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

Risk factors for mortality in Stenotrophomonas maltophilia bacteremia - a meta-analysis

BACKGROUND

Stenotrophomonas maltophilia (S. maltophilia) is a nosocomial pathogen causing life-threatening invasive infections with a high mortality rate in some patient populations, especially those who are severely ill or immunocompromised. There is a need for data on mortality in patients with S. maltophilia bacteremia.

OBJECTIVE

In this meta-analysis, we aimed to investigate risk factors for mortality in S. maltophilia bacteremia.

METHODS

Studies comparing patients who died from S. maltophilia bacteremia with patients who survived were considered for inclusion. Studies were included if they reported one or more risk factors for mortality. Mortality risk factors included clinical predisposing factors, predisposing comorbidities and appropriateness of antibiotic therapy.

RESULTS

Nineteen studies with 1248 patients were included in the meta-analysis. Five hundred and six (40.5%) patients died. The following risk factors for mortality were identified: ICU admission, septic shock, need for mechanical ventilation, indwelling central venous catheter, neutropenia, comorbid hematological malignancies, chronic kidney disease, inappropriate antimicrobial therapy and prior antibiotic use.

CONCLUSIONS

Appropriate antimicrobial therapy had a protective effect against mortality in S. maltophilia bacteremia. Indwelling central venous catheter, neutropenia, hematological malignancies and chronic kidney disease were also risk factors for mortality.

Stenotrophomonas maltophilia Infections in Haematological Malignancies and Hematopoietic Stem Cell Transplantation: A Case Series including Cefiderocol-Based Regimens

Background and Objectives: Stenotrophomonas maltophilia is a ubiquitous, aerobic, Gram-negative bacillus causing increasing concern in patients affected by haematological malignancies. Materials and Methods: We report a case series from two centres in Northern Italy to describe the characteristics, outcome and microbiological response of S. maltophilia infections in patients with haematological malignancies and/or allogenic hematopoietic stem cell transplantation (aHSCT). Results: Ten patients were included. The median age was 67 years, and seven patients (70%) were males. The median Charlson Comorbidity Index was 6 (IQR: 4-8). The most frequent haematological comorbidities were acute myeloid leukaemia (AML; n = 3; 30%) and non-Hodgkin's lymphoma (n = 3; 30%). Three (30%) patients underwent aHSCT before infection, all for AML. All the patients had undergone a recent antibiotics course and had an indwelling central venous catheter before infection. The main clinical presentations were nosocomial pneumonia, with (2; 20%) or without (4; 40%) secondary bloodstream infection and CRBSI (3; 30%). Four patients were treated with cefiderocol in monotherapy or combinations therapy with cotrimoxazole. The rest of the patients were treated with cotrimoxazole or levofloxacin in monotherapy. Conclusions: Despite a high rate of clinical improvement (90%) after starting antimicrobial therapy, we faced high 30-day mortality (30%) and in-hospital mortality (50%) rates in a highly comorbid population.

Emerging infections in vulnerable hosts: Stenotrophomonas maltophilia and Elizabethkingia anophelis

PURPOSE OF REVIEW

This systematic review aimed to explore the recent trends in the epidemiology, risk factors, and antimicrobial susceptibility of two emerging opportunistic pathogens, Stenotrophomonas maltophilia and Elizabethkingia anophelis .

RECENT FINDINGS

Since 2020, numerous outbreaks of S. maltophilia and E. anophelis have been reported worldwide. Most of these outbreaks have been associated with healthcare facilities, although one outbreak caused by E. anophelis in France was considered a community-associated infection. In terms of antimicrobial susceptibility, trimethoprim/sulfamethoxazole (TMP-SMZ), levofloxacin, and minocycline have exhibited good efficacy against S. maltophilia . Additionally, cefiderocol and a combination of aztreonam and avibactam have shown promising results in in vitro susceptibility testing. For E. anophelis , there is currently no consensus on the optimal treatment. Although some studies have reported good efficacy with rifampin, TMP-SMZ, piperacillin/tazobactam, and cefoperazone/sulbactam, minocycline had the most favourable in vitro susceptibility rates. Cefiderocol may serve as an alternative due to its low minimum inhibitory concentration (MIC) against E. anophelis . The role of vancomycin in treatment is still uncertain, although several successful cases with vancomycin treatment, even with high MIC values, have been reported.

SUMMARY

Immunocompromised patients are particularly vulnerable to infections caused by S. maltophilia and E. anophelis , but the optimal treatment strategy remains inconclusive. Further research is necessary to determine the most effective use of conventional and novel antimicrobial agents in combatting these multidrug-resistant pathogens.

