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Gorgun S, Isler H, Turgut MC. Comparison of rapid and conventional methods for investigating of mecA presence in Staphylococcus Species. Pak J Med Sci 2021; 37:1467-1474. [PMID: 34475932 PMCID: PMC8377928 DOI: 10.12669/pjms.37.5.4274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/17/2021] [Accepted: 05/25/2021] [Indexed: 11/22/2022] Open
Abstract
Objectives: Taking the determination of mecA gene by polymerized chain reaction (PCR) method as a reference in determining methicillin resistance in Staphylococcus species, we aimed at comparing the reliability levels of disk diffusion, latex agglutination test and chromogenic agar use methods. Methods: This prospective study was conducted on 228 Staphylococcus strains isolated between January 2020 and December 2020 in Samsun Training and Research Hospital. Disk diffusion, latex agglutination and chromogen agar medium methods were applied along with the polymerized chain reaction (PCR) method. Results: The mecA gene was detected in 47 of the isolates (20.6%) by the PCR method, and these isolates were accepted as methicillin-resistant. When the PCR result was taken as a reference, the sensitivity of the disk diffusion method became 100%, and specificity became 45.9%; sensitivity of latex agglutination was determined as 80.9%, and specificity as 70.2%; sensitivity of chromogenic agar as 85.1% and its specificity was found to be 95%. Only in S. aureus isolates, the highest sensitivity and specificity rate (100% and 88%, respectively) belonged to chromogenic agar. Conclusion: Chromogenic agar provides more reliable data for S. aureus isolates, and the combined use of all three methods does not significantly increase reliability.
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Affiliation(s)
- Selim Gorgun
- Selim Gorgun, Department of Microbiology and Clinical Microbiology, Health Sciences University, Samsun Training and Research Hospital, Samsun, Turkey
| | - Hacer Isler
- Hacer Isler, Department of Microbiology and Clinical Microbiology, Health Sciences University, Samsun Training and Research Hospital, Samsun, Turkey
| | - Mehmet Cenk Turgut
- Mehmet Cenk Turgut, Department of Orthopedics and Traumatology, Health Sciences University, Regional Training and Research Hospital, Erzurum, Turkey
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Development of a Prototype Lateral Flow Immunoassay for Rapid Detection of Staphylococcal Protein A in Positive Blood Culture Samples. Diagnostics (Basel) 2020; 10:diagnostics10100794. [PMID: 33036348 PMCID: PMC7601020 DOI: 10.3390/diagnostics10100794] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 12/22/2022] Open
Abstract
Bloodstream infection (BSI) is a major cause of mortality in hospitalized patients worldwide. Staphylococcus aureus is one of the most common pathogens found in BSI. The conventional workflow is time consuming. Therefore, we developed a lateral flow immunoassay (LFIA) for rapid detection of S. aureus-protein A in positive blood culture samples. A total of 90 clinical isolates including 58 S. aureus and 32 non-S. aureus were spiked in simulated blood samples. The antigens were extracted by a simple boiling method and diluted before being tested using the developed LFIA strips. The results were readable by naked eye within 15 min. The sensitivity of the developed LFIA was 87.9% (51/58) and the specificity was 93.8% (30/32). When bacterial colonies were used in the test, the LFIA provided higher sensitivity and specificity (94.8% and 100%, respectively). The detection limit of the LFIA was 107 CFU/mL. Initial evaluation of the LFIA in 20 positive blood culture bottles from hospitals showed 95% agreement with the routine methods. The LFIA is a rapid, simple and highly sensitive method. No sophisticated equipment is required. It has potential for routine detection particularly in low resource settings, contributing an early diagnosis that facilitates effective treatment and reduces disease progression.
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Hwang H, Lee HJ, Lee MA, Sohn H, Chang YH, Han SG, Jeong JY, Lee SH, Hong SW. Selection and Characterization of Staphylococcus hominis subsp. hominis WiKim0113 Isolated from Kimchi as a Starter Culture for the Production of Natural Pre-converted Nitrite. Food Sci Anim Resour 2020; 40:512-526. [PMID: 32734260 PMCID: PMC7372994 DOI: 10.5851/kosfa.2020.e29] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/10/2020] [Accepted: 04/06/2020] [Indexed: 12/18/2022] Open
Abstract
Synthetic nitrite is considered an undesirable preservative for meat products;
thus, controlling synthetic nitrite concentrations is important from the
standpoint of food safety. We investigated 1,000 species of microorganisms from
various kimchi preparations for their potential use as a starter culture for the
production of nitrites. We used 16S rRNA gene sequence analysis to select a
starter culture with excellent nitrite and nitric oxide productivity, which we
subsequently identified as Staphylococcus hominis subspecies
hominis WiKim0113. That starter culture was grown in NaCl
(up to 9%; w/v) at 10°C–40°C; its optimum growth was
observed at 30°C at pH 4.0–10.0. It exhibited nonproteolytic
activity and antibacterial activity against Clostridium
perfringens, a bacterium that causes food poisoning symptoms.
