Materials and Methods: In this study, 221 fish samples, of which 108 (Oreochromis spp., n=38; C. gariepinus, n=35; and P. hypophthalmus, n=35) were from Kelantan and 113 (Oreochromis spp., n=38; C. gariepinus, n=35; and P. hypophthalmus, n=40) were from Terengganu, were caught using cast nets. Then, samples from their kidneys were cultured on a Rimler Shott agar to isolate Aeromonas spp. Polymerase chain reaction (PCR) was used to confirm this isolation using specific gene primers for species identification. Subsequently, the isolates were tested for their sensitivity to 14 antibiotics using the Kirby-Bauer method, after which the PCR was conducted again to detect resistance genes: sul1, strA-strB, aadA, bla TEM, bla SHV, tetA-tetE, and tetM.
Results: From the results, 61 isolates were identified as being from the genus Aeromonas using PCR, of which 28 were Aeromonas jandaei, 19 were Aeromonas veronii, seven were Aeromonas hydrophila, and seven were Aeromonas sobria. Moreover, 8, 12, and 8 of A. jandaei; 4, 3, and 12 of A. veronii; 6, 0, and 1 of A. hydrophila; and 3, 3, and 1 of A. sobria were obtained from Oreochromis spp., C. gariepinus, and P. hypophthalmus, respectively. In addition, the isolates showed the highest level of resistance to ampicillin (100%), followed by streptomycin (59.0%), each kanamycin and nalidixic acid (41.0%), neomycin (36.1%), tetracycline (19.7%), sulfamethoxazole (14.8%), and oxytetracycline (13.1%). Resistance to gentamicin and ciprofloxacin both had the same percentage (9.8%), whereas isolates showed the lowest resistance to norfloxacin (8.2%) and doxycycline (1.6%). Notably, all Aeromonas isolates were susceptible to chloramphenicol and nitrofurantoin. Results also revealed that the multiple antibiotic resistances index of the isolates ranged from 0.07 to 0.64, suggesting that the farmed fish in these areas were introduced to the logged antibiotics indiscriminately and constantly during their cultivation stages. Results also revealed that the sul1 gene was detected in 19.7% of the Aeromonas isolates, whereas the tetracycline resistance genes, tetA and tetE, were detected in 27.9% and 4.9% of the isolates, respectively. However, β-lactam resistance genes, bla TEM and bla SHV, were found in 44.3% and 13.1% of Aeromonas isolates, respectively, whereas strA-strB and aadA genes were found in 3.3% and 13.1% of the isolates, respectively.
Conclusion: This study, therefore, calls for continuous surveillance of antibiotic-resistant Aeromonas spp. in cultured freshwater fish to aid disease management and better understand their implications to public health.
Materials and Methods: The organ samples were subjected to laboratory testing and postmortem inspection. Escherichia (E.) coli and Mycoplasma (M.) gallisepticum were detected using bacterial isolation and molecular diagnostics using polymerase chain reaction.
Results: Chickens with the infection had widespread fibrin buildup in several organs and hemorrhages on the duodenal mucosa. Additional histology and laboratory analysis of organ samples revealed infection with M. gallisepticum, E. coli, and enteric Eimeria spp., all of which are consistent with complex chronic respiratory disease (CCRD) associated with coccidiosis. Tylosin tartrate 20% (w/w) (2.5 gm/l) was prescribed for 1 week along with a combination of the broad-spectrum bacteriostatic drug streptomycin (25 mg/kg) and coccidiostat (2 gm/5 l).
Conclusion: CCRD and coccidiosis are both infectious diseases that can infect chicken flocks, resulting in production losses and carcass quality degradation. Early disease detection and proper treatment should be provided promptly, and tight farm biosecurity should be implemented to prevent chicken mortality on the farm, as was achieved successfully.