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1.
Antimicrob Agents Chemother ; 66(9): e0050622, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-35950843

RESUMO

Bacteriophages and bacteriophage-derived peptidoglycan hydrolases (endolysins) present promising alternatives for the treatment of infections caused by multidrug resistant Gram-negative and Gram-positive pathogens. In this study, Gp105, a putative lysozyme murein hydrolase from Enterobacter phage myPSH1140 was characterized in silico, in vitro as well as in vivo using the purified protein. Gp105 contains a T4-type lysozyme-like domain (IPR001165) and belongs to Glycoside hydrolase family 24 (IPR002196). The putative endolysin indeed had strong antibacterial activity against Gram-negative pathogens, including E. cloacae, K. pneumoniae, P. aeruginosa, S. marcescens, Citrobacter sp., and A. baumannii. Also, an in vitro peptidoglycan hydrolysis assay showed strong activity against purified peptidoglycans. This study demonstrates the potential of Gp105 to be used as an antibacterial protein to combat Gram-negative pathogens.


Assuntos
Bacteriófagos , N-Acetil-Muramil-L-Alanina Amidase , Antibacterianos/farmacologia , Bacteriófagos/metabolismo , Endopeptidases/metabolismo , Enterobacter/metabolismo , Glicosídeo Hidrolases/metabolismo , Klebsiella pneumoniae/metabolismo , Muramidase/farmacologia , Myoviridae/metabolismo , Peptidoglicano/metabolismo , Pseudomonas aeruginosa/metabolismo
2.
Virus Res ; 279: 197884, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-31981773

RESUMO

Mycobacteriophages are viruses specific to mycobacteria that have gained attention as alternative therapeutic strategies for treating antibiotic-resistant infections. Mycobacteriophages are highly diverse and have been grouped into 29 clusters, 71 sub-clusters and 10 singletons based on the genome sequence. Here, we annotate the genome of PDRPxv, a lytic mycobacteriophage isolated from New Delhi; it belongs to the Siphoviridae family as determined by transmission electron microscopy. This phage survives at higher temperatures (up to 55 °C) and in alkaline conditions (up to pH11). PDRPxv phage genome is 69,171 bp in length with 66.35 % GC content and encodes 107 putative open reading frames and belongs to the B1 sub-cluster. Genome annotation indicated that genes for DNA encapsidation, structural proteins, replication/transcription and lysis of the host are present in functional clusters. Structural proteins encoded by Gp10-Gp12, Gp18, Gp25 and Gp28-Gp33 were identified by mass spectrometry. Interestingly, no gene encoding a holin function was found. Single-step growth curve revealed that PDRPxv has an adsorption time of 45 min, a latency time of 135 min and an average burst size of 99 phage particles per infected cell. The short latency period and the large burst size mark the lytic nature of the PDRPxv phage, which could therefore be a promising therapeutic candidate against pathogenic Mycobacterium species.


Assuntos
Genoma Viral , Micobacteriófagos/classificação , Micobacteriófagos/genética , DNA Viral/genética , Mycobacterium smegmatis/virologia , Filogenia , Análise de Sequência de DNA , Microbiologia do Solo , Sequenciamento Completo do Genoma
3.
Sci Rep ; 9(1): 15242, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645642

RESUMO

Phage therapy is one of the promising alternatives to combat the increasing problem of antibiotic resistance. Lyophilization is used for the preparation of pharmaceutical products to improve their stability in long-term storage. The aim of this study was to improve the stability of lyophilized bacteriophages using different excipients. Three lytic bacteriophages Escherichia phage ECP311, Klebsiella phage KPP235 and Enterobacter phage ELP140 were subjected to lyophilization using six different excipients: glucose, sucrose, gelatin, mannitol, polyethylene glycol and sorbitol. The lyophilized phages were stored at 4 °C and 37 °C and rehydrated using biological saline to test their viability at 5 months interval up to 20 months. The results showed that the use of sucrose, gelatin and their combination was beneficial in maintaining the viability of phages post-lyophilization. When lyophilized phages were stored at 4 °C, their viability was maintained up to 20 months, but at 37 °C there was a reduction in activity after 10 months. This is one of the few studies to report the lyophilization of phage cocktails to have viability for up to 10 months. Our study identified promising lyophilization excipients to effectively lyophilize bacteriophages for pharmaceutical applications and long-term storage.


