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Hwang JH, Park JS, Bae TW, Hwang JH, Lee J. Community-Acquired Solitary Brain Abscesses Caused by Hypervirulent Klebsiella pneumoniae in a Healthy Adult. Microorganisms 2024; 12:894. [PMID: 38792724 PMCID: PMC11124120 DOI: 10.3390/microorganisms12050894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/26/2024] Open
Abstract
A 42-year-old man was admitted to the emergency room complaining of fever and headache. His cerebrospinal fluid showed a cloudy appearance, and his white blood cell count was elevated at 2460/mm3, with a predominance of neutrophils (81%), and abnormal protein and glucose levels (510.7 mg/dL and 5 mg/dL, respectively). A lobulated lesion with rim enhancement, suggestive of abscess, was detected through magnetic resonance imaging. Klebsiella pneumoniae was detected in nasopharyngeal swab and blood cultures. The capsular serotype of K. pneumoniae was K2 and the sequence type determined by multilocus sequence typing was 23. The hypervirulent phenotype was associated with multiple virulent genes, including rmpA, rmpA2, entB, ybtS, kfu, iucA, iutA, iroB mrkD, allS, peg-344, peg-589, and peg-1631. After six weeks of receiving appropriate antibiotics and exhibiting clinical resolution of the brain abscesses, the patient was discharged. We present the first reported case of a healthy community-dwelling adult with solitary brain abscesses, and no other invasive abscesses, related to hypervirulent K. pneumoniae.
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Affiliation(s)
- Joo-Hee Hwang
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
| | - Jung Soo Park
- Department of Neurosurgery, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
| | - Tae Won Bae
- Department of Laboratory Medicine, Presbyterian Medical Center, Jeonju 54987, Republic of Korea;
| | - Jeong-Hwan Hwang
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
| | - Jaehyeon Lee
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea
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Lee J, Hwang JH, Yeom JH, Lee S, Hwang JH. Analysis of virulence profiles in clinical isolates of Klebsiella pneumoniae from renal abscesses: clinical significance of hypervirulent isolates. Front Cell Infect Microbiol 2024; 14:1367111. [PMID: 38606296 PMCID: PMC11007163 DOI: 10.3389/fcimb.2024.1367111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 03/13/2024] [Indexed: 04/13/2024] Open
Abstract
Introduction Klebsiella pneumoniae can cause a wide range of infections. Hypervirulent K. pneumoniae (hvKp), particularly associated with the K1 and K2 capsular types, is an increasingly significant microorganism with the potential to cause invasive infections, including renal abscesses. Despite the rising prevalence of hvKp infections, information on renal abscesses caused by K. pneumoniae is limited, and the clinical significance of hvKp associated with specific virulence genes remains elusive. Methods This study performed at a 1200-bed tertiary hospital sought to identify the clinical and microbiological characteristics of renal abscesses caused by K. pneumoniae, focusing on various virulence genes, including capsular serotypes and multilocus sequence typing (MLST). Results Over an 8-year period, 64 patients with suspected renal abscesses were reviewed. Ten patients diagnosed with K. pneumoniae-related renal abscesses were ultimately enrolled in the study. Among the isolates from the 10 patients, capsular serotype K2 was predominant (40.0%), followed by K1 (30.0%). The most common sequence type by MLST was 23 (40.0%). In particular, six patients (60.0%) harbored specific genes indicative of hvKp: iucA, peg-344, rmpA, and rmpA2. Conclusions Our findings highlight the importance of hvKp as a pathogen in renal abscesses. Although the nature of hvKp is relatively unknown, it is widely recognized as a highly virulent pathogen that can infect relatively healthy individuals of various ages and simultaneously cause infections at multiple anatomical sites. Therefore, when treating patients with K. pneumoniae-related renal abscesses, caution is necessary when considering the characteristics of hvKp, such as potential bacteremia, multi-organ abscess formation, and metastatic spread.
