Infected Offspring Research Articles

Outbreak of persistently infected heifer calves with bovine viral diarrhea virus subgenotypes 1b and 1d in a BVDV-vaccinated open dairy herd

Bovine viral diarrhea virus (BVDV) infection has a significant economic impact on beef and dairy industries worldwide. Fetal infection with a non-cytopathic strain may lead to the birth of persistently infected (PI) offspring, which is the main event in the epidemiological chain of BVDV infection. This report describes the birth of 99 BVDV-PI heifer calves within 52 days of birth in a regular BVDV-vaccinated Brazilian dairy cattle herd and the subgenotypes of the infecting field strains. This study was conducted in a high-yielding open dairy cattle herd that frequently acquired heifers from neighboring areas for replacement. The farm monitors the birth of PI calves by screening all calves born using an ELISA (IDEXX) for BVDV antigen detection. All calves aged 1–7 days were evaluated. For positive and suspected results, the ELISA was repeated when the calves were close to one month old. A total of 294 heifer calves were evaluated between February and March 2021. Of these, 99 (33.7 %) had positive ELISA results and were considered PI calves. To evaluate the predominant BVDV species and subgenotypes in this outbreak, whole blood samples were collected from 31 calves born during the study period. All samples were submitted to the RT-PCR assay for the partial amplification of the BVDV 5′-UTR region, and these amplicons were subjected to nucleotide sequencing. Phylogenetic analysis identified BVDV-1b and BVDV-1d in 16 and 13 heifer calves, respectively. In two calves, it was not possible to determine the BVDV-1 subgenotype. Detection of PI animals and monitoring of circulating BVDV subgenotype strains are central to disease control. This study shows that regular BVDV vaccination alone may be insufficient to prevent BVDV infection in high-yielding open dairy cattle herds. Other biosecurity measures must be adopted to avoid the purchase of cattle with acute infections by BVDV or BVDV-PI, which can cause a break in the health profile of the herd and economic losses.

Treatment of pregnant mice with ABZ had no effect on the immune response of their offspring infected with Trichinella spiralis.

Trichinellosis is a food-borne parasitic disease with a worldwide distribution that not only endangers human health but also leads to economic loss. Infection of pregnant animals with Trichinella spiralis (T. spiralis) may lead to abortion and other adverse consequences, so it is necessary to treat the infection during pregnancy. Albendazole (ABZ) is an effective therapeutic drug for adult T. spiralis worms. The safety of this drug during pregnancy, especially whether it has any effect on offspring, should be fully evaluated. A change in the immune response to T. spiralis in the offspring of pregnant mice treated with ABZ may lead to a difference in susceptibility to T. spiralis compared to that of the offspring of normal mice. However, the safety of ABZ treatment in pregnant mice and the effects on the immune response and susceptibility of their offspring to T. spiralis are poorly understood. Therefore, we assessed whether maternal ABZ treatment during pregnancy affects the immune response or susceptibility to T. spiralis in infected offspring. In this study, mice were infected with T. spiralis at 10days of pregnancy and treated with ABZ at 3days post infection (dpi), and the specific immune response in the pregnant mice and the survival rate and worm burden of their 6-week-old offspring after T. spiralis infection were examined. The results showed that the antiparasitic immune response in pregnant mice was activated by T. spiralis infection. Treatment of pregnant mice with ABZ increased the percentage of CD4+T cells. The percentages of Th2 and Treg cells in the PP, MLN and spleen of pregnant mice in the infection group were significantly increased compared with those of normal mice. ABZ treatment during pregnancy promoted the Th2 and Treg immune responses in pregnant mice infected with T. spiralis. The transcriptional levels of the Th2 and Treg cytokines IL-4, IL-5, IL-13, and TGF-β in the small intestine, MLN and spleen of pregnant mice in the treatment group were significantly higher than those of pregnant mice in the T. spiralis infection only group. The results indicated that ABZ treatment did not cause abortion in pregnant mice or affect the survival rate of their offspring. Furthermore, treatment of pregnant mice with ABZ had no significant effect on the above immune responses in their T. spiralis-infected offspring compared to those of T. spiralis-infected offspring of mice in the normal group. The results also indicated that treatment of pregnant mice infected with T. spiralis with ABZ shifted the immune response to a Th2- and Treg-skewed immune response and that this drug had no effects on the offspring survival rate, immune response or worm burden after T. spiralis infection. This study further indicated that ABZ administration to treat T. spiralis infection in pregnant mice is safe for the select immune response and susceptibility of their offspring.

