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1.
Biofouling ; 38(7): 715-728, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36062553

RESUMO

Extracts of Centella asiatica leaves (LEs), and in-vitro leaf-calli (CEs), were investigated for antibacterial, antibiofilm, and anti-quorum sensing activities. Ethyl acetate extracts from leaves (EALE), leaf-calli (EACE), methanolic extracts from leaves (MELE), and leaf-calli (MECE) showed antibacterial activity; the minimum inhibitory concentrations (MICs) of LEs and CEs ranged from 0.312-2.50 mg ml-1 and 0.625 - 2.50 mg ml-1, respectively. The MICs of EALE and EACE were 2.50 mg ml-1, each, for C. violaceum 12742, and P. aeruginosa PAO1. At sub-MIC levels, EALE and EACE showed anti-quorum sensing (anti-QS) activity, demonstrated by concentration dependent pigment inhibition of C. violaceum 12742. Similarly, EALE and EACE inhibited QS-controlled virulence factors in P. aeruginosa PAO1 (biofilm, pyocyanin, and pyoverdin); again, the inhibition was concentration-dependent. The best effect was at immediate sub-MIC concentration i.e. 1250 µg ml-1. GC-MS analyses revealed the presence of compound 9,12-Octadecadienoic acid, and in silico docking study suggested interactions with QS-receptors CviR', LasI, and LasR proteins for anti-QS activity.


Assuntos
Incrustação Biológica , Centella , Antibacterianos/farmacologia , Biofilmes , Incrustação Biológica/prevenção & controle , Centella/metabolismo , Ácido Linoleico/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta , Pseudomonas aeruginosa , Piocianina/metabolismo , Fatores de Virulência/metabolismo
2.
Medicina (Kaunas) ; 57(2)2021 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-33673004

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a global pandemic and is posing a serious challenge to mankind. As per the current scenario, there is an urgent need for antiviral that could act as a protective and therapeutic against SARS-CoV-2. Previous studies have shown that SARS-CoV-2 is much similar to the SARS-CoV bat that occurred in 2002-03. Since it is a zoonotic virus, the exact source is still unknown, but it is believed bats may be the primary reservoir of SARS-CoV-2 through which it has been transferred to humans. In this review, we have tried to summarize some of the approaches that could be effective against SARS-CoV-2. Firstly, plants or plant-based products have been effective against different viral diseases, and secondly, plants or plant-based natural products have the minimum adverse effect. We have also highlighted a few vitamins and minerals that could be beneficial against SARS-CoV-2.


Assuntos
Antivirais/uso terapêutico , Produtos Biológicos/uso terapêutico , Tratamento Farmacológico da COVID-19 , Nutrientes/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Viroses/tratamento farmacológico , Animais , Quirópteros/virologia , Humanos
3.
J Basic Microbiol ; 57(3): 193-203, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27874198

RESUMO

Green synthesized nanoparticles have gained great attention due to their non-toxic and non-hazardous nature. In the present study, bark extract of the medicinal plant in Ayurveda Crataeva nurvala (Buch-Ham) (CN) was chosen for the biosynthesis of silver nanoparticles (AgNPs). These NPs were characterized by Ultra violet visible spectroscopy, Fourier Transform Infra Red, Atomic Force Microscopy, and Transmission Electron Microscopy (TEM). The average particle size of green synthesized CN-AgNPs was 15.2 ± 1.01 nm. Gas chromatography- mass spectrometry analysis of methanolic bark extract involved in the formation of CN-AgNPs revealed lupeol as a major active component. In this study, CN-AgNPs (15 µg ml-1 ) efficiently suppressed the production of quorum sensing mediated virulence factors viz. pyocyanin, protease, hemolysin, and biofilm formation in Pseudomonas aeruginosa. The pyocyanin production was strongly inhibited (74.64%) followed by proteolysis (47.3%) and hemolysin production (47.7%). However, the biofilm forming ability was maximally reduced up to 79.70%. Moreover, the Confocal Laser Scanning Microscopic Analysis showed that CN-AgNPs inhibit colonization of P. aeruginosa on to the surface. Furthermore, TEM analysis revealed internalization of CN-AgNPs inside the bacterial cell. It is concluded that green synthesized AgNPs have great potential to inhibit virulence factors and biofilm forming ability of drug-resistant clinical isolates of P. aeruginosa.


