Comparison of the mean of MAR index for Vibrio parahaemolyticus isolates of different shrimp species. Each bar represents the mean of the MAR index for V. parahaemolyticus strains from different shrimp species. Label 1, red prawn; Label 2, banana prawn.
Furthermore, the mean of MAR index for V. parahaemolyticus isolates of different shrimp species were compared and the results showed there was significantly difference with p < 0.05 (Figure 1). The mean MAR index of the V. parahaemolyticus isolates recovered from banana prawn species were significantly higher than mean MAR index of V. parahaemolyticus isolates from the red prawn species. Results in this study highlighted that the banana prawn isolates are possible exposed to various antimicrobials that lead to emerging of multiple antibiotic resistant strains.
In the current study, a high percentage (83%) of isolates have MAR index more than 0.2. The range of MAR index was from 0.00 to 0.79, with the highest MAR index attributed from an isolate (VP152; Table 5) from supermarket banana prawn which exhibited resistant to 11 antibiotics. Gwendelynne et al. (2005) stated that MAR indices higher that 0.2 could be due to contamination from high risk sources, thus leading to human health risk. A total of 49/185 isolates exhibited MAR index of 0.07, indicating the isolates were resistant to at least one type of antibiotic. About 28% of the isolates were resistant to three different antibiotics and have a MAR index of 0.21. The study also noted shrimp samples from wetmarket and supermarket had difference MAR indices.