Fetal brain vulnerability to SARS-CoV-2 infection

Whether or not SARS-CoV-2 can cross from mother to fetus during a prenatal infection has been controversial; however, recent evidence such as viral RNA detection in umbilical cord blood and amniotic fluid, as well as the discovery of additional entry receptors in fetal tissues suggests a potential for viral transmission to and infection of the fetus. Furthermore, neonates exposed to maternal COVID-19 during later development have displayed neurodevelopmental and motor skill deficiencies, suggesting the potential for consequential neurological infection or inflammation in utero. Thus, we investigated transmission potential of SARS-CoV-2 and the consequences of infection on the developing brain using human ACE2 knock-in mice. In this model, we found that viral transmission to the fetal tissues, including the brain, occurred at later developmental stages, and that infection primarily targeted male fetuses. In the brain, SARS-CoV-2 infection largely occurred within the vasculature, but also within other cells such as neurons, glia, and choroid plexus cells; however, viral replication and increased cell death were not observed in fetal tissues. Interestingly, early gross developmental differences were observed between infected and mock-infected offspring, and high levels of gliosis were seen in the infected brains 7 days post initial infection despite viral clearance at this time point. In the pregnant mice, we also observed more severe COVID-19 infections, with greater weight loss and viral dissemination to the brain, compared to non-pregnant mice. Surprisingly, we did not observe an increase in maternal inflammation or the antiviral IFN response in these infected mice, despite showing clinical signs of disease. Overall, these findings have concerning implications regarding neurodevelopment and pregnancy complications of the mother following prenatal COVID-19 exposure.

Molecular Biology of Cytoplasmic Incompatibility Caused by Wolbachia Endosymbionts.

Among endosymbiotic bacteria living within eukaryotic cells, Wolbachia is exceptionally widespread, particularly in arthropods. Inherited through the female germline, it has evolved ways to increase the fraction of bacterially infected offspring by inducing parthenogenesis, feminization, male killing, or, most commonly, cytoplasmic incompatibility (CI). In CI, Wolbachia infection of males causes embryonic lethality unless they mate with similarly infected females, creating a relative reproductive advantage for infected females. A set of related Wolbachia bicistronic operons encodes the CI-inducing factors. The downstream gene encodes a deubiquitylase or nuclease and is responsible for CI induction by males, while the upstream product when expressed in females binds its sperm-introduced cognate partner and rescues viability. Both toxin-antidote and host-modification mechanisms have been proposed to explain CI. Interestingly, male killing by either Spiroplasma or Wolbachia endosymbionts involves deubiquitylases as well. Interference with the host ubiquitin system may therefore be a common theme among endosymbiont-mediated reproductive alterations.

Babesia bovis

Babesia bovis is an economically important, obligate intracellular protozoan that causes the most pathogenic form of bovine babesiosis. It occurs in Asia, Africa, Australia, and in Central, South, and southern North America, and parts of southern Europe. Rhipicephalus microplus is its most important vector. Infected female ticks produce infected offspring (transovarial transmission), which are the main source of transmission to cattle. Its life cycle contains an asexual replication in cattle erythrocytes, a sexual replication in the tick midgut, and an asexual replication in tick salivary glands. Younger animals have increased resistance compared with adults. This spleen-dependent resistance is attributed to a strong innate immunity. Prevention relies on the use of acaricides and live attenuated vaccines, available in some endemic countries. Vaccinated animals or those recovered from infection develop adaptive immunity, but they remain infected and may serve as reservoirs for transmission.

