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Objective: Unknown etiology. Background: Meningococcal meningitis is rare in Japan; however, when outbreaks do occur, they predominantly involve domestically infected cases rather than those contracted overseas. Case Report: A Japanese man with diabetes in his 50s experienced fever and loss of consciousness, with no history of international travel. In our hospital, gram-negative diplococci were detected in the cerebrospinal fluid (CSF) of the patient by Gram staining, although the rapid agglutination test and cultures of blood and CSF were negative. Multiplex polymerase-chain reaction (PCR) testing returned positive results for meningococcus and parechovirus. Brain MRI revealed a finding of meningitis, but there were no indications of encephalitis. To determine the serotype and genotype, we sent the sample to the National Institute of Infectious Diseases, which identified the serogroup and sequence type (ST) as type B and 2057, respectively. Despite the unknown antimicrobial susceptibility, the patient responded well to empirical treatment with ceftriaxone at 2 g every 12 h, and was discharged with remaining symptoms of dizziness, headache, difficulty hearing in the left ear, and tinnitus in the left ear. Conclusions: In Japan, vaccines covering serogroups A, C, and W/Y are available but not routinely administered. According to epidemiological surveillance reports, serogroup B is the second most common cause of meningococcal meningitis in Japan, yet there is no corresponding vaccine available in the country. This case has prompted a review of the epidemiology of meningococcus in Japan, encompassing strategies for vaccination and hospital infection control to prevent droplet transmission, which includes post-exposure prophylaxis when no prior measures have been implemented. [ABSTRACT FROM AUTHOR]

We have previously isolated a gram‐negative microaerophilic strain, PAGU2000T from a patient presenting with a fever in Kumamoto Prefecture, Japan. The present study aimed to comprehensively analyze the taxonomy of the isolated strain using a polyphasic approach. The 16S rRNA gene sequence analysis indicated that the strain was a member of enterohepatic Helicobacter. The strain PAGU2000T shared a 97.5% 16S rRNA gene nucleotide identity with Helicobacter valdiviensis, and this taxonomic position was confirmed by phylogenetic analysis of the GyrA amino acid sequences. The proposed strain PAGU2000T has a 1.482 Mbp chromosome with a DNA G + C content of 31.3 mol% and encodes 1520 predicted coding sequences. The average nucleotide identity between the strain PAGU2000T and type strain of H. valdiviensis was 70.3%, which was lower than the recommended threshold of 95% for species delineation. The strain PAGU2000T was a motile, non‐spore‐forming, and spiral‐shaped bacterium, exhibiting catalase and oxidase activities but not urease and nitrate reduction. This study demonstrates that the isolate represents a novel species within enterohepatic Helicobacter, for which the name Helicobacter higonensis is proposed (type strain: PAGU2000T = GTC 16811T = LMG 33095T). In this study, we describe the phenotypic and morphological features of this strain and propose an emended description of some biochemical traits of H. valdiviensis. [ABSTRACT FROM AUTHOR]

In recent years, endotoxins have received considerable attention as substances associated with allergic diseases. Endotoxins are cell wall components of gram-negative bacteria that are widely present in the living environment. Endotoxin concentrations are particularly high in environments where animals are housed. However, while the status of endotoxin concentrations in the general environment is becoming clearer, there remains a scarcity of studies in environments with potentially higher concentrations. In this study, we measured indoor endotoxin concentrations in buildings in Japan that are strongly associated with horses. The target buildings include a "Magariya," an old Japanese house, an accommodation facility connected to a horse stable, and a stable specifically for thoroughbreds. Air and dust samples were collected at these measurement targets and analyzed for air and dust concentrations. Airborne concentrations were higher in buildings with horses present than in buildings without horses, and the presence/absence of horses is thought to have a significant effect on the airborne concentration of endotoxin. Additionally, as the density of horses increases, endotoxin concentrations also tend to increase. Dust concentration had different values in different rooms even in the same building. These results suggest that dust concentrations may be affected by floor materials, frequency of cleaning, and frequency of human traffic from areas of high concentrations. Endotoxin concentrations were high in the stable during the work because of the replacement of the dried straw in the stalls and the removal of horse excrement. These results are expected to be useful in controlling endotoxin concentrations in indoor environments of various building types. [ABSTRACT FROM AUTHOR]

We investigated the epidemiology and antimicrobial susceptibility profiles of seven major Gram-negative bacilli (Escherichia coli , Klebsiella spp., Enterobacter spp., Pseudomonas aeruginosa , Acinetobacter spp., Stenotrophomonas maltophilia , and Bacteroides spp.) that caused bacteremia in Japan. We collected clinical information and isolates from patients aged 20 years or older who developed bacteremia during a year at three Japanese university hospitals and performed microbiological examination. In total, 628 cases were included, half of which were caused by E. coli (315 isolates). P. aeruginosa (56 isolates) was isolated most frequently among non-fermenting bacteria and 33 Bacteroides spp. were isolated. Mortality rates were the highest for P. aeruginosa (7-day, 16.1%; 30-day, 26.8%). The 7- and 30-day mortality rates ranged 3.8–9.0% and 8.3–17.6%, respectively, for Enterobacterales , and they were 15.2% each for Bacteroides spp. Regarding antimicrobial resistance, Enterobacterales and Acinetobacter spp. showed susceptibility to carbapenems and amikacin (98.0–100.0%). The susceptibility rates to ceftolozane/tazobactam ranged 82.4–99.0% for Enterobacterales and 92.9% for P. aeruginosa. More than 30.0% of E. coli isolates were resistant to fluoroquinolone. Extended-spectrum β-lactamase (ESBL) producers were found in 21.0% of E. coli and approximately 80% of those were resistant to fluoroquinolones. The susceptibility of the 33 Bacteroides spp. to carbapenems, ampicillin/sulbactam, and piperacillin/tazobactam was 100.0%. Among the ESBL producers, bla CTX-M group 9 was the major subgroup in E. coli (77.3%), and bla CTX-M group 1 was detected in 18.2% of E. coli and 50.0% of Klebsiella spp. Continuous surveillance is needed to understand the epidemiology and consider appropriate therapeutic strategies. [ABSTRACT FROM AUTHOR]

