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Approximately 20% of patients diagnosed with a phaeochromocytoma or paraganglioma carry a germline mutation in one of the succinate dehydrogenase (SDHx) genes (SDHA, SDHB, SDHC and SDHD), which encode the four subunits of the SDH enzyme. When a pathogenic SDHx mutation is identified in an affected patient, genetic counselling is proposed for first-degree relatives. Optimal initial evaluation and follow-up of people who are asymptomatic but might carry SDHx mutations have not yet been agreed. Thus, we established an international consensus algorithm of clinical, biochemical and imaging screening at diagnosis and during surveillance for both adults and children. An international panel of 29 experts from 12 countries was assembled, and the Delphi method was used to reach a consensus on 41 statements. This Consensus Statement covers a range of topics, including age of first genetic testing, appropriate biochemical and imaging tests for initial tumour screening and follow-up, screening for rare SDHx-related tumours and management of elderly people who have an SDHx mutation. This Consensus Statement focuses on the management of asymptomatic SDHx mutation carriers and provides clinicians with much-needed guidance. The standardization of practice will enable prospective studies in the near future.

Congenital syphilis occurs as a result of maternal transmission of treponema pallidum in utero. This condition is mainly diagnosed by treponemal and non-treponemal serologic tests. However, both maternal nontreponemal and treponemal IgG antibodies can be transferred through the placenta to the fetus, thus complicating its interpretation soon after birth. We report a case of a neonate with congenital syphilis whose mother became infected after the first trimester of pregnancy. We report how skeletal radiographs expedite the clinical decision-making process and direct further management of neonates. This case also highlights the need for repeated syphilis screening in the latter part of pregnancy.

Previous studies have shown that Dnmt2-null sperm block the paternal transmission (through sperm) of certain acquired traits, e.g., high-fat diet–induced metabolic disorders or white tails due to a Kit paramutation. Here, we report that DNMT2 is also required for the transmission of a Kit paramutant phenotype (white tail tip) through the female germline (i.e., oocytes). Specifically, ablation of Dnmt2 led to aberrant profiles of tRNA-derived small RNAs (tsRNAs) and other small noncoding RNAs (sncRNAs) in sperm, which correlate with altered mRNA transcriptomes in pronuclear zygotes derived from wild-type oocytes carrying the Kit paramutation and a complete blockage of transmission of the paramutant phenotype through oocytes. Together, the present study suggests that both paternal and maternal transmissions of epigenetic phenotypes require intact DNMT2 functions in the male germline. Summary sentence Dnmt2-null sperm block maternal transmission of epimutations, suggesting sperm-borne tsRNAs may be required for transmission of epimutations through the female germline.

Here we report for the first time on the maternal transmission of mild Coffin–Siris syndrome (CSS) caused by a SOX11 missense variant. We present two sisters with intellectual disability and muscular hypotonia born to non-consanguineous parents. Cogan ocular motor apraxia was present in both sisters. Body measurements were in a normal range. The mother and both daughters showed hypoplastic nails of the fifth toes. A missense variant in SOX11 [c.139 G > A; p.(Gly47Ser)] in both sisters and their mother was identified. Since 2014, variants in SOX11 are known to cause mild CSS. Most described patients showed intellectual disability, especially concerning acquired language. All of them had hypoplastic nails of the fifth toes. It is of note, that some of these patients show Cogan ocular motor apraxia. The facial dysmorphic features seem not to be specific. We suggest that the combination of Cogan ocular motor apraxia, hypoplastic nails of fifth toes, and developmental delay give the important diagnostic clue for a variant in the SOX11 gene (OMIM 615866, MR 27).

