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BACKGROUND: Individuals that band together create new ecological opportunities for microorganisms. In vertical transmission, theory predicts a conserved microbiota within lineages, especially social bees. Bees exhibit solitary to social behavior among and/or within species, while life cycles can be annual or perennial. Bee nests may be used over generations or only once, and foraging ecology varies widely. To assess which traits are associated with bee microbiomes, we analyzed microbial diversity within solitary and social bees of Apidae, Colletidae, and Halictidae, three bee families in Panama's tropical forests. Our analysis considered the microbiome of adult gut contents replicated through time, localities, and seasons (wet and dry) and included bee morphology and comparison to abdominal (dissected) microbiota. Diversity and distribution of tropical bee microbes (TBM) within the corbiculate bee clade were emphasized. RESULTS: We found the eusocial corbiculate bees tended to possess a more conserved gut microbiome, attributable to vertical transmission, but microbial composition varied among closely related species. Euglossine bees (or orchid bees), corbiculates with mainly solitary behavior, had more variable gut microbiomes. Their shorter-tongued and highly seasonal species displayed greater diversity, attributable to flower-visiting habits. Surprisingly, many stingless bees, the oldest corbiculate clade, lacked bacterial genera thought to predate eusociality, while several facultatively social, and solitary bee species possessed those bacterial taxa. Indeed, nearly all bee species displayed a range of affinities for single or multiple variants of the "socially associated" bacterial taxa, which unexpectedly demonstrated high sequence variation. CONCLUSIONS: Taken together, these results call into question whether specific bacterial associates facilitate eusocial behavior, or are subsequently adopted, or indicate frequent horizontal transmission between perennial eusocial colonies and other social, facultatively social, and solitary bees. Video Abstract.

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Marine multicellular organisms host a diverse collection of bacteria, archaea, microbial eukaryotes, and viruses that form their microbiome. Such host-associated microbes can significantly influence the host's physiological capacities; however, the identity and functional role(s) of key members of the microbiome ("core microbiome") in most marine hosts coexisting in natural settings remain obscure. Also unclear is how dynamic interactions between hosts and the immense standing pool of microbial genetic variation will affect marine ecosystems' capacity to adjust to environmental changes. Here, we argue that significantly advancing our understanding of how host-associated microbes shape marine hosts' plastic and adaptive responses to environmental change requires (i) recognizing that individual host-microbe systems do not exist in an ecological or evolutionary vacuum and (ii) expanding the field toward long-term, multidisciplinary research on entire communities of hosts and microbes. Natural experiments, such as time-calibrated geological events associated with well-characterized environmental gradients, provide unique ecological and evolutionary contexts to address this challenge. We focus here particularly on mutualistic interactions between hosts and microbes, but note that many of the same lessons and approaches would apply to other types of interactions.

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The composition of tick microbiomes varies both within and among tick species. Whether this variation is intrinsic (related to tick characteristics) or extrinsic (related to vertebrate host and habitat) is poorly understood but important, as microbiota can influence the reproductive success and vector competence of ticks. We aimed to uncover what intrinsic and extrinsic factors best explain the microbial composition and taxon richness of 11 species of neotropical ticks collected from eight species of small mammals in 18 forest fragments across central Panama. Microbial richness varied among tick species, life stages, and collection sites but was not related to host blood source. Microbiome composition was best explained by tick life stage, with bacterial assemblages of larvae being a subset of those of nymphs. Collection site explained most of the bacterial taxa with differential abundance across intrinsic and extrinsic factors. Francisella and Rickettsia were highly prevalent, but their proportional abundance differed greatly among tick species, and we found both positive and negative cooccurrence between members of these two genera. Other tick endosymbionts (e.g., Coxiella and Rickettsiella) were associated with specific tick species. In addition, we detected Anaplasma and Bartonella in several tick species. Our results indicate that the microbial composition and richness of neotropical ticks are principally related to intrinsic factors (tick species and life stage) and collection site. Taken together, our analysis informs how tick microbiomes are structured and can help anchor our understanding of tick microbiomes from tropical environments more broadly.IMPORTANCE Blood-feeding arthropod microbiomes often play important roles in disease transmission, yet the factors that structure tick microbial communities in the Neotropics are unknown. Utilizing ticks collected from live animals in neotropical forest fragments, this study teases apart the contributions of intrinsic and extrinsic tick-associated factors on tick microbial composition as well as which specific microbes contribute to differences across tick species, tick life stages, the mammals they fed on, and the locations from where they were sampled. Furthermore, this study provides revelations of how notable tick-associated bacterial genera are interacting with other tick-associated microbes as well as the forest animals they encounter.

