Comprehensive Evaluation of the MBT STAR-BL Module for Simultaneous Bacterial Identification and ß-Lactamase-Mediated Resistance Detection in Gram-Negative Rods from Cultured Isolates and Positive Blood Cultures.

Objective: This study evaluated the capability of a MALDI Biotyper system equipped with the newly introduced MBT STAR-BL module to simultaneously perform species identification and ß-lactamase-mediated resistance detection in bacteremia -causing bacteria isolated from cultured isolates and patient-derived blood cultures (BCs). Methods: Two hundred retrospective cultured isolates and 153 prospective BCs containing Gram-negative rods (GNR) were collected and subjected to direct bacterial identification, followed by the measurement of ß-lactamase activities against ampicillin, piperacillin, cefotaxime, ceftazidime, and meropenem using the MBT STAR-BL module. The results and turnaround times were compared with those of routine microbiological processing. All strains were also characterized by beta-lactamase PCR and sequencing. Results: Using the saponin-based extraction method, MALDI-TOF MS correctly identified bacteria in 116/134 (86.6%) monomicrobial BCs. The detection sensitivities for ß-lactamase activities against ampicillin, piperacillin, third-generation cephalosporin and meropenem were 91.3, 100, 97.9, and 100% for cultured isolates, and 80.4, 100, 68.8, and 40% for monomicrobial BCs (n = 134) respectively. The overall specificities ranged from 91.5 to 100%. Furthermore, the MBT STAR-BL and conventional drug susceptibility test results were concordant in 14/19 (73.7%) polymicrobial cultures. Reducing the logRQ cut-off value from 0.4 to 0.2 increased the direct detection sensitivities for ß-lactamase activities against ampicillin, cefotaxime and meropenem in BCs to 85.7, 87.5, and 100% respectively. The MBT STAR-BL test enabled the reporting of ß-lactamase-producing GNR at 14.16 and 47.64 h before the interim and final reports of routine BCs processing, respectively, were available. Conclusion: The MALDI Biotyper system equipped with the MBT STAR-BL module enables the simultaneous rapid identification of bacterial species and ß-lactamase-mediated resistance from BCs and cultured isolates. Adjustment of the logRQ cut-off value to 0.2 significantly increased the detection sensitivities for clinically important drug-resistant pathogens.

Immunocompromised patients with metastatic cutaneous nodal squamous cell carcinoma of the head and neck: Poor outcome unrelated to the index lesion.

BACKGROUND: Immunocompromised patients with metastatic cutaneous nodal head and neck squamous cell carcinoma (HNSCC) have worse outcomes compared to the immunocompetent. The purpose of this study was to investigate the characteristics of the primary cutaneous squamous cell carcinoma (SCC), nodal pathology, and outcome between these 2 groups. METHODS: Analysis of a prospective database was performed. A 2:1 pooled analysis selected 46 immunocompetent patients matched with 23 immunocompromised patients. Overall survival (OS) and relapse-free survival (RFS) were calculated using the Kaplan-Meier method. RESULTS: No significant difference was found in the primary tumor characteristics between the 2 groups. In the immunocompromised group, RFS (hazard ratio [HR] 2.70; P = .01) and OS (HR 2.32; P = .04) were significantly worse. Extracapsular spread was present in 100% of the immunocompromised patients. CONCLUSION: No significant difference was identified in the primary cutaneous SCC between the immunocompetent and immunocompromised patients. Immunosuppression predicted worse outcome.