Assuntos
Biofilmes/efeitos dos fármacos , Capparaceae/química , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Fatores de Virulência/antagonistas & inibidores , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla , Proteínas Hemolisinas/antagonistas & inibidores , Proteínas Hemolisinas/biossíntese , Proteínas Hemolisinas/efeitos dos fármacos , Nanopartículas Metálicas/ultraestrutura , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Triterpenos Pentacíclicos/farmacologia , Plantas Medicinais/química , Proteólise/efeitos dos fármacos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/ultraestrutura , Piocianina/biossíntese , Percepção de Quorum/efeitos dos fármacos , Prata
4.
Environ Toxicol ; 31(8): 945-56, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25648600

RESUMO

Four-week-old mice, weighing about 25-35 g were divided into five groups (8 mice in each group): vehicle control, low- (0.5 g/kg), middle- (1 g/kg), high- (3 g/kg), and exceptionally high-dose (5 g/kg). After first and second weeks of intraperitoneal exposure to AgNPs, biochemical, histopathological, and electron microscopic ultrastructural changes were investigated. No significant changes were observed in SGOT and ALP levels after first week of exposure, while the level of SGPT significantly increased (p < 0.05) in 2nd week treated mice, indicating that inflammatory of liver might be induced by high-dose (3 and 5 g/kg) of AgNPs. No obvious changes were observed for UA and BUN in all groups of treated mice. However, significant (p < 0.05) decrease in CR level was noticed in all groups of treated mice only at high-dose (3 and 5 g/kg). No remarkable changes in lipid profile were observed. Light microscopic histopathological investigation shows that first week treatment had not perceptible effect on the cytoarchitecture on liver, kidney, and spleen; while, second week treatment had only sporadic mild effects on these organs. However, no ultrastructural electron microscopic changes were observed in liver, kidney, and spleen of mice treated with 0.5, 1, and 3 g/kg of AgNPs when sacrificed on first and second week; while, exceptionally high-dose (5 g/kg) of AgNPs resulted in slight nuclear chromatin condensation and irregularities in nuclear membrane. The results suggested that AgNPs could be well tolerated in mice when given intraperitoneally and no death has been found during the experiment in any groups of treated mice. Interestingly, significant (<0.05) decrease in glucose levels in all experiment group is suggestive of curious hypoglycemic role of AgNPs warranting further study to explore its possible therapeutic potential in hyperglycemic conditions as well as its mechanism of action at molecular level. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 945-956, 2016.


Assuntos
Rim/patologia , Fígado/patologia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Baço/patologia , Animais , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Baço/efeitos dos fármacos
5.
World J Microbiol Biotechnol ; 31(1): 153-64, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25304025

RESUMO

The high prevalence of extended-spectrum ß-lactamases (76.3 %) and metallo-ß-lactamases (7.3 %) amongst the bacteria Pseudomonas aeruginosa is a critical problem that has set forth an enormous therapeutic challenge. The suggested role of nanoparticles as next generation antibiotics, and inadequate information on antibacterial activity of aluminium oxide nanoparticles has led us to investigate the green synthesis of aluminium oxide nanoparticles (Al2O3 NPs) using leaf extracts of lemongrass and its antibacterial activity against extended-spectrum ß-lactamases and metallo-ß-lactamases clinical isolates of P. aeruginosa. The synthesized Al2O3-NPs were characterized by scanning electron microcopy, high resolution-transmission electron microscopy, atomic force microscopy, X-ray diffraction, Zeta potential, and differential light scattering techniques. The X-ray diffraction data revealed the average size of the spherical Al2O3-NPs as 34.5 nm. The hydrodynamic size in Milli Q water and Zeta potential were determined to be 254 nm and +52.2 mV, respectively. The minimal inhibitory concentration of Al2O3-NPs was found to be in the range of 1,600-3,200 µg/ml. Treatment at concentrations >2,000 µg/ml, resulted in complete growth inhibition of extended-spectrum ß-lactamases and metallo-ß-lactamases isolates. Scanning electron microcopy analysis revealed the clusters of nanoparticles attached to the bacterial cell surface, causing structural deformities in treated cells. High resolution-transmission electron microscopy analysis confirmed that nanoparticles crossed the cell membrane to become intracellular. The interaction of nanoparticles with the cell membrane eventually triggered the loss of membrane integrity, most likely due to intracellular oxidative stress. The data explicitly suggested that the synthesized Al2O3-NPs can be exploited as an effective bactericidal agent against extended-spectrum ß-lactamases, non-extended-spectrum ß-lactamases and metallo-ß-lactamases strains of P. aeruginosa, regardless of their drug resistance patterns and mechanisms. The results elucidated the clinical significance of Al2O3-NPs in developing an effective antibacterial therapeutic regimen against the multi-drug resistant bacterial infections. The use of leaf extract of lemongrass for the synthesis of Al2O3-NPs appears to be cost effective, nontoxic, eco-friendly and its strong antibacterial activity against multi-drug resistant strains of P. aeruginosa offers compatibility for pharmaceutical and other biomedical applications.


