Effective contraceptives are a global health imperative for reproductive-aged women. However, there remains a lack of rigorous data regarding the effects of contraceptive options on vaginal bacteria ...and inflammation. Among 218 women enrolled into a substudy of the ECHO Trial (NCT02550067), we evaluate the effect of injectable intramuscular depot medroxyprogesterone acetate (DMPA-IM), levonorgestrel implant (LNG), and a copper intrauterine device (Cu-IUD) on the vaginal environment after one and six consecutive months of use, using 16S rRNA gene sequencing and multiplex cytokine assays. Primary endpoints include incident BV occurrence, bacterial diversity, and bacterial and cytokine concentrations. Secondary endpoints are bacterial and cytokine concentrations associated with later HIV seroconversion. Participants randomized to Cu-IUD exhibit elevated bacterial diversity, increased cytokine concentrations, and decreased relative abundance of lactobacilli after one and six months of use, relative to enrollment and other contraceptive options. Total bacterial loads of women using Cu-IUD increase 5.5 fold after six months, predominantly driven by increases in the concentrations of several inflammatory anaerobes. Furthermore, growth of L. crispatus (MV-1A-US) is inhibited by Cu
ions below biologically relevant concentrations, in vitro. Our work illustrates deleterious effects on the vaginal environment induced by Cu-IUD initiation, which may adversely impact sexual and reproductive health.
Early life microbiota is an important determinant of immune and metabolic development and may have lasting consequences. The maternal gut microbiota during pregnancy or breastfeeding is important for ...defining infant gut microbiota. We hypothesized that maternal gut microbiota during pregnancy and breastfeeding is a critical determinant of infant immunity. To test this, pregnant BALB/c dams were fed vancomycin for 5 days prior to delivery (gestation; Mg), 14 days postpartum during nursing (Mn), or during gestation and nursing (Mgn), or no vancomycin (Mc). We analyzed adaptive immunity and gut microbiota in dams and pups at various times after delivery.
In addition to direct alterations to maternal gut microbial composition, pup gut microbiota displayed lower α-diversity and distinct community clusters according to timing of maternal vancomycin. Vancomycin was undetectable in maternal and offspring sera, therefore the observed changes in the microbiota of stomach contents (as a proxy for breastmilk) and pup gut signify an indirect mechanism through which maternal intestinal microbiota influences extra-intestinal and neonatal commensal colonization. These effects on microbiota influenced both maternal and offspring immunity. Maternal immunity was altered, as demonstrated by significantly higher levels of both total IgG and IgM in Mgn and Mn breastmilk when compared to Mc. In pups, lymphocyte numbers in the spleens of Pg and Pn were significantly increased compared to Pc. This increase in cellularity was in part attributable to elevated numbers of both CD4+ T cells and B cells, most notable Follicular B cells.
Our results indicate that perturbations to maternal gut microbiota dictate neonatal adaptive immunity.
Both maternal microbiota and helminth infection may alter offspring immunity but the relationship between these is underexplored. We hypothesized that maternal helminth exposure prior to pregnancy ...has lasting consequences on offspring intestinal microbiota and consequent immunity. Female BALB/c adult mice were infected with 500L3 Nippostrongylus brasiliensis (N brasiliensis). Infection was cleared by ivermectin treatment, and mice were mated 3 weeks post‐infection (NbM). Control mice were not infected but were exposed to ivermectin (NvM). We analysed maternal gut microbiota during pregnancy, breastmilk microbiota and offspring faecal microbiota and immunity 2 weeks after delivery. During pregnancy, NbM (Mothers previously infected with Nippostrongylus brasiliensis) displayed significantly altered stool bacterial communities (R2 = .242; P = .001), with increased abundance of Enterococcaceae versus NvM (Naive mothers). Similarly, we observed a profound impact on breastmilk microbiota in NbM vs NvM. Moreover, NbM pups showed significantly altered gut microbial communities at 14 days of age versus those born to NvM with increased relative abundance of Coriobacteriaceae and Micrococcaceae. These changes were associated with alterations in pup immunity including increased frequencies and numbers of activated CD4 T cells (CD4 + CD44hi) in NbM offspring spleens. Taken together, we show that preconception helminth infections impact offspring immunity possibly through alteration of maternal and offspring microbiota.
