Strain diversity of Treponema pallidum subsp. pertenue suggests rare interspecies transmission in African nonhuman primates.

In our most recent study, we found that in Tanzania infection with Treponema pallidum (TP) subsp. pertenue (TPE) is present in four different monkey species. In order to gain information on the diversity and epidemiological spread of the infection in Tanzanian nonhuman primates (NHP), we identified two suitable candidate genes for multi-locus sequence typing (MLST). We demonstrate the functionality of the MLST system in invasively and non-invasively collected samples. While we were not able to demonstrate frequent interspecies transmission of TPE in Tanzanian monkeys, our results show a clustering of TPE strains according to geography and not host species, which is suggestive for rare transmission events between different NHP species. In addition to the geographic stability, we describe the relative temporal stability of the strains infecting NHPs and identified multi-strain infection. Differences between TPE strains of NHP and human origin are highlighted. Our results show that antibiotic resistance does not occur in Tanzanian TPE strains of NHP origin.

Genes, geology and germs: gut microbiota across a primate hybrid zone are explained by site soil properties, not host species.

Gut microbiota in geographically isolated host populations are often distinct. These differences have been attributed to between-population differences in host behaviours, environments, genetics and geographical distance. However, which factors are most important remains unknown. Here, we fill this gap for baboons by leveraging information on 13 environmental variables from 14 baboon populations spanning a natural hybrid zone. Sampling across a hybrid zone allowed us to additionally test whether phylosymbiosis (codiversification between hosts and their microbiota) is detectable in admixed, closely related primates. We found little evidence of genetic effects: none of host genetic ancestry, host genetic relatedness nor genetic distance between host populations were strong predictors of baboon gut microbiota. Instead, gut microbiota were best explained by the baboons' environments, especially the soil's geologic history and exchangeable sodium. Indeed, soil effects were 15 times stronger than those of host-population FST, perhaps because soil predicts which foods are present, or because baboons are terrestrial and consume soil microbes incidentally with their food. Our results support an emerging picture in which environmental variation is the dominant predictor of host-associated microbiomes. We are the first to show that such effects overshadow host species identity among members of the same primate genus.

Zika virus infection at mid-gestation results in fetal cerebral cortical injury and fetal death in the olive baboon.

Zika virus (ZIKV) infection during pregnancy in humans is associated with an increased incidence of congenital anomalies including microcephaly as well as fetal death and miscarriage and collectively has been referred to as Congenital Zika Syndrome (CZS). Animal models for ZIKV infection in pregnancy have been developed including mice and non-human primates (NHPs). In macaques, fetal CZS outcomes from maternal ZIKV infection range from none to significant. In the present study we develop the olive baboon (Papio anubis), as a model for vertical transfer of ZIKV during pregnancy. Four mid-gestation, timed-pregnant baboons were inoculated with the French Polynesian ZIKV isolate (104 ffu). This study specifically focused on the acute phase of vertical transfer. Dams were terminated at 7 days post infection (dpi; n = 1), 14 dpi (n = 2) and 21 dpi (n = 1). All dams exhibited mild to moderate rash and conjunctivitis. Viremia peaked at 5-7 dpi with only one of three dams remaining mildly viremic at 14 dpi. An anti-ZIKV IgM response was observed by 14 dpi in all three dams studied to this stage, and two dams developed a neutralizing IgG response by either 14 dpi or 21 dpi, the latter included transfer of the IgG to the fetus (cord blood). A systemic inflammatory response (increased IL2, IL6, IL7, IL15, IL16) was observed in three of four dams. Vertical transfer of ZIKV to the placenta was observed in three pregnancies (n = 2 at 14 dpi and n = 1 at 21 dpi) and ZIKV was detected in fetal tissues in two pregnancies: one associated with fetal death at ~14 dpi, and the other in a viable fetus at 21 dpi. ZIKV RNA was detected in the fetal cerebral cortex and other tissues of both of these fetuses. In the fetus studied at 21 dpi with vertical transfer of virus to the CNS, the frontal cerebral cortex exhibited notable defects in radial glia, radial glial fibers, disorganized migration of immature neurons to the cortical layers, and signs of pathology in immature oligodendrocytes. In addition, indices of pronounced neuroinflammation were observed including astrogliosis, increased microglia and IL6 expression. Of interest, in one fetus examined at 14 dpi without detection of ZIKV RNA in brain and other fetal tissues, increased neuroinflammation (IL6 and microglia) was observed in the cortex. Although the placenta of the 14 dpi dam with fetal death showed considerable pathology, only minor pathology was noted in the other three placentas. ZIKV was detected immunohistochemically in two placentas (14 dpi) and one placenta at 21 dpi but not at 7 dpi. This is the first study to examine the early events of vertical transfer of ZIKV in a NHP infected at mid-gestation. The baboon thus represents an additional NHP as a model for ZIKV induced brain pathologies to contrast and compare to humans as well as other NHPs.

