Genetic characterization of the mechanisms of resistance to amoxicillin/clavulanate and third-generation cephalosporins in Salmonella enterica from three Spanish hospitals

The mechanisms of antimicrobial resistance were characterized in 90 Salmonella enterica isolates either resistant or with intermediate resistance to amoxicillin/clavulanate (AMCR/I) or resistant to third-generation cephalosporins (C3GR). These isolates were recovered in three Spanish hospitals during 2007-2009. The C3GR phenotype was expressed by three isolates that carried the following extended-spectrum β-lactamase genes: phage-associated blaCTX M-10 in S. Virchow, blaCTX-M-14a surrounded by ISEcp1 and IS903 in S. Enteritidis, and blaCTX-M-15 linked to ISEcp1 and orf477 in S. Gnesta (first description in this serotype). The AMCR/I phenotype was found in 87 isolates (79 S. Typhimurim, 7 S. Enteritidis, and one S. Thompson). The blaPSE-1 gene, followed by blaOXA-1 was mostly found among S. Typhimurim, and the blaTEM-1 gene among S. Enteritidis. Three different gene combinations [blaPSE-1+floR+aadA2+sul+tet(G); blaOXA-1+catA+aadA1/strA-strB+sul+tet(B) and blaTEM-1+cmlA1+aadA/strA-strB+sul+tet(A)/tet(B) genes] were associated with the ampicillin-chloramphenicol-streptomycin-sulfonamides-tetracycline phenotype in 68 AMCR/I S. enterica isolates. Class 1 integrons were observed in 79% of the isolates and in most of them (45 isolates) two integrons including the aadA2 and blaPSE-1 gene cassettes, respectively, were detected. The blaOXA-1+aadA1 arrangement was detected in 23 isolates, and the aac(6′)-Ib-cr+blaOXA-1+catB3+arr3 in another one. Non-classicclass 1 integrons were found in three isolates: dfrA12+orfF+aadA2+cmlA1+aadA1 (1 isolate), dfrA12+orfF+aadA2+cmlA1+aadA1+qacH+IS440+sul3 (1 isolate) and dfrA12+orfF+aadA2+cmlA1+aadA1+qacH+IS440+ sul3+orf1+mef(B)Δ-IS26 (1 isolate). Taken together, these results underline the need for clinical concern regarding β-lactam resistance in Salmonella and thus for vigilant monitoring

Durability Assessment of a Plasma-Polymerized Coating with Anti-Biofilm Activity against L. monocytogenes Subjected to Repeated Sanitization

Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).[EN] Biofilm formation on food-contact surfaces is a matter of major concern causing food safety and spoilage issues to this sector. The aim of this study was to assess the durability of the anti-biofilm capacity of a plasma-polymerized coating composed of a base coating of (3-aminopropyl) triethoxysilane (APTES) and a functional coating of acrylic acid (AcAc). Coated and uncoated AISI 316 stainless steel (SS) plates were subjected to five sanitization cycles with sodium hypochlorite (0.05%) and peracetic acid (0.5%). The effectiveness of the coating for the inhibition of multi-strain Listeria monocytogenes biofilm formation was confirmed using a three-strain cocktail, which was grown on the SS plates at 12◦ C for 6 days. Compared to the uncoated SS, relative biofilm productions of 14.6% on the non-sanitized coating, 27.9% on the coating after sanitization with sodium hypochlorite, and 82.3% on the coating after sanitization with peracetic acid were obtained. Morphological and physicochemical characterization of the coatings suggested that the greater anti-biofilm effectiveness after sanitization with sodium hypochlorite was due to the high pH of this solution, which caused a deprotonation of the carboxylic acid groups of the functional coating. This fact conferred it a strong hydrophilicity and negatively charged its surface, which was favorable for preventing bacterial attachment and biofilm formation.SIThis publication is based upon work from COST Action CA19110—PlAgri, supported by COST (European Cooperation in Science and Technology-www.cost.eu). XPS tests were conducted by the Advanced Microscopy Laboratory (LMA) of The Institute of Nanoscience of Aragón (INA), University of Zaragoza. The authors are thankful to the LMA-INA for the access to their equipment and their expertise. The AFM images were taken by the Central Research Support Service (SCAI) of the University of Málaga (UMA). The author P. Fernández-Gómez is grateful to Junta de Castilla y León and the European Social Fund (ESF) for awarding her a predoctoral grant (BOCYL-D-15122017-4). The author M. Oliveira is in receipt of a Juan de la Cierva contract IJC2018-035523-I awarded by the Spanish Ministry of Science, Innovation, and Universities MCIN/AEI/10.13039/501100011033. The author E. Sainz-García, as researcher of the University of La Rioja, is thankful to the postdoctoral training program funded by the Plan Propio of the University of La Rioja. The authors I. Muro-Fraguas and A. Sainz-García are thankful to the program of pre-doctoral contracts for the training of research staff that is funded by the University of La Rioja.This study is part of the Research, Development and Innovation projects AGL2017-82779- C2-R and PID2020-113658RB-C2, funded by MCIN/AEI/10.13039/501100011033 and by ERDF “A way to make Europe”

