Maltophilia Bacteremia Research Articles

Risk factors for mortality in patients with Stenotrophomonas maltophilia bacteremia and clinical impact of quinolone\u2013resistant strains

BackgroundStenotrophomonas maltophilia is an important nosocomial pathogen. This pathogen has intrinsic or acquired resistance to a number of antibiotics classes. Furthermore, Stenotrophomonas infections have been associated with high mortality, mainly in immunocompromised patients. Accordingly, we conducted a retrospective cohort study on the clinical data, microbiological characteristics, and outcomes of patients with S. maltophilia (SM) bacteremia.MethodsA retrospective cohort study was conducted at two tertiary care referral hospitals in Seoul, South Korea. Data were collected between January 2006 and December 2015 from electric medical records. Our analysis aimed to identify the risk factors associated with crude mortality, as well as the predictive factors of quinolone-resistant strains in SM bacteremia patients.ResultsA total of 126 bacteremia patients were enrolled in the study. The mortality rate was 65.1%. On multivariable analysis, hypoalbuminemia (odds ratio [OR], 5.090; 95% confidence interval [CI], 1.321–19.621; P = 0.018), hematologic malignancy (OR, 35.567; 95% CI, 2.517–502.515; P = 0.008) and quinolone-resistant strains (OR, 7.785; 95% CI, 1.278–47.432; P = 0.026) were independent risk factors for mortality. Alternatively, usage of an empirical regimen with quinolone (OR, 0.172; 95% CI, 0.034–0.875; P = 0.034) was an independent protective factor for mortality. The multivariable analysis of predictive factors revealed that high Charlson comorbidity index (OR, 1.190; 95% CI, 1.040–1.361; P = 0.011) and indwelling of a central venous catheter (CVC) (OR, 3.303; 95% CI, 1.194–9.139; P = 0.021) were independent predisposing factors associated with quinolone-resistant strains in SM bacteremia patients.ConclusionsOur findings suggest that a high Charlson comorbidity score and indwelling of a CVC were significantly independent predictors of quinolone-resistant strains in SM bacteremia patients. Therefore, we need to carefully consider the antibiotic use in SM bacteremia patients with these predictive factors.

Successful application of CytoSorb®hemadsorption in an immunocompromised teenager with collapsing glomerulopathy, acute respiratory distress syndrome, and sepsis

CytoSorb® hemadsorption is an adjunctive therapy in order to reduce elevated cytokine levels of interleukin-6, interleukin-1, and tumor necrosis factor alpha. Here we present a successful administration of CytoSorb® hemadsorption in an immunocompromised pediatric patient with collapsing glomerulopathy, acute respiratory distress syndrome, and sepsis. Clinical observations of one patient. Case report. Data sources are clinical observation during patient management and patient's medical records if needed. The patient's consent was obtained prior to the study. A 17-year-old male with diarrhea was admitted to the hospital and was later found to have elevated creatinine levels and proteinuria. The renal biopsy was consistent with collapsing glomerulopathy and treatment with multi immunosuppressive agents including corticosteroids, mycophenolate mofetil, and rituximab coupled with several courses of hemodialysis and plasmapheresis were administered. During the hospital stay, Stenotrophomonas maltophilia bacteremia from the blood and the catheter cultures were identified. No clinical response was achieved, and patient developed severe sepsis despite antibiotics, intravenous immunoglobulin, and supportive management including albumin, platelet and erythrocyte concentrations, and fresh frozen plasma. CytoSorb® hemadsorption was then added to the ongoing treatment for three consecutive days. Subsequent to CytoSorb® hemadsorption, immediate laboratory and clinical response were observed. This is the successful clinical report of an immunocompromised teenager with collapsing nephropathy, sepsis, and multi-organ dysfunction syndrome treated with a combination of renal replacement therapy and CytoSorb® hemadsorption. The usage of CytoSorb® hemadsorption represents a novel approach to improve survival of the patients with multiple organ dysfunction and sepsis.

Epidemiological Trends and Resistance Associated with Stenotrophomonas maltophilia Bacteremia: A 10-Year Retrospective Cohort Study in a Tertiary-Care Hospital in Hungary.

