Seasonal dynamics of tetracycline resistance gene transport in the Sumas River agricultural watershed of British Columbia, Canada

Abstract

Environmental transport of contaminants that can influence the development of antibiotic resistance in bacteria is an important concern in the management of ecological and human health risks. Agricultural regions are locales where practices linked to food crop and livestock production can introduce contaminants that could alter the selective pressures for the development of antibiotic resistance in microbiota. This is important in regions where the use of animal manure or municipal biosolids as waste and/or fertilizer could influence selection for antibiotic resistance in pathogenic bacterial species. To investigate the environmental transport of contaminants that could lead to the development of antibiotic resistance in bacteria, a watershed with one of the highest levels of intensity of agricultural activity in Canada was studied; the Sumas River located 60 km east of Vancouver, British Columbia. This two-year assessment monitored four selected tetracycline resistance genes (tet(O), tet(M), tet(Q), tet(W)) and water quality parameters (temperature, specific conductivity, turbidity, suspended solids, nitrate, phosphate and chloride) at eight locations across the watershed. The tetracycline resistance genes (Tc) abundances in the Sumas River network ranged between 1.47 × 10 and 3.49 × 10 copies/mL and ranged between 2.3 and 6.9 copies/mL in a control stream (located far from agricultural activities) for the duration of the study. Further, Tc abundances that were detected in the wet season months ranged between 1.3 × 10 and 2.29 × 10 copies/mL compared with dry season months (ranging between 0.6 and 31.2 copies/mL). Highest transport rates between 1.67 × 10 and 1.16 × 10 copies/s were observed in November 2005 during periods of high rainfall. The study showed that elevated concentrations of antibiotic resistance genes in the order of 10-10 copies/mL can move through stream networks in an agricultural watershed but seasonal variations strongly influenced specific transport patterns of these genes.

Occurrence and distribution of antibiotic resistance genes in the water and sediments of Qingcaosha Reservoir, Shanghai, China

“…The differences among the three tetracycline resistance genes might be caused by different patterns of tetracycline antibiotic usage and different compositions of microflora [42]. Tetracycline resistance genes have been found to be among the most common ARGs in aquatic environments [43,44]. The levels of tetracycline resistance genes were lower than those of Tai Lake [45], but they were in agreement with those detected in the Huangpu River [41].…”

Genomic Analysis of Third Generation Cephalosporin Resistant Escherichia coli from Dairy Cow Manure

“…As reported in several previous studies, manure generated by dairy cattle may contain potentially harmful antibiotic resistant E. coli [ 36 , 37 , 38 ]. The emergence and spread of ESBL-producing E. coli associated with dairy cattle manure are of particular concern [ 39 , 40 , 41 , 42 , 43 ].…”

Seasonality ofClostridium difficilein the natural environment

“…For some bacteria, such as Streptococcus pneumoniae and Escherichia coli, seasonality in drug resistance has been explained by the fact that there are also fluctuations in antibiotic use, which is especially high during the winter months (Sun, Klein, & Laxminarayan, ; Dagan et al, ). However, in the environment it has recently been reported that seasonal variations strongly influence specific transport patterns of tetracycline resistance genes (Keen, Knapp, Hall, & Graham, ). Therefore, the results of the present study highlight the need for further investigations in this area.…”