Patterns of Antimicrobial Resistance Observed in Escherichia coli Isolates Obtained from Domestic- and Wild-Animal Fecal Samples, Human Septage, and Surface Water

Abstract

A repeated cross-sectional study was conducted to determine the patterns of antimicrobial resistance in 1,286 Escherichia coli strains isolated from human septage, wildlife, domestic animals, farm environments, and surface water in the Red Cedar watershed in Michigan. Isolation and identification of E. coli were done by using enrichment media, selective media, and biochemical tests. Antimicrobial susceptibility testing by the disk diffusion method was conducted for neomycin, gentamicin, streptomycin, chloramphenicol, ofloxacin, trimethoprim-sulfamethoxazole, tetracycline, ampicillin, nalidixic acid, nitrofurantoin, cephalothin, and sulfisoxazole. Resistance to at least one antimicrobial agent was demonstrated in isolates from livestock, companion animals, human septage, wildlife, and surface water. In general, E. coli isolates from domestic species showed resistance to the largest number of antimicrobial agents compared to isolates from human septage, wildlife, and surface water. The agents to which resistance was demonstrated most frequently were tetracycline, cephalothin, sulfisoxazole, and streptomycin. There were similarities in the patterns of resistance in fecal samples and farm environment samples by animal, and the levels of cephalothin-resistant isolates were higher in farm environment samples than in fecal samples. Multidrug resistance was seen in a variety of sources, and the highest levels of multidrug-resistant E. coli were observed for swine fecal samples. The fact that water sample isolates were resistant only to cephalothin may suggest that the resistance patterns for farm environment samples may be more representative of the risk of contamination of surface waters with antimicrobial agent-resistant bacteria.

Presence and antimicrobial resistance ofEscherichia coliisolated from foodstuffs in Hidalgo State (Mexico) Presencia y resistencia a antimicrobianos deEscherichia coliaislados a partir de alimentos en el estado de Hidalgo (México)

“…These results differ from those obtained by other authors such as Sayah et al (2005) or Knezevic and Petrovic (2008) who obtained higher multidrug-resistance for E. coli isolated from pigs than for E. coli isolated from poultry and cattle. Multiresistant strains could have been originated as the result of co-selection of resistance determinants, because exposing a bacterial population to one antimicrobial agent may result in resistance to other agents without any additional exposure (Sayah et al, 2005). Thus, it was reported that higher levels of multiresistant strains in any group may also reflect more recent antibiotic usage (Van den Bogaard et al, 2001).…”

“…In this case, it is reasonable to think that ciprofloxacinresistant E. coli could reach vegetable foods though human or poultry farm-influenced wastewater or sewage (Sabate´et al, 2008;Sayah et al, 2005).…”

“…When compared with the other microorganisms found mostly in foods, Escherichia coli has been a very useful biomarker for evaluating the development of antimicrobial resistance (Von Baum & Marre, 2005). In addition to its high frequency of mutation, which can favour the spontaneous development of antimicrobial resistance, E. coli also has the ability to transfer microbial resistance between individual bacteria (Kijima-Tanaka et al, 2003;Sa´enz et al, 2001;Sayah, Kaneene, Johnson, & Miller, 2005;Von Baum & Marre, 2005). Thus, changes in the resistance of this species may serve as a good indicator of resistance in potentially pathogenic bacteria (Kijima-Tanaka et al, 2003;Von Baum & Marre, 2005).…”

Microbiota cloacal aeróbia de cracídeos cativos no Rio Grande do Sul e sua susceptibilidade a antimicrobianos

“…foram os gêneros e espécies bacterianas com maior percentual de resistência a diferentes antimicrobianos, podendo configurar o possível surgimento, no futuro, de cepas multirresistentes. Estudos realizados com intuito de avaliar a resistência de cepas de Escherichia coli oriundas de aves silvestres (Livermore et al 2001, Sayah et al 2005, Dolejska et al 2007, Gibbs et al 2007, demonstraram o ocorrência de cepas multirresistentes. Este dado reveste-se de relevância tendo em vista que, no momento das colheitas, foi observado que outras espécies de pássaros tinham acesso a fezes desses cracídeos possibilitando a veiculação desta bactéria para outros animais, locais, e inclusive, para humanos.…”

Antimicrobial Susceptibility of Escherichia coli Isolates from Wild Mice in a Forest of a Natural Park in Hokkaido, Japan

“…The usage of antimicrobial agents is considered the most important factor in the selection and dissemination of antimicrobial-resistant bacteria. Although antimicrobial agents are not generally administered to wild animals, the prevalence of antimicrobial-resistant Escherichia coli isolates was determined in some wild animals [4,5,7,10,12,13]. The source of antimicrobial-resistant bacteria among wild animals is still debatable.…”