Assuntos
Óxido de Alumínio/farmacologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Nanopartículas/metabolismo , Nanopartículas/ultraestrutura , Extratos Vegetais/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Óxido de Alumínio/síntese química , Antibacterianos/síntese química , Membrana Celular/efeitos dos fármacos , Cymbopogon/enzimologia , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Difração de Raios X
6.
Korean J Parasitol ; 52(5): 487-91, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25352696

RESUMO

Toxoplasma gondii is an obligate intracellular protozoan that is distributed worldwide. Recently, several tests for avidity of Toxoplasma IgG antibodies have been introduced to help discriminate between recently acquired and distant infections. The study was conducted in Jawaharlal Nehru Medical College and Hospital, India from February 2011 to September 2012. Serum specimens were subjected to Toxoplasma IgM ELISA and IgG avidity ELISA test. Out of 48 patients with abortions, 17 (35.4%) were positive for IgM ELISA, and 8 (16.6%) had low IgG avidity antibodies. Out of 48 patients with other obstetric problems, 23 (47.9%) were positive for IgM ELISA, and 17 (35.4%) had low IgG avidity antibodies. Combining both groups on avidity test, only 25 of 40 (62.5%) IgM-positive women had low-avidity IgG antibodies suggesting a recent T. gondii infection in these women. More importantly, 15 (37.5%) of the IgM-positive women had high-avidity antibodies suggesting that the infection was acquired before gestation The relation of IgM seropositivity with the following risk factors was not found to be statistically significant; contact with cats (0.13), non-vegetarian food habits (0.05), and low socio-economic status (0.49). While, for IgG avidity ELISA, only contact with cats (0.01) was significantly associated with seropositivity. All other risk factors have P-values of >0.05 (not significant). IgG avidity test when used in combination with IgM test was a valuable assay for diagnosis of ongoing or recently acquired T. gondii infection in India.


Assuntos
Anticorpos Antiprotozoários/imunologia , Afinidade de Anticorpos , Imunoglobulina G/fisiologia , Toxoplasma/imunologia , Toxoplasmose/imunologia , Aborto Espontâneo/imunologia , Adolescente , Adulto , Animais , Gatos , Ensaio de Imunoadsorção Enzimática , Feminino , Contaminação de Alimentos , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Índia/epidemiologia , Fatores de Risco , Estudos Soroepidemiológicos , Toxoplasmose/epidemiologia , Adulto Jovem
7.
Microsc Res Tech ; 87(1): 133-148, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37728140

RESUMO

The emergence of multidrug resistance (MDR) in bacterial pathogens is a serious public health concern. A significant therapeutic target for MDR infections is the quorum sensing-regulated bacterial pathogenicity. Determining the anti-quorum sensing abilities of certain medicinal plants against bacterial pathogens as well as the in-silico interactions of particular bioactive phytocompounds with QS and biofilm-associated proteins were the objectives of the present study. In this study, 6 medicinal plants were selected based on their ethnopharmacological usage, screened for Anti-QS activity and Artemisia annua leaf extract (AALE) demonstrated pigment inhibitory activity against Chromobacterium violaceum CV12472. Further, the methanol active fraction significantly inhibited the virulence factors (pyocyanin, pyoverdine, rhamnolipid and swarming motility) of Pseudomonas aeruginosa PAO1 and Serratia marcescens MTCC 97 at respective sub-MICs. The inhibition of biofilm was determined using a microtiter plate test and scanning electron microscopy. Biofilm formation was impaired by 70%, 72% and 74% in P. aeruginosa, C. violaceum and S. marcescens, respectively at 0.5xMIC of the extract. The phytochemical content of the extract was studied using GC-MS and 1, 8-cineole was identified as major bioactive compound. Furthermore, 1, 8-cineole was docked with quorum sensing (QS) proteins (LasI, LasR, CviR, and rhlR) and biofilm proteins (PilY1 and PilT). In silico docking and dynamics simulations studies suggested interactions with QS-receptors CviR', LasI, LasR, and biofilm proteins PilY1, PilT for anti-QS activity. Further, 1, 8-cineole demonstrated 66% and 51% reduction in violacein production and biofilm formation, respectively to validate the findings of computational analysis. Findings of the present investigation suggests that 1, 8-cineole plays a crucial role in the QS and biofilm inhibitory activity demonstrated by Artemisia annua extract. RESEARCH HIGHLIGHTS: Artemisia annua leaf extract (AALE) methanol fraction demonstrated broad-spectrum QS and biofilm inhibition Scanning electron microscopy (SEM) confirmed biofilm inhibition Molecular docking and simulation studies suggested positive interactions of 1,8-cineol with QS-receptors and biofilm proteins.


