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.

Perinatal bisphenol A exposure beginning before gestation enhances allergen sensitization, but not pulmonary inflammation, in adult mice.

Bisphenol A (BPA), a monomer of polycarbonate plastics and epoxide resin, is a high-production-volume chemical implicated in asthma pathogenesis when exposure occurs to the developing fetus. However, few studies have directly examined the effect of in utero and early-life BPA exposure on the pathogenesis of asthma in adulthood. This study examines the influence of perinatal BPA exposure through maternal diet on allergen sensitization and pulmonary inflammation in adult offspring. Two weeks before mating, BALB/c dams were randomly assigned to a control diet or diets containing 50 ng, 50 µg or 50 mg BPA/kg of rodent chow. Dams remained on the assigned diet throughout gestation and lactation until postnatal day (PND) 21 when offspring were weaned onto the control diet. Twelve-week-old offspring were sensitized to ovalbumin (OVA) and subsequently challenged with aerosolized OVA. Sera, splenocytes, bronchoalveolar lavage fluid and whole lungs were harvested to assess allergen sensitization and pulmonary inflammation after OVA challenge. Serum anti-OVA IgE levels were increased two-fold in offspring exposed to 50 µg and 50 mg BPA/kg diet, compared with control animals. In addition, production of interleukin-13 and interferon-γ were increased in OVA-stimulated splenocytes recovered from BPA-exposed mice. Pulmonary inflammation, as indicated by total and differential leukocyte counts, cytokines, chemokines and pulmonary histopathology inflammatory scores, however, was either not different or was reduced in offspring exposed to BPA. Although these data suggest that perinatal BPA exposure beginning before gestation enhances allergen sensitization by increasing serum IgE and splenocyte cytokine production, a substantial impact of BPA on OVA-induced pulmonary inflammation in adulthood was not observed.

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.

Novel genital alphapapillomaviruses in baboons (Papio hamadryas anubis) with cervical dysplasia.

Genital Alphapapillomavirus (αPV) infections are one of the most common sexually transmitted human infections worldwide. Women infected with the highly oncogenic genital human papillomavirus (HPV) types 16 and 18 are at high risk for development of cervical cancer. Related oncogenic αPVs exist in rhesus and cynomolgus macaques. Here the authors identified 3 novel genital αPV types (PhPV1, PhPV2, PhPV3) by PCR in cervical samples from 6 of 15 (40%) wild-caught female Kenyan olive baboons (Papio hamadryas anubis). Eleven baboons had koilocytes in the cervix and vagina. Three baboons had dysplastic proliferative changes consistent with cervical squamous intraepithelial neoplasia (CIN). In 2 baboons with PCR-confirmed PhPV1, 1 had moderate (CIN2, n = 1) and 1 had low-grade (CIN1, n = 1) dysplasia. In 2 baboons with PCR-confirmed PhPV2, 1 had low-grade (CIN1, n = 1) dysplasia and the other had only koilocytes. Two baboons with PCR-confirmed PhPV3 had koilocytes only. PhPV1 and PhPV2 were closely related to oncogenic macaque and human αPVs. These findings suggest that αPV-infected baboons may be useful animal models for the pathogenesis, treatment, and prophylaxis of genital αPV neoplasia. Additionally, this discovery suggests that genital αPVs with oncogenic potential may infect a wider spectrum of non-human primate species than previously thought.

Hemophagocytic syndrome in a pancytopenic simian retrovirus-infected male rhesus macaque (Macaca mulatta).

Hemophagocytic syndrome (HPS) is a macrophage hyperactivation disorder triggered by disrupted T-cell macrophage cytokine interaction. HPS has been reported in humans, dogs, cats, and cattle, and it is infrequent and poorly characterized in animals. A 16-year-old male rhesus macaque was euthanized because of severe pancytopenia, including nonregenerative anemia (hematocrit = 5.5%), neutropenia (0.29 K/µl), and thrombocytopenia (21 K/µl). Bone marrow was hypocellular with normal maturation, myeloid hypoplasia, and few megakaryocytes. There were numerous morphologically normal macrophages (12% of nucleated cells), with 6% of nucleated cells being hemophagocytic macrophages in the bone marrow. Serology was negative, but polymerase chain reaction and immunohistochemistry were positive for simian retrovirus type 2. Blood and bone marrow findings were consistent with HPS. Cytopenias are common in simian retrovirus-infected macaques, but HPS has not been reported. An association between simian retrovirus infection and HPS is undetermined, but retrovirus-associated HPS has been observed in humans.

Prognostic markers for canine melanocytic neoplasms: a comparative review of the literature and goals for future investigation.