Maternal anti-Toxoplasma gondii antibodies IgG2, IgG3 and IgG1 are markers of vertical transmission and clinical evolution of toxoplasmosis in the offspring

Toxoplasma gondii can be transmitted vertically during pregnancy and may cause neurological, ocular, and even systemic damage to the offspring. Congenital toxoplasmosis (CT) can be diagnosed during gestation and/or after birth in the postnatal period. The timely diagnosis is highly relevant for efficient clinical management. The most common laboratory methods for diagnosing CT are based on Toxoplasma-specific humoral immune responses. However, these methods are of low sensitivity or specificity. In a previous study with a small number of cases, the comparison of anti-T. gondii IgG subclasses between mothers and their offspring showed promising results for CT diagnosis and prognosis. Thus, in this work, we analyzed specific IgG subclasses and IgA in 40 T. gondii-infected mothers and their children, of which 27 were congenitally infected and 13 uninfected. A higher frequency of anti-Toxoplasma IgG2, IgG3, IgG4, and IgA antibodies was observed in mothers and congenitally infected offspring. Of these, IgG2 or IgG3 were statistically the most conspicuous. In the CT group, maternal IgG3 antibodies were significantly associated with severe disease of the infants and IgG1 and IgG3 with disseminated disease. The results support that maternal anti-T. gondii IgG3, IgG2 and IgG1 are markers of congenital transmission and severity/spread of disease in the offspring.

Anaplasmosis: Practical principles for the diagnosis, treatment and control of field cases and outbreaks

Anaplasmosis, caused by the rickettsial hemoparasite Ana­plasma marginale (Am), is the most prevalent tick-transmitted disease of cattle worldwide and a major obstacle to profitable beef production in the continental United States. Anaplasmosis is readily transmitted through biological and mechanical vec­tors such as ticks and biting flies and iatrogenically through needles and equipment contaminated with infected blood. Clinical anaplasmosis, characterized by anemia, icterus and fever, is associated with significant production losses, abor­tions and mortalities in cattle. It is estimated that the introduc­tion of anaplasmosis into a previously naïve herd can result in a 3.6% reduction in calf crop, a 30% increase in cull rate and a 30% mortality rate in clinically infected adult cattle. Further­more, a study has shown that 16% of pregnant carrier cows will transmit anaplasmosis in utero producing persistently infected offspring. The existence of both horizontal and vertical ana­plasmosis transmission has important implications for disease control in endemic areas. In this presentation, we will use case studies to examine strategies to treat and control anaplasmosis in beef and dairy herds.

Increased Serum Levels of Growth-Differentiation Factor 3 (GDF3) and Inflammasome-Related Markers in Pregnant Women during Acute Zika Virus Infection.

The systemic inflammatory response elicited by acute Zika virus (ZIKV) infection during pregnancy plays a key role in the clinical outcomes in mothers and congenitally infected offspring. The present study aimed to evaluate the serum levels of GDF-3 and inflammasome-related markers in pregnant women during acute ZIKV infection. Serum samples from pregnant (n = 18) and non-pregnant (n = 22) women with acute ZIKV infection were assessed for NLRP3, IL-1β, IL-18, and GDF3 markers through an enzyme-linked immunosorbent assay. ZIKV-negative pregnant (n = 18) and non-pregnant women (n = 15) were used as control groups. All serum markers were highly elevated in the ZIKV-infected groups in comparison with control groups (p < 0.0001). Among the ZIKV-infected groups, the serum markers were significantly augmented in the pregnant women in comparison with non-pregnant women (NLRP3 p < 0.001; IL-1β, IL-18, and GDF3 p < 0.0001). The IL-18 marker was found at significantly higher levels (p < 0.05) in the third trimester of pregnancy. Bivariate and multivariate analyses showed a strong positive correlation between GDF3 and NLRP3 markers among ZIKV-infected pregnant women (r = 0.91, p < 0.0001). The findings indicated that acute ZIKV infection during pregnancy induces the overexpression of GDF-3 and inflammasome-related markers, which may contribute to congenital disorders and harmful pregnancy outcomes.

