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1.
Dev Comp Immunol ; 124: 104186, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34214518

RESUMO

Antibodies of cartilaginous fish are of scientific interest due to their phylogenetic position. In the present study, we developed antiserum against IgM of the banded houndshark, Triakis scyllium, and characterized binding activity of the IgM against fish pathogenic bacteria. Pentameric and monomeric IgM antibodies were separated by gel filtration chromatography using high performance liquid chromatography and SDS-PAGE. Antisera were developed by immunizing rabbits with unfractionated IgM antibodies separated by SDS-PAGE electrophoresis. Shark serum antibodies were found to have binding affinity for Aeromonas hydrophila, Vibrio anguillarum, Edwardsiella tarda, and Pseudomonas plecoglossicida antigens but not Lactococcus garvieae by enzyme-linked immunosorbent assay. We speculate the binding activities of shark antibodies may confer protection against certain bacterial pathogens.


Assuntos
Anticorpos Antibacterianos/imunologia , Bactérias/imunologia , Tubarões/imunologia , Animais , Anticorpos Antibacterianos/sangue , Afinidade de Anticorpos , Bactérias/classificação , Bactérias/patogenicidade , Soros Imunes/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Coelhos , Tubarões/microbiologia
2.
Sci Rep ; 10(1): 20979, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33262401

RESUMO

Alteration of organic remains during the transition from the bio- to lithosphere is affected strongly by biotic processes of microbes influencing the potential of dead matter to become fossilized or vanish ultimately. If fossilized, bones, cartilage, and tooth dentine often display traces of bioerosion caused by destructive microbes. The causal agents, however, usually remain ambiguous. Here we present a new type of tissue alteration in fossil deep-sea shark teeth with in situ preservation of the responsible organisms embedded in a delicate filmy substance identified as extrapolymeric matter. The invading microorganisms are arranged in nest- or chain-like patterns between fluorapatite bundles of the superficial enameloid. Chemical analysis of the bacteriomorph structures indicates replacement by a phyllosilicate, which enabled in situ preservation. Our results imply that bacteria invaded the hypermineralized tissue for harvesting intra-crystalline bound organic matter, which provided nutrient supply in a nutrient depleted deep-marine environment they inhabited. We document here for the first time in situ bacteria preservation in tooth enameloid, one of the hardest mineralized tissues developed by animals. This unambiguously verifies that microbes also colonize highly mineralized dental capping tissues with only minor organic content when nutrients are scarce as in deep-marine environments.


Assuntos
Esmalte Dentário/metabolismo , Ecossistema , Fósseis , Fenômenos Fisiológicos da Nutrição , Proteínas/metabolismo , Tubarões/microbiologia , Dente/microbiologia , Água , Animais , Apatitas/química , Bactérias/ultraestrutura , Esmalte Dentário/ultraestrutura , Espectrometria por Raios X , Dente/ultraestrutura
3.
Mar Drugs ; 18(2)2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32085415

RESUMO

Bacillus amyloliquefaciens-9 (GBacillus-9), which is isolated from the intestinal tract of the white-spotted bamboo shark (Chiloscyllium plagiosum), can secrete potential antibacterial materials, such as ß-1,3-1,4-glucanase and some antimicrobial peptides. However, the low fermentation production has hindered the development of GBacillus-9 as biological additives. In this study, the Plackett-Burman design and response surface methodology were used to optimize the fermentation conditions in a shake flask to obtain a higher yield and antibacterial activity of GBacillus-9. On the basis of the data from medium screening, M9 medium was selected as the basic medium for fermentation. The data from the single-factor experiment showed that sucrose had the highest antibacterial activity among the 10 carbon sources. The Plackett-Burman design identified sucrose, NH4Cl, and MgSO4 as the major variables altering antibacterial activity. The optimal concentrations of these compounds to enhance antibacterial activity were assessed using the central composite design. Data showed that sucrose, NH4Cl, and MgSO4 had the highest antibacterial activities at concentrations of 64.8, 1.84, and 0.08 g L-1, respectively. The data also showed that the optimal fermentation conditions for the antibacterial material production of GBacillus-9 were as follows: Inoculum volume of 5%, initial pH of 7.0, temperature of 36 °C, rotating speed of 180 rpm, and fermentation time of 10 h. The optimal fermentation medium and conditions achieved to improve the yield of antibacterial materials for GBacillus-9 can enhance the process of developing biological additives derived from GBacillus-9.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Bacillus amyloliquefaciens/metabolismo , Fermentação , Tubarões/microbiologia , Animais , Meios de Cultura
4.
Sci Rep ; 9(1): 7182, 2019 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-31073209

