-
Antimicrobial Resistance and Infection... Jan 2021Stenotrophomonas maltophilia (S. maltophilia) is an opportunistic and nosocomial pathogen that can cause an invasive and fatal infection, particularly in hospitalized...
PURPOSE
Stenotrophomonas maltophilia (S. maltophilia) is an opportunistic and nosocomial pathogen that can cause an invasive and fatal infection, particularly in hospitalized and immunocompromised patients. However, little is known about the impact of S. maltophilia bacteremia in pediatric patients. Therefore, we aimed to identify risk factors for mortality, antibiotics susceptibility to S. maltophilia, and mortality rates in pediatric patients with S. maltophilia bacteremia.
METHODS
We conducted a retrospective cohort study by identifying all S. maltophilia positive blood cultures in the microbiology laboratory database between January 2007 and December 2018 from hospitalized pediatric patients (age 1-14 years). After identifying patients with S. maltophilia bacteremia, medical charts were reviewed for demographics, clinical data, and outcomes within seven days of bacteremia diagnosis. Risk factors associated with mortality in S. maltophilia bacteremia patients were determined using univariate and multivariate analyses.
FINDINGS
Sixty-eight pediatric patients with S. maltophilia bacteremia were identified. All infections were nosocomial infections, and (88.2%) bacteremia cases were catheter-related bloodstream infections. On multivariate analysis, ICU admission prior to bacteremia episode and neutropenia were the major risk factors associated with mortality. S. maltophilia was the most susceptible to trimethoprim and sulfamethoxazole (TMP/SMX, 94.1%), followed by levofloxacin (85.7%). The overall mortality rate within seven days of S. maltophilia bacteremia diagnosis was 33.8%.
CONCLUSION
S. maltophilia bacteremia is a devastating emerging infection associated with high mortality among hospitalized children. Therefore, early diagnosis and prompt management based on local susceptibility data are crucial. Various risk factors, especially ICU admission prior to bacteremia episode and neutropenia, are associated with S. maltophilia bacteremia mortality.
Topics: Adolescent; Anti-Bacterial Agents; Catheter-Related Infections; Child; Child, Preschool; Cross Infection; Female; Gram-Negative Bacterial Infections; Humans; Infant; Intensive Care Units; Male; Microbial Sensitivity Tests; Neutropenia; Retrospective Studies; Risk Factors; Saudi Arabia; Stenotrophomonas maltophilia
PubMed: 33482916
DOI: 10.1186/s13756-021-00888-w -
Infectious Diseases & Clinical... Dec 2022There are many difficulties in diagnosing and treating bacteremia. In this study, we aimed to evaluate "true" and "false-positive bacteremia" and assess mortality risk...
OBJECTIVE
There are many difficulties in diagnosing and treating 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 -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 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 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 bacteremia considering antimicrobial resistance and adverse effects or toxicity.
PubMed: 38633723
DOI: 10.36519/idcm.2022.187 -
Open Forum Infectious Diseases May 2022is an underappreciated source of morbidity and mortality among gram-negative pathogens. Effective treatment options with acceptable toxicity profiles are limited.... (Review)
Review
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 . 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 . Combination therapy is often employed despite the dearth of adequate supporting data.
PubMed: 35415194
DOI: 10.1093/ofid/ofac095 -
Expert Review of Anti-infective Therapy Nov 2019: Infections caused by the opportunistic pathogen in immunocompromised patients are complicated to treat due to antibiotic resistance and the ability of the bacteria to... (Review)
Review
: Infections caused by the opportunistic pathogen in immunocompromised patients are complicated to treat due to antibiotic resistance and the ability of the bacteria to produce biofilm.: A MEDLINE/PubMed search was performed of available literature to describe the role of biofilm produced by in the diseases it causes, including biofilm-influencing factors, the biofilm forming process and composition. The antimicrobial resistance due to biofilm production and current antibiofilm strategies is also included.: Through the production of biofilm, strains can easily adhere to the surfaces in hospital settings and aid in its transmission. The biofilm can also cause antibiotic tolerance rendering some of the therapeutic options ineffective, causing setbacks in the selection of an appropriate treatment. Conventional susceptibility tests do not yet offer therapeutic guidelines to treat biofilm-associated infections. Current biofilm control strategies include natural and synthetic compounds, chelating agents, and commonly prescribed antibiotics. As biofilm age and matrix composition affect the level of antibiotic tolerance, their characterization should be included in biofilm susceptibility testing, in addition to molecular and proteomic analyzes. As for now, several commonly recommended antibiotics can be used to treat biofilm-related infections.
