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Annals of Hematology May 2024Stenotrophomonas maltophilia (SM) bloodstream infections (BSIs) contribute to significant mortality in hematologic malignancy (HM) and hematopoietic stem cell...
Stenotrophomonas maltophilia (SM) bloodstream infections (BSIs) contribute to significant mortality in hematologic malignancy (HM) and hematopoietic stem cell transplantation (HSCT) patients. A risk score to predict SM BSI could reduce time to appropriate antimicrobial therapy (TTAT) and improve patient outcomes. A single center cohort study of hospitalized adults with HM/HSCT was conducted. Patients had ≥ 1 blood culture with a Gram-negative (GN) organism. A StenoSCORE was calculated for each patient. The StenoSCORE2 was developed using risk factors for SM BSI identified via logistic regression. Receiver operating characteristic (ROC) curves were plotted. Sensitivity and specificity for the StenoSCORE and StenoSCORE2 were calculated. Thirty-six SM patients and 534 non-SM patients were assessed. A StenoSCORE ≥ 33 points was 80% sensitive, 68% specific, and accurately classified 69% of GN BSIs. StenoSCORE2 variables included acute leukemia, prolonged neutropenia, mucositis, ICU admission, recent meropenem and/or cefepime exposure. The StenoSCORE2 performed better than the StenoSCORE (ROC AUC 0.84 vs. 0.77). A StenoSCORE2 ≥ 4 points was 86% sensitive, 76% specific, and accurately classified 77% of GN BSIs. TTAT was significantly longer for patients with SM BSI compared with non-SM BSI (45.16 h vs. 0.57 h; p < 0.0001). In-hospital and 28-day mortality were significantly higher for patients with SM BSI compared to non-SM BSI (58.3% vs. 18.5% and 66.7% vs. 26.4%; p-value < 0.0001). The StenoSCORE and StenoSCORE2 performed well in predicting SM BSIs in patients with HM/HSCT and GN BSI. Clinical studies evaluating whether StenoSCORE and/or StenoSCORE2 implementation improves TTAT and clinical outcomes are warranted.
Topics: Adult; Humans; Stenotrophomonas maltophilia; Cohort Studies; Bacteremia; Hematologic Neoplasms; Sepsis; Retrospective Studies; Risk Factors; Gram-Negative Bacterial Infections
PubMed: 38453704
DOI: 10.1007/s00277-024-05686-z -
European Journal of Microbiology &... May 2024Extensive use of carbapenems may lead to selection pressure for Stenotrophomonas maltophilia (SM) in hospital environments. The aim of our study was to assess the...
Extensive use of carbapenems may lead to selection pressure for Stenotrophomonas maltophilia (SM) in hospital environments. The aim of our study was to assess the possible association between systemic antibiotic use and the incidence of SM. A retrospective, observational study was carried out in a tertiary-care hospital in Hungary, between January 1st 2010 and December 31st 2019. Incidence-density for SM and SM resistant to trimethoprim-sulfamethoxazole (SXT) was standardized for 1000 patient-days, while systemic antibiotic use was expressed as defined daily doses (DDDs) per 100 patient-days. Mean incidence density for SM infections was 0.42/1000 patient-days; 11.08% were were resistant to SXT, the mean incidence density for SXT-resistant SM was 0.047/1000 patient-days. Consumption rate for colistin, glycopeptides and carbapenems increased by 258.82, 278.94 and 372.72% from 2010 to 2019, respectively. Strong and significant positive correlations were observed with the consumption of carbapenems (r: 0.8759; P < 0.001 and r: 0.8968; P < 0.001), SXT (r: 0.7552; P = 0.011 and r: 0.7004; P = 0.024), and glycopeptides (r: 0.7542; P = 0.012 and r: 0.8138; P < 0.001) with SM and SXT-resistant SM incidence-density/1000 patient-days, respectively. Implementation of institutional carbapenem-sparing strategies are critical in preserving these life-saving drugs, and may affect the microbial spectrum of infections in clinical settings.
PubMed: 38441614
DOI: 10.1556/1886.2024.00022 -
International Journal of Biological... Apr 2024Infections caused by multidrug-resistant pathogens are one of the biggest challenges facing the healthcare system today. Quorum quenching (QQ) enzymes have the potential...
