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Shen Y, Lin S, You P, Chen Y, Luo Y, Song X, Chen Y, Jin D. Rapid discrimination between clinical Clostridioides difficile infection and colonization by quantitative detection of TcdB toxin using a real-time cell analysis system. Front Microbiol 2024; 15:1348892. [PMID: 38322317 PMCID: PMC10844495 DOI: 10.3389/fmicb.2024.1348892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/08/2024] [Indexed: 02/08/2024] Open
Abstract
Objectives It is important to accurately discriminate between clinical Clostridioides difficile infection (CDI) and colonization (CDC) for effective antimicrobial treatment. Methods In this study, 37 stool samples were collected from 17 CDC and 20 CDI cases, and each sample were tested in parallel through the real-time cell analysis (RTCA) system, real-time PCR assay (PCR), and enzyme-linked immunosorbent assay (ELISA). Results RTCA-measured functional and toxical C. difficile toxin B (TcdB) concentrations in the CDI group (302.58 ± 119.15 ng/mL) were significantly higher than those in the CDC group (18.15 ± 11.81 ng/mL) (p = 0.0008). Conversely, ELISA results revealed no significant disparities in TcdB concentrations between the CDC (26.21 ± 3.57 ng/mL) and the CDI group (17.07 ± 3.10 ng/mL) (p = 0.064). PCR results indicated no significant differences in tcdB gene copies between the CDC (774.54 ± 357.89 copies/μL) and the CDI group (4,667.69 ± 3,069.87 copies/μL) (p = 0.407). Additionally, the functional and toxical TcdB concentrations secreted from C. difficile isolates were measured by the RTCA. The results from the CDC (490.00 ± 133.29 ng/mL) and the CDI group (439.82 ± 114.66 ng/mL) showed no significant difference (p = 0.448). Notably, RTCA-measured functional and toxical TcdB concentration was significantly decreased when mixed with pooled CDC samples supernatant (p = 0.030). Conclusion This study explored the novel application of the RTCA assay in effectively discerning clinical CDI from CDC cases.
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Affiliation(s)
- Yuhang Shen
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
- Institute of Ageing Research, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China
| | - Shan Lin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Peijun You
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Yu Chen
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Yun Luo
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Xiaojun Song
- Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People’s Hospital, Hangzhou Medical College, Hangzhou, China
| | - Yunbo Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Dazhi Jin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
- Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People’s Hospital, Hangzhou Medical College, Hangzhou, China
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Elfassy A, Kalina WV, French R, Nguyen H, Tan C, Sebastian S, Wilcox MH, Davies K, Kutzler MA, Jansen KU, Anderson A, Pride MW. Development and clinical validation of an automated cell cytotoxicity neutralization assay for detecting Clostridioides difficile toxins in clinically relevant stools samples. Anaerobe 2021; 71:102415. [PMID: 34298152 DOI: 10.1016/j.anaerobe.2021.102415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 01/05/2023]
Abstract
OBJECTIVES To improve the diagnostic accuracy of Clostridioides difficile infection, current U.S. and E.U. guidelines recommend multistep testing that detects the presence of C. difficile and toxin in clinically relevant stool samples to confirm active disease. An accepted gold standard to detect C. difficile toxins is the cell cytotoxicity neutralization assay (CCNA). Although highly sensitive, the traditional CCNA has limitations. One such limitation is the subjective interpretation of an analyst to recognize cytopathic effects in cultured cells exposed to a fecal sample containing toxin. To overcome this limitation, an automated CCNA was developed that replaces most human pipetting steps with robotics and incorporates CellTiterGlo® for a semi-quantitative, non-subjective measure of cell viability instead of microscopy. METHODS To determine sample positivity and control for non-specific cytopathic effects, two thresholds were defined and validated by evaluating the sample with/without antitoxin antisera (sample-antitoxin/sample + antitoxin): 1) a >70% cell viability threshold was validated with samples containing anti-toxin, and 2) a >1.2-fold difference cut-off where sample results above the cut-off are considered positive. RESULTS Assay validation demonstrated excellent accuracy, precision, and sample linearity with an LOD of 126.9 pg/mL toxin-B in stool. The positivity cut-offs were clinically validated by comparing 322 diarrheal stool sample results with those run in a predicate, microscopic readout-based CCNA. The automated CCNA demonstrated 96% sensitivity and 100% specificity compared with the predicate CCNA. CONCLUSIONS Overall, the automated CCNA provides a specific, sensitive, and reproducible tool to support determination of CDI epidemiology or the efficacy of interventions such as vaccines.
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Affiliation(s)
- Arik Elfassy
- Pfizer Vaccines Research and Development, Pearl River, NY, USA; Current Affiliation: Elusys Therapeutics, Parsippany, NJ, USA
| | - Warren V Kalina
- Pfizer Vaccines Research and Development, Pearl River, NY, USA
| | - Roger French
- Pfizer Vaccines Research and Development, Pearl River, NY, USA
| | - Ha Nguyen
- Pfizer Vaccines Research and Development, Pearl River, NY, USA
| | - Charles Tan
- Pfizer Vaccines Research and Development, Pearl River, NY, USA
| | - Shite Sebastian
- Pfizer Vaccines Research and Development, Pearl River, NY, USA; Current Affiliation: Affinivax, Lexington, MA, USA
| | - Mark H Wilcox
- Leeds Teaching Hospitals NHS Trust and University of Leeds, Leeds, United Kingdom
| | - Kerrie Davies
- Leeds Teaching Hospitals NHS Trust and University of Leeds, Leeds, United Kingdom
| | | | | | | | - Michael W Pride
- Pfizer Vaccines Research and Development, Pearl River, NY, USA.
