Contamination of Agricultural Soils in Some Baghdad Areas with Antibiotics Resistant Pathogenic Fecal Bacteria

Abstract

Background: Early studies have shown that agricultural soil contains various types of microorganisms, especially bacteria, including coliform bacteria (Salmonella, Shigella, Klebsiella, Escherichia coli, and Enterobacter) with fecal Gram-positive bacteria like Enterococcus faecalis. Therefore, the current study aimed to investigate the contamination of Iraqi agricultural soils with pathogenic fecal bacteria (Escherichia coli and Enterococcus faecalis) and study the antibiotic sensitivity patterns of soil-isolated bacteria because it is a dangerous indicator when transmitted to humans. Methods: Soil samples were collected from six locations (farms) in the capital, Baghdad, which were AL-Jadria, AL-Latifia, Diyala River, AL-Jazera, and AL-Zafraniya (block 1 and block 2) during the study period from the end of November 2021 to August 2022; then were compared with the control samples (house garden). These bacteria were isolated by selective culture media and identified using the VITEK® 2 Compact system, and antibiotic sensitivity tests were carried out against 18 different antibiotics by the Kirby Power method. The t-test was used for the statistical analysis. Results: The bacteriological study of agricultural soil showed the presence of fecal bacteria, and this is evidence of contamination of agricultural soil samples with these bacteria. The highest E. coli count was in the AL-Latifia farm (1. 48× 103), while the highest E. faecalis count was in the Diyala River farm (2.63 × 103). The antibiotic sensitivity profile illustrated that E. coli was resistant to ampicillin, ceftriaxone, cefoxitin, piperacillin, ceftazidime, and Teicoplanin but was sensitive to the rest of the antibiotics used, while E. faecalis was only resistant to levofloxacin and linezolid and highly sensitive to the other tested antibiotics. Conclusion: The current study documented the presence of fecal coliform bacteria in studied soil samples, with markedly high resistance rates toward used antibiotics. These facts might be the result of irrigation with sewage water and the use of organic fertilizers Received:March 2023 Accepted: May 2023 Published: Oct. 2023