Microbiology insights最新文献

{"title":"Spontaneous Cleavages of a Heterologous Protein, the CenA Endoglucanase of <i>Cellulomonas fimi</i>, in <i>Escherichia coli</i>.","authors":"Cheuk Yin Lai,&nbsp;Ka Lun Ng,&nbsp;Hao Wang,&nbsp;Chui Chi Lam,&nbsp;Wan Keung Raymond Wong","doi":"10.1177/11786361211024637","DOIUrl":"https://doi.org/10.1177/11786361211024637","url":null,"abstract":"<p><p>CenA is an endoglucanase secreted by the Gram-positive cellulolytic bacterium, <i>Cellulomonas fimi</i>, to the environment as a glycosylated protein. The role of glycosylation in CenA is unclear. However, it seems not crucial for functional activity and secretion since the unglycosylated counterpart, recombinant CenA (rCenA), is both bioactive and secretable in <i>Escherichia coli</i>. Using a systematic screening approach, we have demonstrated that rCenA is subjected to spontaneous cleavages (SC) in both the cytoplasm and culture medium of <i>E. coli</i>, under the influence of different environmental factors. The cleavages were found to occur in both the cellulose-binding (CellBD) and catalytic domains, with a notably higher occurring rate detected in the former than the latter. In CellBD, the cleavages were shown to occur close to potential N-linked glycosylation sites, suggesting that these sites might serve as 'attributive tags' for differentiating rCenA from endogenous proteins and the points of initiation of SC. It is hypothesized that glycosylation plays a crucial role in protecting CenA from SC when interacting with cellulose in the environment. Subsequent to hydrolysis, SC would ensure the dissociation of CenA from the enzyme-substrate complex. Thus, our findings may help elucidate the mechanisms of protein turnover and enzymatic cellulolysis.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"11786361211024637"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/11786361211024637","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39142779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and Characterization of a Bacterial Strain <i>Enterobacter cloacae</i> (Accession No. KX438060.1) Capable of Degrading DDTs Under Aerobic Conditions and Its Use in Bioremediation of Contaminated Soil.","authors":"Sonal Suman,&nbsp;Tanuja","doi":"10.1177/11786361211024289","DOIUrl":"https://doi.org/10.1177/11786361211024289","url":null,"abstract":"<p><p>DDT is one of the most persistent pesticides among all the different types of organo-chlorine pesticides used. Among all the degradation methods, bacterial degradation of DDT is most effective. The present study was conducted to isolate different bacteria present in waste samples which have the ability to degrade DDT present in the soil in the minimum possible period of time and to observe the effect of different physical and chemical properties of the soil samples. Many pesticide degrading bacteria were isolated and identified through cultural, biochemical tests and further identified by 16S RNA sequencing method. The most potent strain DDT 1 growth in mineral salt medium supplemented with DDT as the only source of carbon (5-100 PPM) and was monitored at an optical density of 600 nm. The growth parameters at different physio-chemical conditions were further optimized. The result showed that <i>Enterobacter cloacae</i> had maximum growth in 15 days. FTIR analysis of the residual DDT after 15 days incubation showed that <i>Enterobacter cloacae</i> was able to degrade pesticide into its further metabolites of DDD, DDE, DDNU and other components can be used for biodegradation of DDT present in contaminated soil and water ecosystems.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"11786361211024289"},"PeriodicalIF":0.0,"publicationDate":"2021-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/11786361211024289","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39043678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibiotic Resistance and Plasmid Profiling of <i>Escherichia coli</i> Isolated from Human Sewage Samples.","authors":"Sanjida Akter,&nbsp;A M Masudul Azad Chowdhury,&nbsp;Sohana Akter Mina","doi":"10.1177/11786361211016808","DOIUrl":"https://doi.org/10.1177/11786361211016808","url":null,"abstract":"<p><p>In developing countries, the occurrence of antibiotic resistance is increasing day by day and antibiotic resistant microorganisms are being found in almost every environmental setting. Plasmids are considered as the main vector in the procurement and propagation of antibiotic resistance in many microorganisms such as <i>Escherichia coli</i> (<i>E. coli</i>). The goal of this study was to examine the antibiotic resistance and screening of plasmid in <i>E. coli</i> strains which were previously identified from human sewage samples. During this study antibiotic susceptibility of <i>E. coli</i> isolates were determined by