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1.
Dig Dis Sci ; 69(4): 1380-1388, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38436866

RESUMO

BACKGROUND AND AIMS: Screening colonoscopy has significantly contributed to the reduction of the incidence of colorectal cancer (CRC) and its associated mortality, with adenoma detection rate (ADR) as the quality marker. To increase the ADR, various solutions have been proposed including the utilization of Artificial Intelligence (AI) and employing second observers during colonoscopies. In the interest of AI improving ADR independently, without a second observer, and the operational similarity between AI and second observer, this network meta-analysis aims at evaluating the effectiveness of AI, second observer, and a single observer in improving ADR. METHODS: We searched the Medline, Embase, Cochrane, Web of Science Core Collection, Korean Citation Index, SciELO, Global Index Medicus, and Cochrane. A direct head-to-head comparator analysis and network meta-analysis were performed using the random-effects model. The odds ratio (OR) was calculated with a 95% confidence interval (CI) and p-value < 0.05 was considered statistically significant. RESULTS: We analyzed 26 studies, involving 22,560 subjects. In the direct comparative analysis, AI demonstrated higher ADR (OR: 0.668, 95% CI 0.595-0.749, p < 0.001) than single observer. Dual observer demonstrated a higher ADR (OR: 0.771, 95% CI 0.688-0.865, p < 0.001) than single operator. In network meta-analysis, results were consistent on the network meta-analysis, maintaining consistency. No statistical difference was noted when comparing AI to second observer. (RR 1.1 (0.9-1.2, p = 0.3). Results were consistent when evaluating only RCTs. Net ranking provided higher score to AI followed by second observer followed by single observer. CONCLUSION: Artificial Intelligence and second-observer colonoscopy showed superior success in Adenoma Detection Rate when compared to single-observer colonoscopy. Although not statistically significant, net ranking model favors the superiority of AI to the second observer.


Assuntos
Adenoma , Neoplasias Colorretais , Humanos , Inteligência Artificial , Colonoscopia/métodos , Adenoma/diagnóstico , Metanálise em Rede , Razão de Chances , Neoplasias Colorretais/diagnóstico
2.
Biotechnol Lett ; 45(8): 967-979, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37227600

RESUMO

At currently, approximately 70 species of magnetotactic bacteria have been identified; thus, there is an urgent need to identify more magnetotactic bacteria from diverse environmental sources with potential applications in industry and biotechnology. To the best of our knowledge, this is the first magnetotactic bacterial strain discovered in Pakistan. The first magnetotactic bacteria, Magnetospirillum moscoviense MS-24, was isolated from Banjosa Lake (Rawalakot), Pakistan, in the current investigation. Magnetospirillum moscoviense MS-24 was screened using the Racetrack method. The Magnetospirillum moscoviense MS-24 were physically characterised using Atomic Force Microscopy, High-Resolution Scanning Electron Microscopy, and Transmission Electron Microscopy. The current study used microscopy to illustrate the shape of bacteria and to find a very obvious chain of magnetosomes within the bacterial cell. The Magnetospirillum moscoviense MS-24 measured about 4 ± 0.04 µm in length and 600 ± 0.02 nm in diameter. The microfluidic chip experiments were also used to detect magnetotaxis behaviour in bacteria.


Assuntos
Magnetossomos , Magnetospirillum , Lagos , Paquistão , Magnetossomos/ultraestrutura , Bactérias
3.
World J Microbiol Biotechnol ; 39(4): 94, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36754876

