Bacterial interactions on nutrient-rich surfaces in the gut lumen.

The intestinal lumen is a turbulent, semi-fluid landscape where microbial cells and nutrient-rich particles are distributed with high heterogeneity. Major questions regarding the basic physical structure of this dynamic microbial ecosystem remain unanswered. Most gut microbes are non-motile, and it is unclear how they achieve optimum localization relative to concentrated aggregations of dietary glycans that serve as their primary source of energy. In addition, a random spatial arrangement of cells in this environment is predicted to limit sustained interactions that drive co-evolution of microbial genomes. The ecological consequences of random versus organized microbial localization have the potential to control both the metabolic outputs of the microbiota and the propensity for enteric pathogens to participate in proximity-dependent microbial interactions. Here, we review evidence suggesting that several bacterial species adopt organized spatial arrangements in the gut via adhesion. We highlight examples where localization could contribute to antagonism or metabolic interdependency in nutrient degradation, and we discuss imaging- and sequencing-based technologies that have been used to assess the spatial positions of cells within complex microbial communities.

Wolbachia action in the sperm produces developmentally deferred chromosome segregation defects during the Drosophila mid-blastula transition.

Wolbachia, a vertically transmitted endosymbiont infecting many insects, spreads rapidly through uninfected populations by a mechanism known as cytoplasmic incompatibility (CI). In CI, a paternally delivered modification of the sperm leads to chromatin defects and lethality during and after the first mitosis of embryonic development in multiple species. However, whether CI-induced defects in later stage embryos are a consequence of the first division errors or caused by independent defects remains unresolved. To address this question, we focused on ~1/3 of embryos from CI crosses in Drosophila simulans that develop apparently normally through the first and subsequent pre-blastoderm divisions before exhibiting mitotic errors during the mid-blastula transition and gastrulation. We performed single embryo PCR and whole genome sequencing to find a large percentage of these developed CI-derived embryos bypass the first division defect. Using fluorescence in situ hybridization, we find increased chromosome segregation errors in gastrulating CI-derived embryos that had avoided the first division defect. Thus, Wolbachia action in the sperm induces developmentally deferred defects that are not a consequence of the first division errors. Like the immediate defect, the delayed defect is rescued through crosses to infected females. These studies inform current models on the molecular and cellular basis of CI.

[Use of collagen-polyvinylpirrolidone in the treatment of Parry-Romberg syndrome.] / Colágeno-polivinilpirrolidona para tratar el síndrome de Parry-Romberg.

Background: Parry-Romberg syndrome is characterized by the presence of progressive hemifacial atrophy that affects the growth and development of structures on one side of the face. Our objective was to introduce collagen-polyvinylpirrolidone as a new therapeutic option for Parry-Romberg syndrome in two clinical cases. Clinical cases: two women, aging 56 and 28 years old, with facial hypocrhomic lesions, and right and left fronto-malar sunken area respectively, treated with topic steroids + penicilamina, fat grafts and silicone implants without improvement. We used collagen-polyvinylpirrolidone and they showed improvement: after six months there were not clinical or esthetical complications. Conclusions: collagen-polivinilpirrolidone could be a new therapeutic option for Parry-Romberg syndrome with good clinical and esthetical results. It is easy to apply and it has few side effects and without complications.

Introducción: el síndrome de Parry-Romberg está caracterizado por la presencia de atrofia hemifacial progresiva, afección del crecimiento y desarrollo de las estructuras de un lado de la cara. El objetivo de este trabajo es describir nuestra experiencia con el colágeno polivinilpirrolidona para tratar el síndrome de Parry-Romberg. Casos clínicos: dos mujeres de 56 y 28 años de edad, con manchas hiperpigmentadas y hundimiento frontomalar derecho e izquierdo, respectivamente, manejadas con esteroides tópicos más penicilamina, injertos grasos e implantes de silicón, sin mejoría. Se decidió iniciar tratamiento con colágeno-polivinilpirrolidona, con lo que se logró una mejoría clínica y estética sin complicaciones después de seis meses de seguimiento. Conclusiones: el colágeno polivinilpirrolidona es una opción terapéutica para el síndrome de Parry-Romberg que ofrece buenos resultados clínicos y estéticos, es de fácil administración, sin complicaciones y mínimos efectos secundarios.