Infections caused by multidrug-resistant pathogens are one of the biggest challenges facing the healthcare system today. Quorum quenching (QQ) enzymes have the potential to be used as innovative enzyme-based antivirulence therapeutics to combat infections caused by multidrug-resistant pathogens. The main objective of this research was to describe the novel YtnP lactonase derived from the clinical isolate Stenotrophomonas maltophilia and to investigate its antivirulence potential against multidrug-resistant Pseudomonas aeruginosa MMA83. YtnP lactonase, the QQ enzyme, belongs to the family of metallo-β-lactamases. The recombinant enzyme has several advantageous biotechnological properties, such as high thermostability, activity in a wide pH range, and no cytotoxic effect. High-performance liquid chromatography analysis revealed the activity of recombinant YtnP lactonase toward a wide range of N-acyl-homoserine lactones (AHLs), quorum sensing signaling molecules, with a higher preference for long-chain AHLs. Recombinant YtnP lactonase was shown to inhibit P. aeruginosa MMA83 biofilm formation, induce biofilm decomposition, and reduce extracellular virulence factors production. Moreover, the lifespan of MMA83-infected Caenorhabditis elegans was prolonged with YtnP lactonase treatment. YtnP lactonase showed synergistic inhibitory activity in combination with gentamicin and acted additively with meropenem against MMA83. The described properties make YtnP lactonase a promising therapeutic candidate for the development of next-generation antivirulence agents.
Topics: Virulence; Pseudomonas aeruginosa; Stenotrophomonas maltophilia; Virulence Factors; Quorum Sensing; Acyl-Butyrolactones; Carboxylic Ester Hydrolases
PubMed: 38423425
DOI: 10.1016/j.ijbiomac.2024.130421 -
Cancer Reports (Hoboken, N.J.) Mar 2024Stenotrophomonas maltophilia is a bacterial pathogen that can be fatal in hospitalized and immunocompromised patients with mortality as high as 69%. Pediatric cancer...
BACKGROUND
Stenotrophomonas maltophilia is a bacterial pathogen that can be fatal in hospitalized and immunocompromised patients with mortality as high as 69%. Pediatric cancer patients often have risk factors that are common for this infection, making them particularly susceptible. Managing S. maltophilia is especially challenging as it has inherent resistance to several antibiotics. Furthermore, soft tissue infections in neutropenic patients may deviate from the typical clinical presentation of S. maltophilia.
CASE DETAILS
This case series describes an in-depth examination of three cases involving immunocompromised pediatric patients with S. maltophilia infections. Each case exhibited a distinct clinical presentation, encompassing infection of the blood, lung, and skin, which highlights the variability in which S. maltophilia manifests in immunocompromised pediatric patients. These patients were treated at MD Anderson Cancer Center (MDACC) from 2020 to 2023, unfortunately resulting in fatality.
CONCLUSIONS
The study aims to provide valuable insights and guidance for the management of patients with S. maltophilia infections. Emphasizing a heightened clinical suspicion will potentially lead to early initiation of directed therapy against S. maltophilia. Timely intervention may play a pivotal role in improving patient outcomes and reduce further burden to the healthcare system.
Topics: Humans; Child; Stenotrophomonas maltophilia; Anti-Bacterial Agents; Neoplasms; Risk Factors
PubMed: 38419283
DOI: 10.1002/cnr2.1982 -
Antimicrobial Stewardship & Healthcare... 2024and are emerging nosocomial, non-glucose fermenting, Gram-negative pathogens. In this nested case-control trial, independent predictors for infections were...
and are emerging nosocomial, non-glucose fermenting, Gram-negative pathogens. In this nested case-control trial, independent predictors for infections were hemodialysis and recent antibiotic usage (overall), while recent usage of fluoroquinolones, was independently associated with infections. Infections were independently associated with multiple worse outcomes.
PubMed: 38415099
DOI: 10.1017/ash.2024.11 -
Microbiology Spectrum Apr 2024complex (BCC) and are nosocomial pathogens that cause various infections and exhibit high resistance to multiple antimicrobial agents. In this study, we aimed to...
complex (BCC) and are nosocomial pathogens that cause various infections and exhibit high resistance to multiple antimicrobial agents. In this study, we aimed to develop a duplex droplet digital PCR (ddPCR) assay for detecting BCC and in bloodstream infections. We optimized the experimental conditions by setting the annealing temperature to 51°C and determining the optimal concentrations of primers and probes, as well as the thermal cycle numbers. The feasibility of the duplex ddPCR reaction system with the optimal conditions was established and verified through parallel reactions with reference strains of BCC and . The specificity of the assay, tested with 33 reference strains, was found to be 100%. The duplex ddPCR assay demonstrated good repeatability and could detect as low as 5.35 copies/reaction of BCC and 7.67 copies/reaction of . This level of sensitivity was consistent in the simulated blood and blood bottle samples. We compared nucleic acid extraction methods and found that the Chelex-100 boiling method and kit extraction method exhibited similar detection sensitivity, suggesting the potential application of the Chelex-100 boiling method in the ddPCR assay. In the clinical samples, the duplex ddPCR assay accurately detected BCC and in 58 cases. In conclusion, our study successfully developed a duplex ddPCR assay that provides accurate and convenient detection of BCC and in bloodstream infections.IMPORTANCE complex (BCC) and are implicated in a wide range of infections, including bloodstream infections (BSIs), pneumonia, and meningitis, and often exhibit high intrinsic resistance to multiple antimicrobial agents, limiting therapeutic options. The gold standard for diagnosing bloodstream infections remains blood culture. However, current blood culture detection and positivity rates do not meet the "rapid diagnosis" required for the diagnosis and treatment of critically ill patients with BSIs. The digital droplet PCR (ddPCR) method is a potentially more powerful tool in the diagnosis of BSIs compared to other molecular methods due to its greater sensitivity, specificity, accuracy, and reproducibility. In this study, a duplex ddPCR assay for the detection of BCC and in BSIs was developed.