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Several universal genomic traits affect trade-offs in the capacity, cost, and efficiency of the biochemical information processing that underpins metabolism and reproduction. We analyzed the role of these traits in mediating the responses of a planktonic microbial community to nutrient enrichment in an oligotrophic, phosphorus-deficient pond in Cuatro Ciénegas, Mexico. This is one of the first whole-ecosystem experiments to involve replicated metagenomic assessment. Mean bacterial genome size, GC content, total number of tRNA genes, total number of rRNA genes, and codon usage bias in ribosomal protein sequences were all higher in the fertilized treatment, as predicted on the basis of the assumption that oligotrophy favors lower information-processing costs whereas copiotrophy favors higher processing rates. Contrasting changes in trait variances also suggested differences between traits in mediating assembly under copiotrophic versus oligotrophic conditions. Trade-offs in information-processing traits are apparently sufficiently pronounced to play a role in community assembly because the major components of metabolism-information, energy, and nutrient requirements-are fine-tuned to an organism's growth and trophic strategy.

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Animal-associated microbiomes are integral to host health, yet key biotic and abiotic factors that shape host-associated microbial communities at the global scale remain poorly understood. We investigated global patterns in amphibian skin bacterial communities, incorporating samples from 2,349 individuals representing 205 amphibian species across a broad biogeographic range. We analysed how biotic and abiotic factors correlate with skin microbial communities using multiple statistical approaches. Global amphibian skin bacterial richness was consistently correlated with temperature-associated factors. We found more diverse skin microbiomes in environments with colder winters and less stable thermal conditions compared with environments with warm winters and less annual temperature variation. We used bioinformatically predicted bacterial growth rates, dormancy genes and antibiotic synthesis genes, as well as inferred bacterial thermal growth optima to propose mechanistic hypotheses that may explain the observed patterns. We conclude that temporal and spatial characteristics of the host's macro-environment mediate microbial diversity.

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Management of hyper-virulent generalist pathogens is an emergent global challenge, yet for most disease systems we lack a basic understanding as to why some host species suffer mass mortalities, while others resist epizootics. We studied two sympatric species of frogs from the Colombian Andes, which coexist with the amphibian pathogen Batrachochytrium dendrobatidis (Bd), to understand why some species did not succumb to the infection. We found high Bd prevalence in juveniles for both species, yet infection intensities remained low. We also found that bacterial community composition and host defense peptides are specific to amphibian life stages. We detected abundant Bd-inhibitory skin bacteria across life stages and Bd-inhibitory defense peptides post-metamorphosis in both species. Bd-inhibitory bacteria were proportionally more abundant in adults of both species than in earlier developmental stages. We tested for activity of peptides against the skin microbiota and found that in general peptides did not negatively affect bacterial growth and in some instances facilitated growth. Our results suggest that symbiotic bacteria and antimicrobial peptides may be co-selected for, and that together they contribute to the ability of Andean amphibian species to coexist with the global pandemic lineage of Bd.

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Animal-associated microbial communities can play major roles in the physiology, development, ecology, and evolution of their hosts, but the study of their diversity has yet focused on a limited number of host species. In this study, we used high-throughput sequencing of partial sequences of the bacterial 16S rRNA gene to assess the diversity of the gut-inhabiting bacterial communities of 212 specimens of tropical anuran amphibians from Brazil and Madagascar. The core gut-associated bacterial communities among tadpoles from two different continents strongly overlapped, with eight highly represented operational taxonomic units (OTUs) in common. In contrast, the core communities of adults and tadpoles from Brazil were less similar with only one shared OTU. This suggests a community turnover at metamorphosis. Bacterial diversity was higher in tadpoles compared to adults. Distinct differences in composition and diversity occurred among gut bacterial communities of conspecific tadpoles from different water bodies and after experimental fasting for 8 days, demonstrating the influence of both environmental factors and food on the community structure. Communities from syntopic tadpoles clustered by host species both in Madagascar and Brazil, and the Malagasy tadpoles also had species-specific isotope signatures. We recommend future studies to analyze the turnover of anuran gut bacterial communities at metamorphosis, compare the tadpole core communities with those of other aquatic organisms, and assess the possible function of the gut microbiota as a reservoir for protective bacteria on the amphibian skin.