Many studies have evaluated various prognostic markers for canine melanocytic neoplasms either as primary or secondary goals; however, design, methodology, and statistical validation vary widely across these studies. The goal of this article was to evaluate and compare published canine melanocytic neoplasm studies in relation to the principals established in the Recommended Guidelines for the Conduct and Evaluation of Prognostic Studies in Veterinary Oncology. Based on this evaluation, we determined which parameters currently have the most statistically supported validity for prognostic use in canine melanocytic neoplasia. This information can also be used as part of evidence-based prospective evaluations of treatment regimens. Additionally, we highlight areas in which the current data are incomplete and that warrant further evaluation. This article represents an initiative of the American College of Veterinary Pathologists' Oncology Committee and has been reviewed and endorsed by the World Small Animal Veterinary Association.

Prognostic evaluation of Ki67 threshold value in canine oral melanoma.

Oral melanoma is a common canine cancer with a historically poor prognosis. Recent evidence suggests that a subset of cases may have a more favorable outcome, defined as long-term survival in the absence of intervention other than initial surgery. Traditional histological parameters have had prognostic significance in some studies but not in others, potentially due to interobserver variation. We evaluated the prognostic utility of Ki67 immunohistochemistry in a group of 79 canine oral melanomas using a technique easily applied in a veterinary diagnostic laboratory. A threshold Ki67 value of >19.5 had a sensitivity and specificity of 87.1% and 85.4%, respectively, at predicting death or euthanasia due to melanoma by 1 year postdiagnosis. Threshold values for classical histological parameters were also identified for most cases and were >4 (>30%; sensitivity = 83.9%, specificity = 86.0%) for the nuclear atypia score and >4/10 hpfs (sensitivity = 90.3%, specificity = 84.4%) for the mitotic index. In this study, the percentages correctly classified with respect to death by 1 year postdiagnosis were comparable for Ki67 (86.1%, 68/79), the nuclear atypia score (86.3%, 63/73), and the mitotic index (86.8%, 66/76). High pigmentation (>50%) had a high negative predictive value of 90.9% (18/20), but overall, only 61.0% (47/77) of cases could be correctly classified by this parameter. Based on these results, we recommend a panel of prognostic parameters, including the nuclear atypia score, the mitotic index, Ki67, and pigmentation quantification to more accurately predict the likely outcome of canine oral melanomas.

Ulcerative typhlocolitis associated with Helicobacter mastomyrinus in telomerase-deficient mice.

Telomerase deficiency induces early senescence and defects in proliferating cell populations, but in mice it has not been associated with inflammatory bowel disease. Genetically engineered mice lacking either telomerase reverse transcriptase (TERT) or telomerase RNA were examined for chronic diarrhea and wasting. Affected mice had pasty stools, thickened nondistensible colon walls, and contracted ceca. Histologically, the cecal mucosa was largely replaced by inflammatory infiltrate consisting of plasma cells, neutrophils, lymphocytes, and macrophages with marked widespread fibrosis and ulceration. Remaining epithelium was disorganized and hyperplastic, with multifocal dysplasia. Colonic mucosa was markedly hyperplastic with similar inflammation and epithelial dysplasia. Multifocal adenomatous hyperplasia, but no inflammation, was present in the small intestine. Microaerophilic spiral bacteria with 16S rRNA gene sequences identical to Helicobacter mastomyrinus were isolated from the colon and cecum. Severe granulomatous typhlocolitis without epithelial dysplasia developed in germ-free recombination-activating gene (RAG) knockout (KO) recipients of CD4+ T cells and inoculated with cecal contents from affected TERT KO mice and in specific pathogen-free recipient RAG KO mice and interleukin-10 KO mice inoculated with H mastomyrinus. Typhlocolitis in mice given H mastomyrinus was more severe than in mice given Helicobacter hepaticus. Telomerase-deficient mice are susceptible to helicobacter-associated typhlocolitis. H mastomyrinus causes severe disease in susceptible mouse strains.

Isolation and characterization of Corynebacterium ulcerans from cephalic implants in macaques.

To determine the prevalence of colonization by Corynebacterium ulcerans, we cultured samples from the cephalic implant-skin margin and pharynx of 26 rhesus macaques and one pig-tailed macaque. All but one of the samples from the cephalic implants yielded a mixed population of bacteria. C. ulcerans grew from the cephalic implants in 56% and from the pharynx in 3% of the implanted animals. We screened nine of these isolates for diphtheria toxin (DT) and phospholipase D (PLD). Polymerase chain reactions (PCR) failed to identify DT in any of the tested isolates, which also lacked DT activity in Elek tests. However, all nine isolates tested had PLD toxin activity as determined by conjoint hemolysis on sheep blood agar plates in the presence of equi factor (Rhodococcus equi). In addition, PCR assays and Southern blot hybridization confirmed the presence of pld in the isolates. The role of the PLD toxin in promoting colonization of cephalic implants by C. ulcerans is unknown. We found C. ulcerans to be a frequent contaminant of the cephalic implant-skin margin. Further studies are necessary to investigate the relative clinical importance of this organism and the efficacy of various implant maintenance protocols in preventing infection.