Risk factors for multidrug-resistant Pseudomonas aeruginosa nosocomial infection

The intestinal reservoir is central to the epidemiology of Pseudomonas aeruginosa, but the dynamics of intestinal colonization by different phenotypes have been poorly described. To determine the impact of antimicrobial exposure on intestinal colonization by multidrug-resistant (MDR) and extensively drug-resistant (XDR) P. aeruginosa, we screened intensive care unit (ICU) patients for rectal colonization on admission and at weekly intervals. During an 18-month study period, 414 ICU patients were enrolled, of whom 179 (43%) were colonized; 112 (63%) of these were identified at ICU admission and 67 (37%) during their ICU stay. At 10 days after ICU admission, the probabilities of carriage were 44%, 24%, and 24% for non-MDR, MDR-non-XDR, and XDR P. aeruginosa strains, respectively (log rank, 0.02). Pulsed-field gel electrophoresis showed 10 pairs of non-MDR P. aeruginosa and subsequent MDR-non-XDR strains isolated from the same patients to be clonally identical and another 13 pairs (8 MDR-non-XDR and 5 XDR) to be unrelated. There was one specific clone between the 8 MDR-non-XDR strains and an identical genotype in the 5 XDR isolates. The Cox regression analysis identified MDR P. aeruginosa acquisition as associated with the underlying disease severity (adjusted hazard ratio [aHR], 1.97; 95% confidence interval [CI], 1.22 to 3.18; P ‫؍‬ 0.006) and prior use of fluoroquinolones (aHR, 1.02; 95% CI, 1.00 to 1.04; P ‫؍‬ 0.039), group 2 carbapenems (aHR, 1.03; 95% CI, 1.00 to 1.07; P ‫؍‬ 0.041), and ertapenem (aHR, 1.08; 95% CI, 1.02 to 1.14; P ‫؍‬ 0.004). The epidemiology of MDR P. aeruginosa is complex, and different clusters may coexist. Interestingly, ertapenem was found to be associated with the emergence of MDR isolates. Pseudomonas aeruginosa is one of the most common nosocomial pathogens worldwide, and continuously evolving resistance to multiple antimicrobial agents has become a significant health problem. The control of multidrug-resistant (MDR) P. aeruginosa in intensive care units (ICUs) is an important method for preserving the limited number of drugs available for treating P. aeruginosa infections. However, this control is difficult to achieve because the path of emergence and dissemination of MDR P. aeruginosa is not fully understood. As an endogenous source of endemic or epidemic infection with Gram-negative bacilli (GNB), the intestinal reservoir is central to the epidemiology of P. aeruginosa because prior rectal colonization is typically present in most patients developing GNB infections (1).Several studies have demonstrated that prior antimicrobial drug exposure is also a strong risk factor for colonization with a drug-resistant pathogen (2, 3). In fact, we have previously reported an association between carbapenem and fluoroquinolone consumption with the probability of colonization by carbapenem-resistant P. aeruginosa in ICU patients (4).In recent years, important changes have occurred in the epidemiology of MDR P. aeruginosa. First, in addition to the characteristic polyclonal pattern of endogenous ...

Section: Discussionsupporting

confidence: 79%

Antibiotic Pressure Is a Major Risk Factor for Rectal Colonization by Multidrug-Resistant Pseudomonas aeruginosa in Critically Ill Patients

Gómez-Zorrilla

Camoez

Tubau

et al. 2014

“…On the other hand, to our knowledge, the use of cefepime has not been identified as a risk factor for resistant P. aeruginosa. Exposure to various antibiotics has been associated with MDRPa, including carbapenems (4,5,18,20,38), piperacillin-tazobactam (18,20), vancomycin (18), aminoglycosides (18,20), cephalosporins (18), ceftazidime (36), and quinolones (3,8,31,39). The mechanisms of resistance of MDRPa in these studies were not defined.…”

Section: Discussionmentioning

confidence: 94%

Risk Factors for Acquisition of Multidrug-Resistant Pseudomonas aeruginosa Producing SPM Metallo-β-Lactamase

Nouér

Nucci

de-Oliveira

et al. 2005

To evaluate risk factors for colonization or infection due to multidrug-resistant Pseudomonas aeruginosa (MDRPa) carrying the bla SPM gene (SPM-MRDPa) among hospitalized patients, we undertook a case control study at a 480-bed, tertiary-care university hospital. Two different case definitions were used. In the first definition, a case patient (SPM case patient) was defined as a patient who had at least one isolate of SPM-MDRPa (14 patients). In the second, a case patient (non-SPM case patient) was defined as a patient who had at least one isolate of non-SPM-MDRPa (18 patients). For each case patient, we selected two controls, defined as a patient colonized and/or infected by a non-MDRPa isolate during the same study period and with the closest duration of hospitalization until the isolation of P. aeruginosa as cases. The use of quinolones was the single independent predictor of colonization and/or infection by bla SPM MDRPa (odds ratrio [OR] ‫؍‬ 14.70, 95% confidence interval [95% CI] ‫؍‬ 1.70 to 127.34, P ‫؍‬ 0.01), whereas the use of cefepime was the single predictor of colonization and/or infection by non-bla SPM MDRPa (OR ‫؍‬ 8.50, 95% CI ‫؍‬ 1.51 to 47.96, P ‫؍‬ 0.01). The main risk factor for MDRPa was a history of antibiotics usage. Stratification of risk factor analysis by a precise mechanism of resistance led us to identify a specific antibiotic, a quinolone, as a predictor for SPM-MDRPa.

