Domestication Impacts the Wheat-Associated Microbiota and the Rhizosphere Colonization by Seed- and Soil-Originated Microbiomes, Across Different Fields

The seed-transmitted microorganisms and the microbiome of the soil in which the plant grows are major drivers of the rhizosphere microbiome, a crucial component of the plant holobiont. The seed-borne microbiome can be even coevolved with the host plant as a result of adaptation and vertical transmission over generations. The reduced genome diversity and crossing events during domestication might have influenced plant traits that are important for root colonization by seed-borne microbes and also rhizosphere recruitment of microbes from the bulk soil. However, the impact of the breeding on seed-transmitted microbiome composition and the plant ability of microbiome selection from the soil remain unknown. Here, we analyzed both endorhiza and rhizosphere microbiome of two couples of genetically related wild and cultivated wheat species (Aegilops tauschii/Triticum aestivum and T. dicoccoides/T. durum) grown in three locations, using 16S rRNA gene and ITS2 metabarcoding, to assess the relative contribution of seed-borne and soil-derived microbes to the assemblage of the rhizosphere microbiome. We found that more bacterial and fungal ASVs are transmitted from seed to the endosphere of all species compared with the rhizosphere, and these transmitted ASVs were species-specific regardless of location. Only in one location, more microbial seed transmission occurred also in the rhizosphere of A. tauschii compared with other species. Concerning soil-derived microbiome, the most distinct microbial genera occurred in the rhizosphere of A. tauschii compared with other species in all locations. The rhizosphere of genetically connected wheat species was enriched with similar taxa, differently between locations. Our results demonstrate that host plant criteria for soil bank’s and seed-originated microbiome recruitment depend on both plants’ genotype and availability of microorganisms in a particular environment. This study also provides indications of coevolution between the host plant and its associated microbiome resulting from the vertical transmission of seed-originated taxa.

Maternal transmission as a symbiont sieve, and the absence of lactation in male mammals

Gut microbiomes of humans carry a complex symbiotic assemblage of microorganisms. As in all mammals, the special mode of feeding newborn infants through milk from the mammary gland enhances the opportunity for vertical transmission of elements of this microbiome. This has potential benefits, but it also brings with it some hazards for the host. We point out here that vertical transmission from both parents would allow host populations to be invaded by elements that are deleterious. In contrast, vertical transmission, when restricted to one parent, acts as a sieve preventing the spread of such elements. Because some transmission from mother to infant is unavoidable in placental mammals, uniparental transmission of symbionts, if it were to be selected, would require some separation of the father from the newborn infant. This paper therefore puts forward the hypothesis that the asymmetry in roles of mother and father, together with the hazards that come with biparental transmission, generate a selection pressure against male lactation in humans, and in mammals in general.

Systemic endotheliitis in terms of novel coronavirus infection COVID-19: gender-related and perinatal risks

The review considers some physiological features that reflect gender differences in the susceptibility to a novel coronavirus infection. Up-to-date information on the impact of COVID-19 on the course of pregnancy and perinatal outcomes is presented. The debatable issues of the possibility of vertical transmission of the SARS-CoV-2 virus are highlighted based on the analysis of available literature data and recommendations of international professional communities.

Persistent Fetal SVT in a COVID-19 Positive Pregnancy

Background. Rapid introduction and spread of SARS-CoV-2 have posed unique challenges in understanding the disease, role in vertical transmission, and in developing management. We present a case of a patient with COVID-19 infection and fetus with new-onset fetal SVT. Case. A 26-year-old gravida 4 para 2012 with third trimester COVID-19 infection was diagnosed with new onset fetal SVT. Successful cardioversion was achieved with flecainide. The patient was followed outpatient until induction of labor at 39 and 3/7 weeks of gestational age resulting in an uncomplicated vaginal delivery. Postpartum course was uncomplicated. Conclusion. Fetal SVT is a potential complication of maternal COVID-19 infection. The use of transplacental therapy with flecainide is an appropriate alternative to digoxin in these cases.

Development of common leaf-footed bug pests depends on the presence and identity of their environmentally-acquired symbionts

