<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.2d1 20170631//EN" "JATS-journalpublishing1.dtd"> <ArticleSet> <Article> <Journal> <PublisherName>emergentresearch</PublisherName> <JournalTitle>Emergent Life Sciences Research</JournalTitle> <PISSN>2395-6658 (</PISSN> <EISSN>) 2395-664X (Print)</EISSN> <Volume-Issue>Online First</Volume-Issue> <PartNumber/> <IssueTopic>Multidisciplinary</IssueTopic> <IssueLanguage>English</IssueLanguage> <Season>for coming issue</Season> <SpecialIssue>N</SpecialIssue> <SupplementaryIssue>N</SupplementaryIssue> <IssueOA>Y</IssueOA> <PubDate> <Year>2025</Year> <Month>03</Month> <Day>3</Day> </PubDate> <ArticleType>Research Article</ArticleType> <ArticleTitle>Comparative analysis of oxytetracycline and chloramphenicol on mutation frequency in Escherichia coli isolates from aquatic environments</ArticleTitle> <SubTitle/> <ArticleLanguage>English</ArticleLanguage> <ArticleOA>Y</ArticleOA> <FirstPage>8</FirstPage> <LastPage>20</LastPage> <AuthorList> <Author> <FirstName>Qurratul Ain</FirstName> <LastName>Qureshi</LastName> <AuthorLanguage>English</AuthorLanguage> <Affiliation/> <CorrespondingAuthor>N</CorrespondingAuthor> <ORCID/> <FirstName>Asif Majeed</FirstName> <LastName>Mir</LastName> <AuthorLanguage>English</AuthorLanguage> <Affiliation/> <CorrespondingAuthor>Y</CorrespondingAuthor> <ORCID/> <FirstName>Asad</FirstName> <LastName>Khan</LastName> <AuthorLanguage>English</AuthorLanguage> <Affiliation/> <CorrespondingAuthor>Y</CorrespondingAuthor> <ORCID/> </Author> </AuthorList> <DOI/> <Abstract>Aquaculture__ampersandsign#39;s rapid expansion raises significant concerns regarding antibiotic resistance, particularly in freshwater systems where Escherichia coli (E. coli) serve as a key indicator of fecal contamination. This study investigates mutation frequencies of E. coli strains from aquatic environments under selective pressure from oxytetracycline and chloramphenicol. Given that E. coli__ampersandsign#39;s antibiotic resistance is a growing public health issue, understanding mutation dynamics is crucial. We evaluated mutation frequencies in five E. coli strains isolated from fish, water, and sediment samples. These strains were initially sensitive to chloramphenicol and oxytetracycline. The mutation rates for oxytetracycline ranged between 4.12 x10-8 and 5.52 x 10-8, while chloramphenicol exposure led to mutation frequencies from 1.19 x 10-4 to 9.62 x 10-5. Cluster analysis using hierarchical methods revealed distinct patterns: E. coli strains exposed to oxytetracycline exhibited more uniform mutation frequencies compared to those exposed to chloramphenicol. The proximity matrix and dendrogram analysis demonstrated that oxytetracycline-treated strains clustered closely together, indicating similar mutational responses. Conversely, chloramphenicol-treated strains displayed greater variability, suggesting that chloramphenicol causes more diverse genetic changes in E. coli. The findings highlight an alarming increase in mutation rates, especially under chloramphenicol exposure, which significantly exceeds typical environmental bacterial mutation rates. These findings indicate a significant risk of antibiotic resistance and underscore the need for strict regulations and regular monitoring in aquaculture to manage it. Future research should investigate the specific mutations, strain genomics, and environmental factors contributing to resistance to address public health concerns related to antibiotic-resistant bacteria.</Abstract> <AbstractLanguage>English</AbstractLanguage> <Keywords>antibiotic resistance, aquaculture, bacteria, cluster analysis, mutation</Keywords> <URLs> <Abstract>https://emergentresearch.org/ubijournal-v1copy/journals/abstract.php?article_id=15620&title=Comparative analysis of oxytetracycline and chloramphenicol on mutation frequency in Escherichia coli isolates from aquatic environments</Abstract> </URLs> <References> <ReferencesarticleTitle>References</ReferencesarticleTitle> <ReferencesfirstPage>16</ReferencesfirstPage> <ReferenceslastPage>19</ReferenceslastPage> <References/> </References> </Journal> </Article> </ArticleSet>