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Applied Microbiology and Biotechnology Dec 2023Androst-4-ene-3,17-dione (AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) are important drug intermediates that can be biosynthesized from phytosterols. However,...
Androst-4-ene-3,17-dione (AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) are important drug intermediates that can be biosynthesized from phytosterols. However, the C9 hydroxylation of steroids via 3-ketosteroid 9α-hydroxylase (KSH) limits AD and 4-HBC accumulation. Five active KshAs, the oxidation component of KSH, were identified in Mycobacterium fortuitum ATCC 35855 for the first time. The deletion of kshAs indicated that the five KshA genes were jointly responsible for C9 hydroxylation during phytosterol biotransformation. MFKDΔkshA, the five KshAs deficient strain, blocked C9 hydroxylation and produced 5.37 g/L AD and 0.55 g/L 4-HBC. The dual function reductase Opccr knockout and 17β-hydroxysteroid dehydrogenase Hsd4A enhancement reduced 4-HBC content from 8.75 to 1.72% and increased AD content from 84.13 to 91.34%, with 8.24 g/L AD being accumulated from 15 g/L phytosterol. In contrast, hsd4A and thioesterase fadA5 knockout resulted in the accumulation of 5.36 g/L 4-HBC from 10 g/L phytosterol. We constructed efficient AD (MFKDΔkshAΔopccr_hsd4A) and 4-HBC (MFKDΔkshAΔhsd4AΔfadA5) producers and provided insights for further metabolic engineering of the M. fortuitum ATCC 35855 strain for steroid productions. KEY POINTS: • Five active KshAs were first identified in M. fortuitum ATCC 35855. • Deactivation of all five KshAs blocks the steroid C9 hydroxylation reaction. • AD or 4-HBC production was improved by Hsd4A, FadA5, and Opccr modification.
Topics: Phytosterols; Mycobacterium fortuitum; Mycobacterium; Mixed Function Oxygenases; Steroids; Biotransformation
PubMed: 37831185
DOI: 10.1007/s00253-023-12812-w -
Tropical Medicine and Health Sep 2023CNS manifestations represent an emerging facet of NTM infection with significant mortality. Due to protean presentation and low index of suspicion, many cases are often... (Review)
Review
BACKGROUND
CNS manifestations represent an emerging facet of NTM infection with significant mortality. Due to protean presentation and low index of suspicion, many cases are often treated erroneously as tubercular meningitis or fungal infections.
OBJECTIVES
Literature on NTM CNS disease is scarce, with most available data on pulmonary disease. This systematic review aimed to evaluate the epidemiology, clinical presentation, diagnostic modalities, and predictors of outcome in CNS NTM infection.
METHODS
The literature search was performed in major electronic databases (PubMed, Google Scholar, and Scopus) using keywords "CNS," "Central nervous system," "brain abscess," "meningitis," "spinal," "Nontuberculous mycobacteria," "NTM". All cases of CNS NTM infection reported between January 1980 and December 2022 were included.
RESULTS
A total of 77 studies (112 cases) were included in the final analysis. The mean age of all patients was 38 years, with most patients male (62.5%). Mycobacterium avium complex (MAC) was the most common aetiology, followed by M. fortuitum and M. abscessus (34.8%, 21.4% and 15.2%, respectively). The disseminated disease was found in 33% of cases. HIV (33.9%) and neurosurgical hardware (22.3%) were the common risk factors. Intracranial abscess (36.6%) and leptomeningeal enhancement (28%) were the most prevalent findings in neuroimaging. The overall case fatality rate was 37.5%. On multivariate analysis, male gender (adjusted OR 2.4, 95% CI 1.2-7.9) and HIV (adjusted OR 3.7, 95% CI 1.8-6.1) were the independent predictors of mortality). M. fortuitum infection was significantly associated with increased survival (adjusted OR 0.18, 95% CI (0.08-0.45), p value 0.012).
CONCLUSIONS
Current evidence shows the emerging role of rapid-grower NTM in CNS disease. Male gender and HIV positivity were associated with significant mortality, while M fortuitum carries favourable outcomes.
PubMed: 37749661
DOI: 10.1186/s41182-023-00546-4 -
Pediatric Allergy and Immunology :... Sep 2023
Topics: Female; Humans; Mycobacterium fortuitum; Histiocytosis; Genetic Predisposition to Disease
PubMed: 37747748
DOI: 10.1111/pai.14027 -
Microbiology Spectrum Sep 2023The clinical utility of rifamycins against non-tuberculous mycobacterial (NTM) disease is limited by intrinsic drug resistance achieved by ADP-ribosyltransferase Arr. By...