Assuntos
Artemisia annua , Plantas Medicinais , Percepção de Quorum , Virulência , Eucaliptol/farmacologia , Plantas Medicinais/química , Artemisia annua/metabolismo , Simulação de Acoplamento Molecular , Metanol/farmacologia , Antibacterianos/química , Biofilmes , Extratos Vegetais/farmacologia , Bactérias
8.
Access Microbiol ; 6(3)2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725590

RESUMO

Introduction. Brucellosis, a globally distributed zoonotic disease, is caused by the Gram-negative bacteria known as Brucella. Humans acquire infection through direct contact with the blood, urine and placenta of animals, inhalation of dust or aerosols at infected animal farms, and raw milk and meat intake. This study aimed to assess the prevalence of brucellosis in dairy farmers in and around the Aligarh region of North India, to document various clinical signs and symptoms in Brucella-positive individuals, and to create awareness in dairy farmers concerning brucellosis and ways to prevent it. Methods. This was an observational study that included 125 dairy farmers in and around the Aligarh region. Serum samples were taken from this high-risk group after obtaining informed consent. Further, a pre-designed proforma was used to collect information about their knowledge, attitude and practices (KAP) concerning brucellosis and assess the risk factors for the disease. The Rose Bengal test (RBT), serum agglutination test (SAT) and enzyme-linked immunosorbent assay (ELISA) were performed to detect the seroprevalence of brucellosis. Result.Brucella infection was diagnosed in 64 (51.20 %) cases by indirect ELISA (IgM+IgG), 41 (32.8 %) by RBT and 4 (3.2 %) by SAT. Significant clustering of patients was seen in the 20-55 years age group. The most common symptoms in ELISA IgM-positive patients were joint pain (16.07 %), fatigue (14.28 %), anorexia (12.50 %), weight loss (8.92 %), malaise (5.35 %), undulant fever (3.57 %), night sweats (3.57 %) and headache (1.78 %). The findings of this study indicate that ELISA (IgM+IgG) exhibits great sensitivity as compared to SAT and RBT. KAP was very poor among dairy farmers. Conclusion. In India, Brucella is a frequent but severely underreported illness. ELISA is the most sensitive serological test for diagnosing brucellosis. No potential vaccine has yet been introduced for humans against brucellosis. Thus, it is necessary to impart awareness and sensitize high-risk groups concerning brucellosis.

9.
Iran J Microbiol ; 15(2): 181-188, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37193231

RESUMO

Background and Objectives: There are conflicting views regarding face mask guidelines amongst healthcare staff to prevent transmission of coronavirus disease 2019 (COVID-19), influenza and other respiratory viral infections (RVIs). We conducted a thorough meta-analysis to statistically compare mask use versus no mask use efficacy for RVIs in healthcare settings. Materials and Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used for selecting researches published between 2003 and June 2022 from different databases, including Publisher Medline (PubMed), Web of Science, etc.; 6 studies qualified for inclusion. Data was pooled from in vivo randomized control, case-control and observational studies dealing with the relationship between face mask use and no use by patients or health personnel and RVI prevention in healthcare setups. Results: The fixed and random-effects model was carried out to determine pooled odds ratios (ORs) and their respective 95 percent confidence intervals (CIs). The results revealed that wearing a face mask significantly reduced the risk of contracting a respiratory viral illness in hospital settings, with pooled OR (95% CI) of 0.11 (0.04 to 0.33) (probability value (P) <0.08). Conclusion: Masks largely succeeded in stopping respiratory virus transmission, as evidenced by the meta-analysis of 6 studies (a total of 927 individuals).

