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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121817, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36084581

RESUMO

With the growing popularity of the non-destructive technique, surface-enhanced Raman spectroscopy (SERS) demands a highly sensitive and reproducible plasmonic nanoparticles substrate. In this study, a novel bimetallic core-shell nanoparticles (Au@Ag@mSiO2NP) substrate consisting of a gold core, silver shell, and a mesoporous silica coating was synthesized. The mesoporous coating structure was created by employing template molecules such as surfactant and their subsequent removal allowing selective screening based on the size of analyte molecules. Results showed that the plasmonic substrate could selectively enhance small molecules by preventing large macromolecules to reach the exciting zone of the substrate core, achieving the detection of chloramphenicol in milk samples with a detection limit of 6.68 × 10-8 M. Moreover, the mesoporous coating provided additional stability to the Au@Ag nanoparticles, leading to the reusability of the substrate. Thus, this work offered a simple and smart Au@Ag@mSiO2NP substrate for effective SERS detection of analytes.


Assuntos
Nanopartículas Metálicas , Prata , Cloranfenicol , Ouro/química , Nanopartículas Metálicas/química , Dióxido de Silício/química , Prata/química , Análise Espectral Raman/métodos , Tensoativos
2.
Chemosphere ; 310: 136839, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36244417

RESUMO

Excess sludge produced from biological wastewater treatment plant in petroleum industry is a kind of hazardous solid waste. Converting the sludge into biochar catalysts may help to reduce its environmental risk, recover resources and increase economic efficiency. However, the role of the sludge biochar in persulfate activation remains unclear, limiting its application in removing organic pollutants from water body. In this study, metal-rich petrochemical sludge was used to produce activated sludge biochar (ASC) via a two-step method of pyrolytic carbonization (400 °C-800 °C) and subsequent KOH activation (abbreviated as ASC 400-800). The physio-chemical properties of ASC 400-800 were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and Raman. The chloramphenicol (CAP) removal performances of ASC 400-800/peroxymonosulfate (PMS) systems were evaluated. Results showed that porous sludge biochar was successfully prepared by the two-step method. At 800 °C, the specific surface area of ASC reached the highest value of 202.92 m2 g-1. At 600-800 °C, Fe3O4, Fe0, and graphitized carbon were formed in ASC. Among ASC 400-800, ASC 800 exhibited the best CAP removal performance in ASC 800/PMS system by adsorption combined with catalytic degradation. The optimal conditions identified for 0.31 mM CAP removal were ASC 800 2.0 g L-1, PMS 6.2 mM, and pH 2.0. SO4•-, •OH, and 1O2 may contribute to CAP degradation. The degradation pathways of CAP were proposed based on the identified degradation intermediates. Overall, this study confirmed that porous biochar derived from petrochemical sludge was an effective adsorbent or PMS catalyst to remove organic pollutants from wastewater.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Águas Residuárias/química , Esgotos , Porosidade , Cloranfenicol , Carvão Vegetal/química , Poluentes Químicos da Água/análise
3.
Int J Food Microbiol ; 384: 109981, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36306546

RESUMO

Poultry meat has been a vehicle of antibiotic resistant bacteria and genes. Yet, the diversity of selective pressures associated with their maintenance in the poultry-production chain remains poorly explored. We evaluated the susceptibility of Enterococcus spp. from chicken meat collected 20 years apart to antibiotics, metals, acidic pH and peracetic acid-PAA. Contemporary chicken-meat samples (n = 53 batches, each including a pool of neck skin from 10 single carcasses) were collected in a slaughterhouse facility using PAA as disinfectant (March-August 2018, North of Portugal). Broilers were raised in intensive farms (n = 29) using CuSO4 and organic acids as feed additives. Data were compared with that of 67 samples recovered in the same region during 1999-2001. All 2018 samples had multidrug resistant-MDR isolates, with >45 % carrying Enterococcus faecalis, Enterococcus faecium or Enterococcus gallinarum resistant to tetracycline, erythromycin, ampicillin, quinupristin-dalfopristin, ciprofloxacin, chloramphenicol or aminoglycosides. Resistance rates were similar (P > 0.05) to those of 1999-2001 samples for all but five antibiotics. The decrease of samples carrying vancomycin-resistant isolates from 46 % to 0 % between 1999-2001 and 2018 was the most striking difference. Isolates from both periods were similarly susceptible to acid pH [minimum-growth pH (4.5-5.0), minimum-survival pH (3.0-4.0)] and to PAA (MIC90 = 100-120 mg/L/MBC90 = 140-160 mg/L; below concentrations used in slaughterhouse). Copper tolerance genes (tcrB and/or cueO) were respectively detected in 21 % and 4 % of 2018 and 1999-2001 samples. The tcrB gene was only detected in E. faecalis (MICCuSO4 > 12 mM), and their genomes were compared with other international ones of chicken origin (PATRIC database), revealing a polyclonal population and a plasmid or chromosomal location for tcrB. The tcrB plasmids shared diverse genetic modules, including multiple antimicrobial resistance genes (e.g. to tetracyclines, chloramphenicol, macrolide-lincosamide-streptogramin B-MLSB, aminoglycosides, bacitracin, coccidiostats). When in chromosome, the tcrB gene was co-located closely to merA (mercury) genes. Chicken meat remains an important vehicle of MDR Enterococcus spp. able to survive under diverse stresses (e.g. copper, acid) potentially contributing to these bacteria maintenance and flux among animal-environment-humans.