Kirby-Bauer disk diffusion method against 5 antibiotics (ampicilin, ceftriaxone, amoxicillin, ciprofloxacin, azithromycin). Furthermore, plasmid extraction of each isolate was done according to the protocol of FavorPrepTMPlasmid Mini Kit and plasmid profiling was done by agarose gel electrophoresis. In antibiotic sensitivity test, all <i>E. coli</i> strains showed resistance to ampicilin, amoxicillin, and ceftriaxone. In the plasmid profiling, it was revealed that all the isolates of <i>E. coli</i> harbored plasmids. The plasmid sizes ranged from approximately 1.5 to 15 kb. The findings of this study prove the consequences of antibiotic resistance as well as relationship of plasmid with antibiotic resistance which necessitates proper surveillance on antibiotic usage in the developing countries.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"11786361211016808"},"PeriodicalIF":0.0,"publicationDate":"2021-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/11786361211016808","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38936850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corona Viruses: A Review on SARS, MERS and COVID-19.","authors":"Nihala Naseefa Chathappady House, Sheeba Palissery, Honey Sebastian","doi":"10.1177/11786361211002481","DOIUrl":"10.1177/11786361211002481","url":null,"abstract":"<p><p>After the outbreak of SARS and MERS, the world is now in the grip of another viral disease named COVID-19 caused by a beta Coronavirus - SARS COV-2 which appears to be the only one with a pandemic potential. The case of COVID-19 was reported in the Hubei province of Wuhan city in Central China at the end of December 2019 and it is suspected that the sea food market played a role in this outbreak which was closed abruptly. Subsequently, a Public Health Emergency of International Concern was declared on 30 January 2020 by the World Health Organization. Both SARS and MERS corona viruses had its reservoir in bats and were transferred to humans from palm civets and camels respectively. This virus can be transmitted through airborne droplets. Natural reservoir and intermediate host of COVID-19 is yet to be identified. This paper reviews the occurrences of viral diseases in the recent times including SARS and MERS. As an addition to this, the paper will contain a detailed examination of the COVID-19 Pandemic.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"11786361211002481"},"PeriodicalIF":0.0,"publicationDate":"2021-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/11786361211002481","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25551142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SARS-CoV-2 as Enteric Virus in Wastewater: Which Risk on the Environment and Human Behavior?","authors":"Yousra Sbaoui, Faïza Bennis, Fatima Chegdani","doi":"10.1177/1178636121999673","DOIUrl":"10.1177/1178636121999673","url":null,"abstract":"<p><p>Microorganisms such as viruses, bacteria, and protozoa are the cause of many waterborne human infections. These microbes are either naturally present in aquatic environments or transferred within them by fecal sources. They remain in these environments for varying lengths of time before contaminating a new host. With the emergence of the COVID-19 pandemic, some studies have reported the presence of viral nucleic acids in stool samples from COVID-19 patients, suggesting the possibility of fecal-oral transmission. The SARS-CoV-2 RNA was thereby detected in the wastewater of symptomatic and asymptomatic people with a risk to human and environmental health. In this work, we try to discuss the different potential sources of this contamination, the forms of persistence in the environment, the techniques of partial elimination, and the possibility of creating new reservoirs.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"1178636121999673"},"PeriodicalIF":0.0,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/98/5b/10.1177_1178636121999673.PMC7968024.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25555278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>In situ</i> Generation of Antibiotics using Bioorthogonal \"Nanofactories\".","authors":"Cheng-Hsuan Li,&nbsp;Rui Huang,&nbsp;Jessa Marie Makabenta,&nbsp;Suzannah Schmidt-Malan,&nbsp;Robin Patel,&nbsp;Vincent M Rotello","doi":"10.1177/1178636121997121","DOIUrl":"https://doi.org/10.1177/1178636121997121","url":null,"abstract":"<p><p>Prodrug strategies use chemical modifications to improve the pharmacokinetic properties and therefore therapeutic effects of parent drugs. Traditional prodrug approaches use endogenous enzymes for activation. Bioorthogonal catalysis uses processes that endogenous enzymes cannot access, providing a complementary strategy for prodrug uncaging. Site-selective activation of prodrugs to drugs (uncaging) using synthetic catalysts is a promising strategy for localized drug activation. We discuss here recent studies that incorporate metal catalysts into polymers and nanoparticle scaffolds to provide biocompatible \"enzyme-like\" catalysts that can penetrate bacterial biofilms and activate prodrug antibiotics <i>in situ</i>, affording a new strategy to treat bacterial biofilm infections with the potential for reduced off-target effects.