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Antimicrobial Agents and Chemotherapy Oct 2020is a genus of nonfermenting Gram-negative bacteria under order Although primarily isolated from respiratory tract of people with cystic fibrosis, spp. can cause a... (Review)
Review
is a genus of nonfermenting Gram-negative bacteria under order Although primarily isolated from respiratory tract of people with cystic fibrosis, spp. can cause a broad range of infections in hosts with other underlying conditions. Their rare occurrence and ever-changing taxonomy hinder defining their clinical features, risk factors for acquisition and adverse outcomes, and optimal treatment. spp. are intrinsically resistant to several antibiotics (e.g., most cephalosporins, aztreonam, and aminoglycosides), and are increasingly acquiring resistance to carbapenems. Carbapenem resistance is mainly caused by multidrug efflux pumps and metallo-β-lactamases, which are not expected to be overcome by new β-lactamase inhibitors. Among the other new antibiotics, cefiderocol, and eravacycline were used as salvage therapy for a limited number of patients with infections. In this article, we aim to give an overview of the antimicrobial resistance in species, highlighting the possible place of new antibiotics in their treatment.
Topics: Achromobacter; Anti-Bacterial Agents; Carbapenems; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans
PubMed: 32816734
DOI: 10.1128/AAC.01025-20 -
Antimicrobial Agents and Chemotherapy Jul 2021Bacterial resistance to carbapenem agents has reached alarming levels. Accordingly, collaborative efforts between national and international organizations and the... (Review)
Review
Bacterial resistance to carbapenem agents has reached alarming levels. Accordingly, collaborative efforts between national and international organizations and the pharmaceutical industry have led to an impressive expansion of commercially available β-lactam agents in recent years. No available agent comes close to the broad range of activity afforded by cefiderocol, a novel siderophore-cephalosporin conjugate. The novelty of and need for cefiderocol are clear, but available clinical data are conflicting, leaving infectious diseases specialists puzzled as to when to prescribe this agent in clinical practice. After a brief overview of cefiderocol pharmacokinetics and pharmacodynamics, safety data, cefiderocol susceptibility testing, and putative mechanisms of cefiderocol resistance, this review focuses on determining cefiderocol's role in the management of specific pathogens, including carbapenem-resistant Acinetobacter baumannii complex, carbapenem-resistant Pseudomonas aeruginosa, carbapenem-resistant , and less commonly identified glucose-nonfermenting organisms such as Stenotrophomonas maltophilia, species, and species. Available preclinical, clinical trial, and postmarketing data are summarized for each organism, and each section concludes with our opinions on where to position cefiderocol as a clinical therapeutic.
Topics: Acinetobacter baumannii; Anti-Bacterial Agents; Cephalosporins; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Humans; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Cefiderocol
PubMed: 34031052
DOI: 10.1128/AAC.02171-20 -
Biomolecules May 2021Salicylic acid (SA) is an active secondary metabolite that occurs in bacteria, fungi, and plants. SA and its derivatives (collectively called salicylates) are... (Review)
Review
Salicylic acid (SA) is an active secondary metabolite that occurs in bacteria, fungi, and plants. SA and its derivatives (collectively called salicylates) are synthesized from chorismate (derived from shikimate pathway). SA is considered an important phytohormone that regulates various aspects of plant growth, environmental stress, and defense responses against pathogens. Besides plants, a large number of bacterial species, such as , , , , , , , and , have been reported to synthesize salicylates through the NRPS/PKS biosynthetic gene clusters. This bacterial salicylate production is often linked to the biosynthesis of small ferric-ion-chelating molecules, salicyl-derived siderophores (known as catecholate) under iron-limited conditions. Although bacteria possess entirely different biosynthetic pathways from plants, they share one common biosynthetic enzyme, isochorismate synthase, which converts chorismate to isochorismate, a common precursor for synthesizing SA. Additionally, SA in plants and bacteria can undergo several modifications to carry out their specific functions. In this review, we will systematically focus on the plant and bacterial salicylate biosynthesis and its metabolism.
