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Skariyachan S, Taskeen N, Kishore AP, Krishna BV, Naidu G. Novel consortia of enterobacter and pseudomonas formulated from cow dung exhibited enhanced biodegradation of polyethylene and polypropylene. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 284:112030. [PMID: 33529882 DOI: 10.1016/j.jenvman.2021.112030] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 01/02/2021] [Accepted: 01/16/2021] [Indexed: 05/25/2023]
Abstract
This study prioritizes the biodegradation potential of novel bacterial consortia formulated from cow dung samples towards low-density polyethylene (LDPE) and polypropylene (PP) in comparison with our previous studies. Ten possible consortia were formulated using 10 selected isolates with >10% weight reduction of LDPE and PP, these were pre-treated under UV for 1 h, and their biodegradation potential was studied for 160 days. The isolates present in prioritized consortia were characterized by standard microbiology and 16SrRNA gene sequencing methods. Out of 10 bacterial consortia formulated, potential consortium-CB3 showed greater percentage degradation (weight reduction) of 64.25 ± 2% and 63.00 ± 2% towards LDPE and PP films, respectively (p < 0.05) at 37 °C compared to other consortia. Significant structural variations due to the formation of bacterial biofilm were observed in CB3 treated LDPE and PP films. The three bacteria-IS1, IS2, and IS3-that constituted CB3 were found to be novel strains and designated to be Enterobacter sp nov. bt DSCE01, Enterobacter cloacae nov. bt DSCE02, and Pseudomonas aeruginosa nov. bt DSCE-CD03, respectively. This novel consortium can be scaled up for enhanced degradation of plastic polymers and probably design cost-effective bio-digester for industrial applications using CB3 as potential inoculum.
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Affiliation(s)
- Sinosh Skariyachan
- Department of Microbiology, St. Pius X College Rajapuram, Kasaragod, Kerala, India.
| | - Neha Taskeen
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, Karnataka, India
| | - Alice Preethi Kishore
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, Karnataka, India
| | - Bhavya Venkata Krishna
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, Karnataka, India
| | - Gautami Naidu
- Department of Biotechnology, Dayananda Sagar College of Engineering, Bangalore, Karnataka, India
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Rautureau GJP, Palama TL, Canard I, Mirande C, Chatellier S, van Belkum A, Elena-Herrmann B. Discrimination of Escherichia coli and Shigella spp. by Nuclear Magnetic Resonance Based Metabolomic Characterization of Culture Media. ACS Infect Dis 2019; 5:1879-1886. [PMID: 31545890 DOI: 10.1021/acsinfecdis.9b00199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Dysentery is a major health threat that dramatically impacts childhood morbidity and mortality in developing countries. Various pathogenic agents cause dysentery, such as Shigella spp. and Escherichia coli, which are very closely related if not identical species. Sensitive and precise detection and identification of the infectious agent is important to target the best therapeutic strategy, but the differential diagnosis of these two groups remains a challenge using conventional methods. Here, we present a nuclear magnetic resonance (NMR) based multivariate classification model employing bacterial metabolic footprints in postculture growth media with remarkable segregation capability, including the discrimination of lactose negative E. coli and Shigella spp. Our results confirm the potential of metabolomic markers in the field of bacterial identification for the distinction of even very closely related species.
