Tigecycline for treatment of nosocomial-acquired pneumonia possibly caused by multi-drug resistant strains of Stenotrophomonas maltophilia

Global prevalence and distribution of antibiotic resistance among clinical isolates of Stenotrophomonas maltophilia: A systematic review and meta-analysis

OBJECTIVES

Stenotrophomonas maltophilia (S. maltophilia), an opportunistic pathogen, causes infection in patients undergoing immunosuppressive therapy, mechanical ventilation, or catheters and in long-term hospitalized patients. Due to its extensive resistance to various antibiotics and chemotherapeutic agents, S. maltophilia is challenging to treat. Using case reports, case series, and prevalence studies, the current study provides a systematic review and meta-analysis of antibiotic resistance profiles across clinical isolates of S. maltophilia.

METHODS

A systematic literature search was performed for original research articles published in Medline, Web of Science, and Embase databases from 2000 to 2022. Statistical analysis was performed using STATA 14 software to report antibiotic resistance of S. maltophilia clinical isolates worldwide.

RESULTS

223 studies (39 case reports/case series and 184 prevalence studies) were collected for analysis. A meta-analysis of prevalence studies demonstrated that the most antibiotic resistance worldwide was to levofloxacin, trimethoprim-sulfamethoxazole (TMP/SMX), and minocycline (14.4%, 9.2%, and 1.4%, respectively). Resistance to TMP/SMX (36.84%), levofloxacin (19.29%), and minocycline (1.75%) were the most prevalent antibiotic resistance types found in evaluated case reports/case series studies. The highest resistance rate to TMP/SMX was reported in Asia (19.29%), Europe (10.52%), and America (7.01%), respectively.

CONCLUSION

Considering the high resistance to TMP/SMX, more attention should be paid to patients' drug regimens to prevent the emergence of multidrug-resistant S. maltophilia isolates.

Tigecycline to treat Stenotrophomonas maltophilia ventilator-associated pneumonia in a trauma intensive care unit as a result of a drug shortage: A case series

WHAT IS KNOWN AND OBJECTIVE

Stenotrophomonas maltophilia is an intrinsically multidrug-resistant (MDR) organism which commonly presents as a respiratory tract infection. S. maltophilia is typically treated with high-dose sulfamethoxazole/trimethoprim (SMX/TMP). However, SMX/TMP and other treatment options for S. maltophilia can be limited because of resistance, allergy, adverse events or unavailability of the drug; use of novel agents may be necessary to adequately treat this MDR infection and overcome these limitations.

CASE DESCRIPTION

This small case series describes two patients who underwent treatment with tigecycline for ventilator-associated pneumonia (VAP) caused by S. maltophilia after admission to a trauma intensive care unit. At the time of admission for the two reported patients, a national drug shortage of intravenous (IV) SMX/TMP prevented its use. Tigecycline was chosen as a novel agent to treat S. maltophilia VAP based on culture and susceptibility data, and it was used successfully. Both patients showed clinical signs of improvement with eventual cure and discharge from the hospital after treatment with tigecycline, and one patient demonstrated confirmed microbiological cure with a negative repeat bronchoscopic bronchoalveolar lavage (BAL).

WHAT IS NEW AND CONCLUSION

To our knowledge, this small case series is the first documentation of utilizing tigecycline to treat S. maltophilia VAP in the United States. Although it likely should not be considered as a first-line agent, tigecycline proved to be an effective treatment option in the two cases described in the setting of a national drug shortage of the drug of choice.

In vitro combination of tigecycline with other antibiotics in Stenotrophomonas maltophilia isolates

Background/aim

The aim of this study was to determine the usefulness of tigecycline in combination treatment of Stenotrophomonas maltophilia infections by evaluating the in vitro synergistic effects of tigecycline with various antibiotics using the E-test method.

Materials and methods

Synergy testing by E-test was performed with various antibiotic combinations in 10 S. maltophilia isolates identified as a cause of infection. The antibiotics used in the study included tigecycline (TGC), cefoperazone-sulbactam (CPS), ceftazidime (TZ), levofloxacin (LEV), and trimethoprim-sulfamethoxazole (cotrimoxazole) (TS). Four different combinations (TGC-CPS, TGC-TZ, TGC-LEV, TGC-TS) were studied with the E-test synergy method.