10.
PLoS One ; 18(12): e0295524, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38113217

RESUMO

The quorum sensing mechanism relies on the detection and response to chemical signals, termed autoinducers, which regulate the synthesis of virulence factors including toxins, enzymes, and biofilms. Emerging therapeutic strategies for infection control encompass approaches that attenuate quorum-sensing systems. In this study, we evaluated the antibacterial, anti-quorum sensing, and anti-biofilm activities of Psidium guajava L. methanolic leaf extracts (PGME). Minimum Inhibitory Concentrations (MICs) of PGME were determined as 500 µg/ml for C. violaceum and 1000 µg/ml for P. aeruginosa PAO1. Significantly, even at sub-MIC concentrations, PGME exhibited noteworthy anti-quorum sensing properties, as evidenced by concentration-dependent inhibition of pigment production in C. violaceum 12742. Furthermore, PGME effectively suppressed quorum-sensing controlled virulence factors in P. aeruginosa PAO1, including biofilm formation, pyoverdin, pyocyanin, and rhamnolipid production, with concentration-dependent inhibitory effects. Phytochemical analysis utilizing GC-MS revealed the presence of compounds such as alpha-copaene, caryophyllene, and nerolidol. In-silico docking studies indicated a plausible mechanism for the observed anti-quorum sensing activity, involving favorable binding and interactions with QS-receptors, including RhlR, CviR', LasI, and LasR proteins. These interactions were found to potentially disrupt QS pathways through suppression of AHL production and receptor protein blockade. Collectively, our findings propose PGME as a promising candidate for the treatment of bacterial infections. Its attributes that mitigate biofilm development and impede quorum-sensing mechanisms highlight its potential therapeutic value.


Assuntos
Psidium , Percepção de Quorum , Psidium/metabolismo , Biofilmes , Fatores de Virulência/metabolismo , Antibacterianos/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Pseudomonas aeruginosa
11.
J Family Med Prim Care ; 12(10): 2385-2391, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38074239

RESUMO

Background: SARS-CoV-causing COVID-19 resulted in mortality, and the clinic-epidemiological profile at the time of admission of patients who died later could provide an insight into pathophysiological consequences due to infection. Method: Retrospective observational study of 64 RTPCR-confirmed COVID-19 non-survivors was conducted from April - June 2021 and January February 2022. Data were analyzed, and a P value<0.05 was taken as significant. Results: 60.94% and 39.06 % were males and females, and 26.57% & 73.43 % of patients had moderate and severe disease, respectively. Fever, cough, and dyspnea were the most common presenting symptoms. 78.12% and 21.88% had pre-existing (diabetes and hypertension were most common) and no co-morbidities, respectively. 65.62 & 17.19 % of patients had bilateral and unilateral ground glass opacities, respectively. Thrombocytopenia, lymphopenia, neutrophilia, elevated monocytes, and neutrophil-lymphocyte ratio (NLR) of 7.52 were hematological findings. D dimer was elevated. ABG showed low PaO2 and SPO2 %. ALT and AST were elevated. Tachycardia was also present. Compared to the first wave, no significant association of gender with severity was found. However, the percentage of male patients was higher. The association of the duration of stay and co-morbidity with disease severity was significant in both the first and subsequent waves of COVID-19. Conclusion: Co-morbidity, disease severity, and radiological lung opacities play a role in the outcome of COVID-19. The associated findings are hematological, renal, liver, cardiovascular, and arterial blood gas derangements.

