Development and evaluation of a single-tube nested PCR with colorimetric assay for Mycobacterium tuberculosis detection.

Molecular techniques have revolutionized tuberculosis (TB) diagnosis by offering a faster and more sensitive approach, detecting Mycobacterium tuberculosis (Mtb) DNA directly from samples. Single-tube nested PCR (STNPCR) combines two PCR reactions with separate oligonucleotide sets in a single tube. Moreover, colorimetric methods in PCR products have been studied for pathogen detection. Thus, this study aimed to establish a novel system based on colorimetric STNPCR for Mtb detection using microtiter plates with IS6110-amplified fragments. The results showed a general colorimetric STNPCR detection limit of 1 pg/µl. Its general sensitivity and specificity were 76.62 and 60.53%, respectively, with kappa index agreement of 0.166.

A total of 318 biological samples (urine, plasma, peripheral blood mononuclear cells, pleural fluid and sputum) from pulmonary/extrapulmonary TB and non-TB patients were used in this study. The colorimetric STNPCR assay using IS6110 as the target gene was developed and optimized for Mtb detection based on similar validated systems. Cut-off values based on receiver operator characteristic curve analysis were defined to determine the sensitivity and specificity for each sample type. The technique's performance was assessed according to kappa index calculations and interpretation.

Evaluation of Polymorphisms in IL8 and IL16 Genes in Patients with Acute Coronary Syndrome

Abstract Background: Acute coronary syndrome (ACS) is a cardiovascular disease caused by obstruction of coronary arteries by atheromatous plaque. Susceptibility to this disease may be related to genetic variations, such as single nucleotide polymorphisms (SNPs). Objective: In this study, we evaluated the relationship between SNPs in IL8 (rs4073; -251 A/T) and IL16 (rs11556218; T/G) genes and SCA in a Brazilian population. Materials and Methods: A sample of 200 patients with ACS and 50 non-ACS patients hospitalized at the Real Hospital Português, Recife - PE, Brazil, and 220 blood donors (donors) was used. Genotyping was carried out by polymerase chain reaction, and DNA sequencing. Statistical analyzes were performed using the Williams G, Chi-square and Kruskal Wallis tests, using the BioEstat 5.0 program, and the data with a value of p < 0.05 were considered significant. Results: In the IL8 gene, the AT genotype was the most frequent (p > 0.05) in all three groups. In the IL16 gene, genotypic distributions were different between patients with ACS and the donor group (p = 0.002), with the most frequent G allele in the second group (p = 0.0052). The IL-16 cytokine was higher in donors than in patients with ACS (p = 0.04) and the G (TG + GG) allele had higher values of this cytokine (p = 0.01). Conclusions: The results demonstrate the important role of the rs11556218 SNP in IL16 gene in SCA, evidencing that the G allele may be associated with a decreased risk of the disease.

Leishmania (Viannia) braziliensis isolated from the saliva of patients in a cutaneous leishmaniasis-endemic area of northeastern Brazil.

Several studies have described the use of non-invasive collection methods, mostly based on the detection of parasite DNA, for diagnosis. However, no Leishmania specimens have been isolated from saliva. Here, we report the first isolation of Leishmania braziliensis from the saliva of humans with cutaneous leishmaniasis but without lesions on their mucosa. The isolates were obtained from salivary fluid inoculated in hamsters and were tested by multilocus enzyme electrophoresis. Seven samples from 43 patients suspected of having the disease were identified for in vivo culture. These findings suggest that saliva is a clinical sample that allows the isolation of Leishmania sp.

