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Shahab SN, van Veen A, Büchler AC, Saharman YR, Karuniawati A, Vos MC, Voor In 't Holt AF, Severin JA. In search of the best method to detect carriage of carbapenem-resistant Pseudomonas aeruginosa in humans: a systematic review. Ann Clin Microbiol Antimicrob 2024; 23:50. [PMID: 38858708 PMCID: PMC11163693 DOI: 10.1186/s12941-024-00707-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 05/13/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND Detection of carbapenem-resistant Pseudomonas aeruginosa (CR-PA) in humans is important to prevent transmission. However, the most optimal culture method to detect CR-PA is unknown. This systematic review aims to determine which culture method is most sensitive and which culture methods are used to detect CR-PA in humans. Second, to establish the most feasible culture method taking into account the turnaround time (TAT), and third, to provide an overview of the sampling sites used to detect carriage. METHODS We systematically searched the electronic databases Embase, Medline Ovid, Cochrane, Scopus, CINAHL, and Web of Science until January 27, 2023. All diagnostic accuracy studies comparing two or more culture methods to detect CR-PA and recent outbreak or surveillance reports on CR-PA carriage or infection in humans, which describe culture methods and their results, were eligible for inclusion. We used QUADAS-2 guideline for diagnostic accuracy studies and the STROBE or ORION guideline for outbreak-surveillance studies to assess the risk of bias. RESULTS Six diagnostic accuracy studies were included. An enrichment broth was found to increase the detection of CR-PA. Using an enrichment broth extended the TAT by 18-24 h, yet selective media could reduce the TAT by 24 h compared to routine media. In total, 124 outbreak-surveillance studies were included, of which 17 studies with surveillance samples and 116 studies with clinical samples. In outbreak-surveillance studies with surveillance samples, perianal, rectal swabs or stools were the most common sampling site/specimen (13/17, 76%). A large variety was observed in whether and which kind of enrichment broth and selective media were used. CONCLUSIONS We found a benefit of using an enrichment step prior to inoculation of the material onto selective media for the detection of CR-PA. More research is needed to determine the most sensitive sampling site and culture method. TRAIL REGISTRATION This study was registered in the PROSPERO International prospective register of systematic reviews (registration number: CRD42020207390, http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42020207390 ).
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Affiliation(s)
- Selvi N Shahab
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
- Department of Clinical Microbiology, Faculty of Medicine, Universitas Indonesia/Dr. Cipto Mangunkusumo General Hospital, Jakarta, Indonesia
| | - Anneloes van Veen
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Andrea C Büchler
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Yulia R Saharman
- Department of Clinical Microbiology, Faculty of Medicine, Universitas Indonesia/Dr. Cipto Mangunkusumo General Hospital, Jakarta, Indonesia
| | - Anis Karuniawati
- Department of Clinical Microbiology, Faculty of Medicine, Universitas Indonesia/Dr. Cipto Mangunkusumo General Hospital, Jakarta, Indonesia
| | - Margreet C Vos
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Anne F Voor In 't Holt
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Juliëtte A Severin
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
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Lapitan LD, Felisilda BMB, Tiangco CE, Rosin Jose A. Advances in Bioreceptor Layer Engineering in Nanomaterial-based Sensing of Pseudomonas Aeruginosa and its Metabolites. Chem Asian J 2024:e202400090. [PMID: 38781439 DOI: 10.1002/asia.202400090] [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: 01/25/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 05/25/2024]
Abstract
Pseudomonas aeruginosa is a pathogen that infects wounds and burns and causes severe infections in immunocompromised humans. The high virulence, the rise of antibiotic-resistant strains, and the easy transmissibility of P. aeruginosa necessitate its fast detection and control. The gold standard for detecting P. aeruginosa, the plate culture method, though reliable, takes several days to complete. Therefore, developing accurate, rapid, and easy-to-use diagnostic tools for P. aeruginosa is highly desirable. Nanomaterial-based biosensors are at the forefront of detecting P. aeruginosa and its secondary metabolites. This review summarises the biorecognition elements, biomarkers, immobilisation strategies, and current state-of-the-art biosensors for P. aeruginosa. The review highlights the underlying principles of bioreceptor layer engineering and the design of optical, electrochemical, mass-based, and thermal biosensors based on nanomaterials. The advantages and disadvantages of these biosensors and their future point-of-care applications are also discussed. This review outlines significant advancements in biosensors and sensors for detecting P. aeruginosa and its metabolites. Research efforts have identified biorecognition elements specific and selective towards P. aeruginosa. The stability, ease of preparation, cost-effectiveness, and integration of these biorecognition elements onto transducers are pivotal for their application in biosensors and sensors. At the same time, when developing sensors for clinically significant analytes such as P. aeruginosa, virulence factors need to be addressed, such as the sensor's sensitivity, reliability, and response time in samples obtained from patients. The point-of-care applicability of the developed sensor may be an added advantage since it enables onsite determination. In this context, optical methods developed for P. aeruginosa offer promising potential.
