RESUMEN
BACKGROUND: Inappropriate use of antibiotics not only increases antibiotic resistance as collateral damage but also increases clinical failure rates and medical costs. The purpose of this study was to determine the relationship between the appropriateness of antibiotic prescription and outcomes of community-acquired acute pyelonephritis (CA-APN). METHODS: A multicenter prospective cohort study was conducted at eight hospitals in Korea between September 2017 and August 2018. All hospitalized patients aged ≥ 19 years who were diagnosed with CA-APN on admission were recruited. The appropriateness of empirical and definitive antibiotics, as well as the appropriateness of antibiotic treatment duration and route of administration, was evaluated in accordance with the guideline and expert opinions. Clinical outcomes and medical costs were compared between patients who were administered antibiotics 'appropriately' and 'inappropriately.' RESULTS: A total of 397 and 318 patients were eligible for the analysis of the appropriateness of empirical and definitive antibiotics, respectively. Of them, 10 (2.5%) and 18 (5.7%) were administered 'inappropriately' empirical and definitive antibiotics, respectively. Of the 119 patients whose use of both empirical and definitive antibiotics was classified as 'optimal,' 57 (47.9%) received antibiotics over a longer duration than that recommended; 67 (56.3%) did not change to oral antibiotics on day 7 of hospitalization, even after stabilization of the clinical symptoms. Patients who were administered empirical antibiotics 'appropriately' had shorter hospitalization days (8 vs. 10 days, P = 0.001) and lower medical costs (2381.9 vs. 3235.9 USD, P = 0.002) than those who were administered them 'inappropriately.' Similar findings were observed for patients administered both empirical and definitive antibiotics 'appropriately' and those administered either empirical or definitive antibiotics 'inappropriately'. CONCLUSIONS: Appropriate use of antibiotics leads to better outcomes, including reduced hospitalization duration and medical costs.
Asunto(s)
Pielonefritis , Antibacterianos/uso terapéutico , Farmacorresistencia Microbiana , Hospitalización , Humanos , Estudios Prospectivos , Pielonefritis/tratamiento farmacológicoRESUMEN
BACKGROUND: Community-acquired acute pyelonephritis (CA-APN) is relatively rare in men. This study aimed to compare the clinical characteristics of CA-APN between male and female patients. METHODS: We prospectively collected the clinical and microbiological data of hospitalized CA-APN patients aged ≥19 years in South Korea from March 2010 to February 2011 in 11 hospitals and from September 2017 to August 2018 in 8 hospitals. Only the first episodes of APN of each patient during the study period were included. RESULTS: From 2010 to 2011, 573 patients from 11 hospitals were recruited, and from 2017 to 2018, 340 patients were recruited from 8 hospitals. Among them, 5.9% (54/913) were male. Male patients were older (66.0 ± 15.2 vs. 55.3 ± 19.0 years, P < 0.001), had a higher Charlson comorbidity index (1.3 ± 1.5 vs. 0.7 ± 1.2, P = 0.027), and had a higher proportion of structural problems in the urinary tract (40.7% vs. 6.1%, P < 0.001) than female patients. Moreover, the total duration of antibiotic treatment was longer (21.8 ± 17.8 d vs. 17.3 ± 9.4 d, P = 0.001) and the proportion of carbapenem usage was higher (24.1% vs. 9.5%, P = 0.001) in men than in women. Male patients were hospitalized for longer durations than female patients (median, 10 d vs. 7 d, P < 0.001). CONCLUSIONS: Male CA-APN patients were older and had more comorbidities than female CA-APN patients. In addition, male patients received antibiotic treatment for a longer duration than female patients.
