Loop-mediated isothermal amplification (LAMP) assay for rapid detection of viable but non-culturable Vibrio cholerae O1.

Vibrio cholerae, an important waterborne pathogen, is a rod-shaped bacterium that naturally exists in aquatic environments. When conditions are unfavorable for growth, the bacterium can undergo morphological and physiological changes to assume a coccoid morphology. This stage in its life cycle is referred to as viable but non-culturable (VBNC) because VBNC cells do not grow on conventional bacteriological culture media. The current study compared polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) to detect and identify VBNC V. cholerae. Because it is difficult to detect and identify VBNC V. cholerae, the results of the current study are useful in showing that LAMP is more sensitive and rapid than PCR in detecting and identifying non-culturable, coccoid forms of V. cholerae. Furthermore, the LAMP method is effective in detecting and identifying very low numbers of coccoid VBNC V. cholerae in environmental water samples, with the added benefit of being inexpensive to perform.

Potential of Bacillus subtilis Against SARS-CoV-2 - A Sustainable Drug Development Perspective.

The COVID-19 pandemic had anomalous yet inevitable impacts on the world's economies, healthcare systems, and all other aspects of life. Researchers began to uncover hidden routes to find a new horizon of hope using underrated resources. Biosurfactants are sustainable biomolecules with an active surface, unique characteristics, and extensive uses. Bacillus species showed the highest amount of biosurfactant activities and Bacillus subtilis is one of them. The antiviral, antimicrobial, and anti-inflammatory activity of B. subtilis was proven recently. The great advantage is its non-toxic nature. Pro-inflammatory cytokines including IL-1 ß, 6, 8, 12, 18, and TNF-(α are secreted in higher amounts when neutrophils and monocytes are triggered by biosurfactant bacteria. This point of view furnishes the potential application of B. subtilis and its biomolecules against COVID-19, either in the form of a vaccine/therapeutic agent, for a greener environment, healthier life, and environmental sustainability. Further in vivo and clinical trials are needed to validate this hypothesis.

Methods for Detecting the Environmental Coccoid Form of Helicobacter pylori.

Helicobacter pylori is recognized as the most common pathogen to cause gastritis, peptic and duodenal ulcers, and gastric cancer. The organisms are found in two forms: (1) spiral-shaped bacillus and (2) coccoid. H. pylori coccoid form, generally found in the environment, is the transformed form of the normal spiral-shaped bacillus after exposed to water or adverse environmental conditions such as exposure to sub-inhibitory concentrations of antimicrobial agents. The putative infectious capability and the viability of H. pylori under environmental conditions are controversial. This disagreement is partially due to the fact of lack in detecting the coccoid form of H. pylori in the environment. Accurate and effective detection methods of H. pylori will lead to rapid treatment and disinfection, and less human health damages and reduction in health care costs. In this review, we provide a brief introduction to H. pylori environmental coccoid forms, their transmission, and detection methods. We further discuss the use of these detection methods including their accuracy and efficiency.

Three Tests Used to Identify Non-Culturable Form of Helicobacter pylori in Water Samples.

BACKGROUND: Helicobacter pylori, causing the most common chronic bacterial infection, exist in two forms; bacilli and coccoid. The coccoid form is identified as viable but non-culturable bacteria. OBJECTIVES: The current study aimed to conduct culture, polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP) tests to identify coccoid forms of H. pylori. MATERIALS AND METHODS: The PCR and LAMP tests were optimized using specific primers for glmM gene. The sensitivity and specificity of the tests were determined. The current experimental study was conducted on 10 different strains isolated from clinical cases (H1-H10). The isolates were added to tap water and incubated at three different temperatures for one and two months intervals. After pure-culturing of the bacteria, DNAs were extracted and PCR and LAMP were performed. RESULTS: Ten copies of targeted DNA were required for PCR detection whereas only five copies gave a positive reaction by LAMP assay, with 100% specificity. Of the 10 isolates inoculated in water for one and two months at three different temperatures 4, 22, and 37°C, only three cases (5%) were found positive in the first month; 13 (21.6%) and 29 cases (48.3%) were also positive by PCR and LAMP tests in the first and second months. CONCLUSIONS: Results of the current study confirmed that molecular methods such as PCR and LAMP were much more sensitive, rapid, and specific than culturing to identify non-culturable coccoid forms of H. pylori in water.