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Antimicrobial Agents and Chemotherapy Mar 2023Bacterial persisters refer to a small fraction of dormant variants that survive treatment with high concentrations of antibiotics. Increasing research indicates that...
Bacterial persisters refer to a small fraction of dormant variants that survive treatment with high concentrations of antibiotics. Increasing research indicates that multidrug efflux pumps play a major role in persister formation in many Gram-negative organisms. In the present study, the roles of the repressor of the AcrAB efflux pump, AcrR, in the regulation of the activity and function of the efflux, as well as in the production of persisters, were investigated in the pathogen Aeromonas veronii, which causes huge economic losses in the aquatic industry and threatens human health. We observed that exclusively in exponential-phase cells, not in stationary-phase cells, the deletion of the gene significantly ( < 0.05) promoted the expression of the and genes and reduced the intracellular accumulation of the efflux substrate Hoechst 33342. Moreover, overexpression of triggered decreased transcription of the promoter of the operon. The persister assay indicated that the loss of the AcrAB pump decreased the formation of persisters under challenge with all tested antibiotic types of chloramphenicol, fluoroquinolone, tetracycline, and β-lactam, while deletion of caused an exponential-phase-specific increase in persister formation against chloramphenicol, tetracycline, and β-lactam. Our results provide molecular insights into the mechanism of bacterial persistence by demonstrating for the first time that the local regulator AcrR is involved in the modulation of persister formation in through its repressive activity on the function of the AcrAB efflux pump during the exponential growth period.
Topics: Humans; Aeromonas veronii; Bacterial Proteins; Anti-Bacterial Agents; Chloramphenicol; beta-Lactams; Tetracyclines; Escherichia coli Proteins
PubMed: 36853030
DOI: 10.1128/aac.00969-22 -
Journal of Oceanology and Limnology Feb 2023Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder (BVC) can significantly strengthen the immunity and boost the...
Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder (BVC) can significantly strengthen the immunity and boost the growth of domestic animals, its application potency still awaits verification in commercial fish species such as the large-scale loach The impacts of 90-day dietary supplementation of 1% and 2% BVC on survival and growth performance of the loach, and on the intestinal morphological characteristics and gut microflora were analyzed. Our data show that the large-scale loach supplied with BVC at the experimental doses had significant higher survival rates and better growth performance (indicated by greater weight gain (1.13-1.14 times), higher specific growth rate (1.04 times), and lower feed conversion ratio (0.88-0.89 times)) compared to that of the control (<0.05). Histological examination revealed significant longer villus (3.22-5.54 times), deeper crypt (1.77-1.87 times), and thicker muscle (1.59-3.17 times) in the intestines of large-scale loach fed with BVC (<0.05). Furthermore, we found that the gut microflora consisted of significantly fewer proportions of potential pathogenic bacterial species ( and ), but significantly greater proportions of beneficial microbes ( and ). Therefore, dietary intake of BVC can promote intestinal tract development and optimize gut microflora, by which the survival and growth of large-scale loach may be improved.
PubMed: 36848297
DOI: 10.1007/s00343-022-1412-y -
Microorganisms Jan 2023According to the findings of a sheep breeding farm in Shaanxi, China, 2.53% (15/594) of sheep exhibited respiratory (clinical) symptoms such as dyspnoea, nasal...
According to the findings of a sheep breeding farm in Shaanxi, China, 2.53% (15/594) of sheep exhibited respiratory (clinical) symptoms such as dyspnoea, nasal discharge, wet cough, fever, and progressive emaciation. Although multi-drug treatment strategies (including ampicillin, tylosin, florfenicol, and ceftiofur) have been attempted to improve clinical outcomes, they have only been met with limited success, with a mortality rate of 40%. Ultimately, () was identified as the causative pathogen for respiratory disease. The rates of symptomatic and asymptomatic sheep positive to were 64.28% (95% CI 52.25-76.31%) and 8.02% (95% CI 6.96-9.08%), respectively. Pathogenicity tests demonstrated that the is pathogenic to sheep and mice. The results of the antibiotic susceptibility tests revealed that the strain was sensitive to cefotaxime, gentamicin, and enrofloxacin and resistant to ampicillin, ceftiofur, amoxicillin, kanamycin, neomycin, streptomycin, tetracycline, florfenicol, and tylosin. We suggest that the combination of cefotaxime and gentamicin is an effective treatment based on the results of an antimicrobial susceptibility test, which exhibited good therapeutic efficacy. To the best of our knowledge, this is the first report in which pathogenic has been documented as the cause of death in sheep in China. We concluded that pathogenic poses a potential risk to the industry of sheep husbandry. This study's findings can help guide prevention and treatment plans for infection in sheep.