Maternally transmitted Wolbachia bacteria infect about half of all insect species. They usually show imperfect maternal transmission and often produce cytoplasmic incompatibility (CI). Irrespective of CI, Wolbachia frequencies tend to increase when rare only if they benefit host fitness. Several Wolbachia, including wMel that infects Drosophila melanogaster, cause weak or no CI and persist at intermediate frequencies. On the island of São Tomé off West Africa, the frequencies of wMel-like Wolbachia infecting Drosophila yakuba (wYak) and Drosophila santomea (wSan) fluctuate, and the contributions of imperfect maternal transmission, fitness effects, and CI to these fluctuations are unknown. We demonstrate spatial variation in wYak frequency and transmission on São Tomé. Concurrent field estimates of imperfect maternal transmission do not predict spatial variation in wYak frequencies, which are highest at high altitudes where maternal transmission is the most imperfect. Genomic and genetic analyses provide little support for D. yakuba effects on wYak transmission. Instead, rearing at cool temperatures reduces wYak titer and increases imperfect transmission to levels observed on São Tomé. Using mathematical models of Wolbachia frequency dynamics and equilibria, we infer that temporally variable imperfect transmission or spatially variable effects on host fitness and reproduction are required to explain wYak frequencies. In contrast, spatially stable wSan frequencies are plausibly explained by imperfect transmission, modest fitness effects, and weak CI. Our results provide insight into causes of wMel-like frequency variation in divergent hosts. Understanding this variation is crucial to explain Wolbachia spread and to improve wMel biocontrol of human disease in transinfected mosquito systems.

Background Early reports of COVID-19 in pregnancy described management by caesarean, strict isolation of the neonate and formula feeding. Is this practice justified? Objective To estimate the risk of the neonate becoming infected with SARS-CoV-2 by mode of delivery, type of infant feeding and mother-infant interaction. Search strategy Two biomedical databases were searched between September 2019 and June 2020. Selection criteria Case reports or case series of pregnant women with confirmed COVID-19, where neonatal outcomes were reported. Data collection and analysis Data were extracted on mode of delivery, infant infection status, infant feeding and mother-infant interaction. For reported infant infection, a critical analysis was performed to evaluate the likelihood of vertical transmission. Main results Forty nine studies included information on mode of delivery and infant infection status for 655 women and 666 neonates. In all, 28/666 (4%) tested positive postnatally. Of babies born vaginally, 8/292 (2.7%) tested positivecompared with 20/374 (5.3%) born by Caesarean. Information on feeding and baby separation were often missing, but of reported breastfed babies 7/148 (4.7%) tested positive compared with 3/56 (5.3%) for reported formula fed ones. Of babies reported as nursed with their mother 4/107 (3.7%) tested positive, compared with 6/46 (13%) for those who were reported as isolated. Conclusions Neonatal COVID-19 infection is uncommon, rarely symptomatic, and the rate of infection is no greater when the baby is born vaginally, breastfed or remains with the mother. Tweetable abstract Risk of neonatal infection with COVID-19 by delivery route, infant feeding and mother-baby interaction.

Background In 2017, Zimbabwe adopted a modified version of the World Health Organization 2016 recommendation on HIV birth testing by offering HIV testing at birth only to infants at "high risk" of HIV transmission. There is limited evidence on the effectiveness of this approach. Our study assessed the sensitivity and specificity of birth testing "high risk" infants only. Methods We conducted a cross-sectional study at 10 health facilities from November 2018 to July 2019. A nucleic acid test for HIV was performed on all HIV-exposed infants identified within 48 hours of life, irrespective of risk status. Univariate and bivariate analyses were used to estimate the performance of the risk screening tool. Results HIV nucleic acid test was successfully performed on 1970 infants (95%), of whom 266 (13.5%) were classified as high-risk infants. HIV prevalence for all infants tested was 1.5% (95% CI: 1% to 2%), whereas prevalence among high-risk infants and low-risk infants was 6.8% (95% CI: 3.7% to 9.8%) and 0.6% (95% CI: 0.3% to 1%) respectively. Sensitivity and specificity of the maternal risk screening tool was at 62.1% (95% CI: 44.4% to 79.7%) and 87.2% (95% CI: 85.7% to 88.7%), respectively; positive and negative predictive values were 6.8% (95% CI: 3.7% to 9.8%) and 99.4% (95% CI: 99.0% to 99.7%) respectively. Conclusions Despite high negative predictive value, sensitivity was relatively low, with potential of missing 2 in every 5 HIV infected infants. Given the potential benefits of early ART initiation for all exposed infants, where feasible, universal testing for HIV-exposed infants at birth may be preferred to reduce missing infected infants.

