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INTRODUCTION: The diagnostic tools of nucleic acid amplification tests and antigen tests have been extensively employed for the detection of Coronavirus disease 2019 (COVID-19). Although the reverse-transcriptase polymerase chain reaction (RT)-PCR test has high sensitivity and specificity, it is a time-consuming and labor-intensive process. On the other hand, antigen tests are simple and prompt, however, their low sensitivity and potential for false positives have been identified as limitations. In light of these factors, the development of novel tests that combine speed and clinical dependability is a promising prospect. METHODS: Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) excites chromophores by means of an enhanced electromagnetic field induced on a gold film surface. It enables the highly sensitive measurement of biomarkers in a short and simple 20-min window. In this study, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) SPFS-based antigen test targeting the SARS-CoV-2 nucleocapsid protein was performed and evaluated in 25 patients with COVID-19 and 10 non-infected controls. RESULTS: A positive correlation was observed between antigen levels determined by SPFS and RNA levels determined via RT-PCR. The sensitivity values were 100 %, 92 %, and 62.5 %; and the specificity values were 100 %, 90 %, and 100 %; for nasopharyngeal swabs, nasal swabs, and saliva specimens when the cutoff values were set to 65.1, 0.2, and 1.5 pg/mL, respectively. No clinically problematic cross-reactivity with analogous coronaviruses was observed. CONCLUSIONS: The SARS-CoV-2 SPFS antigen test showed excellent clinical diagnostic accuracy for nasopharyngeal and nasal swabs, with a rapid turnaround.
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This study aimed to investigate the bacterial characteristics of pneumococcal isolates obtained from a tertiary care hospital in Japan. We analyzed the antimicrobial susceptibility, possession of macrolide resistance genes, pneumococcal serogroup/serotype, and sequence type (ST) of pneumococcal isolates from patients aged 15 years or older between 2011 and 2020 at Nagasaki University Hospital. Of the 73 isolates analyzed, 86.3% showed resistance to macrolides, and 28.8%, 46.6%, and 11.0% harbored mefA, ermB, and both, respectively. Of the isolates possessing ermB, 97.6% showed high levels of macrolide resistance [minimal inhibitory concentration (MIC) range, > 16 µg/mL]. Solithromycin (MIC range, 0.03-0.25 µg/mL), regardless of the presence of macrolide resistance genes, and lascufloxacin (MIC range, 0.06-0.5 µg/mL) showed potent in vitro activity against pneumococci. Serotype 19A was the most prevalent (six isolates), followed by serotypes 10A, 15A, and 15B/C (five isolates each). Four serotypes (11A, 19A, 22F, and 23B) and five STs (36, 99, 433, 558, and 3111) were significantly correlated with the presence of macrolide resistance genes. All four isolates with serotype 11A/ST99 and three isolates with serotype 19A/ST3111 harbored both mefA and ermB. No macrolide resistance genes were detected in either of the two isolates with serotype 22F/ST433, while all ten isolates with serogroup 15 (serotypes 15A and 15B/C, five isolates each) possessed ermB alone. Our study revealed the bacterial characteristics of the pneumococcal isolates obtained from our hospital. In vitro activity of solithromycin and lascufloxacin against these isolates was confirmed.