PubMed: 36838298
DOI: 10.3390/microorganisms11020333 -
Life (Basel, Switzerland) Feb 2023Marketed fish and shellfish are a source of multidrug-resistant and biofilm-forming foodborne pathogenic microorganisms.
BACKGROUND
Marketed fish and shellfish are a source of multidrug-resistant and biofilm-forming foodborne pathogenic microorganisms.
METHODS
Bacteria isolated from and collected from a local market in Hail region (Saudi Arabia) were isolated on selective and chromogenic media and identified by using 16S RNA sequencing technique. The exoenzyme production and the antibiotic susceptibility patterns of all identified bacteria were also tested. All identified bacteria were tested for their ability to form biofilm by using both qualitative and quantitative assays.
RESULTS
Using 16S RNA sequencing method, eight genera were identified dominated by (42.85%), (23.80%), and (9.52%). The dominant species were (23.8%) and (23.80%). All the identified strains were able to produce several exoenzymes (amylases, gelatinase, haemolysins, lecithinase, DNase, lipase, and caseinase). All tested bacteria were multidrug-resistant with a high value of the multiple antibiotic index (MARI). The antibiotic resistance index (ARI) was about 0.542 for spp. and 0.553 for spp. On Congo red agar, six morphotypes were obtained, and 33.33% were slime-positive bacteria. Almost all tested microorganisms were able to form a biofilm on glass tube. Using the crystal violet technique, the tested bacteria were able to form a biofilm on glass, plastic, and polystyrene abiotic surfaces with different magnitude.
CONCLUSIONS
Our findings suggest that marketed and harbor various bacteria with human interest that are able to produce several related-virulence factors.
PubMed: 36836905
DOI: 10.3390/life13020548 -
International Journal of Molecular... Feb 2023Galectins are proteins that are involved in the innate immune response against pathogenic microorganisms. In the present study, the gene expression pattern of (named as...
Galectins are proteins that are involved in the innate immune response against pathogenic microorganisms. In the present study, the gene expression pattern of (named as ) and its function in mediating the defense response to bacterial attack were investigated. The tertiary structure of Gal-1 protein consists of homodimers and each subunit has one carbohydrate recognition domain. Quantitative RT-PCR analysis indicated that was ubiquitously distributed in all the detected tissues and highly expressed in the swim-bladder of , and its expression could be upregulated by the pathogenic attack in the brain. Expression of Gal-1 protein in HEK 293T cells was distributed in the cytoplasm as well as in the nucleus. The recombinant Gal-1 protein by prokaryotic expression could agglutinate red blood cells from rabbit, , and . The agglutination of red blood cells by the recombinant Gal-1 protein was inhibited by peptidoglycan, lactose, D-galactose, and lipopolysaccharide in certain concentrations. In addition, the recombinant Gal-1 protein agglutinated and killed some gram-negative bacteria including , , , , , and . These results set the stage for further studies of Gal-1 protein in the innate immunity of .
Topics: Animals; Rabbits; Galectin 1; Amino Acid Sequence; Galectins; Perciformes; Immunity, Innate; Cloning, Molecular; Phylogeny; Fish Proteins
PubMed: 36834706
DOI: 10.3390/ijms24043298 -
Journal of Infection in Developing... Jan 2023Aeromonas spp. are widely distributed in surface water, sewage, untreated and chlorinated, drinking water, as well as meats, fish, shellfish, poultry, and their... (Review)
Review
Aeromonas spp. are widely distributed in surface water, sewage, untreated and chlorinated, drinking water, as well as meats, fish, shellfish, poultry, and their products. A disease caused by Aeromonas spp. is designated as aeromoniasis. It can affect different aquatic animals, mammals, and birds in different geographic regions. Moreover, gastrointestinal and extra-intestinal disease conditions may be provoked in humans as a result of food poising with Aeromonas spp. Some Aeromonas spp. have been identified, however, Aeromonas hydrophila (A. hydrophila), A. caviae, and A. veronii bv sobria may be of public health significance. Aeromonas spp. are members of family Aeromonadaceae and genus Aeromonas. They are Gram-negative rod-shaped, facultative anaerobic, and oxidase and catalase-positive bacteria. The pathogenicity of Aeromonas in different hosts is mediated by several virulence factors such as endotoxins, cytotoxic enterotoxin, cytotoxins, hemolysins, adhesins, and extracellular enzymes such as proteases, amylases, lipases, ADP-ribosyltransferases, and DNases. Most avian species are susceptible to either natural or experimental infections with Aeromonas spp. Infection usually arises through feacal-oral route. Traveler's diarrhea as well as other systemic and local infections are the clinical picture of food poisoning associated with aeromoniasis in humans. Despite Aeromonas spp. being sensitive to various antimicrobials, multiple drug resistance has been commonly reported worldwide. Accordingly, this review highlights aeromoniasis in poultry regarding Aeromonas virulence factors epidemiology, pathogenicity, zoonosis, and antimicrobial resistance.
