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Hepatitis viral infection can cause severe complications, even mortality in pregnant women and their offspring. Multiple studies have shown that vertical transmission can cause viral hepatitis infections in newborns, especially in hepatitis B, C, and E. Screening for hepatitis viral infection in pregnant women is essential. Once infected, pregnant women should be given timely antiviral treatments, which could effectively alleviate the disease progression and reduce adverse outcomes. Besides, the mechanism of viral hepatitis mediating adverse pregnancy outcomes has been a hot topic. Hepatitis B virus has been found to mediate both mother- to-child and parent-child transmission. Liver injury in hepatitis C virus infection is associated with immune-mediated mechanisms, which can be regulated by hormonal factors as well. The mediating mechanism of adverse maternal and infant outcomes caused by hepatitis E virus infection is mainly related to viral replication in the placenta and changes in cytokine and estrogen. Nevertheless, the specific mechanisms related to hepatitis A virus and hepatitis D virus remain unclear, and more research is needed. This review shows that the existence of viral hepatitis during pregnancy can pose certain risks for pregnant women and infants, and different interventions have been used to treat pregnant women infected with viral hepatitis. It may provide deep insight into adverse pregnancy outcomes caused by viral hepatitis and give guidance on treatment.

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BACKGROUND: Pregnancy is a critical time for women, making them more susceptible to infectious diseases like COVID-19. This study aims to determine the immunogenicity of COVID-19 in pregnant women who have been infected compared to those who have received the inactive COVID-19 vaccine. MATERIALS AND METHODS: In this retrospective cohort study, pregnant women who received the inactivated COVID-19 vaccine (Sinopharm) and those with a history of COVID-19 infection during pregnancy were studied. Participants who had experienced stillbirth, received different COVID-19 vaccines, or had intrauterine fetal death were excluded from the study. Overall, the study included 140 participants. The participants were divided into two groups of 70 participants - pregnant women who received the Sinopharm vaccine and pregnant women who had COVID-19 infection during pregnancy. Before delivery, blood samples were collected from all mothers to evaluate the maternal immunoglobulin G (IgG) level. Blood samples were also taken from the baby's umbilical cord during delivery to measure the newborn's IgG level. Additionally, blood samples were collected from babies whose mothers showed signs of acute infection to measure their IgM levels and evaluate vertical transmission. FINDINGS: The study found a significant relationship between the mean level of maternal IgG and umbilical cord IgG within the groups (P < 0.001). The highest levels of maternal IgG (2.50 ± 2.17) and umbilical cord IgG (2.43 ± 2.09) were observed in pregnant women with a previous COVID-19 infection and no history of vaccination (P < 0.001). Only one baby was born with a positive IgM, and this baby was born to a mother who showed signs of COVID-19 infection in the last five days of pregnancy. The mother was 28 years old, with a BMI of 33; it was her first pregnancy, and she gave birth to a male newborn at term. CONCLUSION: Administering an inactivated vaccine during pregnancy can generate immunity in both the mother and the child. However, the vaccine's immunity level may not be as potent as that conferred by COVID-19 infection during pregnancy. Nonetheless, the risk of vertical transmission of COVID-19 is considered minimal and can be classified as negligible.

Assuntos

Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunoglobulina G , Complicações Infecciosas na Gravidez , SARS-CoV-2 , Humanos , Gravidez , Feminino , COVID-19/imunologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Estudos Retrospectivos , Imunoglobulina G/sangue , Adulto , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/imunologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , Vacinação , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Recém-Nascido , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Gestantes , Imunogenicidade da Vacina