Asunto(s)
Infecciones Comunitarias Adquiridas , Pielonefritis , Enfermedad Aguda , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/epidemiología , Femenino , Humanos , Masculino , Pielonefritis/tratamiento farmacológico , Pielonefritis/epidemiología , República de Corea/epidemiología , Estudios Retrospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Cholecystitis is an important risk factor for gallbladder cancer, but the bile microbiome and its association with gallbladder disease has not been investigated fully. We aimed to analyze the bile microbiome in normal conditions, chronic cholecystitis, and gallbladder cancer, and to identify candidate bacteria that play an important role in gallbladder carcinogenesis. METHODS: We performed metagenome sequencing on bile samples of 10 healthy individuals, 10 patients with chronic cholecystitis, and 5 patients with gallbladder cancer, and compared the clinical, radiological, and pathological characteristics of the participants. RESULTS: No significant bacterial signal was identified in the normal bile. The predominant dysbiotic bacteria in both chronic cholecystitis and gallbladder cancer were those belonging to the Enterobacteriaceae family. Klebsiella increased significantly in the order of normal, chronic cholecystitis, and gallbladder cancer. Patients with chronic cholecystitis and dysbiotic microbiome patterns had larger gallstones and showed marked epithelial atypia, which are considered as precancerous conditions. CONCLUSION: We investigated the bile microbiome in normal, chronic cholecystitis, and gallbladder cancer. We suggest possible roles of Enterobacteriaceae, including Klebsiella, in gallbladder carcinogenesis. Our findings reveal a possible link between a dysbiotic bile microbiome and the development of chronic calculous cholecystitis and gallbladder cancer.
Asunto(s)
Bacterias/aislamiento & purificación , Bilis/metabolismo , Bilis/microbiología , Disbiosis/microbiología , Enfermedades de la Vesícula Biliar/microbiología , Neoplasias de la Vesícula Biliar/microbiología , Vesícula Biliar/microbiología , Adulto , Bacterias/clasificación , Estudios de Casos y Controles , Colecistitis/microbiología , Colecistitis/patología , Humanos , Metagenómica , Microbiota , Persona de Mediana Edad , FilogeniaRESUMEN
Understanding the interactions between nanoparticles (NPs) and human immune cells is necessary for justifying their utilization in consumer products and biomedical applications. However, conventional assays may be insufficient in describing the complexity and heterogeneity of cell-NP interactions. Herein, mass cytometry and single-cell RNA-sequencing (scRNA-seq) are complementarily used to investigate the heterogeneous interactions between silver nanoparticles (AgNPs) and primary immune cells. Mass cytometry reveals the heterogeneous biodistribution of the positively charged polyethylenimine-coated AgNPs in various cell types and finds that monocytes and B cells have higher association with the AgNPs than other populations. scRNA-seq data of these two cell types demonstrate that each type has distinct responses to AgNP treatment: NRF2-mediated oxidative stress is confined to B cells, whereas monocytes show Fcγ-mediated phagocytosis. Besides the between-population heterogeneity, analysis of single-cell dose-response relationships further reveals within-population diversity for the B cells and naïve CD4+ T cells. Distinct subsets having different levels of cellular responses with respect to their cellular AgNP doses are found. This study demonstrates that the complementary use of mass cytometry and scRNA-seq is helpful for gaining in-depth knowledge on the heterogeneous interactions between immune cells and NPs and can be incorporated into future toxicity assessments of nanomaterials.
Asunto(s)
Leucocitos Mononucleares , Nanopartículas del Metal , Plata , Linfocitos B/efectos de los fármacos , Citometría de Flujo , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Nanopartículas del Metal/química , Nanopartículas del Metal/toxicidad , RNA-Seq , Plata/química , Plata/toxicidad , Análisis de la Célula Individual , Distribución TisularRESUMEN
Some of the previously reported clinical isolates of Elizabethkingia meningoseptica may be later named species of Elizabethkingia We determined the accuracy of species identification (with two matrix-assisted laser desorption ionization-time of flight mass spectrometry [MALDI-TOF MS] systems and the Vitek 2 GN card), relative prevalence of three Elizabethkingia spp. in clinical specimens, and antimicrobial susceptibility of the species identified by 16S rRNA gene sequencing. Specimens for culture were collected from patients in a university hospital in Seoul, South Korea, between 2009 and 2015. All 3 Elizabethkingia spp. were detected in patients; among the 86 isolates identified by 16S rRNA gene sequencing, 17 (19.8%) were E. meningoseptica, 18 (20.9%) were Elizabethkingia miricola, and 51 (59.3%) were Elizabethkingia anophelis Only the MALDI-TOF Vitek MS system with an amended database correctly identified all of the isolates. The majority (76.7%) of the isolates were from the lower respiratory tract, and 8 (9.3%) were from blood. Over 90% of E. meningoseptica and E. anophelis isolates were susceptible to piperacillin-tazobactam and rifampin. In contrast, all E. miricola isolates were susceptible to fluoroquinolones except ciprofloxacin. Further studies are urgently needed to determine the optimal antimicrobial agents for the treatment of infections due to each individual Elizabethkingia species.
