scholarly journals Identifying the essential genes of Mycobacterium avium subsp. hominissuis with Tn-Seq using a rank-based filter procedure

2019 ◽  
Author(s):  
William M. Matern ◽  
Robert L. Jenquin ◽  
Joel S. Bader ◽  
Petros C. Karakousis
Keyword(s):  
Mycobacterium Avium ◽  
Genetic Manipulation ◽  
Laboratory Strain ◽  
New Drugs ◽  
Mycobacterium Avium Subsp ◽  
Growth Defect ◽  
Future Research ◽  
Computational Technique ◽  
Curative Therapy

AbstractMycobacterium avium (Mav) is increasingly recognized as a significant cause of morbidity, particularly in elderly patients or those with immune deficiency or underlying structural lung disease. Generally, Mav infection is treated with 2-3 antimicrobial drugs for at least 12 months. Identification of genes essential for Mav growth may yield novel strategies for improving curative therapy. We have generated saturating genome-wide transposon mutant pools in a commonly used laboratory strain of Mycobacterium avium subsp. hominissuis (MAC109) and developed a computational technique for classifying annotated genomic features as essential (ES), growth defect (GD), growth advantage (GA), or no-effect (NE) based on the in vitro effect of disruption by transposon. We identified 270 features as ES with 230 of these overlapping with ES features in Mycobacterium tuberculosis. These results may be useful for identifying drug targets or for informing studies requiring genetic manipulation of Mycobacterium avium, which should seek to avoid disrupting ES features to ensure bacterial viability.ImportanceMycobacterium avium subsp. hominissuis is an emerging cause of morbidity in vulnerable populations in many countries. It is known to be particularly difficult to treat, often requiring years of antibiotic therapy. In this study we report the genes of Mycobacterium avium subsp. hominissuis that are required for the organism to grow in vitro. Our findings may help guide future research into identifying new drugs to improve the treatment of this serious infection.

scholarly journals Foeniculum vulgareMill: A Review of Its Botany, Phytochemistry, Pharmacology, Contemporary Application, and Toxicology

2014 ◽  
Vol 2014 ◽  
pp. 1-32 ◽  
Author(s):  
Shamkant B. Badgujar ◽  
Vainav V. Patel ◽  
Atmaram H. Bandivdekar
Keyword(s):  
Traditional Medicine ◽  
Scientific Evidence ◽  
New Drugs ◽  
Future Research ◽  
Foeniculum Vulgare ◽  
Wide Range ◽  
Research Findings ◽  
Valuable Compounds

Foeniculum vulgareMill commonly called fennel has been used in traditional medicine for a wide range of ailments related to digestive, endocrine, reproductive, and respiratory systems. Additionally, it is also used as a galactagogue agent for lactating mothers. The review aims to gather the fragmented information available in the literature regarding morphology, ethnomedicinal applications, phytochemistry, pharmacology, and toxicology ofFoeniculum vulgare. It also compiles available scientific evidence for the ethnobotanical claims and to identify gaps required to be filled by future research. Findings based on their traditional uses and scientific evaluation indicates thatFoeniculum vulgareremains to be the most widely used herbal plant. It has been used for more than forty types of disorders. Phytochemical studies have shown the presence of numerous valuable compounds, such as volatile compounds, flavonoids, phenolic compounds, fatty acids, and amino acids. Compiled data indicate their efficacy in severalin vitroandin vivopharmacological properties such as antimicrobial, antiviral, anti-inflammatory, antimutagenic, antinociceptive, antipyretic, antispasmodic, antithrombotic, apoptotic, cardiovascular, chemomodulatory, antitumor, hepatoprotective, hypoglycemic, hypolipidemic, and memory enhancing property.Foeniculum vulgarehas emerged as a good source of traditional medicine and it provides a noteworthy basis in pharmaceutical biology for the development/formulation of new drugs and future clinical uses.

scholarly journals Based on Principles and Insights of COVID-19 Epidemiology, Genome Sequencing, and Pathogenesis: Retrospective Analysis of Sinigrin and ProlixinRX (Fluphenazine) Provides Off-Label Drug Candidates