Topics: Animals; Anti-Bacterial Agents; Biofilms; Gram-Negative Bacterial Infections; Humans; Immunocompromised Host; Microbial Sensitivity Tests; Proteomics; Stenotrophomonas maltophilia
PubMed: 31658838
DOI: 10.1080/14787210.2019.1685875 -
Acta Crystallographica. Section F,... Jul 2023The resistance of the emerging human pathogen Stenotrophomonas maltophilia to tetracycline antibiotics mainly depends on multidrug efflux pumps and ribosomal protection...
The resistance of the emerging human pathogen Stenotrophomonas maltophilia to tetracycline antibiotics mainly depends on multidrug efflux pumps and ribosomal protection enzymes. However, the genomes of several strains of this Gram-negative bacterium code for a FAD-dependent monooxygenase (SmTetX) homologous to tetracycline destructases. This protein was recombinantly produced and its structure and function were investigated. Activity assays using SmTetX showed its ability to modify oxytetracycline with a catalytic rate comparable to those of other destructases. SmTetX shares its fold with the tetracycline destructase TetX from Bacteroides thetaiotaomicron; however, its active site possesses an aromatic region that is unique in this enzyme family. A docking study confirmed tetracycline and its analogues to be the preferred binders amongst various classes of antibiotics.
Topics: Humans; Stenotrophomonas maltophilia; Crystallography, X-Ray; Anti-Bacterial Agents; Tetracycline; Oxytetracycline; Microbial Sensitivity Tests
PubMed: 37405486
DOI: 10.1107/S2053230X23005381 -
Future Microbiology Jan 2021To evaluate the activity of five antimicrobials against young and mature biofilms. Nineteen clinical strains from hemoculture of hemodialysis patients were tested for...
To evaluate the activity of five antimicrobials against young and mature biofilms. Nineteen clinical strains from hemoculture of hemodialysis patients were tested for biofilm kinetics, MIC and minimum biofilm inhibitory concentration (MBIC) in young and mature biofilms. All strains were moderate biofilm producers. MIC showed total susceptibility to levofloxacin and trimethoprim-sulfamethoxazole and partial resistance to ceftazidime (63.2%) and gentamicin (21%). Young and mature biofilms showed the lowest MBIC/MIC ratio for gentamicin, chloramphenicol and levofloxacin, respectively. The highest MBIC/MIC was for trimethoprim-sulfamethoxazole (young) and ceftazidime (mature). Gentamicin displayed surprising activity against biofilms. Chloramphenicol was indicated as a good option against young biofilms, and trimethoprim-sulfamethoxazole showed limited antibiofilm activity.
Topics: Anti-Bacterial Agents; Biofilms; Ceftazidime; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacterial Infections; Humans; Levofloxacin; Microbial Sensitivity Tests; Minocycline; Stenotrophomonas maltophilia; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 33470844
DOI: 10.2217/fmb-2020-0115 -
Annals of Clinical Microbiology and... Mar 2024Infections caused by Stenotrophomonas maltophilia are clinically important due to its intrinsic resistance to a broad range of antibiotics. Therefore, selecting the most... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Infections caused by Stenotrophomonas maltophilia are clinically important due to its intrinsic resistance to a broad range of antibiotics. Therefore, selecting the most appropriate antibiotic to treat S. maltophilia infection is a major challenge.
AIM
The current meta-analysis aimed to investigate the global prevalence of antibiotic resistance among S. maltophilia isolates to the develop more effective therapeutic strategies.
METHOD
A systematic literature search was performed using the appropriate search syntax after searching Pubmed, Embase, Web of Science and Scopus databases (May 2023). Statistical analysis was performed using Pooled and the random effects model in R and the metafor package. A total of 11,438 articles were retrieved. After a thorough evaluation, 289 studies were finally eligible for inclusion in this systematic review and meta-analysis.
RESULT
Present analysis indicated that the highest incidences of resistance were associated with doripenem (97%), cefoxitin (96%), imipenem and cefuroxime (95%), ampicillin (94%), ceftriaxone (92%), aztreonam (91%) and meropenem (90%) which resistance to Carbapenems is intrinsic. The lowest resistance rates were documented for minocycline (3%), cefiderocol (4%). The global resistance rate to TMP-SMX remained constant in two periods before and after 2010 (14.4% vs. 14.6%). A significant increase in resistance to tigecycline and ceftolozane/tazobactam was observed before and after 2010.
CONCLUSIONS
Minocycline and cefiderocol can be considered the preferred treatment options due to low resistance rates, although regional differences in resistance rates to other antibiotics should be considered. The low global prevalence of resistance to TMP-SMX as a first-line treatment for S. maltophilia suggests that it remains an effective treatment option.
