RESUMEN
Although citric acid (CA) has antioxidant, antibacterial, and acidulating properties, chronic ingestion of CA can cause urolithiasis, hypocalcemia, and duodenal cancer, emphasizing the need for early detection. There are very few documented electrochemical-based sensing methods for CA detection due to the challenging behavior of electrode fouling caused by reactive oxidation products. In this study, a novel, non-enzymatic, and economical electrochemical sensor based on cobalt oxide nanoparticles (CoOxNPs) is successfully reported for detection CA. The CoOxNPs were synthesized through a simple thermal decomposition method and characterized by SEM, FT-IR, EDX, and XRD techniques. The proposed sensing platform was optimized by various parameters, including pH (7.0), time (15 min), and concentration of nanoparticles (100 mM) etc. In a linear range of 0.05-2500 µM, a low detection limit (LOD) of 0.13 µM was achieved. Theoretical calculations (ΔRT), confirmed hydrogen bonding and electrostatic interactions between CoOxNPs and CA. The detection method exhibited high selectivity in real media like food and biological samples, with good recovery values when compared favorably to the HPLC method. To facilitate effective on-site investigation, such a sensing platform can be assembled into a portable device.
Asunto(s)
Ácido Cítrico , Cobalto , Técnicas Electroquímicas , Óxidos , Cobalto/química , Técnicas Electroquímicas/instrumentación , Óxidos/química , Ácido Cítrico/química , Nanopartículas del Metal/química , Límite de Detección , Nanopartículas/químicaRESUMEN
This study aims to remove Congo red dye from industrial effluent using economical agriculturally-based nano-biosorbents like magnetic orange peel, peanut shells, and tea waste. The nano-biosorbents were characterized by various analytical techniques like SEM, FT-IR, BET and XRD. The highest adsorption capacity was obtained under the following ideal conditions: pH = 6 (orange peel and peanut shells), pH = 3 (tea waste), and dosages of nano-biosorbents with varying timeframes of 50 min for tea waste and peanut shells and 30 min for orange peel. The study found that tea waste had the highest removal rate of 94% due to its high porosity and responsible functional groups, followed by peanut shells at 83% and orange peel at 68%. The Langmuir isotherm model was found to be the most suitable, with R2 values of 0.99 for tea waste, 0.92 for orange peel, and 0.71 for peanut shells. On the other hand, a pseudo-second-order kinetic model was very feasible, showing an R2 value of 0.99 for tea waste, 0.98 for peanut shells and 0.97 for orange peel. The significance of the current study lies in its practical application, enabling efficient waste management and water purification, thereby preserving a clean and safe environment.
Asunto(s)
Rojo Congo , Rojo Congo/química , Cinética , Adsorción , Agricultura , Contaminantes Químicos del Agua/química , Residuos Industriales , Espectroscopía Infrarroja por Transformada de Fourier , Té/química , Arachis/química , Concentración de Iones de HidrógenoRESUMEN
Vitamins are crucial micronutrients found in limited quantities in food, living organisms, and soil. Since most vitamins are not produced within the human body, a lack of these essential nutrients can result in various physiological disorders. Analyzing vitamins typically involves costly, time-consuming methods, requiring skilled personnel, automated equipment, and dedicated laboratory setups. The pressing need is for the development of efficient, portable, and user-friendly detection techniques that are cost-effective, addressing the challenges associated with traditional analytical approaches. In recent years, electrochemical sensors and electrochemical microfluidic devices have garnered prominence owing to their remarkable sensitivity, quick analysis, cost-effectiveness, and facile fabrication procedures. Electrochemical sensing and microfluidics are two distinct fields that are often integrated to create powerful and versatile sensing devices. The connection between them leverages the advantages of both fields to create highly efficient, miniaturized, and portable analytical systems. This interdisciplinary approach has led to the development of innovative devices with broad applications in various scientific, medical, and environmental domains. This review begins by outlining the importance of vitamins in human nutrition and health and emphasizing the need for precise and reliable sensing techniques. Owing to the limited literature available on electrochemical detection of vitamin B complexes, this review offers an in-depth analysis of modern electrochemical sensing of water-soluble vitamins, focusing on B1, B2, B6, B9, and B12. The challenges faced by researchers are addressed, including selectivity, sensitivity, interference, matrix effects, and calibration, while also exploring promising prospects such as nanomaterial integration, miniaturization, microfluidics-based IoTs, and innovative sensor designs.