Assuntos
Galinhas , Enterococcus faecium , Animais , Humanos , Galinhas/microbiologia , Aves Domésticas , Antibacterianos/farmacologia , Cobre/farmacologia , Testes de Sensibilidade Microbiana , Enterococcus , Aminoglicosídeos , Cloranfenicol , Farmacorresistência Bacteriana/genética , Carne/microbiologia
4.
Food Chem ; 401: 134140, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108384

RESUMO

Commercial immunochromatographic assay (ICA) is a convenient tool for controlling antibiotic abuse. Although great efforts have been made to improve the detection performance and quantitative capabilities, simplify the manufacturing process of commercial ICA is rarely mentioned. Here, a proof-of-principle work are developed to solve the above problem. Inspired by dyestuff chemistry, we developed an instant immune-network label strategy by dynamic protonation capacity of neutral red (NR), achieving a desirable labeling efficiency (<1min), and applying for ICA detection of chloramphenicol (CAP). Benefits from the efficiently protonation of NR, lengthy probe production time and organic reagents can be avoided, displaying excellent strip production efficiency and detection performance. Eventually, this strategy presents a visual limit of detection (vLOD) at 3 ng/mL, cut-off value is 9 ng/mL. The assay recoveries in milk and honey were 74.45-107.15 %, with the total RSD of 1.62-6.90 %. We envision that this strategy raises the possibility of commercializing of laboratory prototype products.


Assuntos
Antibacterianos , Cloranfenicol , Cloranfenicol/análise , Vermelho Neutro , Cromatografia de Afinidade/métodos , Limite de Detecção , Antibacterianos/análise , Imunoensaio/métodos
5.
Food Chem ; 402: 134256, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36148763

RESUMO

In this paper, a ternary-emission fluorescence imprinted polymer was one-pot synthesized by sol-gel method after mixing luminescence metal organic framework, green CdTe and near infrared red CdTe for visual detection of chloramphenicol in food. The ternary-emission fluorescence imprinted sensor showed wider linear range within concentration of 10 pM-0.5 nM and 0.5 nM-4.5 nM, with rapid response time of 3 min and the lower detection limit of 3.8 pM toward chloramphenicol. Meanwhile, NH2-UiO-66 improved the fluorescence sensitivity and response speed, the near-infrared CdTe enhanced the anti-interference ability of the imprinted sensor. Compared with the traditional single-emission and dual-emission fluorescence imprinted sensors, the ternary-emission imprinted sensor provided richer color changes from yellowish green to apricot to orange-salmon to amaranth to purple to final blue. It was applied to detect trace chloramphenicol in food with the recoveries of 98.2-101.2 %, which provided a new way for rapid visual detection of chloramphenicol.


Assuntos
Compostos de Cádmio , Estruturas Metalorgânicas , Impressão Molecular , Pontos Quânticos , Telúrio , Impressão Molecular/métodos , Cloranfenicol , Espectrometria de Fluorescência/métodos , Polímeros , Limite de Detecção
6.
Cochrane Database Syst Rev ; 11: CD010452, 2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36420914