12.
Front Mol Biosci ; 10: 1292509, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37965379

RESUMO

Infectious diseases remain among the most pressing concerns for human health. This issue has grown even more complex with the emergence of multidrug-resistant (MDR) bacteria. To address bacterial infections, nanoparticles have emerged as a promising avenue, offering the potential to target bacteria at multiple levels and effectively eliminate them. In this study, silver nanoparticles (AA-AgNPs) were synthesized using the leaf extract of a medicinal plant, Abroma augusta. The synthesis method is straightforward, safe, cost-effective, and environment friendly, utilizing the leaf extract of this Ayurvedic herb. The UV-vis absorbance peak at 424 nm indicated the formation of AA-AgNPs, with the involvement of numerous functional groups in the synthesis and stabilization of the particles. AA-AgNPs exhibited robust antibacterial and antibiofilm activities against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). The MIC values of AA-AgNPs ranged from 8 to 32 µg/mL. Electron microscopic examination of the interaction of AA-AgNPs with the test bacterial pathogens showed a deleterious impact on bacterial morphology, resulting from membrane rupture and leakage of intracellular components. AA-AgNPs also demonstrated a dose-dependent effect in curtailing biofilm formation below inhibitory doses. Overall, this study highlights the potential of AA-AgNPs in the successful inhibition of both the growth and biofilms of MRSA and VRE bacteria. Following studies on toxicity and dose optimization, such AgNPs could be developed into effective medical remedies against infections.

13.
J Clin Microbiol ; 50(5): 1779-82, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22337978

RESUMO

Cefoxitin-resistant Escherichia coli (n = 109) and Klebsiella pneumoniae (n = 16) isolates collected from patients in India in 2009 to 2010 were screened for bla(ampC) families and mobilizing elements (ISEcp1, IS26, ISCR1, and sul-1-type class 1 integrons) and their association with bla(ampC) and for the occurrence of class A beta-lactamases (BLs) (CTX-M, TEM, and SHV). The concurrent occurrences of two distinct AmpC families (bla(CIT) and bla(EBC)) and of class A with class C beta-lactamase were observed. All but one of the isolates harboring CTX-M extended-spectrum BLs (ESBLs) were carrying bla(CTX-M) genogroup 1; the remaining isolate carried bla(CTX-M) genogroup 9. The mobilizing elements occurred in different combinations in the study isolates.


Assuntos
Escherichia coli/enzimologia , Escherichia coli/genética , Integrons , Sequências Repetitivas Dispersas , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Cefoxitina/farmacologia , DNA Bacteriano/química , DNA Bacteriano/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Humanos , Índia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/isolamento & purificação , Dados de Sequência Molecular , Análise de Sequência de DNA , Resistência beta-Lactâmica
14.
Appl Microbiol Biotechnol ; 94(2): 467-77, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22159886

RESUMO

The reemergence of infectious diseases and the continuous development of multidrug resistance among a variety of disease-causing bacteria in clinical setting pose a serious threat to public health worldwide. Extended-spectrum ß-lactamases (ESBLs) that mediate resistance to third-generation cephalosporin are now observed all over the world in all species of Enterobacteriaceae, especially Escherichia coli and Klebsiella pneumoniae. In this work, ZnO nanoparticles (NPs) were synthesized by the sol-gel method and characterized by powder X-ray diffraction, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The image of synthesized ZnO NPs appeared spherical in SEM with a diameter of ≈19 nm and as hexagonal crystal in AFM. Clinical isolates were assessed for ESBL production and shown to be sensitive to ZnO NPs by different methods such as minimal inhibitory concentration (MIC) and minimal bactericidal concentration, time-dependent growth inhibition assay, well diffusion agar methods and estimation of colony forming units (CFU) of bacteria. The lowest MIC value for E. coli and K. pneumoniae was found to be 500 µg/ml. The results showed that ZnO NPs at 1,000 µg/ml completely inhibit the bacterial growth. The antibacterial effect of ZnO nanoparticles was gradual, but time- and concentration-dependent. The maximum inhibition zone at100 µg/ml for E. coli and K. pneumoniae was 22 and 20 mm, respectively. With the increasing ZnO NP loading, there is significant reduction in the numbers of CFU. At the concentration of 1,000 µg/ml, the decline in per cent survival of E. coli and K. pneumoniae was found to be 99.3% and 98.6%, respectively.


Assuntos
Antibacterianos/farmacologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Nanopartículas Metálicas , Óxido de Zinco/farmacologia , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Escherichia coli/enzimologia , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Hospitais , Índia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/crescimento & desenvolvimento , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Difração de Raios X , beta-Lactamases/metabolismo
15.
World J Microbiol Biotechnol ; 28(4): 1605-13, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22805942

