Identification of clinically antibiotic resistant genes Aac(3)-IIa and Aac(6’)-Ib in wastewater samples by multiplex PCR

Aminoglycoside antibiotics are widely used in medical centers, particularly to treat infections.
The resistance developed against these agents is a huge concern in health care. A number of researchers have
reported that hospital and municipal wastewaters are among the most important dissemination sources of
these agent into the environment. Some, however, do not agree with this opinion. In the present study, the
prevalence of aminoglycoside resistance genes was investigated in raw and effluent wastewater from hospital
and municipal wastewater treatment plants.
Methods: To conduct this descriptive-analytical study, 30 samples were taken according to sampling principles
and cold cycle and transferred to the molecular laboratory. DNA was extracted by the freeze-thaw method using
a kit (Promega). The genes aac(3)-IIa and aac(6’)-Ib which code aminoglycoside resistance were examined in
this study.
Results: The results indicated that the studied genes are present in 35% of urban and hospital wastewaters, and
their frequency percentage is higher in hospital wastewater (52%) than urban wastewater (48%). The studied
genes were identified in 61% of raw hospital wastewater samples; however, they were not detected in the output
wastewater from the studied treatment plants.
Conclusion: Although, the studied genes were not detected in the final effluent, there is a high potential for
their release into the environment. The current study demonstrated that the coding genes of aminoglycoside
antibiotic resistance are present in raw urban and hospital wastewaters. In the case of improper exploitation of
wastewater treatment plants, the output water can contaminate other environmental sections, such as soil and
water resources, and result in the emission of these contaminants.
Keywords: Antibiotic resistance, Aminoglycosides, Urban and hospital wastewaters
Citation: Samadi N, Aali R, Asgari E, Mirhosaeini H, Shahriari A, Mahmoodi F, et al. Identification of clinically
antibiotic resistant genes Aac(3)-IIa and Aac(6’)-Ib in wastewater samples by multiplex PCR