Multiple antimicrobial resistance of Escherichia coli isolates from Nile tilapia sold in wet markets in Metro Manila and the conjugative transferability of the drug resistance

• Main Authors: Jose, Mark Anthony I., Cabrera, Esperanza C.
• Format: text
• Published: Animo Repository 2018
• Subjects: Escherichia coli; Drug resistance in microorganisms; Nile tilapia—Microbiology; Conjugation (Biology); Biology
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/1789
• Institution: De La Salle University

Multiple drug resistance (MDR) in Escherichia coli poses great risks to both human and animal health as it compromises the management of diseases caused by E. coli strains. E. coli was isolated from the gills of 35 Oreochromis niloticus or Nile tilapia procured from the Balintawak, Cubao and Libertad wet markets in Metro Manila. The isolates were studied for their antimicrobial susceptibility patterns using the standard disc diffusion method, and for the transferability of their resistance determinants. Results showed the highest percentage resistance of the isolated E. coli to ampicillin (77.14%) and trimethoprim-sulfamethoxazole (60%). These were followed by the resistance to tetracycline (45.71%), cephalothin (17.14%), gentamicin (11.43%), nalidixic acid (8.57%), and the least to ciprofloxacin (5.71%). On the other hand, all the isolates were found to be susceptible to the aminoglycoside amikacin, and were also found to be susceptible to the carbapenem imipenem, suggesting the absence of carbapenemase-producing strains. These were also found to be susceptible to the extended spectrum β-lactams aztreonam, cefotaxime, and ceftazidime signifying absence of extended spectrum β-lactamase (ESBL)-producing E. coli. Multiple drug resistances were found in 21 out of 35 isolates or 60%, while the remaining five or 14.28% were completely susceptible to all test antimicrobials. Moreover, seven of ten isolates completely transferred their resistance determinants to a drug-susceptible, res-E. coli J53-2 through conjugation. Three isolates transferred only the ampicillin resistance gene. © 2018, College of Agriculture and Food Science, University of the Philippines Los Banos. All right reserved.