RESUMEN
Tenofovir (TFV) is an antiviral drug used to treat the co-infections of HIV/HBV viruses. Accurate monitoring of TFV drug levels is essential for evaluating patient adherence, optimizing dosage, and assessing treatment efficacy. Herein, we propose an innovative electrochemical sensing approach by using the alkaline phosphatase (ALP) enzyme with the support of BaTiO3 nanoparticles. An attractive sensitivity and selectivity of the developed sensor towards TFV detection were achieved. First, the nanoparticles were synthesized by following a single-step sol-gel method and characterized through various analytical techniques, including SEM, EDX, FT-IR, BET, zeta potential, XRD, and UV-vis and Raman spectroscopy. The suggested mechanism demonstrated the formation of a strong bond between TFV and the ALP enzyme, primarily through the phosphate group, resulting in enzyme inhibition. Various parameters like nanoparticle amount, electrode modification time with enzyme and BaTiO3 nanoparticles, and drug incubation time were optimized. The biosensor demonstrated an outstanding limit of detection (LOD) of 0.09 nM and recovery percentages of 98.6-106% in human blood serum, indicating adequate repeatability and selectivity. The proposed biosensor can be converted into a portable device for measuring small sample volumes and observing patients for immediate medical care or personalized therapies. It achieved better sensitivity compared to existing methods, making it suitable for precise drug detection in microdoses.
RESUMEN
Being one of the vital reactive oxygen species (ROS), abnormal level of hypochlorite ion (ClO-) may pose detrimental threats to living organisms. Therefore, highly selective, and rapid monitoring of ClO- in living system is of prime importance to protect living organisms from its harmful effects. In this regard, design of synthetic fluorescent probes for ClO- has garnered considerable attention. However less fluorescence emission in aggregated state and less photostability of several existing probes for ClO- inspired us to design aggregation induced emission (AIE) active fluorescent probes SH1 and SH2. Probes were rationally designed by introducing thiourea moiety that selectively reacted through desulfurization reaction and resulted in highly selective detection of ClO-. Hypochlorite induced desulfurization reaction was validated through 1H NMR titration and DFT studies. Fine tuning of probes SH1 and SH2 prompted highly sensitive nanoscale (55 nM and 77 nM) and rapid (15 and 35 sec) detection of ClO-. Probe SH1 displayed less cytotoxic effect to live cells before it was successfully applied for bioimaging of ClO- in live MCF-7 cells. Moreover, probes displayed excellent sensing potential for ClO- in blood serum and real water samples. Advantageously, probe coated portable fluorescent films were fabricated for the easy and fast monitoring of ClO-. Of note, this work offers excellent design strategy for highly selective detection of ClO- that may lead to clinical trials.