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Affiliation(s)
- Jaehyeon Lee
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Republic of Korea
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea
| | - Jeong-Hwan Hwang
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Republic of Korea
| | - Ji Hyun Yeom
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Republic of Korea
| | - Sik Lee
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Republic of Korea
| | - Joo-Hee Hwang
- Research Institute of Clinical Medicine of Jeonbuk National University—Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Republic of Korea
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DI ONOFRIO VALERIA, MAIONE ANGELA, GUIDA MARCO, DE CASTRO OLGA, LIGUORI RENATO, CARRATURO FEDERICA, GALDIERO EMILIA. Screening and isolation of microbes from a Mud Community of Ischia Island Thermal Springs: preliminary analysis of a bioactive compound. JOURNAL OF PREVENTIVE MEDICINE AND HYGIENE 2021; 62:E479-E488. [PMID: 34604589 PMCID: PMC8451329 DOI: 10.15167/2421-4248/jpmh2021.62.2.1792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/22/2021] [Indexed: 11/16/2022]
Abstract
Introduction Balneotherapy centers of Ischia island (Italy) offer treatments for different dermatological diseases (psoriasis, acne, atopic dermatitis) and upper respiratory tract infections. In this study, we integrated morphological and molecular approaches to give a focus on isolation and screening of extremophile bacteria from Ischia thermal mud for potential antimicrobial applications. Methods Samples were collected during 2019 at four sites. Some bacterial strains ATCC for antibacterial and antibiofilm activity were tested. After morphological characterization, screening for antagonistic isolates was made. The colonies isolated from thermal mud samples were submitted to molecular characterization. Susceptibility testing by dilution spotting was carried out and antibacterial efficacies of most active isolate were evaluated with a Minimal inhibition concentration assay. Biofilm formation, inhibition, eradication were examined. Statistical analyses were carried out utilizing Microsoft® Excel 2016/XLSTAT©-Pro. Results We isolated a natural compound with antimicrobial and antibiofilm activities. Conclusions The results obtained in this study are discussed in the context of how hydrothermal systems are important environmental source of uncharted antimicrobial and antibiofilm compounds. In conclusion, to the most effective of our knowledge, this work presents the primary report on the preliminary investigation of thermophile microbial diversity and their antimicrobial and antibiofilm activities for future biotechnological interest.
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Affiliation(s)
- VALERIA DI ONOFRIO
- Department of Sciences and Technologies, University of Naples “Parthenope”, Naples, Italy
| | - ANGELA MAIONE
- Department of Biology, University of Naples “Federico II”, Naples, Italy
| | - MARCO GUIDA
- Department of Biology, University of Naples “Federico II”, Naples, Italy
| | - OLGA DE CASTRO
- Department of Biology, University of Naples “Federico II”, Naples, Italy
| | - RENATO LIGUORI
- Department of Sciences and Technologies, University of Naples “Parthenope”, Naples, Italy
| | - FEDERICA CARRATURO
- Department of Biology, University of Naples “Federico II”, Naples, Italy
| | - EMILIA GALDIERO
- Department of Biology, University of Naples “Federico II”, Naples, Italy
- Correspondence: Emilia Galdiero, Department of Biology, University of Naples “Federico II”, via Cinthia, 80126 Naples, Italy - Tel.: +39 081 679182 - E-mail:
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Hwang JH, Handigund M, Hwang JH, Cho YG, Kim DS, Lee J. Clinical Features and Risk Factors Associated With 30-Day Mortality in Patients With Pneumonia Caused by Hypervirulent Klebsiella pneumoniae (hvKP). Ann Lab Med 2020; 40:481-487. [PMID: 32539304 PMCID: PMC7295963 DOI: 10.3343/alm.2020.40.6.481] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/18/2020] [Accepted: 06/01/2020] [Indexed: 12/02/2022] Open
Abstract
