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1.
J Environ Qual ; 49(3): 754-761, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-33016404

RESUMEN

Land application of manure introduces gastrointestinal microbes into the environment, including bacteria carrying antibiotic resistance genes (ARGs). Measuring soil ARGs is important for active stewardship efforts to minimize gene flow from agricultural production systems; however, the variety of sampling protocols and target genes makes it difficult to compare ARG results between studies. We used polymerase chain reaction (PCR) methods to characterize and/or quantify 27 ARG targets in soils from 20 replicate, long-term no-till plots, before and after swine manure application and simulated rainfall and runoff. All samples were negative for the 10 b-lactamase genes assayed. For tetracycline resistance, only source manure and post-application soil samples were positive. The mean number of macrolide, sulfonamide, and integrase genes increased in post-application soils when compared with source manure, but at plot level only, 1/20, 5/20, and 11/20 plots post-application showed an increase in erm(B), sulI, and intI1, respectively. Results confirmed the potential for temporary blooms of ARGs after manure application, likely linked to soil moisture levels. Results highlight uneven distribution of ARG targets, even within the same soil type and at the farm plot level. This heterogeneity presents a challenge for separating effects of manure application from background ARG noise under field conditions and needs to be considered when designing studies to evaluate the impact of best management practices to reduce ARG or for surveillance. We propose expressing normalized quantitative PCR (qPCR) ARG values as the number of ARG targets per 100,000 16S ribosomal RNA genes for ease of interpretation and to align with incidence rate data.


Asunto(s)
Estiércol , Suelo , Animales , Antibacterianos/farmacología , Productos Agrícolas , Farmacorresistencia Microbiana/genética , Microbiología del Suelo , Porcinos
2.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 45(9): 1068-1073, 2020.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-33051420

RESUMEN

OBJECTIVES: To analyze the pathogenic distribution, antibiotic susceptibility and prognostic factors for acute leukemia (AL) patients with Gram negative (G-) bacterial bloodstream infection (BSI), in order to provide theoretical basis for reducing the infection-related mortality of AL patients. METHODS: The clinical data of 1 055 AL patients with BSI admitted to the hematology ward of three large-scale hospitals in Hunan Province from January 2010 to December 2018 were collected. The etiology, antibiotic susceptibility data and clinical features of patients with G- bacterial infection were analyzed. RESULTS: G- bacterial infection accounted for 622 AL patients with BSI, and the main pathogens were Escherichia coli (277 strains, 44.53%), Klebsiella pneumoniae (138 strains, 22.19%), and Pseudomonas aeruginosa (81 strains, 13.02%). Most G- bacteria were highly sensitive to carbapenems and ß-lactam/ß-lactamase inhibitor. State of disease, Pitt score ≥4, treatment with vasoactive agents and sensitive antibiotic >48 h were independent risk factors of 30-day mortality. CONCLUSIONS: Rational antibacterial treatment of G- bacterial BSI in AL patients requires adequate acquaintance of the local pathogenic epidemiology and antibiotic susceptibility-monitored data. Broad-spectrum antibiotics covering the most common and more virulent pathogens should be timely applicated and adjusted according to antibiotic susceptibility results and efficacy.


Asunto(s)
Bacteriemia , Farmacorresistencia Bacteriana , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Bacteriemia/epidemiología , Humanos , Pruebas de Sensibilidad Microbiana , Pronóstico
3.
J Contemp Dent Pract ; 21(7): 760-764, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33020359

RESUMEN

AIM: One of the most vital characteristics of an ideal root filling material is the capability to inhibit the growth of the microorganisms. Mineral trioxide aggregate (MTA) is one of the most used root repair materials, with approved antibacterial effect. A newly introduced root repair material is nano-fast cement (NFC) which should be investigated. The antibacterial and antifungal activities of NFC were evaluated in the present study. MATERIALS AND METHODS: Enterococcus faecalis (PTCC 1394), Escherichia coli (ATTC 15224), and Candida albicans (PTCC 5027) were employed for the antimicrobial assessment. The following were the steps used to conduct the agar diffusion test (ADT): six agar plates were used. 0.5 McFarland concentration of each strain was cultured on two plates by a sterile cotton-tipped swab. Three holes with 5mm diameter were created on each plate. Freshly mixed cement was placed in the holes of the related plate. After two hours, the plates were incubated at 37°C for 24 hours. Then, the diameter of the growth inhibition zones were measured, and the mean values were used for the analysis. Direct contact test (DCT) was done by using the following steps: Freshly mixed materials were placed in the 96-well microtiter plate. 10 µL of each bacterial suspension was added to the tested cement. After one-hour incubation at 37°C, 245 µL of BHI broth was added to each well, and the plate was vortexed for 2 minutes. About 15 µL of this bacterial suspension was added to a new well which contained 215 µL of fresh medium. The kinetics of the bacterial outgrowth were measured by the microplate spectrophotometer hourly for 12 hours. RESULTS: No significant differences were observed between the diameters of the growth inhibition zones of MTA and NFC groups in ADT. In DCT, the MTA inhibits E. coli more effectively than NFC (p value < 0.001). Both cements had the same inhibitory effect on E. faecalis and C. albicans. CONCLUSION: The MTA and NFC are almost equally effective against the tested microorganisms. CLINICAL SIGNIFICANCE: The antibacterial characteristic of any dental material is an important matter. As well, the antibacterial efficacy of the NFC should be evaluated.