Intra-Abdominal Abscess and Bacteremia Due to Stenotrophomonas maltophilia After Total Gastrectomy: A Case Report and Literature Review

Stenotrophomonas maltophilia (S. maltophilia) is increasingly recognized as a pathogen responsible for nosocomial infections, particularly in immunocompromised patients. The most common types of S. maltophilia infections are pneumonia and catheter-related bloodstream infection, and clinical cases of intra-abdominal abscesses due to S. maltophilia are rare. We present a rare case of intra-abdominal abscess and bacteremia as a surgical site infection (SSI) caused by S. maltophilia in a patient following total gastrectomy. We also reviewed previous literature to elucidate the clinical characteristics of intra-abdominal abscess due to S. maltophilia. The patient, a 75-year-old man with diabetes and polymyositis (treated with prednisolone), developed a fever 17 days after undergoing a total gastrectomy for gastric cancer. Abdominal computed tomography revealed a hypodense solid mass at the esophagojejunostomy site, which appeared to be an intra-abdominal abscess. The culture of both blood and drained abscess pus confirmed only S. maltophilia. Treatment with intravenous trimethoprim-sulfamethoxazole and abscess drainage led to complete resolution. The patient recovered and was discharged and did not experience a recurrence. We reviewed the English literature and found only two additional case reports of intra-abdominal abscesses caused by S. maltophilia. As in our case, the intra-abdominal abscess occurred after abdominal surgery and the source was suspected to be deep SSI. This case highlights the importance of considering S. maltophilia as a potential pathogen in patients with atypical post-surgical abdominal infections. Physicians should be aware that S. maltophilia has the potential to cause intra-abdominal abscesses secondary to SSI, in addition to Enterobacteriaceae, a major causative pathogen of SSI. Further studies are required to elucidate the etiology, epidemiology, and risk factors for SSI caused by S. maltophilia.

Stenotrophomonas maltophilia Infections: A Systematic Review and Meta-Analysis of Comparative Efficacy of Available Treatments, with Critical Assessment of Novel Therapeutic Options

Stenotrophomonas maltophilia (SM) represents a challenging pathogen due to its resistance profile. A systematic review of the available evidence was conducted to evaluate the best treatment of SM infections to date, focusing on trimethoprim/sulfamethoxazole (TMP/SMX), fluoroquinolones (FQs), and tetracycline derivatives (TDs).

MATERIALS

PubMed/MEDLINE and Embase were searched from inception to 30 November 2022. The primary outcome was all-cause mortality. Secondary outcomes included clinical failure, adverse events, and length of stay. A random effects meta-analysis was performed. This study was registered with PROSPERO (CRD42022321893).

RESULTS

Twenty-four studies, all retrospective, were included. A significant difference in terms of overall mortality was observed when comparing as a monotherapy TMP/SMX versus FQs (odds ratio (OR) 1.46, 95% confidence interval (CI) 1.15-1.86, I² = 33%; 11 studies, 2407 patients). The prediction interval (PI) did not touch the no effect line (1.06-1.93), but the results were not robust for the unmeasured confounding (E-value for point estimate of 1.71). When comparing TMP/SMX with TDs, the former showed an association with higher mortality but not significant and with a wide PI (OR 1.95, 95% CI 0.79-4.82, PI 0.01-685.99, I² = 0%; 3 studies, 346 patients). Monotherapies in general exerted a protective effect against death opposed to the combination regimens but were not significant (OR 0.71, 95% CI 0.41-1.22, PI 0.16-3.08, I² = 0%; 4 studies, 438 patients).

CONCLUSIONS

Against SM infections, FQs and, possibly, TDs seem to be reasonable alternative choices to TMP/SMX. Data from clinical trials are urgently needed to better inform therapeutic choices in this setting by also taking into account newer agents.

Risk Factors for Infection and Mortality Associated With Stenotrophomonas maltophilia Bloodstream Infections in Children; Comparison With Pseudomonas aeruginosa Bloodstream Infections

INTRODUCTION

The increasing incidence of Stenotrophomonas maltophilia ( S. maltophilia ) infections raises concern because of the high fatality/case ratio. This study aimed to evaluate the risk factors for infection and mortality associated with S. maltophilia bloodstream infections (BSIs) in children and compare them with Pseudomonas aeruginosa BSIs.

METHODS

All BSIs caused by S. maltophilia (n:73) and P. aeruginosa (n:80) were enrolled in this study between January 2014 and December 2021 at the Medical School of Ege University.

RESULTS

Previous Pediatric Intensive Care Unit (PICU) admission, prior glycopeptide, and carbapenem use were significantly more common in patients with S. maltophilia BSIs ( P = 0.044, P = 0.009, and P = 0.001, respectively) than with P. aeruginosa BSIs. C-reactive protein (CRP) levels were significantly higher in S. maltophilia BSIs ( P = 0.002). Multivariate analysis showed that prior carbapenem use was associated with S. maltophilia BSIs ( P = 0.014, adjusted odds ratio [AOR]: 2.710; 95% confidence interval [CI]: 1.225-5.992). PICU admission because of BSI, prior carbapenem and glycopeptide use, neutropenia, and thrombocytopenia were significantly more common in patients with mortality because of S. maltophilia BSIs ( P < 0.001, P = 0.010, P = 0.007, P = 0.008, P = 0.004, respectively), while only PICU admission because of BSI, and prior glycopeptide use were significant in multivariate analysis (AOR, 19.155; 95% CI: 2.337-157.018; P = 0.006 and AOR, 9.629; 95% CI: 1.053-88.013; P = 0.045, respectively).

CONCLUSION

Prior carbapenem use is a significant risk factor for developing S. maltophilia BSIs. PICU admission because of BSI and prior glycopeptide use are risk factors associated with the mortality rate in patients with S. maltophilia BSIs. Therefore, S. maltophilia should be considered in patients with these risk factors, and empirical treatment should include antibiotics for S. maltophilia .

