Impact of antimicrobial stewardship with the Xpert MRSA/SA BC assay at a tertiary hospital in Japan.

INTRODUCTION: Genetic testing is gaining increasing importance as a part of antimicrobial stewardship (AS). Rapid identification and determination of methicillin susceptibility using the Xpert MRSA/SA BC assay can improve the management of Staphylococcus aureus bacteremia (SAB) and reduce inappropriate antibiotic use. However, few reports have described the effectiveness of this approach. METHODS: The present study aimed to assess the influence of AS using the Xpert MRSA/SA BC assay. Cases were classified into the pre-intervention group (n = 98 patients), in which SAB was identified by traditional culture (November 2017 to November 2019), and the post-intervention group (n = 97 patients), in which the Xpert MRSA/SA BC assay was performed when necessary (December 2019 to December 2021). RESULTS: Patient characteristics, prognosis, duration of antimicrobial use, and length of hospital stay were compared between the groups. The Xpert assay was performed in 66 patients in the post-intervention group (68.0%). The two groups showed no significant differences in severity and mortality. The rate of cases treated with anti-MRSA agents reduced following the intervention (65.3% vs. 40.4%, p = 0.008). The number of cases involving definitive therapy within 24 h was higher in the post-intervention group (9.2% vs. 24.7%, p = 0.007). The hospitalization rate at >60 days was lower in Xpert implementation cases among MRSA bacteremia cases (28.6% vs. 0%, p = 0.01). CONCLUSIONS: Thus, the Xpert MRSA/SA BC assay has potential as an AS tool, especially for early definitive treatment to SAB and reduction of long-term hospitalization in MRSA bacteremia cases.

Impact of coronavirus disease 2019 on infectious disease treatment and infection control at a tertiary hospital in Japan.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has greatly impacted medical care practices. Although the effects on infectious disease treatment and infection control, such as antimicrobial resistance, have been specified, very few reports exist on the specific effects of COVID-19. METHODS: We investigated the effects of COVID-19 on daily medical practices at a tertiary hospital in Japan by comparing the use of hand sanitizers, the detection of bacteria from blood cultures, and the amount dose of antibacterial drugs used for one year before (April 2019 to March 2020, fiscal year 2019.) and after COVID-19 admissions began (April 2020 to March 2021, fiscal year 2020). RESULTS: The use of hand sanitizers increased by 1.4-3 times during the year after COVID-19 admissions began; the incidence of methicillin-susceptible Staphylococcus aureus and all S. aureus detected in blood cultures reduced in all departments. No decrease was observed in the usage of all antibacterial drugs; rather, the usage of all antibacterial drugs tended to increase in all departments. Therefore, no significant change was observed in the detection of drug-resistant bacteria and the trends of antibacterial drug use based on the acceptance of COVID-19 patients. CONCLUSIONS: The prevalence of drug-resistant bacteria and trends of antibacterial drug use remained unchanged despite the increased use of hand sanitizers due to the admission of patients with COVID-19.

Literature review of allograft adenovirus nephritis and a case presenting as mass lesions in a transplanted kidney without symptoms of urinary tract infection or acute kidney injury.

Adenovirus (AdV) infection is a common complication in bone marrow/hematopoietic stem cell transplant and solid organ transplant recipients. AdV infection usually presents as hemorrhagic cystitis, but sometimes it can progress to acute kidney injury showing AdV nephritis (AdVN). We present the case of a 52-year-old Japanese female who had received a living kidney transplantation (KT) from her husband. At 21 months post-KT, the patient presented with a fever, but no renal dysfunction and no abnormal urine findings. A contrast-enhanced computed tomography (CT) scan revealed a few mass lesions with hypoperfusion in the transplanted kidney. An enhanced CT-guided biopsy targeting one of these lesions revealed a necrotizing tubulointerstitial nephritis suggesting AdVN. The polymerase chain reaction tests for ADV were negative in a urine sample but positive in the sera and the frozen kidney biopsy samples. AdVN can manifest as an unusual pattern of acute lobar nephritis/acute focal bacterial nephritis-like localization without symptoms of acute kidney injury or urinary tract infection. Enhanced CT can provide clues for clinical diagnosis.

