Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.798
Filtrar
1.
Braz. j. biol ; 84: e254816, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355894

RESUMO

Abstract Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.


Resumo O Paquistão é um país agrícola, onde a pesca desempenha um papel muito importante para o desenvolvimento econômico. Diferentes doenças são prevalentes em peixes do Paquistão, mas as informações relacionadas aos agentes causadores não são bem conhecidas. Tendo em vista a importância dos patógenos bacterianos como agentes causadores de múltiplas doenças em peixes, o presente estudo foi conduzido para identificação, caracterização e análise de genes de virulência de isolados de Aeromonas spp. de peixes doentes. Foram coletadas 50 amostras de peixes com múltiplas indicações clínicas em diferentes fazendas do distrito de Kasur, Punjab, Paquistão. Para isolar Aeromonas spp., as amostras foram enriquecidas e inoculadas em meio de isolamento. Os isolados foram identificados e caracterizados por diferentes testes bioquímicos, kit Analytical Profile Index (API) 20E, e ensaios de reação em cadeia da polimerase (PCR). Todos os isolados foram selecionados para três genes de virulência putativos, incluindo aerolisina (aer), hemolisina (hyl) e enterotoxina citotônica termolábil (alt). Sete isolados de Aeromonas hydrophila foram recuperados e identificados com base no API 20E. Esses isolados foram posteriormente confirmados como A. hydrophila de acordo com ensaios de PCR. Três isolados indicaram a presença de genes de virulência (alt e hyl), enquanto o gene aerolisina (aer) não esteve presente em nenhum dos isolados de A. hydrophila. O presente estudo confirmou A. hydrophila como o agente causador da síndrome ulcerativa epizoótica e septicemia móvel por Aeromonas em fazendas de peixes, no distrito de Kasur, Punjab, Paquistão. Além disso, a detecção de dois genes de virulência (alt e hyl) em isolados de A. hydrophila é uma ameaça para os consumidores de peixes da área de estudo.


Assuntos
Animais , Infecções por Bactérias Gram-Negativas/veterinária , Infecções por Bactérias Gram-Negativas/epidemiologia , Aeromonas/genética , Paquistão , Aeromonas hydrophila/genética , Enterotoxinas/genética , Peixes
2.
J Aquat Anim Health ; 34(3): 140-148, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36165569

RESUMO

Production of Nile Tilapia Oreochromis niloticus contributes to economic growth in many countries. However, there has been a decline in its production over the years due to the influx of bacterial infections, with Aeromonas jandaei as an emerging threat. In this study, we identified and characterized A. jandaei from cage-cultured Nile Tilapia in Akosombo Stratum II of Lake Volta in Ghana and evaluated its response to commonly used antibiotics using the disc diffusion and agar well diffusion methods for herbal extracts at various concentrations (10, 30, 50, 70, and 100 mg/mL). The herbs considered included guava Psidium guajava leaf, bitter leaf Vernonia amygdalina, neem Azadirachta indica leaf, and their cocktail (GBNL in the ratio of 1:1:1). The bacterium was isolated from swab samples from the head kidneys of 27 moribund Nile Tilapia collected from nine fish farms. Samples were screened for A. jandaei by culturing and identification using morphological and molecular techniques. The bacterium isolate from fish in the study, identified as A. jandaei GH-AS II, had 92-93% identity to A. jandaei reference strains. Infection of healthy Nile Tilapia (n = 210) with the bacterium isolate showed that 1.0 × 105 CFU/mL was the lethal dose causing 50% mortality. Antibiotic susceptibility testing showed that A. jandaei GH-AS II was resistant to tetracycline and ampicillin. Herbal extracts at the various concentrations inhibited the growth of the bacterium isolate, with a significant increment in the zones of inhibition with increasing concentrations of leaf extracts. However, GBNL showed prominence compared to the other extracts only at 100 mg/mL. Management of A. jandaei GH-AS II by using herbal extracts at Nile Tilapia farms in Lake Volta may be recommended since the use of antibiotics, such as tetracycline and ampicillin, may not yield the needed result.


