Near-infrared in vivo imaging system for dynamic visualization of lung-colonizing bacteria in mouse pneumonia.

In vivo imaging of bacterial infection models enables noninvasive and temporal analysis of individuals, enhancing our understanding of infectious disease pathogenesis. Conventional in vivo imaging methods for bacterial infection models involve the insertion of the bacterial luciferase LuxCDABE into the bacterial genome, followed by imaging using an expensive ultrasensitive charge-coupled device (CCD) camera. However, issues such as limited light penetration into the body and lack of versatility have been encountered. We focused on near-infrared (NIR) light, which penetrates the body effectively, and attempted to establish an in vivo imaging method to evaluate the number of lung-colonizing bacteria during the course of bacterial pneumonia. This was achieved by employing a novel versatile system that combines plasmid-expressing firefly luciferase bacteria, NIR substrate, and an inexpensive, scientific complementary metal-oxide semiconductor (sCMOS) camera. The D-luciferin derivative "TokeOni," capable of emitting NIR bioluminescence, was utilized in a mouse lung infection model of Acinetobacter baumannii, an opportunistic pathogen that causes pneumonia and is a concern due to drug resistance. TokeOni exhibited the highest sensitivity in detecting bacteria colonizing the mouse lungs compared with other detection systems such as LuxCDABE, enabling the monitoring of changes in bacterial numbers over time and the assessment of antimicrobial agent efficacy. Additionally, it was effective in detecting A. baumannii clinical isolates and Klebsiella pneumoniae. The results of this study are expected to be used in the analysis of animal models of infectious diseases for assessing the efficacy of therapeutic agents and understanding disease pathogenesis. IMPORTANCE: Conventional animal models of infectious diseases have traditionally relied upon average assessments involving numerous individuals, meaning they do not directly reflect changes in the pathology of an individual. Moreover, in recent years, ethical concerns have resulted in the demand to reduce the number of animals used in such models. Although in vivo imaging offers an effective approach for longitudinally evaluating the pathogenesis of infectious diseases in individual animals, a standardized method has not yet been established. To our knowledge, this study is the first to develop a highly versatile in vivo pulmonary bacterial quantification system utilizing near-infrared luminescence, plasmid-mediated expression of firefly luciferase in bacteria, and a scientific complementary metal-oxide semiconductor camera. Our research holds promise as a useful tool for assessing the efficacy of therapeutic drugs and pathogenesis of infectious diseases.

Prevalence of carbapenem-resistant Enterobacterales with bla IMP-6 predominance in hospitals from 2018 to 2021 in Nara, Japan.

Objectives: Despite the global health risk of carbapenem-resistant Enterobacterales (CRE), especially carbapenemase-producing Enterobacterales (CPE), Japan reports a significantly low frequency of CRE with a predominance of IMP-type carbapenemases. This study aimed to investigate the prevalence and characteristics of CRE isolated from hospitals in the city of Nara, Japan. Methods: We obtained 171 CRE isolates from 16 791 Enterobacterales isolated at 23 hospitals in Nara between January 2018 and December 2021. Isolates of CPE were characterized through antimicrobial susceptibility testing, the carbapenem inactivation method, PCR and DNA sequencing. Genotypic diversity of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae was determined via MLST and PFGE. Results: The prevalence of CRE between 2018 and 2021 was 1.02%, gradually decreasing from 1.13% to 0.74%. Ninety-nine isolates were identified as CPE, representing six species. Ninety-seven CPE isolates harboured bla IMP-6, while the remaining two carried either bla IMP-1 or bla IMP-19. Genotype analysis identified ST131 as the dominant genotype for E. coli, but none for K. pneumoniae. PFGE results suggested clonal spread of CPE in Hospital A, where CRE was isolated in high numbers (n = 44). Conclusions: In this study, CRE prevalence was marginally higher than previously reported in Japan, but still low in frequency. A predominance of Enterobacterales harbouring bla IMP-6 was confirmed in Nara. The spread of CPE at Hospital A suggested the possibility of a nosocomial outbreak due to bla IMP-6 transmission via plasmids or clonal spread. Continued monitoring is crucial for effective management of CRE prevalence in the region.

