جستجوی مقالات مرتبط با کلیدواژه « مایکوباکتریوم توبرکلوزیس » در نشریات گروه « پزشکی »

Tuberculosis (TB) is an old issue that is presently measured as a significant challenge. The present survey was aimed to assess the genetic diversity of M. tuberculosis strains isolated from patients with TB in Karaj, Iran.

Seventeen M. tuberculosis isolates from 2012 to 2013 were collected and subjected to an IS6110 restriction fragment length polymorphism (IS6110-RFLP) analysis. Demographically, 6 females and 14 males who had Iranian citizenship were included in this study.

Sixteen different genetic types were obtained after enzymatic digestion and RFL analysis. Copy numbers of IS6110 in each isolate ranged from 0 to 12. The majority of isolates (66%) harbored copy numbers between 6 and 12. Each isolates harbored 6.9 copies of the IS6110 marker. Nine isolates harbored 10 to 12 copies of the IS6110 marker, 5 isolates harbored 6 to 10 copies, and 2 others harbored copies less than 6. No copy of IS6110 was found among the 4 isolates. No relationship was found between gender and copy numbers.

The high genetic diversity found amongst the M. tuberculosis isolates maybe show different sources of infection and the importance of reemerging of the TB. However, further surveys should perform to assess other molecular epidemiologic aspects of M. tuberculosis in Iran.

In December 2019, a series of pneumonia cases of unknown origin were reported in Wuhan, China, named by the World Health Organization as COVID-19. The risk factors for developing the disease of COVID-19 are still not well known, but evidence shows that some factors, including respiratory diseases such as tuberculosis, are important risk factors in the disease of COVID-19. It should be noted that tuberculosis, like SARS-COV-2, is mainly transmitted through breathing and affects the lungs. Also, some studies show that infection with Mycobacterium tuberculosis causes more rapid and severe pneumonia symptoms in COVID-19 and is the main cause of death due to severe disease. Considering that the disease of COVID-19 is a newly emerging pandemic and the risk factors related to its incidence and severity are still being investigated and considering that tuberculosis is a curable infectious disease that can affect other respiratory diseases. This study was conducted to investigate the probable and definite frequency of COVID-19 (COVID-19) in the first and second peaks of the coronavirus pandemic among patients with a history of tuberculosis.

This study was descriptive-cross-sectional and the study population included patients with a history of tuberculosis whose diagnosis date was between 2015 and 2020. The number of these samples was equal to 1532. The sampling method was census. The time of investigation in terms of contracting COVID-19 was after the first peak and during and after the second peak of Corona (from the second half of May 2019 to November 2019). The data collection tool included a checklist containing demographic variables and clinical symptoms related to COVID-19. The method of collecting information was in the form of telephone interviews and document review. Data collection was done by trained interviewers. For this purpose, the questioners were first given the necessary training on how to complete the checklist. Data entry was done in Excel software and transferred to SPSS V.16 software for analysis. The description of the variables is presented in terms of number, percentage, mean, standard deviation, and median. A chi-square test was conducted to compare the grouped variables.

In this study, the prevalence of probable and definite cases of COVID-19 among patients with a history of tuberculosis was reported as 5.5% (85 people), and suspected, probable and definite cases were reported as 15.6% (239 people). Also, there was no correlation between age groups, gender, place of residence, type of tuberculosis, marriage, diabetes, kidney disease dialysis, immunodeficiency,, and liver disease with the prevalence of COVID-19 among patients with a history of tuberculosis. It should be noted that in this group of patients, heart disease, lung disease, cancer, chemotherapy, high blood pressure, and brain and nerve diseases were related to the spread of COVID-19. Also, the highest frequency of suspected, probable, and definite COVID among patients with a history of tuberculosis was diagnosed respectively in 2019 with 38.5% (25 out of 65 cases with a history of tuberculosis), in 2014 with 26.7% (63 out of 236 cases with a history of tuberculosis) and 20.8% (58 people out of 279 cases with a history of tuberculosis) in 2018.