Assuntos
Ciclídeos , Doenças dos Peixes , Aeromonas , Ágar , Ampicilina , Animais , Antibacterianos/farmacologia , Ciclídeos/microbiologia , Doenças dos Peixes/microbiologia , Gana , Lagos , Tetraciclinas
3.
Front Cell Infect Microbiol ; 12: 945000, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35979091

RESUMO

Aeromonas salmonicida is a typical cold water bacterial pathogen that causes furunculosis in many freshwater and marine fish species worldwide. In our previous study, the pathogenic A. salmonicida (SRW-OG1) was isolated from a warm water fish, Epinephelus coioides was genomics and transcriptomics analyzed. Type II secretion system was found in the genome of A. salmonicida SRW-OG1, while the expressions of tatA, tatB, and tatC were significantly affected by temperature stress. Also, sequence alignment analysis, homology analysis and protein secondary structure function analysis showed that tatA, tatB, and tatC were highly conservative, indicating their biological significance. In this study, by constructing the mutants of tatA, tatB, and tatC, we investigated the mechanisms underlying temperature-dependent virulence regulation in mesophilic A. salmonida SRW-OG1. According to our results, tatA, tatB, and tatC mutants presented a distinct reduction in adhesion, hemolysis, biofilm formation and motility. Compared to wild-type strain, inhibition of the expression of tatA, tatB, and tatC resulted in a decrease in biofilm formation by about 23.66%, 19.63% and 40.13%, and a decrease in adhesion ability by approximately 77.69%, 80.41% and 62.14% compared with that of the wild-type strain. Furthermore, tatA, tatB, and tatC mutants also showed evidently reduced extracellular enzymatic activities, including amylase, protease, lipase, hemolysis and lecithinase. The genes affecting amylase, protease, lipase, hemolysis, and lecithinase of A. salmonicida SRW-OG1 were identified as cyoE, ahhh1, lipA, lipB, pulA, HED66_RS01350, HED66_RS19960, aspA, fabD, and gpsA, which were notably affected by temperature stress and mutant of tatA, tatB, and tatC. All above, tatA, tatB and tatC regulate the virulence of A. salmonicida SRW-OG1 by affecting biofilm formation, adhesion, and enzymatic activity of extracellular products, and are simultaneously engaged in temperature-dependent pathogenicity.


Assuntos
Aeromonas , Proteínas de Escherichia coli , Sistemas de Secreção Tipo II , Aeromonas/metabolismo , Amilases/metabolismo , Animais , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Hemólise , Lipase/genética , Lipase/metabolismo , Proteínas de Membrana Transportadoras/genética , Peptídeo Hidrolases/metabolismo , Fosfolipases/metabolismo , Temperatura , Sistemas de Secreção Tipo II/metabolismo , Virulência/genética , Água/metabolismo
4.
Microb Drug Resist ; 28(8): 893-903, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35972765

RESUMO

Aeromonas hydrophila and other closely related Aeromonas species cause motile aeromonad septicemia, a common fish disease. The disease affects many aquaculture sectors potentially requiring antimicrobial treatments. Therefore, researchers and laboratory diagnosticians need criteria called epidemiological cutoff values (ECVs) to determine whether a bacterial isolate has developed decreased susceptibility to an antimicrobial. To generate ECVs for this bacterium, we assembled a diverse collection of 245 isolates previously identified as A. hydrophila from fish. Using rpoD sequencing, we confirmed that 97 of the 245 isolates were A. hydrophila. We allocated the isolates among three laboratories and tested their susceptibility against eight antimicrobials using standard Clinical and Laboratory Standards Institute (CLSI) disk diffusion and broth microdilution methods. The resulting frequency distributions were statistically analyzed to determine wild-type cutoff estimates, which, along with scatterplots, were used to estimate potential ECVs. In collaboration with the CLSI, aquaculture working group, we proposed ECVs for six of the eight antimicrobials tested. Subsequently, the CLSI Subcommittee on Veterinary Antimicrobial Susceptibility Testing reviewed our data and approved the ECVs to be added to the 2020 edition of the VET04 performance standards for antimicrobial susceptibility testing of aquatic bacteria.


Assuntos
Aeromonas , Anti-Infecciosos , Aeromonas/genética , Aeromonas hydrophila , Animais , Antibacterianos/farmacologia , Peixes , Testes de Sensibilidade Microbiana
5.
Int J Food Microbiol ; 379: 109862, 2022 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-35963079

