A conceptual framework for dynamics of cccDNA in hepatitis B virus / 中华肝脏病杂志

The resolution of the hepatitis C issue has raised expectations for a chronic hepatitis B cure, driving the industry to expand investment in research and development efforts to strengthen functional cure strategies. These strategies have a wide variety of types, and the published research findings are heterogeneous. The theoretical analysis of these strategies is of great significance for determining prioritized research orientations as well as sensibly allocating research and development resources. However, due to a paucity of necessary conceptual models, current theoretical analysis has not been able to unify various therapeutic strategies into a proper theoretical framework. In view of the fact that the decrease in the quantity of cccDNA is an inevitable core event accompanied by the process of functional cure, this paper intends to analyze several chronic hepatitis B cure strategies using cccDNA dynamics as a framework. Furthermore, there are currently few studies on the dynamics of the cccDNA field, hoping that this article can promote recognition and research in this field.

Prevalencia y genotipicación de virus papiloma humano vaginal y cervical en trabajadoras sexuales de un centro de salud sexual en la zona Norte de Santiago, Chile / Prevalence and genotypes of cervical and vaginal HPV in female sex workers attending a Sexual Control Centre, North Area of Santiago, Chile

INTRODUCCIÓN: En Chile, el cáncer de cuello uterino (CCU) es la segunda causa de muerte por neoplasias malignas en la mujer. El principal agente causal es el virus papiloma humano (VPH). Comparando con la población general, los o las trabajadoras(es) sexuales (TS) tienen alto riesgo de adquirir VPH. OBJETIVO: Analizar la prevalencia y genotipos del VPH cervical y vaginal en TS que se atienden en un Centro de Salud Sexual de Santiago, Chile. Pacientes y MÉTODO: Se realizó un estudio transversal en 97 mujeres TS, de 19 a 70 años de edad. Se obtuvieron dos muestras por paciente, una de exocérvix y otra de paredes vaginales. El ADN de VPH fue identificado por reacción de polimerasa en cadena (RPC) y su genotipo fue investigado para 32 tipos de VPH. RESULTADOS: La prevalencia de VPH global fue de 45%, observándose portación cervical en 41,2% y vaginal en 36,1%, con una coinfección de 32%. El 63% de las muestras tenía genotipos de alto riesgo. Los VPH de alto riesgo más frecuentes fueron el VPH 66 (12%), VPH 58 (9,3%), seguidos por VPH 16, VPH 59 y VPH 82 con igual frecuencia (8% c/u). Treinta y dos mujeres (43%) fueron infectadas con genotipos múltiples. CONCLUSIÓN: El VPH es una infección frecuente entre las TS. Este es el primer estudio en Chile sobre prevalencia y genotipos de VPH en TS.

BACKGROUND: In Chile, cervical cancer is the second leading cause of death from malignancy in women. The main causal agent of cervical cancer is the human papillomavirus (HPV). Compared with the general population, sex workers (SW) are at increased risk of acquiring HPV. AIM: To analyze the prevalence and genotypes of cervical and vaginal HPV in female SW attending a Sexual Control Centre. METHODS: A cross-sectional study was carried out on 97 women (19-70 years old). Two samples were taken per patient, one from exocervix and the other from vaginal walls. HPV DNA. was identified by polymerase chain reaction (PCR) and genotyping using specific probes for 32 types of HPV. RESULTS: The overall frequency of HPV was 45%, 41.2% in cervical carrier and 36.1% in vaginal carrier, 32% were co-infected, 63% of HPV were high-risk genotypes. The most frequent high-risk HPV was HPV 66 (12%), HPV 58 (9.3%), followed by HPV 16, HPV 59 and HPV 82 with the same frequency (8% each one). Thirty two (43%) of females were infected with multiple genotypes. CONCLUSION: HPV is frequent infection among SW. This is the first study in Chile on the prevalence and genotypes of HPV in sex workers.

