ANNUAL CONFERENCE ONLINE 2021 26–30 April 2021 POSTER ABSTRACT BOOK #Microbio21 P001 Detection of Extended Spectrum Beta-lactamase Gene (CTX-M) among Representative Multidrug-Resistant Gram Negative Bacterial Isolates from Patients with Urinary Tract Infection in Ekiti State, Nigeria. Ayodele Oluwaseun Ajayi1, Samuel Ayodeji Osanyinlusi1, Amos Ojerinde2, Bryan Ogeneh2 1Federal University Oye Ekiti, Oye-Ekiti, Nigeria. 2Federal University Oye Ekiti, Federal University Oye Ekiti, Nigeria Abstract Urinary tract infection is huge public health burden and the emergence of extended spectrum beta lactamase producing bacterial pathogens increases the burden of infectious diseases in Nigeria. This study determined the current prevalence of cephalosporin resistance among Gram-negative bacteria isolated from patients with urinary tract infections between February 2018 and June 2018. Non- repetitive Gram–negative bacteria were recovered from 106 individuals with urinary tract infections who reported at two tertiary healthcare centers in Ekiti-State, Nigeria. A total of 106 bacterial isolates were obtained which included: Klebsiella pneumoniae 34 (29.1%), Klebsiella oxytoca 17 (16.0%), Proteus vulgaris 10 (9.4%), E. coli 24 (22.6%), Proteus mirabilis 18 (16.9%) and Pseudomonas aeruginosa 3 (2.8%). Sixty five of these organisms showed resistance to ceftazidime while 76 organisms showed resistance to ceftriaxone. Forty representative organisms were selected and tested for presence of extended spectrum beta-lactamase (ESBL) genes using primers specific for different ESBL genes. A total of eight (20.0%) organisms carried the blaCTX-M gene and other variants of the ESBL genes were not detected. The organisms carrying the blaCTX-M gene included E. coli 3 (37.5%), K. pneumoniae 1(12.5%), P. mirabilis 1(12.5%),) and K. oxytoca 3(37.5%). The high prevalence of cephalosporin resistant Gram-negative bacteria among patients with UTI is a serious threat to public health and efforts must be intensified to regulate the clinical use of the cephalosporins. P002 Nitrofurantoin-resistant Escherichia coli in the UK: genetic determinants, diversity, and undetected occurrences Yu Wan1, Ewurabena Mills1,2, Rhoda C.Y. Leung1, Ana Vieira1, Elita Jauneikaite3,1, Xiangyun Zhi1, Nicholas Croucher3,4, Matthew J. Ellington5,1, Shiranee Sriskandan1 1NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Imperial College London, London, United Kingdom. 2Imperial College Healthcare NHS Trust, London, United Kingdom. 3Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, United Kingdom. 4MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, United Kingdom. 5Antimicrobial Resistance and Healthcare Associated Infections laboratory, National Infections Service, Public Health England, London, United Kingdom Abstract Background Antimicrobial resistance in enteric or urinary E. coli might predispose invasive E. coli infection and bacteraemia. Nitrofurantoin resistance occurs in <6% of UK urinary E. coli isolates, however, 2018 national recommendations to prescribe nitrofurantoin for uncomplicated urinary tract infection (UTI) raised concerns for increased prevalence of nitrofurantoin-resistant E. coli in the future. Therefore, we investigated mechanisms of nitrofurantoin resistance in UK E. coli isolates and assessed their occurrences in a large dataset of E. coli genomes. Methods To elucidate chromosomal and acquired genetic determinants of nitrofurantoin resistance in E. coli, we analysed whole-genome sequences of nine randomly selected nitrofurantoin-resistant UTI E. coli isolates from West London. We then performed targeted analysis of 12,412 E. coli genomes collected from across the UK and predicted nitrofurantoin susceptibility from identified genotypes. Results Using comparative genomics, we found known and novel point mutations or insertion sequences (ISs) in chromosomal genes encoding oxygen-insensitive nitroreductases NfsA and NfsB in the nine isolates. Most of these genetic alterations resulted in gene inactivation. We also identified the same kinds of mutations in NfsA, NfsB, and their associated enzyme RibE in a number of 12,412 E. coli genomes. We also observed homoplasic mutations in all these proteins. By contrast, multidrug efflux pump OqxAB, which confers resistance when horizontally transferred, was only encoded by one genome. Conclusions Chromosomal de novo mutations and ISs are main causes of nitrofurantoin resistance in UK E. coli. Prevalence of nitrofurantoin resistance should be monitored among urine, blood, and enteric isolates as nitrofurantoin exposure increases. P003 Trans-cinnamaldehyde - geraniol mixture – antibacterial activity and haemotoxicity Daria Olkiewicz1, Maciej Walczak1, Magdalena Stepczyńska2 1Nicolaus Copernicus University, Toruń, Poland. 