New Delhi metallo-β-lactamase (NDM)-producing gram-negative rods, including Acinetobacter species, are a global problem but have rarely been isolated in Japan. To our knowledge, this is the first study to isolate an NDM-1-producing Acinetobacter soli strain, KUH106, in Japan. We analyzed this strain using next-generation sequencing to examine the plasmid carrying NDM-1. This plasmid, named pKUH106_NDM1, is 41,135 bp in length and contains genetic contexts with the structure IS Aba14 - aph(3′)-VI -IS Aba125 - bla NDM-1 ble- MBL. Comparative analysis of the plasmid revealed that it resembled the plasmids of Acinetobacter detected in various countries, such as the A. soli isolate from Taiwan and the Acinetobacter baumannii isolate from a healthcare facility in Osaka Prefecture, Japan. These results suggest that bla NDM-1 may spread via this plasmid in Acinetobacter species. This phenomenon needs to be confirmed through the genetic analysis of A. baumannii and other carbapenem-resistant Acinetobacter species. In particular, bla NDM-1 and other resistance genes must be investigated, and the spread of these genes in the community must be cautioned. [ABSTRACT FROM AUTHOR]

Reports have documented antimicrobial usage in aquaculture, and the aquatic ecosystem can be considered a genetic storage site for antibiotic-resistant bacteria. This study assessed the prevalence of antimicrobial resistance (AMR) among Gram-negative bacteria recovered from retail seafood in Hiroshima, Japan. A total of 412 bacteria were isolated and screened for the presence of β-lactamases, acquired carbapenemases, and mobile colistin-resistance (mcr) genes. Forty-five (10.9%) isolates were dominated by Morganella (28%), Proteus (22%), Aeromonas (14%), Citrobacter (8%), and Escherichia (8%) and carried AMR genes. The identified AMR genes included those encoded in integrons (19), aac(6՛)-Ib (11), blaTEM-1 (7), blaCTX-M-like (12), blaCTX-M-65 (2), blaSHV-12 (1), blaSHV-27 (1), blaOXA-10 (1), blaOXA-2 (1), and mcr (2). The most common clinical resistances were against ampicillin, colistin, sulfamethoxazole/trimethoprim, tetracycline, and ciprofloxacin. Multidrug resistance (MDR) occurred in 27 (60%) AMR isolates, and multiple antibiotic resistance indices ranged from 0.2 to 0.8. A conjugation experiment showed that 10 of the 11 selected MDR strains harbored conjugable plasmids, although PCR-based replicon typing described seven strains as untypable. IncF replicon was identified in MDR extended-spectrum β-lactamase-producing Escherichia coli of the pathogenic B2 phylogroup. Our findings suggest that retail seafood harbors MDR bacteria of human interest that require strict resistance surveillance in the seafood production continuum. [ABSTRACT FROM AUTHOR]

This study aimed to examine the antimicrobial susceptibility of bovine mastitis pathogens in Japan and develop criteria for testing antimicrobial susceptibility using the simplified agar disk diffusion (ADD) method that is currently being used in clinical practice. Milk samples from 1,349 dairy cows with clinical mastitis were collected and cultured. The minimum inhibitory concentrations (MICs) of the antimicrobials were determined for 504 strains of 28 bacteria. Of the gram-positive bacteria, most Staphylococcus spp. were susceptible to penicillin G (PCG), kanamycin (KM), oxytetracycline (OTC), cefazolin (CEZ), pirlimycin, enrofloxacin, and marbofloxacin. Streptococcus spp. and Trueperella pyogenes showed resistance to OTC and KM. Most gram-negative bacteria were resistant to OTC and CEZ and particularly susceptible to fluoroquinolones. To develop the criteria for a disk diffusion test of the simplified ADD method, the relationships between MICs and diameters of inhibition zones (DIZs) were analyzed and compared with the conventional method. The susceptibility breakpoints of several antimicrobials were lower for both gram-positive and gram-negative bacteria. Particularly for gram-positive bacteria, the application of the new criteria lowers the breakpoint for PCG, suggesting that the use of PCG instead of CEZ may increase. The results suggest that use of these criteria for the simplified ADD method may lead to appropriate antimicrobial choice and consequently the appropriate use of antimicrobials in clinical practice. [ABSTRACT FROM AUTHOR]

Rationale: Bronchiectasis and bronchiolitis are differential diagnoses of asthma; moreover, they are factors associated with worse asthma control. Objective: We determined clinical courses of bronchiectasis/bronchiolitis-complicated asthma by inflammatory subtypes as well as factors affecting them. Methods: We conducted a survey of refractory asthma with non-cystic fibrosis bronchiectasis/bronchiolitis in Japan. Cases were classified into three groups, based on the latest fractional exhaled NO (FeNO) level (32 ppb for the threshold) and blood eosinophil counts (320/µL for the threshold): high (type 2-high) or low (type 2-low) FeNO and eosinophil and high FeNO or eosinophil (type 2-intermediate). Clinical courses in groups and factors affecting them were analysed. Results: In total, 216 cases from 81 facilities were reported, and 142 were stratified: 34, 40 and 68 into the type 2-high, -intermediate and -low groups, respectively. The frequency of bronchopneumonia and exacerbations requiring antibiotics and gram-negative bacteria detection rates were highest in the type 2-low group. Eighty-seven cases had paired latest and oldest available data of FeNO and eosinophil counts; they were analysed for inflammatory transition patterns. Among former type 2-high and -intermediate groups, 32% had recently transitioned to the -low group, to which relatively low FeNO in the past and oral corticosteroid use contributed. Lastly, in cases treated with moderate to high doses of inhaled corticosteroids, the frequencies of exacerbations requiring antibiotics were found to be higher in cases with more severe airway lesions and lower FeNO. Conclusions: Bronchiectasis/bronchiolitis-complicated refractory asthma is heterogeneous. In patients with sputum symptoms and low FeNO, airway colonisation of pathogenic bacteria and infectious episodes are common; thus, corticosteroids should be carefully used. [ABSTRACT FROM AUTHOR]