RESUMO

Natural pristine environments including cold habitats are thought to be the potent reservoirs of antibiotic-resistant genes and have been recurrently reported in polar glaciers' native bacteria, nevertheless, their abundance among the non-polar glaciers' inhabitant bacteria is mostly uncharted. Herein we evaluated antibiotic resistance profile, abundance of antibiotic-resistant genes plus class 1, 2, and 3 integron integrases in 65 culturable bacterial isolates retrieved from a non-polar glacier. The 16S rRNA gene sequencing analysis identified predominantly Gram-negative 43 (66.15%) and Gram-positive 22 (33.84%) isolates. Among the Gram-negative bacteria, Gammaproteobacteria were dominant (62.79%), followed by Betaproteobacteria (18.60%) and Alphaproteobacteria (9.30%), whereas Phyla Actinobacteria (50%) and Firmicutes (40.90%) were predominant among Gram-positive. The Kirby Bauer disc diffusion method evaluated significant antibiotic resistance among the isolates. PCR amplification revealed phylum Proteobacteria predominantly carrying 21 disparate antibiotic-resistant genes like; blaAmpC 6 (100%), blaVIM-1, blaSHV and blaDHA 5 (100%) each, blaOXA-1 1 (100%), blaCMY-4 4 (100%), followed by Actinobacteria 14, Firmicutes 13 and Bacteroidetes 11. Tested isolates were negative for blaKPC, qnrA, vanA, ermA, ermB, intl2, and intl3. Predominant Gram-negative isolates had higher MAR index values, compared to Gram-positive. Alignment of protein homology sequences of antibiotic-resistant genes with references revealed amino acid variations in blaNDM-1, blaOXA-1, blaSHV, mecA, aac(6)-Ib3, tetA, tetB, sul2, qnrB, gyrA, and intI1. Promising antibiotic-resistant bacteria, harbored with numerous antibiotic-resistant genes and class 1 integron integrase with some amino acid variations detected, accentuating the mandatory focus to evaluate the intricate transcriptome analysis of glaciated bacteria conferring antibiotic resistance.


Assuntos
Antibacterianos , Camada de Gelo , Antibacterianos/farmacologia , Paquistão , Prevalência , RNA Ribossômico 16S/genética , Bactérias , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
4.
Arch Microbiol ; 204(6): 332, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35583699

RESUMO

Rock microbes are capable to solubilize phosphate present in the rocks.. In this study, we focused on the isolation of phosphate solubilizing bacteria from rocks of Murree, Pakistan. Both endolithic and epilithic bacteria were screened for phosphate solubilization. Three bacterial strains were selected based on halozone formation inNational Botanical Research Institute for phosphate) medium supplemented with TCP (tribasic calcium phosphate). The solubilization index for these bacteria was recorded as 4.29, 4.03 and 3.99. The pH of the medium dropped from 7.0 to 4.0 after 5 days with continuous shaking at 150 rpm, which facilitate the phosphate solubilization. The strains P26, P4 and N27 were identified as Pseudomonas putida strain (KT004381), Pseudomonas grimontii (KT223621) and Alcaligenes faecalis (KT004385). Strain P26 showed maximum phosphate solubilization (367.54 µg/ml), while P4 and N27 showed 321.88 and 291.36 µg/ml after 3 days of incubation. Such inorganic phosphate solubilization could be attributed to the organic acids production by bacteria. The presence of organic acids is determined by high-performance liquid chromatography. Three different types of acids, gluconic, oxalic and malic acid were the dominant acids found in the culture medium. It may be assumed that these bacteria can play a role in weathering of rocks as well. PSB is likely to serve as an efficient biofertilizer, especially in areas deficient in P to increase the overall performance of crops.


Assuntos
Bactérias , Fosfatos , Paquistão , Fosfatos/química , Microbiologia do Solo
5.
Parasitol Res ; 121(3): 991-998, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35076777

RESUMO

This study was conducted to explore the frequency of positivity of cutaneous leishmaniasis (CL) in the tribal district Bajaur located near the Pak-Afghan border. The present study was conducted at the Leishmaniasis Center of Headquarter Hospital Khar District Bajaur, Pakistan. In total, 646 patients were recruited and included in the study after ethical approval and consent from the patients. CL was confirmed by taking blood samples from the sides of the lesion and observing them under a microscope using Giemsa staining. Information about demographic factors was collected from the study participants with a questionnaire and analyzed by SPSS. It was found that 73.8% of suspected patients were positive and 26.2% were negative for CL. There were 51.9% male and 48.1% female patients. The most frequently affected site was the face (42.6%), and most of the patients (85.8%) had only one lesion. The positivity of CL was higher among those under age 15 years. The area of most positivity, with 45.2% of the cases, was Tehsil Mamund. Most of the patients (46.6%) lived in stone houses, with 98.6% of patients having domestic animals in their houses. Approximately 198 patients were treated with intramuscular and intralesional injections of meglumine antimoniate, and their weekly follow-up revealed that 48% of patients recovered, while the remaining patients left the course of treatment at different stages of therapy. The positivity of CL is high in this area and is confirmed by the detection of Leishmania amastigotes in the blood collected from their lesions. Socioeconomic factors are the main underlying causes of the rapid spread of this disease and meglumine antimoniate is an effective drug.


