Background: Nontuberculous mycobacteria (NTM) are generally free-living and have a potential to cause opportunistic infection. More than 190 species of NTM have been identified ...(http://www.bacterio.net/mycobacterium.html), up to 60 species of them are pathogenic. The distribution is geographically specific for some species and others are cosmopolitan. Understanding their diversity has practical value for the treatment and management of NTM disease. Except for isolated reports, there is no accurate information about NTM spread among Bulgarian patients.
Material and Methods: We retrospectively analysed the data on the NTM isolated from patients throughout the country for the period from January 2010 to December 2017. Identification to the species level was done by Line Probe Assay (LPA).
Results: 586 NTM strains were identified. We calculated the rate of NTM isolation in Bulgaria and NTM disease incidence by applying microbiological criteria defined by the American Thoracic Society (ATS). As a result, the laboratory isolation rate amounted to 1/100 000 people for the period, and when applying only the ATS criteria, the prevalence of NTM disease was 0,23 per 100 000 people. In both cases, we reported that NTM disease incidence remains low as compared to tuberculosis, though with an increasing trend. The prevalence of NTM varied significantly between northern and southern Bulgaria, as well as between the capital and the rest of the country's regions.
Conclusions: Slow growing NTM species predominate in Bulgaria but rapidly growing ones have isolation levels higher than the average for Europe and closer to that of Asian countries. Given the demographic situation in Bulgaria and the changing climatic factors, NTM infections need special attention.
The need of biomarkers predicting the course of MTB infection, and the necessity of specific therapy, is well recognized. We measured the induced expression of effector and regulatory cytokines ...IFN-γ, TNF-α, IL-2, IL-17, IL-6, IL-10 in relation to the lipid mediators PGE2 and LXA4 in: active TB infection (ATB, n=15) before and after therapy (ATB-T, n=6); established latent infection (LTBI, n=22), recent contacts of ATB (RC, n=12); and healthy controls (n=11) A flow cytometry microarray (CBA, BD Biosciences) and quantitative ELISA (SunRed Tech.) were employed. RC were characterized by a high potential for IL-17 and Th1 cytokine secretion, combined with low IL-6 expression, while ATB donors had a partially preserved TNF-α potential, and higher IL-6 expression. PGE2 /LXA4 ratio discriminated between situations with high bacterial load (ATB), and contained infection (LTBI, ATB-T), and defined clearly-cut subgroups among RC and ATB donors. Our results propose that increased PGE2/LXA4 ratio coupled with high induced IL-10 level indicates infection after a recent contact. In the settings of ATB, increased ratio and low TNF-α level point to inefficient granuloma formation in the settings of ATB.
Microorganisms belonging to the Mycobacterium avium complex (MAC) are ubiquitous in the environment, but only a minority of infected persons develop disease. An underlying lung disease or immune ...deficiency is a prerequisite for clinical manifestation. However, disseminated MAC disease primarily manifests in people living with human immunodeficiency virus (HIV) in the severe immunodeficiency stage with a whole host of clinical symptoms. We present two cases of disseminated M. avium infection in people living with HIV in the stage of severe immunodeficiency. Both patients exhibited distinct disease progression, with the absence of pulmonary symptoms being a common characteristic. The first patient predominantly experienced high fever, accompanied by diarrhea and severe anemia. The normothermia in the second patient was incongruent with the presence of marked cachexia, severe abdominal pain, and magnetic resonance imaging evidence of abdominal lymph node involvement. The causative agent was isolated from both sputum and stools. The patients underwent treatment that comprised aminoglycoside, macrolide, ethambutol, and rifampicin. Although both patients achieved optimal viral suppression of HIV, the immunologic response to antiretroviral therapy was suboptimal. The first patient died in the setting of severe immunodeficiency due to the development of decompensated liver cirrhosis, while the second patient demonstrated a slight reverse course of the disease.
Introduction:
Nontuberculous mycobacteria (NTM) are representatives of the genus
Mycobacterium
with a worldwide distribution, associated mainly with water, soil, and biofilms. Some of NTMs, such as
...Mycobacterium avium
complex (MAC), are etiological agents of human diseases - disseminated or with different localization, most often pulmonary.
Aim:
In the present study, we analyzed
Mycobacterium intracellulare
isolates recovered from clinical specimens of tuberculosis (TB) suspected patients in Bulgaria, 2018-2020.
Materials and methods:
The cultures were grown on solid and liquid media. For species identification, we used immune chromatographic (TB Ag MPT64) test and Line Probe Assay (LPA) from the positive cultures.
Results:
M. intracellulare was identified in 32 patients from 82,780 specimens. It was predominantly isolated in females - 62.5% vs. 37.5% in males. The most affected age group was 65 years and over (38%). The distribution of the isolates in Bulgaria was uneven. Most of them (65.6%) were concentrated in two districts of the country: Plovdiv and Sofia-city. All strains were sensitive to macrolides and aminoglycosides except one with macrolide resistance. NTM pulmonary disease was confirmed in 16 patients with
M. intracellulare
isolate.
