Clinical and genomic characteristics of IMP-producing Enterobacter cloacae complex and Klebsiella pneumoniae.

Carbapenemase-producing Enterobacterales (CPEs) are one of the top priority antimicrobial-resistant pathogens. Among CPEs, those producing acquired metallo-ß-lactamases (MBLs) are considered particularly problematic as few agents are active against them. Imipenemase (IMP) is the most frequently encountered acquired MBL in Japan, but comprehensive assessment of clinical and microbiological features of IMP-producing Enterobacterales infection remains scarce. Here, we retrospectively evaluated 62 patients who were hospitalized at a university hospital in Japan and had IMP-producing Enterobacterales from a clinical culture. The isolates were either Enterobacter cloacae complex or Klebsiella pneumoniae, and most of them were isolated from sputum. The majority of K. pneumoniae, but not E. cloacae complex isolates, were susceptible to aztreonam. Sequence type (ST) 78 and ST517 were prevalent for E. cloacae complex and K. pneumoniae, respectively, and all isolates carried blaIMP-1. Twenty-four of the patients were deemed infected with IMP-producing Enterobacterales. Among the infected patients, therapy varied and largely consisted of conventional ß-lactam agents, fluoroquinolones, or combinations. Three (13%), five (21%), and nine (38%) of them died by days 14, 30, and 90, respectively. While incremental mortality over 90 days was observed in association with underlying comorbidities, active conventional treatment options were available for most patients with IMP-producing Enterobacterales infections, distinguishing them from more multidrug-resistant CPE infections associated with globally common MBLs, such as New Delhi metallo-ß-lactamase (NDM) and Verona integron-encoded metallo-ß-lactamase (VIM).

Clinical characteristics and genome epidemiology of Stenotrophomonas maltophilia in Japan.

BACKGROUND: Stenotrophomonas maltophilia is a carbapenem-resistant Gram-negative pathogen increasingly responsible for difficult-to-treat nosocomial infections. OBJECTIVES: To describe the contemporary clinical characteristics and genome epidemiology of patients colonized or infected by S. maltophilia in a multicentre, prospective cohort. METHODS: All patients with a clinical culture growing S. maltophilia were enrolled at six tertiary hospitals across Japan between April 2019 and March 2022. The clinical characteristics, outcomes, antimicrobial susceptibility and genomic epidemiology of cases with S. maltophilia were investigated. RESULTS: In total, 78 patients were included representing 34 infection and 44 colonization cases. The median age was 72.5 years (IQR, 61-78), and males accounted for 53 cases (68%). The most common comorbidity was localized solid malignancy (39%). Nearly half of the patients (44%) were immunosuppressed, with antineoplastic chemotherapy accounting for 31%. The respiratory tract was the most common site of colonization (86%), whereas bacteraemia accounted for most infection cases (56%). The 30 day all-cause mortality rate was 21%, which was significantly higher in infection cases than colonization cases (35% versus 9%; adjusted HR, 3.81; 95% CI, 1.22-11.96). Susceptibility rates to ceftazidime, levofloxacin, minocycline and sulfamethoxazole/trimethoprim were 14%, 65%, 87% and 100%, respectively. The percentage of infection ranged from 13% in the unclassified group to 86% in genomic group 6A. The percentage of non-susceptibility to ceftazidime ranged from 33% in genomic group C to 100% in genomic groups 6 and 7 and genomic group geniculate. CONCLUSIONS: In this contemporary multicentre cohort, S. maltophilia primarily colonized the respiratory tract, whereas patients with bacteraemia had the highest the mortality from this pathogen. Sulfamethoxazole/trimethoprim remained consistently active, but susceptibility to levofloxacin was relatively low. The proportions of cases representing infection and susceptibility to ceftazidime differed significantly based on genomic groups.

Evaluation of the cachexia index using a bioelectrical impedance analysis in elderly patients with non-Hodgkin's lymphoma: A single-center prospective study.

