The current study was aimed to investigate the prevalence of ureC, rsbA, zapA and mrpA virulence genes using polymerase chain reaction (PCR) in Proteus spp. isolated from 5 commercially popular species of pet turtles and comparison of the mrpA gene sequences of Proteus mirabilis isolates with human clinical isolates. A total of 24 isolates in pet turtles were identified, comprised of P. mirabil...

The Bacillus subtilis mrp (multiple resistance and pH) operon supports Na(+) and alkali resistance via an Na(+)/H(+) antiport, as well as cholate efflux and resistance. Among the individual mutants with nonpolar mutations in each of the seven mrp genes, only the mrpF mutant exhibited cholate sensitivity and a cholate efflux defect that were complemented by expression of the deleted gene in tran...

A 5.9-kb region of the Bacillus subtilis chromosome is transcribed as a single transcript that is predicted to encode seven membrane-spanning proteins. Homologues of the first gene of this operon, for which the designation mrp (multiple resistance and pH adaptation) is proposed here, have been suggested to encode an Na+/H+ antiporter or a K+/H+ antiporter. In the present studies of the B. subti...

Proteus mirabilis, an agent of urinary tract infection, expresses at least four fimbrial types. Among these are the MR/P (mannose-resistant/Proteus-like) fimbriae. MrpA, the structural subunit, is optimally expressed at 37 degrees C in Luria broth cultured statically for 48 h by each of seven strains examined. Genes encoding this fimbria were isolated, and the complete nucleotide sequence was d...

ATP-binding cassette (ABC) transporters have been associated with drug resistance in various diseases. The MRPA gene, a transporter of ABCC subfamily, is involved in the resistance by sequestering metal-thiol conjugates in intracellular vesicles of Leishmania parasite. In this study, we performed the molecular characterization of the MRPA transporter, analysis of P-glycoprotein (Pgp) and aquagl...

Antimonial compounds are the mainstay for the treatment of infections with the protozoan parasite Leishmania. We present our studies on Leishmania infantum amastigote parasites selected for resistance to potassium antimonyl tartrate [Sb(III)]. Inside macrophages, the Sb(III)-selected cells are cross-resistant to sodium stibogluconate (Pentostam), the main drug used against Leishmania. Putative ...

Microcystin is a potent inhibitor of eukaryotic protein phosphatases and has been implicated in causing hepatotoxicity to humans and animals worldwide. It is produced primarily by the bloom-forming cyanobacterium Microcystis aeruginosa, although the function of the peptide in this micro-organism is unknown. In this study, a microcystin-related protein, MrpA, was identified using a microcystin-l...

Pseudomonas aeruginosa is an important and frightening microorganism for patients suffering from cancer. Multiresistant P. aeruginosa (MRPA) may appear as a consequence of exposure to multiple antibiotics or from a breakdown in infection control practices. This article reports an MRPA outbreak in a cancer treatment centre and the consequent case control study. Mechanical ventilation was identif...

Transposon mutagenesis of Anabaena sp. PCC7120 led to the isolation of a mutant strain, PHB11, which grew poorly at pH values above 10. The mutant strain exhibited pronounced Na+ sensitivity; this sensitivity was higher under basic conditions. Mutant PHB11 also showed an inhibition of photosynthesis that was much more pronounced at alkaline pH. Reconstruction of the transposon mutation of PHB11...

It has long been known that the three largest subunits in the membrane domain (NuoL, NuoM and NuoN) of complex I are homologous to each other, as well as to two subunits (MrpA and MrpD) from a Na+/H+ antiporter, Mrp. MrpA and NuoL are more similar to each other and the same is true for MrpD and NuoN. This suggests a functional differentiation which was proven experimentally in a deletion strain...