RESUMO

Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), is an important cause of pyogenic skin and soft tissue infections (SSTIs). MRSA is an important pathogen in the healthcare sector that has neither been eliminated from the hospital nor community environment. In humans, S. aureus causes superficial lesions in the skin and localized abscesses, pyogenic meningitis/encephalitis, osteomyelitis, septic arthritis, invasive endocarditis, pneumonia, urinary tract infections and septicemia. Investigations focused in the search of other alternatives for the treatment of MRSA infections are in progress. Among the range of compounds whose bactericidal activity is being investigated, ZnO nanoparticles (ZnO-NPs) appears most promising new unconventional antibacterial agent that could be helpful to confront this and other drug-resistant bacteria. The aim of present study is to investigate the antibacterial potential of ZnO-NPs against Staphylococcus species isolated from the pus and wounds swab from the patients with skin and soft tissue infections in a tertiary care hospital of north India. ZnO-NPs (≈19.82 nm) synthesized by sol-gel process were characterized using scanning electron microscopy, X-ray diffraction , and Atomic force microscopy. The antibacterial potential was assessed using time-dependent growth inhibition assay, well diffusion test, MIC and MBC test and colony forming units methods. ZnO-NPs inhibited bacterial growth of methicillin-sensitive S. aureus (MSSA), MRSA and methicillin-resistant S. epidermidis (MRSE) strains and were effective bactericidal agents that were not affected by drug-resistant mechanisms of MRSA and MRSE.


Assuntos
Antibacterianos/farmacologia , Nanopartículas/ultraestrutura , Infecções dos Tecidos Moles/microbiologia , Infecções Cutâneas Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos , Óxido de Zinco/farmacologia , Humanos , Índia , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanopartículas/química , Staphylococcus aureus/isolamento & purificação , Staphylococcus epidermidis/isolamento & purificação , Supuração/microbiologia , Centros de Atenção Terciária , Ferimentos e Lesões/microbiologia , Difração de Raios X
16.
Surg Infect (Larchmt) ; 22(4): 434-441, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33944586

RESUMO

Background: Surgical antimicrobial prophylaxis (SAP) refers to the utilization of antibiotic agents for the prevention of surgical site infections (SSI), to prevent SSI-associated morbidity and mortality, reduce duration and cost of healthcare, and cause minimal adverse drug effects. The adherence rate among surgeons for the available international and national guidelines and optimal practice remains considerably low in many hospitals, especially in developing countries. The objective of this study was to assess the knowledge and compliance rate for SAP guidelines among various surgical specialties and those involved in providing SAP. Methods: An institution-based exploratory, multi-specialty, collective, mixed method approach (qualitative and quantitative) was used to assess the knowledge and compliance rate for SAP guidelines among the consultants and residents of surgical specialties. Quantitative analysis was performed using a pre-tested questionnaire. For qualitative analysis, focus group discussions were conducted. Thematic analysis was conducted by the Theoretical Domains Framework (TDF) and the Capabilities, Opportunities, Motivation and Behaviour (COM-B) model. Results: Twenty-eight focus groups and 16 paired interviews were undertaken. On thematic analysis six significant themes were noted and mapped to the COM-B model, and subthemes mapped to the relevant TDF domains in a combined framework. Key themes recognized were: (1) solitary focus on surgical skills; (2) following the hierarchy is more important than guideline compliance; (3) doubts and overcautious attitude of surgeons hinders appropriate SAP prescribing; (4) non-availability in-hospital supply of antimicrobial agents; (5) patient characteristics and type of surgery play a role in prescribing SAP; and (6) lack of national and local guidelines. Conclusions: The knowledge and attitudes of surgeons toward appropriate SAP prescribing are crucial factors for execution of guidelines. Including them in policy making decisions can help in strong execution of the same.


Assuntos
Anti-Infecciosos , Antibioticoprofilaxia , Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Fidelidade a Diretrizes , Hospitais de Ensino , Humanos , Infecção da Ferida Cirúrgica/tratamento farmacológico , Infecção da Ferida Cirúrgica/prevenção & controle , Atenção Terciária à Saúde
17.
Front Microbiol ; 12: 738983, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707590