Assuntos
Bacteriófagos/fisiologia , Liofilização/métodos , Colífagos/fisiologia , Enterobacter/virologia , Excipientes/química , Humanos , Klebsiella/virologia , Terapia por Fagos , Temperatura
4.
Access Microbiol ; 1(3): e000024, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32974517

RESUMO

Wastewater has become a potential habitat for multi-drug-resistant bacteria. The present study aims to screen for the presence of carbapenem-resistant bacteria in sewage water samples collected from hospital and non-hospital sources. From a total of 19 sewage water samples collected, 100 carbapenem-resistant non-lactose-fermenting Gram-negative bacteria (CR-NF-GNB) were isolated using MacConkey agar cultured with 8 mg l-1 of meropenem. On screening for beta-lactamase resistance genes (bla NDM, bla OXA-48-like, bla IMP, bla VIM and bla KPC), one isolate, Ochrobactrum intermedium , was found to carry the plasmid-borne bla OXA-48-like gene. To the best of our knowledge, we provide the first report of the rare and emerging opportunistic pathogen Ochrobactrum intermedium encoding the OXA-181 gene in its plasmid.

5.
Access Microbiol ; 1(4): e000036, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32974524

RESUMO

The influence of media composition on the life cycle of bacteriophages to exhibit diverse plaque morphology on various bacteriological media was investigated by a double agar overlay method. Both Staphylococcus aureus phage and Vibrio parahaemolyticus phage showed altered plaque morphology from small to large and from clear to turbid, in different culture media used for the double agar overlay method.

6.
Mol Diagn Ther ; 23(1): 65-82, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30726546

RESUMO

BACKGROUND: Findings from observational clinical studies examining the relationship between biomarker expression and theranosis in colorectal cancer (CRC) have been conflicting. OBJECTIVE: We conducted this systematic review and meta-analysis to summarise the existing evidence to demonstrate the involvement of microRNAs (miRNAs) in chemoresistance and sensitivity in CRC through drug genetic pathways. METHODS: Using PRISMA guidelines, we systematically searched PubMed and Science Direct for relevant studies that took place between 2012 and 2017. A random-effects model of meta-analysis was applied to evaluate the pooled effect size of hazard ratios (HRs) across the included studies. Cochran's Q test and the I2 statistic were used to detect heterogeneity. A funnel plot was used to assess potential publication bias. RESULTS: Of the 4700 studies found, 39 studies comprising 2822 patients with CRC met the inclusion criteria. The included studies used one or a combination of 14 chemotherapy drugs, including 5-fluorouracil and oxaliplatin. Of the 60 miRNAs, 28 were associated with chemosensitivity, 20 with chemoresistance, and one with differential expression and radiosensitivity; ten miRNAs were not associated with any impact on chemotherapy. The results outline the importance of 34 drug-regulatory pathways of chemoresistance and sensitivity in CRC. The mean effect size was 0.689 (95% confidence interval 0.428-1.110), indicating that the expression of miRNAs decreased the likelihood of death by about 32%. CONCLUSION: Studies have consistently shown that multiple miRNAs could act as clinical predictors of chemoresistance and sensitivity. An inclusion of supplementary miRNA estimation in CRC routine practice needs to be considered to evaluate the efficacy of chemotherapy after confirming our findings with large-scale prospective cohort studies. PROSPERO REGISTRATION NUMBER: CRD42017082196.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , MicroRNAs/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Fluoruracila/efeitos adversos , Fluoruracila/uso terapêutico , Humanos , Oxaliplatina/efeitos adversos , Oxaliplatina/uso terapêutico , Nanomedicina Teranóstica/métodos
7.
Cancers (Basel) ; 11(7)2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31252688

RESUMO

BACKGROUND: pancreatic cancer (PC) has increasing incidence and mortality in developing countries, and drug resistance is a significant hindrance to the efficacy of successful treatment. The objective of this systematic review and meta-analysis was to evaluate the association between miRNAs and response to chemotherapy in pancreatic cancer patients. METHODS: the systematic review and meta-analysis was based on articles collected from a thorough search of PubMed and Science Direct databases for publications spanning from January 2008 to December 2018. The articles were screened via a set of inclusion and exclusion criteria based on the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. Data was extracted, collated and tabulated in MS Excel for further synthesis. Hazard ratio (HR) was selected as the effect size metric to be pooled across studies for the meta-analysis, with the random effects model being applied. Subgroup analysis was also conducted, and the presence of publication bias in the selected studies was assessed. Publication bias of the included studies was quantified. FINDINGS: of the 169 articles screened, 43 studies were included in our systematic review and 13 articles were included in the meta-analysis. Gemcitabine was observed to be the principal drug used in a majority of the studies. A total of 48 miRNAs have been studied, and 18 were observed to have possible contributions to chemoresistance, while 15 were observed to have possible contributions to chemosensitivity. 41 drug-related genetic pathways have been identified, through which the highlighted miRNA may be affecting chemosensitivity/resistance. The pooled HR value for overall survival was 1.603; (95% Confidence Interval (CI) 1.2-2.143; p-value: 0.01), with the subgroup analysis for miR-21 showing HR for resistance of 2.061; 95% CI 1.195-3.556; p-value: 0.09. INTERPRETATION: our results highlight multiple miRNAs that have possible associations with modulation of chemotherapy response in pancreatic cancer patients. Further studies are needed to discover the molecular mechanisms underlying these associations before they can be suggested for use as biomarkers of response to chemotherapeutic interventions in pancreatic cancer.

