Endocarditis caused by Stenotrophomonas maltophilia

Stenotrophomonas maltophilia: An Urgent Threat with Increasing Antibiotic Resistance

Stenotrophomonas maltophilia is a Gram-negative opportunistic pathogen that can cause many infections, such as chronic pulmonary infections in patients with cystic fibrosis and infections in immunocompromised patients with hematology-oncology diseases. Because of its remarkable and increasing antimicrobial resistance, the treatment of S. maltophilia infections is quite challenging. Meanwhile, the prevalence of S. maltophilia infections is increasing in recent decades. S. maltophilia is usually considered to be of low virulence but has numerous virulence factors involved in the pathogenesis of infections caused by S. maltophilia. By revealing its pathogenesis associated with virulence factors and molecular mechanisms of antimicrobial resistance, many existing or potential therapeutic strategies have been developed. However, because of the limited treatment options, new strategies are urgently needed. Here, we review the recent progresses in research on S. maltophilia which may help to develop more effective treatments against this increasing threat.

Global prevalence and distribution of antibiotic resistance among clinical isolates of Stenotrophomonas maltophilia: A systematic review and meta-analysis

OBJECTIVES

Stenotrophomonas maltophilia (S. maltophilia), an opportunistic pathogen, causes infection in patients undergoing immunosuppressive therapy, mechanical ventilation, or catheters and in long-term hospitalized patients. Due to its extensive resistance to various antibiotics and chemotherapeutic agents, S. maltophilia is challenging to treat. Using case reports, case series, and prevalence studies, the current study provides a systematic review and meta-analysis of antibiotic resistance profiles across clinical isolates of S. maltophilia.

METHODS

A systematic literature search was performed for original research articles published in Medline, Web of Science, and Embase databases from 2000 to 2022. Statistical analysis was performed using STATA 14 software to report antibiotic resistance of S. maltophilia clinical isolates worldwide.

RESULTS

223 studies (39 case reports/case series and 184 prevalence studies) were collected for analysis. A meta-analysis of prevalence studies demonstrated that the most antibiotic resistance worldwide was to levofloxacin, trimethoprim-sulfamethoxazole (TMP/SMX), and minocycline (14.4%, 9.2%, and 1.4%, respectively). Resistance to TMP/SMX (36.84%), levofloxacin (19.29%), and minocycline (1.75%) were the most prevalent antibiotic resistance types found in evaluated case reports/case series studies. The highest resistance rate to TMP/SMX was reported in Asia (19.29%), Europe (10.52%), and America (7.01%), respectively.

CONCLUSION

Considering the high resistance to TMP/SMX, more attention should be paid to patients' drug regimens to prevent the emergence of multidrug-resistant S. maltophilia isolates.

Xanthogranulomatous Pyelonephritis Caused by Stenotrophomonas maltophilia—The First Case Report and Brief Review

Xanthogranulomatous pyelonephritis (XGP) represents a rare and severe pathology secondary to chronic urinary obstruction and recurrent infections. Commonly, this condition leads to loss of kidney function, and frequently, surgical approach is the only optional treatment. Proteus mirabilis and Escherichia coli are the most frequent pathogens associated with XGP. The actual changes in the pathogen’s characteristics increased the risk of newly acquired infections once considered opportunistic. Stenotrophomonas malthophilia is one of those agents more related to immunocompromised patients, presenting an increased incidence and modified antibiotic resistance profile in the modern era. This case report presents a healthy female patient with an underlying renal stone pathology diagnosed with XGP related to S. maltophilia urinary infection. After a complete biological and imagistic evaluation, the case was treated as pyonephrosis. Empirical antibiotic administration and a surgical approach were considered. A total nephrectomy was performed, but the patient’s condition did not improve. The patient’s status improved when specific antibiotics were administered based on the bacterial identification and antibiotic susceptibility pattern of drained perinephric fluid. Levofloxacin and Vancomycin were considered the optimal combination in this case. The histopathological examination revealed XGP secondary to chronic renal stone. The present study describes the first case of XGP related to an aerobic Gram-negative pathogen such as S. maltophilia, once considered opportunistic, in an apparently healthy female adult.