Resistance to Fluoroquinolones in <i>Pseudomonas aeruginosa</i> from Human, Animal, Food and Environmental Origin: The Role of <i>CrpP</i> and Mobilizable ICEs

Fluoroquinolone resistance and the associated genetic mechanisms were assessed by antimicrobial susceptibility and whole genome sequencing in 56 Pseudomonas aeruginosa strains from human, animal, food and environmental origins. P. aeruginosa PAO1, PA7 and PA14 reference strains were also included in the study. Twenty-two strains (37%) were resistant to, at least, one fluoroquinolone agent. Correlation between the number of changes in GyrA and ParC proteins and the level of fluoroquinolone resistance was observed. Mutations or absence of genes, such as mexZ, mvaT and nalD encoding efflux pumps regulators, were also found in resistant strains. The crpP gene was detected in 43 strains (72.9%; 17 of them non-clinical strains), and coded seven different CrpP variants, including a novel one (CrpP-7). The crpP gene was located in 23 different chromosomal mobile integrative and conjugative elements (ICEs), inserted in two tRNAs integration sites. A great variety of structures was detected in the crpP-ICEs elements, e.g., the fimbriae related cup clusters, the mercury resistance mer operon, the pyocin S5 or S8 bacteriocin encoding genes, and mobilization genes. The location of crpP-like genes in mobilizable ICEs and linked to heavy metal resistance and virulence factors is of significant concern in P. aeruginosa. This work provides a genetic explanation of the fluoroquinolone resistance and crpP-associated pathogenesis of P. aeruginosa from a One-Health approach

Characterization of carbapenem resistance mechanisms and integrons in Pseudomonas aeruginosa strains from blood samples in a French hospital

International audienceMetallo-beta-lactamases (MBLs), porin OprD, integrons, virulence factors and the clonal relationships were characterized in imipenem-resistant Pseudomonas aeruginosa (IRPA) isolates. Fifty-six IRPA strains were recovered from blood samples of different patients at a Toulouse teaching hospital from 2011 to 2013. Susceptibility testing of 14 antibiotics was performed by the disc diffusion method. Detection and characterization of MBLs, the oprD gene and integrons were studied by PCR and sequencing. Thirteen genes involved in the virulence of P. aeruginosa were analysed. Molecular typing of IRPA strains was performed by PFGE and multilocus sequence typing. In this study, 61 % of the IRPA isolates showed a multi-resistance phenotype. The MBL phenotype, detected in three isolates (5.4%), was linked to the bla(VIM)-2 gene. The oprD gene was amplified in 55 (98.2 %) IRPA strains, and variations were observed in 54 of them. Insertion sequences (IS) truncating oprD were detected in eight IRPA strains, with the novel ISPa56 identified in two strains. Class 1 integrons were detected in 24 (42.9%) IRPA strains. The bla(VIM-2) gene was found inside the class 1 integron arrangements. The new integrons In1054 (intl1-aacA56-qacE Delta 1-sul1) and In1160 (intl1-aacA4-aacC1d-ISKpn4-gcuE-qacE Delta 1-sul1) have been described for the first time, to the best of our knowledge, in this study. A high clonal diversity was found in our strains. Among the variety of sequence types (STs) found, ST175, ST233, ST235, ST244 and ST654 were noteworthy as epidemic clones. In conclusion, 5.4% of IRPA strains showed an MBL phenotype linked to the bla(VIM-2) gene. The identified oprD high polymorphism could be implicated in the variable resistance to carbapenems in IRPA strains. The dissemination of high-risk clones is a cause of concern