Antibiotic-resistant E. coli in surface water and groundwater in dairy operations in Northern California

Abstract

Generic Escherichia coli was isolated from surface water and groundwater samples from two dairies in Northern California and tested for susceptibility to antibiotics. Surface samples were collected from flush water, lagoon water, and manure solids, and groundwater samples were collected from monitoring wells. Although E. coli was ubiquitous in surface samples with concentrations ranging from several hundred thousand to over a million colony-forming units per 100 mL of surface water or per gram of surface solids, groundwater under the influence of these high surface microbial loadings had substantially fewer bacteria (3- to 7-log10 reduction). Among 80 isolates of E. coli tested, 34 (42.5%) were resistant to one or more antibiotics and 22 (27.5%) were multi-antibiotic resistant (resistant to ≥3 antibiotics), with resistance to tetracycline, cefoxitin, amoxicillin/clavulanic acid, and ampicillin being the most common. E. coli isolates from the calf hutch area exhibited the highest levels of multi-antibiotic resistance, much higher than isolates in surface soil solids from heifer and cow pens, flush alleys, manure storage lagoons, and irrigated fields. Among E. coli isolates from four groundwater samples, only one sample exhibited resistance to ceftriaxone, chloramphenicol, and tetracycline, indicating the potential of groundwater contamination with antibiotic-resistant bacteria from dairy operations.

Multi-Drug Resistance Pattern of Escherichia coli Isolated from Hospital Effluent and Determination of Tetracycline Resistance Gene

“…The findings of present study is supported by Li et al (2014) and Blaak et al (2014) who stated almost similar prevalence of E. coli in dairy waste water and recreational water. E. coli, isolated from hospital effluent showed highest resistance (ranging from 66% to 100%) against amoxicillin, cephalothin, tetracycline, sulphamethoxazole-trimethoprim, ceftriaxone, nalidixic acid and enrofloxacin.…”

“…The study revealed that the percentage of E. coli in untreated hospital effluent was 100%. Many of the previous studies indicated that the prevalence of E. coli varies widely based on type of environmental samples and it was ranging from 44% to 100% in different environmental samples such as sewage, sludge, recreational water, dairy surface water and ground water (Anastasi et al, 2010;Li et al, 2014;Blaak et al, 2014).…”

“…About 10 (from 6 different groups) anti-microbial agents (Table 1) of public health interest were selected for cultural sensitivity (CS) testing. E. coli isolates showing resistance against at least three groups of anti-microbial agents (≥3) were defined as multi-drug resistant (MDR) isolates (Li et al, 2014). …”

Fate and Removal of Pharmaceuticals and Illegal Drugs Present in Drinking Water and Wastewater

“…coli strains isolated from surface and ground water in Northern California showed resistance towards tetracyclines, chloramphenicol, ampicillin and amoxicillin [15].…”

Antibiotic resistance and virulence genes in coliform water isolates

“…However, widespread application of antibiotics in human and veterinary medicine has led to the emergence, selection, and dissemination of antibiotic resistant bacteria and genes encoding for antibiotic resistance in different environmental compartments such as surface water (Zhang et al, 2015;Stoll et al, 2012), groundwater (Li et al, 2014), drinking water (Schwartz et al, 2003;Guo et al, 2014) and sediments (Rosas et al, 2015) throughout the world. Antibiotic resistance genes (ARGs) and virulence genes (VGs) are emerging environmental contaminants (Pruden et al, 2006;Haack et al, 2009).…”