Asunto(s)
Antibacterianos/farmacología , Técnicas Bacteriológicas/métodos , Infecciones por Flavobacteriaceae/epidemiología , Infecciones por Flavobacteriaceae/microbiología , Flavobacteriaceae/efectos de los fármacos , Flavobacteriaceae/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Anciano , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Femenino , Flavobacteriaceae/clasificación , Flavobacteriaceae/genética , Genes de ARNr , Hospitales Universitarios , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , ARN Ribosómico 16S/genética , República de Corea/epidemiología , Análisis de Secuencia de ADNRESUMEN
We report a first human case of Porphyromonas pogonae causing soft tissue infection in a patient with open fracture. Strong ß-hemolytic, aerotolerant, and non-pigmented gram-negative coccobacilli which matched Porphyromonas pogonae by PCR for 16S rRNA genes were identified from the pus specimen. The clinical course of the patient improved with repeated surgical drainage and tigecycline administration.
Asunto(s)
Infecciones por Bacteroidaceae/diagnóstico , ADN Bacteriano/genética , Fracturas Óseas/diagnóstico , Porphyromonas/aislamiento & purificación , ARN Ribosómico 16S/genética , Infecciones de los Tejidos Blandos/diagnóstico , Adulto , Antibacterianos/uso terapéutico , Infecciones por Bacteroidaceae/tratamiento farmacológico , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/cirugía , Ciprofloxacina/uso terapéutico , Fracturas Óseas/tratamiento farmacológico , Fracturas Óseas/microbiología , Fracturas Óseas/cirugía , Humanos , Masculino , Minociclina/análogos & derivados , Minociclina/uso terapéutico , Porphyromonas/clasificación , Porphyromonas/efectos de los fármacos , Porphyromonas/genética , Rifampin/uso terapéutico , Análisis de Secuencia de ADN , Infecciones de los Tejidos Blandos/tratamiento farmacológico , Infecciones de los Tejidos Blandos/microbiología , Infecciones de los Tejidos Blandos/cirugía , Supuración/microbiología , TigeciclinaRESUMEN
Pancreatic adenocarcinoma up-regulated factor (PAUF) is expressed in pancreatic ductal adenocarcinoma (PDAC) and plays an important role in tumor progression and metastasis. Here we evaluate the anti-tumor efficacy of a human monoclonal antibody against PAUF, PMAb83, to provide a therapeutic intervention to treat the disease. PMAb83 reduced tumor growth and distant metastasis in orthotopically xenografted mice of human PDAC cells. PMAb83 treatment retarded proliferation along with weakened aggressiveness traits of the carcinoma cells. AKT/ß-catenin signaling played a role in the carcinoma cell proliferation and the treated xenograft tumors exhibited reduced levels of ß-catenin and cyclin D1. Moreover PMAb83 abrogated the PAUF-induced angiogenic responses of endothelial cells, reducing the density of CD31(+) vessels in the treated tumors. In combination with gemcitabine, PMAb83 conferred enhanced survival of xenografted mice by about twofold compared to gemcitabine alone. Taken together, our findings show that PMAb83 treatment decreases the aggressiveness of carcinoma cells and suppresses tumor vascularization, which culminates in mitigated tumor growth and metastasis with improved survival in PDAC mouse models.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/uso terapéutico , Carcinoma Ductal Pancreático/terapia , Lectinas/antagonistas & inhibidores , Lectinas/inmunología , Neoplasias Pancreáticas/terapia , Animales , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Neutralizantes/administración & dosificación , Antineoplásicos/administración & dosificación , Carcinoma Ductal Pancreático/patología , Carcinoma Ductal Pancreático/secundario , Línea Celular Tumoral , Terapia Combinada , Ciclina D1/metabolismo , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Progresión de la Enfermedad , Células Endoteliales/patología , Femenino , Humanos , Péptidos y Proteínas de Señalización Intercelular , Ratones , Ratones Desnudos , Neovascularización Patológica/prevención & control , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Ensayos Antitumor por Modelo de Xenoinjerto , beta Catenina/metabolismo , GemcitabinaRESUMEN
This case presents the clinical and genomic aspects of a rare and multidrug-resistant Pseudomonas guariconensis isolate carrying blaVIM-2 and highlights the need for heightened awareness in healthcare facilities. A 63-year-old woman underwent surgery for the diagnosis of a paraspinal abscess and infectious spondylitis. During hospitalization, the patient was diagnosed with heart failure exacerbation. The patient had no symptoms of urinary tract infection and met the criteria for asymptomatic bacteriuria. In urine culture, colonies of the organism grew >105 CFU/mL on blood agar and on MacConkey agar. The Bruker Biotyper mass spectrometry showed P. guariconensis. Based on the 16S rRNA gene sequence showed that a 99.79 % match with as P. guariconensis LMG 27394T. The average nucleotide identity with P. guariconensis LMG 27394T was 91.53 %. Antimicrobial susceptibility testing showed that the isolate was not susceptible to most of the antibiotics. Antimicrobial resistance genes identified were aph(6)-Id, aph(3â³)-Ib, aac(6')-Ib3, aac(3)-If, gyrA mutation (T83I) and blaVIM-2.
