For freshwater, the present single-sample advisory limit is 61 cfu/100 ml for enterococci. The 5-day geometric mean should not exceed 33 cfu/100 ml for enterococci . According to the Australian National Health and Medical Research Council (NHMRC) guidelines, there are four microbial assessment categories, A-D, based on enterococcal counts per ml (A ≤ 40, B 41-200, C201-500 and D > 501) together with associated
health risks . Enterococci are members of the natural intestinal flora of animals and humans and are released into the environment directly or via sewage 4SC-202 solubility dmso outlets . Certain members of the genus, Geneticin ic50 particularly E. faecalis and E. faecium, are becoming increasingly important as opportunistic pathogens [7, 12, 13]. Most important and a contributing factor to the pathogenesis of enterococci is their resistance to a wide range of antibiotics . Enterococci have been found to be increasingly resistant to multiple anti-microbial drugs in last few years [15–17]. Enterococci CP673451 in vivo show either intrinsic resistance where resistance genes are located on the chromosome, or they possess acquired resistance determinants which are located on plasmids or transposons . Examples of the intrinsic antibiotic resistance include resistance to beta-lactams, cephalosporins, sulfonamides, and low levels
of clindamycin and aminoglycosides [18, 19]. Resistance to chloramphenicol, erythromycin, Parvulin high levels of clindamycin
and aminoglycosides, tetracycline, high levels of beta-lactams, fluoroquinolones, and glycopeptides such as vancomycin are examples of acquired resistance . The distribution of infectious enterococcal strains into the environment via water could increase the prevalence of these strains in the human population. Environmental water quality studies may benefit from focusing on a subset of Enterococcus spp. that are consistently associated with sources of faecal pollution such as domestic sewage, rather than testing for the entire genus. E. faecalis and E. faecium are potentially good focal species for such studies, as they have been consistently identified as the dominant Enterococcus spp. in human faeces [20–22] and sewage . The characterisation of E. faecalis and E. faecium is important in studying their population structures, particularly in environmental samples. Different methods have been developed for the characterisation of enterococci [24–28]. However, there is a need to develop and apply new robust, rapid and cost effective techniques which are likely to yield more definitive results for the routine monitoring of E. faecalis and E. faecium. This was addressed in our previous study where we developed a single-nucleotide polymorphisms (SNP) based genotyping method to study the population structure of E. faecalis and E. faecium . A set of eight high-D SNPs was derived from the E. faecalis and E.