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1.
Ecotoxicol Environ Saf ; 191: 110182, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31958628

RESUMO

The gut of aquatic animals was a significant niche for dissemination of antibiotic resistance genes (ARGs) and direct response of living conditions. In this study, the gut microbiota of goldfish Carassius auratus Linnaeus was sampled at 7 days and 21 days after treatment with tetracycline at 0.285 and 2.85 µg L-1 to investigate the influences on the microbial structure and antibiotic resistance. The proportion of tetracycline resistance bacteria was 1.02% in the control group, while increased to 23.00%, 38.43%, 62.05% in groups of high concentration for 7 days (H7), low concentration for 21 days (L21) and high concentration for 21 days (H21), respectively. Compared to the control group, the diversity of isolated Aeromonas spp. was decreased in the treatment groups and the minimal inhibitory concentration (MIC) of resistant isolates was enhanced from 32 to 256 µg mL-1 with the treatment of tetracycline in time- and dose-dependent manners. Furthermore, the abundance of most genes was increased in treatment groups and efflux genes mainly responded to the stress of tetracycline with an average level of 1.0 × 10-2. After treatment with tetracycline, the predominant species were changed both at phylum and genus levels. The present study explored the impact of tetracycline on gut microbiota of goldfish at environmentally realistic concentrations for the first time and our findings will provide a reference for characterizing the microbiome of fish in the natural environment.


Assuntos
Aeromonas/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Carpa Dourada/microbiologia , Resistência a Tetraciclina/genética , Tetraciclina/toxicidade , Aeromonas/classificação , Aeromonas/genética , Aeromonas/isolamento & purificação , Animais , Antibacterianos/toxicidade , Exposição Ambiental/efeitos adversos , Genes Bacterianos , Testes de Sensibilidade Microbiana , Resistência a Tetraciclina/efeitos dos fármacos
2.
J Appl Microbiol ; 128(2): 606-617, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31606917

RESUMO

AIMS: The object of this study was to identify potential health concerns of the Aeromons spp. isolated from marketed Pacific abalone (Haliotis discus hannai) with respect to their virulence and antimicrobial resistance patterns. METHODS AND RESULTS: We identified 29 strains of aeromonads consisting of five species; Aeromonas hydrophila (n = 9), Aeromonas enteropelogenes (n = 14), Aeromonas veronii (n = 3), Aeromonas salmonicida (n = 2) and Aeromonas sobria (n = 1), by employing series of biochemical tests and gene sequencing. In the phenotypic virulence assays, all isolates showed gelatinase and caseinase activities, while lipase formation (69%), phospholipase production (90%), DNase formation (82%), slime production (49%) and haemolysis activity (α = 18% and ß = 82%) were also detected among isolates. Prevalence of virulence genes; aerA (100%), fla (66%), ahyB (73%), act (52%), alt (42%), ast (35%), ser (52%), gcat (69%), ascV (43%), hlyA (83%), lip (52%) and exu (59%) were detected by PCR assays. In disc diffusion test, 100% resistance was detected against ampicillin while cephalothin, rifampicin, oxytetracycline, colistine sulphate, nalidixic acid and piperaciliin were resisted by 86, 73, 42, 35, 28, 20 and 20% of the isolates respectively. Thirteen (45%) of the isolates showed multiple antimicrobial resistance (MAR) indices ≥ 0·2. CONCLUSIONS: Our findings suggest that the potential health risk posed by the abalone-borne Aeromonas spp. should not be underestimated. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first time to evaluate possible public health risks upon consumption of abalone harbored Aeromonas spp. and also to isolate potential pathogenic and multidrug-resistant Aeromonas spp. from Pacific abalone in Korea.


Assuntos
Aeromonas/efeitos dos fármacos , Aeromonas/isolamento & purificação , Farmacorresistência Bacteriana , Gastrópodes/microbiologia , Alimentos Marinhos/microbiologia , Aeromonas/classificação , Aeromonas/genética , Animais , Antibacterianos/farmacologia , Contaminação de Alimentos/análise , Ácido Nalidíxico/farmacologia , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Reação em Cadeia da Polimerase , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , República da Coreia
3.
Food Chem ; 305: 125454, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505413

RESUMO

The effects of the (-)-Epigallocatechin gallate (EGCG)-gelatin biofilm treatment (EGT) on microbial composition and quality of tilapia fillets stored at low temperatures were evaluated. The changes in mechanical properties, microbial reproduction, as well as lipid and protein oxidation during fillets storage were determined. The results showed that EGT reduced the microbial count and the relative abundance of the fillets. And EGT delayed the rate of lipid oxidation and protein denaturation in fillets. Compared with the control group, EGT samples had lower K values (74% on 18 d) and biogenic amines (39 mg/kg for putrescine and 50 mg/kg for cadaverine on 21 d). According to sensory evaluation, the shelf life of tilapia fillets was extended by 6 d in the EGT group. Therefore, EGT improved the quality of cryopreserved tilapia fillets and could be considered as a potential method for fish fillet preservation.