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"1178636121997121"},"PeriodicalIF":0.0,"publicationDate":"2021-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178636121997121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25466763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Matrix Revisited: Opening Night for the Pel Polysaccharide Across Eubacterial Kingdoms.","authors":"Gregory B Whitfield,&nbsp;P Lynne Howell","doi":"10.1177/1178636120988588","DOIUrl":"https://doi.org/10.1177/1178636120988588","url":null,"abstract":"<p><p>Bacteria synthesize and export adhesive macromolecules to enable biofilm formation. These macromolecules, collectively called the biofilm matrix, are structurally varied and often unique to specific bacterial species or subspecies. This heterogeneity in matrix utilization makes it difficult to facilitate direct comparison between biofilm formation mechanisms of different bacterial species. Despite this, some matrix components, in particular the polysaccharides poly-β-1,6-<i>N</i>-acetyl-glucosamine (PNAG) and bacterial cellulose, are utilized by many Gram-negative species for biofilm formation. However, there is a very narrow distribution of these components across Gram-positive organisms, whose biofilm matrix determinants remain largely undiscovered. We found that a genetic locus required for the production of a biofilm matrix component of <i>P. aeruginosa</i>, the Pel polysaccharide, is widespread in Gram-negative bacteria and that there is a variant form of this cluster present in many Gram-positive bacterial species. We demonstrated that this locus is required for biofilm formation by <i>Bacillus cereus</i> ATCC 10987, produces a polysaccharide that is similar to Pel, and is post-translationally regulated by cyclic-3',5'-dimeric-guanosine monophosphate (c-di-GMP) in a manner identical to <i>P. aeruginosa</i>. However, while the proposed mechanism for Pel production appears remarkably similar between <i>B. cereus</i> and <i>P. aeruginosa</i>, we identified several key differences between Gram-negative and Gram-positive Pel biosynthetic components in other monoderms. In particular, 4 different architectural subtypes of the c-di-GMP-binding component PelD were identified, including 1 found only in Streptococci that has entirely lost the c-di-GMP recognition domain. These observations highlight how existing multi-component bacterial machines can be subtly tweaked to adapt to the unique physiology and regulatory mechanisms of Gram-positive organisms. Collectively, our analyses suggest that the Pel biosynthetic locus is one of the most phylogenetically widespread biofilm matrix determinants in bacteria, and that its mechanism of production and regulation is extraordinarily conserved across the majority of organisms that possess it.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"1178636120988588"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178636120988588","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25414755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Letter to the Editor: Microbiota in the Respiratory System-A Possible Explanation to Age and Sex Variability in Susceptibility to SARS-CoV-2.","authors":"Vishal Shah","doi":"10.1177/1178636120988604","DOIUrl":"https://doi.org/10.1177/1178636120988604","url":null,"abstract":"<p><p>The Human respiratory tract is colonized by a variety of microbes and the microbiota change as we age. In this perspective, literature support is presented for the hypothesis that the respiratory system microbiota could explain the differential age and sex breakdown amongst COVID-19 patients. The number of patients in the older and elderly adult group is higher than the other age groups. The perspective presents the possibility that certain genera of bacteria present in the respiratory system microbiota in children and young adults could be directly or through eliciting an immune response from the host, prevent full-fledged infection of SARS-CoV-2. The possibility also exists that the microbiota in older adults and the elderly population have bacteria that make it easier for the virus to cause infection. I call upon the scientific community to investigate the link between human microbiota and SARS-CoV-2 susceptibility to further understand the viral pathogenesis.