Background Reports on metastatic or invasive infections by hypervirulent Klebsiella pneumoniae (hvKP) have increased recently. However, the effects of its virulence on clinical course and outcomes in pneumonia patients have rarely been addressed. We assessed and compared the clinical features of hvKp and classic K. pneumoniae (cKP) strains isolated from patients with pneumonia caused by K. pneumoniae. We also investigated the effects of virulence factors and the K. pneumoniae capsular serotypes K1 and K2 on mortality. Methods In this retrospective study, we enrolled 91 patients diagnosed as having pneumonia caused by K. pneumoniae and obtained their demographic and clinical data from medical records. We evaluated genes for K1 and K2, antimicrobial susceptibility, and the virulence genes rmpA, iutA, entB, ybtS, kfu, mrkD, and allS. Strains that possessed rmpA and iutA were defined as hvKP (N=39), while the remaining were classified as cKP (N=52). Odds ratio (OR) for the risk factors associated with 30-day mortality was calculated using the binary logistic regression model. Results The 30-day mortality in all patients was 23.1%; it was 17.9% (7/39) in the hvKP group and 26.9% (14/52) in the cKP group (P=0.315). Bacteremia (OR=38.1; 95% confidence interval [CI], 2.5–570.2), altered mental status (OR=8.8; 95% CI, 1.7–45.0), and respiratory rate >30 breaths/min (OR=4.8; 95% CI, 1.2–20.0) were independent risk factors for 30-day mortality in all patients. Conclusions Our results suggest that hypervirulence determinants do not have a significant effect on 30-day mortality in patients with pneumonia caused by K. pneumoniae.
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Affiliation(s)
- Jeong-Hwan Hwang
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea.,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea
| | - Mallikarjun Handigund
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Joo-Hee Hwang
- Department of Internal Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea.,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea
| | - Yong Gon Cho
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.,Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Dal Sik Kim
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.,Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea
| | - Jaehyeon Lee
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.,Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea
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Nordin N, Yusof NA, Radu S, Hushiarian R. Development of an Electrochemical DNA Biosensor to Detect a Foodborne Pathogen. J Vis Exp 2018. [PMID: 29912194 DOI: 10.3791/56585] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Vibrio parahaemolyticus (V. parahaemolyticus) is a common foodborne pathogen that contributes to a large proportion of public health problems globally, significantly affecting the rate of human mortality and morbidity. Conventional methods for the detection of V. parahaemolyticus such as culture-based methods, immunological assays, and molecular-based methods require complicated sample handling and are time-consuming, tedious, and costly. Recently, biosensors have proven to be a promising and comprehensive detection method with the advantages of fast detection, cost-effectiveness, and practicality. This research focuses on developing a rapid method of detecting V. parahaemolyticus with high selectivity and sensitivity using the principles of DNA hybridization. In the work, characterization of synthesized polylactic acid-stabilized gold nanoparticles (PLA-AuNPs) was achieved using X-ray Diffraction (XRD), Ultraviolet-visible Spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM), Field-emission Scanning Electron Microscopy (FESEM), and Cyclic Voltammetry (CV). We also carried out further testing of stability, sensitivity, and reproducibility of the PLA-AuNPs. We found that the PLA-AuNPs formed a sound structure of stabilized nanoparticles in aqueous solution. We also observed that the sensitivity improved as a result of the smaller charge transfer resistance (Rct) value and an increase of active surface area (0.41 cm2). The development of our DNA biosensor was based on modification of a screen-printed carbon electrode (SPCE) with PLA-AuNPs and using methylene blue (MB) as the redox indicator. We assessed the immobilization and hybridization events by differential pulse voltammetry (DPV). We found that complementary, non-complementary, and mismatched oligonucleotides were specifically distinguished by the fabricated biosensor. It also showed reliably sensitive detection in cross-reactivity studies against various food-borne pathogens and in the identification of V. parahaemolyticus in fresh cockles.
