Risk factors for bacteraemia attributable to Pseudomonas aeruginosa resistant to imipenem, levofloxacin, or gentamicin

Risk factors for Pseudomonas aeruginosa infections in Asia-Pacific and consequences of inappropriate initial antimicrobial therapy: A systematic literature review and meta-analysis

OBJECTIVES

Treating infections of Gram-negative pathogens, in particular Pseudomonas aeruginosa, is a challenge for clinicians in the Asia-Pacific region owing to inherent and acquired antimicrobial resistance. This systematic review and meta-analysis provides updated information on risk factors for P. aeruginosa infection in Asia-Pacific as well as the consequences (e.g. mortality, costs) of initial inappropriate antimicrobial therapy (IIAT).

METHODS

Embase and MEDLINE databases were searched for Asia-Pacific studies reporting the consequences of IIAT versus initial appropriate antimicrobial therapy (IAAT) in Gram-negative bacterial infections as well as risk factors for serious P. aeruginosa infection. A meta-analysis of unadjusted mortality was performed using a random-effects model.

RESULTS

A total of 22 studies reporting mortality and 13 reporting risk factors were identified. The meta-analysis demonstrated that mortality was significantly lower in patients receiving IAAT versus IIAT, with a 67% reduction observed for 28- or 30-day all-cause mortality (odds ratio=0.33, 95% confidence interval 0.20-0.55; P<0.001). Risk factors for serious P. aeruginosa infection include previous exposure to antimicrobials, mechanical ventilation and previous hospitalisation.

CONCLUSION

High rates of antimicrobial resistance in Asia-Pacific as well as the increased mortality associated with IIAT and the presence of risk factors for serious infection highlight the importance of access to newer and appropriate antimicrobials.

Risk factors for hospital-acquired bacteremia due to carbapenem-resistant Pseudomonas aeruginosa in a Colombian hospital

INTRODUCTION

Bacteremia due to Pseudomonas aeruginosa resistant to carbapenems is a public health problem due to the limitations it places on therapeutic options, as well as the increased time patients must spend in hospital, costs and the risk of mortality. 

OBJECTIVE

To evaluate the risk factors for presentation of bacteremia due to carbapenem-resistant P. aeruginosa acquired in the Hospital Universitario San Ignacio between January 2008 and June 2014. 

MATERIALS AND METHODS

This was a case control study in which the case patients presented bacteremia due to P. aeruginosa resistant to carbapenems and the control group included patients with P. aeruginosa susceptible to this group of antibiotics. Variables such as the previous use of meropenem and ertapenem, immunosuppression and neoplasia were measured. Mortality and duration of hospital were also described. 

RESULTS

In all, 168 patients were evaluated, of which 42 were cases and 126 controls. Using a multivariate model, the risk factors related to bacteremia due to carbapenem-resistant P. aeruginosa acquired in hospital were the following: use of parenteral nutrition (OR=8.28; 95% CI: 2.56-26.79; p=0); use of meropenem (OR=1.15; 95% CI: 1.03-1.28; p=0.01); and use of ciprofloxacin (OR=81.99; 95% CI: 1.14-5884; p=0.043). 

CONCLUSION

In order to prevent the emergence of carbapenem-resistant P. aeruginosa, antimicrobial control programs should be strengthened by promoting the prudent administration of carbapenems and quinolones. The correct use of parenteral nutrition should also be monitored.

The antimicrobial peptide, epinecidin-1, mediates secretion of cytokines in the immune response to bacterial infection in mice

Epinecidin-1, an antimicrobial peptide which encodes 21 amino acids, was isolated from a marine grouper (Epinephelus coioides). In this study, we investigated its immunomodulatory functions in mice co-injected with Pseudomonas aeruginosa. In vivo results showed that the synthetic epinecidin-1 peptide induced significant secretion of immunoglobulin G1 (IgG1) in mice co-injected with P. aeruginosa. Moreover, after injection of 40, 100, 200, or 500 μg epinecidin-1/mouse, we detected IgM, IgG, IgG1, and IgG2a in mice treated for 1, 2, 3, 7, 14, 21, and 28 days. Results showed that there were no significant differences in IgM, IgG, or IgG2a between mice injected with epinecidin-1 alone. IgG1 increased to a peak at 24 h, 7 days, and 28 days after an epinecidin-1 (40 μg/mouse) injection. Injection of 500 μg epinecidin-1/mouse increased IgG1 to peaks at 2 and 3 days; injection of 100 μg epinecidin-1/mouse increased IgG1 to a peak at 21 days. This supports epinecidin-1 being able to activate the Th2 cell response (enhance IgG1 production) against P. aeruginosa infection. Treatment with different concentrations of epinecidin-1 in mice elevated plasma interleukin (IL)-10 to initial peaks at 24 and 48 h, and it showed a second peak at 16 days. In RAW264.7 cells, treatment with epinecidin-1 alone did not produce significant changes in tumor necrosis factor (TNF)-α protein secretion at 1, 6, or 24h after treatment with 3.75, 7.5, or 15 μg/ml epinecidin-1 compared to the lipopolysaccharide group.