Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria

Arzanlou, Mohsen; Chai, Wern Chern; Venter, Henrietta

doi:10.1042/ebc20160063

Cited by 160 publications

(119 citation statements)

References 88 publications

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“…The high MIC values shown against Ps. aeruginosa may be due to the overexpression of efflux pumps and the presence of outer membrane permeability barrier in the Gram-negative pathogen, which enhances the outer cell membrane resistance towards antimicrobials as reported previously (Poole et al 1993;Mandsberg et al 2009;Arzanlou et al 2017). Thus, a combination effect of either cinnamon oil or cinnamaldehyde with EDTA was investigated against Ps.…”

Section: Discussionmentioning

confidence: 57%

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Antimicrobial effects of cinnamon essential oil and cinnamaldehyde combined with EDTA against canine otitis externa pathogens

Sim

Khazandi

et al. 2019

J Appl Microbiol

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Aims The antimicrobial activity of cinnamon essential oil and cinnamaldehyde against bacterial and fungal pathogens associated with canine otitis externa, as well as the effect of their combination with EDTA were investigated. Methods and Results Antimicrobial susceptibility testing was performed using the broth microdilution method while spot‐plating technique was used to determine their bactericidal activity. Time‐kill kinetics and checkerboard assays were performed to confirm the bactericidal activity and combination effects of the compounds. Cinnamon oil and cinnamaldehyde exhibited antimicrobial activity against Gram‐positive and Gram‐negative pathogens, as well as Malassezia pachydermatis. Synergistic interaction was shown when EDTA (672 μg ml−1) was combined with cinnamon oil (41 μg ml−1) and cinnamaldehyde (22 μg ml−1) against Pseudomonas aeruginosa. Cinnamaldehyde exhibited significantly stronger antimicrobial activity than cinnamon bark oil. Conclusions Cinnamon essential oil and cinnamaldehyde, either used alone or in combination with EDTA, were effective against the causative micro‐organisms of canine otitis externa. The data suggest that cinnamaldehyde could be a promising antimicrobial agent against canine otitis externa. Significance and Impact of the Study This study shows that cinnamon essential oil and cinnamaldehyde, especially the latter, could be used in combination with EDTA as novel treatment for sensitive and resistant bacterial and fungal pathogens involved in canine otitis externa.

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Section: Discussionmentioning

confidence: 57%

“…; Arzanlou et al . ). Thus, a combination effect of either cinnamon oil or cinnamaldehyde with EDTA was investigated against Ps.…”

Section: Discussionmentioning

confidence: 97%

Antimicrobial effects of cinnamon essential oil and cinnamaldehyde combined with EDTA against canine otitis externa pathogens

Sim

Khazandi

et al. 2019

J Appl Microbiol

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“…Phage predation accounts for a significant proportion of bacterial mortality, up to 80% in some systems ( Rohwer et al, 2009 ), and thus presents a remarkably strong source of selective pressure for bacterial immunity systems. Known bacterial immunity systems can be divided into categories analogous to either intrinsic or acquired antimicrobial resistance systems as denoted by Arzanlou et al (2017) . Indeed, a wide variety of phage defense systems have been found that are analogous to intrinsic mechanisms of antimicrobial resistance, where bacteria constitutively express systems that mediate phage resistance, such as Restriction/Modification systems ( Tock and Dryden, 2005 ), Toxin/Anti-toxin systems ( Dy et al, 2014 ), and the Bacteriophage Exclusion (BREX) system ( Goldfarb et al, 2015 ).…”

Section: Introductionmentioning

confidence: 99%

Comparative transcriptomics reveals a conserved Bacterial Adaptive Phage Response (BAPR) to viral predation

Blasdel

Ceyssens

Chevallereau

et al. 2018

Preprint

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Intrinsic and acquired defenses against bacteriophages, including Restriction/Modification, CRISPR/Cas, and Toxin/Anti-toxin systems have been intensely studied, with profound scientific impacts. However, adaptive defenses against phage infection analogous to adaptive resistance to antimicrobials have yet to be described. To identify such mechanisms, we applied an RNAseq-based, comparative transcriptomics approach in different Pseudomonas aeruginosa strains after independent infection by a set of divergent virulent bacteriophages. A common host-mediated adaptive stress response to phages was identified that includes the Pseudomonas Quinolone Signal, through which infected cells inform their neighbors of infection, and what may be a resistance mechanism that functions by reducing infection vigor. With host transcriptional machinery left intact, we also observe phage-mediated differential expression caused by phage-specific stresses and molecular mechanisms. These responses suggest the presence of a conserved Bacterial Adaptive Phage Response mechanism as a novel type of host defense mechanism, and which may explain transient forms of phage persistence.

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“…Effective treatment of bacterial infections is becoming increasingly difficult with the emergence of resistance to multiple classes of antimicrobial drugs. In particular, sepsis due to the multidrug‐resistant (MDR) ESKAPE pathogens ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa , and E. coli / Enterobacter species) contribute significantly to morbidity and mortality associated with antimicrobial resistance (700 000 deaths annually) worldwide . Therefore, the discovery and development of new broad‐spectrum antimicrobials with activity against pan‐resistant resistant ESKAPE pathogens causing sepsis is one of the highest global priorities .…”

Section: Introductionmentioning

confidence: 99%

Gram‐Positive and Gram‐Negative Antibiotic Activity of Asymmetric and Monomeric Robenidine Analogues

Russell

Stevens

et al. 2018

ChemMedChem

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Desymmetrisation of robenidine (1: N′,2‐bis((E)‐4‐chlorobenzylidene)hydrazine‐1‐carboximidhydrazide) and the introduction of imine alkyl substituents gave good antibiotic activity. Of note was the increased potency of two analogues against vancomycin‐resistant Enterococci (VRE), one of which returned a MIC of 0.5 μg mL−1. Five analogues were found to be equipotent or more potent than the lead 1. Introduction of an indole moiety resulted in the most active robenidine analogue against methicillin‐resistant S. aureus (MRSA), with a MIC of 1.0 μg mL−1. Imine C=NH isosteres (C=O/C=S) were inactive. Monomeric analogues were 16–64 μg mL−1 active against MRSA and VRE. An analogue that lacks the terminal hydrazide NH moiety showed modest Gram‐negative activity at 64 μg mL−1. A 4‐tert‐butyl analogue was shown to be active against both Gram‐positive and ‐negative strains at 16–64 μg mL−1. In general, additional modifications with aromatic moieties was poorly tolerated, except with concomitant introduction of an imine C‐alkyl group. The activity of these analogues against MRSA and VRE ranged from 8 μg mL−1 to inactive (MIC>128 μg mL−1) with the naphthyl and indole analogues. Gram‐negative activity was most promising with two compounds at 16 μg mL−1 against E. coli. Against P. aeruginosa, the highest activity observed was with MIC values of 32 μg mL−1 with another two analogues. Combined, these findings support the further development of the (E)‐2‐benzylidenehydrazine‐1‐carboximidamide scaffold as a promising scaffold for the development of antibiotics against Gram‐positive and Gram‐negative strains.

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Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria

Cited by 160 publications

References 88 publications

Antimicrobial effects of cinnamon essential oil and cinnamaldehyde combined with EDTA against canine otitis externa pathogens

Antimicrobial effects of cinnamon essential oil and cinnamaldehyde combined with EDTA against canine otitis externa pathogens

Comparative transcriptomics reveals a conserved Bacterial Adaptive Phage Response (BAPR) to viral predation

Gram‐Positive and Gram‐Negative Antibiotic Activity of Asymmetric and Monomeric Robenidine Analogues

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