Stenotrophomonas maltophilia Infections in a General Hospital: Patient Characteristics, Antimicrobial Susceptibility, and Treatment Outcome

Abstract

Introduction Stenotrophomonas maltophilia is acquiring increasing importance as a nosocomial pathogen.MethodsWe retrospectively studied the characteristics and outcome of patients with any type of S. maltophilia infection at the University Hospital of Heraklion, Crete, Greece, between 1/2005–12/2010. S. maltophilia antimicrobial susceptibility was tested with the agar dilution method. Prognostic factors for all-cause in-hospital mortality were assessed with multivariate logistic regression.ResultsSixty-eight patients (median age: 70.5 years; 64.7% males) with S. maltophilia infection, not related to cystic fibrosis, were included. The 68 patients were hospitalized in medical (29.4%), surgical (26.5%), hematology/oncology departments (23.5%), or the intensive care units (ICU; 20.6%). The most frequent infection types were respiratory tract (54.4%), bloodstream (16.2%), skin/soft tissue (10.3%), and intra-abdominal (8.8%) infection. The S. maltophilia-associated infection was polymicrobial in 33.8% of the cases. In vitro susceptibility was higher to colistin (91.2%), trimethoprim/sulfamethoxazole and netilmicin (85.3% each), and ciprofloxacin (82.4%). The empirical and the targeted treatment regimens were microbiologically appropriate for 47.3% and 63.6% of the 55 patients with data available, respectively. Most patients received targeted therapy with a combination of agents other than trimethoprim/sulfamethoxazole. The crude mortality and the mortality and the S. maltophilia infection-related mortality were 14.7% and 4.4%, respectively. ICU hospitalization was the only independent prognostic factor for mortality.Conclusion S. maltophilia infection in a general hospital can be associated with a good prognosis, except for the patients hospitalized in the ICU. Combination reigmens with fluoroquinolones, colistin, or tigecycline could be alternative treatment options to trimethoprim/sulfamethoxazole.

Association of <i>sul</i> genes and class 1 integron with trimethoprimsulfamethoxazole Resistance in <i>Stenotrophomonas maltophilia</i> clinical isolates in Zagazig University, Egypt

“…The most effective antibiotics in vitro were tigecycline, colistin, levofloxacin, SXT, then ticaricillin-clavulunic and ceftazidime, which showed the highest sensitivity (62.5%) among the β-lactams used in this study. Similar results were obtained by Samonis et al (16) who reported that colistin and tigecycline could be considered as new therapeutic options against S. maltophilia infections. This is also in line with Zhanel et al (20) who stated that tigecycline displayed good in vitro activity against MDR isolates of S. maltophilia.…”

“…The association of sul genes and Integron 1 with resistance to SXT had a statistically significant difference (x 2 =23.9, P<0.0001) (Table 3 & Fig.1). (19) reported that 59% of S. were from respiratory specimen (16.22%), blood (14.87%) and urine Samonis et al (16) reported that infection associated with S. maltophilia tractinfection (54.4%) followed infections (16.2%), skin and soft (10%) and lastly urinary tract infection…”

Haemorrhagic pneumonia caused by Stenotrophomonas maltophilia in two newborns

“…TMP/SMX, ticarcillin-clavulanate, fluoroquinolone, colistin, and tigecycline are agents that show consistent therapeutic activity against SM. However, because resistant strains of SM have increased, combination regimens are recommended [5]. We have treated patients with a combination of TMP/SMX and fluoroquinolone with successful outcomes.…”

The effect of interspecies signaling on Stenotrophomonas maltophilia growth.

“…It general, S. maltophilia is unable to infect human hosts because it is unable to easily bypass the basic immune defenses (3) . In spite of this, S. maltophilia has been gaining increased attention as an emerging pathogen in the past two decades for a number of reasons, especially in hospital settings (2,6,8,10) . S. maltophilia has been shown to be highly resistant to a suite of antibiotics, including quinones, β-lactams (carbapenems, penicillins, cephalosporins) and aminoglycosides (3) .…”

“…As a result, it is now commonly found on a variety of common medical equipment, including catheters, endotracheal tubes, and other indwelling-lines that aid in the bacteria's transmission into its host (3) . Once entry into the a host has been established, S. maltophilia infection primarily results in pneumonia, but bloodstream infections (septicemia), infection on the skin and soft tissues, urinary tract infections, intraabdominal infections, and even ocular infections can also occur (8) .…”