Stenotrophomonas species are non-fermentative Gram-negative bacteria that are widely distributed in environment and are highly resistant to numerous antibiotics. Thus, Stenotrophomonas serves as a reservoir of genes encoding antimicrobial resistance (AMR). The detection rate of Stenotrophomonas is rapidly increasing alongside their strengthening intrinsic ability to tolerate a variety of clinical antibiotics. This review illustrated the current genomics advances of antibiotic resistant Stenotrophomonas, highlighting the importance of precise identification and sequence editing. In addition, AMR diversity and transferability have been assessed by the developed bioinformatics tools. However, the working models of AMR in Stenotrophomonas are cryptic and urgently required to be determined. Comparative genomics is envisioned to facilitate the prevention and control of AMR, as well as to gain insights into bacterial adaptability and drug development.
Stenotrophomonas/genetics* ; Drug Resistance, Bacterial/genetics* ; Anti-Bacterial Agents/pharmacology* ; Gram-Negative Bacteria ; Genomics ; Microbial Sensitivity Tests

BACKGROUND: Prolonged transport or poor accessibility of blood culture equipment during night time may cause delayed entry of blood culture bottles. The effect of prestorage conditions on time to detection (TTD) for the blood culture was evaluated for the important gram-negative lactose nonfermentative bacteria. METHODS: Three different clinical isolates of Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and Burkholdera cepacia were diluted to 150 CFU/mL and 15 CFU/mL and inoculated into standard aerobic bottles. These were stored at 25℃ and at 37℃ for 0, 6, 12, 18, and 24 h. They were entered to BacT/Alert 3D Systems (bio-Mérieux Inc.) and TTD was monitored for each condition. RESULTS: At the 150 CFU/mL concentration, P. aeruginosa and A. baumannii showed false-negative for the bottles prestored at 37℃ for 18 h and 24 h, respectively. However, there was no false-negative for S. maltophilia or B. cepacia at any prestorage conditions. There was a significant decrease of TTD for all experimental microorganisms except P. aeruginosa prestored for 24 h either at 25℃ or at 37℃ (P< 0.05). CONCLUSION: Delayed entry may cause false-negative, especially for the high level of bacteremia of P. aeruginosa or A. baumannii when the bottles are stored at 37℃ for ≥18 h. TTD could be reduced by prestorage of the bottles at 37℃ until 12 h without false-negative for nonfermentative bacteria.
Acinetobacter baumannii ; Bacteremia ; Bacteria ; Lactose* ; Pseudomonas ; Pseudomonas aeruginosa ; Sepsis ; Stenotrophomonas maltophilia

PURPOSE: To describe the clinical manifestations, treatment results, and antibiotic susceptibility in 6 cases of Stenotrophomonas maltophilia endophthalmitis. METHODS: We retrospectively reviewed 6 eyes of 6 patients who were diagnosed with Stenotrophomonas maltophilia endophthalmitis. Specifically, we considered each patient's age, sex, past history, visual acuity, hypopyon, treatment, and prognosis. RESULTS: For our study, we considered patients treated during the period of January 2008 to December 2015. Stenotrophomonas maltophilia (6 eyes) was the second most common gram-negative bacteria cause of total bacterial endophthalmitis while Pseudomonas aeruginosa (14 eyes) was the most common gram-negative bacteria cause during the same period. Visual disturbance was the dominant symptom being found in all 6 patients. Other symptoms include ocular pain and hypopyon. The initial visual acuity was light perception (1 patient), hand motion (3 patients), finger count (1 patient), and 0.02 (1 patient). Excluding the 1 patient with light perception, the mean initial visual acuity was logMAR 1.72 (Snellen equivalent; 20/1,049). Overall, 5 patients underwent vitrectomy and intravitreal antibiotics injection, while, the remaining other patient was treated with intravitreal antibiotics injection, followed by vitrectomy. All 6 patients showed sensitivity to Ceftazidime and Levofloxacin and 2 patients showed sensitivity to Trimethoprim/Sulfamethoxazole. CONCLUSIONS: Stenotrophomonas maltophilia endophthalmitis was the second most common gram negative organism to cause endophthalmitis after cataract surgery. All 6 of the tested isolates were found to be sensitive to ceftazidime and levofloxacin. Urgent treatment outcomes were similar to previous reports.
Anti-Bacterial Agents ; Cataract* ; Ceftazidime ; Endophthalmitis* ; Fingers ; Gram-Negative Bacteria ; Hand ; Humans ; Levofloxacin ; Prognosis ; Pseudomonas aeruginosa ; Retrospective Studies ; Stenotrophomonas maltophilia* ; Stenotrophomonas* ; Visual Acuity ; Vitrectomy