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Antibacterianos , Farmacorresistência Bacteriana , Macrolídeos , Testes de Sensibilidade Microbiana , Infecções Pneumocócicas , Sorogrupo , Streptococcus pneumoniae , Centros de Atenção Terciária , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pneumoniae/classificação , Humanos , Infecções Pneumocócicas/microbiologia , Japão , Antibacterianos/farmacologia , Macrolídeos/farmacologia , Farmacorresistência Bacteriana/genética , Adulto Jovem , Adolescente , Fenótipo , Idoso , Pessoa de Meia-Idade , Adulto , Proteínas de Bactérias/genética , Feminino , Masculino , Metiltransferases/genética , Idoso de 80 Anos ou mais , População do Leste Asiático , Proteínas de MembranaRESUMO
INTRODUCTION: A clonal shift from staphylococcal cassette chromosome mec (SCCmec) type II/ST5 methicillin-resistant Staphylococcus aureus (MRSA) to SCCmec type IV/clonal complex (CC)1 MRSA has occurred rapidly in Japan. Our previous research in a geriatric hospital found SCCmec type IV/CC1 MRSA prevalence in long-term care wards. Due to intensive personal care requirements, frequent contact with healthcare providers can potentially cause unintentional nosocomial MRSA transmission. We performed polymerase chain reaction-based open reading frame typing (POT) and core genome multilocus sequence typing (cgMLST) to investigate the occurrence of nosocomial transmission and to compare the results of these methods. METHODS: POT and whole genome sequencing were performed in 83 MRSA isolates. Commercial automated software (Ridom SeqSphere+) was used to perform cgMLST. MRSA isolates with 0-8 allelic differences were considered related, and medical records were consulted in these cases. RESULTS: SCCmec type IV/CC1 MRSA was the most frequently detected clone (n = 56, 67.5 %), which was divided into 14 POT types, followed by SCCmec type I/ST8 (n = 9) and SCCmec type IV/ST8 (n = 8). Identical POT types were found across 7 of 11 wards. However, cgMLST analysis identified only three cases (six strains) of high genetic similarity, indicating nosocomial transmission; only one involved SCCmec type IV/CC1 (two strains). The mean allelic difference in the core genomes between strains with identical POT types in the same ward was 55.3 ± 22.0. CONCLUSIONS: The cgMLST method proved more effective for identifying nosocomial transmissions compared to POT, highlighting its utility in tracking MRSA spread in healthcare settings.
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PURPOSE: Despite the importance of abscess lesions in clinical decisions regarding anaerobic bacteremia (AB), their impact on clinical characteristics remains unclear. Herein, we aimed to elucidate the clinical factors associated with AB that were unaccompanied by detectable abscess lesions during the initial phase of infection. METHODS: This was a multicenter retrospective observational study involving patients with culture-proven AB at six tertiary hospitals in Japan between January 2012 and March 2022. Data on clinical characteristics, laboratory and radiological findings were collected, and their associations with the absence of detectable abscess lesions were analyzed. RESULTS: In total, 393 participants were included. Abscess lesions were absent in 42.7% of the entire cohort and detectable in the remaining patients. No differences were identified in the malignancy, severity, or 30-day mortality between patients with and without detectable abscess lesions. Multivariate logistic regression analysis adjusted for age and the modified Charlson comorbidity score revealed that the immunosuppressive status (febrile neutropenia or corticosteroid use), C-reactive protein (CRP) level ≤9.8 mg/dL at onset, and the presence of gram-positive anaerobic rods (GPARs) were independently associated with AB unaccompanied by detectable abscess lesions [odds ratios (ORs) 3.24, 3.00, and 2.81, respectively; p < 0.05]. CONCLUSION: This study elucidated distinctive clinical and microbiological characteristics of AB unaccompanied by detectable abscess lesions, with relatively lower CRP elevation, immunosuppressive status, and GPARs as the causative anaerobes.
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Candida vulturna is a recently discovered and not widely documented ascomycetous yeast phylogenetically related to the outbreak-causing and multidrug-resistant Candida auris. A middle-aged Japanese man with no discernible immunodeficiency was admitted to hospital with ileal diverticulitis. Following laparoscopic right hemicolectomy against abscess formation on postoperative day (POD) 7, continuous fungemia occurred due to Candida haemulonii, identified using a conventional method by confirming the biochemical phenotype. Micafungin was initiated; however, the fungus was persistently isolated from blood cultures. Eventually, the antifungal agent was changed to a combination of liposomal amphotericin B (L-AMB) and caspofungin (CPFG), which cleared the infection, and no pathogens were detected in the blood cultures on POD 31. Contrast-enhanced computed tomography showed septic emboli in the lungs and spleen; however, no evidence of vasculitis was observed. Moreover, sequential echocardiography did not reveal any signs of infectious endocarditis. Finally, CPFG and L-AMB were administered to the patient for 7 and 9 weeks, respectively, during which the patient's symptoms did not relapse. The strain was later genetically identified as C. vulturna. This case report illustrates a clinical presentation of C. vulturna and provides the diagnostic approach and treatment methods for this pathogen.