Results

S. maltophilia isolates were found to have the highest level of susceptibility to trimethoprim-sulfamethoxazole, tigecycline, and levofloxacin. The fractional inhibitory concentration (FIC) index was calculated as FIC = MICAB/MICA + MICBA/MICB. The FIC index values were calculated and classified as synergistic (FIC < 0.5), additive (FIC = 0.5–1), indifferent (FIC = 1–4), and antagonistic (FIC > 4). According to FIC index values, synergy was found with the highest rate with TGC-CPS and TGC-LEV combinations (20%). Antagonistic activity was not found in any combination.

Conclusion

When trimethoprim-sulfamethoxazole cannot be used because of resistance or allergy, tigecycline alone or in combination may be included as an alternative option. Although in vitro results are promising, clinical data are required.

Antimicrobial susceptibility of stenotrophomonas maltophilia isolates from Korea, and the activity of antimicrobial combinations against the isolates

The aim of this study was to determine antimicrobial susceptibility of recent clinical Stenotrophomonas maltophilia isolates from Korea, and to compare the activity levels of several combinations of antimicrobials. A total of 206 non-duplicate clinical isolates of S. maltophilia was collected in 2010 from 11 university hospitals. Antimicrobial susceptibility testing was performed using the Clinical Laboratory Standards Institute agar dilution method. In vitro activity of antimicrobial combinations was tested using the checkerboard method. The susceptibility rates to trimethoprim-sulfamethoxazole and minocycline were 96% and 99%, respectively. The susceptibility rate to levofloxacin was 64%. All of four antimicrobial combinations showed synergy against many S. maltophilia isolates. A combination of trimethoprim-sulfamethoxazole plus ticarcillin-clavulanate was most synergistic among the combinations. None of the combinations showed antagonistic activity. Therefore, some of the combinations may be more useful than individual drugs in the treatment of S. maltophilia infection. Further clinical studies are warranted to validate our in vitro test results.

Tigecycline as a therapeutic option in Stenotrophomonas maltophilia infections

Trimethoprim-sulfamethoxazole (TMP-SMZ) is recommended as the treatment of choice for Stenotrophomonas maltophilia infections. However, when the administration of TMP-SMZ is not possible, alternative treatment options for S. maltophilia infections has not been clearly established. We compare the efficacy of tigecycline treatment with TMP-SMZ in nosocomial S. maltophilia infections during a 3-year period. For the treatment of S. maltophilia infection, 26 (57.8%) patients received TMP-SMZ and 19 (42.2%) patients received tigecycline. Culture positivity rate was 95.7% in TMP-SMZ group and 70.6% in tigecycline group at the seventh day (P = 0.028), whereas 26.3% versus 18.8% at the fourteenth day (P = 0.700). Clinical improvement was observed 69.2% in TMP-SMZ group and 68.4% in tigecycline group at the fourteenth day (P = 0.954). Mortality rates at the thirtieth day were respectively, 30.8 and 21.1% in TMP-SMZ and tigecycline groups (P = 0.517). There were no significant differences in mortality and clinical response rates between TMP-SMZ and tigecycline treatment. Tigecycline can be considered as an alternative option beyond TMP-SMZ in treatment of S. maltophilia infections.

Stenotrophomonas maltophilia infections in a general hospital: patient characteristics, antimicrobial susceptibility, and treatment outcome

Introduction

Stenotrophomonas maltophilia is acquiring increasing importance as a nosocomial pathogen.

Methods

We 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.

Results

Sixty-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.

Potential role of tigecycline in the treatment of community-acquired bacterial pneumonia

Tigecycline is a member of the glycylcycline class of antimicrobials, which is structurally similar to the tetracycline class. It demonstrates potent in vitro activity against causative pathogens that are most frequently isolated in patients with community-acquired bacterial pneumonia (CABP), including (but not limited to) Streptococcus pneumoniae (both penicillin-sensitive and -resistant strains), Haemophilus influenzae and Moraxella catarrhalis (including β-lactamase-producing strains), Klebsiella pneumoniae, and ‘atypical organisms’ (namely Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila). Comparative randomized clinical trials to date performed in hospitalized patients receiving tigecycline 100 mg intravenous (IV) × 1 and then 50 mg IV twice daily thereafter have demonstrated efficacy and safety comparable to the comparator agent. Major adverse effects were primarily gastrointestinal in nature. Tigecycline represents a parenteral monotherapy option in hospitalized patients with CABP (especially in patients unable to receive respiratory fluoroquinolones). However, alternate and/or additional therapies should be considered in patients with more severe forms of CABP in light of recent data of increased mortality in patients receiving tigecycline for other types of severe infection.