Article
Environmental Sciences
B. Reyneke, M. Waso, T. Ndlovu, T. Clements, B. Havenga, S. Khan, W. Khan
Summary: This study compared the effectiveness of EMA and PMA combined with ABS and qPCR assays in detecting viable bacterial species in rainwater. The results showed that both EMA and PMA reduced the detection of nonviable bacteria in rainwater samples, but EMA treatment significantly altered the relative abundance of dominant bacterial families and genera, as well as decreased the detection of unclassified bacteria. Additionally, the use of EMA and PMA increased the detection of less abundant pathogenic bacteria. The combination of viability pre-treatments with ABS and qPCR provides a comprehensive monitoring approach for detecting less abundant bacterial genera and/or pathogens in water sources.
WATER AIR AND SOIL POLLUTION
(2022)
Article
Immunology
Shuo Zhao, Jingyun Zhang, Zhe Li, Yu Han, Biao Kan
Summary: VBNC cells, a survival strategy adopted by bacterial species like Vibrio cholerae under environmental stress, require accurate methods for identification and enumeration. Quantitative PCR methods, particularly ddPCR, show higher accuracy and sensitivity in counting VBNC cells. PMA-ddPCR method presented in this study offers a new tool for quantifying VBNC cells, which can be extended to other bacterial species.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2021)
Article
Microbiology
Aifen Ou, Kan Wang, Yanrui Ye, Ling Chen, Xiangjun Gong, Lu Qian, Junyan Liu
Summary: A method using propidium monoazide-crossing priming amplification (PMA-CPA) was developed to detect Salmonella enterica rapidly with high sensitivity and identify VBNC cells in food samples. Specific primers and testing on 20 bacterial strains confirmed the effectiveness and specificity of this method in detecting S. enterica. The successful application of PMA-CPA in detecting S. enterica in VBNC state from food samples was demonstrated with significant color change.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Shuo Zhao, Xin Lu, JingYun Zhang, Biao Kan
Summary: When bacterial pathogens are exposed to adverse conditions, they can enter the viable but nonculturable (VBNC) state. Detecting and quantifying VBNC cells is necessary for microbiological studies and pathogen monitoring. In this study, a droplet digital PCR (ddPCR) method with a chromosomal single-copy gene as an internal reference was developed to accurately enumerate Vibrio cholerae VBNC cells. This method showed greater accuracy and sensitivity than qPCR and has the potential to be extended to other bacterial VBNC cells.
MICROBIOLOGY SPECTRUM
(2022)
Article
Engineering, Environmental
Vu Duc Canh, Midori Yasui, Shotaro Torii, Kumiko Oguma, Hiroyuki Katayama
Summary: UV-LEDs are effective in disinfecting water by inactivating pathogens. Both non-enveloped virus (T4) and enveloped virus (Phi6) can be inactivated by UV-LED treatment, although enveloped viruses are more resistant. The sensitivity of viruses to UV-LED treatment is influenced by their genomic properties.
ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY
(2023)
Article
Biotechnology & Applied Microbiology
Minji Kim, Karen Shapiro, Veronica B. Rajal, Andrea Packham, Beatriz Aguilar, Lezlie Rueda, Stefan Wuertz
Summary: The study evaluated the efficacy of RT-qPCR for selective detection of viable protozoan pathogens in spinach. Among the methods tested, RT-qPCR was more effective in discriminating viable from inactivated pathogens. The application of viability methods on leafy greens can be adopted by the produce industry and regulatory agencies for screening purposes.
Article
Engineering, Environmental
A. S. Deshpande, N. L. Fahrenfeld
Summary: Shotgun metagenomic studies have examined antibiotic resistance genes (ARGs) in various environments, and combining this method with viability-based techniques can enhance our understanding of ARG hazards. This study evaluated different methods for separating extracellular DNA (eDNA) and putative non-viable cell DNA to investigate their impact on ARG-host assignments. The results showed significant differences in bacterial community structure and ARG profiles between PMA-DNA and total DNA extracts, indicating the importance of sample preparation methods in assessing the potential hazard of riverine ARGs.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Nutrition & Dietetics
Lisa F. Stinson, Michelle L. Trevenen, Donna T. Geddes
Summary: This study characterized the viable bacterial content and total bacterial DNA content in fresh human milk, finding that the majority of DNA recovered was from non-viable organisms. Samples treated with PMA showed significant differences in bacterial composition compared to untreated samples. These results suggest that the total bacterial DNA content in human milk does not accurately represent the viable human milk microbiome, raising questions about the validity of previous conclusions in this field.