Distributive characteristics of HBV DNA CpG islands in HBsAg positive mothers and its relationship with intrauterine transmission / 中华流行病学杂志

Objective: To investigate the type, length, and CG loci of HBV DNA CpG islands in HBsAg positive maternal C genotype and its relationship with intrauterine HBV transmission, so as to provide a new perspective for the study of intrauterine transmission of HBV. Methods: From June 2011 to July 2013, HBsAg-positive mothers and their newborns who delivered in the obstetrics and gynecology department of the Third People's Hospital of Taiyuan were collected. Epidemiological data were collected through face-to-face questionnaires and electronic medical records. Serum HBV markers and serum HBV DNA were detected by electrochemiluminescence and quantitative fluorescence PCR, respectively. Intrauterine transmission of HBV was determined by positive HBsAg and/or HBV DNA in femoral venous blood before injection of HBV vaccine/Hepatitis B immunoglobulin within 24 h of birth. A total of 22 mothers and their newborns with HBV DNA load ≥106 IU/ml in intrauterine transmission were selected as the intrauterine transmission group, and 22 mothers with HBV DNA load ≥106 IU/ml without intrauterine transmission were chosen as the control group by random seed method. The distribution prediction of CpG islands of HBV DNA in 39 mothers with genotype C by HBV DNA sequencing was analyzed. Results: Among 39 mothers with HBV C genotype, 19 were in the intrauterine transmission group, and 20 were in the control group. The HBV DNA of 39 patients with genotype C traditional CpG island Ⅱ and Ⅲ, while the control group had traditional CpG island Ⅰ and novel CpG island Ⅳ and Ⅴ. The length of CpG island Ⅱ and Ⅲ and the number of CG loci of CpG island Ⅱ in the intrauterine transmission group differed from those in the control group (P<0.05). The CpG island Ⅱ length ≥518 bp and the number of CG loci ≥40 in the intrauterine transmission group (11/19) were significantly higher than those in the control group (2/20) (P<0.05). The length of CpG island Ⅱ and the number of CG loci in the X gene promoter region (Xp region) were higher than those in the control group (P<0.05). In the HBV intrauterine transmission group, most of maternal (12/19) HBV DNA CpG island Ⅱ completely covered the Xp region, which was significantly higher than that in the control group (5/20), and the number of HBV DNA Xp region CG loci was higher than that in the control group (P<0.05). Conclusions: The distribution of maternal C genotype HBV DNA CpG islands is related to intrauterine transmission. The length of CpG island Ⅱ and the number of CG sites may increase the risk of intrauterine transmission of HBV.

Analysis on influencing factors of HBV intrauterine transmission based on integration of decision tree model and logistic regression model / 中华流行病学杂志

Objective: To investigate the influencing factors of HBV intrauterine transmission and their interaction effects by integrating logistic regression model and Chi-squared automatic interaction detector (CHAID) decision tree model. Methods: A total of 689 pairs of HBsAg-positive mothers and their neonates in the obstetrics department of the Third People's Hospital of Taiyuan from 2007 to 2013 were enrolled, and the basic information of mothers and their neonates were obtained by questionnaire survey and medical record review, such as the general demographic characteristics, gestational week and delivery mode. HBV DNA and HBV serological markers of the mothers and newborns were detected by fluorescence quantitative PCR and electrochemiluminescence immunoassay respectively. The CHAID decision tree model and unconditional logistic regression analysis were used to explore the factors influencing HBV intrauterine transmission in neonates of HBsAg-positive mothers. Results: Among the 689 neonates, the incidence of HBV intrauterine transmission was 11.47% (79/689). After adjusted for confounding factors, the first and second logistic multivariate analysis showed that cesarean delivery was a protective factor for HBV intrauterine transmission (OR=0.25, 95%CI: 0.14-0.43; OR=0.27, 95%CI: 0.15-0.46); both models indicated that maternal HBeAg positivity and HBV DNA load ≥2×105 IU/ml before delivery were risk factors of HBV intrauterine transmission (OR=3.89, 95%CI: 2.32-6.51; OR=3.48, 95%CI: 2.12-5.71), respectively. The CHAID decision tree model screened three significant factors influencing HBV intrauterine transmission, the most significant one was maternal HBeAg status, followed by delivery mode and maternal HBV DNA load. There were interactions between maternal HBeAg status and delivery modes, as well as delivery mode and maternal HBV DNA load before delivery. The rate of HBV intrauterine transmission in newborns of HBeAg-positive mothers by vaginal delivery increased from 19.08% to 29.37%; among HBeAg-positive mothers with HBV DNA ≥2×105 IU/ml, the rate of HBV intrauterine transmission increased to 33.33% in the newborns by vaginal delivery. Conclusions: Maternal HBeAg positivity,maternal HBV DNA ≥2×105 IU/ml and vaginal delivery could be risk factors for HBV intrauterine transmission in newborns. Interaction effects were found between maternal HBeAg positivity and vaginal delivery, as well as vaginal delivery and high maternal HBV DNA load. Logistic regression model and the CHAID decision tree model can be used in conjunction to identify the high-risk populations and develop preventive strategies accurately.