Increased levels of circulating cell-free DNA in COVID-19 patients with respiratory failure.

Cell-free DNA (cfDNA) is released from injured cells and aggravates inflammation. Patients with coronavirus disease (COVID-19) often develop pneumonia and respiratory failure, and require oxygen therapy (OT), including mechanical ventilation (MV). It remains unclear whether cfDNA predicts the risk of receiving OT or MV in COVID-19 patients. Therefore, we hypothesized that circulating cfDNA levels could reflect the severity of respiratory failure and determine a therapeutic approach for oxygenation in patients with COVID-19. We analyzed cfDNA levels in serum samples from 95 hospitalized patients with COVID-19 at Showa University Hospital (Tokyo, Japan). cfDNA levels were assessed by measuring the copy numbers of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) using quantitative real-time PCR (qPCR). Both cf-nDNA and cf-mtDNA levels were negatively correlated with adjusted SpO2 for FiO2 (SpO2/FiO2 ratio). Elevated cf-nDNA and cf-mtDNA levels were associated with the requirement for OT or MV during patient admission. Multivariate logistic regression analysis revealed that cf-nDNA and cf-mtDNA levels were independent risk factors for OT and MV. These results suggest that both serum cf-nDNA and cf-mtDNA could serve as useful early biomarkers to indicate the necessity of OT or MV in patients with COVID-19.

Impact of Multiplex Polymerase Chain Reaction Test in Patients With Meningitis or Encephalitis.

Background: The objective of this study was to evaluate the impact of the FilmArray meningitis/encephalitis panel (FAME) on length of stay (LOS) and duration of antimicrobial treatment in children and adults in a Japanese community hospital. Methods: This retrospective cohort study was conducted in Japan between January 2016 and December 2022. We included hospitalized patients with cerebrospinal fluid (CSF) samples and those aged <2 months or who had 5 or more white blood cells/µL in the CSF. To compare the days of therapy (DOT) and LOS between the pre-FAME and FAME periods, multivariate Poisson regression analyses were conducted without an offset term. Results: The number of cases undergoing pathogen-specific polymerase chain reaction increased from 3.7% in the pre-FAME period to 57.5% in the FAME period (P < .001). The pathogen identification rate also increased during the FAME period, from 0.4% to 18.7% (P < .001). While the antibacterial DOT was not statistically different between the 2 periods (adjusted rate ratio [aRR], 1.06 [95% confidence interval {CI}, 1.00-1.13]; P = .063]), the antiviral DOT was significantly shorter in the FAME period (aRR, 0.80 [95% CI, .71-.89]; P < .001). Conclusions: This study revealed a significant reduction in antiviral use during the FAME period, whereas LOS and antibacterial use did not decrease. Given the possibility of factors (eg, the COVID-19 pandemic) affecting the epidemiology of meningitis and encephalitis, the indications and impact of the FAME test should be evaluated with continuous monitoring of the epidemiology of meningitis and encephalitis and its clinical impact.

Antiviral Effect of Candies Containing Persimmon-Derived Tannin against SARS-CoV-2 Delta Strain.

Inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the mouth has the potential to reduce the spread of coronavirus disease 2019 (COVID-19), due to the virus being readily transmitted by dispersed saliva. Persimmon-derived tannin has strong antioxidant and antimicrobial activity owing to its strong adhesion to proteins, and it also exhibited antiviral effects against non-variant and Alpha-variant SARS-CoV-2 in our previous study. In this study, we first demonstrated the antiviral effects of persimmon-derived tannin against the Delta variant of SARS-CoV-2 in vitro via the plaque assay method. We then examined the effects of candy containing persimmon-derived tannin. Remarkably, the saliva samples provided by healthy volunteers while they were eating tannin-containing candy showed that the virus titers of the SARS-CoV-2 Delta variant were suppressed. In addition, we found that the SARS-CoV-2 viral load in saliva from patients with COVID-19 collected immediately after they had eaten the tannin-containing candy was below the level of detection via PCR for SARS-CoV-2. These data suggest that adding persimmon-derived tannin to candy and holding such candy in the mouth is an effective method for inactivating SARS-CoV-2 in saliva, and the application of this approach shows potential for inhibiting the transmission of COVID-19.

