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

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

PURPOSE: In the present study, we cultured specimens and evaluated the types of bacteria existing at the stent and their antibiotic sensitivities from removed nasolacrimal polyurethane stents (Song's stents) due to recurrent inflammation or Song's stent obstruction after placement of Song's stents without fluoroscopic guidance for the treatment of obstructed nasolacrimal ducts. METHODS: In 11 eyes of 11 patients who received Song's stent intubation to resolve nasolacrimal duct obstruction, the Song's stents were removed due to either recurred symptoms, signs of chronic dacryocystitis, or tube obstruction. Song's stents were cultured to identify bacteria and tested for their antibiotic sensitivity. RESULTS: The Song's stent removal was from 3 years 7 months to 17 years 1 month after intubation, thus the average duration was 10 years. The species of cultured bacteria were Pseudomonas in 7 eyes, Staphylococcus aureus in 2 eyes, and Stenotrophomonas maltophilia in 2 eyes. In antibiotics sensitivity tests, 5 of 7 eyes with Pseudomonas were resistant to trimethoprime/sulfamethoxazole (Bactrim(R), Roche, Basel, Switzerland) and 2 eyes with Staphylococcus aureus were resistant to penicillin. Ten eyes underwent silicone tube intubation simultaneously during Song's stent removal and 1 eye underwent Song's stent removal only. CONCLUSIONS: The most common bacteriological etiology of Song's stent obstruction or recurrent inflammation is Pseudomonas species. The use of efficient antibiotics is necessary to avoid antibiotic intolerance and simultaneous silicone tube intubation during Song's stent removal and is essential for the management of epiphora.
Anti-Bacterial Agents ; Bacteria ; Dacryocystitis ; Humans ; Inflammation ; Intubation ; Lacrimal Apparatus Diseases ; Nasolacrimal Duct* ; Penicillins ; Polyurethanes* ; Pseudomonas ; Silicones ; Staphylococcus aureus ; Stenotrophomonas maltophilia ; Stents*

Emerging resistance to trimethoprim/sulfamethoxazole (SXT) poses a serious threat to the treatment of Stenotrophomonas maltophilia infections. We determined the prevalence and molecular characteristics of acquired SXT resistance in recent clinical S. maltophilia isolates obtained from Korea. A total of 252 clinical isolates of S. maltophilia were collected from 10 university hospitals in Korea between 2009 and 2010. Antimicrobial susceptibility was determined by using the CLSI agar dilution method. The sul1, sul2, and sul3 genes, integrons, insertion sequence common region (ISCR) elements, and dfrA genes were detected using PCR. The presence of the sul1 gene and integrons was confirmed through sequence analysis. Among the 32 SXT-resistant isolates, sul1 was detected in 23 isolates (72%), all of which demonstrated high-level resistance (> or =64 mg/L) to SXT. The sul1 gene (varying in size and structure) was linked to class 1 integrons in 15 of the 23 isolates (65%) harboring this gene. None of the SXT-susceptible isolates or the SXT-resistant isolates with a minimum inhibitory concentration of 4 and 8 mg/L were positive for sul1. Moreover, the sul2, sul3, and dfrA genes or the ISCR elements were not detected. The sul1 gene may play an important role in the high-level SXT resistance observed in S. maltophilia.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics ; Drug Resistance, Bacterial/genetics ; Gram-Negative Bacterial Infections/microbiology/pathology ; Humans ; Integrons/*genetics ; Microbial Sensitivity Tests ; Stenotrophomonas maltophilia/*drug effects/genetics/isolation & purification ; Trimethoprim, Sulfamethoxazole Drug Combination/*pharmacology