Stenotrophomonas maltophilia has been recognized as an emerging nosocomial pathogen in invasive infections of immunocompromised, severely debilitated patients with significant underlying illnesses. The first-choice drug in these infections is sulfamethoxazole-trimethoprim (SMX/TMP), and resistance to this antimicrobial is a daunting challenge for clinicians. The aim of this study was to assess the prevalence of S. maltophilia bacteremia and SMX/TMP-resistance levels at a tertiary-care university hospital. A total of 175 episodes of S. maltophilia bacteremia were identified (2008–2012: n = 82, 2013–2017: n = 93; p = 0.061), 52% of affected patients were 60 years of age, and had recent surgery, severe injuries or underlying conditions (malignant hematologic diseases and solid tumors) in their history. Sixteen percent of isolates were resistant to SMX/TMP (2008–2012: n = 13.8%, 2013–2017: n = 17.2%; p = 0.076), and out of the resistant strains, 32.7% were also resistant to levofloxacin and colistin. Our findings on the SMX/TMP-resistance were similar to global literature data.

Treatment Outcomes of Stenotrophomonas maltophilia Bacteremia in Critically Ill Children: A Multicenter Experience.

Stenotrophomonas maltophilia is a gram-negative opportunistic bacterium that may cause a myriad of clinical diseases in immunocompromised individuals. We aimed to describe the clinical characteristics, risk factors, mortality, and treatment of S. maltophilia bacteremia in critically ill children, a topic on which data are sparse. A multicenter observational retrospective study in which medical charts of critically ill children with S. maltophilia bacteremia were reviewed between 2012 and 2017. Data were collected from each of the four largest PICUs nationwide, allocated in tertiary medical centers to which children with complex conditions are referred regularly. A total of 68 suitable cases of S. maltophilia bacteremia were retrieved and reviewed. The total occurrence rate of S. maltophilia isolation had increased significantly during the study period (r = 0.65; p = 0.02). The crude mortality was 42%, and the attributed mortality was 18%. Significant risk factors for mortality were a longer length of hospital stay prior to infection (33 d in nonsurvivors vs 28 in survivors; p = 0.03), a nosocomial source of infection (p = 0.02), presentation with septic shock (p < 0.001), and treatment with chemotherapy (p = 0.007) or carbapenem antibiotics (p = 0.05) prior to culture retrieval. On multivariate analysis, septic shock (odds ratio, 14.6; 95% CI, 1.45-147.05; p = 0.023) and being treated with chemotherapy prior to infection (odds ratio, 5.2; 95% CI, 1.59-17.19; p = 0.006)] were associated with mortality. The combination of ciprofloxacin, trimethoprim-sulfamethoxazole, and minocycline resulted in the longest survival time (p < 0.01). The significant attributed mortality associated with S. maltophilia bacteremia in critically ill children calls for an aggressive therapeutic approach. The findings of this investigation favor a combination of trimethoprim-sulfamethoxazole, ciprofloxacin, and minocycline.

1042. Stenotrophomans maltophilia Bacteremia, A 10-Year Tertiary Center Experience

Background Stenotrophomonas maltophilia is a hospital acquired infection that is associated with high morbidity and mortality. There has been a reported rise in S. maltophilia infections, presumed secondary to the increase in the population at risk.MethodsWe retrospectively reviewed all hospitalized adult patients in Mayo Clinic, MN with S. maltophilia bacteremia from January 2008 through January 2018. We analyzed patient population and described patients at risk, sources of infection, and changes in antimicrobial susceptibility profile.ResultsA total of 94 patients were analyzed, including 52 males, median age of 56 (46–65.75 IQR). The population included 60 infections in those with malignancies and 30 infections in transplant recipients. At presentation, 58 (61.7%) were febrile, while 54 (58.1%) presented with hemodynamic instability. Majority (70.2%) received broad-spectrum antimicrobials within 2 weeks of presentation. The most common source was catheter associated infection (n = 60), 15 cases were secondary to gastrointestinal, and 9 due to a pulmonary source. Almost half, 46 (48.9%) required ICU admission. Two patients were diagnosed with endocarditis. Most isolates, 61(64.9%), were resistant to ceftazidime, 2 (2.2%) resistant to TMP/SMX and 20 (21.5%) were resistant to levofloxacin. Exposure to a quinolone in the 30 days prior to presentation did not impact fluoroquinolone resistance. Five patients were exposed to Trimethoprim/Sulfamethoxazole (TMP/SMX) in the 30 days prior to presentation, which was associated with higher rate of TMP/SMX resistance compared with those without exposure (80% vs. 98.8%, P = 0.004). Treatment options commonly included combination therapy, and TMP/SMX was a primary agent used in the majority, 59 (62.8%). All-cause in-hospital mortality was 26.6%. All-cause mortality was lower for line associated infections (16.67%) vs. other sources (44.12%) with P = 0.0038.Conclusion S. maltophilia bacteremia should be considered in hospitalized patients with recent use of broad-spectrum antibiotics. Although TMP/SMX continues to have reliable activity, use of empiric ceftazidime pending susceptibility testing should be avoided as trend toward increasing resistance is noted. We noted a drop in TMP/SMX susceptibility in those with recent reported TMP/SMX use. Disclosures All authors: No reported disclosures.