White rice ethanol extract is qualitatively, but not quantitatively, equivalent to that of brown rice as an antioxidant source.

The purpose of this study is to compare the potentials to exhibit biologically active antioxidant actions between white rice (WR) and brown rice (BR) in in vitro assays and a cellular model. The Trolox equivalent (TE) per 1 mg ethanol extract of WR for the 1,1-diphenyl-2-picrylhydrazyl assay was slightly higher than that of BR, whereas the TE per 1 g whole WR was much lower than that for BR. This tendency was very comparable to those for the oxygen radical absorbance capacity and total polyphenol content. Both of the ethanol extracts also similarly suppressed the hydrogen peroxide-induced cytotoxicity and enhanced the gene expression of drug-metabolizing enzymes. Based on the α-tocopherol quantity, its contribution to the cytoprotective effect of the rice extracts is very limited. Taken together, the ethanol extract of WR might be a qualitatively, but not quantitatively, equivalent source of antioxidative phytochemicals to that of BR.

Three-year epidemiological analysis of Clostridioides difficile infection and the value of hospital-infection control measures in a tertiary-care teaching hospital in Japan using PCR-based open-reading frame typing.

INTRODUCTION: Clostridioides difficile is an important causative pathogen in antibiotic-associated colitis and nosocomial infections. This study aimed to assess immunochromatographic test results for C. difficile infection and the utility of PCR-based open-reading frame typing (POT) for potentially controlling the intra-ward transmission of C. difficile. METHODS: We conducted a molecular epidemiological analysis using POT to investigate 102 inpatients who tested positive for the C. difficile toxin using immunochromatography in a tertiary-care teaching hospital in Japan between 2016 and 2018; isolates from the patients were obtained and cultured. RESULTS: The number of POT numbers detected in 2016, 2017, and 2018 were 27 (among 34 patients), 20 (among 31 patients), and 28 (among 37 patients), respectively. During this three-year period, there were seven cases whose bacterial strains with the same POT number was identified in the same ward within 6 months. The intra-ward transmission rate was the highest in 2017 (16.1%). Intra-ward transmission was identified at a higher rate in patients whose sample cultures tested toxin-positive than in patients whose sample cultures tested toxin- and glutamate-dehydrogenase-positive via immunochromatography (16% vs. 3%, p < 0.05). CONCLUSIONS: We conclude that the use of immunochromatographic tests for C. difficile diagnosis and epidemiological analyses via POT may be helpful for evaluating intra-ward transmission of C. difficile.

The effect of intervention by an antimicrobial stewardship team on anaerobic bacteremia.

The effect of antimicrobial stewardship (AS) on anaerobic bacteremia is uncertain. This study aimed to assess the effect of interventions by the AS team (AST) on clinical and microbiological outcomes and antimicrobial use. An AS program was introduced at Osaka City University Hospital in January 2014; an interdisciplinary AST was established. We enrolled patients with anaerobic bacteremia between January 2009 and December 2018. Patients were classified into the pre-intervention group (from January 2009 to December 2013) and the post-intervention group (from January 2014 to December 2018). A significant decrease in definitive carbapenem use (P = 0.0242) and an increase in empiric tazobactam/piperacillin use (P = 0.0262) were observed in the post-intervention group. The de-escalation rate increased significantly from 9.38% to 32.7% (P = 0.0316) in the post-intervention group. The susceptibility of Bacteroides species and 30-day mortality did not worsen in the post-intervention group. These results showed that interventions by an AST can reduce carbapenem use and increase the de-escalation rate without worsening patient outcomes.

The effects of antifungal stewardship programs at a tertiary-care teaching hospital in Japan.

