Background & objectives: Members of the family enterobacteriaceae comprise the most common gram-negative isolates in microbiology laboratories. Amongst these members, multiple antibiotic-resistant isolates including those producing extended spectrum β-lactamases (ESBL) and AmpC β-lactamases (AmpC) have increased steadily. Further, metallo-β-lactamase (MBL) producing strains are also recently de...

The increasing incidence of inducible chromosomal AmpC β-lactamases within the clinic is a growing concern because these enzymes deactivate a broad range of even the most recently developed β-lactam antibiotics. As a result, new strategies are needed to block the action of this antibiotic resistance enzyme. Presented here is a strategy to combat the action of inducible AmpC by inhibiting the β-...

D2 differed from one another by fewer than five single nucleotide differences, but only the WM98 sequence was not interrupted by large insertions or deletions (positions of insertions/deletions are indicated in Figure 1). AB307-0294 (GenBank accession number CP001172) was also identical over most of this span, but contained patches that differed and lacked a large span. The AB0057 sequence (Gen...

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...

BACKGROUND & OBJECTIVES Non-fermenting Gram-negative bacilli (NFGNB) including Pseudomonas aeruginosa and Acinetobacter baumannii have been implicated in a variety of infections, particularly in the Intensive Care Units (ICUs). This study was aimed to overview the burden of multidrug-resistant NFGNB causing infections in ICU and also to assess the occurrence of extended-spectrum beta-lactamases...

Escherichia coli (E. coli) is a common opportunistic pathogen for nosocomial infection. The aim of the study was to examine the phenotype, genotype and epidemiology of plasmid-mediated AmpC β-lactamases in E. coli. In total, 96 clinical isolates of repeated E. coli were collected from different hospitals between August and October 2012. Using a cefoxitin disk diffusion method to identify the ph...

BACKGROUND & OBJECTIVES Plasmid mediated AmpC β-lactamase (PMABL) resistance in Escherichia coli and Klebsiella spp. is an emerging problem worldwide. Phenotypic methods are commonly used for detection of PMABL production in Gram-negative isolates, but molecular data about the prevalence of plasmid-mediated AmpC-type resistance at the national level are needed. Hence, a prospective study was un...

Extended-spectrum-β-lactamase (ESBL)/AmpC producing Enterobacteriaceae have been reported worldwide amongst isolates obtained from humans, food-producing animals, companion animals, and environmental sources. However, data on prevalence of fecal carriage of ESBL/AmpC producing Enterobacteriaceae in healthy companion animals is limited. This pilot study describes the prevalence of ESBL/AmpC enco...

BACKGROUND & OBJECTIVE The production of carbapenemases is an important mechanism responsible for the carbapenem resistance. A simple and inexpensive testing method for screening of carbapenemase producers is essential. A prospective study was undertaken to detect metallo-beta-lactamases (MBLs) and AmpC beta-lactamases in nonfermentative Gram negative bacteria and to evaluate the various method...

This study aimed to characterize the role of Pseudomonas aeruginosa low-molecular-mass penicillin-binding proteins (LMM PBPs), namely, PBP4 (DacB), PBP5 (DacC), and PBP7 (PbpG), in peptidoglycan composition, β-lactam resistance, and ampC regulation. For this purpose, we constructed all single and multiple mutants of dacB, dacC, pbpG, and ampC from the wild-type P. aeruginosa PAO1 strain. Peptid...