Topics: Bacteria; Biosynthetic Pathways; Plant Growth Regulators; Plants; Salicylic Acid; Siderophores
PubMed: 34065121
DOI: 10.3390/biom11050705 -
Microbial Cell Factories Aug 2020Lipases are very versatile enzymes, and produced the attention of the several industrial processes. Lipase can be achieved from several sources, animal, vegetable, and... (Review)
Review
Lipases are very versatile enzymes, and produced the attention of the several industrial processes. Lipase can be achieved from several sources, animal, vegetable, and microbiological. The uses of microbial lipase market is estimated to be USD 425.0 Million in 2018 and it is projected to reach USD 590.2 Million by 2023, growing at a CAGR of 6.8% from 2018. Microbial lipases (EC 3.1.1.3) catalyze the hydrolysis of long chain triglycerides. The microbial origins of lipase enzymes are logically dynamic and proficient also have an extensive range of industrial uses with the manufacturing of altered molecules. The unique lipase (triacylglycerol acyl hydrolase) enzymes catalyzed the hydrolysis, esterification and alcoholysis reactions. Immobilization has made the use of microbial lipases accomplish its best performance and hence suitable for several reactions and need to enhance aroma to the immobilization processes. Immobilized enzymes depend on the immobilization technique and the carrier type. The choice of the carrier concerns usually the biocompatibility, chemical and thermal stability, and insolubility under reaction conditions, capability of easy rejuvenation and reusability, as well as cost proficiency. Bacillus spp., Achromobacter spp., Alcaligenes spp., Arthrobacter spp., Pseudomonos spp., of bacteria and Penicillium spp., Fusarium spp., Aspergillus spp., of fungi are screened large scale for lipase production. Lipases as multipurpose biological catalyst has given a favorable vision in meeting the needs for several industries such as biodiesel, foods and drinks, leather, textile, detergents, pharmaceuticals and medicals. This review represents a discussion on microbial sources of lipases, immobilization methods increased productivity at market profitability and reduce logistical liability on the environment and user.
Topics: Bacteria; Biotechnology; Enzymes, Immobilized; Fungi; Industrial Microbiology; Lipase
PubMed: 32847584
DOI: 10.1186/s12934-020-01428-8 -
Microbiology Spectrum Mar 2023Microbiota can influence the occurrence, development, and therapeutic response of a wide variety of cancer types by modulating immune responses to tumors. Recent studies...
Microbiota can influence the occurrence, development, and therapeutic response of a wide variety of cancer types by modulating immune responses to tumors. Recent studies have demonstrated the existence of intratumor bacteria inside ovarian cancer (OV). However, whether intratumor microbes are associated with tumor microenvironment (TME) and prognosis of OV still remains unknown. The RNA-sequencing data and clinical and survival data of 373 patients with OV in The Cancer Genome Atlas (TCGA) were collected and downloaded. According to the knowledge-based functional gene expression signatures (Fges), OV was classified into two subtypes, termed immune-enriched and immune-deficient subtypes. The immune-enriched subtype, which had higher immune infiltration enriched with CD8 T cells and the M1 type of macrophages (M1) and higher tumor mutational burden, exhibited a better prognosis. Based on the Kraken2 pipeline, the microbiome profiles were explored and found to be significantly different between the two subtypes. A prediction model consisting of 32 microbial signatures was constructed using the Cox proportional-hazard model and showed great prognostic value for OV patients. The prognostic microbial signatures were strongly associated with the hosts' immune factors. Especially, M1 was strongly associated with five species (Achromobacter deleyi and Microcella alkaliphila, sp. strain LEGU1, Ancylobacter pratisalsi, and Acinetobacter seifertii). Cell experiments demonstrated that Acinetobacter seifertii can inhibit macrophage migration. Our study demonstrated that OV could be classified into immune-enriched and immune-deficient subtypes and that the intratumoral microbiota profiles were different between the two subtypes. Furthermore, the intratumoral microbiome was closely associated with the tumor immune microenvironment and OV prognosis. Recent studies have demonstrated the existence of intratumoral microorganisms. However, the role of intratumoral microbes in the development of ovarian cancer and their interaction with the tumor microenvironment are largely unknown. Our study demonstrated that OV could be classified into immune-enriched and -deficient subtypes and that the immune enrichment subtype had a better prognosis. Microbiome analysis showed that intratumor microbiota profiles were different between the two subtypes. Furthermore, the intratumor microbiome was an independent predictor of OV prognosis that could interact with immune gene expression. Especially, M1 was closely associated with intratumoral microbes, and Acinetobacter seifertii could inhibit macrophage migration. Together, the findings of our study highlight the important roles of intratumoral microbes in the TME and prognosis of OV, paving the way for further investigation into its underlying mechanisms.
