Middle meatus microbiome in patients with eosinophilic chronic rhinosinusitis in a Japanese population.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease and is subdivided into eosinophilic and noneosinophilic forms. There are few reports investigating the nasal microbiome and its pathological functions in patients with CRS. OBJECTIVE: We sought to analyze factors contributing to variations of the nasal microbiome in CRS, and on the basis of these factors, to elucidate whether the bacterial metabolites were related to the pathogenesis. METHODS: Nasal swabs were collected, and the V3 to V4 variable region of the 16S ribosomal RNA gene was amplified and sequenced. Factors contributing to variations of the nasal microbiome in patients with CRS were compared. The most influential factor was whether CRS was eosinophilic, and we compared α- and ß-diversity, bacterial species, and predictive bacterial functions between the 2 patient groups. In addition, the metabolites of the key bacteria were extracted, and we evaluated the predicted bacterial functions in airway epithelial cells. RESULTS: In total, 110 patients with CRS and 33 control subjects were enrolled. On the basis of the factors of variation, it was found that patients with eosinophilic CRS (n = 65) had different microbiomes with weighted UniFrac ß-diversity and lower α-diversity compared with those with noneosinophilic CRS (n = 45). A higher abundance of Fusobacterium nucleatum and an increased LPS pathway were observed in patients with noneosinophilic CRS compared with those with eosinophilic CRS. In airway epithelial cells, LPS derived from F nucleatum suppressed the expression levels of ALOX15 induced by TH2 cytokines. CONCLUSIONS: The differences in the nasal microbiome may play a key role in the pathophysiology of CRS.

A longitudinal study of Candida bloodstream infections in a Japanese university hospital: species distribution, drug susceptibility, clinical features, and mortality predictors.

We aimed to detect possible changes in Candida species distribution over time and to know the antifungal susceptibility profile of isolates obtained from patients with bloodstream infection (BSI) due to this pathogen. Risk factors associated with 30-day mortality were also assessed. We conducted a retrospective cohort study of patients diagnosed with Candida BSI at a Japanese university hospital from 2013 to 2021. The change in the distribution pattern of the Candida spp. isolated was examined by considering three successive sub-periods of 3 years each. Risk factors for 30-day mortality were determined using Cox regression analysis. In the entire study period, Candida albicans was the most frequent species (46.7%), followed by Candida glabrata (21.5%) and Candida parapsilosis (18.7%). There was no change in Candida species distribution comparing the three sub-periods analyzed. All isolates were susceptible to micafungin, and most were susceptible to fluconazole, except for C. glabrata. No isolates were resistant to amphotericin B or voriconazole. The overall 30-day mortality was 40.2%. Univariate analysis revealed an association between 30-day mortality and central venous catheter (CVC) removal at any time, high Pitt bacteremia score (PBS), and high Charlson comorbidity index (CCI). Multivariate Cox analysis found that high PBS was the only independent predictor of 30-day mortality; subsequent multivariate Cox regression demonstrated that early CVC removal significantly reduced 30-day mortality. Candida species distribution and antifungal susceptibility profile in our hospital remained similar from 2013 to 2021. Early CVC removal may improve candidemia outcomes.

Genetic polymorphism and decreased expression of HLA class II DP genes are associated with HBV reactivation in patients treated with immunomodulatory agents.

Hepatitis B virus (HBV) reactivation can be triggered by immunosuppressive chemotherapy. HLA class II molecules may play a role in HBV reactivation. Genetic polymorphism and mRNA expression of HLA class II were examined in patients with latent HBV infection treated with immunosuppressive therapies. Subjects with resolved HBV infection who had undergone treatment with immunosuppressive chemotherapies were retrospectively enrolled (n = 42) and divided into reactivated (n = 9) and non-reactivated groups (n = 33). Patients were genotyped for 17 single nucleotide polymorphisms (SNPs) within HLA class II DPA1, and DPB1, and mRNA expression levels of HLA class II genes were assessed. The frequency of the AA genotype of rs872956, a SNP in HLA-DPB1, was significantly higher in the reactivated group than in the non-reactivated group (55.6% vs 12.1%, P < 0.05). The frequencies of the T allele and non-AA genotypes (AT/TT) of rs3116996 (located in DPB1) were significantly higher in the reactivated group (T allele frequency: 16.7% vs 0.0% [P < 0.01], non-AA genotype frequency: 22.2% vs 0.0% [P < 0.05]). Multivariate logistic regression identified the AA genotype of rs872956 as an independent protective factor against HBV reactivation (odds ratio [OR] = 18.1, 95% confidence interval [CI] = 2.6-126.7, P < 0.01). mRNA expression of HLA-DPB1 was lower in the HBV reactivated group than in the non-reactivated group (median 276.1 ± 165.6/ß-actin vs 371.4 ± 407.5/ß-actin [P < 0.05]). These results suggest the involvement of HLA class II molecules in HBV reactivation after treatment with immunomodulatory agents.

