Two major hospitals in Kano, North West Nigeria have recorded increasing resistance of clinical pathogens to broad spectrum β lactams, mediated by extended spectrum β-lactamase (ESβL) and non ESBLs. A study was therefore undertaken to determine the occurrence and prevalence of plasmid and chromosomal mediated AmpC βL and carbapenemase in addition to already known ESBL due to increasing resistan...

Constitutive AmpC hyperproduction is the most frequent mechanism of resistance to the weak AmpC inducers antipseudomonal penicillins and cephalosporins. Previously, we demonstrated that inhibition of the β-N-acetylglucosaminidase NagZ prevents and reverts this mechanism of resistance, which is caused by ampD and/or dacB (PBP4) mutations in Pseudomonas aeruginosa. In this work, we compared NagZ ...

Carbapenem-resistance is a great challenge for antimicrobial therapy in Pseudomonas aeruginosa multidrug-resistant infections, as it reduces therapeutic options. This study investigated carbapenem-resistance mechanisms six strains of non-carbapenemase-producing P. aeruginosa. Minimal inhibitory concentrations imipenem and meropenem were determined by epsilometric test broth microdilution. Mutat...

CFE-1 is a unique plasmid-encoded AmpC β-lactamase with the regulator gene ampR. It imparts high resistance to most cephalosporins with constitutive high-level β-lactamase activity. Here, the β-lactamase activities and expression levels of ampC with or without ampR were investigated. Results suggested that the resistance of CFE-1 to cephalosporins is caused by a substitution in AmpR, in which t...

TEM/SHV+ ESBL+ E. coli. There is no immediate explanation for these results, particularly since several other TEM, SHV and CTX-M ESBL+ isolates were correctly identified as ‘exhibiting another resistance mechanism’. The ESBL activity might have been masked by the AmpC inducer (incorporated into all three discs), and hence these results highlight an important limitation of the D69C kit, i.e. it ...

DHA-1, a plasmid-mediated cephalosporinase from a single clinical Salmonella enteritidis isolate, conferred resistance to oxyimino-cephalosporins (cefotaxime and ceftazidime) and cephamycins (cefoxitin and moxalactam), and this resistance was transferable to Escherichia coli HB101. An antagonism was observed between cefoxitin and aztreonam by the diffusion method. Transformation of the transcon...

A clinical strain of Proteus mirabilis (CF09) isolated from urine specimens of a patient displayed resistance to amoxicillin (MIC >4,096 microg/ml), ticarcillin (4,096 microg/ml), cefoxitin (64 microg/ml), cefotaxime (256 microg/ml), and ceftazidime (128 microg/ml) and required an elevated MIC of aztreonam (4 microg/ml). Clavulanic acid did not act synergistically with cephalosporins. Two beta-...

UNLABELLED Objective : The objective of the study was to observe the antimicrobial resistance of AmpC β-lactamase producing E. coli. METHODS Six hundred and seventy E. coli were isolated from 20,257 various pathological samples collected from The Children's Hospital and Institute of Child Health, Lahore, Pakistan. The isolates showed resistance to ceftazidime which were further examined for A...

background :   ampc β-lactamases are important cephalosporinases chromosomally encoded in many of enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. the six different families of plasmid-mediated ampc β-lactamases have been described, but no phenotypic test can discriminate among them. ampc multiplex pcr has been succ...

Acinetobacter baumannii is a troublesome opportunistic pathogen with a high capacity for clonal dissemination. We announce the establishment of a database for the ampC locus in A. baumannii, in which novel ampC alleles are differentiated based on the occurrence of ≥ 1 nucleotide change, regardless of whether it is silent or missense. The database is openly accessible at the pubmlst platform for...