During a two-month period (2017–2018), 336 urine samples positive for Escherichia coli were collected from Tunisian patients. Of the 336 samples, 266 were collected from community patients and 70 from hospital settings. In all, 15 ESBL producers were identified (8 and 7, respectively) and assigned to 13 pulsotypes, including four ESBL-producing E. coli (ESBL-E) with E1 and E2 profiles (2 isolates each) from community patients. The two strains E1 were identified as B2-ST131 subclade C2 and the two isolates E2, A-ST617. The four strains carrying both CTX-M-15 and CTX-M-27, exhibited the multireplicon IncFII/F1A/F1B with the same formula F31:A4:B1. Two isolates with patterns E3 and E4 (Dice coefficient, 78.7%) isolated from community and hospital settings of two geographic areas were assigned to the emerging ST131 C1-M27 subclade and contained the replicon F1:A-:B20. The remaining ESBL-E divided into different sequence types/associated CTX-M: 2 ST131-C2/CTX-M-15 and ST744/CTX-M-55, ST617/CTM-15, ST2973/CTX-M-55, ST6448/CTX-M-15, ST224/CTX-M-15, ST1431/CTX-M-15, and ST38/CTX-M-27, one isolate each. Our study reports for the first time the presence in the Tunisian community of two clones of E. coli, including the virulent clone ST131-C2 harboring both CTX-M-15 and CTX-M-27, and confirms the spread of the emergent clone ST131-C1-M-27, notably in community urinary tract infections.

25CTX-M ESBLs have been increasingly reported from human enterobacteria isolates in 26 Tunisia. NDM-1 carbapenemase was recently reported in isolates from Tunisian Hospitals. 27 During a 2-month period (December 2017 to January 2018), we have collected 23 ESBL- 28 producing Enterobacteriaceae (ESBL-E) from urines of patients hospitalized in three health 29 care facilities and from community, situated in two distinct Tunisian geographical regions. 30 They were divided into 15 Escherichia coli and eight Klebsiella pneumoniae. The aim of this 31 study was to characterize ESBL-E with regard to their β-lactamase content and their 32 epidemiological relationship. The results indicated a high rate (47%) of E. coli producing both 33 CTX-M group-1 and -9. For the first time, we demonstrated the presence of E. coli having 34 concomitantly CTX-M-15 and CTX-M-27 which belong to two sequences types (ST), ie. A-35 ST617 (2 isolates) and B2-ST131 subclade C2 (2 isolates). All four E. coli isolates carried a 36 multireplicon IncF with an identical allelic combination, F31:A4:B1. This study reports also 37 the first description of K. pneumoniae belonging to the clone ST147 carrying the 38 carbapenemase NDM-1 in the Tunisian community. In conclusion, our data confirms the need 39 for monitoring the resistance to extended-spectrum cephalosporins and to carbapenems 40 among enterobacteria in Tunisia. 41 42 43Resistance to extended-spectrum cephalosporins (ESC) is widespread among 44 Enterobacteriaceae species and is mainly due to the production of extended-spectrum ß-45 lactamases (ESBLs). The dissemination of ESBLs is become a growing concern since they 46 are considered as a major cause of morbidity and mortality. Up to the end of the 1990s, TEM-47 and SHV-type ESBLs were mainly produced by the Klebsiella pneumoniae and Enterobacter 48 spp. responsible for nosocomial infections (1, 2). Since 2000s, CTX-M ESBLs have gained 49 prominence mainly in Escherichia coli and K. pneumoniae strains and are now considered as 50 pandemic enzymes. Many bla CTX-M variants exist, but they can be divided into two main 51 clusters (groups -1 and -9); each cluster of CTX-M genotypes has a corresponding progenitor 52 gene sharing homology with different environmental Kluyvera spp. from which bla CTX-M 53 genes originated. Among CTX-M enzymes, CTX-M-15 belonging to group 1, has currently 54 been the most frequent all over the world (1, 3) 55 The majority of CTX-M type ESBL-associated E. coli infections is often concentrated within 56 specific extraintestinal pathogenic E. coli (ExPEC) lineages belonging to highly virulent 57 phylogenetic group B2, and recognizable by their sequence type (ST). The bla CTX-M-15 is the 58 dominant ESBL gene in the virulent E. coli ST131 clone, in particular in the subclade ST131-59 C2 (4). However other genetically divergent CTX-M genes also occur in this ST, such as 60 bla CTX-M-14/14-like variants in Canada, China, and Spain (5, 6). A subclade of E. coli ST131 61 producing the CTX-M-27 (group 9 enzyme, CTX-M-1...