Environmental concentrations of antibiotics induced polymyxin B tolerance in Aeromonas hydrophila.

Polymyxin B is one of the last lines of defense in infections caused by multidrug-resistant Gram-negative bacteria. Aeromonas hydrophila are important fish pathogens and the occurrence of polymyxin B-resistant A. hydrophila isolates is increasing.

Phenothiazine Derivatives: The Importance of Stereoisomerism in the Tolerance and Efficacy of Antimicrobials.

Unlabelled: Stereoisomers are molecules that are identical in atomic constitution and bonding. The biological properties may, however, differ significantly between two enantiomers (individual stereoisomers). JBC 1847, a phenothiazine derivative with strong antimicrobial activity against Gram-positive bacteria, exists in two enantiomers, S and R.

Inhibition of Plasmid Conjugation in by Targeting Gene Using CRISPRi System.

Bacterial conjugation constitutes a major horizontal gene transfer mechanism for the dissemination of antibiotic-resistant genes (ARGs) among human pathogens. The spread of ARGs can be halted or diminished by interfering with the conjugation process. In this study, we explored the possibility of using an gene as a single target to inhibit plasmid-mediated horizontal gene transfer in by CRISPR interference (CRISPRi) system.

Efflux Pumps and Different Genetic Contexts of (X4) Contribute to High Tigecycline Resistance in from Pigs.

Tigecycline is a last-resort antibiotic for the treatment of infections caused by multidrug-resistant bacteria. The emergence of plasmid-mediated tigecycline resistance genes is posing a serious threat to food safety and human health and has attracted worldwide attention. In this study, we characterized six tigecycline-resistant strains from porcine nasal swab samples collected from 50 swine farms in China.

Antimicrobial Activity of Sertraline on .

We explored the antimicrobial activity of sertraline on and further investigated the effects of sertraline on biofilm formation and the virulence gene expression of . The minimum inhibitory concentration and minimum bactericidal concentration for sertraline against were in the range of 16-32 μg/mL and 64 μg/mL, respectively. Sertraline-dependent damage of the cell membrane and a decrease in intracellular ATP and pH in were observed.

Dramatic increase in slaughter condemnations due to Escherichia coli ST23 and ST101 within the Danish broiler production.

Escherichia coli constitutes a major challenge to poultry even when the prevalence of colibacillosis is low. Additionally, specific E. coli strains can severely enhance the detrimental effects on productivity, animal welfare and antimicrobial use.

Characterization of extended-spectrum cephalosporins and fluoroquinolone resistance of a serovar Thompson isolate from ready-to-eat pork product in China.

is a leading cause of foodborne illness worldwide and is a common concern in food safety. displaying resistance to extended-spectrum cephalosporins (ESCs) and fluoroquinolone (FQs) has been deemed a high-priority pathogen by the World Health Organization. Co-resistance to ESCs and FQs has been reported in serovar Thompson (.

Genetic context of and genes in a foodborne serotype Saintpaul isolate from China.

resistant to fluoroquinolones (FQs) and extended-spectrum cephalosporins (ESCs) has been deemed a high-priority pathogen by the WHO. serovar Saintpaul (. Saintpaul) co-resistant to ESCs and FQs and harboring corresponding resistance genes ( and ) have been previously reported.

Genomic Characterization of --Carrying Foodborne serovar Typhimurium and Identification of a Transferable Plasmid Carrying -, , , and Genes From Ready-to-Eat Pork Product in China.

resistant to colistin, third-generation cephalosporins (3GCs), and fluoroquinolones (FQs) has been deemed a high-priority pathogen by the World Health Organization (WHO). The objective of this study was to characterize 11 --harboring serovar Typhimurium isolates from raw pork and ready-to-eat (RTE) pork products in Guangzhou, China. All isolates were multi-drug resistant and contained 6-24 antibiotic-resistant genes.

Longitudinal study on background lesions in broiler breeder flocks and their progeny, and genomic characterisation of Escherichia coli.