Genetic relatedness of third-generation cephalosporin-resistant Escherichia coli among livestock, farmers, and patients in Japan.

Objectives: The third-generation cephalosporin (3GC)-resistant E. coli strains have been detected worldwide in humans and animals. Hence, in this study, we evaluated the prevalence and genetic characteristics of 3GC-resistant E. coli in livestock, farmers, and patients to further analyse if livestock serves as a potential reservoir of antimicrobial-resistant bacteria. Methods: Faecal samples were collected from 330 healthy livestock (216 cattle and 114 swine), 61 healthy livestock farmers (52 cattle farmers and 9 swine farmers), and 68 non-duplicate 3GC-resistant E. coli isolates were also obtained from the clinical specimens of patients in Japan between 2013 and 2015. Genes associated with resistance in 3GC-resistant E. coli were identified using polymerase chain reaction (PCR) and DNA sequencing. Genotypic diversity was determined by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Results: We obtained 39 and 17 non-duplicated 3GC-resistant E. coli strains from healthy livestock (33 cattle and six swine) and livestock farmers, respectively. All isolates carried either CTX-M-type extended-spectrum ß-lactamase or plasmid-mediated AmpC ß-lactamase genes, with CTX-M-14 being the most frequent. CTX-M producers from livestock and patients belonged to 22 and 19 different sequence types (STs), respectively, and only three STs were the same. Among the 3GC-resistant E. coli from livestock and farmers, three types of CTX-M producers have shown similar characteristics (CTX-M genotype, ST, PFGE patterns, and antimicrobial susceptibilities) and were identified as clonal isolates shared among their farms. Conclusions: Our study findings indicate that CTX-M-14 is predominant in Japan. No distinct relationship was observed between the 3GC-resistant E. coli isolated from livestock and patients; however, some clonal relatedness was observed between the isolates from livestock and farmers due to their close contact.

Pasteurella bettyae infection requiring finger amputation due to rapid deterioration and tissue damage.

We report a case of infection of the middle finger of a 69-year-old man who visited our hospital. Pus was collected from the erythematous and swollen area of the nail cage of the left-hand middle finger and evaluated in our microbiology laboratory. Gram staining of the specimen revealed multinucleated leukocytes and abundant gram-negative bacilli. Isolated colonies were identified as Pasteurella bettyae using VITEK MS and 16 S ribosomal RNA (rRNA) gene sequencing. The patient's blood test results improved after treatment with penicillin, but the local factors affecting the finger did not improve, and amputation of the middle finger had to be performed. This case represents a report of a very rare hand infection caused by P. bettyae. Polymorphic identification methods, such as MALDI-TOF MS and 16 S rRNA gene sequencing, are needed for members of the genus Pasteurella isolated from severe infections and abnormal sites, and further studies are warranted.

Chorioamnionitis and early pregnancy loss caused by ampicillin-resistant non-typeable Haemophilus influenzae.

Haemophilus influenzae can cause intra-amniotic infection and early pregnancy loss. The mode of transmission and risk factors for H. influenzae uterine cavity infections are unknown. Here, we present the case of chorioamnionitis caused by ampicillin-resistant H. influenzae in a 32-year-old Japanese woman at 16 weeks of gestation. Despite empirical treatment, including ampicillin, as recommended by the current guidelines, she had fetal loss. The antimicrobial regimen was changed to ceftriaxone, and the treatment was completed without complications. Although the prevalence and risk factors for chorioamnionitis caused by ampicillin-resistant H. influenzae are unknown, clinicians need to recognize H. influenzae as a potentially drug-resistant and lethal bacterium for pregnant women.

Epidemiology of respiratory tract infections using multiplex PCR in a Japanese acute care hospital during the COVID19 pandemic.

