Occurrence of antibiotic resistant bacteria and resistance genes in agricultural irrigation waters from Valencia city (Spain)

[EN] The increasing use of antibiotics has become one of the main environmental and health problems today, worldwide. In addition to causing toxic effects on non-targeted organisms, their presence in the environment promotes the horizontal transfer of resistance genes, thus increasing the presence of resistant bacteria in the environment and, consequently, the risk of super-resistant bacterial infections. In the present work, we have investigated the occurrence of antibiotic-resistant E. coli and genes (blaTEM, qnrS, tetW, sulI and ermB) in surface water samples from different agricultural irrigation ditches located around Valencia city (Spain). Results of the research showed the presence of antibiotic resistance genes in all the analysed samples with mean percentages of 100% for tetW, 96% for blaTEM, 80% for sulI, 72% for qnrS and ermB in 60% of samples. The higher antibiotic resistance rates were detected in the samples whose waters had more contact with human or animal activities. Our study detected a high proportion (79.2%) of multi-resistant E. coli isolates, which presented a total of 26 multi-resistance patterns. The high levels of antibiotic resistances in irrigation waters observed in this work could help to both, better understanding and management, of the contamination caused by antibiotics and related resistance genes in agricultural environments, in order to implement appropriate measures for control. Moreover, appropriate surveillance of the quality of these waters as well as developing sanitation techniques are necessary to decrease antibiotic resistance rates in irrigation water in our geographical area.This work was supported by the Ministerio de Ciencia e Innovacion, Spain, (Project: PID2019-105691RB-I00) .Amato, M.; Dasí, D.; González Pellicer, A.; Ferrús Pérez, MA.; Castillo López, M. (2021). Occurrence of antibiotic resistant bacteria and resistance genes in agricultural irrigation waters from Valencia city (Spain). Agricultural Water Management. 256:1-10. https://doi.org/10.1016/j.agwat.2021.10709711025

Antibiotic Resistance in Seawater Samples from East Coast of Spain

[EN] Seawater has been proposed as a reservoir for antibiotic-resistant bacteria and antibiotic resistance genes, thus representing a risk to public health. In this study, we evaluated the presence of antibiotic resistance determinants (bacteria and genes) in 77 seawater samples collected at different points along the coast of the Gulf of Valencia (Spain). Specifically, indicators of fecal contamination bacteria, Escherichia coli and Enterococcus sp., were isolated, and their antibiotic resistance profiles were analyzed through the use of the Sensititre® system, followed by the detection of the main antibiotic resistance genes (blaTEM, qnrS, tetW, sulI, and ermB). The highest frequencies of resistance in the E. coli isolates were detected for ampicillin (35.1%) and ciprofloxacin (17.5%), followed by sulfamethoxazole and trimethoprim (15.7%), while 23% of enterococci isolates showed resistance to a single antibiotic, 20% against tetracycline and 3% against daptomycin. Through PCR analysis, 93% of the E. coli strains showed the blaTEM and sulI resistance genes. Among the enterococci, the presence of the blaTEM gene was detected in 40% of the isolates, while the rest of the genes were present at very low rates. Among the water samples, 57% were positive for at least one of the tested genes, italic format with blaTEM being the most commonly found gene (47%), followed by the qnrS (33%) and sulI (23%) genes. These results show that seawater, in addition to being subjected to a high rate of fecal contamination, can contribute to the spread of antibiotic resistance.This research was funded by CIAICO/2021/149. Generalitat Valenciana (Comunitat Valenciana, Spain).Dasí, D.; Camaró-Sala. Maria Luisa; González Pellicer, A.; García-Ferrús, M.; Jiménez Belenguer, AI.; Castillo López, M. (2024). Antibiotic Resistance in Seawater Samples from East Coast of Spain. Applied Sciences. 14(5). https://doi.org/10.3390/app1405196514

Antibiotic Resistance in Seawater Samples from East Coast of Spain

Seawater has been proposed as a reservoir for antibiotic-resistant bacteria and antibiotic resistance genes, thus representing a risk to public health. In this study, we evaluated the presence of antibiotic resistance determinants (bacteria and genes) in 77 seawater samples collected at different points along the coast of the Gulf of Valencia (Spain). Specifically, indicators of fecal contamination bacteria, Escherichia coli and Enterococcus sp., were isolated, and their antibiotic resistance profiles were analyzed through the use of the Sensititre® system, followed by the detection of the main antibiotic resistance genes (blaTEM, qnrS, tetW, sulI, and ermB). The highest frequencies of resistance in the E. coli isolates were detected for ampicillin (35.1%) and ciprofloxacin (17.5%), followed by sulfamethoxazole and trimethoprim (15.7%), while 23% of enterococci isolates showed resistance to a single antibiotic, 20% against tetracycline and 3% against daptomycin. Through PCR analysis, 93% of the E. coli strains showed the blaTEM and sulI resistance genes. Among the enterococci, the presence of the blaTEM gene was detected in 40% of the isolates, while the rest of the genes were present at very low rates. Among the water samples, 57% were positive for at least one of the tested genes, italic format with blaTEM being the most commonly found gene (47%), followed by the qnrS (33%) and sulI (23%) genes. These results show that seawater, in addition to being subjected to a high rate of fecal contamination, can contribute to the spread of antibiotic resistance