| Samples were collected from cultured | | | | Ofloxacin, Norfloxacin and Gentamycin, but |
| P.monodon in 2 different bheries located in West | | | | resistant to Ampicillin, Oxytetracycline and |
| Bengal, where outbreak of disease with high | | | | Erythromycin . Similar observations have been |
| mortality was reported. Microbiological analysis of | | | | made by Thakur et al., (2003), who observed |
| affected shrimp revealed presence of | | | | higher sensitivity of Vibrio parahaemolyticus, V. |
| predominantly Vibrio spp. in hemolymph and | | | | alginolyticus, V. anguillarum and V. vulnificus isolates |
| hepatopancreas and V.parahaemolyticus, | | | | from moribund shrimps to Erythromycin, |
| V.alginolyticus, V.harveyi and some Aeromonas | | | | Chloramphenicol and Streptomycin but resistant to |
| were isolated. Presumptive Vibrio counts (PVC) on | | | | Ampicillin, Oxytetracycline and Polymyxin-B. |
| TCBS in hemolymph and hepatopancreas were in | | | | In the present study Vibrios and Aeromonas |
| the range of 1.2 x 102 - 2.5x103 CFU hp-1 and 1.6 | | | | isolates were found to be sensitive to |
| x102 – 2.8 x104 CFU hp-1 in infected | | | | chloramphenicol, norfloxacin, ciprofloxacin, ofloxacin |
| P.monodon, respectively. These values were | | | | and gentamycin indicating their usefulness to |
| found to be comparatively lower in hemolymph | | | | control bacterial infection. However, as a general |
| (3.0 - 1.6x101 CFUml-1) and hepatopancreas (1.7 x | | | | guideline USFDA has banned use of such chemicals |
| 101 – 3.4x102 CFU hp-1) collected from | | | | in aquaculture use due to their high health risks |
| apparently healthy P.monodon. Similarly the TPC | | | | (FDA, 1986). It has been observed that in some |
| of hemolymph and hepatopancreas on ZMA was | | | | countries like in India, with no specific strict |
| in the range of 2.2 x 103 - 2.5x105 CFUml-1 and | | | | regulation governing the use of these |
| 2.3x 103 – .4.2 x106 CFU hp-1, respectively. | | | | chemotherapeutants in fish culture, such chemicals |
| These values were much lower both in | | | | are being widely used in hatcheries and culture |
| hemolymph and hepatopancreas samples from | | | | ponds and tanks (Hameed and Rao, 1994). |
| uninfected shrimps. The low Vibrio count in | | | | Considering the potential hazards of antibiotics |
| unaffected shrimp and high Vibrio and total | | | | responsible for development of antibiotic resistant |
| bacterial count in affected shrimp indicated that | | | | bacteria in aquatic ecosystem, use of alternative |
| Vibrios were the inducing etiological agents | | | | antibacterial chemicals like BKC, formalin and |
| responsible for high mortality in P.monodon. The | | | | Potassium permanganate, may be advocated for |
| results indicated that most of the isolates were | | | | use in aquaculture operations for disease |
| sensitive to Chloramphenicol, Ciprofloxacin, | | | | management. |