Asunto(s)
Antifúngicos/farmacología , Escherichia coli , Compuestos de Aluminio , Antibacterianos/farmacología , Compuestos de Calcio , Combinación de Medicamentos , Óxidos , Materiales de Obturación del Conducto Radicular , Silicatos
4.
BMC Infect Dis ; 20(1): 729, 2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-33028225

RESUMEN

BACKGROUND: This study describes the disease burden, clinical characteristics, antibiotic management, impact of multidrug resistance and outcome of Pseudomonas aeruginosa bloodstream infection (PABSI) among children admitted to a tertiary referral hospital for children in Cape Town, South Africa. METHODS: A retrospective descriptive study was conducted at a paediatric referral hospital in Cape Town, South Africa. Demographic and clinical details, antibiotic management and patient outcome information were extracted from medical and laboratory records. Antibiotic susceptibility results of identified organisms were obtained from the National Health Laboratory Service database. RESULTS: The incidence risk of PABSI was 5.4 (95% CI: 4.34-6.54) PABSI episodes / 10,000 hospital admissions and the most common presenting feature was respiratory distress, 34/91 (37.4%). Overall, 69/91 (75.8%) of the PA isolates were susceptible to all antipseudomonal antibiotic classes evaluated. Fifty (54.9%) of the PABSI episodes were treated with appropriate empiric antibiotic therapy. The mortality rate was 24.2% and in multivariable analysis, empiric antibiotic therapy to which PA isolates were not susceptible, infections present on admission, and not being in the intensive care unit at the time that PABSI was diagnosed were significantly associated with 14-day mortality. CONCLUSIONS: PABSI caused appreciable mortality, however, appropriate empiric antibiotic therapy was associated with reduced 14-day mortality.


Asunto(s)
Infecciones por Pseudomonas/diagnóstico , Pseudomonas aeruginosa/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Niño , Preescolar , Farmacorresistencia Bacteriana/efectos de los fármacos , Femenino , Hospitales Pediátricos , Humanos , Lactante , Unidades de Cuidados Intensivos , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/mortalidad , Pseudomonas aeruginosa/efectos de los fármacos , Estudios Retrospectivos , Sudáfrica/epidemiología , Tasa de Supervivencia , Centros de Atención Terciaria
5.
Dental Press J Orthod ; 25(4): 51-58, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32965387

RESUMEN

OBJECTIVE: To investigate the effect of ZnO nanocoating on mechanical properties of NiTi orthodontic wires and antibacterial activity. METHODS: 0.016 x 0.022-in NiTi orthodontic wires were coated with ZnO nanoparticles using an electrochemical deposition method with three electrodes system in 0.1M Zn(NO3)2. Mechanical properties and frictional resistance of the coated wires were investigated using an universal testing machine. Antibacterial effect of ZnO coating was also investigated. RESULTS: A stable adhered ZnO nanocoating on NiTi wires was obtained. The coated wires have a significant antibacterial activity against S. aureus, S. pyogens and E. coli, and a reduction of frictional forces by 34%. CONCLUSION: ZnO nanocoating may improve the antibacterial effects of NiTi wires and reduce the frictional resistance. Coating may be implanted in orthodontic practice for faster and safer treatment.


Asunto(s)
Óxido de Zinc/farmacología , Antibacterianos/farmacología , Aleaciones Dentales , Escherichia coli , Ensayo de Materiales , Níquel , Alambres para Ortodoncia , Staphylococcus aureus , Propiedades de Superficie , Titanio/farmacología , Zinc
6.
Nat Commun ; 11(1): 4379, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32873785