Induction of transgenerational innate immune memory against Vibrio infections in a brine shrimp (Artemia franciscana) model

The occurrence of transgenerational innate immune memory in invertebrates possibly offers an opportunity for the creation of offspring with increased resistance against infectious diseases. Shrimps, being invertebrates rely on their innate immune system as the main defence mechanism to combat invading pathogens. Thus, creating transgenerational innate immune memory could be used for disease prevention in shrimp farming. However, the mechanisms behind the induction of transgenerational innate immune memory and the creation of a broad spectrum protective immune memory are still not fully understood. Here, the creation of transgenerational innate immune memory and the mechanisms involved were studied using the brine shrimp (Artemia franciscana) as a model for shrimps. Hereto, a parental generation was primed by exposure to a live or dead Vibrio parahaemolyticus PV1 while another parental generation was primed with live or dead Vibrio campbellii LMG21363. Both Vibrio strains are known to cause diseases in farmed shrimps, resulting in significant economic losses. Axenic larvae of three subsequent generations were exposed either to the homologous or heterologous (viable) Vibrio species and their survival was recorded. In general, progenies from primed F0 parents developed innate immune memory as compared to offspring of non-primed control F0 parents as they were significantly protected against a subsequent Vibrio infection. Protection in the infected offspring was more pronounced when they were infected with the homologous Vibrio strain. Disease resistance was associated with significantly increased transcription of especially peroxinectin (pxn), prophenoloxidase (proPO), lipopolysaccharide and β-1,3-glucan-binding protein (LGBP), high mobility group box 1 (HMGB1) and heat shock protein 90 (hsp90) genes and significant changes in histone H3 and H4 acetylation and m6A RNA methylation. Overall, results might lead to procedures at shrimp brood stock level for parental conditioning and creation of transgenerational innate immune memory in offspring.

Prevalence of Hepatitis C in Pregnant Women at Tertiary Care Hospital

Background: Hepatitis caused by viruses is a serious worldwide health issue that affects 2 to 15 million individuals annually. HCV-infected mothers give birth to an approximately 40,000 children annually, resulting in up to 4000 additional perinatal infected offspring Methodology: This was cross sectional study carried out at Obstetrics and Gynaecology, Department, Women and Children Hospital, Charsadda for aperiod of six months from August 2021 to January 2022. Totally 300 pregnant women were included in our study. Blood samples were taken from all the participants and sent to hospital diagnostic laboratory for the diagnosis of hepatitis C virus through immune-chromatographic technique. All the data analysis was carried out by using IBM SPSS version 20. Results: The mean age in our study was 33.12 years with standard deviation of ± 4.11. In our study, hepatitis C virus prevalence was 8.66% (n=26) in pregnant women. In our study, 17 (18.18%) of the HCV positive subjects were observed in age group 18-25 years. While the HCV positive subjects observed in age group 26-35 years, 36-45 years were 6 (4%) and 2 (3.33%) respectively. Conclusion: Our study concludes that the prevalence of hepatitis C amongst pregnant women was 8.66%. Despite the fact that the incidence of hepatitis C was shown to be lower among pregnant females visiting tertiary care hospitals, regular anti-HCV antibody testing of all pregnant females is strongly recommended for prompt identification of illness in mothers and to prevent their transmission to newborns. Keywords: Prevalence; Hepatitis C; Pregnant Women

Neighbourhood-level income and Zika virus infection during pregnancy in Recife, Pernambuco, Brazil: an ecological perspective, 2015–2017

Zika virus (ZIKV) infections during pregnancy can lead to adverse neurodevelopmental and clinical outcomes in congenitally infected offspring. As the city of Recife in Pernambuco State, Brazil—the epicentre of the...

