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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
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
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.
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COVID-19 , Influenza Humana , Orthomyxoviridae , Humanos , Influenza Humana/diagnóstico , SARS-CoV-2/genética , Técnicas de Diagnóstico MolecularRESUMO
BACKGROUND: This study investigated the diagnostic utility of the BioFire FilmArray Pneumonia Panel (PN panel), an automated and multiplexed nucleic acid detection system that rapidly detects 26 pathogens (18 bacteria and eight viruses) and seven antimicrobial resistance markers in a single assay. METHODS: We analyzed the targets in lower respiratory tract specimens using the PN panel and compared the detection results with those of bacterial culture methods and antimicrobial susceptibility testing. RESULTS: Of the 57 samples analyzed, the PN panel detected 97 targets (84 bacteria, four viruses, and nine antimicrobial resistance markers). Detection of bacteria and antimicrobial resistance was three times greater than that of the bacterial culture (25 bacteria and two resistant isolates) against the targets available in the panel. The overall positive and negative percent agreements between the PN panel and culture methods for bacterial detection were 100.0% and 92.9%, respectively. Multiple pathogens were detected by the PN panel in 24 samples (42.1%), ranging from two pathogens in 11 samples (19.3%) to six pathogens in one sample (1.8%). The PN panel semiquantitatively detected higher copies (≥ 106 copies/mL) of bacterial targets if the bacteria were positive by the culture method. In contrast, the semiquantitative values obtained by the panel varied (104 to 107 ≤ copies/mL) among bacteria that were negative by the culture method. CONCLUSIONS: The PN panel enhanced the detection of pathogens and antimicrobial resistance markers in lower respiratory tract specimens.
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Pneumonia , Infecções Respiratórias , Antibacterianos/farmacologia , Bactérias , Farmacorresistência Bacteriana , Humanos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase Multiplex , Sistema Respiratório , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/microbiologiaRESUMO
BACKGROUND: The plasmid-mediated bacterial colistin-resistant gene, mcr, is of global concern in clinical healthcare. However, there are few reports of surveillance for mcr in Japan. The aim of this study was to assess the prevalence of colistin resistance by identifying nine mcr genes in extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and carbapenem-resistant Enterobacteriaceae (CRE) isolates in Japan. METHODS: A total of 273 ESBL and CRE clinical isolates were collected from patients in five tertiary hospitals from August 2016 to March 2017. Minimum inhibitory concentration (MIC) of colistin was measured using the microdilution method. Polymerase chain reaction (PCR) was performed to detect mcr-1 to mcr-9 genes in all strains. Whole-genome sequencing (WGS) analysis was conducted for any mcr-genes identified that had not been previously reported in patients from Japan. RESULTS: The rate of colistin resistance was 7.7% in all strains, with a higher rate in the CRE strains than in the ESBL-producing strains (20.4% versus 1.1%). The mcr-5 and mcr-9 gene were detected in one ESBL-producing Escherichia coli strain (1/273, 0.37%) and three CRE strains (3/273, 1.1%), respectively. As the ESBL-producing E. coli strain was the first clinical strain with mcr-5 in Japan, WGS analysis was performed for the strain. The sequence type of the mcr-5-positive strain was ST1642 and it carried two distinct plasmids, ESBL gene-carrying pN-ES-6-1, and mcr-5.1-carrying pN-ES-6-2. CONCLUSIONS: The results of this study showed that the frequency of colistin resistance and mcr-positive strains is not high in Japan. As the MIC for colistin was low in the mcr-5.1 and mcr-9 gene-positive strain, continuous monitoring of mcr genes is necessary.