RESUMEN

The gut microbiome harbors a 'silent reservoir' of antibiotic resistance (AR) genes that is thought to contribute to the emergence of multidrug-resistant pathogens through horizontal gene transfer (HGT). To counteract the spread of AR, it is paramount to know which organisms harbor mobile AR genes and which organisms engage in HGT. Despite methods that characterize the overall abundance of AR genes in the gut, technological limitations of short-read sequencing have precluded linking bacterial taxa to specific mobile genetic elements (MGEs) encoding AR genes. Here, we apply Hi-C, a high-throughput, culture-independent method, to surveil the bacterial carriage of MGEs. We compare two healthy individuals with seven neutropenic patients undergoing hematopoietic stem cell transplantation, who receive multiple courses of antibiotics, and are acutely vulnerable to the threat of multidrug-resistant infections. We find distinct networks of HGT across individuals, though AR and mobile genes are associated with more diverse taxa within the neutropenic patients than the healthy subjects. Our data further suggest that HGT occurs frequently over a several-week period in both cohorts. Whereas most efforts to understand the spread of AR genes have focused on pathogenic species, our findings shed light on the role of the human gut microbiome in this process.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Microbioma Gastrointestinal/genética , Transferencia de Gen Horizontal , Genes Bacterianos/efectos de los fármacos , Adulto , Anciano , Antibacterianos/uso terapéutico , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Microbioma Gastrointestinal/efectos de los fármacos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Secuencias Repetitivas Esparcidas/efectos de los fármacos , Persona de Mediana Edad
7.
Nat Commun ; 11(1): 4648, 2020 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-32938927

RESUMEN

Emergence of tigecycline-resistance tet(X) gene orthologues rendered tigecycline ineffective as last-resort antibiotic. To understand the potential origin and transmission mechanisms of these genes, we survey the prevalence of tet(X) and its orthologues in 2997 clinical E. coli and K. pneumoniae isolates collected nationwide in China with results showing very low prevalence on these two types of strains, 0.32% and 0%, respectively. Further surveillance of tet(X) orthologues in 3692 different clinical Gram-negative bacterial strains collected during 1994-2019 in hospitals in Zhejiang province, China reveals 106 (2.7%) tet(X)-bearing strains with Flavobacteriaceae being the dominant (97/376, 25.8%) bacteria. In addition, tet(X)s are found to be predominantly located on the chromosomes of Flavobacteriaceae and share similar GC-content as Flavobacteriaceae. It also further evolves into different orthologues and transmits among different species. Data from this work suggest that Flavobacteriaceae could be the potential ancestral source of the tigecycline resistance gene tet(X).


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana/genética , Infecciones por Flavobacteriaceae/epidemiología , Flavobacteriaceae/genética , Tigeciclina/farmacología , China/epidemiología , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Evolución Molecular , Flavobacteriaceae/efectos de los fármacos , Flavobacteriaceae/aislamiento & purificación , Infecciones por Flavobacteriaceae/microbiología , Humanos , Filogenia
8.
Nat Commun ; 11(1): 4608, 2020 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-32929085

RESUMEN

Actinobacteria produce antibacterial and antifungal specialized metabolites. Many insects harbour actinobacteria on their bodies or in their nests and use these metabolites for protection. However, some actinobacteria produce metabolites that are toxic to insects and the evolutionary relevance of this toxicity is unknown. Here we explore chemical interactions between streptomycetes and the fruit fly Drosophila melanogaster. We find that many streptomycetes produce specialized metabolites that have potent larvicidal effects against the fly; larvae that ingest spores of these species die. The mechanism of toxicity is specific to the bacterium's chemical arsenal: cosmomycin D producing bacteria induce a cell death-like response in the larval digestive tract; avermectin producing bacteria induce paralysis. Furthermore, low concentrations of volatile terpenes like 2-methylisoborneol that are produced by streptomycetes attract fruit flies such that they preferentially deposit their eggs on contaminated food sources. The resulting larvae are killed during growth and development. The phenomenon of volatile-mediated attraction and specialized metabolite toxicity suggests that some streptomycetes pose an evolutionary risk to insects in nature.


Asunto(s)
Bacterias/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/microbiología , Actinobacteria/fisiología , Animales , Antraciclinas/farmacología , Antibacterianos/química , Antibacterianos/farmacología , Canfanos/toxicidad , Muerte Celular/efectos de los fármacos , Drosophila melanogaster/efectos de los fármacos , Larva/efectos de los fármacos , Larva/microbiología , Metaboloma , Esporas Bacterianas/metabolismo , Esporas Bacterianas/fisiología , Streptomyces/fisiología , Análisis de Supervivencia , Compuestos Orgánicos Volátiles/farmacología
9.
Antivir Chem Chemother ; 28: 2040206620961712, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32972196

