Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Interaction Of Legionella Pneumophila Serogroup 2-14 Strains With Bacteria Sharing The Same Habitat

L. pneumophila is a Gram-negative, aerobic, rod shaped bacteria that causes Legionnaries’ disease. This bacteria frequently inhabits in natural aquatic environment such lakes, rivers, ponds and streams. When they transmit to man made aquatic systems such as cooling tower, shower head, ice machine, nebulizator, jakuzi they colonize because of the suitable conditions. By inhalation of contaminated aerosols they cause infections at human.

Heat of the water system, dead points at water distribution systems and water tanks, the source of nutrient, existence of heterotrophic bacteria and protoza cause poliferation of L. pneumophila in such environment. There are many microorganisms that helps survival and colonisation of Legionella sharing the same habitat with it.

This is clear that ecological balance in water systems is very important for survival of Legionella. Legionella bacteria using aminoacids as carbon and energy source, are differ from other microorganisms because of their essential necessity to L-cysteine and iron (III). Because of this necessity Non-Legionella bacteria are one of the most important reason of Legionella to survive.

In this study, 4 potable water sample, 3 cooling tower water and 3 biofilm sample from cooling tower water tank, totally 10 samples have been collected from 7 different hotels. 24 Non-Legionella bacteria isolated from this samples has been examined as inhibiting or stimulating effect on 2 L. pneumophila SG 2-14 which are isolated from the same samples. It is intended to understand the interactions between Legionella bacteria and Non-Legionella bacteria sharing the same habitat with Legionella by studying bacteria-bacteria and cell-free fluid interactions.

In addition, molecules of cell-free fluid of Non-Legionella bacteria that has inhibitory effect on L. pneumophila SG 2-14 was intended to characterize by enzyme and heat treatment.

Consequently, it is seen that Legionella bacteria and Non-Legionella bacteria sharing the same habitat with Legionella are in contact. The colonisation of Legionella in water systems is dependent on Non-Legionella bacteria and the effect of these bacteria on Legionella differs from species to species. It is seen that after enzyme and heat treatment the inhibitory effect of cell-free fluid of Non-Legionella bacteria loses its activity