Antibiotic resistance in soil and water environments

Abstract

Seven locations were screened for antibiotic-resistant bacteria using a modified agar dilution technique. Isolates resistant to high levels of antibiotics were screened for r plasmids. Low-level resistance (25 micro g x ml(-1)) was widespread for ampicillin, penicillin, tetracycline, vancomycin and streptomycin but not for kanamycin. Resistant populations dropped sharply at high antibiotic levels, suggesting that intrinsic non-emergent mechanisms were responsible for the multiple drug resistance exhibited at low doses. Dairy farm manure contained significantly (P < 0.01) more (%) resistant bacteria than the other sites. Bacteria isolated from a dairy water canal, a lake by a hospital and a residential garden (fertilized by farm manure) displayed resistance frequencies of 77, 75 and 70%, respectively. Incidence of tetracycline resistance was most prevalent at 47-89% of total bacteria. Out of 200 representative isolates analyzed, Pseudomonas, Enterococcus-like bacteria, Enterobacter and Burkholderia species constituted the dominant reservoirs of resistance at high drug levels (50-170 micro g x ml(-1)). Plasmids were detected in only 29% (58) of these bacteria with tetracycline resistance accounting for 65% of the plasmid pool. Overall, resistance trends correlated to the abundance and type of bacterial species present in the habitat. Environmental reservoirs of resistance include opportunistic pathogens and constitute some public health concern.

Effect of sulfonamide antibiotics on microbial diversity and activity in a Californian Mollic Haploxeralf

“…(2) Microorganisms tolerant to sulfonamides could have provided the observed UA: bacteria resistant to several antibiotics (sulfonamides were not tested) have been previously identified both in dairy farm manure and garden soil fertilized with farm manure (Esiobu et al 2002), and an increase of tolerance of microorganisms against another sulfonamide over time has also previously been shown (Schmitt et al 2004). Thus, if microorganisms susceptible to sulfonamides were effectively inhibited, the 'baseline' UA measured at t=380 h may have been provided by bacteria tolerant to or resistant against sulfonamides.…”

Framing the agricultural use of antibiotics and antimicrobial resistance in UK national newspapers and the farming press

“…Indeed this may be an instance where the mainstream print media is playing host to dissident voices that are otherwise frozen out of other spheres of influence including government policy (Miller, 1999). Esiobu et al 2002). Finally, more work is needed on a key finding raised by our media analysis within the UK, namely, the potential for animal health implications of animal antibiotic use and the rise of AMR to be taken more seriously than has been the case in a discussion largely centred on human health consequences alone.…”

In vitro assessment of gastrointestinal viability of two photosynthetic bacteria, Rhodopseudomonas palustris and Rhodobacter sphaeroides

“…Unfortunately, the abuse of such antimicrobials in disease prevention and even growth promotion has led to the evolution of resistant strains of bacteria (Esiobu et al, 2002;Fuller, 1989;Sarter et al, 2007;Weston, 1996), so environment-friendly aquaculture has been brought forward to resolve this problem and develop sustainable aquaculture, and research of probiotics for aquatic animals is increasing with this demand (Gatesoupe, 1999). Probiotics are viable bacteria that beneficially influence the host by improving its intestinal microbial balance (Wang and Xu, 2006).…”