Multiple mutations of Mycobacterium intracellulare subsp. chimaera causing false-negative reaction to the transcription-reverse transcription concerted method for pathogen detection.

OBJECTIVES: To report an isolate of Mycobacterium intracellulare subsp. chimaera with multiple mutations in 16S ribosomal RNA (rRNA) gene, resulting in the false-negative reaction to the transcription-reverse transcription concerted (TRC) method for Mycobacterium avium-intracellulare complex. METHODS: We used TRC, polymerase chain reaction (PCR), and Matrix-assisted laser desorption/ionization Time-of-Flight/Mass Spectrometry (MALDI-TOF/MS) methods to identify a clinical isolate in 2021. Due to the discordant results between TRC and PCR or MALDI-TOF MS methods, 16S rRNA sequencing, whole-genome shotgun (WGS) sequencing, and average nucleotide identity (ANI) analysis were employed to identify the isolate. RESULTS: A mycobacterial isolate from a sputum sample gave negative results for the detection of Mycobacterium tuberculosis complex or M. avium-intracellulare complex by the TRC method. However, the isolate was identified as M. intracellulare by both PCR method and MALDI-TOF MS method. WGS sequencing of 16S rRNA genome revealed eight substitution mutations and one insertion mutation within the region, which could hamper the correct reaction to TRC method. Subsequent ANI analysis between the isolate and various species of nontuberculosis mycobacteria revealed that the isolate could be identified as M. intracellulare subsp. chimaera. CONCLUSION: Rare mutations within the 16S rRNA genome resulted in the false-negative identification of Mycobacterium chimaera by the TRC method. WGS sequencing and ANI analysis was necessary to identify the isolate.

Emerging resistance to beta-lactams in Pantoea ananatis isolated from an immunocompetent patient with bacteremia.

We observed an emerging resistance to ß-lactams in a P. ananatis bacteremia case. Whole genome sequence analysis detected two ß-lactamase genes as well as related genes that regulate the ß-lactamase genes in the chromosome. The induction experiment resulted in the expression of the class A ß-lactamase gene in the isolate.

Surveillance of the current situation regarding influenza vaccination according to medical oncologists in Japan.

This study aimed to clarify the attitude of oncologists toward influenza vaccination and the current situation and issues regarding influenza vaccination for patients on chemotherapy in Japan. A web-based survey of medical oncologists certified by the Japanese Society of Medical Oncology was conducted between November 1 and December 31, 2019. Of the 1369 medical oncologists who were invited to participate, 415 (30.3%) responded to our survey. The questionnaire comprised 4 sections: "oncologist characteristics," "oncologist attitude toward influenza vaccines and the current status of influenza vaccination for cancer patients undergoing chemotherapy," "incidence of influenza infection and associated treatment complications," and "treatment policy for influenza infection." In total, 153 (36.9%) physicians replied that they did not actively encourage influenza vaccination for patients undergoing chemotherapy. The primary reasons given were lack of evidence (48/153, 31.4%) and uncertainty of appropriate timing (46/153, 30.1%). There was diverse variation in the timing of vaccination and in the levels of encouragement based on the cancer location and medication type. Two hundred eighty-three (68.2%) oncologists reported that their cancer patients had experienced influenza infection while undergoing chemotherapy, and 169 (40.7%) responded that their patients had experienced an administration delay or discontinuation of medication because of influenza infection. Our surveillance revealed some oncologists considered evidence regarding the administration of influenza vaccine to cancer patients undergoing chemotherapy (particularly the optimal timing and level of recommendation by cancer location and medication) to be lacking. It also exposed the adverse impact of influenza infection in cancer patients.

Development of risk factor-based scoring system for detection of hypervirulent Klebsiella pneumoniae bloodstream infections.

BACKGROUND: Hypervirulent Klebsiella pneumoniae (HVKp) infections have distinct clinical manifestations from classical K. pneumoniae infections. The hallmark of HVKp infections are liver abscess formation and metastatic infections. Due to the severe sequelae of these complications, method to identify patients at-risk of HVKp infections should be developed. RESULTS: A retrospective cohort study of 222 patients with K. pneumoniae bloodstream infections (BSIs) was performed. Patient demographics, clinical manifestations, and bacterial characteristics were investigated. Ten cases of liver abscesses were identified. Characteristics such as community-onset BSIs, hypermucoviscosity phenotype, and capsular serotype K1 were identified as risk factors for HVKp infections. A scoring system was developed based on the risk factors. The area under the receiver operating characteristic curve for the scoring system was 0.90. A score of ≥ 2 points provided sensitivity and specificity of 0.70 and 0.94, respectively. CONCLUSIONS: Simple scoring system was developed for the diagnosis of HVKp infections. The system allows early identification of patients with K. pneumoniae BSIs in whom hypervirulent infections should be evaluated. Prospective evaluation is expected.

