We report the first study on the occurrence of high-level
aminoglycoside-resistant (HLAR) Enterococci in coastal bathing waters and beach
sand in Malaysia. None of the encountered isolates were resistant to high levels of
gentamicin (500 μg/mL). However, high-level resistance to
kanamycin (2,000 μg/mL) was observed in 14.2 % of tested isolates, the highest proportions observed being among beach
sand isolates. High-level resistance to
kanamycin was higher among Enterococcus faecalis and Enterococcus faecium than Enterococcus spp. Chi-square analysis showed no significant association between responses to tested
antibiotics and the species allocation or source of isolation of all tested Enterococci. The species classification of encountered Enterococci resistance to
vancomycin was highest among Enterococcus spp. (5.89 %) followed by E. faecium (4.785) and least among E. faecalis. A total of 160 isolates were also tested for virulence characteristics. On the whole,
caseinase production was profoundly highest (15.01 %) while the least prevalent virulence characteristic observed among tested beach Enterococci was
haemolysis of rabbit blood (3.65 %). A strong association was observed between the source of isolation and responses for each of
caseinase (C = 0.47, V = 0.53) and slime (C = 0.50, V = 0.58) assays. Analysis of obtained spearman's coefficient showed a strong correlation between
caseinase and each of the slime production (p = 0.04),
gelatinase (p = 0.0035) and haemolytic activity on horse blood (p = 0.004), respectively. Suggestively, these are the main virulent characteristics of the studied beach Enterococci. Our findings suggest that recreational beaches may contribute to the dissemination of Enterococci with HLAR and virulence characteristics.