Cancer cachexia is a disorder that affects patient outcomes. The present study prospectively evaluated the prognostic value of the cachexia index (CXI) in elderly patients with non-Hodgkin's lymphoma (NHL). We prospectively analyzed 51 elderly patients who were diagnosed with NHL at our institution. CXI was calculated as follows: CXI = SMI × Alb/NLR (SMI: skeletal muscle index, Alb: serum albumin, NLR: neutrophil-to-lymphocyte ratio). SMI was measured by a bioelectrical impedance analysis (BIA) using the InBody 720. We determined the sex-specific cutoff values of the CXI by a receiver operating characteristic curve analysis and divided all patients into low- and high-CXI groups. The median age at the diagnosis was 78 years (60-93 years), and 28 (55%) were male. The histologic subtypes were B-cell lymphoma in 49 patients and T-cell lymphoma in 2. Twenty-eight (55%) patients were categorized into the high-CXI group, and 23 (45%) were categorized into the low-CXI group. The overall survival (OS) in the low-CXI group was significantly shorter than that in the high-CXI group (3-year OS, 70.4% vs. 95.7%, p = 0.007). Among 23 patients with DLBCL, patients with low-CXI had shorter OS than those with high-CXI (3-year OS, 55.6% vs. 92.9%, p = 0.008). On the other hand, sarcopenia had less impact on the clinical outcome of DLBCL patients. Low-CXI was associated with poor outcomes in elderly NHL and the CXI may be a clinical useful index for predicting prognosis. Further large prospective studies are needed to verify this conclusion.

Effectiveness of cefmetazole versus meropenem for invasive urinary tract infections caused by extended-spectrum ß-lactamase-producing Escherichia coli.

Cefmetazole is active against extended-spectrum ß-lactamase-producing Escherichia coli (ESBLEC) and is a potential candidate for carbapenem-sparing therapy. This multicenter, observational study included patients hospitalized for invasive urinary tract infection due to ESBLEC between March 2020 and November 2021 at 10 facilities in Japan, for whom either cefmetazole or meropenem was initiated as a definitive therapy within 96 h of culture collection and continued for at least 3 d. Outcomes included clinical and microbiological effectiveness, recurrence within 28 d, and all-cause mortality (14 d, 30 d, in-hospital). Outcomes were adjusted for the inverse probability of propensity scores for receiving cefmetazole or meropenem. Eighty-one and forty-six patients were included in the cefmetazole and meropenem groups, respectively. Bacteremia accounted for 43% of the cefmetazole group, and 59% of the meropenem group. The crude clinical effectiveness, 14 d, 30 d, and in-hospital mortality for patients in the cefmetazole and meropenem groups were 96.1% vs 90.9%, 0% vs 2.3%, 0% vs 12.5%, and 2.6% vs 13.3%, respectively. After propensity score adjustment, clinical effectiveness, the risk of in-hospital mortality, and the risk of recurrence were similar between the two groups (P = 0.54, P = 0.10, and P = 0.79, respectively). In all cases with available data (cefmetazole : n = 61, meropenem : n = 22), both drugs were microbiologically effective. In all isolates, bla CTX-M was detected as the extended-spectrum ß-lactamase gene. The predominant CTX-M subtype was CTX-M-27 (47.6%). Cefmetazole showed clinical and bacteriological effectiveness comparable to meropenem against invasive urinary tract infection due to ESBLECs.

In Vitro Activity and Clinical Efficacy of Faropenem against Third-Generation Cephalosporin-Resistant Escherichia coli and Klebsiella pneumoniae.

Faropenem (FRPM) is active against extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales, but evidence for its efficacy is lacking. This study determined the correlation between the susceptibility by disk diffusion method and the MIC of FRPM for third-generation cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae, and the effectiveness of FRPM for the treatment of urinary tract infection (UTI) caused by these two bacteria in a retrospective cohort analysis. Of the 48 third-generation cephalosporin-resistant clinical isolates tested, 44 isolates produced ESBL, and 8 isolates produced AmpC, including 4 isolates produced both ESBL and AmpC. Thirty-seven isolates had an FRPM MIC of ≤1 mg/L, and seven had an FRPM MIC of 2 mg/L. An FRPM MIC of >2 mg/L was observed with four isolates. In a retrospective cohort analysis, 63 patients with UTI treated with FRPM were identified. All isolates of ESBL-producing E. coli (n = 54) and K. pneumoniae (n = 9) treated with FRPM showed disk diffusion zone diameters larger than 16.0 mm (estimated MIC, 2.2 mg/L). All patients completed the scheduled treatment courses with FRPM, but 28- and 90-day relapses happened in 10 patients (16%) and 16 patients (25%), respectively. No significant risk factors for the 28- and 90-day relapses were found. FRPM can be used according to disk diffusion susceptibility testing in UTI. Further investigations are necessary to assess the clinical breakpoint of FRPM for ESBL-producing Enterobacterales and the candidates most likely to benefit from using FRPM.