Assuntos
Antiprotozoários , Leishmaniose Cutânea , Compostos Organometálicos , Adolescente , Animais , Antiprotozoários/uso terapêutico , Feminino , Seguimentos , Humanos , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/epidemiologia , Masculino , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Paquistão/epidemiologia
6.
Water Sci Technol ; 85(1): 420-432, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35050893

RESUMO

Lignin is a major by-product of pulp and paper industries, and is resistant to depolymerization due to its heterogeneous structure. Degradation of lignin can be achieved by the use of potential lignin-degrading bacteria. The current study was designed to evaluate the degradation efficiency of newly isolated Bacillus altitudinis SL7 from pulp and paper mill effluent. The degradation efficiency of B. altitudinis SL7 was determined by color reduction, lignin content, and ligninolytic activity from degradation medium supplemented with alkali lignin (3 g/L). B. altitudinis SL7 reduced color and lignin content by 26 and 44%, respectively, on the 5th day of incubation, as evident from the maximum laccase activity. Optimum degradation was observed at 40 °C and pH 8.0. FT-IR spectroscopy and GC-MS analysis confirmed lignin degradation by emergence of the new peaks and identification of low-molecular-weight compounds in treated samples. The identified compounds such as vanillin, 2-methyoxyhenol, 3-methyl phenol, oxalic acid and ferulic acid suggested the degradation of coniferyl and sinapyl groups of lignin. Degradation efficiency of B. altitudinis SL7 towards high lignin concentration under alkaline pH indicated the potential application of this isolate in biological treatment of the lignin-containing effluents.


Assuntos
Resíduos Industriais , Lignina , Bacillus , Biodegradação Ambiental , Papel , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Appl Microbiol Biotechnol ; 105(23): 8921-8936, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34738169

RESUMO

Microbial communities in cave ecosystems have specific survival strategies, which is far from being well explicated. Here, we reported the genetic and functional diversity of bacteria and archaea in typical limestone (Kashmir Cave) and silicate-containing (Tiser Cave) caves. X-ray diffraction (XRD) and Fourier transform infrared spectroscopic (FTIR) analyses revealed the different geochemical and mineral compositions of the two caves. Amplicon barcode sequencing revealed the dominancy of Actinobacteria and Proteobacteria in Kashmir and Tiser Caves. Bacteroidetes and Firmicutes were the dominant phyla in Tiser Cave, and the abundance is relatively small in Kashmir Cave. Archaea was also abundant prokaryotes in Kashmir Cave, but it only accounted for 0.723% of the total prokaryote sequences in Tiser Cave. Functional analysis based on metagenomic sequencing data revealed that a large number of functional potential genes involved in nutrient metabolism and biosynthesis of bioactive compounds in Tiser and Kashmir Cave samples could significantly influence the biogeochemical cycle and secondary metabolite production in cave habitats. In addition, the two caves were also found to be rich in biosynthetic genes, encoding bioactive compounds, such as monobactam and prodigiosin, indicating that these caves could be potential habitats for the isolation of antibiotics. This study provides a comprehensive insight into the diversity of bacteria and archaea in cave ecosystems and helps to better understand the special survival strategies of microorganisms in cave ecosystems.Key points• Geochemically distinct caves possess unique microbial community structure.• Cavernicoles could be important candidates for antibiotic production.• Cavernicoles are important for biogeochemical cycling.


