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result(s) for
"Ramis, Ivy Bastos"
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Genotyping methods and their contributions to the study of tuberculosis dynamic in Latin America
by
Castillos de Ibrahim das Neves, Yasmin
,
Perdigão, João
,
Bastos Ramis, Ivy
in
Collaboration
,
genotyping
,
IS6110-RFLP
2023
Introduction: Mycobacterium tuberculosis genotyping has impacted evolutionary studies worldwide. Nonetheless, its application and the knowledge generated depend on the genetic marker evaluated and the detection technologies that have evolved over the years. Here we describe the timeline of main genotypic methods related to M. tuberculosis in Latin America and the main findings obtained. Methodology: Systematic searches through the PubMed database were performed from 1993 to May 2021. A total of 345 articles met the inclusion criteria and were selected. Results: Spacer oligonucleotide typing (spoligotyping) was the most widely used method in Latin America, with decreasing use in parallel with increasing use of mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) and whole genome sequencing (WGS). Among the countries, Brazil, Mexico, and Argentina had the most publications, and a considerable part of the articles were in collaboration with Latin American or non-Latin American institutions; a small proportion of studies needed partnerships to perform the genotypic methods. The genotypic methods allowed the identification of M. tuberculosis genotypes with greater capacity for clonal expansion and revealed the predominance of the Euro-American lineage in Latin America. There was a notable presence of the Beijing family in Peru and Colombia. Conclusions: The data obtained demonstrated the importance of expanding collaborative networks of tuberculosis (TB) research groups to countries with low productivity in this area, the commitment of the few Latin American countries to advance TB research, as well as the inestimable value of building a Latin America database, considering ease of population mobility between countries.
Journal Article
The interplay between mutations in cagA, 23S rRNA, gyrA and drug resistance in Helicobacter pylori
by
Gastal, Otávio Leite
,
Gonçalves, Carla Vitola
,
Silva, Pedro Eduardo Almeida da
in
Anti-Bacterial Agents - pharmacology
,
Antigens, Bacterial - genetics
,
Antimicrobial resistance
2018
In this study, we evaluated the mutations of Helicobacter pylori associated with resistance to clarithromycin and levofloxacin. Furthermore, based on the proposed interaction between antimicrobial resistance and pathogenicity, we correlated the mutation profiles of the strains with the presence of the pathogenicity gene cagA. We analyzed 80 gastric biopsy specimens from H. pylori-infected patients for point mutations in the 23S rRNA gene region and in the gyrA gene, which are related to clarithromycin and levofloxacin resistance, respectively, and investigated the presence of the cagA gene in these strains. We observed that in the assayed biopsies, 8.7% (7/80) had mutations in the 23S rRNA gene region at positions 2143 and 2142, while 22.5% (18/80) had mutations in gyrA at codons 87 and 91. Moreover, absence of the CagA-EPIYA pathogenicity factor was observed in 68% (17/25) of resistant samples. The knowledge of the local profile of antimicrobial resistance and the complex interplay involving resistance and pathogenicity can contribute to an appropriate clinical approach.
Journal Article
Completude dos dados do sistema de informações de tuberculose de pessoas privadas de liberdade do Rio Grande do Sul, Brasil
by
Possuelo, Lia Gonçalves
,
Silva, Pedro Eduardo Almeida da
,
Busatto, Caroline
in
Acquired immune deficiency syndrome
,
AIDS
,
Completeness
2022
Resumo A tuberculose (TB) apresenta incidências elevadas em todo o mundo, sendo ainda mais grave em pessoas privadas de liberdade (PPL). Foi avaliada a completude das notificações de TB de PPL no SINAN realizadas por equipes de atenção primária prisional (eAPP) ou por outros estabelecimentos de saúde do RS. Estudo descritivo, transversal, utilizando dados de notificações de PPL feitas no SINAN TB pelas eAPP ou por outros estabelecimentos de saúde, de janeiro de 2014 a novembro de 2018. Foi analisado o percentual de completude das variáveis: sexo, raça/cor, escolaridade, HIV, tipo de entrada, baciloscopia de escarro, cultura do escarro, Aids, tratamento antirretroviral durante o tratamento para a TB, tratamento diretamente observado (TDO), baciloscopia de 6º mês e situação de encerramento. Praticamente 53% dos casos de TB em PPL foram notificados por eAPP, e 47,1% foram notificados por outros estabelecimentos de saúde. Oitenta por cento das variáveis foram classificadas na categoria 4 (75,1% a 100% de completude). No entanto, as variáveis TDO e baciloscopia de 6º mês foram classificadas na categoria 3 (50,1% e 75% de completude). Embora não comprometa a