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Affiliation(s)
- Noordiana Nordin
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia;
| | - Nor Azah Yusof
- Laboratory of Functional Device, Institute of Advanced Technology, Universiti Putra Malaysia; Department of Chemistry, Faculty of Science, Universiti Putra Malaysia
| | - Son Radu
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia
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Mariat D, Robert V, Langella P, Chatel JM. Plasmid transfer efficiency using Lactoccocus lactis strains depends on invasiveness status but also on plasmid copy number. FEMS Microbiol Lett 2018; 364:3827360. [PMID: 28505315 DOI: 10.1093/femsle/fnx100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/12/2017] [Indexed: 12/19/2022] Open
Abstract
Lactic acid bacteria as Lactococcus lactis are used as vector for protein but also DNA delivery into intestinal cells in vitro and in vivo. For the plasmid delivery strategy, the plasmid copy number per bacteria (PCN) is thus of great importance. The aim of this paper is to determine the physiological conditions when PCN is the highest in the bacteria. PCN was characterized by qPCR in five different recombinant Lactococcus lactis strains, containing one (mono-) or two different plasmids (biplasmidic), at exponential or stationary phase. We showed that in all cases but one, PCN is higher at exponential than stationary phase. PCN seems to depend on (i) monoplasmidic or biplasmidic strain; (ii) origin of replication of the plasmid; and (iii) the DNA load of the bacteria. Then we studied plasmid transfer in vitro from recombinant L. lactis to eukaryotic COS-7 cells using culture at exponential or stationary phase. We showed that plasmid transfer can be improved in vitro by using bacteria at exponential phase.
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Affiliation(s)
- Denis Mariat
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Véronique Robert
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Philippe Langella
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Jean-Marc Chatel
- MICALIS Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
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Nordin N, Yusof NA, Abdullah J, Radu S, Hushiarian R. A simple, portable, electrochemical biosensor to screen shellfish for Vibrio parahaemolyticus. AMB Express 2017; 7:41. [PMID: 28205102 PMCID: PMC5311015 DOI: 10.1186/s13568-017-0339-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 02/03/2017] [Indexed: 11/17/2022] Open
Abstract
An earlier electrochemical mechanism of DNA detection was adapted and specified for the detection of Vibrio parahaemolyticus in real samples. The reader, based on a screen printed carbon electrode, was modified with polylactide-stabilized gold nanoparticles and methylene blue was employed as the redox indicator. Detection was assessed using a microprocessor to measure current response under controlled potential. The fabricated sensor was able to specifically distinguish complementary, non-complementary and mismatched oligonucleotides. DNA was measured in the range of 2.0 × 10−8–2.0 × 10−13 M with a detection limit of 2.16 pM. The relative standard deviation for 6 replications of differential pulse voltammetry (DPV) measurement of 0.2 µM complementary DNA was 4.33%. Additionally, cross-reactivity studies against various other food-borne pathogens showed a reliably sensitive detection of the target pathogen. Successful identification of Vibrio parahaemolyticus (spiked and unspiked) in fresh cockles, combined with its simplicity and portability demonstrate the potential of the device as a practical screening tool.
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Carraturo F, Gargiulo G, Giorgio A, Aliberti F, Guida M. Prevalence, Distribution, and Diversity of Salmonella spp. in Meat Samples Collected from Italian Slaughterhouses. J Food Sci 2016; 81:M2545-M2551. [PMID: 27626599 DOI: 10.1111/1750-3841.13430] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/14/2016] [Accepted: 07/25/2016] [Indexed: 11/26/2022]
Abstract
Recently worldwide food safety authorities indicated the rise of foodborne outbreaks linked to Salmonella: this highlighted the need to intensify monitoring and apply more targeted controls to help manage the spread of the disease. The aim of this study was to assess the prevalence and distribution of Salmonella serotypes in 7 slaughterhouses, located in different areas of Naples province (Regione Campania, Italy). Meat samples collected from the slaughterhouses were submitted for standardized microbiological analysis in 2015. Results of routine testing for Salmonella spp. were analyzed and then compared to biochemical and molecular evaluations. Salmonella spp. were detected in 12% of 320 samples examined (39/320) and the isolation rates ranged from 87% (32 samples) for raw poultry meat to 13% (7 samples) for pork meat. Biochemical serotyping showed that approximately 50% of the isolates belonged to Salmonella enterica serotype Choleraesuis. Rapid detection methods, such as molecular analysis (polymerase chain reaction and gel electrophoresis), able to confirm food matrices contamination, represent a valid support to the fast identification of Salmonella species. A further aspect of the study consisted, indeed, on analyzing isolated strains through molecular evaluations. By amplifying bacterial DNA-using invA primers, selective for Salmonella-it was possible, in less than 3 h, to classify the isolates as Salmonella spp., confirming the results of microbiological outcomes. Results of distribution analysis, supported by rapid molecular approaches, showed the difficulty of reducing Salmonella risk on food chain. This emphasized the importance of periodic surveillance to prevent outbreaks.