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Carbapenêmicos/análise , Colistina/análise , Farmacorresistência Bacteriana Múltipla/genética , Enterobacteriaceae/genética , Proteínas de Escherichia coli/genética , beta-Lactamases/genética , Proteínas de Escherichia coli/análise , Variação Genética , Genótipo , Humanos , Japão , Vigilância da População , beta-Lactamases/análiseRESUMO
This retrospective study evaluated stored nasopharyngeal swab samples from Japanese patients with influenza-like illness during the 2019/2020 season. We aimed to determine whether COVID-19 had spread in the community before the first confirmed case. The period of influenza season during 2019/2020 in Nagasaki was shorter than in previous influenza seasons. When the first COVID-19 case was reported in Nagasaki prefecture, the number of influenza cases were very low. No positive results for SARS-CoV-2 were detected in 182 samples that were obtained from adult outpatients. Our results revealed no large-scale spread of COVID-19 in the community before the first confirmed case.
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COVID-19/diagnóstico , COVID-19/epidemiologia , Teste de Ácido Nucleico para COVID-19 , Humanos , Influenza Humana/epidemiologia , Japão/epidemiologia , Estudos Retrospectivos , SARS-CoV-2/isolamento & purificaçãoRESUMO
We evaluated a novel transcription-reverse transcription concerted reaction (TRC) assay that can detect influenza A and B within 15 min using nasopharyngeal swab and gargle samples obtained from patients with influenza-like illness, between January and March 2018 and between January and March 2019. Based on the combined RT-PCR and sequencing results, in the nasal swabs, the sensitivity and specificity of TRC for detecting influenza were calculated as 1.000 and 1.000, respectively. In the gargle samples, the sensitivity and specificity of TRC were 0.946 and 1.000, respectively. The TRC assay showed comparable performance to RT-PCR in the detection of influenza viruses.
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Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/diagnóstico , Influenza Humana/virologia , Nasofaringe/virologia , Adulto , Idoso , Testes Diagnósticos de Rotina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
We investigated the efficiency of the Verigene Enteric Pathogens Nucleic Acid Test (Verigene EP test), which is an automated microarray-based assay system that enables rapid and simultaneous genetic detection of gastrointestinal pathogens and toxins, including those in the Campylobacter Group, Salmonella species, Shigella species, the Vibrio Group, Yersinia enterocolitica, Shiga toxin 1 and 2, norovirus GI/GII, and rotavirus A. Three clinical laboratories evaluated the Verigene EP test, using 268 stool samples for bacterial and toxin genes and 167 samples for viral genes. Culture-based reference methods were used for the detection of bacteria and toxins, while a different molecular assay was used for viral detection. The overall concordance rate between the Verigene EP test and the reference methods for the 1940 assays was 99.0%. The overall sensitivity and specificity of the Verigene EP test were 97.0% and 99.3%, respectively. Of the 19 samples with discordant results, 13 samples were false positives and six were false negatives. The Verigene EP test simultaneously detected two targets in 11 samples; overall, the test demonstrated high efficiency in detecting crucial diarrheagenic pathogens, indicating its suitability for clinical practice.
