characterizing-multidrug-efflux-systems-acinetobacter-baumannii-using

Characterizing Multidrug Efflux Systems in Acinetobacter baumannii Using an Efflux&#45;Deficient Bacterial Strain and a Single&#45;Copy Gene Expression System

Acinetobacter baumannii is recognized as a challenging Gram-negative pathogen due to its widespread resistance to antibiotics. It is crucial to comprehend ...

galleria-mellonella-as-an-infection-antibiotic-treatment-model-for

Galleria mellonella as an Infection and Antibiotic Treatment Model for Acinetobacter baumannii

Galleria mellonella, commonly known as the greater wax moth or waxworm, is an insect infection model that provides researchers with an informative, ...

University of Manitoba

Salicylic acids have been used in human and veterinary medicine for their anti-pyretic, anti-inflammatory, and analgesic properties for centuries. A key role of salicylic acid-immune modulation in response to microbial infection-was first recognized during studies of their botanical origin. The effects of salicylic acid on bacterial physiology are diverse. In many cases, they impose selective pressures leading to development of cross-resistance to antimicrobial compounds. Initial characterization of these interactions was in , where salicylic acid activates the multiple antibiotic resistance () operon, resulting in decreased antibiotic susceptibility. Studies suggest that stimulation of the  phenotype presents similarly in closely related . Salicylic acids also affect virulence in many opportunistic pathogens by decreasing their ability to form biofilms and increasing persister cell populations. It is imperative to understand the effects of salicylic acid on bacteria of various origins to illuminate potential links between environmental microbes and their clinically relevant antimicrobial-resistant counterparts. This review provides an update on known effects of salicylic acid and key derivatives on a variety of bacterial pathogens, offers insights to possible potentiation of current treatment options, and highlights cellular regulatory networks that have been established during the study of this important class of medicines.

Salicylic acids and pathogenic bacteria: new perspectives on an old compound.

The microbiological content of water is an ongoing concern in First Nations communities in Canada. Many communities lack water treatment plants and continue to be under drinking water advisories. However, lack of access to treatment plants is only a part of the problem as poor water distribution systems also contribute to the failure to provide safe drinking water. Here, we studied the microbial diversity and antibiotic resistome from water stored in cisterns from two First Nations communities in Manitoba, Canada. We found that the cistern water contained a high number of bacteria and showed the presence of diverse antimicrobial resistance genes. Interestingly, the bacterial diversity and antimicrobial resistance genes varied considerably from that of the untreated source water, indicating that the origin of contamination in the cistern water came from within the treatment plant or along the delivery route to the homes. Our study highlights the importance of proper maintenance of the water distribution system in addition to access to water treatment facilities to ensure a supply of safe water to First Nations communities in Canada.IMPORTANCEThe work described addresses a critical issue in First Nations communities in Canada-the microbiological content of water. Many of these communities lack access to water treatment plants and frequently experience drinking water advisories. This study focused on the microbial diversity and antibiotic resistome in water stored in cisterns within two First Nations communities in Manitoba, Canada. These findings reveal that cistern water, a common source of drinking water in these communities, contains a high number of bacteria and a wide range of antimicrobial resistance genes. This highlights a serious health risk as exposure to such water can lead to the spread of drug-resistant infections, posing a threat to the well-being of the residents.

Bacterial diversity and resistome analysis of drinking water stored in cisterns from two First Nations communities in Manitoba, Canada.

We report the whole-genome sequence and antibiotic-resistance gene profile of an  isolate, designated AC001_UM, taken from soil along the Red River in Winnipeg, Manitoba, Canada. The genome comprised 3,916,544 nucleotides (GC content: 38.7%). Antibiotic-resistance gene analysis revealed a class D β-lactamase and three efflux pump families.

Complete genome of  AC001_UM from Red River soil banks in Winnipeg, Manitoba, Canada.

Our study aimed to identify the bacterial source of a previously detected mobile antibiotic-resistant gene, , found in a lake that serves as a source to a water treatment plant operated by a First Nation reserve. Three methicillin-resistant presumptive  spp. isolated from the sample using selective media were verified as  positive by PCR. MALDI-TOF and whole-genome sequencing of each isolate confirmed that all three were . Antibiotic-resistant gene analysis of the assembled genomes predicted  with 99.7% sequence identity, and phylogenetic analysis grouped our three  genes with the  allele from a methicillin-resistant strain of . Identifying microbial species known to harbour mobile antibiotic-resistant elements can provide greater depth of information about drinking water, an especially essential need in First Nation reserves where water quality too frequently is poor.

Identification of Mammaliicoccus fleurettii as the source of a methicillin-resistant gene in a First Nation reserve lake in Manitoba, Canada.

 is an opportunistic pathogen that is often studied in commonly used rich media in laboratories worldwide. Due to the metabolic versatility of , it can be cultured in different growth mediums; however, this can lead to genotypic and phenotypic variations. In this study, we compared phenotypic and transcriptomic changes in  ATCC17978-VU cultured in M9 minimal media supplemented with 20 mmol/L sodium succinate and rich lysogeny broth media. Phenotypically, growth was significantly slowed, virulence in  was attenuated, and susceptibility to a variety of antibiotic classes was reduced when  ATCC17978-VU was grown in minimal media versus rich media. Transcriptomic analysis showed differential regulation of >700 genes-including those associated with energy production and ribosomal function-when the two growth conditions were compared, with the majority of the upregulated genes seen in minimal media of unknown function. This study showed that culture media has a profound effect on the phenotype and cellular workings of a bacteria, highlighting the need for more studies of pathogens like  ATCC17978-VU in minimal media.

Phenotypic and transcriptomic changes in  in rich and minimal growth mediums.

Regulatory elements controlling gene expression fine-tune bacterial responses to environmental cues, including antimicrobials, to optimize survival. Acinetobacter baumannii, a pathogen notorious for antimicrobial resistance, relies on efficient efflux systems. Though the role of efflux systems in antibiotic expulsion are well recognized, the regulatory mechanisms controlling their expression remain understudied. This review explores the current understanding of these regulators, aiming to inspire strategies to combat bacterial resistance and improve therapeutic outcomes.

ArticleTotal : 2	Year
Publication title Cited by 1	2024
Publication title Cited by 2	2025

Article	Year
Salicylic acids and pathogenic bacteria: new perspectives on an old compound. Canadian journal of microbiology\| PubMed ID: 37699258	2024
Bacterial diversity and resistome analysis of drinking water stored in cisterns from two First Nations communities in Manitoba, Canada. Microbiology spectrum\| PubMed ID: 38305192	2024
Complete genome of AC001_UM from Red River soil banks in Winnipeg, Manitoba, Canada. Microbiology resource announcements\| PubMed ID: 38634680	2024
Identification of Mammaliicoccus fleurettii as the source of a methicillin-resistant gene in a First Nation reserve lake in Manitoba, Canada. Access microbiology\| PubMed ID: 39697996	2024
Phenotypic and transcriptomic changes in in rich and minimal growth mediums. Canadian journal of microbiology\| PubMed ID: 39819063	2025
Targeting Acinetobacter baumannii resistance-nodulation-division efflux pump transcriptional regulators to combat antimicrobial resistance. npj antimicrobials and resistance\| PubMed ID: 39863717	2025

Dawn White

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