•Five complete crAssphage genomes from feces of South African woman and unrelated infants.•Elevated positive selection in RNA polymerase and phage tail protein genes.•Hotspots of selection may be ...mediated by selection pressure from bacterial partners.
crAssphages are a broad group of diverse bacteriophages in the order Caudovirales that have been found to be highly abundant in the human gastrointestinal tract. Despite their high prevalence, we have an incomplete understanding of how crAssphages shape and respond to ecological and evolutionary dynamics in the gut. Here, we report genomes of crAssphages from feces of one South African woman and three infants. Across the complete genome sequences of the South African crAssphages described here, we identify particularly elevated positive selection in RNA polymerase and phage tail protein encoding genes, contrasted against purifying selection, genome-wide. We further validate these findings against a crAssphage genome from previous studies. Together, our results suggest hotspots of selection within crAssphage RNA polymerase and phage tail protein encoding genes are potentially mediated by interactions between crAssphages and their bacterial partners.
Introduction Infants who are born from mothers with HIV (infants who are HIV exposed but uninfected; iHEU) are at higher risk of morbidity and display multiple immune alterations compared to infants ...who are HIV-unexposed (iHU). Easily implementable strategies to improve immunity of iHEU, and possibly subsequent clinical health outcomes, are needed. iHEU have altered gut microbiome composition and bifidobacterial depletion, and relative abundance of Bifidobacterium infantis has been associated with immune ontogeny, including humoral and cellular vaccine responses. Therefore, we will assess microbiological and immunological phenotypes and clinical outcomes in a randomized, double-blinded trial of B. infantis RosellR-33 versus placebo given during the first month of life in South African iHEU. Methods This is a parallel, randomised, controlled trial. Two-hundred breastfed iHEU will be enrolled from the Khayelitsha Site B Midwife Obstetric Unit in Cape Town, South Africa and 1:1 randomised to receive 8 x 10.sup.9 CFU B. infantis RosellR-33 daily or placebo for the first 4 weeks of life, starting on day 1-3 of life. Infants will be followed over 36 weeks with extensive collection of meta-data and samples. Primary outcomes include gut microbiome composition and diversity, intestinal inflammation and microbial translocation and cellular vaccine responses. Additional outcomes include biological (e.g. gut metabolome and T cell phenotypes) and clinical (e.g. growth and morbidity) outcome measures. Discussion The results of this trial will provide evidence whether B. infantis supplementation during early life could improve health outcomes for iHEU. Ethics and dissemination Approval for this study has been obtained from the ethics committees at the University of Cape Town (HREC Ref 697/2022) and Seattle Children's Research Institute (STUDY00003679). Trial registration Pan African Clinical Trials Registry Identifier: PACTR202301748714019. Clinical.trials.gov: NCT05923333. Protocol Version: Version 1.8, dated 18 July 2023. Keywords: HIV exposure, South Africa, Live biotherapeutic, Randomised controlled trial, Bifidobacterium
Whether antibiotic treatment during gestation impacts T cell immunity to vaccination in offspring is unexplored. Dams treated with polymyxin B (PMB) during gestation (Mg) displayed altered microbial ...communities prior to delivery compared to control dams (Mc). Differences in microbiota were also evident in pups born to polymyxin B-treated dams (Pg) compared to control pups (Pc). When pups were immunized with Bacille Calmette-Guerin (BCG), we observed no difference in TB10.4-specific T cells between Pc and Pg 4 weeks postimmunization. Significantly fewer splenic CD4 T cells from BCG-vaccinated Pg produced interleukin-2 (IL-2) upon stimulation, suggesting a possible functional deficiency. There was no difference in purified protein derivative (PPD)-specific IgG between Pc and Pg at this time point. However, when infected with Mycobacterium tuberculosis, Pg displayed significantly higher bacterial burden in the lung than Pc. Our results show that maternal PMB treatment during gestation may not impact splenic antigen-specific T cell responses following BCG vaccination but alters susceptibility to M. tuberculosis in offspring.
The composition of the pioneer microbiota that colonize the infant gut are determined by the mother. Polymyxin B-induced changes in the maternal microbiota during pregnancy impact the offspring gut microbiota but not vaccine-specific CD4 T cell response. However, when infected with Mycobacterium tuberculosis, offspring born to mothers with an altered gut microbiota are susceptible to infection compared to those born to mothers not exposed to antibiotics.
New reagents have emerged allowing researchers to assess a growing number of vaccine-associated immune parameters. Multiplex immunoassay(s) are emerging as efficient high-throughput assays in malaria ...serology. Currently, commercial vendors market several bead reagents for cytometric bead assays (CBA) but relative performances are not well published. We have compared two types of bead-based multiplex assays to measure relative antibody levels to malarial antigens.
Assays for the measurement of antibodies to five
vaccine candidates using non-magnetic and magnetic fluorescent microspheres were compared for their performances with a Bio-Plex
instrument. Mean fluorescence intensity (MFI) was determined from individuals from western Kenya and compared to known positive and negative control plasma samples.
recombinant antigens were successfully coupled to both non-magnetic and magnetic beads in multiplex assays. MFIs between the two bead types were comparable for all antigens tested. Bead recovery was superior with magnetic beads for all antigens. MFI values of stored non-magnetic coupled beads did not differ from freshly coupled beads, though they showed higher levels of bead aggregation.