Assuntos
Cavernas , Microbiota , Archaea/genética , Bactérias/genética , RNA Ribossômico 16S/genética
8.
J Behav Med ; 44(6): 811-821, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34106368

RESUMO

Individuals with chronic low back pain (cLBP) frequently report sleep disturbances. Living in a neighborhood characterized by low-socioeconomic status (SES) is associated with a variety of negative health outcomes, including poor sleep. Whether low-neighborhood SES exacerbates sleep disturbances of people with cLBP, relative to pain-free individuals, has not previously been observed. This study compared associations between neighborhood-level SES, pain-status (cLBP vs. pain-free), and daily sleep metrics in 117 adults (cLBP = 82, pain-free = 35). Neighborhood-level SES was gathered from Neighborhood Atlas, which provides a composite measurement of overall neighborhood deprivation (e.g. area deprivation index). Individuals completed home sleep monitoring for 7-consecutive days/nights. Neighborhood SES and pain-status were tested as predictors of actigraphic sleep variables (e.g., sleep efficiency). Analyses revealed neighborhood-level SES and neighborhood-level SES*pain-status interaction significantly impacted objective sleep quality. These findings provide initial support for the negative impact of low neighborhood-level SES and chronic pain on sleep quality.


Assuntos
Dor Lombar , Adulto , Humanos , Estudos Longitudinais , Dor Lombar/epidemiologia , Características de Residência , Sono , Classe Social , Fatores Socioeconômicos
9.
BMC Musculoskelet Disord ; 22(1): 429, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33971876

RESUMO

BACKGROUND: Biopsychosocial factors above and beyond pathoanatomical changes likely contribute to the severity of chronic low back pain. A pro-nociceptive endogenous pain modulatory balance (↓inhibition and ↑facilitation) may be an important contributor to chronic low back pain severity and physical function; however, additional research is needed to address this possibility. The objective of this study was to determine whether quantitative sensory tests of endogenous pain inhibition and facilitation prospectively predict movement-evoked pain and cLBP severity self-reported on a validated questionnaire. METHODS: One hundred thirty-four individuals with chronic low back pain were enrolled in this two-session study. During the first study session, temporal summation of mechanical pain and conditioned pain modulation were assessed at the lumbar spine to determine endogenous pain facilitation and inhibition, respectively. One week later, participants returned for a second study session whereby they reported their pain severity and pain interference using the Brief Pain Inventory-Short Form. Movement-evoked pain and physical function capacity were assessed upon completion of the balance, walking, and transition from sit to stand tests of the Short Physical Performance Battery. RESULTS: Temporal summation of mechanical pain, but not conditioned pain modulation, significantly and prospectively predicted greater movement-evoked pain and poorer physical function on the Short Physical Performance Battery. Neither temporal summation nor conditioned pain modulation were significantly related to self-reported pain severity or pain interference on the Brief Pain Inventory-Short Form. CONCLUSIONS: Findings suggest that a pro-nociceptive pain modulatory balance characterized by enhanced pain facilitation may be an important driver of movement-evoked pain severity and poor physical function in individuals with chronic low back pain.


Assuntos
Dor Crônica , Dor Lombar , Adulto , Dor Crônica/diagnóstico , Humanos , Dor Lombar/diagnóstico , Vértebras Lombares , Movimento , Medição da Dor , Limiar da Dor , Inquéritos e Questionários
10.
J Med Virol ; 92(12): 3179-3186, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31696948

RESUMO

Multiple Rotavirus A (RVA) strains are linked with gastrointestinal infections in children that fall in age bracket of 0 to 60 months. However, the problem is augmented with emergence of unique strains that reassort with RVA strains of animal origin. The study describes the sequence analysis of a rare G6P[1] rotavirus strain isolated from a less than 1 year old child, during rotavirus surveillance in Rawalpindi district, Pakistan in 2010. Extracted RNA from fecal specimen was subjected to high throughput RT-PCR for structural and nonstructural gene segments. The complete rotavirus genome of one isolate RVA/Human-wt/PAK/PAK99/2010/G6P[1] was sequenced for phylogenetic analysis to elucidate the evolutionary linkages and origin. Full genome examination of novel strain RVA/Human-wt/PAK/PAK99/2010/G6P[1] revealed the unique genotype assemblage: G6-P[1]-I2-R2-C2-M2-A3-N2-T6-E2-H1. The evolutionary analyses of VP7, VP4, NSP1 and NSP3 gene segments revealed that PAK99 clustered with bovine, or cattle-like rotavirus strains from other closely related species, in the genotypes G6, P[1], A3 and T6 respectively. Gene segments VP6, VP1, VP2, VP3, NSP2 and NSP4 all possessed the DS-1-like bovine genotype 2 and bovine (-like) RVA strains instead of RVA strains having human origin. However, the NSP5 gene was found to cluster closely with contemporary human Wa-like rotavirus strains of H1 genotype. This is the first report on bovine-human (Wa-like reassortant) genotype constellation of G6P[1] strain from a human case in Pakistan (and the second description worldwide). Our results emphasize the significance of incessant monitoring of circulating RVA strains in humans and animals for better understanding of RV evolution.