Optimization and application of a high-resolution melting protocol in the characterization of avian infectious laryngotracheitis virus

Resumen En un estudio epidemiológico realizado previamente en Argentina, se analizó la secuencia de un fragmento del gen US5 del virus de la laringotraqueítis infecciosa (ILTV), lo que permitió diferenciar las cepas de campo de las vacunales. También esto permitió definir cinco haplotipos del ILTV, con variaciones específicas en las posiciones 461, 484, 832, 878 y 894 del gen US5. La caracterización de las cepas virales también puede lograrse mediante el análisis de la disociación de alta resolución o high-resolution melting analysis (HRMA), descripto como un método efectivo, rápido y sensible para detectar mutaciones en productos de PCR. En el presente estudio se desarrolló un protocolo de disociación de alta resolución con el objetivo de caracterizar cepas del ILTV circulantes en Argentina. Para ello,se confirmó la especificidad de esta herramienta en diferentes diluyentes del ADN de las muestras, sin observarse interferencias en presencia de ADN heterólogo u otros metabolitos celulares. Asimismo, la concentración de sales en el buffer de elución utilizado durante la extracción de ADN no alteró los perfiles de las curvas. Se obtuvieron perfiles bien definidos con concentraciones de ADN más elevadas (Ct = 26.0), mientras que concentraciones más bajas presentaron curvas heterogéneas (Ct = 32.5). El HRMA mostró una concordancia del 97.49% con la técnica de referencia, la secuenciación. El protocolo de disociación de alta resolución amplifica el ADN antes de su caracterización, por lo que esta técnica podría ser eventualmente utilizada para confirmar la presencia del ILTV y, al mismo tiempo, distinguir haplotipos, optimizando su valor como herramienta de diagnóstico. Esta característica implica una reducción significativa en el tiempo dedicado al procesamiento de muestras.

Actualización epidemiológica: variantes de SARS-CoV-2 en las Américas - 24 de marzo de 2021 / Epidemiological update: SARS-CoV-2 variants in the Americas - March 24, 2021

A la fecha, 141 los países/territorios han detectado casos de infección por alguna de las tres variantes de preocupación (VOC) reconocidas actualmente por la Organización Mundial de la Salud (OMS). De ese total, 32 países/territorios corresponden a la Región de las Américas.

Hepatitis B virus genotypes prevalence in patients from hepatology services in Ceará, Brazil

Abstract INTRODUCTION: Hepatitis B virus (HBV) infection is a public health problem; therefore, we aimed to report HBV genotypes in Ceará, Brazil. METHODS: A total of 103 HBsAg-positive samples were subjected to HBV genotyping and subgenotyping. RESULTS: The following genetic compositions of samples were found: F-54% (F2-83.33%), A-40% (A1-65%), D-6%, C2-1%, E-1%, and G-1%. CONCLUSIONS: Some genotypes are only prevalent in certain parts of the world; however, the State of Ceará is a hub for migration and has one of the most important liver transplantation centers in Brazil, which can explain the prevalence of the F genotype.