RESUMO

SARS-CoV-2-infected patients are reported to show immunocompromised behavior that gives rise to a wide variety of complications due to impaired innate immune response, cytokine storm, and thrombo-inflammation. Prolonged use of steroids, diabetes mellitus, and diabetic ketoacidosis (DKA) are some of the factors responsible for the growth of Mucorales in such immunocompromised patients and, thus, can lead to a life-threatening condition referred to as mucormycosis. Therefore, an early diagnosis and cell-based management cosis is the need of the hour to help affected patients overcome this severe condition. In addition, extended exposure to antifungal drugs/therapeutics is found to initiate hormonal and neurological complications. More recently, mesenchymal stem cells (MSCs) have been used to exhibit immunomodulatory function and proven to be beneficial in a clinical cell-based regenerative approach. The immunomodulation ability of MSCs in mucormycosis patient boosts the immunity by the release of chemotactic proteins. MSC-based therapy in mucormycosis along with the combination of short-term antifungal drugs can be utilized as a prospective approach for mucormycosis treatment with promising outcomes. However, preclinical and in mucormyIn mucormycosis, the hyphae of clinical trials are needed to establish the precise mechanism of MSCs in mucormycosis treatment.

18.
J Commun Dis ; 42(2): 153-6, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22471175

RESUMO

Malaria is one of the most common parasitic infection in India. The diagnosis largely depends on peripheral blood smear examination. Newer diagnostic methods like various antigen detection assays are now in use for prompt diagnosis and treatment. This study was done to determine the effectiveness of Diagnos Malaria Stix (antigen detection) assay in diagnosis of malaria. This involves detection of PfHRP-2 antigen and P.V. specific pLDH antigen. 162 patients with signs and symptoms of malaria included in the study. Leishman stained blood smear examination was done for all patients. Commercially available Diagnos Malaria Stix assay was used. Diagnos Malaria Stix showed sensitivity, specificity positive and negative predictive values of 100% each while Sensitivity, specificity, positive and negative predictive values of Leishman stained blood smear examination were 45.45%, 100%, 100% and 92% respectively.


Assuntos
Antígenos de Protozoários/sangue , Malária/diagnóstico , Plasmodium vivax/imunologia , Proteínas de Protozoários/sangue , Humanos , Imunoensaio , Valor Preditivo dos Testes , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
19.
Antibiotics (Basel) ; 9(5)2020 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-32429514

RESUMO

Synthesis of nanoparticles using the plants has several advantages over other methods due to the environmentally friendly nature of plants. Besides being environmentally friendly, the synthesis of nanoparticles using plants or parts of the plants is also cost effective. The present study focuses on the biosynthesis of zinc oxide nanoparticles (ZnO NPs) using the seed extract of Butea monsoperma and their effect on to the quorum-mediated virulence factors of multidrug-resistant clinical isolates of Pseudomonas aeruginosa at sub minimum inhibitory concentration (MIC). The synthesized ZnO NPs were characterized by different techniques, such as Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM). The average size of the nanoparticles was 25 nm as analyzed by TEM. ZnO NPs at sub MIC decreased the production of virulence factors such as pyocyanin, protease and hemolysin for P. aeruginosa (p ≤ 0.05). The interaction of NPs with the P. aeruginosa cells on increasing concentration of NPs at sub MIC levels showed greater accumulation of nanoparticles inside the cells as analyzed by TEM.

20.
Antibiotics (Basel) ; 9(3)2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32120845

RESUMO

Abstract: Plant-based synthesis of eco-friendly nanoparticles has widespread applications in many fields, including medicine. Biofilm-a shield for pathogenic microorganisms-once formed, is difficult to destroy with antibiotics, making the pathogen resistant. Here, we synthesized gold nanoparticles (AuNPs) using the stem of an Ayurvedic medicinal plant, Tinospora cordifolia, and studied the action of AuNPs against Pseudomonas aeruginosa PAO1 biofilm. The synthesized AuNPs were characterized by techniques such as ultraviolet-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, energy-dispersive X-ray diffraction, X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy. The AuNPs were spherically shaped with an average size of 16.1 nm. Further, the subminimum inhibitory concentrations (MICs) of AuNPs (50, 100, and 150 µg/mL) greatly affected the biofilm-forming ability of P. aeruginosa, as observed by crystal violet assay and SEM, which showed a decrease in the number of biofilm-forming cells with increasing AuNP concentration. This was further justified by confocal laser scanning microscopy (CLSM), which showed irregularities in the structure of the biofilm at the sub-MIC of AuNPs. Further, the interaction of AuNPs with PAO1 at the highest sub-MIC (150 µg/mL) showed the internalization of the nanoparticles, probably affecting the tendency of PAO1 to colonize on the surface of the nanoparticles. This study suggests that green-synthesized AuNPs can be used as effective nano-antibiotics against biofilm-related infections caused by P. aeruginosa.

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