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Mother-to-child transmission (MTCT) of HIV remains a significant public health challenge in Uganda, necessitating a focused examination of the state of laboratory systems to ensure accurate diagnoses and effective prevention. The aim of this narrative review is to assess the current state of laboratory systems supporting MTCT prevention programs in Uganda, identify challenges hindering accurate diagnoses, and propose strategies for strengthening these systems to enhance the effectiveness of MTCT prevention efforts. This narrative review explores the current landscape of laboratory infrastructure in Uganda, addressing challenges unique to the country and proposing strategies for improvement. The discussion encompasses the integration of molecular testing, the role of point-of-care diagnostics, the implementation of quality assurance programs, and capacity-building initiatives for laboratory personnel. Additionally, technological innovations and their applicability in the Ugandan context are explored alongside the crucial aspect of integrating laboratory services into antenatal care. Drawing on global lessons, the review provides tailored recommendations for Uganda, spanning policy considerations, funding mechanisms, infrastructure enhancements, and workforce development. Looking towards the future, the review outlines potential collaborations, technological advancements, and strategic investments that can further fortify laboratory systems, ultimately contributing to the elimination of MTCT in Uganda.

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The COVID-19 pandemic has significantly impacted public health and the global economy. It has also been found to have potential effects on pregnancy, neonatal outcomes, and mother-to-infant transmission. This systematic review aims to provide an overview of the maternal and perinatal outcomes associated with pregnancy. A systematic review study was conducted by searching the PubMed, MEDLINE, Embase, and Web of Science databases according to PRISMA guidelines from December 1, 2019, to December 23, 2022. The results indicate that there was an increase in the rate of cesarean delivery among mothers infected with SARS-CoV-2. However, the study found that the mode of delivery for pregnant women infected with SARS-CoV-2 did not increase or decrease the risk of infection for newborns. During the COVID-19 pandemic, there has been an increase in maternal and infant mortality rates, as well as stillbirths and ruptured ectopic pregnancies. Research has shown that SARS-CoV-2 can potentially be transmitted during pregnancy, although vertical transmission is rare. However, additional data are needed to investigate this adverse effect, especially regarding reports of disease recurrence in mothers infected with SARS-CoV-2.

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Four infants potentially exposed to syphilis infection in utero, meeting World Health Organization surveillance criteria of congenital syphilis (CS), were diagnosed in Croatia between September 2020 and January 2024. We conducted a retrospective analysis of epidemiological, clinical and laboratory data of these cases to assess compliance with surveillance case definitions. As only one confirmed CS case has been reported in Croatia in over 2 decades, these reports signal an increased risk of syphilis vertical transmission and warrant strengthening antenatal screening.

Assuntos

Transmissão Vertical de Doenças Infecciosas , Complicações Infecciosas na Gravidez , Sífilis Congênita , Humanos , Croácia/epidemiologia , Feminino , Sífilis Congênita/epidemiologia , Sífilis Congênita/transmissão , Gravidez , Estudos Retrospectivos , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/diagnóstico , Recém-Nascido , Sífilis/epidemiologia , Sífilis/transmissão , Sífilis/diagnóstico , Masculino , Lactente , Diagnóstico Pré-Natal , Adulto , Sorodiagnóstico da Sífilis , Treponema pallidum/isolamento & purificação

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Senecavirus A (SVA) is a Picornaviridae RNA virus that causes vesicular disease (VD) and transitory neonatal losses in pigs. The major ways SVA is spread are by oral, nasal, and feces. Vertical transmission of SVA was investigated during a VD epidemic in a farrow-to-finish herd in Brazil. Vesicular lesions were observed on sows before farrowing and on piglets within 24 h of birth. Analyses included RT-qPCR, viral isolation, sequencing, and virus-neutralization assays on serum, vesicular fluid, colostrum, and milk. Five out of ten sows were viremic before farrowing, and 46.7% of tested piglets had high viral loads in the first 24 h after birth. Infectious virus was detected in colostrum and milk from one postnatal sow. Despite high levels of neutralizing antibodies (nAbs) in piglet serum, colostrum, and milk, piglets were not protected from viremia and clinical illness. These findings support the vertical and congenital transmission of SVA.