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Affiliation(s)
- Federica Carraturo
- Laboratory of Hygiene, Dept. of Biology, Univ. of Naples "Federico II,", Via Mezzocannone 16, 80134, Naples, Italy. ,
| | - Giuseppe Gargiulo
- Laboratory of Hygiene, Dept. of Biology, Univ. of Naples "Federico II,", Via Mezzocannone 16, 80134, Naples, Italy
| | - Antonella Giorgio
- Laboratory of Hygiene, Dept. of Biology, Univ. of Naples "Federico II,", Via Mezzocannone 16, 80134, Naples, Italy
| | - Francesco Aliberti
- Laboratory of Hygiene, Dept. of Biology, Univ. of Naples "Federico II,", Via Mezzocannone 16, 80134, Naples, Italy
| | - Marco Guida
- Laboratory of Hygiene, Dept. of Biology, Univ. of Naples "Federico II,", Via Mezzocannone 16, 80134, Naples, Italy
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Nordin N, Yusof NA, Abdullah J, Radu S, Hushiarian R. Sensitive detection of multiple pathogens using a single DNA probe. Biosens Bioelectron 2016; 86:398-405. [PMID: 27414245 DOI: 10.1016/j.bios.2016.06.077] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/22/2016] [Accepted: 06/26/2016] [Indexed: 10/21/2022]
Abstract
A simple but promising electrochemical DNA nanosensor was designed, constructed and applied to differentiate a few food-borne pathogens. The DNA probe was initially designed to have a complementary region in Vibrio parahaemolyticus (VP) genome and to make different hybridization patterns with other selected pathogens. The sensor was based on a screen printed carbon electrode (SPCE) modified with polylactide-stabilized gold nanoparticles (PLA-AuNPs) and methylene blue (MB) was employed as the redox indicator binding better to single-stranded DNA. The immobilization and hybridization events were assessed using differential pulse voltammetry (DPV). The fabricated biosensor was able to specifically distinguish complementary, non-complementary and mismatched oligonucleotides. DNA was measured in the range of 2.0×10(-9)-2.0×10(-13)M with a detection limit of 5.3×10(-12)M. The relative standard deviation for 6 replications of DPV measurement of 0.2µM complementary DNA was 4.88%. The fabricated DNA biosensor was considered stable and portable as indicated by a recovery of more than 80% after a storage period of 6 months at 4-45°C. Cross-reactivity studies against various food-borne pathogens showed a reliably sensitive detection of VP.
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Affiliation(s)
- Noordiana Nordin
- Institute of Advanced Technology, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia; Food Safety Research Centre, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia
| | - Nor Azah Yusof
- Institute of Advanced Technology, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia; Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia.
| | - Jaafar Abdullah
- Institute of Advanced Technology, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia; Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia
| | - Son Radu
- Food Safety Research Centre, Faculty of Food Science and Technology, Universiti Putra Malaysia, UPM, 43400 Serdang, Selangor, Malaysia
| | - Roozbeh Hushiarian
- La Trobe Institute for Molecular Science, La Trobe University, Victoria 3086, Australia.
