Pseudomonas aeruginosa – a phenomenon of bacterial resistance

Abstract

Pseudomonas aeruginosa is one of the leading nosocomial pathogens worldwide. Nosocomial infections caused by this organism are often hard to treat because of both the intrinsic resistance of the species (it has constitutive expression of AmpC b-lactamase and efflux pumps, combined with a low permeability of the outer membrane), and its remarkable ability to acquire further resistance mechanisms to multiple groups of antimicrobial agents, including b-lactams, aminoglycosides and fluoroquinolones. P. aeruginosa represents a phenomenon of bacterial resistance, since practically all known mechanisms of antimicrobial resistance can be seen in it: derepression of chromosomal AmpC cephalosporinase; production of plasmid or integronmediated b-lactamases from different molecular classes (carbenicillinases and extendedspectrum b-lactamases belonging to class A, class D oxacillinases and class B carbapenemhydrolysing enzymes); diminished outer membrane permeability (loss of OprD proteins); overexpression of active efflux systems with wide substrate profiles; synthesis of aminoglycosidemodifying enzymes (phosphoryltransferases, acetyltransferases and adenylyltransferases); and structural alterations of topoisomerases II and IV determining quinolone resistance. Worryingly, these mechanisms are often present simultaneously, thereby conferring multiresistant phenotypes. This review describes the known resistance mechanisms in P. aeruginosa to the most frequently administrated antipseudomonal antibiotics: b-lactams, aminoglycosides and fluoroquinolones.

Prevalence of ESBL and MBL Producing Pseudomonas aeruginosa in a Tertiary Care Hospital in Tirunelveli

“…Multidrug resistance in P. aeruginosa makes treatment of infections caused by this organism both difficult and expensive. Improved methods for antimicrobial susceptibility testing are needed, including detection of emerging strains producing ESBLs and MBLs (Strateva and Yordanov, 2009). With increasing isolation of ESBL producing isolates in the hospital setting necessitating the use of carbapenems, the problem of MBL production is also increasing (Manoharan et al, 2010).…”

“…Multi-drug resistance in Pseudomonas aeruginosa makes treatment of infections caused by this organism both difficult and expensive (Strateva and Yordanov, 2009). …”

Resistance Pattern of Pseudomonas aeruginosa in a Tertiary Care Hospital of Kanchipuram, Tamilnadu, India

“…P.aeruginosa is notorious for being intrinsically resistant to many structurally unrelated antimicrobial agents by exhibiting low permeability of its outer membrane, the constitutive expression of various efflux pumps and the naturally occurring chromosomal AmpC β lactamase, and it can acquire additional resistant gene form other organisms via plasmids, transposons, bacteriophages, and also by biofilm production [2,3]. Despite advances in medical and surgical care and wide variety of anti pseudomonal agents, life threatening infections caused by P.aeruginosa is still considered as most challenging pathogen.…”

Synthesis and Evaluation of l-Rhamnose 1C-Phosphonates as Nucleotidylyltransferase Inhibitors

“…2−5 Bacterial chemo-resistance, including resistance to synergistic treatments using β-lactams and aminoglycosides, is a growing barrier to the treatment of invasive pathogens (i.e., S. pneumoniae and M. tuberculosis). 6 Cell wall biosynthesis is a commonly pursued target for a variety of bacterial enzyme inhibitors as cell wall assembly is essential for bacterial survival and virulence. L-Rhamnose (6-deoxy-L-mannose) serves as the linking unit between arabinogalactan and peptidoglycan 7,8 and is a necessary constituent of the bacterial cell wall in many bacterial species.…”