RESUMO

Aeromonas spp. are opportunistic and ubiquitous bacteria considered emerging pathogens that can cause infections in animals, especially fish, as well as humans. In humans, these bacteria are associated with gastroenteritis but can also be related to extraintestinal diseases. Its main infection route is through water, but it has been increasingly associated with foods. Their association with ready-to-eat foods may be a concern, especially because these products are for immediate consumption. This study aimed to investigate the prevalence of Aeromonas spp. in ready-to-eat foods (temakis, cheeses and minimally processed fruits) and to characterize the virulence profile and antimicrobial resistance of the isolates. The species A. hydrophila, A. caviae and A. veronii were identified using polymerase chain reaction (PCR), which was later compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The performance of two isolation selective agars (starch-ampicillin agar-SAA and Aeromonas agar-AA) was also evaluated. Aeromonas spp. was isolated in 66.67 % (20/30) of temaki, 3.23 % (1/31) of fruits and none (0/30) of cheeses, observing high microorganism counts from <102 to 2.6 × 105 CFU/g. A. caviae (26.39 %) was the most prevalent species, followed by A. hydrophila (20.83 %) and A. veronii (8.34 %), and 44.44 % were classified as Aeromonas sp. The performance analysis between PCR and MALDI-TOF/MS for Aeromonas identification was not statistically significant, and the Kappa index showed moderate agreement (p < 0.01 and Kappa = 0.718). The SAA selective medium performed better than AA. We identified seventeen virulence profiles, and 59.72 % of the isolates had some of the genes studied. The aerA gene (47.2 %) was the most abundant, followed by act (41.7 %), hlyA and alt (38.9 %), and ast (18.1 %). A. hydrophila was the species most associated with these genes. The antimicrobial susceptibility test showed that 90 % of the isolates were resistant to amoxicillin-clavulanic acid, 17 % to tetracycline, 10 % to imipenem and 3 % to aztreonam. The results showed that temakis are carriers of potentially pathogenic Aeromonas spp. and therefore should be avoided by children, elderly individuals, pregnant women, and immunocompromised people. We also found strains resistant to antimicrobials, meaning that these microorganisms need constant monitoring.


Assuntos
Aeromonas , Ágar , Idoso , Animais , Antibacterianos/farmacologia , Criança , Farmacorresistência Bacteriana/genética , Feminino , Humanos , Incidência , Gravidez
6.
Microb Pathog ; 169: 105662, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35781004

RESUMO

Aeromonas spp. is a pathogenic bacteria that potentially cause infection in farmed fish, including Catfishes. In the present study, dominant bacteria were isolated from diseased Clarias magur and tentatively named BLBM-05. Based on morphological, physiological, and biochemical features as well as 16S rRNA gene sequence and gyrB gene sequences (Gen Bank accession number: MT973994.1 and MZ398017.1), the bacteria in the isolate was found to be Aeromonas caviae. Further, the isolate was screened for five known virulence genes, namely ß-hemolysin, lafA, exu, ompA1 and ascV. Among them, three virulence genes related to pathogenicity, including aerolysin (aer), outer membrane protein (ompA1), lateral flagella (lafA), were identified in the A. caviae isolate. The median lethal dosage (LD50) of the BLBM-05 isolate for magur was determined as 1.53x106 CFU/mL. The histopathological analysis showed that the BLBM-05 isolate induced considerable histological lesions in the magur fish, including necrosis, hemolysis of erythrocytes, myolysis, hemorrhage, and desquamation in the intestinal tissue, tissue loosening, and infiltration of inflammatory cells. Drug sensitivity test showed that the isolate was susceptible to Gentamicin, Ceftazidine, Ceftrioxone, Amikacin, Tetracycline, Meropener and Oxytetracycline. The present results provide a scientific basis to identify A. caviae further, a line of treatment for magur infected by this pathogen.


Assuntos
Aeromonas caviae , Aeromonas , Infecções por Bactérias Gram-Negativas , Aeromonas caviae/genética , Animais , Antibacterianos/farmacologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , RNA Ribossômico 16S/genética , Virulência/genética
7.
Front Immunol ; 13: 875689, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35874671

RESUMO

Aeromonas are autochthonous bacteria of aquatic environments that are considered to be emerging pathogens to humans, producing diarrhea, bacteremia, and wound infections. Genetic identification shows that 95.4% of the strains associated with clinical cases correspond to the species Aeromonas caviae (37.26%), Aeromonas dhakensis (23.49%), Aeromonas veronii (21.54%), and Aeromonas hydrophila (13.07%). However, few studies have investigated the human immune response against some Aeromonas spp. such as A. hydrophila, Aeromonas salmonicida, and A. veronii. The present study aimed to increase the knowledge about the innate human immune response against six Aeromonas species, using, for the first time, an in vitro infection model with the monocytic human cell line THP-1, and to evaluate the intracellular survival, the cell damage, and the expression of 11 immune-related genes (TLR4, TNF-α, CCL2, CCL20, JUN, RELA, BAX, TP53, CASP3, NLRP3, and IL-1ß). Transcriptional analysis showed an upregulated expression of a variety of the monocytic immune-related genes, with a variable response depending upon the Aeromonas species. The species that produced the highest cell damage, independently of the strain origin, coincidentally induced a higher expression of immune-related genes and corresponded to the more prevalent clinical species A. dhakensis, A. veronii, and A. caviae. Additionally, monocytic cells showed an overexpression of the apoptotic and pyroptotic genes involved in cell death after A. dhakensis, A. caviae, and Aeromonas media infection. However, the apoptosis route seemed to be the only way of producing cell damage and death in the case of the species Aeromonas piscicola and Aeromonas jandaei, while A. veronii apparently only used the pyroptosis route.