Cerebrospinal fluid challenges for the diagnosis of herpes simplex infection in the central nervous system / Desafios do exame do líquido cefalorraquidiano para o diagnóstico de infecção por herpes simplex no sistema nervoso central

Abstract Herpes simplex virus (HSV) is a cause of a severe disease of the central nervous system (CNS) in humans. The demonstration of specific antibodies in the cerebrospinal fluid (CSF) may contribute to the retrospective neurological diagnosis. However, the commercial immunological tests for HSV infection are for use in serum samples. Objective: The aim of the present study was to adapt a commercial kit anti-HSV IgG used for serum samples to be performed with a CSF sample. Methods: Forty CSF specimens from 38 patients with suspected CNS HSV infection were serially diluted for detecting anti-HSV IgG by enzyme immunoassay (EIA). The same samples were also analyzed with the polymerase chain reaction (PCR). Results: The sensitivity of EIA test for HSV was 5% (dilution 1:40) and 65% (dilution 1:2) in CSF, and HSV DNA PCR was 15%. The combined analysis of EIA (dilution 1:2) and PCR increased the sensitivity up to 72.5%. The inflammatory CSF was associated with positive HSV PCR. Conclusions: We demonstrated the importance to adapt serological anti-HSV IgG EIA test for CSF assays to increase the accuracy of the analysis, considering the low concentration of specific antibodies in CSF.

Resumo O vírus herpes simples (HSV) é um dos agentes causadores de uma doença grave no sistema nervoso central (SNC) em humanos. A detecção de anticorpos específicos no líquido cefalorraquidiano (LCR) pode contribuir para o diagnóstico neurológico retrospectivo. Entretanto, os testes imunológicos comerciais são para uso em amostras de soro. Objetivo: Adaptar um kit comercial sorológico anti-HSV IgG para ser utilizado no de LCR. Metodos: Quarenta amostras de LCR de 38 pacientes com suspeita de infecção por HSV no SNC foram diluídas pesquisa de anticorpos anti-HSV IgG pelo método imunoenzimático (EIA). Além disso, as mesmas amostras também foram analisadas por reação em cadeia da polimerase (PCR). Resultados: A sensibilidade do teste EIA para o HSV consistiu em 5% (diluição 1:40) e 65% (diluição 1:2) no LCR, e o PCR do DNA do HSV, 15%. A análise combinada de EIA (diluição 1:2) e PCR aumentou a sensibilidade para 72,5%. Houve associação entre presença do LCR inflamatório e PCR positiva para HSV. Conclusões: Demonstramos a importância na adaptação previa do teste sorológico anti-HSV IgG EIA para ensaios do no LCR, a fim de aumentar a acuracia da análise, considerando a baixa concentração de anticorpos específicos no LCR.

Human papillomavirus infection in men with condyloma acuminatum: Genotype analysis of 70 cases / 中华男科学杂志

Objective@#To investigate the distribution of the gene subtypes of human papillomavirus (HPV) in male patients with condyloma acuminatum (CA) and analyze the characteristics of the gene subtypes.@*METHODS@#We extracted genomic DNA of the HPV virus from the genital tissue of 70 male CA patients, detected the DNA subtypes of HPV using the PCR-reverse dot hybridization technique, and analyzed the rates of different subtypes identified and their characteristics of distribution in different age groups.@*RESULTS@#The male HPV-positive patients were mainly infected at the age of 20－39 years, primarily with high- and low-risk mixed infection of various subtypes, which accounted for 61.54% in the 20- to 29-year-olds and 42.86% in the 30- to 39-year-olds. Among the 70 CA patients, 22 HPV subtypes were identified, the top five subtypes including HPV 11 (21.08%), HPV 6 (19.46%), HPV 42 (6.49%), HPV 59 (6.49%) and HPV 53 (5.95%); 20 infected with a single subtype (28.57%), 19 with two subtypes (27.14%) and 31 with three or more (44.29%); and 30 infected with a low-risk single subtype (42.86%) and 40 with both high- and low-risk multiple subtypes (57.14%).@*CONCLUSIONS@#Male patients with CA are mainly infected with HPV 11 and HPV 6, with a significantly higher rate of multi-subtype than single-subtype infection, and the multi-subtype patients chiefly with high- and low-risk mixed infection. Men aged 20－39 years old are most commonly affected by CA.