Magnetic and non-magnetic beads performed similarly in
antibody assays. Magnetic beads were more expensive, but had higher bead recovery, were more convenient to use, and provided rapid and easy protocol manipulation. Magnetic beads are a suitable alternative to non-magnetic beads in malarial antibody serology.
Background: HIV-1 drug resistance (HIVDR) assays are critical components of HIV clinical management programs in the face of emerging drug resistance. However, the high costs associated with existing ...commercial HIVDR assays prohibit their routine usage in resource-limited settings. We present the performance characteristics of a modified commercial HIVDR testing assay.
Methods: A total of 26 plasma samples were used to validate and assess the accuracy, precision, reproducibility and amplification sensitivity of a modified HIVDR assay by HIV genotyping. In addition, a cost comparison between the original and the modified assay was performed using the ingredient costing approach.
Results: The performance characteristics of the modified assay were in agreement with the original assay. Accuracy, precision and reproducibility showed nucleotide sequence identity of 98.5% (confidence interval (CI), 97.9-99.1%), 98.67% (CI, 98.1-99.23) and 98.7% (CI, 98.1-99.3), respectively. There was no difference in the type of mutations detected by the two assays (χ
2 = 2.36,
p = 0.26). Precision and reproducibility showed significant mutation agreement between replicates (kappa = 0.79 and 0.78), respectively (
p < 0.05). The amplification sensitivity of the modified assay was 100% and 62.5% for viremia ≥1000 copies/ml and <1000 copies/ml respectively. Our assay modification translates to a 39.2% reduction in the cost of reagents.
Conclusions: Our findings underscore the potential of modifying commercially available HIVDR testing assays into cost-effective, yet accurate assays for use in resource-limited settings.
Bacille Calmette-Guerin (BCG) vaccine can elicit good T
1 responses in neonates. We hypothesized that the pioneer gut microbiota affects vaccine T cell responses. Infants who are HIV exposed but ...uninfected (iHEU) display an altered immunity to vaccination. BCG-specific immune responses were analyzed at 7 weeks of age in iHEU, and responses were categorized as high or low.
subsp.
was enriched in the stools of high responders, while
was enriched in low responders at time of BCG vaccination. Neonatal germ-free or SPF mice orally gavaged with live
exhibited significantly higher BCG-specific T cells compared with pups gavaged with
and
differentially affected stool metabolome and colonic transcriptome. Human colonic epithelial cells stimulated with
induced a unique gene expression profile versus
. We thus identified a causal role of
in early-life antigen-specific immunity.
Maternal microbiota during pregnancy, as well as maternal disease state, may impact offspring gut bacterial colonisation. Here, we explore the impact of maternal antibiotics during gestation and/or ...nursing on offspring gut microbiota. Further, we investigate the effect of preconception helminth infections on maternal and infant gut microbiota. For maternal antibiotic experiments, dams were fed vancomycin, polymyxin B, or both, in drinking water during gestation, nursing or gestation plus nursing, and their offspring microbiota analysed at 14 days of life, alongside immunity in the spleens. Offspring born to vancomycin treated mothers had significantly higher relative abundance of Proteobacteria and Tenericutes while maternal oral polymyxin B led to significantly lower abundance of Proteobacteria and Deferribacteres in infants. Maternal oral vancomycin led to significant reduction in proportions of infant central memory CD4+ T cells (CD4+CD44hiCD62Lhi) regardless of antibiotic timing. Effector memory CD4+ T cells were significantly lower in pups born to dams treated with polymyxin B while nursing while proportions of central memory CD4 T cells were significantly increased in gestation only or gestation plus nursing pups. In addition, oral vancomycin in dams during nursing resulted in significantly reduced proportions of both total and follicular B cells in offspring born to antibiotic treated dams. Pups born to Vancomycin treated mothers had a significant delay in growth when infected with Respiratory Syncytial Virus (RSV). On the other hand, pups born to mothers treated with Polymyxin B during gestation or gestation plus nursing were susceptible to Nippostrongylus brasiliensis (Nb) infection. In the second study, we infected female BALB/c mice with 500Nb L3 three weeks prior to mating and examined the effect of preconception helminth infection on offspring microbiota and immunity. Preconception Nb infections led to alterations of maternal gut microbiota during pregnancy. In addition, we observed dramatic differences in offspring microbiota in pups born to previously helminth infected dams. Coriobacteriaceae were predominant in pups born to previously Nb infected dams when compared to uninfected dams. Overall, manipulation of maternal microbiota during gestation or lactation profoundly impacts offspring growth, intestinal microbiota and immunity to RSV and helminths.
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