RESUMEN

Macrolides are a large group of antibiotics characterised by the presence of a macro-lactone ring of variable size. The prototype of macrolide antibiotics, erythromycin was first produced by Streptomyces and associated species more than half a century ago; other related drugs were developed. These drugs have been shown to have several pharmacological properties: in addition to their antibiotic activity, they possess some anti-inflammatory properties and have been also considered against non-bacterial infections. In this review, we analysed the available clinical evidences regarding the potential anti-viral activity of macrolides, by focusing on erythromycin, clarithromycin and azithromycin. Overall, there is no significant evidences so far that macrolides might have a direct benefit on most of viral infections considered in this review (RSV, Influenza, coronaviruses, Ebola and Zika viruses). However, their clinical benefit cannot be ruled out without further and focused clinical studies. Macrolides may improve the clinical course of viral respiratory infections somehow, at least through indirect mechanisms relying on some and variable anti-inflammatory and/or immunomodulatory effects, in addition to their well-known antibacterial activity.


Asunto(s)
Antibacterianos/farmacología , Antivirales/farmacología , Infecciones por Coronavirus/tratamiento farmacológico , Macrólidos/farmacología , Neumonía Viral/tratamiento farmacológico , Animales , Antibacterianos/farmacocinética , Antibacterianos/uso terapéutico , Antivirales/farmacocinética , Antivirales/uso terapéutico , Betacoronavirus/efectos de los fármacos , Humanos , Macrólidos/farmacocinética , Macrólidos/uso terapéutico , Pandemias
10.
BMC Infect Dis ; 20(1): 651, 2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32887563

RESUMEN

BACKGROUND: Risk factors related to mortality due to invasive pneumococcal disease (IPD) have been unveiled previously, but early clinical manifestations of IPD based on prognosis remain uncovered. METHODS: The demographic characteristics, clinical features, serotype, antibiotic susceptibility, and outcomes of 97 hospitalized children with laboratory-confirmed IPD from Suzhou, China, were collected and analyzed retrospectively. RESULTS: The median age was 0.69 (0.49-1.55) years in the non-survivor group compared with 2.39 (0.90-3.81) years in the survivor group. The mortality of 97 children with laboratory-confirmed IPD was 17.5% (17/97), and 53.6% of them were aged less than 2 years. Pathogens were mainly from the blood and cerebrospinal fluid, and sepsis was the most frequent type. Statistically significant differences were found in hyperpyrexia, vomiting, anorexia, lethargy, poor perfusion of extremities, Hb level, and Plt count between the nonsurvival and survival groups. Further, the multivariate regression analysis showed that early signs, including hyperpyrexia, vomiting, anorexia, lethargy, and poor perfusion of extremities, were independent risk factors for the in-hospital mortality of children with laboratory-confirmed IPD. The mortality was also associated with antimicrobial sensitivity in pneumococcal isolates. The microbes in 1/17 (5.9%) children who were prescribed an antibiotic showed antimicrobial sensitivity in the nonsurvival group, compared with 21/80 (26.3%) children who survived. The most common serotypes identified were 6B (35.3%, 6/17), 14 (23.5%, 4/17), 19F (23.5%, 4/17), 19A (5.9%, 1/17), 23F (5.9%, 1/17), and 20 (5.9%, 1/17) in the nonsurvival group. The coverage of IPD serotypes of the 7-valent pneumococcal conjugate vaccine (PCV7) was 88.2% (15/17), while that of the 13-valent S. pneumoniae vaccine (PCV13) was 94.1% (16/17) of the coverage in the nonsurvival group. CONCLUSIONS: Recurrent hyperpyrexia, vomiting, anorexia, lethargy, and poor perfusion of extremities in the early stage were independent predictors for the in-hospital mortality of children with laboratory-confirmed IPD. Appropriate use of antibiotics and PCV immunization were the keys to improve the outcome of IPD.


Asunto(s)
Infecciones Neumocócicas/microbiología , Infecciones Neumocócicas/mortalidad , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Preescolar , Femenino , Vacuna Neumocócica Conjugada Heptavalente/uso terapéutico , Mortalidad Hospitalaria , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/uso terapéutico , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Sepsis/microbiología , Streptococcus pneumoniae/aislamiento & purificación , Cobertura de Vacunación
11.
BMC Infect Dis ; 20(1): 646, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32873235