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Affiliation(s)
- Lorico Ds Lapitan
- Department of Chemical Engineering, Faculty of Engineering, University of Santo Tomas, España Boulevard, Manila, Philippines, Center for Advanced Materials and Technologies-CEZAMAT, Warsaw University of Technology, 02-822, Warsaw, Poland
| | - Bren Mark B Felisilda
- Department of Electrode Processes, Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland, Department of Chemistry, College of Arts & Sciences, Xavier University-Ateneo de Cagayan, Corrales Street, Cagayan de Oro, Philippines
| | - Cristina E Tiangco
- Research Center for the Natural and Applied Sciences and, Department of Chemical Engineering, Faculty of Engineering, University of Santo Tomas, España Boulevard, Manila, Philippines
| | - Ammu Rosin Jose
- Department of Chemistry, Sacred Heart College (Autonomous), Pandit Karuppan Rd, Thevara, Ernakulam, Kerala, India
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Zhang P, Yuan L, Zeng J, Zou K, Liu B, Qing T, Feng B. Alginate production of Pseudomonas strains and its application in preparation of alginate-biomass hydrogel for heavy metal adsorption. Int J Biol Macromol 2022; 222:1511-1521. [DOI: 10.1016/j.ijbiomac.2022.09.252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/21/2022] [Accepted: 09/27/2022] [Indexed: 11/29/2022]
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Evaluation of a Novel Chromogenic Medium for the Detection of Pseudomonas aeruginosa in Respiratory Samples from Patients with Cystic Fibrosis. Microorganisms 2022; 10:microorganisms10051004. [PMID: 35630446 PMCID: PMC9144526 DOI: 10.3390/microorganisms10051004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 02/01/2023] Open
Abstract
Pseudomonas aeruginosa is a dominant cause of respiratory infection in individuals with cystic fibrosis (CF), leading to significant morbidity and mortality. Detection of P. aeruginosa is conducted by culture of respiratory samples but this process may occasionally be compromised due to overgrowth by other bacteria and fungi. We aimed to evaluate a novel chromogenic medium, Pseudomonas aeruginosa chromogenic agar (PACA), for culture of P. aeruginosa from respiratory samples, from patients with CF. A total of 198 respiratory samples were cultured onto PACA and three other media: CHROMID®P. aeruginosa, CHROMagar™ Pseudomonas and MacConkey agar. P. aeruginosa was recovered from 66 samples (33%), using a combination of all media. After 72 h incubation, the sensitivity of the four chromogenic media was as follows: 91% for PACA and CHROMagar™ Pseudomonas, 85% for CHROMID®P. aeruginosa and 83% for MacConkey agar. For the three chromogenic media, the positive predictive value after 72 h was as follows: 95% for PACA, 56% for CHROMagar™ Pseudomonas and 86% for CHROMID®P. aeruginosa. PACA proved to be a highly effective culture medium for the isolation and specific detection of P. aeruginosa from respiratory samples.