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Stabilized gene duplication enables long-term selection-free heterologous pathway expression. Nat Biotechnol 2009; 27:760-5. [DOI: 10.1038/nbt.1555] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 06/29/2009] [Indexed: 11/08/2022]
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Golshani A, Kolev V, Mironova R, AbouHaidar MG, Ivanov IG. Enhancing activity of epsilon in Escherichia coli and Agrobacterium tumefaciens cells. Biochem Biophys Res Commun 2000; 269:508-12. [PMID: 10708584 DOI: 10.1006/bbrc.2000.2327] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epsilon (epsilon) sequence is a bacterial enhancer of translation found in the bacteriophage T7 gene 10. It is believed that its enhancing effect of epsilon is due to a base-pairing with the nucleotides 458-467 from the helical domain 17 of Escherichia coli 16S rRNA. To prove this we have taken advantage of the difference of this domain in Agrobacterium tumefaciens and E. coli. To evaluate the significance of nucleotide complementarity for the enhancing activity of epsilon, a series of nucleotide sequences matching either E. coli or A. tumefaciens domain 17 are cloned in a binary expression vector in front of the chloramphenicol acetyltransferase (CAT) gene. The CAT assay shows that: (i) the epsilon in combination with an SD consensus sequence increases the yield of CAT in both microorganisms over that obtained with the SD alone; (ii) the epsilon sequence complementary to the A. tumefaciens domain 17 leads to a 2.71-fold increase in the yield of CAT in homologous cells but not in E. coli cells; (iii) the yield of CAT correlates with the free energy of base-pairing with the helical domain 17 in both microorganisms.
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Affiliation(s)
- A Golshani
- Department of Botany, Virology Group, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
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Abstract
A series of expression vectors have been developed which all contain an identical expression cassette comprised of the lacIq gene, the tac promoter, a multiple cloning site (MCS) and a downstream transcriptional terminator. This cassette has been inserted into four distinct plasmid backbones, each of which is from a separate incompatibility group and carries a different drug resistance gene. Therefore, different combinations of these expression plasmids can be stably maintained together.
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Affiliation(s)
- D M Dykxhoorn
- Department of Microbiology and Immunology, Faculty of Medicine, University of Western Ontario, London, Canada
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Ivanov IG, Alexandrova RA, Dragulev BP, AbouHaidar MG. A second putative mRNA binding site on the Escherichia coli ribosome. Gene X 1995; 160:75-9. [PMID: 7628721 DOI: 10.1016/0378-1119(95)00134-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Translation in bacteria is initiated by a base-pairing interaction between the extreme 3'-end of the small-subunit rRNA and a purine-rich domain (Shine-Dalgarno (SD) sequence) preceding the initiation codon at the 5'-end of most bacterial mRNAs. Here, we describe the identification of a second functional and alternative site on the Escherichia coli ribosome which is capable of interacting with mRNA devoid of SD sequences and initiate the translation. This site is localized between nt 1340 and 1360 of the 16S rRNA in E. coli and is complementary to the untranslated region at the 5'-end of tobacco mosaic virus RNA (omega sequence).
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MESH Headings
- Base Sequence
- Binding Sites
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Molecular Sequence Data
- Peptide Chain Initiation, Translational
- Protein Biosynthesis
- RNA, Messenger/metabolism
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- RNA, Viral/chemistry
- RNA, Viral/metabolism
- Ribosomes/metabolism
- Sequence Homology, Nucleic Acid
- Tobacco Mosaic Virus/genetics
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Affiliation(s)
- I G Ivanov
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia
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Ivanov IG, Alexandrova R, Dragulev B, Leclerc D, Saraffova A, Maximova V, Abouhaidar MG. Efficiency of the 5'-terminal sequence (omega) of tobacco mosaic virus RNA for the initiation of eukaryotic gene translation in Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 209:151-6. [PMID: 1396694 DOI: 10.1111/j.1432-1033.1992.tb17271.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recent studies have demonstrated that the 5' leader (omega sequence) of tobacco mosaic virus RNA has a certain enhancing capacity for translation of mRNA in both prokaryotes and eukaryotes. In order to estimate the efficiency of omega to initiate translation of mRNA in Escherichia coli, in comparison to the Shine-Dalgarno (S/D) sequence, we have inserted eight different eukaryotic genes into two types of E. coli expression vectors containing one constitutive promoter (P1) but different translation-initiation sites (S/D or omega delta 3 sequence, respectively). The efficiency of transcription and translation in vivo was evaluated for these vectors by measuring the yield of protein and both the level and stability of mRNA. We report that substitution of omega delta 3 for S/D decreases the yield of expressed protein 4-1900-fold and the content of gene-specific mRNA is decreased by about sevenfold. However, in comparison with the S/D sequence, the level of protein expressed under the translational control of omega delta 3 is less sensitive to changes in the 5' coding region. We also report that the omega sequence contains a region of 10-12 nucleotides complementary to the small ribosomal subunit RNA (rRNA) of E. coli, Eikenella corrodens and Xenopus laevis, and to the rRNA of the (small ribosomal) subunit of Oryza sativa.