RESUMO

BACKGROUND: Typhoid and paratyphoid (enteric fever) are febrile bacterial illnesses common in many low- and middle-income countries. The World Health Organization (WHO) currently recommends treatment with azithromycin, ciprofloxacin, or ceftriaxone due to widespread resistance to older, first-line antimicrobials. Resistance patterns vary in different locations and are changing over time. Fluoroquinolone resistance in South Asia often precludes the use of ciprofloxacin. Extensively drug-resistant strains of enteric fever have emerged in Pakistan. In some areas of the world, susceptibility to old first-line antimicrobials, such as chloramphenicol, has re-appeared. A Cochrane Review of the use of fluoroquinolones and azithromycin in the treatment of enteric fever has previously been undertaken, but the use of cephalosporins has not been systematically investigated and the optimal choice of drug and duration of treatment are uncertain. OBJECTIVES: To evaluate the effectiveness of cephalosporins for treating enteric fever in children and adults compared to other antimicrobials. SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, the WHO ICTRP and ClinicalTrials.gov up to 24 November 2021. We also searched reference lists of included trials, contacted researchers working in the field, and contacted relevant organizations. SELECTION CRITERIA: We included randomized controlled trials (RCTs) in adults and children with enteric fever that compared a cephalosporin to another antimicrobial, a different cephalosporin, or a different treatment duration of the intervention cephalosporin. Enteric fever was diagnosed on the basis of blood culture, bone marrow culture, or molecular tests. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were clinical failure, microbiological failure and relapse. Our secondary outcomes were time to defervescence, duration of hospital admission, convalescent faecal carriage, and adverse effects. We used the GRADE approach to assess certainty of evidence for each outcome. MAIN RESULTS: We included 27 RCTs with 2231 total participants published between 1986 and 2016 across Africa, Asia, Europe, the Middle East and the Caribbean, with comparisons between cephalosporins and other antimicrobials used for the treatment of enteric fever in children and adults. The main comparisons are between antimicrobials in most common clinical use, namely cephalosporins compared to a fluoroquinolone and cephalosporins compared to azithromycin. Cephalosporin (cefixime) versus fluoroquinolones Clinical failure, microbiological failure and relapse may be increased in patients treated with cefixime compared to fluoroquinolones in three small trials published over 14 years ago: clinical failure (risk ratio (RR) 13.39, 95% confidence interval (CI) 3.24 to 55.39; 2 trials, 240 participants; low-certainty evidence); microbiological failure (RR 4.07, 95% CI 0.46 to 36.41; 2 trials, 240 participants; low-certainty evidence); relapse (RR 4.45, 95% CI 1.11 to 17.84; 2 trials, 220 participants; low-certainty evidence). Time to defervescence in participants treated with cefixime may be longer compared to participants treated with fluoroquinolones (mean difference (MD) 1.74 days, 95% CI 0.50 to 2.98, 3 trials, 425 participants; low-certainty evidence). Cephalosporin (ceftriaxone) versus azithromycin Ceftriaxone may result in a decrease in clinical failure compared to azithromycin, and it is unclear whether ceftriaxone has an effect on microbiological failure compared to azithromycin in two small trials published over 18 years ago and in one more recent trial, all conducted in participants under 18 years of age: clinical failure (RR 0.42, 95% CI 0.11 to 1.57; 3 trials, 196 participants; low-certainty evidence); microbiological failure (RR 1.95, 95% CI 0.36 to 10.64, 3 trials, 196 participants; very low-certainty evidence). It is unclear whether ceftriaxone increases or decreases relapse compared to azithromycin (RR 10.05, 95% CI 1.93 to 52.38; 3 trials, 185 participants; very low-certainty evidence). Time to defervescence in participants treated with ceftriaxone may be shorter compared to participants treated with azithromycin (mean difference of -0.52 days, 95% CI -0.91 to -0.12; 3 trials, 196 participants; low-certainty evidence). Cephalosporin (ceftriaxone) versus fluoroquinolones It is unclear whether ceftriaxone has an effect on clinical failure, microbiological failure, relapse, and time to defervescence compared to fluoroquinolones in three trials published over 28 years ago and two more recent trials: clinical failure (RR 3.77, 95% CI 0.72 to 19.81; 4 trials, 359 participants; very low-certainty evidence); microbiological failure (RR 1.65, 95% CI 0.40 to 6.83; 3 trials, 316 participants; very low-certainty evidence); relapse (RR 0.95, 95% CI 0.31 to 2.92; 3 trials, 297 participants; very low-certainty evidence) and time to defervescence (MD 2.73 days, 95% CI -0.37 to 5.84; 3 trials, 285 participants; very low-certainty evidence). It is unclear whether ceftriaxone decreases convalescent faecal carriage compared to the fluoroquinolone gatifloxacin (RR 0.18, 95% CI 0.01 to 3.72; 1 trial, 73 participants; very low-certainty evidence) and length of hospital stay may be longer in participants treated with ceftriaxone compared to participants treated with the fluoroquinolone ofloxacin (mean of 12 days (range 7 to 23 days) in the ceftriaxone group compared to a mean of 9 days (range 6 to 13 days) in the ofloxacin group; 1 trial, 47 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: Based on very low- to low-certainty evidence, ceftriaxone is an effective treatment for adults and children with enteric fever, with few adverse effects. Trials suggest that there may be no difference in the performance of ceftriaxone compared with azithromycin, fluoroquinolones, or chloramphenicol. Cefixime can also be used for treatment of enteric fever but may not perform as well as fluoroquinolones.  We are unable to draw firm general conclusions on comparative contemporary effectiveness given that most trials were small and conducted over 20 years previously. Clinicians need to take into account current, local resistance patterns in addition to route of administration when choosing an antimicrobial.


Assuntos
Anti-Infecciosos , Febre Paratifoide , Febre Tifoide , Criança , Adulto , Humanos , Adolescente , Febre Paratifoide/tratamento farmacológico , Febre Tifoide/tratamento farmacológico , Cefalosporinas/uso terapêutico , Azitromicina/efeitos adversos , Ceftriaxona/uso terapêutico , Cefixima/uso terapêutico , Fluoroquinolonas/uso terapêutico , Antibacterianos/uso terapêutico , Cloranfenicol/uso terapêutico , Anti-Infecciosos/uso terapêutico , Monobactamas/uso terapêutico , Ciprofloxacina/uso terapêutico , Ofloxacino/uso terapêutico , Recidiva , Paquistão
7.
Water Res ; 227: 119324, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36368084

RESUMO

In this study, a novel and efficient heterogeneous electro-Fenton (EF) process with a potassium ferrate (K2FeO4) modified carbon felt (Fe-CF) cathode was developed for chloramphenicol (CAP) removal. The catalytic activity was assessed by the comparison of different systems and the effects of multiple operating parameters (K2FeO4 dosage, initial solution pH, applied current) and co-existing constituents. Results indicated that the Fe-CF cathode exhibited excellent performance for CAP degradation (almost 100% removal efficiency within 60 min) over a wide range of pH (pH 3-9) during heterogeneous EF ascribed to the synergistic effect of embedded iron species and porous graphitic carbon structure and effective utilization of the in-situ generated H2O2. Moreover, the Fe-CF cathode possessed good recyclability with low metal leaching (98.2% CAP removal efficiency after reused for 5 times) and outstanding real water application performance. The ∙OH and O2∙- were responsible for CAP degradation, while ∙OH played a main role. Moreover, the toxicity evaluation by E. coli growth experiments demonstrated an efficient toxicity reduction in this system. Overall, a novel heterogeneous EF functional cathode with superior performance was fabricated via a green, low-cost one-step method, which shows promising application potential for actual wastewater treatment.