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Căpățînă D, Feier B, Hosu O, Tertiș M, Cristea C. Analytical methods for the characterization and diagnosis of infection with Pseudomonas aeruginosa: A critical review. Anal Chim Acta 2022; 1204:339696. [DOI: 10.1016/j.aca.2022.339696] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 02/05/2022] [Accepted: 03/06/2022] [Indexed: 12/11/2022]
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Thompson R, Stephenson D, Sykes HE, Perry JD, Stanforth SP, Dean JR. Detection of β-alanyl aminopeptidase as a biomarker for Pseudomonas aeruginosa in the sputum of patients with cystic fibrosis using exogenous volatile organic compound evolution. RSC Adv 2020; 10:10634-10645. [PMID: 35492910 PMCID: PMC9051645 DOI: 10.1039/c9ra08386c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/02/2020] [Indexed: 12/15/2022] Open
Abstract
A novel, rapid and sensitive analytical method has been developed and applied to 105 sputum samples from patients with cystic fibrosis, including 5 samples from post-lung transplant patients. This new method is specifically targeted to measure β-alanyl aminopeptidase activity which is characteristic of some important Gram-negative pathogens. Of relevance to this study are Pseudomonas aeruginosa and pathogens of the Burkholderia cepacia complex both of which are commonly associated with respiratory infections as well as increased morbidity and mortality in adult cystic fibrosis patients. The analytical method involves the addition of a novel enzyme substrate (i.e. 3-amino-N-(3-fluorophenyl)propanamide) that interacts with β-alanyl aminopeptidase to generate an exogenous volatile organic compound 3-fluoroaniline (LOD 0.02 μg mL−1; LOQ 0.06 μg mL−1). 3-Fluoroaniline was determined at 20 times above its calculated limit of quantification in the sputum samples by HS-SPME-GC-MS and then the results compared with standard culture methods and bacterial identification using MALDI-TOF-MS. Detection of 3-fluoroaniline was possible after only 8 h incubation of the sputum samples with a 95% success rate; this increased to 100% at 24 h which was well within the typical routine timeframe of 48 h. To our knowledge, this is the first demonstration of detection of P. aeruginosa by use of a custom-designed substrate to liberate a detectable and unique VOC. The very high negative predictive value (100% in this study) means such an assay could be appropriate as a screening technique for patients who are not yet colonized by this pathogen. A novel, rapid and sensitive analytical method has been developed and applied to 105 sputum samples from patients with cystic fibrosis, including 5 samples from post-lung transplant patients.![]()
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Affiliation(s)
- Ryan Thompson
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
| | - Dominic Stephenson
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
- Department of Microbiology
| | - Hannah E. Sykes
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
| | - John D. Perry
- Department of Microbiology
- Freeman Hospital
- Newcastle upon Tyne
- UK
| | | | - John R. Dean
- Department of Applied Sciences
- Northumbria University
- Newcastle upon Tyne
- UK
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A Decade of Development of Chromogenic Culture Media for Clinical Microbiology in an Era of Molecular Diagnostics. Clin Microbiol Rev 2017; 30:449-479. [PMID: 28122803 DOI: 10.1128/cmr.00097-16] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In the last 25 years, chromogenic culture media have found widespread application in diagnostic clinical microbiology. In the last decade, the range of media available to clinical laboratories has expanded greatly, allowing specific detection of additional pathogens, including Pseudomonas aeruginosa, group B streptococci, Clostridium difficile, Campylobacter spp., and Yersinia enterocolitica. New media have also been developed to screen for pathogens with acquired antimicrobial resistance, including vancomycin-resistant enterococci, carbapenem-resistant Acinetobacter spp., and Enterobacteriaceae with extended-spectrum β-lactamases and carbapenemases. This review seeks to explore the utility of chromogenic media in clinical microbiology, with particular attention given to media that have been commercialized in the last decade. The impact of laboratory automation and complementary technologies such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is also assessed. Finally, the review also seeks to demarcate the role of chromogenic media in an era of molecular diagnostics.
