HTLV-1 intrafamilial transmission among Japanese immigrants in Brazil.

Human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The aim of this study was to investigate the intrafamilial transmission of HTLV-1 among Japanese immigrants and their descendants living in a non-endemic area of central Brazil. Six families were investigated. Thirty-seven relatives of the six index cases were tested by ELISA for the presence of anti-HTLV antibodies, and the positive cases were confirmed by Western blot. HTLV-1 isolates were genotyped by partial nucleotide sequencing (5' LTR) of the proviral DNA. All individuals, including index cases and relatives, were asymptomatic. In five families, at least one relative was infected with HTLV-1. In all, eight (22%) relatives (one mother, four wives, one brother, and two brothers-in-law) were infected. However, none of the 22 individuals under 55 years of age was infected. In each family, the HTLV-1 sequences from the relatives were identical or almost identical to that of the index case, except in one case. Pedigrees of the families, together with socio-demographic data of the HTLV-1 infected individuals, strongly suggested the occurrence of both vertical and sexual transmission, with breastfeeding as an important risk factor. Whether and why the virus transmission is less effective among younger generations deserves to be further investigated.

Epidemiological and molecular analysis of hepatitis B virus infection in manicurists in Central Brazil.

The aim of this study was to investigate the serological and molecular prevalence of hepatitis B virus (HBV) infection in 514 manicurists/pedicurists and identify the risk factors related with this infection. Samples were tested for HBV serological markers, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) by enzyme-linked immunosorbent assay (ELISA). Anti-HBc-positive samples were tested to investigate occult hepatitis B by PCR. HBsAg-positive samples were genotyped and the viral loads of HBV-DNA positive samples were quantified. The overall HBV prevalence was 5.6% (29/514) and of HBsAg was 0.4% (2/514). One case of occult hepatitis B was found. The genotypes A1 and F2 were identified in two HBsAg-positive samples. Low level of education, not being born in the State of Mato Grosso do Sul and working in the central region of the city were associated with the HBV infection. No single manicurist/pedicurist was infected by HCV or HIV. These findings suggest that despite the exposure to blood contact, this occupation was not associated to an increased risk of acquiring HBV, HCV, and HIV infections.

HIV seroprevalence and high-risk sexual behavior among female sex workers in Central Brazil.

Female sex workers (FSWs) are considered a high-risk group for human immunodeficiency virus (HIV) infection due to their social vulnerability and factors associated with their work. We estimated the prevalence of HIV, and identified viral subtypes and risk factors among FSWs. A cross-sectional study using respondent-driven sampling (RDS) method was conducted among 402 FSWs in Campo Grande city, Brazil, from 2009 to 2011. Participants were interviewed using a standardized questionnaire about sociodemograpic characteristics and risk behavior. Blood samples were collected for serological testing of HIV. Of the 402 FSWs, median age and age of initiating sex work were 25 years (Interquartile range [IQR]: 9) and 20 years (IQR: 6), respectively. The majority reported use of alcohol (88.5%), had 5-9 years (median: 9; IQR: 3) of schooling (54.5%), 68.6% had tattoos/body piercings, and 45.1% had more than seven clients per week (median: 7; IQR: 10). Only 32.9% of FSW reported using a condom with nonpaying partners in the last sexual contact. Prevalence of HIV infection was 1.0% (95% CI: 0.1-2.6%). Genotyping for HIV-1 performed on three samples detected subtypes B, C, and F1. Sex work in the Midwestern region of Brazil is characterized by reduced education, large numbers of clients per week, and inconsistent condom use, mainly with nonpaying partners. Although prevalence of HIV infection is currently low, elevated levels of high-risk sexual behavior confirm a need to implement prevention measures. Specific interventions targeting FSWs must emphasize the risk associated with both clients and nonpaying partners while providing knowledge about HIV prevention.

Increasing HIV prevalence rate among men who have sex with men: results of a comparison of two national surveys.

