Legionella micdadei ( L. micdadei ), a less frequently reported sub-type of Legionella , poses a diagnostic challenge due to its fastidious growth. Legionella infections represent a significant public health concern. Traditional culture-based methods for the detection of Legionella species in water systems are often time-consuming and exhibit limited sensitivity, especially in samples containing competing microbial flora that can inhibit the growth of Legionella during cultivation. In this study, we report the development of an electrochemical aptasensor for the rapid and efficient detection of Legionella micdadei . First, 8 aptamers were identified via cell-SELEX (Systematic Evolution of Ligands by Exponential Enrichment) to bind L. micdadei . The aptamer A40 exhibiting the best affinity with the dissociation constant of 28.26 nM was employed in the fabrication of the electrochemical biosensor. Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the aptasensor fabrication steps, while the specific binding interaction between the aptamer A40 and L. micdadei was monitored using differential pulse voltammetry. The developed sensor demonstrated excellent performance within the wide linear range of 10 to 10 6 CFU/mL, and a low detection limit of 19.95 CFU/mL. The aptasensor also showed good selectivity against other bacterial strains, including Legionella pneumophila serogroup 1, Fluoribacter bozemanae , Fluoribacter dumoffii, Escherichia coli, and Staphylococcus aureus . To validate the practical applicability of our technique, the developed aptasensor was tested in water samples spiked with varying concentrations of L. micdadei , showing excellent recovery rates close to 100%. • Legionella micdadei ( L. micdadei ) poses a diagnostic challenge due to its fastidious growth. Legionella infections represent a significant public health concern. • Eight aptamers sequences were selected using SELEX. The aptamer A40 exhibiting the best affinity with the dissociation constant of 28.26 nM. • Electrochemical aptasensor was developed for the rapid and efficient detection of Legionella micdadei . • The developed sensor demonstrated excellent performance within the wide linear range of 10 to 10 6 CFU/mL. and a low detection limit of 10 CFU/mL. • The aptasensor also showed good selectivity against other bacterial strains, including Legionella pneumophila serogroup 1, Fluoribacter bozemanae , and Fluoribacter dumoffii . • The developed sensor was validated using spiked water samples spiked with varying concentrations of L. micdadei , showing excellent recovery rates close to 100%.
Shaukat et al. (Sun,) studied this question.