An Efficient Analytical Method for Determining the Effects of Silver Nanoparticles on Vibrio parahaemolyticus in Estuarine Water
In virtue of their distinctive antimicrobial properties, silver nanoparticles (Ag NPs) are some of the most commonly used nanomaterials in the world, with applications in medical equipment, cosmetics, textiles, electronics, toys, and household appliances. As a result, they inevitably end up in river...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Science Press, PR China
2025-04-01
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| Series: | Progress in Fishery Sciences |
| Subjects: | |
| Online Access: | http://journal.yykxjz.cn/yykxjz/ch/reader/view_abstract.aspx?file_no=20240327001 |
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| Summary: | In virtue of their distinctive antimicrobial properties, silver nanoparticles (Ag NPs) are some of the most commonly used nanomaterials in the world, with applications in medical equipment, cosmetics, textiles, electronics, toys, and household appliances. As a result, they inevitably end up in rivers, lakes, estuaries, and coastal waters via wastewater, atmospheric deposition, and other pathways. Recent explorations have increased concerns regarding their adverse effects on the ecological health of estuarine environments. For risk assessment of nanomaterials in estuarine environments, microorganisms - especially bacteria - are ideal candidates as bioreporters. Reliable and effective methods for determining the effects of nanomaterials on microorganisms are of significance for assessing ecotoxicities. Growth curve-based methods are popular because they can fully reflect the toxicity of nanomaterials. Genotypic methods, which are based on DNA analysis, provide attractive alternatives. These phenotypic and genotypic methods have performed well in determining the effects of nanomaterials on microorganisms in simple laboratory media. However, when they are used in realistic matrices, such as estuarine water, which is complex in physical, chemical, and ecological characteristics, pretreatment steps for separation and purification are unavoidably applied prior to the determination steps. These pretreatment steps usually pose the risk of subjective and objective errors and poor efficiency. To date, more efficient and accurate analytical methods are still needed for assessing the ecotoxicity of nanomaterials.Recently, our research group contributed to an alternative concept for online monitoring of microbial growth by developing a multichannel capacitively coupled contactless conductivity (C4) detector. C4 detection is a particular type of conductivity-based analytical method, where the electrodes are not in direct contact with the tested medium. The magnitude of the detected signal (C4 output) is proportional to the concentration and mobility of the ionic charge carriers within the medium. It not only shares the advantages of common electrochemical techniques, such as instrumental simplicity, affordability, rapid response, nontransparent requirement, and easy miniaturization, but is also free of polarization, passivation, and fouling risks. Based on a 32-channel C4 detector and special algorithms, we developed a 32-channel electronic microbial growth analyzer (EMGA). EMGA could determine repeatable bacterial growth curves with a high temporal resolution in both homogeneous simple laboratory mediums and heterogeneous matrices.The EMGA method was used to evaluate the antibacterial effects of Ag NPs on Vibrio parahaemolyticus, compared with the use of the broth microdilution method (BMD) and plate counting methods. The minimum inhibitory concentration (MIC) of Ag NPs against V. parahaemolyticus in estuarine water samples determined by using the EMGA method is 24.0 mg/L, which is consistent with the results obtained by using the BMD and plate counting methods. The results obtained by using the EMGA method are in good agreement with the MIC values of the BMD and plate counting methods, with an essential agreement (EA) of 75% and minor error (mE) of 25%. No major error (ME) was found, indicating that the EMGA method for measuring the effects of Ag NPs on V. parahaemolyticus in estuarine water samples is reliable. In addition, the MIC values obtained by using the EMGA method are often higher than or equal to the results obtained by using the BMD and plate counting methods, due to the higher sensitivity of automated instruments compared to visual observation. Therefore, the antibacterial activity obtained by using the EMGA method is reliable than the results based on visual judgment.This study established a phenotypic method for determining the antibacterial activity of Ag NPs against V. parahaemolyticus in estuarine water. This method requires only two manual steps rather than three as in classical methods such as BMD and plate counting. In addition, due to the elimination of complex coexistent substances, it effectively reduces the risk of subjective and objective operational errors. This automated method based on sensor recognition results has higher sensitivity compared with the BMD and plate counting methods. Thus, the newly proposed method has the advantages of simplicity, time-saving, low-labor intensive, greater precision, and good repeatability. In addition, the sensitivity of this automatic instrument-based method is higher compared with eye-based methods. This efficient method provides a new approach for assessing ecotoxicity of nanomaterials in realistic environmental matrices, such as estuarine water. |
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| ISSN: | 2095-9869 |