Analysis of Staphylococcus hominis subspecies
hominis WiKim0113 with an API ZYM system did not reveal the
presence of β-glucuronidase, and tests of the starter culture on
5% (v/v) sheep blood agar showed no hemolytic activity. Our results
demonstrated the remarkable stability of coagulase-negative
Staphylococcus hominis subspecies hominis
WiKim0113, especially in strain negative for staphylococcal enterotoxins and
sensitive to clinically relevant antibiotics. Moreover, Staphylococcus
hominis subspecies hominis WiKim0113 exhibited a
45.5% conversion rate of nitrate to nitrite, with nitrate levels reduced
to 25% after 36 h of culturing in the minimal medium supplemented with
nitrate (200 ppm). The results clearly demonstrated the safety and utility of
Staphylococcus hominis subspecies hominis
WiKim0113, and therefore its suitability as a starter culture.
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Affiliation(s)
| | - Ho Jae Lee
- World Institute of Kimchi, Gwangju 61755, Korea
| | - Mi-Ai Lee
- World Institute of Kimchi, Gwangju 61755, Korea
| | - Hyejin Sohn
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
| | - You Hyun Chang
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
| | - Sung Gu Han
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
| | - Jong Youn Jeong
- School of Food Biotechnology and Nutrition, Kyungsung University, Busan 48434, Korea
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Ombelet S, Barbé B, Affolabi D, Ronat JB, Lompo P, Lunguya O, Jacobs J, Hardy L. Best Practices of Blood Cultures in Low- and Middle-Income Countries. Front Med (Lausanne) 2019; 6:131. [PMID: 31275940 PMCID: PMC6591475 DOI: 10.3389/fmed.2019.00131] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/29/2019] [Indexed: 12/25/2022] Open
Abstract
Bloodstream infections (BSI) have a substantial impact on morbidity and mortality worldwide. Despite scarcity of data from many low- and middle-income countries (LMICs), there is increasing awareness of the importance of BSI in these countries. For example, it is estimated that the global mortality of non-typhoidal Salmonella bloodstream infection in children under 5 already exceeds that of malaria. Reliable and accurate diagnosis of these infections is therefore of utmost importance. Blood cultures are the reference method for diagnosis of BSI. LMICs face many challenges when implementing blood cultures, due to financial, logistical, and infrastructure-related constraints. This review aims to provide an overview of the state-of-the-art of sampling and processing of blood cultures, with emphasis on its use in LMICs. Laboratory processing of blood cultures is relatively straightforward and can be done without the need for expensive and complicated equipment. Automates for incubation and growth monitoring have become the standard in high-income countries (HICs), but they are still too expensive and not sufficiently robust for imminent implementation in most LMICs. Therefore, this review focuses on "manual" methods of blood culture, not involving automated equipment. In manual blood cultures, a bottle consisting of a broth medium supporting bacterial growth is incubated in a normal incubator and inspected daily for signs of growth. The collection of blood for blood culture is a crucial step in the process, as the sensitivity of blood cultures depends on the volume sampled; furthermore, contamination of the blood culture (accidental inoculation of environmental and skin bacteria) can be avoided by appropriate antisepsis. In this review, we give recommendations regarding appropriate blood culture sampling and processing in LMICs. We present feasible methods to detect and speed up growth and discuss some challenges in implementing blood cultures in LMICs, such as the biosafety aspects, supply chain and waste management.
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Affiliation(s)
- Sien Ombelet
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, KULeuven, Leuven, Belgium
| | - Barbara Barbé
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Dissou Affolabi
- Centre National Hospitalier Universitaire—Hubert Koutoucou Maga, Cotonou, Benin
| | | | - Palpouguini Lompo
- Clinical Research Unit of Nanoro, Institut de Recherche en Science de la Santé, Nanoro, Burkina Faso
| | - Octavie Lunguya
- National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo
- Department of Medical Biology, Cliniques Universitaires, Université de Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, KULeuven, Leuven, Belgium
| | - Liselotte Hardy
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
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Rapid Waterborne Pathogen Detection with Mobile Electronics. SENSORS 2017; 17:s17061348. [PMID: 28598391 PMCID: PMC5492157 DOI: 10.3390/s17061348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 05/28/2017] [Accepted: 06/07/2017] [Indexed: 12/31/2022]
Abstract
Pathogen detection in water samples, without complex and time consuming procedures such as fluorescent-labeling or culture-based incubation, is essential to public safety. We propose an immunoagglutination-based protocol together with the microfluidic device to quantify pathogen levels directly from water samples. Utilizing ubiquitous complementary metal–oxide–semiconductor (CMOS) imagers from mobile electronics, a low-cost and one-step reaction detection protocol is developed to enable field detection for waterborne pathogens. 10 mL of pathogen-containing water samples was processed using the developed protocol including filtration enrichment, immune-reaction detection and imaging processing. The limit of detection of 10 E. coli O157:H7 cells/10 mL has been demonstrated within 10 min of turnaround time. The protocol can readily be integrated into a mobile electronics such as smartphones for rapid and reproducible field detection of waterborne pathogens.