Community-acquired Disseminated Exophiala dermatitidis Mycosis with Necrotizing Fasciitis in Chronic Graft-versus-host Disease.

We herein report a case of systemic phaeohyphomycosis by Exophiala dermatitidis (E. dermatitidis) with chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). The patient had been taking oral corticosteroids for years to control the GVHD. Yeast-like fungi were identified in a blood culture, so treatment with micafungin (150 mg/day) was begun, with no improvement. The patient passed away on hospital Day 12. A sequence analysis of rRNA revealed the isolate to be E. dermatitidis. This report brings attention to an emerging mycosis of community-acquired Exophiala species infection in the very-late phase after allogenic HSCT in patients with chronic GVHD.

Prognostic factors for candidaemia in intensive care unit patients: a retrospective analysis.

INTRODUCTION: Candidaemia, recognised as a fairly common disease among intensive care unit (ICU) patients, carries a poor prognosis. However, as studies on the prognostic factors associated with candidaemia in ICU patients are limited, this study aimed to establish the best prognostic factor for ICU patients with candidaemia in a tertiary care hospital in Japan. METHODS: We conducted a retrospective cohort study of patients with candidaemia in the emergency ICU at Fukuoka University Hospital, Fukuoka, Japan, from April 2010 to March 2015. Demographic and clinical data was collected from the patients' medical records and laboratory databases. RESULTS: A total of 25 patients were included in the study. However, 18 patients died during hospitalisation, resulting in an in-hospital mortality rate of 72.0%. The variables of Sequential Organ Failure Assessment (SOFA) score and cumulative number of risk factors for invasive candidiasis showed significant differences between patients in the survivor and non-survivor groups (p < 0.05). The areas under the receiver operating characteristic curves for the SOFA score and cumulative number of risk factors for invasive candidiasis were 0.873 (95% confidence interval [CI] 0.72-1.00) and 0.937 (95% CI 0.84-1.00), respectively. CONCLUSION: Our results suggest that the cumulative number of risk factors for invasive candidiasis was the most useful prognostic indicator for candidaemia in ICU patients.

Influence of the bacterial phenotypes on the clinical manifestations in Klebsiella pneumoniae bacteremia patients: A retrospective cohort study.

Ninety-four episodes of Klebsiella pneumoniae bloodstream infection were identified at a university hospital in Japan. After excluding extended-spectrum beta lactamase-producing strains, 83 blood isolates from these patients were assayed in terms of their bacterial phenotypes such as the mucoid and hypermucoviscosity phenotypes. Bacterial phenotypes were correlated with the patients' clinical manifestations. The hypermucoviscosity phenotype was significantly associated with septic shock at the onset of infections (odds ratio, 15.92; 95% confidence interval, 1.27-468.12), but was not associated with liver abscess formation. Mortality was determined by the presence of septic shock. RmpA gene was associated with the induction of the hypermucoviscosity phenotype. These results reveal unique roles of bacterial phenotypes on the patient's clinical condition in K. pneumoniae bacteremia.

A simple high-performance liquid chromatography for the determination of linezolid in human plasma and saliva.

Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. A practical high-performance liquid chromatography method was developed for the determination of linezolid in human plasma and saliva. Linezolid and an internal standard (o-ethoxybenzamide) were extracted from plasma and saliva with ethyl acetate and analyzed on a Capcell Pak C18 MG column with UV detection at 254 nm. The calibration curve was linear through the range 0.5-50 µg/mL using a 200 µL sample volume. The intra- and interday precisions were all <6.44% for plasma and 5.60% for saliva. The accuracies ranged from 98.8 to 110% for both matrices. The mean recoveries of linezolid were 80.8% for plasma and 79.0% for saliva. This method was used to determine the plasma and saliva concentrations of linezolid in healthy volunteers who were orally administered a 600 mg dose of linezolid. Our liquid-liquid extraction procedure is easy and requires a small volume of plasma or saliva (200 µL). This small volume can be advantageous in clinical pharmacokinetic studies, especially if children participate.