RESUMEN

BACKGROUND: COVID-19 is known as a new viral infection. Viral-bacterial co-infections are one of the biggest medical concerns, resulting in increased mortality rates. To date, few studies have investigated bacterial superinfections in COVID-19 patients. Hence, we designed the current study on COVID-19 patients admitted to ICUs. METHODS: Nineteen patients admitted to our ICUs were enrolled in this study. To detect COVID-19, reverse transcription real-time polymerase chain reaction was performed. Endotracheal aspirate samples were also collected and cultured on different media to support the growth of the bacteria. After incubation, formed colonies on the media were identified using Gram staining and other biochemical tests. Antimicrobial susceptibility testing was carried out based on the CLSI recommendations. RESULTS: Of nineteen COVID-19 patients, 11 (58%) patients were male and 8 (42%) were female, with a mean age of ~ 67 years old. The average ICU length of stay was ~ 15 days and at the end of the study, 18 cases (95%) expired and only was 1 case (5%) discharged. In total, all patients were found positive for bacterial infections, including seventeen Acinetobacter baumannii (90%) and two Staphylococcus aureus (10%) strains. There was no difference in the bacteria species detected in any of the sampling points. Seventeen of 17 strains of Acinetobacter baumannii were resistant to the evaluated antibiotics. No metallo-beta-lactamases -producing Acinetobacter baumannii strain was found. One of the Staphylococcus aureus isolates was detected as methicillin-resistant Staphylococcus aureus and isolated from the patient who died, while another Staphylococcus aureus strain was susceptible to tested drugs and identified as methicillin-sensitive Staphylococcus aureus. CONCLUSIONS: Our findings emphasize the concern of superinfection in COVID-19 patients due to Acinetobacter baumannii and Staphylococcus aureus. Consequently, it is important to pay attention to bacterial co-infections in critical patients positive for COVID-19.


Asunto(s)
Infecciones por Acinetobacter/complicaciones , Acinetobacter baumannii/aislamiento & purificación , Betacoronavirus/fisiología , Coinfección/epidemiología , Infecciones por Coronavirus/complicaciones , Neumonía Viral/complicaciones , Infecciones Estafilocócicas/complicaciones , Staphylococcus aureus/aislamiento & purificación , Infecciones por Acinetobacter/epidemiología , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Complicaciones de la Diabetes/epidemiología , Femenino , Cardiopatías/complicaciones , Humanos , Hipertensión/complicaciones , Unidades de Cuidados Intensivos , Masculino , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Persona de Mediana Edad , Pandemias , Neumonía Viral/epidemiología , Neumonía Viral/virología , Sistema Respiratorio/microbiología , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos
12.
Nat Commun ; 11(1): 4365, 2020 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-32868761

RESUMEN

Current approaches explore bacterial genes that change transcriptionally upon stress exposure as diagnostics to predict antibiotic sensitivity. However, transcriptional changes are often specific to a species or antibiotic, limiting implementation to known settings only. While a generalizable approach, predicting bacterial fitness independent of strain, species or type of stress, would eliminate such limitations, it is unclear whether a stress-response can be universally captured. By generating a multi-stress and species RNA-Seq and experimental evolution dataset, we highlight the strengths and limitations of existing gene-panel based methods. Subsequently, we build a generalizable method around the observation that global transcriptional disorder seems to be a common, low-fitness, stress response. We quantify this disorder using entropy, which is a specific measure of randomness, and find that in low fitness cases increasing entropy and transcriptional disorder results from a loss of regulatory gene-dependencies. Using entropy as a single feature, we show that fitness and quantitative antibiotic sensitivity predictions can be made that generalize well beyond training data. Furthermore, we validate entropy-based predictions in 7 species under antibiotic and non-antibiotic conditions. By demonstrating the feasibility of universal predictions of bacterial fitness, this work establishes the fundamentals for potentially new approaches in infectious disease diagnostics.


Asunto(s)
Bacterias/genética , Evolución Molecular Dirigida , Farmacorresistencia Bacteriana/genética , Estrés Fisiológico , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/metabolismo , Fenómenos Fisiológicos Bacterianos , Enfermedades Transmisibles/diagnóstico , Entropía , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Genoma Bacteriano , Análisis de Secuencia de ARN , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo , Transcriptoma
13.
J Environ Manage ; 275: 111234, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32866924

RESUMEN

Effective and efficient utilization of antimicrobial drugs has been one of the important cornerstone of modern medicine. However, since antibiotics were first discovered by Alexander Fleming about a century ago, the time clock of antimicrobial resistance (AMR) started ticking somewhat leading to a global fear of a possible "post-antimicrobial era". Antibiotic resistance (AR) remains a serious challenge causing global outcry in both the clinical setting and the environment. The huge influence of municipal wastewater effluent discharges on the aquatic environment has made the niche a hotspot of research interest in the study of emergence and spread of AMR microbes and their resistance determinants/genes. The current review adopted a holistic approach in studying the proliferation of antibiotic resistance determinants (ARDs) as well as their impacts and fate in municipal wastewater effluents and the receiving aquatic environments. The various strategies deployed hitherto for the removal of resistance determinants in municipal effluents were carefully reviewed, while the potential for the use of nanotechnology as a viable alternative is explicitly explored. Also, highlighted in this review are the knowledge gaps to be filled in order to curtail the spread of AMR in aquatic environment and lastly, suggestions on the applicability of nanotechnology in eliminating AMR determinants in municipal wastewater treatment facilities are proffered.