Topics: Animals; Humans; Diarrhea; Poultry; Drug Resistance, Bacterial; Travel; Bacterial Infections; Aeromonas; Virulence Factors; Gram-Negative Bacterial Infections; Mammals
PubMed: 36795920
DOI: 10.3855/jidc.17186 -
Cell Reports Feb 2023The commensal microbiota regulates the self-renewal and differentiation of hematopoietic stem and progenitor cells (HSPCs) in bone marrow. Whether and how the microbiota...
The commensal microbiota regulates the self-renewal and differentiation of hematopoietic stem and progenitor cells (HSPCs) in bone marrow. Whether and how the microbiota influences HSPC development during embryogenesis is unclear. Using gnotobiotic zebrafish, we show that the microbiota is necessary for HSPC development and differentiation. Individual bacterial strains differentially affect HSPC formation, independent of their effects on myeloid cells. Early-life dysbiosis in chd8 zebrafish impairs HSPC development. Wild-type microbiota promote HSPC development by controlling basal inflammatory cytokine expression in kidney niche, and chd8 commensals elicit elevated inflammatory cytokines that reduce HSPCs and enhance myeloid differentiation. We identify an Aeromonas veronii strain with immuno-modulatory activities that fails to induce HSPC development in wild-type fish but selectively inhibits kidney cytokine expression and rebalances HSPC development in chd8 zebrafish. Our studies highlight the important roles of a balanced microbiome during early HSPC development that ensure proper establishment of lineal precursor for adult hematopoietic system.
Topics: Animals; Zebrafish; Hematopoietic Stem Cells; Hematopoiesis; Bone Marrow; Cytokines; Stem Cell Niche
PubMed: 36795566
DOI: 10.1016/j.celrep.2023.112116 -
Ecotoxicology and Environmental Safety Mar 2023Interactions between host and pathogen are involving various dynamic changes in transcript expression and critical for understanding host immunity against infections and...
Interactions between host and pathogen are involving various dynamic changes in transcript expression and critical for understanding host immunity against infections and its associated pathogenesis. Herein, we established a model of channel catfish infected with Aeromonas veronii. The infected fish had prominent body surface bleeding, and the spleen showed hyperemia and swelling. Then, the spleen of channel catfish infected with A. veronii was analyzed by dual RNA sequencing (RNA-seq), and the transcriptome data were compared with uninfected channel catfish spleen or bacteria cultured in vitro. The transcript expression profile of pathogen-host interaction between A. veronii and channel catfish was successfully studied. During infection, the host was enriched for multiple immune-related signaling pathways, such as the Toll-like receptor signaling pathway, Cytokine-cytokine receptor interaction, and T cell receptor signaling pathway; and significantly upregulated for many innate immune-related genes, including IL-8. At the same time, we found that A. veronii mainly harmed the host spleen through hemolysin. Our current findings are of great significance in clarifying the pathogenesis of channel catfish induced by A. veronii and provide gene targets for developing preventive measures.
Topics: Animals; Ictaluridae; Aeromonas veronii; RNA-Seq; Spleen; Sequence Analysis, RNA; Host-Pathogen Interactions; Fish Diseases; Gram-Negative Bacterial Infections
PubMed: 36739739
DOI: 10.1016/j.ecoenv.2023.114609 -
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 -
Journal of Medical Case Reports Jan 2023Skin and soft tissue infections are common because of exposure to aquatic environment, while severe infections caused by Aeromonas veronii are rare.
INTRODUCTION
Skin and soft tissue infections are common because of exposure to aquatic environment, while severe infections caused by Aeromonas veronii are rare.
CASE PRESENTATION
We report a case of severe skin and soft tissue infection of the left upper limb caused by Aeromonas veronii. A 50-year-old Chinese woman, who had a history of cardiac disease and type 2 diabetes mellitus, accidentally injured her left thumb while cutting a fish. Early antibiotic therapy and surgical debridement was performed before the result of bacterial culture came back. Whole-genome sequencing was further performed to confirm the pathogen and reveal the drug resistance and virulence genes. The wound was gradually repaired after 1 month of treatment, and the left hand recovered well in appearance and function after 3 months of rehabilitation.
CONCLUSION
Early diagnosis, surgical intervention, and administration of appropriate antibiotics are crucial for patients who are suspected of having skin and soft tissue infection, or septicemia caused by Aeromonas veronii.
Topics: Animals; Female; Humans; Aeromonas veronii; Soft Tissue Infections; Aeromonas; Diabetes Mellitus, Type 2; Gram-Negative Bacterial Infections; Anti-Bacterial Agents; Upper Extremity
PubMed: 36710352
DOI: 10.1186/s13256-023-03770-y