SXT int harboring bacteria as effective indicators to determine high-risk reservoirs of multiple antibiotic resistance in different aquatic environments of western coast of Gujarat, India

Autor: Ambika Hemant Shinde, Soumya Haldar, Ishan H. Raval
Rok vydání: 2020
Předmět:
Zdroj: Ecological Indicators. 113:106143
ISSN: 1470-160X
Popis: Unregulated use of antibiotics in the developing countries has led to the development of Multiple Antibiotic Resistant (MAR) strains. Resistance transferring elements like SXT play crucial role in dissemination of the resistance genes. Persistence of antibiotics and their resistance elements in an aquatic ecosystem depends on the physicochemical properties, and thus may depend on the type of whole water body in general. The study focuses on isolation of bacteria possessing SXT integrase from diverse aquatic bodies like polluted sources, freshwater ponds, groundwater and seawaters of western Gujarat coast, and studying distribution of multidrug resistance in them. Initially, 246 Co-Trimoxazole resistant microbes were isolated from various environmental samples on the basis of morphological distinction. In the PCR analysis, 45 of them were found to be positive for the SXT integrase gene and subsequent analysis confirmed the presence of SXT or SXT-variants. Partial 16S rRNA gene sequencing and diversity analysis on the basis of Shannon’s diversity indices revealed bacterial class-wise diversity trend to be pond water > seawaters > ground water > polluted sources. Antibiogram of these organisms revealed the order of antibiotic resistance indices to be polluted sources > groundwater sources > freshwater ponds > seawater sources. However, the trend of percentage resistance towards antibiotic classes separately in the studied aquatic environments was groundwater sources > polluted sources > freshwater ponds > seawater. Further, the trend for therapeutic efficiency of antibiotic classes was similar in all waters to that of total isolates i.e. Aminoglycosides > Fluoroquinolones > Amphenicols > Cephalosporins > Imidazolidinedione derivatives > Glycopeptide > Quinolones > Macrolides > Penicillins > Sulfa drugs. Positive correlation was observed between prevalence of SXT int positive bacteria and multiple antibiotic resistance incidences; but negative correlation was observed between SXT int positive bacteria and class wise bacterial diversity in four designated type of aquatic environment. Thus, screening for occurrence frequency of SXT integrase gene in the bacterial isolates, may prove as an effective parameter to estimate the multiple antibiotics’ resistance indices in any of the four studies aquatic ecosystems, and thereby determine the antibiotic pollution resulting in the corresponding pressure. The overall quantitative values were logically higher in polluted sources in terms of total resistance indices, and freshwater ponds in terms of diversity. But the groundwater sites may be regarded as the prominent high-risk zones of contamination with multiple antibiotic and/or their resistance traits qualitatively.
Databáze: OpenAIRE
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