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Microbes and Infection Jun 2003About 25% of humans with chronic gastritis are negative for Helicobacter pylori, suggesting that other bacteria are capable of causing inflammation. Bacterial overgrowth... (Review)
Review
About 25% of humans with chronic gastritis are negative for Helicobacter pylori, suggesting that other bacteria are capable of causing inflammation. Bacterial overgrowth may occur in the stomach under conditions of reduced acid secretion. In this review, we will explore what is generally known about non-H. pylori organisms and their ability to induce gastritis, with particular focus on Acinetobacter lwoffi.
Topics: Acinetobacter; Acinetobacter Infections; Gastric Mucosa; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Models, Biological; Virulence Factors
PubMed: 12787741
DOI: 10.1016/s1286-4579(03)00099-6 -
Clinical and Experimental Allergy :... Apr 2022Although lung macrophages are directly exposed to external stimuli, their exact immunologic roles in asthma are still largely unknown. The aim of this study was to...
BACKGROUND
Although lung macrophages are directly exposed to external stimuli, their exact immunologic roles in asthma are still largely unknown. The aim of this study was to investigate the anti-asthmatic effect of Acinetobacter lwoffii in terms of lung macrophage modulation.
METHODS
Six-week-old female BALB/c mice were sensitized and challenged with ovalbumin (OVA) with or without intranasal administration of A. lwoffii during the sensitization period. Airway hyperresponsiveness and inflammation were evaluated. Using flow cytometry, macrophages were subclassified according to their activation status. In the in vitro study, a murine alveolar macrophage cell line (MH-S) treated with or without A. lwoffii before IL-13 stimulation were analysed by quantitative RT-PCR.
RESULTS
In a murine asthma model, the number of inflammatory cells, including macrophages and eosinophils, decreased in mice treated with A. lwoffii (A. lwoffii/OVA group) compared with untreated mice (OVA group). The enhanced expression of MHCII in macrophages in the OVA group was decreased by A. lwoffii treatment. M2 macrophage subtypes were significantly altered. A. lwoffii treatment decreased CD11b M2a and CD11b M2c macrophages, which showed strong positive correlations with Th2 cells, ILC2 and eosinophils. In contrast, CD11b M2b macrophages were significantly increased by A. lwoffii treatment and showed strong positive correlations with ILC1 and ILC3. In vitro, A. lwoffii down-regulated the expression of M2 markers related but up-regulated those related to M2b macrophages.
CONCLUSIONS AND CLINICAL RELEVANCE
Intranasal A. lwoffii exposure suppresses asthma development by suppressing the type 2 response via modulating lung macrophage activation, shifting M2a and M2c macrophages to M2b macrophages.
Topics: Acinetobacter; Animals; Asthma; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Female; Humans; Immunity, Innate; Inflammation; Lung; Lymphocytes; Macrophage Activation; Mice; Mice, Inbred BALB C; Ovalbumin
PubMed: 34874580
DOI: 10.1111/cea.14077 -
Nature Immunology Oct 2019The revolution in microbiota research over the past decade has provided invaluable knowledge about the function of the microbial species that inhabit the human body. It... (Review)
Review
The revolution in microbiota research over the past decade has provided invaluable knowledge about the function of the microbial species that inhabit the human body. It has become widely accepted that these microorganisms, collectively called 'the microbiota', engage in networks of interactions with each other and with the host that aim to benefit both the microbial members and the mammalian members of this unique ecosystem. The lungs, previously thought to be sterile, are now known to harbor a unique microbiota and, additionally, to be influenced by microbial signals from distal body sites, such as the intestine. Here we review the role of the lung and gut microbiotas in respiratory health and disease and highlight the main pathways of communication that underlie the gut-lung axis.
Topics: Acinetobacter; Animals; Bifidobacterium; Dietary Supplements; Female; Gastrointestinal Microbiome; Host-Pathogen Interactions; Humans; Lactobacillus; Lung; Lung Diseases; Maternal Exposure; Microbiota; Pregnancy; Probiotics
PubMed: 31501577
DOI: 10.1038/s41590-019-0451-9 -
Infectious Disorders Drug Targets 2015Acinetobacter species are ubiquitous in the environment and are important causative agent for nososcomial infection especially in immunocompromised patients. Multi drug...