Native valve infective endocarditis due to sequence type 97 community-associated methicillin-resistant Staphylococcus aureus complicated by meningitis and multiple septic emboli in a young healthy adult.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) can cause a wide variety of infections, ranging from skin and soft tissue infections to life-threatening invasive diseases such as necrotizing pneumonia and infective endocarditis. Here, we present a case of a healthy young female presenting with fever, headache and nausea, who was diagnosed with mitral valve infective endocarditis due to CA-MRSA and whose course was complicated by meningitis and multiple septic emboli. The causative MRSA strain belonged to sequence type 97 and harbored SCCmec Ⅳc but not lukS/F-PV genes. ST97, which is frequently isolated from livestock animals and known as a common lineage of livestock-associated MRSA, may cause invasive infection in the community.

Periprosthetic joint infection due to Mycoplasma hominis in a multiple sclerosis patient treated with fingolimod.

Mycoplasma hominis is a commensal pathogen normally found in urogenital tract of humans and has been associated with a wide variety of extra-genitourinary infections, such as mediastinitis, bacteremia, and septic arthritis, particularly in immunocompromised patients. Here, we present a case of a 48-year-old male, who had been treated with fingolimod for relapsing multiple sclerosis and presented with fever and right-sided hip pain following total hip arthroplasty. CT scan revealed localized fluid collection in the right quadriceps femoris muscle adjacent to the joint cavity of right hip. The percutaneously aspirated fluid grew M. hominis, which was also isolated from blood culture. With diagnosis of periprosthetic joint infection, the patient underwent surgical debridement with retained prosthesis and was treated with antimicrobial agents. Infected granulation tissues excised from the hip was observed under an electron microscope, which revealed electron-dense rounded structures contained in neutrophils, consistent with Mycoplasma particles. Fingolimod, an immunomodulatory drug that acts on the sphingosine-1-phosphate receptor and prevents the egress of lymphocytes from lymph nodes, might increase host susceptibility to a systemic M. hominis infection.

Lung Pathology of Mutually Exclusive Co-infection with SARS-CoV-2 and Streptococcus pneumoniae.

Postmortem lung pathology of a patient in Japan with severe acute respiratory syndrome coronavirus 2 infection showed diffuse alveolar damage as well as bronchopneumonia caused by Streptococcus pneumoniae infection. The distribution of each pathogen and the accompanying histopathology suggested the infections progressed in a mutually exclusive manner within the lung, resulting in fatal respiratory failure.

The prognostic value of the Fibrinogen-Albumin Ratio Index in patients with myelodysplastic syndrome and acute myeloid leukemia with myelodysplasia-related changes treated with azacitidine.

Inflammation is a major hallmark of several cancers. The present study evaluated the prognostic value of the Fibrinogen-Albumin Ratio Index (FARI) at the diagnosis in patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) treated with azacitidine (AZA). A retrospective study was conducted in a single cohort of 99 patients with de novo MDS and AML-MRC who were treated with AZA between May 2011 and June 2019 in our hospital. Plasma fibrinogen and serum albumin levels were measured before the start of AZA treatment. A total of 99 patients were included in the analysis. The optimal cut-off value of FARI for predicting the 1-year overall survival (OS) was determined by a receiver operating characteristic (ROC) analysis to be 0.079. A total of 59 (60%) and 40 (40%) patients had an FARI ≥0.079 (high-FARI group) and < 0.079 (low-FARI group), respectively. The high-FARI patients had a significantly shorter OS than low-FARI patients (1-year OS, 35.6% vs. 77.5%, p < 0.001). In a multivariate analysis, parameters with independent adverse significance for the OS were a high FARI (≥0.079) (hazard ratio (HR) 2.41, 95% confidence interval (CI), 1.36-4.29; p = 0.006), and Revised-International Prognostic Scoring System (IPSS-R) very high (HR 1.483, 95% CI, 1.12-1.963, p = 0.006). A high FARI was found to be associated with a poor outcome in MDS and AML-MRC patients treated with AZA, and FARI was an independent prognostic factor for the OS in these patients. Further internal and external validations are needed to clarify the prognostic role of the FARI for MDS and AML-MRC patients.