Assuntos
Aeromonas , Infecções por Bactérias Gram-Negativas , Aeromonas/genética , Aeromonas hydrophila , Linhagem Celular , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Imunidade
8.
Fish Shellfish Immunol ; 127: 375-385, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35777708

RESUMO

Pre-treatment of Streptomyces sp. SH5 on zebrafish lead to a significant enhancement of larvae survival upon Aeromonas hydrophila challenging. SH5 was able to colonize in zebrafish approximately at 1 × 102.6 cells per fish for at least seven days. The presence of SH5 strongly repelled the A. hydrophila colonization in zebrafish, and maximally, a 67.53% reduction rate was achieved. A more diversified flora was discovered in the SH5-treated zebrafish larvae at both phylum and genus levels. The expression of immune response genes of SH5-treated zebrafish, including TLR3, lysozyme and NOS2α, were enhanced at initial stage, while, that of various inflammatory stimuli genes including 1L-1ß, 1L-6 and MyD88 were decreased at all tested timepoints. SH5 was shown to inhibit virulence factors production and the expression of corresponding virulence genes in A. hydrophila, suggesting its quorum sensing inhibitory potential. These results indicated favorable application perspectives of SH5 in resisting pathogenic infection in aquaculture.


Assuntos
Aeromonas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Probióticos , Streptomyces , Aeromonas hydrophila/fisiologia , Animais , Larva , Probióticos/farmacologia , Streptomyces/genética , Peixe-Zebra
9.
FEMS Microbiol Lett ; 369(1)2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35883218

RESUMO

Worldwide, Aeromonas salmonicida is a major bacterial pathogen of fish in both marine and freshwater environments. Despite psychrophilic growth being common for this species, the number of characterized mesophilic strains is increasing. Thus, this species may serve as a model for the study of intraspecies lifestyle diversity. Although bacteria are preyed upon by protozoan predators, their interaction inside or outside the phagocytic pathway of the predator can provide several advantages to the bacteria. To correlate intraspecies diversity with predation outcome, we studied the fate of psychrophilic and mesophilic strains of A. salmonicida cocultured with the ciliate Tetrahymena pyriformis. A total of three types of outcome were observed: digestion, resistance to phagocytosis, and pathogenicity. The psychrophilic strains are fully digested by the ciliate. In contrast, the mesophilic A. salmonicida subsp. pectinolytica strain is pathogenic to the ciliate. All the other mesophilic strains display mechanisms to resist phagocytosis and/or digestion, which allow them to survive ciliate predation. In some cases, passage through the phagocytic pathway resulted in a few mesophilic A. salmonicida being packaged inside fecal pellets. This study sheds light on the great phenotypic diversity observed in the complex range of mechanisms used by A. salmonicida to confront a predator.


Assuntos
Aeromonas salmonicida , Aeromonas , Doenças dos Peixes , Tetrahymena pyriformis , Aeromonas salmonicida/genética , Animais , Doenças dos Peixes/microbiologia , Peixes , Virulência
10.
Microbiol Spectr ; 10(4): e0246921, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35880869