Due to the significant difference in the prevalence of Covid 19 in patients who have not received the flu vaccine, it is necessary to inject the flu vaccine in these patients. Advice to quit smoking in these patients should be a priority. Because no independent study on Covid disease was observed in patients with tuberculosis, further studies in this field are necessary.

Pyrazinamide is one of the effective drugs for treating tuberculosis. Inclusion of this drug in the treatment regimen shortens the duration of tuberculosis treatment. The mutation in pncA gene causes loss of pyrazinamidase activity, the most important resistance mechanism in Mycobacterium tuberculosis isolates. Therefore, the purpose of this study is to investigate the phenotypic and genotypic resistance to pyrazinamide antibiotic in multidrug-resistant (MDR) Mycobacterium tuberculosis isolates in Khuzestan province between 2017 and 2022.

This study was conducted on 40 isolates of Mycobacterium tuberculosis in Ahvaz TB Regional Laboratory. Drug sensitivity of the isolates was determined by the relative method in the antibiotic pyrazinamide in the isolates. Then, the frequency of pncA gene mutations related to pyrazinamide resistance in MDR isolates was determined using sequencing.

According to the results of the drug sensitivity to rifampin and isoniazid antibiotics, there were 25 isolates, of which 16 strains were resistant to two drugs, namely isoniazid and rifampin (MDR-TB), and 9 were single-drug resistant isolates (8 isolates resistant to rifampin and 1 isolate resistant to Isoniazid). Of the 17 samples that had the pncA gene and were resistant to pyrazinamide, 13 had mutations in the pncA gene while 4 did not have any mutations. The most common mutation was a non-synonymous mutation in which the amino acid Val had changed to Phe.

According to the results of this study, there is a high frequency of resistance to pyrazinamide in MDR strains. Also, there is a high percentage of single-resistance mutations in the pncA gene, while there is lower prevalence of mutations in the panD and rpsA genes, which provide quick and accurate information about the sensitivity to pyrazinamide for MDR-TB and mono-resistant isolates. Therefore, the best method for detecting resistance to pyrazinamide is sequencing and whole pncA DNA sequence to confirm pyrazinamide resistance instead of the usual methods covering mutated hotspots.

The emergence of drug resistance and treatment- renitent Mycobacterium tuberculosis has made controlling the disease a challenge. World Health Organization (WHO) estimates that approximately 500,000 new cases of tuberculosis occur annually. Considering that mechanisms involved in drug resistance are yet to be elucidated and results of the studies are not consistent, we decided to investigate the correlation between mutations in thyA gene and resistance to para- aminosalicylic acid (PAS).

In this descriptive cross- sectional study, a total of 255 positive MTB specimens were isolated during a three- year period using standard microscopic and culture methods from which 68 Multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis samples were selected through drug susceptibility testing. Then, to determine potential mutations in thyA gene, the fragment was amplified using conventional PCR and products were sequenced. Afterward, mutations which have been induced amino acid substitutions were evaluated with various protein prediction tools. Also, the correlation between mutations and drug resistance was statistically determined using chi-square test.

From 255 clinical TB samples, 68 (26.7%, CI 21.3%) MDR / or XDR-TB strains were isolated. In total, 13 (19.1%) were PAS- resistant and 5 (38.4%) of them had different nucleotide mutations in thyA gene. All of the mutations were statistically correlated with drug resistance. Moreover, the results of bioinformatics showed that identified mutations could lead to the structural and functional disruption of the protein.

According to our results, mutations in thyA gene have appeared to be associated with resistance to PAS. Also, our findings have shed light on the potential of the analysis of short genomic regions and new computational tools in unraveling the molecular mechanisms of drug resistance.

Multidrug- resistant (MDR) tuberculosis (TB) is caused by a strain of Mycobacterium tuberculosis (MTB) that was at least resistant to isoniazid (INH) and rifampicin (RIF). World Health Organization reported 399,000-501,000 cases of RIF resistance and they reported this case without knowing about this situation in Tehran. So, it is an important concern.

