Analysis of Six Gene Homologs in Bacteroides fragilis Revealed That is Essential for Survival in Experimental Intestinal Colonization and Intra-Abdominal Infection.

The opportunistic, anaerobic pathogen and commensal of the human large intestinal tract, Bacteroides fragilis strain 638R, contains six predicted TonB proteins, termed TonB1-6, four ExbBs orthologs, ExbB1-4, and five ExbDs orthologs, ExbD1-5. The inner membrane TonB/ExbB/ExbD complex harvests energy from the proton motive force (Δp), and the TonB C-terminal domain interacts with and transduces energy to outer membrane TonB-dependent transporters (TBDTs). However, TonB's role in activating nearly one hundred TBDTs for nutrient acquisition in B.

Efficacy of methylene blue in a murine model of amlodipine overdose.

Introduction: Amlodipine overdoses have significant cardiac toxicity and are difficult to treat. Methylene blue has potential as a treatment for overdoses.

Methods: A randomized controlled study of methylene blue as a treatment for amlodipine toxicity was conducted in C57Bl/6 mice.

The and Genes Conserved among Tetrapyrrole Synthesizing-Deficient Are Involved in Bacteroides fragilis Heme Assimilation and Survival in Experimental Intra-abdominal Infection and Intestinal Colonization.

The human intestinal anaerobic commensal and opportunistic pathogen does not synthesize the tetrapyrrole protoporphyrin IX in order to form heme that is required for growth stimulation and survival Consequently, acquires essential heme from host tissues during extraintestinal infection. The absence of several genes necessary for heme biosynthesis is a common characteristic of many anaerobic bacteria; however, the gene, encoding a uroporphyrinogen III synthase for an early step of heme biosynthesis, is conserved among the heme-requiring that inhabit the mammalian gastrointestinal tract. In this study, we show that the ability of to utilize heme or protoporphyrin IX for growth was greatly reduced in a Δ mutant.

Nontraditional Laboratory Animal Species (Cephalopods, Fish, Amphibians, Reptiles, and Birds).

Aquatic vertebrates and cephalopods, amphibians, reptiles, and birds offer unique safety and occupational health challenges for laboratory animal personnel. This paper discusses environmental, handling, and zoonotic concerns associated with these species.