Asunto(s)
Antibacterianos , Antiinfecciosos , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Nanotecnología , Aguas Residuales
14.
Anal Chem ; 92(19): 13396-13404, 2020 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-32867467

RESUMEN

Rapid, accurate, reliable, and risk-free tracking of pathogenic microorganisms at the single-cell level is critical to achieve efficient source control and prevent outbreaks of microbial infectious diseases. For the first time, we report a promising approach for integrating the concepts of a remarkably large Stokes shift and dual-recognition into a single matrix to develop a pathogenic microorganism stimuli-responsive ratiometric fluorescent nanoprobe with speed, cost efficiency, stability, ultrahigh specificity, and sensitivity. As a proof-of-concept, we selected the Gram-positive bacterium Staphylococcus aureus (S. aureus) as the target analyte model, which easily bound to its recognition aptamer and the broad-spectrum glycopeptide antibiotic vancomycin (Van). To improve the specificity and short sample-to-answer time, we employed classic noncovalent π-π stacking interactions as a driving force to trigger the binding of Van and aptamer dual-functionalized near-infrared (NIR) fluorescent Apt-Van-QDs to the surface of an unreported blue fluorescent π-rich electronic carbon nanoparticles (CNPs), achieving S. aureus stimuli-responsive ratiometric nanoprobe Apt-Van-QDs@CNPs. In the assembly of Apt-Van-QDs@CNPs, the blue CNPs (energy donor) and NIR Apt-Van-QDs (energy acceptor) became close to allow the fluorescence resonance energy transfer (FRET) process, leading to a remarkable blue fluorescence quenching for the CNPs at ∼465 nm and a clear NIR fluorescence enhancement for Apt-Van-QDs at ∼725 nm. In the presence of S. aureus, the FRET process from CNPs to Apt-Van-QDs was disrupted, causing the nanoprobe Apt-Van-QDs@CNPs to display a ratiometric fluorescent response to S. aureus, which exhibited a large Stokes shift of ∼260 nm and rapid sample-to-answer detection time (∼30.0 min). As expected, the nanoprobe Apt-Van-QDs@CNPs showed an ultrahigh specificity for ratiometric fluorescence detection of S. aureus with a good detection limit of 1.0 CFU/mL, allowing the assay at single-cell level. Moreover, we also carried out the precise analysis of S. aureus in actual samples with acceptable results. We believe that this work offers new insight into the rational design of efficient ratiometric nanoprobes for rapid on-site accurate screening of pathogenic microorganisms at the single-cell level in the early stages, especially during the worldwide spread of COVID-19 today.


Asunto(s)
Bacterias/química , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Técnicas Biosensibles/métodos , Colorantes Fluorescentes/síntesis química , Nanotecnología/métodos , Antibacterianos/farmacología , Aptámeros de Nucleótidos , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/microbiología , Fluorescencia , Transferencia Resonante de Energía de Fluorescencia , Microbiología de Alimentos/métodos , Humanos , Nanopartículas , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/microbiología , Sensibilidad y Especificidad , Espectroscopía Infrarroja Corta , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/química , Vancomicina/farmacología
15.
Nat Commun ; 11(1): 4522, 2020 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-32908144

RESUMEN

A unique, protective cell envelope contributes to the broad drug resistance of the nosocomial pathogen Acinetobacter baumannii. Here we use transposon insertion sequencing to identify A. baumannii mutants displaying altered susceptibility to a panel of diverse antibiotics. By examining mutants with antibiotic susceptibility profiles that parallel mutations in characterized genes, we infer the function of multiple uncharacterized envelope proteins, some of which have roles in cell division or cell elongation. Remarkably, mutations affecting a predicted cell wall hydrolase lead to alterations in lipooligosaccharide synthesis. In addition, the analysis of altered susceptibility signatures and antibiotic-induced morphology patterns allows us to predict drug synergies; for example, certain beta-lactams appear to work cooperatively due to their preferential targeting of specific cell wall assembly machineries. Our results indicate that the pathogen may be effectively inhibited by the combined targeting of multiple pathways critical for envelope growth.


