Publications by authors named "Shigeru Tansho-Nagakawa"

Objectives: The third-generation cephalosporin (3GC)-resistant strains have been detected worldwide in humans and animals. Hence, in this study, we evaluated the prevalence and genetic characteristics of 3GC-resistant in livestock, farmers, and patients to further analyse if livestock serves as a potential reservoir of antimicrobial-resistant bacteria.

Methods: Faecal samples were collected from 330 healthy livestock (216 cattle and 114 swine), 61 healthy livestock farmers (52 cattle farmers and 9 swine farmers), and 68 non-duplicate 3GC-resistant isolates were also obtained from the clinical specimens of patients in Japan between 2013 and 2015.

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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.

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Article Synopsis
  • The study focused on analyzing lung infections in mice caused by different strains of a pathogen known for causing severe lung infections, comparing two strains (ATCC 19606 and TK1090) with a more virulent strain (PAO-1).
  • Results showed that mice infected with ATCC 19606 and TK1090 had lower mortality rates than those infected with PAO-1, but all strains led to significant immune cell accumulation in the lungs.
  • The findings indicate that while immune cells infiltrate the lungs following infection, the pathogen remains present, suggesting ongoing inflammation and the need for further research to develop effective treatments and vaccines.
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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.

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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.

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Article Synopsis
  • Nosocomial infections caused by multidrug-resistant bacteria pose significant health risks, with colistin being a key treatment targeting lipopolysaccharides (LPS).
  • However, these bacteria can develop resistance to colistin by losing their LPS, which affects their virulence and interaction with host immune cells.
  • Research shows that neutrophils can still effectively kill LPS-deficient strains of bacteria, primarily using the enzyme lysozyme, offering insights for developing therapies against drug-resistant infections, especially in immunocompromised patients.
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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.

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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.

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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.

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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.

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Hydrosol prepared from the flowers of Rosa damascena (rose water) has been traditionally used for various health-related issues, including skin troubles such as erythema, itchiness, swelling. For the care of these skin troubles caused by microbial infection, both antimicrobial and antiinflammatory effects are required. Here, we investigated the effects of rose water on the growth of Candida albicans and methicillin-resistant Staphylococcus aureus (MRSA), which cause skin infections, and on the function of neutrophils, which play a major role in the regulation of inflammatory reactions.

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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.

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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.

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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.

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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.

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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.

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We developed a PCR-RFLP assay to detect mutations in the quinolone-resistance determining regions of gyrA and parC associated with fluoroquinolone resistance in Enterobacteriaceae. The assay detected mutations associated with reduced susceptibility to fluoroquinolones and may therefore serve as a specific, rapid, inexpensive, and simple testing alternative.

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The aim of the present study was to assess changes of cell membrane antigens on neutrophils in septic patients. Expression levels of neutrophil membrane antigens were measured employing a FACS calibur flow cytometer with several fluorescence-labeled monoclonal antibodies. Expression levels of the CD14 antigen were higher in patients with sepsis than in healthy individuals.

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