Antibiotic resistance marker genes as environmental pollutants in GMO-pristine agricultural soils in Austria

Environ Pollut. 2015 Nov:206:342-51. doi: 10.1016/j.envpol.2015.07.028. Epub 2015 Jul 30.


Antibiotic resistance genes may be considered as environmental pollutants if anthropogenic emission and manipulations increase their prevalence above usually occurring background levels. The prevalence of aph(3')-IIa/nptII and aph(3')-IIIa/nptIII - frequent marker genes in plant biotechnology conferring resistance to certain aminoglycosides - was determined in Austrian soils from 100 maize and potato fields not yet exposed to but eligible for GMO crop cultivation. Total soil DNA extracts were analysed by nptII/nptIII-specific TaqMan real time PCR. Of all fields 6% were positive for nptII (median: 150 copies/g soil; range: 31-856) and 85% for nptIII (1190 copies/g soil; 13-61600). The copy-number deduced prevalence of nptIII carriers was 14-fold higher compared to nptII. Of the cultivable kanamycin-resistant soil bacteria 1.8% (95% confidence interval: 0-3.3%) were positive for nptIII, none for nptII (0-0.8%). The nptII-load of the studied soils was low rendering nptII a typical candidate as environmental pollutant upon anthropogenic release into these ecosystems.

Keywords: Aminoglycosides; Antibiotics; Real time PCR; Resistance; Soil contamination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / analysis*
  • Austria
  • Crops, Agricultural / genetics
  • Crops, Agricultural / growth & development*
  • DNA, Bacterial / genetics
  • Drug Resistance, Bacterial / genetics*
  • Genes, Bacterial*
  • Kanamycin Resistance / genetics
  • Soil / chemistry*
  • Soil / standards
  • Soil Microbiology*
  • Soil Pollutants / analysis*
  • Solanum tuberosum / genetics
  • Solanum tuberosum / growth & development
  • Zea mays / genetics
  • Zea mays / growth & development


  • Anti-Bacterial Agents
  • DNA, Bacterial
  • Soil
  • Soil Pollutants