Implication of genotypes for prognosis of Candida glabrata bloodstream infections.

BACKGROUND: Genotyping isolates of a specific pathogen may demonstrate unique patterns of antimicrobial resistance, virulence or outcomes. However, evidence for genotype-outcome association in Candida glabrata is scarce. We aimed to characterize the mycological and clinical relevance of genotypes on C. glabrata bloodstream infections (BSIs). METHODS: Non-duplicated C. glabrata blood isolates from hospitalized adults were genotyped by MLST, and further clustered by the unweighted pair group method with arithmetic averages (UPGMA). A clonal complex (CC) was defined by UPGMA similarities of >90%. Antifungal susceptibility testing was performed by a colorimetric microdilution method and interpreted following CLSI criteria. RESULTS: Of 48 blood isolates evaluated, 13 STs were identified. CC7 was the leading CC (n = 14; 29.2%), including 13 ST7. The overall fluconazole and echinocandin resistance rates were 6.6% and 0%, respectively. No specific resistance patterns were associated with CC7 or other CCs. Charlson comorbidity index (adjusted OR, 1.49; 95% CI, 1.05-3.11) was the only predictor for CC7. By multivariable Cox regression analyses, CC7 was independently associated with 28 day mortality [adjusted HR (aHR), 3.28; 95% CI, 1.31-8.23], even after considering potential interaction with neutropenia (aHR, 3.41; 95% CI, 1.23-9.42; P for interaction, 0.24) or limited to 34 patients with monomicrobial BSIs (aHR, 2.85; 95% CI, 1.15-7.08). Also, the Kaplan-Meier estimate showed greater mortality with CC7 (P = 0.003). Fluconazole resistance or echinocandin therapy had no significant impact on mortality. CONCLUSIONS: Our data suggested comorbid patients were at risk of developing CC7 BSIs. Further, CC7 was independently associated with worse outcomes.

Serological responses to COVID-19 vaccination in patients with chronic liver diseases.

Longitudinal analysis of antibody responses following three-dose COVID-19 vaccination in patients with chronic liver disease (CLD) has been limited. From August 2021 to February 2023, sequential anti-SARS-CoV-2 spike IgG titers were determined in 45 patients with CLD who received two or three doses of COVID-19 vaccine. The geometric mean of anti-spike IgG at four weeks after the second and third doses were 1313.16 BAU/mL and 3042.29 BAU/mL, respectively, and it decreased significantly from four to 24 weeks after the second (1313.16 vs. 198.42 BAU/mL, p = 0.002) and the third (3042.29 vs. 636.71 BAU/mL, p < 0.001) dose. The anti-spike IgG titers in participants receiving prime-boost homologous mRNA vaccines (BNT162b2 or mRNA-1273) were comparable between participants with and those without significant liver fibrosis at each follow-up time point. This study demonstrated a notable decrease in anti-spike IgG after completion of the vaccination schedule in patients with CLD, highlighting the importance of additional booster doses.

CXCL9 as a Reliable Biomarker for Discriminating Anti-IFN-γ-Autoantibody-Associated Lymphadenopathy that Mimics Lymphoma.

The diagnosis of adult-onset immunodeficiency syndrome associated with neutralizing anti-interferon γ autoantibodies (AIGA) presents substantial challenges to clinicians and pathologists due to its nonspecific clinical presentation, absence of routine laboratory tests, and resemblance to certain lymphoma types, notably nodal T follicular helper cell lymphoma, angioimmunoblastic type (nTFHL-AI). Some patients undergo lymphadenectomy for histopathological examination to rule out lymphoma, even in the absence of a preceding clinical suspicion of AIGA. This study aimed to identify reliable methods to prevent misdiagnosis of AIGA in this scenario through a retrospective case-control analysis of clinical and pathological data, along with immune gene transcriptomes using the NanoString nCounter platform, to compare AIGA and nTFHL-AI. The investigation revealed a downregulation of the C-X-C motif chemokine ligand 9 (CXCL9) gene in AIGA, prompting an exploration of its diagnostic utility. Immunohistochemistry (IHC) targeting CXCL9 was performed on lymph node specimens to assess its potential as a diagnostic biomarker. The findings exhibited a significantly lower density of CXCL9-positive cells in AIGA compared to nTFHL-AI, displaying a high diagnostic accuracy of 92.3% sensitivity and 100% specificity. Furthermore, CXCL9 IHC demonstrated its ability to differentiate AIGA from various lymphomas sharing similar characteristics. In conclusion, CXCL9 IHC emerges as a robust biomarker for differentiating AIGA from nTFHL-AI and other similar conditions. This reliable diagnostic approach holds the potential to avert misdiagnosis of AIGA as lymphoma, providing timely and accurate diagnosis.

