Human Vγ9Vδ2 T cells exhibit antifungal activity against Aspergillus fumigatus and other filamentous fungi.

Invasive aspergillosis (IA) and mucormycosis are life-threatening diseases, especially among immunocompromised patients. Drug-resistant Aspergillus fumigatus strains have been isolated worldwide, which can pose a serious clinical problem. As IA mainly occurs in patients with compromised immune systems, the ideal therapeutic approach should aim to bolster the immune system. In this study, we focused on Vγ9Vδ2 T cells that exhibit immune effector functions and examined the possibility of harnessing this unconventional T cell subset as a novel therapeutic modality for IA. A potent antifungal effect was observed when A. fumigatus (Af293) hyphae were challenged by Vγ9Vδ2 T cells derived from peripheral blood. In addition, Vγ9Vδ2 T cells exhibited antifungal activity against hyphae of all Aspergillus spp., Cunninghamella bertholletiae, and Rhizopus microsporus but not against their conidia. Furthermore, Vγ9Vδ2 T cells also exhibited antifungal activity against azole-resistant A. fumigatus, indicating that Vγ9Vδ2 T cells could be used for treating drug-resistant A. fumigatus. The antifungal activity of Vγ9Vδ2 T cells depended on cell-to-cell contact with A. fumigatus hyphae, and degranulation characterized by CD107a mobilization seems essential for this activity against A. fumigatus. Vγ9Vδ2 T cells could be developed as a novel modality for treating IA or mucormycosis. IMPORTANCE: Invasive aspergillosis (IA) and mucormycosis are often resistant to treatment with conventional antifungal agents and have a high mortality rate. Additionally, effective antifungal treatment is hindered by drug toxicity, given that both fungal and human cells are eukaryotic, and antifungal agents are also likely to act on human cells, resulting in adverse effects. Therefore, the development of novel therapeutic agents specifically targeting fungi is challenging. This study demonstrated the antifungal activity of Vγ9Vδ2 T cells against various Aspergillus spp. and several Mucorales in vitro and discussed the mechanism underlying their antifungal activity. We indicate that adoptive immunotherapy using Vγ9Vδ2 T cells may offer a new therapeutic approach to IA.

Evaluation of the Effectiveness and Use of Anti-Methicillin-Resistant Staphylococcus aureus Agents for Aspiration Pneumonia in Older Patients Using a Nationwide Japanese Administrative Database.

Studies indicated potential harm from empirical broad-spectrum therapy. A recent study of hospitalizations for community-acquired pneumonia suggested that empirical anti-methicillin-resistant Staphylococcus aureus (MRSA) therapy was associated with an increased risk of death and other complications. However, limited evidence supports empirical anti-MRSA therapy for older patients with aspiration pneumonia. In a nationwide Japanese database, patients aged ≥65 years on admission with aspiration pneumonia were analyzed. Patients were divided based on presence of respiratory failure and further sub-categorized based on their condition within 3 days of hospital admission, either receiving a combination of anti-MRSA agents and other antibiotics, or not using MRSA agents. An inverse probability weighting method with estimated propensity scores was used. Out of 81,306 eligible patients, 55,098 had respiratory failure, and 26,208 did not. In the group with and without respiratory failure, 0.93% and 0.42% of the patients, respectively, received anti-MRSA agents. In patients with respiratory failure, in-hospital mortality (31.38% vs. 19.03%, p < 0.001), 30-day mortality, and 90-day mortality were significantly higher, and oxygen administration length was significantly longer in the anti-MRSA agent combination group. Anti-MRSA agent combination use did not improve the outcomes in older patients with aspiration pneumonia and respiratory failure, and should be carefully and comprehensively considered.

Assessment of oral health in elderly patients with dementia by measuring volatile sulfur compounds and its relationship with pneumonia development: A pilot study.

BACKGROUND: This study aimed to clarify the involvement of anaerobes in aspiration pneumonia by measuring volatile sulfur compounds (VSCs), which are metabolites of anaerobic bacteria in the mouth. METHODS: This study included 84 older adult patients (mean age, 82.5 ± 7.34 years) who had dementia and were hospitalized for more than 6 months. We measured the VSCs in the patient's mouth with Oral Chroma and obtained the data of pneumonia development in the past 6 months. We also evaluated the association or correlation of VSCs and some factors which might be the risk factors of aspiration pneumonia. RESULTS: The development of pneumonia had no significant association with the VSCs in the patient's mouth. CONCLUSION: The present pilot study suggests that anaerobes might not be the main causative pathogens of aspiration pneumonia in older adult patients.

Clinical and experimental phenotype of azole-resistant Aspergillus fumigatus with a HapE splice site mutation: a case report.