“…MDR P. AERUGINOSA MDR in P. aeruginosa is usually defined as resistance to three or more of the following antimicrobial agents: antipseudomonal penicillins (e.g., piperacillin), antipseudomonal cephalosporins (e.g., ceftazidime), fluoroquinolones (e.g., ciprofloxacin), carbapenems (imipenem, meropenem, and doripenem), and the aminoglycosides (gentamicin, tobramycin, or amikacin) (17). Resis- tance is often caused by the interplay of various resistance mechanisms, including ␤-lactamases, aminoglycoside-modifying enzymes, topoisomerase mutations, decreased permeability, and the activities of efflux pumps (6).…”

Section: E Coli and K Pneumoniae Strains Resistant To Extended-specmentioning

confidence: 99%

“…The topics covered in this report are resistance to extendedspectrum cephalosporins in E. coli and Klebsiella pneumoniae, MDR (resistance to three or more antipseudomonal agents) (17) in P. aeruginosa, and carbapenem resistance in Acinetobacter spp. PubMed (www.ncbi.nih.gov; accessed on 31 October 2007) searches were performed by using the following search terms: (Escherichia coli OR Klebsiella pneumoniae) AND ESBL, (Escherichia coli OR Klebsiella pneumoniae) AND cephalosporin resistance, Pseudomonas AND multidrug resistance, Acinetobacter AND carbapenem resistance, antibiotic resistance AND (Pseudomonas OR Acinetobacter OR Escherichia coli OR Klebsiella) AND mortality, antibiotic resistance AND (Pseudomonas OR Acinetobacter OR Escherichia coli OR Klebsiella) AND length of stay, and antibiotic resistance AND (Pseudomonas OR Acinetobacter OR Escherichia coli OR Klebsiella) AND cost.…”

mentioning

confidence: 99%

Clinical and Economic Impact of Common Multidrug-Resistant Gram-Negative Bacilli

Giske

Monnet

Cars

et al. 2008

555

360

5During the last decade, the efforts to combat multidrugresistant (MDR) microorganisms mainly focused on gram-positive bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. While a large number of hospitals have implemented more rigorous infection control measures, drug companies have developed novel antimicrobial agents to combat these bacteria, resulting in several new compounds with novel mechanisms of action, e.g., linezolid and daptomycin (66). Paralleling the developments in gram-positive bacteria, infections caused by MDR gram-negative bacilli have become a growing problem (71). In a recent report the Infectious Diseases Society of America specifically addressed three categories of MDR gram-negative bacilli, namely, extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp., MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter spp. (70). Unfortunately, and contrary to what happened with gram-positive bacteria, no antibiotic from a new class has been developed specifically for MDR gram-negative bacilli. It might be argued that the glycylcycline tigecycline is an exception from the statement made above, but although this drug has in vitro activity against many MDR gram-negative bacilli, the drug was not developed specifically for the purpose of treating infections caused by such bacteria (64). Moreover, there are now a growing number of reports of cases of infections caused by gram-negative organisms for which no adequate therapeutic options exist (20). This return to the preantibiotic era has become a reality in many parts of the world (14, 55, 80). The present report aims at estimating the prevalence of infections due to MDR gramnegative bacilli, as well as the consequences with respect to mortality, hospital length of stay (LOS), and increased hospital costs.The topics covered in this report are resistance to extendedspectrum cephalosporins in E. coli and Klebsiella pneumoniae, MDR (resistance to three or more antipseudomonal agents) (17) in P. aeruginosa, and carbapenem resistance in Acinetobacter spp. PubMed (www.ncbi.nih.gov; accessed on 31 October 2007) searches were performed by using the following search terms: (Escherichia coli OR Klebsiella pneumoniae) AND ESBL, (Escherichia coli OR Klebsiella pneumoniae) AND cephalosporin resistance, Pseudomonas AND multidrug resistance, Acinetobacter AND carbapenem resistance, antibiotic resistance AND (Pseudomonas OR Acinetobacter OR Escherichia coli OR Klebsiella) AND mortality, antibiotic resistance AND (Pseudomonas OR Acinetobacter OR Escherichia coli OR Klebsiella) AND length of stay, and antibiotic resistance AND (Pseudomonas OR Acinetobacter OR Escherichia coli OR Klebsiella) AND cost. The searches were performed to address the issues of prevalence, mortality, increased LOS, and increased hospital costs. Following the review of all abstracts, a total of 85 papers were considered relevant and were evaluated for the preparation of this report. All included papers on the clinica...