Conjugative plasmidic AmpC detected in Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae human clinical isolates from Portugal

Abstract

AmpC is a type of β-lactamase enzyme produced by bacteria; these enzymes are classified in Class C and Group 1, and these confer resistance to cephamycin. Enterobacterales producing AmpC are reported worldwide and have great clinical importance due to therapeutic restriction and epidemiological importance once the easy dissemination by plasmidic genes to other bacteria is a real threat. These genes are naturally found in some enterobacteria as Enterobacter cloacae, Morganella morganii, and Citrobacter freundii, but other species have demonstrated similar resistance phenotype of AmpC production. Genes carried in plasmids have been described in these species conferring resistance to cefoxitin and causing therapeutic failure in some bacterial infections. This work detected and described five clinical strains of Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae that presented plasmid ampC (pAmpC) isolated from the north of Portugal collected in 2009. AmpC production was confirmed by inhibition of the enzyme by cloxacillin and boronic acid in agar diffusion tests. Also, PCR (polymerase chain reaction) was performed for the detection of gene universal to AmpC, bla ampC , and others to AmpC group: bla ACC , bla CIT , bla CMY , bla DHA , and bla EBC. The conjugation in liquid medium for 24 h was realized to determine if gene is localized in chromosome or plasmid. The isolates and their conjugants showed phenotypic characteristics and bla CMY and bla CIT were detected by PCR corroborating the AmpC characteristics observed in these bacteria. Confirmation of transfer of plasmid containing genes encoding AmpC is of high epidemiological relevance to the hospital studied and demonstrated the importance of AmpC surveillance and studies in hospital and community environments in order to choose the appropriate therapy for bacterial infections.

Synthesis and photodynamic antimicrobial chemotherapy against multi-drug resistant Proteus mirabilis of ornithine-porphyrin conjugates in vitro and in vivo

“…Beta-lactam resistance was often found in MRPM due to the production of extended-spectrum beta-lactamases, AmpC enzymes, or metallo-betalactamases. Point mutations in gyrA, gyrB, and parC genes on chromosomes of P. mirabilis could Meng et al 10.3389/fmicb.2023.1196072 Frontiers in Microbiology 02 frontiersin.org cause resistance to quinolones (Dougnon et al, 2020;Santiago et al, 2020;Shaaban et al, 2022). Therefore, it is essential to discover efficient antimicrobial methods that apply different mechanisms for the treatment of P. mirabilis infection.…”

Plasmid-Mediated AmpC (pAmpC) Genotypes Among Uropathogenic Escherichia coli: A Hospital-Based Study From Western Uttar Pradesh

“…The Bush-Jacoby-Medeiros functional classification of AmpC enzymes places them in group 1, but the Ambler structural classification places them in class C [ 3 ]. AmpC β-lactamase genes were originally transmitted via a chromosomal transfer, but plasmids are also capable of doing so [ 4 ]. The plasmid-mediated AmpC (pAmpC) β-lactamases are a serious concern and have caused the emergence and spread of MDR strains, which are important from the clinical and epidemiological standpoints [ 5 ].…”

Prevalence of plasmid-mediated AmpC β-lactamases among uropathogenic Escherichia coli isolates in southwestern Iran

“…AmpC-type β-lactamases are in the C group of Ambler and their common genotypes include bla FOX , bla MOX , bla CIT , bla DHA , bla EBC , and bla ACC . Originally, these genes were transferred chromosomally, but they can also be disseminated by plasmids or other mobile elements [ 4 ]. The acquisition of plasmid-mediated AmpC (pAmpC) β-lactamases genes by organisms such as E. coli has prompted major concerns because it leads to the emergence and wide dissemination of multidrug-resistant (MDR) strains that are clinically and epidemiologically very important [ 5 ].…”