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"14 ","pages":"1178636120988604"},"PeriodicalIF":0.0,"publicationDate":"2021-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178636120988604","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25314162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neutrophil Swarms Are More Than the Accumulation of Cells.","authors":"Daniel Irimia","doi":"10.1177/1178636120978272","DOIUrl":"https://doi.org/10.1177/1178636120978272","url":null,"abstract":"<p><p>Neutrophils move from the blood into tissues, migrate under the guidance of chemical gradients, and accumulate at sites of infection, where they phagocytose and kill microbes within minutes. These processes have been considered the keystone of innate immune responses for more than five decades. However, it appears that these processes accurately describe only the situation when neutrophils encounter small numbers of disparate microbes. Recent observations revealed that when neutrophils encounter large fungi or clusters of bacteria that are too large for individual neutrophils to kill, one more process, known as swarming, is needed. During this process, the first neutrophils that reach the microbial target release leukotrienes and other molecules that stimulate more neutrophils in the vicinity to converge on the same target. A chain reaction ensues between the leukotrienes guiding the neutrophils toward the swarm and the attracted neutrophils releasing more leukotrienes. This chain reaction empowers multiple neutrophils to coordinate their activities, drives the explosively-fast accumulation of neutrophils, and enables neutrophils to neutralize large microbes and clusters of microbes, which would otherwise be outside the neutrophils reach. The molecular and cellular details of this chain reaction and the mechanisms that stop the chain reaction from damaging healthy tissues are just beginning to emerge, enabled by innovative, engineered tools.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"13 ","pages":"1178636120978272"},"PeriodicalIF":0.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1178636120978272","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38743897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the Serological Point-of-Care Testing of Infectious Mononucleosis by Data of External Quality Control Samples.","authors":"Salla J Kiiskinen, Oskari Luomala, Teija Häkkinen, Susanna Lukinmaa-Åberg, Anja Siitonen","doi":"10.1177/1178636120977481","DOIUrl":"10.1177/1178636120977481","url":null,"abstract":"<p><p>Timely and reliable laboratory diagnostics is a necessity for patient safety and good patient management. Success in external quality assessment (EQA) reflects on the everyday work in a clinical laboratory. This study evaluated the reliability of serological point-of-care (POC) testing for the Epstein-Barr virus (EBV) that causes infectious mononucleosis (IM). Data from the results of 95 external quality control (EQC) samples, altogether 18 885 results during an eight-year period (2010-2017) were collected from 273 Finnish testing sites. Diagnosing acute infectious mononucleosis (EBV IM) is based on clinical, haematological and serological findings. Heterophile antibody tests are used for this purpose because they can be carried out at POC and are cheap and robust to perform. In this study, the data showed that the testing sites used 3 test methods and 17 different test kits; of the kits, 4 were used during the whole study period. The most commonly used test methods were immunochromatographic assays (12 test kits, 17 959 EQC results). Latex agglutination (4 test kits, 504 results) and immunofiltration test methods (one kit, 422 results) were also used. The overall success rate was 99.3% (for positive samples 99.6%, for negative samples 99.1%). The success rates of the different test methods varied from 94.3% for the immunofiltration method to 99.6% for the latex agglutination method. The lowest success rates were found for negative samples: 82.0% (QuickVue, Quidel [immunochromatographic method]), 91.3% (RDT EBV IgM Assay, Bio-Rad [immunofiltration method]). The results of the negative samples that represented old EBV immunity were the most difficult to interpret with a success rate of 98.9% compared to success rates of clearly positive (99.6%) and negative (99.5%) samples (<i>P</i> < .001). Especially the immunofiltration method (RDT EBV IgM Assay) produced 13.7% false positive results for samples of old immunity. The data showed that 42 of the studied 95 EBV IM EQA rounds were reported as expected (true positive or true negative) by all testing sites.</p>","PeriodicalId":74187,"journal":{"name":"Microbiology insights","volume":"13 ","pages":"1178636120977481"},"PeriodicalIF":0.0,"publicationDate":"2020-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7720297/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38718450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}