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BACKGROUND AND AIMS: Not all plant-pollinator interactions are mutualistic, and in fact, deceptive pollination systems are widespread in nature. The genus Arisaema has a pollination system known as lethal deceptive pollination, in which plants not only attract pollinating insects without providing any rewards, but also trap them until they die. Many Arisaema species are endangered from various disturbances including reduction in forest habitat, modification of the forest understory owing to increasing deer abundance, and plant theft for horticultural cultivation. We aimed to theoretically investigate how lethal deceptive pollination can be maintained from a demographic perspective and how plant and pollinator populations respond to different types of disturbance. METHODS: We developed and analysed a mathematical model to describe the population dynamics of a deceptive plant species and its victim pollinator. Calibrating the model based on empirical data, we assessed the conditions under which plants and pollinators could coexist, while manipulating relevant key parameters. KEY RESULTS: The model exhibited qualitatively distinct behaviours depending on certain parameters. The plant becomes extinct when it has a low capability for vegetative reproduction and slow transition from male to female, and plant-insect co-extinction occurs especially when the plant is highly attractive to male insects. Increasing deer abundance has both positive and negative effects because of removal of other competitive plants and diminishing pollinators, respectively. Theft for horticultural cultivation can readily threaten plants whether male or female plants are frequently collected. The impact of forest habitat reduction may be limited compared to that of other disturbance types. CONCLUSIONS: Our results have emphasised that the demographic vulnerability of lethal deceptive pollination systems would differ qualitatively from that of general mutualistic pollination systems. It is therefore important to consider the demographics of both victim pollinators and deceptive plants to estimate how endangered Arisaema populations respond to various disturbances.
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OBJECTIVE: To clarify the infection control measures required in the event of a new infectious disease outbreak, we conducted a questionnaire survey on the infection control measures implemented against coronavirus disease 2019 (COVID-19). METHODS: An invitation to participate in this survey was sent to the heads of 2689 facilities affiliated with the members of the Japanese Society for Infection Prevention and Control in February 2023, requesting responses to the online survey using Google Forms by March 2023. RESULTS: Six hundred and forty-five facilities, including 20 clinics and 625 hospitals, participated in the survey. This survey revealed that various infection control measures were implemented, including universal masking in the non-COVID-19 ward (96.5 %), screening tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on scheduled admission (89.0 %), SARS-CoV-2 tests (98.7 %), and isolation in private rooms (76.5 %) for inpatients with fever. However, nosocomial infections and clusters of COVID-19 occurred in 94.4 % and 90.9 % of cases during the investigation period, respectively. One of the reasons for these results is that healthcare personnel (HCP) and patients were common index cases of nosocomial infections, and the most common cause of clusters was the work of symptomatic HCPs. These results suggest that HCPs should understand that they can be index cases or spreaders. On the other hand, the most common support from external facilities was healthcare centers, followed by physicians or nurses from other hospitals. CONCLUSION: In response to the emergence of infections, it is important to consider implementing infection control measures for HCPs and patients.
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INTRODUCTION: Antimicrobial susceptibility patterns of bacterial pathogens isolated from patients with complicated urinary tract infections were analyzed using the national surveillance data, comprising 793 bacterial strains from eight clinically relevant species. MATERIALS AND METHODS: Data were collected for the fourth national surveillance project from July 2020 to December 2021 by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Disease, and the Japanese Society of Clinical Microbiology. Surveillance was supervised with the cooperation of 43 medical institutions throughout Japan. RESULTS: Fluoroquinolone required a minimum inhibitory concentration (MIC) of 2-64 mg/L to inhibit the 330 tested Escherichia coli strains. The proportion of levofloxacin-resistant E. coli strains increased from 28.6% in 2008 to 29.6% in 2011, 38.5% in 2015, and 44.5% in 2021. The proportion of levofloxacin-resistant strains of Pseudomonas aeruginosa also increased from previous survey results, showing a continuing downward trend. Conversely, the proportion of levofloxacin-resistant strains of Enterococcus faecalis decreased relative to previous reports. Neither multidrug-resistant P. aeruginosa nor carbapenem-resistant Enterobacteriaceae were detected. For methicillin-resistant Staphylococcus aureus (MRSA), the proportion of vancomycin-susceptible strains (MIC of 2 µg/mL) decreased from 14.7% to 7.7%. DISCUSSION: Bacterial strains that produced extended-spectrum ß-lactamase included E. coli (82/330 strains, 24.8%), Klebsiella pneumoniae (11/68 strains, 16.2%), and Proteus mirabilis (4/26 strains, 15.4%). As compared to previous surveillance reports, these strains showed an increase in proportion over the years.