1053. Biofilm Production and Clinical Characteristics of S. maltophilia Causing Persistent or Relapsing Bacteremia

BackgroundThis study aimed to identify clinical or microbiological factors related to persistence or recurrence of Stenotrophomonas maltophilia bacteremia in adult patients.Methods S. maltophilia isolated from blood in two tertiary hospitals between 2011 and 2017 were investigated. Persistent bacteremia was defined as the consecutive blood culture positive for ≥5 days after initiation of appropriate antibiotics therapy. Relapse was defined as isolation of S. maltophilia from blood after completion of antibiotics treatment for the first episode of bacteremia. Biofilm formation was assessed in 96-well polystyrene plate with Trypticase Soy Broth using 0.5% crystal violet staining. The presence of smf-1 gene was detected by polymerase chain reaction.ResultsOf total 100 patients with S. maltophilia bacteremia, 10 of persistent, 8 of relapsing, and 46 of nonpersistent, nonrelapsing cases were investigated. The presence of indwelling urinary catheter (P = 0.011), nasogastric tube (P = 0.003), mechanical ventilator treatment (P = 0.001), and previous colonization of S. maltophilia (P = 0.016) were more frequently observed in patients with persistent bacteremia compared with nonpersistent, nonrelapsing bacteremia cases. In patients with relapsing bacteremia, hematologic malignancy (P = 0.022), neutropenia (P = 0.001), and concomitant isolation of S. maltophilia in clinical samples other than blood (P = 0.041) were more common than nonpersistent, nonrelapsing bacteremia patients. Catheter-related infection (37.0%) followed by pneumonia (28.3%) was the most common primary focus of nonpersistent, nonrelapsing bacteremia whereas pneumonia was the most frequent cause of bacteremia in both of persistent and relapsing cases (40.0% and 50.0%). Most of isolates (63 of 64) were susceptible to cotrimoxazole. The resistance to levofloxacin were comparable among isolates from persistent, relapsing and nonpersistent, nonrelapsing cases (10.0% vs. 12.5% vs. 15.2%, P = 0.988). Biofilm formation ability was not significantly different between three groups (optical density at 595, mean ± SD, 0.69 ± 0.34 vs. 0.78 ± 0.33 vs. 0.70 ± 0.33, P = 0.529). The smf-1 gene was found in all isolates.ConclusionMore careful treatment approaches to patients with risk factors for S.maltophilia treatment failure should be warranted.Disclosures All authors: No reported disclosures.

Pathogenic significance of hemorrhagic pneumonia in hematologic malignancy patients with Stenotrophomonas maltophilia bacteremia: clinical and microbiological analysis

Hemorrhagic pneumonia (HP) is known as the clinical manifestation of Stenotrophomonas maltophilia infection, while catheter-related blood stream infection (CRBSI) is the common clinical presentation of S. maltophilia bacteremia (SMB). The purpose of this study is to evaluate the risk factors for mortality in hematologic malignancy patients with SMB and to analyze clinical and microbiological characteristics of HP associated with SMB and CRBSI. SMB cases of patients with a hematologic malignancy were collected from 2006 through 2016. The overall 30-day mortality rate and mortality risk factors were assessed. The expression of major virulence-associated genes from S. maltophilia isolates, which included genes encoding type-1 fimbriae (smf-1), proteases (StmPr1 and StmPr2), and esterase (Smlt3773), from the blood of patients with HP and CRBSI was investigated. The phenotypic and genotypic traits were also compared. A total of 118 cases of SMB were included. The overall 30-day mortality rate was 61.0%. A multivariable analysis showed that HP was the most important risk factor for mortality (adjusted OR = 106.41; 95% CI = 5.18-2184.55). Although no statistical significance was observed in microbiological analysis, isolates from HP have a trend toward a higher protease activity (93.8% vs. 73.3%, P = 0.172). Clinical analysis showed that thrombocytopenia (P = 0.037) and prolonged neutropenia (P = 0.043) were significant factors associated with HP. Our data, which includes hematologic malignancy patients with SMB, suggest that HP is the significant risk factor for mortality and that the unique characteristics of patients and microbes contribute to the pathogenesis.

