Bacteroides fragilis expresses three proteins similar to Porphyromonas gingivalis HmuY: Hemophore-like proteins differentially evolved to participate in heme acquisition in oral and gut microbiomes.

Oral and gut microbiomes are important for the maintenance of homeostasis in the human body. Altered or disturbed mutualism between their members results in dysbiosis with local injury and subsequent systemic diseases. The high bacterial density causes intense competition among microbiome residents to acquire nutrients, including iron and heme, the latter of high importance for heme auxotrophic members of the Bacteroidetes phylum. Our main hypothesis is that the heme acquisition mechanism, with the leading role played by a novel HmuY family of hemophore-like proteins, can be used to fulfill nutritional requirements and increase virulence. We characterized HmuY homologs expressed by Bacteroides fragilis and compared their properties with the first representative of this family, the HmuY protein of Porphyromonas gingivalis. In contrast to other Bacteroidetes members, B. fragilis produces three HmuY homologs (Bfr proteins). All bfr transcripts were produced at higher levels in bacteria starved of iron and heme (fold change increase ~60, ~90, and ~70 for bfrA, bfrB, and bfrC, respectively). X-ray protein crystallography showed that B. fragilis Bfr proteins are structurally similar to P. gingivalis HmuY and to other homologs, except for differences in the potential heme-binding pockets. BfrA binds heme, mesoheme, and deuteroheme, but preferentially under reducing conditions, using Met175 and Met146 to coordinate heme iron. BfrB binds iron-free protoporphyrin IX and coproporphyrin III, whereas BfrC does not bind porphyrins. HmuY is capable of heme sequestration from BfrA, which might increase the ability of P. gingivalis to cause dysbiosis also in the gut microbiome.

Intrapartum epidural catheter displacement: Comparison of three dressing methods (Migración de catéter epidural intraparto: Comparación de tres métodos de fijación).

AIM: To compare the effect on epidural catheter migration of three different types of dressing used in labor. INTRODUCTION: Failure of labor epidural is due to multiple factors including catheter migration. Epidural catheter migration has been showed to be related to body mass index and patient position. The dressing technique also influences catheter migration and the risk of epidural failure. METHODS: Patients were randomly allocated to one of three groups based on type of dressing of labor epidural: TegadermTM (Group T), TegadermTM with sticky pad (Group P), and TegadermTM with Steri-StripTM (Group S). Measured variables included parity, gestational age, body mass index (BMI), level of puncture and distance of epidural catheter migration. RESULTS: There was an overall difference in epidural catheter migration (ECM) distance among different groups (p<0.05). Pairwise comparison revealed only a significant difference between groups P and T (0.76±1.35 vs. -0.14±1.03, p<0.01). CONCLUSION: Taping the lumbar epidural catheter used for labor analgesia with TegadermTM is inferior to TegadermTM with sticky pad or with Steri-StripTM in terms of catheter migration. There is no association of catheter migration and BMI.

Objetivo: Comparar el efecto de tres diferentes tipos de fijación sobre la migración del catéter epidural durante el trabajo de parto. Introducción: El fallo del bloqueo epidural en el trabajo de parto se debe a múltiples factores incluyendo la migración de catéter. La migración de catéter epidural se ha relacionado con el índice de masa corporal y la posición, así como con movimientos del paciente. La técnica de fijación también afecta la migración de catéter y el riesgo de bloqueo epidural fallido. Método: Las pacientes fueron aleatorizadas y asignadas a uno de tres grupos según el tipo de fijación: TegadermTM (Grupo T), TegadermTM con almohadilla adhesiva (Grupo P) y Tegaderm TM con Steri-StripTM (Grupo S). Las variables evaluadas incluyeron paridad, edad gestacional, índice de masa corporal (IMC), nivel de punción y distancia de migración del catéter epidural. Resultados: Se detectó una diferencia en la distancia de migración de catéter epidural entre los diferentes grupos (p<0.05). La comparación reveló diferencia únicamente entre los grupos P y T (0.76±1.35 vs. -0.14±1.03, p<0.01). Conclusión: TegadermTM como método de fijación de catéter epidural en el trabajo de parto resultó ser inferior al TegadermTM con almohadilla adhesiva o con Steri-StripTM en términos de migración de catéter. No existe una asociación entre migración de catéter epidural e IMC.