RESUMO

Mobile genetic elements contribute to the emergence and spread of multidrug-resistant bacteria by enabling the horizontal transfer of acquired antibiotic resistance among different bacterial species and genera. This study characterizes the genetic backbone of blaGES in Aeromonas spp. and Klebsiella spp. isolated from untreated hospital effluents. Plasmids ranging in size from 9 to 244 kb, sequenced using Illumina and Nanopore platforms, revealed representatives of plasmid incompatibility groups IncP6, IncQ1, IncL/M1, IncFII, and IncFII-FIA. Different GES enzymes (GES-1, GES-7, and GES-16) were located in novel class 1 integrons in Aeromonas spp. and GES-5 in previously reported class 1 integrons in Klebsiella spp. Furthermore, in Klebsiella quasipneumoniae, blaGES-5 was found in tandem as a coding sequence that disrupted the 3' conserved segment (CS). In Klebsiella grimontii, blaGES-5 was observed in two different plasmids, and one of them carried multiple IncF replicons. Three Aeromonas caviae isolates presented blaGES-1, one Aeromonas veronii isolate presented blaGES-7, and another A. veronii isolate presented blaGES-16. Multilocus sequence typing (MLST) analysis revealed novel sequence types for Aeromonas and Klebsiella species. The current findings highlight the large genetic diversity of these species, emphasizing their great adaptability to the environment. The results also indicate a public health risk because these antimicrobial-resistant genes have the potential to reach wastewater treatment plants and larger water bodies. Considering that they are major interfaces between humans and the environment, they could spread throughout the community to clinical settings. IMPORTANCE In the "One Health" approach, which encompasses human, animal, and environmental health, emerging issues of antimicrobial resistance are associated with hospital effluents that contain clinically relevant antibiotic-resistant bacteria along with a wide range of antibiotic concentrations, and lack regulatory status for mandatory prior and effective treatment. blaGES genes have been reported in aquatic environments despite the low detection of these genes among clinical isolates within the studied hospitals. Carbapenemase enzymes, which are relatively unusual globally, such as GES type inserted into new integrons on plasmids, are worrisome. Notably, K. grimontii, a newly identified species, carried two plasmids with blaGES-5, and K. quasipneumoniae carried two copies of blaGES-5 at the same plasmid. These kinds of plasmids are primarily responsible for multidrug resistance among bacteria in both clinical and natural environments, and they harbor resistant genes against antibiotics of key importance in clinical therapy, possibly leading to a public health problem of large proportion.


Assuntos
Aeromonas , beta-Lactamases , Aeromonas/genética , Animais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Variação Genética , Hospitais , Humanos , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos/genética , beta-Lactamases/genética
11.
Fish Shellfish Immunol ; 127: 340-348, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35772675

RESUMO

The current perspective is a pioneer to assess the efficacy of Salvia officinalis leave powder (SOLP) on growth, intestinal enzymes, physiological and antioxidant status, immunological response, and gene expression of Common carp (Cyprinus carpio). We also looked into fish resistance after being challenged with Aeromonas sobria, a pathogenic zoonotic bacteria. Fish (N = 120) were fed four different experimental diets in triplicate for 8 weeks. The control diet (SOLP0 - without SOLP); meanwhile, the other three diets included SOLP of 2, 4, and 8 g kg-1 concentrations (SOLP2, SOLP4, and SOLP8), respectively. Findings demonstrated that fish fed SOLP4 and SOLP8 diets had better growth performance and improved digestion by noticeable enhancing lipase and amylase enzymes activity than other groups. Additionally, the antioxidant (superoxide dismutase and glutathione peroxidase) and immune activities (immunoglobulin M, nitric oxide, and antiprotease) clarified a significant increase (p < 0.05) in SOLP4 and SOLP8 groups. Enriched diets with SOLP4 and SOLP8 exhibited better expression of splenic genes (IL-1ß, IL-6, IL-10, TLR-2, and SOD), intestinal genes (Slc26a6) and (PepT1 or Slc15a1), and muscular genes (IGF-1 and SOD), while MSTN was down-regulated. After 8 weeks of the experimental trial, C. carpio challenged by A. sobria exhibited the highest cumulative mortality (66.67%), while SOLP8-dietary intervention showed the best results in enhancing the fish resistance against A. sobria by lessening mortalities to 13.33% followed by SOLP4 diet (20%). The outcomes indicate that the expression of splenic, muscular, and intestinal genes confirm the efficacy of SOLP on enhancing growth, digestion, and immune-antioxidant status, and recommend the potential use of SOLP especially at 4 g kg-1 level as a valuable natural economic diet additive in C. carpio culture for sustaining aquaculture.


Assuntos
Carpas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Salvia officinalis , Aeromonas , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Carpas/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Infecções por Bactérias Gram-Negativas/veterinária , Salvia officinalis/metabolismo , Superóxido Dismutase
12.
Arch Microbiol ; 204(7): 392, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35704068

RESUMO

Natural products with antimicrobial activity and their association with synthetic antimicrobials are a sustainable option in fish farming. The objective of this study was to determine antimicrobial activity, antibiofilm potential and synergism of five essential oils (EOs) with florfenicol against motile Aeromonas isolated from Amazonian Colossoma macropomum. As their major constituent, the EOs of the species of Aloysia triphylla, Croton cajucara (red and white morphotype), Cymbopongo citratus and Lippia gracilis present ß-pinene (22.1%), germacrene D (11.5%), linalool (23%), geranial (45.7%) and carvacrol (42.2%), respectively. The EOs of L. gracilis and C. citratus showed the best antimicrobial activities against the Aeromonas strains (5 mg mL-1). All EOs interfered with biofilm formation and consolidated biofilm. The EOs of A. triphylla, C. citratus and L. gracilis showed a synergistic effect with florfenicol, reducing the amount of the chemical into the water systems while treatment.


