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Virulence Dec 2022The genus consists of Gram-negative proteobacteria that are ubiquitously distributed in environment. As the members of this genus have rapidly increased within the past... (Review)
Review
The genus consists of Gram-negative proteobacteria that are ubiquitously distributed in environment. As the members of this genus have rapidly increased within the past decade, several species have become emerging pathogens worldwide, attracting the attention of the medical community. These species are also associated with severe community- and hospital-acquired infections. Patients infected with spp. had experiences of occupational or recreational exposure; meanwhile, the process of infection is complex and the pathogenicity is influenced by a variety of factors. Here, an exhaustive internet-based literature search was carried out in PUBMED using terms "," "," "" and "" to search literatures published between 1978 and June 2022. We provided a comprehensive review on the epidemiology, clinical features and pathogenicity of , which will contribute a better understanding of its clinical aetiology, and facilitate the timely diagnosis and effective treatment of infection for clinicians and public health professionals.
Topics: Cross Infection; Gram-Negative Bacterial Infections; Humans; Shewanella; Shewanella putrefaciens; Virulence
PubMed: 36065099
DOI: 10.1080/21505594.2022.2117831 -
Heliyon May 2022Drought stress is among the most destructive stresses for agricultural productivity. It interferes with normal metabolic activities of the plants resulting, a negative... (Review)
Review
Drought stress is among the most destructive stresses for agricultural productivity. It interferes with normal metabolic activities of the plants resulting, a negative impact on physiology and morphology of the plants. The management of drought stress requires various adaptive and alleviation strategies in which stress adaptive microbiomes are exquisite bioresources for plant growth and alleviation of drought stress. Diverse drought adaptive microbes belonging to genera and have been reported worldwide. These bioresources exhibit a wide range of mechanisms such as helping plant in nutrient acquisition, producing growth regulators, lowering the levels of stress ethylene, increasing the concentration of osmolytes, and preventing oxidative damage under water deficit environmental conditions. Horticulture is one of the potential agricultural sectors to speed up the economy, poverty and generation of employment for livelihood. The applications of drought adaptive plant growth promoting (PGP) microbes as biofertilizers and biopesticides for horticulture is a potential strategy to improve the productivity and protection of horticultural crops from abiotic and biotic stresses for agricultural sustainability.
PubMed: 35647359
DOI: 10.1016/j.heliyon.2022.e09493 -
Microbiology Spectrum Feb 2023The genus includes opportunistic pathogens that can cause chronic infections in immunocompromised patients, especially in people with cystic fibrosis (CF). Treatment of...
The genus includes opportunistic pathogens that can cause chronic infections in immunocompromised patients, especially in people with cystic fibrosis (CF). Treatment of infections is complicated by antimicrobial resistance. In this study, a collection of clinical isolates, from CF and non-CF sources, was investigated for polymyxin B (PmB) resistance. Additionally, the effect of PmB challenge in a subset of isolates was examined and the presence of PmB-resistant subpopulations within the isolates was described. Further, chemical and mass spectrometry analyses of the lipid A of clinical isolates enabled the determination of the most common structures and showed that PmB challenge was associated with lipid A modifications that included the addition of glucosamine and palmitoylation and the concomitant loss of the free phosphate at the C-1 position. This study demonstrates that lipid A modifications associated with PmB resistance are prevalent in and that subresistant populations displaying the addition of positively charged residues and additional acyl chains to lipid A can be selected for and isolated from PmB-sensitive clinical isolates. species can cause chronic and potentially severe infections in immunocompromised patients, especially in those with cystic fibrosis. Bacteria cannot be eradicated due to 's intrinsic multidrug resistance. We report that intrinsic resistance to polymyxin B (PmB), a last-resort antimicrobial peptide used to treat infections by multiresistant bacteria, is prevalent in clinical isolates; many isolates also display increased resistance upon PmB challenge. Analysis of the lipopolysaccharide lipid A moiety of several species reveals a penta-acylated lipid A, which in the PmB-resistant isolates was modified by the incorporation of glucosamine residues, an additional acyl chain, loss of phosphates, and hydroxylation of acyl chains, all of which can enhance PmB resistance in other bacteria. We conclude that PmB resistance, particularly in isolates from chronic respiratory infections, is a common phenomenon, and that lipid A displays modifications that may confer increased resistance to polymyxins and potentially other antimicrobial peptides.