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Introduction: sub-Saharan Africa is experiencing a boom in the number of adolescents and young adults living with HIV (AYALHIV). Existing HIV intervention programs are mainly for children and adults living with HIV, with little attention paid to AYALHIV. Characterizing this population is necessary for planning, and designing, AYALHIV-centered HIV intervention programs. Methods: a retrospective single-center, hospital-based chart review was conducted at the largest HIV clinic in Ghana. We examined routinely collected data for AYALHIV (aged 10-24 years) on antiretroviral therapy (ART) for at least 1 year and in active care from 1st January to 31st December 2019. Data was collected using a structured data extraction form. The Chi-square and the Student´s t-test were used to compare characteristics between adolescents and young adults. Results: of 252 AYALHIV, 68% (172/252) were adolescents with a median age of 17 years (IQR 13-19); 32% were young adults with a median age of 22 years (IQR: 20-24). Most (56.7% (143/252)) AYALHIV were female. Almost 40% were orphans. Eighty-six percent of AYALHIV had HIV type I infection. The commonest mode of HIV acquisition among adolescents was vertical transmission (70.5%) and that among young adults was via unprotected sex (31.3%). Eighty-eight percent (88%) of AYALHIV were on non-nucleoside reverse transcriptase inhibitors-based regimen. The viral suppression rate among AYALHIV was 78%. Conclusion: the study shows there is a growing population of AYALHIV most of which are adolescents. About two-fifths were orphans. Policymakers and HIV programs should ensure AYALHIV-centred interventions are developed for this vulnerable population.

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Fármacos Anti-HIV , Infecções por HIV , Humanos , Gana/epidemiologia , Adolescente , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/tratamento farmacológico , Masculino , Estudos Retrospectivos , Adulto Jovem , Criança , Fármacos Anti-HIV/administração & dosagem

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The ongoing epidemic of flaviviruses worldwide has underscored the importance of studying flavivirus vector competence, considering their close association with mosquito vectors. Tembusu virus is an avian-related mosquito-borne flavivirus that has been an epidemic in China and Southeast Asia since 2010. However, the reason for the outbreak of Tembusu virus in 2010 remains unclear, and it is unknown whether changes in vector transmission played an essential role in this process. To address these questions, we conducted a study using Culex quinquefasciatus as a model for Tembusu virus infection, employing both oral infection and microinjection methods. Our findings confirmed that both vertical and venereal transmission collectively contribute to the cycle of Tembusu virus within the mosquito population, with persistent infections observed. Importantly, our data revealed that the prototypical Tembusu virus MM_1775 strain exhibited significantly greater infectivity and transmission rates in mosquitoes than did the duck Tembusu virus (CQW1 strain). Furthermore, we revealed that the viral E protein and 3' untranslated region are key elements responsible for these differences. In conclusion, our study sheds light on mosquito transmission of Tembusu virus and provides valuable insights into the factors influencing its infectivity and transmission rates. These findings contribute to a better understanding of Tembusu virus epidemiology and can potentially aid in the development of strategies to control its spread.

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Culex , Infecções por Flavivirus , Flavivirus , Mosquitos Vetores , Animais , Culex/virologia , Flavivirus/fisiologia , Infecções por Flavivirus/veterinária , Infecções por Flavivirus/transmissão , Infecções por Flavivirus/virologia , Mosquitos Vetores/virologia , Feminino

RESUMO

BACKGROUND: Serodiagnosis of TORCH infections should be performed in pre-pregnancy and reproductive-age women to prevent vertical transmission. Herein, we conducted a 5-year cross-sectional retrospective study in childbearing age women to provide prevalence data. Also, stratifying the cohort into three age groups, we identified those most susceptible to acute TORCH infections. METHODS: Between 2019 and 2023, serum samples from 2286 childbearing age women attending the "R. Dulbecco" University Hospital of Catanzaro were collected. Screening for TORCH pathogens, such as: Toxoplasma gondii (TOX), Cytomegalovirus (CMV), Rubella Virus (RUB), Parvovirus B19 (ParvoB19), Herpes Simplex Virus types 1 and 2 (HSV1, HSV2) and Treponema pallidum was carried out using serological tests. Chemiluminescent immunoassay was performed to detect TOX, CMV and ParvoB19 Immunoglobulin M (IgM) and Immunoglobulin G (IgG) antibodies, while Enzyme Linked Fluorescent Assay was performed to detect RUB IgM and IgG antibodies and CMV and TOX IgG Avidity. Enzyme Linked Immunosorbent Assay was performed to detect HSV1 IgG, HSV2 IgG, HSV1/2 IgM, T. pallidum total antibodies and RUB IgG Avidity. Binomial logistic regression models were developed to compare seroprevalence rates among different age groups. RESULTS: The highest immunological protection was observed for RUB infection (87 %), probably associated with vaccination practice, followed by HSV1 and CMV (82 % and 63 %). The 16-25 year age group results as the most susceptible to acute infections as demonstrated by odds of CMV IgM positivity (primary infection) which decreased with age. CONCLUSIONS: The TORCH serological screening program should be implemented in women before pregnancy to formulate strategies for serological screening of childbearing age women and guiding clinicians in making decisions.