Stenotrophomonas maltophilia Bacteremia: From Diagnosis to Treatment

Objective

There are many difficulties in diagnosing and treating Stenotrophomonas maltophilia bacteremia. In this study, we aimed to evaluate "true" and "false-positive bacteremia" and assess mortality risk factors and the impact of different treatment regimens.

Materials and Methods

Hospitalized adult patients with S. maltophilia-positive blood cultures were assessed by a two-stage analysis. First, the clinical significance of blood cultures was assessed, and patients were divided into "true" and "false-positive bacteremia" groups. Then, excluding false positives, we analyzed the antimicrobial regimens and the factors associated with 28-day mortality in true bacteremia cases performing univariate and multivariate analyses.

Results

The study included 127 out of 138 patients with S. maltophilia bacteremia. True bacteremia was identified in 51.2% and false-positive bacteremia in 48.8% of patients. In the true bacteremia group, hypotension, nosocomial bacteremia, concomitant infections, a source of bacteremia, two positive blood culture sets, and 28-day mortality were more common. The 28-day mortality was 50.7% among true bacteremia cases. In multivariate analysis, age and solid tumor were the independent predictors of 28-day mortality. Early effective antimicrobial therapy and different antimicrobial regimens, including trimethoprim-sulfamethoxazole (SXT), fluoroquinolones (FQs), and tigecycline (TGC), did not have any significant impact on survival.

Conclusion

Patients with S. maltophilia bacteremia should first be assessed regarding clinical significance. Clinical findings, the presence of multiple positive blood culture sets and the primary sources of bacteremia are useful parameters while discriminating true from false-positive bacteremia. Patients with advanced age and solid tumors should be followed carefully in terms of mortality. Antimicrobial regimens, including SXT, FQs, or TGC, can be preferred in patients with S. maltophilia bacteremia considering antimicrobial resistance and adverse effects or toxicity.

Risk Factors for Mortality in Hospitalized Patients with Stenotrophomonas maltophilia Bacteremia

Objective

Stenotrophomonas maltophilia (S. maltophilia) is an opportunistic and nosocomial pathogen with high mortality. And it has intrinsic resistance to a number of antibiotics classes. In this study, we investigated risk factors for death due to S. maltophilia bacteremia.

Methods

A retrospective cohort study was conducted at a tertiary-care hospital in Beijing, China. The patients from the hospital database with S. maltophilia bacteremia between January 2011 and December 2020 were investigated. Univariate and multivariate analyses were performed to identify factors associated with mortality.

Results

51 patients with S. maltophilia bacteremia were identified. The mortality rate was 37.3%. Based on the univariate analysis, pulmonary disease (P=0.019), chronic kidney disease (P=0.014), shock (P=0.002), foley catheter (P=0.011), the Acute Physiology and Chronic Health Evaluation II (APACHE II) score (P<0.001), procalcitonin (PCT) (P=0.045) and using antifungal agent (P=0.033) were significantly related to mortality. Based on the multivariate analysis, the APACHE II score (odds ratio [OR] =1.211; 95% confidence interval [CI]: 1.061, 1.382; P=0.005) was independent factor associated with mortality. S. maltophilia was the most susceptible to minocycline (94.7%), followed by trimethoprim and sulfamethoxazole (TMP/SMX, 92.2%).

Conclusion

Our findings suggested that the APACHE II score was a significantly independent predictor in S. maltophilia bacteremia patients. The use of TMP/SMX or minocycline might be the first choice for the treatment of S. maltophilia bacteremia.

Overcoming Stenotrophomonas maltophilia Resistance for a More Rational Therapeutic Approach

Stenotrophomonas maltophilia is an underappreciated source of morbidity and mortality among gram-negative pathogens. Effective treatment options with acceptable toxicity profiles are limited. Phenotypic susceptibility testing via commercial automated test systems is problematic and no Food and Drug Administration breakpoints are approved for any of the first-line treatment options for S maltophilia. The lack of modern pharmacokinetic/pharmacodynamic data for many agents impedes dose optimization, and the lack of robust efficacy and safety data limits their clinical utility. Levofloxacin has demonstrated similar efficacy to trimethoprim-sulfamethoxazole, although rapid development of resistance is a concern. Minocycline demonstrates the highest rate of in vitro susceptibility, however, evidence to support its clinical use are scant. Novel agents such as cefiderocol have exhibited promising activity in preclinical investigations, though additional outcomes data are needed to determine its place in therapy for S maltophilia. Combination therapy is often employed despite the dearth of adequate supporting data.