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Affiliation(s)
- Gilles J. P. Rautureau
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France
| | - Tony L. Palama
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France
| | - Isabelle Canard
- bioMérieux, Innovation Unit—Microbiology Research, 38390 La Balme-les-Grottes, France
| | - Caroline Mirande
- bioMérieux, Innovation Unit—Microbiology Research, 38390 La Balme-les-Grottes, France
| | - Sonia Chatellier
- bioMérieux, Innovation Unit—Microbiology Research, 38390 La Balme-les-Grottes, France
| | - Alex van Belkum
- bioMérieux, Innovation Unit—Microbiology Research, 38390 La Balme-les-Grottes, France
| | - Bénédicte Elena-Herrmann
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France
- Université Grenoble Alpes, CNRS, INSERM, IAB, Allée des Alpes, 38000 Grenoble, France
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Furuta T, Baba S, Yamade M, Uotani T, Kagami T, Suzuki T, Tani S, Hamaya Y, Iwaizumi M, Osawa S, Sugimoto K. High incidence of autoimmune gastritis in patients misdiagnosed with two or more failures of H. pylori eradication. Aliment Pharmacol Ther 2018; 48:370-377. [PMID: 29920721 DOI: 10.1111/apt.14849] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 02/12/2018] [Accepted: 05/23/2018] [Indexed: 12/16/2022]
Abstract
BACKGROUND Although autoimmune gastritis (AIG) is generally considered relatively rare, we frequently encounter AIG among patients at to our hospital who have experienced at least two episodes of Helicobacter pylori eradication failure. AIMS We investigated the incidence of AIG in consecutive patients who consulted our department for H. pylori eradication with reference to eradication history. METHODS A total of 404 consecutive patients who visited the H. pylori-specific out-patient unit of our hospital from June 2015 to June 2017 were enrolled. Of these, 137 were treatment-naive, 47 had failed treatment once (single failure), and 220 had failed treatment twice or more (multiple failures) by 13 C-UBT. Gastroscopy was performed in all patients. Culture tests of gastric mucosal samples were performed for H. pylori and other bacteria positive for urease activity. Anti-parietal cell antibody (APCA) was measured. Patients with severe atrophy in the gastric corpus and positivity for APCA were diagnosed as having AIG. RESULTS A total of 43 patients were diagnosed as having AIG, of whom two were treatment-naive (1.5%, 2/137), 1 failed eradication once (2.1% 1/47), and 40 failed treatment at least twice (18.2%, 40/220). The incidence of AIG was significantly higher in the multiple failure group than in the single failure or treatment-naive groups. Urease-positive bacteria, such as Klebsiella pneumoniae and alpha-streptococcus, were identified in 33 of the 35 AIG patients who underwent culture testing. CONCLUSION AIG patients were often misdiagnosed as refractory to eradication therapy, probably because achlorhydria in AIG might allow urease-positive bacteria other than H. pylori to colonise the stomach, causing positive 13 C-UBT results.
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Affiliation(s)
- T Furuta
- Center for Clinical Research, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - S Baba
- Department of Diagnostic Pathology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - M Yamade
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - T Uotani
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - T Kagami
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - T Suzuki
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - S Tani
- Department of Endoscopic and Photodynamic Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - Y Hamaya
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - M Iwaizumi
- Department of Laboratory Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - S Osawa
- Department of Endoscopic and Photodynamic Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
| | - K Sugimoto
- First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
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Enhanced polymer degradation of polyethylene and polypropylene by novel thermophilic consortia of Brevibacillus sps. and Aneurinibacillus sp. screened from waste management landfills and sewage treatment plants. Polym Degrad Stab 2018. [DOI: 10.1016/j.polymdegradstab.2018.01.018] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Skariyachan S, Setlur AS, Naik SY, Naik AA, Usharani M, Vasist KS. Enhanced biodegradation of low and high-density polyethylene by novel bacterial consortia formulated from plastic-contaminated cow dung under thermophilic conditions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:8443-8457. [PMID: 28188552 DOI: 10.1007/s11356-017-8537-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 01/31/2017] [Indexed: 05/06/2023]