Topics: Humans; Trimethoprim, Sulfamethoxazole Drug Combination; Minocycline; Stenotrophomonas maltophilia; Microbial Sensitivity Tests; Anti-Bacterial Agents; Cefiderocol; Drug Resistance, Microbial; Gram-Negative Bacterial Infections
PubMed: 38504262
DOI: 10.1186/s12941-024-00685-4 -
Oman Medical Journal May 2023The aim of this study was to determine the phenotypic and genotypic characteristics of isolates obtained from blood culture samples of pediatric patients hospitalized...
OBJECTIVES
The aim of this study was to determine the phenotypic and genotypic characteristics of isolates obtained from blood culture samples of pediatric patients hospitalized in Borujerd and Hamadan hospitals in western Iran.
METHODS
Oxidase-negative isolates were collected from the blood cultures of pediatric patients. isolates were identified and confirmed by routine microbiological and molecular testing. Antibiotic susceptibility of the isolates was determined. The phenotypic and genotypic biofilm-forming ability of the isolates were investigated. Molecular typing of all isolates was performed by repetitive element sequence-based polymerase chain reaction.
RESULTS
Out of 450 oxidase-negative bacilli, 72 (16.0%) were identified as isolates. Biofilm assay results showed strong biofilm formation in 19 (26.4%) isolates, moderate in 38 (52.8%), weak in 10 (13.9%), and no biofilm formation in five (6.9%) isolates. Biofilm-associated genes , F, and M were detected respectively in 59 (81.9%), 54 (75.0%), and 72 (100%) of isolates. Antimicrobial susceptibility testing showed that 67 (93.1%) isolates were sensitive to trimethoprim-sulfamethoxazole. All isolates were sensitive to levofloxacin and resistant to ceftazidime. The isolates were grouped into 14 different types of repetitive sequence by repetitive element sequence-based polymerase chain reaction analysis.
CONCLUSIONS
The results of this study indicate that should be considered an important opportunistic pathogen in pediatric units. Different genotypes of with the ability to form a biofilm (an important virulence factor) were circulating in the hospitals investigated. Levofloxacin and trimethoprim-sulfamethoxazole are recommended to treat infections.
PubMed: 37346891
DOI: 10.5001/omj.2023.76 -
Journal of Medical Microbiology Jan 2021has emerged as one of the most common multi-drug-resistant pathogens isolated from people with cystic fibrosis (CF). However, its adaptation over time to CF lungs has...
has emerged as one of the most common multi-drug-resistant pathogens isolated from people with cystic fibrosis (CF). However, its adaptation over time to CF lungs has not been fully established. Sequential isolates of from a Brazilian adult patient are clonally related and show a pattern of adaptation by loss of virulence factors. To investigate antimicrobial susceptibility, clonal relatedness, mutation frequency, quorum sensing (QS) and selected virulence factors in sequential isolates from a Brazilian adult patient attending a CF referral centre in Buenos Aires, Argentina, between May 2014 and May 2018. The antibiotic resistance of 11 S. isolates recovered from expectorations of an adult female with CF was determined. Clonal relatedness, mutation frequency, QS variants (RpfC-RpfF), QS autoinducer (DSF) and virulence factors were investigated in eight viable isolates. Seven isolates were resistant to trimethoprim-sulfamethoxazole and five to levofloxacin. All isolates were susceptible to minocycline. Strong, weak and normomutators were detected, with a tendency to decreased mutation rate over time. PFGE revealed that seven isolates belong to two related clones. All isolates were RpfC-RpfF1 variants and DSF producers. Only two isolates produced weak biofilms, but none displayed swimming or twitching motility. Four isolates showed proteolytic activity and amplified and genes. Only the first three isolates were siderophore producers. Four isolates showed high resistance to oxidative stress, while the last four showed moderate resistance. The present study shows the long-time persistence of two related clones in an adult female with CF. During the adaptation of the prevalent clones to the CF lungs over time, we identified a gradual loss of virulence factors that could be associated with the high amounts of DSF produced by the evolved isolates. Further, a decreased mutation rate was observed in the late isolates. The role of all these adaptations over time remains to be elucidated from a clinical perspective, probably focusing on the damage they can cause to CF lungs.
Topics: Adult; Anti-Bacterial Agents; Bacterial Proteins; Cystic Fibrosis; Drug Resistance, Bacterial; Female; Genotype; Gram-Negative Bacterial Infections; Humans; Lung; Male; Mutation; Phenotype; Phylogeny; Sputum; Stenotrophomonas maltophilia; Young Adult
PubMed: 33258754
DOI: 10.1099/jmm.0.001281 -
Journal of the European Academy of... Jun 2023
Topics: Humans; Stenotrophomonas maltophilia; Anti-Bacterial Agents; Cellulitis; Skin Diseases, Infectious
PubMed: 36682050
DOI: 10.1111/jdv.18902