PubMed: 36975828
DOI: 10.1128/spectrum.03549-22 -
Cell Reports Aug 2023How the opportunistic Gram-negative pathogens of the genus Achromobacter interact with the innate immune system is poorly understood. Using three Achromobacter clinical...
How the opportunistic Gram-negative pathogens of the genus Achromobacter interact with the innate immune system is poorly understood. Using three Achromobacter clinical isolates from two species, we show that the type 3 secretion system (T3SS) is required to induce cell death in human macrophages by inflammasome-dependent pyroptosis. Macrophages deficient in the inflammasome sensors NLRC4 or NLRP3 undergo pyroptosis upon bacterial internalization, but those deficient in both NLRC4 and NLRP3 do not, suggesting either sensor mediates pyroptosis in a T3SS-dependent manner. Detailed analysis of the intracellular trafficking of one isolate indicates that the intracellular bacteria reside in a late phagolysosome. Using an intranasal mouse infection model, we observe that Achromobacter damages lung structure and causes severe illness, contingent on a functional T3SS. Together, we demonstrate that Achromobacter species can survive phagocytosis by promoting macrophage cell death and inflammation by redundant mechanisms of pyroptosis induction in a T3SS-dependent manner.
Topics: Humans; Animals; Mice; Pyroptosis; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Type III Secretion Systems; Achromobacter; Disease Models, Animal; Calcium-Binding Proteins; CARD Signaling Adaptor Proteins
PubMed: 37598340
DOI: 10.1016/j.celrep.2023.113012 -
Viruses Jul 2023species colonization of Cystic Fibrosis respiratory airways is an increasing concern. Two adult patients with Cystic Fibrosis colonized by CF418 or CF116 experienced...
species colonization of Cystic Fibrosis respiratory airways is an increasing concern. Two adult patients with Cystic Fibrosis colonized by CF418 or CF116 experienced fatal exacerbations. spp. are naturally resistant to several antibiotics. Therefore, phages could be valuable as therapeutics for the control of . In this study, thirteen lytic phages were isolated and characterized at the morphological and genomic levels for potential future use in phage therapy. They are presented here as the Kumeyaay phage collection. Six distinct phage genome clusters were identified based on a comprehensive phylogenetic analysis of the Kumeyaay collection as well as the publicly available phages. The infectivity of all phages in the Kumeyaay collection was tested in 23 clinical isolates; 78% of these isolates were lysed by at least one phage. A cryptic prophage was induced in CF418 when infected with some of the lytic phages. This prophage genome was characterized and is presented as phage CF418-P1. Prophage induction during lytic phage preparation for therapy interventions require further exploration. Large-scale production of phages and removal of endotoxins using an octanol-based procedure resulted in a phage concentrate of 1 × 10 plaque-forming units per milliliter with an endotoxin concentration of 65 endotoxin units per milliliter, which is below the Food and Drugs Administration recommended maximum threshold for human administration. This study provides a comprehensive framework for the isolation, bioinformatic characterization, and safe production of phages to kill spp. in order to potentially manage Cystic Fibrosis (CF) pulmonary infections.
