Effect of organotins on fecal pollution indicator organisms

Abstract

Pure cultures of Escherichia coli and Streptococcusfaecalis and environmental water samples were examined for the possibility that pollution involving organotin compounds could decrease the values for indicator organisms when standard methods were applied to the analysis of water samples. (CH3)2SnCl2 and (CH3)3SnCl decreased viable counts at about 10 to 100 mg of Sn liter-' (8.4 x 10-5 to 8.4 x 10-4 mol of Sn liter-'), and tributyltin chloride was effective at about 0.1 to 1.0 mg of Sn liter-' (8.4 x 10-7 to 8.4 x 10-6 mol of Sn liter-'. These concentrations, particularly for the methyltin compounds, are greater than the concentrations reported to date for these compounds in aquatic ecosystems. Thus, organotin compounds alone would not be likely to cause reductions in counts of indicator organisms measured by standard methods. However, it is suggested that, when combined with other environmental stressors or upon long exposure, organotins such as butyltins may contribute to the injury of indicator organisms. * Corresponding author. waters and sediments in areas impacted by human activity (32, 40). MATERIALS AND METHODS Microorganisms and culture preparation. Pure cultures of Streptococcusfaecalis ATCC 19433 and of an environmental isolate of E. coli coded UMB-1 were maintained on Trypticase soy agar slants. The E. coli was isolated from water obtained from Boston Harbor, Boston, Mass. It was identified as an E. coli based on indole-methyl red-Voges-Proskauer-citrate reactions and the production of acid and gas from lactose at 44.5°C. Cultures for experiments were grown in Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) at 20 to 22°C for 24 h. A 1% (vol/vol) inoculum was then transferred to fresh Trypticase soy broth and incubated for 18 h.

Tributyltin-resistant bacteria from estuarine and freshwater sediments

“…Effect of medium on TBT resistance. A number of factors can influence the apparent toxicity of tin compounds (20,21,23,39). Since the presence of agar in a medium greatly influenced the toxicity of inorganic tin for estuarine bacteria (20), we examined its effect on the toxicity of TBT.…”

Pattern of organotin inhibition of methanogenic bacteria

“…Virtually all studies on organotin toxicity have been conducted with aerobic organisms, including marine animals, fungi, yeasts, and bacteria (5-7, 11,12,15,19,20). Diand trisubstituted compounds are more toxic than monoor tetrasubstituted compounds, and trisubstituted compounds are usually the most toxic.…”

Comparative survival of antibiotic-resistant and -sensitive fecal indicator bacteria in estuarine water

“…When incubated in filtered estuarine water taken in December (29.%oo salinity), sensitive Enterococcusfaecalis isolates did not die off after a 2-day incubation (data not shown); however, when water sampled in May of the following year was used (30.7%o salinity), sensitive Enterococcus faecalis isolates decreased by approximately 70% in 2 days (Table 2). Although the salinity did not vary greatly, other chemical constituents such as chlorine (8), toxic organic compounds (4), metals (2,13,25), and organometals (24,36,43) can affect the survival of indicators in aquatic ecosystems. The effects of various environmental factors on Escherichia coli have been described (5,8,9,15,16,20), but few analogous studies have been conducted for the fecal streptococci.…”