Many beneficial symbioses between bacteria and their terrestrial arthropod hosts are vertically transmitted from mother to offspring, ensuring the progeny acquire necessary partners. Unusually, in several families of coreoid and lygeoid bugs (Hemiptera), nymphs must instead ingest the beneficial symbiont, Burkholderia ( sensu lato ), from the environment early in development. We studied the effects of Burkholderia on development of two species of leaf-footed bug (Coreidae) in the genus Leptoglossus, L. zonatus and L. phyllopus. We found no evidence for vertical transmission of the symbiont, but found stark differences in performance between symbiotic and aposymbiotic individuals. Symbiotic nymphs grew more rapidly, were approximately four times more likely to survive to adulthood than aposymbiotic bugs, and were two times larger. These findings suggest that Burkholderia is an obligate symbiont for Leptoglossus species. We also tested for variation in fitness effects conferred by four symbiont isolates representing different species within Burkholderia ’s insect-associated Stinkbug Beneficial and Environmental (SBE) clade. While three isolates conferred similar benefits to hosts, nymphs associated with the fourth isolate grew more slowly and weighed significantly less as adults. The effects of the four isolates were similar for both Leptoglossus species. This work indicates that both Burkholderia acquisition and isolate identity play critical roles in the growth and development of Leptoglossus. Importance Leptoglossus zonatus and L. phyllopus are important polyphagous pests and both species have been well-studied, but generally without regard to their dependance on a bacterial symbiont. Our results indicate that the central role of Burkholderia in the biology of these insects, as well as in other leaf-footed bugs, should be considered in future studies of coreid life history, ecology and pest management. Our work suggests acquisition of Burkholderia is critical for the growth and development of Leptoglossus species. Further, we found that there was variation in performance outcomes according to symbiont identity, even among members of the Stinkbug Beneficial and Environmental clade. This suggests that although environmental acquisition of a symbiont can provide extraordinary flexibility in partner associations, it also carries a risk if the partner is sub-optimal.

Effect of parity segregation on Mycoplasma hyopneumoniae infection dynamics and pneumonic lesions in pigs

ABSTRACT: Gilts represent a group risk for Mycoplasma hyopneumoniae vertical transmission in swine herds. Therefore, parity segregation can be an alternative to control M. hyopneumoniae infections. The study evaluated the effect of parity segregation on M. hyopneumoniae infection dynamics and occurrence and severity of lung lesions at slaughter. For that, three multiple site herds were included in the study. Herd A consisted of the farm where gilts would have their first farrowing (parity order (PO) 1). After the first farrowing PO 1 sows were transferred to herd B (PO2-6). Herd C was a conventional herd with gilt replacement (PO1-6). Piglets born in each herd were raised in separated nursery and finishing units. Sows (n = 33 (A), 37 (B), 34 (C)) in all herds were sampled prior to farrowing and piglets (n = 54 (A), 71 (B), 66 (C)) were sampled longitudinally at 21, 63, 100, 140 days of age and at slaughter for M. hyopneumoniae detection by PCR and lung lesions scoring. M. hyopneumoniae prevalence in sows did not differ among herds. Prevalence of positive piglets was higher at weaning in the PO1 herd (A) (P < 0.05). However, prevalence of positive pigs from 100 days of age to slaughter age was higher in the PO2-6 herd (B) (P < 0.05). Lung lesion occurrence and severity were higher in herd B. The authors suggested that the lack of a proper gilt acclimation might have influenced the results, leading to sows being detected positive at farrowing, regardless of the parity.

Knowledge about vertical transmission of HIV and associated factors among women living with HIV or AIDS attending antiretroviral therapy clinic, Western Ethiopia

Background: The United Nations Program on HIV or AIDS has committed to eliminating the vertical transmission of human immunodeficiency virus. However, significant number of newborn and children are acquiring HIV every year. Therefore, the aim of this study was to assess knowledge of mother on vertical transmission of HIV and associated factors among non-pregnant women receiving antiretroviral therapy in the West Wollega, Western Ethiopia. Methods: A facility-based cross-sectional study design was used on a sample of 422 non-pregnant women attending antiretroviral therapy clinic in West Wollega from 26 February to 26 March 2019. Systematic sampling was used to select the study participants. Pretested and structured interviewer-administered questionnaires and telephone interview were used to collect the data. Multivariable logistic regression model was used to identify factors associated with the knowledge of mother on vertical transmission of HIV. Odds ratio along with 95% confidence interval were estimated to measure the strength of the association. Level of statistical significance was declared at p-value less than 0.05. Result: Out of total participants, 94.1% (95% confidence interval: (91.7%, 96.2%)) of them were knowledgeable about vertical transmission of HIV. Urban resident (adjusted odds ratio: 2.36, 95% confidence interval: (1.27, 4.39)), primary school (adjusted odds ratio: 2.94, 95% confidence interval: (1.11, 7.83)), secondary school (adjusted odds ratio: 3.39, 95% confidence interval: (1.53, 7.55)), being on antiretroviral therapy for greater than 2 years (adjusted odds ratio: 2.67, 95% confidence interval: 1.02, 6.99)), and having child living with HIV (adjusted odds ratio: 1.54, 95% confidence interval: (1.07, 3 .83)) were significantly associated with the knowledge of mother on vertical transmission of HIV. Conclusion: The study indicated that 5.9% of the women lack knowledge about vertical transmission of HIV. This knowledge associated with sociodemographic factors, such as residence, educational status, experiences of having child living with HIV, and being on antiretroviral therapy for greater than 2 years. Thus, interventions toward the elimination of new newborn HIV infections should consider these factors.