Effects of Thelytokous Parthenogenesis-Inducing Wolbachia on the Fitness of Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) in Superparasitised and Single-Parasitised Hosts

ThelytokousWolbachia-infectedTrichogrammaspecies have long been considered as biological control agents against lepidopteran pests in agriculture and forestry.Wolbachiahas been suggested to increase the probability of the superparasitism ofTrichogramma, but the fate of infected offspring in the superparasitised host is still unknown. The present study aimed to evaluate the fitness of thelytokousWolbachia-infected (TDW) and bisexualWolbachia-free (TD)Trichogramma dendrolimiMatsumura (Hymenoptera: Trichogrammatidae) lines in superparasitised or single-parasitised hosts. The results showed that irrespective of whetherTrichogrammawasps were developed from superparasitised or single-parasitised hosts, the TDW line was characterized by reduced fitness, including lower fecundity, shorter longevity, and smaller body size of F1 offspring, and lower emergence rate of F2 offspring than the TD line. This was not true for the survival rate and developmental time of F1 offspring. Additionally, the fitness parameters ofT. dendrolimithat developed from superparasitised hosts were lower compared with that ofT. dendrolimithat developed from single-parasitised hosts. Interestingly,Wolbachia-infected females had higher dispersal capacity than bisexual females when they developed from superparasitised hosts. The results indicated thatWolbachianegatively affects fitness ofT. dendrolimi, but enhance dispersal capacity ofT. dendrolimifemales in superparasitism condition. Further studies need to be carried out to select the best line that will allowWolbachiaand their hostTrichogrammato be better adapted to one another.

Transovarial transmission of Nosema pyrausta in three generations of Ostrinia nubilalis in laboratory tests

AbstractThe microsporidium Nosema pyrausta (Paillot) (Nosematidae) is a widespread and persistent entomopathogen with integrated pest management implications. Nosema pyrausta is capable of horizontal and vertical transmissions in Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) populations. After experimental per os infection, N. pyrausta virulence decreased with the instar of the host larvae used. At a dosage of 100,000 spores per fourth instar, 47% pupae and 36% adults survived and gave rise to transovarially infected offspring. The infection persisted through three laboratory generations of the host with prevalence levels ranging between 29 and 92%. Mature microsporidian spores were not found in smears prepared from the eggs laid by infected females, but cryosections demonstrated parasite cells within the host egg’s cytoplasm. A short region of N. pyrausta hexokinase was amplified using cDNA samples from infected females’ eggs, confirming the expression of the parasite’s DNA. Thus, vertical transmission of N. pyrausta is achieved through infection of insect eggs with prespore stages of the parasite.

Mycobacterium tuberculosis-Induced Maternal Immune Activation Promotes Autism-Like Phenotype in Infected Mice Offspring.

The maternal system’s exposure to pathogens during pregnancy influences fetal brain development causing a persistent inflammation characterized by elevated pro-inflammatory cytokine levels in offspring. Mycobacterium tuberculosis (Mtb) is a global pathogen that causes tuberculosis, a pandemic responsible for health and economic burdens. Although it is known that maternal infections increase the risk of autism spectrum disorder (ASD), it is not known whether Mtb infection is sufficient to induce ASD associated behaviors, immune dysregulation and altered expression of synaptic regulatory genes. The current study infected pregnant Balb/c mice with Mtb H37Rv and valproic acid (VPA) individually and in combination. Plasma cytokine profiles were measured in offspring using the Bio-plex Th17 pro mouse cytokine panel. Mtb infection increased plasma interleukin (IL)-6 and IL-17A, while tumor necrosis factor alpha (TNF-α), interferon (IFN)-γ and IL-1β were reduced when compared with saline. Mtb-induced maternal immune activation (MIA) offspring displayed increased grooming behavior. The study also revealed dysregulation in gene expression of synaptic molecules in the cerebellum. MIA rescued the VPA-induced effects on self-grooming and social interaction behaviors. Our finding therefore highlights a potential role of Mtb as a MIA agent that can potentially contribute to ASD.

