Direct Species Identification in Positive Blood Culture Bottles From Patients With Hematologic Malignancies.

Background In patients with hematologic malignancies, faster species identification is particularly important in the management of bloodstream infection because of their immunocompromised and neutropenic status. In the present study, we analyzed direct species identification in patients with hematologic malignancies, and the factors that might influence the results of species identification. Methods We performed direct species identification using a Sepsityper® kit (Bruker Corporation, Billerica, Massachusetts, United States) and compared the results with a conventional method in patients with hematologic malignancies. Forty-five positive blood culture bottles containing single microorganisms from 37 patients were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). And patients' clinical data were compared between the groups with spectral scores at acceptable and unacceptable levels. Results Direct species identification correctly identified 42 of 45 isolates and three were misidentified. While 35 of 45 isolates showed a spectral score ≥1.7 (acceptable identification), 10 isolates had a spectral score <1.7 (unacceptable identification) including three misidentified isolates. The group with a spectral score ≥1.7 had significantly lower white blood cell (p<0.01), neutrophil (p<0.01), and platelet (p<0.01) counts in addition to more frequent central venous (CV) line insertion (p=0.01). Multivariate analysis revealed that pathogen type (gram-positive or negative) and CV line insertion were associated with spectral scores. Conclusion Direct species identification using the Sepsityper kit is an upcoming approach for blood culture bottles, which were flagged as positive even in patients with hematologic malignancies when the spectral score was ≥ 1.7. Our study also indicates that direct identification is more accurate in patients with CV lines, and may be less accurate when gram-positive bacteria are detected.

Multicenter Study of the Effectiveness of Antifungal Stewardship Team Intervention for Candidemia in Japan in 2008-2021.

Candidemia, linked to high mortality rates, requires prompt antifungal therapy for better outcomes. Treatment is structured as an action bundle, which is beneficial when followed closely. However, the Japanese action bundle lacks detailed guidance on severe complications like endocarditis or ocular issues. To address this, we adjusted the action bundle and assessed outcomes with and without AFT intervention. We strengthened protocols for blood cultures and organ assessments, and the AFT contacted the primary physician when yeast-like fungi were detected in the patient's blood culture bottles. Analyzing 204 candidemia cases from 2008-2021, we observed increased adherence and reduced mortality post-AFT intervention. Ophthalmology consultations rose significantly, but many patients had only one visit, suggesting inadequate follow-up. If endophthalmitis is diagnosed, a change in the treatment approach may be necessary. There is a possibility that abnormal ocular findings will be detected during subsequent visits, which highlights the need for improvement in ophthalmology follow-up rates as a future challenge for our AFT activities.

COVID-19 and Listeria Meningitis Treated by Ampicillin, Sulfamethoxazole/Trimethoprim and Meropenem.

Background: Secondary bacterial infection was initially rare in SARS-CoV-2 infectious disease (COVID-19) patients, but COVID-19-associated bacterial infectious diseases have recently been increasing. Furthermore, it might be difficult to distinguish COVID-19 from bacterial meningitis by the symptoms, and one might be uncertain about antibiotic therapy for Listeria meningitis infection-typically caused by eating contaminated food-in elderly persons and pregnant women. Case Report: A 96-year-old woman who had been living alone was found to have SARS-CoV-2 infection in February 2023. She was admitted to our hospital with high fever and disturbance of consciousness and was started on treatment with remdesivir. Two days later, her consciousness was still disturbed, and she was found to have a stiff neck. In addition, increased white blood cell counts and C-reactive protein suggested bacterial infection. Therefore, a lumbar puncture was done, and Listeria monocytogenes was ultimately isolated from blood cultures and its genetic material was detected in cerebrospinal fluid. She had previously eaten refrigerated food and cheese products. Intravenous ampicillin 1.0 g 6×/day was started, but one week later, loss of consciousness continued, and the cerebrospinal findings were not improved, although nasal swab became negative for SARS-CoV-2. Intravenous sulfamethoxazole/trimethoprim (ST) 80/400 mg 3×/day was added, and her consciousness and fever improved by one week later. A drug rash appeared after ST was started, and she was switched to meropenem. Her condition finally improved. Conclusion: COVID-19-associated secondary listeria infection was found in an elderly woman. She was treated with not only ampicillin, but also ST and meropenem. Meningitis caused by Listeria monocytogenes should be considered as a secondary complication and carefully treated with antibiotics during the period of the COVID-19 pandemic.