Research progress on etiologic diagnosis of ocular viral diseases / 浙江大学学报·医学版

A large number of viruses have been found to be associated with ocular diseases, including human adenovirus, human herpesvirus (HHV), human T lymphotropic virus type-1 (HTLV-1), and newly emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This group of diseases is prone to be misdiagnosed or missed diagnosis, resulting in serious tissue and visual damage. Etiological diagnosis is a powerful auxiliary mean to diagnose the ocular diseases associated with human adenovirus, herpes simplex virus 1 and varicella-zoster virus, and it provides the leading diagnosis evidence of infections with herpes simplex virus 2, Epstein-Barr virus, cytomegalovirus, HHV-6/7, HHV-8, HTLV-1 and SARS-CoV-2. Virus isolation, immunoassay and genetic diagnosis are usually used for etiologic diagnosis. For genetic diagnosis, the PCR technique is the most important approach because of its advantages of rapid detection, convenient operation, high sensitivity and high specificity.

DNA sequences homologous to hepatitis C virus (HCV) in the extrachromosomal circular DNA in peripheral blood mononuclear cells of HCV-negative subjects / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

OBJECTIVE@#This study aimed to investigate DNA sequences that are substantially homologous to the corresponding RNA sequence sections of the hepatitis C virus (HCV). These DNA sequences are present in the whole DNA extracted from peripheral blood mononuclear cells (PBMCs) of HCV-negative subjects. We presumed that these experimentally proven 5'-noncoding region (5'-NCR) homologous DNA sequences could be contained in the extrachromosomal circular DNA (eccDNA) fraction as part of the whole cellular DNA.@*METHODS@#Home-made polymerase chain reaction (PCR) with whole cellular and isolated eccDNA, nucleotide basic local alignment search tool (BLASTn) alignments, and tests for patterns of methylation in selected sequence sections were performed.@*RESULTS@#The PCR tests revealed DNA sequences of up to 320 bp that broadly matched the corresponding sequence sections of known HCV genotypes. In contrast, BLASTn alignment searches of published HCV 5'-NCR sequences with human genome databases revealed only sequence segments of up to 36 bp of the 5'-NCR. The composition of these sequences shows missing base pairs, base pair mismatches as well as complete homology with HCV reference sequences. These short sequence sections are present in numerous copies on both the same and different chromosomes. The selected sequence region within the DNA sequences of the 5'-NCR revealed a broad diversity of individual patterns of methylation.@*CONCLUSIONS@#The experimental results confirm our assumption that parts of the HCV 5'-NCR genomic RNA sequences are present at the DNA level in the eccDNA fraction of PBMCs. The tests for methylation patterns therein revealed individual methylomes which could represent an epigenetic feature. The respective sequence section might be subject to genetic regulation.

Human virome in nasopharynx and tracheal secretion samples

BACKGROUND In Brazil the implementation of the Sentinel Surveillance System of Influenza began in 2000. Central public health laboratories use reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for diagnosis of respiratory viruses, but this protocol identifies only specific targets, resulted in inconclusive diagnosis for many samples. Thus, high-throughput sequencing (HTS) would be complementary method in the identification of pathogens in inconclusive samples for RT-qPCR or other specific detection protocols. OBJECTIVES This study aimed to detect unidentified viruses using HTS approach in negative samples of nasopharynx/tracheal secretions by the standard RT-qPCR collected in the Federal District, Brazil. METHODS Nucleic acids were extracted from samples collected in winter period of 2016 and subjected to HTS. The results were confirmed by the multiplex PR21 RT-qPCR, which identifies 21 respiratory pathogens. FINDINGS The main viruses identified by HTS were of families Herpesviridae, Coronaviridae, Parvoviridae and Picornaviridae, with the emphasis on rhinoviruses. The presence of respiratory viruses in the samples was confirmed by the PR21 multiplex RT-qPCR. Coronavirus, enterovirus, bocavirus and rhinovirus were found by multiplex RT-qPCR as well as by HTS analyses. MAIN CONCLUSIONS Wide virus diversity was found by different methodologies and high frequency of rhinovirus occurrence was confirmed in population in winter, showing its relevance for public health.