Descriptive method and research was done on 1000 clinical samples of people suspected of tuberculosis. All the samples were studied in the TB center of the province for microscopic examination and culture. Using the ratio method, the drug sensitivity test to the first- line anti- tuberculosis drug was performed for positive MTB cultures on Löwenstein- Jensen (LJ) culture medium. All isolates resistant and sensitive to RIF were identified by GeneXpert and the prevalence of resistance in the samples was determined and its actual level in the community was estimated. Then, using SPSS software, the level of resistance and factors affecting it were checked.

According to theprevalence in these samples in this research, out of 440 positive samples, 3 positive samples, or 0.07% were resistant.

It seems that resistance to rifampin is not a big problem and is not a cause for concern. As a result, the prevalence of drug resistance in this study area was relatively low. Our suggestion is to conduct more studies in different regions of this country to evaluate the efficiency of GeneXpert and whether it can be useful and effective in Iran.

Tuberculosis is one of the major global health problems with high mortality. Establishing a rapid and low-cost identification method is significant, especially in developing countries. In this study, we aimed to design an indirect ELISA system with low molecular weight antigens secreted by Mycobacterium tuberculosis strain C, for identification of Mycobacterium tuberculosis Complex infection in human.

The secretory proteins from culture filtrate of Mtb strain C extracted by Sephadex-G50 were used as target antigen in designing an indirect ELISA system. Then, human sera with tuberculin skin test, culture, acid-fast bacilli smear, and PCR test results were selected to detect human serum antibodies against these low molecular weight proteins.

During gel chromatography and SDS-PAGE (12.5%) analysis, the purified protein F2 fractions with approximately 0.7 mg/ml and molecular weights in the range of 14-40 kDa were used as the target antigen in designing the indirect ELISA system. The ELISA system designed by F2 showed 78% sensitivity and 92% specificity in identifying tuberculosis.

The ELISA results based on low molecular weight proteins, with the sensitivity and specificity achieved in this study, might support the hypothesis that the Mtb culture filtrate antigens could be used as a rapid and sensitive assay in ELISA test for detection of pulmonary TB.

Tuberculosis (TB) remains a serious public health problem worldwide, causing millions of deaths annually. It is estimated that one-third of the world population is infected with latent TB. Drug-resistant TB is considered a major and growing global threat. In this study, we aimed to indicate the drug-susceptibility of Mycobacterium tuberculosis isolates from patients, presented to Mollahadi Sabzevari Tuberculosis Center in Isfahan, Iran to the first-line drugs.

In this study, Mycobacterium tuberculosis was isolated from 438 patients with pulmonary tuberculosis referred to the Regional Reference Laboratory of tuberculosis in Isfahan province during 2017-2019, 33 resistant isolates were studied. Drug susceptibility testing to first-line drugs was performed by proportion method, and the H37Rv reference strain sensitive to all drugs was used for quality control.

Out of 438 isolates, 20 isolates (37.7%) were drug-sensitive and 33 isolates (62.3%) were resistant to the first-line drug by phenotypic method, which was isoniazid (INH) 22 isolates (66.7%), rifampin (RIF) 18 isolates (54.5%), ethambutol (EMB) 4 isolates (12.1%) and pyrazinamide (PZA) 5 isolates (15.2%) respectively. Also, 10 isolates (30.3%) were multidrug-resistant tuberculosis (MDR-TB).

The pattern of drug resistance in Mycobacterium tuberculosis is different in each region and in the Isfahan region due to the increasing drug resistance of tuberculosis. Further research is needed to determine the drug resistance of Mycobacterium tuberculosis.

Tuberculosis is a threat to public health. The epidemiology of tuberculosis can be effective in identifying the source of infection, the dominant circulating strains and achieving transmission pathways in the world. The aim of this study was to determine the genotype of Mycobacterium tuberculosis (M. tb) strains in patients referred to Pasteur Institute of Iran between 2018 and 2019.