Identification of novel variants in HLA class II region related to HLA DPB1 expression and disease progression in patients with chronic hepatitis C.

Recent genome-wide studies have demonstrated that HLA class II gene may play an important role in viral hepatitis. We studied genetic polymorphism and RNA expression of HLA class II genes in HCV-related liver diseases. The study was performed in groups consisting of 24 patients with HCV-related liver disease (12 of persistent normal ALT: PNALT group and 12 of advanced liver disease: ALD group) and 26 patients without HCV infection (control group). In PBMC samples, RNA expression of HLA class II genes (HLA-DPA1, DPB1, DQA1, DQB1, and DRB1) was analyzed by real-time RT-PCR. Furthermore, 22 single nucleotide polymorphisms (SNPs) in HLA class II gene and two SNPs in IL28B gene were genotyped by genetic analyzer (GENECUBE®). In expression analysis, only DPB1 level was significantly different. Mean expression level of DPB1gene in control group was 160.0, PNALT group 233.8, and ALD group 465.0 (P < 0.01). Of 24 SNPs, allele frequencies were statistically different in two SNPs (rs2071025 and rs3116996) between PNALT groups and ALD group (P < 0.01). In rs2071025, TT genotype was frequently detected in ALD group and expression level was significantly higher than the other genotypes (449.2 vs 312.9, P < 0.01). In rs3116996, TA or TT (non AA) genotype was frequently detected in ALD group and expression level was significantly higher than genotype AA (457.1 vs 220.9, P < 0.01). Genotyping and expression analysis in HLA class II gene revealed that two SNPs of HLA-DPB1 (rs2071025 and rs3116996) were significantly correlated to RNA expression and progression of HCV-related liver diseases.

Antibody level dynamics until after the third dose of COVID-19 vaccination.

The antibody titers of volunteers, including elderly people, were investigated after the second dose of the BNT162b2 vaccine (Pfizer-BioNTech) as an mRNA vaccine against the coronavirus disease 2019 (COVID-19). Serum samples were collected from 105 volunteers (44 healthcare workers and 61 elderly people) 7-14 days after the second vaccine dose, and antibody titers were measured. The antibody titers of study participants in their 20s were significantly higher than those of other age groups. Furthermore, the antibody titers of participants aged <60 years were significantly higher than those of participants aged ≥60 years. Serum samples were repeatedly collected from 44 healthcare workers until after the third vaccine dose. Eight months after the second round of vaccination, the antibody titer levels decreased to the same level as that before the second vaccine dose. After the third booster vaccination, the antibody titer recovered to the same level as that after the second dose. Neutralizing activities were also investigated at four time points before and after the second vaccine dose. The antibody titers and neutralizing activity were positively correlated. Therefore, neutralizing activity can be predicted by measuring the antibody titer. In conclusion, the antibody titers in the elderly population were significantly lower than those in the younger population. Although the antibody titers increased following vaccination, their levels showed a decline after several months, returning to the same level as that after a single dose of mRNA vaccination. The antibody titer levels recovered after the third dose of vaccination, which had already been administered in Japan. Routine administration of vaccine should be considered in the future.

Exploration of sepsis assisting parameters in hospital autopsied-patients: a prospective study.

