Extraction of Klebsiella pneumoniae and Candida albicans Biofilm and Studying their Cytotoxic Effects on Human Lymphocytes

Abstract

The microbial polymeric biofilm matrix belongs to a single microbial species or multiple microbial species that are directly or indirectly responsible for over 80% of all microbial infections. A six-month laboratory study was conducted to extract the biofilms from Klebsiella pneumoniae and Candida albicans isolates to study their properties and their toxic effects on blood lymph. The results showed that treating 20 samples of K. pneumoniae and 100 samples of C. albicans biofilms with gentamicin and fluconazole antibiotics led to the inhibition of biofilm production for all the studied isolates by 74.9% and 64.32%, respectively. The results of screening electron microscopy (SEM) showed that the diameters of some K. pneumoniae cells ranged from 0.18-0.47 µm, while the diameters of C. albicans cells ranged from 121.82-133.89 nm. Fourier-Transform Infrared Spectroscopy (FTIR) of biofilmrevealed the presence of compounds in the matrix of the biofilm of K. pneumoniae, such as mannans and carboxylate (C=O), indicating the presence of sugar acids, proteins, and hydrocarbons. The results of the analysis of the biofilm produced by C. albicans showed a high percentage of sugars, as well as carboxyl and 2' acetyl. The Biofilm produced by K. pneumoniae inhibited the lymphocytes by 34.8% from the 150 μL sample. The lymphocytes showed higher inhibitory activity against C. albicans alone and against the combined biofilm of C. albicans and K. pneumoniae, where the highest percentage of inhibition reached 74.82% and 69.5% for the two treatments, respectively, at a sample volume of 100 µL. This leads to the conclusion that the biofilms of K. pneumoniae and C. albicans are responsible for over 80% of microbial infections. The use of antibiotics such as gentamicin and fluconazole led to the inhibition of biofilm production by up to 74.9% and 64.32% respectively, indicating the effectiveness of antibiotics in controlling biofilm growth.