Clinical Characteristics and Prognostic Factors of Patients With Stenotrophomonas maltophilia Pneumonia: 10-Year Experience From a Single Center

INTRODUCTION

Stenotrophomonas maltophilia infection is gaining importance as an important cause of nosocomial pneumonia. S. maltophilia infection occurs especially in patients with a history of immunosuppression, comorbidity, or multiple antibiotherapy uses. A retrospective 10-year study was carried out to determine the clinical characteristics of all patients with S. maltophilia pneumonia, antibiotic resistance pattern, and risk factors associated with hospital mortality.

MATERIALS AND METHODS

Hospitalized pneumonia patients with S. maltophilia culture positivity were identified, and their medical records were reviewed. Risk factors associated with hospital mortality were analyzed. Any variable with a significant association with mortality in the univariate analysis was entered in a multivariate forward stepwise logistic regression model to identify independent risk factors for death.

RESULTS

Seventy-two patients (mean age: 67.3 years, 65.2% males) with S. maltophilia pneumonia were included in the study. All patients had at least one comorbidity. The most common comorbidities were chronic obstructive pulmonary disease, diabetes mellitus, chronic renal failure, malignancy, and cardiac diseases. Percentage resistance to trimethoprim-sulfamethoxazole (5.5%) was lower than that for fluoroquinolones (12.5%). By using multivariate analysis, respiratory insufficiency needed mechanical ventilation, low hemoglobin level, age>65 years, previous antibiotic usage, and hypotension were the independent prognostic factors for mortality.

CONCLUSION

S. maltophilia is emerging as an important pathogen with an increased risk of mortality in patients with respiratory insufficiency who need mechanical ventilation, a low hemoglobin level, >65 years of age, previous antibiotic usage, and hypotension. Empiric therapy should include agents active against S. maltophilia, such as newer fluoroquinolones and trimethoprim-sulfamethoxazole.

Evaluation of Weight-Based Co-trimoxazole Dosing in a Saudi Tertiary Hospital

BACKGROUND

Infections caused by Stenotrophomonas maltophilia (S. maltophilia) and Pneumocystis jirovecii (Pneumocystis jirovecii pneumonia (PJP)) require weight-based dosing for co-trimoxazole. The aim of this study is to assess the appropriateness of co-trimoxazole dosing in adult inpatients for the treatment of these infections.

METHODOLOGY

This is a single-center, cross-sectional study that included adult inpatients treated with co-trimoxazole for a weight-based dose indication (S. maltophilia and PJP). The primary outcome was the appropriateness of co-trimoxazole dosing for these infections.

RESULTS

Forty-three patients were included in the study. Of the 43 patients, 29 (67.4%) were using co-trimoxazole for PJP treatment, and 14 (32.6%) were using it for S. maltophilia treatment. The co-trimoxazole dose was appropriate in 22 (51.2%) patients, 21 (72.4%) in the PJP treatment group, and one (7.1%) in the S. maltophilia treatment group. Underdosing was observed in 21 (48.8%) patients, of whom eight (27.6%) were in the PJP treatment group and 13 (92.9%) were in the S. maltophilia treatment group.

CONCLUSIONS

This study found a relatively high rate of underdosing of co-trimoxazole based on weight in hospitalized adults with PJP and S. maltophilia infections.

Impact of COVID-19 on the distribution of pathogenic bacteria in the lower respiratory tract of the elderly

BACKGROUND

To investigate the distribution of bacterial pathogens of lower respiratory tract infection (LRTI) in hospitalized elderly patients during the COVID-19 epidemic and to explore the influence of COVID-19 on the distribution of bacterial pathogens, to provide guidance for clinical diagnosis.

METHODS

Specimens of sputum from elderly LRTIs patients at Fuding Hospital of China were consecutively collected from October 2022 to January 2023. Cultures and identification were done, and RT-PCR was employed to detect SARS-Cov-2 nucleic acid.

RESULTS

A total of 195 isolates were characterized in 163 sputum samples of consecutive hospitalized elderly patients, of which 11.3% were Gram-positive bacteria and 88.7% were Gram-negative. The top of frequently isolated pathogens was Klebsiella pneumonia (30.3%), Pseudomonas aeruginosa (19.0%), Acinetobacter baumannii (12.8%), Stenotrophomonas maltophili, (7.7%), Escherichia coli (7.2%). According to the results of novel coronavirus nucleic acid detection, the 163 patients were divided into COVID-19 group and non-COVID control (CNT) group. The comparison of bacterial distribution between the groups revealed that Stenotrophomonas maltophilia was lower in the COVID-19 than in the CNT group, while A. baumannii was higher in the COVID-19 group, and the difference was statistically significant (p < .05).