Subject(s)
Anti-Bacterial Agents , Levofloxacin , Microbial Sensitivity Tests , Urinary Tract Infections , Humans , Urinary Tract Infections/microbiology , Urinary Tract Infections/epidemiology , Urinary Tract Infections/drug therapy , Japan/epidemiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Levofloxacin/pharmacology , Levofloxacin/therapeutic use , Drug Resistance, Bacterial , Bacteria/drug effects , Bacteria/isolation & purification , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Escherichia coli/drug effects , Escherichia coli/isolation & purification , Male , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Female , Enterococcus faecalis/drug effects , Enterococcus faecalis/isolation & purification , Fluoroquinolones/pharmacology , Fluoroquinolones/therapeutic use , Epidemiological Monitoring , East Asian PeopleABSTRACT
The Japanese surveillance committee conducted a third nationwide surveillance of antimicrobial susceptibility of acute uncomplicated cystitis at 55 facilities throughout Japan between April 2020 and September 2021. In this surveillance, we investigated the susceptibility of Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), and Staphylococcus saprophyticus (S. saprophyticus) for various antimicrobial agents by isolating and culturing bacteria from urine samples. In total, 823 strains were isolated from 848 patients and 569 strains of target bacteria, including E. coli (n = 529, 92.9 %), K. pneumoniae (n = 28, 4.9 %), and S. saprophyticus (n = 12, 2.2 %) were isolated. The minimum inhibitory concentrations of 18 antibacterial agents were determined according to the Clinical and Laboratory Standards Institute manual. In premenopausal patients, there were 31 (10.5 %) and 20 (6.8 %) fluoroquinolone (FQ)-resistant E. coli and extended-spectrum ß-lactamase (ESBL)-producing E. coli, respectively. On the other hand, in postmenopausal patients, there were 75 (32.1 %) and 36 (15.4 %) FQ-resistant E. coli and ESBL-producing E. coli, respectively. The rate of FQ-resistant E. coli and ESBL-producing E. coli in post-menopausal women was higher than that for our previous nationwide surveillance (20.7 % and 32.1 %: p = 0.0004, 10.0 % and 15.4 %; p = 0.0259). For pre-menopausal women, there was no significant difference in the rate of FQ-resistant E. coli and ESBL-producing E. coli between this and previous reports, but the frequency of FQ-resistant E. coli and ESBL-producing E. coli exhibited a gradual increase. For appropriate antimicrobial agent selection and usage, it is essential for clinicians to be aware of the high rate of these antimicrobial-resistant bacteria in acute uncomplicated cystitis in Japan.
Subject(s)
Cystitis , Escherichia coli , Humans , Female , Klebsiella pneumoniae , Staphylococcus saprophyticus , Japan/epidemiology , Bacteria , Fluoroquinolones , Cystitis/drug therapy , Cystitis/epidemiology , Cystitis/microbiologyABSTRACT
The present study compared trends in antimicrobial resistance patterns in pathogens isolated from skin and soft-tissue infections (SSTIs) in Japan with those of a nationwide survey conducted in 2013. Three organisms that caused most of the SSTIs were collected from 12 dermatology departments in medical centers and 12 dermatology clinics across Japan between April 2019 and August 2020. A total of 390 strains, including 267 Staphylococcus aureus, 109 coagulase-negative staphylococci (CNS), and 14 Streptococcus pyogenes strains were submitted to a central laboratory for antimicrobial susceptibility testing. Patient demographic and clinical information was collated. Methicillin-resistant S. aureus (MRSA) was detected in 25.8% (69/267) of the S. aureus strains. The prevalence of MRSA between the present study and the 2013 survey did not differ significantly. Furthermore, there were no significant differences in MIC values and susceptibility patterns of the MRSA strains to other agents, regardless of a history of hospitalization within 1 year or invasive medical procedures. Methicillin-resistant CNS (MRCNS) was detected in 48.6% (53/109) of CNS isolates, higher than the 35.4% prevalence in the 2013 survey. This difference could be attributed to the heterogeneity in the members of the MRCNS, which comprises multiple staphylococci species, between the 2013 and 2019 surveys. However, it was noted that the susceptibility profiles of the MRCNS to each antibiotic were not significantly different from those identified in the 2013 survey. Most strains of S. pyogenes were susceptible to each antibiotic, similar to the 2013 survey. Continuous monitoring of trends in pathogen and susceptibility profiles is important to advise local public health efforts regarding the appropriate treatment of SSTIs.