Asunto(s)
Colorantes Fluorescentes , Ácido Hipocloroso , Humanos , Colorantes Fluorescentes/toxicidad , Colorantes Fluorescentes/química , Ácido Hipocloroso/química , Suero , Células MCF-7 , Imagen ÓpticaRESUMEN
Dyes are valuable color compounds used in textile industries but at the same time their toxic and carcinogenic properties distract environmental system due to the chemical intricacy and multiplicity smearing them non-biodegradable. Therefore, the aim of present research rests in the use of cost effective, easily available and eco-friendly reformed novel biosorbents of Dodonaea Viscosa (DV). For this purpose AC-alginate beads were synthesized successfully through clogging AC derived from Dodonaea Viscosa (ACAB) into beads of calcium-alginate for removal of methylene blue (MB) from diluted solution. The external morphology (SEM, EDX) and functional groups (FT-IR) supported the favorable conditions for adsorption. The thermal properties have been evaluated using thermo-gravimetric study (TGA). After proper optimization like at pH 8, and biosorbent dose of 250 mg, temperature 350 K and time at 60 min the obtained adsorption capacity for DV leaves was set up to be 239 mg/g and for ACAB was 370 mg/g. By applying different adsorption isotherm models, the Freundlich was found to be best suited with highest R2 = 0.998 for DV and 0.995 for ACAB biosorbents. While the various kinetics models were also verified and data was well matched to Pseudo-second order kinetics model (R2 = 0.99 for DV and 0.99 for ACAB). Thermodynamics parameters enlightened that the adsorption process was endothermic (ΔH = 19,097 for ACAB and 10,899.6 J/mol for DV, ΔS = 89,087 for ACAB and 5.94 (J/mol for DV) and spontaneous in nature. The desorption study was satisfactory up to five number of absorption-desorption cycles for both the adsorbents particularly ACAB reflected an excellent percent removal (>90%). Consequently, the viability of DV can be used as a possible potential precursor for AC preparation besides cost effective adsorbent in the real sample treatment for dye removal.
Asunto(s)
Alginatos , Contaminantes Químicos del Agua , Alginatos/química , Azul de Metileno/química , Carbón Orgánico/química , Calcio , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/química , Termodinámica , Cinética , Adsorción , Colorantes/química , Concentración de Iones de HidrógenoRESUMEN
Salmonella enteric serovar Typhimurium is the most common enteric pathogen in humans and animals. Consumption of contaminated food or water triggers inflammation that allows Salmonella to spread into the gut and causes gastrointestinal diseases. The infection spreads by intestinal invasion, phagocyte internalization and subsequent dissemination in many other patients. This research used TolA, a Salmonella typhimurium membrane protein, to computationally design a multi-epitope vaccine against the pathogen. Complete consistency of the candidate vaccine was checked In silico, and molecular dynamics simulations confirmed the vaccine's stability. According to docking report, the vaccine has a good affinity with toll-like receptors. In silico cloning and codon optimization techniques improved the vaccine's efficacy in Salmonella typhimurium manifestation process. The candidate vaccine induced an efficient immune response, as determined by In silico immune simulation. Computational studies revealed that the engineered multi-epitope vaccine is structurally stable, capable of eliciting particular immunological reactions, and therefore a candidate for a latent Salmonella typhimurium vaccine. However, wet lab studies and further investigations are required to confirm the results.
RESUMEN
An alternative method of electrochemical oxidation was employed to degrade persistent compounds in the form of antibiotics using strong oxidizing agents such as hydroxyl ions. A 24 factorial design was employed to check the effect of four factors namely pH, current density, electrolysis time and electrolyte concentration set at their high (+) and low (-) levels on the antibiotics (amoxicillin, ciprofloxacin and erythromycin) degradation in water. The response was obtained in the form of COD (chemical oxygen demand) removal. A prediction model was developed to predict the values of COD removal. Later the main effect, contribution and interactions were studied with Design Expert Software 7.0. About 89.5% COD removal was obtained when pH and time were set at their high level and the other two factors at their low level. It was determined that the pH when set at high level (pH 9) had the most effect (24.68) and contribution (43.6) in the degradation process and hence the removal of COD. This technology of electrochemical oxidation can be employed in industries to efficiently remove pharmaceuticals, paints, dyes and other organic compounds.
