ISRN Microbiology最新文献_第7页

Antagonistic Roles for GcvA and GcvB in hdeAB Expression in Escherichia coli. GcvA和GcvB在大肠杆菌hdeAB表达中的拮抗作用。

ISRN Microbiology Pub Date : 2012-05-16 Print Date: 2012-01-01 DOI: 10.5402/2012/697308

Lorraine T Stauffer, George V Stauffer

{"title":"Antagonistic Roles for GcvA and GcvB in hdeAB Expression in Escherichia coli.","authors":"Lorraine T Stauffer, George V Stauffer","doi":"10.5402/2012/697308","DOIUrl":"https://doi.org/10.5402/2012/697308","url":null,"abstract":"In E. coli, the periplasmic proteins HdeA and HdeB have chaperone-like functions, suppressing aggregation of periplasmic proteins under acidic conditions. A microarray analysis of RNA isolated from an E. coli wild type and a ΔgcvB strain grown to mid-log phase in Luria-Bertani broth indicated the hdeAB operon, encoding the HdeA and HdeB proteins, is regulated by the sRNA GcvB. We wanted to verify that GcvB and its coregulator Hfq play a role in regulation of the hdeAB operon. In this study, we show that GcvB positively regulates hdeA::lacZ and hdeB::lacZ translational fusions in cells grown in Luria-Bertani broth and in glucose minimal media + glycine. Activation also requires the Hfq protein. Although many sRNAs dependent on Hfq regulate by an antisense mechanism, GcvB regulates hdeAB either directly or indirectly at the level of transcription. GcvA, the activator of gcvB, negatively regulates hdeAB at the level of transcription. Although expression of gcvB is dependent on GcvA, activation of hdeAB by GcvB occurs independently of GcvA's ability to repress the operon. Cell survival and growth at low pH are consistent with GcvA negatively regulating and GcvB positively regulating the hdeAB operon.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"697308"},"PeriodicalIF":0.0,"publicationDate":"2012-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5402/2012/697308","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31595111","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}

引用次数: 13

Optimization of Antioxidant Potential of Penicillium granulatum Bainier by Statistical Approaches. 用统计方法优化肉芽青霉的抗氧化潜力。

ISRN Microbiology Pub Date : 2012-05-15 Print Date: 2012-01-01 DOI: 10.5402/2012/452024

Priyanka Chandra, Daljit Singh Arora

引用次数: 12

Modulation of neutrophil apoptosis by antimicrobial peptides. 抗菌肽对中性粒细胞凋亡的调节。

ISRN Microbiology Pub Date : 2012-03-27 Print Date: 2012-01-01 DOI: 10.5402/2012/345791

Isao Nagaoka, Kaori Suzuki, François Niyonsaba, Hiroshi Tamura, Michimasa Hirata

{"title":"Modulation of neutrophil apoptosis by antimicrobial peptides.","authors":"Isao Nagaoka, Kaori Suzuki, François Niyonsaba, Hiroshi Tamura, Michimasa Hirata","doi":"10.5402/2012/345791","DOIUrl":"https://doi.org/10.5402/2012/345791","url":null,"abstract":"Peptide antibiotics possess the potent antimicrobial activities against invading microorganisms and contribute to the innate host defense. Human antimicrobial peptides, α-defensins (human neutrophil peptides, HNPs), human β-defensins (hBDs), and cathelicidin (LL-37) not only exhibit potent bactericidal activities against Gram-negative and Gram-positive bacteria, but also function as immunomodulatory molecules by inducing cytokine and chemokine production, and inflammatory and immune cell activation. Neutrophil is a critical effector cell in host defense against microbial infection, and its lifespan is regulated by various pathogen- and host-derived substances. Here, we provided the evidence that HNP-1, hBD-3, and LL-37 cannot only destroy bacteria but also potently modulate (suppress) neutrophil apoptosis, accompanied with the phosphorylation of ERK-1/-2, the downregulation of tBid (an proapoptotic protein) and upregulation of Bcl-xL (an antiapoptotic protein), and the inhibition of mitochondrial membrane potential change and caspase 3 activity, possibly via the actions on the distinct receptors, the P2Y6 nucleotide receptor, the chemokine receptor CCR6, and the low-affinity formyl-peptide receptor FPRL1/the nucleotide receptor P2X7, respectively. Suppression of neutrophil apoptosis results in the prolongation of their lifespan and may be advantageous for the host defense against bacterial invasion.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"345791"},"PeriodicalIF":0.0,"publicationDate":"2012-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5402/2012/345791","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31470254","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}