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INTRODUCTION: As well as preventing nosocomial and healthcare-associated infections, a reliable and eco-friendly washer for medical equipment would also be safe for the global environment. The aim of this study was to evaluate the efficacy of a newly developed automatic washing system (Nano-washer) that uses electrolyzed water and ultrasonication without detergent for washing endoscopes. METHODS: Patients who underwent laparoscopic lobectomy or laparoscopic colectomy at Nagasaki University between 2018 and 2022 were included. A total of 60 cases of endoscope use were collected and classified according to endoscope washing method into the Nano-washer group (using no detergent) (n = 40) and the manual washing group (n = 20). Protein and bacterial residues were measured before and after washing, using absorbance spectrometry and 16S rRNA polymerase chain reaction. The effectiveness of protein and bacterial removal and endoscope surface damage after washing were compared under specular vision between the groups. RESULTS: Nano-washer did not use detergent unlike manual washing. There was no difference in demographic or clinical characteristics between the groups except for the presence of comorbidities in the lobectomy group (Nano-washer, 85%; manual washing, 40%, P = .031). Compared with the manual washing group, residual protein levels in the Nano-washer group were significantly reduced after washing (lobectomy, 0.956 mg/mL vs 0.016 mg/mL, P < .001; colectomy, 0.144 mg/mL vs 0.002 mg/mL, P = .008). Nano-washer group showed a significant reduction in bacteria between before and after lobectomy (9437 copies/cm2 vs 4612 copies/cm2 , P = .024). CONCLUSION: Nano-washer is a promising, effective, and eco-friendly automatic washing device that is safer and more efficient than manual washing.
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Detergentes , Desinfecção , Humanos , Desinfecção/métodos , Estudos de Viabilidade , RNA Ribossômico 16S , Contaminação de Equipamentos/prevenção & controle , Endoscópios/microbiologiaRESUMO
Saliva is a key component of mucosal immunity, which protects the oral cavity from viral infections. However, salivary immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in terms of immunoglobulin dynamics and recognition, have not been investigated sufficiently. In this study, saliva samples were collected from individuals that received SARS-CoV-2 vaccine, and immunoglobulin G (IgG), IgM, and IgA against whole spike protein and S1 protein were measured. IgA against whole spike protein increased significantly following vaccination, while IgA against S1 protein did not. Of note, the IgA response was evident two weeks after the first vaccine dose and continued to rise thereafter. On the contrary, IgG antibodies against S1 increased significantly at four weeks after vaccination. These results reveal the dynamics and recognition antigens of immunoglobulins in saliva, indicating the function of IgA in the mucosal immune system. These findings may pave the way for further studies on mucosal immune response induced by vaccination.
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Vacinas contra COVID-19 , COVID-19 , Humanos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , COVID-19/prevenção & controle , Vacinação , Imunoglobulina G , Imunoglobulina A , Anticorpos AntiviraisRESUMO
BACKGROUND: A test-based strategy against coronavirus disease 2019 (COVID-19) is one of the measures to assess the need for isolation and prevention of infection. However, testing with high sensitivity methods, such as quantitative RT-PCR, leads to unnecessary isolation, whereas the lateral flow antigen test shows low sensitivity and false negative results. The purpose of this study was to evaluate the performance of the LumiraDx SARS-CoV-2 Ag test (Lumira Ag), a rapid microfluidic immunofluorescence method, in assessing infectivity. METHODS: This study was performed from March 2022 to July 2022. A pair of nasopharyngeal swab samples were obtained from each patient with mild COVID-19. One swab was used for Lumira Ag testing, and the other for quantitative RT-PCR testing and virus culture. RESULTS: A total of 84 patients were included in the study. Among them, PCR, Lumira Ag test, and virus culture indicated positivity for 82, 66, and 24 patients, respectively. When comparing the Lumira Ag test to virus culture, its sensitivity was 100.0% (24/24), specificity, 30.0% (18/60); positive predictive value, 36.3% (24/66); and negative predictive value (NPV), 100.0% (18/18). The positive sample for virus culture was observed until the ninth day from the onset of symptoms, while the Lumira Ag test was observed until day 11. CONCLUSIONS: The Lumira Ag test showed high sensitivity and NPV (100% each) compared to virus culture. A test-based strategy using the Lumira Ag test can effectively exclude COVID-19 infectiousness.