Asunto(s)
Amoxicilina/análisis , Análisis de la Demanda Biológica de Oxígeno/métodos , Ciprofloxacina/análisis , Técnicas Electroquímicas/métodos , Eritromicina/análisis , Agua/análisis , Amoxicilina/metabolismo , Antibacterianos/análisis , Antibacterianos/metabolismo , Ciprofloxacina/metabolismo , Eritromicina/metabolismo , Agua/metabolismo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodosRESUMEN
The Vitex negeundo is a widely used medicinal plant which has not been fully investigated in the past. We assessed the in vivo hepatoprotective and in vitro antioxidant, antibacterial, cytotoxicity and antiproliferative study of leaf extracts of V. Neugundo. The chemically profiled using HPLC, three flavonoids were quantified and GC-MS analysis revealed the presence of two new compounds those were not reported earlier. The animal study was conducted on mice treated with CCl4 using methanolic and chloroform extracts (100, 200 and 300 mg/kg b.w), with silymarin as a positive control. Hepatoprotective effects were determined by analyzing blood for liver marker enzymes, direct bilirubins and hematological parameters (RBC, WBC and platelets). The methanolic extract (300 mg/kg b.w) has shown the stronger hepatoprotective effects against abnormalities produced by CCl4. The in vivo hepatoprotective effects correlated well with the in vitro antioxidant, cytotoxicity and antiproliferative activities and with high levels of flavonoids and other organic compounds analyzed from plant extracts. The leaf extracts of this plant could be good candidates for lead compound required for the development of antioxidant/anticancer drugs.
Asunto(s)
Extractos Vegetales/química , Plantas Medicinales/química , Animales , Antioxidantes/química , Antioxidantes/farmacología , Artemia/efectos de los fármacos , Tetracloruro de Carbono/farmacología , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión/métodos , Femenino , Flavonoides/química , Flavonoides/farmacología , Células Hep G2 , Humanos , Hígado/efectos de los fármacos , Masculino , Ratones , Fitoterapia/métodos , Extractos Vegetales/farmacología , Hojas de la Planta/química , Silimarina/química , Silimarina/farmacología , Vitex/químicaRESUMEN
The Vitex negeundo is a widely used medicinal plant which has not been fully investigated in the past. We assessed the in vivo hepatoprotective and in vitro antioxidant, antibacterial, cytotoxicity and anti proliferative study of leaf extracts of V. neugundo. The chemically profiled using HPLC, three flavonoids were quantified and GC-MS analysis revealed the presence of two new compounds those were not reported earlier from the leaf extract of V. neugundo. The animal study was conducted on mice treated with CCl4 using methanolic and chloroform extracts (100, 200 and 300mg/kg b.w), with silymarin as a positive control. Hepatoprotective effects were determined by analyzing blood for liver marker enzymes, direct bilirubins and hematological parameters (RBC, WBC and platelets). The methanolic extract (300mg/kg b.w) has shown the stronger hepatoprotective effects against abnormalities produced by CCl4. The in vivo hepatoprotective effects correlated well with the in vitro antioxidant, cytotoxicity and antiproliferative activities and with high levels of flavonoids and other organic compounds analyzed from plant extracts. The leaf extracts of this plant could be good candidates for lead compound required for the development of antioxidant/anticancer drugs.
Asunto(s)
Extractos Vegetales/química , Extractos Vegetales/farmacología , Vitex/química , Animales , Antibacterianos/química , Antibacterianos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Artemia , Tetracloruro de Carbono/toxicidad , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Cromatografía Líquida de Alta Presión , Evaluación Preclínica de Medicamentos , Femenino , Cromatografía de Gases y Espectrometría de Masas , Células Hep G2 , Humanos , Masculino , Ratones , Hojas de la Planta/química , Plantas Medicinales/química , Sustancias Protectoras/química , Sustancias Protectoras/farmacologíaRESUMEN
The consumption of fruits and vegetables has increased in recent years due to their health benefits as fruits and vegetables contain secondary metabolites, those has been reported to possess different pharmacological effects against many human ailments. In the current study antioxidants, antimicrobial and cytotoxic effects of leaves and fruit extracts of Carica papaya were evaluated. The antioxidant activities of plant extracts were carried out by using 2,2 -diphenyl-1- picrylhydrazyl. (DPPH), H2O2, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and reducing power assays and were compared with standards compounds (Ascorbic acid and Rutin). Antibacterial and antifungal activities of leaves and fruit extracts were assessed against four bacterial and fungal strains and also their minimum inhibitory concentration (MIC) values were calculated. Whereas for evaluation of cytotoxicity of plant extracts, brine shrimps cytotoxic assay was performed. Plant extracts were finally analyzed for phytochemicals by using UV/Visible spectrophotometer and High performance liquid chromatography (HPLC). Results indicates that plants extracts contained important compounds (phenols, flavonoids and other secondary metabolites) those have higher antioxidants and antimicrobial as well as lower proportion of MIC values. Whereas cytotoxic index of plant extracts were minor that specifies its appropriateness to use as a pharmaceutical materials probably be essential for drugs preparation. It is expected that such drugs could be lesser toxic and have lower cost as compared to drugs already available in market.
