Antibiotics2022, 11, x. https://doi.org/10.3390/xxxxx www.mdpi.com/journal/antibiotics Article Investigating the Role of Antibiotics on Induction, Inhibition and Eradication of Biofilms of Poultry Associated Escherichia coliIsolated from Retail Chicken Meat Aisha Noreen 1,† , Hamid Masood 1,† , Jaweria Zaib 1 , Zara Rafaque 2 , Areeta Fatima 1 , Hira Shabbir 1 , Javaria Alam 1 , Aisha Habib 1 , Saba Noor 1 , Kinza Dil 1 and Javid Iqbal Dasti 1, * 1 Lab of Microbial Genomics and Epidemiology, Department of Microbiology, Quaid-i-Azam University, Islamabad 45320, Pakistan; anoreen@bs.qau.edu.pk (A.N.); hamidmasood99@gmail.com (H.M.); leos336221@gmail.com (J.Z.); areetafatima11@gmail.com (A.F.); hirashabbir30@gmail.com (H.S.); jaweriaalam@gmail.com (J.A.); aisha.noreen.a@gmail.com (A.H.); saba.noor08@yahoo.com (S.N.); dil.kinza225@gmail.com (K.D.) 2 Department of Microbiology, Hazara University, Mansehra 21120, Pakistan; zararafaq@gmail.com * Correspondence: iqbal78@hushmail.com † These authors contributed equally to this work. Abstract: Background: Widespread use of antibiotics as growth promoters and prophylactic agents has dramatic consequences for the development of antibiotic resistance. In this study, we investi- gatedeffects of selected antibiotics on bacterial biofilms and performed extensive antibiotic and VF profiling of poultry-meat associated E. coli strains. Methods: Antibiotic susceptibility was per- formed by a disc diffusion method, followed by molecular screening of resistance and virulence determinants. Further biofilm formation assays, MIC-p, MIC-b, MBIC and MBEC, were performed using standard tissue culture plate method. Results:In total, 83 (75%) samples were confirmed as E. coli from poultry sources, 26 different antibiotics were tested, and maximum numbers of the iso- lates were resistant to lincomycin (100%), while the least resistance was seen against cefotaxime (1%) and polymyxin B (1%). Overall, 48% of the isolates were ESBL producers and 40% showed carbapenemase activity; important virulence genes were detected in following percentages:fimH32 (39%),papC21 (25%), iutA34 (41%), kpsMT-II23 (28%),papEF9 (11%),papGII22 (27%)and fyuA13 (16%). Colistin showed remarkable anti-biofilm activity, while at sub-MIC levels, gentamicin, ceftriaxone and enrofloxin significantly (p <0.01) inhibited the biofilms. A strong induction of bac- terial biofilm, after exposure to sub-minimal levels of colistin clearly indicates risk of bacterial overgrowth in a farm environment, while use of colistin aggravates the risk of emergence of col- istin resistant Enterobacteriaceae, a highly undesirable public health scenario. Keywords: biofilm; colistin; multidrug resistance; virulence; E. coli; sub-MIC 1. Introduction Escherichia coli (E. coli), a Gram-negative rod-shaped bacterium belongs to the family Enterobacteriaceae. As a part of human microbiota, it aids in digestion process and syn- thesis of vitamins. E. coliare one of the first microorganisms that colonizeinfant gut after birth [1]. Pathogenic E. colistrains equipped withdiversevirulence factors cause different infections, including urinary tract infections, hospital-acquired pneumonia, GI tract in- fections and meningitis [2]. Based on site of infection, E. coliare categorized into two major sub-groups; intestinal and extra-intestinal pathogenic E. coli. ExPEC include uro- pathogenic, septicemia-associated, meningitis-associated and avian pathogenic strains. Isolates from different environmental samples such as sewage, food, water, domestic and wild animals show remarkable resemblance toExPEC, causing human infections [3]. Re- Citation: Noreen, A.; Masood, H.; Zaib, J.; Rafaque, Z.; Fatima, A.; Shabbir, H.; Alam, J.; Habib, A.; Noor, S.; Dil, K.; et al. Investigating the Role of Antibiotics on Induction, Inhibition and Eradication of Bio- films of Poultry Associated Esche- richia coli Isolated from Retail Chicken Meat. Antibiotics 2022, volume number, x. https://doi.org/10.3390/xxxxx Academic Editor(s): Theerthankar Das Received: 10 October 2022 Accepted: 7 November 2022 Published: date Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and insti- tutional affiliations. Copyright: © 2022 by the authors. Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/license s/by/4.0/).