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Antimicrobial Agents and Chemotherapy Nov 2017Two adjacent colistin resistance gene variants, termed and -like, were identified in the chromosome of an isolate obtained from retail chicken meat. The variants...
Two adjacent colistin resistance gene variants, termed and -like, were identified in the chromosome of an isolate obtained from retail chicken meat. The variants showed 95.20% and 84.19% nucleotide sequence identity, respectively, to from porcine Functional cloning indicated that only conferred polymyxin resistance in both and The -like segment was also observed in other species, including , , and .
Topics: Aeromonas veronii; Animals; Anti-Bacterial Agents; Bacterial Proteins; Chickens; China; Chromosomes, Bacterial; Cloning, Molecular; Colistin; Drug Resistance, Bacterial; Food Microbiology; Microbial Sensitivity Tests; Polymyxins
PubMed: 28848017
DOI: 10.1128/AAC.01272-17 -
Frontiers in Cellular and Infection... 2022spp. are recognized as opportunistic pathogens causing diseases. Infections in humans can result mainly in gastrointestinal and wound diseases with or without...
spp. are recognized as opportunistic pathogens causing diseases. Infections in humans can result mainly in gastrointestinal and wound diseases with or without progression to septicemia. Although spp. are not known uropathogens and they rarely cause urinary tract infection, we hypothesize that the presence of these bacteria in the water and the contact during, .., recreational and bathing activity can create the conditions for the colonization of the human body and may result to diseases in various locations, including the urinary tract. Our study presents the occurrence of aeromonad fluoroquinolone-susceptible phenotypes with the presence of plasmid-mediated fluoroquinolone resistance (PMQR) genes in a natural freshwater reservoir occasionally used for recreational activities. Sixty-nine isolates collected during the bathing period were identified by mass spectrometry and screened for the presence of fluoroquinolone-resistant phenotypes and genotypes. Fluoroquinolone susceptibility was determined as minimal inhibitory concentration values. PMQR genes were detected by PCR. Isolates comprising eight species, namely, mainly (50.7% isolates) and (24.6% isolates) and rarely , , , , and , were selected. All isolates were phenotypically susceptible either to ciprofloxacin or levofloxacin. Unexpectedly, at least one to three of the PMQR genes were detected in 42.0% of the fluoroquinolone-susceptible spp. phenotypes. Mainly the (34.8% isolates) and (14.5% isolates) determinants were detected. In conclusion, the freshwater reservoir occasionally used for bathing was tainted with aeromonads, with a high occurrence of opportunistic pathogens such as and . MALDI-TOF MS is a powerful technique for aeromonad identification. Our data reveals the mismatch phenomenon between fluoroquinolone-susceptible aeromonad phenotypes and the presence of plasmid-mediated resistance genes. It suggests that phenotypically susceptible bacteria might be a potential source for the storage and transmission of these genes. The exposure during, .., a recreational activity may create the potential risk for causing infections, both diagnostically and therapeutically difficult, after expressing the resistance genes and quinolone-resistant strain selection.
Topics: Aeromonas; Anti-Bacterial Agents; Drug Resistance, Bacterial; Fluoroquinolones; Fresh Water; Phenotype; Plasmids; Quinolones
PubMed: 35646727
DOI: 10.3389/fcimb.2022.885360 -
Infection and Drug Resistance 2023The purpose of this study is to examine the variations between extra-intestinal and intestinal infections of in terms of strain types, risk factors, drug susceptibility...
PURPOSE
The purpose of this study is to examine the variations between extra-intestinal and intestinal infections of in terms of strain types, risk factors, drug susceptibility results, and the distribution of drug resistance and virulence genes.
PATIENTS AND METHODS
A total of 188 strains were identified to the species level using housekeeping genes (, and ). The risk factors for extra-intestinal and intestinal infection, as well as mortality, were retrospectively examined in this study. The broth microdilution method was used to investigate the antimicrobial susceptibility profiles. Touchdown polymerase chain reaction (PCR) assays and DNA sequencing were employed to confirm virulence and the presence of drug resistance genes.
RESULTS
The housekeeping genes identified 188 strains into 7 species. Extra-intestinal isolates generally contained and , while intestinal were (p=0.0001). Extra-intestinal infections (158/188) were the main type and accounted for 24/27 of all fatalities. Malignant tumors, hepatobiliary diseases, anemia, and hypoproteinemia were linked to infections. Poor results were associated with septic shock. Using the broth microdilution method, over 80% isolates were susceptible to most antimicrobials, except for ceftazidime (79.8%) and ceftriaxone (69.7%). Except for imipenem, intestinal strains were more susceptible to other medications than extra-intestinal. Using touch-down polymerase chain reaction testing and DNA sequencing, 6 strains, 31 strains, and a strain only had , , and , respectively. Two each possessed + , and + + + ; two each possessed + + + , and + . Thirty-four of the 42 strains mentioned above were isolated from extra-intestinal. , and , were in intestinal more frequently, but , and were in extra-intestinal more frequently.
