Revista Do Instituto De Medicina Tropical De Sao Paulo最新文献

This study describes an outbreak of Streptococcus equi subspecies zooepidemicus infections that caused meningoencephalitis and bacteremia related to unpasteurized milk consumption in northeastern Brazil. Epidemiological investigations and a brief literature review were conducted. Strains with possible neurotropism had not been identified in Brazil before these cases; however, in 2023, another case of meningoencephalitis caused by Streptococcus equi sp. zooepidemicus was described, revealing the need to maintain surveillance and highlighting that these neurotropic strains continue to circulate in the environment.

The human T-cell lymphotropic virus type 1 (HTLV-1) is a single-stranded positive-sense RNA virus that belongs to the Retroviridae family, genus Deltaretro, and infects approximately five to 10 million people worldwide. Although a significant number of individuals living with HTLV-1 remain asymptomatic throughout their lives, some develop one or more severe clinical conditions, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a progressive and debilitating disease, and/or a subtype of non-Hodgkin's lymphoma with a more threatening course known as adult T-cell leukemia/lymphoma (ATLL). Moreover, current therapeutic options are limited and focus primarily on treating symptoms and controlling viral latency. CRISPR-Cas9 gene editing is proposed as a promising tool to address the intricate links associated with HTLV-1. By targeting or silencing key genes during initial infection and dysregulating immune signaling pathways, CRISPR-Cas9 offers potential intervention opportunities. In this review, we address the therapeutic potential of CRISPR-Cas9 gene editing, as well as examine the primary mechanisms involved in editing potential target genes and discuss the existing evidence in the current scientific literature.

Waste pickers constitute a marginalized demographic engaged in the collection of refuse, facing considerable occupational hazards that heighten their susceptibility to contract infectious diseases. Moreover, waste pickers contend with societal stigmatization and encounter barriers to accessing healthcare services. To explore the viral profile of waste pickers potentially linked to their occupational environment, we conducted a metagenomic analysis on 120 plasma specimens sampled from individuals employed at the Cidade Estrutural dumpsite in Brasilia city, Brazil. In total, 60 blood donors served as a comparative control group. Specimens were pooled and subjected to Illumina NextSeq 2000 sequencing. Viral abundance among waste pickers revealed the presence of significant pathogens, including HIV, HCV, and Chikungunya, which were not detected in the control group. Additionally, elevated levels of anelloviruses and Human pegivirus-1 were noted, with a comparable incidence in the control group. These findings underscore the utility of metagenomics in identifying clinically relevant viral agents within underserved populations. The implications of this study extend to informing public health policies aimed at surveilling infectious diseases among individuals facing socioeconomic disparities and limited access to healthcare resources.

Yellow fever vaccine (YFV) is a live attenuated vaccine that can cause a mild infection in immunocompetent patients. However, it may not be self-limiting in patients with inborn errors of immunity (IEI) and may be the first and most severe presentation in these patients. A 10-month-old female infant sought emergency care presenting fever for three days and diffuse exanthema. She was a previous healthy child of consanguineous parents. The child had received YFV 28 days before the onset of symptoms. Upon hospital admission, petechial rash on the limbs and hepatosplenomegaly were noted on physical exam. Laboratory tests showed thrombocytopenia, increased serum aminotransferases and elevated gamma-glutamyl transferase (GGT) and alkaline phosphatase levels. During hospitalization she developed hypoactivity, drowsiness, and hypotonia. The possibility of viscerotropic and neurotropic vaccine associated disease was suspected and a possible primary immunodeficiency disease considered. The patient was tested for antibodies against the yellow fever virus (MAC ELISA) on serum and cerebrospinal fluid (CSF) samples, showing positive IgM results. Immunophenotyping showed low levels of lymphocytes and absence of T-cell receptor excision circles (TREC), leading to diagnose of severe combined immunodeficiency disease (SCID). Despite treatment, after 35 days of hospitalization, she evolved to cardiorespiratory arrest and death. Serious adverse events after administration of the YFV are rare and associated with neurological or visceral involvement in most cases. The unfavorable outcome highlights the importance of neonatal screening for SCID and the clinical suspicion of primary immunodeficiencies in infants who have serious adverse events to live virus vaccines.