In vitro Time Kill of Trimethoprim/Sulfamethoxazole against Stenotrophomonas maltophilia versus Escherichia coli using Cation Adjusted Muller Hinton Broth and ISO-Sensitest Broth

Trimethoprim/sulfamethoxazole (TMP/SMZ) is considered the treatment of choice for infections caused by Stenotrophomonas maltophilia , but limited pharmacodynamic data are available to support current susceptibility breakpoints or guide optimal dosing. Time-kill studies using a TMP/SMZ concentration of 4/40 μg/mL were conducted to compare 4 S. maltophilia with 4 Escherichia coli having the same MICs (0.25/4.75-4/76 μg/mL) in cation adjusted Mueller Hinton Broth (CAMHB) and ISO-Sensitest™ broth (ISO). With the exception of the resistant isolates (4/76 μg/mL), which resulted in regrowth approaching control, TMP/SMZ displayed significantly greater killing for E. coli compared with S. maltophilia at each MIC. Against E. coli , mean changes at 24 hour were -4.49, -1.73, -1.59, and +1.83 log 10 colony forming units (CFU) for isolates with MICs of 0.25/4.75, 1/19, 2/39, and 4/74 μg/mL, respectively. The f AUC/MIC required for stasis, 1-log 10 , and 2-log 10 CFU reductions were 40.7, 59.5, and 86.3, respectively. In contrast, TMP/SMZ displayed no stasis or CFU reductions against any S. maltophilia regardless of MIC, and no pharmacodynamic thresholds were quantifiable. Observations were consistent in both CAMHB and ISO broth. These data add increasing evidence that current TMP/SMZ susceptibility breakpoints against S. maltophilia should be reassessed.

Healthcare-Associated Stenotrophomonas maltophilia Bacteraemia: Retrospective Evaluation of Treatment and Outcome

Introduction

Stenotrophomonas maltophilia (SM) is one of the common gram-negative pathogens that cause nosocomial infections. The aim of the present study is to evaluate the treatment and outcome of SM bacteraemia.

Materials and Methods

We retrospectively evaluated antimicrobial treatment in adult patients with nosocomial SM bacteraemia, with the 14th and 30th-day mortality as the outcome.

Results

In total, 140 adult patients with SM bacteraemia who were diagnosed between January 1, 2002, and December 31, 2016 were enrolled in the present study. Seventy-one (50.7%) patients were in the intensive care unit (ICU). The 14th and the 30th-day mortality rates were 32.9% (n=46) and 45.7% (n=64), respectively. Female sex (OR, 7.47; 95% CI 1.61-34.47, p<0.01), steroid use within the last month (OR, 10.2; 95% CI 1.27-82.27, p=0.029), Pittsburgh bacteraemia score (PBS) ≥4 (OR, 39.9; 95% CI 4.96-321.32, p<0.001) and solid organ malignancy (OR, 9.6; 95% CI 1.73-53.72, p<0.01) were independent risk factors for 14th day mortality. Removal of the catheter was an independent protective factor for both 14th (OR, 0.05; 95% CI 0.22-0.010, p<0.001) and 30th day (OR, 0.039;95% CI 0.164-0.009, p<0.001) mortality. We did not detect any difference between treatment regimens including trimethoprim-sulfamethoxazole (TMP/SMX) or levofloxacin in terms of mortality. We found that TMP/SMX and levofloxacin combination did not significantly improve patient prognosis.

Conclusion 

Due to the high mortality rates associated with nosocomial SM bacteraemia, adequate antibiotic therapy should be initiated immediately in the suspicion of infection, and prompt removal of any indwelling central venous catheter is important.

Stenotrophomonas maltophilia Infections in Pediatric Patients - Experience at a European Center for Pediatric Hematology and Oncology

Stenotrophomonas maltophilia is an important nosocomial pathogen in immunocom-promised individuals and characterized by intrinsic resistance to broad-spectrum antibacterial agents. Limited data exists on its clinical relevance in immunocompromised pediatric patients, particularly those with hematological or oncological disorders. In a retrospective single center cohort study in pediatric patients receiving care at a large european pediatric hematology and oncology department, ten cases of invasive S.maltophilia infections (blood stream infections (BSI), 4; BSI and pneumonia, 3, or soft tissue infection, 2; and pneumonia, 1) were identified between 2010 and 2020. Seven patients had lymphoblastic leukemia and/or were post allogeneic hematopoietic cell transplantation. Invasive S.maltophilia infections occurred in a setting of indwelling central venous catheters, granulocytopenia, defective mucocutaneous barriers, treatment with broad-spectrum antibacterial agents, and admission to the intensive care unit. Whole genome sequencing based typing revealed no genetic relationship among four individual S.maltophilia isolates. The case fatality rate and mortality at 100 days post diagnosis were 40 and 50%, respectively, and three patients died from pulmonary hemorrhage. Invasive S.maltophilia infections are an emerging cause of infectious morbidity in patients receiving care at departments of pediatric hematology and oncology and carry a high case fatality rate.

Antimicrobial resistance and multilocus sequence types of Stenotrophomonas maltophilia isolated from dogs and cats in Japan

As the representative multidrug-resistant pathogen, Stenotrophomonas maltophilia has multiple intrinsic and acquired resistances, including carbapenem resistance. In companion animals, the antimicrobial susceptibility and sequence types (STs) of S. maltophilia are not well understood due to its limited isolation rate. We investigated the antimicrobial susceptibilities and multilocus sequence types (MLSTs) of 38 S. maltophilia strains isolated from dogs and cats in Japan. Prevalence of resistance was detected for imipenem (100 %), aztreonam (94.7 %), piperacillin (65.8 %), trimethoprim-sulfamethoxazole (65.8 %), and ceftazidime (60.5 %). Rates of resistances to chloramphenicol, minocycline, and levofloxacin were low (2.6-5.3 %). MLST analysis revealed that all 38 strains were assigned to 34 STs, including 11 previously reported STs and 23 newly identified STs. Phylogenetic analysis of MLSTs enabled categorization of 13 isolates (34.2 %) into genogroup 6, which is a major genogroup of human isolates. Multinational surveillance would be needed to clarify the significance of antimicrobial-resistant S. maltophilia isolates from companion animals.

