Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Antibiotic Resistance Profiles of Enterobacteria Isolated from Küçükçekmece Lagoon (İstanbul)

The Kucukcekmece Lagoon is situated in the western part of the city of Istanbul mapping reference 41 º 00΄ N- 28 º 43΄ E. The lagoon is connected to the Marmara Sea via a narrow channel. Despite this connection, the lagoon’s main water sources are underground spring water, several ephemeral brooks and three nutrient-rich streams (Sazlıdere, Ispartakule and Nakkas). Therefore, the lagoon has been subjected to heavy nutrient inputs because of poor sanitary treatment of wastewater associated with human population growth around the lake.

Samples were taken monthly from June 2006 to April 2008 on clear and bright days. A number of samplings were taken from the lagoon to analyze the presence of the most common species of the Enterobacteriaceae family. Ten water samples were taken in total, five water samples were taken from the surface at the junction point between the stream and the lagoon. The other five samples were taken from various points within the Lagoon and from the surface and different depths (50 cm, 1 m, 5 m, 10 m and occasionally 15 m).

One of the studies focuses on the Enterobacteriaceae family, their density (with DAFOR scale) and the bacteriological pollutions, together with their threat over human health. In addition, some physico-chemical data are discussed. The results achieved from the water samples were not acceptable according to the Water Pollution Control Regulation Standards.

To make a general evaluation, the most intensively apparent species was Escherichia coli, the percentage of this genus was found to be as high as 59, 65% in this study. The second most common species was Citrobacter and the third was Enterobacter, both species were apparent where E. coli was not present; this was expected since they are more resistant than E. coli against environmental conditions. Many researchers also determined the same findings and reached the same results. Therefore E. coli became the most apparent species in such type of streams because they are affected by the anthropogenic pollutants in the stream.

The aim of this study is to find out the density of the fecal bacteria and to check the side effects of the antibiotics as well as the resistance profiles of Enterobacteria isolated from the Kucukcekmece Lagoon samples. With this study, the precaution for the usage of the rational antibiotics will be determined.

Cloramphenicol, Tetrasiclin, Nalidixic Acid, Ampicillin, Imipenem, Ceftazidime, Amicasin, Streptomycin and Amoxicillin+ Clavulonic Acid were used in the antibiogram tests. The antibiotic resistance profile resulted in Enterobacteria being the most resistant against Ampisilin (76,29%) and the most sensitive against Imipenem (6,90%). The same antibiogram test was carried out for E. coli, which has a higher density than the other bacteria, and the result was 62,50% resistant against Ampicillin.

In addition to this study, there is an ongoing investigation about the negative effects of these bacterium groups on coastal ecosystems that reach the sea directly, especially the ability of dissemination and molecular epidemiology of the resistance and virulence genes between related bacterial species such as E. coli, Citrobacter sp. and Enterobacter sp.

Key Words : Antibiotic resistance, Enterobacteriaceae, Antibiogram, Kucukcekmece Lagoon, Istanbul

HAMZA Ethem ,
Danışman : Doç. Dr. Nilgün BALKAYA

Anabilim Dalı : Çevre Mühendisliği

Mezuniyet Yılı : 2008

Tez Savunma Jürisi : Doç. Dr. Nilgün BALKAYA (Danışman)

Prof. Dr. Semiha ARAYICI

Prof. Dr. Enver ÜLGER

Doç. Dr. Gülten GÜRDAĞ

Doç. Dr. Erol ERÇAĞ