Abstract
The current study aimed to devise eco-friendly, safe, and cost-effective strategies for enhanced degradation of low- and high-density polyethylene (LDPE and HDPE) using newly formulated thermophilic microbial consortia from cow dung and to assess the biodegradation end products. The plastic-degrading bacteria from cow dung samples gathered from highly plastic-acclimated environments were enriched by standard protocols. The degradation ability was comprehended by zone of clearance method, and the percentage of degradation was monitored by weight reduction process. The best isolates were characterized by standard microbiological and molecular biology protocols. The best isolates were employed to form several combinations of microbial consortia, and the degradation end products were analyzed. The stability of 16S ribosomal DNA (rDNA) was predicted by bioinformatics approach. This study identified 75 ± 2, 55 ± 2, 60 ± 3, and 43 ± 3% degradation for LDPE strips, pellets, HDPE strips, and pellets, respectively, for a period of 120 days (p < 0.05) at 55 °C by the formulated consortia of IS1-IS4, and the degradation efficiency was found to be better in comparison with other formulations. The end product analysis by Fourier transform infrared, scanning electron microscopy, energy-dispersive spectroscopy, and nuclear magnetic resonance showed major structural changes and formation of bacterial biofilm on plastic surfaces. These novel isolates were designated as Bacillus vallismortis bt-dsce01, Psuedomonas protegens bt-dsce02, Stenotrophomonas sp. bt-dsce03, and Paenibacillus sp.bt-dsce04 by 16S rDNA sequencing and suggested good gene stability with minimum Gibb's free energy. Therefore, this study imparts substantial information regarding the utilization of these thermophilic microbial consortia from cow dung for rapid polyethylene removal.
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Affiliation(s)
- Sinosh Skariyachan
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India.
- Visvesvaraya Technological University, Belagavi, Karnataka, India.
| | - Anagha Shamsundar Setlur
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Sujay Yashwant Naik
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Ashwini Amaresh Naik
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Makam Usharani
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Kiran S Vasist
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
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Skariyachan S, Manjunatha V, Sultana S, Jois C, Bai V, Vasist KS. Novel bacterial consortia isolated from plastic garbage processing areas demonstrated enhanced degradation for low density polyethylene. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:18307-19. [PMID: 27278068 DOI: 10.1007/s11356-016-7000-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 05/27/2016] [Indexed: 05/26/2023]
Abstract
This study aimed to formulate novel microbial consortia isolated from plastic garbage processing areas and thereby devise an eco-friendly approach for enhanced degradation of low-density polyethylene (LDPE). The LDPE degrading bacteria were screened and microbiologically characterized. The best isolates were formulated as bacterial consortia, and degradation efficiency was compared with the consortia formulated using known isolates obtained from the Microbial Culture Collection Centre (MTCC). The degradation products were analyzed by FTIR, GC-FID, tensile strength, and SEM. The bacterial consortia were characterized by 16S ribosomal DNA (rDNA) sequencing. The formulated bacterial consortia demonstrated 81 ± 4 and 38 ± 3 % of weight reduction for LDPE strips and LDPE pellets, respectively, over a period of 120 days. However, the consortia formulated by MTCC strains demonstrated 49 ± 4 and 20 ± 2 % of weight reduction for LDPE strips and pellets, respectively, for the same period. Furthermore, the three isolates in its individual application exhibited 70 ± 4, 68 ± 4, and 64 ± 4 % weight reduction for LDPE strips and 21 ± 2, 28 ± 2, 24 ± 2 % weight reduction for LDPE pellets over a period of 120 days (p < 0.05). The end product analysis showed structural changes and formation of bacterial film on degraded LDPE strips. The 16S rDNA characterization of bacterial consortia revealed that these organisms were novel strains and designated as Enterobacter sp. bengaluru-btdsce01, Enterobacter sp. bengaluru-btdsce02, and Pantoea sp. bengaluru-btdsce03. The current study thus suggests that industrial scale-up of these microbial consortia probably provides better insights for waste management of LDPE and similar types of plastic garbage.
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Affiliation(s)
- Sinosh Skariyachan
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India.