11.
Extremophiles ; 24(1): 135-145, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31655895

RESUMO

In the present study, cyanobacterium isolate CHS1 isolated from Hopar glacier, Pakistan, was analyzed for the first time for cell membrane fatty acids and production of pigments. Sequencing of the 16-23S intergenetic region confirmed identification of the isolate CHS1 as Nodularia spumigena. All chlorophyll and carotenoid pigments were quantified using high-performance liquid chromatography and experiments to test tolerance against a range of physico-chemical conditions were conducted. Likewise, the fatty acid profile of the cell membrane CHS1 was analyzed using gas chromatography and mass spectroscopy. The cyanobacterium isolate CHS1 demonstrated tolerance to 8 g/L% NaCl, 35°C and pH 5-9. The characteristic polyunsaturated fatty acid (PUFA) of isolate CHS1, C18:4, was observed in fatty acid methyl esters (FAMEs) extracted from the cell membrane. CHS1 was capable of producing saturated fatty acids (SFA) (e.g., C16:0), monounsaturated fatty acids (MUFA) (e.g., C18:1) and polyunsaturated fatty acids (e.g., C20:5) in the cell membrane. In this study, we hypothesize that one mechanism of cold adaptation displayed by isolate CHS1 is the accumulation of high amounts of PUFA in the cell membrane.


Assuntos
Membrana Celular , Camada de Gelo , Nodularia , Ácidos Graxos , Paquistão
12.
Appl Microbiol Biotechnol ; 104(7): 2777-2801, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32020277

RESUMO

More than 80% of the Earth surface is consisted of hostile and harsh environments, classified as extreme from an anthropogenic perspective. Microorganisms with acclimatized nature dominate these extreme ecosystems of the biosphere. Survivals in such environments initiate an inductive force leading to the production of noteworthy metabolites having peculiar biochemistry. Recent investigations on extremophilic fungi for unprecedented bioactive compounds emphasize their remarkable potential as sources of new therapeutics. The present review covers the literature published in the last 15 years and highlights the biological activities and structure of compounds isolated from the extremophilic fungi. The compounds are grouped based on their biological functions such as cytotoxicity, lipid-lowering ability, and antimicrobial, antioxidant, nematocidal, anti-inflammatory, anti-malarial, and antifouling activities. A total of 155 compounds isolated from 25 Penicillium species, 16 Aspergillus species, and 23 other species are presented, which include 105 new and 50 known bioactive compounds. Out of these, 77 have known cytotoxic activity and 46 are antimicrobial in nature, while there are 32 other compounds with different activities including nematocidal, anti-allergic, antioxidant, and anti-inflammatory. KEY POINTS: • A broad compilation of bioactive compounds from extremophilic fungi. • Classification of bioactive compounds based on their biological functions. • Production of cytotoxic compounds is common among all kind of extremophilic fungi. • Bioactive compounds have no direct role in adaptation process of extremophiles.


Assuntos
Fatores Biológicos/metabolismo , Extremófilos/metabolismo , Fungos/metabolismo , Adaptação Fisiológica/fisiologia , Antibacterianos/metabolismo , Anti-Inflamatórios/metabolismo , Antimaláricos/metabolismo , Antinematódeos/metabolismo , Antioxidantes/metabolismo , Ecossistema
13.
Pain Med ; 21(11): 3161-3171, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32330282