The clinical utility of rifamycins against non-tuberculous mycobacterial (NTM) disease is limited by intrinsic drug resistance achieved by ADP-ribosyltransferase Arr. By blocking the site of ribosylation, we recently optimized a series of analogs with substantially improved potency against . Here, we show that a representative member of this series is significantly more potent than rifabutin against major NTM pathogens expressing Arr, providing a powerful medicinal chemistry approach to expand the antimycobacterial spectrum of rifamycins. IMPORTANCE Lung disease caused by a range of different species of non-tuberculous mycobacteria (NTM) is difficult to cure. The rifamycins are very active against which causes tuberculosis (TB), but inactive against many NTM species. Previously, we showed that the natural resistance of the NTM to rifamycins is due to enzymatic inactivation of the drug by the bacterium. We generated chemically modified versions of rifamycins that prevent inactivation by the bacterium and thus become highly active against Here, we show that such a chemically modified rifamycin is also highly active against several additional NTM species that harbor the rifamycin inactivating enzyme found in , including , , and . This finding expands the potential therapeutic utility of our novel rifamycins to include several currently difficult-to-cure NTM lung disease pathogens beyond
PubMed: 37681986
DOI: 10.1128/spectrum.01900-23 -
Infection & Chemotherapy Mar 2024The distribution of species and characteristics of non
- tuberculous mycobacteria (NTM) differ, and surveillance data for changes in antimicrobial...BACKGROUND
The distribution of species and characteristics of non
- tuberculous mycobacteria (NTM) differ, and surveillance data for changes in antimicrobial susceptibilities of NTM is insufficient. This study analyzed the changes in antimicrobial susceptibility trends across NTM species and assessed the appropriateness of empirical antimicrobial drugs for NTM.MATERIALS AND METHODS
We retrospectively analyzed the clinical characteristics, including demographics, distribution of NTM species, antimicrobial drug susceptibilities, and outcomes, at a teaching hospital in Jeju Island from 2009 - 2022.
RESULTS
Overall, 342 patients were included in the analysis; 93.0% were classified into the pulmonary group (PG) and 7.0% into the extrapulmonary group (EPG). The isolation rate of was significantly higher in PG (36.8% 0%, = 0.001), while that of was significantly higher in EPG (4.5% 31.3%, = 0.001). The antimicrobial susceptibility rate is higher against clarithromycin (89.9%) and amikacin (83.3%) and lower against rifampin (54.7%) and ethambutol (28.1%). The susceptibility rate to clarithromycin was over 80%, but those to rifampin and ethambutol showed decreasing annual trends. Of the 162 patients who received empirical antimicrobial therapy, actual antimicrobial susceptibility rates were high (90.1%) using empirical macrolide, and relatively low using ethambutol and rifampin (28.0% and 58.8%, respectively).
CONCLUSION
This is the first study of analysis of the distribution, baseline characteristics, and antimicrobial susceptibility of isolated NTM species in pulmonary and extrapulmonary patients in Jeju Island over 10 years. Policies that continuously monitor changes in susceptibility rate are required to ensure effective treatment strategies.
PubMed: 37674341
DOI: 10.3947/ic.2023.0052 -
Annals of Laboratory Medicine Jan 2024Limited data are available regarding the activity of SPR719, a derivative of benzimidazole, against diverse nontuberculous mycobacteria (NTM) species. We investigated...
Limited data are available regarding the activity of SPR719, a derivative of benzimidazole, against diverse nontuberculous mycobacteria (NTM) species. We investigated the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of SPR719 against clinical NTM isolates, including clarithromycin- and amikacin-resistant strains. NTM isolates were obtained from patients with NTM-pulmonary disease caused by various NTM species, including complex, (subspecies and ), , and . Regardless of clarithromycin or amikacin resistance, the MIC and MBC values of SPR719 were comparable among these major pathogenic NTM species. In over 70% of the isolates, the MIC values were ≤2 μg/mL with MBC values of ≤4 μg/mL. The MIC and MBC values of were relatively lower than those of the other species with little difference between them, demonstrating the bactericidal properties of SPR719. The activity of SPR719 against major clinical NTM species suggests that SPR719 can serve as a novel treatment option for NTM-pulmonary disease.
Topics: Humans; Clarithromycin; Amikacin; Nontuberculous Mycobacteria; Benzimidazoles; Anti-Bacterial Agents; Mycobacterium Infections, Nontuberculous
PubMed: 37665290
DOI: 10.3343/alm.2024.44.1.92 -
Methods in Molecular Biology (Clifton,... 2023The phytosterol-biotransforming strains can be selected from Mycobacterium sp. using a high concentration of β-sitosterol. The selection is made by culturing the...