Subject(s)
Dermatology , Methicillin-Resistant Staphylococcus aureus , Soft Tissue Infections , Staphylococcal Infections , Staphylococcal Skin Infections , Humans , Staphylococcus aureus , Staphylococcal Skin Infections/drug therapy , Staphylococcal Skin Infections/epidemiology , Staphylococcal Skin Infections/microbiology , Japan/epidemiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Staphylococcal Infections/drug therapy , Staphylococcus , Soft Tissue Infections/drug therapy , Soft Tissue Infections/epidemiology , Soft Tissue Infections/microbiology , Streptococcus pyogenes , Microbial Sensitivity TestsABSTRACT
The trends and prevalence of antimicrobial susceptibility of pathogens vary by country, region, and time. Long-term regular surveillance is required to investigate trends in the antimicrobial resistance of various isolated bacterial pathogens. We report the results of a nationwide surveillance on the antimicrobial susceptibility of bacterial respiratory pathogens in Japan conducted by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology. The isolates were collected from clinical specimens obtained from adult patients who visited a collaborating medical facility between June 2019 and December 2020 and were diagnosed with respiratory tract infections by a physician. Antimicrobial susceptibility testing was performed in a centralized laboratory according to the methods recommended by the Clinical and Laboratory Standards Institute. Susceptibility testing was performed for 932 strains (201 Staphylococcus aureus, 158 Streptococcus pneumoniae, 6 S. pyogenes, 136 Haemophilus influenzae, 127 Moraxella catarrhalis, 141 Klebsiella pneumoniae, and 163 Pseudomonas aeruginosa) collected from 32 facilities in Japan. The proportions of methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae were 35.3% and 0%, respectively. In H. influenzae, 16.2% and 16.9% were ß-lactamase-producing ampicillin resistant and ß-lactamase-negative ampicillin resistant, respectively. Extended-spectrum ß-lactamase-producing K. pneumoniae accounted for 5.0% of all K. pneumoniae infections. Carbapenemase-producing K. pneumoniae and multi-drug-resistant P. aeruginosa with metallo-ß-lactamase were not detected in this study. This surveillance will be a useful reference for treating respiratory infections in Japan and will provide evidence to enhance the appropriate use of antimicrobial agents.
Subject(s)
Communicable Diseases , Methicillin-Resistant Staphylococcus aureus , Respiratory Tract Infections , Adult , Humans , Ampicillin , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteria , beta-Lactamases , Communicable Diseases/drug therapy , Drug Resistance, Bacterial , Haemophilus influenzae , Microbial Sensitivity Tests , Respiratory Tract Infections/drug therapy , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology , JapanABSTRACT
Neisseria gonorrhoeae is one of the important pathogens of sexually transmitted infections. N. gonorrhoeae is rapidly becoming antimicrobial resistant, and there are few drugs that are effective in the initial treatment of gonorrhea. To understand the trends of antimicrobial susceptibility of N. gonorrhoeae, the Surveillance Committee of the Japanese Society of Infectious Diseases, the Japanese Society for Chemotherapy, and the Japanese Society of Clinical Microbiology conducted the third nationwide antimicrobial susceptibility surveillance of N. gonorrhoeae isolated from male urethritis. The specimens were collected from male patients with urethritis at 30 facilities from May 2016 to July 2017. From the 159 specimens collected, 87 N. gonorrhoeae strains were isolated, and 85 were tested for susceptibility to 21 antimicrobial agents. All strains were non-susceptible to penicillin G. Seven strains (8.2%) were ß-lactamase-producing strains. The rates of susceptibility to cefixime and cefpodoxime were 96.5% and 52.9%, respectively. Three strains were non-susceptible with a minimum inhibitory concentration (MIC) of 0.5 mg/L for cefixime. None of the strains were resistant to ceftriaxone or spectinomycin. The susceptibility rate for ciprofloxacin was 23.5% (20 strains), and no strains showed intermediate susceptibility. The susceptibility rate against azithromycin was 81.2%, with one strain isolated with a MIC of 8 mg/L against azithromycin. The results of this surveillance indicate that ceftriaxone and spectinomycin, which are currently recommended for gonococcal infections in Japan, appear to be effective. It will be necessary to further expand the scale of the next surveillance to understand the current status of drug-resistant N. gonorrhoeae in Japan.