Introduction: We aimed to investigate the epidemiology of respiratory infections by season and age during the COVID-19 pandemic in a Japanese acute care hospital using multiplex PCR testing. Methods: We detected 21 pathogens in specimens from outpatients with respiratory symptoms at the Nara Prefecture General Medical Center using the multiplex PCR-based FilmArray Respiratory Panel 2.1 (bioMérieux). Results: Of the 3177 cases, 1215 (38.2%) were infected with at least one causative virus, and 1641 viruses were detected. The most common viruses detected were human rhinovirus/enterovirus (n = 655) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 264). Additionally, 321 (10.1%) of these cases were infected with two or more overlapping viruses. There were 23 cases of co-infection with SARS-CoV-2 and other viruses. In the winter months from December 2020 to March 2021, the number of detected viruses was relatively low, followed by the surge of human rhinovirus/enterovirus, respiratory syncytial virus (RSV), and parainfluenza type 3 in the spring and summer of 2021. While the number of human rhinovirus/entero-virus remained relatively high after the 2021 summer, the number of other viruses detected since September 2021 was low. After December 2021, the number of SARS-CoV-2 increased rapidly. Conclusions: Continuous monitoring of the epidemiology of respiratory infection is important to understand the prolonged impact of the COVID-19 pandemic.

Impact of the COVID-19 pandemic and multiplex polymerase chain reaction test on outpatient antibiotic prescriptions for pediatric respiratory infection.

This study aimed to evaluate the impact of the prolonged COVID-19 pandemic on outpatient antibiotic prescriptions for pediatric respiratory infections at an acute care hospital in Japan in order to direct future pediatric outpatient antibiotic stewardship. The impact of the COVID-19 pandemic and the FilmArray Respiratory Panel (RP) on outpatient antibiotic prescriptions was assessed from January 2019 to December 2021 using an interrupted time series analysis of children <20 years. The overall antimicrobial prescription rate decreased from 38.7% to 22.4% from the pre-pandemic period to the pandemic. The pandemic (relative risk [RR] level, 0.97 [0.58-1.61]; P = 0.90; RR slope, 1.05 [0.95-1.17] per month; P = 0.310) and FilmArray RP (RR level, 0.90 [0.46-1.75]; P = 0.75; RR slope, 0.95 [0.85-1.06] per month; P = 0.330) had no significant effect on the monthly antibiotic prescription rates. The COVID-19 pandemic was not significantly related to the antibiotic prescription rate, suggesting that it did not impact physicians' behavior toward antibiotic prescriptions. Replacing rapid antigen tests with the FilmArray RP introduced on December 1, 2020, did not affect the magnitude of the reduction in antibiotic prescription rate for pediatric respiratory infections.

Transition of Antibody Titers after SARS-CoV-2 mRNA Vaccination in Japanese Healthcare Workers.

Since February 2021, healthcare workers in Japan have been preferentially vaccinated with a messenger RNA vaccine (BNT162b2; Pfizer/BioNTech) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While many studies have confirmed that this vaccine is highly effective in reducing hospitalization and deaths from coronavirus disease 2019 (COVID-19), antibody titers tend to decline at 3 months after vaccination, leading to a risk of breakthrough infections. Thus, information is needed to support the decision regarding the 3rd vaccination. In this study, we investigated the transition of anti-SARS-CoV-2 spike protein receptor-binding domain (RBD) IgG and neutralizing antibody titers in 37 vaccinated Japanese healthcare workers. Samples were collected 6 times starting before vaccination until 6 months after the second vaccination. The levels of anti-SARS-CoV-2 RBD IgG peaked 1 week after the 2nd vaccination, then declined over time and decreased to < 10% at 6 months after the 2nd vaccination. Additionally, approximately one-third of the healthcare workers were seronegative for the Omicron variant 6 months after the 2nd vaccination. Workers with low anti-SARS-CoV-2 RBD IgG levels also had low neutralizing antibody titers. These data support booster dose administration for healthcare workers, especially those with low anti-SARS-CoV-2 RBD IgG levels.

Comparison of MALDI-TOF mass spectrometry and rpoB gene sequencing for the identification of clinical isolates of Aeromonas spp.