Theory and preliminary evidence suggests that parental beliefs and cognitions may be transmitted to their offspring. Transmission of maladaptive cognitions may play a role in the development of anxiety disorders in childhood. However, few studies have investigated such transmission using longitudinal designs. The objective of this study was to investigate the interaction between maternal and child metacognitions and their role in the development of childhood anxiety. We used a longitudinal design with self-report measures of maternal and child anxiety symptoms and metacognitions. Participants were 107 mothers and their children who were assessed when the children were between 7 and 12 years old and again 3 years later. Child metacognitions at baseline did not predict later child anxiety symptoms. Baseline maternal metacognitions approached significance in predicting anxiety symptoms in children at the follow-up, when controlling for known risk factors, including female gender and higher levels of anxiety in mother and child at baseline. Mediation analyses revealed that child metacognitions at baseline, as well as at follow-up fully mediated the relationship between maternal baseline metacognitions and child anxiety 3 years later. Examinations of how child and maternal metacognitions affect child anxiety levels after three years revealed that current levels of child metacognitions play a greater role in predicting child anxiety than child and maternal metacognitions at baseline.

Mitochondrial DNA (mtDNA) is maternally transmitted in animals and therefore, individuals are expected to have a single mtDNA haplotype (homoplasmy). Yet, heteroplasmic individuals have been observed in a large number of animal species. Heteroplasmy may emerge as a result of somatic mtDNA mutations, paternal leakage during fertilization or be inherited from a heteroplasmic mother. Understanding the causes of heteroplasmy could shed light into the evolution of mtDNA inheritance. In this study we examined heteroplasmy in progeny from heterospecific crosses of Drosophila for two consecutive generations. We studied the generation of heteroplasmy from paternal leakage and the maternal transmission of heteroplasmy. Our data reveal non-random patterns in the emergence and transmission of heteroplasmy and suggest that heteroplasmy depends on the family of origin.

In this article, we formulate and study a discrete equation model depicting the pattern of Wolbachia infection in a mosquito population. A domain in $\mathcal {R}_+^2 $ is called a Wolbachia infection enhancing (or decaying) domain if in which the Wolbachia infection frequency of the next generation is always bigger (or smaller) than that of the current generation. We first give a complete analysis of the equivalent Wolbachia infection frequency curves. And then we clearly characterize the Wolbachia infection enhancing domain and decaying domain for all of the parameters, respectively. Finally, some numerical examples are also provided to illustrate our theoretical results.

Anxiety aggregates in families. The key putative environmental mediators of risk transmission from parents to children include parental psychological control and behavioral control, which are important features of parenting in Chinese culture. It is unclear, however, whether Chinese parents’ own anxiety is associated with their partners’ controlling behaviors and whether control mediates the transmission of anxiety. This study aimed to examine whether and how anxiety is transmitted from parents to children with a mediation model incorporating an actor–partner interdependent model. We conducted a prospective longitudinal study with parents of Chinese children aged 7–12 years old (N = 651). Our results found the intergenerational transmission of anxiety from parents to children and maternal transmission of anxiety was mediated by maternal psychological control. Parental anxiety was positively associated with parents’ own psychological, but not behavioral, control. The data showed no association between parents’ own anxiety and their partners’ psychological or behavioral control. These findings support parental anxiety and maternal psychological control as critical risk factors in children’s development of anxiety in Chinese families.

Environmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of Wolbachia symbionts for the control of dengue arboviruses. The potential of Wolbachia to invade, persist and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating Wolbachia densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on Wolbachia density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains wMel and wAlbB, two Wolbachia strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity and dengue inhibition capacity were observed for wMel. In contrast wAlbB-carrying Ae. aegypti maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, wMel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures. When choosing the Wolbachia strain to be used in a dengue control programme it is important to consider the effects of environmental temperatures on invasiveness and virus inhibition.Author summaryIn the past decades, dengue incidence has dramatically increased all over the world. An emerging dengue control strategy utilizes Ae. aegypti mosquitoes artificially transinfected with the bacterial symbiont Wolbachia, with the ultimate aim of replacing wild mosquito populations. Wolbachia is transmitted from mother to offspring and is able to interfere with virus transmission within the mosquito vector. However, the rearing temperature of mosquito larvae is known to impact on some Wolbachia strains. In this study, we compared the effects of a temperature cycle mimicking natural breeding sites in tropical climates on two Wolbachia strains, currently used for open field trials. We observed that the strain wMel was susceptible to high larval rearing temperatures, while the strain wAlbB resulted to be more stable. These results underlines the importance of understanding the impact of environmental factors on released mosquitoes, in order to ensure the most efficient strategy for dengue control.

Background Malaria control relies mainlyon insecticide-based tools. However, the effectiveness of these tools is threatened by widespread insecticide resistance in malaria vectors, highlighting the need for alternative control approaches. The endosymbiont Asaia has emerged as a promising candidate for paratransgenic control of malaria, but its biology and genetics still need to be further analyzed across Africa. Here, we investigated the prevalence of Asaia and its maternal transmission in the natural population of Anopheles mosquitoes in Cameroon. Methods Indoor-resting adult mosquitoes belonging to four species (An. coluzzii, An. arabiensis, An. funestus and An. gambiae) were collected from eight localities across Cameroon from July 2016 to February 2020. PCR was performed on the Asaia-specific 16S ribosomal RNA gene, and samples positive by PCR for Asaia were confirmed by Sanger sequencing and phylogenetic analysis. The vertical transmission of Asaia was investigated by screening F1 mosquitoes belonging to F0Asaia-positive females. Results A total of 895 mosquitoes were screened. We found 43% (384) Asaia infection prevalence in four mosquito species. Phylogenetic analysis revealed that Asaia from Cameroon clustered together with the strains of Asaia isolated from other parts of the world. In addition, seven nucleotide sequence variants were found with low genetic diversity (π = 0.00241) and nucleotide sequence variant diversity (Hd = 0.481). Asaia was vertically transmitted with high frequency (range from 42.5 to 100%). Conclusions This study provides field-based evidence of the presence of Asaia in Anopheles mosquitoes in Cameroon for exploitation as a symbiont in the control of malaria in sub-Saharan Africa. Graphical abstract

OBJECTIVE: To investigate viral prevalence in a large neonatal cohort and determine the impact on pregnancy and birth outcomes. STUDY DESIGN: We prospectively collected 1044 neonatal samples from remnant neonatal cord blood RPR samples. We performed qRT-PCR/qPCR reactions for: adenovirus, anellovirus (alphatorquevirus and betatorquevirus), cytomegalovirus (CMV), Epstein-Barr virus (EBV), enterovirus, human herpesvirus 6 (HHV6), parechovirus, and parvovirus B19. RESULT: Overall viral prevalence was 5.6% with 58 positive samples. Alphatorquevirus (2%) and HHV6 (1.2%) were the two most prevalent viruses detected. Viral detection was most common in samples collected in the fall (September-November) and least common in those collected in winter (December–February). There was no statistical difference detected in viral prevalence or viral load by gestational age, preterm delivery, pre-eclampsia or chorioamnionitis. CONCLUSION: While there is seasonal variation in viral prevalence in neonatal cord blood samples, individual virus presence does not seem to effect pregnancy or birth outcomes.

Human herpesviruses 6A and 6B (HHV-6A/6B) are ubiquitous pathogens that persist lifelong in latent form and can cause severe conditions upon reactivation. They are spread by community-acquired infection of free virus (acqHHV6A/6B) and by germline transmission of inherited chromosomally- integrated HHV-6A/6B (iciHHV-6A/6B) in telomeres. We exploited a hypervariable region of the HHV- 6B genome to investigate the relationship between acquired and inherited virus and revealed predominantly maternal transmission of acqHHV-6B in families. Remarkably, we demonstrate that some copies of acqHHV-6B in saliva from healthy adults gained a telomere, indicative of integration and latency, and that the frequency of viral genome excision from telomeres in iciHHV-6B carriers is surprisingly high and varies between tissues. In addition, newly formed short telomeres generated by partial viral genome release are frequently lengthened, particularly in telomerase-expressing pluripotent cells. Consequently, iciHHV-6B carriers are mosaic for different iciHHV-6B structures, including circular extra-chromosomal forms that have the potential to reactivate. Finally, we show transmission of an HHV-6B strain from an iciHHV-6B mother to her non-iciHHV-6B son. Altogether we demonstrate that iciHHV-6B can readily transition between telomere-integrated and free virus forms.

