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Journal of Advanced Veterinary and... Sep 2023Whole genome sequencing (WGS) of Alim_AV_1000 isolated from ulcerative lesions of Shing fish (stringing catfish; ) was performed during the outbreak year 2021.
OBJECTIVE
Whole genome sequencing (WGS) of Alim_AV_1000 isolated from ulcerative lesions of Shing fish (stringing catfish; ) was performed during the outbreak year 2021.
MATERIALS AND METHODS
Using next-generation sequencing (Illumina) technology, WGS was accomplished, resulting in the sequencing, assembly, and analysis of the entire genome of the strain. Moreover, the genomic features, virulence factors, antimicrobial resistome, and phylogenetic analysis for the molecular evolution of this strain were also examined.
RESULTS
The genome size of the Alim_AV_1000 strain was 4,494,515 bp, with an average G+C content of 58.87%. Annotation revealed the known transporters and genes linked to virulence, drug targets, and antimicrobial resistance.
CONCLUSION
The findings of the phylogenetic analysis revealed that the strain of the present study has a close relationship with the China strain TH0426 and strain B56. This study provides novel information on isolated from Shing fish in Bangladesh.
PubMed: 37969805
DOI: 10.5455/javar.2023.j711 -
Marine Biotechnology (New York, N.Y.) Dec 2023As an opportunistic pathogen, Aeromonas veronii can cause hemorrhagic septicemia of various aquatic animals. In our present study, a dominant strain SJ4, isolated from...
As an opportunistic pathogen, Aeromonas veronii can cause hemorrhagic septicemia of various aquatic animals. In our present study, a dominant strain SJ4, isolated from naturally infected mandarin fish (Siniperca chuatsi), was identified as A. veronii according to the morphological, physiological, and biochemical features, as well as molecular identification. Intraperitoneal injection of A. veronii SJ4 into S. chuatsi revealed clinical signs similar to the natural infection, and the median lethal dosage (LD) of the SJ4 to S. chuatsi in a week was 3.8 × 10 CFU/mL. Histopathological analysis revealed that the isolate SJ4 could cause cell enlargement, obvious hemorrhage, and inflammatory responses in S. chuatsi. Detection of virulence genes showed the isolate SJ4 carried act, fim, flgM, ompA, lip, hly, aer, and eprCAL, and the isolate SJ4 also produce caseinase, dnase, gelatinase, and hemolysin. In addition, the complete genome of A. veronii SJ4 was sequenced, and the size of the genome of A. veronii SJ4 was 4,562,694 bp, within a G + C content of 58.95%, containing 4079 coding genes. Nine hundred ten genes encoding for several virulence factors, such as type III and VI secretion systems, flagella, motility, etc., were determined based on the VFDB database. Besides, 148 antibiotic resistance-related genes in 27 categories related to tetracyclines, fluoroquinolones, aminoglycosides, macrolides, chloramphenicol, and cephalosporins were also annotated. The present results suggested that A. veronii was etiological agent causing the bacterial septicemia of S. chuatsi in this time, as well as provided a valuable base for revealing pathogenesis and resistance mechanism of A. veronii.
Topics: Animals; Aeromonas veronii; Fishes; Virulence; Virulence Factors; Anti-Bacterial Agents; Gram-Negative Bacterial Infections; Fish Diseases
PubMed: 37947961
DOI: 10.1007/s10126-023-10253-0 -
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 -
Animals : An Open Access Journal From... May 2023Nanotechnology can enhance nutrient delivery and bioavailability; hence, it has recently been considered the most practical alternative technology for nutritional...
Nanotechnology can enhance nutrient delivery and bioavailability; hence, it has recently been considered the most practical alternative technology for nutritional supplements and disease control in fish farming. The present study was designed to evaluate the effects of mangosteen peel extract loaded in nanoemulsion (MSNE) on the inhibition of (in vitro) and in vivo growth performance, serum biochemical parameters, the immune response, and the disease resistance of Nile tilapia () against challenge. The particle size, polydispersity index, and particle surface charge of MSNE were 151.9 ± 1.4 nm, >0.3, and -30 mV, respectively. Furthermore, MSNE, mangosteen peel extract (MPE), and nanoemulsion (NE) improved the antimicrobial activity against . Fish fed MSNE, MPE, and NE-supplemented diets had a significantly lower ( < 0.05) feed conversion ratio (FCR) and higher specific growth rate (SGR) than fish fed the control diet. Furthermore, the MSNE had significantly higher serum glucose and protein levels than the control group in Nile tilapia. Total immunoglobulin, serum lysozyme, alternative complement activity, and survival of Nile tilapia fed with MSNE were significantly higher ( < 0.05) than the control diet. Therefore, MSNE has the potential to be employed as a supplement in sustainable Nile tilapia farming.
