SULFUR BACTERIA

Sulfur Bacteria

Sulfur Bacteria

Introduction

Mycobacterium tuberculosis is a slow-growing facultative intracellular parasite. During infection it is exposed to many different environmental conditions depending on the stage and the severity of the disease. It is able to multiply inside the macrophage phagosome, in which the environment is generally hostile for most bacteria. It can also replicate extracellularly in the open lung cavities that are found during the late stages of the disease (Dannenberg and Rook, 1994). M. tuberculosis can spread to other tissues or organs such as lymph nodes, bones, joints, skin, the central nervous system, the urinary tract and the abdomen, or it can give a disseminated form of disease (miliary tuberculosis) (Grange, 1996). The host immune response to M. tuberculosis initially involves the recruitment of activated macrophages to the site of infection in the lung where they can form a tuberculous granuloma that serves to delimit the infection. Bacteria trapped in the granuloma face a hostile environment that becomes anoxic and rich in toxic fatty acids (Dannenberg and Rook, 1994; Grange, 1996). M. tuberculosis under these conditions has been postulated to assume a dormant status in which it can remain viable for years without causing observable disease (Wayne, 1994). A subsequent failure of the immune system of the host may permit its emergence from this dormant status, resulting in reactivation of the latent disease. The necessity to adapt to different environments and the possibility of entering a dormant status suggest a major role for the regulation of gene expression in the pathogen city of M. tuberculosis. However, as a result of its slow growth rate and the lack of genetic tools, little is known about gene regulation in this important pathogen.

Introduction

Some medical plants have been used for a wide variety of purposes such as food preservation, pharmaceutical, alternative medicine, and natural therapies for many thousands of years. It is generally considered that compounds produced naturally, rather than synthetically, will be biodegraded more easily and therefore be more environmentally acceptable.In recent years, multiple drug resistance in both human and plant pathogenic microorganisms have been developed due to the indiscriminate use of commercial antimicrobial drugs commonly used in the treatment of infectious diseases (Davis, 1994; Service, 1995). In order to find new therapeutic agents, plants that have antimicrobial activity have attracted attention (Kalemba and Kunika, 2003; Juliani and Simson, 2002; Falerio et al., 2003).

Materials and Methods

Plant material

Ocimum basilicum L. (voucher No. 1281) was selected as a test plant. Fresh plants of O. basilicum were collected from Van (Turkey) during June-September of 2004. These plants were identified and preserved at Yuzuncuyil University, Faculty of Agriculture, Department of Plant Protection, and then all plants were airdried.

Preparation of plant extracts

To prepare plant extracts three different solvents were used. Dried leaves of plants were mechanically ground, and 2 g of plant was extracted with 20 ml of acetone or chloroform or methanol, then it was gently heated. Upon heating, it was rinsed for 24 h at room temperature. Then the extracts were filtered using Whitman filter paper ...