Topics: Adult; Humans; Bacteriophages; Cystic Fibrosis; Phylogeny; Achromobacter; Achromobacter denitrificans; Prophages; Endotoxins
PubMed: 37632008
DOI: 10.3390/v15081665 -
Microbiological Research Oct 2022Bacteria belonging to the genus Achromobacter are widely distributed in natural environments and have been recognized as emerging pathogens for their contribution to a... (Review)
Review
Bacteria belonging to the genus Achromobacter are widely distributed in natural environments and have been recognized as emerging pathogens for their contribution to a wide range of human infections. In particular, patients with cystic fibrosis (CF) are the subjects most frequently colonized by Achromobacter spp., which can cause persistent infections in their respiratory tract. Although many clinical aspects and pathogenic mechanisms still remain to be elucidated, Achromobacter spp. have been a source of expanding interest in recent years. This review examines the current literature regarding Achromobacter spp. role in CF, focusing on taxonomy, prevalence in CF lung infections, genomic characteristics, and adaptation strategies including modifications of metabolism and virulence, acquisition of antibiotic resistance, exchange of mobile genetic elements and development of hypermutation.
Topics: Achromobacter; Achromobacter denitrificans; Cystic Fibrosis; Gram-Negative Bacterial Infections; Humans; Lung; Prevalence
PubMed: 35931003
DOI: 10.1016/j.micres.2022.127140 -
Microbial Genomics Jul 2021spp. are emerging pathogens in patients with cystic fibrosis (CF) and spp. caused infections are associated with more severe disease outcomes and high intrinsic...
spp. are emerging pathogens in patients with cystic fibrosis (CF) and spp. caused infections are associated with more severe disease outcomes and high intrinsic antibiotic resistance. While conventional CF pathogens are studied extensively, little is known about the genetic determinants leading to antibiotic resistance and the genetic adaptation in spp. infections. Here, we analysed 101 spp. genomes from 51 patients with CF isolated during the course of up to 20 years of infection to identify within-host adaptation, mutational signatures and genetic variation associated with increased antibiotic resistance. We found that the same regulatory and inorganic ion transport genes were frequently mutated in persisting clone types within and between species, indicating convergent genetic adaptation. Genome-wide association study of six antibiotic resistance phenotypes revealed the enrichment of associated genes involved in inorganic ion transport, transcription gene enrichment in β-lactams, and energy production and translation gene enrichment in the trimethoprim/sulfonamide group. Overall, we provide insights into the pathogenomics of spp. infections in patients with CF airways. Since emerging pathogens are increasingly recognized as an important healthcare issue, our findings on evolution of antibiotic resistance and genetic adaptation can facilitate better understanding of disease progression and how mutational changes have implications for patients with CF.
Topics: Achromobacter; Adaptation, Physiological; Cystic Fibrosis; Denmark; Disease Progression; Drug Resistance, Multiple, Bacterial; Energy Metabolism; Genome, Bacterial; Genome-Wide Association Study; Gram-Negative Bacterial Infections; Host-Pathogen Interactions; Humans; Respiratory Tract Infections
PubMed: 34232117
DOI: 10.1099/mgen.0.000582 -
Antimicrobial Agents and Chemotherapy Jul 2023We conducted antimicrobial susceptibility testing of 267 isolates for 16 antibiotics from 2017 to 2022. The highest susceptibility was found for...
We conducted antimicrobial susceptibility testing of 267 isolates for 16 antibiotics from 2017 to 2022. The highest susceptibility was found for piperacillin-tazobactam (70%) and ceftazidime-avibactam (62%). Between 30% and 49% of strains were susceptible to tigecycline, ceftazidime, and meropenem. We applied species-specific Achromobacter xylosoxidans breakpoints for piperacillin-tazobactam, meropenem, and trimethoprim-sulfamethoxazole and EUCAST pharmacokinetic/pharmacodynamic (PK/PD) breakpoints for the others. A. xylosoxidans was the most frequently isolated species, followed by Achromobacter insuavis and Achromobacter ruhlandii.
Topics: Humans; Meropenem; Cystic Fibrosis; Microbial Sensitivity Tests; Anti-Bacterial Agents; Achromobacter; Piperacillin; Tazobactam
PubMed: 37310234
DOI: 10.1128/aac.00379-23