CONCLUSION
inside and outside intestinal differed in their clinical characteristics, drug susceptibility, drug resistance and virulence genes.
PubMed: 36721629
DOI: 10.2147/IDR.S393347 -
Carbohydrate Research Apr 2022Presented herein is the synthesis of the Aeromonas veronii disaccharide repeating unit which has been achieved in 11 steps starting from d-fucose and d-galactosamine.
Presented herein is the synthesis of the Aeromonas veronii disaccharide repeating unit which has been achieved in 11 steps starting from d-fucose and d-galactosamine.
Topics: Aeromonas; Aeromonas veronii; Disaccharides; Fucose
PubMed: 35263695
DOI: 10.1016/j.carres.2022.108530 -
PeerJ 2021Endogenous hydrogen sulfide (HS) is generated in many metabolism pathways, and has been recognized as a second messenger against antibiotics and reactive oxygen species...
Endogenous hydrogen sulfide (HS) is generated in many metabolism pathways, and has been recognized as a second messenger against antibiotics and reactive oxygen species (ROS). In , Small Protein B (SmpB) plays an important role in resisting stress. The absence of could trigger sulfate assimilation pathway to adapt the nutrient deficiency, of which was mediated by up-regulation of and genes and followed with enhancing HS production. To figure out the mutual regulations of and genes, a series of experiments were performed. Compared with the wild type, was down-regulated significantly in deletion by qRT-PCR. The fluorescence analysis further manifested that Cbl had a positive regulatory effect on the promoter of . Bacterial one-hybrid analysis and electrophoretic mobility shift assay (EMSA) verified that Cbl bound with the promoter of . Collectively, the tolerance to adversity could be maintained by the production of HS when SmpB was malfunctioned, of which the activity of promoter was positively regulated by upstream Cbl protein. The outcomes also suggested the enormous potentials of in environmental adaptability.
PubMed: 34589297
DOI: 10.7717/peerj.12058 -
Antibiotics (Basel, Switzerland) Jul 2021() is one of the main pathogens causing bacterial diseases in aquaculture. Although previous studies have shown that hepcidin as an antimicrobial peptide can promote...
() is one of the main pathogens causing bacterial diseases in aquaculture. Although previous studies have shown that hepcidin as an antimicrobial peptide can promote fish resistance to pathogenic bacterial infections, but the mechanisms remain unclear. Here, we expressed and purified recombinant yellow catfish () hepcidin protein (rPfHep). rPfHep can up-regulate the expression of ferritin and enhance the antibacterial activity in primary hepatocytes of yellow catfish. We employed berberine hydrochloride (BBR) and Fursultiamine (FSL) as agonists and antagonists for hepcidin, respectively. The results indicated that agonist BBR can inhibit the proliferation of pathogenic bacteria, and the antagonist FSL shows the opposite effect. After gavage administration, rPfHep and the agonist BBR can enhance the accumulation of iron in liver, which may hinder the iron transport and limit the amount of iron available to pathogenic bacteria. Moreover, rPfHep and the agonist BBR can also reduce the mortality rate, bacterial load and histological lesions in yellow catfish infected with . Therefore, hepcidin is an important mediator of iron metabolism, and it can be used as a candidate target for prevent bacterial infections in yellow catfish. Hepcidin and BBR have potential application value in preventing anti-bacterial infection.
PubMed: 34356769
DOI: 10.3390/antibiotics10070848 -
Journal of Veterinary Research Jun 2023Bioactive proteins and peptides generated from fruit, vegetables, meat or fish have great potential as functional food or substitutes for antibiotics. In recent years it...
INTRODUCTION
Bioactive proteins and peptides generated from fruit, vegetables, meat or fish have great potential as functional food or substitutes for antibiotics. In recent years it has also been demonstrated that the fungus kingdom could be a source of these compounds. The study investigated the bioactivity of an extract of the lignicolous fungus and its hydrolysate.
MATERIAL AND METHODS
The fungus was collected in a mixed forest in October, extracted and hydrolysed. To inspect the protein and peptide profiles before and after hydrolysis, matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometric analysis was performed. To evaluate the antioxidant properties of the preparations, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays were used. The activity of the fungus extract and hydrolysate against , , , , , , , Typhimurium, , , , , and was determined by the minimum inhibitory concentration and minimum bactericidal concentration values.
RESULTS
The extract and its hydrolysate showed almost 100% ABTS and DPPH radical scavenging with a low half maximal inhibitory concentration. The water extract and hydrolysate of exhibited antimicrobial activity against two strains, , and Typhimurium.
CONCLUSION
These results provide compelling evidence that the analysed fungus extract and its hydrolysate hold promise with their antibacterial and antioxidant properties.
