Metal contamination and coexistence of metal and antibiotic resistance in Vibrio species recovered from aquaculture ponds with and without history of antibiotic usage in Southwest Nigeria

Abstract

Background The use of metal-containing and antimicrobial compounds is a common practice in aquaculture operations in Nigeria. Only a few studies have focused on the impact of these chemicals on metal and antibiotic resistance development in the bacterial flora of aquaculture. This study therefore sets out to fill this gap. Results Five metals, namely copper (Cu), zinc (Zn), lead (Pb), nickel (Ni) and chromium (Cr), were detected at different concentrations in the pond water samples, with most values obtained exceeding the maximum recommended national standard for fisheries and recreation water quality criteria set by the National Environmental Standards and Regulations Enforcement Agency (NESREA) in Nigeria. A total of 121 Vibrio spp. were recovered from the aquaculture pond water with Vibrio cholerae having the highest frequency (37) followed by Vibrio parahaemolyticus (36), Vibrio vulnificus (36) and Vibrio alginolyticus (12). Seventy-five isolates were recovered from ponds with history of antibiotic use, while the ponds with no recognized history of antibiotic use had forty-six isolates. The percentage resistance to antibiotics in the isolates was: ampicillin (88.5%), amoxicillin–clavulanate (44.3%), tetracycline (41%), trimethoprim-sulfamethoxazole (22.1%), chloramphenicol (15.6%), ciprofloxacin (11.5%), imipenem (5.7%), ceftazidime (4.1%) and gentamicin (0%). All the isolates tolerated all the metals to 400 µg/mL concentration while only the trio of Pb, Ni and Cr were tolerated beyond the concentration. Zn and Cu appeared to be the most toxic metals on Vibrio spp., with no isolate surviving beyond the 400 µg/mL concentration mark, while 57 of the 121 isolates survived Cr at the highest concentration (3200 µg/mL), making it the most tolerated of the metals. Conclusion This study reports a high level of metal contamination in the aquaculture ponds studied. The concentration of the metals exceeded the maximum permissible limits in Nigeria. Also, there was coexistence of metal and antibiotic resistance in the bacteria recovered from the aquaculture ponds. There is a need to regulate the use of chemicals, especially antibiotics and some biocidal compounds, to clamp down on the introduction of metals and antibiotics into the aquaculture systems, as these chemicals could facilitate the development of resistance traits in aquaculture bacteria by creating a selective pressure in the aquaculture environment.

Potentially pathogenic multidrug-resistant <i>Vibrio</i> sp. isolated from dumpsites in Rivers State, Nigeria

“…The highest rates of resistance in this study were observed against two beta-lactam antibiotics, augmentin (67.7%) and cefuroxime (68.8%). This rate was slightly higher than observed in a 2021 study (Adekanmbi et al, 2021) which reported a 44.3% resistance. Other studies simply tested against ampicillin and reported rates ranging from 76.92% to 94.1% (Islam et al, 2021;Gxalo et al, 2021).…”

Antibiotic resistance and virulence genes profiling of Vibrio cholerae and Vibrio mimicus isolates from some seafood collected at the aquatic environment and wet markets in Eastern Cape Province, South Africa

“…The El Tor strains compare to the classical strains are more adapted and resilient to the environment, cause a higher infection-to-case ratio and have more asymptomatic carriers [95,126]. Some studies have reported low resistance of the SA-NAG V. cholerae against amoxicillin/clavulanate [117,127,128] however, other studies like ours have shown that different V. cholerae serotypes can exhibit high resistance against amoxicillin/clavulanate [129,130].…”

“…cholerae against amoxicillin/clavulanate [ 117 , 127 , 128 ] however, other studies like ours have shown that different V . cholerae serotypes can exhibit high resistance against amoxicillin/clavulanate [ 129 , 130 ].…”

Co-occurrence of heavy metals and antibiotics resistance in bacteria isolated from metal-polluted soil

“…Similarly, Di-Cesare et al [ 42 ] reported co-selection of bacteria isolated from freshwater at Lake Orta, Italy to heavy metals and antibiotics. Adekanmbi et al [ 43 ] also reported co-existence of resistance to metals and antibiotics in Vibrio species isolated from fish ponds with and without antibiotics usage history. This observation is a major cause of concern for public health since illnesses caused by multidrug-resistant bacteria are difficult to treat and should they possess genes conferring such resistance, they may be transferred by different means to other bacteria present in their immediate environment, thereby conferring resistance to many classes of antibiotics as well.…”