Duplex nested-PCR for detection of small ruminant lentiviruses

Abstract Small ruminant lentiviruses (SRLV) have high genetic variability which results in different viral strains around the world. This create a challenge to design sensible primers for molecular diagnosis in different regions. This work proposes a protocol of duplex nested-PCR for the precise diagnosis of SRLV. The technique was designed and tested with the control strains CAEV Co and MVV 1514. Then, field strains were submitted to the same protocol of duplex nested-PCR. Blood samples of sheep and goats were tested with AGID and nested PCR with specific primers for pol, gag and LTR. The AGID results showed low detection capacity of positive animals, while the nested PCR demonstrated a greater capacity of virus detection. Results demonstrated that LTR-PCR was more efficient in detecting positive sheep samples, whereas gag-PCR allowed a good detection of samples of positive goats and positive sheep. In addition, pol-PCR was more efficient with goat samples than for sheep. Duplex nested PCR performed with standard virus samples and field strains demonstrated that the technique is more efficient for the detection of multiple pro-viral DNA sequences. This study demonstrated a successful duplex nested PCR assay allowing a more accurate diagnosis of SRLV.

Association of breast cancer with human papillomavirus (HPV) infection in Northeast Brazil: molecular evidence

OBJECTIVE: The aim of this study is to investigate the presence of human papillomavirus DNA and genotypes in breast cancer and normal breast tissue samples obtained from women from the northeast region of Brazil. METHOD: One hundred three breast cancer samples and 95 normal breast samples, as the non-malignant controls, were studied. DNA extraction was verified by human beta-globin gene amplification, and polymerase chain reaction was conducted based on HPV L1-specific consensus primers MY09/MY11 and GP5+/GP6+, followed by nested multiplex polymerase chain reaction with type-specific primers for the E6/E7 consensus region. RESULTS: Human papillomavirus DNA was detected in 51 (49.5%) breast carcinoma samples and 15 (15.8%) normal breast samples (p<0.0001). Human papillomavirus genotypes 6 and 11 were identified in 15.2% of all samples. CONCLUSIONS: The high frequency of human papillomavirus infection in breast cancer samples indicates a potential role of this virus in breast carcinogenesis in the studied participants.

Variantes en los genes TNFA , IL6 e IFNG asociadas con la gravedad del dengue en una muestra de población colombiana / Variants in the TNFA , IL6 and IFNG genes associated with dengue severity in a sample of Colombian population