Hepatic injuries in COVID-19 are not yet fully understood and indirect pathways (without viral replication in the liver) have been associated with the activation of vascular mechanisms of liver injury in humans infected with SARS-CoV-2. Golden Syrian hamsters are an effective model for experimental reproduction of moderate and self-limiting lung disease during SARS-CoV-2 infection. As observed in humans, this experimental model reproduces lesions of bronchointerstitial pneumonia and pulmonary vascular lesions, including endotheliitis (attachment of lymphoid cells to the luminal surface of endothelium). Extrapulmonary vascular lesions are well documented in COVID-19, but such extrapulmonary vascular lesions have not yet been described in the Golden Syrian hamster model of SARS-CoV-2 infection. The study aimed to evaluate microscopic liver lesions in Golden Syrian hamsters experimentally infected with SARS-CoV-2. In total, 38 conventional Golden Syrian hamsters, divided into infected group (n=24) and mock-infected group (n=14), were euthanized at 2-, 3-, 4-, 5-, 7-, 14-, and 15-days post infection with SARS-CoV-2. Liver fragments were evaluated by histopathology and immunohistochemical detection of SARS-CoV-2 Spike S2 antigens. The frequencies of portal vein endotheliitis, lobular activity, hepatocellular degeneration, and lobular vascular changes were higher among SARS-CoV-2-infected animals. Spike S2 antigen was not detected in liver. The main results indicate that SARS-CoV-2 infection exacerbated vascular and inflammatory lesions in the liver of hamsters with pre-existing hepatitis of unknown origin. A potential application of this animal model in studies of the pathogenesis and evolution of liver lesions associated with SARS-CoV-2 infection still needs further evaluation.

Neonatal sepsis leads to severe morbidity and occasionally death among neonates within the first week following birth, particularly in low- and middle-income countries. Empirical therapy includes antibiotics recommended by WHO. However, these have been ineffective against antimicrobial multidrug-resistant bacterial strains such as Klebsiella spp, Escherichia coli, and Staphylococcus aureus species. To counter this problem, new molecules and alternative sources of compounds with antibacterial activity are sought as options. Actinobacteria, particularly pathogenic strains, have revealed a biotechnological potential still underexplored. This study aimed to determine the presence of biosynthetic gene clusters and the antimicrobial activity of actinobacterial strains isolated from clinical cases against multidrug-resistant bacteria implicated in neonatal sepsis. In total, 15 strains isolated from clinical cases of actinomycetoma were used. PCR screening for the PKS-I, PKS-II, NRPS-I, and NRPS-II biosynthetic systems determined their secondary metabolite-producing potential. The strains were subsequently assayed for antimicrobial activity by the perpendicular cross streak method against Escherichia fergusonii Sec 23, Klebsiella pneumoniae subsp. pneumoniae H1064, Klebsiella variicola H776, Klebsiella oxytoca H793, and Klebsiella pneumoniae subsp. ozaenae H7595, previously classified as multidrug-resistant. Finally, the strains were identified by 16S rRNA gene sequence analysis. It was found that 100% of the actinobacteria had biosynthetic systems. The most frequent biosynthetic system was NRPS-I (100%), and the most frequent combination was NRPS-I and PKS-II (27%). All 15 strains showed antimicrobial activity. The strain with the highest antimicrobial activity was Streptomyces albus 94.1572, as it inhibited the growth of the five multidrug-resistant bacteria evaluated.

Stenotrophomonas maltophilia was considered to be a low-virulence organism. But it has emerged as a prominent opportunistic pathogen in patients with certain risk factors. This study aimed to describe an outbreak experienced in our hospital with all dynamics while evaluating previous S. maltophilia outbreak reports. S. maltophilia isolates were obtained from a university hospital in Türkiye in a seven-months period. Antimicrobial resistance, type of infections, predisposing factors of infected patients, antibiotic therapy, outcome of infections, and outbreak source were investigated. Also, S. maltophilia outbreaks in the literature were reviewed. In the 12 months prior to the outbreak, prevalence rate of clinical samples including S. maltophilia was 7/1,000 patient per day, opposed to 113/1,000 patient per day during the outbreak. Although a large number of cases were observed in a short seven-month period, a source of contamination could not be detected. Stable mortality rates (or remaining close to the average) during outbreaks can be attributed to the careful attention paid by laboratory and clinic physicians during procedures. S. maltophilia has potential to spread outbreaks and infect patients in operating rooms and intensive care units during invasive procedures.

