Search

Aeromonas spp. are gram-negative facultatively anaerobic bacilli recovered mainly from aquatic environments. Aeromonas spp. were reported to be associated with infections primarily in aquatic and to a lesser extent in terrestrial animals as well as in humans. Up-to-date little is known about aeromonads associated with wild animals, especially with rodents. This study reported the first isolation and characterization of two Aeromonas spp. from internal organs of apparently healthy wild rodents Apodemus uralensis and Apodemus flavicollis captured in the wild environment in the European part of Russia. Isolates were identified as A. hydrophila M-30 and A. encheleia M-2 using the multilocus sequence analysis (MLSA) approach. The isolation of the A. encheleia from rodents is the first described case. Both strains demonstrated beta-hemolytic activity towards human erythrocytes. Antimicrobial susceptibility testing showed that both Aeromonas strains were resistant and intermediate to carbapenems and piperacillin-tazobactam, which was caused by the expression of the genus-specific CphA carbapenemases. A. hydrophila M-30 also demonstrated trimethoprim resistant phenotype. This is usually caused by the carriage of the dfrA or dfrB genes in aeromonads which are frequently associated with integron class I. The latter however was absent in both isolates. Our results expand our understanding of possible aeromonad reservoirs and demonstrate the likelihood of the formation of natural foci of Aeromonas infection and a new link in the chain of the spread of antimicrobial resistance as well. [ABSTRACT FROM AUTHOR]

Studies of factors affecting wound-healing rates are encouraged by a critical need for new treatments to manage an increasing burden of non-healing wounds. The InlB protein produced by the Gram-positive bacterium Listeria monocytogenes is an agonist of the tyrosine kinase receptor c-Met and a functional analog of the hepatocyte growth factor (HGF), which is a mammalian ligand of c-Met. The recombinant InlB321 protein, which is the c-Met-binding InlB domain (amino acids 31-321), was cloned from the L. monocytogenes serovar 4b clinical strain VIMHA015 and serovar 1/2a strain EGDe (InlB321/15 and InlB321/EGDe, respectively). Both InlB321 variants stimulated proliferation of endothelial HUVEC cells. InlB321/15 was more active in Erk1/2 phosphorylation assay, and more potent than InlB321/EGDe in the 2D-scratch wound-healing assay. Scratch closure reached 86%, 29% and 72% for InlB321/15, InlB321/EGDe and HGF, respectively, 72 h post-wounding (p < 0.05). Topically applied glycerol-mixed InlB321/15 (300 µg ml− 1) increased abrasion wound-healing rates in mice. The 50% wound closing time (CT50) was reduced by InlB321/15 (4.18 ± 0.91 days; CI: 3.05; 5.31) compared with control animals (5.51 ± 1.21 days; CI: 4.01; 7.01; p < 0.05). Taken together, obtained results suggested a potential of InlB321/15 as a means of accelerating wound healing. [ABSTRACT FROM AUTHOR]