Assuntos
Aeromonas , Anti-Infecciosos , Óleos Voláteis , Tianfenicol , Animais , Óleos Voláteis/farmacologia , Tianfenicol/análogos & derivados , Tianfenicol/farmacologia
13.
J Water Health ; 20(6): 903-914, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35768966

RESUMO

Carbapenemase-producing Aeromonas species are an emerging health threat. This study aimed to determine carbapenemase-mediated resistance among Aeromonas isolates from the Akaki river, Ethiopia during the dry and wet seasons in 2019-2020. Antimicrobial susceptibility to carbapenems and cephalosporins was determined and carbapenemase production was confirmed. Of 163 isolates, the majority were human pathogens Aeromonas caviae (62), Aeromonas hydrophila (33) and Aeromonas veronii (49). These isolates were resistant to carbapenem and cephalosporin antibiotics, with the highest resistance to cefotaxime 86 (59.7%), ertapenem 71 (49.3%) and imipenem 65 (45.1%). Resistance to carbapenem antibiotics varied between species, where most A. veronii 37 (75.5%) and A. hydrophila 28 (84.8%) were resistant to imipenem and all A. caviae were sensitive. A. veronii, A. caviae and A. hydrophila resistance to meropenem was 31 (63.3%), 3 (4.8%) and 19 (57.6%), respectively. Of isolates resistant to carbapenem, 82.1% A. hydrophila and 94.4% A. veronii were carbapenemase producers. Cephalosporin resistance also varied among the different species. The highest resistance to carbapenem antibiotics was in isolates collected during the wet season (p<0.05); however, it was not consistent across all classes of antibiotics tested. The rivers in megacities could be reservoirs of carbapenemase-producing Aeromonas spp.


Assuntos
Aeromonas , Antibacterianos/farmacologia , Proteínas de Bactérias , Carbapenêmicos/farmacologia , Etiópia , Humanos , Imipenem , Testes de Sensibilidade Microbiana , Rios , beta-Lactamases
14.
PLoS One ; 17(6): e0269423, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35657908

RESUMO

In this study, the purposefulness of using the API20E biochemical identification system as a supportive tool for enhancing the discrimination of environmental bacteria by MALDI-TOF MS method was evaluated. The identification results of MALDI-TOF MS and API20E for 321 Gram-negative strains isolated from the riverine freshwater and its sediment, and from the tissues of fish from the same water body were compared. Of 190 isolates identified with probable to highly probable species-level identification, and secure genus to probable species identification, 14 isolates (7.37%) had identification score over 2.300, and from the same group 19 isolates (10%) had excellent or very good identification to the genus by API20E system. With regard to agreement at genus level, out of 231 strains with genus designation available by API20E at any level of identification reliability, MALDI-TOF MS genus identification agreed in 163 (70.6%) strains. Of these, 135 (82.8%) were Aeromonas species and the remaining isolates belonged to 7 different genera. Although API20E resulted in frequent misidentification due to a limited profile index, its individual biochemical reactions might contribute to overall characterization of isolates. For example, for all reliable A. hydrophila strain identifications with MALDI-TOF MS, ONPG, GLU and OX reactions were unarguably positive for all fish and water/sediment isolates, whereas only fish isolates yielded additional 100% positive TDA and VP reactions. Thus, after initial identification with MALDI-TOF MS, environmental isolates with lower identification scores should be further analyzed. Before commencing confirmatory testing with nucleic acid-based methods, biochemical API20E tests could be applied as a purposeful and inexpensive identification support in targeting better identification accuracy. In this study, this was particularly evident with A. hydrophila, Chryseobacterium sp. and Pseudomonas sp. This identification strategy could significantly resolve methodological and cost-related shortcomings frequently occurring with large number of environmental isolates.


Assuntos
Aeromonas , Animais , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Água
15.
Carbohydr Res ; 519: 108602, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35717683

RESUMO

The structure of the O-specific polysaccharide (OPS) from Aeromonas encheleia strain A4 lipopolysaccharide was investigated. A. encheleia strain A4, classified into the new provisional serogroup PGO1 predominating among aeromonads in Polish aquaculture, was isolated from common carp tissues during an outbreak of MAI/MAS disease on a fish farm. The high-molecular-weight OPS fraction liberated from the lipopolysaccharide after mild acid hydrolysis followed by gel-permeation chromatography was studied with chemical methods, mass spectrometry, and one- and two-dimensional 1H and 13C NMR spectroscopy techniques. Inter-residue correlations were identified in 1H,13C-heteronuclear multiple-bond correlation (HMBC) and 1H,1H NOESY experiments. It was found that the O-specific polysaccharide of A. encheleia strain A4 consists of branched pentasaccharide repeating units with the following structure:→2)[α-d-Fucp3NRHb-(1→3)]-α-l-Rhap-(1→3)-ß-l-Rhap-(1→4)-α-l-Rhap-(1→3)-ß-d-QuipNAc-(1→.