Although Sepsis-3 doesn't require evidence of bacteremia to diagnose sepsis, clinicians often want to identify the causative pathogen at autopsy. In principle, if the blood cultures are the same at ante- and postmortem, the cause of death is obvious. However, interpretations of postmortem blood cultures are often difficult due to discordance, negativity, mixed infection, and contamination, of pathogens occupying ≥ 50% of the tests. To increase specificity identifying agonal phase sepsis in the situations where blood cultures are discordant, multiple or negative at postmortem, we established a scoring system using blood cultures, procalcitonin (PCN) showing highest sensitivity and specificity for postmortem serum, and bone marrow polyhemophagocytosis (PHP). Histological sepsis showed significantly higher levels of culture score (2.3 ± 1.5 vs. 0.4 ± 0.5, p < 0.001), PHP score (2.5 ± 0.8 vs. 1.0 ± 1.1, p < 0.001), and PCN score (1.8 ± 0.8 vs. 0.8 ± 0.6, p < 0.01) than non-septic patients. Receiver operating characteristic curve analysis indicated that estimation of three scores was the most reliable indicator for recognizing agonal phase sepsis. These findings suggest that the combination of these three inspections enables to determine the pathological diagnoses of sepsis even it is not obvious by discordant, mixed or negative blood cultures.

Rapid detection of the Mycobacterium tuberculosis complex by use of quenching probe PCR (geneCube).

Early detection of tuberculosis (TB) is essential for infection control. The geneCube (Toyobo) is a novel fully automated gene analyzer that can amplify target DNAs within 60 min. In this study, we evaluated the ability of the geneCube to directly detect Mycobacterium tuberculosis complex (MTBC) and Mycobacterium avium complex (MAC) in clinical specimens. The results were then compared with those obtained using conventional culture, microscopy, and the Cobas Amplicor assay (Roche). We examined a total of 516 frozen samples from 69 patients who showed culture-positive infection (73 samples; 39 MTBC, 32 MAC, and 2 mixed infections) and from 354 patients who were culture negative (443 samples). Assays using the geneCube had a sensitivity of 85.4% and a specificity of 99.8% for detection of MTBC and a sensitivity of 85.3% and a specificity of 99.8% for detection of MAC. These results are similar to those obtained using the Amplicor system but were obtained much more rapidly (1 h with the geneCube versus 5.5 h with the Amplicor system). The geneCube thus enables a significant shortening of the assay time with no loss of sensitivity or specificity.

Development and evaluation of a novel quenching probe PCR (GENECUBE) assay for rapidly detecting and distinguishing between Chlamydia pneumoniae and Chlamydia psittaci.

Early detection of the family Chlamydiaceae as pathogens is essential worldwide for the rapid and sufficient management of atypical pneumonia. GENECUBE (TOYOBO) is a novel fully automated gene analyzer capable of amplifying and detecting target DNAs within 50 min. In this study, we developed a new PCR assay with a specific quenching probe (PCR-QC assay) for rapidly distinguishing between Chlamydia pneumoniae (CPN) and Chlamydia psittaci (CPS). The PCR-QC assay enabled us to precisely and simultaneously detect the 2 different types of DNA fragments even in a mixed sample by identifying unique melting temperatures. Next, we examined a total of 300 frozen samples from patients with respiratory tract infection using the PCR-QC assay and the cell culture method as the gold standard. Kappa index for agreement between the PCR-QC assay and the culture method was 0.43 (95% confidential interval (CI): 0.08-0.78). The sensitivity and specificity of the PCR-QC assay were 36.3% (4/11; 95% CI: 10.9-69.2%)) and 99.0% (286/289; 95% CI: 97.0-99.8%), respectively. The samples positive for CPN (n = 13) or CPS (n = 1) by either method were also examined by a conventional PCR TaqMan assay, which produced the same results as those from the PCR-QC assay. Furthermore, the PCR-QC assay using GENECUBE shortened the full detection time for CPN or CPS (within 50 min vs. more than 2 to 3 h) compared with conventional PCR TaqMan assays. Therefore, the new PCR-QC assay system equipped with GENECUBE is useful for rapidly detecting CPN or CPS pathogens in clinical laboratory, and may improve the management of atypical pneumonia.