Assuntos
Materiais Biomiméticos/química , Catequina/análogos & derivados , Armazenamento de Alimentos/métodos , Gelatina/química , Alimentos Marinhos/análise , Aeromonas/efeitos dos fármacos , Animais , Aminas Biogênicas/análise , Materiais Biomiméticos/farmacologia , Catequina/química , Peroxidação de Lipídeos/efeitos dos fármacos , Desnaturação Proteica/efeitos dos fármacos , Proteínas/química , Pseudomonas/efeitos dos fármacos , Alimentos Marinhos/microbiologia , Paladar/efeitos dos fármacos , Temperatura
4.
Food Microbiol ; 86: 103356, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703863

RESUMO

Quorum sensing (QS), bacterial cell-to-cell communication, is a gene regulatory mechanism that regulates virulence potential and biofilm formation in many pathogens. Aeromonas sobria, a common aquaculture pathogen, was isolated and identified by our laboratory from the deteriorated turbot, and its potential for virulence factors and biofilm production was regulated by QS system. In view of the interference with QS system, this study was aimed to investigate the effect of methyl anthranilate at sub-Minimum Inhibitory Concentrations (sub-MICs) on QS-regulated phenotypes in A. sobria. The results suggested that 0.5 µL/mL of methyl anthranilate evidently reduced biofilm formation (51.44%), swinging motility (74.86%), swarming motility (71.63%), protease activity (43.08%), and acyl-homoserine lactone (AHL) production. Furthermore, the real-time quantitative PCR (RT-qPCR) and in silico analysis showed that methyl anthranilate might inhibit QS system in A. sobria by interfering with the biosynthesis of AHL, as well as competitively binding with receptor protein. Therefore, our data indicated the feasibility of methyl anthranilate as a promising QS inhibitor and anti-biofilm agent for improving food safety.


Assuntos
Aeromonas/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , ortoaminobenzoatos/farmacologia , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Aeromonas/genética , Aeromonas/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
5.
Food Microbiol ; 86: 103313, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31703873

RESUMO

This study investigated the effect of phytic acid and lysozyme on the microbial composition and quality of grass carp (Ctenopharyngodon idellus) fillets stored at 4 °C. The control, 0.5 mg/mL lysozyme-treated fillets (T1), 0.5 mg/mL phytic acid-treated fillets (T2) and 0.25 mg/mL lysozyme + 0.25 mg/mL phytic acid-treated fillets (T3) were evaluated based on sensory assessment, biogenic amines, ATP-related compounds, total volatile basic nitrogen (TVB-N), and total viable counts (TVC). Changes in microbial composition were analyzed using high-throughput sequencing. Results showed that phytic acid and lysozyme treatment delayed the decrease in sensory scores, reduced the rate of degradation of IMP to Hx, inhibited the growth of microorganisms, and attenuated the increase in TVB-N and putrescine. Phytic acid exhibited better preservation effects than lysozyme and their combination was more effective than using either alone. High-throughput sequencing showed that Acinetobacter and Kocuria were the predominant bacteria in fresh grass carp, but Pseudomonas rose rapidly with storage time; Pseudomonas, Shewanella, and Aeromonas constituted the main spoilage bacteria of grass carp fillets. Lysozyme treatment significantly reduced the proportion of Shewanella and Acinetobacter, and phytic acid and the combination of phytic acid and lysozyme significantly reduced the proportion of Pseudomonas in spoiled grass carp fillets.


Assuntos
Carpas/microbiologia , Produtos Pesqueiros/microbiologia , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Microbiota/efeitos dos fármacos , Muramidase/farmacologia , Ácido Fítico/farmacologia , Acinetobacter/efeitos dos fármacos , Acinetobacter/crescimento & desenvolvimento , Aeromonas/efeitos dos fármacos , Aeromonas/crescimento & desenvolvimento , Animais , Aminas Biogênicas/análise , Conservação de Alimentos/instrumentação , Armazenamento de Alimentos , Humanos , Pseudomonas/efeitos dos fármacos , Pseudomonas/crescimento & desenvolvimento , Shewanella/efeitos dos fármacos , Shewanella/crescimento & desenvolvimento , Paladar
6.
Braz J Infect Dis ; 23(5): 336-342, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31541615