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Toxinas Bacterianas/isolamento & purificação , Diarreia/diagnóstico , Gastroenterite/microbiologia , Microbioma Gastrointestinal , Toxinas Bacterianas/genética , Diarreia/genética , Diarreia/microbiologia , Fezes/microbiologia , Gastroenterite/diagnóstico , Gastroenterite/genética , Humanos , Técnicas de Diagnóstico Molecular , Norovirus/genética , Norovirus/isolamento & purificação , Norovirus/patogenicidade , Técnicas de Amplificação de Ácido Nucleico/métodos , Toxina Shiga I/química , Toxina Shiga I/genética , Toxina Shiga I/isolamento & purificação , Shigella/genética , Shigella/isolamento & purificação , Shigella/patogenicidadeRESUMO
INTRODUCTION: Digital immunoassays (DIAs) and molecular point-of-care (POC) tests for influenza were recently developed. We aimed to evaluate and compare the positive rate with molecular POC tests and DIAs in detecting influenza virus A, B and respiratory syncytial virus (RSV). METHODS: A prospective observational study was conducted in 2019-2020. Nasopharyngeal swab samples were collected from adult outpatients with influenza-like illness who visited four hospitals and clinics in Japan. DIAs were performed at each facility. The clinical diagnosis was determined based on the findings of DIAs, history taking, and physical assessment. Molecular POC test and reverse transcription polymerase chain reaction (RT-PCR) were performed later. RESULTS: A total of 182 patients were evaluated. The positive rate for influenza virus with molecular POC test was significantly higher than that with DIAs (51.6% versus 40.7%, p = 0.046). In patients who tested positive for influenza virus with only molecular POC test, the presence of influenza virus was confirmed by RT-PCR. In a comparison between the patients who were positive for influenza virus with only molecular POC test and those with both molecular POC test and DIA, the percentage of patients who sought consultation within 18 h after the onset of symptoms was significantly higher in the molecular POC test only group than in the both methods group (70.0% versus 43.2%, p = 0.044). CONCLUSIONS: A molecular POC test could contribute to the accurate diagnosis of influenza in patients with influenza-like illness, especially those who visited a hospital immediately after the onset of symptoms.
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Vírus da Influenza A , Influenza Humana , Orthomyxoviridae , Infecções por Vírus Respiratório Sincicial , Adulto , Humanos , Imunoensaio , Vírus da Influenza A/genética , Vírus da Influenza B/genética , Influenza Humana/diagnóstico , Japão , Orthomyxoviridae/genética , Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Infecções por Vírus Respiratório Sincicial/diagnóstico , Sensibilidade e EspecificidadeRESUMO
This study investigated the molecular and phenotypic characteristics of carbapenemase-producing Klebsiella pneumoniae, and identified the risk factors underlying its acquisition. We evaluated K. pneumoniae isolated in Nagasaki University Hospital between January 2009 and June 2015. The presence of carbapenemase genes and plasmid characteristics were investigated. We performed multilocus sequence typing (MLST), and generated a dendrogram based on the results of pulsed-field gel electrophoresis (PFGE) for carbapenemase-producing strains. We also performed a case-control study of patients. Of the 88 K. pneumoniae strains that showed minimum inhibitory concentration ≥1 µg/mL for imipenem and/or meropenem, and that were available from our bacterial collection, 18 had the IMP-type carbapenemase gene, all of which were IMP-1 according to sequencing analysis. Strains included seven different sequence types (STs), of which the most common was ST1471. A dendrogram showed the significant similarity of some strains with relationships in PFGE patterns, STs, and the wards in which they were isolated. Plasmid incompatibility group was similar among the IMP-1 producers. Regarding risk factors, multivariate analysis showed that liver disease and previous uses of carbapenems and anti-fungal drugs were significant factors for the acquisition of IMP-1-producing strains. Our results demonstrate that IMP-1 is a major carbapenemase produced by K. pneumoniae. The PFGE results indicated the possibility of transmission in the hospital. The identified risk factors should be considered for appropriate antibiotic therapy and infection-control measures.
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Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Centros de Atenção Terciária/estatística & dados numéricos , Idoso , Antibacterianos/uso terapêutico , Técnicas de Tipagem Bacteriana/métodos , Carbapenêmicos/uso terapêutico , Estudos de Casos e Controles , Criança , Pré-Escolar , Farmacorresistência Bacteriana Múltipla/genética , Feminino , Humanos , Lactente , Controle de Infecções/métodos , Controle de Infecções/estatística & dados numéricos , Japão/epidemiologia , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/transmissão , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus/métodos , Estudos Retrospectivos , Fatores de Risco , beta-LactamasesRESUMO
Although viruses are the major pathogen that causes upper respiratory tract infection (URTI) and acute bronchitis, antibiotics have been prescribed. This was a prospective observational study in influenza epidemics that enrolled adult outpatients who visited a hospital with respiratory tract infection symptoms. In this study, we evaluated the usefulness of FilmArray respiratory panel (RP). Fifty patients were enrolled. FilmArray RP detected the pathogens in 28 patients. The common pathogens were influenza virus (n = 14), respiratory syncytial virus (n = 6), and human rhinovirus (n = 6). Of the 14 patients with influenza virus, 6 were negative for the antigen test. The physicians diagnosed and treated the patients without the result of FilmArray in this study. Of the patients with positive FilmArray RP, 9 were treated with antibiotics; however, bacteria were detected in only 3 patients. By implementing FilmArray RP, URTI and acute bronchitis would be precisely diagnosed, and inappropriate use of antibiotics can be reduced.