Conclusions:
Analysing the 32
M. intracellulare
isolates identified among TB suspected patients in Bulgaria between 2018 and 2020, we found that only half of them met the American Thoracic Society (ATS) diagnostic criteria for NTM pulmonary disease. For the remaining patients with
M. intracellulare
isolates we did not have sufficient data to support this diagnosis. Efforts by Bulgarian respiratory and microbiological societies are needed for adherence to the international guidelines.
This study aimed to describe the first two microbiologically confirmed cases of cutaneous and soft tissue
Mycobacterium marinum
infection in Bulgaria. The isolation of the Nontuberculous Mycobacteria ...(NTM) strains and their species identification was performed at NRL TB, NCIPD using specific media and cultivation conditions, and PCR based Line Probe Assay (LPA) from the positive cultures. The two patients had closely related jobs to fishes and water reservoirs and both of them had a similar clinical manifestation of
M. marinum
infection known as "swimming pool" or "fish tank" granuloma. The prolonged specific treatment with at least two-drug combination of rifampicin plus ethambutol and some complications were a big challenge for clinicians as well as the patients.
Isoniazid (H; INH) is an important first-line drug for the treatment of active tuberculosis (TB) and latent TB infection because of its potent early bactericidal activity against Мycobacterium ...tuberculosis. Currently, TB resistant to INH, alone or in combination with other drugs, is the most common type of drug-resistant TB. Epidemiology of INH-resistant TB, the molecular mechanisms of drug resistance, current methods for diagnosis and therapeutic regimens of this TB form are presented. Studies in the last years have shown that resistance to INH reduces the probability of treatment success and increases the risk of acquiring resistance to other important first-line drugs. Based on the most recent meta-analyses, the last WHO recommendations for treatment of INH-resistant TB are to include rifampicin (RIF), ethambutol, pyrazinamide and levofloxacin for 6 months, and not to add streptomycin or other injectable agents to the drug regimen. The guideline emphasizes the importance of excluding resistance to RIF before starting the regimen for INH-resistant TB because of the risk for development of multidrug-resistant TB during the treatment course. The WHO recommendations are based on observational studies, not randomized controlled trials, and are thus conditional and based on low certainty in the estimates of effect. Therefore, further work is needed to optimize the treatment and control of INH-resistant TB.
Introduction:
The transmission of drug-resistant tuberculosis is one of the greatest challenges facing the global tuberculosis control.
Aim:
The aim of the study was to investigate the resent ...transmission of rifampicin resistant tuberculosis in Bulgaria and to describe the mutations related to the antimicrobials' resistance using whole genome sequencing.
Materials and methods:
As part of an ECDC funded pilot study for evaluation of the systematic use of whole genome sequencing (WGS) of
Mycobacterium tuberculosis
(MTB) surveillance (EUSeqMyTB), Bulgaria provided 65 rifampicin resistant isolates over a three years' timeframe (2017-2019) representing 87.5% of the notified rifampicin resistant cases. Drug resistance prediction and relatedness analysis of the resistant isolates was performed in collaboration with San Raffaele Scientific Institute, Milan, Italy.
Results:
Almost all of the isolates were identified as Euro-American lineage (96.9%); 18.5% of the isolates were found to be resistant to fluoroquinolones, but no mutations conferring resistance to bedaquiline or linezolid could be identified. Less than half (43.3%) of the isolates were clustered (<5 SNPs distance) into a total of seven national SNP-based clusters, while a total of six isolates were found to be part of different cross-border clusters. All clustered cases originated from Bulgaria.
Conclusions:
WGS has proven to be a reliable tool for surveillance and tracing of recent transmission of tuberculosis and has the potential for resistance prediction for most of the antituberculosis drugs.
ISONIAZID - MONORESISTANT TUBERCULOSIS IN BULGARIA Stanislava Yordanova; Ana Baykova; Yuliana Atanasova ...
Problems of infectious and parasitic diseases,
05/2020, Letnik:
48, Številka:
1
Journal Article
Odprti dostop
Background. Isoniazid is a common drug in the treatment regimens for TB infection. Monoisoniazid resistance reduces the probability of a successful treatment outcome and increases the risk of ...acquiring additional drug resistance. Material and methods. For the period 2015-2016 a total of 36 TB cases were confirmed in NRL TB, Sofia, as isoniazid-monoresistant Mycobacterium tuberculosis complex. Minimum inhibitory concentration testing for isoniazid was conducted with BАСТЕС MGIT 960 System in the following concentrations of the drug: 0.1 μg/ml, 0.15μg/ml, 0.2μg/ml, 0.3μg/ml, 0.4μg/ml. Molecular testing was performed with GenoType ® MTBDRplus in order to detect the most common mutations associated with resistance to isoniazid. Results. Only 25% of the tested M. tuberculosis complex isolates with phenotypic isoniazid monoresistance had the S315T1 mutation in katG; all isolates were with MIC over 0.4 μg/ml. C15T in the promoter region of inhA was detected in 22.22% of cases and only 1 of them showed MIC below 0.4 μg/ml. No mutations were detected in nearly half of the cases (n=19, 52.78%) and most of these isolates were with lower MIC values (n=12). Conclusion. The rapid testing with GenoType ® MTBDRplus can be used as a screening procedure indicating whether further examination of isoniazid MIC is relevant in resistant M. tuberculosis and whether higher doses could be considered.
PDF