Effectiveness and Safety of Linezolid Versus Vancomycin, Teicoplanin, or Daptomycin against Methicillin-Resistant Staphylococcus aureus Bacteremia: A Systematic Review and Meta-Analysis.

Vancomycin (VCM) and daptomycin (DAP) are standard therapies for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, despite concerns regarding clinical utility and growing resistance. Linezolid (LZD) affords superior tissue penetration to VCM or DAP and has been successfully used as salvage therapy for persistent MRSA bacteremia, indicating its utility as a first-choice drug against MRSA bacteremia. In a systematic review and meta-analysis, we compared the effectiveness and safety of LZD with VCM, teicoplanin (TEIC), or DAP in patients with MRSA bacteremia. We evaluated all-cause mortality as the primary effectiveness outcome, clinical and microbiological cure, hospital length of stay, recurrence, and 90-day readmission rates as secondary effectiveness outcomes, and drug-related adverse effects as primary safety outcomes. We identified 5328 patients across 2 randomized controlled trials (RCTs), 1 pooled analysis of 5 RCTs, 1 subgroup analysis (1 RCT), and 5 case-control and cohort studies (CSs). Primary and secondary effectiveness outcomes were comparable between patients treated with LZD versus VCM, TEIC, or DAP in RCT-based studies and CSs. There was no difference in adverse event incidence between LZD and comparators. These findings suggest that LZD could be a potential first-line drug against MRSA bacteremia as well as VCM or DAP.

A Mycobacterium tuberculosis-Infected Patient Who Could Not Tolerate Oral Intake Successfully Treated Using an Intravenous Tedizolid-Containing Regimen.

BACKGROUND Mycobacterium tuberculosis (M. tuberculosis) is usually treated by oral antimycobacterial agents, including rifampicin, ethambutol, and pyrazinamide, but the treatment regimen with intravenous and/or intramuscular antimycobacterial agents for patients who cannot take medications orally remains unclear. CASE REPORT A 77-year-old man with chronic renal failure had an esophageal-skin fistula after he had surgeries for removal of esophageal and gastric cancers and reconstruction using jejunum, and he showed a cavity, tree-in-bud formation, and pleural effusions in his left upper lung fields on his chest X-ray after treatment of cellulitis and bacteremia/candidemia by meropenem, teicoplanin, and micafungin. M. tuberculosis was isolated from his sputum and exudate fluid from the reconstructed esophageal-skin fistula. Although he could not take antimycobacterial agents orally, treatment was started with intravenous agents combining levofloxacin (LVFX) every other day, isoniazid (INH), and linezolid (LZD). However, his platelets were decreased 21 days after treatment started, and it was thought to be an adverse effect of LZD and/or INH. After changing LZD to tedizolid (TZD), in addition to changing from INH to intramuscular streptomycin twice per week, his platelet counts increased. Intravenous TZD could be continued, and it maintained his condition without exacerbations of thrombocytopenia and renal failure. The M. tuberculosis disappeared, and the abnormal chest X-ray shadows were improved 2 months after the start of treatment. CONCLUSIONS Administration of intravenous TZD, in addition to intravenous LVFX and intramuscular SM in combination, might be a candidate regimen for M. tuberculosis patients who cannot take oral medications.

Thoracic aortic mycotic aneurysm due to Staphylococcus argenteus: A case report.

Staphylococcus argenteus was subdivided as a novel species from Staphylococcus aureus in 2014. We herein report a case of mycotic aneurysm caused by S. argenteus. A 59-year-old woman with diabetes and schizophrenia visited at the emergency room because of falling. Chest computed tomography revealed a left humerus fracture and a thoracic aortic aneurysm. With her elevated WBC count and CRP level, she was suspected to have a mycotic aneurysm. After being transferred to our hospital, vascular graft replacement surgery was performed. Isolates of blood cultures and surgical specimens were identified as S. argenteus by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MAS MALDI Biotyper Ver. 8.0). Although S. argenteus lacks staphyloxanthin, a carotenoid pigment, it is coagulase positive. In addition to traditional and automated biochemical identification systems, even MALDI-TOF MAS may misidentify the organism as S. aureus depending on its version. S. argenteus should be considered when coagulase-negative Staphylococcus like colonies are obtained from samples of S. aureus infection. To our knowledge, this is the first case of aortic mycotic aneurysm caused by S. argenteus in Japan. Although S. argenteus is considered less virulent than Staphylococcus aureus, we should closely monitor the prevalence and the clinical impact of this pathogen on community-acquired infections and health care-associated infections.