What Is Known and Objective: In this study, changes in patient outcomes were analysed to evaluate the effects of prospective audit and feedback (PAF), which was promoted under a new system of antimicrobial stewardship (AS), in patients with gram‐negative rod (GNR)‐positive blood cultures. Methods: This study included patients with positive blood cultures treated at Kagawa University Hospital between 2019 and 2020. The effects of PAF, as promoted in 2020 and performed within a few days of treatment initiation, were examined in terms of patient prognosis and estimated cost of extra hospital stay associated with GNR infection. Results and Discussion: As AS activities under the new system, proposals were made for targeted therapy based on susceptibility results and for the duration of antimicrobial therapy, escalation and dose increases, and imaging evaluation. Between 2019 and 2020, there was no difference in the rate of de‐escalation in the form of switching to a narrower‐spectrum intravenous antimicrobial, the rate of image inspection, but the rate of switching to oral therapy after receiving culture results increased from 19.7% to 31.3%, the rate of sensitivity‐based treatment increased from 76.4% to 92.2%. Regarding patient outcomes, the 90‐day mortality rate and the duration of hospital stay were similar between the groups. The rate of recurrent bloodstream infections decreased from 8.7% to 0.9%. What Is New and Conclusion: Most of the changes in the indicators related to patient outcomes analysed in this study suggest that the increased use of PAF in AS activities improved patient outcomes. [ABSTRACT FROM AUTHOR]

Background: Polymyxin E (colistin) is a last-resort antibiotic to treat infections caused by carbapenemase-producing Enterobacteriaceae (CPE). However, reports of CPEs resistant to colistin have been increasing, and the mcr genes are emerging as resistance mechanisms. Among them, plasmid-mediate mcr-9 is known to be associated with colistin resistance, whereas reports on chromosomal mcr-9 and its association with colistin resistance in humans are few.Case Presentation: We identified Enterobacter asburiae harboring mcr-9 and blaIMP-60 in the pleural fluid of a patient with empyema. The long-read sequencing technique revealed that these genes were located on its chromosome. Despite the lack of exposure to colistin, the organism showed microcolonies in the inhibition circle in the E-test and disk diffusion test. Antibiotic susceptibility testing by broth microdilution confirmed its resistance to colistin.Conclusion: Our case report showed that mcr-9 can be present not only on plasmids but also on the chromosome in E. asburiae, and that the presence of mcr-9 on its chromosome may influence its susceptibility to colistin. [ABSTRACT FROM AUTHOR]

A novel anaerobic, thermophilic bacterium of the class Atribacteria , strain M15T, was isolated from a high-temperature gas reservoir, Japan. Cells of strain M15T were gram-negative, short oval-shaped, and lacked flagella. Growth occurred at 45–75 °C (optimum 70–75 °C) and pH 6.5–8.5 (optimum pH 7.5–8.0) and was fast under optimal conditions (doubling time 11.4 h). Yeast extract was required for growth. Fermentative growth with glucose, arabinose, xylose, and cellobiose was observed. The major fermentative end products of glucose were acetate and hydrogen. The major cellular fatty acids were C 16:0 , iso -C 15:0 , and C 18:0. The genomic G + C content was 46.0 mol%. Fluorescence and electron microscopy observations revealed the intracellular localization of genomic DNA surrounded by a membrane in the cells of strain M15T as reported in a sole validly described species of the class Atribacteria in the phylum Atribacterota , Atribacter laminatus strain RT761T, suggesting that the unique morphological traits are widely shared in this class. Phylogenetic analyses indicated that strain M15T belongs to a distinct family-level lineage in the class Atribacteria and shows low similarities to Atribacter laminatus strain RT761T (16S rRNA gene sequence identity of 90.1 %, average nucleotide identity [ANI] of 66.1 %, average amino acid identity [AAI] of 55.8 %). Phenotypic traits of strain M15T (thermophilic, fast-growing, relatively high G + C content, etc.) were clearly distinct from A. laminatus. Based on these phenotypic and genomic properties, we propose a novel genus and species, Atrimonas thermophila gen. nov., sp. nov. for strain M15T (=JCM39389T, =KCTC25731T) representing a novel family Atrimonadaceae fam., nov. in the class Atribacteria. [ABSTRACT FROM AUTHOR]

Multidrug resistant microorganisms are a serious threat to human health. Under the circumstances, a front line of antimicrobials in clinical setting may be carbapenem β-lactams (CRBP). However, emergence of CRBP resistant (CRBP-r) Gram-negative bacteria are the most alarming. CRBP-r is mainly caused to the production of β-lactamase, down and up expression of the diffusion channel and the efflux pump genes, respectively. Among them, production of metallo-β-lactamase (MBL) is a major cause of high-level of CRBP-r. We analyzed the MBL subtypes by PCR and DNA sequencing in CRBP-r Psudomonas aeruginosa in the collection of the joint program by the Japanese Association for Infectious Diseases, Japan Society for Clinical Microbiology and Japanese Society of Chemotherapy (2006–2015 in Japan). Among 275 strains out of a total 1716 isolates, 23 (8.3%) were MBL-positive exhibiting resistant to meropenem (MEPM), imipenem, ceftazidime, cefepime, ciprofloxacin and levofloxacin without exception and the MIC of MEPM appeared over 128 μg/mL. Their MBL subtype analysis revealed that 16, 2, and 2 isolates were IMP-1, IMP-7 and VIM-2 positive, respectively, and one isolate each expressed either IMP-10, IMP-34 or IMP-41. This study revealed that all the MBL-positive CRBP-r isolates were highly resistant to carbapenems dominating IMP-1 production. [ABSTRACT FROM AUTHOR]

Recently, increased frequencies of carbapenemase-producing Enterobacteriaceae have been reported worldwide. Among multiple genetic subtypes, oxacillinase (OXA)-48 β-lactamase-producing strains have been associated with inbound infection because they have been detected predominantly in patients who traveled outside of Japan. However, a recent case report of OXA-48 β-lactamase-producing Enterobacteriaceae suggested the latent spread of domestic infections. Due to a lack of specific inhibitors, culture-based detection of OXA-48 β-lactamase-producing bacteria is difficult. Thus, DNA-based detection methods, including PCR, direct sequencing and loop-mediated isothermal amplification (LAMP), have been employed. Among these methods, LAMP detection is more favorable than other methods because of its technical simplicity and low cost. We designed novel LAMP primers to detect OXA-48 β-lactamase-producing bacteria and investigated their possible clinical applications with bacterial genome-spiked human materials (cerebrospinal fluid, blood, feces, urine, and sputum). We evaluated the specificity of the LAMP primers using 37 bacterial strains: 8 standard, 9 reference, and 20 clinical Gram-negative strains. Our LAMP primers detected 10 copies of the OXA-48 type β-lactamase gene and exhibited no cross reactivity with other β-lactamase genes. Sensitivity was not influenced in any clinical sample, in contrast to PCR detection, which was strongly inhibited by substances in fecal samples. These results suggest the superior performance of LAMP compared with conventional PCR for detecting the OXA-48 type β-lactamase gene in various clinical samples. [ABSTRACT FROM AUTHOR]