Leaf fungal endophytes (LFEs) contribute to plant growth and responses to stress. Fungi colonize leaves through maternal transmission, e.g. via the seed, and through environmental transmission, e.g. via aerial dispersal. The relative importance of these two pathways in assembly and function of the LFE community is poorly understood. We used amplicon sequencing to track switchgrass ( Panicum virgatum ) LFEs in a greenhouse and field experiment as communities assembled from seed endophytes and rain fungi (integration of wet and dry aerial dispersal) in germinating seeds, seedlings, and adult plants. Rain fungi varied temporally and hosted a greater portion of switchgrass LFE richness (greater than 65%) than were found in seed endophytes (greater than 25%). Exposure of germinating seeds to rain inoculum increased dissimilarity between LFE communities and seed endophytes, increasing the abundance of rain-derived taxa, but did not change diversity. In the field, seedling LFE composition changed more over time, with a decline in seed-derived taxa and an increase in richness, in response to environmental transmission than LFEs of adult plants. We show that environmental transmission is an important driver of LFE assembly, and likely plant growth, but its influence depends on both the conditions at the time of colonization and plant life stage.

Significance Many animals depend on maternally transmitted symbiotic bacteria that provide nutrients or other benefits. The evolution of these symbionts is complicated: natural selection can act on hosts, favoring symbionts that increase host reproduction, or on symbionts, favoring symbionts that spread within hosts. Furthermore, transmission bottlenecks can facilitate the spread of mutations deleterious to both. By measuring changes in frequencies of symbiont genotypes within individual insect matrilines, we estimated within-host selection and transmission bottleneck size. Results revealed surprisingly strong selection, with some symbiont genotypes more successful in colonizing progeny, as well as a severe transmission bottleneck, consistent with observations of deleterious mutation accumulation in symbiont genomes. Findings elucidate the forces driving evolution of heritable symbionts and generating their distinctive genomic features., Numerous animal lineages have maternally inherited symbionts that are required for host reproduction and growth. Endosymbionts also pose a risk to their hosts because of the mutational decay of their genomes through genetic drift or to selfish mutations that favor symbiont fitness over host fitness. One model for heritable endosymbiosis is the association of aphids with their obligate bacterial symbiont, Buchnera. We experimentally established heteroplasmic pea aphid matrilines containing pairs of closely related Buchnera haplotypes and used deep sequencing of diagnostic markers to measure haplotype frequencies in successive host generations. These frequencies were used to estimate the effective population size of Buchnera within hosts (i.e., the transmission bottleneck size) and the extent of within-host selection. The within-host effective population size was in the range of 10 to 20, indicating a strong potential for genetic drift and fixation of deleterious mutations. Remarkably, closely related haplotypes were subject to strong within-host selection, with selection coefficients as high as 0.5 per aphid generation. In one case, the direction of selection depended on the thermal environment and went in the same direction as between-host selection. In another, a new mutant haplotype had a strong within-host advantage under both environments but had no discernible effect on host-level fitness under laboratory conditions. Thus, within-host selection can be strong, resulting in a rapid fixation of mutations with little impact on host-level fitness. Together, these results show that within-host selection can drive evolution of an obligate symbiont, accelerating sequence evolution.