[Necessity of personalized initial loading dose calculation of teicoplanin by clinical pharmacist-examination of the utility of using systemic inflammatory response syndrome score-].

When teicoplanin (TEIC) is injected at the maintenance dose, a long period is required for achievement of the target plasma trough concentration because of its long elimination half-life. An initial loading dose is necessary for rapid achievement of an effective plasma trough concentration. Thus, we proposed that it is necessary for a pharmacist determine the initial loading dose of TEIC to reach an effective plasma trough concentration rapidly after its administration to a patient. In the present study, we evaluated the effectiveness of initial loading dose determination by pharmacists and physicians by comparing the achievement rate of target plasma trough concentrations (>15 µg/mL) and expression of adverse effects. Among 61 patients, 34 were treated according to an initial loading dose determined by a pharmacist (pharmacist intervention) and 27 were treated according to the treating physician's discretion (non-pharmacist intervention). The achievement rate of target concentrations was 91.2% (plasma trough concentration 23.3±5.3 µg/mL) in the pharmacist intervention group and 25.9% (plasma trough concentration 14.0±5.9 µg/mL) in the non-pharmacist intervention group. There was no difference in the incidence of adverse effects between the two groups. Also, we found that systemic inflammatory response syndrome (SIRS) may have a correlation with plasma trough concentrations of TEIC. We suggest that the SIRS score could become a means way of determining initial loading dose. These findings suggest that it is potentially effective for a pharmacist to determine this initial dose in order to rapidly achieve the target plasma trough concentration of TEIC.

Peyer's patch inducer cells play a leading role in the formation of B and T cell zone architecture.

Peripheral lymphoid tissues, such as lymph nodes and Peyer's patches (PPs), are organs required for mounting highly efficient immune responses to small quantities of Ag. The compartmentalization of the cellular components involved in the immune response into distinct zones supports the function of these tissues; however, little is known about how this compartmentalization is achieved. In this study, we analyzed neonatal PP development and present evidence that the CD3(-)IL-7Rα(+) PP inducer cells that initially play a pivotal role in the formation of the PP anlagen are involved in the formation of B and T cell zones in neonatal mice. PP inducer cells migrate between these zones by undergoing chemokine receptor switching.

Organizer-like reticular stromal cell layer common to adult secondary lymphoid organs.

Mesenchymal stromal cells are crucial components of secondary lymphoid organs (SLOs). Organogenesis of SLOs involves specialized stromal cells, designated lymphoid tissue organizer (LTo) in the embryonic anlagen; in the adult, several distinct stromal lineages construct elaborate tissue architecture and regulate lymphocyte compartmentalization. The relationship between the LTo and adult stromal cells, however, remains unclear, as does the precise number of stromal cell types that constitute mature SLOs are unclear. From mouse lymph nodes, we established a VCAM-1(+)ICAM-1(+)MAdCAM-1(+) reticular cell line that can produce CXCL13 upon LTbetaR stimulation and support primary B cell adhesion and migration in vitro. A similar stromal population sharing many characteristics with the LTo, designated marginal reticular cells (MRCs), was found in the outer follicular region immediately underneath the subcapsular sinus of lymph nodes. Moreover, MRCs were commonly observed at particular sites in various SLOs even in Rag2(-/-) mice, but were not found in ectopic lymphoid tissues, suggesting that MRCs are a developmentally determined element. These findings lead to a comprehensive view of the stromal composition and architecture of SLOs.

Peyer's patches are required for intestinal immunoglobulin A responses to Salmonella spp.

Previous studies have shown that Peyer's patches (PP) are not required for intestinal immunoglobulin A (IgA) responses to orally administered soluble protein. However, the roles of PP in regulation of mucosal immune responses against bacterial antigen remain to be clarified. In the present study, we generated several gut-associated lymphoreticular tissue-null mice by treatment with anti-interleukin-7 receptor antibody, the fusion protein of lymphotoxin beta receptor and IgG Fc, and/or tumor necrosis factor receptor p55 and IgG Fc. These mice were then immunized with recombinant Salmonella expressing the C fragment of the tetanus toxin (rSalmonella-Tox C). Orally immunized PP-null mice as well as isolated lymphoid follicle (ILF)-null, PP/ILF-null, and PP/ILF/mesenteric lymph node-null mice induced identical levels of tetanus toxoid (TT)-specific systemic IgG responses to those of control mice. However, PP-null mice, but not ILF-null mice, failed to induce TT-specific intestinal IgA antibodies. Analysis of TT-specific CD4+ T-cell responses showed a reduction of gamma interferon (IFN-gamma) synthesis in the intestinal lamina propriae of PP-null mice given oral rSalmonella-Tox C. In contrast, TT-specific IFN-gamma responses in the spleen and delayed-type hypersensitivity responses were intact in those immunized mice. Interestingly, Salmonella lipopolysaccharide (LPS)-specific fecal IgA responses were not elicited in PP-null mice, while serum IgG anti-LPS antibodies were identical to those of control mice. These results suggest that while none of the gut-associated lymphoreticular tissues are required for the induction of systemic immune responses, PP are an essential lymphoid tissue for induction and regulation of intestinal IgA immunity against orally administered rSalmonella.