Patients with invasive fungal diseases (IFDs) generally have a high mortality rate, and resistance to antifungal drugs and the high costs associated with it have led to recent problems, necessitating the appropriate use of antifungals. To this end, we launched Antifungal Stewardship Programs (AFSPs) in our hospital. Patients who were systemically administered antifungals from January 2011 to December 2016 were enrolled this study and divided into pre-intervention and intervention groups. No significant difference was observed in defined daily doses per 1000 patient-days (23.3 ± 8.0 vs 20.4 ± 10.8, p = 0.251) between the groups. The monthly average for the days of therapy per 1000 patient-days was significantly lower in the intervention group (15.1 ± 3.1 vs 12.7 ± 4.3, p = 0.009). The cost of the antifungals reduced over the 3-year period by $260,520 (13.5%). Furthermore, a decreasing trend was observed in both the 30-day mortality (40.9% vs 30.0%, p = 0.414) and in-hospital mortality (63.6% vs 36.7%, p = 0.054) in patients with candidemia. Our results indicate that AFSPs are efficacious and cost-effective approaches.

The intervention by an antimicrobial stewardship team can improve clinical and microbiological outcomes of resistant gram-negative bacteria.

Antibiotic stewardship (AS) improves patient outcomes and rates of antibiotic susceptibilities. However, the long-term effect of AS programs (ASPs) on mortality is unclear. This study aimed to assess the impact of bedside interventions by an AS team (AST) on clinical and microbiological outcomes. This retrospective study enrolled patients with bloodstream infections (BSI) and long-term use of broad-spectrum antibiotics (more than 7 days). The main outcomes were 30-day and in-hospital mortality of patients with BSI. The secondary outcomes were the day of therapy (DOT) and susceptibility of antipseudomonal agents. Cases were classified into two groups: the pre-ASP group comprised cases between 2011 and 2013 and the post-ASP group, between 2014 and 2016. The outcomes were then compared between the two groups. Among the patients with all BSI (n = 1187), no significant differences in 30-day mortality were observed between those in the pre-ASP and post-ASP groups. However, in-hospital mortality was significantly lower in the post-ASP group than that in the pre-ASP group (24.8% vs. 18.0%; P = 0.004). Furthermore, the 30-day and in-hospital mortality of resistant gram-negative bacteraemia was significantly lower (20.4% vs.10.5%; P = 0.04 and 28.0% vs.16.1%; P = 0.03). The DOT of broad-spectrum antibiotics decreased except that of tazobactam/piperacillin. The susceptibilities of tazobactam/piperacillin, ceftazidime, cefepime, sulbactam/cefoperazone, gentamicin, ciprofloxacin levofloxacin, imipenem and meropenem were significantly better. Interventions by the AST can improve the clinical and microbiological outcomes, especially resistant gram-negative bacteria. Furthermore, this effect of our ASP can continue for a long term.

Transcription factor MafB may play an important role in secondary hyperparathyroidism.

The transcription factor MafB is essential for development of the parathyroid glands, the expression of which persists after morphogenesis and in adult parathyroid glands. However, the function of MafB in adult parathyroid tissue is unclear. To investigate this, we induced chronic kidney disease (CKD) in wild-type and MafB heterozygote (MafB+/-) mice by feeding them an adenine-supplemented diet, leading to secondary hyperparathyroidism. The elevated serum creatinine and blood urea nitrogen levels in heterozygous and wild-type mice fed the adenine-supplemented diet were similar. Interestingly, secondary hyperparathyroidism, characterized by serum parathyroid hormone elevation and enlargement of parathyroid glands, was suppressed in MafB+/- mice fed the adenine-supplemented diet compared to similarly fed wild-type littermates. Quantitative RT-PCR and immunohistochemical analyses showed that the increased expression of parathyroid hormone and cyclin D2 in mice with CKD was suppressed in the parathyroid glands of heterozygous CKD mice. A reporter assay indicated that MafB directly regulated parathyroid hormone and cyclin D2 expression. To exclude an effect of a developmental anomaly in MafB+/- mice, we analyzed MafB tamoxifen-induced global knockout mice. Hypocalcemia-stimulated parathyroid hormone secretion was significantly impaired in MafB knockout mice. RNA-sequencing analysis indicated PTH, Gata3 and Gcm2 depletion in the parathyroid glands of MafB knockout mice. Thus, MafB appears to play an important role in secondary hyperparathyroidism by regulation of parathyroid hormone and cyclin D2 expression. Hence, MafB may represent a new therapeutic target in secondary hyperparathyroidism.