In broiler breeders, background mortality is rarely addressed, however, it represents the death of a vast number of birds, a constant productivity loss, welfare concerns and it might affect chick quality. The study aimed to unveil lesions leading to mortality in a study population perceived as healthy, combined with whole-genome sequencing (WGS) of Escherichia coli, a well-known contributor to disease problems in poultry. Broiler breeders (n = 340) originating from three distinct, putative healthy flocks and their progeny (n = 154) were subjected to a comprehensive post-mortem examination, bacteriological sampling, and sequencing of 77 E.

Engineering a CRISPR interference system targeting AcrAB-TolC efflux pump to prevent multidrug resistance development in Escherichia coli.

Objectives: We engineered a CRISPR interference (CRISPRi) system targeting the AcrAB-TolC efflux pump to prevent MDR development in Escherichia coli.

Methods: Nine specific single-guide RNAs (sgRNAs) were designed to target the components of the AcrAB-TolC efflux pump, namely AcrA, AcrB and TolC. A total of thirteen CRISPRi recombinant plasmids were constructed with single or clustered sgRNAs.

Exploring the resistome, virulome, mobilome and microbiome along pork production chain using metagenomics.

In order to understand and minimize microbial contaminants spread from animal to raw pork products, we explored the diversity of antibiotic resistance genes (ARGs), virulence factors (VFs), mobile genetic elements (MGEs) and the bacterial community composition in feces of pigs, processing areas as well as the end pork products in a large-scale pig slaughterhouse in China using metagenomics. The abundance and diversity of microbial community was higher in arrival and slaughtering room area and decreased sharply in the end pork products. Furthermore, the relative abundance of some clinically relevant pathogens and opportunity pathogens were greater in the end pork products and cutter samples.

Assessment of automated assays for serum amyloid A, haptoglobin (PIT54) and basic biochemistry in broiler breeders experimentally infected with Escherichia coli.

Biomarkers of inflammation are valuable tools for health status evaluation in numerous species. However, in poultry, methods for measuring acute phase proteins (APP) are sparse and rely on manual laboratory labour reserving these parameters mainly for research studies with APP as a focus point. To extend the use of APP beyond tightly focused research studies, blood from experimentally infected and control hens was analysed using equipment available in many veterinary clinics in order to identify easily accessible biomarkers of infection.

Short- and long-read metagenomics insight into the genetic contexts and hosts of mobile antibiotic resistome in Chinese swine farms.

Antibiotic resistance genes (ARGs) are emerging environmental contaminants posing a threat to public health. Intensive swine farms are recognized as hotspots for antibiotic resistance genes (ARGs). However, antibiotic resistome and their genetic contexts, hosts, and transferability in Chinese swine farms remain largely unexplored.

Insight Into the Anti-staphylococcal Activity of JBC 1847 at Sub-Inhibitory Concentration.

Multidrug-resistant pathogens constitute a serious global issue and, therefore, novel antimicrobials with new modes of action are urgently needed. Here, we investigated the effect of a phenothiazine derivative (JBC 1847) with high antimicrobial activity on , using a wide range of assays, flow cytometry, and RNA transcriptomics. The flow cytometry results showed that JBC 1847 rapidly caused depolarization of the cell membrane, while the macromolecule synthesis inhibition assay showed that the synthesis rates of DNA, RNA, cell wall, and proteins, respectively, were strongly decreased.

Protective Potential of an Autogenous Vaccine in an Aerogenous Model of Infection in Broiler Breeders.

Unlabelled: In poultry, is a common cause of high-cost infections. Consequently, autogenous vaccines are often used despite limited and conflicting evidence on their effectiveness have been presented. The present study aimed to investigate the efficacy of a commonly used autogenous vaccine, previously deemed ineffective, in an aerosol model of colibacillosis.

Corrigendum: First Report of a Foodborne Serovar Gloucester (4:i:l,w) ST34 Strain Harboring and Genes Located in IS-Mediated Composite Transposon.