Assuntos

Toxoplasmose , Humanos , Feminino , Estudos Transversais , Estudos Retrospectivos , Adulto , Estudos Soroepidemiológicos , Adulto Jovem , Adolescente , Toxoplasmose/epidemiologia , Pessoa de Meia-Idade , Imunoglobulina M/sangue , Anticorpos Antivirais/sangue , Imunoglobulina G/sangue , Fatores Etários , Gravidez , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/imunologia , Suscetibilidade a Doenças , Prevalência , Toxoplasma/imunologia , Parvovirus B19 Humano/imunologia , Treponema pallidum/imunologia , Herpes Simples/epidemiologia , Infecções por Citomegalovirus/epidemiologia , Vírus da Rubéola/imunologia , Anticorpos Antibacterianos/sangue , Herpesvirus Humano 1/imunologia

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Congenital Chagas disease (CCD) is a worldwide neglected problem with significant treatment limitations. This study aimed to evaluate the potential of Copaifera spp. oleoresins (ORs) against Trypanosoma cruzi infection in trophoblast cells (BeWo lineage) and human chorionic villous explants (HCVE). The cytotoxicity of ORs was investigated using LDH and MTT assays. T. cruzi (Y strain) proliferation, invasion and reversibility were assessed in OR-treated BeWo cells, and proliferation was evaluated in OR-treated HCVE. The ultrastructure of T. cruzi trypomastigotes and amastigotes treated with ORs were analyzed by scanning and transmission electronic microscopy. ROS production in infected and treated BeWo cells and cytokines in BeWo and HCVE were measured. The ORs irreversibly decreased T. cruzi invasion, proliferation and release in BeWo cells by up to 70 %, 82 % and 80 %, respectively, and reduced parasite load in HCVE by up to 80 %. Significant structural changes in treated parasites were observed. ORs showed antioxidant capacity in BeWo cells, reducing ROS production induced by T. cruzi infection. Also, T. cruzi infection modulated the cytokine profile in both BeWo cells and HCVE; however, treatment with ORs upregulated cytokines decreased by T. cruzi infection in BeWo cells, while downregulated cytokines increased by the T. cruzi infection in HCVE. In conclusion, non-cytotoxic concentrations of Copaifera ORs demonstrated promising potential for controlling T. cruzi infection in models of the human maternal-fetal interface.

Assuntos

Doença de Chagas , Fabaceae , Placenta , Extratos Vegetais , Trofoblastos , Trypanosoma cruzi , Humanos , Trofoblastos/parasitologia , Trofoblastos/efeitos dos fármacos , Trofoblastos/metabolismo , Trypanosoma cruzi/efeitos dos fármacos , Feminino , Extratos Vegetais/farmacologia , Doença de Chagas/parasitologia , Doença de Chagas/tratamento farmacológico , Gravidez , Placenta/parasitologia , Placenta/efeitos dos fármacos , Placenta/metabolismo , Fabaceae/química , Espécies Reativas de Oxigênio/metabolismo , Citocinas/metabolismo , Linhagem Celular