Asunto(s)
Infecciones por Acinetobacter/tratamiento farmacológico , Acinetobacter baumannii/genética , Antibacterianos/farmacología , Proteínas Bacterianas/antagonistas & inhibidores , Infección Hospitalaria/tratamiento farmacológico , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pared Celular/efectos de los fármacos , Pared Celular/genética , Pared Celular/metabolismo , Infección Hospitalaria/microbiología , Análisis Mutacional de ADN , Elementos Transponibles de ADN/genética , ADN Bacteriano/genética , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Sinergismo Farmacológico , Humanos , Pruebas de Sensibilidad Microbiana , Mutación
16.
Pestic Biochem Physiol ; 170: 104695, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32980058

RESUMEN

In this study, thirty 1,3,4-oxadiazole sulfone derivatives containing 3,4-dichloroisothiazolamide moiety were designed and synthesized, and their antibacterial activities were evaluated. Bioassay results showed that some compounds exhibited excellent antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) in vitro and in vivo. Notably, the EC50 values of compounds 2 and 3 against Xoo were 0.79 and 0.85 µg/mL, respectively, which were superior to those of the control agents isotianil, bismerthiazol, and thiodiazole copper. In addition, in vivo antibacterial activities revealed that the compound 2 at 50 µg/mL possessed protective and curative activities of 43.99% and 41.06% against Xoo, respectively, which were better than positive controls. Furthermore, the preliminary mechanism study disclosed that compound 2 exhibited effective antibacterial activity against Xoo by inhibiting the formation of extracellular polysaccharides from Xoo, increasing cell permeability, and changing the shape of cells. This study suggested that 1,3,4-oxadiazole sulfone derivatives containing 3,4-dichloroisothiazolamide moiety displayed excellent antibacterial activity and could be further explored and developed as commercial pesticides.


Asunto(s)
Oryza , Xanthomonas , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Oxadiazoles , Enfermedades de las Plantas , Sulfonas/farmacología
17.
Adv Exp Med Biol ; 1267: 117-133, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32894480

RESUMEN

Antibiotic resistance is a global epidemic, becoming increasingly pressing due to its rapid spread. There is thus a critical need to develop new therapeutic approaches. In addition to searching for new antibiotics, looking into existing mechanisms of natural host defense may enable researchers to improve existing defense mechanisms, and to develop effective, synthetic drugs guided by natural principles. Histones, primarily known for their role in condensing mammalian DNA, are antimicrobial and share biochemical similarities with antimicrobial peptides (AMPs); however, the mechanism by which histones kill bacteria is largely unknown. Both AMPs and histones are similar in size, cationic, contain a high proportion of hydrophobic amino acids, and possess the ability to form alpha helices. AMPs, which mostly kill bacteria through permeabilization or disruption of the biological membrane, have recently garnered significant attention for playing a key role in host defenses. This chapter outlines the structure and function of histone proteins as they compare to AMPs and provides an overview of their role in innate immune responses, especially regarding the action of specific histones against microorganisms and their potential mechanism of action against microbial pathogens.


Asunto(s)
Antibacterianos/química , Antibacterianos/inmunología , Bacterias/inmunología , Histonas/química , Histonas/inmunología , Animales , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias/efectos de los fármacos , Histonas/farmacología , Inmunidad Innata
18.
BMC Infect Dis ; 20(1): 676, 2020 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-32938420

RESUMEN

BACKGROUND: Raoultella planticola(R.planticola) is a very rare opportunistic pathogen and sometimes even associated with fatal infection in pediatric cases. Recently,the emergence of carbapenem resistance strains are constantly being reported and a growing source of concern for pediatricians. CASE PRESENTATION: We reported 4 cases of neonatal septicemia caused by Raoultella planticola. Their gestational age was 211 to 269 days, and their birth weight was 1490 to 3000 g.The R. planticola infections were detected on the 9th to 27th day after hospitalization and occured between May and June. They clinically manifested as poor mental response, recurrent cyanosis, apnea, decreased heart rate and blood oxygen, recurrent jaundice, fever or nonelevation of body temperature. The C-reactive protein and procalcitonin were elevated at significantly in the initial phase of the infection,and they had leukocytosis or leukopenia. Prior to R.planticola infection,all of them recevied at least one broad-spectrum antibiotic for 7-27d.All the R.planticola strains detected were only sensitive to amikacin, but resistant to other groups of drugs: cephalosporins (such as cefazolin, ceftetan,etc) and penicillins (such as ampicillin-sulbactam,piperacillin,etc),and even developed resistance to carbapenem. All the infants were clinically cured and discharged with overall good prognosis. CONCLUSION: Neonatal septicemia caused by Raoultella planticola mostly occured in hot and humid summer, which lack specific clinical manifestations. Pediatricians should keep in mind that R. planticola can be a potential source of neonatal sepsis and even has the potential to acquire carbapenem-resistance. Preventing outbreaks of epidemics requires early detection, timely diagnosis and treatment, and active isolation.