notificação da TB no SINAN, a ausência de dados pode prejudicar a qualidade das informações sobre a doença. Abstract Tuberculosis (TB) has a high incidence in several countries and is even more severe in prisoners. We evaluated the completeness of prisoners TB notifications in the Notifiable Disease Information System (SINAN) carried out by prison primary care teams (eAPP) or by other health facilities in the state of Rio Grande do Sul (RS). This descriptive cross-sectional study used prisoners data notifications in the SINAN TB by the eAPP or other health facilities from January 2014 to November 2018. We analyzed the percentage of completeness of the variables: gender, ethnicity, schooling, HIV, entry type, sputum smear, sputum culture, AIDS, ART during TB treatment, directly observed treatment (DOT), sixth-month smear, and closure status. Around 52.9% of TB cases in prisoners were reported by eAPP, and other health facilities reported 47.1% of the cases. Eighty percent of the variables were classified in category 4 (75.1% to 100% completeness). However, the DOT and sixth-month smear variables were classified into category 3 (50.1% and 75% completeness). While it does not compromise the notification of TB in the SINAN, the lack of data can impair the quality of information about the disease.
Journal Article
Evaluation of diagnostic methods for the detection of Helicobacter pylori in gastric biopsy specimens of dyspeptic patients
by
Rodrigues, Obirajara
,
Fernandes, Márcia Silveira
,
Silva, Pedro Eduardo Almeida da
in
Diagnostic tests
,
Gastrointestinal diseases
,
Gram-negative bacteria
2012
Helicobacter pylori infects nearly 50% of the world's population. This microorganism is accepted as the most important agent of gastritis and as a risk factor for peptic ulcer disease and gastric adenocarcinoma. Currently many diagnostic methods exist for detecting H. pylori, however they all have limitations, thus it is recommend a combination of at least two methods. The aim of this study was to evaluate diagnostic methods, such as in-house urease test, culture and Polymerase Chain Reaction (PCR), for the detection of the H. pylori in gastric biopsy specimens of 144 dyspeptic patients, using as gold standard the association between histology and rapid urease test. According to the gold standard used in this study, 48 (33.3%) patients were infected with H. pylori, while 96 (66.7%) were classified as not infected. The in-house urease test and the PCR were the most sensitive methods (100%), followed by culture (85.4%). However, the inhouse urease test and the culture were the most specific (100%), followed by PCR (75%). In conclusion, this study showed that, in comparison with the combination of histology and rapid urease test, the in-house urease test and the PCR presented 100% of sensitivity in the diagnosis of gastric infection by H. pylori, while the in-house urease test and the culture reached 100% of specificity. These finding suggest that the combination of two or more methods may improve the accuracy of the H. pylori detection.
Journal Article
Relationship of interleukin-1B gene promoter region polymorphism with Helicobacter pylori infection and gastritis
by
Gonçalves, Carla Vitola
,
Da Silva, Pedro Eduardo Almeida
,
Lara, Caroline
in
Biopsy
,
cagA gene
,
Female
2015
Introduction: Helicobacter pylori infection is associated with gastritis, peptic ulcer disease and gastric carcinoma. The severity of damage is determined by the interplay between environmental/behavioral factors, bacterial pathogenicity genes and host genetic polymorphisms that can influence the secretion levels of inflammatory cytokines. Accordingly, this study aimed to identify polymorphisms in the IL-1B and IL-1RN genes and their associations with H. pylori infection, cagA gene of H. pylori, and gastroduodenal diseases. Methodology: Gastric biopsy samples from 151 patients infected with H. pylori and 76 uninfected individuals were analyzed. H. pylori infection was diagnosed by histology and PCR. Polymorphisms at positions -511, -31 and +3954 of the IL-1B gene were detected by PCR-RFLP, and an analysis of the VNTR polymorphism of the IL-1RN gene was performed by PCR. Results: It was observed that the presence of the T/T genotype at position -511 and the C/C genotype at position -31 were associated with H. pylori infection and with an increased risk of gastritis in H. pylori-positive patients. Additionally, strains from patients H. pylori-positive carrying the cagA gene was significantly related with the T/T genotype at position -511 of IL-1B. No association of polymorphisms at position +3954 of IL-1B and in the IL-1RN with H. pylori infection and with risk of severe gastric diseases was found. Conclusions: We demonstrated that polymorphisms in the promoter region of the IL-1B gene (at positions -511 and -31) are associated with an enhanced risk of H. pylori infection as well as gastritis in H. pylori-positive patients.