RESUMO

Oropouche virus (OROV) is an emerging arbovirus endemic in Latin America and the Caribbean that causes Oropouche fever, a febrile illness that clinically resembles some other arboviral infections. It is currently spreading through Brazil and surrounding countries, where, from 1 January to 1 August 2024, more than 8000 cases have been identified in Bolivia, Brazil, Columbia, and Peru and for the first time in Cuba. Travelers with Oropouche fever have been identified in the United States and Europe. A significant occurrence during this epidemic has been the report of pregnant women infected with OROV who have had miscarriages and stillborn fetuses with placental, umbilical blood and fetal somatic organ samples that were RT-PCR positive for OROV and negative for other arboviruses. In addition, there have been four cases of newborn infants having microcephaly, in which the cerebrospinal fluid tested positive for IgM antibodies to OROV and negative for other arboviruses. This communication examines the biology, epidemiology, and clinical features of OROV, summarizes the 2023-2024 Oropouche virus epidemic, and describes the reported cases of vertical transmission and congenital infection, fetal death, and microcephaly in pregnant women with Oropouche fever, addresses experimental animal infections and potential placental pathology findings of OROV, and reviews other bunyavirus agents that can cause vertical transmission. Recommendations are made for pregnant women travelling to the regions affected by the epidemic.

Assuntos

Infecções por Bunyaviridae , Transmissão Vertical de Doenças Infecciosas , Microcefalia , Orthobunyavirus , Placenta , Complicações Infecciosas na Gravidez , Natimorto , Gravidez , Feminino , Humanos , Microcefalia/virologia , Microcefalia/epidemiologia , Orthobunyavirus/genética , Orthobunyavirus/isolamento & purificação , Complicações Infecciosas na Gravidez/virologia , Complicações Infecciosas na Gravidez/epidemiologia , Placenta/virologia , Infecções por Bunyaviridae/transmissão , Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/virologia , Recém-Nascido , Feto/virologia , Animais

RESUMO

Insect-specific viruses (ISVs) include viruses that are restricted to the infection of mosquitoes and are spread mostly through transovarial transmission. Despite using a distinct mode of transmission, ISVs are often phylogenetically related to arthropod-borne viruses (arboviruses) that are responsible for human diseases and able to infect both mosquitoes and vertebrates. ISVs can also induce a phenomenon called "superinfection exclusion", whereby a primary ISV infection in an insect inhibits subsequent viral infections of the insect. This has sparked interest in the use of ISVs for the control of pathogenic arboviruses transmitted by mosquitoes. In particular, insect-specific flaviviruses (ISFs) have been shown to inhibit infection of vertebrate-infecting flaviviruses (VIFs) both in vitro and in vivo. This has shown potential as a new and ecologically friendly biological approach to the control of arboviral disease. For this intervention to have lasting impacts for biological control, it is imperative that ISFs are maintained in mosquito populations with high rates of vertical transmission. Therefore, these strategies will need to optimise vertical transmission of ISFs in order to establish persistently infected mosquito lines for sustainable arbovirus control. This review compares recent observations of vertical transmission of arboviral and insect-specific flaviviruses and potential determinants of transovarial transmission rates to understand how the vertical transmission of ISFs may be optimised for effective arboviral control.

Assuntos

Culicidae , Infecções por Flavivirus , Flavivirus , Transmissão Vertical de Doenças Infecciosas , Mosquitos Vetores , Vertebrados , Animais , Flavivirus/fisiologia , Flavivirus/genética , Flavivirus/classificação , Mosquitos Vetores/virologia , Culicidae/virologia , Infecções por Flavivirus/transmissão , Infecções por Flavivirus/virologia , Humanos , Vertebrados/virologia , Arbovírus/fisiologia , Arbovírus/classificação

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We specifically addressed the persistent challenge of dengue in endemic regions, highlighting the potential seriousness of dengue infection through vertical transmission. Vertical dengue transmission has been well documented, particularly in hyper-endemic regions, including Ecuador. Herein, we present a neonate diagnosed with congenital dengue and review similar cases from previously published reports. Although congenital dengue is commonly infected with severe serotypes of DENV (DENV-1 and DENV-2) infections, favorable outcomes are generally observed.