Asunto(s)
Infecciones por Enterobacteriaceae/diagnóstico , Enterobacteriaceae/aislamiento & purificación , Sepsis Neonatal/diagnóstico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Peso al Nacer , Cefalosporinas/farmacología , Cefalosporinas/uso terapéutico , Enterobacteriaceae/efectos de los fármacos , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana , Sepsis Neonatal/tratamiento farmacológico , Piperacilina/farmacología , Piperacilina/uso terapéutico
19.
BMC Infect Dis ; 20(1): 673, 2020 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-32938424

RESUMEN

BACKGROUND: Urinary tract infection is one of the most common bacterial infections in children. Understanding the characteristics of uropathogens and their antimicrobial susceptibility pattern in a particular setting can provide evidence for the appropriate management of cases. This study aimed to assess the bacterial profile of urinary tract infection, their antimicrobial susceptibility pattern and associated factors among clinically suspected children attending at Felege-Hiwot Comprehensive Specialized Hospital, Northwest Ethiopia. METHODS: A hospital-based cross-sectional study was conducted from February-April, 2019. A systematic sampling technique was employed. A mid-stream urine sample was inoculated on cystine lactose electrolyte deficient media and incubated for 24-48 h. Sub-culturing was done on Mac-Conkey and blood agar. Antimicrobial susceptibility test was done on Muller-Hinton agar. A binary logistic regression model was used to see the association between dependent and independent factors. A p-value< 0.05 at 95% CI was considered as statistically significant. RESULTS: The overall prevalence of urinary tract infection was 16.7% (95% CI 12.4-21.1). Both Gram-negative and Gram-positive bacterial isolates were recovered with a rate of 44/50 (88%) and 6/50 (12%) respectively. Among Gram-negative isolates, E. coli 28/44(63.6%) was predominant while S. saprophyticus 2/6(33.3%) was prevalent among Gram-positive bacterial isolates. Overall, a high level of resistance to ampicillin, augmentin, and tetracycline was shown by Gram-negative bacteria with a rate of 44/44(100%), 39/44(88.6%), and36/44 (81.8%) respectively. About 33/50(66%) of overall multidrug resistance was observed (95% CI 52-78). About six Gram-negative bacterial isolates were extended spectrum beta-lactamase (ESBL) producers. Having a history of urinary tract infection (P-0.003, AOR 1.86-22.15) and male uncircumcision (p-0.00, AOR 5.5-65.35) were the independent variables that associate for urinary tract infections. CONCLUSION: In the present study, the prevalence of urinary tract infection among children was high and considerably a high proportion of multidrug resistance was observed. This result will have a significant impact on the selection of appropriate antimicrobial agents for the treatment of urinary tract infection.


Asunto(s)
Infecciones Urinarias/diagnóstico , Adolescente , Antibacterianos/farmacología , Niño , Preescolar , Estudios Transversales , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Etiopía/epidemiología , Femenino , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/aislamiento & purificación , Hospitales , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Oportunidad Relativa , Estudios Prospectivos , Infecciones Urinarias/microbiología , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
20.
Western Pac Surveill Response J ; 11(1): 41-46, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32963890

RESUMEN

Problem: Emerging bacterial antimicrobial (antibiotic) resistance (AMR) is a global threat to human health. However, most lower income countries do not have microbiological diagnostic testing for prompt, reliable confirmation of bloodstream infection and identification of AMR. Context: Clinicians in Pacific island nations are increasingly challenged by patients who have infection due to antimicrobial-resistant bacteria. Treatment of infection remains empirical because of a lack of diagnostic testing capacity and may follow guidelines that were formulated without reference to local measures of AMR prevalence. There is limited understanding among clinicians of microbiology testing and test interpretation. Action: Examine the lessons learnt from pilot laboratory development programmes in two Pacific island nations that focused on establishing standard procedures for micrological diagnostics and antimicrobial susceptibility testing (AST) and on improving the training of clinicians to increase their use of laboratory services. Outcome: The pilot programmes addressed a range of logistical difficulties and evaluated two blood culture systems. They also examined and improved internal QC implementation and evaluated the prevalence of AMR. Discussion: Continued development of microbiological diagnostic capability in the Pacific region is paramount. Pacific Island nations need to develop the capability of at least one central laboratory to culture AMR pathogens and subject them to quality-controlled AST or arrange for suitable referral to a nearby country. Discussion: This study demonstrated a persistently high prevalence of three major bacterial STIs across four countries in WHO's Western Pacific Region during nearly two decades. Further strengthening of strategies to control and prevent STIs is warranted.


Asunto(s)
Antibacterianos/farmacología , Técnicas Bacteriológicas/normas , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana/normas , Técnicas de Diagnóstico Molecular/normas , Humanos , Islas del Pacífico , Proyectos Piloto , Control de Calidad
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