In which cases of pneumonia should we consider treatments for Stenotrophomonas maltophilia?

BACKGROUND

Stenotrophomonas maltophilia is a pathogen commonly associated with respiratory infection. However, the characteristics of pneumonia caused by S. maltophilia remain unknown.

AIM

To evaluate the characteristics of and risk factors for S. maltophilia pneumonia.

METHODS

A retrospective evaluation was undertaken of 2002 patients with sputum cultures positive for S. maltophilia between January 2010 and December 2019. Cases were excluded based on clinical information and laboratory results. Included cases were divided into two groups: the S. maltophilia pneumonia group (patients with pneumonia caused by S. maltophilia) and the non-S. maltophilia pneumonia group (patients with pneumonia caused by pathogens other than S. maltophilia). Patient characteristics, clinical data and Sequential Organ Failure Assessment (SOFA) scores were compared between the groups.

FINDINGS

Eight and 91 patients were assigned to the S. maltophilia pneumonia and non-S. maltophilia pneumonia groups, respectively. The median age was significantly lower in the S. maltophilia pneumonia group than in the non-S. maltophilia pneumonia group (63.4 vs 73.1 years; P<0.01), and the SOFA score was significantly higher in the S. maltophilia pneumonia group (7.5 vs 3.0; P<0.01). Underlying malignancy and pre-administration of antipseudomonal β-lactams and steroids were confirmed in seven of the eight cases in the S. maltophilia pneumonia group, suggesting an association with immunosuppression.

CONCLUSIONS

Pneumonia due to S. maltophilia is a rare occurrence. Treatment for this pathogen should be considered in cases of pneumonia with: (1) predominance of S. maltophilia in sputum cultures; (2) pre-administration of broad-spectrum antibiotics; (3) immunodeficiency; and (4) a high SOFA score.

Nosocomial Non-fermentative gram negative bacteria bloodstream infections in children; Risk factors and clinical outcomes of carbapenem resistance

INTRODUCTION

Non-fermentative Gram-negative bacterias (NFGNBs) are a major cause of life threatening infections in hospitalized children. In this study, we aimed to evaluate the demographic and clinical characteristics of NFGNBs infections and identify the risk factors and outcomes of bloodstream infections (BSIs) caused by carbapenem-resistant (CR) NFGNBs infections.

METHODS

A retrospective cohort was designed to evaluate the patients with a BSI caused by NFGNBs between in January 2014 and December 2017.

RESULTS

A total of 131 episodes from 115 patients were evaluated. The mean age of the patients was 4.79±(4.74) year. The most commonly isolated NFGNBs species was Acinetobacter spp. (35.9%), Pseudomonas spp. (34.4%), and Stenotrophomonas maltophilia (13%). The rate of carbapenem-resistance was 38.2% in Acinetobacter spp. and 26.6% in Pseudomonas spp. The comparison of CR group with carbapenem-susceptible (CS) group showed statistical significance for the length of hospital stay prior to onset of infection and total hospital stay (P values were 0.001, 0.008). Based on the univariate analysis, requirement of mechanical ventilation, central venous catheter, nasogastric tube, Foley catheter, severe neutropenia (<100/mm3), prolonged neutropenia (≥14 days), prior intensive care unit admission and prior antimicrobial treatment (carbapenems, colistin, glycopeptide) were more common in carbapenem-resistant NFGNBs infections (P values are 0.001, 0.012, 0.000, 0.005, 0.042, 0.027, 0.007, 0.007). In patients with NFGNBs infections 14-day and 30-day mortality rates were %16.8 and 21.4%.

CONCLUSION

CR infections were more common in children with prolonged and severe neutropenia. Prior antimicrobial use and intensive care unit admission were more common in CR infections.

Emergent Pneumonia in Children

In recent decades there have been multiple pathogens, viruses and bacteria, which have emerged as causal agents of pneumonia affecting adults, albeit less frequently, to children. For the purposes of this article we have classified emerging pathogens as follows: True emerging, to pathogens identified for the very first time affecting human population (SARS-CoV-1, SARS-CoV-2, MERS-CoV, avian influenza, and hantavirus); Re-emerging, to known pathogens which circulation was controlled once, but they have reappeared (measles, tuberculosis, antimicrobial resistant bacteria such as CA-MRSA, Mycoplasma pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and new serotypes of post-vaccine pneumococcal); and finally, those that we have called old known with new presentations, including common pathogens that, in particular condition, have changed their form of presentation (rhinovirus, and non-SARS coronavirus). We will review for each of them their epidemiology, forms of presentation, therapy, and prognosis in children compared to the adult with the aim of being able to recognize them to establish appropriate therapy, prognostics, and effective control measures.

Risk Factors of Stenotrophomonas maltophilia Blood Stream Infections: Comparison With Other Gram-Negative Blood Stream Infections in Children

BACKGROUND

Stenotrophomonas maltophilia, is a nonfermentative, aerobic, Gram-negative bacilli which is intrinsically resistance to several antibiotics. Treatment options for this bacteria are quite different from the other Gram-negative bacilli, which can represent a therapeutic challenge. To initiate appropriate empiric treatment and to reduce mortality, differentiation of S. maltophilia from other Gram-negative bacteria is critically important. The aim of this study is to distinguish the risk factors of S. maltophilia blood stream infections (BSI) from other Gram-negative BSI.