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COVID-19 , Microfluídica , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Imunofluorescência , Testes Imunológicos , Sensibilidade e Especificidade , Antígenos ViraisRESUMO
BACKGROUND: Current microbiological tests fail to identify the causative microorganism in more than half of all pneumonia cases. We explored biomarkers that could be used for differentiating between bacterial and viral pneumonia in patients with community-acquired pneumonia (CAP). METHODS: In this prospective cohort study conducted in Japan, data obtained from adult patients with bacterial pneumonia, including bacterial and viral coinfections (bacterial pneumonia [BP] group), and purely viral pneumonia (VP group) at diagnosis were analyzed using multivariate logistic regression analysis to identify predictors of bacterial pneumonia. Furthermore, a decision tree was developed using the predictors. RESULTS: A total of 210 patients were analyzed. The BP and VP groups comprised 108 and 18 patients, respectively. The other 84 patients had no identified causative microorganism. The two groups shared similar characteristics, including disease severity; however, a significant difference (p < 0.05) was observed between the two groups regarding sputum type; sputum volume score; neutrophil counts; and serum levels of interleukin (IL)-8, IL-10, and α1-antitrypsin (AAT). Sputum volume score (p < 0.001), IL-10 (p < 0.001), and AAT (p = 0.008) were ultimately identified as predictors of BP. The area under the curve for these three variables on the receiver operating characteristic (ROC) curve was 0.927 (95% confidence interval [CI]: 0.881-0.974). The ROC curve for sputum volume score and an AAT/IL-10 ratio showed a diagnostic cutoff of 1 + and 65, respectively. Logistic regression analysis using dichotomized variables at the cutoff values showed that the odds ratios for the diagnosis of BP were 10.4 (95% CI: 2.2-50.2) for sputum volume score (absence vs. presence) and 19.8 (95% CI: 4.7-83.2) for AAT/IL-10 ratio (< 65 vs. ≥ 65). CONCLUSIONS: Considering that obtaining a definitive etiologic diagnosis with the current testing methods is difficult and time consuming, a decision tree with two predictors, namely sputum volume and the AAT/IL-10 ratio, can be useful in predicting BP among patients diagnosed with CAP and facilitating the appropriate use of antibiotics. TRIAL REGISTRATION: UMIN000034673 registered on November 29, 2018.
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AIM: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial infection-causing pathogen. The clonal shift from staphylococcal cassette chromosome mec (SCCmec) type II MRSA to SCCmec type IV MRSA has occurred rapidly in acute-care hospitals. However, the epidemiology and clinical impacts of MRSA in geriatric hospitals are poorly documented. We performed a molecular epidemiological analysis of the clinical isolates and retrospectively investigated the clinical characteristics of SCCmec type IV MRSA in elderly individuals. METHODS: MRSA isolates were grouped according to the SCCmec type and virulence genes (tst, sea, seb, sec, and lukS/F-PV), and multi-locus sequence typing (MLST) was performed. RESULTS: Of the 145 MRSA isolates obtained from patients with a median age of 85 years, 100 (69.0%) were obtained from sputum samples, 22 (15.2%) from skin and soft tissues, and seven (4.8%) from blood samples. The most prevalent clone was SCCmec type IV/clonal complex (CC)1/sea+ (59.3%), followed by SCCmec type I/sequence type (ST) 8 (17.3%). Of the 17 (11.7%) strains to which an anti-MRSA drug was administered by a physician, only three were SCCmec type IV/CC1/sea+ (17.6%) and five were SCCmec type I/ST8 (29.4%). SCCmec type IV/CC1/sea+ MRSA was more frequently isolated in long-term care wards than were SCCmec type I/ST8 strains (odds ratio: 2.85, 95% confidence interval: 1.08-7.54) and was less frequently treated as the cause of MRSA infections (odds ratio: 0.15, 95% confidence interval: 0.03-0.73). CONCLUSIONS: SCCmec type IV/CC1/sea+ MRSA was the predominant clone and could be easily transmissible and be capable of colonization. Geriatr Gerontol Int 2023; 23: 744-749.