Our objective was to compare HIV prevalence between two national surveys among men who have sex with men in Brazil in 2009 and 2016. HIV prevalence was estimated stratifying by age and socioeconomic status. HIV prevalence increased from 11.9% [95% confidence interval (CI): 9.9-14.3], in 2009, to 19.1% (95% CI: 16.5 - 22.0), in 2016 [odds ratio (OR) = 1.8; 95% CI: 1.3-2.3] increasing 320% among Young MSM of low SES. Political leadership is needed to develop a scientifically sound and inclusive solution.

Hot-wiring dynein-2 establishes roles for IFT-A in retrograde train assembly and motility.

Intraflagellar transport (IFT) trains, built around IFT-A and IFT-B complexes, are carried by opposing motors to import and export ciliary cargo. While transported by kinesin-2 on anterograde IFT trains, the dynein-2 motor adopts an autoinhibitory conformation until it needs to be activated at the ciliary tip to power retrograde IFT. Growing evidence has linked the IFT-A complex to retrograde IFT; however, its roles in this process remain unknown. Here, we use CRISPR-Cas9-mediated genome editing to disable the dynein-2 autoinhibition mechanism in Caenorhabditis elegans and assess its impact on IFT with high-resolution live imaging and photobleaching analyses. Remarkably, this dynein-2 "hot-wiring" approach reignites retrograde motility inside IFT-A-deficient cilia without triggering tug-of-war events. In addition to providing functional evidence that multiple mechanisms maintain dynein-2 inhibited during anterograde IFT, our data establish key roles for IFT-A in mediating motor-train coupling during IFT turnaround, promoting retrograde IFT initiation, and modulating dynein-2 retrograde motility.

Iron Compounds in Anaerobic Degradation of Petroleum Hydrocarbons: A Review.

Waste and wastewater containing hydrocarbons are produced worldwide by various oil-based industries, whose activities also contribute to the occurrence of oil spills throughout the globe, causing severe environmental contamination. Anaerobic microorganisms with the ability to biodegrade petroleum hydrocarbons are important in the treatment of contaminated matrices, both in situ in deep subsurfaces, or ex situ in bioreactors. In the latter, part of the energetic value of these compounds can be recovered in the form of biogas. Anaerobic degradation of petroleum hydrocarbons can be improved by various iron compounds, but different iron species exert distinct effects. For example, Fe(III) can be used as an electron acceptor in microbial hydrocarbon degradation, zero-valent iron can donate electrons for enhanced methanogenesis, and conductive iron oxides may facilitate electron transfers in methanogenic processes. Iron compounds can also act as hydrocarbon adsorbents, or be involved in secondary abiotic reactions, overall promoting hydrocarbon biodegradation. These multiple roles of iron are comprehensively reviewed in this paper and linked to key functional microorganisms involved in these processes, to the underlying mechanisms, and to the main influential factors. Recent research progress, future perspectives, and remaining challenges on the application of iron-assisted anaerobic hydrocarbon degradation are highlighted.

WDR60-mediated dynein-2 loading into cilia powers retrograde IFT and transition zone crossing.

The dynein-2 motor complex drives retrograde intraflagellar transport (IFT), playing a pivotal role in the assembly and functions of cilia. However, the mechanisms that regulate dynein-2 motility remain poorly understood. Here, we identify the Caenorhabditis elegans WDR60 homologue, WDR-60, and dissect the roles of this intermediate chain using genome editing and live imaging of endogenous dynein-2/IFT components. We find that loss of WDR-60 impairs dynein-2 recruitment to cilia and its incorporation onto anterograde IFT trains, reducing retrograde motor availability at the ciliary tip. Consistent with this, we show that fewer dynein-2 motors power WDR-60-deficient retrograde IFT trains, which move at reduced velocities and fail to exit cilia, accumulating on the distal side of the transition zone. Remarkably, disrupting the transition zone's NPHP module almost fully restores ciliary exit of underpowered retrograde trains in wdr-60 mutants. This work establishes WDR-60 as a major contributor to IFT, and the NPHP module as a roadblock to dynein-2 passage through the transition zone.

The IFT20 homolog in Caenorhabditis elegans is required for ciliogenesis and cilia-mediated behavior.