Baboon vaginal microbial flora.

BACKGROUND: Knowledge of the composition of vaginal microbial ecosystem is essential for understanding the etiology, prevention, and treatment of vaginal diseases. A baboon model has been used to provide detailed understanding of reproductive physiology and immunology applicable to women. However, little is known about the composition of its vaginal microbial ecosystem. METHODS: Gram stain and Nugent scores were used for assessment of baboon vaginal microbial flora. Biochemical identification and analysis of isolates were performed using the api(®) kits and identification software. RESULTS: Species of Lactobacilli, Staphylococci, Clostridia, Bacilli, Corynebacteria, Gram-negative rods, other Gram-positive rods, cocci and Candida, were isolated. Healthy vaginal microbiota consisted mainly of lactobacillus morphotypes. Animals with high Nugent scores had increased number of Gram-positive cocci and variable rods, with increased number of Gram-negative morphotypes. CONCLUSIONS: The baboon vaginal microbiota is heterogeneous in terms of species composition and is typified by a scarcity of lactobacilli.

Influence of age, reproductive cycling status, and menstruation on the vaginal microbiome in baboons (Papio anubis).

The vaginal microbiome is believed to influence host health by providing protection from pathogens and influencing reproductive outcomes such as fertility and gestational length. In humans, age-associated declines in diversity of the vaginal microbiome occur in puberty and persist into adulthood. Additionally, menstruation has been associated with decreased microbial community stability. Adult female baboons, like other non-human primates (NHPs), have a different and highly diverse vaginal microbiome compared to that of humans, which is most commonly dominated by Lactobacillus spp. We evaluated the influence of age, reproductive cycling status (cycling vs. non-cycling) and menstruation on the vaginal microbiome of 38 wild-caught, captive female olive baboons (Papio anubis) by culture-independent sequencing of the V3-V5 region of the bacterial 16S rRNA gene. All baboons had highly diverse vaginal microbial communities. Adult baboons had significantly lower microbial diversity in comparison to subadult baboons, which was attributable to decreased relative abundance of minor taxa. No significant differences were detected based on cycling state or menstruation. Predictive metagenomic analysis showed uniformity in relative abundance of metabolic pathways regardless of age, cycle stage, or menstruation, indicating conservation of microbial community functions. This study suggests that selection of an optimal vaginal microbial community occurs at puberty. Since decreased diversity occurs in both baboons and humans at puberty, this may reflect a general strategy for selection of adult vaginal microbial communities. Comparative evaluation of vaginal microbial community development and composition may elucidate mechanisms of community formation and function that are conserved across host species or across microbial community types. These findings have implications for host health, evolutionary biology, and microbe-host ecosystems.

Impact of a hormone-releasing intrauterine system on the vaginal microbiome: a prospective baboon model.

BACKGROUND: Use of a levonorgestrel-releasing intrauterine system (LNG-IUS) in humans may alter vaginal microbial populations and susceptibility to pathogens. This study evaluated the time-dependent effects of an LNG-IUS on the vaginal microbiome of the baboon, a useful animal model for reproductive studies. METHODS: Levonorgestrel-releasing intrauterine systems were inserted into three reproductively mature, female baboons. The animals were evaluated for 6 months by physical examination and Gram-stained cytology. The vaginal microbiota was characterized at each timepoint by culture-independent analysis of the 16S rRNA-encoding gene. RESULTS: Each baboon harbored a diverse vaginal microbiome. Interindividual variation exceeded intra-individual variation. Diversity declined over time in one baboon and showed mild fluctuations in the other two. There were no significant community differences from early to late post-LNG-IUS placement. CONCLUSIONS: The baboon vaginal microbiome is unique to each individual and is polymicrobial. In this pilot study, the vaginal microbiome remained stable from early to late post-LNG-IUS placement.

[Campylobacter in the etiology of acute intestinal infections in primates].

The subjects of the study were 1,249 primates of different species, kept in a nursery in the city of Adler. The subjects varied in age, were either clinically healthy, diseased, or dead (the death had been caused by an acute intestinal disease). Biological, molecular-genetic (PCR), and immunological (coagglutination reaction) methods were used in diagnostics of campilobacter infections. The study found campilobacter in 20.9% of healthy animals on the average; this number varied depending on the species and age. The frequency of campilobacter infection in diseased and dead animals was higher than that in healthy ones (40.1% and 20.9%, respectively.) Two types of Campilobacter were identified: C. jejuni (73.4% of cases), and C. coli (14.2%). Clinical and pathomorphological manifestations of campilobacteriosis in primates and humans are similar. The portion of campilobacteriosis in acute intestinal diseases of primates is 40.1%.