FT-like proteins induce transposon silencing in the shoot apex during floral induction in rice.

Floral induction is a crucial developmental step in higher plants. Florigen, a mobile floral activator that is synthesized in the leaf and transported to the shoot apex, was recently identified as a protein encoded by FLOWERING LOCUS T (FT) and its orthologs; the rice florigen is Heading date 3a (Hd3a) protein. The 14-3-3 proteins mediate the interaction of Hd3a with the transcription factor OsFD1 to form a ternary structure called the florigen activation complex on the promoter of OsMADS15, a rice APETALA1 ortholog. However, crucial information, including the spatiotemporal overlap among FT-like proteins and the components of florigen activation complex and downstream genes, remains unclear. Here, we confirm that Hd3a coexists, in the same regions of the rice shoot apex, with the other components of the florigen activation complex and its transcriptional targets. Unexpectedly, however, RNA-sequencing analysis of shoot apex from wild-type and RNA-interference plants depleted of florigen activity revealed that 4,379 transposable elements (TEs; 58% of all classifiable rice TEs) were expressed collectively in the vegetative and reproductive shoot apex. Furthermore, in the reproductive shoot apex, 214 TEs were silenced by florigen. Our results suggest a link between floral induction and regulation of TEs.

Diverse subcellular localizations of the insect CMP-sialic acid synthetases.

The occurrence and biological importance of sialic acid (Sia) and its metabolic enzymes in insects have been studied using Drosophila melanogaster. The most prominent feature of D. melanogaster CMP-Sia synthetase (DmCSS) is its Golgi-localization, contrasted with nuclear localization of vertebrate CSSs. However, it remains unclear if the Golgi-localization is common to other insect CSSs and why it happens. To answer these questions, Aedes aegypti (mosquito) CSS (AaCSS) and Tribolium castaneum (beetle) CSS (TcCSS) were cloned and characterized for their activity and subcellular localization. Our new findings show: (1) AaCSS and TcCSS share a common overall structure with DmCSS in terms of evolutionarily conserved motifs and the absence of the C-terminal domain typical to vertebrate CSSs; (2) when expressed in mammalian and insect cells, AaCSS and TcCSS showed in vivo and in vitro CSS activities, similar to DmCSS. In contrast, when expressed in bacteria, they lacked CSS activity because the N-terminal hydrophobic region appeared to induce protein aggregation; (3) when expressed in Drosophila S2 cells, AaCSS and TcCSS were predominantly localized in the ER, but not in the Golgi. Surprisingly, DmCSS was mainly secreted into the culture medium, although partially detected in Golgi. Consistent with these results, the N-terminal hydrophobic regions of AaCSS and TcCSS functioned as a signal peptide to render them soluble in the ER, while the N-terminus of DmCSS functioned as a membrane-spanning region of type II transmembrane proteins whose cytosolic KLK sequence functioned as an ER export signal. Accordingly, the differential subcellular localization of insect CSSs are distinctively more diverse than previously recognized.

Anti-oxidative Activity of Hydrolysate from Rice Bran Protein in HepG2 Cells.

