Class 1 Integrons, Selected Virulence Genes, and Antibiotic Resistance in Escherichia coli Isolates from the Minjiang River, Fujian Province, China

Abstract

Widespread fecal pollution of surface waters in developing countries is a threat to public health and may represent a significant pathway for the global dissemination of antibiotic resistance. The Minjiang River drainage basin in Fujian Province is one of China's most intensive livestock and poultry production areas and is home to several million people. In the study reported here, Escherichia coli isolates (n ‫؍‬ 2,788) were sampled (2007 and 2008) from seven surface water locations in the basin and evaluated by PCR for carriage of selected genes encoding virulence factors, primarily for swine disease. A subset of isolates (n ‫؍‬ 500) were evaluated by PCR for the distribution and characteristics of class 1 integrons, and a subset of these (n ‫؍‬ 200) were evaluated phenotypically for resistance to a range of antibiotics. A total of 666 (24%) E. coli isolates carried at least one of the virulence genes elt, fedA, astA, fasA, estA, stx 2e , paa, and sepA. Forty-one percent of the isolates harbored class 1 integrons, and these isolates had a significantly higher probability of resistance to tobramycin, cefoperazone, cefazolin, ciprofloxacin, norfloxacin, azitromycin, and rifampin than isolates with no class 1 integron detected. Frequencies of resistance to selected antibiotics were as high as or higher than those in fecal, wastewater, and clinical isolates in published surveys undertaken in China, North America, and Europe. Overall, E. coli in the Minjiang River drainage basin carry attributes with public health significance at very high frequency, and these data provide a powerful rationale for investment in source water protection strategies in this important agricultural and urban setting in China.

Antibiotic resistance and virulence genes in coliform water isolates

“…A similar incidence of class 1 integrons in E. coli isolated from wastewater (9.6 %), and surface water of the River Seine, France (11 %) and surface water of the Rio Grande, Mexico (13 %) have been reported previously (Laroche et al, 2009;Ferreira da Silva et al, 2007;Roe et al, 2003). In a study form China, a higher occurrence of class 1 integrons in E. coli isolated from Minjiang River (41 %) was reported however, the authors concluded that the high frequency was probably due to the widespread use of numerous antimicrobial agents in human therapy, livestock, poultry, and fish production in the study area (Chen et al, 2011). High prevalence of E. coli isolates carrying integrons in surface water from China has been reported in a number of studies.…”

“…Frequent detection of potential EPEC strains from contaminated marine recreational water in Avalon Bay, California USA has also reported (Hamilton et al, 2010). In another study, about a quarter of the E. coli isolated from Minjiang River in China carried at least one of the 11 virulence genes evaluated (Chen et al, 2011). Similarly, presence of EPEC, EAEC, EIEC, EHEC and ETEC pathotypes has also been reported in sub-tropical surface water collected in Brisbane, Australia (Sidhu et al, 2013).…”

“…Out of these nine isolates, five could be allocated to the phylogenetic groups B2 and D (noncommensal (Sidhu et al, 2013;Chen et al, 2011;Hamilton et al, 2010;Koczura et al, 2013). Antibiotic resistant shiga toxin producing E. coli (STEC) and ETEC were detected in surface water samples from River Ganga and River Gomti in India (Ram et al, 2008).…”

Impact of Manure Fertilization on the Abundance of Antibiotic-Resistant Bacteria and Frequency of Detection of Antibiotic Resistance Genes in Soil and on Vegetables at Harvest

“…The abundance, types of resistance, and distribution of resistance in populations of commensal and pathogenic bacteria vary enormously, no doubt due to varied factors, in particular exposure of the enteric flora to antibiotics in human medicine or as commonly employed in commercial animal production (9,10). Emissions of antibiotic residues and resistant bacteria from various human activities, including animal production, fish production, wastewater treatment, and antibiotic manufacturing, will increase the burden of antibiotic resistance in exposed environmental matrices (11)(12)(13)(14)(15)(16). The abundance and the mobility of antibiotic resistance genes in agricultural soils may be enhanced by various management practices, for example, the application of animal manures, wastewater, or waste treatment residues that contain antibiotic resistance genes on mobile elements and antibiotic residues (17)(18)(19)(20).…”

Water quality and antibiotic resistance at beaches of the Galápagos Islands

“…The guidelines were established based on testing of clinical isolates however there are no equivalent standards for environmental isolates. Furthermore, using these standards allows for comparison to other published papers that report results of resistance analysis, including other papers that test environmental E. coli (Reinthaler et al, 2003;Chen et al, 2011;Holvoet et al, 2013;Skariyachan et al, 2015). Five classes of antibiotics commonly used in human medicine were included in the antibiotic resistance testing, including beta-lactams (ampicillin, 10 µg), fluoroquinolones (ciprofloxacin, 5 µg), aminoglycosides (gentamicin, 10 µg), tetracyclines (tetracycline, 30 µg), and sulfonamides (trimethoprim/sulfamethoxazole, 1.25/23.75 µg).…”