In vitro activity of cefiderocol and comparator antibiotics against multidrug-resistant non-fermenting Gram-negative bacilli.

Background: This study evaluated the in vitro activity of cefiderocol, ceftazidime/avibactam, and aztreonam/avibactam against clinically important multidrug-resistant non-fermenting Gram-negative bacilli. Methods: Bacteraemic isolates of 126 multidrug-resistant Acinetobacter baumannii (MDRAB), 110 imipenem-resistant Pseudamoas aeruginosa [including 14 difficult-to-treat resistant P. aeruginosa (DTRPA)], 45 beta-lactam-non-susceptible Burkholderia cepacia complex (BCC), 47 levofloxacin or trimethoprim/sulfamethoxazole-non-susceptible Stenotrophomonas maltophilia and 22 ciprofloxacin-non-susceptible Elizabethkingia spp. collected between 2019 and 2021 were subjected to MIC determination for cefiderocol, ceftazidime/avibactam and aztreonam/avibactam. Results: The MIC50/90s of cefiderocol for drug-resistant A. baumannii, P. aeruginosa, BCC, S. maltophilia and Elizabethkingia spp. were 0.25/2, 0.25/1, ≤0.06/≤0.06, ≤0.06/0.25 and >32/>32 mg/L, respectively. Cefiderocol inhibited 94.4% (119/126) of MDRAB, 100% of imipenem-resistant P. aeruginosa, 100% of DTRPA and 100% of BCC at an MIC ≤4 mg/L, and 97.9% (46/47) of S. maltophilia at ≤1 mg/L. Ceftazidime/avibactam inhibited 76.4% (84/110) of imipenem-resistant P. aeruginosa, 21.4% (3/14) of DTRPA and 68.9% (31/45) of BCC at an MIC ≤8 mg/L. Aztreonam/avibactam had MIC50/90s of 16/>32, 8/16 and 4/8 mg/L for imipenem-resistant P. aeruginosa, BCC and S. maltophilia, respectively. At ≤8 mg/L, aztreonam/avibactam inhibited 7.1% (1/14) of DTRPA and 93.6% (44/47) of S. maltophilia isolates. Elizabethkingia spp. demonstrated high MICs for cefiderocol, ceftazidime/avibactam and aztreonam/avibactam, with all MIC50s and MIC90s > 32 mg/L. Conclusion: Cefiderocol may serve as an alternative treatment for multidrug-resistant A. baumannii, P. aeruginosa, BCC and S. maltophilia when other antibiotics have been ineffective or intolerable. The role of ceftazidime/avibactam and aztreonam/avibactam in the management of BCC or S. maltophilia infections warrants further investigation.

Case Report: Pericardial Actinomycosis in a 79-Year-Old Man with Poor Dental Hygiene.

Actinomycosis is an uncommon infection caused by Actinomyces species, and the diagnosis is often challenging owing to low prevalence and diverse clinical manifestations. Pericardial involvement of actinomycosis is particularly rare. Here, we present a case of a 79-year-old man who initially complained of exertional dyspnea, orthopnea, and decreased urine amount. There was no fever, chest pain, or productive cough. Physical examination was remarkable for decreased breath sounds at the left lower lung field. Poor dental hygiene and a firm, well-defined mass without discharge over the hard palate were noted. Echocardiography revealed reduced ejection fraction of the left ventricle, global hypokinesia, and thickened pericardium (> 5 mm) with a small amount of pericardial effusion. On admission, the patient underwent diagnostic thoracentesis, and the results suggested an exudate. However, bacterial and fungal cultures were all negative. There was no malignant cell by cytology. Computed tomography revealed contrast-enhanced pericardial nodular masses. Video-assisted thoracoscopic pericardial biopsy was performed. Histopathology confirmed actinomycosis with chronic abscess formation, and a tissue culture yielded Aggregatibacter actinomycetemcomitans. The symptoms resolved with administration of clindamycin for 6 months. This case highlights the challenge in the diagnosis of cardiac actinomycosis, the potential role of concomitant microorganisms as diagnostic clues, and the favorable clinical response achieved with appropriate antibiotic treatment.

Ribotypes and antimicrobial susceptibility profiles of clinical Clostridioides difficile isolates: A multicenter, laboratory-based surveillance in Taiwan, 2019-2021.