PubMed: 37889734
DOI: 10.3390/ani13111798 -
Journal of Fish Diseases Feb 2024Aeromonas septicemia still represents a serious challenge facing the global aquaculture sector. In the present study, Aeromonas caviae and A. veronii were isolated from...
Aeromonas septicemia still represents a serious challenge facing the global aquaculture sector. In the present study, Aeromonas caviae and A. veronii were isolated from four diseased European seabass (Dicentrarchus labrax) farms experiencing a high mortality rate. Diseased fish showed haemorrhages on the external body surface with exophthalmia, cataracts, scale desquamation, skin ulcers and fin erosions. The most common post-mortem findings were congested internal organs, particularly the liver and posterior kidney. Twenty-eight A. Veronii and 11 A. caviae isolates were identified biochemically by the Vitek 2 system and then confirmed by PCR and phylogenetic analysis. Hemolysin (hlyA) and aerolysin (aer) were the most abundant virulence genes in the recovered isolates, followed by cytotoxic enterotoxin (act) and heat-stable enterotoxin (ast). A. caviae was more virulent than A. veronii for D. labrax fingerlings as LD ranging between (>1 × 10 -6.2 × 10 ) for A. veronii and (2.9 × 10 -8.3 × 10 ) for A. caviae. The sensitivity test indicated the effectiveness of norfloxacin, doxycycline and oxytetracycline against the tested isolates. Serum cortisol significantly increased in the infected groups, while catalase and glutathione peroxidase activities significantly decreased at 2 days post-infection (DPI) and then increased at 6 DPI. The presence of virulence genes was associated with bacterial pathogenicity expressed in fish mortality rate. Virulence genes also drastically affect cortisol levels more than catalase and glutathione peroxidase levels.
Topics: Animals; Aeromonas; Virulence; Bass; Catalase; Genotype; Phylogeny; Hydrocortisone; Fish Diseases; Enterotoxins; Glutathione Peroxidase; Gram-Negative Bacterial Infections
PubMed: 37881027
DOI: 10.1111/jfd.13878 -
Veterinary World Sep 2023The high diversity of spp. results in various pathogenicity levels. This group of bacteria causes a serious disease named motile septicemia (MAS) in catfish ( spp.)....
BACKGROUND AND AIM
The high diversity of spp. results in various pathogenicity levels. This group of bacteria causes a serious disease named motile septicemia (MAS) in catfish ( spp.). This study aimed to characterize the species and virulence gene diversity of spp. isolated from diseased catfish.
MATERIALS AND METHODS
Nine spp. were isolated from infected catfish cultivated in Java, Indonesia, and they were identified at the phenotypic and molecular levels (16S rDNA). The virulence genes assessed included , , , , , and .
RESULTS
Phylogenetic analysis identified nine isolates of spp.: (11.11%), (11.11%), bv. (44.44%), and (33.33%). Virulence genes, such as , , , , , and , were detected in all isolates at frequencies of approximately 100%, 66.67%, 88.89%, 100%, 55.56%, and 66.67%, respectively. This study is the first report on recovered from an Indonesian catfish culture. Furthermore, our study revealed the presence of . bv , a biovar that has not been reported before in Indonesia.
CONCLUSION
This finding confirms that MAS was caused by multiple species of , notably and . bv , within Indonesian fish culture. The presence of these species with multiple virulence genes poses a significant threat to the freshwater aquaculture industry.
PubMed: 37859968
DOI: 10.14202/vetworld.2023.1974-1984 -
Virulence Dec 2023The emergence of antibiotic-resistant strains in clinical settings has presented an escalating burden on human and public health. The dissemination of antibiotic...