CONCLUSION

The major bacteria identified in sputum culture of hospitalized elderly patients were K. pneumonia, P. aeruginosa, A. baumannii, S. maltophilia, and E. coli. Furthermore, the distribution of S. maltophilia and A. baumannii between the COVID-19 and CNT groups was found to be significantly different (p < .05), while there were no significant differences in the distribution of other bacteria.

Clinical and microbiological characteristics of patients colonized or infected by Stenotrophomonas maltophilia : is resistance to sulfamethoxazole/trimethoprim a problem?

Stenotrophomonas maltophilia has emerged as an important opportunistic pathogen in the last decade. Increased resistance to sulfamethoxazole/trimethoprim (SMX/TMP) has been reported in S. maltophilia strains in the past few years, leading to few therapeutic options. We conducted a prospective multicenter study at two Brazilian teaching hospitals that identified S. maltophilia isolates and evaluated their antimicrobial susceptibility profile, SMX/TMP resistance genes and their clonality profile. A total of 106 non-repeated clinical samples of S. maltophilia were evaluated. Resistance to SMX/TMP was identified in 21.6% of the samples, and previous use of SMX/TMP occurred in 19 (82.6%). PCR detected the sul1 gene in 14 of 106 strains (13.2%). Of these isolates, nine displayed resistance to SMX/TMP. The resistant strains presented a polyclonal profile. This opportunistic pathogen has emerged in immunocompromised hosts, with few therapeutic options, which is aggravated by the description of emerging resistance mechanisms, although with a polyclonal distribution profile.

Unusual case of rapid growing intraabdominal abscess caused by Stenotrophomonas maltophilia after laparoscopic appendectomy due to perforated appendicitis: A case report

INTRODUCTION

An intraabdominal abscess due to Stenotrophomonas maltophilia (S maltophilia) infection is a very rare clinical manifestation. S maltophilia is a glucose nonfermentative, aerobic, gram-negative, mobile, and biofilm-forming bacterium. It is an opportunistic pathogen and uncommon cause of infection. Respiratory tract infections (pneumonia) and bloodstream infections (bacteremia) are the most common clinical manifestations of S maltophilia infection.

CONCLUSIONS

This case report describes an unusual case of a rapidly growing, extremely large intraabdominal abscess (within 1 week during antibiotic therapy), which was detected 2 weeks after a laparoscopic appendectomy was performed for perforated appendicitis and was caused by multidrug-resistant S maltophilia infection.

Antibiotic treatment for Stenotrophomonas maltophilia in people with cystic fibrosis

BACKGROUND

Stenotrophomonas maltophilia is one of the most common emerging multi-drug resistant organisms found in the lungs of people with cystic fibrosis and its prevalence is increasing. Chronic infection with Stenotrophomonas maltophilia has recently been shown to be an independent predictor of pulmonary exacerbation requiring hospitalization and antibiotics. However, the role of antibiotic treatment of Stenotrophomonas maltophilia infection in people with cystic fibrosis is still unclear. This is an update of a previously published review.

OBJECTIVES

The objective of our review is to assess the effectiveness of antibiotic treatment for Stenotrophomonas maltophilia in people with cystic fibrosis. The primary objective is to assess this in relation to lung function and pulmonary exacerbations in the setting of acute pulmonary exacerbations. The secondary objective is to assess this in relation to the eradication of Stenotrophomonas maltophilia.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched a registry of ongoing trials and the reference lists of relevant articles and reviews.Date of latest search: 27 May 2016.

SELECTION CRITERIA

Any randomized controlled trial of Stenotrophomonas maltophilia mono-infection or Stenotrophomonas maltophilia co-infection with Pseudomonas aeruginosa in either the setting of an acute pulmonary exacerbation or a chronic infection treated with suppressive antibiotic therapy.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed the trials identified by the search for potential inclusion in the review.

MAIN RESULTS

The initial search strategy identified only one trial of antibiotic treatment of pulmonary exacerbations that included people with cystic fibrosis with Stenotrophomonas maltophilia. However, this trial had to be excluded because data was not available per pathogen.

AUTHORS' CONCLUSIONS

This review did not identify any evidence regarding the effectiveness of antibiotic treatment for Stenotrophomonas maltophilia in people with cystic fibrosis. Until such evidence becomes available, clinicians need to use their clinical judgement as to whether or not to treat Stenotrophomonas maltophilia infection in people with cystic fibrosis. Randomized clinical trials are needed to address these unanswered clinical questions.