In the recent years, issues related to drug‐resistant bacteria have evolved worldwide, and various countermeasures have been taken to control their spread. Among a wide variety of drug‐resistant bacterial species, carbapenem‐resistant Gram‐negative bacteria, including carbapenem‐resistant Enterobacteriaceae (CRE) and carbapenem‐resistant Acinetobacter baumannii (CRAb), are those for which countermeasures are particularly important. Carbapenems are the last resort antibiotics for any bacterial infection; therefore, infectious diseases caused by these drug‐resistant bacteria are difficult to treat. In the case of CRE, since carbapenemases responsible for carbapenem resistance are mostly encoded on transmissible plasmids, it is known that susceptible bacteria can easily become carbapenem‐resistant by transfer of plasmids between Enterobacteriaceae. In addition, Enterobacteriaceae are common bacterial species found in the guts of animals, including humans. Acinetobacter is ubiquitously isolated in the environment. Due to these characteristics, it is quite difficult to prevent the intrusion of multi‐drug resistant pathogens in hospitals. Therefore, effective countermeasures should be developed and utilized against such dangerous pathogens based on molecular epidemiological analyses. In this review, there are also some examples presented on how to manage to monitor and control those troublesome drug‐resistant bacteria conducted in Japan and Southeast Asia. [ABSTRACT FROM AUTHOR]

This study was conducted to characterize carbapenemase-producing Klebsiella pneumoniae and Acinetobacter baumannii isolated from fresh vegetables in Japan. Two K. pneumoniae isolates (AO15 and AO22) and one A. baumannii isolate (AO22) were collected from vegetables in the city of Higashihiroshima, Japan, and subjected to antimicrobial susceptibility testing, conjugation experiments, and complete genome sequencing using Illumina MiniSeq and Oxford Nanopore MinION sequencing platforms. The two K. pneumoniae isolates were clonal, belonging to sequence type 15 (ST15), and were determined to carry 19 different antimicrobial resistance genes, including blaNDM-1. Both the isolates carried blaNDM-1 on a self-transmissible IncFII(K):IncR plasmid of 122,804 bp with other genes conferring resistance to aminoglycosides [aac(69)-Ib, aadA1, and aph(3')-VI], β-lactams (blaCTX-M-15, blaOXA-9, and blaTEM-1A), fluoroquinolones [aac(6')-Ib-cr], and quinolones (qnrS1). A. baumannii AO22 carried blaOXA-66 on the chromosome, while blaOXA-72 was found as two copies on a GR2-type plasmid of 10,880 bp. Interestingly, A. baumannii AO22 harbored an AbaR4-like genomic resistance island (GI) of 41,665 bp carrying genes conferring resistance to tetracycline [tet(B)], sulfonamides (sul2), and streptomycin (strAB). Here, we identified Japanese carbapenemase-producing Gram-negative bacteria isolated from vegetables, posing a food safety issue and a public health concern. Additionally, we reported a GR2-type plasmid carrying two copies of blaOXA-72 and an AbaR4-like resistance island from a foodborne A. baumannii isolate. [ABSTRACT FROM AUTHOR]

Sesame seeds are used in many traditional Japanese foods for their flavor and taste but commercial sesame can be highly contaminated with bacteria. We therefore examined the bacterial populations, including Bacillus spp., Enterobacteriaceae bacteria and standard plate count bacteria in sesame samples purchased from markets in Japan. A total of 8 sesame samples were tested, of which 4 (50.0%) harbored 4.3-5.6 log cfu/g standard plate count and 2.7-4.3 log cfu/g Enterobacteriaceae bacilli. Pantoea dispersa, P. septica and P. agglomerans were identified by a MALDI-TOF MSbased test. One (12.5%) sample harbored 3.6 log cfu/g Bacillus cereus, but this strain lacked the gene encoding of the enzyme responsible for cereulide synthesis and did not produce enterotoxin. B. cereus was also isolated from a heated sample (98 °C for 20 mins). Metagenome analysis showed that 4 samples were contaminated with bacteria belonging to the 5 genera Pantoea, Serratia, Pseudomonas, Xanthomonas and Rosenbergiella. Pantoea and Pseudomonas DNA was detected in all positive samples but the bacterial load varied. Our study revealed that sesame can become contaminated with Enterobacteriaceae bacteria and B. cereus. Dishes containing contaminated sesame could potentially cause B. cereus food poisoning, although the B. cereus isolates obtained in this study did not contain the gene encoding the enzyme responsible for cereulide synthesis and did not produce enterotoxin. To prevent food poisoning caused by bacterial contamination, it is important to roast sesame seeds at a sufficiently high temperature, do not leave the cooked food with sesame at room temperature for a long time and avoiding cross-contamination from sesame to ready-to-eat food. [ABSTRACT FROM AUTHOR]