Assuntos
Peróxido de Hidrogênio , Poluentes Químicos da Água , Fibra de Carbono , Peróxido de Hidrogênio/química , Carbono , Cloranfenicol , Escherichia coli , Poluentes Químicos da Água/química , Oxirredução , Ferro/química , Eletrodos
8.
Georgian Med News ; (328-329): 154-157, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36318861

RESUMO

The purpose of the was to compare the antibiotic resistance of the oropharyngeal normoflora in children with frequent Viral respiratory infections (VRIs). Investigated were 33 children in 2016 and 33 children in 2021 who were treated in the Infectious Diseases Department of the Ternopil Regional (Ukraine) Children's Clinical Hospital. The obtained material from the oropharynx from the examined contingent was studied by a generally accepted microbiological method. Determination of antibiotic susceptibility of the selected strains was performed by the method of standard disks. Among surveyed children in 2016 year were 20 (60.60%) carriers of staphylococci, with 12 children of them actually S. aureus. In 2021 were different types of streptococci were isolated from almost half (15 patient) of the subjects: α-hemolytic - 51.60%, ß-hemolytic - 45.50% of patients with VRIs and S. aureus. -48.5 %. Analysis of antibiotic susceptibility of staphylococci and streptococci revealed a significant reduction in the number of susceptible staphylococcal strains to cephalosporin and penicillin, moderate - against aminoglycosides and chloramphenicol. Almost all of the studied microorganisms were insensitive to erythromycin. Over the past 5 years, the number of staphylococcal strains sensitive to ceftriaxone decreased by more than 50% (65.0% in 2016 and 14.3% in 2021), to chloramphenicol by 28.7%, ampicillin by 14.4%. The number of streptococci sensitive to all groups of antibiotics decreased by 3-4% 2021 compared to 2016, only to ampicillin the number of sensitive strains decreased by 16%.


Assuntos
Infecções Respiratórias , Staphylococcus aureus , Criança , Humanos , Testes de Sensibilidade Microbiana , Resistência Microbiana a Medicamentos , Antibacterianos/uso terapêutico , Streptococcus , Cloranfenicol/uso terapêutico , Staphylococcus , Infecções Respiratórias/tratamento farmacológico , Orofaringe , Ampicilina/uso terapêutico
9.
Int J Pharm ; 628: 122323, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36280222

RESUMO

This study focused on the incorporation ofchloramphenicol (CAP)intowhey protein (WPI)(CAP-MPs) and was further formulated into a thermoresponsivein situgel for wound healing treatment.CAP microparticleswereproduced by two steps emulsification process.The modification ofthe mixing time and speed, as well as the variation of WPI and CAP concentration, resulted in various particle sizes(0.95 ± 0.07to 8.94 ± 0.32 µm). The optimum formulation was achieved using 15 % WPI in water, and 2 mL CAP in propylene glycol withatotal amount in the mixture was 100 mg, and 5 % oil phase, with homogenization time and speed at 15 min and 7500 rpm, respectively. The characterization of CAP-MP's showed PDI values at 0.110 ± 0.007, drug entrapment efficiency at70.64 ± 1.12 %,and drug loading at 8.80 ± 0.12 %.SEM analysis of CAP-MPs showedspherical, uniform particlesdispersed across the surface of the emulsion droplets.FTIR analysis showed strong development of hydrogen bonds proving the encapsulation was effective. Pluronic® F127, Pluronic® F68, and hydroxypropyl methylcellulose (HPMC)were used for the thermoresponsive hydrogel formulation with desired properties. The gel formulationcouldprovideliquid form at room temperature (25 °C) andformagel at 31 °C.This optimum formula was able to increase the bioadhesivity (28160.92 ± 3902.09 dyne/cm2) as well as the percentage of gels skin occlusivity after 24 h (32.82 ± 0.004),and to be considered, it did not show hemolytic activities. In anex vivoantibacterial activity, this combination approach showed a 99.95 % reduction in theStaphylococcus aureus(SA) population.


Assuntos
Hidrogéis , Poloxâmero , Hidrogéis/química , Poloxâmero/química , Proteínas do Soro do Leite , Cicatrização , Cloranfenicol
10.
Appl Microbiol Biotechnol ; 106(22): 7683-7697, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36205764

RESUMO

In recent years, the risk from environmental pollution caused by chloramphenicol (CAP) has emerged as a serious concern worldwide, especially for the co-selection of antibiotic resistance microorganisms simultaneously exposed to CAP and salts. In this study, the multistage contact oxidation reactor (MCOR) was employed for the first time to treat the CAP wastewater under the co-existence of CAP (10-80 mg/L) and salinity (0-30 g/L NaCl). The CAP removal efficiency reached 91.7% under the co-existence of 30 mg/L CAP and 10 g/L NaCl in the influent, but it fluctuated around 60% with the increase of CAP concentration and salinity. Trichococcus and Lactococcus were the major contributors to the CAP and salinity shock loads. Furthermore, the elevated CAP and salinity selection pressures inhibited the spread of CAP efflux pump genes, including cmlA, tetC, and floR, and significantly affected the composition and abundance of antibiotic resistance genes (ARGs). As the potential hosts of CAP resistance genes, Acinetobacter, Enterococcus, and unclassified_d_Bacteria developed resistance against high osmotic pressure and antibiotic environment using the efflux pump mechanism. The results also revealed that shifting of potential host bacteria significantly contributed to the change in ARGs. Overall, the co-existence of CAP and salinity promoted the enrichment of core genera Trichococcus and Lactococcus; however, they inhibited the proliferation of ARGs. KEY POINTS: • Trichococcus and Lactococcus were the core bacteria related to CAP biodegradation • Co-existence of CAP and salinity inhibited proliferation of cmlA, tetC, and floR • The microorganism resisted the CAP using the efflux pump mechanism.