Avaliação do Polimorfismo -174 G/C do gene IL-6 na Síndrome Coronariana Aguda no Nordeste do Brasil / Evaluation of IL-6 (-174 G/C) Polymorphism in Acute Coronary Syndrome in the Northeast of Brazil

Fundamento: A síndrome coronariana aguda (SCA) é a principal causa de morbidade e mortalidade no mundo. É uma doença multifatorial causada por obstrução das artérias coronárias por placa ateromatosa que leva à isquemia cardíaca. Diversos estudos sugerem que alguns polimorfismos genéticos alteram os níveis de citocinas e influenciam o desenvolvimento de SCA. Objetivo: Neste estudo, avaliamos o polimorfismo - 174 G/C do gene IL-6 , níveis séricos de citocina e sua relação com SCA e escore de risco de thrombolysis in myocardial infarction (TIMI). Materiais e métodos: Foram selecionados 200 pacientes com SCA [risco de TIMI ­ Baixo (70), Intermediário (89), Alto (41)] na população brasileira. A genotipagem foi feita pela reação em cadeia da polimerase (PCR), seguida de sequenciamento de DNA. Resultados: Não houve diferenças significativas na distribuição dos genótipos (p = 0,53) e dos alelos (p = 0,32) entre grupos de pacientes com SCA e sem SCA no polimorfismo alélico do IL-6 , nem entre os três escores de risco TIMI (p > 0,05). Além disso, o polimorfismo do IL-6 não afetou os níveis de citocina, os quais não estavam relacionados ao escore de TIMI. Conclusões: Com esses resultados, sugerimos que o polimorfismo ­ 174 G/C do gene IL-6, até agora, não está relacionado à SCA e não alterou os níveis de citocina na população estudada. Novos estudos em populações diferentes devem ser feitos para verificar esses resultados. É importante enfatizar que, como a SCA é uma doença multifatorial, outros fatores de risco e outras citocinas pró-inflamatórias devem ser avaliadas para o conhecimento dessa patologia

Background: Acute coronary syndrome (ACS) is a leading cause of morbidity and mortality worldwide. It is a multifactorial disease caused by obstruction of the coronary arteries by atheromatous plaques and leads to heart ischemia. Several studies suggest that some genetic polymorphisms change the cytokines levels and influence ACS development. Objective: In this study, we evaluated the IL-6 polymorphism -174 G/C, serum levels of cytokine and its relationship with ACS and the thrombolysis in myocardial infarction (TIMI) risk score. Materials and Methods: A sample of 200 patients with ACS [TIMI risk ­ Low (70); Intermediate (89); High (41)] in Brazilian population was used. Genotyping was carried out by polymerase chain reaction, followed by DNA sequencing. Results: There was no significant differences in genotype (p = 0.53) and allele (p = 0.32) distributions between ACS patient and without ACS patients groups on IL-6 allelic polymorphism and between the three different TIMI risk score (p > 0.05). Moreover IL-6 polymorphism did not affect the cytokine levels and these levels were not related to the TIMI score. Conclusions: With these results, we suggest that the IL-6 (-174 G/C) polymorphism, until now, is not related to ACS and did not change the levels of the cytokine in studied population. Further studies with different populations should be done to verify those results. It is important to emphasize that, since ACS is a multifactorial disease, other risk factors and other pro-inflammatory cytokines should be assessed to better understand this pathology

Occupationally acquired american cutaneous leishmaniasis.

WE REPORT TWO OCCUPATIONALLY ACQUIRED CASES OF AMERICAN CUTANEOUS LEISHMANIASIS (ACL): one accidental laboratory autoinoculation by contaminated needlestick while handling an ACL lesion sample, and one acquired during field studies on bird biology. Polymerase chain reaction (PCR) assays of patient lesions were positive for Leishmania, subgenus Viannia. One isolate was obtained by culture (from patient 2 biopsy samples) and characterized as Leishmania (Viannia) naiffi through an indirect immunofluorescence assay (IFA) with species-specific monoclonal antibodies (mAbs) and by multilocus enzyme electrophoresis (MLEE). Patients were successfully treated with N-methyl-glucamine. These two cases highlight the potential risks of laboratory and field work and the need to comply with strict biosafety procedures in daily routines. The swab collection method, coupled with PCR detection, has greatly improved ACL laboratory diagnosis.