Comparison of clinical characteristics of bacteremia from Elizabethkingia meningoseptica and other carbapenem-resistant, non-fermenting Gram-negative bacilli at a tertiary medical center.

Acquired carbapenem resistance among non-fermenting Gram-negative bacilli (NFGNB), such as Pseudomonas aeruginosa and Acinetobacter calcoaceticus-Acinetobacter baumannii complex (ACB complex), is a serious problem in nosocomial infections. We previously reported that patients infected with the intrinsically carbapenem-resistant Elizabethkingia meningoseptica were associated with high mortality. However, little information is available regarding the clinical outcome of E. meningoseptica bacteremia when compared to that of other carbapenem-resistant NFGNB. We conducted an observational study that included consecutive patients with E. meningoseptica, carbapenem-resistant ACB complex, carbapenem-resistant P. aeruginosa, and Stenotrophomonas maltophilia bacteremia at a Taiwanese medical center in 2015. We compared the clinical characteristics and outcomes between patients with E. meningoseptica bacteremia and those with other carbapenem-resistant NFGNB bacteremia. We identified 30 patients with E. meningoseptica, 71 with carbapenem-resistant ACB complex, 25 with S. maltophilia, and 17 with carbapenem-resistant P. aeruginosa bacteremia. The clinical characteristics, disease severity, and previous antibiotic exposures were similar between patients with bacteremia either due to E. meningoseptica or other carbapenem-resistant NFGNB. Patients with E. meningoseptica bacteremia had a higher rate of appropriate empirical antibiotics than those with other carbapenem-resistant NFGNB and was less associated with central venous catheterization. The 28-day mortality rates were similar between patients with E. meningoseptica and the other carbapenem-resistant NFGNB bacteremia (46.7% vs 46%, p=0.949). The mortality rate of E. meningoseptica bacteremia was as high as other carbapenem-resistant NFGNB infections. The emerging E. meningoseptica infection calls for active surveillance and continued awareness from clinical physicians for this serious carbapenem-resistant infection.

Stenotrophomonas maltophilia bacteremia and pneumonia at a tertiary-care oncology center: a review of 16years.

The aim of this study was to describe the clinical characteristics and antimicrobial patterns of Stenotrophomonas maltophilia bloodstream infections (BSI) and pneumonia episodes in patients with cancer. Patients with S. maltophilia BSI or pneumonia admitted from 1 Jan. 2000 to 31 Dec. 2016 were identified at the Instituto Nacional de Cancerología (INCan), a tertiary-care oncology hospital in Mexico City. During the study period, there were 171 isolates identified. The mean age of the whole group was 46.9 ± 17.4years; 99 (57.9%) were women. There were 95 BSI: 64 ambulatory catheter-related BSI (CRBSI), 20 nosocomial CRBSI, and 11 secondary BSI. Mortality was higher in nosocomial CRBSI (40%) vs. that in ambulatory CRBSI (7.8%) (p = 0.001). There were 76 pneumonia episodes; all were nosocomial acquired; 46 (60.5%) ventilator-associated. From all the group, nine strains (5.2%) were resistant to sulfamethoxazole/trimethoprim/(SMX/TMP). At the first month, 54 patients (31.6%) have died, 38 due to pneumonia (70%) and 16 due to BSI (30%, p < 0.001). Multivariate analysis showed that removal of central venous catheter was associated with a favorable outcome in patients with bacteremia. For patients with pneumonia, age ≥ 65years and inappropriate antimicrobial treatment were risk factors associated with 30-day mortality. S. maltophilia related with ambulatory CRBSI have a better prognosis than other sources of BSI. Older patients with pneumonia who do not receive appropriate antibiotics have higher mortality. SMX/TMP is still the antibiotic of choice.

Predictive implications of albumin and C-reactive protein for progression to pneumonia and poor prognosis in Stenotrophomonas maltophilia bacteremia following allogeneic hematopoietic stem cell transplantation