Aeromonas spp., widely present in rivers and soil, cause mild gastroenteritis, severe septicemia, and soft tissue infections in humans. Treatment of these infections require accurate identification of pathogenic Aeromonas spp. However, identification at the species level using conventional methods is highly challenging. In this study, we aimed to compare the accuracy of two different approaches developed for bacterial identification: (i) housekeeping gene sequencing (rpoB) in conjunction with phylogenetic analysis and (ii) matrix-assisted laser desorption ionization mass spectrometry-time of flight (MALDI-TOF MS) (MALDI Biotyper and VITEK MS), for differentiating Aeromonas spp. We analyzed 58 Aeromonas isolates recovered from patients at different medical institutions in Japan using both identification methods. The rpoB sequencing method was the most accurate, identifying all Aeromonas isolates at the species level. Meanwhile, the MALDI Biotyper system correctly identified 53 (91.4%) isolates at the genus level and an additional 30 (51.7%) at the species level. The VITEK MS system correctly identified 58 (100%) isolates at the genus level and an additional 34 (58.6%) at the species level. Thus, MALDI Biotyper and VITEK MS accurately identified isolates at the genus level, but differences were found in the accuracy of identification of species. However, the low cost and ease of analysis make MALDI-TOF MS-based methods strong candidates for use in clinical laboratories that require easy-to-use identification methods.

Structural insights into the substrate specificity of IMP-6 and IMP-1 metallo-ß-lactamases.

IMP-type metallo-ß-lactamases confer resistance to carbapenems and a broad spectrum of ß-lactam antibiotics. IMP-6 and IMP-1 differ by only a point mutation: Ser262 in IMP-1 and Gly262 in IMP-6. The kcat/Km values of IMP-1 for imipenem and meropenem are nearly identical; however, for IMP-6, the kcat/Km for meropenem is 7-fold that for imipenem. In clinical practice, this may result in an ineffective therapeutic regimen and, consequently, in treatment failure. Here, we report the crystal structures of IMP-6 and IMP-1 with the same space group and similar cell constants at resolutions of 1.70 and 1.94 Å, respectively. The overall structures of IMP-6 and IMP-1 are similar. However, the loop region (residues 60-66), which participates in substrate binding, is more flexible in IMP-6 than in IMP-1. This difference in flexibility determines the substrate specificity of IMP-type metallo-ß-lactamases for imipenem and meropenem. The amino acid at position 262 alters the mobility of His263; this affects the flexibility of the loop via a hydrogen bond with Pro68, which plays the role of a hinge in IMP-type metallo-ß-lactamases. The substitution of Pro68 with a glycine elicited an increase in the Km of IMP-6 for imipenem, whereas the affinity for meropenem remained unchanged.

Emergence and Evolution of Unique Plasmids Harboring blaIMP-70 and blaCTX-M-253 in Multidrug-Resistant Providencia rettgeri.

Although the prevalence of carbapenem-resistant Enterobacterales remains low in Japan, these bacteria are a growing problem worldwide, owing to their multidrug resistance phenotype. We isolated a multidrug-resistant Providencia rettgeri strain, NR1418, harboring a rare blaIMP variant, blaIMP-70, a novel blaCTX-M variant, designated blaCTX-M-253, and blaMOX-1. This strain is resistant to ß-lactams, amikacin, levofloxacin, and colistin. Genomic analysis revealed that NR1418 carries two plasmids, designated pNR1418-1 and pNR1418-2. The pNR1418-1 plasmid harbors blaCTX-M-253, blaTEM-1, and blaMOX-1, while the pNR1418-2 plasmid harbors blaIMP-70, which is located in a class 1 integron. Both plasmids exhibit high similarities with the plasmid of the P. rettgeri isolate BML2526, which also harbors blaIMP-70 and was identified in the same region of Japan as NR1418 at a different point in time. This indicates the possibility of the emergence and evolution of IMP-70-producing P. rettgeri and suggests that the plasmid of BML2526 may have occurred following recombination of the two plasmids harbored by NR1418. Further, blaIMP-70 and blaCTX-M-253 were found on unique plasmids, indicating that they likely evolved through mutations and recombination. IMPORTANCE Although Providencia rettgeri is an opportunistic pathogen, its intrinsic resistance to colistin and tigecycline makes the treatment of carbapenem-resistant P. rettgeri challenging. We isolated a multidrug-resistant P. rettgeri strain which harbored a rare blaIMP variant, blaIMP-70, a novel blaCTX-M variant, blaCTX-M-253, and blaMOX-1 from a urinary sample obtained in Osaka, Japan. We investigated its genetic structure and evaluated the evolution of the plasmids carrying these genes. We show that blaIMP-70, blaCTX-M-253, and blaMOX-1 are present on unique plasmids and that they have high similarities to the plasmid of another IMP-70-producing P. rettgeri isolate that was identified as being from the same location. The evolution of plasmids through mutations and recombination may play a role in the development and spread of multidrug resistance.

