Medical and Clinical Microbiology

Biography

Biography: Dr.Virendra Kumar

Abstract

The nanoparticles of new age drugs can combat conditions to fight human pathogens like bacteria. The development of new resistant strains of bacteria to current antibiotics has become a serious problem in public health; therefore, there is a strong incentive to develop new bactericides. Bacterial biofilms are often associated with  infections specially with medical implants such as catheters and other medical devices. In the natural world more than 99% of bacteria exist as biofilms and according to NIH report more then  68% of all human infections are associated with  biofilms formation. Biofilms are found almost everywhere in nature, including soil, water pipes, and even inside the human body. Attachment of mycobacteria involved in biofilm formation in the liquid air interface is a complex process, with many variables such as pH, nutrient levels, iron, oxygen, ionic strength and temperature, affecting the outcome.

We had taken four mycobacterial species for study of Mycobacterial biofilm. The isolates were subcultured and characterized biochemically and molecularly. The large quantity of biofilm was produced by M.smegmatis at temperature 37^oC and 42 ⁰C as compared to 30⁰C. M. fortuitum developed more amount of biofilm at 30^oC as compared to 37^oC and 42^oC. M.avium developed strong amount of biofilm at 30^oC and 42^oC  as compared to 37⁰C. M tuberculosis (H37Rv) developed strong biofilm at 37 ⁰C  and no biofilm at 30⁰C and 42⁰C in MB 7H9 media and Sauton’s media. The selected non tuberculosis mycobacteria  and  H37Rv developed strong biofilm in the presence of OADC enrichment in MB7H9   as well as Sauton’s medium. Antibiotic susceptibility of biofilms at ultrastructural level was also studied in fast growing clinical isolates M. smegmatis in presence of  Streptomycin, Isoniazid Rifampicin, Ethambutol and Pyrazinamide. Electron microscopy revealed that control (no drug) biofilms consisted primarily of bacterial clusters a mid fibrillar elements. Isoniazid showed strong inhibited  biofilm in fast grower and sensitive isolates. However, Pyrazinamide and Isoniazid  inhibited  biofilm of M.tuberculosis (H37Rv) and in MDR isolates Ethionamide and Moxifloxacin inhibited biofilm in slow grower and fast grower Mycobacteria. However, many  mycobacterial species are known to form biofilms, little is known about either  the genetic requirements, patterns of gene expression. In micro array hybridisation we have found that six genes were expressed in M.avium.  In M. tuberculosis MDR isolates seven genes were expressed and two genes Rv0359 and Rv3526 were homologus as earlier reported in  P. areuginosa and M. avium  which might be responsible for biofilm formation.