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Cellier M, James AL, Orenga S, Perry JD, Turnbull G, Stanforth SP. The Synthesis of L-Alanyl and β-Alanyl Derivatives of 2-Aminoacridone and Their Application in the Detection of Clinically-Important Microorganisms. PLoS One 2016; 11:e0158378. [PMID: 27391894 PMCID: PMC4938530 DOI: 10.1371/journal.pone.0158378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/15/2016] [Indexed: 11/30/2022] Open
Abstract
In clinical microbiology the speed with which pathogenic microorganisms may be detected has a direct impact on patient health. One important strategy used in the laboratory is the growth of cultures in the presence of an enzymatic substrate which, once transformed by the appropriate microbial enzyme, generates a detectable colour or fluorescence output. Such substrates have previously been prepared by our group and others and are available as commercial diagnostic kits, however they all suffer from some degree of diffusion when used in a solid growth medium. This diffusion complicates the detection and differentiation of species in polymicrobial cultures and so we sought to improve on our previous work. In this work we have prepared and evaluated a series of novel fluorogenic enzyme substrates based on N-substituted-2-aminoacridones. All of the prepared substrates were found to be suitable for the detection and differentiation of certain microorganisms, however those based on the 2-amino-10-benzylacridone core in particular showed no apparent diffusion when incorporated into solid growth media. On transformation these substrates generated brightly fluorescent colonies that are clearly contrasted with the background medium due to the difference in emission wavelength (λem 445–450 nm for the substrate, λem 550 nm for the product). Here we have shown that our L-alanyl aminopeptidase substrate, 2-(N-L-alanylamino)-10-benzylacridone, is particularly suited to the detection of Gram-negative bacteria, and our β-alanyl aminopeptidase substrate, 2-(N- β-alanylamino)-10-benzylacridone, to the detection of Pseudomonas aeruginosa and Serratia marcescens when grown on solid media incorporating these substrates. The resulting fluorophore shows no apparent diffusion from the colonies of interest, and the enhanced sensitivity offered by fluorescent emission may allow for the detection of these organisms as microcolonies using automated fluorescence microscopy.
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Affiliation(s)
- Marie Cellier
- Research & Development Microbiology, bioMérieux SA, La-Balme-les-Grottes, France
| | - Arthur L. James
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Sylvain Orenga
- Research & Development Microbiology, bioMérieux SA, La-Balme-les-Grottes, France
| | - John D. Perry
- Department of Microbiology, Freeman Hospital, Newcastle upon Tyne, United Kingdom
| | - Graeme Turnbull
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- * E-mail:
| | - Stephen P. Stanforth
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
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9
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Bedernjak AF, Zaytsev AV, Babolat M, Cellier M, James AL, Orenga S, Perry JD, Groundwater PW, Anderson RJ. Synthesis and Evaluation of Novel 7- and 8-Aminophenoxazinones for the Detection of β-Alanine Aminopeptidase Activity and the Reliable Identification of Pseudomonas aeruginosa in Clinical Samples. J Med Chem 2016; 59:4476-87. [PMID: 27094856 DOI: 10.1021/acs.jmedchem.5b01591] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A series of novel 8-aminophenoxazin-3-one and 7-aminophenoxazin-3-one chromogens and their corresponding β-alanine derivatives were synthesized and evaluated for their ability to detect β-alanyl aminopeptidase activity in bacteria known to hydrolyze β-alanine derivatized substrates. The results provided insight into the structural requirements for effective visualization of enzymatic activity and the mechanism of formation of phenoxazinon-3-ones. 8-Aminophenoxazin-3-one substrates 23c, 23d, and 23e were prepared in good to high overall yield and were selective for β-alanyl aminopeptidase activity in bacteria, producing a lighter agar background coloration facilitating visualization of colored colonies, with variable localization to the colonies, but had lower sensitivities for the detection of Pseudomonas aeruginosa in comparison to the analogous 7-aminophenoxazin-3-one substrates. The synthetic methodology employed here allows the preparation of a range of substrates for evaluation and the establishment of structure-activity relationships. For example, the 2-pentyl substituted aminophenoxazin-3-one 22b performed with analogous sensitivity to the corresponding 1-pentyl-7-aminophenoxazin-3-one substrate 1 used commercially, highlighting that the position of the pentyl substituent can be varied while maintaining detection sensitivity.
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Affiliation(s)
| | - Andrey V Zaytsev
- Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France
| | - Michèle Babolat
- Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France
| | - Marie Cellier
- Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France
| | - Arthur L James
- School of Life Sciences, Northumbria University , Newcastle upon Tyne, NE1 8ST, U.K
| | - Sylvain Orenga
- Department of Microbiology, bioMérieux , 38390 La Balme-les-Grottes, France
| | - John D Perry
- Department of Microbiology, Freeman Hospital , Newcastle upon Tyne NE7 7DN, U.K
| | - Paul W Groundwater
- Sunderland Pharmacy School, University of Sunderland , Sunderland SR1 3SD, U.K
| | - Rosaleen J Anderson
- Sunderland Pharmacy School, University of Sunderland , Sunderland SR1 3SD, U.K
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Váradi L, Hibbs DE, Orenga S, Babolat M, Perry JD, Groundwater PW. β-Alanyl aminopeptidase-activated fluorogenic probes for the rapid identification of Pseudomonas aeruginosa in clinical samples. RSC Adv 2016. [DOI: 10.1039/c6ra12875k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The fluorogenic self-immolative substrates8are specifically hydrolyzed by β-alanyl aminopeptidase, resulting in a 1,6-elimination and the release of the highly fluorescent hydroxycoumarins6.