This study aimed to systematically review interventions to prevent mother-to-child transmission of HIV during breastfeeding. We conducted a systematic review and meta-analysis using specific criteria to identify randomized controlled trials that focused on pregnant and breastfeeding women living with HIV and their children from birth to 2 years of age. We extensively searched electronic databases, including Web of Science, Scopus, PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar up to October 24, 2023. After screening 3,110 titles and abstracts, we reviewed 306 full texts. Of these, we assessed the quality and risk of bias of fifty-five articles, ultimately identifying seven studies. Four of these studies, which focused on antiretroviral therapy (ART), were included in the meta-analysis. There was little heterogeneity in study methodology and pooled estimates. The postnatal HIV transmission rate was found to be 0.01 (95%CI: 0.00 - 0.02). Therefore, the risk of mother-to-child transmission among breastfeeding mothers with HIV was significantly lower in the intervention groups than in the placebo groups. Analysis of funnel plots and Egger's test (p = 0.589) showed no evidence of publication bias. In addition to the four articles, two studies compared different ART regimens and one study compared the administration of high-dose vitamin A to the mother or the child. The results suggest that the use of ART significantly reduces the risk of postnatal HIV transmission compared with placebo. However, the effectiveness of different ART regimens or other therapies, including high-dose vitamin A, is unclear.

The main social impact of toxoplasmosis stems from its ability to be vertically transmitted. Postnatally acquired infection is generally asymptomatic in approximately 70-90% of cases, making diagnosis often dependent on laboratory tests using serological methods to search for anti-T. gondii antibodies. This study aimed to investigate the ability of the VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays to confirm recent toxoplasmosis. In total, 341 pregnant women with suspected acute toxoplasmosis were systematically monitored in the Program for Control of Congenital Toxoplasmosis in Minas Gerais State, Brazil. We conducted an observational analytical-descriptive cross-sectional study and grouped according to clinical and laboratory criteria as having acute or chronic toxoplasmosis. The VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays were evaluated to investigate the capacity to identify acute infection. IgG avidity showed good performance in identifying acute toxoplasmosis when the IgG avidity index was lower than or equal to 0.1. Values greater than or equal to 3.16 according to the TOXO IgM kit were associated with a greater chance of acute infection. These results may contribute to a more adequate diagnosis of acute gestational toxoplasmosis and, consequently, the avoidance of inadequate or unnecessary treatments.

Women living with human immunodeficiency virus are at an increased risk of developing cancers related to human papillomavirus (HPV). Thus, it is important to combine clinical assessments, serological screening, and HPV data for planning prevention policies. This study aimed to identify HPV and its specific types in the cervical, anal, and oral mucosa of HIV-seropositive women, associating it with viral load and lymphocyte count. Sociodemographic characteristics, health data (CD4+ and CD8+ T cell counts and viral load), and biological samples (cervical, anal, and oral) were collected from 86 HIV-positive women undergoing antiretroviral therapy. Data were classified according to the presence or absence of HPV-DNA, HPV-DNA presence at one or more anatomic sites, and level of oncogenic risk, considering low- and high-risk oncogenic HPV-DNA groups. The presence of HPV in the cervicovaginal site was 65.9%, 63.8% in anal canal, and 4.2% in oral mucosa. A viral load ≥75 HIV copies/mL was associated with the presence of HPV-DNA. There was an association between viral load and the low-risk HPV or high-risk HPV groups. We found a high prevalence of HPV infection in HIV-seropositive women, particularly in the cervical and anal mucosa, with viral load ≥75 HIV copies/mL being associated with HPV-DNA presence.