Doenças Infecciosas
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Programa de Pós-Graduação em Doenças Infecciosas
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URL do programa: http://doencasinfecciosas.ufes.br/pos-graduacao/PPGDI
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Navegando Doenças Infecciosas por Autor "Almeida Júnior, Pedro Sousa de"
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- ItemInfluência da terapia antituberculose sobre Mycobacterium tuberculosis ativos e dormentes em amostras de escarro de pacientes com tuberculose pulmonar(Universidade Federal do Espírito Santo, 2019-08-16) Almeida Júnior, Pedro Sousa de; Palaci, Moises; https://orcid.org/0000000320136071; http://lattes.cnpq.br/2602694352713051; https://orcid.org/; http://lattes.cnpq.br/9774221817421517; Spano, Liliana Cruz; https://orcid.org/0000000262056988; http://lattes.cnpq.br/7451382455806895; Santos, Kenia Valeria dos; https://orcid.org/; http://lattes.cnpq.br/9074173162086323; Ribeiro, Fabiola Karla Correa; https://orcid.org/; http://lattes.cnpq.br/9887373751252283; Hadad, David Jamil; http://lattes.cnpq.br/1780085142505190Tuberculosis (TB) is one of the oldest infectious-contagious diseases in the world and the eradication of which remains a challenge. One of the major problems related to TB is the latent infection in which Mycobacterium tuberculosis (MTB) is found in its host in a metabolic state characterized as "numbness". In this state, the microorganism is not recognized by the immune system and is not detected by conventional diagnostic methods. This work aims to detect metabolically diverse populations of MTB in sputum samples of patients with pulmonary TB and to analyse the influence of tuberculosis therapy on these bacilli. The secondary objective of this study is to verify whether persistent bacilli populations may imply therapeutic failure. For this purpose, the 48 wells plate dilution technique was used, which determines the amount of microorganisms by calculating the Most Probable Number (MPN). The MPN determines the amount of microorganisms that grow in liquid medium (7H 9) and in liquid medium after the addition of liquid culture supernatant of MTB (SN). In addition, conventional diagnostic methods, bacilloscopy and solid and liquid cultures were performed. Sputum samples were collected prior to treatment (M0) and monthly until the end of treatment (M1 to M6). To lower the rate of contamination during the procedure, oral hygiene with chlorhexidine 0.12% was standardized. The preliminary clinical and epidemiological data show that the population studied is young (39.6 ± 19.4), with body mass index (BMI) within the international standards of normality (20.5 ± 1.6), being 57% male patients and 43% female. The most reported symptoms were cough and fever, with time of disease progression around 1 to 3 months as the most frequent period (71% for each). The preliminary radiographic data indicate that all patients had radiographic images suggestive of abnormal TB, with six (86%) of these patients characterized with advanced disease and one (14%) with moderate, with the same proportion found in relation to cavitation. The microbiological data reveal that only one (20%) of the conventional cultures (Ogawa or MGIT) remained positive for MTB after two months of treatment. A preliminary analysis indicated that 84% of the bacilli of the samples M0 and 98% of the M1-M4 samples are dormant or SN-dependent bacilli. When analysing the effect of TB therapy on the different MTB populations in sputum samples of patients under treatment, a progressive decrease in the amount of microorganisms over the months of treatment was observed, mainly in relation to metabolically active microorganisms.
- ItemMetodização do isolamento e análise do perfil de suscetibilidade aos antimicrobianos das populações ressuscitáveis e metabolicamente ativas de Mycobacterium tuberculosis(Universidade Federal do Espírito Santo, 2021-07-29) Brunetti, Manuela Negrelli; Almeida Júnior, Pedro Sousa de; https://orcid.org/0000-0002-8977-6141; http://lattes.cnpq.br/9774221817421517; Palaci, Moisés; https://orcid.org/0000000320136071; http://lattes.cnpq.br/2602694352713051; https://orcid.org/0000-0002-2139-2889; http://lattes.cnpq.br/9382497302950043; Santos, Kênia Valéria dos; https://orcid.org/0000-0001-6871-3128; http://lattes.cnpq.br/9074173162086323; Ferrazoli, Lucilaine; https://orcid.org/0000-0002-5389-7056; http://lattes.cnpq.br/8786839834967611An effective antimicrobial therapy is one of the biggest challenges in combating Tuberculosis (TB), since therapeutic failures can happen for several reasons. The bacillus that causes the disease can be found in different metabolic states in sputum samples from patients with TB, and it has been demonstrated that these bacilli in dormant states are more tolerant to some drugs and are not visualized by conventional diagnostic methods, which may justify eventual therapeutic failures for no apparent reason. This study aimed to assess whether the antimicrobial susceptibility profile of the total population (resuscitable + active) of Mycobacterium tuberculosis, isolated from sputum samples from patients with pulmonary TB, differs from the profile of the metabolically active population. The study was divided into two stages. The first consisted of standardizing the obtainment of the total population of bacilli by using a culture medium with MTB liquid culture supernatant filtrate (SN), and standardizing the Antimicrobial Susceptibility Test (AST) by the broth microdilution method. The second stage tested standardized methods for obtaining the total bacterial population using sputum samples from patients with pulmonary TB and followed by performing AST on these samples. Our results showed that the 7H9 liquid culture medium added with SN was superior to the others tested in relation to the recovery of resuscitable bacilli and with sufficient bacterial concentration to carry out the AST directly. However, due to the high contamination rate of this medium, the indirect method was used to obtain MTB populations, before the AST. The addition of SN to the 7H9 liquid growth medium has been shown to decrease the positivity time by up to 1.5 days. The use of Optical Density as a growth detection tool in liquid culture was shown to be inferior to the automated system, not having any correlation with bacterial growth. Additionally, our results showed that the washing and freezing step seems to reduce the inhibitory factors present in the sputum, by decreasing the growth inhibition rate after freezing the samples, however, it does not eliminate them. The use of SN has shown, in tests with reference strain, that it accelerates the growth of active MTB, but does not alter bacterial quantification by the Most Probable Number (MPN) technique. The AST with the total population of bacilli, although presenting higher MIC values more frequently, does not imply changes in sensitivity and resistance in the population of patients without previous treatment for pulmonary TB. Nevertheless, our results suggest that the susceptibility profile of the total population of bacilli compared to the active population, of the only case of a patient under treatment included in this study, showed possibly different sensitivity/resistance patterns in this population of patients, suggesting the need for new studies involving patients undergoing treatment with suspected resistance, therapeutic failure or relapse.