Subject(s)
Anti-Infective Agents , Gonorrhea , Urethritis , Humans , Male , Neisseria gonorrhoeae , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cefixime/pharmacology , Cefixime/therapeutic use , Ceftriaxone/therapeutic use , Azithromycin/therapeutic use , Spectinomycin/pharmacology , Spectinomycin/therapeutic use , Urethritis/drug therapy , Urethritis/epidemiology , Urethritis/microbiology , Japan/epidemiology , Gonorrhea/drug therapy , Gonorrhea/epidemiology , Anti-Infective Agents/therapeutic use , Microbial Sensitivity TestsABSTRACT
Understanding how cells change their identity and behaviour in living systems is an important question in many fields of biology. The problem of inferring cell trajectories from single-cell measurements has been a major topic in the single-cell analysis community, with different methods developed for equilibrium and non-equilibrium systems (e.g. haematopoeisis vs. embryonic development). We show that optimal transport analysis, a technique originally designed for analysing time-courses, may also be applied to infer cellular trajectories from a single snapshot of a population in equilibrium. Therefore, optimal transport provides a unified approach to inferring trajectories that is applicable to both stationary and non-stationary systems. Our method, StationaryOT, is mathematically motivated in a natural way from the hypothesis of a Waddington's epigenetic landscape. We implement StationaryOT as a software package and demonstrate its efficacy in applications to simulated data as well as single-cell data from Arabidopsis thaliana root development.
Subject(s)
Cell Physiological Phenomena/physiology , Computational Biology/methods , Epigenesis, Genetic , Models, Biological , Single-Cell Analysis/methods , Arabidopsis/cytology , Plant Cells/metabolism , Plant Cells/physiology , Plant Roots/cytology , Time FactorsABSTRACT
INTRODUCTION: Invasive pneumococcal disease (IPD) is often fatal, requiring prompt diagnosis and treatment. To evaluate the factors associated with IPD in adults, we retrospectively investigated its characteristics compared to pneumococcal pneumonia without confirmation of invasion (PP). METHODS: Patients >18 years with PP (n = 79) and IPD (n = 53) from whom Streptococcus pneumoniae was isolated were enrolled from two hospitals between 2011 and 2017. Clinical backgrounds, blood test results at admission, initial antimicrobials administered, isolate serotypes, and outcomes were compared between the PP and IPD groups. RESULTS: Patients with IPD exhibited higher mortality (28.3%) than those with PP (2.5%) (p<0.001), regardless of the type of antimicrobials first administered. The majority (80.0%) of fatal cases of IPD were due to vaccine serotypes. Almost all patients with PP (97.4%) and IPD (88.7%) had underlying disease. C-reactive protein (CRP) ≥17.0 mg/dL (odds ratio [OR], 7.1; 95% CI, 2.7-19.0; p<0.001), white blood cell counts <11.0 × 103/µL (OR, 3.2; 95% CI, 1.3-8.4; p = 0.016), and platelet (PLT) counts <16.2 × 104/µL (OR, 2.8; 95% CI, 1.1-7.4; p = 0.036) were significantly more common in IPD. Moreover, 89.5% of cases with both CRP ≥23.8 mg/dL and PLT <18.5 × 104/µL were diagnosed with IPD. CONCLUSION: Laboratory blood test findings at admission, particularly high CRP and low PLT values, are useful early indicators of IPD in adults. These results could be used to initiate rapid and intensive treatment and improve prognosis.
Subject(s)
Pneumococcal Infections , Pneumonia, Pneumococcal , Hematologic Tests , Humans , Infant , Pneumococcal Infections/diagnosis , Pneumococcal Infections/drug therapy , Pneumococcal Vaccines , Pneumonia, Pneumococcal/diagnosis , Pneumonia, Pneumococcal/drug therapy , Retrospective Studies , SerogroupABSTRACT
INTRODUCTION: A limited number of studies have shown a decline in antibody titers in healthcare workers beyond six months after the second dose of the BNT162b2 vaccine, and has been insufficiently investigated yet in the respective Asian ethnic groups. METHODS: We conducted a longitudinal observational study on 187 healthcare workers and other personnel and healthy adults at least eight months after vaccination at the International University of Health and Welfare. RESULTS: The baseline (before the third dose of BNT162b2) anti-receptor binding domain (RBD) IgG level was 569[377-943] AU/mL 245[240-250] days after the second dose. The mean antibody titer of participants aged 20-29 years was 4.6 times higher than that of participants aged 70-79 years. After booster vaccination, serum anti-RBD antibody levels were elevated in all participants with a median titer of 23,250[14,612-33,401] AU/mL 21[19-23] days after the third dose. The median post-booster antibody titers in the 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years age groups were 30.6, 33.0, 33.8, 27.4, 50.1, and 90.3 times, respectively, higher than the pre-booster ones. Antibody levels were 15% lower in daily drinkers compared to nondrinkers, suggesting that daily alcohol consumption can prevent antibody levels from increasing after vaccination. Our results show decreased antibody titers after two doses of the vaccine, especially in the elderly; however, the third dose of the vaccine resulted in a significant increase in antibody titers in all age groups. CONCLUSIONS: We provided information on antibody responses following primary and booster doses of the BNT162b2 mRNA COVID-19 vaccine in Japan.