RESUMO

INTRODUCTION: Aeromonas species are renowned enteric pathogens with virulence determinants linked to human diseases, such as gastroenteritis, skin, soft-tissue and muscle infections, and septicemia. A recent concern of resistance in this organism has emerged, especially the presence carbapenemases. Herein we describe a case series of emerging carbapenem-resistant Aeromonas species infection in our hospital in Cali, Colombia. MATERIALS AND METHODS: Cases from 2012 to 2018 are reported. Clinical data was abstracted from the clinical charts and laboratory information. Phenotypic detection of resistance was identified using the VITEK®2 system (BioMérieux) and broth microdilution MicroScan WalkAway plus System (Beckman Coulter). CARBA NP-test and multiplex qPCR assay was performed in 11 isolates to identify genes encoding carbapenemases (blaKPC, blaVIM, blaIMP and blaNDM). RESULTS: 21 cases of Aeromonas infection in hospitalized patients with phenotypic resistance to carbapenems were studied. The median age was 50 years, 55% (12/21) were male, and 67% (14/21) were healthcare-associated infections (HAI). Aeromonas hydrophila was the most common species (19/21). Forty-three percent (9/21) of the patients were immunocompromised. The mortality was 33% (7/21), and in patients with bacteremia was 100%. Most patients received empirical treatment with meropenem and failed to this treatment. PCR amplification tests showed negative results for the carbapenemases analyzed. CONCLUSION: Emerging phenotypic carbapenem-resistant infection has been seen in our hospital, most as HAI. High mortality was found, especially in immunocompromised patients and in those who failled empirical treatment with carbapenems. As the main carbapenemases tested were negative, carbapenem-resistant could be attributed to an intrinsic metallo-ß-lactamase, CphA encoded by the cphA gene, possible hyperproduction of ampC ß-lactamase and/or porins expression.


Assuntos
Aeromonas/genética , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Infecções por Bactérias Gram-Negativas/microbiologia , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , Adulto , Aeromonas/efeitos dos fármacos , Aeromonas/enzimologia , Idoso , Colômbia , Estudos Transversais , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fenótipo
8.
APMIS ; 127(8): 570-576, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31231825

RESUMO

Two quite different disc contents are used for antimicrobial susceptibility testing of two fluoroquinolone drugs, flumequine and enrofloxacin, in the disc diffusion test, 30 and 5 µg, respectively. Using the SRA method, single-strain regression analysis, we studied the impact of disc content when testing two relevant bacterial species, Aeromonas sobria and Vibrio anguillarum. There were no major differences between the antimicrobial regression lines for the two species. Wild-type strains produced acceptable zones of inhibition over a wide range of disc contents. The flumequine 30 µg disc should be lowered in its drug content. No rational reasons for choosing so different disc contents for the two antimicrobials were apparent. At present, the choice of disc content for new antimicrobials are outside the realm of clinical microbiologists. It is recommended that reference authorities, such as EUCAST, CLSI and USCAST, are consulted for the choice of disc contents in the future.


Assuntos
Aeromonas/efeitos dos fármacos , Enrofloxacina/farmacologia , Fluoroquinolonas/farmacologia , Testes de Sensibilidade Microbiana/métodos , Vibrio/efeitos dos fármacos , Aeromonas/crescimento & desenvolvimento , Antibacterianos/farmacologia , Análise de Regressão , Vibrio/crescimento & desenvolvimento
9.
J Appl Microbiol ; 127(3): 941-952, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31211903

RESUMO

AIMS: Manila clam (Ruditapes philippinarum) is one of the most popular seafood in Korea, owing to their unique taste and nutritional value. This study aimed to disclose the antibiotic and heavy metal resistance characteristics of Aeromonas spp. isolated from marketed Manila clam in Korea. METHODS AND RESULTS: A total of 36 Aeromonas spp. strains were isolated and subjected to two tests: an antibiotic disk diffusion test to determine their resistance to antibiotics, and a broth dilution test to determine their resistance to heavy metals. PCR-based amplification was performed to detect the resistance genes. A high level of resistance to ampicillin (100%) and cephalothin (89%) was observed, while 42, 39, 36 and 36% of the isolates were resistant to oxytetracycline, imipenem, nalidixic acid and tetracycline respectively. In addition, among the tested heavy metals, cadmium (Cd) recorded the highest resistance rate (61%), followed by chromium (Cr) (50%), lead (Pb) (47%) and copper (Cu) (37%). However, mercury (Hg) resistance was not observed. PCRs revealed the occurrence of blaTEM , blaSHV , blaCTX-M , qnrS, tetB, tetE, aac(6')-Ib, strA-strB and intI1 genes among 100, 31, 31, 78, 78, 89, 25, 50 and 72% of the isolates respectively. Moreover, heavy metal resistance genes, copA, merA and czcA were detected in 25, 47 and 61% of the isolates respectively. CONCLUSIONS: The results suggest the importance of multi-drug and heavy metal-resistant aeromonads in Manila clam to assess the consumer safety and public health. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to elaborate on the importance of multi-drug and heavy metal-resistant aeromonads in Manila clam. Particularly, the presence of extended-spectrum-ß-lactamase genes and other antibiotic resistance genes intensifies the possible health risks and may complicate therapeutic treatments upon infection, while heavy metal resistance suggests possible heavy metal exposure.