In this study, 50 confirmed M. tb strains were evaluated. After M. tb strains identification and determining the drug susceptibility test, all strains were genotyped by MIRU-VNTR (Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat) method.

The most frequent genotype in all strains was CAS/Delhi (42%), followed by Haarlem (24%), NEW-1 (10%), LAM (8%), Beijing (8%), Cameroon (4%), EAI (% 2) and S (2%). Three clonal complexes and 44 singleton isolates were identified. Beijing genotype was the common genotype in MDR-TB strains. Also, QUB26 and QUB4156 loci had shown the highest of discriminative and allelic diversity.

CAS/Delhi and Beijing genotypes were introduced as the dominant genotypes in drug sensitive and MDR strains, respectively.

 Tuberculosis (TB) is a chronic bacterial infection. Simultaneous onset of diabetes and TB can interfere with the treatment and control of TB. 

 This study aims to investigate the prevalence of TB in diabetic patients living in rural areas of northern Iran.

 Participants were 925 diabetic patients living in rural areas of Kordkuy County, Golestan, Iran. Data were collected using a checklist surveying demographic characteristics and medical records of patients. To diagnose TB, they underwent a TB skin test, sputum smear test, chest radiography, and referring to an infectious diseases specialist, if needed. 

 Seven hundred sixteen of participants were female. The mean age of participants and their mean duration of diabetes were 58.4±11.1 and 8.39±5.47 years, respectively. Results of test showed that 62 patients had abnormal chest x-ray; 14 had coughing more than two weeks; 1 had fever; 2 had night sweats; 11 had sputum; 152 had positive TB skin test result; 10 had a history of previous TB; and 1 had active TB. 

 The prevalence and incidence of TB in diabetic patients is 60 and 6 times higher than in general population, respectively.

Mycobacterium tuberculosis is a pathogen that can cause tuberculosis in the host. Although Mycobacterium tuberculosis is the oldest known bacterium in humans, it is still a deadly disease worldwide. Mycobacterium tuberculosis can survive in the human body for decades without any symptoms. However, it may be activated in people with defective immune systems or people with diseases such as diabetes, AIDS or malnutrition, leading to tuberculosis. The aim of this study was to evaluate the dosT gene in patients with Mycobacterium tuberculosis The presence of dosT gene in patients with Mycobacterium tuberculosis was determined by PCR and the presence of this gene in susceptible and resistant samples of Mycobacterium tuberculosis was analyzed by many statistical methods. The dosT gene was detected in all patients with E. coli by PCR (219 bp). The frequency of dosT gene in isolates of patients with Mycobacterium tuberculosis was determined (94.3%). The percentage of dosT gene presence in patients with susceptible and resistant Mycobacterium tuberculosis was determined (78.8% and 21.2% in patients with recessive tuberculosis) The presence of dosT gene was detected in almost all patients with Mycobacterium tuberculosis and it was shown that this gene is more common in susceptible isolates of Mycobacterium tuberculosis.

Tuberculosis is one of the infectious diseases that have long threat human health. The purpose of this study was to evaluate the circulation of Mycobacterium tuberculosis in Delfan city to achieve better care of the disease.

This is a descriptive-analytical study conducted in Delfan. The study data were collected from the records of all patients referred to health centers of Delfan from 2011 to 2020 using census method. SPSS 23 software was used for data collection. Frequency tables and Chi-square tests were used to analyze the data.

The mean age of the patients was 47.56 ± 22.34. from a total of 125 cases present, 76 were positive pulmonary smear tuberculosis, 18 were negative smear and 31 were extra-pulmonary tuberculosis. Eighty percent of patients have illiteracy and primary education. On average, the interval between the onset of symptoms and the diagnosis of the disease in all forms of tuberculosis was approximately 97 days. Also, a statistical relationship was observed between the type of tuberculosis and the place of residence (p≤. / 006), age (p≤. / 004) and delay in diagnosis (p≤ / 022).