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease, and bacterial infection plays a role in its pathogenesis. Bacteria secrete nanometer-sized extracellular vesicles (EVs), which may induce more immune dysfunction and inflammation than the bacteria themselves. We hypothesized that the microbiome of lung EVs might have distinct characteristics depending on the presence of COPD and smoking status. We analyzed and compared the microbiomes of 13 nonsmokers with normal spirometry, 13 smokers with normal spirometry (healthy smokers) and 13 patients with COPD by using 16S ribosomal RNA gene sequencing of surgical lung tissue and lung EVs. Subjects were matched for age and sex in all groups and for smoking levels in the COPD and healthy smoker groups. Each group included 12 men and 1 woman with the same mean age of 65.5 years. In all groups, EVs consistently showed more operational taxonomic units (OTUs) than lung tissue. In the healthy smoker and COPD groups, EVs had a higher Shannon index and a lower Simpson index than lung tissue and this trend was more prominent in the COPD group. Principal component analysis (PCA) showed clusters based on sample type rather than participants' clinical characteristics. Stenotrophomonas, Propionibacterium and Alicyclobacillus were the most commonly found genera. Firmicutes were highly present in the EVs of the COPD group compared with other samples or groups. Our analysis of the lung microbiome revealed that the bacterial communities present in the EVs and in the COPD group possessed distinct characteristics with differences in the OTUs, diversity indexes and PCA clustering.
Alicyclobacillus ; Bacteria ; Bacterial Infections ; Extracellular Vesicles* ; Female ; Firmicutes ; Humans ; Inflammation ; Lung* ; Male ; Microbiota* ; Passive Cutaneous Anaphylaxis ; Principal Component Analysis ; Propionibacterium ; Pulmonary Disease, Chronic Obstructive* ; RNA, Ribosomal, 16S ; Smoke ; Smoking ; Spirometry ; Stenotrophomonas

Stenotrophomonas maltophilia (S. maltophilia) is a rare, but globally emerging gram-negative multiple-drug-resistant organism usually found in a nosocomial setting in immunocompromised patients. To our best knowledge, computed tomography (CT) features of community-acquired S. maltophilia pneumonia have not been previously reported in an immunocompetent patient. Herein, we presented the CT findings of a previous healthy 56-year-old male with S. maltophilia pneumonia.
Humans ; Immunocompromised Host ; Male ; Middle Aged ; Pneumonia* ; Stenotrophomonas maltophilia* ; Stenotrophomonas*

Although trimethoprim-sulfamethoxazole (TMP-SXT) is considered the first-line therapy for Stenotrophomonas maltophilia infections, there is debate on the use of the bacteriostatic drug in serious infections, and recently, there has been an increasing occurrence of acquired resistance to TMP-SXT. In the present study, the effect of efflux pump inhibitors on the susceptibility of TMP-SXT and other antibiotics were investigated in S. maltophilia complex. The sul and/or dfrA genes were identified in only up to 27.8% of all 36 TMP-SXT-resistant S. maltophilia complex isolates. Thus, TMP-SXT resistance in S. maltophilia was not explained completely by the presence of sul and dfrA genes. Carbonyl cyanide-m-chlorophenylhydrazone (CCCP) decreased the minimum inhibitory concentration (MIC) of TMP-SXT by eight to 128 folds in all 14 isolates. In contrast, 2,4-dinitrophenol (DNP), phenyl-arginine-β-naphthylamide (PAβN), and reserpine did not reduce the MIC of TMP-SXT. In addition to TMP-SXT, slight decrease in MICs was observed for tigecycline and piperacillin/tazobactam by CCCP (by two folds) in one isolate. Although efflux pump may play a role in TMP-SXT resistance in S. maltophilia, inhibition of the efflux pump could be done by active proton pore.
2,4-Dinitrophenol ; Anti-Bacterial Agents ; Carbonyl Cyanide m-Chlorophenyl Hydrazone ; Korea* ; Microbial Sensitivity Tests ; Protons ; Reserpine ; Stenotrophomonas maltophilia* ; Stenotrophomonas* ; Thiram* ; Trimethoprim, Sulfamethoxazole Drug Combination*