Glutathione (GSH) is an ubiquitous thiol-containing tripeptide, which plays important roles in cellular protection from oxidative stress. In our search for a dietary source that can increase GSH levels, we discovered that a 24 h treatment of HepG2 cells with rice bran protein hydrolysate (RBPH), prepared by Umamizyme G-catalyzed hydrolysis, increased the GSH content in a dose-dependent manner. RBPH elevated the expression levels of γ-glutamylcysteine synthetase (γ-GCS), which constitutes the rate-limiting enzyme of GSH synthesis, and of another two enzymes, hemeoxygenase-1 (HO-1) and reduced nicotinamide adenine dinucleotide (phosphate): quinone oxidoreductase 1 (NQO1). This induction was preceded by the accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) inside the nucleus, which is a key transcription factor for the expression of the γ-GCS, HO-1, and NQO1. Pre-treatment of cells with RBPH produced a significant protective effect against cytotoxicity caused by H2O2 or ethanol. These results indicate that RBPH exerts a protective effect against oxidative stress by modulating GSH levels and anti-oxidative enzyme expression via the Nrf2 pathway.

Hepatoprotective effects of rice-derived peptides against acetaminophen-induced damage in mice.

Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We found that rice peptides increased intracellular glutathione levels in human hepatoblastoma HepG2 cells. Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of rice peptides on acetaminophen-induced hepatotoxicity in mice. ICR mice were orally administered rice peptides (0, 100 or 500 mg/kg) for seven days, followed by the induction of hepatotoxicity via intraperitoneal injection of acetaminophen (700 mg/kg). Pretreatment with rice peptides significantly prevented increases in serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels and protected against hepatic glutathione depletion. The expression of γ-glutamylcysteine synthetase, a key regulatory enzyme in the synthesis of glutathione, was decreased by treatment with acetaminophen, albeit rice peptides treatment recovered its expression compared to that achieved treatment with acetaminophen. In addition, histopathological evaluation of the livers also revealed that rice peptides prevented acetaminophen-induced centrilobular necrosis. These results suggest that rice peptides increased intracellular glutathione levels and could protect against acetaminophen-induced hepatotoxicity in mice.

Sake lees hydrolysate protects against acetaminophen-induced hepatotoxicity via activation of the Nrf2 antioxidant pathway.

Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of sake lees hydrolysate against acetaminophen-induced hepatotoxicity in mice. Sake lees hydrolysate was administered orally to ICR mice for seven days. Six hours after acetaminophen treatment, the mice were sacrificed, and blood and liver samples were collected for analysis. Treatment with acetaminophen markedly increased the levels of serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase. Pretreatment with sake lees hydrolysate significantly prevented the increases in the serum levels of these enzymes and inhibited acetaminophen-mediated glutathione depletion. In addition, histopathological evaluation of the livers also revealed that sake lees hydrolysate prevented acetaminophen-induced centrilobular necrosis. The expression of γ-glutamylcysteine synthetase (γ-GCS), hemeoxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the liver were decreased after acetaminophen treatment, whereas pretreatment with sake lees hydrolysate led to an increased expression of all three proteins. Furthermore, sake lees hydrolysate induced the expression of these proteins in HepG2. These results suggested that sake lees hydrolysate could induces HO-1 and γ-GCS expression via activation of the Nrf2 antioxidant pathway, and protects against acetaminophen-induced hepatotoxicity in mice.

PKCα regulates TMEM16A-mediated Cl⁻ secretion in human biliary cells.