In the present study, most of the patients were illiterate, so training and preventive measures to control tuberculosis are recommended for this group. Also, due to the large distance between the disease and the diagnosis, it is necessary to follow the tuberculosis care program in this city more seriously in order to shorten this distance

The emergence of drug resistance in Mycobacterium tuberculosis and especially drug resistant strains has created problems for the treatment of tuberculosis control, worldwide. This study was performed to evaluate the changes in N-acetyltransferase (NAT) pattern of methylsonone in patients who did not respond to first-line treatment for Mycobacterium tuberculosis.

This descriptive-analytical study was performed on 200 patients with tuberculosis. After preparing the blood sample, saturated salt method was used to extract DNA. For the determination of quantity and quality of DNA, two methods of spectrophotometry and electrophoresis on agarose gel were used. The methylation pattern of NAT1 gene was investigated by HRM method.

34 patients were resistant to the first line of treatment. 18 patients showed hypermethylation pattern, 12 patients showed non-methylated pattern and 4 patients showed hypomethylated pattern. 166 patients were not resistant to the first line, of which 23 patients in hypermethylated group, 120 patients in group Non-methylated and 23 patients were in the hypomethylated row. There was a statistically significant relationship between methylation level and drug resistance (P<0.05).

This study showed that resistance to first-line treatment of Mycobacterium tuberculosis was related to the level of N-acetyltransferase gene methylation.

Necrotizing pneumonia is an uncommon disorder with a high mortality rate. Different factors are involved in the incidence of this disease.

A 73 years old man was admitted to the hospital with a chief complaint of dyspnea and productive cough. Chest x-ray showed a consolidation in the lower lobe of the left lung and a CT-scan revealed a cavity in the lingula. Bronchoscopy was performed and examination of bronchoalveolar lavage (BAL) fluid was positive for acid-fast bacilli. Anti-tuberculosis drugs were started for the patient.

Our case demonstrates a rare manifestation of tuberculosis associated with lung necrosis and cavitation, which emphasizes the necessity of examination and work-ups for mycobacterium TB in patients with drug resistant chronic pulmonary disease.

Tuberculosis (TB) with more than 10 million new cases per year and one of the top 10 causes of death worldwide, is still one of the most important global health problems. Also, multi drug-resistant tuberculosis (MDR) is a serious danger to public health. Understanding of the epidemiological pattern of mycobacterium tuberculosis (MTB), Estimates of recent transmission and recurrence of infection, it is possible with molecular typing methods. The present study was performed aiming to track and determine the type of Mycobacterium tuberculosis infection, as well as its relationship with demographic factors, using PGRS-RFLP.

In this study, 90 samples collected from TB patients from the North West provinces of Iran, Molecular typing by Characterization highly abundant polymorphic GC-rich-repetitive sequence. Investigated Demographic factors associated with the transmission of the disease.

All isolates were grouped into 44 clusters 28types (33.3%) of the subspecies were in unique stains and 66.7% (from 56 patients) had clustered isolates. The largest cluster contained 8 isolates (9.52%) was the West provinces of Iran.

Genetic variation of Mycobacterium tuberculosis is high in this region. The rate of recent transmission based on clustering was unexpected (The global average is 30%-40%). The recent transmission was more dynamic in the west than northwest Iran. Clustering based on PGRS-RFLP can demonstrate the high correlation between molecular and classic information. In addition, the significant relationship between vaccination record and clustering highlights the necessity to conduct more extensive studies.

Molecular detection has recently been proposed by nucleic acid amplification, known as polymerase chain reaction (PCR). The aim of this study was to compare the diagnostic method of smear and polymerase chain reaction with culture in terms of sensitivity, specificity, positive and negative predictive value in the diagnosis of pulmonary tuberculosis.