Asunto(s)
Bacteriuria , Pseudomonas , beta-Lactamasas , Humanos , Femenino , Persona de Mediana Edad , beta-Lactamasas/genética , Bacteriuria/diagnóstico , ADN Bacteriano/genética , ADN Bacteriano/química , ARN Ribosómico 16S/genética , Agar , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Antibacterianos/uso terapéuticoRESUMEN
OBJECTIVES: Acute rhinosinusitis (ARS) is a common upper respiratory tract infection that is mostly of viral origin. However, little is known about the nasal microbiome profile at presentation and the changes caused by antibiotics in acute bacterial rhinosinusitis (ABRS). METHODS: This was a prospective single-center study. Overall, 43 ARS patients were screened and were assessed with the symptom questionnaires, nasal endoscopy, and Water's view. Five healthy subjects were recruited as controls. Middle meatal mucus samples were obtained using a cotton swab (for bacterial culture and antimicrobial susceptibility testing) and the suction technique (for 16S rRNA sequencing). After 1 week of antibiotic use (amoxicillin with clavulanic acid), we enrolled 13 patients with ABRS with positive isolates and middle meatal samples for 16S rRNA sequencing were obtained again. RESULTS: Overall, we demonstrated a significantly lower abundance of the Lactobacillaceae family in ABRS patients than in healthy controls. Resistant ABRS had different characteristics of middle meatal microbiomes when compared to sensitive ABRS as follows: (1) lower proportion of lactic acid bacteria, (2) increased pathogens such as Rhodococcus sp., Massila sp., Acinetobacter sp., and H. influenza, and (3) increased beta diversity. However, no remarkable changes were observed in the middle meatal microbiome after antibiotic use. CONCLUSION: We showed the roles of Lactobacillaceae in ABRS, and Acinetobacter and Massilia in case of amoxicillin resistance. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1081-1088, 2024.
Asunto(s)
Microbiota , Rinitis , Rinosinusitis , Sinusitis , Humanos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , ARN Ribosómico 16S , Estudios Prospectivos , Rinitis/diagnóstico , Sinusitis/diagnóstico , Amoxicilina , Enfermedad AgudaRESUMEN
Understanding the sepsis-induced immunological response can be facilitated by identifying phenotypic changes in immune cells at the single-cell level. Mass cytometry, a novel multiparametric single-cell analysis technique, offers considerable benefits in characterizing sepsis-induced phenotypic changes in peripheral blood mononuclear cells. Here, we analyzed peripheral blood mononuclear cells from 20 sepsis patients and 10 healthy donors using mass cytometry and employing 23 markers. Both manual gating and automated clustering approaches (PhenoGraph) were used for cell identification, complemented by uniform manifold approximation and projection (UMAP) for dimensionality reduction and visualization. Our study revealed that patients with sepsis exhibited a unique immune cell profile, marked by an increased presence of monocytes, B cells, and dendritic cells, alongside a reduction in natural killer (NK) cells and CD4/CD8 T cells. Notably, significant changes in the distributions of monocytes and B and CD4 T cells were observed. Clustering with PhenoGraph unveiled the subsets of each cell type and identified elevated CCR6 expression in sepsis patients' monocyte subset (PG#5), while further PhenoGraph clustering on manually gated T and B cells discovered sepsis-specific CD4 T cell subsets (CCR4low CD20low CD38low) and B cell subsets (HLA-DRlow CCR7low CCR6high), which could potentially serve as novel diagnostic markers for sepsis.