The Japanese Three Academic Societies Joint Antimicrobial Susceptibility Surveillance Committee conducted a nationwide surveillance on six otorhinolaryngological diseases and investigated the antimicrobial susceptibility patterns and isolation rates of the causative pathogens. The surveillance program was conducted in the otorhinolaryngological departments of 12 universities, and 36 affiliated hospitals and clinics. Patients with acute otitis media (children under six years old), chronic otitis media, acute nasal sinusitis, chronic nasal sinusitis, acute tonsillitis, and peritonsillar abscess (over 20 years old) between December 2015 and June 2017 were investigated. The collected swab or incision samples were cultivated for microbial identification, and the antimicrobial susceptibility of the detected bacteria was measured at the Kitasato University Research Center for Infections and Antimicrobials. The surveillance focused on three gram-positive bacteria (Streptococcus pneumoniae , Streptococcus pyogenes , and Staphylococcus aureus), three gram-negative bacteria (Haemophilus influenzae , Moraxella catarrhalis , and Pseudomonas aeruginosa), and three anaerobic bacteria (anaerobic gram-positive cocci, Prevotella spp., Porphyromonas spp., and Fusobacterium spp.). Bacterial susceptibility to 40 antimicrobial agents was investigated. We were unable to completely mitigate the rise in the occurrence of resistant bacteria, such as methicillin-resistant S. aureus , penicillin-resistant S. pneumoniae , penicillin-intermediate resistant S. pneumoniae , beta-lactamase non-producing ampicillin-resistant H. influenzae , and beta-lactamase producing ampicillin-resistant H. influenzae. We suggest promoting the proper usage of antimicrobial agents to prevent the spread of these bacteria. We also suggested that immunization with pneumococcal vaccines is useful for decreasing the occurrence of otorhinolaryngological infectious diseases caused by pneumococci. [ABSTRACT FROM AUTHOR]

We report a severe case of Chromobacterium haemolyticum pneumonia associated with near-drowning and detail the investigation of the pathogen and river water. Our genomic and environmental investigation demonstrated that river water in a temperate region can be a source of C. haemolyticum causing human infections. [ABSTRACT FROM AUTHOR]

Background: For residents of long-term care facilities (LTCFs), antimicrobial-resistant bacteria (ARB) are a risk factor, yet their oral colonisation, potentially leading to aspiration pneumonia, remains unclear. This study was undertaken to survey the prevalence, phenotypic characteristics, and molecular epidemiology of antimicrobial-resistant Gram-negative bacteria in the oral cavity of LTCF residents, and to analyse the risk factors for such carriers. Methods: This study involved 98 residents of a LTCF in Hiroshima City, Japan, aged between 55 and 101 years. Oropharyngeal swabs were collected and plated on screening media for ESBL-producing and carbapenem-resistant bacteria; isolates were identified and tested for antibiotic susceptibility; biofilm formation was tested in vitro; identification of epidemic clones were pre-determined by PCR; resistance genes, sequence types, and whole-genome comparison of strains were conducted using draft genome sequences. Demographic data and clinical characterisations were collected and risk factors analysed. Results: Fifty-four strains from 38% of the residents grew on screening media and comprised predominantly of Acinetobacter spp. (35%), Enterobacteriaceae spp. (22%), and Pseudomonas spp. (19%). All Escherichia coli isolates carried CTX-M-9 group and belonged to the phylogroup B2, O25:H4 ST131 fimH30 lineage. Six Acinetobacter baumannii isolates presented identical molecular characteristics and revealed more biofilm production than the others, strongly suggesting their clonal lineage. One Acinetobacter ursingii isolate displayed extensive resistance to various ß-lactams due to multiple acquired resistance genes. One Pseudomonas aeruginosa isolate showed exceptional resistance to all ß-lactams including carbapenems, aminoglycosides, and a new quinolone, showing a multidrug-resistant Pseudomonas aeruginosa (MDRP) phenotype and remarkable biofilm formation. Genome sequence analysis revealed this isolate was the blaIMP-1-positive clone ST235 in Japan. Strokes (cerebral infarction or cerebral haemorrhage) and percutaneous endoscopic gastrostomy tubes were recognised as risk factors for oral colonisation by ARB in the LTCF residents. Conclusions: ARB, as defined by growth on screening agar plates, which carried mobile resistance genes or elements or conferred high biofilm formation, were already prevalent in the oral cavity of LTCF residents. Health-care workers involved in oral care should be aware of antimicrobial resistance and pay special attention to transmission prevention and infection control measures to diminish ARB or mobile resistance elements dissemination in LTCFs. [ABSTRACT FROM AUTHOR]

This study investigated the epidemiology of adult patients with bacteremia caused by seven major gram-negative bacteria during a year at four university hospitals in Japan. Of the 438 cases included, Escherichia coli (247 patients) was the most frequently isolated pathogen, followed by Klebsiella species (89 patients), Enterobacter species (31 patients), Pseudomonas aeruginosa (29 patients), Bacteroides species (19 patients), Acinetobacter species (12 patients) and Stenotrophomonas maltophilia (11 patients). The overall, crude in-hospital mortality was 16.4%, ranging from 9.7% with Enterobacter species to 54.5% with S. maltophilia. Community- and hospital-acquired bacteremia accounted for 52.5% and 47.5%, respectively. Enterobacteriaceae were isolated from 93.0% of patients with community-acquired bacteremia, whereas non-fermenting bacteria were isolated from 21.6% of patients with hospital-acquired bacteremia. Of the 423 patients analyzed, 86.8% and 13.2% were monomicrobial and polymicrobial infections, respectively, and their in-hospital mortalities were 13.9% and 30.4%, respectively. Although carbapenem-resistant Enterobacteriaceae were not detected, extended-spectrum β-lactamase (ESBL) production was seen in 24.3% of E. coli and 6.7% of Klebsiella species, respectively. E. coli producing ESBL showed high resistance rates to fluoroquinolones (approximately 90%), in contrast to non-producing- E. coli (approximately 21%). The susceptibilities to carbapenems and fluoroquinolones were approximately 80% for P. aeruginosa , whereas all Acinetobacter species were susceptible to these antibiotics. Bacteroides species showed 100% susceptibility to piperacillin/tazobactam and carbapenems, but only 47.4% were susceptible to clindamycin. Further studies, as well as continued surveillance, are required to determine the appropriate therapeutic strategy for gram-negative bacteremia. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have suggested that peripheral venous catheter is a significant source of gram-negative bacteraemia in patients with malignancy. We aimed to identify risk factors and develop a clinical prediction rule for the involvement of gram-negative organisms in peripheral venous catheter-associated bloodstream infections (PVC-BSIs) among patients with malignancy. Methods: This retrospective cohort study was conducted at a 700-bed cancer hospital in Japan. Consecutive patients diagnosed with PVC-BSI based on clinical and microbiological criteria were included in this study. Based on clinical and microbiological characteristics of PVC-BSIs in cancer patients, a logistic regression model for predicting gram-negative organisms as causative organisms in PVC-BSIs was then developed. Results: Of the 99 patients included in our cohort, 60 patients (60.6%) had gram-negative PVC-BSIs. The median age of patients with PVC-BSIs was 67 years (interquartile range [IQR], 59–74 years), and the median Pitt bactearemia score was 1 (IQR, 0–3). The median duration of catherization was 5 days (IQR, 4–7 days) and 70 patients (70.7%) received peripheral parenteral nutrition that contained amino acids. On multivariable analysis, age ≥65 years (odds ratio [OR], 3.07; 95% confidence interval [CI], 1.10–8.62), showering (OR, 3.15; 95% CI, 1.07–9.26), Pitt bacteraemia score ≥2 points (OR, 6.96; 95% CI, 2.52–19.2), and use of peripheral parenteral nutrition (OR, 0.31; 95% CI, 0.10–0.98) were independent predictors for gram-negative PVC-BSIs among all PVC-BSIs. The simplified PVC-GN scores established to predict gram-negative PVC-BSIs had a optimism-corrected c-index of 0.775. Conclusion: Gram-negative bacteria were more commonly responsible for PVC-BSI than Gram-positive bacteria among cancer patients in this cohort. Involvement of Gram-negative bacteria in PVC-BSIs could be predicted with readily available clinical variables. [ABSTRACT FROM AUTHOR]