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Reação em Cadeia da Polimerase Multiplex/métodos , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/virologia , Doença Aguda/terapia , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Feminino , Humanos , Influenza Humana/diagnóstico , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/tratamento farmacológico , Infecções por Picornaviridae/virologia , Estudos Prospectivos , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/tratamento farmacológico , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/genética , Infecções Respiratórias/tratamento farmacológicoRESUMO
Phenotypic detection of extended-spectrum ß-lactamase (ESBL) is important for public health and infection control; however, plasmid-mediated AmpC ß-lactamases (pAmpCs) can interfere with the ESBL phenotyping. We focused on Enterobacteriaceae strains that were susceptible to cefepime but had a mildly elevated minimum inhibitory concentration (MIC) of ceftazidime and studied the effect of pAmpC on the ESBL phenotyping in this population. Genotyping of ESBL and pAmpC was performed on 528 clinical isolates of Escherichia coli, Klebsiella spp., and Proteus spp. with a ceftazidime MIC of ≥2 µg/mL and cefepime MIC≤8 µg/mL; these isolates were collected at Nagasaki University Hospital from January 2005 to March 2011. In this sample, 145 isolates (27.5%) tested positive for pAmpC (pAmpC group). The concordance rates of phenotypic and genotypic detection of ESBLs were 69.2% in the pAmpC group and 88.8% in the non-pAmpC group (P=0.04). pAmpC was more commonly detected in isolates with non-CTX-M genes (5/53, 9.4%) than in isolates with CTX-M genes (8/121, 6.6%). Our data suggest that the presence of pAmpC increases the false negative detection of ESBL. When ESBL phenotyping is used, the underestimation of the prevalence of ESBL producers should be taken into account.
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Antibacterianos/farmacologia , Ceftazidima/farmacologia , Cefalosporinas/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Resistência beta-Lactâmica , beta-Lactamases/análise , beta-Lactamases/genética , Cefepima , Erros de Diagnóstico , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/microbiologia , Genótipo , Humanos , Japão , Testes de Sensibilidade Microbiana/métodos , FenótipoRESUMO
The narrow-spectrum macrocyclic antibiotic fidaxomicin is approved for treatment of Clostridium difficile infection in many countries and is currently under evaluation in Japan for this indication. This study was conducted to evaluate the effects of fidaxomicin and its major metabolite, OP-1118, on Clostridium spp. isolated in Nagasaki University Hospital, Japan. Isolates were cultured and antimicrobial susceptibility analyses performed according to the Clinical Laboratory Standards Institute methods. Ninety-eight isolates were obtained between 2012 and 2015, 50 of C. difficile and 48 of eight other Clostridium spp. Fidaxomicin had the lowest minimum inhibitory concentration (MIC) of the antimicrobials tested against C. difficile, with MIC90 (MIC range) 0.12 µg/mL (0.015-0.25), versus vancomycin MIC90 0.5 µg/mL (0.5), metronidazole MIC90 0.5 µg/mL (0.12-0.5), and OP-1118 MIC90 4.0 µg/mL (0.5-4.0). Fidaxomicin and OP-1118 each had a similar spectrum of activity against the other Clostridium spp. C. butyricum and the 29 fidaxomicin- and OP-1118-susceptible C. perfringens isolates had the lowest MIC values, and C. bolteae and C. hathewayi higher. All the C. ramosum isolates (n = 6) and one of 30 C. perfringens isolates had low susceptibility to fidaxomicin and OP-1118 (i.e., MIC >64 µg/mL). In summary, this study showed that fidaxomicin was active against a number of Clostridium spp., including C. difficile. Fidaxomicin was generally more effective than its major metabolite OP-1118, but both showed a similar spectrum of activity, suggesting that OP-1118 contributes to the antimicrobial activity of fidaxomicin. These findings were broadly in accordance with those of similar studies conducted in other settings.