Asunto(s)
Citometría de Flujo , Sepsis , Humanos , Sepsis/inmunología , Masculino , Femenino , Persona de Mediana Edad , Citometría de Flujo/métodos , Monocitos/inmunología , Anciano , Leucocitos Mononucleares/inmunología , Fenotipo , Células Dendríticas/inmunología , Linfocitos B/inmunología , Adulto , Inmunofenotipificación , Células Asesinas Naturales/inmunología , Linfocitos T CD4-Positivos/inmunología , Biomarcadores/sangre , Biomarcadores/análisisRESUMEN
BACKGROUND: This study aimed to examine the clinical and microbiological characteristics of female patients with recurrent acute pyelonephritis (APN). METHODS: A retrospective cohort study was conducted at a tertiary care hospital in South Korea from July 2019 to December 2021. All female patients aged ≥ 19 years who were diagnosed with community-acquired APN on admission were enrolled. The recurrent group included patients with APN who experienced urinary tract infections within the previous year. The clinical characteristics, types of causative organisms, major antibiotic resistance, and molecular characteristics of Escherichia coli strains were compared between the recurrent and non-recurrent groups. RESULTS: A total of 285 patients with APN were analyzed, including 41 (14.4%) in the recurrent group. Compared to the non-recurrent group, the recurrent group had a higher Charlson Comorbidity Index (1.8 ± 2.1 vs. 1.1 ± 1.5; P = 0.01) and a higher proportion of bladder abnormalities, such as neurogenic bladder (12.2% vs. 2.0%; P = 0.001) and urinary catheterization (12.2% vs. 1.6%; P < 0.001). Escherichia coli was the most common causative organism in both groups. The proportion of Klebsiella pneumoniae (17.1% vs. 4.7%; P = 0.007) and Pseudomonas aeruginosa (5.7% vs. 0.5%; P = 0.014) as a causative organism was higher in the recurrent group. Regarding the microbiological characteristics of Escherichia coli, there were no significant differences in the proportion of antibiotic resistance, phylogenetic groups, resistance genes, and virulence factors between the two groups. Multivariable analysis showed that neurogenic bladder and a history of admission or antibiotic use during 1 year prior to inclusion were significantly associated with recurrent APN. CONCLUSIONS: The proportion of causative organisms except Escherichia coli was higher in the recurrent group than in the non-recurrent group. Neurogenic bladder and a history of admission or antibiotic use during 1 year prior to inclusion were risk factors for recurrent APN.
Asunto(s)
Infecciones Comunitarias Adquiridas , Infecciones por Escherichia coli , Pielonefritis , Vejiga Urinaria Neurogénica , Infecciones Urinarias , Humanos , Femenino , Infecciones por Escherichia coli/epidemiología , Estudios Retrospectivos , Vejiga Urinaria Neurogénica/tratamiento farmacológico , Filogenia , Infecciones Comunitarias Adquiridas/microbiología , Infecciones Urinarias/microbiología , Pielonefritis/epidemiología , Pielonefritis/tratamiento farmacológico , Pielonefritis/microbiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Escherichia coli/genéticaRESUMEN
Understanding how nanoparticles (NPs) interact with biological systems is important in many biomedical research areas. However, the heterogeneous nature of biological systems, including the existence of numerous cell types and multitudes of key environmental factors, makes these interactions extremely challenging to investigate precisely. Here, using a single-cell-based, high-dimensional mass cytometry approach, we demonstrated that the presence of protein corona has significant influences on the cellular associations and cytotoxicity of gold NPs for human immune cells, and those effects vary significantly with the types of immune cells and their subsets. The altered surface functionality of protein corona reduced the cytotoxicity and cellular association of gold NPs in most cell types (e.g., monocytes, dendritic cells, B cells, natural killer (NK) cells, and T cells) and those immune cells selected different endocytosis pathways such as receptor-mediated endocytosis, phagocytosis, and micropinocytosis. However, even slight alterations in the major cell type (phagocytic cells and non-phagocytic cells) and T cell subsets (e.g., memory and naive T cells) resulted in significant protein corona-dependent variations in their cellular dose of gold NPs. Especially, naive T killer cells exhibited additional heterogeneity than memory T killer cells, with clusters exhibiting distinct cellular association patterns in single-cell contour plots. This multi-parametric analysis of mass cytometry data established a conceptual framework for a more holistic understanding of how the human immune system responds to external stimuli, paving the way for the application of precisely engineered NPs as promising tools of nanomedicine under various clinical settings, including targeted drug delivery and vaccine development.