BACKGROUND: The recent increase in cases of azole-resistant Aspergillus fumigatus (ARAf) infections is a major clinical concern owing to its treatment limitations. Patient-derived ARAf occurs after prolonged azole treatment in patients with aspergillosis and involves various cyp51A point mutations or non-cyp51A mutations. The prognosis of patients with chronic pulmonary aspergillosis (CPA) with patient-derived ARAf infection remains unclear. In this study, we reported the case of a patient with ARAf due to HapE mutation, as well as the virulence of the isolate. CASE PRESENTATION: A 37-year-old male was presented with productive cough and low-grade fever. The patient was diagnosed with CPA based on the chronic course, presence of a fungus ball in the upper left lobe on chest computed tomography (CT), positivity for Aspergillus-precipitating antibody and denial of other diseases. The patient underwent left upper lobe and left S6 segment resection surgery because of repeated haemoptysis during voriconazole (VRC) treatment. The patient was postoperatively treated with VRC for 6 months. Since then, the patient was followed up without antifungal treatment but relapsed 4 years later, and VRC treatment was reinitiated. Although an azole-resistant isolate was isolated after VRC treatment, the patient did not show any disease progression in either respiratory symptoms or radiological findings. The ARAf isolated from this patient showed slow growth, decreased biomass and biofilm formation in vitro, and decreased virulence in the Galleria mellonella infection model compared with its parental strain. These phenotypes could be caused by the HapE splice site mutation. CONCLUSIONS: This is the first to report a case demonstrating the clinical manifestation of a CPA patient infected with ARAf with a HapE splice site mutation, which was consistent with the in vitro and in vivo attenuated virulence of the ARAf isolate. These results imply that not all the ARAf infections in immunocompetent patients require antifungal treatment. Further studies on the virulence of non-cyp51A mutations in ARAf are warranted.

Severe Fever with Thrombocytopenia Syndrome Virus RNA in Semen, Japan.

Severe fever with thrombocytopenia syndrome virus (SFTSV) can be transmitted between humans. We describe a case of severe fever with thrombocytopenia syndrome in which SFTSV RNA was detected in semen after its disappearance from serum. Our findings indicate possible sexual transmission of this emerging virus.

An iliopsoas abscess caused by Parvimonas micra: a case report.

BACKGROUND: Parvimonas micra, a Gram-positive anaerobic coccus, is a rare pathogen for psoas abscess. We describe a case of a patient with iliopsoas abscess caused by P. micra. CASE PRESENTATION: An 81-year-old Asian man presented to our department with complaints of fever since the preceding day. Abdominal computed tomography revealed the presence of a low-density mass in the right iliopsoas muscle indicative of a psoas abscess. Computed tomography-guided percutaneous drainage of the psoas abscess was performed. Results of organism cultures of the abscess and blood were positive for P. micra. However, our patient had no known primary focus of infection. On the basis of these findings, a primary psoas abscess caused by P. micra was diagnosed, and treatment with ampicillin/sulbactam 1.5 g, administered intravenously every 8 h, was initiated. By day 7, the patient's white blood cell count normalized. By day 20, his C-reactive protein level was decreased to 0.35 mg/dl. CONCLUSION: Iliopsoas abscesses caused by anaerobic bacteria are relatively rare, and iliopsoas abscesses caused by P. micra are especially rare. Our patient's case revealed that P. micra can cause iliopsoas abscess. Therefore, clinicians should be aware of the possibility that P. micra may cause iliopsoas abscess.

Miliary tuberculosis with co-existing pulmonary cryptococcosis in non-HIV patient without underlying diseases: a case report.

BACKGROUND: Tuberculosis and cryptococcosis co-infection usually occurs in immunosuppressed patients with impaired cell-mediated immunity. However, there are few reports about such co-infection in non-HIV patients without underlying diseases. Here, we report a case of miliary tuberculosis with co-existing pulmonary cryptococcosis in non-HIV patient without underlying diseases. CASE PRESENTATION: An 84-year-old Asian female presented to our hospital with complaints of a 1-week history of abdominal pain and appetite loss. Chest computed tomography (CT) showed diffuse micronodules in random patterns in both lung fields. Liver, skin and bone marrow biopsies showed epithelioid cell granuloma. Polymerase chain reaction of gastric aspirate was positive for Mycobacterium tuberculosis. According to these findings, miliary tuberculosis was suspected and antimycobacterial therapy was initiated. After a 6-month treatment course, chest radiograph showed new multiple nodules in the right middle lung field. Chest CT showed that a right S6 small nodule was increased and new multiple nodules appeared in the right lower lobe. Flexible fiberoptic bronchoscopy was subsequently perfomed. Cytology of the bronchial lavage showed a small number of Periodic acid-Schiff-positive bodies, suggesting Cryptococcus species. Moreover, serum cryptococcal antigen testing was positive. According to these findings, pulmonary cryptococcosis was diagnosed, although the culture was negative. Oral fluconazole therapy was subsequently initiated. After a 6-month treatment course, chest radiograph showed gradual improvement. CONCLUSION: Although tuberculosis and cryptococcosis co-infection is relatively rare in immunocompromised hosts, such as those with acquired immunodeficiency syndrome, clinicians should be aware that these infections can co-exist even in non-HIV patients without underlying diseases.