Tamagnini lm, González rd

Language: English
References: 15
Page: 84-87
PDF size: 87.54 Kb.

ABSTRACT

Testing for evidence of faecal contamination in river water has been traditionally accomplished by enumeration of thermotolerant coliform bacteria. In this work, deoxycholate lactose and m-Endo Agar LES media were evaluated using different techniques. The colony count methods were pour plate technique on Deoxycholate Agar (DCL pour plate), spread plating on m-Endo Agar LES (ELS spread), and membrane filtration on m-Endo Agar LES (ELF filtration). Typical thermotolerant coliform colonies were analysed by conventional biochemical tests. The three matched pairs showed statistically significant differences (P ‹ 0.05) by the Wilcoxon signed rank test. One hundred and twenty three isolates obtained on m-Endo Agar LES (65%) were confirmed as E. coli. Likewise, one hundred and twenty isolates obtained on Deoxycholate Agar (71%) were confirmed as E. coli. The results of this study showed that the matched DCL-ELF presented the smaller statistically significant difference (P = 0.042) so, DCL could be used as alternative to ELF.

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