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BACKGROUND: 5-aminolevulinic acid (5-ALA), a natural amino acid that is marketed alongside sodium ferrous citrate (SFC) as a functional food, blocks severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proliferation in vitro and exerts anti-inflammatory effects. In this phase II open-label, prospective, parallel-group, randomized trial, we aimed to evaluate the safety and efficacy of 5-ALA in patients with mild-to-moderate coronavirus disease 2019. METHODS: This trial was conducted in patients receiving 5-ALA/SFC (250/145 mg) orally thrice daily for 7 days, followed by 5-ALA/SFC (150/87 mg) orally thrice daily for 7 days. The primary endpoints were changes in SARS-CoV-2 viral load, clinical symptom scores, and 5-ALA/SFC safety (adverse events [AE] and changes in laboratory values and vital signs). RESULTS: A total of 50 patients were enrolled from 8 institutions in Japan. The change in SARS-CoV-2 viral load from baseline was not significantly different between the 5-ALA/SFC (n = 24) and control (n = 26) groups. The duration to improvement was shorter in the 5-ALA/SFC group than in the control group, although the difference was not significant. The 5-ALA/SFC group exhibited faster improvement rates in "taste abnormality," "cough," "lethargy," and "no appetite" than the control group. Eight AEs were observed in the 5-ALA/SFC group, with 22.7% of patients experiencing gastrointestinal symptoms (decreased appetite, constipation, and vomiting). AEs occurred with 750/435 mg/day in 25.0% of patients in the first phase and with 450/261 mg/day of 5-ALA/SFC in 6.3% of patients in the second phase. CONCLUSION: 5-ALA/SFC improved some symptoms but did not influence the SARS-CoV-2 viral load or clinical symptom scores over 14 days. The safety of 5-ALA/SFC in this study was acceptable. Further evaluation using a larger sample size or modified method is warranted.
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Ácido Aminolevulínico , COVID-19 , Humanos , Ferro , Fosfatos , Estudos Prospectivos , SARS-CoV-2RESUMO
Neutrophils are an essential cellular component of innate immunity and control bacterial infections through a combination of intracellular and extracellular killing methods. Although the importance of neutrophils has been established, the exact methods used to handle particular bacterial challenges and the efficiency of bacterial killing remain not well understood. In this study, we addressed how neutrophils eliminate Streptococcus pneumoniae (Spn), a leading cause of community acquired and post-influenza bacterial pneumonia. We analyzed killing methods with variable bacterial:neutrophil concentrations and following priming with PAM3CSK4 (P3CSK), an agonist for Toll-like-receptor 2 (TLR2). Our results show that murine neutrophils display surprisingly weak bactericidal activity against Spn, employing a predominantly extracellular mode of killing at lower concentrations of bacteria, whereas challenges with higher bacterial numbers induce both extracellular and intracellular elimination modes but require TLR2 activation. TLR2 activation increased reactive oxygen species (ROS) and neutrophil extracellular trap (NET) formation in response to Spn. Despite this, supernatants from P3CSK-stimulated neutrophils failed to independently alter bacterial replication. Our study reveals that unstimulated neutrophils are capable of eliminating bacteria only at lower concentrations via extracellular killing methods, whereas TLR2 activation primes neutrophil-mediated killing using both intracellular and extracellular methods under higher bacterial burdens.
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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 ß-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, blaCTX-M group 9 was the major subgroup in E. coli (77.3%), and blaCTX-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.
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Background: Extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) is a great public health concern globally not only in hospitals but also in the community. To our knowledge, there have been few studies on the prevalence of ESBL-E and much less about carbapenem-resistant Enterobacterales (CRE) among children in the community, and there is no such study in Japan despite such situations. This study aimed to clarify their carriage status among Japanese infants in the community by taking the opportunity of the 4-month health checkup. Methods: This prospective analysis was conducted from April 2020 to March 2021 in Shimabara City, Nagasaki Prefecture, Japan. The research-related items were mailed to all subjects with official documents for the checkup. The fecal samples were obtained from the diaper by guardians beforehand and were collected with the questionnaire and then screened for ESBL-E and CRE by a clinical laboratory company with selective agars followed by identification and confirmation. Only the positive samples were analyzed about resistant genotypes. Results: One hundred fifty infants aged 4-5 months, over half of the subjects, participated in this study. The overall ESBL-E carriage rate was 19.3% (n = 29), and no CRE carrier was detected among them. All identified ESBL-E were E. coli except for one K. pneumoniae. A significantly higher carriage rate was recorded among the infants born at "Hospital A" (25.0%) than the others (11.3%). Enterobacterales producing CTX-M-9 ± TEM were broadly distributed among the positive samples (65.5%), whereas the CTX-M-1 group was exclusively detected among those from "Hospital A". Recursive partitioning analysis suggested that delivery facilities might be an important factor for ESBL-E colonization, although the effect could be decreased as they grow. In contrast, no significant effect was observed for other factors such as parent(s) as healthcare worker(s), having a sibling(s), and the mode of delivery. Conclusion: This study revealed the ESBL-E and CRE carriage status of Japanese infants in the community for the first time, although the setting is somewhat limited. Our findings indicated that environmental factors, especially delivery facilities, influenced ESBL-E colonization among infants aged 4-5 months, implying the need for strengthening countermeasures against antimicrobial resistance at delivery facilities and communities outside the hospitals.