RESUMEN
Background: The incidence of early- and late-onset sepsis and meningitis in neonates due to maternal rectovaginal group B Streptococcus (GBS) colonization may differ with serotype distribution and clonal complex (CC). CC17 strains are associated with hypervirulence and poor disease outcomes. GBS serotypes are distinguished based on the polysaccharide capsule, the most important virulence factor. We determined the sequence type distribution of GBS isolates from pregnant women in Korea and validated whole-genome sequencing (WGS)-based prediction of antimicrobial susceptibility and capsular serotypes in GBS isolates. Methods: Seventy-five GBS isolates collected from pregnant Korean women visiting Wonju Severance Christian Hospital, Wonju, Korea between 2017 and 2019 were subjected to WGS using the NovaSeq 6000 system (Illumina, San Diego, CA, USA). Multilocus sequence types, serotypes, antimicrobial resistance genes, and hemolysin operon mutations were determined by WGS, and the latter three were compared with the results of conventional phenotypic methods. Results: The predominant lineage was CC1 (37.3%), followed by CC19 (32.0%), CC12 (17.3%), and CC17 (4.0%). All isolates were cps typeable (100%, (75/75), and 89.3% of cps genotypes (67/75) were concordant with serotypes obtained using latex agglutination. The cps genotypes of the 75 isolates were serotypes III (24.0%), V (22.7%), and VIII (17.3%). All isolates harboring intact ermB and tet were non-susceptible to erythromycin and tetracycline, respectively. Three non-hemolytic strains had 1-bp frameshift insertions in cylE. Conclusions: The low prevalence of CC17 GBS colonization may explain the low frequency of neonatal GBS infections. WGS is a useful tool for simultaneous genotyping and antimicrobial resistance determination.
Asunto(s)
Mujeres Embarazadas , Infecciones Estreptocócicas , Recién Nacido , Femenino , Humanos , Embarazo , Proteínas Hemolisinas/genética , Tipificación de Secuencias Multilocus , Streptococcus agalactiae , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/tratamiento farmacológico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Eritromicina , Tetraciclina , Factores de Virulencia/genéticaRESUMEN
Accurate detection of metallo-ß-lactamase (MBL)-producing Pseudomonas spp. and Acinetobacter spp. became very important with the increasing prevalence of carbapenem-nonsusceptible clinical isolates. The performance of phenotypic MBL detection methods may depend on the types of MBL and the characteristics of the isolates. A high false-positive rate is a problem with EDTA-based MBL detection methods. We evaluated the performance of double-disk potentiation tests (DDPTs) and disk potentiation tests (DPTs) with dipicolinic acid (DPA) using 44 isolates of Pseudomonas spp. and Acinetobacter spp. producing IMP-1-like, VIM-2-like, and SIM-1 type MBLs. Also, we characterized P. aeruginosa isolates with positive imipenem (IPM)-DPA DDPT, but negative meropenem (MEM)-DPA DDPT, and determined possibility of improving a DDPT by using MacConkey agar. Among five different DDPT methods, the IPM-DPA 250-µg method showed the highest sensitivity (97.7%) and specificity (100%). Among four DPT tests, the highest sensitivity (100%) was shown by the IPM-EDTA 1,900-µg disk method, but the specificity was very low (11.4%). Five of six P. aeruginosa isolates with false-negative DDPTs with MEM-DPA 250-µg disks carried bla(IMP-6,) and the high level resistance to MEM (MIC ≥ 512 µg/ml) was reduced by the presence of phenylalanine arginine ß-naphtylamide. Improvement of DDPTs was observed when MacConkey agar was used instead of Mueller-Hinton agar. In conclusion, DPA is a better MBL inhibitor than EDTA for detection of Pseudomonas spp. and Acinetobacter spp. with IMP-1-like, VIM-2-like, and SIM-1-type MBLs. In DPA DDPTs, IPM disks perform better than MEM disks when the isolates are highly resistant to MEM due to the overexpression of efflux pumps.