Resumen Introducción. La composición genética del huésped determina, entre otros aspectos, el perfil clínico del dengue, lo cual se debería al efecto de variantes en los genes que codifican citocinas proinflamatorias. Objetivo. Evaluar la asociación entre las variantes de tres polimorfismos en los genes candidatos TNFA, IL6 e IFNG con la gravedad del dengue en una población colombiana. Materiales y métodos. Se evaluaron los polimorfismos rs1800750, rs2069843 y rs2069705 de los genes TNFA, IL6 e IFNG, respectivamente, en 226 pacientes con dengue. Los genotipos se tipificaron usando la reacción en cadena de la polimerasa (PCR) y los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP). Para determinar el riesgo de diferentes fenotipos del dengue, se compararon las frecuencias alélicas con la prueba de ji al cuadrado, y los genotipos y los haplotipos, con regresión logística. Por último, los análisis se ajustaron utilizando datos de autoidentificación o del componente genético ancestral. Resultados. El alelo A del rs2069843, ajustado por autoidentificación, se asoció con casos de dengue hemorrágico en afrocolombianos. En la muestra completa, dicho polimorfismo, ajustado por componente genético ancestral, fue reproducible. Además, hubo asociaciones significativas entre las combinaciones alélicas GGT y GAC de los rs1800750, rs2069843 y rs2069705 en pacientes con dengue hemorrágico, con ajuste por componente genético ancestral y sin él. Además, la combinación alélica AGC produjo 58,03 pg/ml más de interleucina 6 que la GGC, independientemente de los componentes genéticos europeo, amerindio y africano. Conclusión. Las variantes de los polimorfismos GGT y GAC de los rs1800750, rs2069843 y rs2069705 en los genes TNFA, IL6 e IFNG, respectivamente, se correlacionaron con la gravedad del dengue en esta muestra de población colombiana.

Abstract Introduction: The genetic makeup of the host contributes to the clinical profile of dengue. This could be due to the effect of variants in the genes encoding pro-inflammatory cytokines. Objective: To evaluate the association between the variants of three polymorphisms in TNFA, IL6 and IFNG candidate genes with dengue severity in a sample of Colombian population. Materials and methods: We evaluated the rs1800750, rs2069843, and rs2069705 polymorphisms in TNFA, IL6 and IFNG candidate genes, respectively, in 226 patients with dengue infection. The genotypes were typed using both polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). To determine the risk of different dengue phenotypes, we compared allele frequencies with chisquare and genotypes and haplotypes using logistic regression. Finally, these analyzes were adjusted with data from self-identification or the ancestral genetic component. Results: The A allele in the rs2069843 polymorphism, adjusted by self-identification, was associated with dengue hemorrhagic fever cases in Afro-Colombians. In the entire sample, this polymorphism, adjusted by the ancestral genetic component, was reproducible. In addition, there were significant associations between GGT and GAC allelic combinations of rs1800750, rs2069843, and rs2069705 in dengue hemorrhagic fever patients, with and without adjustment by ancestral genetic component. Additionally, the AGC allelic combination produced 58.03 pg/ml of interleukin-6 more than the GGC combination, regardless of European, Amerindian and African genetic components. Conclusions: The variants of GGT and GAC polymorphisms of rs1800750, rs2069843, and rs2069705 in the TNFA, IL6 and IFNG genes, respectively, were correlated with the susceptibility to dengue severity in a sample of Colombian population.

Complete genome sequence of community-associated methicillin-resistant staphylococcus aureus (strain USA400-0051), a prototype of the USA400 clone

Staphylococcus aureus subsp. aureus, commonly referred as S. aureus, is an important bacterial pathogen frequently involved in hospital- and community-acquired infections in humans, ranging from skin infections to more severe diseases such as pneumonia, bacteraemia, endocarditis, osteomyelitis, and disseminated infections. Here, we report the complete closed genome sequence of a community-acquired methicillin-resistant S. aureus strain, USA400-0051, which is a prototype of the USA400 clone.

Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil

Abstract Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p = 0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p = 0.0028), while AST levels did not differ between groups (p = 0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.

Distribution of HBV subgenotypes in Ribeirão Preto, Southeastern Brazil: a region with history of intense Italian immigration