RESUMO

OBJECTIVE: For most patients with chronic low back pain (cLBP), the cause is "nonspecific," meaning there is no clear association between pain and identifiable pathology of the spine or associated tissues. Laypersons and providers alike are less inclined to help, feel less sympathy, dislike patients more, suspect deception, and attribute lower pain severity to patients whose pain does not have an objective basis in tissue pathology. Because of these stigmatizing responses from others, patients with cLBP may feel that their pain is particularly unjust and unfair. These pain-related injustice perceptions may subsequently contribute to greater cLBP severity. The purpose of this study was to examine whether perceived injustice helps explain the relationship between chronic pain stigma and movement-evoked pain severity among individuals with cLBP. METHODS: Participants included 105 patients with cLBP who completed questionnaires assessing chronic pain stigma and pain-related injustice perception, as well as a short physical performance battery for the assessment of movement-evoked pain and physical function. RESULTS: Findings revealed that perceived injustice significantly mediated the association between chronic pain stigma and cLBP severity (indirect effect = 6.64, 95% confidence interval [CI] = 2.041 to 14.913) and physical function (indirect effect = -0.401, 95% CI = -1.029 to -0.052). Greater chronic pain stigma was associated with greater perceived injustice (P = 0.001), which in turn was associated with greater movement-evoked pain severity (P = 0.003). CONCLUSIONS: These results suggest that perceived injustice may be a means through which chronic pain stigma impacts nonspecific cLBP severity and physical function.


Assuntos
Dor Crônica , Dor Lombar , Adulto , Catastrofização , Avaliação da Deficiência , Humanos , Medição da Dor
14.
Curr Microbiol ; 77(8): 1622-1636, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32277275

RESUMO

A fungus, designated as strain SS2 able to degrade aliphatic polyesters, poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), was isolated from soil. Strain SS2 was identified through rDNA gene sequencing and showed maximum closeness to Penicillium oxalicum. The newly isolated P. oxalicum strain SS2 had completely degraded PHB and PHBV both in emulsion and films form within 36-48 h at 30 °C. Furthermore, P. oxalicum SS2 degraded PHB and PHBV films in soil environment in lab-built soil microcosms within 1 week. The polymer films were evaluated for changes after degradation through scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and Fourier Transform Infrared spectroscopy (FTIR). The PHBV depolymerase enzyme was purified to homogeneity through column chromatography and molecular mass was found approximately 36 kDa. The depolymerase was stable over a wide range of temperature (15-60 °C) and pH (3.0-8.0) with optimum 40 °C and pH 5.0. The enzyme activity was significantly affected by various metal ions and surfactants. The enzyme activity was strongly enhanced in the presence of divalent cationic metal Cu2+ while inhibited by Zn2+ and non-polar detergents Tween 20 and Tween 60. Finally, it is concluded that P. oxalicum strain SS2 has profound degradation capabilities, and can be applied for the treatment of plastic-contaminated environments.


Assuntos
Ácido 3-Hidroxibutírico/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Penicillium/enzimologia , Poliésteres/metabolismo , Microbiologia do Solo , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Penicillium/isolamento & purificação , Temperatura
15.
Curr Microbiol ; 77(7): 1245-1253, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32125445

RESUMO

A radio-resistant bacterium labeled as strain TMC-6 was isolated from Thal desert, Pakistan and identified through 16S rRNA gene sequencing as Bacillus indicus strain TMC-6 (MN721293). The isolate was found to be resistant to UV radiation dose of 6.780 × 103 J/m2 and showed 50% survivability to mitomycin C (6 µg/ml) and H2O2 (30 mM). The bacterium showed yellowish orange coloration when grown on tryptone yeast glucose (TGY) medium. The cellular metabolite was extracted in methanol and purified through solid phase extraction with C18 column cartridge. The compound was characterized through UV/Visible spectrophotometry, Fourier Transform Infra-Red (FT-IR) spectroscopy and Liquid Chromatography Mass Spectrometry (LC-MS). The LC-MS analysis of the compound revealed a molar mass of 769 [m/z]- that matched the chemical formula C34H42O20 and identified as a glycosylated flavonoid xanthorhamnin. The compound showed significant antioxidant (77.05%) and metal chelation (79.80%) activities. Xanthorhamnin showed promising oxidative damage inhibitory actions in bovine serum albumin (65.32%) and mice liver lipids (71.61%) and prevented DNA strand breaks from oxidative stress. Cytotoxicity in brine shrimp larvae was observed when compared with mitomycin C indicating its effect toward cancerous cells. These findings concluded that xanthorhamnin from radio-resistant Bacillus indicus strain TMC-6 has high antioxidant, radioprotective, and antitumor properties against UV-mediated oxidative damages.