In vitro Antiviral Activity of Leaf Extracts Plantago major, Plantago lanceolata, Rubus idaeus

Advances in organic chemistry, biochemistry, biotechnology and molecular virology have made it possible to synthesize a large number of antiviral drugs belonging to different pharmacological groups. However, one but significant disadvantage of these drugs is their significant toxicity. Therefore, along with the screening of new drugs among synthetic compounds, scientists are actively conducting research on antiviral agents of natural origin. Natural products with antiviral properties have advantages over synthetic compounds due to their low toxicity, minimal side effects, and mild action by various mechanisms. The aim of the study was to investigate the antiviral properties of aqueous-alcoholic extracts of plantain leaves (Plantago major L. and Plantago lanceolata L.), wild and garden raspberry leaves (Rubus idaeus L.) and their fermented variants on the model of human adenoviruses (HAdV3, HAdV5 and HAdV7). Methods. Determination of cytotoxicity and antiviral action of extracts was performed by standard methods using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The titer of the virus, synthesized in the presence of drugs was determined by the end of dilution of the virus, which causes 50% development of the cytopathic effect of the virus on cells (СPE). Neoflazid was used as a reference drug. Neoflazid, developed by Ecopharm (Ukraine), it contains carboxylic acids and flavonoid glycosides isolated from wild cereals Deschampsia caespitosa L. (pike, turf) and Calamagrostis epigeios L. (dugout). All studies were performed in three replicates; the number of parallel determinations was 3–4. Calculated mean values, standard deviation, mean error. Differences in averages were considered significant at p&lt;0.05. The research results were processed using Microsoft Office Excel 2010. Results. Low cytotoxicity of extracts of Plantago major L. and Rubus idaeus L. (wild) leaves and their fermented variants was shown, CC50 is &gt;3 mg/mL. For extracts from the leaves of Plantago lanceolata L. and Rubus idaeus L. (garden) and their fermented variants, the toxicity was slightly higher (CC50=1.5 mg/mL). Extracts showed either a slight antiviral effect or its complete absence when used in a prophylactic regimen. We observed effective inhibition of reproduction of adenoviruses, when using extracts after adsorption of viruses. Extract of plantain leaves in concentrations of 0.06–3 mg/mL inhibited the reproduction of HAdV5 by 68–83% and inhibited the reproduction of HAdV3 and HAdV7 in concentration 3 mg/mL by 55% and 11%, respectively. Extract of Rubus idaeus L. (wild) leaves in the concentration range of 0.06–3 mg/mL inhibited the reproduction of HAdV5 by 65–89%, HAdV3 by 41–84% and HAdV7 by 22–59%. The maximum inhibition of reproduction of HAdV3 by 34% is shown for the extract from the leaves of Rubus idaeus L. (garden) at a concentration of 0.38 mg/mL, the reproduction of other viruses was suppressed by only 4–22%. It has been shown that the extracts of plantain and wild raspberry significantly affected the infectivity of viral offspring. Extract of plantain at a concentration of 3 mg/mL inhibited the reproduction of HAdV5 by 1.5 lg, fermented extract of plantain – by 1 lg. Fermented plantain extract at a concentration of 0.06 mg/mL inhibited the formation of new viral offspring, the index of reproductive inhibition (IRI) was 1.6 lg. Both fermented and unfermented Rubus idaeus L. (wild) extract had almost the same antiviral activity, IRI was 1.45 lg – 1.6 lg. Extracts of plantain and raspberry, regardless of the concentrations used, effectively inhibited the formation of infectious offspring of the HAdV3. The maximum IRI was 1.44 lg for plantain extract and 1.5 lg for fermented plantain extract. Both raspberry extracts (fermented and non-fermented) inhibited the synthesis of adenovirus serotype 3 by 1.46 – 1.54 lg. The drug Neoflazid completely inhibited the formation of infectious adenovirus at a concentration of 7.1 μg/mL. Virulicidal activity of all extracts against human adenoviruses 3, 5 and 7 serotypes was not detected. We found different antiviral activity of extracts of wild and garden raspberry leaves; we can assume that the flavonoid composition of the extracts plays an important role in their activity. Conclusions. Our new data on a wide range of anti-adenoviral activity of plantain and raspberry extracts is a prerequisite for further studies of the properties of individual components of extracts, in order to create an anti-adenoviral drug and recommendations for its pharmacological use.