Asunto(s)
Acinetobacter/enzimología , Técnicas Bacteriológicas/métodos , Pseudomonas/enzimología , beta-Lactamasas/análisis , Acinetobacter/aislamiento & purificación , Infecciones por Acinetobacter/microbiología , Medios de Cultivo/química , Humanos , Ácidos Picolínicos/metabolismo , Pseudomonas/aislamiento & purificación , Infecciones por Pseudomonas/microbiología , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: The increasing trend of Escherichia coli that produce extended-spectrum beta-lactamases and carbapenemases is a global public health concern. Sequence type (ST)131, a high-risk clone, is most likely responsible for the global distribution of E. coli that carry the carbapenemase gene such as bla KPC. In this study, carbapenemase-producing E. coli (CPEC) isolates were recovered from the stool of patients in a tertiary care hospital in 2019 and 2020. METHODS: We randomly selected nine isolates among CPEC isolates carrying KPC, NDM and OXA-type carbapenemase genes for whole genome sequencing (WGS). WGS was performed using the Illumina system (Illumina, Inc., San Diego, CA, USA) at Macrogen (Seoul, Korea). De novo assembly and assembly validation were performed at Macrogen. The whole genome of isolates was analyzed using the Center for Genomic Epidemiology website (http://www.genomicepidemiology.org/). RESULTS: Seven sequence types were detected: ST131, ST410, ST68, ST216, ST405, ST224 and ST409 variant. Six isolates harbored CTX-M-type genes such as bla CTX-M-15, bla CTX-M-14 and bla CTX-M-27. Plasmid replicons such as IncFIA, IncFIB, IncFII and IncX3 types were detected. CONCLUSIONS: The present study showed the diversity of the molecular characteristics of CPEC by analysis of the whole genome of bacteria. WGS is a useful tool that provides much information in the clinical microbiology.
Asunto(s)
Escherichia coli , beta-Lactamasas , Humanos , Escherichia coli/genética , beta-Lactamasas/genética , Secuenciación Completa del Genoma , GenómicaRESUMEN
BACKGROUND: Extraintestinal pathogenic Escherichia coli (ExPEC) causes various infections, including urinary tract infection (UTI), sepsis, and neonatal meningitis. ExPEC strains have virulence factors (VFs) that facilitate infection by allowing bacterial cells to migrate into and multiply within the host. We compared the microbiological characteristics of ExPEC isolates from blood and urine specimens from UTI patients. METHODS: We conducted a single-center, prospective study in an 855-bed tertiary-care hospital in Korea. We consecutively recruited 80 hospitalized UTI patients with E. coli isolates, which were isolated from blood and/or urine, and urine alone between March 2019 and May 2020. We evaluated the 80 E. coli isolates for the presence of bacterial genes encoding the sequence types (STs), antimicrobial resistance, and VFs using whole-genome sequencing (WGS). RESULTS: We found no significant differences in STs, antimicrobial resistance patterns, or VFs between isolates from blood and urine specimens. ST131, a pandemic multidrug-resistant clone present in both blood and urine, was the most frequent ST (N=19/80, 24%), and ST131 isolates carried more virulence genes, especially, tsh and espC, than non-ST131 isolates. The virulence scores of the ST131 group and the ST69, ST95, and ST1193 groups differed significantly (P<0.05). CONCLUSIONS: We found no STs and VFs associated with bacteremia in WGS data of E. coli isolates from UTI patients. ST131 was the most frequent ST among UTI causing isolates and carried more VF genes than non-ST131 isolates.
Asunto(s)
Bacteriemia , Infecciones por Escherichia coli , Infecciones Urinarias , Antibacterianos/farmacología , Bacteriemia/diagnóstico , Escherichia coli/genética , Infecciones por Escherichia coli/diagnóstico , Humanos , Estudios Prospectivos , Infecciones Urinarias/diagnóstico , Factores de Virulencia/genéticaRESUMEN
Increasing production and application of silver nanoparticles (Ag NPs) have raised concerns on their possible adverse effects on human health. However, a comprehensive understanding of their effects on biological systems, especially immunomodulatory responses involving various immune cell types and biomolecules (e.g., cytokines and chemokines), is still incomplete. In this study, a single-cell-based, high-dimensional mass cytometry approach is used to investigate the immunomodulatory responses of Ag NPs using human peripheral blood mononuclear cells (hPBMCs) exposed to poly-vinyl-pyrrolidone (PVP)-coated Ag NPs of different core sizes (i.e., 10-, 20-, and 40-nm). Although there were no severe cytotoxic effects observed, PVPAg10 and PVPAg20 were excessively found in monocytes and dendritic cells, while PVPAg40 displayed more affinity with B cells and natural killer cells, thereby triggering the release of proinflammatory cytokines such as IL-2, IL-17A, IL-17F, MIP1ß, TNFα, and IFNγ. Our findings indicate that under the exposure conditions tested in this study, Ag NPs only triggered the inflammatory responses in a size-dependent manner rather than induce cytotoxicity in hPBMCs. Our study provides an appropriate ex vivo model to better understand the human immune responses against Ag NP at a single-cell level, which can contribute to the development of targeted drug delivery, vaccine developments, and cancer radiotherapy treatments.
