Update on the treatment of Pseudomonas aeruginosa pneumonia

Abstract

Pseudomonas aeruginosa is an important cause of nosocomial pneumonia associated with a high morbidity and mortality rate. This bacterium expresses a variety of factors that confer resistance to a broad array of antimicrobial agents. Empirical antibiotic therapy is often inadequate because cultures from initial specimens grow strains that are resistant to initial antibiotics. Surveillance data, hospital antibiogram and individualization of regimens based on prior antibiotic use may reduce the risk of inadequate therapy. The use of combination therapies for P. aeruginosa pneumonia has been a long-advocated practice, but the potential increased value of combination therapy over monotherapy remains controversial. Doripenem and biapenem are new carbapenems that have excellent activity against P. aeruginosa; however, they lack activity against strains that express resistance to the currently available carbapenems. The polymyxins remain the most consistently effective agents against multidrug-resistant P. aeruginosa. Strains that are panantibiotic-resistant are rare, but their incidence is increasing. Antibiotic combinations that yield some degree of susceptibility in vitro are the recourse, although the efficacy of these regimens has yet to be established in clinical studies. Experimental polypeptides may provide a new therapeutic approach. Among these, the anti-PcrV immunoglobulin G antibody that blocks the type III secretion system-mediated virulence of P. aeruginosa has recently entered Phase I/II clinical trials.

In vivo development of antimicrobial resistance in Pseudomonas aeruginosa strains isolated from the lower respiratory tract of Intensive Care Unit patients with nosocomial pneumonia and receiving antipseudomonal therapy

“…30%, with inability to control the infection being the main likely cause of death for approximately one-half of these patients. In contrast to an A c c e p t e d M a n u s c r i p t earlier report in which rates of primary resistance of P. aeruginosa in the ICU were relatively low [38], here it was found, as in another recent study [39], that MDR organisms are frequent at the very early onset of the disease. Although not designed to provide a true epidemiological estimate, the present study clearly shows that the clinician's choice of active antibiotics has become increasingly narrow when P. aeruginosa is among the causative organisms.…”

“…As was the case in this study, combination therapy is actually often used in daily practice and is advocated as being essential to obtain a satisfactory response [39,43]. A first main conclusion from this study is, therefore, that significant efforts must be deployed to accelerate the early assessment of bacterial susceptibility in order to decrease the risk of therapeutic failure [44] while at the same time avoiding unnecessary use of wide-spectrum combinations.…”

Adaptation-Based Resistance to Siderophore-Conjugated Antibacterial Agents by Pseudomonas aeruginosa

“…While its frequency and persistence within the lungs of cystic fibrosis (CF) patients have been the focus of a substantial amount of research effort, its virulence has also been linked to other non-CF disease states or conditions such as burns (15), wound infections (16), and nosocomial pneumonia (17). The pathogenic versatility of P. aeruginosa can be attributed to the myriad of virulence factors that it is capable of producing, including multiple toxins (18,19), degradative enzymes (20), a functional type III secretion system (21), and several different polysaccharides (22)(23)(24), each of which have been demonstrated to protect this pathogen in various stages of its life cycle.…”

Coleta De Secreção Traqueal: Estudo Comparativo De Técnicas

“…O estudo de Cook e Mandell 11 confirma o valor de amostras de secreção traqueal para identificar o patógeno etiológico em pacientes com PAV. Nas amostras qualitativas de secreção traqueal é raro não crescer um organismo que também será encontrado no tecido pulmonar No ambiente hospitalar, as fontes de maior contaminação são o ventilador mecânico, sistemas de hemodiálise, pias e materiais de limpeza 19 Segundo estudos 14,15,16 as bactérias de coloração Gram negativa são as mais frequentes em UTI, entre elas o Acinetobacter baumanni e Pseudomonas aeuriginosa, concordando com os achados dessa pesquisa (59,9%). A característica mais importante das Gram negativas é sua versatilidade nutricional, que permite se adaptar de forma eficaz para o ambiente hospitalar.…”