Assuntos
Aeromonas/efeitos dos fármacos , Antibacterianos/farmacologia , Bivalves/microbiologia , Resistência Microbiana a Medicamentos/genética , Metais Pesados/farmacologia , Aeromonas/genética , Aeromonas/isolamento & purificação , Animais , Humanos , Reação em Cadeia da Polimerase , República da Coreia
10.
Lett Appl Microbiol ; 69(1): 2-10, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30980564

RESUMO

Aeromonas sp. are opportunistic pathogenic bacteria which are associated with various diseases in ornamental fish, aquaculture raised species and wild fisheries. In our study, antimicrobial resistance patterns, antimicrobial resistance genes and class 1 integron gene cassettes of 52 guppy-borne Aeromonas sp. were examined. The isolates were identified as A. veronii (n = 34), A. dhakensis (n = 10), A. hydrophila (n = 3), A. caviae (n = 3) and A. enteropelogenes (n = 2) by gyrB gene sequencing. Every isolate was resistant to at least four antimicrobials in disc diffusion test. The resistance to amoxicillin, nalidixic acid and oxytetracycline was 100% among the tested isolates. 92·30, 76·92, 71·15, 51·92, 51·92 and 50·00% of the isolates were resistant to ampicillin, rifampicin, imipenem, cephalothin, tetracycline and trimethoprim respectively. The multiple antibiotic resistance index values ranged from 0·28 to 0·67. PCR amplification of antimicrobial resistance genes implied the occurrence of tetracycline resistance (tetA (65·39%), tetE (25·00%) and tetB (15·38%)), plasmid-mediated quinolone resistance (qnrS (26·92%) and qnrB (17·31%)) and aminoglycoside resistance (aphaAI-IAB (7·69%) and aac (6')-Ib (3·84%)) genes in the isolates. The IntI gene was positive for 36·54% of the isolates and four class 1 integron gene cassette profiles (aadA2, qacE2-orfD, aadA2-catB2 and dfrA12-aadA2) were identified. These data suggest that ornamental guppy can be a reservoir of multidrug-resistant Aeromonas sp. which comprise different antimicrobial resistance genes and class 1 integrons. SIGNIFICANCE AND IMPACT OF THE STUDY: Antimicrobial resistance genes and integron gene cassettes of ornamental fish-borne aeromonads are poorly studied. The antimicrobial resistance patterns, antimicrobial resistance genes and class 1 integron gene cassettes of Aeromonas sp. isolated from ornamental guppy were characterized for the first time in Korea. The incidence of different antimicrobial resistance genes and class 1 integron gene cassettes were observed in multidrug-resistant Aeromonas isolates. This result suggests that better management practices are necessary to prevent and address the serious consequences of indiscriminate and inappropriate antimicrobial use, and the distribution of multidrug-resistant bacteria.


Assuntos
Aeromonas/efeitos dos fármacos , Aeromonas/genética , Farmacorresistência Bacteriana Múltipla/genética , Integrons/genética , Poecilia/microbiologia , Aeromonas/isolamento & purificação , Animais , Antibacterianos/farmacologia , Aquicultura , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , República da Coreia
11.
Microb Pathog ; 130: 146-155, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30826430

RESUMO

Application of antibiotics to combat bacterial diseases in fish has been criticized due to likely emergence of drug resistance. Therefore, investigation of new bioactive compounds from natural sources has been taken into account. This study was designed to purify and characterize the bioactive compound in the cell free supernatant (CFSs) of autochthonous gut bacteria (Bacillus methylotrophicus KU556164, B. amyloliquefaciens KU556165, Pseudomonas fluorescens KU556166 and B. licheniformis KU556167) isolated from rohu, Labeo rohita. CFSs were antagonistic to fish pathogenic Aeromonas spp., moderately thermo-tolerant and active in wide range of pH (5-11). Antibacterial activity of the CFSs was reduced by the action of proteases (e.g., Proteinase K and Trypsin), indicating proteinaceous nature of the bioactive compound like the bacteriocins. Three-step purification procedure resulted in recovery of 16.97%, 18.04%, 33.33% and 6.38% activity of the antimicrobial protein produced by B. methylotrophicus, B. amyloliquefaciens, P. fluorescens and B. licheniformis, respectively. Purification at each step revealed decrease in protein content with gradual increase in the specific activity of the antimicrobial protein. The purified antibacterial compound ranged between 18.2 and 25.6 kDa. Identification through MALDI-TOF MS/MS and database search through Mascot search engine predicted that the bactericidal compound belonged to either alkaline proteases, or, transcriptional regulator and some hypothetical proteins. Apart from potential technological application of the antibacterial compound, the present study might show promise for application of gut-associated bacteriocinogenic bacteria to control diseases in fish caused by pathogenic bacteria.