[Epidemiology of multiple myeloma].

Death rates due to multiple myeloma are increasing by every year in Japan since 1970. 1,896 men and 1,889 women were died, during 2005. Crude mortality rates are also rising since 1970 and reach 3.04 per 100,000 and 2.89 per 100,000 among men and women, respectively in 2005. Age-adjusted mortality rates (using the 1985 Japan Standard) reach 1.5-1.6 per 100,000 in 1995 and persist its value till now.

Distinct activities of stromal cells involved in the organogenesis of lymph nodes and Peyer's patches.

It is now well established that the interaction between "inducer" cells of hemopoietic origin and "organizer" cells of mesenchymal lineage is involved in the organogenesis of lymph node (LN) and Peyer's patch (PP). Organizer cells are defined by the expression of VCAM-1 and ICAM-1 and the production of homeostatic chemokines. However, several studies suggested the presence of a diversity among these cells from different lymphoid tissues. Thus, we attempted to define the difference of organizer cells of LN and PP in terms of gene expression profile. Microarray analyses of organizer cells revealed that these cells isolated from embryonic mesenteric LN expressed higher levels of genes that are related to inflammation, tissue remodeling, and development of mesenchymal lineage compared with those from PP. Several transcription factors related to epithelial-mesenchymal interactions were also up-regulated in organizer cells from LN. These results indicate that organizer cells in LN and PP are indeed distinct and suggest that the organizer cells in LN are at a more activated stage than those in PP.

Defective chemokine-directed lymphocyte migration and development in the absence of Rho guanosine diphosphate-dissociation inhibitors alpha and beta.

Rho family small GTP-binding proteins, including Rho, Rac, and Cdc42, are key determinants of cell movement and actin-dependent cytoskeletal morphogenesis. Rho GDP-dissociation inhibitor (GDI) alpha and Rho GDIbeta (or D4/Ly-GDI), closely related regulators for Rho proteins, are both expressed in hemopoietic cell lineages. Nevertheless, the functional contributions of Rho GDIs remain poorly understood in vivo. In this study, we report that combined disruption of both the Rho GDIalpha and Rho GDIbeta genes in mice resulted in reduction of marginal zone B cells in the spleen, retention of mature T cells in the thymic medulla, and a marked increase in eosinophil numbers. Furthermore, these mice showed lower CD3 expression and impaired CD3-mediated proliferation of T cells. While B cells showed slightly enhanced chemotactic migration in response to CXCL12, peripheral T cells showed markedly reduced chemotactic migration in response to CCL21 and CCL19 associated with decreased receptor levels of CCR7. Overall, Rho protein levels were reduced in the bone marrow, spleen, and thymus but sustained activation of the residual part of RhoA, Rac1, and Cdc42 was detected mainly in the bone marrow and spleen. Rho GDIalpha and Rho GDIbeta thus play synergistic roles in lymphocyte migration and development by modulating activation cycle of the Rho proteins in a lymphoid organ-specific manner.

Lipocalin 2-deficient mice exhibit increased sensitivity to Escherichia coli infection but not to ischemia-reperfusion injury.