Cilia are microtubule-based organelles that carry out a wide range of critical functions throughout the development of higher animals. Regardless of their type, all cilia rely on a motor-driven, bidirectional transport system known as intraflagellar transport (IFT). Of the many components of the IFT machinery, IFT20 is one of the smallest subunits. Nevertheless, IFT20 has been shown to play critical roles in the assembly of several types of mammalian cilia. Here we show that the IFT20 homolog in Caenorhabditis elegans, IFT-20, is also important for correct cilium assembly in sensory neurons. Strikingly, however, we find that IFT-20-deficient animals are able to assemble short, vestigial cilia. In spite of this, we show that practically all IFT-20-deficient animals fail to respond to environmental cues that are normally detected by cilia to modulate their behavior. Altogether, our results indicate that IFT-20 is critical for both the correct assembly and function of cilia in C. elegans.

HAV infection in Brazilian men who have sex with men: The importance of surveillance to avoid outbreaks.

BACKGROUND: Hepatitis A is a fecal-oral infection caused by hepatitis A virus (HAV). Men who have sex with men (MSM) and transgender women (TW) have been reported as target groups for HAV infection. This study aimed to determine the seroprevalence, risk factors, and circulating strains associated with HAV infection among MSM and TW in Central Brazil. METHODS: A cross-sectional study was conducted from November 2011 to September 2013. Serum samples were collected from 425 individuals for anti-HAV antibody testing and HAV molecular characterization. Of them, 149 (35.1%) participants were self-identified as transgender women. Statistical analysis was performed to evaluate the risk factors of HAV seropositivity. RESULTS: The seroprevalence of HAV exposure was 69.7% (95% Confidence Interval: 65.3-74.0%). Serological evidence of HAV was significantly higher in participants who self-identified as transgender women (83.2%) than MSM (62.3%). Increasing age, non-white race, and lower monthly household income were independently associated with HAV exposure among MSM. Only lower monthly household income was independently associated with HAV exposure among TW. One anti-HAV IgM positive sample, from a transgender woman (0.2%), was detected and classified as subgenotype IA. CONCLUSIONS: High HAV prevalence was observed, markedly among TW. Considering the risky sexual behaviors this population is exposed to, HAV vaccination and prevention programs targeting this population should be considered to prevent outbreaks and the burden of the disease.

Human T-cell leukemia virus type 1 infection among Japanese immigrants and their descendants living in Southeast Brazil: A call for preventive and control responses.

Human T-cell leukemia virus type 1 (HTLV-1) has worldwide distribution and is considered endemic in southwestern Japan. HTLV-1 infection has been associated with adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) besides other diseases. This cross-sectional study aimed to investigate the prevalence, risk factors and molecular characterization of HTLV-1, among the world's largest population of Japanese immigrants and their descendants outside of Japan, in São Paulo, Southeast Brazil, as well as to analyze the phylogenetic relationship among isolates of HTLV-1. From July to December 2017, 2,139 individuals from five Japanese associations were interviewed and submitted to blood collection. All serum samples were first tested for the presence of anti-HTLV-1/2 antibodies by ELISA and then peripheral blood from individuals with positive serological results were analyzed for the presence of HTLV-1 5'LTR proviral DNA. Partial sequencing of the 5'LTR region of HTLV-1 proviral DNA was performed by Sanger. The prevalence of HTLV-1 infection was 5.1% (CI 95%: 4.2-6.0). In the multiple logistic regression model, HTLV-1 infection was associated with age ≥ 45 years, female sex, being first and second-generation Japanese immigrants, and having sexual partners with history of blood transfusion. The phylogenetic analysis revealed that all HTLV-1 were classified as Cosmopolitan (1a) subtype. Of them, 47.8% were classified as Transcontinental (A) subgroup and 52.2% as belonging to the Japanese (B) subgroup. Although most HTLV-1-infected patients were asymptomatic (97.3%), blurred vision was associated with HTLV-1 infection. The high prevalence of HTLV-1 infection found in this studied population and especially the intra- and interfamily HTLV-1 transmission presents an urgent call for preventive and control responses of this infection in Brazil.