BackgroundStenotrophomonas maltophilia (S. maltophilia) bacteremia causes significant morbidity and mortality in immunocompromised hosts. However, incidence and risk factors for mortality in S. maltophilia bacteremia following allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain controversial. The primary aim of this study is to clarify factors associated with poor prognosis of allo-HSCT recipients with S. maltophilia bacteremia.MethodsFrom January 2005 to December 2014, patients with hematological diseases and S. maltophilia bacteremia at a single transplantation center in Japan were examined for incidence and 90-day mortality. Prognostic factors associated with 90-day mortality among allo-HSCT recipients were analyzed by log-rank test, and significant variables in the univariate analysis were included in the multivariate Cox proportional-hazards regression model.ResultsA total of 65 patients, including 47 patients undergoing allo-HSCT, developed S. maltophilia bacteremia. The incidence of S. maltophilia bacteremia was significantly higher in allo-HSCT recipients compared to patients not receiving allo-HSCT (6.53 vs. 0.36 per 100 admissions, respectively; p < 0.01). The overall 90-day mortality in allo-HSCT recipients was 43%. Independent risk factors for 90-day mortality were low serum albumin (<3.0 g/dl) (HR = 10.86; 95% CI, 3.27–36.12) and high serum C-reactive protein (CRP) (≥10.0 mg/dl) (HR = 3.28; 95% CI, 1.00–10.72). Among 9 patients with both high CRP and low albumin, 5 had pneumonia at the onset of bacteremia and the remaining 4 patients developed pneumonia in a median of 3 days (range, 1 to 8 days) even under effective treatment. All 9 patients eventually died in a median of 2 days (range, 2 to 32 days). The probabilities of developing pneumonia in patients with or without high CRP and low albumin levels were 100% (9/9) and 10.5% (4/38), respectively (p < 0.01).ConclusionsAllo-HSCT recipients had higher rates of S. maltophilia bacteremia than did patients not receiving allo-HSCT. High serum CRP and low serum albumin at the onset of bacteremia are predictive of disease progression to pneumonia and poor prognosis.

Evaluation of trimethoprim-sulfamethoxazole based combination therapy against Stenotrophomonas maltophilia: in vitro effects and clinical efficacy in cancer patients

ObjectivesThe aim of this study was to evaluate the in vitro effects and clinical efficacies of trimethoprim-sulfamethoxazole (SXT) combined with other antimicrobial agents against Stenotrophomonas maltophilia. MethodsIn vitro analysis was conducted on 89 S. maltophilia strains isolated from blood and the respiratory tract between June 2012 and October 2014. Levofloxacin (LVX), ticarcillin-clavulanic acid (TIM), and minocycline (MIN) were selected for an examination of their effects when individually combined with SXT by the checkerboard method. In addition, 29 S. maltophilia bacteremia cases were reviewed and the clinical efficacies of SXT-based combination therapies were analyzed. ResultsSXT+LVX showed synergy in 21, no interactions in 61, and antagonism in 7. SXT+TIM showed synergy in 71, and no interactions in 18. SXT+MIN showed synergy in 10, and no interactions in 79. The review of clinical data indicated that a combination of SXT+fluoroquinolone was not associated with improved prognosis compared with monotherapy. ConclusionsThe in vitro data indicated that SXT+TIM had beneficial microbiological effects and was not antagonistic. Our in vitro and clinical data analyses do not support the routine use of SXT+fluoroquinolone combination therapy for S. maltophilia infection.

Molecular epidemiology and characteristics of 16 cases with Stenotrophomonas maltophilia bacteraemia in pediatric Intensive Care Units.

Recently, Stenotrophomonas maltophilia has increasingly been reported as an important nosocomial opportunistic pathogen. Limited therapeutic options of S. maltophilia infections demand early identification and knowledge about the probable risk factors for controlling its spread. The present study aimed to investigate the risk factors and trend of antibiotic susceptibility, along with genetic analysis in bacteraemia cases at pediatric intensive care units (PICUs). A total of 16 S. maltophilia isolates were obtained, during 4 months from August to November 2015, from blood cultures of patients admitted to PICUs at Nemazee teaching hospital, Shiraz, Iran. S. maltophilia isolates were identified by conventional tests and confirmed by specific PCR primers. Minimum inhibitory concentrations (MICs) were determined by the MIC strip test as described by the Clinical and Laboratory Standards Institute's (CLSI) recommendation. The genetic relatedness among the isolates was assessed by ERIC-PCR. All isolates of S. maltophilia were susceptible to ciprofloxacin, co-trimoxazole and colistin, and only 1 (6.2%) isolate was resistant against ceftazidime. The MIC50/MIC90 of ciprofloxacin, trimethoprim/sulfamethoxazole, colistin and ceftazidime was 0.25/0.38 mg/mL, 0.125/0.19 mg/mL, 0.25/0.38 mg/mL, and 2/4 mg/mL, respectively. Genotypic analysis of ERIC-PCR results revealed two distinct types of pattern. Interestingly, the only ceftazidime resistant isolate showed different patterns with other isolates. Our findings indicated the importance of routine surveillance in infection control, since early detection of pathogens prevented the spread of nosocomial infections and granted effectiveness to care practices. Moreover, the results suggest that the routine drug of choice for S. maltophilia was mostly active against clinical isolates in our region.