Vagococcus fluvialis as a causative pathogen of bloodstream and decubitus ulcer infection: Case report and systematic review of the literature.

BACKGROUND: Vagococcal infections are uncommon in humans; there are limited studies on the clinical manifestations, the optimal methods for identifications, and antimicrobial susceptibility testing for vagococcal infections. Here, we have reported a case of Vagococcus fluvialis-induced bacteremia and decubitus ulcer and have systematically reviewed other reported Vagococcus infections. CASE PRESENTATION: A 74-year-old man presented to our emergency department with muscle weakness on his left extremities, dysarthria, and altered mental status along with fever for the past 4 days. Physical examination revealed a decubitus ulcer with foul smelling and yellowish exudative pus on his left chest wall and abdomen, forearm, thigh, and lower leg. He was empirically treated with 2.25 mg of piperacillin/tazobactam every 8 hours and 0.5 g of vancomycin every 24 hours intravenously (IV) for his decubitus ulcer. Vagococcus fluvialis was detected in both aerobic and anaerobic blood cultures (upon admission) using the VITEC 2 GP ID card (bioMérieux) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). We continued the mentioned IV antimicrobial therapies for 4 weeks following which the patient was transferred to a long-term care facility for further rehabilitation. CONCLUSIONS: To our best knowledge, this is the first literature review of Vagococcus infections in humans. Since it is challenging to distinguish Vagococcus from Enterococcus by a conventional method due to the similarity of its biochemical properties to those of Enterococcus, based on our literature review, 16S rRNA sequencing or analysis of bacterial protein profile using MALDI-TOF MS may be useful for the precise identification.

Virological and genomic analysis of SARS-CoV-2 from a favipiravir clinical trial cohort.

INTRODUCTION: Several clinical studies have reported the efficacy of favipiravir in reducing viral load and shortening the duration of symptoms. However, the viability of SARS-CoV-2 in the context of favipiravir therapy and the potential for resistance development is unclear. METHODS: We sequenced SARS-CoV-2 in nasopharyngeal specimens collected from patients who participated in a randomized clinical trial of favipiravir at hospitals across Japan between March and May 2020. Paired genomes were sequenced from those who remained RT-PCR-positive 5-8 days into favipiravir therapy. Daily nasopharyngeal specimens from 69 patients who were RT-PCR-positive at randomization were examined for a cytopathic effect (CPE). RESULTS: Some strains early in the trial belonged to clade 19 B, whereas the majority belonged to clade 20 B. The median time from the disease onset to negative CPE was 9 days. CPE was strongly correlated with the time from disease onset, viral load, age, and male sex. Among 23 patients for whom paired genomes were available, all except one had identical genomes. Two mutations were observed in one patient who received favipiravir, neither in the RdRp gene. CONCLUSIONS: The SARS-CoV-2 genome distribution in this clinical trial conducted in Japan reflected the early influx of strains from China followed by replacement by strains from Europe. CPE was significantly associated with age, male sex, and viral loads but not with favipiravir therapy. There was no evidence of resistance development during favipiravir therapy.

Disseminated nocardiosis due to Nocardia terpenica.

We report the first case of disseminated nocardiosis due to trimethoprim/sulfamethoxazole-resistant Nocardia terpenica successfully treated with meropenem and clarithromycin. The patient travelled to Japan from Australia via Southeast Asia, which led to differential diagnoses of multiple lung nodules including miliary tuberculosis and melioidosis as well as nocardiosis. Because of variety of susceptibility depending on the Nocardia species, clinicians need to confirm the species and investigate its susceptibility.

Infected aortic aneurysm caused by Helicobacter cinaedi: case series and systematic review of the literature.

BACKGROUND: Helicobacter cinaedi is rarely identified as a cause of infected aneurysms; however, the number of reported cases has been increasing over several decades, especially in Japan. We report three cases of aortic aneurysm infected by H. cinaedi that were successfully treated using meropenem plus surgical stent graft replacement or intravascular stenting. Furthermore, we performed a systematic review of the literature regarding aortic aneurysm infected by H. cinaedi. CASE PRESENTATION: We present three rare cases of infected aneurysm caused by H. cinaedi in adults. Blood and tissue cultures and 16S rRNA gene sequencing were used for diagnosis. Two patients underwent urgent surgical stent graft replacement, and the other patient underwent intravascular stenting. All three cases were treated successfully with intravenous meropenem for 4 to 6 weeks. CONCLUSIONS: These cases suggest that although aneurysms infected by H. cinaedi are rare, clinicians should be aware of H. cinaedi as a potential causative pathogen, even in immunocompetent patients. Prolonged incubation periods for blood cultures are necessary for the accurate detection of H. cinaedi.