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PURPOSE: Injuries to the female urethra associated with pelvic fracture are uncommon. They may vary from urethral contusion to partial or circumferential rupture. When disruption has occurred at the level of the proximal urethra, it is usually complete and often associated with vaginal laceration. We retrospectively reviewed the records of a series of girls with pelvic fracture urethral stricture and present surgical treatment to restore urethral continuity and the outcome. MATERIALS AND METHODS: Between 1984 and 1997, 8 girls 4 to 16 years old (median age 9.6) with urethral injuries associated with pelvic fracture were treated at our institutions. Immediate therapy involved suprapubic cystostomy in 4 cases, urethral catheter alignment and simultaneous suprapubic cystostomy in 3, and primary suturing of the urethra, bladder neck and vagina in 1. Delayed 1-stage anastomotic repair was performed in 1 patient with urethral avulsion at the level of the bladder neck and in 5 with a proximal urethral distraction defect, while a neourethra was constructed from the anterior vaginal wall in a 2-stage procedure in 1 with mid urethral avulsion. Concomitant vaginal rupture in 7 cases was treated at delayed urethral reconstruction in 5 and by primary repair in 2. The surgical approach was retropubic in 3 cases, vaginal-retropubic in 1 and vaginal-transpubic in 4. Associated injuries included rectal injury in 3 girls and bladder neck laceration in 4. Overall postoperative followup was 6 months to 6.3 years (median 3 years). RESULTS: Urethral obliteration developed in all patients treated with suprapubic cystostomy and simultaneous urethral realignment. The stricture-free rate for 1-stage anastomotic repair and substitution urethroplasty was 100%. In 1 girl complete urinary incontinence developed, while another has mild stress incontinence. Retrospectively the 2 incontinent girls had had an associated bladder neck injury at the initial trauma. Two recurrent vaginal strictures were treated successfully with additional transpositions of lateral labial flaps. CONCLUSIONS: This study emphasizes that combined vaginal-partial transpubic access is a reliable approach for resolving complex obliterative urethral strictures and associated urethrovaginal fistulas or severe bladder neck damage after traumatic pelvic fracture injury in female pediatric patients. Although our experience with the initial management of these injuries is limited, we advocate early cystostomy drainage and deferred surgical reconstruction when life threatening clinical conditions are present or extensive traumatized tissue in the affected area precludes immediate ideal surgical repair.

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The statistical optimization of sustained-release matrix tablets of lobenzarit disodium salt (LDS) was performed using the central composite experiment design 2(3) for three independent variables: the amount of polymer (Eudragit RS-PO) AP, the total volume of granulation solvent VS, and the amount of filler (microcrystalline cellulose) CE. The t90% was selected as the response variable. The response surfaces were performed from a statistical mathematical model. The optimal formulation was obtained for the variables (AP = 15 mg, VS = 60 microliters, and CE = 0).

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Two strains of Venezuelan equine encephalomyelitis virus, which differ in virulence for mice, have been studied for their production of and sensitivity to chick and mouse interferon. Little interferon was produced by chick cells in response to the virulent Trinidad strain or the attenuated TC-83 strain without either aging or priming the cultures. Consistent differences in the production of chick interferon were not found between the two strains. Plaque variants of the Trinidad strain produced higher titers of mouse interferon than the TC-83 strain in both primed and control L-cell cultures. The TC-83 strain was found to be more sensitive than the Trinidad strain to the inhibitory effects of interferon. The greater sensitivity of the TC-83 strain was observed at both high and low multiplicities and for both chick and mouse interferons. These results are consistent with the hypothesis that interferon sensitivity may have a role as a determinant of virulence in some virus-host systems.

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A time study of the public health nursing programme was carried out at 3 Health Centres in Barbados. The object was to find out what duties were performed by the nurses and the time spent on those duties. The study revealed how much time was spent on each different service provided and how much time spent on duties which could be assigned to non-professional workers. It was found that more time was spent on maintenance and records than on treatment and care of patients (AU)

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