Assuntos
Antibacterianos/metabolismo , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Produtos Biológicos/metabolismo , Cyprinidae/microbiologia , Microbioma Gastrointestinal , Aeromonas/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antibiose , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/farmacologia , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Concentração de Íons de Hidrogênio , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
12.
BMC Infect Dis ; 19(1): 158, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30764764

RESUMO

BACKGROUND: Clinical characteristics (taxonomy, virulence genes and antimicrobial resistance ) of Aeromonas in isolated from extra-intestinal and intestinal infections were investigated to describe epidemiology, associated virulence factors and optimal therapy options. METHODS: Clinical samples (n = 115) of Aeromonas were collected from a general hospital in Beijing between the period 2015 and 2017. Taxonomy was investigate by Multilocus phylogenetic analysis (MLPA), 10 putative virulence factors by use of polymerase chain reaction (PCR) and antimicrobial resistance to 15 antibiotics by use of the microbroth dilution method. RESULTS: The most common species of Aeromonas detected in samples of intestinal tract included; A. caviae (43.9%), A. veronii (35.7%), and A. dhakensis (12.2%). Prevalent species of Aeromonas collected from extra-intestinal infections included; A. hydrophila (29.4%), A. caviae (29.4%), and A. dhakensis (23.5%). A. hydrophila were detected in 1% of stool samples and 29.4% (5/17) of extra-intestinal infections. A. hydrophila strains in extra-intestinal infections were related to malignancy. The most common medical conditions among patients with Aeromonas infections included malignancy and liver-transplant related cholecystitis. Multiple drug resistance (MDR) was prevalent in extra-intestinal isolates (82.3%, 14/17) and was greater than the prevalence in intestinal isolates (30.6%, 30/98) (P < 0.05). Resistant rates of extra-intestinal isolates were 70.6, 35.3, 23.5 and 5.9% for ceftriaxone, ciprofloxacin, gentamicin and imipenem, respectively, and were higher than found in previous studies. Despite differences in the number and type of virulence genes among samples of Aeromonas, no significant correlation was found between invasion and virulent genes in intestinal or extra-intestinal infections. CONCLUSIONS: Overall results of this study support a role for Aeromonas spp. as a potential causative infectious agent of gastroenteritis, and malignancy, liver cirrhosis, post liver transplantation in immunocompromised patients. A. hydrophila was more prevalent in samples of extra-intestinal infections when compared to samples of intestinal infections, and was especially prominent in samples of patients presenting with malignancy. Aeromonas isolates from extra-intestinal samples had high rates of drug resistance but 3rd generation cephalosporins, fluoroquinolones and aminoglycosides remain as options to treat severe diarrhea. However, increasing MDR of extra-intestinal infection samples warrants monitoring.


Assuntos
Aeromonas/classificação , Aeromonas/isolamento & purificação , Farmacorresistência Bacteriana , Infecções por Bactérias Gram-Negativas/microbiologia , Enteropatias/microbiologia , Infecções Intra-Abdominais/microbiologia , Fatores de Virulência/genética , Adolescente , Adulto , Aeromonas/efeitos dos fármacos , Aeromonas/genética , Antibacterianos/uso terapêutico , Técnicas de Tipagem Bacteriana , Criança , Pré-Escolar , China/epidemiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Feminino , Gastroenterite/tratamento farmacológico , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Humanos , Hospedeiro Imunocomprometido , Enteropatias/tratamento farmacológico , Enteropatias/epidemiologia , Infecções Intra-Abdominais/tratamento farmacológico , Infecções Intra-Abdominais/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Filogenia , Prevalência , Virulência/genética , Adulto Jovem
13.
Lett Appl Microbiol ; 68(5): 370-377, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30790321

RESUMO

Aeromonas spp. are Gram-negative opportunistic bacteria which have been commonly associated with fish diseases. In this study, antibiogram, antimicrobial resistance genes and integrons of 43 zebrafish-borne Aeromonas spp. were studied. The isolates were identified as six Aeromonas species (A. veronii biovar veronii (n = 26), A. veronii biovar sobria (n = 3), A. hydrophila (n = 8), A. caviae (n = 3), A. enteropelogenes (n = 2) and A. dhakensis (n = 1)). Antibiogram of the isolates indicated that most of them were resistant to amoxicillin (100·00%), nalidixic acid (100·00%), oxytetracycline (100·00%), ampicillin (93·02%), tetracycline (74·42%), rifampicin (67·44%) and imipenem (65·15%). Multiple antimicrobial resistance (MAR) index values ranged from 0·19-0·44 to 90·70% isolates showed multidrug resistance. PCR of antimicrobial resistance genes revealed that the tetracycline resistance gene (tetA) was the most predominant (67·44%) among the isolates. The qnrS (53·49%), tetB (30·23%), tetE (30·23%), qnrB (23·26%) and aac(6')-Ib-cr (4·65%) genes were also detected. Class 1 integrase (IntI1) gene was found in 46·51% of the isolates. Two types of class 1 integron gene cassette profiles (qacG-aadA6-qacG and drfA1) were identified. The results showed that zebrafish-borne aeromonads can harbour different types of antimicrobial resistance genes and class 1 integrons. SIGNIFICANCE AND IMPACT OF THE STUDY: Aeromonas spp. are important pathogens found in diverse environments. Antimicrobial resistance genes and integrons of ornamental fish-borne Aeromonas spp. are not well studied. The antibiogram, antimicrobial resistance genes and class 1 integrons of Aeromonas spp. isolated from zebrafish were characterized for the first time in Korea. The prevalence of tetracycline resistance genes, plasmid-mediated quinolone resistance genes and class 1 integron gene cassettes were observed among the isolates. The qacG-aadA6-qacG gene cassette was identified for the first time in Aeromonas spp. The results suggest that the wise use of antimicrobials is necessary for the better management of the ornamental fish.