Wolbachia is the most common bacterial endosymbiont of arthropods, such as the medically important Aedes albopictus and Aedes aegypti. Both Wolbachia and mitochondrial DNA are maternally inherited. This study collected 12 adult Aedes albopictus and 359 Aedes aegypti from 183 households in a dengue-prone area, Manila, Philippines, between June and September 2017. Aedes larvae (n = 509) were also collected from 17 water containers from 11 households. The DNA of the Aedes larvae and adults were screened for the presence of Wolbachia using the wsp and 16S markers, following optimized polymerase chain reaction (PCR) conditions, and sequenced. We also performed PCR using the mitochondrial DNA cox1 marker and sequenced the Wolbachia-positive samples. Our results showed that three out of 359 (0.84%) adult Ae. aegypti and 12 out of 12 (100%) adult Ae. albopictus were Wolbachia positive, while all of the larvae tested negative for Wolbachia (0/509; 0%). The wsp marker revealed six Wolbachia-positive Ae. albopictus, while the 16S marker showed Wolbachia in three Ae. aegypti and 10 Ae. albopictus. Three Wolbachia-positive Ae. albopictus from one household were found to have a single haplotype for all Wolbachia (wsp and 16S) and mitochondrial cox1 markers. This result indicates maternal transmission of Wolbachia in the household because siblings of a Wolbachia-infected mother mosquito share the Wolbachia and mitochondrial genomes. Our results showed the feasibility of combined sequencing analyses of Wolbachia (wsp and 16S) and mitochondrial DNA to test maternal transmission in field-collected mosquitoes.

In this context of COVID-19 pandemic, great interest has been aroused by the potential maternal transmission of SARS-CoV-2 by transplacental route, during delivery, and, subsequently, through breastfeeding. Some open questions still remain, especially regarding the possibility of finding viable SARS-CoV-2 in breast milk (BM), although this is not considered a worrying route of transmission. However, in BM, it was pointed out the presence of antibodies against SARS-CoV-2 and other bioactive components that could protect the infant from infection. The aim of our narrative review is to report and discuss the available literature on the detection of anti-SARS-CoV-2 antibodies in BM of COVID-19 positive mothers, and we discussed the unique existing study investigating BM of SARS-CoV-2 positive mothers through metabolomics, and the evidence regarding microbiomics BM variation in COVID-19. Moreover, we tried to correlate metabolomics and microbiomics findings in BM of positive mothers with potential effects on breastfed infants metabolism and health. To our knowledge, this is the first review summarizing the current knowledge on SARS-CoV-2 effects on BM, resuming both “conventional data” (antibodies) and “omics technologies” (metabolomics and microbiomics).

Background In 2010, Rwanda adopted ART for prevention of mother to child transmission of HIV from pregnant women living with HIV during pregnancy and breasfeeding period. This study examines rates of mother-to-child-transmission of HIV at 6–10 weeks postpartum and risk factors for mother-to-child transmission of HIV (MTCT) among HIV infected women on ART during pregnancy and breastfeeding. Methods A cross-sectional survey study was conducted between July 2011–June 2012 among HIV-exposed infants aged 6–10 weeks and their mothers/caregivers. Stratified multi-stage, probability proportional to size and systematic sampling to select a national representative sample of clients. Consenting mothers/caregivers were interviewed on demographic and program interventions. Dry blood spots from HIV-exposed infants were collected for HIV testing using DNA PCR technique. Results are weighted for sample realization. Univariable analysis of socio-demographic and programmatic determinants of early mother-to-child transmission of HIV was conducted. Variables were retained for final multivariable models if they were either at least of marginal significance (p-value 10% change on the effect estimate). Results The study sample was 1639 infants with HIV test results. Twenty-six infants were diagnosed HIV-positive translating to a weighted MTCT estimate of 1.58% (95% CI 1.05–2.37%). Coverage of most elimination of MTCT (EMTCT) program interventions, was above 80, and 90.4% of mother-infant pairs received antiretroviral treatment or prophylaxis. Maternal ART and infant antiretroviral prophylaxis (OR 0.01; 95%CI 0.001–0.17) and maternal age older than 25 years were significantly protective (OR 0.33; 95%CI 0.14–0.78). No disclosure of HIV status, not testing for syphilis during pregnancy and preterm birth were significant risk factors for MTCT. Factors suggesting higher socio-demographic status (flush toilet, mother self-employed) were borderline risk factors for MTCT. Conclusion ART for all women during pregnancy and breastfeeding was associated with the estimated low MTCT rate of 1.58%. Mothers who did not receive a full package of anti-retroviral therapy according to the Rwanda EMTCT protocol, and young and single mothers were at higher risk of MTCT and should be targeted for support in preventing HIV infection.