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Portador Sadio , Farmacorresistência Bacteriana Múltipla , Escherichia coli , Humanos , Lactente , beta-Lactamases/genética , Carbapenêmicos/farmacologia , População do Leste Asiático , Fezes , Klebsiella pneumoniae , Portador Sadio/epidemiologiaRESUMO
BD Phoenix CPO Detect panels can identify and classify carbapenemase-producing organisms (CPOs) simultaneously with antimicrobial susceptibility testing (AST) for Gram-negative bacteria. Detection and classification of carbapenemase producers were performed using the BD Phoenix CPO Detect panels NMIC/ID-441 for Enterobacterales, NMIC/ID-442 for nonfermenting bacteria, and NMIC-440 for both. The results were compared with those obtained using comparator methods. A total of 133 strains (32 Klebsiella pneumoniae, 37 Enterobacter cloacae complex, 33 Pseudomonas aeruginosa, and 31 Acinetobacter baumannii complex strains), including 60 carbapenemase producers (54 imipenemases [IMPs] and 6 OXA type), were analyzed. Using panels NMIC-440 and NMIC/ID-441 or NMIC/ID-442, all 54 IMP producers were accurately identified as CPOs (positive percent agreement [PPA], 100.0%; 54/54). Among the 54 IMP producers identified as CPOs using panels NMIC-440 and NMIC/ID-441, 12 and 14 Enterobacterales were not resistant to carbapenem, respectively. Among all 54 IMP producers, 48 (88.9%; 48/54) were correctly classified as Ambler class B using panel NMIC-440. Using panels NMIC-440 and NMIC/ID-442, all four OXA-23-like carbapenemase-producing A. baumannii complex strains (100.0%, 4/4) were correctly identified as CPOs, and three (75.0%, 3/4) were precisely classified as class D using panel NMIC-440. Both carbapenemase producers harboring the blaISAba1-OXA-51-like gene were incorrectly identified as non-CPOs using panels NMIC-440 and NMIC/ID-442. For detecting carbapenemase producers, the overall PPA and negative percent agreement (NPA) between panel NMIC-440 and the comparator methods were 96.7% (58/60) and 71.2% (52/73), respectively, and the PPA and NPA between panels NMIC/ID-441 or NMIC/ID-442 and the comparator methods were 96.7% (58/60) and 74.0% (54/73), respectively. BD Phoenix CPO Detect panels can successfully screen carbapenemase producers, particularly IMP producers, regardless of the presence of carbapenem resistance and can be beneficial in routine AST workflows. IMPORTANCE Simple and efficient screening methods of detecting carbapenemase producers are required. BD Phoenix CPO Detect panels effectively screened carbapenemase producers, particularly IMP producers, with a high overall PPA. As the panels enable automatic screening for carbapenemase producers simultaneously with AST, the workflow from AST to confirmatory testing for carbapenemase production can be shortened. In addition, because carbapenem resistance varies among carbapenemase producers, the BD Phoenix CPO Detect panels, which can screen carbapenemase producers regardless of carbapenem susceptibility, can contribute to the accurate detection of carbapenemase producers. Our results report that these panels can help streamline the AST workflow before confirmatory testing for carbapenemase production in routine microbiological tests.