Assuntos
Cloranfenicol , Microbiota , Cloranfenicol/farmacologia , Antibacterianos/farmacologia , Salinidade , Cloreto de Sódio , Genes Bacterianos , Resistência Microbiana a Medicamentos/genética , Águas Residuárias/análise , Bactérias/genética
11.
Sci Rep ; 12(1): 17054, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224225

RESUMO

Improper discharge of waste dry cell batteries and untreated antibiotics laden effluents to the environment pose serious threat to the sustenance of the ecosystem. In this study, synthesis of reduced graphene oxide-ZnO (rGO-ZnO) nanocomposite was achieved via a bioreduction process using waste dry cell battery rod as graphene oxide (GO) precursor. The nanocomposite was applied in the ultraviolet photocatalytic degradation of chloramphenicol (CAP) at 290 nm in the presence of hydrogen peroxide. RGO-ZnO nanocomposite was characterized by SEM, TEM, XRD, BET and FTIR. TEM image of the nanocomposite revealed a polydispersed, quasi-spherical zinc oxide on a coarse reduced graphene oxide surface. XRD patterns showed sharp, prominent crystalline wurtzite hexagonal phases of ZnO and rGO. BET surface area of the nanocomposite was 722 m2/g with pore size of 2 nm and pore volume of 0.4 cc/g. % photo-removal efficiency increased with increasing irradiation time but diminished at higher pH, temperature and CAP concentration. Photocatalytic adsorption process fitted more accurately into the Freundlich model (R2 = 0.99) indicating a multilayer adsorption mechanism. 92.74% reduction in chemical oxygen demand (COD) level of veterinary effluent was obtained after treatment with the nanocomposite thus affirming its effectiveness in real waste water samples.


Assuntos
Óxido de Zinco , Antibacterianos , Catálise , Cloranfenicol , Ecossistema , Grafite , Peróxido de Hidrogênio , Águas Residuárias , Óxido de Zinco/química
12.
Biomed Res Int ; 2022: 8101866, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36203487

RESUMO

This study was designed to identify Enterococcus faecalis from clinical mastitis of cattle and determine their antimicrobial resistance and virulence determinants to evaluate their potential public health significance. A total of 105 composite milk samples (80 from cattle with clinical mastitis and 25 from apparently healthy cattle) were analyzed. E. faecalis were isolated by culturing on enterococcal selective media and identified by PCR and sequencing. Antimicrobial resistance phenotype was elucidated by the disc diffusion method, and MIC was determined by broth microdilution method according to CLSI guidelines. Detection of antimicrobial resistance and virulence genes was done by PCR. E. faecalis were isolated from 11.25% (9/80) of the clinical mastitis and 4% (1/25) of the apparently healthy cattle milk samples. The disc diffusion test revealed 40% isolates as resistant to tetracycline and azithromycin, respectively. Among them, 20% (2/10) of isolates showed resistance to both tetracycline and azithromycin. Tetracycline-resistant isolates showed MIC ranging from ≥64 to >128 µg/ml and carried tetracycline-resistant genes tetK, tetL, and tetM in 25%, 25%, and 50% of the resistant isolates, respectively. On the other hand, all the isolates were sensitive to amoxicillin, ampicillin, bacitracin, chloramphenicol, gentamicin, penicillin, and vancomycin. In addition, the isolates carried at least one of the nine virulence genes screened with pil having the highest frequency, followed by fsrB, fsrC, ace, sprE, gelE, and agg genes. Positive correlations were evident between ace, fsrC, gelE, and sprE genes that are associated with the attachment and biofilm formation in E. faecalis. E. faecalis isolated in this study carried antibiotic resistance and virulence determinants which explain their competence to be potential human pathogens.


Assuntos
Enterococcus faecalis , Mastite , Amoxicilina , Ampicilina , Animais , Antibacterianos/farmacologia , Azitromicina , Bacitracina , Bangladesh , Bovinos , Cloranfenicol , Farmacorresistência Bacteriana/genética , Feminino , Gentamicinas/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Penicilinas , Saúde Pública , Tetraciclinas , Vancomicina , Virulência/genética , Fatores de Virulência/genética
13.
World J Microbiol Biotechnol ; 38(12): 237, 2022 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-36244035

RESUMO

The current study was carried out to investigate metabolic activities and main probiotic characteristics of two Latilactobacillus sakei strains (8.P1 and 28.P2) isolated from pastirma, a highly seasoned, air-dried cured beef. Both strains showed antimicrobial activity against important foodborne pathogens like Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa and so forth. For the characterization of antimicrobial activity, the effect of various enzymes, temperature and pH were tested. The results of the tests demonstrated that the antimicrobial activity of strains was based on the production of protein-structured compounds such as bacteriocin or bacteriocin like peptides. In metabolic activity studies, amounts of the lactic acid, proteolytic activity and hydrogen peroxide produced by the 8.P1 and 28.P2 were found to range between 16.09 and 17.32 mg/mL, 0.24 and 0.04 mg/mL and 0.98 and 0.04 µg/mL, respectively. It was also observed that neither strain could produce exopolysaccharide. Both strains were found susceptible to vancomycin, chloramphenicol, gentamicin, tetracycline, and netilmicin sulfate. When the strains are evaluated with respect to their probiotic potential, 28.P2 could tolerate acidic conditions, but 8.P1 showed sensitivity. The survival rate of the strains in the simulated gastric juice and their adhesion abilities were found suitable to stay alive in the gastrointestinal tract and to proliferate in the intestine. The evaluation of all the features of both strains demonstrated that both strains had the potential to be used as a protective culture. In addition, it was observed that 8.P1 and 28.P2 were more suitable as a starter culture and a probiotic candidate respectively.


