Pollution-Induced Community Tolerance of Soil Microbial Communities Caused by the Antibiotic Sulfachloropyridazine

Abstract

Little is known about the environmental hazards linked to the treatment of farm animals with antibiotics and subsequent spreading of manure, especially regarding soil microbial communities. In this investigation, pollutioninduced community tolerance (PICT) of bacteria from soils artificially spiked with the sulfonamide sulfachloropyridazine (SCP) was investigated. Tolerance of the bacterial communities after 3 weeks' exposure to SCP was determined by analyzing the sensitivity of 31 microbial metabolic processes in microtiter plates. Bacterial suspensions extracted from soils containing higher concentrations of SCP showed an increased tolerance of their metabolic activities to this antibiotic. An increase in tolerance by 10% was found at 7.3 mg/kg dw SCP. The PICT effect could be demonstrated by both a shift in the tolerance of the average of all metabolic activities and a shift of the physiological process sensitivity distributions made up from the single metabolic processes. The PICT effect was accompanied by smaller changes in the communitylevel physiological profile (CLPP). To conclude, PICT has been shown to be a versatile and illustrative method for the detection of the effects of antibacterial agents on soil microorganisms.

Impact Assessment of Soil Contamination with Antibiotics (for Example, an Ordinary Chernozem)

“…1 and 2) that all the studied concentrations of antibiotics have a suppressing effect on population densities of soil microorganisms; the same result was obtained in (Colinas et al, 1994). At the same time, there are data attesting to astimulating effect of antibiotics in low concentrations (0.1-0.5 mg kg −1 ) on microorganisms (Schmitt et al, 2004). Close correlation was found between concentrations of antibiotics and the change in population densities of the studied groups of soil microorganisms (r = -0.68-0.86).…”

Changes in functional diversity of soil microbial community with addition of antibiotics sulfamethoxazole and chlortetracycline

“…Compared with time length of SMX inhibition, Biolog method resulted in a longer time of SMX inhibition on functional diversity of soil microbial community than SIR. Some previous studies also reported that antibiotic-induced changes of soil microbial community structures might proceed a longer time once initiated (Hammesfahr et al 2008;Schmitt et al 2004;Thiele-Bruhn and Beck 2005). In another study (Westergaard et al 2001), antibiotic effects of tylosin on soil microbial community structure were, respectively, measured by denaturing gradient gel electrophoresis (DGGE) and Biolog method.…”

“…Compared to the Biolog method, molecular techniques such as 16S rRNA sequence analysis, DNA melting profiles, and denaturing gradient gel electrophoresis also offer useful approaches to analyze soil microbial community, but these techniques fail to give any indication of the functional diversity of soil microbial communities (Saul-Tcherkas and Steinberger 2009). EcoPlate, one kind of Biolog Microplate, has been successfully applied to study the effect of sulfachloropyridazine on the pollution-induced community tolerance (PICT) of soil microbial communities (Schmitt et al 2004). There are still some criticized opinions about the utilization of the Biolog method because the Biolog Microplate mainly reflects a part of microbial community in environmental samples, but it has proved to be a useful tool to differentiate disturbance in soil microbial functional diversity and community from different environmental stresses (Du Plessis et al 2005;Hayyis-Hellal et al 2009;Liu et al 2009b;Lupwayi et al 2009;Wang et al 2010).…”

Effect of veterinary oxytetracycline on functional diversity of soil microbial community

“…And the Shannon diversity at soils treated with highest or higher OTC concentrations were significantly different from that without OTC, further indicating OTC effects on the function of soil microbial community (Figure 4b). Higher AWCD at high OTC level may be related to changes in community composition at these OTC concentrations, which were shown to occur for tetracyclines in soil (Schmitt et al 2004, Demoling et al 2009). Thiele-Bruhn and Beck (2005) indicated that basal respiration and dehydrogenase activity were uninfluenced by 1000 ppm tetracycline, which may be contributed to biostasis and dormant state of most soil microbes, and OTC can exert a temporary selective pressure on soil microbes.…”