Evaluation of the safety profile of the vaccine candidate Brucella melitensis 16MΔvjbR strain in goats

Small ruminant brucellosis is caused by the Gram negative cocci-bacillus Brucella (B.) melitensis, the most virulent Brucella species for humans. In goats and sheep, middle to late-term gestation abortion, stillbirths and the delivery of weak infected offspring are the characteristic clinical signs of the disease. Vaccination with the currently available Rev. 1 vaccine is the best option to prevent and control the disease, although it is far from ideal. In this study, we investigate the safety of the B. melitensis 16MΔvjbR strain during a 15-month period beginning at vaccination of young goats, impregnation, delivery and lactation. Forty, 4 to 6 months old, healthy female crossbreed goats were randomly divided into four groups (n = 10) and immunized subcutaneously with a single vaccine dose containing 1x109 CFU of B. melitensis 16MΔvjbR delivered in alginate microcapsules or non-encapsulated. Controls received empty capsules or the commercially available Rev.1 vaccine. Seven months post-vaccination, when animals were sexually mature, all goats were naturally bred using brucellosis-free males, and allowed to carry pregnancies to term. Blood samples to assess the humoral immune response were collected throughout the study. At two months post-delivery, all dams and their offspring were euthanized and a necropsy was performed to collect samples for bacteriology and histology. Interestingly, none of the animals that received the vaccine candidate regardless of the formulation exhibited any clinical signs associated with vaccination nor shed the vaccine strain through saliva, vagina or the milk. Gross and histopathologic changes in all nannies and offspring were unremarkable with no evidence of tissue colonization or vertical transmission to fetuses. Altogether, these data demonstrate that vaccination with the mutant strain 16MΔvjbR is safe for use in the non-pregnant primary host.

Vertical transmission of zika virus in Aedes albopictus

BackgroundZika virus (ZIKV) is an arthropod-borne flavivirus transmitted by Aedes mosquitoes. Aedes albopictus is an important vector of ZIKV worldwide. To date, most experiments have focused on the vertical transmission of ZIKV in Ae. aegypti, while studies on Ae. albopictus are very limited. To explore vertical transmission in Ae. albopictus, a series of laboratory studies were carried out.Methodology/Principal findingsIn this study, Ae. albopictus were blood-fed with ZIKV-infectious blood, and the ovaries and offspring viral infection rates were analyzed by reverse transcription PCR (RT-PCR), real-time reverse transcription PCR (RT-qPCR) and immunohistochemistry (IHC). ZIKV was detected in the ovaries and oviposited eggs in two gonotrophic cycles. The minimum filial egg infection rates in two gonotrophic cycles were 2.06% and 0.69%, and the effective population transmission rate was 1.87%. The hatching, pupation, and emergence rates of infected offspring were not significantly different from those of uninfected offspring, indicating that ZIKV did not prevent the offspring from completing the growth and development process. ZIKV was detected in three of thirteen C57BL/6 suckling mice bitten by ZIKV-positive F1 females, and the viremia persisted for at least seven days.Conclusions/SignificanceZIKV can be vertically transmitted in Ae. albopictus via transovarial transmission. The vertical transmission rates in F1 eggs and adults were 2.06% and 1.87%, respectively. Even though the vertical transmission rates were low, the female mosquitoes infected via the congenital route horizontally transmitted ZIKV to suckling mice through bloodsucking. This is the first experimental evidence of offspring with vertically transmitted ZIKV initiating new horizontal transmission. The present study deepens the understanding of the vertical transmission of flaviviruses in Aedes mosquitoes and sheds light on the prevention and control of mosquito-borne diseases.