引用次数: 36

Trends of Antibiotic Resistance in Mesophilic and Psychrotrophic Bacterial Populations during Cold Storage of Raw Milk. 生乳冷藏期间嗜中性和嗜心理营养细菌群体的抗生素耐药性趋势。

ISRN Microbiology Pub Date : 2012-03-12 Print Date: 2012-01-01 DOI: 10.5402/2012/918208

Patricia Munsch-Alatossava, Jean-Pierre Gauchi, Bhawani Chamlagain, Tapani Alatossava

{"title":"Trends of Antibiotic Resistance in Mesophilic and Psychrotrophic Bacterial Populations during Cold Storage of Raw Milk.","authors":"Patricia Munsch-Alatossava, Jean-Pierre Gauchi, Bhawani Chamlagain, Tapani Alatossava","doi":"10.5402/2012/918208","DOIUrl":"10.5402/2012/918208","url":null,"abstract":"Psychrotrophic bacteria in raw milk are most well known for their spoilage potential and cause significant economic losses in the dairy industry. Despite their ability to produce several exoenzyme types at low temperatures, psychrotrophs that dominate the microflora at the time of spoilage are generally considered benign bacteria. It was recently reported that raw milk-spoiling Gram-negative-psychrotrophs frequently carried antibiotic resistance (AR) features. The present study evaluated AR to four antibiotics (ABs) (gentamicin, ceftazidime, levofloxacin, and trimethoprim-sulfamethoxazole) in mesophilic and psychrotrophic bacterial populations recovered from 18 raw milk samples, after four days storage at 4°C or 6°C. Robust analysis of variance and non parametric statistics (e.g., REGW and NPS) revealed that AR prevalence among psychrotrophs, for milk samples stored at 4°C, often equalled the initial levels and equalled or increased during the cold storage at 6°C, depending on the AB. The study performed at 4°C with an intermediate sampling point at day 2 suggested that (1) different psychrotrophic communities with varying AR levels dominate over time and (2) that AR (determined from relative amounts) was most prevalent, transiently, after 2-day storage in psychrotrophic or mesophilic populations, most importantly at a stage where total counts were below or around 10(5) CFU/mL, at levels at which the milk is acceptable for industrial dairy industrial processes.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"918208"},"PeriodicalIF":0.0,"publicationDate":"2012-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3658802/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31471825","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}

引用次数: 0

Escherichia coli ATCC 8739 Adapts to the Presence of Sodium Chloride, Monosodium Glutamate, and Benzoic Acid after Extended Culture. 大肠杆菌ATCC 8739对氯化钠、谷氨酸钠和苯甲酸的培养具有适应性。

ISRN Microbiology Pub Date : 2012-03-05 Print Date: 2012-01-01 DOI: 10.5402/2012/965356