Asunto(s)
Carica/química , Frutas/química , Fitoquímicos/química , Fitoquímicos/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Animales , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antioxidantes/farmacología , Artemia/efectos de los fármacos , Bacterias/efectos de los fármacos , Citotoxinas/química , Citotoxinas/farmacología , Hongos/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodosRESUMEN
Environmental monitoring is important to determine the extent of eco-system pollution and degradation so that effective remedial strategies can be formulated. In this study, an environmentally friendly and cost-effective sensor made up of novel carbon electrode modified with cellulose and hydroxyapatite was developed for the detection of trace lead ions in aqueous system and palm oil mill effluent. Zinc, cadmium, and copper with lead were simultaneously detected using this method. The electrode exhibited high tolerance towards twelve common metal ions and three model surface active substances - sodium dodecyl sulfate, Triton X-100, and cetyltrimethylammonium bromide. Under optimum conditions, the sensor detected lead ions in palm oil mill effluent in the concentration range of 10-50⯵g/L with 0.11⯱â¯0.37⯵g/L limit of detection and 0.37⯱â¯0.37⯵g/L limit of quantification. The validation using tap water, blood serum and palm oil mill effluent samples and compared with Atomic Absorption Spectroscopy, suggested excellent sensitivity of the sensor to detect lead ions in simple and complex matrices. The cellulose produced based on "green" techniques from agro-lignocellulosic wastes, in combination with hydroxyapatite, were proven effective as components in the carbon electrode composite. It has great potential in both clinical and environmental use.
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Carbono , Celulosa , Monitoreo del Ambiente/métodos , Durapatita , Electrodos , Iones , Plomo/análisis , Aceite de PalmaRESUMEN
Antibacterial, antifungal, antioxidant, cytotoxic, and anti-haemolytic activity of various rhizome extracts of Bergenia ciliata were evaluated in this study. The results showed inhibition of the growth of all selected bacterial and fungal strains in comparison with standard antibiotics. The antioxidant activities of Bergenia ciliata extracts were evaluated against DPPH, H2O2, ABTS, total antioxidant capacity and reducing power assays. The order of antioxidant activity of various extracts were methanol> ethanol>n-hexane> aqueous>chloroform. The cytotoxicity ( brine shrimp assay) and anti-haemolytic activities of plant extracts were also promising and varies in dose depended manner. The phytochemical analysis of rhizome extracts of Bergenia ciliata revealed presence of various secondary metabolites which might be responsible for the antimicrobial, antioxidant, cytotoxic and anti-haemolytic activities.
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Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Hojas de la Planta , Rizoma , Saxifragaceae , Animales , Artemia , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/fisiología , Humanos , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/fisiología , Pruebas de Sensibilidad Microbiana/métodos , Fitoquímicos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificaciónRESUMEN
A novel synthesis and characterization of cellulose, hydroxyapatite and chemically-modified carbon electrode (Cellulose-HAp-CME) composite was reported for the analysis of trace Pb(II) ions detection and its validation in blood serum. The Field Emission Scanning Electron Microscopy (FESEM) analyses showed that the composite retained the orderly porous structure but with scattered particle size agglomeration. The Fourier Transform Infrared Spectroscopy (FTIR) spectra suggested the presence of functional groups associated with the bending and stretching of carbon bonds and intermolecular H-bonding. X-ray Diffraction (XRD) analyses further elucidated that the crystallite size could have influenced the properties of the electrode. Based on Thermo-gravimetric Analysis (TGA/DTG), the composites showed thermal stability with more than 60% residual content at 700°C. The sensor was successfully developed for trace Pb(II) ions detection in complex medium such as blood serum, in the physiologically relevant range of 10-60ppb, with resulting Limit of Detection (LOD) of 0.11±0.36ppb and Limit of Quantification (LOQ) of 0.36±0.36ppb. The newly fabricated electrode could be advantageous as a sensing platform with favourable electrochemical characteristics for robust, in situ and rapid environmental and clinical analyses of heavy metal ions.