Clinical Characteristics of Stenotrophomonas maltophilia Bacteremia: A Regional Report and a Review of a Japanese Case Series.

Objective Stenotrophomonas maltophilia is an emerging nosocomial pathogen that causes fatal infections in critically ill or immunocompromised patients. S. maltophilia bacteremia (SMB) is a rare condition, and its clinical characteristics in Japanese settings are not well known. Methods The medical charts of patients with SMB were retrospectively reviewed at two medical facilities (Okayama University Hospital and Tsuyama Chuo Hospital) for seven years. The data were analyzed along with those previously reported from other Japanese facilities. Result A total of 181 patients (110 men and 71 women) were evaluated. The major underlying diseases included hematologic malignancy (36.5%), solid organ malignancy (25.4%), and neutropenia (31.5%). The recent use of carbapenem was seen in 56.9% of the cases in total, and more than one-third of the patients in our hospitals were treated with carbapenem at the onset of SMB. Of 28 (63.6%) of 44 cases treated for S. maltophilia, those who did not survive were more likely to have been treated with broad-spectrum antibiotics. A multivariate analysis revealed that a higher updated Charlson Comorbidity Index [odds ratio (95% confidence interval), 1.75 (1.11-2.75); p=0.015] and intubation [odds ratio (95% confidence interval), 12.6 (1.62-97.9); p=0.016] were associated with mortality in our cases. Pathogens were often resistant to ceftazidime but susceptible to minocycline, trimethoprim/sulfamethoxazole, and fluoroquinolones. The overall mortality rates within 30 and 90 days were 37.5% and 62.5%, respectively. Conclusion The clinical characteristics of SMB in Japanese cases were similar to those reported from other countries. Clinicians should be aware that breakthrough infection by S. maltophilia may occur during administration of carbapenem.

Comparative effectiveness of Trimethoprim-Sulfamethoxazole vs. Levofloxacin for Stenotrophomonas maltophilia Bacteremia: Analysis of targeted therapy at 90 US Hospitals, 2000–2014

Comparative effectiveness of Trimethoprim-Sulfamethoxazole vs. Levofloxacin for Stenotrophomonas maltophilia Bacteremia: Analysis of targeted therapy at 90 US Hospitals, 2000–2014

Predictive Factors Associated With Stenotrophomonas maltophilia Bacteremia Infected by Antibiotic-Resistant Strains

Predictive Factors Associated With Stenotrophomonas maltophilia Bacteremia Infected by Antibiotic-Resistant Strains

Risk factors for mortality in patients with Stenotrophomonas maltophilia bacteremia.

Stenotrophomonas maltophilia is a nosocomial pathogen associated with high morbidity and mortality, particularly in immunocompromised or critically ill patients. In this study, we investigated the risk factors for mortality in patients with S. maltophilia bacteremia.Retrospectively, medical records from all patients with S. maltophilia bacteremia between December 2005 and 2014 at Severance Hospital, a 2000-bed tertiary care hospital in Seoul, Korea, were reviewed. Analysis was performed to identify factors associated with 28-day mortality.In total, 142 bacteremia patients were enrolled in this study. The overall 28-day mortality rate was 36.6%. Based on the univariate analysis, hematologic malignancy (P = 0.015), Sepsis-related Organ Failure Assessment (SOFA) score (P < 0.001) and the removal of a central venous catheter (CVC) (P = 0.040) were significantly related to mortality. In the intensive care unit patients, the Acute Physiology and Chronic Health Evaluation II score (P = 0.001) also had significance. Based on the multivariate analysis, the SOFA score (odds ratio [OR] = 1.323; 95% confidence interval [CI]: 1.159, 1.509; P < 0.001) and removal of the CVC (OR = 0.330; 95% CI: 0.109, 0.996; P = 0.049) were independent factors associated with mortality.Our results suggest that removing a CVC may considerably reduce mortality in patients with S. maltophilia bacteremia.