Vertical Transmission: A Vector-Independent Transmission Pathway of Babesia microti in the Natural Reservoir Host Peromyscus leucopus.

Babesia microti, a malaria-like pathogen, is increasing in mammal and human populations in endemic areas and is unlikely to be the sole result of horizontal pathogen transmission. Peromyscus leucopus mice, natural reservoir hosts, were infected via Ixodes scapularis nymphs. Infected parental females (n = 6) produced F1 offspring (n = 36) that were screened for B. microti using quantitative PCR. Xenodiagnostic larvae were fed on infected offspring to determine horizontal transmission and pathogen viability. Fifty engorged larvae were screened; the rest were allowed to molt and then screened to determine transstadial transmission. Infected F1 generation offspring were placed in breeding groups, producing 34 F2 offspring and screened for B. microti infection. Chronic infection was monitored in parental females since time of initial vector infection. Vertical transmission of B. microti was 74% efficient in offspring born in the first 6 months. Horizontal transmission occurred in larvae (61% prevalence) and molted nymphs (58% prevalence); these nymphs were able to infect susceptible hosts. F2 generation offspring infection prevalence was 38%. Chronic infection persisted for 1 year in some adults. These results demonstrate that vertical transmission is an important nonvector-mediated pathway of B. microti transmission in the natural reservoir host.

Age-related changes in cerebral congenital toxoplasmosis: Histopathological and immunohistochemical evaluation

Congenital toxoplasmosis is a widespread worldwide disease producing varying degrees of damage to the fetus including ocular and neurological impairment. However, the underlying mechanisms are not yet clear. Therefore, the current study aimed to investigate the progress of congenital cerebral toxoplasmosis in experimentally infected offspring animal model at different age groups till become adults. To fulfill this aim, the offspring of Me49 T. gondii infected pregnant mice were divided into groups; embryo, infant, young and adult phases. Blood and brain samples were collected for further hormonal and histopathological studies and immunohistochemical staining of glial fibrillary acidic protein (GFAP) and synaptophysin (SYN). Our results showed several encephalitic changes in the infected groups ranging from gliosis to reduced cortical cell number and fibrinoid degeneration of the brain. We showed increased expression of GFAP and SYN indicating activation of astrocytes and modification of the synaptic function, respectively. These changes started intrauterine following congenital infection and increased progressively afterward. Moreover, infected mice had elevated corticosterone levels. In conclusion, the current study provided new evidences for the cellular changes especially in the infected embryo and highlighted the role of GFAP and SYN that may be used as indicators for T. gondii-related neuropathy.

Propagation of the Microsporidian Parasite Edhazardia aedis in Aedes aegypti Mosquitoes.

Edhazardia aedis is a microsporidian parasite of Aedes aegypti mosquitoes, a disease vector that transmits multiple arboviruses which cause millions of disease cases each year. E. aedis causes mortality and reduced reproductive fitness in the mosquito vector and has been explored for its potential as a biocontrol agent. The protocol we present for culturing E. aedis is based on its natural infection cycle, which involves both horizontal and vertical transmission at different life stages of the mosquito host. Ae. aegypti mosquitoes are exposed to spores in the larval stage. These infected larvae then mature into adults and transmit the parasite vertically to their offspring. Infected offspring are then used as a source of spores for future horizontal transmission. Culturing E. aedis can be challenging to the uninitiated given the complexities of the parasite's life cycle, and this protocol provides detailed guidance and visual aids for clarification.