Asunto(s)
Análisis Químico de la Sangre/instrumentación , Carbono/química , Celulosa/química , Durapatita/química , Plomo/sangre , Plomo/química , Límite de Detección , Técnicas de Química Sintética , Electroquímica , Electrodos , Monitoreo del Ambiente , Humanos , Agua/químicaRESUMEN
In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS). Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local brands while significant concentration of Cd was observed in both brands. For Cr, the level in tobacco of local brands was higher than their emitted smoke, whereas imported brands showed higher level in smoke than in tobacco. The cigarette ash retained 65 to 75% of the metal and about 25 to 30% went into the body. While this study revealed the serious requirement to standardize the manufacturing of tobacco products, more importantly is the urgent need for stronger enforcements to put in place to alert the general population about the hazardous effects of cigarettes and the health risks associated with these toxic metals.
Asunto(s)
Metales/toxicidad , Nicotiana/química , Humo/análisis , Metales/química , Pakistán , Espectrofotometría AtómicaRESUMEN
El gen de la proteína A se usó como marcador genético para la caracterización de aislados de Staphylococcus aureus resistentes a la meticilina (SAMR). De un total de 130 aislados de Staphylococcus aureus, 90 fueron identificados como SAMR y 81 de éstos se pudieron caracterizar por tipificación spa. Todos estos aislados fueron obtenidos de cinco Hospitales Nacionales de la Comunidad. Se utilizaron dos juegos diferentes de cebadores para amplificar la región-X del gen de la proteína A en las cepas de SAMR. Un conjunto de cebadores, spa-F/spa-R ha identificado tres tipos de repeticiones diferentes, a saber, 7 repeticiones (spa 2), 8 repeticiones (spa 3) y 10 repeticiones (spa 4) y otro conjunto de cebadores, spa-1113F/spa-1514R ha identificado 4 tipos de repeticiones diferentes, a saber, 6 repeticiones (spa 1), 15 repeticiones (spa 6), y 17 repeticiones (spa 7) y 19 repeticiones (spa 8). Se identificó la repetición 11 (spa 5) con ambos conjuntos de cebadores. Los tipos de SAMR esporádicos que portaban las repeticiones 6, 7, 10, 17 y 19 fueron poco prevalentes mientras que los SAMR epidémicos con 8, 11, y 15 repeticiones fueron más prevalentes y se los consideró involucrados en la transmisión entre los pacientes dentro de los diferentes hospitales. Este trabajo concluye que la técnica spa es lo suficientemente eficiente como para diferenciar las cepas epidémicas, esporádicas y aquéllas que se transforman lentamente de esporádicas a epidémicas.
Protein A gene was used as a genetic marker for the characterization of Pakistani methicillin resistant Staphylococcus aureus (MRSA) isolates. Out of a total of 130 Staphylococcus aureus isolates, 90 were identified as MRSA and of these 90 MRSA, 81 MRSA isolates were characterized by spa typing. All of these isolates were collected from five National Community Hospitals. Two different sets of primers were used to amplify the X-region of Protein A gene in MRSA strains. One set of primers i.e, spa-F/spa-R identified three types of different repeats viz., 7 repeats (spa 2), 8 repeats (spa 3) and 10 repeats (spa 4) and another set of primers i.e. spa-1113F/spa-1514R identified 4 types of different repeats viz., 6 repeats (spa 1), 15 repeats (spa 6), and 17 repeats (spa 7) and 19 repeats (spa 8). Repeat 11 (spa 5) was identified with both sets of primers. Sporadic MRSA types carrying 6, 7, 10, 17 and 19 repeats were less prevalent, while the epidemic MRSA with 8, 11 and 15 repeats were more prevalent and considered to be involved in transmission among the patients within different hospitals. Research work concludes that spa technique is efficient enough to differentiate spa strains carrying variations in general and those slowly transforming from sporadic to epidemic outbreak in particular.