2020 ◽  
Vol 25 (10) ◽  
pp. 1123-1140
Author(s):  
Jilan Nazeam ◽  
Esraa Z. Mohammed ◽  
Mariam Raafat ◽  
Mariam Houssein ◽  
Asmaa Elkafoury ◽  
...  
Keyword(s):  
Natural Products ◽  
Evidence Synthesis ◽  
Drug Repurposing ◽  
New Drugs ◽  
Future Research ◽  
Nitrogenous Compounds ◽  
Future Research Agenda ◽  
Starting Point

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of pandemic coronavirus disease 2019 (COVID-19). So far, no approved therapy has been developed to halt the spread of the pathogen, and unfortunately, the strategies for developing a new therapy will require a long time and very extensive resources. Therefore, drug repurposing has emerged as an ideal strategy toward a smart, versatile, quick way to confine the lethal disease. In this endeavor, natural products have been an untapped source for new drugs. This review represents the confederated experience of multidisciplinary researchers of 99 articles using several databases: Google Scholar, Science Direct, MEDLINE, Web of Science, Scopus, and PubMed. To establish the hypothesis, a Bayesian perspective of a systematic review was used to outline evidence synthesis. Our docking documentation of 69 compounds and future research agenda assumptions were directed toward finding an effective and economic anti-COVID-19 treatment from natural products. Glucosinolate, flavones, and sulfated nitrogenous compounds demonstrate direct anti-SARS-CoV-2 activity through inhibition protease enzymes and may be considered potential candidates against coronavirus. These findings could be a starting point to initiate an integrative study that may encompass interested scientists and research institutes to test the hypothesis in vitro, in vivo, and in clinics after satisfying all ethical requirements.

scholarly journals Comparative Study of the Anti-Human Cytomegalovirus Activities and Toxicities of a Tetrahydrofuran Phosphonate Analogue of Guanosine and Cidofovir

1999 ◽  
Vol 43 (3) ◽  
pp. 557-567 ◽  
Author(s):  
Jean Bedard ◽  
Suzanne May ◽  
Martin Lis ◽  
Leander Tryphonas ◽  
John Drach ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Guinea Pigs ◽  
Laboratory Strain ◽  
Drug Regimen ◽  
New Drugs ◽  
Murine Cytomegalovirus ◽  
Mcmv Infection ◽  
Drug Induced ◽  
Nuclear Modifications

ABSTRACT Cidofovir is the first nucleoside monophosphate analogue currently being used for the treatment of human cytomegalovirus (HCMV) retinitis in individuals with AIDS. Unfortunately, the period of therapy with the use of this compound may be limited due to the possible emergence of serious irreversible nephrotoxic effects. New drugs with improved toxicity profiles are needed. The goal of this study was to investigate the anticytomegaloviral properties and drug-induced toxicity of a novel phosphonate analogue, namely, (−)-2-(R)-dihydroxyphosphinoyl-5-(S)-(guanin-9′-yl-methyl) tetrahydrofuran (compound 1), in comparison with those of cidofovir. The inhibitory activities of both compounds on HCMV propagation in vitro were similar against the AD 169 and Towne strains, with 50% inhibitory concentrations ranging from 0.02 to 0.17 μg/ml for cidofovir and <0.05 to 0.09 μg/ml for compound 1. A clinical HCMV isolate that was resistant to ganciclovir and that had a known mutation within the UL54 DNA polymerase gene and a cidofovir-resistant laboratory strain derived from strain AD 169 remained sensitive to compound 1, whereas their susceptibilities to ganciclovir and cidofovir were reduced by 33- and 10-fold, respectively. Both compound 1 and cidofovir exhibited equal potencies in an experimentally induced murine cytomegalovirus (MCMV) infection in mice, with a prevention or prolongation of mean day to death at dosages of 1.0, 3.2, and 10.0 mg/kg of body weight/day. In cytotoxicity experiments, compound 1 was found to be generally more toxic than cidofovir in cell lines Hs68, HFF, and 3T3-L1 (which are permissive for HCMV or MCMV replication) but less toxic than cidofovir in MRC-5 cells (which are permissive for HCMV replication). Drug-induced toxic side effects were noticed for both compounds in rats and guinea pigs in a 5-day repeated-dose study. In guinea pigs, a greater weight loss was noticed with cidofovir than with compound 1 at dosages of 3.0 and 10.0 mg/kg/day. An opposite effect was detected in rats, which were treated with the compounds at relatively high dosages (up to 100 mg/kg/day). Compound 1 and cidofovir were nephrotoxic in both rats and guinea pigs, with the epithelium lining the proximal convoluted tubules in the renal cortex being the primary target site. The incidence and the severity of the lesions were found to be dose dependent. The lesions observed were characterized by cytoplasm degeneration and nuclear modifications such as karyomegaly, the presence of pseudoinclusions, apoptosis, and degenerative changes. In the guinea pig model, a greater incidence and severity of lesions were observed for cidofovir than for compound 1 (P < 0.001) with a drug regimen of 10 mg/kg/day.