Chin How Lee, Jack S H Oon, Kun Cheng Lee, Maurice H T Ling

{"title":"Escherichia coli ATCC 8739 Adapts to the Presence of Sodium Chloride, Monosodium Glutamate, and Benzoic Acid after Extended Culture.","authors":"Chin How Lee, Jack S H Oon, Kun Cheng Lee, Maurice H T Ling","doi":"10.5402/2012/965356","DOIUrl":"https://doi.org/10.5402/2012/965356","url":null,"abstract":"Escherichia coli is commonly found in intestine of human, and any changes in their adaptation or evolution may affect the human body. The relationship between E. coli and food additives is less studied as compared to antibiotics. E. coli within our human gut are consistently interacting with the food additives; thus, it is important to investigate this relationship. In this paper, we observed the evolution of E. coli cultured in different concentration of food additives (sodium chloride, benzoic acid, and monosodium glutamate), singly or in combination, over 70 passages. Adaptability over time was estimated by generation time and cell density at stationary phase. Polymerase chain reaction (PCR)/restriction fragments length polymorphism (RFLP) using 3 primers and restriction endonucleases, each was used to characterize adaptation/evolution at genomic level. The amplification and digestion profiles were tabulated and analyzed by Nei-Li dissimilarity index. Our results demonstrate that E. coli in every treatment had adapted over 465 generations. The types of stress were discovered to be different even though different concentrations of same additives were used. However, RFLP shows a convergence of genetic distances, suggesting the presence of global stress response. In addition, monosodium glutamate may be a nutrient source and support acid resistance in E. coli.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"965356"},"PeriodicalIF":0.0,"publicationDate":"2012-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5402/2012/965356","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31471826","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}

引用次数: 21

Detection and typing of human papilloma virus by multiplex PCR with type-specific primers. 人乳头瘤病毒型别特异性引物多重PCR检测及分型研究。

ISRN Microbiology Pub Date : 2012-03-01 Print Date: 2012-01-01 DOI: 10.5402/2012/186915

Francisco Romero-Pastrana

引用次数: 27

Chromosomal Arrangement of AHL-Driven Quorum Sensing Circuits in Pseudomonas. 假单胞菌ahl驱动的群体感应电路的染色体排列。

ISRN Microbiology Pub Date : 2012-02-29 Print Date: 2012-01-01 DOI: 10.5402/2012/484176

Zsolt Gelencsér, Borisz Galbáts, Juan F Gonzalez, K Sonal Choudhary, Sanjarbek Hudaiberdiev, Vittorio Venturi, Sándor Pongor

引用次数: 15

Isolation of Cellulolytic Bacillus subtilis Strains from Agricultural Environments. 农业环境中纤维素降解枯草芽孢杆菌的分离。

ISRN Microbiology Pub Date : 2012-02-29 Print Date: 2012-01-01 DOI: 10.5402/2012/650563

Yu-Kyoung Kim, Shin-Chan Lee, Young-Yun Cho, Hyun-Jeong Oh, Young Hwan Ko

{"title":"Isolation of Cellulolytic Bacillus subtilis Strains from Agricultural Environments.","authors":"Yu-Kyoung Kim, Shin-Chan Lee, Young-Yun Cho, Hyun-Jeong Oh, Young Hwan Ko","doi":"10.5402/2012/650563","DOIUrl":"https://doi.org/10.5402/2012/650563","url":null,"abstract":"The bioconversion of cellulose and hemicellulose to soluble sugars is important for global stabilization and a sustainable human society. Here, hundreds of cellulolytic bacteria were screened and isolated from soil, compost, and animal waste slurry in Jeju Island, South Korea. Among the isolates, three strains, SL9-9, C5-16, and S52-2, showing higher potential for practical uses were purified on carboxymethyl cellulose (CMC) agar plates and identified as Bacillus subtilis strains by morphological, physiological, and biochemical characterization and 16S rRNA gene analysis. The production patterns of cellulose or hemicellulose-degrading enzymes were investigated during cell culture. All three isolated strains produced CMCase, Avicelase, β-glucosidase, and xylanase enzymes, which suggested synergic cellulolytic systems in Bacillus subtilis. The enzymes showing CMCase, Avicelase, and xylanase activities existed in cell-free culture supernatant, meanwhile β-glucosidase activity was detected in cell debris suggesting that three of the enzymes, including CMCase, Avicelase, and xylanase, were extracellular, and β-glucosidase was cell membrane bound. The three isolates, SL9-9, C5-16, and S52-2, were not the same strains, presenting slight differences in biochemical characteristics, 16S rRNA gene sequences, and cellulolytic enzyme activities.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"650563"},"PeriodicalIF":0.0,"publicationDate":"2012-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5402/2012/650563","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31471311","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}