Retrospective Evaluation of Incidence and Prognostic Factors for Stenotrophomonas Maltophilia Bacteremia Following Allogeneic Hematopoietic Stem Cell Transplantation

Background:Stenotrophomonas maltophilia (S. maltophilia) bacteremia in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients is associated with significant morbidity and mortality rate. Although several predisposing risk factors for S. maltophilia bacteremia following allo-HSCT have been identified, there is no agreement or consistency among clinical factors on whether to predict treatment outcome or not.Methods: From January 2005 to December 2014, data on demographic and clinical characteristics, treatment and outcome were collected for all S. maltophilia bacteremia cases observed at an 800-bed tertiary care hospital with a 32-bed transplantation ward. They were analyzed with respect to incidence and 90-day mortality. The risk factors associated with 90-day mortality of allo-HSCT recipients with S. maltophilia bacteremia were also analyzed by Log-rank test according to age, sex, neutropenia, platelet, C-reactive protein (CRP), albumin, creatinine, engraftment, graft-versus-host disease, primary disease risk, severe sepsis or septic shock, complicated infection, and conditioning intensity. Significant variables in the univariate analysis were included in the multivariate Cox proportional-hazards regression model.Results: A total of 65 patients (47 patients in allo-HSCT recipients and 18 patients in non allo-HSCT recipients) with S. maltophilia bacteremia were identified, with the incidence of 1.17 cases per 100 admissions and 0.35 cases per 1000 patient-days. The incidence was significantly high in allo-HSCT recipients compared to non allo-HSCT recipients (6.53 vs 0.36 per 100 admission, p<0.001) and was apparently increased during the last 2010 to 5 years (1.79 vs 0.63 per 100 admission, p<0.001). The 90-day mortality including all causes of death in allo-HSCT recipients and non allo-HSCT recipients were 43% and 28%, respectively.In multivariate analysis, the independent risk factors associated with 90-day mortality of allo-HSCT recipients were a high CRP level (>=10.0 mg/dl) (adjusted hazard ratio [aHR], 4.43; 95% confidence interval [CI], 1.55-12.63; p<0.001) and a low albumin level (<3.0 g/dl) (aHR, 12.67; 95%CI, 3.94-40.71; p<0.001) (Figure 1, 2, and Table). Patients with high CRP or low albumin level were likely to carry the complicated infection or the failure of the initial antimicrobial therapy (P =0.001). Among nine patients with high CRP and low albumin level, five of them had pneumonia at the onset of bacteremia and the others developed pneumonia under effective treatment in median three-days.Conclusion: The incidence of S. maltophilia bacteremia was increasing during the last 5 years and 90-day mortality was high in allo-HSCT setting compared to non allo-HSCT setting. Higher CRP value or lower albumin level as a result of more complicated infection may predict poor prognosis of patients with S. maltophilia bacteremia. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A Study in the Clinical Characteristics of Stenotrophomonas Maltophilia Bacteremia in Hematological Patients

Introduction: Stenotrophomonas maltophilia is an important nosocomial pathogen, particularly in immunocompromised patients, especially in patients with hematologic diseases.Methods: We reviewed the clinical characteristics and prognosis of patients with S. maltophilia bacteremia over a five-year period from January 2010 to December 2014. Species identification was performed using the automated Vitek 2 compact system (bioMe rieux).Results: The incidence of S. maltophilia bacteremia was 25.1 per 10 000 admissions in our study. Thirty-four patients (median age: 34 years; 64.7% males) with S. maltophilia bacteremia were analyzed. The S. maltophilia bacteremia related 30-day mortality was 44.1%. Risk factors associated with mortality in patients with S. maltophilia infection in the univariate and multivariate analysis were represented in Tables I and II. In the univariate analysis, risk factors included T>39.0¡æ, septic shock, respiratory failure and non-remission after treatment for primary hematological diseases (P <0.05). In the multivariate analysis, respiratory failure and non-remission status after treatment forhematological diseases were independent prognostic factors for mortality. In vitro susceptibility was higher to ciprofloxacin(82.4%), ceftazidime(70.6%), sulbactam and cefoperazone(58.8%), which was shown in Table III.Conclusion: Combination regimens with ciprofloxacin and ceftazidime, or sulbactam and cefoperazone could be alternative treatment. Novel antibiotics are required for treatment of S. maltophilia infection, as well as infection control practices of environmental reserves, rapid detection of pathogens, risk stratification strategy and appropriate treatment for primary hematologic malignancies, which might conjointly contribute to better survival outcome of S. maltophilia bacteremia.Univariate analysis of prognostic factors associated with mortality from S. maltophilia bacteremiaTable 1FactorMortalityHR95%CIP-valueWithfactorWithoutfactorT>39.0¡æ75%16.7%2.4901.318-4.7040.005Septic shock90.0%25.0%2.5441.473-4.3930.001Respiratory failure100%20.8%4.6722.366-9.2250.000Treatment outcome for hematological diseasesRemission10.0%85.7%0.2470.116-0.5260.000HR, hazard ratio; CI, confidence interval; HSCT, Hematopoietic stem cell transplantationTable 2Multivariate analysis of prognostic factors associated with mortality from S. maltophilia bacteremiaFactorHR95%CIP-valueRespiratory failure2.6881.297-5.5690.008Remission after treatment for hematological diseases0.3670.153-0.8790.025HR, hazard ratio; CI, confidence intervalTable 3Susceptibility pattern of the 34 patients with Stenotrophomonas maltophilia bacteremiaAntimicrobial agentsS (%)I (%)Ceftazidime24(70.6%)1(2.9%)Cefoperazone19(44.1%)6(17.6%)Sulbactam and Cefoperazone20(58.8%)5(14.7%)Piperacillin7(20.6%)6(17.6%)Piperacillin-Tazobactam11(32.3%)7(20.6%)Amikacin6(17.6%)0(0%)Ciprofloxacin28(82.4%)1(2.9%)S, susceptible; I, intermediately susceptible. DisclosuresNo relevant conflicts of interest to declare.