- Visvesvaraya Technological University, Belagavi, Karnataka, India.
| | - Vishal Manjunatha
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Subiya Sultana
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Chandana Jois
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Vidya Bai
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
| | - Kiran S Vasist
- R&D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, 560 078, India
- Visvesvaraya Technological University, Belagavi, Karnataka, India
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Ahmadi M, Karimi Torshizi MA, Rahimi S, Dennehy JJ. Prophylactic Bacteriophage Administration More Effective than Post-infection Administration in Reducing Salmonella enterica serovar Enteritidis Shedding in Quail. Front Microbiol 2016; 7:1253. [PMID: 27555842 PMCID: PMC4977285 DOI: 10.3389/fmicb.2016.01253] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 07/28/2016] [Indexed: 11/22/2022] Open
Abstract
Infections caused by Salmonella bacteria, often through poultry products, are a serious public health issue. Because of drawbacks associated with antibiotic prophylaxis, alternative treatments are sought. Bacterial viruses (bacteriophages) may provide an effective alternative, but concerns remain with respect to bacteriophage stability and effectiveness. To this end, we assessed the stability of a novel bacteriophage isolated from poultry excreta, siphovirus PSE, and its effectiveness in reducing Salmonella enterica serovar Enteritidis colonization in vitro and in vivo. Moreover, we sought to determine how the timing (prophylactic or therapeutic) and route (oral gavage or vent lip) of PSE administration impacted its effectiveness. Here we report that significant quantities of viable PSE bacteriophages were recovered following exposure to high and low pH, high temperatures, and bile salts, testifying to its ability to survive extreme conditions. In addition, we found that ileal lactic acid bacteria and Streptococcus spp. counts increased, but colibacilli and total aerobe counts decreased, in quail receiving phage PSE through both oral gavage and vent lip routes. In other experiments, we assessed the efficiency of PSE administration, in both prophylactic and therapeutic contexts, via either oral gavage or vent lip administration, on S. Enteritidis colonization of quail cecal tonsils. Our results demonstrate that administration of PSE as a preventive agent could reduce the S. Enteritidis colonization more effectively than post-challenge administration. Furthermore, oral administration of PSE phage is a more effective prophylactic tool for reduction of S. Enteritidis shedding in poultry than is vent lip administration.
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Affiliation(s)
- Mosab Ahmadi
- Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University Tehran, Iran
| | - M Amir Karimi Torshizi
- Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University Tehran, Iran
| | - Shaban Rahimi
- Department of Poultry Science, Faculty of Agriculture, Tarbiat Modares University Tehran, Iran
| | - John J Dennehy
- Biology Department, Queens College and The Graduate Center of the City University of New York, New York NY, USA
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Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Bacterial Gastroenteritis. Clin Microbiol Rev 2015; 28:3-31. [PMID: 25567220 DOI: 10.1128/cmr.00073-14] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Bacterial gastroenteritis is a disease that is pervasive in both the developing and developed worlds. While for the most part bacterial gastroenteritis is self-limiting, identification of an etiological agent by bacterial stool culture is required for the management of patients with severe or prolonged diarrhea, symptoms consistent with invasive disease, or a history that may predict a complicated course of disease. Importantly, characterization of bacterial enteropathogens from stool cultures in clinical laboratories is one of the primary means by which public health officials identify and track outbreaks of bacterial gastroenteritis. This article provides guidance for clinical microbiology laboratories that perform stool cultures. The general characteristics, epidemiology, and clinical manifestations of key bacterial enteropathogens are summarized. Information regarding optimal specimen collection, transport, and processing and current diagnostic tests and testing algorithms is provided. This article is an update of Cumitech 12A (P. H. Gilligan, J. M. Janda, M. A. Karmali, and J. M. Miller, Cumitech 12A, Laboratory diagnosis of bacterial diarrhea, 1992).
