ABSTRACT Zika virus (ZIKV) is an enveloped, single-stranded RNA arbovirus belonging to the genus Flavivirus. It was first isolated from a sentinel monkey in Uganda in 1947. More recently, ZIKV has undergone rapid geographic expansion and has been responsible for outbreaks in Southeast Asia, the Pacific Islands, and America. In this review, we have highlighted the influence of viral genetic variants on ZIKV pathogenesis. Two major ZIKV genotypes (African and Asian) have been identified. The Asian genotype is subdivided into Southwest Asia, Pacific Island, and American strains, and is responsible for most outbreaks. Non-synonymous mutations in ZIKV proteins C, prM, E, NS1, NS2A, NS2B, NS3, and NS4B were found to have a higher prevalence and association with virulent strains of the Asian genotype. Consequently, the Asian genotype appears to have acquired higher cellular permissiveness, tissue persistence, and viral tropism in human neural cells. Therefore, mutations in specific coding regions of the Asian genotype may enhance ZIKV infectivity. Considering that mutations in the genomes of emerging viruses may lead to new virulent variants in humans, there is a potential for the re-emergence of new ZIKV cases in the future.

Abstract Vitamin D exerts an immuno-modulatory activity on several immune system cells through the vitamin D receptor (VDR). Herein, we verified that age and a therapeutic regimen containing protease inhibitors are associated with failures in antiretroviral therapies (ARVs). In addition, we assessed whether a VDR SNP (rs11568820: C allele and CC genotype) and GC (rs2228570-rs11568820) allelic combinations are associated with immunological failure (p < 0.05). Our findings suggest a possible role of VDR SNPs on immunological failure in HIV-1+ individuals undergoing regular ARVs.

Abstract β-Defensin-1, an antimicrobial peptide encoded by the DEFB1 gene, is known to play an important role in lung mucosal immunity. In our association study we analyzed three DEFB1 functional polymorphisms -52G>A (rs1799946), -44C>G (rs1800972) and -20G>A (rs11362) in 92 tuberculosis patients and 286 healthy controls, both from Northeast Brazil: no association was found between the studied DEFB1 polymorphisms and the disease. However we cannot exclude that this lack of association could be due to the low number of subjects analyzed, as suggested by the low statistical power achieved for the three analyzed SNPs (values between 0.16 and 0.50).

Inter-individual heterogeneity in the response to human T-lymphotropic virus 1 (HTLV-1) infection has been partially attributed to host genetic background. The antiviral activity of the inflammasome cytoplasmic complex recognises viral molecular patterns and regulates immune responses via the activation of interleukin (IL)-1 family (IL-1, IL-18 and IL-33) members. The association between polymorphisms in the inflammasome receptors NLRP1 and NLRP3 and HTLV-1 infection was evaluated in a northeastern Brazilian population (84 HTLV-1 carriers and 155 healthy controls). NLRP3 rs10754558 G/G was associated with protection against HTLV-1 infection (p = 0.012; odds ratio = 0.37). rs10754558 affects NLRP3 mRNA stability; therefore, our results suggest that higher NLRP3 expression may augment first-line defences, leading to the effective protection against HTLV-1 infection.

O advento dos métodos moleculares tem, nos últimos anos, revolucionado a detecção e caracterização dos microorganismos em diversas áreas médicas diagnósticas, tais como virologia, micologia, parasitologia, microbiologia e odontologia. Dentre as técnicas baseadas em biologia molecular, a PCR (Polymerase Chain Reaction) trouxe enormes benefícios e desenvolvimentos científicos, se mostrando como um excelente caminho para a rápida detecção de patógenos, até mesmo aqueles de difícil cultivo. Derivada da PCR convencional, a PCR em Tempo Real se mostra como uma inovação tecnológica e vem conquistando espaço nos diagnósticos clínicos e nos laboratórios de pesquisa por apresentar a capacidade de gerar, além de resultados qualitativos, resultados quantitativos, se mostrando de forma mais rápida e precisa. Este trabalho de revisão tem por objetivo explorar a utilidade clínica da técnica de PCR convencional e em Tempo real nas diversas áreas médicas supracitadas, abrangendo seus principais usos e avanços, direcionando para o cotidiano profissional.

Recent developments in molecular methods have revolutionized the detection and characterization of microorganisms in a broad range of medical diagnostic fields, including virology, mycology, parasitology, microbiology and dentistry. Among these methods, Polymerase Chain Reaction (PCR) has generated great benefits and allowed scientific advancements. PCR is an excellent technique for the rapid detection of pathogens, including those difficult to culture. Along with conventional PCR techniques, Real-Time PCR has emerged as a technological innovation and is playing an ever-increasing role in clinical diagnostics and research laboratories. Due to its capacity to generate both qualitative and quantitative results, Real-Time PCR is considered a fast and accurate platform. The aim of the present literature review is to explore the clinical usefulness and potential of both conventional PCR and Real-Time PCR assays in diverse medical fields, addressing its main uses and advances.

This study compares the detection rates of Chlamydia trachomatis by two techniques, direct immunofluorescence (IMF) and real time polymerase chain reaction (PCR), in patients with and without intra-epithelial cervical lesions (SIL) in Recife. We conducted a transversal study involving 35 women with SIL and 35 without SIL attended at Ambulatório Especializado da Mulher, Recife, Brazil. They were tested for Chlamydia trachomatis using two techniques, direct IMF or real time PCR. The rates of Chlamydia trachomatis detection were compared and the association with intra-epithelial cervical lesions was determined using the chi-square test at a 5% level of significance. Concordance between the tests was evaluated using kappa. The global prevalence of Chlamydia infection was 47.1% by direct IMF and 58.6% by real time PCR. A significant association was observed between Chlamydia diagnosis and presence of intra-epithelial cervical lesions, with about 80% positive results by direct IMF and 77.1% by real time PCR. However, the detected rate of infection with Chlamydia trachomatis was significantly greater in patients without intra-epithelial cervical lesions tested by real time PCR (40%) when compared to direct IMF (14.3%). The concordance between the tests was weak, with a kappa coefficient of 0.4. Both real time PCR and direct IMF detected elevated rates of Chlamydia infection in patients with intra-epithelial cervical lesions (80%) but the tests were discordant when patients without cervical lesions were tested, possibly because sensitivity of real time PCR is greater.