Association of methicillin resistance with mortality of hospital-acquired Staphylococcus aureus bacteremia.

OBJECTIVE: Methicillin-resistant (MR) Staphylococcus aureus bacteremia (SAB) is associated with higher mortality rates than methicillin-susceptible (MS) SAB. This study assessed potential predictors of mortality and evaluated the association of methicillin resistance with mortality in patients with SAB. METHODS: We conducted a retrospective cohort study in patients with hospital-acquired SAB, from 2009 to 2018. Clinical features of patients with MR-SAB were compared with those of patients with MS-SAB and predictors of 30-day mortality were determined using Cox regression analysis. RESULTS: Among 162 patients, 56.8% had MR-SAB. Overall 30-day mortality was 19.1%; MR-SAB had higher mortality (25.0%) than MS-SAB (11.4%). Univariate analysis highlighted long-term hospitalization, prior antibiotics use, and delayed initiation of appropriate antibiotics as risk factors. Cox regression analysis showed that respiratory tract source, Pitt bacteremia score, Charlson comorbidity index, and appropriate antibiotic therapy within 24 hours were independently and significantly associated with 30-day mortality outcome. CONCLUSIONS: Methicillin resistance was not an independent risk factor for mortality in patients with SAB. Early, appropriate antibiotic treatment is an important prognostic factor.

Clinical evaluation of a non-purified direct molecular assay for the detection of Clostridioides difficile toxin genes in stool specimens.

Recently, a new rapid assay for the detection of tcdB gene of Clostridioides difficile was developed using the GENECUBE. The assay can directly detect the tcdB gene from stool samples without a purification in approximately 35 minutes with a few minutes of preparation process. We performed a prospective comparative study of the performance of the assay at eight institutions in Japan. Fresh residual stool samples (Bristol stool scale ≥5) were used and comparisons were performed with the BD MAX Cdiff assay and toxigenic cultures. For the evaluation of 383 stool samples compared with the BD MAX Cdiff assay, the sensitivity, and specificity of the two assays was 99.0% (379/383), 98.1% (52/53), 99.1% (327/330), respectively. In the comparison with toxigenic culture, the total, sensitivity, and specificity were 96.6% (370/383), 85.0% (51/60), and 98.8% (319/323), respectively. The current investigation indicated the GENECUBE Clostridioides difficile assay has equivalent performance with the BD MAX Cdiff assay for the detection of tcdB gene of C. difficile.

[In vitro susceptibilities to levofloxacin and various antibacterial agents of 12,919 clinical isolates obtained from 72 centers in 2007].

We have reported in this journal in vitro susceptibilities of clinical isolates to antibiotics every year since 1992. In this paper, we report the results of an analysis of in vitro susceptibilities of 12,919 clinical isolates from 72 centers in Japan to selected antibiotics in 2007 compared with the results from previous years. The common respiratory pathogens, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae maintained a high susceptibility to fluoroquinolones (FQs). The resistance of S. pyogenes to macrolides has been increasing every year and this was especially clear this year. Most strains of Enterobacteriaceae except for Escherichia coli showed a high susceptibility to FQs. Almost 30% of E. coli strains were resistant to FQs and the resistance increased further this year. FQs resistance of methicillin-resistant Staphylococcus aureus (MRSA) was approximately 95% with the exception of 45% for sitafloxacin (STFX). FQs resistance of methicillin-susceptible S. aureus (MSSA) was low at about 10%. FQs resistance of methicillin-resistant coagulase negative Staphylococci (MRCNS) was higher than that of methicillin-susceptible coagulase negative Staphylococci (MSCNS), but it was lower than that of MRSA. However, FQs resistance of MSCNS was higher than that of MSSA. FQs resistance of Enterococcus faecalis was 22.5% to 29.6%, while that of Enterococcusfaecium was more than 85% except for STFX (58.3%). In clinical isolates of Pseudomonas aeruginosa derived from urinary tract infections, FQs resistance was 21-27%, which was higher than that of P. aeruginosa from respiratory tract infections at 13-21%, which was the same trend as in past years. Multidrug resistant strains accounted for 5.6% in the urinary tract and 1.8% in the respiratory tract. Acinetobacter spp. showed high susceptibility to FQs. The carbapenem resistant strains, which present a problem at present, accounted for 2.7%. Neisseria gonorrhoeae showed high resistance of 86-88% to FQs. The results of the present survey indicated that although methicillin-resistant Staphylococci, Enterococci, E. coli, P. aeruginosa, and N. gonorrhoeae showed resistance tendencies, and other species maintained high susceptibility rates more than 90% against FQs, which have been used clinically for over 15 years.

