Wyniki wyszukiwania - BazTech

1

Mathematical modeling and analysis of mycobacterium tuberculosis transmission in humans with hospitalization and reinfection

Mustapha Umar T., Idris Buhari, Musa Salihu S., Yusuf Abdullahi

Journal of Applied Mathematics and Computational Mechanics

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2022

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Vol. 21, nr 1

55--66

EN

Tuberculosis (TB), a serious public health infection that mainly affects the lungs, is caused by bacteria (Mycobacterium tuberculosis, TB). This research is designed and analyzed using a compartmental modelling approach to study the transmission dynamics of TB with different stages of infection. Qualitative analysis of the proposed model reveals that the model exhibits two equilibrium points: the disease-free equilibrium point (DFE) and the endemic equilibrium (EE). The basic reproduction number (R0 ) is determined using the next generation matrix technique, and stability analysis is carried out to show whether the disease can persist or die out in population. Further analysis of the model shows that the EE is globally asymptotically stable (GAS) when R0 > 1. With the aid of the forward sensitivity index method, we determine the most sensitive parameters of the model to control the spread of TB infection effectively. Our analysis shows that treatment (medication) and campaign awareness coupled with other key control measures, could help maintain the spread of MTB infection in human geographical boundaries.

2

Automatic detection of tuberculosis bacilli from microscopic sputum smear images using deep learning methods

Panicker R. O., Kalmady K. S., Rajan J., Sabu M. K.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 3

691--699

EN

An automatic method for the detection of Tuberculosis (TB) bacilli from microscopic sputum smear images is presented in this paper. According to WHO, TB is the ninth leading cause of death all over the world. There are various techniques to diagnose TB, of which conventional microscopic sputum smear examination is considered to be the gold standard. However, the aforementioned method of diagnosis is time intensive and error prone, even in experienced hands. The proposed method performs detection of TB, by image binarization and subsequent classification of detected regions using a convolutional neural network. We have evaluated our algorithm using a dataset of 22 sputum smear microscopic images with different backgrounds (high density and low-density images). Experimental results show that the proposed algorithm achieves 97.13% recall, 78.4% precision and 86.76% F-score for the TB detection. The proposed method automatically detects whether the sputum smear images is infected with TB or not. This method will aid clinicians to predict the disease accurately in a short span of time, thereby helping in improving the clinical outcome.

3

Adenozyno-5’-o-(n-acylosulfamoilowe) pochodne jako potencjalne leki przeciwgruźlicze

Kulik K., Baraniak J.

Wiadomości Chemiczne

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2016

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[Z] 70, 7-8

455--472

EN

Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis (TB), is the leading bacterial cause of infectious disease mortality. The current WHOapproved treatment for TB involves a three- or four-drug regimen comprising isoniazid, rifampin, pyrazinamide, and/or ethambutol for a minimum of 6 months. While these first-line agents remain useful in treating susceptible Mycobacterium tuberculosis strains, the emergence of multidrug resistant tuberculosis demands the development of new drugs [1]. Iron acquisition is an essential process for M. tuberculosis as well as almost all other microorganisms. However, this essential micronutrient is highly sequestered in a mammalian host. In response to iron starvation, Mtb produces small-molecule iron chelators, a pair of related peptidic siderophores known as mycobactin and carboxymycobactins that vary by the appended lipid residue termed siderophores [4, 5, 7, 8]. Because mycobactins are critical for growth and virulence of M. tuberculosis, they have emerged as attractive targets for the development of anti-TB agents [4]. Biosynthesis of mycobactin is initiated by the aryl acid adenylation enzyme MbtA which activates salicylic acid forming an acyladenylate intermediate (Sal- AMP). MbtA is also responsible for loading the acyladenylate intermediate onto the thiolation domain of MbtB-SH – the enzyme taking part in the next step of biosynthesis process [10]. Given the documented importance of many siderophores for virulence and lack of human aryl acid adenylation enzymes homologues, several analogues possessing stable linkers as bioisosteres of the labile acyl phosphate function have been synthesized as the potent enzyme inhibitors [13]. The initial lead compound 5’-O-[N- (salicyl)sulfamoyl]adenosine (Sal-AMS) has emerged as a promising inhibitor of MbtA and was shown to possess promising whole-cell activity toward M. tuberculosis.

4

Prątek gruźlicy jako czynnik zagrożenia zdrowia

Remiszewski W., Łupina T., Milanowski J.

Bezpieczeństwo Pracy : nauka i praktyka

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2014

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nr 4

30-32

PL

W artykule przedstawiono ryzyko zakażenia prątkiem gruźlicy w różnych grupach zawodowych. Najbardziej narażeni na ten czynnik są pracownicy szeroko pojętej ochrony zdrowia.

EN

The risk of tuberculosis infection in different occupational groups is showed in this paper. The most exposed to this factor are employees broadly def med as health care workers.

5

HPLC analysis of mycolic acids in evaluation of drug susceptibility of Mycobacterium tuberculosis strains - comparison with conventional methods

Walkiewicz R., Chazan R., Grubek-Jaworska H.

Biocybernetics and Biomedical Engineering

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2010

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Vol. 30, no. 2

3-14

EN

The commonly used phenotypic tests of M. tuberculosis drug susceptibility evaluate drug effects on quantity of colony forming units (CFU) on solid media or CO2 secretion/O2 con-sumption by cultures in liquid media. These tests are not precise enough and need a long time for the growth of the bacilli, so new more accurate and rapid methods are highly needed. The aim of this study was to determine the utility of quantitative HPLC analysis of mycolic acids for drug susceptibility of M. tuberculosis. In 119/120 (99.16%) of the performed tests the HPLC methods showed excellent agreement with the conventional phenotypic tests. The quantitative HPLC analysis of mycolic acids is a fairly exact indicator of tubercle bacilli growth and may be used as a quick and reliable measure of their drug sensitivity.

6

Computerized "mycobacterium" type recognition using numerical data base of mycolic acids elution profiles

Glapiński J., Walkiewicz R., Safianowska A., Grubek-Jaworska H.

Biocybernetics and Biomedical Engineering

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2004

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Vol. 24, no. 1

25-38

EN

The aim of this study was to create a standarized numerical data base of high pressure liquid chromatography elution (HPLC) profiles of mycolic acids extracted from the "Mycobacterium" cell wall, with 28 mycobacterial American Type Culture Collection (ATCC) strains taken as a reference for the study. The final result of our work is a notebook of standarized elution profiles and a computer program (MYCAM) for highly effective and specific automatic "Mycobacterium" species identification.