scholarly journals Enterohemorrhagic Escherichia coli O157:H7 gal Mutants Are Sensitive to Bacteriophage P1 and Defective in Intestinal Colonization

2006 ◽  
Vol 75 (4) ◽  
pp. 1661-1666 ◽  
Author(s):  
Theresa Deland Ho ◽  
Matthew K. Waldor
Keyword(s):  
Escherichia Coli ◽  
Genetic Manipulation ◽  
Enterohemorrhagic Escherichia Coli ◽  
Deletion Strain ◽  
Growth Defect ◽  
Intestinal Colonization ◽  
Wild Type ◽  
E Coli ◽  
O Antigen

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC), especially E. coli O157:H7, is an emerging cause of food-borne illness. Unfortunately, E. coli O157 cannot be genetically manipulated using the generalized transducing phage P1, presumably because its extensive O antigen obscures the P1 receptor, the lipopolysaccharide (LPS) core subunit. The GalE, GalT, GalK, and GalU proteins are necessary for modifying galactose before it can be assembled into the repeating subunit of the O antigen. Here, we constructed E. coli O157:H7 gal mutants which presumably have little or no O antigen. These strains were able to adsorb P1. P1 lysates grown on the gal mutant strains could be used to move chromosomal markers between EHEC strains, thereby facilitating genetic manipulation of E. coli O157:H7. The gal mutants could easily be reverted to a wild-type Gal+ strain using P1 transduction. We found that the O157:H7 galETKM::aad-7 deletion strain was 500-fold less able to colonize the infant rabbit intestine than the isogenic Gal+ parent, although it displayed no growth defect in vitro. Furthermore, in vivo a Gal+ revertant of this mutant outcompeted the galETKM deletion strain to an extent similar to that of the wild type. This suggests that the O157 O antigen is an important intestinal colonization factor. Compared to the wild type, EHEC gal mutants were 100-fold more sensitive to a peptide derived from bactericidal permeability-increasing protein, a bactericidal protein found on the surface of intestinal epithelial cells. Thus, one way in which the O157 O antigen may contribute to EHEC intestinal colonization is to promote resistance to host-derived antimicrobial polypeptides.

Controversies in the Management of Mycobacterium Avium Complex Infection in AIDS Patients

1993 ◽  
Vol 27 (7-8) ◽  
pp. 928-937 ◽  
Author(s):  
Charles A. Peloquin
Keyword(s):  
Mouse Models ◽  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Susceptibility Testing ◽  
Traditional Approach ◽  
Clinical Manifestations ◽  
Future Research ◽  
General Description ◽  
Aids Patients