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BACKGROUND: Despite worldwide vaccination efforts, Hepatitis B virus (HBV) infection remains a significant global health burden, particularly in regions where vertical transmission is prevalent. Given Romania's history as an endemic area for hepatitis B from the 1990s until the early 2000s and the previously high infection rates among children, it is crucial to continually evaluate HBV infection in this population to monitor current trends, assess the long-term impact of vaccination programs, and address any remaining gaps in prevention and treatment efforts. This study aims to identify childhood risk factors associated with HBV acquisition, examining the role of maternal HBV status in child HBV infection, focusing on vertical transmission among a cohort of 654 children, with maternal infection as the independent variable and child infection as the dependent variable. METHODS: We assessed potential risk factors and vaccination coverage among these children. The cohort included 148 children who tested positive for chronic hepatitis B from those 654 tested for HBsAg. Anamnestic data and vaccination history were analyzed, with particular attention to birth type and surgical interventions. RESULTS: Of the 148 HBV-positive children, 80.4% were delivered naturally. Among these, 130 had received hepatitis B vaccination, and 5 were also given hepatitis B immunoglobulin at birth, 4 of whom were born via cesarean section. In the control group, comprising 418 vaccinated children, a lesser proportion were unvaccinated (2.2%). Documented surgical interventions included general and dental surgeries, as well as a single blood transfusion. CONCLUSIONS: The study emphasizes the need for comprehensive vaccination strategies and illuminates potential correlations between birth type and vaccination status with childhood HBV infection. Crucially, it highlights the necessity of diligent monitoring and treatment of pregnant women with HBV to prevent vertical transmission as effectively as possible.

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Parent-offspring interactions constitute the first contact of many newborns with their environment, priming community assembly of microbes through priority effects. Early exposure to microbes can have lasting influences on the assembly and functionality of the host's microbiota, leaving a life-long imprint on host health and disease. Studies of the role played by parental care in microbial acquisition have primarily focused on humans and hosts with agricultural relevance. Anuran vertebrates offer the opportunity to examine microbial community composition across life stages as a function of parental investment. In this study, we investigate vertical transmission of microbiota during parental care in a poison frog (Family Dendrobatidae), where fathers transport their offspring piggyback-style from terrestrial clutches to aquatic nurseries. We found that substantial bacterial colonization of the embryo begins after hatching from the vitelline envelope, emphasizing its potential role as microbial barrier during early development. Using a laboratory cross-foster experiment, we demonstrated that poison frogs performing tadpole transport serve as a source of skin microbes for tadpoles on their back. To study how transport impacts the microbial skin communities of tadpoles in an ecologically relevant setting, we sampled frogs and tadpoles of sympatric species that do or do not exhibit tadpole transport in their natural habitat. We found more diverse microbial communities associated with tadpoles of transporting species compared to a non-transporting frog. However, we detected no difference in the degree of similarity between adult and tadpole skin microbiotas, based on whether the frog species exhibits transporting behavior or not. Using a field experiment, we confirmed that tadpole transport can result in the persistent colonization of tadpoles by isolated microbial taxa associated with the caregiver's skin, albeit often at low abundance. This is the first study to describe vertical transmission of skin microbes in anuran amphibians, showing that offspring transport may serve as a mechanism for transmission of parental skin microbes. Overall, these findings provide a foundation for further research on how vertical transmission in this order impacts host-associated microbiota and physiology.