Assuntos
Aeromonas/genética , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Integrases/genética , Integrons/genética , Aeromonas/classificação , Aeromonas/efeitos dos fármacos , Animais , Doenças dos Peixes/microbiologia , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Reação em Cadeia da Polimerase , República da Coreia , Peixe-Zebra/microbiologia
14.
J Appl Microbiol ; 126(1): 288-299, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30218592

RESUMO

AIMS: Yesso scallop (Patinopecten yessoensis) is a popular seafood in Korea. Aeromonas spp., well-known pathogenic bacteria, has been reported in some molluscan shellfish, but it has not been studied in scallops so far. Therefore, we aimed to isolate, identify and characterize the Aeromonas spp. isolated from marketed Yesso scallops to estimate their potential risk to public health. METHODS AND RESULTS: Thirty-two Aeromonas spp. including A. hydrophila (n = 13), A. salmonicida (n = 11), A. media (n = 3), A. caviae (n = 2), A. veronii (n = 2) and A. enteropelogenes (n = 1) were isolated from 105 marketed scallops and tested for phenotypic pathogenicity, virulence genes and antimicrobial susceptibility. Mean total bacterial count of scallop meat was 1·34 × 104 CFU per gram. Slime production and lipase tests were positive in 97% of the isolates while DNase, protease, gelatinase, phospholipase and haemolysis were shown by 88, 88, 81, 88 and 72% of the isolates respectively. Eleven virulence genes were detected among Aeromonas spp. (act (75%), alt (59%), ast (47%), aerA (78%), lip (59%), ahyB (94%), ser (75%), hlyA (75%), fla (64%), gcat (84%) and ascV (23%)), and exu was negative in all isolates. Aeromonas hydrophila and A. salmonicida harboured ≥7 virulence genes and positive for enterotoxin genes, act, alt and ast. All the isolates were multidrug resistant and 100% resistant to ampicillin, colistin, vancomycin and cephalothin. Also, 30, 31, 20, 21, 29, 24, 27 and 27 of the isolates were resistant to piperacillin, clindamycin, erythromycin, nalidixic acid, imipenem, meropenem, trimethoprim-sulfamethoxazole and rifampicin respectively. CONCLUSIONS: It is obvious with our results that the Aeromonas spp. isolated from Yesso scallops are highly virulent and potentially pathogenic, whereas the multidrug resistance further expedite their importance. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first study reporting Aeromonas spp. in scallop. This implies that not only the common varieties like oysters, but other bivalves can also harbour potentially pathogenic aeromonads which may have impacts on consumer health.


Assuntos
Aeromonas , Pectinidae/microbiologia , Alimentos Marinhos/microbiologia , Aeromonas/efeitos dos fármacos , Aeromonas/genética , Aeromonas/isolamento & purificação , Aeromonas/patogenicidade , Animais , Antibacterianos/farmacologia , Filogenia , Virulência/genética
15.
Infect Disord Drug Targets ; 19(3): 269-273, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30179147

RESUMO

INTRODUCTION: Aeromonas have recently emerged as opportunistic pathogens and only a few studies are available regarding the isolation of these bacteria from burn wound infections. This study aimed at isolating Aeromonas as an infrequent cause of infection in this group of immunocompromised patients. METHODS: A total of 300 samples were collected from the wounds of burn patients hospitalized in Gotbodin Shirazi Burn Center in 2013. The samples were cultured on Aeromonas specific media and then confirmed using standard biochemical tests and 16S rRNA gene amplification and sequencing. The antibiotic susceptibility of the isolates was determined using the disk diffusion and broth microdilution methods. RESULTS: Biochemical tests demonstrated five presumptive samples of Aeromonas, while, molecular testing confirmed only three. All isolates were resistant to ampicillin-sulbactam, erythromycin, oxacillin, and vancomycin. However, they were susceptible to gentamicin, meropenem, nitrofurantoin, chloramphenicol, cephalexin, and cefotaxime. Two Aeromonas veronii isolates were resistant to sulfamethoxazole-trimethoprim and sensitive to nalidixic acid, while Aeromonas bestiarum was sensitive to the former and resistant to the latter antibiotics. Lastly, only one of the A. veronii isolates was found to be resistant to tetracycline. CONCLUSION: This study is the first to report on the isolation of Aeromonas spp. from burn patients in Iran. Moreover, this is the first report of isolating A. bestiarum from burn wounds. The results of this study confirm earlier findings that the use of molecular methods is essential to accurately identify these bacteria.