Assuntos
Antioxidantes , Bacillus , Quercetina , Protetores contra Radiação , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Antioxidantes/toxicidade , Artemia/efeitos dos fármacos , Bacillus/química , Bacillus/fisiologia , Glicosilação , Larva/efeitos dos fármacos , Fígado/química , Fígado/efeitos dos fármacos , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Viabilidade Microbiana/efeitos da radiação , Quercetina/análogos & derivados , Quercetina/química , Quercetina/farmacologia , Quercetina/toxicidade , Protetores contra Radiação/química , Protetores contra Radiação/farmacologia , Protetores contra Radiação/toxicidade , Microbiologia do Solo , Testes de Toxicidade , Raios Ultravioleta
16.
J Basic Microbiol ; 60(5): 444-457, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32147851

RESUMO

The Hindu Kush mountains spread over Northern areas of Pakistan having hundreds of glaciers representing a unique ecosystem driven by the specific geochemistry and climate. The current study measured the distribution of culturable fungi in Tirich Mir glacier, Hindu Kush range, and the potential of these isolates to show antimicrobial activity and produce biotechnologically important enzymes. Samples of glacial ice, sediments, and meltwater were collected from Tirich Mir glacier, and 46 fungal strains were isolated and characterized for identity and biotechnological applications. The findings revealed Penicillium (10) as the most common genus, followed by Alternaria (9), Cladosporium (7), Coprinopsis, two isolates each belonging to genus Phoma, Ulocladium, Epicoccum, Onygenales, and Didymella, and one isolate of genus Davidiella, Aspergillus, Geomyces, Dothideomycetes, Pseudogymnoascus, Irpex, Scopulariopsis, Ascochyta, Tomicus, and Davidiellaceae. Davidiella tassiana HTF9 showed growth in the presence of 18% NaCl and pH 2, 3, 5, 7, 9, and 11. The isolates Ulocladium sp. and Onygenales sp. inhibited the growth of test fungi, Gram-negative and positive bacteria. Fungal strains were capable of producing cold-active enzymes, including cellulase, lipase, amylase, and deoxyribonuclease. The isolate Penicillium chrysogenum HTF24 was an efficient producer of amylase, deoxyribonuclease, and cellulase. The fungi of high-altitude glaciers are potent candidates for biotechnological applications; however, studies using more sensitive techniques are needed for further exploration.


Assuntos
Biotecnologia , Fungos/isolamento & purificação , Fungos/fisiologia , Camada de Gelo/microbiologia , Anti-Infecciosos/metabolismo , Biodiversidade , Contagem de Colônia Microbiana , DNA Fúngico/genética , Proteínas Fúngicas/metabolismo , Fungos/classificação , Paquistão , Filogenia
17.
J Basic Microbiol ; 60(7): 600-612, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32363591

RESUMO

Industrial applications require enzymes to be highly stable and economically viable in terms of reusability. Enzyme immobilization is an exciting alternative to improve the stability of enzymatic processes. Immobilization of ß-1,4-xylanase produced by Bacillus licheniformis S3 is performed by using two polymer supports (agar-agar and calcium alginate). The maximum enzyme immobilization yield was achieved at a concentration of 3% agar, whereas a combination of sodium alginate, 4%, and calcium chloride, 0.3 M, was used for the formation of immobilized beads. The immobilization process increased the optimum reaction time from 10 min to 35 and 40 min for agar and calcium alginate, respectively, and the incubation temperature increased from 55°C to 60°C for agar, but it remained unchanged for calcium alginate. The pH profile of free and immobilized xylanase was quite similar in both cases. Both the techniques altered the kinetic parameters of immobilized ß-1,4-xylanase as compared with the free enzyme. The diffusion limit of high molecular weight xylan caused a decline in Vmax of the immobilized enzyme, whereas there was an increase in the Km value. However, calcium alginate-immobilized enzyme displayed broad thermal stability as compared with agar-agar-immobilized enzyme and retained 57.1% of its initial activity at 80°C up to 150 min. Biotechnological characterization showed that the reusability of enzymes was the most striking finding, particularly of immobilized xylanase using agar-agar as immobilization carrier, which after six cycles retained 23% activity.