METHODS

This was a retrospective, case-control study. Patients with S. maltophilia BSI were selected as cases and patients with non-S. maltophilia Gram-negative BSI were selected as controls. Demographic and clinical characteristics of patients were recorded.

RESULTS

Forty-eight cases with S. maltophilia BSI and 144 controls were enrolled in the study. Risk factors for S. maltophilia BSI compared with the control group includes prior use of antibiotics, especially carbapenem, pediatric intensive care unit stay, mechanical ventilator use, indwelling catheters and duration of hospitalization.

CONCLUSIONS

Breakthrough infection by S. maltophilia can occur in severely ill patients being treated with carbapenem. In the presence of risk factors, to reduce morbidity and mortality, S. maltophilia should be kept in mind when starting empiric treatment.

Stenotrophomonas maltophilia: An Emerging Pathogen of the Respiratory Tract

Patient: Female, 70-year-old

Final Diagnosis:Stenotrophomonas maltophilia

Symptoms: Difficult to breath, patient could not wean from oxygen/premature

Medication: —

Clinical Procedure: —

Specialty: General and Internal Medicine

Characteristics of Stenotrophomonas maltophilia infection in children in Sichuan, China, from 2010 to 2017

Stenotrophomonas maltophilia (S. maltophilia) is an important nosocomial bacterial pathogen. However, the clinical features of children with S. maltophilia infection, the predisposing factors, and the antibiotic susceptibility of the bacteria have not been fully evaluated.In this study, the data of children with S. maltophilia infection from the West China Second University Hospital of Sichuan University (Chengdu, China) between July 2010 and October 2017 were collected and analyzed. The clinical features of enrolled children, the predisposing factors, and the antibiotic susceptibility were reported.In total, infection of S. maltophilia was identified in 128 patients. Most of these patients were under 1 year old (67.2%) and were mainly diagnosed as pneumonia (69%). A large proportion had underlying diseases (45.3%), received immunosuppressive therapy (53.1%), had undergone invasive operations (41.4%), had a history of carbapenem antibiotics use within 7 days before culture acquisition (54.7%), history of intensive care unit (ICU) hospitalization within previous 30 days (34.4%), and other risk factors. In particular, invasive operation (95% confidence interval [CI]: 1.125-14.324, P = .032), especially mechanical ventilation (95% CI: 1.277-20.469, P = .021), and ICU admission (95% CI: 1.743-22.956, P = .005) were independent risk factors for the children to develop severe S. maltophilia infection. As for antibiotic susceptibility, trimethoprim sulfamethoxazole (TMP-SMX), piperacillin tazobactam, ticarcillin clavulanate, and ceftazidime exhibited strong antibacterial activities against S. maltophilia, the susceptibility rates were 97.5%, 86.7%, 92.9%, and 81.5%, respectively.We report the clinical features of children with S. maltophilia infection, the predisposing factors and the antibiotic susceptibility. TMP-SMX can continue to be the first choice for the treatment of S. maltophilia infection. Piperacillin tazobactam, ticarcillin clavulanate, and the third generation cephalosporins can be used as alternative drugs.

Stenotrophomonas Bacteremia Antibiotic Susceptibility and Prognostic Determinants: Mayo Clinic 10-Year Experience

Background

Stenotrophomonas maltophilia is a gram-negative, opportunistic infection that is usually hospital-acquired and associated with high morbidity and mortality. The reported increase in S. maltophilia infections is presumed to be due to an increase in the population at risk.

Methods

We retrospectively reviewed 10-year data for S. maltophilia bacteremia in hospitalized adults at our institution to determine the population at risk, sources of infection, common complications, antimicrobial susceptibility profiles, and clinical outcome trends over the past decade.

Results

Among the 98 patients analyzed, the most common source of infection was catheter-related (62, 63.3%). Most isolates (61, 65%) were resistant to ceftazidime; fewer were resistant to trimethoprim-sulfamethoxazole (TMP-SMX; 2, 2.1%) and levofloxacin (22, 23.4%). All-cause in-hospital mortality was 29.6% (29 patients). The highest mortality, 53.8%, was observed in pulmonary sources of bacteremia.

Conclusions

Although TMP-SMX continues to have reliable activity in our cohort, we noted resistance to TMP-SMX in patients with recent TMP-SMX exposure, including a case with developing resistance to TMP-SMX while on therapy.