引用次数: 107

Bacterial growth on chitosan-coated polypropylene textile. 细菌在壳聚糖涂层聚丙烯织物上的生长。

ISRN Microbiology Pub Date : 2012-02-19 Print Date: 2012-01-01 DOI: 10.5402/2012/749694

D Erben, V Hola, J Jaros, J Rahel

{"title":"Bacterial growth on chitosan-coated polypropylene textile.","authors":"D Erben, V Hola, J Jaros, J Rahel","doi":"10.5402/2012/749694","DOIUrl":"https://doi.org/10.5402/2012/749694","url":null,"abstract":"Biofouling is a problem common in all systems where microorganisms and aqueous environment meet. Prevention of biofouling is therefore important in many industrial processes. The aim of this study was to develop a method to evaluate the ability of material coating to inhibit biofilm formation. Chitosan-coated polypropylene nonwoven textile was prepared using dielectric barrier discharge plasma activation. Resistance of the textile to biofouling was then tested. First, the textile was submerged into a growth medium inoculated with green fluorescein protein labelled Pseudomonas aeruginosa. After overnight incubation at 33°C, the textile was observed using confocal laser scanning microscopy for bacterial enumeration and biofilm structure characterisation. In the second stage, the textile was used as a filter medium for prefiltered river water, and the pressure development on the in-flow side was measured to quantify the overall level of biofouling. In both cases, nontreated textile samples were used as a control. The results indicate that the chitosan coating exhibits antibacterial properties. The developed method is applicable for the evaluation of the ability to inhibit biofilm formation.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"749694"},"PeriodicalIF":0.0,"publicationDate":"2012-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5402/2012/749694","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31471314","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}

引用次数: 4

Molecular Characterisation of Bacterial Community Structure along the Intestinal Tract of Zebrafish (Danio rerio): A Pilot Study. 斑马鱼肠道细菌群落结构的分子特征:一项初步研究。

ISRN Microbiology Pub Date : 2012-02-14 Print Date: 2012-01-01 DOI: 10.5402/2012/590385

Chuan-Ching Lan, Donald R Love

{"title":"Molecular Characterisation of Bacterial Community Structure along the Intestinal Tract of Zebrafish (Danio rerio): A Pilot Study.","authors":"Chuan-Ching Lan, Donald R Love","doi":"10.5402/2012/590385","DOIUrl":"https://doi.org/10.5402/2012/590385","url":null,"abstract":"The bacterial composition along the intestinal tract of Danio rerio was investigated by cultivation-independent analysis of the 16S rRNA gene. Clone libraries were constructed for three compartments of the intestinal tract of individual fish. 566 individual clones were differentiated by amplified 16S rRNA gene restriction analysis (ARDRA), and clone representatives from each operational taxonomic unit (OTU) were sequenced. As reported in other studies, we found that Proteobacteria was the most prominent phylum among clone libraries from different fish. Data generated from this pilot study indicated some compositional differences in bacterial communities. Two dominant classes, Gammaproteobacteria and Bacilli, displayed different levels of abundance in different compartments; Gammaproteobacteria increased along the intestinal tract, while Bacilli decreased its abundance along the proximal-distal axis. Less obvious spatial patterns were observed for other classes. In general, bacterial diversity in the intestinal bulb was greater than that in the posterior intestine. Interindividual differences in bacterial diversity and composition were also noted in this study.","PeriodicalId":14849,"journal":{"name":"ISRN Microbiology","volume":"2012 ","pages":"590385"},"PeriodicalIF":0.0,"publicationDate":"2012-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5402/2012/590385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31471310","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}

引用次数: 31