Characteristics of Stenotrophomonas maltophilia bacteremia in children.

Empiric antimicrobial coverage in compromised hosts commonly includes pseudomonal coverage but often lacks coverage against Stenotrophomonas maltophilia. Identification of risk factors specific for S. maltophilia infection may lead to prompt initiation of appropriate antibiotics and improved outcome. We conducted a retrospective analysis of pediatric patients with bacteremia due to S. maltophilia or Pseudomonas aeruginosa from April 2002 to July 2014 at a tertiary children's hospital. Patient demographics, underlying disease, clinical course, and treatment were compared between S. maltophilia and P. aeruginosa cases. Nineteen children with S. maltophilia bacteremia and 49 children with P. aeruginosa bacteremia were identified. On multivariate logistic regression analysis, use of carbapenems within 7 days prior to onset (OR, 5.00; 95%CI: 1.25-20.07; P = 0.02) and previous intensive care unit stay (OR, 3.75; 95%CI: 1.13-12.47; P = 0.03) were significantly associated with S. maltophilia bacteremia compared with P. aeruginosa bacteremia. The majority of the S. maltophilia bacteremia patients had central line-associated bloodstream infection (79%), compared with the P. aeruginosa bacteremia patients (37%, P = 0.002). There were nine children (47%) who had polymicrobial infection in the S. maltophilia bacteremia group, in contrast to four (8%) in the P. aeruginosa bacteremia group (OR, 10.13; 95%CI: 2.59-39.56; P = 0.001). Consultation with an infectious diseases physician was associated with a lower rate of persistent S. maltophilia bacteremia (P = 0.04). Stenotrophomonas maltophilia should be considered in breakthrough bacteremia in pediatric patients who receive carbapenems within 7 days prior to onset.

Risk Factors Associated with Stenotrophomonas maltophilia Bacteremia: A Matched Case-Control Study.

Stenotrophomonas maltophilia is an important nosocomial bacterial pathogen, as is Pseudomonas aeruginosa. Differentiation of these bacteria as bacteremic agents is critical in the clinical setting and to define a therapeutic strategy; however, the associated factors and prognosis for S. maltophilia bacteremia have not been fully evaluated to adequately characterize these factors. We first conducted a matched case-control study to clarify these questions. A total of 30 case patients with S. maltophilia bacteremia were compared with 30 control patients with P. aeruginosa bacteremia between January 2005 and August 2014, according to matching criteria based on underlying disease, age, and gender. The 30-day mortality rate for the case patients (53.3%) was significantly higher than that of the control group (30.0%) (P = 0.047, using the log-rank test). Conditional logistic regression analysis showed that the predisposing factors specific for the detection of S. maltophilia bacteremia were indwelling artificial products other than a central venous catheter, ICU stay, and previous use of anti-MRSA drugs. The high severity of illness was associated with mortality in both case and control patients. Interestingly, inappropriate antimicrobial treatment was an additional independent risk factor for mortality in only the case patients with S. maltophilia bacteremia (odds ratio = 13.64, P = 0.048). Monotherapy with fluoroquinolones inactive against the S. maltophilia isolates was mainly responsible for the inappropriate treatment. These results suggest that more precise prediction and more appropriate treatment might improve the prognosis of patients with S. maltophilia bacteremia.