ABSTRACT
The emergence of novel resistant markers hampers the efficacy of beta-lactam antibiotics to treat infections caused by micro-organisms carrying such resistances. This study investigated the antimicrobial susceptibility pattern, the carpapenem-associated determinants and the molecular epidemiology of Klebsiella pneumoniae showing a New Delhi (NDM) metallo-ß-lactamase phenotype, isolated from a patient admitted to intensive care unit of the main hospital for acute care of Molise region, central Italy. Antimicrobial susceptibility was assessed for nineteen antibiotics by disc diffusion and agar dilution methods. Carbapenem-associated resistance determinants were detected through gene-specific amplifications, targeting blaNDM-1 , blaSHV and blaTEM , blaCTX-M , blaKPC , blaVIM , blaIMP , blaGES and blaOXA-48-lixe . Molecular characterization was carried out through multilocus sequence typing. The strain showed a multidrug resistant profile, and PCR and sequencing confirmed the presence of blaNDM-1 gene. Among the multiple resistance-associated determinants tested, the isolate, which was assigned to the sequence type ST11, only harboured blaSHV and blaTEM genes. This is the first report of NDM-1 variant in the regional healthcare setting for acute patients, raising significant concerns about the increase in the antimicrobials resistance spread through a different mechanism from the endemic KPC carbapenemase, and underlining the circulation of a virulent clone never identified before in this area.
Subject(s)
Bacterial Proteins/metabolism , Klebsiella Infections/microbiology , Klebsiella pneumoniae/isolation & purification , beta-Lactamases/metabolism , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Drug Resistance, Bacterial , Hospitals/statistics & numerical data , Humans , Italy/epidemiology , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/genetics , Male , Microbial Sensitivity Tests , Molecular Epidemiology , Multilocus Sequence Typing , beta-Lactamases/geneticsABSTRACT
Applications of laser therapy in biostimulation and healing injured tissues are widely described in medical literature. The present study focuses on the effects of laser irradiation on the growth rate and differentiation of human osteoblast-like cells seeded on titanium or zirconia surfaces. Cells were laser irradiated with low therapeutical doses at different intervals and the effects of irradiation were evaluated at each time-point. After 3 hours lasered cells showed an enhanced mitogen activity compared to non-lasered control cells and a higher alkaline phosphatase activity, marker of bone formation. At the same time, the mRNA of RUNX2 and OSTERIX, two genes involved in osteoblast differentiation, showed a clear decrease in lasered cells. This reached the lowest value 6 to 12 hours after irradiation, after which the transcripts started to increase, indicating that the laser treatment did promote the osteogenic potential of growth-induced cells. These results indicate that Low Level Laser Treatment (LLLT) stimulates osteogenic cell proliferation.