BACKGROUND
Acinetobacter species are ubiquitous in the environment and are important causative agent for nososcomial infection especially in immunocompromised patients. Multi drug resistant Acinetobacter lwoffii are emerging as a pathogen in neoanatal sepsis.
AIMS AND OBJECTIVE
This study was aimed to evaluate the clinical and antibiotic profile of Acinetobacter lwoffii.
MATERIAL AND METHODS
This study was done on blood samples from neonates admitted to neonatal intensive care unit during a period of one year from January to December 2012, who developed Acinetobacter infection. The diagnosis of isolates and antibiotic susceptibility testing was done by both conventional as well as by automated system.
RESULTS
Out of total 13,133 blood samples received for culture, 1418(10.8%) were from NICU. Ninety (6.3%) isolates were found to be positive for the growth of Acinetobacter species. Of these isolates 31.11% were found to be Acinetobacter lwoffii, 68.9% were Acinetobacter baumannii calcaetius complex. Acinetobacter lwoffii isolates were most commonly sensitive to imepenem 16(57%), cotrimoxazole 9(32%), ciprofloxacin 6(21%) followed by amoxyclavulanic acid 2(7%) and cefuroxime 1(3.5%).
CONCLUSION
Multi drug resistant Acinetobacter lwoffii infection is increasing particularly in premature and very low-birth weight neonates. Judicious and timely antibiotic use in NICUs are one of the important key in controlling multi-drug resistant Acinetobacter infection and improving clinical outcome.
Topics: Acinetobacter; Acinetobacter Infections; Acinetobacter baumannii; Anti-Bacterial Agents; Blood; Child; Communicable Diseases, Emerging; Cross Infection; Drug Resistance, Multiple, Bacterial; Humans; India; Infant, Newborn; Intensive Care Units, Neonatal; Male; Microbial Sensitivity Tests; Sepsis
PubMed: 26307173
DOI: 10.2174/1871526515666150826114745 -
Transboundary and Emerging Diseases Dec 2018Acinetobacter lwoffii, a serious human pathogen, has been identified as a cause of nosocomial infections such as bacteremia, pneumonia and meningitis. There are only a...
Acinetobacter lwoffii, a serious human pathogen, has been identified as a cause of nosocomial infections such as bacteremia, pneumonia and meningitis. There are only a few studies reporting A. lwoffii as a pathogen of fish. During 2016 and 2017, six bacterial strains, isolated from diseased fish of the Schizothorax genus, were identified as A. lwoffii by morphology, biochemical tests, 16S rDNA and gyrB gene sequencing analysis. One of these isolates was selected for experimental infection of Sclizothorax prenanti, Schizothorax davidi and Schizothorax wangchiachii, to confirm its pathogenicity. Experimentally infected fish showed similar symptoms to those observed in fish after natural outbreaks. Susceptibility of the isolates to 14 antibiotics was tested using a disc diffusion method; all isolates were resistant to cephalothin, aminoglycosides and β-lactams, and sensitive only to some fluoroquinolones and tetracyclines. Histological examination revealed that A. lwoffii infection could cause pathological lesions in multiple organs and tissues, especially in liver, kidney, spleen and heart. These lesions included extensive haemorrhage, vacuolar degeneration, necrosis and inflammatory cell infiltration. To our knowledge, this is the first report on A. lwoffii as a virulent pathogen for fish of the Schizothorax genus.
Topics: Acinetobacter; Acinetobacter Infections; Animals; Anti-Bacterial Agents; China; Communicable Diseases, Emerging; DNA Gyrase; Drug Resistance, Multiple, Bacterial; Fish Diseases; Fishes; RNA, Ribosomal, 16S; Sequence Analysis
PubMed: 30239149
DOI: 10.1111/tbed.12957 -
Allergy May 2023Early-life exposure to certain environmental bacteria including Acinetobacter lwoffii (AL) has been implicated in protection from chronic inflammatory diseases including...