Journal Article
cagE as a biomarker of the pathogenicity of Helicobacter pylori
by
Silva, Pedro Eduardo Almeida da
,
Vianna, Júlia Silveira
,
Von Groll, Andrea
in
Adolescent
,
Adult
,
Aged
2013
Helicobacter pylori infection is associated with gastro-duodenal diseases. Genes related to pathogenicity have been described for H. pylori and some of them appear to be associated with more severe clinical outcomes of the infection. The present study investigates the role of cagE as a pathogenicity biomarker of H. pylori compare it to cagA, vacA, iceA and babA2 genes and correlate with endoscopic diagnoses.
Were collected biopsy samples of 144 dyspeptic patients at the Hospital of the Federal University of Rio Grande, Rio Grande do Sul, Brazil. After collection, the samples were sent for histological examination, DNA extraction and detection of all putative pathogenicity genes by PCR.
Of the 144 patients undergoing endoscopy, 57 (39.6%) presented H. pylori by histological examination and PCR by detection of the ureA gene. Based on the endoscopic diagnoses, 45.6% (26/57) of the patients had erosive gastritis, while 54.4% (31/57) had enanthematous gastritis. The genes cagA, cagE, vacAs1/m1, vacAs1/m2 and iceA1 were related to erosive gastritis, while the genes vacAs2/m2, iceA2 and babA2 were associated to enanthematous gastritis. We found a statistically significant association between the presence of cagE and the endoscopic diagnosis. However, we detect no statistically significant association between the endoscopic diagnosis and the presence of cagA, vacA, iceA and babA2, although a biological association has been suggested. Conclusions Thus, cagE could be a risk biomarker for gastric lesions and may contribute to a better evaluation of the H. pylori pathogenic potential and to the prognosis of infection evolution in the gastric mucosa.
Journal Article
Improving tuberculosis control through the partnership between university and the health system
by
Macedo, Maíra Bidart de
,
von Groll, Andrea
,
Silva, Pedro Eduardo Almeida da
in
Adolescent
,
Adult
,
Brazil
2012
INTRODUCTION: Tuberculosis (TB) control is linked to the availability of qualified methods for microbiological diagnostics; however, microscopy with limited sensitivity is the only method available in many locations. The objective of this study was to evaluate the introduction of culture, drug susceptibility testing (DST), and genotyping in the routine of a Municipal Program of Tuberculosis Control. METHODS: Direct microscopy of sputum and culture in Ogawa-Kudoh were performed on 1,636 samples from 787 patients. DST of positive cultures was performed by resazurin microtiter assay and genotyping by mycobacterial interspersed repetitive units-variable number tandem repeat. RESULTS: A total 91 patients with TB were identified. The culture increased case detection by 32% compared with the microscopy; acquired resistance was 3.3% and the genotyping showed high genetic diversity. CONCLUSIONS: Ogawa-Kudoh contributed significantly to the increase in case detection and is suitable for implementation in poor-resource locations. The acquired resistance rate was lower than that reported in a recent Brazilian survey. The high genetic diversity is possibly related to the high TB prevalence in the population, as well as to early detection and suitable treatment of patients. The interaction between research and health care is important for reorienting the practice, transferring technology, and improving TB control. INTRODUÇÃO: O controle da tuberculose (TB) está relacionado com a disponibilidade de métodos de diagnóstico microbiológico qualificados, no entanto a microscopia com a sua limitada sensibilidade é o único método disponível em muitos locais.O objetivo deste estudo foi avaliar a introdução da cultura, teste de sensibilidade aos antimicrobianos (TSA) e genotipagem na rotina de um Programa Municipal de Controle da Tuberculose. MÉTODOS:A baciloscopia direta do escarro e cultura em Ogawa-Kudoh foram realizadas em 1.636 amostras de 787 pacientes. O TSA das culturas positivas foi realizado pelo método de microdiluição e a genotipagem por Mycobacterial Interspersed Repetitive Units - Variable Number Tandem Repeat (MIRU-VNTR). RESULTADOS:Foram identificados 91 pacientes com TB, com a cultura aumentando em 32% a detecção de casos em comparação com a microscopia; a resistência adquirida foi de 3,3% e a genotipagem mostrou alta diversidade genética. CONCLUSÕES: O cultivo em Ogawa-Kudoh contribuiu significativamente para o aumento na detecção de casos e é adequado para ser implementado em locais com poucos recursos. A taxa de resistência adquirida foi menor do que a relatada em recente inquérito nacional. A alta diversidade genética está possivelmente relacionada à alevada prevalência de TB na população, detecção precoce e tratamento adequado dos pacientes.A interação entre a pesquisa e serviço de saúde pública é importante para reorientar a prática, transferir tecnologia e melhorar o controle da TB.