Evaluation of NG-Test CARBA 5 for the detection of carbapenemase-producing Gram-negative bacilli.

Carbapenemase-producing Enterobacterales (CPE) pose one of the most serious antimicrobial resistance threats to public health worldwide. The outcome of CPE infection differs depending on the resistance mechanism. Therefore, rapid detection of CPE infection is essential for optimizing patient management. The carbapenem inactivation method (CIM) and modified CIM (mCIM) are standard methods for detecting CPE, but they usually require 24 h to generate results. Recently, an immunochromatographic assay, NG-Test CARBA 5, has become commercially available. It detects the five most common carbapenemase producers (KPC, IMP, NDM, VIM, and OXA-48) rapidly and accurately. We aimed to evaluate the diagnostic accuracy of NG-Test CARBA 5 for detecting carbapenemase-producing Gram-negative bacilli (CPGNB). We used 116 carbapenemase-producing strains and 48 non-carbapenemase-producing strains. Of the 116 carbapenemase-producing strains, 107 harboured genes for at least one of the five most common carbapenemases, KPC, IMP, NDM, VIM, and OXA-48-like. Forty-eight non-carbapenemase-producing strains, including carbapenem-resistant Enterobacterales, harboured genes for extended-spectrum ß-lactamases (CTX-M groups [n=25] and SHV groups [n=2]) or plasmid-mediated AmpC ß-lactamases (DHA [n=3], CMY-2 [n=2], and CFE-1 [n=1]). Antimicrobial susceptibility was tested using the agar dilution method, according to the Clinical and Laboratory Standards Institute guidelines. Of the 116 carbapenemase-producing strains, 79 were resistant to at least meropenem or imipenem. The sensitivity and specificity of the NG-Test CARBA 5 for the strains were 99.1 % (106 strains positive for 107 strains of the five most common carbapenemase producers) and 100 % (60 strains negative for other types of CPGNB [n=10] and non-CPGNB strains [n=48]), respectively. The carbapenemase-producing strain with a false-negative result produced IMP-66. The NG-Test CARBA 5 had high sensitivity and specificity for detecting carbapenemase-producing strains.

Inactivation of various variant types of SARS-CoV-2 by indoor-light-sensitive TiO2-based photocatalyst.

Photocatalysts are promising materials for solid-state antiviral coatings to protect against the spread of pandemic coronavirus disease (COVID-19). This paper reports that copper oxide nanoclusters grafted with titanium dioxide (CuxO/TiO2) inactivated the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, including its Delta variant, even under dark condition, and further inactivated it under illumination with a white fluorescent bulb. To investigate its inactivation mechanism, the denaturation of spike proteins of SARS-CoV-2 was examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent assay (ELISA). In addition to spike proteins, fragmentation of ribonucleic acids in SARS-CoV-2 was investigated by real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). As a result, both spike proteins and RNAs in the SARS-CoV-2 virus were damaged by the CuxO/TiO2 photocatalyst even under dark condition and were further damaged under white fluorescent bulb illumination. Based on the present antiviral mechanism, the CuxO/TiO2 photocatalyst will be effective in inactivating other potential mutant strains of SARS-CoV-2. The CuxO/TiO2 photocatalyst can thus be used to reduce the infectious risk of COVID-19 in an indoor environment, where light illumination is turned on during the day and off during the night.

Predominance of CTX-M-9 Group Among ESBL-Producing Escherichia coli Isolated from Healthy Individuals in Japan.