TMEM16A is a newly identified Ca(2+)-activated Cl(-) channel in biliary epithelial cells (BECs) that is important in biliary secretion. While extracellular ATP stimulates TMEM16A via binding P2 receptors and increasing intracellular Ca(2+) concentration ([Ca(2+)]i), the regulatory pathways have not been elucidated. Protein kinase C (PKC) contributes to ATP-mediated secretion in BECs, although its potential role in TMEM16A regulation is unknown. To determine whether PKCα regulates the TMEM16A-dependent membrane Cl(-) transport in BECs, studies were performed in human biliary Mz-cha-1 cells. Addition of extracellular ATP induced a rapid translocation of PKCα from the cytosol to the plasma membrane and activation of whole cell Ca(2+)-activated Cl(-) currents. Currents demonstrated outward rectification and reversal at 0 mV (properties consistent with TMEM16A) and were inhibited by either molecular (siRNA) or pharmacologic (PMA or Gö6976) inhibition of PKCα. Intracellular dialysis with recombinant PKCα activated Cl(-) currents with biophysical properties identical to TMEM16A in control cells but not in cells after transfection with TMEM16A siRNA. In conclusion, our studies demonstrate that PKCα is coupled to ATP-stimulated TMEM16A activation in BECs. Targeting this ATP-Ca(2+)-PKCα signaling pathway may represent a therapeutic strategy to increase biliary secretion and promote bile formation.

Association between CT-Diagnosed Pneumonia and Endoscopic Submucosal Dissection of Gastric Neoplasms.

BACKGROUND/AIMS: This prospective cohort study aimed to elucidate the incidence and characteristics of pneumonia associated with endoscopic submucosal dissection (ESD) of gastric neoplasms using CT. METHODS: We included consecutive 188 patients with gastric neoplasms treated with ESD. All patients underwent CT before ESD and the day after ESD. Pneumonia associated with ESD was defined as lung ground glass opacity or consolidation by CT the day after ESD. RESULTS: In 188 patients, 28 patients had diabetes mellitus. Pneumonia was observed by CT in 21 patients (11.2%) after ESD. Of those, 7 patients had diabetes mellitus. By univariate analysis, compared with patients with non-pneumonia complications, risk factors for pneumonia were significantly increased in patients with diabetes mellitus (p = 0.01) and in those who underwent a long procedure time (p = 0.02). By multivariate analysis, pneumonia was significantly increased in patients with diabetes mellitus (OR 4.06, 95% CI 1.35-12.19) and in those who underwent a long procedure time (OR 1.01, 95% CI 1.00-1.02). CONCLUSIONS: The incidence of CT-diagnosed pneumonia associated with ESD was relatively high. Furthermore, it was revealed that diabetes mellitus and a long procedure time were risk factors of CT-diagnosed pneumonia.

Effectiveness of weekly polymerase chain reaction-based open reading frame typing analysis of all newly isolated methicillin-resistant Staphylococcus aureus strains for controlling nosocomial infections.

Polymerase chain reaction (PCR)-based open reading frame typing (POT) helps differentiate between bacterial strains based on the open reading frames (ORFs) of the prophage-encoding genes; multiplex PCR screening is performed to identify strains based on keeping patterns. At our hospital, surveillance of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) transmission is undertaken using POT to conduct molecular epidemiological analysis for all newly detected MRSA strains. In 2014, we performed POT only once a month; however, in 2015, we increased the frequency of POT to once a week, which helped us detect nosocomial transmission that would normally be difficult to detect, and thus achieve 40% reduction in nosocomial transmission, compared to that in 2014. This suggests that weekly POT screening for all MRSA strains is one of the effective methods available for minimizing nosocomial transmission of MRSA.

Spontaneous germline excision of Tol1, a DNA-based transposable element naturally occurring in the medaka fish genome.

DNA-based transposable elements are ubiquitous constituents of eukaryotic genomes. Vertebrates are, however, exceptional in that most of their DNA-based elements appear to be inactivated. The Tol1 element of the medaka fish, Oryzias latipes, is one of the few elements for which copies containing an undamaged gene have been found. Spontaneous transposition of this element in somatic cells has previously been demonstrated, but there is only indirect evidence for its germline transposition. Here, we show direct evidence of spontaneous excision in the germline. Tyrosinase is the key enzyme in melanin biosynthesis. In an albino laboratory strain of medaka fish, which is homozygous for a mutant tyrosinase gene in which a Tol1 copy is inserted, we identified de novo reversion mutations related to melanin pigmentation. The gamete-based reversion rate was as high as 0.4%. The revertant fish carried the tyrosinase gene from which the Tol1 copy had been excised. We previously reported the germline transposition of Tol2, another DNA-based element that is thought to be a recent invader of the medaka fish genome. Tol1 is an ancient resident of the genome. Our results indicate that even an old element can contribute to genetic variation in the host genome as a natural mutator.