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Lai H, Huang C, Cai J, Ye J, She J, Zheng Y, Wang L, Wei Y, Fang W, Wang X, Tang YW, Luo Y, Jin D. Simultaneous detection and characterization of toxigenic Clostridium difficile directly from clinical stool specimens. Front Med 2017; 12:196-205. [PMID: 29058256 DOI: 10.1007/s11684-017-0560-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 05/17/2017] [Indexed: 02/08/2023]
Abstract
We employed a multiplex polymerase chain reaction (PCR) coupled with capillary electrophoresis (mPCR-CE) targeting six Clostridium difficile genes, including tpi, tcdA, tcdB, cdtA, cdtB, and a deletion in tcdC for simultaneous detection and characterization of toxigenic C. difficile directly from fecal specimens. The mPCR-CE had a limit of detection of 10 colony-forming units per reaction with no cross-reactions with other related bacterial genes. Clinical validation was performed on 354 consecutively collected stool specimens from patients with suspected C. difficile infection and 45 isolates. The results were compared with a reference standard combined with BD MAX Cdiff, real-time cell analysis assay (RTCA), and mPCR-CE. The toxigenic C. difficile species were detected in 36 isolates and 45 stool specimens by the mPCR-CE, which provided a positive rate of 20.3% (81/399). The mPCR-CE had a specificity of 97.2% and a sensitivity of 96.0%, which was higher than RTCA (x2 = 5.67, P = 0.017) but lower than BD MAX Cdiff (P = 0.245). Among the 45 strains, 44 (97.8%) were determined as nonribotype 027 by the mPCR-CE, which was fully agreed with PCR ribotyping. Even though ribotypes 017 (n = 8, 17.8%), 001 (n = 6, 13.3%), and 012 (n = 7, 15.6%) were predominant in this region, ribotype 027 was an important genotype monitored routinely. The mPCR-CE provided an alternative diagnosis tool for the simultaneous detection of toxigenic C. difficile in stool and potentially differentiated between RT027 and non-RT027.
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Affiliation(s)
- Hanjiang Lai
- The First People's Hospital of Xiaoshan District, Hangzhou, 311021, China
| | - Chen Huang
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Jian Cai
- Department of Disease Control and Prevention, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Julian Ye
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China
| | - Jun She
- The First People's Hospital of Xiaoshan District, Hangzhou, 311021, China
| | - Yi Zheng
- Biotherapy Center for Medical Oncology, the First Affiliated Hospital, Zhejiang University, Hangzhou, 310003, China
| | - Liqian Wang
- Department of Laboratory Medicine, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Yelin Wei
- The First People's Hospital of Xiaoshan District, Hangzhou, 311021, China
| | - Weijia Fang
- Biotherapy Center for Medical Oncology, the First Affiliated Hospital, Zhejiang University, Hangzhou, 310003, China
| | - Xianjun Wang
- Department of Laboratory Medicine, Hangzhou First People's Hospital, Hangzhou, 310006, China
| | - Yi-Wei Tang
- Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.,Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Yun Luo
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China.
| | - Dazhi Jin
- Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051, China.
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Monitoring in real time the cytotoxic effect of Clostridium difficile upon the intestinal epithelial cell line HT29. J Microbiol Methods 2015; 119:66-73. [PMID: 26436983 DOI: 10.1016/j.mimet.2015.09.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 09/29/2015] [Accepted: 09/29/2015] [Indexed: 01/05/2023]
Abstract
The incidence and severity of Clostridium difficile infections (CDI) has been increased not only among hospitalized patients, but also in healthy individuals traditionally considered as low risk population. Current treatment of CDI involves the use of antibiotics to eliminate the pathogen, although recurrent relapses have also been reported. For this reason, the search of new antimicrobials is a very active area of research. The strategy to use inhibitors of toxin's activity has however been less explored in spite of being a promising option. In this regard, the lack of fast and reliable in vitro screening methods to search for novel anti-toxin drugs has hampered this approach. The aim of the current study was to develop a method to monitor in real time the cytotoxicity of C. difficile upon the human colonocyte-like HT29 line, since epithelial intestinal cells are the primary targets of the toxins. The label-free, impedance based RCTA (real time cell analyser) technology was used to follow overtime the behaviour of HT29 in response to C. difficile LMG21717 producing both A and B toxins. Results obtained showed that the selection of the medium to grow the pathogen had a great influence in obtaining toxigenic supernatants, given that some culture media avoided the release of the toxins. A cytotoxic dose- and time-dependent effect of the supernatant obtained from GAM medium upon HT29 and Caco2 cells was detected. The sigmoid-curve fit of data obtained with HT29 allowed the calculation of different toxicological parameters, such as EC50 and LOAEL values. Finally, the modification in the behaviour of HT29 reordered in the RTCA was correlated with the cell rounding effect, typically induced by these toxins, visualized by time-lapsed captures using an optical microscope. Therefore, this RTCA method developed to test cytotoxicity kinetics of C. difficile supernatants upon IEC could be a valuable in vitro model for the screening of new anti-CDI agents.
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