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COVID-19 Vaccines , COVID-19 , Adult , Aged , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , Health Personnel , Humans , Japan , SARS-CoV-2ABSTRACT
INTRODUCTION: Invasive extraintestinal pathogenic Escherichia coli (ExPEC) disease (IED), characterised by sepsis and bacteraemia, is a major global healthcare concern worsened by emerging multidrug resistant (MDR) strains. The development of multivalent prophylactic vaccines targeting E. coli strains of IED-associated O-serotypes could address this. A better understanding of O-serotype distribution is required for this purpose. Here, we characterised O-serotype prevalence and drug resistance among ExPEC bacteraemia isolates in Japan. METHODS: E. coli blood isolates from patients aged ≥60 years with bacteraemia were obtained from a retrospective surveillance study in Japan (2015-2017). O-serotyping was performed by agglutination; for isolates non-typeable by agglutination, O-genotyping was performed. Antimicrobial susceptibility was evaluated by broth microdilution using a 21-antibiotic panel. The frequency of drug resistant (DR) isolates was evaluated by antimicrobial susceptibility testing. RESULTS: Of 401 ExPEC bacteraemia isolates evaluated, the most prevalent O-serotype (≥1%) was O25 (28.7% [n = 115]), followed by O1 (14.2% [n = 57]), O2 (8.5% n = 34]), O6 (5.5% [n = 22]), O75, O18, O13, O16, O15, O4, O46/O134, O86, O8 and O83 (each <5% prevalence). These 14 O-serotypes accounted for 81.5% of isolates collected. In total, 19% (n = 77) of isolates were DR ≥ 3, of which 59.7% were O25. Fluoroquinolone-resistance among all and O25 isolates was most prevalent (35.7% and 84.3%, respectively). Almost all (98%) isolates identified as O25 were of subtype O25B. CONCLUSIONS: E. coli serotype O25B showed the highest prevalence and highest multidrug resistance among ExPEC bacteraemia isolates from patients ≥60 years in Japan. Our data may inform development of multivalent glycoconjugate vaccines to prevent IED.
Subject(s)
Anti-Infective Agents , Bacteremia , Escherichia coli Infections , Extraintestinal Pathogenic Escherichia coli , Vaccines , Bacteremia/epidemiology , Drug Resistance, Microbial , Escherichia coli , Escherichia coli Infections/drug therapy , Escherichia coli Infections/epidemiology , Extraintestinal Pathogenic Escherichia coli/genetics , Humans , Japan/epidemiology , Retrospective Studies , Serogroup , SerotypingABSTRACT
The Urogenital Sub-committee and the Surveillance Committee of the Japanese Society of Chemotherapy, The Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology conducted the second nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis. In this second surveillance study, clinical urethral discharge specimens were collected from patients with urethritis in 26 hospitals and clinics from May 2016 to July 2017. Based on serial cultures, the minimum inhibitory concentration (MIC) could be determined for 41 isolates; the MICs (MIC90) of ciprofloxacin, levofloxacin, tosufloxacin, sitafloxacin, doxycycline, minocycline, erythromycin, clarithromycin, azithromycin and solithromycin were 2 µg/ml (2 µg/ml), 1 µg/ml (0.5 µg/ml), 0.25 µg/ml (0.25 µg/ml), 0.125 µg/ml (0.063 µg/ml), 0.125 µg/ml (0.125 µg/ml), 0.25 µg/ml (0.25 µg/ml), 0.031 µg/ml (0.031 µg/ml), 0.25 µg/ml (0.125 µg/ml), and 0.016 µg/ml (0.008 µg/ml), respectively. In summary, this surveillance project did not identify any strains resistant to fluoroquinolone, tetracycline, or macrolide agents in Japan. In addition, the MIC of solithromycin was favorable and lower than that of other antimicrobial agents. However, the MIC of azithromycin had a slightly higher value than that reported in the first surveillance report, though this might be within the acceptable margin of error. Therefore, the susceptibility of azithromycin, especially, should be monitored henceforth.