2Kazimierz Wielki University, Bydgoszcz, Poland Abstract Abstract The aim of this study was to test the antibacterial activity and haemotoxicity of (trans)-cinnamaldehyde and geraniol. Conducted analyzes showed that (trans)-cinnamaldehyde- geraniol mixture have antibacterial properties against S. aureus ATCC6538, E. coli ATCC8739 and P. aeruginosa KKP991. MIC and MBC of the mixture was determined for each strain. For S. aureus MIC=0.065 mg/ml, MBC=1.25 mg/ml, for E. coli MIC= 0.5 mg/ml, MBC=1 mg/ml and for P. aeruginosa MIC=0.5 mg/ml, MBC=1.25 mg/ml. Also the blood compatibility test was done, and it showed that MIC for S. aureus (0.025 mg/ml) is non-haemotoxic, but other MICs and all MBCs, unfortunately are. P004 Phytochemicals As Novel Alternative Antimicrobials Ryan Sweet, Mark Webber, Paul Kroon Quadram Institute Bioscience, Norwich, United Kingdom Abstract As the incidence of AMR rises globally, and discovery of novel antibiotic classes remains stagnant, novel antimicrobials are urgently required to control AMR pathogens within a wide variety of clinical and non- clinical contexts. Phytochemicals, especially polyphenols, include secondary metabolites produced by plants for numerous functions; one such being as antimicrobial defences. These compounds are a promising source of novel bioactive structures and have been investigated for their potential as alternative sources of antimicrobials. We screened a phytochemical panel for antimicrobial activity against the common foodborne pathogens Salmonella enterica, Staphylococcus aureus, Listeria monocytogenes and Pseudomonas aeruginosa. A range of phenotypic assays were used to investigate the impact of the polyphenols on growth rates and cellular permeability, as well as to identify compounds that synergised with existing antibiotics. Various phytochemicals exhibited antimicrobial activity; naringenin reduced the growth rate of Salmonella by ~30% and Staphylococcus by >95%. Thymol was particularly potent reducing the growth rate of Salmonella and Staphylococcus by ~47% and ~48% respectively, with a >95% reduction in the growth rate of Pseudomonas. In terms of synergistic capacities, caffeic acid significantly increased the membrane permeability of Salmonella by ~46%, a property which holds promise for potentiating known antibiotic classes in synergistic antimicrobial chemotherapies. The potential for selection of mutants resistant to thymol was investigated using selective agar-plating methods, and was observed to induce tolerant mutants at a frequency of ~3.77x10-8 for Salmonella, Staphylococcus and Pseudomonas. The data gathered throughout this project highlights the promise of phytochemicals as alternative sources of antimicrobials, with both direct and synergistic capabilities. P005 Antimicrobial resistance Salmonella isolates recovered from food products of animal origin in the Russian Federation Galina Skitovich, Kseniya Serova, Yevgenia Korchagina, Natalya Shadrova FGBI “Federal Centre for Animal Health”, Vladimir, Russian Federation Abstract The study was aimed at Salmonella isolation from samples of animal food products submitted for testing from various regions of the Central part of the RF and serotyping of the recovered isolates and their testing for antibiotic resistance. A total of 2,342 tests were performed and 87 (3.7%) Salmonella isolates were recovered. Most of them (54 isolates) were recovered from poultry meat and poultry meat preparation samples submitted for testing. Besides, 25 isolates were recovered from pork and pork preparation samples, 7 isolates – from beef samples, 1 isolate – from hard cheese samples. Serotyping of 64 Salmonella isolates showed that the majority of the isolates (57.8 %) belonged to О7 group. Also, Salmonella isolates belonging to О9 (21.9%), О8 (9.4%), О4,5 (6.2%) and О10 (4.7%) were detected in food products. S. Enteritidis, (23.3%), and S. Infantis (18.7%), were predominant based on the number of detections. Also, the following serovars were identified: S. typhimurium, S. nigeria, S. montevideo, S. derby, S. meleagridis, S. virchov, S. oranienburg. Tests of 87 Salmonella isolates for their antibiotic resistance with disk diffusion method revealed that they were highly resistant to nalidixic acid (70.1%), tetracycline (49.4%), trimethoprim/sulfamethoxazol (40.2%). Moreover, nalidixic acid-resistance was common for all identified isolates. Seventeen isolates (19.5%) demonstrated multiple antibiotic resistance and two isolates were found to be resistant to ≥7 antibiotics. All recovered isolates were susceptible to