Introduction: Leptospirosis is a global zoonotic disease spread through contact with contaminated water/soil. The US soldiers at the military bases in these countries are extremely vulnerable, as most of them are immunologically naïve to the responsible pathogen. No recent sero-epidemiological data of leptospirosis among US Marines stationed in Japan were available.Materials and Methods: In this study, we analyzed the presence of leptospirosis in US Marines stationed in Japan. One thousand posttour sera samples were analyzed by enzyme-linked immunosorbent assay for Leptospira-specific Immunoglobulin G.Results: Among these 1,000 posttour samples, 85 of them were positive and corresponding pretour samples were analyzed by enzyme-linked immunosorbent assay also. Seroconversion occurred for 35 (3.5%) Marines during their assignment to Japan. These results also indicate that 50 Marine personnels were exposed to leptospires before their assignment to Japan, perhaps because of previous exposure to leptospires at home.Conclusion: The 5% rate of seroconversion in 2013 and 2014 suggests that leptospirosis is a potential threat for Marines in the endemic region in Japan. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Klebsiella pneumoniae and Escherichia coli , multidrug-resistant Pseudomonas aeruginosa and vancomycin-resistant Enterococcus faecium were isolated from a single patient. The patient came to Japan for advanced medical treatment after having undergone laparoscopic cholecystectomy and hospitalization in Vietnam. Whole-genome sequence analysis revealed that K. pneumoniae harbored bla OXA-48 that was found on a Col156 -type small plasmid, E. coli harbored bla NDM-5 and P. aeruginosa harbored both bla NDM-1 and 16S rRNA methyltransferase (rmtB). To the best of our knowledge, this is the first report of detection of K. pneumoniae harboring bla OXA-48 on a Col156-type small plasmid in the world and P. aeruginosa coharboring genes encoding NDM-1 and RmtB in Japan. [ABSTRACT FROM AUTHOR]

Many arthropods including insects have symbiotic relationships with diverse microorganisms that can confer fitness benefits to their hosts. Riptortus pedestris is a serious pest on leguminous crops in East Asia including South Korea and Japan. Recently, has been reported that R. pedestris form symbiosis with Gram‐negative bacteria in the genus Burkholderia where they acquire symbionts from soil environments without vertical transmission from each generation. In order to address how R. pedestris acquire their symbiont from environment, we hypothesized that R. pedestris would detect and exhibit preference toward the Burkholderia symbionts. In this study, we conducted a series of dual‐choice experiments and Y‐tube olfactometer experiments to monitor and evaluate behavioral responses by 2nd instar R. pedestris toward the Burkholderia treatment and untreated control under various experimental settings in the laboratory. In dual‐choice experiments, there was no significant preference by R. pedestris to the Burkholderia treatment compared with untreated control. Also, no significant difference was detected in the first choice frequency, visiting frequency, and residence time of the insects between the two treatments. Likewise, there was no detectable preference by R. pedestris to microbial odors from the symbionts in Y‐tube experiments. Therefore, our results indicate that there was no evidence supporting that 2nd instar R. pedestris exhibit preference to the Burkholderia symbiont in the laboratory conditions of this study. Further studies are required to evaluate behavioral responses of later immature stages (i.e., 3rd and 4th instar) to the symbionts and provide choice settings at larger semi‐field arenas. [ABSTRACT FROM AUTHOR]

The emergence and spread of aminoglycoside-resistant bacteria are a public health concern. The acquisition of the genes encoding 16S rRNA methylases, such as armA, rmtA, and rmtB, confers high-level resistance to aminoglycosides. However, the prevalence has not been well investigated in Japanese veterinary fields. To determine the prevalence of 16S rRNA methylases in animals, we detected 16S rRNA methylases genes in Gram-negative bacteria from animals. Here, we report the isolation of rmtB amd armA from two of the 446 Escherichia coli (0.5%) and one of the 103 Klebsiella spp. isolates (1.0%) from companion animals, respectively. However, none of the isolations were observed from 2445 E. coli isolates derived from livestock in Japan. The prevalence of 16S rRNA methylases in animals, especially in companion animals, should be carefully monitored in Japanese veterinary fields to avoid the spreading of the genes. [ABSTRACT FROM AUTHOR]

Because damselflies are ubiquitously but focally present in natural environments and play a critical role as predators of other insect species, the fecal matter of damselflies may be useful for investigating antibiotic-resistant bacterial populations, including human pathogens, in local environments. We therefore examined the prevalence of antibiotic-resistant bacteria, including Enterobacterales, in fecal material from 383 damselflies (adults and larvae) collected from seven locations around Sapporo City, Japan, in 2016 and 2017. Fecal samples were plated on soybean casein digest (SCD) agar plates with and without antibiotics (SCD-A and SCD-w/o, respectively) to identify environmental bacteria and gut bacteria, respectively, and on MacConkey agar plates with antibiotics (MacConkey-A) to select for Gram-negative bacteria, including human pathogenic Enterobacterales species. The prevalence of colonies on each of the plates was compared, and representative colonies on MacConkey-A plates were identified to the species level using an API 20E kit and the MALDI Biotyper system. Overall, SCD-w/o plates showed a gut bacterial load of approximately 108 colony-forming units per adult damselfly or larva. There was a significant difference between the prevalence of colonies on the SCD-A and MacConkey-A plates, and a significantly increased prevalence of antibiotic-resistant bacteria on MacConkey-A plates was observed in samples collected from Shinoroshinkawa. Cluster analysis based on minimum inhibitory concentration values of 59 representative isolates from MacConkey-A agar plates revealed that samples from Shinoroshinkawa contained a higher prevalence of Enterobacterales than those from other sampling locations. Thus, fecal materials discharged by adult damselflies could be used in future studies as a simple tool for estimating antibiotic-resistant bacteria, including Enterobacterales species, in the local environment. [ABSTRACT FROM AUTHOR]