Assuntos
Bacteriocinas , Lactobacillus sakei , Probióticos , Animais , Antibacterianos/farmacologia , Bacteriocinas/química , Bovinos , Cloranfenicol , Peróxido de Hidrogênio/farmacologia , Ácido Láctico , Netilmicina , Tetraciclinas , Vancomicina
14.
Pol J Microbiol ; 71(3): 395-409, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36185024

RESUMO

Lactic acid bacteria are used in various types of probiotic products. Due to the constantly growing probiotics market, new strains with pro-health properties are sought. The present study compared 39 strains of Lactobacillus, Lacticaseibacillus, and Lactiplantibacillus, isolated from probiotic products and healthy people. The current research aimed to search for new, potentially probiotic strains. For this purpose the relationship between Lactobacillaceae strains was carried out; moreover, the basic properties of probiotic microorganisms, such as survival at low pH and bile salt environment, antibiotic susceptibility, aggregation and antagonism were estimated. The properties of these isolates were also compared with the properties of probiotic strains from the ATCC collection. In comparing the genetic relationship (PFGE method) between the tested isolates, it was observed that some of them show a high degree of similarity. All tested strains tolerated an environment with a pH value of 3.0, and the addition of 0.3% bile salt; showed auto-aggregation properties and displayed antagonism against pathogenic microorganisms. In the present study, the bacteria were susceptible to tetracycline, chloramphenicol and ampicillin; the resistance to vancomycin depended on the bacteria type. All the properties were strain-depended. Most of the tested strains had properties comparable to the reference strains. Three L. acidophilus strains isolated from cervical swabs seem to be promising candidates for probiotic strains.


Assuntos
Probióticos , Vancomicina , Ampicilina , Antibacterianos/farmacologia , Ácidos e Sais Biliares/farmacologia , Cloranfenicol , Humanos , Tetraciclinas
15.
Mikrochim Acta ; 189(11): 419, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36251095

RESUMO

A novel strategy is reported to access high-performance nanozymes via the self-coordination of ferrocyanides ([Fe(CN)6]4-) onto the surface of the Cu3BiS3 (CBS) nanorods. Notably, the in situ formed nanozymes had high catalytic activity, good stability, low cost, and easy mass production. The formed nanozyme catalyzed the oxidation of the typical chromogenic substrate of 3,3',5,5'-tetramethylbenzidine (TMB) with a distinctive absorption peak at 652 nm, accompanied by a blue color development. Moreover, the attachment of deoxyribonucleoside 5'-monophosphates (dNMP) beforehand onto the surface of CBS prevented coordination of ferrocyanides and resulted in the tunable formation of the nanozyme, thereby enabling the construction of an exquisite biosensing platform. Taking the aptasensing of chloramphenicol (CAP) as an example, the engineered nanozyme allowed the construction of a homogenous, label-free, and high-performance bioassay in terms of its convenience and high sensitivity. Under the optimal conditions, changes in the absorption intensity at 652 nm for the oxidized TMB provides a good linear correlation with the logarithm of CAP concentrations in the range 0.1 pM to 100 nM, and the limit of detection was 0.033 pM (calculated from 3σ/s). Considering a vast number of bioreactions can be connected to dNMP production, we expect the engineerable nanozyme as a universal signal transduction scaffold for versatile applications in bioassays. Through the attachment of deoxyribonucleoside 5'-monophosphate (dNMP) on the surface of CBS to regulate the generation of self-coordinated nanozyme CBS/BiHCF, a homogeneous, label-free, and high-performance universal aptasensing platform was constructed.


Assuntos
Ferrocianetos , Nanotubos , Benzidinas , Cloranfenicol , Compostos Cromogênicos , Desoxirribonucleosídeos
16.
Molecules ; 27(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36234859

RESUMO

New Ni (II) and Cu (II) complexes with pyridoxal-semicarbazone were synthesized and their structures were solved by X-ray crystallography. This analysis showed the bis-ligand octahedral structure of [Ni(PLSC-H)2]·H2O and the dimer octahedral structure of [Cu(PLSC)(SO4)(H2O)]2·2H2O. Hirshfeld surface analysis was employed to determine the most important intermolecular interactions in the crystallographic structures. The structures of both complexes were further examined using density functional theory and natural bond orbital analysis. The photocatalytic decomposition of methylene blue in the presence of both compounds was investigated. Both compounds were active toward E. coli and S. aureus, with a minimum inhibition concentration similar to that of chloramphenicol. The obtained complexes led to the formation of free radical species, as was demonstrated in an experiment with dichlorofluorescein-diacetate. It is postulated that this is the mechanistic pathway of the antibacterial and photocatalytic activities. Cyclic voltammograms of the compounds showed the peaks of the reduction of metal ions. A molecular docking study showed that the Ni(II) complex exhibited promising activity towards Janus kinase (JAK), as a potential therapy for inflammatory diseases, cancers, and immunologic disorders.