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Introduction: Symbiotic bacteria play key roles in a variety of important life processes of insects such as development, reproduction and environmental adaptation, and the elucidation of symbiont population structure and dynamics is crucial for revealing the underlying regulatory mechanisms. The marmalade hoverfly (Episyrphus balteatus) is not only a remarkable aphid predator, but also a worldwide pollinator second to honeybees. However, its symbiont composition and dynamics remain unclear. Methods: Herein, we investigate the symbiotic bacterial dynamics in marmalade hoverfly throughout whole life cycle, across two sexes, and in its prey Megoura crassicauda by 16S rRNA sequencing. Results: In general, the dominant phyla were Proteobacteria and Firmicutes, and the dominant genera were Serratia and Wolbachia. Serratia mainly existed in the larval stage of hoverfly with the highest relative abundance of 86.24% in the 1st instar larvae. Wolbachia was found in adults and eggs with the highest relative abundance of 62.80% in eggs. Significant difference in species diversity was observed between the adults feeding on pollen and larvae feeding on M. crassicauda, in which the dominant symbiotic bacteria were Asaia and Serratia, respectively. However, between two sexes, the symbionts exhibited high similarity in species composition. In addition, our results suggested that E. balteatus obtainded Serratia mainly through horizontal transmission by feeding on prey aphids, whereas it acquired Wolbachia mainly through intergeneration vertical transmission. Taken together, our study revealed the effects of development stages, diet types and genders of E. balteatus on symbionts, and explored transmission modes of dominant bacteria Serratia and Wolbachia. Discussion: Our findings lay a foundation for further studying the roles of symbiotic bacteria in E. balteatus life cycle, which will benefit for revealing the co-adaptation mechanisms of insects and symbiotic bacteria.

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Known for over a century, seed transmission of plant viruses promotes trans-continental virus dissemination and provides the source of infection to trigger devastating disease epidemics in crops. However, it remains unknown whether there is a genetically defined immune pathway to suppress virus vertical transmission in plants. Here, we demonstrate potent immunosuppression of cucumber mosaic virus (CMV) seed transmission in its natural host Arabidopsis thaliana by antiviral RNA interference (RNAi) pathway. Immunofluorescence microscopy reveals predominant embryo infection at four stages of embryo development. We show that antiviral RNAi confers resistance to seed infection with different genetic requirements and drastically enhanced potency compared with the inhibition of systemic infection of whole plants. Moreover, we detect efficient seed transmission of a mutant CMV lacking its RNAi suppressor gene in mutant plants defective in antiviral RNAi, providing further support for the immunosuppression of seed transmission by antiviral RNAi.

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INTRODUCTION: Despite national guidelines and use of intrapartum antibiotic prophylaxis (IAP), Streptococcus agalactiae (group B streptococci (GBS)) is still a leading cause of morbidity and mortality in newborns in Europe and the United States. The European DEVANI (Design of a Vaccine Against Neonatal Infections) program assessed the neonatal GBS infection burden in Europe, the clinical characteristics of colonized women and microbiological data of GBS strains in colonized women and their infants with early-onset disease (EOD). METHODS: Overall, 1083 pregnant women with a GBS-positive culture result from eight European countries were included in the study. Clinical obstetrical information was collected by a standardized questionnaire. GBS strains were characterized by serological and molecular methods. RESULTS: Among GBS carriers included in this study after testing positive for GBS by vaginal or recto-vaginal sampling, 13.4% had at least one additional obstetrical risk factor for EOD. The five most common capsular types (i.e., Ia, Ib, II, III and V) comprised ~ 93% of GBS carried. Of the colonized women, 77.8% received any IAP, and in 49.5% the IAP was considered appropriate. In our cohort, nine neonates presented with GBS early-onset disease (EOD) with significant regional heterogeneity. CONCLUSIONS: Screening methods and IAP rates need to be harmonized across Europe in order to reduce the rates of EOD. The epidemiological data from eight different European countries provides important information for the development of a successful GBS vaccine.