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Shangguan J, Li Y, He D, He X, Wang K, Zou Z, Shi H. A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus. Analyst 2016; 140:4489-97. [PMID: 25963028 DOI: 10.1039/c5an00535c] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Staphylococcus aureus (S. aureus) is an important human pathogen that causes several diseases ranging from superficial skin infections to life-threatening diseases. Here, a method combining positive dielectrophoresis (pDEP) driven on-line enrichment and aptamer-fluorescent silica nanoparticle label has been developed for the rapid and sensitive detection of S. aureus in microfluidic channels. An aptamer, having high affinity to S. aureus, is used as the molecular recognition tool and immobilized onto chloropropyl functionalized fluorescent silica nanoparticles through a click chemistry approach to obtain S. aureus aptamer-nanoparticle bioconjugates (Apt(S.aureus)/FNPs). The pDEP driven on-line enrichment technology was used for accumulating the Apt(S.aureus)/FNP labeled S. aureus. After incubating with S. aureus, the mixture of Apt(S.aureus)/FNP labeled S. aureus and Apt(S.aureus)/FNPs was directly introduced into the pDEP-based microfluidic system. By applying an AC voltage in a pDEP frequency region, the Apt(S.aureus)/FNP labelled S. aureus moved to the electrodes and accumulated in the electrode gap, while the free Apt(S.aureus)/FNPs flowed away. The signal that came from the Apt(S.aureus)/FNP labelled S. aureus in the focused detection areas was then detected. Profiting from the specificity of aptamer, signal amplification of FNP label and pDEP on-line enrichment, this assay can detect as low as 93 and 270 cfu mL(-1)S. aureus in deionized water and spiked water samples, respectively, with higher sensitivities than our previously reported Apt(S.aureus)/FNP based flow cytometry. Moreover, without the need for separation and washing steps usually required for FNP label involved bioassays, the total assay time including sample pretreatment was within 2 h.
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Affiliation(s)
- Jingfang Shangguan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Changsha 410082, China.
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Ferreira DDC, Silva GRD, Cavalcante FS, Carmo FLD, Fernandes LA, Moreira S, Passos MRL, Colombo APV, Santos KRND. Methicillin-resistant Staphylococcus aureus in HIV patients: risk factors associated with colonization and/or infection and methods for characterization of isolates - a systematic review. Clinics (Sao Paulo) 2014; 69:770-6. [PMID: 25518036 PMCID: PMC4256048 DOI: 10.6061/clinics/2014(11)11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 05/09/2014] [Indexed: 11/22/2022] Open
Abstract
Staphylococcus aureus is an important cause of infections and HIV-infected individuals are frequently susceptible to this pathogen. The aim of this study was to perform a systematic review to identify both the risk factors associated with colonization/infection by methicillin-resistant S. aureus in HIV patients and the methods used for characterization of isolates. An electronic search of articles published between January 2001 and December 2013 was first conducted. Among 116 studies categorized as being at a quality level of A, B or C, only 9 studies were considered to have high methodological quality (level A). The majority of these studies were retrospective (4/9 studies). The risk factors associated with colonization/infection by S. aureus were use of antimicrobials (4/9 studies), previous hospitalization (4/9 studies) and low CD4+ T lymphocyte counts (<200 cells/μl) (3/9 studies). Culture in mannitol salt agar (3/9 studies) and the latex agglutination test (5/9 studies) were the main methods used for bacterial phenotypic identification. Genotypic profiles were accessed by pulsed-field gel electrophoresis (6/9 studies) and USA300 was the most prevalent lineage (5/9 studies). Most isolates were resistant to erythromycin (3/9 studies) and susceptible to vancomycin (4/9 studies). Ultimately, use of antimicrobials and previous hospitalization were the main risk factors for colonization/infection by methicillin-resistant S. aureus in HIV-infected individuals. However, the numbers of evaluated patients, the exclusion and inclusion criteria and the characterization of the S. aureus isolates were not uniform, which made it difficult to establish the characteristics associated with HIV patients who are colonized/infected by S. aureus.
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Affiliation(s)
- Dennis de Carvalho Ferreira
- Bolsista da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), CAPES Foundation, Brasilia, DF, Brazil
| | | | | | - Flavia Lima do Carmo
- Laboratório de Ecologia Microbiana Molecular, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | - Suelen Moreira
- Laboratório de Infecção Hospitalar, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | - Ana Paula Vieira Colombo
- Laboratório de Microbiologia Oral, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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