Topics: Humans; Burkholderia cepacia complex; Stenotrophomonas maltophilia; Reproducibility of Results; Polymerase Chain Reaction; Sepsis; Anti-Infective Agents; Polystyrenes; Polyvinyls
PubMed: 38411052
DOI: 10.1128/spectrum.03569-23 -
Erratum to time-course transcriptome analysis of lungs from mice infected with inhaled aerosolized .Journal of Thoracic Disease Jan 2024[This corrects the article DOI: 10.21037/jtd-23-1138.].
[This corrects the article DOI: 10.21037/jtd-23-1138.].
PubMed: 38410534
DOI: 10.21037/jtd-2023-20 -
International Journal of Infectious... May 2024Doxycycline post exposure prophylaxis (PEP) has been shown to reduce the incidence of bacterial STIs. However, if there is genetic linkage between resistance to...
OBJECTIVES
Doxycycline post exposure prophylaxis (PEP) has been shown to reduce the incidence of bacterial STIs. However, if there is genetic linkage between resistance to tetracycline and other antimicrobials, then it could also select for resistance to these other antimicrobials. We therefore undertook to evaluate if there is an association between the minimum inhibitory concentrations (MICs) of tetracycline and other antimicrobials in 19 clinically important bacterial species.
METHODS
Mixed-effects linear regression was used to assess if minocycline MICs were associated with the MICs of eight other antimicrobials (ceftriaxone, ampicillin, oxacillin, vancomycin, erythromycin, levofloxacin, amikacin, and trimethoprim-sulfamethoxazole) in 19 bacterial species in the Antimicrobial Testing Leadership and Surveillance (ATLAS) database.
RESULTS
With the notable exception of vancomycin, where no association was found, strong positive associations were typically found between the MICs of minocycline and each of the eight antimicrobials in each of the species assessed. For example, the minocycline MICs of all the Gram-positive species were positively associated with ampicillin, ceftriaxone, oxacillin and erythromycin MICs (all P-values < 0.001). The only exceptions were ampicillin for Streptococcus pyogenes and ceftriaxone for S. dysgalactiae, where no significant associations were found. Similarly in the Gram-negative species, the minocycline MICs of all the species except Haemophilus influenzae and Stenotrophomonas maltophilia were positively associated with the MICs of ceftriaxone, ampicillin, levofloxacin and amikacin (all P-values < 0.001).
CONCLUSIONS
There is a theoretical risk that doxycycline PEP could select for resistance not only to tetracyclines but to a range of other antimicrobials in each of the 19 pathobionts assessed.
Topics: Humans; Doxycycline; Minocycline; Levofloxacin; Post-Exposure Prophylaxis; Ceftriaxone; Tetracycline; Amikacin; Vancomycin; Anti-Bacterial Agents; Anti-Infective Agents; Erythromycin; Ampicillin; Oxacillin; Microbial Sensitivity Tests
PubMed: 38395219
DOI: 10.1016/j.ijid.2024.02.017 -
Frontiers in Medicine 2024
PubMed: 38357653
DOI: 10.3389/fmed.2024.1340358 -
Frontiers in Microbiology 2024Endosymbiotic bacteria (ESB) have important effects on their hosts, contributing to its growth, reproduction and biological functions. Although the effects of exogenous...
Endosymbiotic bacteria (ESB) have important effects on their hosts, contributing to its growth, reproduction and biological functions. Although the effects of exogenous bacteria on the trap formation of nematode-trapping fungi (NTF) have been revealed, the effects of ESB on NTF remain unknown. In this study, we investigated the species diversity of ESB in the NTF using high-throughput sequencing and culture-dependent approaches, and compared bacterial profiles to assess the effects of strain source and culture media on . PICRUSt2 and FAPROTAX were used to predict bacterial function. Our study revealed that bacterial communities in displayed high diversity and heterogeneity, with Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria as the dominant phyla. The ESB between groups isolated from different habitats and cultured in the same medium were more similar to each other than the other groups isolated from the same habitat but cultured in different media. Function analysis predicted a broad and diverse functional repertoire of ESB in , and unveiled that ESB have the potential to function in five modules of the nitrogen metabolism. We isolated nitrogen-fixing and denitrifying bacteria from the ESB and demonstrated their effects on trap formation of . Among seven bacteria that we tested, three bacterial species , and were found to be efficient in inducing trap formation. In conclusion, this study revealed extensive ESB diversity within NTF and demonstrated that these bacteria likely play important roles in nitrogen cycling, including nematode trap formation.
PubMed: 38348183
DOI: 10.3389/fmicb.2024.1349447