Alicia Fajardo-Lubian

The University of Sydney · Centre for Infectious Diseases and Microbiology, The University of Sydney and The Westmead Institute for Medical Research

The Australian Group on Antimicrobial Resistance (AGAR) performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric gram-negative pathogens. The 2021 survey was the ninth year to focus on bloodstream infections caused by Enterobacterales, and the seventh year where Pseudomonas aeruginosa and Acineto...

Bacteriophages (phages) are selective viral predators of bacteria. Abundant and ubiquitous in nature, phages can be used to treat bacterial infections (phage therapy), including refractory infections and those resistant to antibiotics. However, despite an abundance of anecdotal evidence of efficacy, significant hurdles remain before routine impleme...

Multidrug resistant Klebsiella pneumoniae are agents of life-threatening infections in animals and humans, with several multidrug resistant clones causing outbreaks of disease worldwide. It is generally accepted that only one clone will be dominant in an infection episode.

The Australian Group on Antimicrobial Resistance (AGAR) performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric gram-negative pathogens. The 2020 survey was the eighth year to focus on bloodstream infections caused by Enterobacterales, and the sixth year in which Pseudomonas aeruginosa and Acine...

Effective antimicrobial stewardship requires a better understanding of the impact of different antibiotics on the gut microflora. Studies in humans are confounded by large inter-individual variability and difficulty in identifying control cohorts. However, controlled murine models can provide valuable information. Here, we examine the impact of a p...

The Australian Group on Antimicrobial Resistance (AGAR) performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric gram-negative pathogens. The 2019 survey was the seventh year to focus on bloodstream infections, and included Enterobacterales, Pseudomonas aeruginosa and Acinetobacter species. Eight...

Effective antimicrobial stewardship requires a better understanding of the impact of different antibiotics on the gut microflora. Studies in humans are confounded by large inter-individual variability and difficulty in identifying control cohorts. However, controlled murine models can provide valuable information. We examined the impact of a penici...

Objectives: Evaluate the role of porins in the susceptibility of Klebsiella pneumoniae to ceftaroline and ceftaroline-avibactam. Methods: Susceptibility to ceftaroline and ceftaroline-avibactam was tested by broth microdilution method in Klebsiella pneumoniae isolates (n = 65), including isogenic mutants (n = 30) and clinical isolates (n = 35), wit...

As human population density and antibiotic exposure increase, specialised bacterial subtypes have begun to emerge. Arising among species that are common commensals and infrequent pathogens, antibiotic-resistant 'high-risk clones' have evolved to better survive in the modern human. Here, we show that the major matrix porin (OmpK35) of Klebsiella pne...

As human population density and antibiotic exposure increases, specialised bacterial subtypes have begun to emerge. Arising among species that are common commensals and infrequent pathogens, antibiotic-resistant ‘high-risk clones’ have evolved to better survive in the modern human. Here, we show that the major matrix porin (OmpK35) of Klebsiella pn...

The minimal concentration of antibiotic required to inhibit growth of different isolates of a given species with no acquired resistance mechanisms has a normal distribution. We have previously shown that the presence or absence of transmissible antibiotic resistance genes has excellent predictive power for phenotype. In this study we analysed the d...

Aims Aztreonam/clavulanic acid combination therapy is a potential treatment for multi-resistant Enterobacteriaceae containing MBLs and ESBLs. We describe an aztreonam/clavulanic acid based phenotypic detection and susceptibility test for MBL and ESBL-containing multi-resistant Enterobacteriaceae derived from initial genotypic characterisation. Met...

Objectives: Previous work showed that PA5542 inactivation increases Pseudomonas aeruginosa 59.20 susceptibility to carbapenems. The objective of the current study was to purify PA5542, to determine its role in carbapenem resistance and to analyse the kinetic constants of this putative new β-lactamase. Methods: PA5542 was cloned and expressed in...

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 27-11-2009 Bibliogr.: p.196-209

The capacity of a bacterial pathogen to produce a disease in a treated host depends on the former's virulence and resistance to antibiotics. Several scattered pieces of evidence suggest that these two characteristics can be influenced by bacterial metabolism. This potential relationship is particularly important upon infection of a host, a situatio...

Multidrug efflux pumps have emerged as relevant elements in the intrinsic and acquired antibiotic resistance of bacterial pathogens. In contrast with other antibiotic resistance genes that have been obtained by virulent bacteria through horizontal gene transfer, genes coding for multidrug efflux pumps are present in the chromosomes of all living or...

Antibiotics are likely the most important compounds used for human therapy. Conversely, antibiotic resistance is a relevant medical problem. However, besides their relevance for human health, antibiotics and their resistance genes are important elements that can influence the structure of microbial populations. In this article, we discuss antibioti...

Pseudomonas aeruginosa infections are increasingly associated with acute exacerbations in chronic obstructive pulmonary disease (COPD). We aimed to determine whether an underlying chronic infection might be behind this process and to determine the epidemiological characteristics of the isolates involved, to implement useful protocols for preventing...

Antibiotic resistance is one of the few examples of evolution that can be addressed experimentally. The present review analyses this resistance, focusing on the networks that regulate its acquisition and its effect on bacterial physiology. It is widely accepted that antibiotics and antibiotic resistance genes play fundamental ecological roles - as...

The ecological and evolutionary roles of antibiotics have been usually inferred from their therapeutical activity. Since those compounds inhibit bacterial growth, it was thought that they should be produced by soil microorganisms to inhibit the growth of competitors in natural habitats. It has been shown however that antibiotics modulate transcript...

Relative susceptibility and chromosomal position of P. aeruginosa mutations that alter the level of antibiotic susceptibility. (0.16 MB DOC)

Bacteria with intrinsic resistance to antibiotics are a worrisome health problem. It is widely believed that intrinsic antibiotic resistance of bacterial pathogens is mainly the consequence of cellular impermeability and activity of efflux pumps. However, the analysis of transposon-tagged Pseudomonas aeruginosa mutants presented in this article sho...