O gene da proteína A foi usado como marcador genético para a caracterização de isolados de Staphylococcus aureus resistentes à meticilina (SAMR). De um total de 130 isolados de Staphylococcus aureus, 90 foram identificados como SAMR e 81 destes puderam se caracterizar por tipificação spa. Todos estes isolados foram obtidos de cinco Hospitais Nacionais da Comunidade. Utilizaram-se dois jogos diferentes de cevadores para amplificar a região-X do gene da proteína A nas cepas de SAMRUn conjunto de cevadores, spa-F/spa-R tem identificado três tipos de repetições diferentes, a saber, 7 repetições (spa 2), 8 repetições (spa 3) e 10 repetições (spa 4) e outro conjunto de cevadores, spa-1113F/spa-1514R tem identificado 4 tipos de repetições diferentes, a saber, 6 repetições (spa 1), 15 repetições (spa 6), e 17 repetições (spa 7) e 19 repetições (spa 8). Foi identificada a repetição 11 (spa 5) com ambos os conjuntos de cevadores. Os tipos de SAMR esporádicos que tinham as repetições 6, 7, 10, 17 e 19 foram pouco prevalecentes enquanto que os SAMR epidêmicos com 8, 11, e 15 repetições foram mais prevalecentes e são considerados envolvidos na transmissão entre os pacientes dentro dos diferentes hospitais. Este trabalho conclui que a técnica spa é o suficientemente eficiente como para diferenciar as cepas epidêmicas, esporádicas e aquelas que se transformam lentamente de esporádicas em epidêmicas.
RESUMEN
El gen de la proteína A se usó como marcador genético para la caracterización de aislados de Staphylococcus aureus resistentes a la meticilina (SAMR). De un total de 130 aislados de Staphylococcus aureus, 90 fueron identificados como SAMR y 81 de éstos se pudieron caracterizar por tipificación spa. Todos estos aislados fueron obtenidos de cinco Hospitales Nacionales de la Comunidad. Se utilizaron dos juegos diferentes de cebadores para amplificar la región-X del gen de la proteína A en las cepas de SAMR. Un conjunto de cebadores, spa-F/spa-R ha identificado tres tipos de repeticiones diferentes, a saber, 7 repeticiones (spa 2), 8 repeticiones (spa 3) y 10 repeticiones (spa 4) y otro conjunto de cebadores, spa-1113F/spa-1514R ha identificado 4 tipos de repeticiones diferentes, a saber, 6 repeticiones (spa 1), 15 repeticiones (spa 6), y 17 repeticiones (spa 7) y 19 repeticiones (spa 8). Se identificó la repetición 11 (spa 5) con ambos conjuntos de cebadores. Los tipos de SAMR esporádicos que portaban las repeticiones 6, 7, 10, 17 y 19 fueron poco prevalentes mientras que los SAMR epidémicos con 8, 11, y 15 repeticiones fueron más prevalentes y se los consideró involucrados en la transmisión entre los pacientes dentro de los diferentes hospitales. Este trabajo concluye que la técnica spa es lo suficientemente eficiente como para diferenciar las cepas epidémicas, esporádicas y aquéllas que se transforman lentamente de esporádicas a epidémicas.(AU)
Protein A gene was used as a genetic marker for the characterization of Pakistani methicillin resistant Staphylococcus aureus (MRSA) isolates. Out of a total of 130 Staphylococcus aureus isolates, 90 were identified as MRSA and of these 90 MRSA, 81 MRSA isolates were characterized by spa typing. All of these isolates were collected from five National Community Hospitals. Two different sets of primers were used to amplify the X-region of Protein A gene in MRSA strains. One set of primers i.e, spa-F/spa-R identified three types of different repeats viz., 7 repeats (spa 2), 8 repeats (spa 3) and 10 repeats (spa 4) and another set of primers i.e. spa-1113F/spa-1514R identified 4 types of different