The detection rate of extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales, microorganisms associated with health care settings, has significantly increased worldwide. Moreover, their community incidence has increased in several countries. In this study, we investigated the prevalence and genetic diversity of ESBL-producing Escherichia coli isolated from 547 nonduplicated stool specimens from healthy Japanese individuals, between 2015 and 2019. E. coli were isolated on deoxycholate-hydrogen sulfide-lactose (DHL) agar and identified by MALDI-TOF MS, ESBL were screened through disk diffusion method (cefotaxime with or without clavulanate), and genetic detection and genotyping were performed by PCR and DNA sequencing. Clonal similarities between ESBL-producing and nonproducing isolates were assessed by multilocus sequence typing (MLST). The prevalence of ESBL-producing E. coli was 9.7% (53/547). These bacteria harbored CTX-M genes, from which CTX-M-9 (31/53, 58.5%) and CTX-M-1 (13/53, 24.5%) groups were the predominant. The MLST analysis revealed that ST131 genotype prevailed within ESBL-producing E. coli (15/53), whereas ST95 (10/53) and ST73 (8/53) prevailed among non-ESBL producers, with ST131 being present in only four isolates. Overall, a high prevalence rate of CTX-M-type ESBL-producing E. coli was detected. CTX-M-9 group-producing ST131 predominated among healthy Japanese individuals, similar to that observed in hospital isolates. CTX-M-type ESBL may disseminate clonally among hospital patients and subsequently, within the community.

Persimmon-derived tannin has antiviral effects and reduces the severity of infection and transmission of SARS-CoV-2 in a Syrian hamster model.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world. Inactivating the virus in saliva and the oral cavity represents a reasonable approach to prevent human-to-human transmission because the virus is easily transmitted through oral routes by dispersed saliva. Persimmon-derived tannin is a condensed type of tannin that has strong antioxidant and antimicrobial activity. In this study, we investigated the antiviral effects of persimmon-derived tannin against SARS-CoV-2 in both in vitro and in vivo models. We found that persimmon-derived tannin suppressed SARS-CoV-2 titers measured by plaque assay in vitro in a dose- and time-dependent manner. We then created a Syrian hamster model by inoculating SARS-CoV-2 into hamsters' mouths. Oral administration of persimmon-derived tannin dissolved in carboxymethyl cellulose before virus inoculation dramatically reduced the severity of pneumonia with lower virus titers compared with a control group inoculated with carboxymethyl cellulose alone. In addition, pre-administration of tannin to uninfected hamsters reduced hamster-to-hamster transmission of SARS-CoV-2 from a cohoused, infected donor cage mate. These data suggest that oral administration of persimmon-derived tannin may help reduce the severity of SARS-CoV-2 infection and transmission of the virus.

Infection Control for a Carbapenem-Resistant Enterobacteriaceae Outbreak in an Advanced Emergency Medical Services Center.

BACKGROUND: A carbapenem-resistant Enterobacteriaceae (CRE) outbreak occurred in an advanced emergency medical service center [hereafter referred to as the intensive care unit (ICU)] between 2016 and 2017. AIM: Our objective was to evaluate the infection control measures for CRE outbreaks. METHODS: CRE strains were detected in 16 inpatients located at multiple sites. Environmental cultures were performed and CRE strains were detected in 3 of 38 sites tested. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and detection of ß-lactamase genes were performed against 25 CRE strains. FINDINGS: Molecular typing showed the PFGE patterns of two of four Klebsiella pneumoniae strains were closely related and the same MLST (ST2388), and four of five Enterobacter cloacae strains were closely related and same MLST (ST252). Twenty-three of 25 CRE strains harbored the IMP-1 ß-lactamase gene and 15 of 23 CRE strains possessed IncFIIA replicon regions. Despite interventions by the infection control team, new inpatients with the CRE strain continued to appear. Therefore, the ICU was partially closed and the inpatients with CRE were isolated, and the ICU staff was divided into two groups between inpatients with CRE and non-CRE strains to avoid cross-contamination. Although the occurrence of new cases dissipated quickly after the partial closure, a few months were required to eradicate the CRE outbreak. CONCLUSION: Our data suggest that the various and combined measures that were used for infection control were essential in stopping this CRE outbreak. In particular, partial closure to isolate the ICU and division of the ICU staff were effective.