Dietary supplement product composed of natural ingredients as a suspected cause of erythema multiforme: A case report and identification for the confident false positivity of lymphocyte transformation test.

Growing and sustainable consumption of health-care products raises a controversial issue underlying the reliability of an in vitro diagnostic approach for adverse skin reaction. This report aimed to: (i) discuss the causative nature of a commercial dietary supplement composed of natural ingredients, particularly an Euglena-containing product, suspicious for erythema multiforme in our exemplified case; and (ii) to address the assay suitability of the lymphocyte transformation test (LTT) for identifying allergic reaction to any ingredient(s) of the product. A Japanese elderly man developed erythema multiforme after intake of a commercially available natural dietary product, whose LTT was positive. His clinical course and positive LTT suggested a provisional diagnosis of natural dietary product-induced eruption. We conducted an inquiry survey for the standard LTT with any commercial products containing Euglena in three major Japanese laboratory services and identified 22 subjects, almost all of whom (21/22, 95.6%) showed a positive LTT for any Euglena-containing products as a suspected causative. Seven normal healthy volunteers who had no intake history of Euglena-containing products showed an equivalent LTT positivity rate with the same product taken by our case; culprit components of the product included Euglena, Angelica keiskei, Barley grass and Chlorella. A cell-free culture system and enzyme-linked immunoassay suggest that the high LTT positivity relies on the non-specific lymphoproliferative activity, and not contamination of uncharacterized microorganisms and endotoxins. Because of the constitutive false positivity of LTT, this assay is unreliable for in vitro supportive diagnosis of adverse skin events caused by dietary products containing particular natural ingredients, as well as herbal materials.

Evaluation of performance of the GENECUBE assay for rapid molecular identification of Staphylococcus aureus and methicillin resistance in positive blood culture medium.

Rapid identification of causative agents from positive blood culture media is a prerequisite for the timely targeted treatment of patients with sepsis. The GENECUBE (TOYOBO Co., Ltd.) is a novel, fully-automated gene analyzer that can purify DNAs and amplify target DNAs. In this study, we evaluated the ability of two newly developed GENECUBE assays to directly detect the nuc and mecA genes in blood culture medium; nuc is specific to Staphylococcus aureus, and mecA indicates methicillin resistance. We examined 263 positive blood culture samples taken at three hospitals from patients suspected of having staphylococcal bacteremia. The results were then compared with those obtained using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, antimicrobial susceptibility testing (Microscan system or Dry-plate EIKEN), and sequencing analysis. The GENECUBE assays had sensitivity and specificity of 100% in detecting both S. aureus and methicillin resistance in positive blood culture. The turnaround time of the examination was evaluated for 36 positive blood culture samples. The time between the initiation of incubation and completion of the GENECUBE examination was 23 h (interquartile range: IQR 21-37 h); the time between reporting of Gram stain examination and completion of the GENECUBE examination was 52 min (IQR 48-62 min). These findings show that the GENECUBE assays significantly reduce the assay time with no loss of sensitivity or specificity.

Association of C-Type Lectin Mincle with FcεRIßγ Subunits Leads to Functional Activation of RBL-2H3 Cells through Syk.