repeats viz., 6 repeats (spa 1), 15 repeats (spa 6), and 17 repeats (spa 7) and 19 repeats (spa 8). Repeat 11 (spa 5) was identified with both sets of primers. Sporadic MRSA types carrying 6, 7, 10, 17 and 19 repeats were less prevalent, while the epidemic MRSA with 8, 11 and 15 repeats were more prevalent and considered to be involved in transmission among the patients within different hospitals. Research work concludes that spa technique is efficient enough to differentiate spa strains carrying variations in general and those slowly transforming from sporadic to epidemic outbreak in particular.(AU)
O gene da proteína A foi usado como marcador genético para a caracterizaþÒo de isolados de Staphylo¡coccus aureus resistentes O meticilina (SAMR). De um total de 130 isolados de Staphylococcus aureus, 90 foram identificados como SAMR e 81 destes puderam se caracterizar por tipificaþÒo spa. Todos estes isolados foram obtidos de cinco Hospitais Nacionais da Comunidade. Utilizaram-se dois jogos diferentes de cevadores para amplificar a regiÒo-X do gene da proteína A nas cepas de SAMRUn conjunto de ce¡vadores, spa-F/spa-R tem identificado trÛs tipos de repetiþ§es diferentes, a saber, 7 repetiþ§es (spa 2), 8 repetiþ§es (spa 3) e 10 repetiþ§es (spa 4) e outro conjunto de cevadores, spa-1113F/spa-1514R tem identificado 4 tipos de repetiþ§es diferentes, a saber, 6 repetiþ§es (spa 1), 15 repetiþ§es (spa 6), e 17 repetiþ§es (spa 7) e 19 repetiþ§es (spa 8). Foi identificada a repetiþÒo 11 (spa 5) com ambos os conjuntos de cevadores. Os tipos de SAMR esporádicos que tinham as repetiþ§es 6, 7, 10, 17 e 19 foram pouco prevalecentes enquanto que os SAMR epidÛmicos com 8, 11, e 15 repetiþ§es foram mais prevalecentes e sÒo considerados envolvidos na transmissÒo entre os pacientes dentro dos diferentes hospitais. Este trabalho conclui que a técnica spa é o suficientemente eficiente como para diferenciar as cepas epidÛmicas, esporádicas e aquelas que se transformam lentamente de esporádicas em epidÛmicas.(AU)
RESUMEN
Uncontrolled exposure of active and passive smokers to trace metals causes increase in health risks. The primary objective of this study was to determine whether local and imported cigarette brands used in Pakistan, have elevated levels of metals or not. Six metals manganese (Mn), cobalt (Co), copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) were determined in tobacco of twenty cigarette brands (local and imported) used in Pakistan by flame atomic absorption Spectrophotometry. To overcome contamination chances and for complete digestion of analytes a microwave digester was used. The analytical results showed highest concentration of Mn (84.78 microg/g dry weight), Cd (0.525 microg/g dry weight) and Zn (14.34 microg/g dry weight) metals in imported brands in relation to counterparts from the local brands. Certain elevated levels were observed for Co (3.344 microg/g dry weight), Pb (14.16 microg/g dry weight) and Cu (7.889 microg/g dry weight) metals in local brands. The inter-metal relationships in the tobacco of local and imported cigarette brands showed some integrated variation in the selected metal levels. In view of health risk associated with the above metals, there should be a strict quality control over monitoring of heavy metals during growing, processing and smoking of tobacco. Therefore, it is prudent to minimize exposure to toxic substances whenever possible because smoking and exposure to cigarette smoke is a confounder to be taken into account when carrying out epidemiological studies on human exposure to metals.