Clinical Features, Outcomes, and Risk Factors of Bloodstream Infections due to Stenotrophomonas maltophilia in a Tertiary-Care Hospital of China: A Retrospective Analysis

Background. Stenotrophomonas maltophilia bacteremia (SMB) is the most perilous situation as compared to other types of S. maltophilia infection. The present study aimed to investigate the clinical features, distribution, drug resistance, and predictors of survival of SMB in a tertiary-care hospital of China. Methods. SMB that occurred in a tertiary-care hospital in Beijing, China, within 9 years (2010-2018) was investigated in a retrospective study. Demographics, incidence, commodities, drug resistance, mortality, as well as antibiotics administration were summarized according to the electronic medical records. The risk factors for survival were analyzed by Chi-square test, Kaplan-Meier curve and Cox regression. Results. A total of 76 episodes of SMB were analyzed. The overall incidence of SMB fluctuated from 3.4 to 15.4 episodes per 1000 admissions over 9 years. Malignancy was the most common comorbidity. High in vitro sensitivity was observed to minocycline (96.1%), levofloxacin (81.6%), and trimethoprim-sulfamethoxazole (89.5%). Central venous catheter (CVC) (p = 0.004), mechanical ventilation (MV) (p = 0.006), hemodialysis (p = 0.024), and septic shock (p = 0.016) were significantly different between survival and death group. The 30-day mortality was 34.2% within 30 days after confirmation of blood culture. Factors such as hemodialysis (OR 0.287, 95% CI: 0.084-0.977, p = 0.046), T-tube (OR 0.160, 95% CI: 0.029-0.881, p = 0.035), and septic shock (OR 0.234, 95% CI: 0.076-0.719, p = 0.011) were associated with survival. Conclusions. S. maltophilia is the major nosocomial blood stream infectious pathogenic bacteria. Trimethoprim-sulfamethoxazole and minocycline are optimal antibiotics for the treatment of SMB. T-tube, hemodialysis, and septic shock were the risk factors associated with survival of SMB patients.

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

Background

Stenotrophomonas 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.

Methods

A 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.

Results

A 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.

Conclusions

Our 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.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4394-4) contains supplementary material, which is available to authorized users.

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

OBJECTIVES

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.

DESIGN

A multicenter observational retrospective study in which medical charts of critically ill children with S. maltophilia bacteremia were reviewed between 2012 and 2017.

SETTING

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.

PATIENTS

A total of 68 suitable cases of S. maltophilia bacteremia were retrieved and reviewed.

MEASUREMENTS AND MAIN RESULTS

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).

CONCLUSIONS

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.

Metagenomic Analysis Identified Stenotrophomonas maltophilia Pneumonia in an Infant Suffering From Unexplained Very Severe Pneumonia

Pneumonia poses a significant global morbidity and mortality burden on children. Etiological diagnosis and matched anti-microbial therapy are particularly important for very severe pneumonia. Although great advances have been achieved in diagnostic approaches, it remains challenging to identify pathogens in unexplained pneumonia (UP) cases. In this study, we applied next-generation sequencing (NGS) technology and a metagenomic approach to detect and characterize respiratory bactiera in an UP case in infant. Stenotrophomonas maltophilia was the only bacterial pathogen detected in blood. Metagenomic sequencing also provided bacteria genomic sequences, which could be used to evaluate the role of this pathogen in the disease. This NGS method has the potential to improve the identification of causative organisms in patients with pneumonia and the delivery of appropriate, pathogen-directed antibiotic therapy.

Fluoroquinolones versus trimethoprim-sulfamethoxazole for the treatment of Stenotrophomonas maltophilia infections: a systematic review and meta-analysis

BACKGROUND

Fluoroquinolones are a popular alternative to trimethoprim-sulfamethoxazole for Stenotrophomonas maltophilia infections.

OBJECTIVES

To compare the effects of fluoroquinolones and trimethoprim-sulfamethoxazole on mortality of S. maltophilia infections.

DATA SOURCES

PubMed and EMBASE.

STUDY ELIGIBILITY CRITERIA

Clinical studies reporting mortality outcomes of S. maltophilia infections.

PARTICIPANTS

Patients with clinical infections caused by S. maltophilia.

INTERVENTIONS

Fluoroquinolone monotherapy in comparison with trimethoprim-sulfamethoxazole monotherapy.

METHODS

Systematic review with meta-analysis technique.

RESULTS

Seven retrospective cohort and seven case-control studies were included. Three cohort studies were designed to compare the two drugs, whereas others had other purposes. A total of 663 patients were identified, 332 of which were treated with trimethoprim-sulfamethoxazole (50.1%) and 331 with fluoroquinolones (49.9%). Three cohort studies were designed to compare the effect of the two drugs, whereas the others had other purposes. Levofloxacin was most frequently used among fluoroquinolones (187/331, 56.5%), followed by ciprofloxacin (114/331, 34.4%). The overall mortality rate was 29.6%. Using pooled ORs for the mortality of each study, fluoroquinolone treatment (OR 0.62, 95% CI 0.39-0.99) was associated with survival benefit over trimethoprim-sulfamethoxazole treatment, with low heterogeneity (I² = 18%). Specific fluoroquinolones such as ciprofloxacin (OR 0.44, 95% CI 0.17-1.12) and levofloxacin (OR 0.78, 95% CI 0.48-1.26) did not show a significant difference in comparison with trimethoprim-sulfamethoxazole. In the sub-group analyses of adult and bacteraemic patients, significant differences in mortality were not observed between fluoroquinolones and trimethoprim-sulfamethoxazole.

CONCLUSIONS

Based on a meta-analysis of non-randomized studies, fluoroquinolones demonstrated comparable effects on mortality of S. maltophilia infection to trimethoprim-sulfamethoxazole, supporting the use of fluoroquinolones in clinical S. maltophilia infections. Although the pooled analysis of overall studies favoured fluoroquinolones over trimethoprim-sulfamethoxazole, the studies included were observational, and sub-group analyses of certain fluoroquinolone agents did not show statistical differences with trimethoprim-sulfamethoxazole. Randomized clinical studies are needed to address these issues.