Topics: Humans; Polymyxins; Achromobacter; Polymyxin B; Lipid A; Lipopolysaccharides; Cystic Fibrosis; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 36519943
DOI: 10.1128/spectrum.03729-22 -
Pathogens (Basel, Switzerland) Jan 2022is an opportunistic pathogen that mainly causes chronic lung infections in cystic fibrosis (CF) patients and is associated with increased mortality. Little is known...
is an opportunistic pathogen that mainly causes chronic lung infections in cystic fibrosis (CF) patients and is associated with increased mortality. Little is known about spp. in the lung transplant recipient (LTXr) population. We aimed at describing rates of spp. infection in LTXr prior to, in relation to, and after transplantation, as well as all-cause mortality proportion in infected and uninfected LTXr. We included 288 adult LTXr who underwent lung transplantation (LTX) between 1 January 2010 and 31 December 2019 in Denmark. Bronchoalveolar lavage was performed at regular intervals starting two weeks after transplantation. Positive cultures of spp. were identified in nationwide microbiology registries, and infections were categorized as persistent or transient, according to the proportion of positive cultures. A total of 11 of the 288 LTXr had transient ( = 7) or persistent ( = 4) spp. infection after LTX; CF was the underlying disease in 9 out of 11 LTXr. Three out of the four patients, with persistent infection after LTX, also had persistent infection before LTX. The cumulative incidence of the first episode of infection one year after LTX was 3.8% (95% CI: 1.6-6.0). The incidence rates of transient and persistent infection in the first year after LTX were 27 (12-53) and 15 (5-37) per 1000 person-years of follow-up, respectively. The all-cause mortality proportion one year after LTX was 27% in the spp. infected patients and 12% in the uninfected patients ( = 0.114). spp. mainly affected LTXr with CF as the underlying disease and was rare in non-CF LTXr. Larger studies are needed to assess long-term outcomes of spp. in LTXr.
PubMed: 35215124
DOI: 10.3390/pathogens11020181 -
Microbial Genomics Jul 2020Several members of the Gram-negative environmental bacterial genus are associated with serious infections, with being the most common. Despite their pathogenic...
Several members of the Gram-negative environmental bacterial genus are associated with serious infections, with being the most common. Despite their pathogenic potential, little is understood about these intrinsically drug-resistant bacteria and their role in disease, leading to suboptimal diagnosis and management. Here, we performed comparative genomics for 158 spp. genomes to robustly identify species boundaries, reassign several incorrectly speciated taxa and identify genetic sequences specific for the genus and for . Next, we developed a Black Hole Quencher probe-based duplex real-time PCR assay, Ac-Ax, for the rapid and simultaneous detection of spp. and from both purified colonies and polymicrobial clinical specimens. Ac-Ax was tested on 119 isolates identified as spp. using phenotypic or genotypic methods. In comparison to these routine diagnostic methods, the duplex assay showed superior identification of spp. and , with five isolates failing to amplify with Ac-Ax confirmed to be different genera according to 16S rRNA gene sequencing. Ac-Ax quantified both spp. and down to ~110 genome equivalents and detected down to ~12 and ~1 genome equivalent(s), respectively. Extensive analysis, and laboratory testing of 34 non- isolates and 38 adult cystic fibrosis sputa, confirmed duplex assay specificity and sensitivity. We demonstrate that the Ac-Ax duplex assay provides a robust, sensitive and cost-effective method for the simultaneous detection of all spp. and and will facilitate the rapid and accurate diagnosis of this important group of pathogens.
Topics: Achromobacter; Achromobacter denitrificans; Cystic Fibrosis; Early Diagnosis; Genomics; Gram-Negative Bacterial Infections; Humans; Multilocus Sequence Typing; Phenotype; Phylogeny; RNA, Ribosomal, 16S; Real-Time Polymerase Chain Reaction; Sequence Analysis, DNA; Sputum
PubMed: 32667877
DOI: 10.1099/mgen.0.000406 -
Access Microbiology 2023is a Gram-negative, motile, obligate aerobic and non-fermentative bacterium. It is an emerging pathogen in the hospital environment as it is frequently found in various...
INTRODUCTION
is a Gram-negative, motile, obligate aerobic and non-fermentative bacterium. It is an emerging pathogen in the hospital environment as it is frequently found in various solutions.
HYPOTHESIS/GAP STATEMENT
Information about the incidence and risk factors of bacteremia from India is limited.