Assuntos
Bacillus licheniformis/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Enzimas Imobilizadas/metabolismo , Xilanos/metabolismo , Ágar/química , Alginatos/química , Enzimas Imobilizadas/química
18.
Arch Virol ; 164(7): 1781-1791, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31079214

RESUMO

Introduction of animal group A rotavirus (RVA) gene segments into the human RVA population is a major factor shaping the genetic landscape of human RVA strains. The VP6 and NSP4 genes of 74 G/P-genotyped RVA isolates collected in Rawalpindi during 2010 were analyzed, revealing the presence of VP6 genotypes I1 (60.8%) and I2 (39.2%) and NSP4 genotypes E1 (60.8%), E2 (28.3%) and E-untypable (10.8%) among the circulating human RVA strains. The typical human RVA combinations I1E1 and I2E2 were found in 59.4% and 24.3% of the cases, respectively, whereas 5.4% of the RVA strains were reassortants, i.e., either I1E2 or I2E1. The phylogeny of the NSP4 gene showed that one G2P[4] and two G1P[6] RVA strains clustered with porcine E1 RVA strains or RVA strains that were considered to be (partially) of porcine origin. In addition, the NSP4 gene segment of the unusual human G6P[1] RVA strains clustered closely with bovine E2 RVA strains, further strengthening the hypothesis of an interspecies transmission event. The study further demonstrates the role of genomic re-assortment and the involvement of interspecies transmission in the evolution of human RVA strains. The VP6 and NSP4 nucleotide sequences analyzed in the study received the GenBank accession numbers KC846908- KC846971 and KC846972-KC847037, respectively.


Assuntos
Antígenos Virais/genética , Proteínas do Capsídeo/genética , Glicoproteínas/genética , Infecções por Rotavirus/transmissão , Rotavirus/genética , Rotavirus/isolamento & purificação , Toxinas Biológicas/genética , Proteínas não Estruturais Virais/genética , Sequência de Aminoácidos , Animais , Bovinos , Pré-Escolar , Gastroenterite/virologia , Genoma Viral/genética , Genótipo , Humanos , Paquistão , Filogenia , Infecções por Rotavirus/virologia , Alinhamento de Sequência , Suínos , Zoonoses/virologia
19.
Mol Biol Rep ; 46(4): 4565-4580, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31243724

RESUMO

Polysaccharides including resistant starch are categorized as dietary fiber and are used as an important prebiotic. Similar to soluble fibers, resistant starch also has a number of physiological effects that have been shown to be beneficial for health. Starch hydrolyzing enzymes, most importantly amylases, play essential roles in the production of resistant starch. This study aimed to develop α-amylase-treated maize flour with slow digestibility and unique physicochemical characteristics compared to native maize flour. In the current study, resistant starch type III from maize flour was prepared using α-amylase obtained from indigenously isolated Bacillus licheniformis. The α-amylase gene from B. licheniformis was amplified and cloned into the pET-24(a) vector, expressed in E. coli BL21 (DE3) cells and purified by metal ion affinity chromatography. The purified enzyme enhanced the yield of resistant starch 16-fold in maize flour. Scanning electron microscopy revealed that the granular structure of maize flour was disrupted into a dense network with irregular structure, and X-ray diffractograms confirmed the transformation from an amorphous to a crystalline structure upon α-amylase treatment. Thermogravimetric analysis revealed increased amylose content of α-amylase-treated maize flour. Moreover, α-amylase-treated maize flour resulted in a significant enhancement of the desired properties of maize flour, such as resistant starch content, amylose, milk absorption capacity, and iodine and fatty acid complexing ability, and a reduction in swelling power, water binding, oil absorption capacity, and in vitro digestibility compared to untreated maize flour. Resistant starch type III showed low digestibility and increased complexing ability with iodine and fatty acid and therefore could be a safe and beneficial alternative as a coating material for the delivery of active, sensitive ingredients to the colon.


Assuntos
Amido/biossíntese , Zea mays/metabolismo , alfa-Amilases/metabolismo , Amilose , Bacillus licheniformis/enzimologia , Bacillus licheniformis/metabolismo , Farinha , Hidrólise , Polissacarídeos/química , alfa-Amilases/genética
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