8.
3 Biotech ; 8(1): 55, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29354366

RESUMO

ABSTRACT: Ten aerobic corrosive bacterial strains were isolated from a cooling tower water system (CWS) which were identified based on the biochemical characterization and 16S rRNA gene sequencing. Out of them, dominant corrosion-causing bacteria, namely, Bacillus thuringiensis EN2, Terribacillus aidingensis EN3, and Bacillus oleronius EN9, were selected for biocorrosion studies on mild steel 1010 (MS) in a CWS. The biocorrosion behaviour of EN2, EN3, and EN9 strains was studied using immersion test (weight loss method), electrochemical analysis, and surface analysis. To address the corrosion problems, an anti-corrosive study using a biocide, bronopol was also demonstrated. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses of the MS coupons with biofilm developed after exposure to CWS confirmed the accumulation of extracellular polymeric substances and revealed that biofilms was formed as microcolonies, which subsequently cause pitting corrosion. In contrast, the biocide system, no pitting type of corrosion, was observed and weight loss was reduced about 32 ± 2 mg over biotic system (286 ± 2 mg). FTIR results confirmed the adsorption of bronopol on the MS metal surface as protective layer (co-ordination of NH2-Fe3+) to prevent the biofilm formation and inhibit the corrosive chemical compounds and thus led to reduction of corrosion rate (10 ± 1 mm/year). Overall, the results from WL, EIS, SEM, XRD, and FTIR concluded that bronopol was identified as effective biocide and corrosion inhibitor which controls the both chemical and biocorrosion of MS in CWS.

9.
PLoS One ; 13(10): e0206278, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30356310

RESUMO

Phage therapy is the use of lytic bacteriophages to cure infections caused by bacteria. The aim of this study is to isolate and to characterize the bacteriophages against Escherichia coli isolated from clinical samples. For isolation of bacteriophages, water samples were collected from the Ganges River, and phage enrichment method was followed for phage isolation. Microbiological, genomic and lyophilization experiments were carried out to characterize the bacteriophage. Galleria mellonella was used to study the potential of phages against E. coli infection. Escherichia phage myPSH1131 belonging to Podoviridae family and found to have broad host range infectivity (n = 31) to infect Enterohemorrhagic E. coli (n = 9), Enteropathogenic E. coli (n = 6), Enterotoxigenic E. coli (n = 3), Enteroaggregative E. coli (n = 3), Uropathogenic E. coli (n = 9) and one unknown E. coli. The genome size is 76,163 base pairs (97 coding regions) and their genes show high similarity to SU10 phage. Lyophilization studies showed that the use of 1M sucrose, 2% gelatin and the combination of both 0.5M sucrose plus 1% gelatin could restore phage viability up to 20 months at 4°C. For in vivo studies, it was observed that a single phage dose can reduce the E. coli infection but to achieve 100% survival rate the infected larvae should be treated with three phage doses (20 µL, 10(3) PFU/mL) at 6 hours interval. The characterized Escherichia phage myPSH1131 was found to have broad host range activity against E. coli pathogens and in vivo studies showed that multiple doses are required for effective treatment.