Assuntos
Lipopolissacarídeos , Antígenos O , Aeromonas , Aquicultura , Sequência de Carboidratos , Lipopolissacarídeos/química , Antígenos O/química , Polônia , Sorogrupo
16.
Front Cell Infect Microbiol ; 12: 885360, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35646727

RESUMO

Aeromonas 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 Aeromonas 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, e.g., 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 qnr genes were detected by PCR. Isolates comprising eight species, namely, mainly Aeromonas veronii (50.7% isolates) and Aeromonas media (24.6% isolates) and rarely Aeromonas eucrenophila, Aeromonas caviae, Aeromonas bestiarum, Aeromonas ichthiosmia, and Aeromonas hydrophila, 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 Aeromonas spp. phenotypes. Mainly the qnrS (34.8% isolates) and qnrA (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 A. veronii and A. media. 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 qnr resistance genes. It suggests that phenotypically susceptible bacteria might be a potential source for the storage and transmission of these genes. The exposure during, e.g., 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.


Assuntos
Aeromonas , Quinolonas , Aeromonas/genética , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Fluoroquinolonas/farmacologia , Água Doce , Fenótipo , Plasmídeos/genética , Quinolonas/farmacologia
17.
Infect Genet Evol ; 103: 105320, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35753622

RESUMO

The genus Aeromonas is found worldwide in freshwater and marine environments and has been implicated in the etiology of human and animal diseases. In fish, among Aeromonas species, A. salmonicida causes massive mortality and great economic losses in marine and continental aquaculture species. Currently, several aspects of the clinical signs and pathogenesis of this Gram-negative bacterium have been described; however, determination of an appropriate reference gene is essential to normalize cellular mRNA data remain unknown. Here we evaluate the stability of seven candidate reference genes to be used for data normalization during ex vivo and in vivo experiments conducted in Atlantic cod, Atlantic salmon, and lumpfish. To assess this, raw Ct values obtained were evaluated by using geNorm, NormFinder, BestKeeper, Delta Ct comparison, and the comprehensive ranking, through the bioinformatic open-access portal RefFinder. We determined that fabD and era were most suitable reference genes in Atlantic cod primary macrophages, hfq and era in Atlantic salmon primary macrophages, rpoB and fabD in lumpfish head kidney samples, and hfq and era in lumpfish spleen. Our study demonstrates that use of multiple reference genes and its validation before measurements helps to minimize variability arising in qPCR studies that evaluate A. salmonicida gene expression in fish tissues. Overall, this study provided with an expanded list of reliable reference genes for A. salmonicida gene expression using qPCR during fish infection studies.


Assuntos
Aeromonas salmonicida , Aeromonas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Salmo salar , Aeromonas salmonicida/genética , Animais , Doenças dos Peixes/microbiologia , Peixes , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Humanos , Salmo salar/genética
18.
J Fish Dis ; 45(10): 1477-1489, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35749548

RESUMO

Aeromonas veronii is a significant pathogen that is capable of infecting humans, animals, and aquatic animals. The type III secretion system (T3SS) is intimately associated with bacterial pathogenicity. The ascO gene is an important core component of T3SS in A. veronii, but its function is still unclear. The ascO gene of A. veronii TH0426 was deleted by using the pRE112 suicide plasmid to study its function. The study results showed that the ability of ∆ascO to adhere and invade EPC cells was significantly reduced by 1.28 times. The toxicity of the mutant strain ΔascO to EPC cells was consistently significantly lower than wild-type strain TH0426 at 1, 2, and 4 h. The LD50 values of ∆ascO against zebrafish and Carassius auratus (C. auratus) were 53 and 15 times that of the wild-type strain. In addition, the bacterial load of the mutant strain ΔascO in blood, heart, liver, and spleen was lower than wild-type strain TH0426. The Hoechst staining showed that the apoptotic degree of EPC cells induced by the mutant strain ΔascO was lower than that of the wild-type strain TH0426. Furthermore, real-time quantitative PCR (RT-qPCR) analysis revealed lower expression levels of pro-apoptotic genes (including cytC, cas3, cas9, TNF-α, and IL-1ß) in C. auratus tissues infected with the mutant strain ΔascO compared to the wild-type strain TH0426. The results of in vivo and in vitro experiments have shown that ascO gene mutation can reduce the adhesion and toxicity of A. veronii to EPC and reduce the level of apoptosis induced by A. veronii. As a result, these insights will help further elucidate the function of the ascO gene and thus contribute to understanding the pathogenesis of A. veronii.