BACKGROUND: The clinical burden of Clostridioides difficile infections (CDIs) remains substantial globally. This study aimed to investigate the ribotypes (RTs) and antimicrobial susceptibility of C. difficile isolates collected in Taiwan. METHODS: C. difficile isolates were prospectively collected from four medical centers in Taiwan from 2019 to 2021. In a reference laboratory, in vitro susceptibility to clindamycin, moxifloxacin, metronidazole, vancomycin, fidaxomicin, and rifaximin were tested, and ribotyping was conducted to determine their genetic diversity. RESULTS: A total of 568 C. difficile isolates were included. Metronidazole resistance was not observed, and the susceptibility rate of vancomycin was 99.5 %. Clindamycin showed poor activity against these isolates, with a resistance rate of 74.8 %. Fidaxomicin exhibited potent activity and 97.4 % of isolates were inhibited at 0.25 µg/mL. Rifaximin MIC90 increased from 0.015 µg/mL in 2019 to 0.03 µg/mL in 2020 and 2021. Of 40 RTs identified, two predominant RTs were RT 078/126 (78, 14 %) and 014/020 (76, 13 %). RT 017, traditional harboring truncated tcdA, accounted for 3 % (20 isolates) and there was no isolate belonging to RT 027. The proportions of RT 078 increased from 11.2 % in 2019 to 17.1 % in 2021, and the predominance of RT 078/126 was more evident in central Taiwan. CONCLUSIONS: Vancomycin, fidaxomicin, and metronidazole remain in vitro effective against clinical C. difficile isolates in Taiwan. The reservoirs and genetic relatedness of two major RTs with zoonotic potentials, RT 078/126 and 014/020, warrant further investigations.

Evaluation of the synergistic effect of eravacycline and tigecycline against carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae.

BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a substantial healthcare challenge. This study assessed the in vitro efficacy of selected antibiotic combinations against CRKP infections. METHODS: Our research involved the evaluation of 40 clinical isolates of CRKP, with half expressing Klebsiella pneumoniae carbapenemase (KPC) and half producing Metallo-ß-lactamase (MBL), two key enzymes contributing to carbapenem resistance. We determined the minimum inhibitory concentrations (MICs) of four antibiotics: eravacycline, tigecycline, polymyxin-B, and ceftazidime/avibactam. Synergistic interactions between these antibiotic combinations were examined using checkerboard and time-kill analyses. RESULTS: We noted significant differences in the MICs of ceftazidime/avibactam between KPC and MBL isolates. Checkerboard analysis revealed appreciable synergy between combinations of tigecycline (35%) or eravacycline (40%) with polymyxin-B. The synergy rates for the combination of tigecycline or eravacycline with polymyxin-B were similar among the KPC and MBL isolates. These combinations maintained a synergy rate of 70.6% even against polymyxin-B resistant isolates. In contrast, combinations of tigecycline (5%) or eravacycline (10%) with ceftazidime/avibactam showed significantly lower synergy than combinations with polymyxin-B (P < 0.001 and P = 0.002, respectively). Among the MBL CRKP isolates, only one exhibited synergy with eravacycline or tigecycline and ceftazidime/avibactam combinations, and no synergistic activity was identified in the time-kill analysis for these combinations. The combination of eravacycline and polymyxin-B demonstrated the most promising synergy in the time-kill analysis. CONCLUSION: This study provides substantial evidence of a significant synergy when combining tigecycline or eravacycline with polymyxin-B against CRKP strains, including those producing MBL. These results highlight potential therapeutic strategies against CRKP infections.

Clinical manifestations and risk factors for COVID-19 and its severity in patients with hematological malignancies.

BACKGROUND: Patients with hematological malignancies (HM) were at a high risk of developing severe disease from coronavirus disease 2019 (COVID-19). We aimed to assess the clinical outcome of COVID-19 in hospitalized patients with HM. METHODS: Adult patients with HM who were hospitalized with a laboratory-confirmed COVID-19 between May, 2021 and November, 2022 were retrospectively identified. Primary outcome was respiratory failure requiring mechanical ventilation or mortality within 60 days after hospitalization. We also analyzed associated factors for de-isolation (defined as defervescence with a consecutive serial cycle threshold value > 30) within 28 days. RESULTS: Of 152 eligible patients, 22 (14.5%) developed respiratory failure or mortality in 60 days. Factors associated with developing respiratory failure that required mechanical ventilation or mortality included receipt of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) (adjusted hazards ratio [aHR], 5.10; 95% confidence interval [CI], 1.64-15.85), type 2 diabetes mellitus (aHR, 2.47; 95% CI, 1.04-5.90), lymphopenia at admission (aHR, 6.85; 95% CI, 2.45-19.15), and receiving <2 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines (aHR, 3.00; 95% CI, 1.19-7.60). Ninety-nine (65.1%) patients were de-isolated in 28 days, against which two hazardous factors were identified: receipt of B-cell depletion therapies within one year prior to COVID-19 (aHR, 0.55, 95% CI, 0.35-0.87) and lymphopenia upon admission (aHR, 0.65; 95% CI, 0.43-1.00). CONCLUSION: We found a high rate of respiratory failure and mortality among patients with HM who contracted the SARS-CoV-2. Factors associated with developing respiratory failure or mortality in 60 days included receipt of allo-HSCT, type 2 diabetes mellitus and lymphopenia upon admission. Having received ≥2 doses of vaccination conferred protection against clinical progression.