Assuntos
Aeromonas/genética , Aeromonas/isolamento & purificação , Queimaduras/microbiologia , Infecção dos Ferimentos/microbiologia , Adulto , Aeromonas/efeitos dos fármacos , Antibacterianos/farmacologia , Coinfecção/microbiologia , Estudos Transversais , Farmacorresistência Bacteriana , Feminino , Humanos , Hospedeiro Imunocomprometido , Irã (Geográfico) , Masculino , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Adulto Jovem
16.
Probiotics Antimicrob Proteins ; 11(2): 676-686, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30143998

RESUMO

K4 is a de novo peptide with antibacterial activity on human pathogens. It has a short sequence (14 amino acids), with a cationic N-terminal moiety and an amphipathic ɑ-helix structure. The present paper demonstrates its activity on Vibrio bacteria in a marine environment. It was found non-toxic on marine organisms including Artemia salina, Dicentrarchus labrax, and Magallana gigas at different developmental stages, but influenced the growth of unicellular organisms like microalgae, depending on the algal strain and on K4 concentration. Furthermore, an original approach coupling liquid chromatography (RP-HPLC) and mass spectrometry (MS/MS) allowed us to monitor the degradation time course of the peptide for the first time in conditions close to a hatchery environment, i.e., in the presence of oyster spat. We detected truncated forms over time, and the full K4 was gradually no longer found in these filter-feeder oysters. Finally, using an automated optical density meter, we monitored the growth of several aquatic bacteria identified as pathogenic on animals. K4 had a bactericidal effect on Aeromonas salmonicida and Vibrio splendidus LGP32 at concentrations below 45 µg mL-1. Our results show that K4 could be an environment-friendly alternative to antibiotics, non-toxic to several marine organisms. The use of K4 would be particularly useful to decrease the bacterial load associated with food intake in the early developmental stages of marine animals reared in hatcheries.


Assuntos
Aeromonas/efeitos dos fármacos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Vibrio/efeitos dos fármacos , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/toxicidade , Organismos Aquáticos , Vibrio/crescimento & desenvolvimento , Microbiologia da Água
17.
Food Sci Technol Int ; 25(2): 101-108, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30193534

RESUMO

The selection and use of natural compounds with antimicrobial activity against foodborne pathogens is of major importance. The present study evaluated the antimicrobial activity of commercial essential oils against multidrug-resistant Enterococcus spp. and Aeromonas spp. Cymbopogon flexuosus and Thymus vulgaris essential oils presented the highest inhibitory zones against both bacterial groups ( p < 0.05). Subsequent determination of the minimum inhibitory concentrations showed values between 0.47 and 1.9 mg/ml for Aeromonas spp. and from 1.9 to 15 mg/ml for Enterococcus spp. The antimicrobial effect of C. flexuosus and T. vulgaris essential oils was also assessed against biofilms. Bacteria in biofilm state were subjected to 30 min or 1 h of exposure to each essential oil and eradication ability estimated by colony counting. Both essential oils exhibited antimicrobial activity against preformed Aeromonas biofilms, but were unable to successfully eradicate biofilms produced by enterococci, in the conditions under investigation. Nonetheless, the presumptive use of essential oils in the food industry should be considered in further investigations.


Assuntos
Aeromonas/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Enterococcus/efeitos dos fármacos , Magnoliopsida/química , Óleos Voláteis/farmacologia , Cymbopogon , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Plâncton , Extratos Vegetais/farmacologia , Thymus (Planta)
18.
F1000Res ; 7: 415, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30363877

RESUMO

Backgrounds: Bacteriocin has been used widely in industry as a biopreservative agent. The objective of the present study was to investigate the potency of Bacteriocin isolated from tiger prawn Penaeus monodon and freshwater shrimp Macrobrachium rosenbergii as an anti-bacterial on fish. Methods: A total of ten candidates of probiotic bacteria consisted of five isolates from tiger shrimps (H1, H2, H3, H4, H5) and five isolates from freshwater prawns (W1, W2, W3, W4, W5) were evaluated. Bacteriocin wasBacteriocin was produced by centrifugation at a speed of 150 rpm and at 37 °C for 24 hours. The bacteriocin extract was purified by adding sulphate ammonium salt {(NH4) 2SO4} at 80% of the saturation level. Bacteriocin activity was determined using a diffusion method against pathogenic bacteria Vibrio alginolyticus, Aeromonas hydrophillaAeromonas hydrophilla and Pseudomonas stutzeri. Bacteriocins were analyzed usinganalyzedusing High Performance Liquid Chromatography (HPLC) and Fourier Transform Infra-Red (FTIR). The data were subjected to analysis of variance (ANOVA) and followed with Duncans multiple range test. Results: Bacteriocins produced by bacteria isolate H4 from tiger prawn indicated the highest bacteriocin activity againstbacteriocin activity against Pseudomonas stutzeri at stutzeri at the diameter of inhibition zone of 887.10 ± 409.24 mm 2/mL. While isolate W2 from freshwater shrimp indicated inhibition zone of 1466.96 ± 127.62 mm 2/mL. Both bacteriocins were purified by chromatography column using Sephadex LH-20. Conclusion s: This finding showed that bacterial isolates H4 and W2 have the potential to produce bacteriocins which inhibit the pathogenic bacteria. FTIR analysis showed an amide group at wave number 1652cm -1 contained in the bacteriocins of isolates H4 and W2.