Since the 2016 Zika outbreak and the understanding of the teratogenic effect of this infection, there has been a newfound interest in arbovirus infections and their effects on pregnancy, resulting in numerous publications in the last 5 years. However, limited literature focuses on arbovirus infection in different stages of pregnancy and their effect on the neonate. There is currently no consensus management of perinatal acquisition of arboviruses, and current evidence is largely anecdotal observational reports. Teratogens can have different effects on the developing fetus depending on the time of infection, so infections during pregnancy should be analyzed by trimester. A better understanding of arbovirus infection in the perinatal period is required to assist obstetric, neonatal, and pediatric clinicians in making decisions about the management of mother and neonate. Our objective was to assess the evidence of adverse neonatal outcomes for several arboviral infections when contracted during the perinatal period to guide clinicians in managing these patients. There are 8 arboviruses for which neonatal outcomes from maternal acquisition in the perinatal period have been reported, with the most data for dengue and Chikungunya virus infections. The evidence reviewed in this article supports the adoption of preventive strategies to avoid ticks and mosquitoes close to the date of delivery. For the other arbovirus infections, further community-based cohort studies during outbreaks are required to evaluate whether these infections have a similar teratogenic impact.

An intracellular bacterium, strain IAST, was observed to infect several species of the plant-parasitic nematode genus Xiphinema (Xiphinema astaregiense, Xiphinema incertum, Xiphinema madeirense, Xiphinema pachtaicum, Xiphinema parapachydermum and Xiphinema vallense). The bacterium could not be recovered on axenic medium. The 16S rRNA gene sequence of IAST was found to be new, being related to the family Burkholderiaceae, class Betaproteobacteria. Fungal endosymbionts Mycoavidus cysteinexigens B1-EBT (92.9 % sequence identity) and ‘Candidatus Glomeribacter gigasporarum’ BEG34 (89.8 % identity) are the closest taxa and form a separate phylogenetic clade inside Burkholderiaceae. Other genes (atpD, lepA and recA) also separated this species from its closest relatives using a multilocus sequence analysis approach. These genes were obtained using a partial genome of this bacterium. The localization of the bacterium (via light and fluorescence in situ hybridization microscopy) is in the X. pachtaicum females clustered around the developing oocytes, primarily found embedded inside the epithelial wall cells of the ovaries, from where they are dispersed in the intestine. Transmission electron microscopy (TEM) observations supported the presence of bacteria inside the nematode body, where they occupy ovaries and occur inside the intestinal epithelium. Ultrastructural analysis of the bacterium showed cells that appear as mostly irregular, slightly curved rods with rounded ends, 0.8–1.2 µm wide and 2.5–6.0 µm long, possessing a typical Gram-negative cell wall. The peptidoglycan layer is, however, evident only occasionally and not detectable by TEM in most cells. Another irregularly occurring shell surrounding the endosymbiont cells or the cell clusters was also revealed, probably originating from the host cell membrane. Flagella or spore-like cells do not occur and the nucleoid is diffusely distributed throughout the cell. This endosymbiont is transmitted vertically through nematode generations. These results support the proposal of IAST as a new species, although its obligate intracellular and obligate endosymbiont nature prevented isolation of a definitive type strain. Strain IAST is therefore proposed as representing ‘Candidatus Xiphinematincola pachtaicus’ gen. nov., sp. nov., This research was financially supported by grant 201740E042, ‘Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos’ from the Spanish National Research Council (CSIC) and grant RTI2018-095925-A-100 from the Ministerio de Ciencia, Innovación y Universidades, Spain. The first author acknowledges the Spanish Ministry of Economy and Competitiveness for the ‘Ramon y Cajal’ Fellowship RYC-2017-22228.