Macrophage-inducible C-type lectin (Mincle) interacts with the γ-subunit of high-affinity IgE receptor (FcεRIγ) and activates Syk by recognizing its specific ligand, trehalose-6,6'-dimycolate, a glycolipid produced by Mycobacterium tuberculosis. It has been suggested that mast cells participate in the immune defense against pathogenic microbes including M. tuberculosis, although the functions are still uncertain. In this study, we examined the Mincle-mediated signaling pathway and cellular responses using RBL-2H3 cells. Mincle formed a protein complex with not only FcεRIγ but also FcεRIß in a stable cell line expressing myc-tagged Mincle. In addition, engagement of Mincle increased the levels of protein tyrosine phosphorylation and ERK phosphorylation. A pull-down assay demonstrated that cross-linking of Mincle induced binding of FcεRIßγ subunits to the Src homology 2 domain of Syk. Pharmacological and genetic studies indicated that activation of Syk was critical for Mincle-mediated activation of phospholipase Cγ2, leading to the activation of ERK and nuclear factor of activated T cells. Moreover, engagement of Mincle efficiently induced up-regulation of characteristic mast cell genes in addition to degranulation. Taken together, our present results suggest that mast cells contribute to Mincle-mediated immunity through Syk activation triggered by association with the FcεRIßγ complex.

Clinical effect of a multidisciplinary team approach to the initial treatment of patients with hospital-acquired bloodstream infections at a Japanese university hospital.

BACKGROUND: Hospital-acquired bloodstream infections (BSIs) are significant causes of mortality, and strategies to improve outcomes are needed. We aimed to evaluate the clinical efficacy of a multidisciplinary infection control team (ICT) approach to the initial treatment of patients with hospital-acquired BSI. METHODS: A before-after quasiexperimental study of patients with hospital-acquired BSI was performed in a Japanese university hospital. The ICT provided immediate recommendations to the attending physician about appropriate antimicrobial therapy and management after reviewing blood cultures, Gram's stain, final organism, and antimicrobial susceptibility results. RESULTS: The sample included 469 patients with hospital-acquired BSI (n = 210, preintervention group; n = 259, postintervention group). There were no significant differences between the groups in background or microbiologic characteristics. The 30-day mortality was significantly lower and significantly more patients received appropriate antimicrobial therapy in the postintervention group (22.9% vs 14.3%; P = .02 and 86.5% vs 69.0%; P < .001, respectively). Multivariate analysis confirmed that the ICT intervention was significantly associated with appropriate antimicrobial therapy (odds ratio, 2.22; 95% confidence interval, 1.27-3.89) and 30-day mortality (odds ratio, 0.49; 95% confidence interval, 0.25-0.95). CONCLUSIONS: A timely multidisciplinary team approach decreases the delay of appropriate antimicrobial treatment and may improve HABSI patient outcomes.

A specific serum IgA antibody discriminates pneumonia from colonization state in patients with Pseudomonas aeruginosa in sputum culture.

We attempted to develop a new specific antibody detection method for discriminating infection state from colonization state in hospitalized immunocompromised patients with a positive sputum culture for Pseudomonas aeruginosa. Serum samples from 65 patients with P. aeruginosa in sputum culture (total PA patients), including 24 patients with P. aeruginosa-related pulmonary infections (PA infection group) and 21 patients without pulmonary infections (PA colonization group), as well as samples from 20 patients positive for other bacteria in blood culture (non-PA infection group) and 38 healthy controls were examined and compared for IgG and IgA anti-P. aeruginosa antibodies by a newly developed enzyme-linked immunosorbent assay (ELISA). Both IgG and IgA antibody ELISA showed satisfactory reproducibility with low coefficient of variation (CV) percent, and western blotting analysis showed two protein bands as the corresponding antigens common to both antibodies. The serum levels of both antibodies in all the PA patients were higher than those in the healthy controls with high significance (p<0.0001). The PA infection group showed significantly higher mean levels of both IgG and IgA class antibodies than the PA colonization group, non-PA infection group and healthy controls (each, p<0.0001). In receiver operating characteristic (ROC) curves analysis to differentiate between total PA infections and the PA colonization group, the area under curve (AUC) of the IgA antibody (0.848) was significantly larger than the AUC of the IgG antibody (0.677) (p=0.019). At the optimal IgA antibody cutoff value for differentiation of 1.37 units/mL, the sensitivity and specificity of IgA anti-P. aeruginosa ELISA were 83.3% and 85.7%, respectively. These findings suggest that IgA antibody ELISA, rather than IgG antibody ELISA, may be useful for differentiating P. aeruginosa-related pneumonia from latent colonization in immunocompromised patients with a positive sputum culture.