Japanese spotted fever (JSF) and scrub typhus (ST) are endemic to Japan and share similar clinical features. To document the clinical and epidemiologic characteristics that distinguish these 2 rickettsial diseases, during 2004-2015 we recruited 31 JSF patients, 188 ST patients, and 97 nonrickettsial disease patients from the southern Boso Peninsula of Japan. JSF occurred during April-October and ST during November-December. Patients with JSF and ST were significantly older and more likely to reside in wooded areas than were patients with nonrickettsial diseases. Spatial analyses revealed that JSF and ST clusters rarely overlapped. Clinical findings more frequently observed in JSF than in ST patients were purpura, palmar/plantar rash, hyponatremia, organ damage, and delayed defervescence after treatment. Although their clinical features are similar, JSF and ST differ in seasonality, geographic distribution, physical signs, and severity. Because a considerable percentage of patients did not notice rash and eschar, many rickettsial diseases might be underdiagnosed in Japan. [ABSTRACT FROM AUTHOR]

A novel Vibrio strain, JCM 31412T, was isolated from seawater collected from the Inland Sea (Setonaikai), Japan, and characterized as a Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, ovoid-shaped bacterium with one polar flagellum. Based on 16S rDNA gene identity, strain JCM 31412T showed a close relationship with type strains of Vibrio brasiliensis (LMG 20546T, 98.2% identity), V. harveyi (NBRC 15634T, 98.2%), V. caribbeanicus (ATCC BAA-2122T, 97.8%) and V. proteolyticus (NBRC 13287T, 97.8%). The G+C content of strain JCM 31412T DNA was 46.8%. Multi-locus sequence analysis (MLSA) of eight loci (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; 5535bp) further clustered strain JCM 31412T in the Nereis clade, genus Vibrio. Phenotypically, strain JCM 31412T differed from the closest related Vibrio species in its utilization of melibiose and raffinose, and its lack of casein and gelatin hydrolysis. It was further differentiated based on its fatty acid composition, specifically properties of C12:03OH and summed features, which were significantly different from those of V. brasiliensis, V. nigripulchritudo and V. caribbeanicus type strains. Overall, the results of DNA-DNA hybridization, and physiological and biochemical analysis differentiated strain JCM 31412T from other described species of the genus Vibrio. Based on these polyphasic taxonomic findings, it was therefore concluded that JCM 31412T was a novel Vibrio species, for which the name Vibrio japonicus sp. nov. was proposed, with JCM 31412T (= LMG 29636T = ATCC TSD-62T) as the type strain. [ABSTRACT FROM AUTHOR]

The global spread of antimicrobial resistance (AMR) is alarming. Escherichia coli is a Gram-negative bacterium that causes healthcare-associated infections and is a major threat to public health. Currently, no comprehensive antimicrobial surveillance of multidrug-resistant E. coli of diverse phylogroups along the meat value chain has been implemented in Higashihiroshima, Japan. Therefore, by employing the One Health approach, 1183 bacterial isolates, including 303 recovered from meat samples in 2009, were screened for the presence of antimicrobial resistance determinants using multiplex PCR and DNA sequencing techniques. Seventy-seven non-duplicate E. coli isolates that harbored AMR genes were subjected to antimicrobial susceptibility testing and the detection of integrons. Phylogenetic characterization, which has not been previously investigated, was used to assign E. coli to one of the eight phylogroups. Twenty-six out of 33 (78.8%) and 34 out of 44 (77.3%) E. coli isolates from 2009 and 2021 exhibited multidrug resistance (MDR) phenotypes, respectively. The most common clinical resistance was observed against ampicillin, tetracycline, kanamycin, sulfamethoxazole/trimethoprim, cefotaxime, and chloramphenicol. Overall, 22.1% (17/77) of the E. coli isolates carried extended-spectrum β-lactamase (ESBL)-encoding genes and showed the ESBL-resistant phenotypes. For the two isolation years, AmpC/ESBL prevalence decreased from 42.4% in 2009 to 20.5% in 2021. The identified AMR genes included bla CTX-M-1 , bla CTX-M-2 , bla CTX-M-14 , bla CTX-M-15 , and bla SHV-12 (ESBL-types); bla SHV-1 , bla TEM-1 , bla TEM-135 , and bla TEM-176 (narrow-spectrum types); bla CMY-4 , bla ADC-32 , bla ADC-216 , bla ACT-48 , and bla ACT-51 (AmpC types); and integrons. All E. coli isolates were negative for carbapenemase-encoding genes, whereas one isolate from 2009 carried mcr-5.1 allele. Approximately 52% of E. coli isolates identified in 2009 were assigned to phylogroup A compared to the 20.5% in 2021. Notably, the highest proportions of E. coli phylogroups exhibiting MDR were groups A, B1, and F, suggesting that members of these groups are mostly associated with drug resistance. This study highlights the role of meat as a significant reservoir of MDR E. coli and potential source for transmission of AMR genes. Our findings emphasize the importance of continuous monitoring to track the changes in the spread of antimicrobial resistance in the food chain. • Multidrug resistance occurred in 78.8 % (2009) and 77.3 % (2021) of E. coli isolates. • AmpC/ESBL production decreased from 42.4 % in 2009 to 20.5 % in 2021. • There was higher resistance against cephalosporins in 2009 compared to 2021. • One E. coli isolate carried mcr-5.1 allele, and none was positive for carbapenemases. • The highest proportions of MDR E. coli phylogroups were A, B1, and F. [ABSTRACT FROM AUTHOR]