The emergence of antibiotic-resistant strains in clinical settings has presented an escalating burden on human and public health. The dissemination of antibiotic resistance in is predominantly facilitated by chromosome-borne accessory genetic elements, although the existing literature on this subject remains limited. Hence, the primary objective of this study is to comprehensively investigate the genomic characteristics of chromosome-borne accessory genetic elements in . Moreover, the study aims to uncover novel genetic environments associated with antibiotic resistance on these elements. were screened from nonduplicated strains collected from two tertiary hospitals in China. Complete sequencing and population genetics analysis were performed. BLAST analysis was employed to identify related elements. All newly identified elements were subjected to detailed sequence annotation, dissection, and comparison. We identified and newly designated 19 chromosomal elements, including 18 integrative and mobilizable elements (IMEs) that could be classified into four categories: Tn-related, Tn-related, Tn-related, and Tn-related IMEs. Each class exhibited a distinct pattern in the types of resistance genes carried by the IMEs. Several novel antibiotic resistance genetic environments were uncovered in these elements. Notably, we report the first identification of the gene and gene in clinical genome, the first presence of a (E)-(E) resistance gene environment within the backbone region in IMEs, and a new resistance gene environment. The implications of these findings are substantial, as they provide new insights into the evolution, structure, and dissemination of chromosomal-borne accessory elements.
Topics: Humans; Aeromonas; Drug Resistance, Microbial; Anti-Bacterial Agents; Chromosomes; China
PubMed: 37848422
DOI: 10.1080/21505594.2023.2271688 -
Fish & Shellfish Immunology Nov 2023There is a long-standing debate on the attributes of temperature for fish health. We recently showed that thermoregulatory programs exerted through natural behavioural...
There is a long-standing debate on the attributes of temperature for fish health. We recently showed that thermoregulatory programs exerted through natural behavioural fever drive molecular and cellular responses that contribute to pathogen clearance, inflammation control, and tissue repair. These offered a mechanistic basis for the survival advantage conferred through fever. Herein, we show the attributes of mechanical replication of this fever response. Central to our approach was consideration of both, the maximal temperatures naturally selected by fish after infection, as well as the dynamics of thermal changes induced through this response. Coarse replication of the febrile thermal program as well as shorter truncated thermal schedules offered immune-regulatory capacity. Most notably, these promoted induction of acute inflammation and significant enhancements to pathogen clearance. However, the coarse protocols tested only partially recapitulated enhancements to induction and control of tissue repair. Our findings highlight a promising new alternative to combat infections in fish using a natural, drug-free, sustainable approach.
Topics: Animals; Aeromonas veronii; Gram-Negative Bacterial Infections; Fishes; Inflammation; Fish Diseases; Aeromonas
PubMed: 37832750
DOI: 10.1016/j.fsi.2023.109157 -
Environmental Research Dec 2023The overuse of antibiotics in aquaculture drives the emergence of multi-drug-resistant bacteria, and antibiotic-resistant genes (ARGs) can be disseminated to other...
The overuse of antibiotics in aquaculture drives the emergence of multi-drug-resistant bacteria, and antibiotic-resistant genes (ARGs) can be disseminated to other bacteria through vertical- and horizontal gene transfer (VGT and HGT) under selective pressure. Profiling the antibiotic resistome and understanding the global distribution of ARGs constitutes the first step in developing a control strategy. Hence, this study utilized extensive genomic data from hundreds of Aeromonas strains in aquaculture to profile resistome patterns and explores their association with isolation year, country, and species characteristics. Overall, ∼400 Aeromonas genomes were used to predict the ARGs from A. salmonicida, A. hydrophila, A. veronii, A. media, and A. sobria. ARGs such as sul1, tet(A), and tet(D), which display a similar proportion of positive strains among species, were subjected to phylodynamic and phylogeographic analyses. More than a hundred ARGs were identified, some of which exhibited either species-specific or non-species-specific patterns. A. salmonicida and A. media were found to have a higher proportion of species-specific ARGs than other strains, which might lead to more distinct patterns of ARG acquisition. Overall, ∼25% of strains have either sul1, tet(A), or tet(D) gene(s), but no significant difference was observed in the proportion of positive strains by species. Phylogeographic analysis revealed that the abundant numbers of sul1, tet(A), and/or tet(D) introduced in a few East Asian and North American countries could spread to both adjacent and faraway countries. In recent years, the proportions of these ARGs have dramatically increased, particularly in strains sourced from aquatic environments, suggesting control is required of the overuse of antibiotics in aquaculture. The findings of this research offer significant insights into the global dissemination of ARGs.
Topics: Aeromonas; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Aquaculture; North America; Genes, Bacterial
PubMed: 37805184
DOI: 10.1016/j.envres.2023.117273 -
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