Diverse functions have been reported for lipocalin 2. To investigate these functions in vivo, we generated gene-targeted lipocalin 2-deficient mice (Lcn2-/- mice). In vitro studies have suggested that lipocalin 2 is important for cellular apoptosis induced by IL-3 withdrawal, and for the induction of kidney differentiation during embryogenesis. Analysis of Lcn2-/- mice showed normal cell death upon IL-3 withdrawal and normal kidney development. However, we found that Lcn2-/- mice exhibited an increased susceptibility to bacterial infections, in keeping with the proposed function of lipocalin 2 in iron sequestration. Neutrophils isolated from Lcn2-/- mice showed significantly less bacteriostatic activity compared with WT controls. The bacteriostatic property of the WT neutrophils was abolished by the addition of exogenous iron, indicating that the main function of lipocalin 2 in the antibacterial innate immune response is to limit this essential element. Another important function ascribed to lipocalin 2 has been its protective role against kidney ischemia-reperfusion injury. We analyzed Lcn2-/- mice using a mouse model for severe renal failure and could not detect any significant differences compared with their WT littermates.

A phase II study of VEPA/FEPP chemotherapy for aggressive lymphoma in elderly patients: Japan Clinical Oncology Group Study JCOG9203.

The Lymphoma Study Group (LSG) of the Japan Clinical Oncology Group conducted a phase II trial of LSG12 therapy for 45 elderly patients with aggressive lymphoma to clarify whether LSG12 reduces severe infection without lowering the complete response (CR) rate in comparison with LSG4. LSG12, which consisted of a regimen of vincristine, cyclophosphamide, prednisolone, doxorubicin, vindesine, etoposide, and procarbazine (VEPA/FEPP), excluded bleomycin and methotrexate of LSG4 therapy, reduced the dosages of doxorubicin and cyclophosphamide, and increased etoposide and procarbazine dosages instead. Inclusion criteria consisted of a patient age of 70 to 75 years, a World Health Organization performance status of 0 to 2, and acceptable organ function. The treatment was completed in 47% of the patients and terminated early for disease progression in 20% and for toxicity in 16%. The CR rate was 60% (95% confidence interval [CI], 44%-74%). The 5-year overall survival (OS) rate was 42% (95% CI, 27%-57%), and the median OS time was 4.3 years. Leukopenia of grade 3 to 4 occurred in 98% of the patients, and severe infection occurred in 9%. Eight patients with hepatitis C virus (HCV) antibody showed no severe hepatic toxicity and had a better CR or OS rate than the 37 HCV-negative patients. Although the outcomes of LSG12 met our expectations with a reduction in severe infection and equivalent CR and OS outcomes compared with LSG4 and CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone), the possibility of a regimen more beneficial than LSG12 for aggressive lymphoma in the elderly patient should be explored because of frequent hematologic toxicity and poor compliance in LSG12.

High-dose chemotherapy and autologous peripheral blood stem cell transplantation in high-risk multiple myeloma.

We compared the effect of high-dose therapy together with autologous peripheral blood stem cell transplantation (autoPBSCT) in 60 patients with multiple myeloma (MM) with 90 patients who underwent conventional chemotherapy. We scored the prognostic factors according to our reported classification system that includes measurements of serum albumin, serum beta-2-microglobulin, and morphology of myeloma cells selected by multivariate analysis. We separated the patients into three risk groups at stratification level I (low, intermediate and high) and into two risk groups at stratification level II (low and high). AutoPBSCT tended to be as effective for high, as for low-risk patients in level I, and was obviously as helpful for high, as for low-risk patients in stratification II. In conclusion, high-risk patients with MM should be treated with high-dose therapy accompanied with autoPBSCT like low-risk patients.

[Thalidomide treatment of patients with refractory myeloma in the institutes participating in the Japan Myeloma Study Group].

Thalidomide was used in 73 patients with refractory myeloma in 15 of 45 institutes participating in the Japan Myeloma Study Group. The mean age and male/female ratio were 63.8 years and 0.92 (35/38), respectively. Thirty-four patients (47%) were treated with only thalidomide, 27 patients (37%) were treated with thalidomide and steroids, and 12 (16%) were treated with thalidomide and chemotherapy. The mean initial, maximum, and maintenances dose of thalidomide were 111.0, 204.8, and 163.0 mg/day, respectively. Almost all of the patients were maintained on low-dose thalidomide between 100-200 mg/day. Complete, near complete and partial response was obtained in 31 patients (42.5%). The progression-free and overall survivals after thalidomide therapy were 9.8 and 21.3 months, respectively. The most common adverse effects were gastrointestinal disturbance, peripheral neuropathy, psychological signs, and skin eruption. In contrast to reports from Europe and America, no deep vein thrombosis was observed in this study. On the other hand, leukopenia was relatively frequently observed, and might be recognized as a serious adverse effect in myeloma patients. In conclusion, low-dose thalidomide is a useful and safe tool for the treatment of refractory myeloma.