This study aimed to examine the antimicrobial susceptibility of bovine mastitis pathogens in Japan and develop criteria for testing antimicrobial susceptibility using the simplified agar disk diffusion (ADD) method that is currently being used in clinical practice. Milk samples from 1,349 dairy cows with clinical mastitis were collected and cultured. The minimum inhibitory concentrations (MICs) of the antimicrobials were determined for 504 strains of 28 bacteria. Of the gram-positive bacteria, most Staphylococcus spp. were susceptible to penicillin G (PCG), kanamycin (KM), oxytetracycline (OTC), cefazolin (CEZ), pirlimycin, enrofloxacin, and marbofloxacin. Streptococcus spp. and Trueperella pyogenes showed resistance to OTC and KM. Most gram-negative bacteria were resistant to OTC and CEZ and particularly susceptible to fluoroquinolones. To develop the criteria for a disk diffusion test of the simplified ADD method, the relationships between MICs and diameters of inhibition zones (DIZs) were analyzed and compared with the conventional method. The susceptibility breakpoints of several antimicrobials were lower for both gram-positive and gram-negative bacteria. Particularly for gram-positive bacteria, the application of the new criteria lowers the breakpoint for PCG, suggesting that the use of PCG instead of CEZ may increase. The results suggest that use of these criteria for the simplified ADD method may lead to appropriate antimicrobial choice and consequently the appropriate use of antimicrobials in clinical practice.

Although microbial contamination of ice machines has been reported, no previous study has addressed microbial contamination of ice produced by machines equipped with activated charcoal (AC) filters in hospitals. The aim of this study was to provide clinical data for evaluating AC filters to prevent microbial contamination of ice. We compared microbial contamination in ice samples produced by machines with (n = 20) and without an AC filter (n = 40) in Shunan City Shinnanyo Municipal Hospital. All samples from the ice machine equipped with an AC filter contained 10-116 CFUs/g of glucose nonfermenting gram-negative bacteria such as Pseudomonas aeruginosa and Chryseobacterium meningosepticum. No microorganisms were detected in samples from ice machines without AC filters. After the AC filter was removed from the ice machine that tested positive for Gram-negative bacteria, the ice was resampled (n = 20). Analysis found no contaminants. Ice machines equipped with AC filters pose a serious risk factor for ice contamination. New filter-use guidelines and regulations on bacterial detection limits to prevent contamination of ice in healthcare facilities are necessary. [ABSTRACT FROM AUTHOR]

Hydroxy fatty acids (FAs) in fresh snow from Sapporo, one of the heaviest snowfall regions in the world, have been studied to ascertain the airborne bacterial endotoxin concentrations and their biomass. The presence of β-hydroxy FAs (C9-C28), constituents of Gram-negative bacteria (GNB), suggests long-range transport of soil microbes. Likewise, the occurrence of α- and ω-hydroxy FAs (C9-C30 and C9-C28, respectively) in snow reveals their contribution from epicuticular waxes and soil microorganisms. Estimated endotoxin and GNB mass can aid in assessing their possible impacts on the diversity and functioning of aquatic and terrestrial ecosystems, as well as lethal effects on pedestrians through dispersal of microbes. Air mass back trajectories together with hydroxy FAs unveil their sources from Siberia, Russian Far East and North China by the Asian monsoon. This study highlights the role of fresh snow that reduces the human health risk of GNB and endotoxin by scavenging from the air. [ABSTRACT FROM AUTHOR]

Background and Objective Epithelial cells are recognized as the first line of defense against bacterial infection and environmental harmful stimuli such as cigarette smoke ( CS). Although previous studies explored the effects of nicotine on host cells, mechanisms by which CS affects cellular functions remain uncertain. The present study investigated the effects of CS condensate ( CSC) on in vitro wound closure of gingival epithelial cells and their potential interactions with a major periodontal pathogen, Porphyromonas gingivalis. Material and Methods Human gingival epithelial cells (Ca9-22) were treated with CSC for 24 h. Cell proliferation was determined using a WST-1 assay. Cell migration was assessed using a wound closure model. The expression of integrins was analyzed by confocal scanning laser microscopy and real-time PCR. Intracellular invasion of P. gingivalis was evaluated by confocal scanning laser microscopy and an antibiotic protection assay. Results Low concentrations (1-10 μg/mL) of CSC showed no significant effect on cell proliferation. CSC demonstrated dual effects on epithelial wound closure of Ca9-22 cells: high concentrations (i.e. 250 μg/mL) significantly inhibited the wound closure whereas low concentrations (i.e. 10 μg/mL) promoted it ( p < 0.01). CSC induced distinct changes in cytoskeleton. When CSC-exposed cells were infected with P. gingivalis for 2 h, a significant inhibition of wound closure was observed concurrent with a decrease in integrin α3 expression near the wound area. A significantly increased P. gingivalis invasion into Ca9-22 was observed when exposed to low concentrations of CSC. Conclusion Low concentrations of CSC increased invasion of human gingival epithelial cells by P. gingivalis and induced changes in cytoskeleton and integrin expression, thereby modulating the cell migration. [ABSTRACT FROM AUTHOR]

A strictly aerobic, Gram-negative, beige-pigmented, short-rod-shaped, non-motile and chemoheterotrophic bacteria, designated K2-48 was isolated from seawater collected in the Western North Pacific Ocean near Japan. Preliminary analysis based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated with the family Oceanospirillaceae within the class Gammaproteobacteria and that it showed the highest sequence similarity (93.7 %) to Neptunomonas qingdaonensis P10-2-4. The strain could be differentiated phenotypically from recognized members of the family Oceanospirillaceae. The major fatty acids of strain K2-48 were identified as summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH) and C16:0 as defined by the MIDI system. The DNA G+C content was determined to be 43.2 mol%, the major respiratory quinone was identified as ubiquinone 9 and a polar lipid profile was present consisting of phosphatidylethanolamine, a phosphatidylglycerol and an unidentified phospolipid. On the basis of polyphasic taxonomic studies, it was concluded that strain K2-48 represents a novel genus sp. We propose the name Pelagitalea pacifica gen. nov., sp. nov. for this strain; its type strain is K2-48 (=KCCM 90119). [ABSTRACT FROM AUTHOR]