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Affiliation(s)
- I G Ivanov
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia
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15
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Antoine R, Locht C. Isolation and molecular characterization of a novel broad-host-range plasmid from Bordetella bronchiseptica with sequence similarities to plasmids from gram-positive organisms. Mol Microbiol 1992; 6:1785-99. [PMID: 1321324 DOI: 10.1111/j.1365-2958.1992.tb01351.x] [Citation(s) in RCA: 196] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A 2.6 kb plasmid, named pBBR1, was isolated from Bordetella bronchiseptica S87. After insertion of an antibiotic resistance marker, this plasmid could be transferred into Escherichia coli, Bordetella pertussis, B. bronchiseptica, Vibrio cholerae, Rhizobium meliloti, and Pseudomonas putida by transformation or conjugation. Conjugation was possible only when the IncP group transfer functions were provided in trans. As shown by incompatibility testing, pBBR1 does not belong to the broad-host-range IncP, IncQ or IncW groups. DNA sequence analysis revealed two open reading frames: one was called Rep, involved in replication of the plasmid, and the other, called Mob, was involved in mobilization. Both the amino-terminal region of Mob and its promoter region show sequence similarities to Mob/Pre proteins from plasmids of Gram-positive bacteria. In spite of these sequence similarities, pBBR1 does not replicate via the rolling-circle mechanism commonly used by small Gram-positive plasmids. We therefore speculate that pBBR1 may combine a mobilization mechanism of Gram-positive organisms with a replication mechanism of Gram-negative organisms. Determination of the plasmid copy number in E. coli and B. pertussis indicated that pBBR1 has a rather high copy number, which, in conjunction with its small size and broad host range, renders it particularly interesting for studies of broad-host-range replicons and for the development of new cloning vectors for a wide range of Gram-negative bacteria.
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Affiliation(s)
- R Antoine
- Molecular and Cellular Biology Department, Smith Kline Beecham-Biologicals, Rixensart, Belgium
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16
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Casado C, Llagostera M, Barbé J. Expression ofnrdAandnrdBgenes ofEscherichia coliis decreased under anaerobiosis. FEMS Microbiol Lett 1991. [DOI: 10.1111/j.1574-6968.1991.tb04432.x-i1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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17
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Allen SP, Blaschek HP. Plasmid copy number and stability determination inClostridium perfringenstransformants. FEMS Microbiol Lett 1990. [DOI: 10.1111/j.1574-6968.1990.tb03910.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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18
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Bachvarov D, Jay E, Ivanov I. Construction of a Co1E1 plasmid bearing inducible high-copy-number phenotype. Folia Microbiol (Praha) 1990; 35:177-82. [PMID: 1698694 DOI: 10.1007/bf02820482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In order to construct plasmids bearing inducible high-copy-number phenotype, the cloning plasmid pBR322 was modified as follows: a DNA fragment containing a strong synthetic promoter (P1), synthetic lac operator (O1), DNA sequence corresponding to the RNAI/RNAII region of the Co1E1 replicon and the CAT gene transcription terminator was substituted for the 29 bp EcoRI/HindIII DNA fragment. Two types of plasmids were constructed in this way, differing in the orientation of the RNAI/RNAII fragment. Depending on the orientation these plasmids coded for RNA molecules representing either RNAI or RNAII domains. It was found that when RNAII molecules were overproduced the plasmid copy number was about 4 times higher than that of pBR322 and only negligible change in the plasmid copy-number value was observed upon overproduction of RNAI molecules.