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Skin microbes play an important role in amphibian tissue regeneration. Xenopus spp. (African clawed frogs) are well-established model organisms, and standard husbandry protocols, including use of antibiotics, may affect experimental outcomes by altering bacterial assemblages. It is therefore essential to improve knowledge of Xenopus bacterial community characteristics and inheritance. We undertook bacterial 16S rRNA gene sequencing and source tracking of a captive Xenopus laevis colony, including various life stages and environmental samples across multiple aquarium systems. Tank environments supported the most complex bacterial communities, while those of egg jelly were the most diverse of frog life stages; tadpole bacterial communities were relatively simple. Rhizobium (Proteobacteria) and Chryseobacterium (Bacteroidota) were dominant in tadpoles, whereas Chryseobacterium, Vogesella (Proteobacteria), and Acinetobacter (Proteobacteria) were common in females. Tadpoles received approximately two thirds of their bacteria via vertical transmission, though twenty-three genera were differentially abundant between females and tadpoles. Female frog skin appears to select for specific taxa, and while tadpoles inherit a proportion of their skin bacteria from females via the egg, they support a distinct and less diverse community. The outcomes of this study suggest the impacts of breaking the bacterial transmission chain with antibiotic treatment should be considered when raising tadpoles for experimental purposes.

RESUMO

Duck circovirus (DuCV) is widely recognized as a prominent virus in China's duck farming industry, known for its ability to cause persistent infections and significant immunosuppression, which can lead to an increased susceptibility to secondary infections, posing a significant threat to the duck industry. Moreover, clinical evidence also indicates the potential vertical transmission of the virus through duck embryos to subsequent generations of ducklings. However, the limited availability of suitable cell lines for in vitro cultivation of DuCV has hindered further investigation into the molecular mechanisms underlying its infection and pathogenicity. In this study, we observed that oral DuCV infection in female breeding ducks can lead to oviduct, ovarian, and follicular infections. Subsequently, the infection can be transmitted to the fertilized eggs, resulting in the emergence of virus-carrying ducklings upon hatching. In contrast, the reproductive organs of male breeding ducks were unaffected by the virus, thus confirming that vertical transmission of DuCV primarily occurs through infection in female breeding ducks. By analyzing transcriptome sequencing data from the oviduct, we focused on claudin-2, a gene encoding the tight junction protein CLDN2 located on the cell membrane, which showed significantly increased expression in DuCV-infected oviducts of female breeding ducks. Notably, CLDN2 was confirmed to interact with the unique structural protein of DuCV, namely capsid protein (Cap), through a series of experimental approaches including co-immunoprecipitation (co-IP), GST pull-down, immunofluorescence, and adhesion-blocking assays. Furthermore, we demonstrated that the Cap protein binds to the extracellular loop structural domains EL1 and EL2 of CLDN2. Subsequently, by constructing a series of truncated bodies of the CLDN2 promoter region, we identified the transcription factor SP5 for CLDN2. Moreover, we found that DuCV infection triggers the activation of the MAPK-ERK signaling pathway in DEF cells and ducks, leading to an upregulation of SP5 and CLDN2 expression. This process ultimately leads to the transportation of mature CLDN2 to the cell surface, thereby facilitating increased virus adherence to the target organs. In conclusion, we discovered that DuCV utilizes host CLDN2 proteins to enhance adhesion and infection in oviducts and other target organs. Furthermore, we elucidated the signaling pathways involved in the interaction between DuCV Cap proteins and CLDN2, which provides valuable insights into the molecular mechanism underlying DuCV's infection and vertical transmission. IMPORTANCE: Although duck circovirus (DuCV) poses a widespread infection and a serious hazard to the duck industry, the molecular mechanisms underlying DuCV infection and transmission remain elusive. We initially demonstrated vertical transmission of DuCV through female breeding ducks by simulating natural infection. Furthermore, a differentially expressed membrane protein CLDN2 was identified on the DuCV-infected oviduct of female ducks, and its extracellular loop structural domains EL1 and EL2 were identified as the interaction sites of DuCV Cap proteins. Moreover, the binding of DuCV Cap to CLDN2 triggered the intracellular MAPK-ERK pathway and activated the downstream transcription factor SP5. Importantly, we demonstrated that intracellular Cap also interacts with SP5, leading to upregulation of CLDN2 transcription and facilitating enhanced adherence of DuCV to target tissue, thereby promoting viral infection and transmission. Our study sheds light on the molecular mechanisms underlying vertical transmission of DuCV, highlighting CLDN2 as a promising target for drug development against DuCV infection.