BACKGROUND
Early-life exposure to certain environmental bacteria including Acinetobacter lwoffii (AL) has been implicated in protection from chronic inflammatory diseases including asthma later in life. However, the underlying mechanisms at the immune-microbe interface remain largely unknown.
METHODS
The effects of repeated intranasal AL exposure on local and systemic innate immune responses were investigated in wild-type and Il6 , Il10 , and Il17 mice exposed to ovalbumin-induced allergic airway inflammation. Those investigations were expanded by microbiome analyses. To assess for AL-associated changes in gene expression, the picture arising from animal data was supplemented by in vitro experiments of macrophage and T-cell responses, yielding expression and epigenetic data.
RESULTS
The asthma preventive effect of AL was confirmed in the lung. Repeated intranasal AL administration triggered a proinflammatory immune response particularly characterized by elevated levels of IL-6, and consequently, IL-6 induced IL-10 production in CD4 T-cells. Both IL-6 and IL-10, but not IL-17, were required for asthma protection. AL had a profound impact on the gene regulatory landscape of CD4 T-cells which could be largely recapitulated by recombinant IL-6. AL administration also induced marked changes in the gastrointestinal microbiome but not in the lung microbiome. By comparing the effects on the microbiota according to mouse genotype and AL-treatment status, we have identified microbial taxa that were associated with either disease protection or activity.
CONCLUSION
These experiments provide a novel mechanism of Acinetobacter lwoffii-induced asthma protection operating through IL-6-mediated epigenetic activation of IL-10 production and with associated effects on the intestinal microbiome.
Topics: Animals; Mice; Interleukin-10; Administration, Intranasal; Interleukin-6; Disease Models, Animal; Asthma; Lung; Inflammation; Microbiota; Mice, Inbred BALB C; Ovalbumin
PubMed: 36458896
DOI: 10.1111/all.15606 -
Indian Journal of Medical Microbiology Jan 2021Many pathogenic organisms do produce different types of the pigments, helpful in the presumptive laboratory diagnosis of the microorganisms. These pigments are...
Many pathogenic organisms do produce different types of the pigments, helpful in the presumptive laboratory diagnosis of the microorganisms. These pigments are malevolent as well as benevolent to the mankind. Most of the time, the pigmented organisms do display resistance to the many classes of the drugs in vitro and in vivo. Most of Acinetobacter sp are nonpigmented. Few strains produce diffusible brown pigment and rarely produce black and indigo coloured pigments (Liu1 and Nizet, 2009; Nosanchuk and Casadevall, 2003; Moazamian et al., 2018; Saviola, 2018; Saviola, 2014; Kirti et al., 2014; German et al., 2018; Coelho-Souza et al., 2014) [1-8]. This is the first Indian human case report is of "The Viridescent Acinetobacter lwoffii" (dark green pigmented) isolated from the central line blood culture which was susceptible to the many classes of the drugs in vitro and correlated well with in vivo compliance.
Topics: Acinetobacter; Acinetobacter Infections; Humans; India; Pigmentation
PubMed: 33610246
DOI: 10.1016/j.ijmmb.2020.09.001 -
Biology Sep 2021Microbial life can be supported at subzero temperatures in permafrost up to several million years old. Genome analysis of strains isolated from permafrost provides a...
Genome Analysis of Strains Isolated from Permafrost Soils Aged from 15 Thousand to 1.8 Million Years Revealed Their Close Relationships with Present-Day Environmental and Clinical Isolates.
Microbial life can be supported at subzero temperatures in permafrost up to several million years old. Genome analysis of strains isolated from permafrost provides a unique opportunity to study microorganisms that have not previously come into contact with the human population. is a typical soil bacterium that has been increasingly reported as hospital pathogens associated with bacteremia. In order to identify the specific genetic characteristics of ancient permafrost-conserved strains of and their differences from present-day clinical isolates, we carried out a genome-wide analysis of five strains of isolated from permafrost aged from 15 thousand to 1.8 million years. Surprisingly, we did not identify chromosomal genetic determinants that distinguish permafrost strains from clinical isolates and strains from other natural habitats. Phylogenetic analysis based on whole genome sequences showed that permafrost strains do not form a separate cluster and some of them are most closely related to clinical isolates. The genomes of clinical and permafrost strains contain similar mobile elements and prophages, which indicates an intense horizontal transfer of genetic material. Comparison of plasmids of modern and permafrost strains showed that plasmids from the modern strains are enriched with antibiotic resistance genes, while the content of genes for resistance to heavy metals and arsenic is nearly the same. The thawing of permafrost caused by global warming could release new potentially pathogenic strains of .