Assuntos
Aeromonas/efeitos dos fármacos , Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Crustáceos/microbiologia , Peixes/microbiologia , Pseudomonas/efeitos dos fármacos , Vibrio/efeitos dos fármacos , Animais , Antibacterianos/biossíntese , Bacteriocinas/biossíntese , Bacteriocinas/isolamento & purificação , Testes de Sensibilidade Microbiana , Probióticos
19.
Food Microbiol ; 76: 257-266, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166149

RESUMO

The present study investigated the effect of ε-Polylysine on bacterial communities, sensorial, and chemical properties [total volatile basic nitrogen (TVB-N), biogenic amines, and breakdown products of adenosine triphosphate] of bighead carp (Aristichthys nobilis) fillets stored at 4 ±â€¯1 °C. Bacterial communities were explored by the culture-dependent method and the high-throughput sequencing targeting on 16S rRNA genes. The results showed that the major genera in spoiled control samples were Aeromonas, Pseudomonas, Shewanella, and Acinetobacter. ε-Polylysine inhibited the growth of Pseudomonas, Shewanella, and Acinetobacter. Consequently, Aeromonas and Janthinobacterium were dominant in spoiled treated samples. The sensorial shelf-life of the control and treated groups were 8 days and 10 days, respectively. Furthermore, due to the inhibitory effect of ε-Polylysine on bacteria, chemical changes of the treated group were slower, reflecting as lower concentrations of TVB-N, putrescine, cadaverine, and hypoxanthine, and higher contents of inosine 5'-monophosphate and hypoxanthine riboside at the end of storage. In conclusion, ε-Polylysine altered the bacterial communities and delayed quality deterioration of bighead carp fillets during chilled storage.


Assuntos
Bactérias/efeitos dos fármacos , Carpas/microbiologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Consórcios Microbianos/efeitos dos fármacos , Técnicas Microbiológicas/métodos , Polilisina/farmacologia , Aeromonas/efeitos dos fármacos , Aeromonas/genética , Aeromonas/isolamento & purificação , Animais , Bactérias/isolamento & purificação , Carpas/anatomia & histologia , Contagem de Colônia Microbiana/métodos , Consórcios Microbianos/genética , Consórcios Microbianos/fisiologia , Polilisina/química , Pseudomonas/efeitos dos fármacos , Pseudomonas/genética , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Alimentos Marinhos/análise , Alimentos Marinhos/microbiologia
20.
Food Microbiol ; 76: 52-61, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166183

RESUMO

This study evaluated the antimicrobial effects of tea polyphenols (TP) on changes in microbiota composition and quality attributes in silver carp fillets stored at 4 °C. During storage, TP treatment was found to be effective in enhancing sensory quality, inhibiting microbial growth, and attenuating chemical quality deterioration. Meanwhile, the composition of microbiota of silver carp fillets was investigated using culture-dependent and culture-independent methods. Initially, compared to the control, TP obviously decreased the relative abundance of Aeromonas, which allowed Acinetobacter and Methylobacterium to become the dominant microbiota in TP treated fillets on day 0. The controls, 0.5% TP-treated fillets, and 1% TP-treated fillets were rejected by sensory panelists on days 8, 12, and 12, respectively. At the time of sensory rejection, Aeromonas, followed by Acinetobacter and Pseudomonas, became the main spoilers in the control on day 8. However, TP treatment inhibited the growth of Aeromonas and Acinetobacter significantly. Consequently, Aeromonas followed by Pseudomonas and Shewanella became the predominant microbiota in all TP-treated fillets on day 12. Therefore, TP improved the quality of fillets during chilled storage, which was mainly due to their modulating effects on microbiota that resulted in the change in pattern and process of spoilage in fillets.


Assuntos
Anti-Infecciosos/farmacologia , Carpas/microbiologia , Microbiota/efeitos dos fármacos , Polifenóis/farmacologia , Chá/química , Acinetobacter/efeitos dos fármacos , Acinetobacter/crescimento & desenvolvimento , Acinetobacter/isolamento & purificação , Aeromonas/efeitos dos fármacos , Aeromonas/crescimento & desenvolvimento , Aeromonas/isolamento & purificação , Animais , Técnicas Bacteriológicas/métodos , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Conservantes de Alimentos/química , Conservantes de Alimentos/farmacologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Polifenóis/química , Pseudomonas/efeitos dos fármacos , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação , Alimentos Marinhos/microbiologia
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