OBJECTIVE: To update readers on the clinical management of infections secondary to Mycobacterium avium complex (MAC) in patients with AIDS. A general description of the organism, culture and susceptibility testing, and clinical manifestations of the disease is provided. Several aspects of the treatment of the disease, including an historical perspective, current approaches, and future research opportunities, are described. DATA SOURCES: Current medical literature, including abstracts presented at international meetings, is reviewed. References were identified through MEDLINE, Current Contents, and published meeting abstracts. STUDY SELECTION: Data regarding the epidemiology, clinical manifestations, culture and susceptibility testing, and treatment of MAC are cited. Specific attention is given to the management of patients with MAC infection. DATA EXTRACTION: Information contributing to the discussion of the topics selected by the author is reviewed. Data supporting and disputing specific conclusions are presented. DATA SYNTHESIS: Disseminated MAC infection is diagnosed antemortem in approximately 30 percent of patients with AIDS; postmortem rates of isolation exceed 50 percent. The incidence of MAC may increase as attempts at isolating the organism become more aggressive. The traditional approach to the isolation, susceptibility testing, and treatment of MAC has been derived from the management of Mycobacterium tuberculosis, with disappointing results. Newer radiometric in vitro methods of susceptibility testing appear to show more promise. Current mouse models of MAC are not true AIDS models; new CD4-deficient mouse models are being developed. Clinical mycobacteriologic and pharmacokinetic laboratory support have been underused, with treatment generally proceeding empirically. New agents that may contribute to the management of disseminated MAC infection include the macrolide derivatives clarithromycin and azithromycin. Research also continues with new rifamycins (including rifabutin) and fluoroquinolones (ciprofloxacin, sparfloxacin). Preliminary results suggest a central role for macrolides in the treatment of disseminated MAC; effective companion drugs are needed to prevent the rapid emergence of macrolide-resistant MAC. CONCLUSIONS: Treatment results for disseminated MAC infection remain poor. Therapy may be improved by selecting drugs on the basis of susceptibility data for each isolate, rather than by using empiric regimens based on susceptibility trends. Significant antimycobacterial drug malabsorption has been documented, and may contribute to poor outcomes. More-potent agents are needed to improve the clinical outcome in AIDS patients with MAC.

scholarly journals Mycobacterium avium Subsp. avium and Subsp. hominissuis Give Different Cytokine Responses after in vitro Stimulation of Human Blood Mononuclear Cells

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e34391 ◽  
Author(s):  
Johanna Thegerström ◽  
Bodil Jönsson ◽  
Lars Brudin ◽  
Björn Olsen ◽  
Agnes E. Wold ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Human Blood ◽  
Mononuclear Cells ◽  
Mycobacterium Avium Subsp ◽  
Cytokine Responses ◽  
Blood Mononuclear Cells ◽  
Stimulation Of

scholarly journals Short-Chain Fatty Acids Promote Mycobacterium avium subsp. hominissuis Growth in Nutrient-Limited Environments and Influence Susceptibility to Antibiotics

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 700
Author(s):  
Carlos Adriano de Matos e Silva ◽  
Rajoana Rojony ◽  
Luiz E. Bermudez ◽  
Lia Danelishvili
Keyword(s):  
Mycobacterium Avium ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Mycobacterium Avium Subsp ◽  
Intracellular Pathogen ◽  
Pulmonary Infections ◽  
Chronic Lung Diseases ◽  
Metabolic Remodeling ◽  
Antibiotic Efficacy

Mycobacterium avium subsp. hominissuis (MAH) is a common intracellular pathogen that infects immunocompromised individuals and patients with pre-existing chronic lung diseases, such as cystic fibrosis, who develop chronic and persistent pulmonary infections. The metabolic remodeling of MAH in response to host environmental stresses or within biofilms formed in bronchial airways plays an important role in development of the persistence phenotype contributing to the pathogen’s tolerance to antibiotic treatment. Recent studies suggest a direct relationship between bacterial metabolic state and antimicrobial susceptibility, and improved antibiotic efficacy has been associated with the enhanced metabolism in bacteria. In the current study, we tested approximately 200 exogenous carbon source-dependent metabolites and identified short-chain fatty acid (SCFA) substrates (propionic, butyric and caproic acids) that MAH can utilize in different physiological states. Selected SCFA enhanced MAH metabolic activity in planktonic and sessile states as well as in the static and established biofilms during nutrient-limited condition. The increased bacterial growth was observed in all conditions except in established biofilms. We also evaluated the influence of SCFA on MAH susceptibility to clinically used antibiotics in established biofilms and during infection of macrophages and found significant reduction in viable bacterial counts in vitro and in cultured macrophages, suggesting improved antibiotic effectiveness against persistent forms of MAH.

scholarly journals In vitro inactivation of Mycobacterium avium subsp. paratuberculosis (MAP) by use of copper ions

2018 ◽  
Vol 18 (1) ◽  
Author(s):  
P. Steuer ◽  
C. Avilez ◽  
C. Tejeda ◽  
N. Gonzalez ◽  
A. Ramirez-Reveco ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Copper Ions ◽  
Mycobacterium Avium Subsp ◽  
Mycobacterium Avium Subsp Paratuberculosis
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