Stenotrophomonas maltophilia: an emerging global opportunistic pathogen

Stenotrophomonas maltophilia is an emerging multidrug-resistant global opportunistic pathogen. The increasing incidence of nosocomial and community-acquired S. maltophilia infections is of particular concern for immunocompromised individuals, as this bacterial pathogen is associated with a significant fatality/case ratio. S. maltophilia is an environmental bacterium found in aqueous habitats, including plant rhizospheres, animals, foods, and water sources. Infections of S. maltophilia can occur in a range of organs and tissues; the organism is commonly found in respiratory tract infections. This review summarizes the current literature and presents S. maltophilia as an organism with various molecular mechanisms used for colonization and infection. S. maltophilia can be recovered from polymicrobial infections, most notably from the respiratory tract of cystic fibrosis patients, as a cocolonizer with Pseudomonas aeruginosa. Recent evidence of cell-cell communication between these pathogens has implications for the development of novel pharmacological therapies. Animal models of S. maltophilia infection have provided useful information about the type of host immune response induced by this opportunistic pathogen. Current and emerging treatments for patients infected with S. maltophilia are discussed.

Stenotrophomonas maltophilia: antimicrobial resistance and molecular typing of an emerging pathogen in a Turkish university hospital

Despite its limited pathogenicity, Stenotrophomonas maltophilia is an emerging nosocomial pathogen. This study investigated the isolation frequency, antimicrobial resistance and genotypic relationships of 205 S. maltophilia isolates from 188 patients in a university hospital between 1998 and 2003. Susceptibility profiles for 11 antimicrobial agents were determined by the NCCLS agar dilution method for non-fermentative bacteria, while enterobacterial repetitive intergenic consensus sequence (ERIC)-PCR and pulsed-field gel electrophoresis (PFGE) were used for genotyping of the isolates. Of the 205 isolates, 56.1% were isolated in the last 2 years of the study. The risk of S. maltophilia isolation was higher in intensive care units, S. maltophilia was isolated mostly (86.8%) after hospitalisation for >or= 48 h, and 90.4% of the patients had underlying diseases. Resistance levels were>60% for all antimicrobial agents tested except co-trimoxazole. High genetic diversity was found among the S. maltophilia isolates, and cross-infection with S. maltophilia was not common. Although ERIC-PCR revealed fewer genotypes than PFGE, it proved to be a rapid and easy method for S. maltophilia genotyping, and was more economical than PFGE.

Stenotrophomonas maltophilia endocarditis

Stenotrophomonas maltophilia is a gram-negative bacillus that is increasingly associated with serious nosocomial infections, especially in immunocompromised patients; however, the occurrence of endocarditis due to this organism is rare. This report describes a case of S. maltophilia endocarditis associated with a central venous catheter. The literature on Stenotrophomonas endocarditis is reviewed. Given the high morbidity and mortality of these infections, early antibiotic therapy utilizing trimethoprim-sulfamethoxazole, along with a second agent and removal of prosthetic devices, is recommended.

Stenotrophomonas maltophilia endocarditis: a systematic review

The disease characteristics, management, and outcome of Stenotrophomonas maltophilia endocarditis were evaluated by examining the reports on the subject identified through a comprehensive literature search. Twenty-three (17 male) cases of S.. maltophilia endocarditis were identified. Mean age was 41 +/- 15 years. All patients presented with fever. Prosthetic valves were involved in 12 (52%) cases. Among native valves, the aortic valve was most frequently involved (50%), followed by the tricuspid valve (36%). Twenty (87%) patients had underlying risk factors for the development of endocarditis, including prior valvular or congenital heart disease surgery (60%), intravenous drug abuse (32%), and infected intravascular lines (18%). The endocarditis was postoperative in 14 patients. Seventeen (74%) patients experienced complications including septic embolism (23%), cardiac abscesses (23%), and congestive heart failure (18%). A combination of two or more antibiotics was used in all cases except one. The frequently used antibiotics were aminoglycosides (59%), trimethoprim-sulfamethoxazole (48%), and penicillins (48%). One half of the patients required cardiac surgery, but the proportion of surgically treated cases was higher among prosthetic valve endocarditis (62%). Mortality was 39% and was equally distributed between patients with prosthetic and native valve endocarditis. The S. maltophilia endocarditis carries high complication and mortality rates. The antibiotic regimen should consist of a combination of multiple antibiotics guided by the sensitivity panel. Early surgery may be considered in patients not responding to antibiotic treatment and in those with prosthetic valve endocarditis.