Assuntos
Aeromonas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Aeromonas/genética , Aeromonas veronii/genética , Animais , Apoptose , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Humanos , Fosforilcolina/análogos & derivados , Virulência/genética , Peixe-Zebra/genética
19.
Fish Shellfish Immunol ; 126: 150-163, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35580798

RESUMO

Atlantic salmon is one of the most famous and economically important fish species globally. However, bacterial diseases constantly constrain salmon aquaculture. Thereinto, Aeromonas salmonicida subsp. masoucida (ASM), classified as atypical A. salmonicida, caused huge losses to salmonid industry in China. In this regard, we conducted transcriptome analysis in Atlantic salmon head kidney following the administration of ASM vaccination to reveal genes, their expression patterns, and pathways involved in immune responses. A total of 448.71 million clean reads were obtained, and 397.69 million reads were mapped onto the Atlantic salmon reference genome. In addition, 117, 1891, 741, 207, and 377 genes were significantly up-regulated, and 183, 1920, 695, 83, and 539 genes were significantly down-regulated post ASM vaccination at 12 h, 24 h, 1 m, 2 m, and 3 m, respectively. Furthermore, KEGG pathway analysis revealed that many differentially expressed genes (DEGs) following ASM vaccination were involved in cell adhesion molecules (H2-Aa-l and CD28-l),cytokine-cytokine receptor interaction (IL10, CXCL9, CXCL11, CXCR3, and CCL19), herpes simplex infection (IL1B, SOCS3-l, and C3-l), HTLV-I infection (Il1r2 and BCL2L1), influenza A (CXCL8 and Il12b), and PI3K-Akt signaling pathway (PIK3R3-l and Ddit4-l). Finally, the results of qRT-PCR showed a significant correlation with RNA-Seq results, suggesting the reliability of RNA-Seq for gene expression analysis. This study sets the foundation for further study on the vaccine protective mechanism in Atlantic salmon as well as other teleost species.


Assuntos
Aeromonas salmonicida , Doenças dos Peixes , Salmo salar , Vacinas , Aeromonas , Aeromonas salmonicida/fisiologia , Animais , Rim Cefálico , Fosfatidilinositol 3-Quinases/genética , Reprodutibilidade dos Testes , Transcriptoma
20.
Fish Shellfish Immunol ; 125: 180-189, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35561950

RESUMO

Aeromonas veronii is a freshwater bacterium associated with many diseases in aquatic animals. However, few cases of A. veronii infection were reported in Odontobutis potamophila, which has been becoming a promising fish species in China in recent years. In this study, the dominant bacteria were isolated from diseased O. potamophila showing signs of hemorrhage on fins, ulceration on the dorsal and abdomen. The representative isolate Stl3-1was identified as A. veronii based on analysis of its morphological, physiological, and biochemical features, as well as 16S rRNA and gyrB gene sequences. The median lethal dosage (LD50) of the isolate Stl3-1 for O. potamophila was determined as 4.5 × 105 CFU/mL. Histopathological analysis revealed that the isolate Stl3-1caused considerable histological lesions in the fish, including tissue cell degeneration, necrosis, and inflammatory cell infiltrating. Detection of virulence-related genes showed that A. veronii Stl3-1 was positive for exu, ompA, lip, flaH, hlyA, aer, flgM, tapA, act, flgA, gcaT and flgN. Additionally, quantitive real-time PCR (qRT-PCR) was also undertaken to analyses the host defensive response in O. potamophila infected by A. veronii. The immune-related gene expressions in O. potamophila during experimental infection were monitored at different point of time, and the results showed that the expression levels of MHC II, Myd88, TLR, and SOD were significantly up-regulated in liver, gill, spleen, and head kidney. The results revealed that A. veronii was a pathogen causing mass mortalities of O. potamophila and will contribute to better understanding the host defensive response against A. veronii infection.


Assuntos
Aeromonas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Perciformes , Aeromonas/genética , Aeromonas veronii/genética , Animais , Doenças dos Peixes/microbiologia , Peixes/genética , Infecções por Bactérias Gram-Negativas/microbiologia , Imunidade , Perciformes/genética , RNA Ribossômico 16S/genética , Virulência/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...