Subject(s)
Chlamydia trachomatis , Urethritis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Azithromycin/pharmacology , Drug Resistance, Bacterial , Humans , Japan/epidemiology , Male , Microbial Sensitivity Tests , Urethritis/drug therapy , Urethritis/epidemiologyABSTRACT
BACKGROUND AND AIMS: Interspecific difference in pollinators (pollinator isolation) is important for reproductive isolation in flowering plants. Species-specific pollination by fungus gnats has been discovered in several plant taxa, suggesting that they can contribute to reproductive isolation. Nevertheless, their contribution has not been studied in detail, partly because they are too small for field observations during flower visitation. To quantify their flower visitation, we used the genus Arisaema (Araceae) because the pitcher-like spathe of Arisaema can trap all floral visitors. METHODS: We evaluated floral visitor assemblage in an altitudinal gradient including five Arisaema species. We also examined interspecific differences in altitudinal distribution (geographic isolation) and flowering phenology (phenological isolation). To exclude the effect of interspecific differences in altitudinal distribution on floral visitor assemblage, we established ten experimental plots including the five Arisaema species in high- and low-altitude areas and collected floral visitors. We also collected floral visitors in three additional sites. Finally, we estimated the strength and contribution of these three reproductive barriers using a unified formula for reproductive isolation. KEY RESULTS: Each Arisaema species selectively attracted different fungus gnats in the altitudinal gradient, experimental plots and additional sites. Altitudinal distribution and flowering phenology differed among the five Arisaema species, whereas the strength of geographic and phenological isolations were distinctly weaker than those in pollinator isolation. Nevertheless, the absolute contribution of pollinator isolation to total reproductive isolation was weaker than geographic and phenological isolations, because pollinator isolation functions after the two early-acting barriers in plant life history. CONCLUSIONS: Our results suggest that selective pollination by fungus gnats potentially contributes to reproductive isolation. Since geographic and phenological isolations can be disrupted by habitat disturbance and interannual climate change, the strong and stable pollinator isolation might compensate for the weakened early-acting barriers as an alternative reproductive isolation among the five Arisaema species.
Subject(s)
Arisaema , Pollination , Flowers , Fungi , Reproductive IsolationABSTRACT
INTRODUCTION: The incidence of Clostridioides difficile infection (CDI) has been continuously increasing and thereby became an important issue worldwide. Appropriate diagnosis, management, and infection control are required for patients with CDI. Enzyme immunoassay (EIA) is a widely used standard diagnostic tool for C. difficile-specific glutamate dehydrogenase (GDH) and C. difficile toxins (toxins A and B). However, the sensitivity of EIA in detecting C. difficile toxins has been reported to be relatively low, resulting in CDI underdiagnosis. Therefore, nucleic acid amplification tests (NAAT) are recently developed for higher sensitivity/specificity test. METHODS: In this study, a total of 279 stool samples submitted for CDI diagnosis were examined using an independently developed new high-speed polymerase chain reaction (PCR) device (PathOC RightGene, Metaboscreen). In parallel, results were compared with those of definitive diagnosis and conventional diagnostic methods (EIA, real-time PCR) to assess the inspection accuracy. RESULTS: PathOC RightGene showed high sensitivity (96.7%) and specificity (96.7%). Regarding the measurement time, C. difficile-specific and C. difficile toxin genes were simultaneously detected in approximately 25 min for one sample (including the preprocessing and measurement time). CONCLUSION: PathOC RightGene has been found to show both excellent sensitivity and rapidity and thus can be used for the reliable and early diagnosis, which are needed for the appropriate management of CDI.
Subject(s)
Bacterial Toxins , Clostridioides difficile , Clostridium Infections , Bacterial Proteins/genetics , Bacterial Toxins/genetics , Clostridioides , Clostridioides difficile/genetics , Clostridium Infections/diagnosis , Feces , Humans , Immunoenzyme Techniques , Polymerase Chain Reaction , Sensitivity and SpecificityABSTRACT
BACKGROUND: In 2019, the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases reported nationwide, cross-sectional questionnaire survey data investigating the clinical status of clinic doctors' attitudes to antimicrobial stewardship. This study aimed to identify factors determining clinic doctors' attitudes concerning antimicrobial prescription for patients with a common cold or bronchitis. METHODS: In February 2018, 1500 randomly selected community-based medical clinics in Japan were sent a questionnaire. Primary and secondary endpoints were clinic doctors' attitudes concerning antimicrobial prescription, and antimicrobial medication types prescribed for patients with a common cold or bronchitis, respectively. We used multivariable linear regression analysis to identify factors associated with primary and secondary outcomes. RESULTS: We analyzed 269 of 274 responses (response rate, 18.3%). Linear regression analysis was used to identify determinants of proactive attitudes to antimicrobial prescription, including whether clinic doctors encountering patients with upper respiratory symptoms and no underlying illnesses, and diagnosed with a common cold would prescribe antimicrobial medication (ß = 0.283, t = 4.279, p = 0.000); whether clinic doctors frequently experienced requests from patients (or their families) with a common cold to prescribe antimicrobial medication (ß = 0.389, t = 6.133, p = 0.000), and; clinic doctors' awareness of antimicrobial stewardship in the past year (ß = -0.157, t = -2.456, p = 0.015). Determinants of proactive attitudes to prescribing broader-spectrum antimicrobials for patients with a common cold included clinic doctors' attitudes concerning antimicrobial prescription (ß = 0.165, t = 2.622, p = 0.009), whether the respondent was a pediatrician (ß = -0.288, t = -4.583, p = 0.000), and clinic doctors' attitudes to antimicrobial prescription (ß = 0.262, t = 4.075, p = 0.000) for patients with bronchitis. CONCLUSION: This study identified factors among clinic doctors that determined their attitudes to antimicrobial prescription concerning patients with a common cold or bronchitis. Identification and targeting of clinic doctors who unnecessarily prescribe antimicrobial medication is urgently required to promote antimicrobial stewardship in an outpatient setting.