Assuntos
Infecções por Escherichia coli/prevenção & controle , Escherichia coli/virologia , Mariposas/microbiologia , Terapia por Fagos , Podoviridae/patogenicidade , Animais , Podoviridae/classificação , Podoviridae/isolamento & purificação
10.
Medicine (Baltimore) ; 97(52): e13680, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30593138

RESUMO

BACKGROUND: Breast Cancer (BC) is the leading cause of deaths in Indian women. Emerging reports reveal alarming evidence of increasing incidence and mortality of BC among young Indian women in addition to the late presentation and poor prognosis. Despite the significant incidence, there is a lack of reliable data resources and comprehensive epidemiologic studies relating to BC. The objective of this protocol is to conduct a full-scale systematic review and meta-analyses on the incidence, prevalence, and mortality of BC in 29 states and seven union territories of India. METHODS: Data sources used will be Cochrane Review, MEDLINE, PubMed, Scopus, Science Direct, Web of Science, and international and national cancer registries such as World Health Organization, International Agency for Research on Cancer (IARC), and National Centre for Disease Information and Research (NCDIR)-National Cancer Registry Program initiated by Indian Council of Medical Research. Relevant data will be extracted using a predefined data collection form. A defined search strategy will be implemented along with selection criteria to obtain full-text articles of relevant studies. This study protocol was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Protocols 2015 guidelines. Odds ratios (ORs) will be used to measure effect size. The random or fixed-effects meta-analyses model will be employed to aggregate the pooled estimates (ORs) with 95% confidence intervals (CIs) separately. A forest plot will be produced to assess ORs and 95% CIs. Publication bias will be assessed using funnel plot, and Egger regression will be applied to test the symmetry of the funnel plot. ETHICS AND DISSEMINATION: This proposed study will be based on published studies and the data from cancer registries. Therefore, human research ethics approval is not required. The results of this study will be published in a peer-reviewed journal. PROSPERO REGISTRATION NO: CRD42018084003.


Assuntos
Neoplasias da Mama/epidemiologia , Metanálise como Assunto , Revisões Sistemáticas como Assunto , Protocolos Clínicos , Estudos Epidemiológicos , Feminino , Humanos , Incidência , Índia/epidemiologia , Prevalência
11.
Appl Biochem Biotechnol ; 175(6): 2895-906, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25575588

RESUMO

This study aimed to explore the effect of sodium bicarbonate (0-200 mM) on the production of ß-carotene and lipid content in Dunaliella salina and Dunaliella bardawil. Total carotenoid and chlorophyll content were determined at regular intervals by a UV-VIS spectrophotometer. The ß-carotene and lipid contents were analyzed using high-performance liquid chromatography (HPLC) and gas chromatography coupled with mass spectrometry (GC-MS). The HPLC results revealed a twofold increase of ß-carotene in D. salina and D. bardawil cultures grown with sodium bicarbonate. Moreover, total fatty acid profiles from GC-MS indicated a maximum relative percentage of saturated fatty acids (tetradecanoic acid, 10,13-diethyl, methyl ester and methyl 16-methyl-heptadecanoate) compared to polyunsaturated fatty acids in both algae. Our results indicate that the optimum concentration of bicarbonate (100 to 150 mM) was required to stimulate a positive effect on ß-carotene production as well as the lipid profile in Dunaliella sp.


Assuntos
Clorófitas/metabolismo , Ácidos Graxos/biossíntese , Bicarbonato de Sódio/metabolismo , beta Caroteno/biossíntese , Clorofila/análise , Clorofila/metabolismo , Clorófitas/química , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/análise , beta Caroteno/análise
13.
Indian J Microbiol ; 51(3): 273-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22754002

RESUMO

The study comprised of 60 Candida spp., 50 isolates from HIV and TB positive individuals (immunocompromised) and 10 isolates from non-HIV and -TB patients (immunocompetent). Among the 60 Candidal isolates, 83.3% were identified as C. albicans, 11.6% as C. glabrata and rest 5% as C. krusei. There is no study in production pattern of extracellular enzymes of Candida spp. isolated from HIV and TB patients in comparison with non-HIV and -TB patients in India. The comparison of phospholipase activities showed that there was a significant difference between the groups at (P = 0.001). The non-HIV and -TB groups of C. glabrata and C. krusei did not show detectable phospholipase activity when compared to the HIV and TB groups. The mean difference in the phospholipase activities of these two groups was significant (P = <0.001). Candida spp. of both the groups do not possess the ability to hydrolyze gelatin. All the strains possessed the ability to show alpha haemolysis. Even though it had shown alpha haemolysis, the significant difference in haemolytic activity was observed only in C. albicans (P = <0.001). None of the isolates from the two groups possessed the ability to hydrolyze gelatin. In the resistance profile of Candida spp., C. albicans of HIV and TB groups had shown resistance to fluconazole, Itraconazole, ketaconazole, nystatin but showed 100% sensitivity towards amphotericin-B. The isolates of C. krusei and C. glabrata showed no resistance to any of the drugs tested. In the case of, non-HIV and -TB patients the resistance pattern was low.

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