RESUMEN
PURPOSE: This study aimed to examine the changes in the characteristics of community-onset fluoroquinolone-resistant (FQ-R) Escherichia coli isolates causing community-acquired acute pyelonephritis (APN) in South Korea. METHODS: Blood or urine samples were prospectively collected from patients aged ≥15 years with community-acquired APN who were admitted to one of the eight Korean hospitals included in this study between September 2017 and August 2018. Phylogenetic typing, multilocus sequence typing, and molecular characterization of ß-lactamase resistance and plasmid-mediated quinolone resistance (PMQR) determinants were performed. The data were compared with those from a previous study with the same design conducted in 2010-2011. RESULTS: A total of 300 and 346 isolates were identified in 2010-2011 and 2017-2018, respectively. Among them, 76 (22.0%) and 77 (25.7%) FQ-R isolates were identified in 2010-2011 and 2017-2018, respectively. A significantly higher antimicrobial resistance against third-to fourth-generation cephalosporins, including cefotaxime (23.9% vs. 77.9%, P < 0.001), were observed among FQ-R isolates in 2017-2018 than among those in 2010-2011. A higher proportion of ST131 isolates (27.6% vs. 66.2%, P < 0.001), as well as isolates that had extended-spectrum ß-lactamase (ESBL)/plasmid-mediated AmpC ß-lactamase (PABL) (23.7% vs. 79.2%, P < 0.001), was observed in 2017-2018 than in 2010-2011. Further, more PMQR determinants (11.8% vs. 40.8%, P < 0.001) were observed in 2017-2018 than in 2010-2011. CONCLUSIONS: Among uropathogenic FQ-R E. coli isolates in South Korea, the prevalence of ST131 and the proportion of isolates containing ESBL and/or PMQR determinants have increased.
Asunto(s)
Infecciones por Escherichia coli , Pielonefritis , Quinolonas , Escherichia coli Uropatógena , Antibacterianos , Farmacorresistencia Bacteriana , Fluoroquinolonas , Humanos , Tipificación de Secuencias Multilocus , Filogenia , República de Corea , beta-LactamasasRESUMEN
We investigated an outbreak caused by carbapenem-resistant Acinetobacter baumannii carrying the bla(OXA-23) gene. A novel insertion sequence (IS), named ISAba10, was found to be inserted into the ISAba1 element preceding the bla(OXA-23) gene in a group of isolates showing higher carbapenem MICs. The presence of ISAba10 was associated with increased OXA-23 expression, likely by providing additional promoter sequences. ISAba10 was also inserted into the carO outer membrane protein gene in most of these isolates.
Asunto(s)
Acinetobacter baumannii/genética , Proteínas de la Membrana Bacteriana Externa/genética , Datos de Secuencia Molecular , Mutagénesis Insercional , Regiones Promotoras Genéticas/genéticaRESUMEN
Elafin, a serine protease inhibitor, induces the intrinsic apoptotic pathway in human melanoma cells, where its expression is transcriptionally silenced. However, it remains unknown how the elafin gene is repressed in melanoma cells. We here demonstrate that elafin expression is modulated via epigenetically regulated expression of the transcription factor Foxa2. Treatment of melanoma cells with a DNA methyltransferase inhibitor induced elafin expression, which was specifically responsible for reduced proliferation and increased apoptosis. Suppression of Foxa2 transcription, mediated by DNA hypermethylation in its promoter region, was released in melanoma cells upon treatment with the demethylating agent. Luciferase reporter assays indicated that the Foxa2 binding site in the elafin promoter was critical for the activation of the promoter. Chromatin immunoprecipitation assays further showed that Foxa2 bound to the elafin promoter in vivo. Analyses of melanoma cells with varied levels of Foxa2 revealed a correlated expression between Foxa2 and elafin and the ability of Foxa2 to induce apoptosis. Our results collectively suggest that, in melanoma cells, Foxa2 expression is silenced and therefore elafin is maintained unexpressed to facilitate cell proliferation in the disease melanoma.