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Skariyachan S, Megha M, Kini MN, Mukund KM, Rizvi A, Vasist K. Selection and screening of microbial consortia for efficient and ecofriendly degradation of plastic garbage collected from urban and rural areas of Bangalore, India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:4174. [PMID: 25504187 DOI: 10.1007/s10661-014-4174-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 11/17/2014] [Indexed: 06/04/2023]
Abstract
Industrialization and urbanization have led to massive accumulation of plastic garbage all over India. The persistence of plastic in soil and aquatic environment has become ecological threat to the metropolitan city such as Bangalore, India. Present study investigates an ecofriendly, efficient and cost-effective approach for plastic waste management by the screening of novel microbial consortia which are capable of degrading plastic polymers. Plastic-contaminated soil and water samples were collected from six hot spots of urban and rural areas of Bangalore. The plastic-degrading bacteria were enriched, and degradation ability was determined by zone of clearance method. The percentage of polymer degradation was initially monitored by weight loss method, and the main isolates were characterized by standard microbiology protocols. These isolates were used to form microbial consortia, and the degradation efficiency of the consortia was compared with individual isolate and known strains obtained from the Microbial Type Culture Collection (MTCC) and Gene Bank, India. One of the main enzymes responsible for polymer degradation was identified, and the biodegradation mechanism was hypothesized by bioinformatics studies. From this study, it is evident that the bacteria utilized the plastic polymer as a sole source of carbon and showed 20-50% weight reduction over a period of 120 days. The two main bacteria responsible for the degradation were microbiologically characterized to be Pseudomonas spp. These bacteria could grow optimally at 37 °C in pH 9.0 and showed 35-40% of plastic weight reduction over 120 days. These isolates were showed better degradation ability than known strains from MTCC. The current study further revealed that the microbial consortia formulated by combining Psuedomonas spp. showed 40 plastic weight reduction over a period of 90 days. Further, extracellular lipase, one of the main enzymes responsible for polymer degradation, was identified. The computational docking studies suggested that polyethylene glycol and polystyrene present in the plastics might have good interaction towards the microbial lipase with stable binding and interacting forces which probably could be one of the reasons for the degradative mechanisms.
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Affiliation(s)
- Sinosh Skariyachan
- R & D Centre, Department of Biotechnology Engineering, Dayananda Sagar Institutions, Bangalore, Karnataka, 560 078, India,
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Stock T, Selzer M, Connery S, Seyhan D, Resch A, Rother M. Disruption and complementation of the selenocysteine biosynthesis pathway reveals a hierarchy of selenoprotein gene expression in the archaeon Methanococcus maripaludis. Mol Microbiol 2011; 82:734-47. [PMID: 21992107 DOI: 10.1111/j.1365-2958.2011.07850.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Proteins containing selenocysteine are found in members of all three domains of life, Bacteria, Eukarya and Archaea. A dedicated tRNA (tRNA(sec)) serves as a scaffold for selenocysteine synthesis. However, sequence and secondary structures differ in tRNA(sec) from the different domains. An Escherichia coli strain lacking the gene for tRNA(sec) could only be complemented with the homologue from Methanococcus maripaludis when a single base in the anticodon loop was exchanged demonstrating that this base is a crucial determinant for archaeal tRNA(sec) to function in E. coli. Complementation in trans of M. maripaludis JJ mutants lacking tRNA(sec) , O-phosphoseryl-tRNA(sec) kinase or O-phosphoseryl-tRNA(sec) :selenocysteine synthase with the corresponding genes from M. maripaludis S2 restored the mutant's ability to synthesize selenoproteins. However, only partial restoration of the wild-type selenoproteome was observed as only selenocysteine-containing formate dehydrogenase was synthesized. Quantification of transcripts showed that disrupting the pathway of selenocysteine synthesis leads to downregulation of selenoprotein gene expression, concomitant with upregulation of a selenium-independent backup system, which is not re-adjusted upon complementation. This transcriptional arrest was independent of selenophosphate but depended on the 'history' of the mutants and was inheritable, which suggests that a stable genetic switch may cause the resulting hierarchy of selenoproteins synthesized.
