Antibiogram and heavy metal resistance of pathogenic bacteria isolated from moribund cage cultured silver catfish (Pangasius sutchi) and red hybrid tilapia (Tilapia sp.)

Abstract

Antibiogram and heavy metal resistance of pathogenic bacteria isolated from moribund cage cultured silver catfish (Pangasius sutchi) and red hybrid tilapia (Tilapia sp.)Abstract Antibiogram and heavy metal resistance patterns of pathogenic bacteria isolated from moribund cage cultured silver catfish (Pangasius sutchi) and red hybrid tilapia (Tilapia sp.) from Sungai Manir, Terengganu, Malaysia were studied and characterized. Sungai Manir is one of the famous rivers in Terengganu for its wide variety of cage cultured freshwater fish. However, to date, the baseline information of antibiogram and heavy metal resistance patterns of the pathogenic bacteria attacking the freshwater fish cultured in Sungai Manir is still lacking. Therefore, this study was carried out, which may be useful for fish farmers as a guideline for fish prophylactic and treatment purposes. Furthermore, present studies also provide information on the safety level of consuming freshwater fish produced from Sungai Manir. In the present study, bacteria were isolated from 100 fish of each moribund silver catfish and red hybrid tilapia using seven media including tryptic soy agar (TSA), Mac Conkey, thiosulphate citrate bile salt (TCBS), eosin methylene blue (EMB), glutamate starch pseudomonas (GSP), xylose lysine deoxycholate (XLD) and Baird Parker media. Identification of bacteria was carried out using conventional biochemical tests and confirmed by commercial bacterial identification kit. Antibiogram of the bacterial isolates against 18 antibiotics; oxolinic acid (2 µg), ampicillin (10 µg), erythromycin (15 µg), furazolidone (15 µg), lincomycin (15 µg), oleandomycin (15 µg), amoxicillin (25 µg), colistin sulphate (25 µg), sulphamethoxazole (25 µg), chloramphenicol (30 µg), doxycycline (30 µg), florfenicol (30 µg), flumequine (30 µg), kanamycin (30 µg), nalidixic acid (30 µg), tetracycline (30 µg), nitrofurantoin (50 µg) and spiramycin (100 µg) was carried out using disk diffusion method, whereas heavy metal resistance patterns (Hg 2+ , Cd 2+ , Cr 6 + and Cu 2+ ) of the bacterial isolates was determined through twofold agar dilution method. The results showed that the percentage of sensitivity case of the 120 bacterial isolates to the tested antibiotics was 62.7%. This was followed by resistance (26.9%) and intermediary sensitive (10.4%) cases. In terms of the heavy metal resistance patterns, all bacterial isolates were resistant to Hg 2+ and Cr 6 + . However, only 27.8% and 16.7% of the bacterial isolates were sensitive to Cu 2+ and Cd 2+ , respectively. The multiple antibiotic resistance (MAR) indices indicated that the cage cultured silver catfish and red hybrid tilapia were under high exposure to the tested antibiotic. Overall, the results of the present studies showed that Sungai Manir may be polluted with heavy metal and antibiotic residues.

Antibiotic and heavy metal resistance of Aeromonas hydrophila and Edwardsiella tarda isolated from red hybrid tilapia (Oreochromis spp.) coinfected with motile aeromonas septicemia and edwardsiellosis

“…Antibiotic susceptible test was performed using disk diffusion method [ 1 ]. The bacterial cells were prepared by propagated the bacteria using Luria Broth (Oxoid, England), followed by centrifugation at 14,500 rpm for 10 min using MiniSpin (Eppendorf, Germany).…”

“…A. hydrophila and E. tarda were successfully isolated from moribund cage cultured silver catfish ( Pangasius sutchi ), striped catfish ( Pangasianodon hypophthalmus ), and red hybrid tilapia ( Tilapia spp.) [ 1 , 2 ]. According to Zhang et al .…”

Foodborne Agents Associated with the Consumption of Aquaculture Catfish

“…At the preprocessing stage, Vibrio was not detected in catfish intestinal contents (65). However, in a more recent study 15 antibiotic-resistant Vibrio colonies were isolated from the internal organs of 100 silver catfish in Malaysia (57). In another study of 240 catfish fillets taken from three processing plants during 1 year, seasonal variation in V. cholerae prevalence was documented; 27.5% of fillet samples (33 of 120) taken during the summer and fall were positive for V. cholera, but none of the 120 fillet samples taken in the winter and spring were positive for this microorganism (40).…”

“…Salmonella isolated from catfish imported to the United States from Thailand were resistant to a variety of antibiotics, including nalidixic acid, streptomycin, tetracycline, and kanamycin (139). In a more recent study, 11 antibiotic-resistant Salmonella colonies were isolated from the internal organs of 100 silver catfish (Pangasius sutchi) obtained in Malaysia (57). These data imply that catfish are exposed to antibiotics that might affect bacterial resistance patterns.…”

Streptococcus agalactiae isolates from cultured fishes in Malaysia manifesting low resistance pattern towards selected antibiotics

“…A study in Terengganu River, Malaysia, revealed the multiple antibiotic resistance of bacteria which indicated that the cage-cultured silver catfish, Pangasius sutchi (Fowler) and red hybrid tilapia there were under high exposure to the several antibiotics, including streptomycin, amoxicillin, chloramphenicol, erythromycin, ampicillin, sulfamethoxazole and tetracycline (Lee et al 2010). Interestingly, their study area was at the same river with our present study.…”