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Enterobacteriáceas Resistentes a Carbapenêmicos , Técnicas Microbiológicas , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Testes de Sensibilidade Microbiana , Enterobacteriáceas Resistentes a Carbapenêmicos/classificação , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/normas , Reprodutibilidade dos Testes , Especificidade da EspécieRESUMO
We investigated the clinical features of bloodstream infections (BSIs) caused by Klebsiella pneumoniae harboring rmpA and molecular characteristics of the bacteria. We retrospectively investigated adult patients with K. pneumoniae BSI from January 2010 to March 2021 at Nagasaki University Hospital. A matched case-control study in a 1:3 ratio was conducted to clarify the clinical and bacterial characteristics of BSI caused by rmpA-positive K. pneumoniae compared with those caused by rmpA-negative isolates. Antimicrobial susceptibility testing and multilocus sequence typing (MLST) were performed for rmpA-positive isolates. The rmpA was detected in 36 (13.4%) of the 268 isolates. Of these 36 isolates, 31 (86.1%) harbored iucA and 35 (97.2%) each possessed peg-344 and iroB; capsular types were identified as K1 in 9 (25.0%) and K2 in 10 isolates (27.8%). Contrarily, of the 108 rmpA-negative isolates, which were matched for case-control studies, 5 isolates (4.6%) harbored iucA and 1 (0.9%) each possessed peg-344 and iroB; 2 (1.9%) and 3 isolates (2.8%) had K1 and K2 capsular types, respectively. Among the rmpA-positive isolates, ST23/K1 (eight isolates) was the most frequent, followed by ST412/non-K1/K2 (seven isolates), ST86/K2 (five isolates), and ST268/non-K1/K2 (four isolates). In a multivariate analysis using clinical factors, liver abscess positively correlated with rmpA-positive isolates, whereas biliary tract infection and use of anticancer drugs negatively correlated with rmpA-positive isolates in patients with K. pneumoniae BSI. Considering the correlation between rmpA-positive isolates and clinical features, rmpA can be used as a marker for understanding the pathophysiology of K. pneumoniae BSI.
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Bacteriemia , Proteínas de Bactérias , Infecções por Klebsiella , Klebsiella pneumoniae , Adulto , Humanos , Bacteriemia/diagnóstico , Bacteriemia/genética , Bacteriemia/microbiologia , Bacteriemia/fisiopatologia , Proteínas de Bactérias/sangue , Proteínas de Bactérias/genética , Estudos de Casos e Controles , População do Leste Asiático , Japão , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/patogenicidade , Tipagem de Sequências Multilocus , Estudos Retrospectivos , Sepse/diagnóstico , Sepse/genética , Sepse/microbiologia , Sepse/fisiopatologia , Fatores de Virulência/genética , Fatores de Virulência/isolamento & purificaçãoRESUMO
The IgG antibody titer against SARS-CoV-2 receptor binding protein (RBD) after mRNA vaccine were compared between those with and without previous infection (PI) for up to 48 weeks. Though sustained higher IgG-RBD were observed in the PI group after two doses of vaccines, both groups benefited from the booster shots of the third vaccine. This data supports the necessity of the booster shots to those with PI.
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INTRODUCTION: We investigated the performance of the cobas® 6800 system and cobas SARS-CoV-2 & Influenza A/B, a fully automated molecular testing system for influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This enabled an assay in a batch of 96 samples in approximately 3 h. METHODS: An assay was performed using the cobas SARS-CoV-2 & Influenza A/B on the cobas 6800 system for samples collected in four facilities between November 2019 and March 2020 in our previous study. The results were compared with those obtained using the reference methods. RESULTS: Of the 127 samples analyzed, the cobas SARS-CoV-2 & Influenza A/B detected influenza A virus in 75 samples, of which 73 were positive using the reference methods. No false negative results were observed. The overall positive and negative percent agreement for influenza A virus detection were 100.0% and 96.3%, respectively. There were no positive results for the influenza B virus or SARS-CoV-2. CONCLUSION: The cobas 6800 system and cobas SARS-CoV-2 & Influenza A/B showed high accuracy for influenza A virus detection and can be useful for clinical laboratories, especially those that routinely assay many samples.
Assuntos
COVID-19 , Influenza Humana , Orthomyxoviridae , Humanos , Influenza Humana/diagnóstico , SARS-CoV-2/genética , Técnicas de Diagnóstico MolecularRESUMO
Blood culture, a method for identifying causative agents of bacterial sepsis, requires several days. The combination of cell-direct polymerase chain reaction and nucleic acid lateral flow immunoassay (cdPCR-NALFIA) is a simple and sensitive detection method for identifying pathogenic bacteria. Furthermore, this assay, when applied directly to blood samples yields results within 4.5 h, without requiring culture. This study was performed at five hospitals in Japan between 2013 and 2016. Blood samples from 73 patients with clinically suspected sepsis yielded 18 positive blood cultures, and the isolated bacterial species were detectable using cdPCR-NALFIA in nine samples. Thirteen samples were positive on cdPCR-NALFIA. In total, 17 samples confirmed to have bacterial species were detectable using cdPCR-NALFIA and/or blood culture with a true positive rate of 76.5% and 64.7%, respectively. The combination of blood culture and cdPCR-NALFIA could improve the rate of detection of bacterial sepsis.