Journal Article
Efflux systems driving resistance and virulence across biological domains
by
Viveiros, Miguel
,
Ramis, Ivy
,
Ramos, Daniela
in
ABC transporters
,
Antimicrobial agents
,
Bacteria
2025
Efflux pumps (EPs) are key contributors to multidrug resistance (MDR) in bacteria, fungi, and cancer cells. These membrane proteins actively extrude a variety of therapeutic agents, reducing their intracellular concentration and thus compromising the efficacy of treatment. Beyond resistance, EPs are also involved in virulence, biofilm formation, immune evasion, and environmental persistence.
This review aimed to provide a comprehensive and critical synthesis of the role of efflux pumps in antimicrobial and antitumoral resistance, as well as their contribution to virulence and persistence across biological domains.
A narrative review was conducted following a structured search strategy in PubMed, Scopus, and Web of Science using combinations of terms related to efflux systems, efflux pumps, resistance mechanisms, virulence factors, detection methods, and inhibitors. The review integrates data from
,
, and clinical studies, including both classical detection strategies and emerging technologies such as clustered regularly interspaced short palindromic repeats (CRISPR)-based modulation, biosensors, and microfluidics.
Efflux pumps from different families (
, resistance-nodulation-division (RND), ATP-binding cassette (ABC), major facilitator superfamily (MFS)) are implicated in the active extrusion of antimicrobial agents, facilitating MDR and treatment failure in pathogens such as
,
,
,
, and cancer cells. EPs also regulate biofilm formation, virulence factor secretion, and metabolic adaptation. Classical methods for detecting efflux (
, minimum inhibitory concentration (MIC) shifts with inhibitors, fluorometric assays) have technical limitations, while novel technologies offer improved precision. Several natural and synthetic efflux pump inhibitors (EPIs) have demonstrated efficacy in preclinical studies, yet few have progressed to clinical use due to toxicity and pharmacokinetic barriers. CRISPR interference systems and combinatory therapies represent promising advances in overcoming EP-mediated resistance.
Efflux systems are central players in both drug resistance and pathogenicity. Although the development of effective EIs remains challenging, advances in molecular detection, gene editing, and drug design hold potential for translational breakthroughs. A deeper understanding of efflux dynamics across organisms is essential to develop adjuvant therapies and reduce the clinical impact of MDR.
Journal Article
Spread of Mycobacterium tuberculosis in Southern Brazilian persons deprived of liberty: a molecular epidemiology study
by
Perdigão, João
,
Croda, Julio
,
de Souza, Mariana Quaresma
in
Biomedical and Life Sciences
,
Biomedicine
,
Brazil - epidemiology
2023
To evaluate the genetic diversity and clustering rates of
M. tuberculosis
strains to better understand transmission among persons deprived of liberty (PDL) in Rio Grande do Sul (RS), southern Brazil. This is a cross-sectional study, including strains of
M. tuberculosis
isolated from PDL, stored at the Central Laboratory of RS, in the period from 2013 to 2018. The molecular characterization was performed using the MIRU-VNTR 15
loci
method. A total of 598 M
. tuberculosis
strains were genotyped, and 37.5% were grouped into 53 clusters. Cluster sizes ranged from 2 to 34 strains. The largest cluster of the study had strains from 34 PDL, and 58.8% of the PDL of this cluster were in P01. Among the clusters formed, in 60.3%, there was at least one strain from P01. The most common strains in RS were LAM (53.2%) and Haarlem (31.1%). The LAM strain was the most likely to form clusters, and Haarlem was associated with anti-TB drug resistance. This was translational research, and the results can collaborate with the TB control programs, leading to improved strategies that allow the reduction of the TB burden in prisons.
Journal Article