In this cross-sectional study, sputum samples were collected from 58 patients with suspected pulmonary tuberculosis referred to Ghaem Hospital in Mashhad from the beginning of April 2017 to the end of March 2018. The samples were delivered to the laboratory in less than 72 hours. Patients were sampled for three times. Bronchoscopy and Broncho alveolar lavage were performed in patients who were unable to produce sputum. The smear test was reported by Ghaem’s Laboratory after 24 hours. In our study, the culture method was considered as the gold standard and the sensitivity and specificity of the PCR methods and smear were compared with it.

Patients ranged in age from 18 to 89 years. Among 58 suspected pulmonary tuberculosis, the method of cultivation confirmed the presence of the disease in 25 cases (43.1%). However, with smear, the presence of the disease has been proved in 27 patients (46.6%) and with the method of PCR in 24 patients was (41.4%). Sensitivity of smear in the diagnosis of pulmonary tuberculosis was (100%), and its specificity was 93.9%, the positive predictive value of this test was (92.6%) and the negative predictive value was (100.0%). The sensitivity of the PCR method in diagnosis of pulmonary tuberculosis was 88.0% and its specificity was 93.9%. The positive predictive value of this was (91.7%) and the negative predictive value was (91.2%).

In this study, between the two methods of smear and polymerase chain reaction, the acid fast smear method was more sensitive to the diagnosis of pulmonary tuberculosis than the polymerase chain reaction and the specificity of both methods were the same.

Tuberculin skin test is a screening test for tuberculosis. The aim of this investigation has studied in vitro the immunity level out of Bacillus Calmette–Guerin (BCG) vaccine, through measurement of interferon gamma (IFN γ) in growth medium, in the students of Shavoor city. This research is an experimental study that was performed on 32 male and female students of the three educational levels. After blood sampling, the peripheral blood mononuclear cells were isolated with 5 or 20 μl B.C.G vaccine were co-cultured in CO2 incubator in 37°C for 48 and 72 hours, and IFN γ level measured by the enzyme-linked immunosorbent method. For statistical analyses, independent t-test was used to analyze the differences between the two groups using SPSS software version 23. Analysis of the results showed that there was a significant difference between the size of the induration at different ages of 13 years old (P <0.05). Also, there was no significant difference between the size of the induration in boys and girls (P> 0.05).There was a significant difference between the age, time, and amounts of the bacterium 5 or 20 μL of the B.C.G vaccine used with the level of IFN γsecretion in the two groups (P <0.05). With regard to the results, IFN γ secretion is directly related to the dose of bacteria used and the monocular blood cells of the students and incubation time. Also, the level of IFN γsecretion at younger ages was lower than that at an early age.

Mycobacterium tuberculosis affects millions of people in the world and Iran is one of the endemic areas. This disease has a wide range of manifestations, which is pulmonary in 80 – 85% of cases and extrapulmonary in 15 – 20% of cases. The most notable extrapulmonary infection sites are lymph nodes, pleura, genitourinary system and digestive system. Considering the prevalence of tuberculosis in Iran, familiarity with the uncommon manifestations of this infection seems to be essential for timely diagnosis and treatment. Therefore, a rare extrapulmonary manifestation of tuberculosis is reported here.

CASE REPORT:

The patient was a 64 – year – old woman who was hospitalized due to fever, icterus, decreased consciousness and progressive asymmetrical weakness of the limbs. Symptoms of focal neurologic deficits and heart murmurs were found in examinations. During the tests, including brain and spinal imaging, cerebrospinal fluid analysis, computed tomography of the abdomen and pelvis, and echocardiography, extrapulmonary tuberculosis (cerebral abscess, spondylitis, liver and spleen abscess, psoas muscle abscess, and possible endocarditis) was confirmed. Four-drug regimen including isoniazid, rifampin, ethambutol, and pyrazinamide with vitamin B6 was started for two months, and two-drug regimen continued for 10 months. At the end of the course of treatment, the patient was able to walk with the cane in good general condition. 

Considering the reported case, paying attention to some of the more uncommon manifestations of the disease can prevent mortality and disability.