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Affiliation(s)
- Linda Váradi
- Faculty of Pharmacy
- The University of Sydney
- Camperdown Campus
- Sydney
- Australia
| | - David E. Hibbs
- Faculty of Pharmacy
- The University of Sydney
- Camperdown Campus
- Sydney
- Australia
| | - Sylvain Orenga
- bioMérieux
- R&D Microbiologie
- 38 390 La Balme-les-Grottes
- France
| | - Michèle Babolat
- bioMérieux
- R&D Microbiologie
- 38 390 La Balme-les-Grottes
- France
| | - John D. Perry
- Microbiology Department
- Freeman Hospital
- Newcastle upon Tyne
- UK
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Weiser R, Donoghue D, Weightman A, Mahenthiralingam E. Evaluation of five selective media for the detection of Pseudomonas aeruginosa using a strain panel from clinical, environmental and industrial sources. J Microbiol Methods 2014; 99:8-14. [DOI: 10.1016/j.mimet.2014.01.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 01/17/2014] [Accepted: 01/17/2014] [Indexed: 12/27/2022]
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Salman M, Ali A, Haque A. A novel multiplex PCR for detection of Pseudomonas aeruginosa: A major cause of wound infections. Pak J Med Sci 2013; 29:957-61. [PMID: 24353667 PMCID: PMC3817763 DOI: 10.12669/pjms.294.3652] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 11/15/2022] Open
Abstract
Background and Objective: Wound infections are often difficult to treat due to various bacterial pathogens. Pseudomonas aeruginosa is one of the common invaders of open wounds. Precise diagnosis of this etiological agent in wound infections is of critical importance particularly in treatment of problematic cases. The existing diagnostic methods have certain limitations particularly related to specificity. Our objective was to to establish a comprehensive and reliable multiplex PCR to confirm diagnosis of P. aeruginosa. Methods: A multiplex PCR test was developed for rapid and comprehensive identification of P. aeruginosa. Four highly specific genes were targeted simultaneously for detection of genus, species and exotoxin production (16S rDNA, gyrB, oprL and ETA) in P. aeruginosa; additionally one internal control gene (invA) of Salmonella was used. The specificity of the multiplex PCR was confirmed using internal and negative controls. Amplified fragments were confirmed by restriction analysis and DNA sequencing. Results: The developed method was applied on 40 morphologically suspected P. aeruginosa isolates (from 200 pus samples) and 18 isolates were confirmed as P. aeruginosa. In comparison, only 12 could be identified biochemically. Conclusions: Combination of the four reported genes in multiplex PCR provided more confident and comprehensive detection of P. aeruginosa which is applicable for screening of wound infections and assisting treatment strategy.