Subject(s)
Anti-Infective Agents , Bronchitis , Common Cold , Communicable Diseases , Anti-Infective Agents/therapeutic use , Bronchitis/drug therapy , Common Cold/drug therapy , Cross-Sectional Studies , Health Knowledge, Attitudes, Practice , Humans , Japan , Practice Patterns, Physicians' , Surveys and QuestionnairesABSTRACT
A nationwide surveillance of the antimicrobial susceptibility of pediatric patients to bacterial pathogens was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in Japan in 2017. The isolates were collected from 18 medical facilities between March 2017 and May 2018 by the three societies. Antimicrobial susceptibility testing was conducted at the central laboratory (Infection Control Research Center, Kitasato University, Tokyo) according to the methods recommended by the Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 926 strains (331 Streptococcus pneumoniae, 360 Haemophilus influenzae, 216 Moraxella catarrhalis, 5 Streptococcus agalactiae, and 14 Escherichia coli). The ratio of penicillin-resistant S. pneumoniae was 0% based on CLSI M100-ED29 criteria. However, three meropenem or tosufloxacin resistant S. pneumoniae isolates were obtained. Among H. influenzae, 13.1% of them were found to be ß-lactamase-producing ampicillin resistant strains, while 20.8% were ß-lactamase non-producing ampicillin-resistant strains. No capsular type b strains were detected. In M. catarrhalis, 99.5% of the isolates were ß-lactamase-producing strains. All S. agalactiae and E. coli strains were isolated from sterile body sites (blood or cerebrospinal fluid). The ratio of penicillin-resistant S. agalactiae was 0%, while that of extended spectrum ß-lactamase-producing E. coli was 14.3%.
Subject(s)
Communicable Diseases , Respiratory Tract Infections , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Child , Communicable Diseases/drug therapy , Drug Resistance, Bacterial , Escherichia coli , Haemophilus influenzae , Humans , Japan/epidemiology , Microbial Sensitivity Tests , Respiratory Tract Infections/drug therapy , TokyoABSTRACT
Inappropriate antimicrobial therapy for surgical site infections (SSIs) can lead to poor outcomes and an increased risk of antibiotic resistance. A nationwide survey was conducted in Japan from 2018 to 2019 to investigate the antimicrobial susceptibility of pathogens isolated from SSIs. The data were compared with those obtained in 2010 and 2014-2015 surveillance studies. Although the rate of detection of extended-spectrum ß-lactamase producing strains of Escherichia coli was increased from 9.5% in 2010 to 23% in 2014-2015, the incidence decreased to 8.7% in 2018-2019. Although high susceptibility rates were detected to piperacillin/tazobactam (TAZ), the geometric mean MICs were substantially higher than to meropenem (2.67 vs 0.08 µg/mL). By contrast, relatively low geometric mean MICs (0.397 µg/mL) were demonstrated for ceftolozane/TAZ. Although the MRSA incidence rate decreased from 72% in the first surveillance to 53% in the second, no further decrease was detected in 2018-2019. For the Bacteroides fragilis group species, low levels of susceptibility were observed for moxifloxacin (65.3%), cefoxitin (65.3%), and clindamycin (CLDM) (38.9%). In particular, low susceptibility against cefoxitin was demonstrated in non-fragilis Bacteroides, especially B. thetaiotaomicron. By contrast, low susceptibility rates against CLDM were demonstrated in both B. fragilis and non-fragilis Bacteroides species, and a steady decrease in susceptibility throughout was observed (59.3% in 2010, 46.9% in 2014-2015, and 38.9% in 2018-2019). In conclusion, Japanese surveillance data revealed no significant lowering of antibiotic susceptibility over the past decade in organisms commonly associated from SSIs, with the exception of the B. fragilis group.