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Aminoglicosídeos/farmacologia , Anti-Infecciosos/farmacologia , Clostridium/efeitos dos fármacos , Aminoglicosídeos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Clostridium/classificação , Clostridium/isolamento & purificação , Infecções por Clostridium/tratamento farmacológico , Fidaxomicina , Humanos , Japão , Testes de Sensibilidade MicrobianaRESUMO
Laboratory underdiagnosis of toxigenic Clostridium difficile can lead to inappropriate management of C. difficile infection (CDI). A fully automated molecular test (FAMT), BD MAX, and enzyme immunoassays for C. difficile glutamate dehydrogenase (GDH) and for toxin A/B antigen test were evaluated using clinical specimens. Laboratory analysis of 231 fecal specimens from patients suspected with CDI, indicated that the sensitivity (Sn), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of FAMT was 98.1%, 98.9%, 96.3%, and 99.4%, while that of toxin A/B antigen was 52.8%, 100.0%, 100.0%, and 87.7%, respectively, compared to toxigenic culture. Sn, Sp, PPV, and NPV of GDH test compared to toxigenic culture was 92.5%, 94.4%, 83.1%, and 97.7%, respectively. FAMT can support the accurate laboratory diagnosis of toxigenic C. difficile and be an effective tool for appropriate treatment of CDI.
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Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Clostridioides difficile/metabolismo , Infecções por Clostridium/microbiologia , Enterotoxinas/metabolismo , Fezes/microbiologia , Feminino , Glutamato Desidrogenase/metabolismo , Humanos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
BD Phoenix™ is an automated bacterial identification and susceptibility testing system. Here, its performance in screening IMP-producing Enterobacteriaceae was evaluated. The system identified 97.8% of IMP producers as being nonsusceptible to imipenem or meropenem, which was higher than that identified by the broth microdilution method (91.3%, imipenem; 41.3%, meropenem).
Assuntos
Automação Laboratorial/métodos , DNA Bacteriano/genética , Enterobacter cloacae/isolamento & purificação , Infecções por Enterobacteriaceae/diagnóstico , Inosina Monofosfato/metabolismo , Klebsiella pneumoniae/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/metabolismo , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/enzimologia , Infecções por Enterobacteriaceae/microbiologia , Imipenem/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Meropeném/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
PURPOSE: Fluoroquinolone resistance (FQ-r) in extended-spectrum ß-lactamase (ESBL) producers is an urgent health concern in countries where ESBL-producing K. pneumoniae (ESBL-Kpn) is prevalent. We investigated FQ-r in Japan where ESBL-Kpn is less prevalent. METHODOLOGY: Clinical ESBL-Kpn isolates from 2011 to 2013 were collected in Nagasaki University Hospital. The ESBL genotypes included CTX-M-15, and the mechanisms of FQ-r through plasmid-mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining regions (QRDRs) were examined. Clonality was analysed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and multi-locus sequence typing was performed on selected isolates.Results/Key findings. Thirty ESBL-Kpn isolates, including seven levofloxacin-resistant isolates, were obtained from different patients. An increase in CTX-M-15-producing strains was observed during the study period (0/11 in 2011, 3/8 in 2012, and 5/11 in 2013). PMQR was detected in 53.3â% of the isolates and aac-(6')-Ib-cr was the most common (36.7â%). ST15 was observed in 60.0â% of the isolates, and for the most predominant ERIC-PCR profiles, 62.5â% of the isolates possessed the CTX-M-15 genotype and 71.4â% were levofloxacin-resistant. Levofloxacin-resistance