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Affiliation(s)
- Muhammad Salman
- Muhammad Salman BS, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Aamir Ali
- Dr. Aamir Ali, PhD, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Abdul Haque
- Dr. Abdul Haque, PhD, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
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Goncalves-Vidigal P, Grosse-Onnebrink J, Mellies U, Buer J, Rath PM, Steinmann J. Stenotrophomonas maltophilia in cystic fibrosis: Improved detection by the use of selective agar and evaluation of antimicrobial resistance. J Cyst Fibros 2011; 10:422-7. [DOI: 10.1016/j.jcf.2011.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/21/2011] [Accepted: 06/23/2011] [Indexed: 10/18/2022]
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Farrell HP, Garvey M, Cormican M, Laffey JG, Rowan NJ. Investigation of critical inter-related factors affecting the efficacy of pulsed light for inactivating clinically relevant bacterial pathogens. J Appl Microbiol 2009; 108:1494-508. [PMID: 19796119 DOI: 10.1111/j.1365-2672.2009.04545.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To investigate critical electrical and biological factors governing the efficacy of pulsed light (PL) for the in vitro inactivation of bacteria isolated from the clinical environment. Development of this alternative PL decontamination approach is timely, as the incidence of health care-related infections remains unacceptably high. METHODS AND RESULTS Predetermined cell numbers of clinically relevant Gram-positive and Gram-negative bacteria were inoculated separately on agar plates and were flashed with <or=60 pulses of broad-spectrum light under varying operating conditions, and their inactivation measured. Significant differences in inactivation largely occurred depending on the level of the applied lamp discharge energy (range 3.2-20 J per pulse), the amount of pulsing applied (range 0-60 pulses) and the distance between light source and treatment surface (range 8-20 cm) used. Greater decontamination levels were achieved using a combination of higher lamp discharge energies, increased number of pulses and shorter distances between treatment surface and the xenon light source. Levels of microbial sensitivity also varied depending on the population type, size and age of cultures treated. Production of pigment pyocynanin and alginate slime in mucoid strains of Pseudomonas aeruginosa afforded some protection against lethal action of PL; however, this was evident only by using a combination of reduced amount of pulsing at the lower lamp discharge energies tested. A clear pattern was observed where Gram-positive bacterial pathogens were more resistant to cidal effects of PL compared to Gram negatives. While negligible photoreactivation of PL-treated bacterial strains occurred after full pulsing regimes at the different lamp discharge energies tested, some repair was evident when using a combination of reduced pulsing at the lower lamp discharge energies. Strains harbouring genes for multiple resistances to antibiotics were not significantly more resistant to PL treatments. Slight temperature rises (<or=4.2 degrees C) were measured on agar surfaces after extended pulsing at higher lamp discharge energies. Presence of organic matter on treatment surface did not significantly affect PL decontamination efficacy, nor did growth of PL-treated bacteria on selective agar diminish survival compared to similarly treated bacteria inoculated and enumerated on nonselective agar plates. CONCLUSIONS Critical inter-related factors affecting the effective and repeatable in vitro decontamination performance of PL were identified during this study that will aid further development of this athermal process technology for applications in health care and in industry. Very rapid reductions (c. 7 log(10) CFU cm(-2) within <or=10 pulses) occurred using discharge energy of 20 J for all tested clinically relevant bacteria under study when treated at 8 cm distance from xenon light source. While no resistant flora is expected to develop for treatment of microbial pathogens on two-dimensional surfaces, careful consideration of scale up factors such as design and operational usage of this PL technique will be required to assure operator safety. SIGNIFICANCE AND IMPACT OF THE STUDY Findings and conclusions derived from this study will enable further development and optimization of this decontamination technique in health care and in food preparation settings, and will advance the field of nonthermal processing technologies.
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Affiliation(s)
- H P Farrell
- Department of Nursing and Health Science, Athlone Institute of Technology, Athlone, Westmeath, Ireland.
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Orenga S, James AL, Manafi M, Perry JD, Pincus DH. Enzymatic substrates in microbiology. J Microbiol Methods 2009; 79:139-55. [PMID: 19679151 DOI: 10.1016/j.mimet.2009.08.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 07/24/2009] [Accepted: 08/03/2009] [Indexed: 11/15/2022]
Abstract
Enzymatic substrates are powerful tools in biochemistry. They are widely used in microbiology to study metabolic pathways, to monitor metabolism and to detect, enumerate and identify microorganisms. Synthetic enzymatic substrates have been customized for various microbial assays, to detect an expanding range of both new enzymatic activities and target microorganisms. Recent developments in synthetic enzymatic substrates with new spectral, chemical and biochemical properties allow improved detection, enumeration and identification of food-borne microorganisms, clinical pathogens and multi-resistant bacteria in various sample types. In the past 20 years, the range of synthetic enzymatic substrates used in microbiology has been markedly extended supporting the development of new multi-test systems (e.g., Microscan, Vitek 2, Phoenix) and chromogenic culture media. The use of such substrates enables an improvement in time to detection and specificity over conventional tests that employ natural substrates. In the era of intense developments in molecular biology, phenotypic tests involving enzymatic substrates remain useful to analyse both simple and complex samples. Such tests are applicable to diagnostic and research laboratories all over the world.
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Affiliation(s)
- Sylvain Orenga
- Research & Development Microbiology, bioMérieux, 3 route de Port Michaud, La Balme-les-Grottes, France.
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