Article
Engineering, Chemical
Ji Yoon Kim, Eun Bi Jeon, Min Gyu Song, Kwang Soo Ha, Sang Hyeon Jeong, Yeoun Joong Jung, Shin Young Park
Summary: This study explored the combined effects of ultrasonic waves and DBD plasma treatment on reducing human norovirus in fresh sea squirt. The results showed that DP treatment alone reduced HNV to a greater extent compared to UW treatment alone. The combined UW 60 min + DP 60 min achieved a significant reduction of viable HNV GII. 4, suggesting a potential nonthermal method for reducing HNV in seafood.
JOURNAL OF FOOD PROCESS ENGINEERING
(2021)
Article
Agriculture, Dairy & Animal Science
Dan Mu, Donggen Zhou, Guoyang Xie, Ju Liu, Zhengzheng Wang, Qin Xiong, Hengyi Xu
Summary: In this study, a method for detecting viable E. coli O157:H7 in food products was established using an enhanced nucleic acid binding dye called improved propidium monoazide (PMAxx) coupled with rRAA assay. The PMAxx-rRAA assay showed high sensitivity and good specificity, and could resist interference from dead bacteria and nontarget bacteria.
JOURNAL OF DAIRY SCIENCE
(2022)
Review
Immunology
Aurelie Lotoux, Eliane Milohanic, Helene Bierne
Summary: The VBNC state of bacteria, particularly in the case of Lm pathogens, has important implications for environmental, agricultural, and food industry settings, as well as potential risks in the host. The hypothesis that VBNC forms contribute to adaptation, persistence, and transmission of Lm between different ecological niches is put forth.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2022)
Article
Veterinary Sciences
Liu Yang, Yunzhi Long, Qianqian Li, Wenbo Song, Ying Huang, Gong Liang, Daobing Yu, Mingguang Zhou, Gaoyuan Xu, Yao Chen, Chao Huang, Xibiao Tang
Summary: Currently, there is no effective experimental method for detecting the infectivity of suid herpesvirus 1 (SHV-1) in pigs. This study combined propidium monoazide (PMA) with quantitative polymerase chain reaction (qPCR) to determine the infectivity of SHV-1. Heat inactivation proved to be able to differentiate the infective status of the virus, while UV inactivation did not. The method exhibited high stability with a detection rate of 96%.
FRONTIERS IN VETERINARY SCIENCE
(2022)
Article
Biotechnology & Applied Microbiology
Wannes Van Holm, Justien Ghesquiere, Nico Boon, Tim Verspecht, Kristel Bernaerts, Naiera Zayed, Ioanna Chatzigiannidou, Wim Teughels
Summary: The use of viability quantitative PCR (v-qPCR) has revolutionized the assessment of microbial viability, but the selection of qPCR amplicon length is crucial for accurate live/dead distinction. Longer amplicon lengths increase the difference in quantification cycle (C-q) between live and dead cells, but decrease qPCR efficiency. The optimal amplicon length for v-qPCR is around 400 bp, balancing efficiency with the ability to distinguish between live and dead bacteria.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Environmental Sciences
Yulong Fu, Hongxi Peng, Jingqing Liu, Thanh H. Nguyen, Muhammad Zaffar Hashmi, Chaofeng Shen
Summary: This study quantified the culturability of waterborne pathogens in biofilms from a metropolitan drinking water distribution system, finding that pipe material significantly influences the culturability of pathogens and microbial communities. Stainless steel clad pipe was identified as a better choice for pathogen control compared to other metal pipes. These findings provide valuable insights into managing water quality in DWDS.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Food Science & Technology
Huayou Chen, Lingyu Kang, Keyi Li, Tao Feng, Zhong Ni, Ebin Gao, Zhen Fang
Summary: Real-time monitoring of harmful bacteria in feed fermentation is crucial for enhancing feed quality. This study combined propidium monoazide dyes (PMA) with qPCR technology to investigate microflora changes during artificially contaminated feed fermentation. The results showed that PMA-qPCR had higher Cycle Threshold (Ct) values compared to qPCR, effectively eliminating the influence of dead bacteria. The growth of Escherichia coli O157:H7, Shigella flexneri, and Staphylococcus aureus was inhibited during soybean meal feed fermentation, whereas beneficial bacteria were unaffected. These findings suggest that anaerobically fermented feed can be a promising alternative to antibiotics, and real-time monitoring of harmful bacteria in fermented feed using PMA-qPCR will enhance safety risk assessment.
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
(2023)