was significantly more common in CTX-M-15 isolates (62.5â%) compared to non-CTX-M-15 isolates (9.1â%). Three QRDR mutations and aac(6')-Ib-cr, but not qnrB and qnrS, were significantly enriched in the CTX-M-15 isolates (100.0â%) compared to the non-CTX-M-15 isolates (13.6â%). CONCLUSION: Cumulatively, these results indicate that the epidemic strain, the CTX-M-15-producing K. pneumoniae ST15, is covertly spreading even when ESBL producers are not prevalent. Monitoring these epidemic strains and ESBLs in general is important for quickly identifying health crises and minimizing future risks from FQ-r ESBL-Kpn.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Fluoroquinolonas/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Centros de Atenção Terciária , beta-Lactamases/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Humanos , Japão , Klebsiella pneumoniae/enzimologia , Técnicas de Amplificação de Ácido Nucleico , beta-Lactamases/genéticaRESUMO
The Verigene®Clostridium difficile nucleic acid test (Verigene® CDF test) is an automatic and rapid detection system for the genes encoding tcdA, tcdB, binary toxin, and the single nucleotide deletion at base pair 117 in the tcdC based on microarray and PCR amplification. We compared the performance of the Verigene® CDF test to that of two enzyme immunoassays, C. DIFF QUIK CHEK COMPLETE and X/Pect Toxin A/B, using 118 specimens. We found overall concordance rates of 81.4% and 78.8% between C. DIFF QUIK CHEK COMPLETE and Verigene® CDF test, and X/Pect Toxin A/B and Verigene® CDF test. The Verigene® CDF test showed the highest sensitivity (93.9%) and had a specificity of 96.5%. The sensitivity and specificity were respectively 45.5 and 94.1% for C. DIFF QUIK CHEK COMPLETE and 27.3 and 100.0% for X/Pect Toxin A/B. These results indicated that the Verigene® CDF test was highly accurate for the detection of C. difficile toxin in fecal specimens and supported its use in daily diagnostic practice.
Assuntos
Toxinas Bacterianas/genética , Clostridioides difficile/genética , Ácidos Nucleicos/genética , Proteínas de Bactérias/genética , Técnicas Bacteriológicas/métodos , Enterocolite Pseudomembranosa/microbiologia , Enterotoxinas/genética , Fezes/microbiologia , Humanos , Técnicas Imunoenzimáticas/métodos , Reação em Cadeia da Polimerase/métodos , Sensibilidade e EspecificidadeRESUMO
Removal of pathogenic organisms from reprocessed surgical instruments is essential to prevent iatrogenic infections. Some bacteria can make persistent biofilms on medical devices. Contamination of non-disposable equipment with prions also represents a serious risk to surgical patients. Efficient disinfection of prions from endoscopes and other instruments such as high-resolution cameras remains problematic because these instruments do not tolerate aggressive chemical or heat treatments. Herein, we develop a new washing system that uses both the alkaline and acidic water produced by electrolysis. Electrolyzed acidic water, containing HCl and HOCl as active substances, has been reported to be an effective disinfectant. A 0.15% NaCl solution was electrolyzed and used immediately to wash bio-contaminated stainless steel model systems with alkaline water (pH 11.9) with sonication, and then with acidic water (pH 2.7) without sonication. Two bacterial species (Staphylococcus aureus and Pseudomonas aeruginosa) and a fungus (Candida albicans) were effectively removed or inactivated by the washing process. In addition, this process effectively removed or inactivated prions from the stainless steel surfaces. This washing system will be potentially useful for the disinfection of clinical devices such as neuroendoscopes because electrolyzed water is gentle to both patients and equipment and is environmentally sound.