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Affiliation(s)
- Tilmann Stock
- Institut für Molekulare Biowissenschaften, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
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11
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De Ryck R, Struelens MJ, Serruys E. Rapid biochemical screening for Salmonella, Shigella, Yersinia, and Aeromonas isolates from stool specimens. J Clin Microbiol 1994; 32:1583-5. [PMID: 8077408 PMCID: PMC264043 DOI: 10.1128/jcm.32.6.1583-1585.1994] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Four screens for the rapid (4 to 6 h) biochemical detection of pathogens from enteric isolation media are described. The Salmonella screen consisted of Kligler iron agar (KIA), motility-indole-urea-tryptophan-deamination semisolid medium (MIU-TDA), and the o-nitrophenyl-beta-D-galactopyranoside (ONPG) test; the Shigella screen consisted of KIA, MIU-TDA, the ONPG test, and the lysine decarboxylation-indole test; the Yersinia screen consisted of a rhamnose broth; the Aeromonas screen consisted of a xylose agar plate. When tested on 2,102 fresh isolates and 71 stock strains, the screens correctly detected 212 enteric pathogens (sensitivity, 100%), with a specificity of 98.1%.
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Affiliation(s)
- R De Ryck
- Laboratoire de Microbiologie, Hôpital Erasme, Université Libre de Bruxelles, Belgium
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12
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Imperatrice CA, Nachamkin I. Evaluation of the Vitek EPS enteric pathogen screen card for detecting Salmonella, Shigella, and Yersinia spp. J Clin Microbiol 1993; 31:433-5. [PMID: 8432832 PMCID: PMC262782 DOI: 10.1128/jcm.31.2.433-435.1993] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We evaluated the Vitek EPS card as a screen for the enteric pathogens Salmonella spp., Shigella spp., and Yersinia enterocolitica. Salmonella spp., Shigella spp., and Y. enterocolitica (125, 54, and 5 isolates, respectively) and 81 nonenteric pathogens that might be selected for screening from primary plates (non-lactose fermenters) were tested. The EPS card correctly identified 183 of 184 pathogens tested (sensitivity, 99.5%). Of 81 nonenteric pathogens screened with the EPS card, 8 were identified as possible enteric pathogens (specificity, 90.1%). We reviewed our stool culture records over the past 1.5 years and analyzed the specificities of TSI-urea screens for 300 stool cultures that had suspicious colonies. From 55 of 300 stool cultures, either Salmonella spp. or Shigella spp. were isolated, and from 245 stool cultures, no pathogen was isolated. Of the 245 negative cultures, 166 gave false-positive screening-test results that resulted in further biochemical identification procedures (Analytab Products or Vitek identification). Thus, the specificity of the TSI-urea screen in our experience was 32.2%. The Vitek EPS card was shown to be a more cost-effective screening procedure than the TSI-urea screen.
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Affiliation(s)
- C A Imperatrice
- Department of Pathology, Hospital of the University of Pennsylvania, Philadelphia 19104-4283
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13
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Villasante PA, Agulla A, Merino FJ, Pérez T, Ladrón de Guevara C, Velasco AC. Rapid automated method for screening of enteric pathogens from stool specimens. J Clin Microbiol 1987; 25:584-5. [PMID: 3553230 PMCID: PMC266004 DOI: 10.1128/jcm.25.3.584-585.1987] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A total of 800 colonies suggestive of Salmonella, Shigella, or Yersinia species isolated on stool differential agar media were inoculated onto both conventional biochemical test media (triple sugar iron agar, urea agar, and phenylalanine agar) and Entero Pathogen Screen cards of the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.). Based on the conventional tests, the AutoMicrobic system method yielded the following results: 587 true-negatives, 185 true-positives, 2 false-negatives, and 26 false-positives (sensitivity, 99%; specificity, 96%). Both true-positive and true-negative results were achieved considerably earlier than false results (P less than 0.001). The Entero Pathogen Screen card method is a fast, easy, and sensitive method for screening for Salmonella, Shigella, or Yersinia species. The impossibility of screening for oxidase-positive pathogens is a minor disadvantage of this method.