PubMed: 37786431
DOI: 10.2478/jvetres-2023-0036 -
Cell Host & Microbe Aug 2021Animal microbiomes are assembled predominantly from environmental microbes, yet the mechanisms by which individual symbionts regulate their transmission into hosts...
Animal microbiomes are assembled predominantly from environmental microbes, yet the mechanisms by which individual symbionts regulate their transmission into hosts remain underexplored. By tracking the experimental evolution of Aeromonas veronii in gnotobiotic zebrafish, we identify bacterial traits promoting host colonization. Multiple independently evolved isolates with increased immigration harbored mutations in a gene we named sensor of proline diguanylate cyclase enzyme (SpdE) based on structural, biochemical, and phenotypic evidence that SpdE encodes an amino-acid-sensing diguanylate cyclase. SpdE detects free proline and to a lesser extent valine and isoleucine, resulting in reduced production of intracellular c-di-GMP, a second messenger controlling bacterial motility. Indeed, SpdE binding to amino acids increased bacterial motility and host colonization. Hosts serve as sources of SpdE-detected amino acids, with levels varying based on microbial colonization status. Our work demonstrates that bacteria use chemically regulated motility, or chemokinesis, to sense host-emitted cues that trigger active immigration into hosts.
Topics: Amino Acids; Animals; Bacteria; Bacterial Proteins; Biofilms; Chemokines; Cues; Cyclic GMP; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Host Microbial Interactions; Phosphorus-Oxygen Lyases; Symbiosis; Zebrafish
PubMed: 34233153
DOI: 10.1016/j.chom.2021.06.003 -
Veterinary World May 2020The present study aimed at highlighting the effects of oyster mushroom (), as a dietary supplement on growth performance, differential leukocytes population, and...
AIM
The present study aimed at highlighting the effects of oyster mushroom (), as a dietary supplement on growth performance, differential leukocytes population, and histological changes of melanomacrophage centers (MMCs) in spleen and kidney of fancy carp on bacterial infection.
MATERIALS AND METHODS
A total of 60 fancy carp were allocated into four groups according to feed formulations including; (1) basal diet with 2% crude extract of , (2) basal diet with 2% b-glucan, whereas Group 3, and Group 4 were positive and negative control, which were fed only basal diet. Diets were provided for 30 days, thereafter, fish of Group 1 to Group 3 were intraperitoneally injected with (1.8×10 CFU), whereas Group 4 was injected with normal saline. At day 7 post-bacterial inoculation, all fish were weighed, whole blood was collected for differential white blood cell count, and two visceral organs, posterior kidney and spleen, were collected from euthanized fish to observe histological changes, particularly MMCs.
RESULTS
No significant differences in body weight were found (p>0.05) at 1 week of the experiment; however, fish body weight was significantly increased from week 2 to week 4 of the experiment. Increased monocyte number was found in carp fish fed with the or b-glucan supplemented diets compared to the control groups (p<0.05). The proliferation of monocyte in fish was consistent with increased number and size of MMCs in hemotopoietic organs, posterior kidney and spleen, especially in fancy carp fed with of crude extract and commercially available b-glucan before bacterial inoculation in fish.
CONCLUSION
These findings indicate that crude polysaccharide from . can be potentially used as a feed additive that might promote innate immune function in fish.
PubMed: 32636602
DOI: 10.14202/vetworld.2020.1010-1016 -
Applied and Environmental Microbiology Nov 2023can adhere to host cells through different adherence factors including outer-membrane proteins (OMPs), lipopolysaccharide (LPS), and pili, but its adherence mechanisms...
can adhere to host cells through different adherence factors including outer-membrane proteins (OMPs), lipopolysaccharide (LPS), and pili, but its adherence mechanisms are still unclear. Here, we evaluated the effect of autoinducer-2 (AI-2) on adherence of and its regulation mechanism. After determination of the promotion effect of AI-2 on adherence, we investigated which adherence factor was regulated by AI-2, and the results show that AI-2 only limits the formation of pili. Among the four distinct pili systems, only the mannose-sensitive hemagglutinin (MSHA) type IV pili genes were significantly downregulated after deficiency of AI-2. MshE, an ATPase belonged to MSHA type IV pilin, was confirmed as c-di-GMP receptor, that can bind with c-di-GMP which is positively regulated by AI-2, and the increase of c-di-GMP can promote the expression of MSHA type IV pili genes and adherence of . Therefore, this study confirms that c-di-GMP positively regulated by AI-2 binds with MshE, then increases the expression of MSHA pili genes, finally promoting adherence of , suggesting a multilevel positive regulatory adhesion mechanism that is responsible for adherence.
Topics: Aeromonas veronii; Hemagglutinins; Mannose; Fimbriae, Bacterial
PubMed: 37902393
DOI: 10.1128/aem.00819-23