Mutation in crrB encoding a sensor kinase increases expression of the RND-type multidrug efflux pump KexD in Klebsiella pneumoniae.

Background: RND-type multidrug efflux systems in Gram-negative bacteria protect them against antimicrobial agents. Gram-negative bacteria generally possess several genes which encode such efflux pumps, but these pumps sometimes fail to show expression. Generally, some multidrug efflux pumps are silent or expressed only at low levels.

Production and Functional Evaluation of Anti- Sera Raised by Immunizations of Rabbits with Mutated Recombinant Phospholipases-D.

Loxoscelism is the clinical condition triggered after the bite of spiders of the genus . The main species involved in accidents in South America are , and . The only specific treatment is the anti- serum produced with crude venoms.

A protective vaccine against the toxic activities following Brown spider accidents based on recombinant mutated phospholipases D as antigens.

Accidents involving Brown spiders are reported throughout the world. In the venom, the major toxins involved in the deleterious effects are phospholipases D (PLDs). In this work, recombinant mutated phospholipases D from three endemic species medically relevant in South America (Loxosceles intermedia, L.

Brown spider venom toxins: what are the functions of astacins, serine proteases, hyaluronidases, allergens, TCTP, serpins and knottins?

Accidents caused by the bites of brown spiders () generate a clinical condition that often includes a threatening necrotic skin lesion near the bite site along with a remarkable inflammatory response. Systemic disorders such as hemolysis, thrombocytopenia, and acute renal failure may occur, but are much less frequent than the local damage. It is already known that phospholipases D, highly expressed toxins in venom, can induce most of these injuries.