AIM
We conducted this study to identify the risk factors and underlying conditions predisposing to bacteremia by spp. and analyse the antibiotic resistance pattern of the isolates.
METHODOLOGY
We performed a retrospective observational study where automated blood cultures positive for spp. were assessed for clinical characteristics and antibiotic susceptibility patterns from January 2022 to December 2022 in the microbiology laboratory of a tertiary care centre in Northern India.
RESULTS
A total of 14 cases (14/2435, 0.57 %) of spp. were identified from bloodstream infections in one year. The mean age of the patients was 37.59±23.17 years with a male predominance (8/14, 57.1 %). All patients were managed on intravenous antibiotics and intravenous access as peripheral line catheters and only 5(5/14, 35.7 %) patients were managed on central line catheters. The isolates were found highly susceptible to ticarcillin-clavulanic acid (14/14, 100.0 %) followed by fluoroquinolones (12/14, 85.72 %) and trimethoprim-sulphamethoxazole (12/14, 85.72 %). Only 57.14 % (8/14, 57.14 %) of the patients were susceptible to piperacillin-tazobactam. The all-cause 40 day mortality was observed in 35.7 % (5/14, 35.7 %) with two deaths that were directly attributable to sepsis.
CONCLUSION
This study provides insight into the incidence of bacteremia at our centre and the necessary antibiotic therapy to combat it.
PubMed: 37841106
DOI: 10.1099/acmi.0.000588.v3 -
Frontiers in Microbiology 2022genus (including , the most prevalent species in patients with cystic fibrosis) is poorly susceptible to most conventional antibiotics. Contribution of efflux by...
genus (including , the most prevalent species in patients with cystic fibrosis) is poorly susceptible to most conventional antibiotics. Contribution of efflux by AxyABM, AxyXY-OprZ, and AxyEF-OprN and of target mutations were studied in clinical isolates of and Forty-one isolates longitudinally collected from 21 patients with CF were studied by whole-genome sequencing (WGS)-typing, determination of minimum inhibitory concentrations (MICs) of β-lactams, aminoglycosides, colistin, azithromycin, ciprofloxacin, chloramphenicol, and doxycycline, and expression (quantitative RT-PCR) and function (measure of the uptake of a fluorescent substrate) of efflux pumps. WGS-based typing resulted in 10 clusters comprising 2 or 3 isolates and 20 singletons. The efflux activity was high in strains with elevated MICs for amikacin or azithromycin. This work sheds a new light on the impact of efflux and target mutations in resistance of to several drugs.
PubMed: 35418957
DOI: 10.3389/fmicb.2022.762307 -
Microbiology Spectrum Mar 2024spp. are opportunistic pathogens of environmental origin increasingly isolated in patients with underlying conditions like cystic fibrosis (CF). Despite recent...
UNLABELLED
spp. are opportunistic pathogens of environmental origin increasingly isolated in patients with underlying conditions like cystic fibrosis (CF). Despite recent advances, their virulence factors remain incompletely studied, and siderophore production has not yet been investigated in this genus. The aim of this study was to evaluate the production of siderophores in a large collection of spp. and evaluate the variability according to the origin of the strain and species. A total of 163 strains were studied, including 128 clinical strains (CF and non-CF patients) and 35 strains of environmental origin. Siderophores were quantified by the liquid chrome azurol-sulphonate assay. Species were identified by gene-based phylogeny. Strains were assigned to 20 species, with being the most represented (51.5% of strains). Siderophore production was observed in 72.4% of the strains, with amounts ranging from 10.1% to 90% siderophore units. A significantly higher prevalence of siderophore-producing strains and greater production of siderophores were observed for clinical strains compared with strains of environmental origin. Highly variable observations were made according to species: presented unique characteristics (one of the highest prevalence of producing strains and highest amounts produced, particularly by CF strains). Siderophores are important factors for bacterial growth commonly produced by members of the genus. The significance of the observations made during this study must be further investigated. Indeed, the differences observed according to species and the origin of strains suggest that siderophores may represent important determinants of the pathophysiology of spp. infections and also contribute to the particular epidemiological success of in human infections.
