strain of Acinetobacter baumannii to determine their effect on the virulence characteristics of the isolates.

Methodology: The mRNA levels of omps and proinflammatory cytokines were analyzed by quantitative real-time PCR. For adherence assay, after human lung epithelial cells (A549) were co-cultured with A.

A novel bacterial transport mechanism of Acinetobacter baumannii via activated human neutrophils through interleukin-8.

Hospital-acquired infections as a result of Acinetobacter baumannii have become problematic because of high rates of drug resistance. Although neutrophils play a critical role in early protection against bacterial infection, their interactions with A. baumannii remain largely unknown.

Loop-mediated isothermal amplification: Rapid and sensitive detection of the antibiotic resistance gene ISAba1-blaOXA-51-like in Acinetobacter baumannii.

Carbapenem-resistant Acinetobacter baumannii, which are mainly induced by the production of OXA-type β-lactamases, are among the leading causes of nosocomial infections worldwide. Among the β-lactamase genes, the presence of the OXA-51-like gene carrying the upstream insertion sequence, ISAba1, was found to be one of the most prevalent carbapenem resistance mechanisms utilized by these bacteria. Consequently, it is necessary to develop a rapid detection method for ISAba1-blaOXA-51-like sequence for the timely and appropriate antibiotic treatment of A.

Gene expression analysis in human polymorphonuclear leukocytes stimulated by LPSs from nosocomial opportunistic pathogens.

Innate immunity coordinates LPS detection via TLR4 on polymorphonuclear leukocytes (PMNs) to elicit responses to many Gram-negative bacteria. In this study, we describe the effects of five subtypes of LPS [isolated from Escherichia coli B4, Pseudomonas aeruginosa PAO1, multidrug-resistant P. aeruginosa (MDRP), Acinetobacter baumannii and multidrug-resistant A.

Rapid detection of the Klebsiella pneumoniae carbapenemase (KPC) gene by loop-mediated isothermal amplification (LAMP).

Klebsiella pneumoniae carbapenemases (KPC), which are associated with resistance to carbapenem, have recently spread worldwide and have become a global concern. It is necessary to detect KPC-producing organisms in clinical settings to be able to control the spread of this resistance. We have developed a loop-mediated isothermal amplification (LAMP) method for rapid detection of KPC producers.

Acinetobacter baumannii escape from neutrophil extracellular traps (NETs).

Acinetobacter baumannii and Pseudomonas aeruginosa are the same aerobic gram-negative bacillus and are usually harmless but cause infectious diseases in compromised hosts. Neutrophils play a critical role in infective protection against the extracellular growth of bacteria. Recently, a new biological defense mechanism called neutrophil extracellular traps (NETs) has been attracting attention.

Effects of erythromycin and rifampicin on immunomodulatory gene expression and cellular function in human polymorphonuclear leukocytes.

Background: We investigated the effects of two antibiotics, erythromycin and rifampicin, on the immunomodulatory gene expression and cellular function of human polymorphonuclear leukocytes (PMNs).

Methods: We used real-time quantitative PCR to examine the expression of immunomodulatory genes. The production of reactive oxygen species (ROS) was determined by fluorescence-activated cell sorting.

Gene expression analysis of TREM1 and GRK2 in polymorphonuclear leukocytes as the surrogate biomarkers of acute bacterial infections.

Objective: In the acute stage of infectious diseases such as pneumonia and sepsis, sequelae hypercytokinemia and cytokine storm are often observed simultaneously. During bacterial infections, activated polymorphonuclear leukocytes (PMNs) cause inflammation and organ dysfunction in severely ill patients. Gene expression of the triggering receptor on myeloid cells (TREM)-1 and G-coupled-protein receptor kinase (GRK)-2 in PMNs isolated from patients was analysed to identify genes correlated with the severity of pathophysiological conditions.