Distribution of Quinolones, Sulfonamides, Tetracyclines in Aquatic Environment and Antibiotic Resistance in Indochina

Abstract

Southeast Asia has become the center of rapid industrial development and economic growth. However, this growth has far outpaced investment in public infrastructure, leading to the unregulated release of many pollutants, including wastewater-related contaminants such as antibiotics. Antibiotics are of major concern because they can easily be released into the environment from numerous sources, and can subsequently induce development of antibiotic-resistant bacteria. Recent studies have shown that for some categories of drugs this source-to-environment antibiotic resistance relationship is more complex. This review summarizes current understanding regarding the presence of quinolones, sulfonamides, and tetracyclines in aquatic environments of Indochina and the prevalence of bacteria resistant to them. Several noteworthy findings are discussed: (1) quinolone contamination and the occurrence of quinolone resistance are not correlated; (2) occurrence of the sul sulfonamide resistance gene varies geographically; and (3) microbial diversity might be related to the rate of oxytetracycline resistance.

Understanding the contribution of environmental factors in the spread of antimicrobial resistance

“…Selective pressure imposed by antibiotics is notably evidenced among pathogenic bacteria in clinical settings, the community and throughout the commercial food chain [34]. Interestingly, while selective pressure occurs from environmentally persistent antibiotics, [38,39] the presence of intrinsic resistance genes in the environment (for e.g. genes present in manure; sewage; hospital waste) significantly contributes to environmental pollution with resistance genes [40].…”

“…This suggests that as a result of exposure to high concentrations of various antibiotics, the risk of colonisation with antibiotic-resistant bacteria and genes increases in the intestinal tracts of livestock. The antibiotic resistance genes can then be transferred to other environments and humans through water and the food supply [39]. Antibiotic resistance selection occurs among gastrointestinal bacteria, which are also excreted in manure and stored in waste holding systems.…”

“…Antibiotic resistance selection occurs among gastrointestinal bacteria, which are also excreted in manure and stored in waste holding systems. Manure then acts as a reservoir for resistant bacteria and antibiotic compounds [39,47]. It is therefore necessary to prevent or limit the transfer of antibiotic resistance genes from farming environments to humans and other environments, through water and the food supply.…”

“…Nonpathogenic bacteria in this environment can act as a reservoir of resistance genes and platforms [39,45,54]. With the progressive accumulation of antimicrobial agents, detergents, disinfectants, and residues from industrial pollution, as heavy metals introduced into the environment, the evolution and spread of such resistant organisms in the water environment is facilitated [55].…”

Antibiotic resistant bacteria in terrestrial and aquatic environments: A review

“…Nhiem et al [11] reported antibiotic residues in marketed pork in Vietnam. In Indo-China, antibiotic residues have been found in shrimp ponds, rivers, canals and other habitats [12].…”