Aspergillus meningitis in a patient with chronic lymphocytic leukemia.

Central nervous system aspergillosis is relatively rare and difficult to diagnose. Here, we report a case of 90-year-old man with chronic lymphocytic leukemia who presented with a month-long gradually worsening headache followed by 3 days of low-grade fever associated with altered mental status. Aspergillus meningitis diagnosed using Aspergillus galactomannan antigen in the cerebrospinal fluid and treated with voriconazole. Delayed diagnosis and treatment of Aspergillus meningitis is typically associated with high mortality; therefore, it is imperative to include this disease in the differential diagnoses of subacute meningitis.

Intravenous itraconazole compared with liposomal amphotericin B as empirical antifungal therapy in patients with neutropaenia and persistent fever.

BACKGROUND: Fungal infections are a major complication of neutropaenia following chemotherapy. Their early diagnosis is difficult, and empirical antifungal treatment is widely used, and uses of less toxic drugs that reduce breakthrough infection are required. OBJECTIVE: We conducted a multicentre, open-label, randomised, non-inferiority trial to compare the safety and efficacy of intravenous itraconazole (ivITCZ) and liposomal amphotericin B (LAmB) as empirical antifungal therapy in patients with haematological malignancies with neutropaenia and persistent fever. METHODS: Patients with haematological malignancies who developed fever refractory to broad-spectrum antibacterial agents under neutropaenia conditions were enrolled. Patients were randomised for treatment with LAmB (3.0 mg/kg/d) or ivITCZ (induction: 400 mg/d, maintenance: 200 mg/d). RESULTS: Observed overall favourable response rates of 17/52 (32.7%) and 18/50 (36.0%) in the LAmB and ivITCZ groups, with a model-based estimate of a 4% difference (90% CI, -12% to 20%), did not fulfil the statistical non-inferiority criterion. In the LAmB group, there were two cases of breakthrough infection and five cases of probable invasive fungal disease, whereas in the itraconazole group, neither breakthrough infection nor probable invasive fungal disease occurred. Patients in the ivITCZ group had significantly fewer grade 3-4 hypokalaemia-related events than LAmB group patients (P < .01). The overall incidence of adverse events tended to be lower in the ivITCZ group (P = .07). CONCLUSION: ivITCZ showed similar efficacy and safety as LAmB as empirical antifungal therapy in haematological malignancy patients with febrile neutropaenia, although the small sample size and various limitations prevented demonstration of its non-inferiority.

[Acute myeloid leukemia with sudden onset bilateral lower extremity paralysis caused by disseminated mucormycosis following unrelated bone marrow transplantation].

A 63-year-old woman was admitted to our hospital with relapsed acute myeloid leukemia. On day10 after reinduction therapy, she became febrile. Computed tomography on day15 revealed right upper lobe consolidation. Because the ß-D glucan and Aspergillus galactomannan antigen tests were negative, we considered pulmonary mucormycosis as a breakthrough infection under voriconazole administration. Liposomal amphotericin B was initiated, and the patient underwent unrelated bone marrow transplantation although not in complete remission. She developed right shoulder pain on day1, and her pneumonia worsened on day3. She reported right lower extremity paralysis on day15, and developed bilateral lower extremity motor and sensory paralysis the next day. T2-enhanced magnetic resonance imaging revealed hyperdense lesions in the spinal cord at Th11. Transverse myelitis was diagnosed, and she underwent antiviral therapy. After engraftment, she died of pneumonia on day24. Postmortem examination revealed disseminated mucormycosis involving the lungs, liver, diaphragm, blood vessels, and dura matter of the spinal cord; it also revealed that the sudden bilateral lower extremity paralysis was caused by disseminated mucormycosis. This case stresses the possibility of mucormycosis, particularly in prolonged neutropenic patients with pain, fever, and focal neurological findings.