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Affiliation(s)
- D Bachvarov
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia
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19
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Chopra I, Hacker K, Misulovin Z, Rothstein DM. Sensitive biological detection method for tetracyclines using a tetA-lacZ fusion system. Antimicrob Agents Chemother 1990; 34:111-6. [PMID: 2158271 PMCID: PMC171530 DOI: 10.1128/aac.34.1.111] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A sensitive microbiological detection system for tetracyclines, utilizing an Escherichia coli strain containing a cloned tetA-lacZ gene fusion, is described. Expression of beta-galactosidase by the fusion plasmid pUB3610 remained subject to regulatory control by the TetR repressor protein, with the presence of tetracyclines in the growth medium leading to a 12-fold induction of beta-galactosidase synthesis. Because synthesis of beta-galactosidase was influenced to a small extent by the carbon source and the addition of cyclic AMP to the medium, cells were grown in the presence of cyclic AMP to enhance the sensitivity of the assay. All commonly marketed tetracyclines and some derivatives at concentrations as low as 0.1 ng/ml could be detected in the growth medium. A plate assay utilizing the fusion plasmid that detects 1 ng of tetracycline has also been developed.
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Affiliation(s)
- I Chopra
- Department of Microbiology, School of Medical Sciences, University of Bristol, United Kingdom
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20
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Abstract
The effect of amino acids (presence or absence from the growth media) and metal ions on the replication of Escherichia coli plasmids in rel A+ strains was studied. It was found that: (i) The absence of one amino acid from the growth media had no effect on the plasmid copy number in prototrophic E. coli strains: (ii) The presence of only one amino acid in artificial media free of amino acids had a negligible effect on the plasmid copy number for the amino acids Ala, Arg, Glu, His, Leu, Phe, Thr, Trp, and Tyr: (iii) The combination of Met and Thr caused a rise in pBR322 plasmid copy number up to 90-100 plasmid copies per cell: (iv) The Fe3+ concentration had an amplification effect on E. coli plasmids. The pBR322 plasmid copy number for media free of amino acids and supplemented with 0.2-0.4 mM FeCl3 was 60-80 plasmid copies per cell: (v) The combination of Fe3+ with certain amino acids (Ala, Arg, Glu, Leu, Thr, and Trp) leads to a dramatic increase in the plasmid copy number reaching 180-270 plasmid copies per cell for the plasmid pBR322 and 20-24 for the plasmid pR100.
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Affiliation(s)
- I Angelov
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia
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21
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Alexciev K, Uscheva A, Pavlova M, Yavachev L, Ivanov I. Expression of synthetic calcitonin genes in plasmid vectors containing tandemly repeated non-overlapping ribosome binding sites. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1989; 21:987-96. [PMID: 2480257 DOI: 10.1016/0020-711x(89)90231-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. Expression plasmids containing non-overlapping tandemly repeated ribosome binding sites (RBS) were constructed in order to stabilize mRNA and enhance translation. 2. Two synthetic genes (human calcitonin tetramer gene and a fusion gene human gamma-interferon-human calcitonin) were cloned in these vectors and the effect of multiplicity of Shine-Dalgarno (S/D) sequence on heterologous gene expression was studied. 3. It was found that duplication and triplication of RBS had no effect on the stability of mRNA but led to a strong decrease in the level of recombinant protein and mRNA in the cell. 4. Plasmids bearing four times repeated S/D sequences gave longer-lived mRNAs and maintained a level of protein and mRNA very close to the values obtained with a single S/D containing plasmids.
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Affiliation(s)
- K Alexciev
- Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia
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22
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Taylor DE, Brose EC. Modified Birnboim-Doly method for rapid detection of plasmid copy number. Nucleic Acids Res 1988; 16:9056. [PMID: 3050895 PMCID: PMC338666 DOI: 10.1093/nar/16.18.9056] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- D E Taylor
- Department of Medical Microbiology and Infectious Diseases, University of Alberta, Edmonton, Canada
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