Abstract Hepatitis B virus (HBV) is distributed worldwide, with geographical variations regarding prevalence of the different genotypes. The aim of this study was to determine the HBV genotypes and subgenotypes circulating in Southeast Brazil and compare the genetic sequences found with HBV sequences previously described in the world. Sequences from 166 chronic HBV carriers were analyzed using the fragment constituted by 1306 base pairs comprising surface and polymerase regions of the HBV genome. The sequences obtained were submitted to phylogenetic analysis. HBV subgenotypes A1, A2, D1-D4, F2a, and F4 were found. HBV genotype D was the most frequent, found in 99 patients (58.4%). Within this group, subgenotype D3 was the most prevalent, in 73 patients (42.9%). HBV genotype A was identified in 58 (36%) patients, subgenotype A1, in 48 (29.8%) subjects. Genotype F was identified in 9 (5.4%). According to the phylogenetic analysis, the sequences found were grouped with sequences from Europe, Asia and Middle East (subgenotypes D1, D2, D3) and sequences from Latin America and Africa (subgenotype A1). HBV D3 grouped in different clusters inside D3 clade, several of them with sequences isolated in Italy. We also identified eight families whose relatives were infected with the same HBV subgenotype, most with high similarity between sequences. In conclusion, the distribution of the HBV sequences obtained interweaved with sequences from other continents, corresponding to regions from where many immigrants came to this region, in accordance to the hypothesis that the HBV detected over there were brought during the colonization times.

Human papillomavirus type distribution and HPV16 intratype diversity in southern Brazil in women with and without cervical lesions

BACKGROUND Increasing evidence suggests that human papillomavirus (HPV) intratype variants (specific lineages and sublineages) are associated with pathogenesis and progression from HPV infection to persistence and the development of cervical cancer. OBJECTIVES This study aimed to verify the prevalence of HPV infection and distribution of HPV types and HPV16 variants in southern Brazil in women with normal cytology or intraepithelial lesions. METHODS HPV typing was determined by L1 gene sequencing. To identify HPV16 variants, the LCR and E6 regions were sequenced, and characteristic single nucleotide variants were identified. FINDINGS A total of 445 samples were studied, with 355 from cervical scrapes and 90 from cervical biopsies. HPV was detected in 24% and 91% of these samples, respectively. The most prevalent HPV types observed were 16 (cervical, 24%; biopsies, 57%) and 58 (cervical, 12%; biopsies, 12%). Seventy-five percent of the HPV16-positive samples were classified into lineages, with 88% defined as lineage A, 10% as lineage D, and 2% as lineage B. MAIN CONCLUSIONS This study identified a high frequency of European and North American HPV16 lineages, consistent with the genetic background of the human population in southern Brazil.

Detection and molecular characterisation of a diagnosis escape variant associated with occult hepatitis B virus in Brazil

BACKGROUND Many studies have identified mutations in the hepatitis B surface antigen (HBsAg) as important factors limiting the ability of commercial serological assays to detect this viral antigen. However, an association between mutations in the HBsAg gene and the occurrence of occult HBV infection (OBI) in patients has not been established. OBJECTIVES To detect hepatitis B virus (HBV) DNA in patients with anti-HBc as a unique serological marker, a previously published, cost-effective TaqMan-based real-time polymerase chain reaction (PCR) test with minor groove binding probes was adapted for use in this study. The current study also aimed to investigate HBsAg mutations and genotypes of HBV in OBI at the Viral Hepatitis Ambulatory Clinic in Rio de Janeiro to determine any possible association. METHODS Intra-assay and inter-assay reproducibility were determined, and the mean coefficient of variation values obtained were 2.07 and 3.5, respectively. Probit analysis indicated that the 95% detection level was 25 IU/mL. The prevalence of OBI was investigated in 35 serum samples with an ‘anti-HBc alone’ profile from individuals who attended our clinic between 2011 and 2013. FINDINGS HBV DNA was detected in only one sample, resulting in an OBI rate of 2.9%. Nucleotide sequencing of the pre-S/S region was performed to genotype and analyse mutations within the HBsAg gene of this HBV DNA. The HBV in the OBI case was classified as sub-genotype A1, and a sequence analysis of the small S gene revealed 12 mutations in the major hydrophilic region compared to the consensus A1 sequence. Most of these mutations occurred in amino acid residues that have been reported as clinically relevant because they have been implicated in vaccine escape and/or inability to detect HBsAg by commercial serological assays. MAIN CONCLUSIONS Our study suggests the importance of specific HBsAg mutations, different from those in D, B, and C genotypes, in sub-genotype A1 HBV associated with OBI.