IMPORTANCE
spp. are recognized as emerging opportunistic pathogens in humans with various underlying diseases, including cystic fibrosis (CF). Although their pathophysiological traits are increasingly studied, their virulence factors remain incompletely described. Particularly, siderophores that represent important factors of bacterial growth have not yet been studied in this genus. A population-based study was performed to explore the ability of members of the genus to produce siderophores, both overall and in relevant subgroups ( species; strain origin, either clinical-from CF or non-CF patients-or environmental). This study provides original data showing that siderophore production is a common trait of strains, particularly observed among clinical strains. The major species, , encompassed both one of the highest prevalence of siderophore-producing strains and strains producing the largest amounts of siderophores, particularly observed for CF strains. These observations may represent additional advantages accounting for the epidemiological success of this species.
Topics: Humans; Achromobacter; Cystic Fibrosis; Prevalence; Gram-Negative Bacterial Infections; Achromobacter denitrificans; Virulence Factors; Siderophores
PubMed: 38315029
DOI: 10.1128/spectrum.02953-23 -
International Journal of Applied &... 2023causes opportunistic nosocomial infections in immunocompromised patients with high mortality. It is underreported as it is often misidentified by conventional...
BACKGROUND
causes opportunistic nosocomial infections in immunocompromised patients with high mortality. It is underreported as it is often misidentified by conventional microbiological methods.
AIMS
The aim of the study is to access the clinicomicrobiological profile and antibiogram of . from clinical isolates.
MATERIALS AND METHODS
It is an observational study done from July 2020 to December 2021 in our hospital. All nonduplicate isolates of from blood and respiratory samples were initially identified with VITEK-2 GN card system and further confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiogram and treatment outcomes were also studied.
RESULTS
. was isolated from 14 patients. Blood samples yielded most isolates (71.4%; = 10) followed by tracheal aspirate and bronchoalveolar lavage fluid. Bacteremia followed by pneumonia was the most common clinical manifestation of infection. All the isolates were identified as . and showed 100% susceptibility to minocycline and piperacillin-tazobactam. Diabetes mellitus and malignancy were the most common underlying condition in these patients. A favorable outcome was seen in 78.6% of the individuals with timely institution of antibiotics and proper diagnosis.
CONCLUSION
Infections due to are on the rise in developing countries like India. Resistance to many classes of antimicrobials makes its treatment more challenging therefore it should always be guided by antibiograms. The present study highlights the significance of this rare bacterium in patients with malignancies in India and advocates greater vigilance toward appropriate identification of this organism.
PubMed: 37614834
DOI: 10.4103/ijabmr.ijabmr_520_22 -
Frontiers in Microbiology 2022The purpose of this study was to investigate the specific alterations in gut microbiome and serum metabolome and their interactions in patients with polycystic ovary...
OBJECTIVE
The purpose of this study was to investigate the specific alterations in gut microbiome and serum metabolome and their interactions in patients with polycystic ovary syndrome (PCOS).
METHODS
The stool samples from 32 PCOS patients and 18 healthy controls underwent the intestinal microbiome analysis using shotgun metagenomics sequencing approach. Serum metabolome was analyzed by ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry. An integrative network by combining metagenomics and metabolomics datasets was constructed to explore the possible interactions between gut microbiota and circulating metabolites in PCOS, which was further assessed by fecal microbiota transplantation (FMT) in a rat trial.
RESULTS
Fecal metagenomics identified 64 microbial strains significantly differing between PCOS and healthy subjects, half of which were enriched in patients. These changed species showed an ability to perturb host metabolic homeostasis (including insulin resistance and fatty acid metabolism) and inflammatory levels (such as PI3K/Akt/mTOR signaling pathways) by expressing sterol regulatory element-binding transcription factor-1, serine/threonine-protein kinase mTOR, and 3-oxoacyl-[acyl-cattier-protein] synthase III, possibly suggesting the potential mechanisms of gut microbiota underlying PCOS. By integrating multi-omics datasets, the panel comprising seven strains (, sp. M1, , sp. HL-46, , sp. ANG-Vp, and ) and three metabolites [ganglioside GM3 (d18:0/16:0), ceramide (d16:2/22:0), and 3Z,6Z,9Z-pentacosatriene] showed the highest predictivity of PCOS (AUC: 1.0) with sensitivity of 0.97 and specificity of 1.0. Moreover, the intestinal microbiome modifications by FMT were demonstrated to regulate PCOS phenotypes including metabolic variables and reproductive hormones.
CONCLUSION
Our findings revealed key microbial and metabolite features and their interactions underlying PCOS by integrating multi-omics approaches, which may provide novel insights into discovering clinical diagnostic biomarkers and developing efficient therapeutic strategies for PCOS.
PubMed: 36338055
DOI: 10.3389/fmicb.2022.1017147