PubMed: 34571748
DOI: 10.3390/biology10090871 -
Fukushima Journal of Medical Science Nov 2023The incidence of Acinetobacter infections has increased in recent years. Acinetobacter infections are resistant to most antibiotics and can be found in hospitalized...
The incidence of Acinetobacter infections has increased in recent years. Acinetobacter infections are resistant to most antibiotics and can be found in hospitalized patients. Pregnancies complicated by severe sepsis or septic shock are associated with a higher rate of preterm labor and delivery, fetal infection, and operative delivery. This case report describes septic shock due to Acinetobacter lwoffii infection in the 31st week of gestation. A 47-year-old woman, with a gestation of 31 weeks and one day, presented with a fever, and signs of bacterial infection on laboratory tests. Although the patient was started on tazobactam/piperacillin, she went into septic shock, and was transferred to our hospital. Cesarean section was performed at a gestation of 31 weeks and 4 days because of severe maternal pneumonia and non-reassuring fetal status. A. lwoffii was detected in blood cultures collected at the previous hospital, and susceptibility to piperacillin and meropenem to A. lwoffii was confirmed. The pneumonia responded to antibiotic treatment and there were no findings of infection in the neonate. Maternal sepsis is an infrequent but important complication, causing significant maternal and fetal morbidity and fetal and neonatal mortality; therefore, early antibiotic therapy is required to improve the clinical outcome.
Topics: Infant, Newborn; Humans; Pregnancy; Female; Middle Aged; Shock, Septic; Acinetobacter Infections; Cesarean Section; Anti-Bacterial Agents; Piperacillin; Pneumonia
PubMed: 37766560
DOI: 10.5387/fms.2022-43 -
Gut Sep 2020is associated with gastric inflammation, precancerous gastric atrophy (GA) and intestinal metaplasia (IM). We aimed to identify microbes that are associated with... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
is associated with gastric inflammation, precancerous gastric atrophy (GA) and intestinal metaplasia (IM). We aimed to identify microbes that are associated with progressive inflammation, GA and IM 1 year after eradication.
DESIGN
A total of 587 -positive patients were randomised to receive eradication therapy (295 patients) or placebo (292 patients). Bacterial taxonomy was analysed on 404 gastric biopsy samples comprising 102 pairs before and after 1 year eradication and 100 pairs before and after 1 year placebo by 16S rRNA sequencing.
RESULTS
Analysis of microbial sequences confirmed the eradication of in treated group after 1 year. Principal component analysis revealed distinct microbial clusters reflected by increase in bacterial diversity (p<0.00001) after eradication. While microbial interactions remained largely unchanged after placebo treatment, microbial co-occurrence was less in treated group. , and were enriched while and were depleted in patients with persistent inflammation 1 year after eradication. A distinct cluster of oral bacteria comprising , , , and were associated with emergence and persistence of GA and IM. Probiotic was depleted in subjects who developed GA following eradication. Functional pathways including amino acid metabolism and inositol phosphate metabolism were enriched while folate biosynthesis and NOD-like receptor signalling decreased in atrophy/IM-associated gastric microbiota.
CONCLUSION
This study identified that gastric microbes contribute to the progression of gastric carcinogenesis after eradication.
Topics: Bacteria; Biopsy; Carcinogenesis; Disease Eradication; Disease Progression; Female; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Metaplasia; Microbial Interactions; Middle Aged; Sequence Analysis, RNA; Stomach
PubMed: 31974133
DOI: 10.1136/gutjnl-2019-319826