Management of Stenotrophomonas maltophilia Infections in Critically Ill Children

BACKGROUND

Stenotrophomonas maltophilia is a life-threatening nosocomial pathogen with profound multidrug-resistant attributes. It is associated with high mortality, particularly in immunocompromised patients. Data on therapy for S. maltophilia infections are scarce, especially in children hospitalized in intensive care settings (pediatric intensive care unit).

METHODS

A retrospective chart review of pediatric patients with isolates of S. maltophilia hospitalized over a 5-year period in 2 pediatric intensive care units.

RESULTS

Thirty-one patients and 91 isolates from blood, respiratory secretions and soft tissues were identified and reviewed. The overall incidence of S. maltophilia infections increased during the study period (P = 0.003). The all-cause crude mortality was 61%, and the attributed mortality was approximately 16%. Risk factors associated with mortality included longer hospitalization before infection (P = 0.002), septic shock (P = 0.003), mechanical ventilation (P = 0.004), an indwelling central vein catheter (P = 0.03) and prior use of steroids (P = 0.04) and carbapenems (P = 0.004). On multivariate analysis, mortality was associated with mechanical ventilation (P = 0.02) and preinfection hospitalization days (P = 0.01). Combination treatment of trimethoprim and sulfamethoxazole, ciprofloxacin and/or minocycline significantly extended survival time (P < 0.001). The method of treatment did not significantly affect the interval between S. maltophilia isolation to resolution of infection (P = 0.200).

CONCLUSIONS

Combinations of trimethoprim and sulfamethoxazole, ciprofloxacin and minocycline are proposed for pediatric intensive care unit patients harboring S. maltophilia. Meticulous evaluation of central vascular access and prior treatment with carbapenems are indicated, especially for mechanically ventilated and septic children.

The updated Charlson comorbidity index is a useful predictor of mortality in patients with Staphylococcus aureus bacteraemia

The objective was to compare the performance of the updated Charlson comorbidity index (uCCI) and classical CCI (cCCI) in predicting 30-day mortality in patients with Staphylococcus aureus bacteraemia (SAB). All cases of SAB in patients aged ⩾14 years identified at the Microbiology Unit were included prospectively and followed. Comorbidity was evaluated using the cCCI and uCCI. Relevant variables associated with SAB-related mortality, along with cCCI or uCCI scores, were entered into multivariate logistic regression models. Global model fit, model calibration and predictive validity of each model were evaluated and compared. In total, 257 episodes of SAB in 239 patients were included (mean age 74 years; 65% were male). The mean cCCI and uCCI scores were 3.6 (standard deviation, 2.4) and 2.9 (2.3), respectively; 161 (63%) cases had cCCI score ⩾3 and 89 (35%) cases had uCCI score ⩾4. Sixty-five (25%) patients died within 30 days. The cCCI score was not related to mortality in any model, but uCCI score ⩾4 was an independent factor of 30-day mortality (odds ratio, 1.98; 95% confidence interval, 1.05-3.74). The uCCI is a more up-to-date, refined and parsimonious prognostic mortality score than the cCCI; it may thus serve better than the latter in the identification of patients with SAB with worse prognoses.

Risk factors for death from Stenotrophomonas maltophilia bacteremia

PURPOSE

Stenotrophomonas maltophilia has low pathogenicity potential, but if it causes bacteremia it can be fatal, because it has shown high resistance to many antibiotics and can be difficult to treat. Patient death from S. maltophilia bacteremia has increased since 2014 in our hospital. In this study, we investigated risk factors for death due to S. maltophilia bacteremia.

METHODS

Seventy patients from the hospital database with S. maltophilia bacteremia between January 2010 and July 2017 were investigated. We retrospectively analyzed risk factors including gender, age, wards, hospitalized duration, clinical history, devices, source of S. maltophilia identification, polymicrobial bacteremia, prior antimicrobial therapy, antimicrobial therapy after bacteremia, and resistance to antibiotics. The statistical analysis was performed to compare the period from 2010 to 2013 to from 2014 to 2017.

RESULTS

Comparing the 2010-2013 period to the 2014-2017 period, it revealed that history of hospitalization, identification of S. maltophilia from sputum, polymicrobial bacteremia, prior carbapenem use, and mortality was significantly different in S. maltophilia bacteremia (p = 0.028, p = 0.004, p < 0.001, p = 0.034, and p = 0.007, respectively). Comparison between non-survivors and survivors for 2010-2013 and 2014-2017 found ICU admission and ventilator use were seen more often in non-survivors (p = 0.030 vs p = 0.013 and p = 0.027 vs p = 0.010, respectively).

CONCLUSIONS

Our analyses showed increase in mortality from S. maltophilia bacteremia from 2014 to 2017, and that non-survivors had a higher frequency of ICU admission and ventilator use in both the 2010-2013 and 2014-2017 periods. There were more combination antimicrobial therapy cases after bacteremia in 2014-2017. Further prospective studies with larger numbers of patients should be undertaken for definitive conclusions.