Synthesis of gold nanoparticles conjugated lectin and using it for enhancement the antibacterial activity of lectin purified from Acinetobacter baumannii

Introduction: Lectin was originally called hemagglutinin or agglutinin due to its ability to agglutinate of human and animal erythrocytes. Lectins are heterogeneous group of proteins or glycoproteins of non-immune origin.... [ view full abstract ]

Introduction: Lectin was originally called hemagglutinin or agglutinin due to its ability to agglutinate of human and animal erythrocytes. Lectins are heterogeneous group of proteins or glycoproteins of non-immune origin. These proteins are ubiquitous in nature, and occur in animals, plants, bacteria, viruses, and fungi. Lectin has a wide range of applications in many fields as anti-tumor, anti-insect, antiviral and antifungal drug.  

Methods: Here we reported lectin production from Acinetobacterbaumannii isolated from sewage water by microscopic glass slide and microtiter plate methods and detection the best producer. Lectin was extracted with glass beads method and purified with three steps including ammonium sulfate precipitation, ion exchange chromatography by using DEAE -cellulose column and gel filtration chromatography by sephadex G-150 column. the purified lectin was pulsed with Au nanoparticles by using laser ablation technique to produce Au nanoparticles conjugated lectin. Different UTI causing bacteria were  collected UTI cases from many hospitals in Baghdad city and separately treated with ciprofloxacin as antibiotic disc, purified lectin, Au nanoparticles and Au nanoparticles conjugated lectin for determining their effects as antibacterial agents.

Results and discussion:    In the present study a novel strain, Acinetobacter baumannii W₁₃ isolated from water sewage samples gave the highest production level of lectin by microscopic glass slide and microtiter plate methods. Lectin was purified to homogeneity by using ammonium sulfate at 35% saturation followed by DEAE -cellulose ion exchange chromatography and sephadex G-150 gel filtration chromatography with 45.3 fold of purification  and a yield of 57.1%. Au nanoparticles was prepared by laser ablation and conjugated to lectin by pulses method. The Au nanoparticles  conjugated lectin led to enhancement of  lectin activity against all tested  UTI causing in comparison with ciprofloxacin antibiotic that used for treatment of  UTI infections, where used  it showed high effectiveness against Enterobacter sp. followed by Salmonella sp. and Streptococcus sp. in comparison with the other tested bacteria. So that Au nanoparticles conjugated lectin may be used as a useful antibacterial agent for the treatment of increasing urinary tract infections.