[A comparison of susceptibility of Pseudomonas aeruginosa clinical isolates to carbapenem antibiotics in our hospital].

We investigated the susceptibility of 400 Pseudomonas aeruginosa (P. aeruginosa) clinical isolates to 3 antipseudomonal carbapenems, namely, doripenem (DRPM), meropenem (MEPM), and imipenem (IPM). The test strains were isolated from the following specimens: respiratory (n = 194), urinary (n = 61), digestive (n = 38), pus (n = 36), skin (n = 21), blood (n = 9), upper respiratory tract and oral cavity (n = 8), and others (n = 33) at Osaka City University Hospital from July to October 2013. Test strains were categorized as susceptible, ≤ 2 µg/mL; intermediate, 4 µg/mL; and resistant, ≥ 8 µg/mL according to Clinical and Laboratory Standards Institute criteria (M100-S22), updated on January 2012. To compare the antimicrobial activities of these 3 carbapenems, the susceptibility rate for each agent was analyzed. Susceptibility to DRPM, MEPM, and IPM was 78.3%, 74.3%, and 64.8%, respectively, whereas resistance was 12.5%, 22.8%, and 28.5%, respectively. The frequency of strains resistant to DRPM was significantly lower than that for MEPM (p < 0.001) and IPM (p < 0.001). To compare the activities of the 3 carbapenems against the P. aeruginosa clinical isolates, we plotted the numbers of strains against each minimum inhibitory concentration (MIC) level. The MICs of DRPM were lower than those of MEPM in 19.8% of strains, and lower than those of IPM in 41.8% of strains, and the MICs of MEPM were lower than those of IPM in 33.0% of strains. Further, we found that 7.7% of the MEPM-resistant strains were susceptible to DRPM, 23.7% of the IPM-resistant strains were susceptible to DRPM, and 9.6% of the IPM-resistant strains were susceptible to MEPM; however, none of the MEPM-resistant strains was susceptible to IPM, and none of the DRPM-resistant strains was susceptible to MEPM or IPM. In conclusion, the in vitro activity of DRPM against the P. aeruginosa clinical isolates was superior to those of MEPM and IPM.

Carbon stable isotopes of glucose during the degradation of rice by the koji fungus Aspergillus oryzae.

Glucose, a key component of traditional Japanese fermented foods, is derived from rice starch via saccharification by hydrolytic enzymes produced by Aspergillus oryzae. The δ 13C value of glucose reflects that of its rice source. However, the influence of saccharification parameters (glucose concentration, degradation temperature, and reaction time) on glucose δ 13C values is unclear. Here, we investigated the influence of saccharification on the δ 13C value of glucose. Our experiments showed a significant difference in the δ 1³C value of glucose (-27.0 ± 0.1 ‰) obtained from saccharification compared to the ingredient rice (-27.1 ± 0.1 ‰) and remaining solid residue (-27.1 ± 0.1 ‰); however, it did not differ significantly from those of rice koji (-27.0 ± 0.1 ‰) and steamed rice (-27.1 ± 0.1 ‰), despite all values being within 0.1 ‰. Notably, glucose concentration, degradation temperature, and reaction time did not significantly affect glucose δ 13C values. These findings demonstrate the remarkable preservation of glucose δ 13C values. The δ 13C values remain aligned with the original δ 13C value of the rice, even with up to 60 % degradation during A. oryzae saccharification. This persistence of the δ 13C value throughout the process offers a potential tool for authenticating the origin of rice-fermented beverages based on the δ 13C value of their glucose component.