Subject(s)
Bacteroides fragilis , Surgical Wound Infection , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Humans , Japan/epidemiology , Microbial Sensitivity Tests , Surgical Wound Infection/drug therapy , Surgical Wound Infection/epidemiologyABSTRACT
INTRODUCTION: This study aimed to investigate the in vitro effects of a combination of antimicrobials other than colistin (CL) and tigecycline (TGC) on carbapenem-resistant Enterobacteriaceae (CRE). METHODS: We used 72 CRE strains including 65 carbapenemase-producing Enterobacteriaceae (CPE) that produce IMP-1, IMP-6, NDM, KPC, and OXA-48-like carbapenemases; and 7 carbapenemase-nonproducing Enterobacteriaceae (non-CPE) strains. These strains were assessed using antimicrobial susceptibility testing, breakpoint checkerboard (BC) plate method, and kill curve experiment to determine the effect of the combination therapy. RESULTS: NDM, KPC, and OXA-48-like carbapenemase-producers showed higher MICs of carbapenem and aminoglycosides, and lower MICs of minocycline, compared to non-CPE and IMP-1/-6-producers. The results of the BC plate method suggested that the suitability of combinations of antimicrobials differ depending on the type of carbapenemases. Killing curve experiments demonstrated bactericidal or bacteriostatic action of the combination of antimicrobials even in sub-MIC concentrations of drugs. Our results suggest that the most effective antimicrobial combinations for each carbapenemase-producers are as follows; IMP-1 (tobramycin + tazobactam/piperacillin), IMP-6 (gentamicin + meropenem), NDM (minocycline + biapenem), KPC (arbekacin + doripenem) and OXA-48-like (minocycline + imipenem). CONCLUSION: These results suggest that the combination of antimicrobials other than CL and TGC may be another candidate for the treatments of CPE infections, even though we have to choose effective antimicrobial combinations depending on the type of carbapenemase.
Subject(s)
Anti-Infective Agents/pharmacology , Enterobacteriaceae Infections/drug therapy , Enterobacteriaceae/drug effects , Carbapenem-Resistant Enterobacteriaceae/drug effects , Colistin/therapeutic use , Drug Therapy, Combination , Humans , Microbial Sensitivity Tests , Tigecycline/therapeutic useABSTRACT
Ulcerative colitis (UC) is a representative intestinal chronic inflammatory disease whose incidence is rapidly increasing worldwide. It was previously shown that some specific probiotics help to guard against UC. In this study, we analyzed the effect of Lactococcus lactis subsp. lactis JCM5805 (L. lactis), which has been put to practical use as a probiotic, on the pathogenesis of UC using a dextran sulfate sodium-induced colitis mouse model. Survival rate, length, and histopathological parameters of the colon were elucidated. Further, the concentrations of inflammatory cytokines in serum were measured. As a result, the oral administration of high-dose L. lactis showed significant decreases in survival rate and colon length. Histopathological analysis showed that a bleeding appearance was observed in the L. lactis group, and the histology scores in the L. lactis group were significantly higher than those in the normal saline group. Furthermore, the levels of interferon gamma, tumor necrosis factor alpha, and interleukin-6 were significantly elevated in the L. lactis group. These results support that high-dose administration of L. lactis deteriorates intestinal inflammation and suggest that the careful selection of probiotics strains and administration dose is important for improving colitis including UC.
Subject(s)
Colitis, Ulcerative/pathology , Lactococcus lactis , Probiotics/administration & dosage , Probiotics/adverse effects , Animals , Colitis, Ulcerative/chemically induced , Colitis, Ulcerative/microbiology , Colon/immunology , Colon/pathology , Cytokines/blood , Dextran Sulfate , Disease Models, Animal , Female , Mice , Mice, Inbred C57BL , Survival AnalysisABSTRACT
INTRODUCTION: Streptococcus pneumoniae is a commensal bacterium of the human nasopharynx and a major causative pathogen of bacterial diseases worldwide. Pilus of S. pneumoniae is one of the virulence factors which enhance the adhesion to the host epitherial cells in the upper respiratory tract. METHODS: We analyzed the serotype distribution and presence of pilus genes, rrgC and sipA, among 785 S. pneumoniae isolates from specimens of patients with invasive or non-invasive disease in a regional Japanese hospital between October 2014 and August 2018. We next performed multilocus sequence typing and penicillin-resistant genotyping for 86 isolates of serotype 35B. RESULTS: Serotype 35B was the most frequent serotype which accounted for 11.0% of total isolates and had pilus genes at high rate (80.2%). Clonal complex (CC) 558 isolates accounted for 77.9% of serotype 35B and were highly positive for rrgC and gPRSP (98.5%). In contrast, all CC2755 isolates (19.8%) were rrgC-negative and gPISP. CONCLUSIONS: Our results suggest that CC558 may assist the prevalence of serotype 35B after the introduction of vaccines, as that clone has pili as adhesins in addition to non-susceptibility against penicillin. These results may be useful information for development of optimal preventive strategies. Continuous studies on serotype distribution and virulence factors of S. pneumoniae are necessary.