Objective: To investigate the frequency of integrase genes intI1, intI2 and intI3 of Escherichia coli strains, and their association with resistance to routinely used antibiotics. Methods: A total of 120 Escherichia c...Objective: To investigate the frequency of integrase genes intI1, intI2 and intI3 of Escherichia coli strains, and their association with resistance to routinely used antibiotics. Methods: A total of 120 Escherichia coli strains were collected from patients with urinary tract infection in Ahvaz, Southwest of Iran. Antibiotic susceptibility testing was performed. The presence of intI1, intI2, and intI3 genes was determined by polymerase chain reaction. Results: Antibiotic susceptibility testing disclosed the highest resistance rate to ampicillin (91.7%) followed by trimethoprim/sulfamethoxazole (65.8%), and ceftazidime (56.7%). The imipenem susceptibility rate was 91.7%. IntI1 and intI2 were identified in 74 (61.6%) and 8 (6.6%) of Escherichia coli strains, respectively, but intI3 was not found in any isolates. The presence of integrons was significantly associated with resistance to ampicillin, trimethoprim/sulfamethoxazole, ceftazidime, and ciprofloxacin antibiotics (P<0.05). Conclusions: The high resistant Escherichia coli isolates harboring class 1 integrons (intI1) were detected in patients with urinary tract infection in our region. Therefore, preventive strategies are necessary to restrict further dissemination of resistant strains.展开更多
The coastal area of the East China Sea has experienced rapid urbanization and industrialization in China since 1980 s, resulting in severe pollution of its environments.Antibiotic resistance genes(ARGs) are regarded a...The coastal area of the East China Sea has experienced rapid urbanization and industrialization in China since 1980 s, resulting in severe pollution of its environments.Antibiotic resistance genes(ARGs) are regarded as a kind of emerging pollutant with potential high risk. The sediment samples were collected from Hangzhou Bay(HB),Xiangshan Bay(XB), and Taizhou Bay(TB) to investigate the spatial occurrence and distribution of 27 ARGs and class I integron–integrase gene(intI1) in the coastal area of the East China Sea. The PCR results showed the frequent presence of 11 ARGs and intI1 in the sediments of the three bays. The qPCR results further showed that sulfonamide resistance was the most prevalent ARG type and antibiotic target replacement and protection were the most important resistance mechanisms in the sediments. Regarding the subtype of ARGs, sulI, tetW, and dfrA13 were the most abundant ARGs, in which sulI was higher in TB(based on both the absolute and relative abundances) and dfrA13 was higher in HB(based on the relative abundances). The network analysis revealed that intI1 had significant correlations with tetC, sulI, sulII, and blaPSE-1. Oil was the key connected factor, which had positive connections with sulI, sulII, and blaPSE-1. In addition, the joint effect of heavy metals and nutrients & organic pollutants might be crucial for the fate of ARGs in the coastal sediments.展开更多
文摘Objective: To investigate the frequency of integrase genes intI1, intI2 and intI3 of Escherichia coli strains, and their association with resistance to routinely used antibiotics. Methods: A total of 120 Escherichia coli strains were collected from patients with urinary tract infection in Ahvaz, Southwest of Iran. Antibiotic susceptibility testing was performed. The presence of intI1, intI2, and intI3 genes was determined by polymerase chain reaction. Results: Antibiotic susceptibility testing disclosed the highest resistance rate to ampicillin (91.7%) followed by trimethoprim/sulfamethoxazole (65.8%), and ceftazidime (56.7%). The imipenem susceptibility rate was 91.7%. IntI1 and intI2 were identified in 74 (61.6%) and 8 (6.6%) of Escherichia coli strains, respectively, but intI3 was not found in any isolates. The presence of integrons was significantly associated with resistance to ampicillin, trimethoprim/sulfamethoxazole, ceftazidime, and ciprofloxacin antibiotics (P<0.05). Conclusions: The high resistant Escherichia coli isolates harboring class 1 integrons (intI1) were detected in patients with urinary tract infection in our region. Therefore, preventive strategies are necessary to restrict further dissemination of resistant strains.
基金supported by the National Natural Science Foundation of China(No.51678003)
文摘The coastal area of the East China Sea has experienced rapid urbanization and industrialization in China since 1980 s, resulting in severe pollution of its environments.Antibiotic resistance genes(ARGs) are regarded as a kind of emerging pollutant with potential high risk. The sediment samples were collected from Hangzhou Bay(HB),Xiangshan Bay(XB), and Taizhou Bay(TB) to investigate the spatial occurrence and distribution of 27 ARGs and class I integron–integrase gene(intI1) in the coastal area of the East China Sea. The PCR results showed the frequent presence of 11 ARGs and intI1 in the sediments of the three bays. The qPCR results further showed that sulfonamide resistance was the most prevalent ARG type and antibiotic target replacement and protection were the most important resistance mechanisms in the sediments. Regarding the subtype of ARGs, sulI, tetW, and dfrA13 were the most abundant ARGs, in which sulI was higher in TB(based on both the absolute and relative abundances) and dfrA13 was higher in HB(based on the relative abundances). The network analysis revealed that intI1 had significant correlations with tetC, sulI, sulII, and blaPSE-1. Oil was the key connected factor, which had positive connections with sulI, sulII, and blaPSE-1. In addition, the joint effect of heavy metals and nutrients & organic pollutants might be crucial for the fate of ARGs in the coastal sediments.
