In recent years isolates of community-associated (CA-MRSA) have been identified too [165]. The traditional antibiotic therapy for MRSA has always been glycopeptides. The widespread occurrence of MRSA induced an inevitable increase of vancomycin and teicoplanin use, causing a selective pressure to develop glycopeptides resistance so that in 1997 the first vancomycin-intermediate Staphylococcus

aureus (VISA) was reported and after some years the first vancomycin-resistent Staphylococcus aureus (VRSA) was also documented [166]. Multiresistant Staphylococcus aureus diffusion highlights the importance of the development of new agents for the appropriate treatment of infections where highly resistant pathogens are suspected or known. buy Navitoclax The list of antimicrobial agents with activity against MRSA is short, including Quinupristin/dalfopristin, daptomycin, linezolid and tigecicline. BMN673 Recently resistances also to linezolid were identified [167]. Empiric antimicrobial against MRSA

should be provided to patients with health care-associated intra-abdominal infections who are known to be colonized with the organism or who are suspected of having an infection due to this organism because of prior treatment failure and significant antibiotic exposure [103]. Extended-spectrum β-lactamases (ESBLs) producing Enterobacteriaceae Over the past few years a notable increase in antibiotic resistance among Gram-negative bacteria recovered from hospitalized patients has been reported, especially in critically ill patients [168]. During the last decade, the emergence of multidrug-resistant (MDR) Gram-negative bacteria such as Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia and extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae has become a growing problem. In the specific context of intra-abdominal infections, resistance to β-lactams,

mediated by extended-spectrum β-lactamases (ESBLs) is a particular concern [169, 170]. Acquired resistance to beta-lactams is mainly mediated by extended-spectrum beta-lactamases (ESBLs) that DAPT cell line confer resistance to the penicillins, first-, second-, and third-generation cephalosporins, and aztreonam, and are inhibited by b-lactamase inhibitors. Extended-spectrum beta-lactamases (ESBLs) which are encoded by genes that can be exchanged between bacteria. Beta-lactamase genes are often associated with resistance determinants to non-beta-lactam agents such as aminoglycosides and fluoroquinolones, and strains producing ESBLs often exhibit complex multidrug resistant phenotypes and sometimes are panresistant [171, 172].