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BAILEY JS, COX NA. Presumptive Identification of Stock Cultures and Food Isolates As Salmonella, Shigella, or Yersinia with the Enteric Pathogen Screen. J Food Sci 1986. [DOI: 10.1111/j.1365-2621.1986.tb11176.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yong DC, Thompson JS, Prytula A. Rapid microbiochemical method for presumptive identification of gastroenteritis-associated members of the family Enterobacteriaceae. J Clin Microbiol 1985; 21:914-8. [PMID: 4008622 PMCID: PMC271817 DOI: 10.1128/jcm.21.6.914-918.1985] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A method for rapid screening of isolates of pathogenic members of the family Enterobacteriaceae is described. Flow charts are used in conjunction with triple sugar iron agar, o-nitrophenyl-beta-D-galactopyranoside-phenylalanine-motility sulfate screening media, oxidase test, and six rapid biochemical tests, namely, lysine decarboxylase, urease, indole, esculin hydrolysis, malonate, and xylose. This scheme is used to provide an inexpensive but rapid presumptive identification of Salmonella, Shigella, Edwardsiella, Aeromonas, Plesiomonas, Vibrio, and Yersinia isolates from stool cultures.
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Teti G, Burdash NM, Zamboni C, Fava C, Tomasello F, Mastroeni P. Evaluation of a rapid method to exclude the presence of certain enteric pathogens in stool specimens. J Clin Microbiol 1984; 20:1049-52. [PMID: 6394610 PMCID: PMC271515 DOI: 10.1128/jcm.20.6.1049-1052.1984] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A new commercial method intended to exclude the presence of Salmonella spp., Shigella spp., and Yersinia enterocolitica and to presumptively identify Salmonella isolates within 2 h after primary isolation from stool specimens was evaluated. This system is marketed in Europe as API Z and in the United States as Rapid SST. The strip consists of five pairs of cupules for the screening of five lactose-negative colonies. The first cupule of each pair detects the presence of five enzymatic activities, whereas the second serves to maintain the strain for additional testing if necessary. A total of 197 fresh isolates from stool specimens and 217 stock cultures of Salmonella spp., Shigella spp., and Yersinia enterocolitica were tested, with the API 20E system as a reference method. In the stool specimens, 77.3% of the bacteria could be excluded from further workup for the presence of these organisms within 2 h. Over 97% of the stock strains and each of three fresh Salmonella isolates tested produced a reaction pattern corresponding to a correct presumptive identification. This reaction pattern was not produced by any isolate other than the Salmonella isolates. The API Z system can be used as a screen for the presence of Salmonella and Shigella spp. and can provide an accurate presumptive identification of Salmonella isolates within 2 h after primary isolation.
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Hilger AE, Lancaster MV. Spectral analysis of biochemical reactions used for identification of bacteria. EUROPEAN JOURNAL OF CLINICAL MICROBIOLOGY 1984; 3:310-5. [PMID: 6386460 DOI: 10.1007/bf01977479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
To define parameters for optimizing automated discrimination of bacterial biochemical reactions certain theoretical considerations of spectrophotometric analysis were explored. One-hundred and one recent clinical isolates of gram-negative bacilli (21 species) were inoculated into AP1 20 E strips and read manually after 24 hours. With spectrophotometric scanning, the AP1 reactions could be classified into three analytical categories: pH change, production of new products, and darkening of the medium. Whereas single wavelength analysis gave 2.9% disagreement from the visual, multiple wavelength analyses were uniformly more accurate. The best results for pH change reactions were obtained by calculating a ratio of two wavelengths. New color reactions were best interpreted by demonstration of the new peak, whereas darkening reactions required quantitation of the area under the entire curve. With these methods, a 99.3% overall agreement of individual reactions and a 97% agreement of identification were achieved. Multiple-point analysis of spectra coupled with computerized interpretation of the data should help resolve the problem of equivocal reactions in bacterial identification schemes optimized for spectral analysis.
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