Assuntos
Complexos de Coordenação , Semicarbazonas , Antibacterianos/farmacologia , Cloranfenicol , Complexos de Coordenação/química , Cristalografia por Raios X , Escherichia coli/metabolismo , Janus Quinases/metabolismo , Ligantes , Azul de Metileno , Simulação de Acoplamento Molecular , Estrutura Molecular , Piridoxal , Staphylococcus aureus/metabolismo , Níquel , Cobre
17.
PLoS One ; 17(10): e0276625, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36269734

RESUMO

Thermophilic Campylobacter species are common cause of animal and human bacterial diseases with growing resistance to antimicrobials. The aim of this study was to determine the prevalence and antimicrobial susceptibility pattern of Campylobacter species from bovine, knives and personnel in Jimma Town, Ethiopia. Faecal samples and carcasses swabs were collected from cattle systematically selected from the annual plan of Jimma Municipal Abattoir. Personnel hand and knife swabs were collected after slaughtering each selected cattle. A cross-sectional study with systematic sampling method was conducted from October 2019 to September 2020 for the isolation, identification and antimicrobial susceptibility pattern of thermophilic Campylobacter species. Isolation and identification of Campylobacter species were performed according to the techniques recommended by the International Organization for Standardization, and in vitro antibiotic susceptibility testing was screened using the standard agar disc diffusion method as recommended by Clinical and Laboratory Standards Institutions. A total of 684 samples (171 samples from faeces, carcasses, knives and personnel hands, were collected independently). The overall prevalence of thermophilic Campylobacterspecies was 5.6% (38/684). Majority of the isolates were from faecal samples (12.9%, n = 22) followed by carcass swabs(4.1% n = 7), knife swabs(3.5% n = 6) and personnel hand swabs(1.8% n = 3). Isolated and identified species of C.jejuni, C. coli and C. lari accounted for 63.2%, 23.7% and 13.2%, respectively. The isolated Campylobacter species were found to be resistant to Cephalothin (100%), Ampicillin (60.5%), Cefotaxime (60.5%), Chloramphenicol (47.4%) and Tetracycline (42.1%). On the other hand, the isolates were susceptible to Nalidixic acid (86.8%), Ciprofloxacin (86.8%), Sulphamethazole (84.2%), Ceftriaxone (78.9%), Clindamycin (68.4%) and Cefixime (65.8%). 84.2% of the isolates showed multi-drug resistance for three-to-six drug classes. All the C. lari isolates were multidrug resistant. All the three isolated species of Campylobacter were resistant to Cephalothin, and most were multidrug resistant. Isolation of Campylobacter species from faecal, carcass, knife and hand swabs revealed possible risk of contamination and exposure to Campylobacter infection of those who consume raw meat. Therefore, enactment of hygienic practices during the slaughtering process, proper handling and cooking of meat and awareness creation on jurisdictional antibiotic usage are required to avoid Campylobacter infection.


Assuntos
Infecções por Campylobacter , Campylobacter , Bovinos , Animais , Humanos , Infecções por Campylobacter/microbiologia , Matadouros , Ácido Nalidíxico , Cefalotina , Estudos Transversais , Cefixima , Ceftriaxona , Clindamicina , Ágar , Etiópia/epidemiologia , Resistência Microbiana a Medicamentos , Antibacterianos/farmacologia , Tetraciclina , Ciprofloxacina , Cloranfenicol/farmacologia , Ampicilina , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana
18.
Vet Med Sci ; 8(6): 2482-2493, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36253836

RESUMO

BACKGROUND: Campylobacter jejuni and Campylobacter coli are the most significant Campylobacter species responsible for severe gastrointestinal disorders. Raw poultry meat is considered a source of Campylobacter transmission to the human population. OBJECTIVES: The present study was aimed to assess the prevalence rate, antibiotic resistance properties, virulence characters and molecular typing of C. jejuni and C. coli strains isolated from raw poultry meat samples. METHODS: Three hundred and eighty raw poultry meat samples were collected and analysed for the presence of Campylobacter spp. using the microbial culture. Species identification was done using the Polymerase Chain Reaction. Disk diffusion was developed to assess the antimicrobial resistance pattern of isolates. The distribution of virulence and antimicrobial resistance genes was determined by PCR. Enterobacterial Repetitive Intergenic Consensus-PCR was used for molecular typing. RESULTS: Campylobacter species were isolated from 6.25% of examined samples. C. jejuni and C. coli contamination rates were found to be 57.44% and 48.14%, respectively. C. jejuni strains harboured the highest resistance rate against serythromycin (42.59%), ampicillin (38.88%), ciprofloxacin (33.33%), chloramphenicol (31.48%) and tetracycline (31.48%). C. coli isolates harboured the highest resistance rate against ampicillin (73.07%), ciprofloxacin (73.07%), erythromycin (65.38%) and chloramphenicol (50%). AadE1 (44.44%), blaOXA-61 (42.59%) and tet(O) (35.18%) were the most commonly detected resistance genes in C. jejuni and cmeB (34.61%) and blaOXA-61 (34.61%) were the most commonly detected among C. coli strains. The most frequent virulence factors among the C. jejuni isolates were flaA (100%), ciaB (100%), racR (83.33%), dnaJ (81.48%), cdtB (81.48%), cdtC (79.62%) and cadF (74.07%). The most frequent virulence factors among the C. coli isolates were flaA (100%), ciaB (100%), pldA (65.38%) and cadF (61.53%). CONCLUSIONS: The majority of C. jejuni and C. coli strains had more than 80% similarities in their ERIC-PCR pattern, which may show their common source of transmission. The role of goose and quebec meat samples as reservoirs of virulent and antimicrobial resistant Campylobacter spp. was determined.