No abstract available.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics ; Carrier Proteins/*genetics ; Drug Resistance, Multiple, Bacterial/*genetics ; Humans ; Stenotrophomonas maltophilia/drug effects/*genetics/isolation & purification ; Transposases/*genetics ; Trimethoprim, Sulfamethoxazole Drug Combination/*pharmacology

BACKGROUND: Stenotrophomonas maltophilia is one of several opportunistic pathogens of growing significance. Several studies on the molecular epidemiology of S. maltophilia have shown clinical isolates to be genetically diverse. MATERIALS AND METHODS: A total of 121 clinical isolates tentatively identified as S. malophilia from seven tertiary-care hospitals in Korea from 2007 to 2011 were included. Species and groups were identified using partial gyrB gene sequences and antimicrobial susceptibility testing was performed using a broth microdilution method. Multi locus variable number of tandem repeat analysis (MLVA) surveys are used for subtyping. RESULTS: Based on partial gyrB gene sequences, 118 isolates were identified as belonging to the S. maltophilia complex. For all S. maltophilia isolates, the resistance rates to trimethoprime-sulfamethoxazole (TMP/SMX) and levofloxacin were the highest (both, 30.5%). Resistance rate to ceftazidime was 28.0%. 11.0% and 11.9% of 118 S. maltophilia isolates displayed resistance to piperacillin/tazobactam and tigecycline, respectively. Clade 1 and Clade 2 were definitely distinguished from the data of MLVA with amplification of loci. All 118 isolates were classified into several clusters as its identification. CONCLUSION: Because of high resistance rates to TMP/SMX and levofloxacin, the clinical laboratory department should consider providing the data about other antimicrobial agents and treatment of S. maltophilia infections with a combination of antimicrobials can be considered in the current practice. The MLVA evaluated in this study provides a fast, portable, relatively low cost genotyping method that can be employed in genotypic linkage or transmission networks comparing to analysis of the gyrB gene.
Anti-Infective Agents ; Ceftazidime ; Korea ; Levofloxacin ; Methods ; Molecular Epidemiology ; Stenotrophomonas maltophilia* ; Stenotrophomonas* ; Tandem Repeat Sequences*

No abstract available.
Humans ; Stenotrophomonas maltophilia*

PURPOSE: Ventilator-associated pneumonia (VAP) is a serious threat in critically ill pediatric patients. Data regarding Stenotrophomonas maltophilia VAP in pediatric population is limited. We evaluated the clinical data of S. maltophilia associated VAP in critically ill pediatric patients. METHODS: A retrospective chart review was performed in pediatric patients 18 years old or younger who developed S. maltophilia associated VAP at Samsung Medical Center, Seoul Korea from January 2008 to December 2012. RESULTS: A total of 31 patients were identified S. maltophilia associated VAP. Median age was 8 months (range, 0.5 month to 16.6 years) and 13 patients were male (40.6%). Underlying illnesses were cardiologic diseases (n=11, 34.4%), hematologic oncologic malignancies (n=7, 25%), neurologic diseases (n=4, 12.5%), pulmonary diseases (n=3, 9.4%), and others (n=4, 12.5%). The median duration of ventilator use before S. maltophilia VAP diagnosis was 14 days (range, 4-256 days). Overall mortality at 30 days was 12.5% (4/32). CONCLUSIONS: S. maltophilia should be also considered as a possible pathogen for VAP in critically ill pediatric patients. Empiric antibiotic choice should include agents that are active against S. maltophilia in patients who are deteriorating on broad spectrum beta-lactam antimicrobial agents.
Anti-Infective Agents ; Child ; Critical Illness* ; Diagnosis ; Humans ; Korea ; Lung Diseases ; Male ; Mortality ; Pneumonia ; Pneumonia, Ventilator-Associated* ; Retrospective Studies* ; Seoul ; Stenotrophomonas maltophilia* ; Stenotrophomonas* ; Ventilators, Mechanical