The phytosterol-biotransforming strains can be selected from Mycobacterium sp. using a high concentration of β-sitosterol. The selection is made by culturing the strains in a medium enriched with 14 g/L of β-sitosterol as the unique source of carbon. During 2 months, the bacterial cultures are transferred successively. The extraction of the biotransformation products is made with methanol and ethyl acetate. The qualitative and quantitative analyses are made by means of thin-layer chromatography, gas-liquid chromatography (GLC), and GLC-mass spectrometry. Under these conditions, it is observed that after seven transfers, the strains Mycobacterium sp. MB-3683 and Mycobacterium fortuitum B-11045 increase their biotransformation capacity from 20% to 64% and from 34% to 55%, respectively. The products in the highest proportion identified for each trial are androstenedione and androstadienedione. The results suggest that the high substrate concentration could be a selective mechanism to obtain strains more efficient in the biotransformation of β-sitosterol into steroidal bases.
Topics: Phytosterols; Gas Chromatography-Mass Spectrometry; Androstenedione; Carbon; Chromatography, Thin Layer
PubMed: 37642837
DOI: 10.1007/978-1-0716-3385-4_3 -
Frontiers in Cellular and Infection... 2023Mycobacteriophages are viruses that infect members of genus . Because of the rise in antibiotic resistance in mycobacterial diseases such as tuberculosis,...
Mycobacteriophages are viruses that infect members of genus . Because of the rise in antibiotic resistance in mycobacterial diseases such as tuberculosis, mycobacteriophages have received renewed attention as alternative therapeutic agents. Mycobacteriophages are highly diverse, and, on the basis of their genome sequences, they are grouped into 30 clusters and 10 singletons. In this article, we have described the isolation and characterization of a novel mycobacteriophage Kashi-VT1 (KVT1) infecting mc 155 () and isolated from Varanasi, India. KVT1 is a cluster K1 temperate phage that belongs to family as visualized in transmission electron microscopy. The phage genome is 61,010 base pairs with 66.5% Guanine/Cytosine (GC) content, encoding 101 putative open reading frames. The KVT1 genome encodes an immunity repressor, a tyrosine integrase, and an excise protein, which are the characteristics of temperate phages. It also contains genes encoding holin, lysin A, and lysin B involved in host cell lysis. The one-step growth curve demonstrated that KVT1 has a latency time of 90 min and an average burst size of 101 phage particles per infected cell. It can withstand a temperature of up to 45°C and has a maximum viability between pH 8 and 9. Some mycobacteriophages from cluster K are known to infect the pathogenic (); hence, KVT1 holds potential for the phage therapy against tuberculosis, and it can also be engineered to convert into an exclusively lytic phage.
Topics: Humans; Mycobacteriophages; Genome, Viral; Mycobacterium tuberculosis; Mycobacterium smegmatis; Tuberculosis; Bacteriophages
PubMed: 37545854
DOI: 10.3389/fcimb.2023.1173894 -
Applied Microbiology and Biotechnology Oct 2023Biofilm formation by Mycobacterium fortuitum causes serious threats to human health due to its increased contribution to nosocomial infections. In this study, the first... (Comparative Study)
Comparative Study
Biofilm formation by Mycobacterium fortuitum causes serious threats to human health due to its increased contribution to nosocomial infections. In this study, the first comprehensive global proteome analysis of M. fortuitum was reported under planktonic and biofilm growth states. A label-free Q Exactive Quadrupole-Orbitrap tandem mass spectrometry analysis was performed on the protein lysates. The differentially abundant proteins were functionally characterized and re-annotated using Blast2GO and CELLO2GO. Comparative analysis of the proteins among two growth states provided insights into the phenotypic switch, and fundamental pathways associated with pathobiology of M. fortuitum biofilm, such as lipid biosynthesis and quorum-sensing. Interaction network generated by the STRING database revealed associations between proteins that endure M. fortuitum during biofilm growth state. Hypothetical proteins were also studied to determine their functional alliance with the biofilm phenotype. CARD, VFDB, and PATRIC analysis further showed that the proteins upregulated in M. fortuitum biofilm exhibited antibiotic resistance, pathogenesis, and virulence. Heatmap and correlation analysis provided the biomarkers associated with the planktonic and biofilm growth of M. fortuitum. Proteome data was validated by qPCR analysis. Overall, the study provides insights into previously unexplored biochemical pathways that can be targeted by novel inhibitors, either for shortened treatment duration or for eliminating biofilm of M. fortuitum and related nontuberculous mycobacterial pathogens. KEY POINTS: • Proteomic analyses of M. fortuitum reveals novel biofilm markers. • Acetyl-CoA acetyltransferase acts as the phenotype transition switch. • The study offers drug targets to combat M. fortuitum biofilm infections.
Topics: Mycobacterium fortuitum; Biofilms; Microscopy, Electron, Scanning; Proteome; Metabolic Networks and Pathways; Acetyl-CoA C-Acetyltransferase; Quorum Sensing
PubMed: 37542577
DOI: 10.1007/s00253-023-12705-y