[This corrects the article DOI: 10.3389/fmicb.2021.

First report of two foodborne Salmonella enterica subsp. enterica serovar Bovismorbificans isolates carrying a novel mega-plasmid harboring bla and qnrB4 genes.

Salmonella enterica displaying resistance to extended-spectrum cephalosporins and fluoroquinolone (FQs) has been deemed a high-priority pathogen by the World Health Organization (WHO). While CTX-M type acquired β-lactamases have been detected in S. enterica serovar Bovismorbificans, DHA enzymes have been rarely reported in S.

Development of an aerogenous Escherichia coli infection model in adult broiler breeders.

Escherichia coli constitutes an immense challenge to the poultry industry due to its devastating effect on productivity, mortality, and carcass condemnations. To aid future studies on disease mechanisms and interventions, an aerogenous infection model was established in adult broiler breeders. Hens (n = 120) were randomly allocated into six groups receiving either aerosolised E.

A new phenothiazine derivate is active against Clostridioides difficile and shows low cytotoxicity.

The rapid evolution of antibiotic resistance in Clostridioides difficile and the consequent effects on prevention and treatment of C. difficile infections (CDIs) are matters of concern for public health. Thioridazine, a compound belonging to the phenothiazine group, has previous shown antimicrobial activity against C.

Efficacy of a novel antimicrobial hydrogel for eradication of , and from preformed biofilm and treatment performance in an MRSA wound model.

Background: Bacterial biofilm formation is a complicating factor in the antimicrobial treatment of bacterial infections.

Objectives: In this study, we assessed the impact of a novel hydrogel with the active antimicrobial compound JBC 1847 on eradication of preformed biofilms of , and MRSA , and evaluated the efficacy of MRSA wound treatment.

Methods: Biofilms were exposed to JBC 1847 for 24 h and subsequently the treatments were neutralized and surviving biofilm-associated bacteria recovered and enumerated.

First Report of a Foodborne Serovar Gloucester (4:i:l,w) ST34 Strain Harboring and Genes Located in IS-Mediated Composite Transposon.

Extended-spectrum β-lactamases (ESBLs) production and (fluoro)quinolone (FQ) resistance among pose a public health threat. The objective of this study was the phenotypic and genotypic characterization of an ESBL-producing and nalidixic acid-resistant serovar Gloucester isolate (serotype 4:i:l,w) of sequence type 34 (ST34) from ready-to-eat (RTE) meat products in China. Whole-genome short and long read sequencing (HiSeq and MinION) results showed that it contained , , and genes, with and located in chromosomal IS-mediated composite transposon (IS--IS-Tn-- -IS-IS).

A Novel Promazine Derivative Shows High and Antimicrobial Activity Against .

The emergence of multidrug-resistant bacteria constitutes a significant public health issue worldwide. Consequently, there is an urgent clinical need for novel treatment solutions. It has been shown that phenothiazines can act as adjuvants to antibiotics whereby the minimum inhibitory concentration (MIC) of the antibiotic is decreased.

A Novel Derivative of Thioridazine Shows Low Toxicity and Efficient Activity against Gram-Positive Pathogens.

Thioridazine hydrochloride (HCl) has been suggested as a promising antimicrobial helper compound for the treatment of infections with antimicrobial-resistant bacteria. Unfortunately, the therapeutic concentration of thioridazine HCl is generally higher than what can be tolerated clinically, in part due to its toxic side effects on the central nervous system. Therefore, we aimed to synthesize a less toxic thioridazine derivative that would still retain its properties as a helper compound.

GtxA is a virulence factor that promotes a Th2-like response during Gallibacterium anatis infection in laying hens.

GtxA, a leukotoxic RTX-toxin, has been proposed a main virulence factor of Gallibacterium anatis. To evaluate the impact of GtxA during infection, we experimentally infected laying hens with a G. anatis wild-type (WT) strain and its isogenic gtxA deletion mutant (ΔgtxA), respectively, and monitored the birds during a 6 day period.