Assuntos
Campylobacter , Humanos , Animais , Aves Domésticas/genética , Aves Domésticas/microbiologia , Virulência/genética , Antibacterianos/farmacologia , Prevalência , Farmacorresistência Bacteriana/genética , Fatores de Virulência/genética , Carne/microbiologia , Tipagem Molecular/veterinária , Ciprofloxacina , Ampicilina , Cloranfenicol
19.
Biomed Res Int ; 2022: 3463472, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36299705

RESUMO

Background: Dental caries is a major public oral infectious disease globally due to its high prevalence and significant social impact. Many studies have been conducted on dental caries in Ethiopia; however, they fail to convey the antimicrobial resistance in the oral environment. Objective: This study was conducted to determine the antimicrobial susceptibility patterns and biofilm formation in the bacteria isolated from dental caries and its associated factors of dental caries in THE Ayder Comprehensive Specialized Hospital and private dental clinics located at Mekelle, Ethiopia. Methods: A cross-sectional study was conducted from September 2019 to October 2020. Sociodemographic characteristic, behavioral, and clinical data were collected using structured questionnaires. A total of 422 dental caries-suspected patients were selected and coronal caries scraps were collected by the dentist aseptically; these samples were transported to a microbiological laboratory to identify the antibiotic sensitivity assay and biofilm formation by the isolated pathogens. The data was analyzed using SPSS version 22. The P value of ≤0.05 was considered statistically significant. Results: The overall prevalence of culture-positive samples was found to be 196 (46.4%). From the 196 culture-positive samples, 327 bacteria were isolated. Out of 327 bacterial isolates, 196 (46.4%) were identified as Streptococcus mutans and 69 (35.2%) were identified to be Staphylococcus aureus. From the isolated bacteria, 311 (95.1%) organisms were identified as positive for biofilm formation. From the AST assay, we have identified that penicillin has the highest resistance rate of 76.5%, followed by tetracycline at 64.8%. In contrast, the antibiotics such as cefoxitin and chloramphenicol have a sensitivity of 83.5% and 81.6% to all the bacterial isolates. The overall prevalence of multidrug resistance (MDR) in the isolates was found to be 40.4%. With respect to the associated risk factors, the white spot (AOR = 3.885, 95% CI 1.282-11.767, P = 0.016), gum bleeding (AOR = 2.820, 95% CI 1.006-7.907, P = 0.049), toothache (AOR = 2.27, 95% CI 0.58-0.885, P = 0.033), and chocolate consumption (AOR = 5.314, 95% CI 1.760-16.040, P = 0.003) were statically associated with dental caries bacterial infection. Conclusion: Based on our findings, we recommend the integration of routine culture and AST into clinical practice that might support the diagnosis and management of MDR in dental caries. The education on proper dietary habits might support the prevention and control of dental caries. It is important to provide health education on how to improve oral health in the study area. The education on proper dietary habits might support the prevention and control of dental caries. Further study is needed to find the other determinant factors of dental caries.


Assuntos
Cefoxitina , Cárie Dentária , Humanos , Estudos Transversais , Etiópia/epidemiologia , Cárie Dentária/epidemiologia , Cárie Dentária/tratamento farmacológico , Clínicas Odontológicas , Bactérias , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Hospitais , Penicilinas , Cloranfenicol , Tetraciclinas , Testes de Sensibilidade Microbiana
20.
Surg Infect (Larchmt) ; 23(9): 834-840, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36251956

RESUMO

Background: International guidelines advise against prophylactic antimicrobial agents for primarily closed surgical incisions, but most oculoplastic surgeons report using chloramphenicol ointment. We evaluated baseline surgical site infection (SSI) rates in patients undergoing eyelid surgery who received prophylactic chloramphenicol ointment post-operatively. Withdrawal of prophylaxis was then prospectively audited to establish whether infection rates changed in a clinically meaningful way. This article reports the early findings. Patients and Methods: A single-center retrospective audit was undertaken; electronic medical records were reviewed for consecutive patients who underwent eyelid surgery with primary incision closure. All patients received post-operative prophylactic chloramphenicol. Those with histopathologic evidence of malignancy were excluded. Patient demographics, surgical details, evidence of post-operative SSI and other complications were recorded. Local policy was changed in accordance with national guidelines; prophylactic chloramphenicol ointment was withheld, and the above information collected prospectively. Our policy excluded skin malignancies, full thickness skin grafts, patients on systemic immunosuppression, and diabetes mellitus because of potential increased infection risk. Results: There were no statistically significant differences between the groups, except seniority of surgeon. Surgical site infection was identified in 14 of 872 eyes (1.6%) receiving post-operative chloramphenicol, and three of 133 eyes (2.25%) without antibiotic agents, which was not statistically significant. Conclusions: Post-operative SSI rates in eyelid surgery are low. Routine use of prophylactic antibiotic agents in primarily closed surgical eyelid incisions does not adhere to international standards and may contribute to antimicrobial resistance. Early results suggest infection rates remain low without prophylactic chloramphenicol; clinicians should consider withdrawing it from routine practice in suitable patients.


Assuntos
Antibioticoprofilaxia , Infecção da Ferida Cirúrgica , Humanos , Antibioticoprofilaxia/métodos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Infecção da Ferida Cirúrgica/etiologia , Projetos Piloto , Estudos Retrospectivos , Pomadas , Antibacterianos/uso terapêutico , Pálpebras , Cloranfenicol
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