Effect of early dexamethasone on outcomes of COVID-19: A quasi-experimental study using propensity score matching.

BACKGROUND: The RECOVERY trial demonstrated that the use of dexamethasone is associated with a 36% lower 28-day mortality in hospitalized patients with COVID-19 on invasive mechanical ventilation. Nevertheless, the optimal timing to start dexamethasone remains uncertain. METHODS: We conducted a quasi-experimental study at National Taiwan University Hospital (Taipei, Taiwan) using propensity score matching to simulate a randomized controlled trial to receive or not to receive early dexamethasone (6 mg/day) during the first 7 days following the onset of symptoms. Treatment was standard protocol-based, except for the timing to start dexamethasone, which was left to physicians' decision. The primary outcome is 28-day mortality. Secondary outcomes include secondary infection within 60 days and fulfilling the criteria of de-isolation within 20 days. RESULTS: A total of 377 patients with COVID-19 were enrolled. Early dexamethasone did not decrease 28-day mortality in all patients (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.97-1.10) or in patients who required O2 for severe/critical disease at admission (aOR, 1.05; 95%CI, 0.94-1.18); but is associated with a 24% increase in superinfection in all patients (aOR, 1.24; 95% CI, 1.12-1.37) and a 23% increase in superinfection in patients of O2 for several/critical disease at admission (aOR, 1.23; 95% CI, 1.02-1.47). Moreover, early dexamethasone is associated with a 42% increase in likelihood of delayed clearance of SARS-CoV-2 virus (adjusted hazard ratio, 1.42; 95% CI, 1.01-1.98). CONCLUSION: An early start of dexamethasone (within 7 days after the onset of symptoms) could be harmful to hospitalized patients with COVID-19.

Effectiveness and evolution of anti-SARS-CoV-2 spike protein titers after three doses of COVID-19 vaccination in people with HIV.

BACKGROUND: Real-world vaccine effectiveness following the third dose of vaccination against SARS-CoV-2 remains less investigated among people with HIV (PWH). METHODS: PWH receiving the third dose of BNT162b2 and mRNA-1273 (either 50- or 100-µg) were enrolled. Participants were followed for 180 days until the fourth dose of COVID-19 vaccination, SARS-CoV-2 infection, seroconversion of anti-nucleocapsid IgG, death, or loss to follow-up. Anti-spike IgG was determined every 1-3 months. RESULTS: Of 1427 participants undergoing the third-dose COVID-19 vaccination, 632 (44.3%) received 100-µg mRNA-1273, 467 (32.8%) 50-µg mRNA-1273, and 328 (23.0%) BNT162b2 vaccine and the respective rate of SARS-CoV-2 infection or seroconversion of anti-nucleocapsid IgG was 246.1, 280.8 and 245.2 per 1000 person-months of follow-up (log-rank test, p = 0.28). Factors associated with achieving anti-S IgG titers >1047 BAU/mL included CD4 count <200 cells/mm3 (adjusted odds ratio [aOR], 0.11; 95% CI, 0.04-0.31), plasma HIV RNA >200 copies/mL (aOR, 0.27; 95% CI, 0.09-0.80), having achieved anti-spike IgG >141 BAU/mL within 3 months after primary vaccination (aOR, 3.69; 95% CI, 2.68-5.07), receiving BNT162b2 vaccine as the third dose (aOR, 0.20; 95% CI, 0.10-0.41; reference, 100-µg mRNA-1273), and having previously received two doses of mRNA vaccine in primary vaccination (aOR, 2.46; 95% CI, 1,75-3.45; reference, no exposure to mRNA vaccine). CONCLUSIONS: PWH receiving different types of the third dose of COVID-19 vaccine showed similar vaccine effectiveness against SARS-CoV-2 infection. An additional dose with 100-µg mRNA-1273 could generate a higher antibody response than with 50-µg mRNA-1273 and BNT162b2 vaccine.