RESUMO

Fourteen juvenile scalloped hammerhead sharks (Sphyrna lewini; SHS) were captured between November and December 2014 in the Rewa Delta in Fiji, and assessed for intestinal microflora characterisation using 16S rRNA amplicon sequencing by Illumina Miseq. The microbial population revealed a fluctuating dominance between the Enterobacteriaceae and Vibrionaceae families, namely Citrobacter and Photobacterium spp. Other related marine operational taxonomic units were closely related to Afipia felis, Chloroflexus aggregans, Psychrobacter oceani, Pontibacter actiniarum and Shigella sonnei. Two sharks had distinctive profiles that were dominated by known pathogens, namely Aeromonas salmonicida and Klebsiella pneumonia. The presence of a Methanosaeta species, and of Shigella and Psychrobacter, would suggest sewage contamination because of a spill that occurred on the 6th of December 2014. This study successfully establishes a baseline for future research.


Assuntos
Intestinos/microbiologia , Microbiota , Tubarões/microbiologia , Aeromonas salmonicida/genética , Aeromonas salmonicida/isolamento & purificação , Animais , Fiji , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Análise de Componente Principal , RNA Ribossômico 16S/genética , Tubarões/crescimento & desenvolvimento
5.
Acta Histochem ; 121(4): 516-521, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31027729

RESUMO

Marine organisms are able to produce light using either their own luminous system, called intrinsic bioluminescence, or symbiotic luminous bacteria, called extrinsic bioluminescence. Among bioluminescent vertebrates, Osteichthyes are known to harbor both types of bioluminescence, while no study has so far addressed the potential use of intrinsic/extrinsic luminescence in elasmobranchs. In sharks, two families are known to emit light: Etmopteridae and Dalatiidae. The deep-sea bioluminescent Etmopteridae, Etmopterus spinax, has received a particular interest over the past fifteen years and its bioluminescence control was investigated in depth. However, the nature of the shark luminous system still remains enigmatic. The present work was undertaken to assess whether the light of this shark species originates from a bioluminescent bacterial symbiosis. Using fluorescent in situ hybridization (FISH) and transmission electron microscopy (TEM) image analyses, this study supports the conclusion that the bioluminescence in the deep-sea lanternshark, Etmopterus spinax, is not of bacterial origin.


Assuntos
Bactérias/metabolismo , Luminescência , Tubarões/microbiologia , Tubarões/fisiologia , Animais , Hibridização in Situ Fluorescente , Microscopia Eletrônica de Transmissão
6.
Med Mycol ; 56(5): 591-601, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29420818

RESUMO

Fusarium spp. are saprobic moulds that are responsible for severe opportunistic infections in humans and animals. However, we need epidemiological tools to reliably trace the circulation of such fungal strains within medical or veterinary facilities, to recognize environmental contaminations that might lead to infection and to improve our understanding of factors responsible for the onset of outbreaks. In this study, we used molecular genotyping to investigate clustered cases of Fusarium solani species complex (FSSC) infection that occurred in eight Sphyrnidae sharks under managed care at a public aquarium. Genetic relationships between fungal strains were determined by multi-locus sequence typing (MLST) analysis based on DNA sequencing at five loci, followed by comparison with sequences of 50 epidemiologically unrelated FSSC strains. Our genotyping approach revealed that F. keratoplasticum and F. solani haplotype 9x were most commonly isolated. In one case, the infection proved to be with another Hypocrealian rare opportunistic pathogen Metarhizium robertsii. Twice, sharks proved to be infected with FSSC strains with the same MLST sequence type, supporting the hypothesis the hypothesis that common environmental populations of fungi existed for these sharks and would suggest the longtime persistence of the two clonal strains within the environment, perhaps in holding pools and life support systems of the aquarium. This study highlights how molecular tools like MLST can be used to investigate outbreaks of microbiological disease. This work reinforces the need for regular controls of water quality to reduce microbiological contamination due to waterborne microorganisms.


Assuntos
Microbiologia Ambiental , Doenças dos Peixes/microbiologia , Fusariose/veterinária , Fusarium/classificação , Tipagem de Sequências Multilocus/veterinária , Filogenia , Tubarões/microbiologia , Animais , DNA Fúngico/genética , Doenças dos Peixes/patologia , Fusariose/microbiologia , Fusariose/patologia , Fusarium/genética , Fusarium/isolamento & purificação , Genes Fúngicos/genética , Técnicas de Tipagem Micológica/veterinária
7.
Environ Microbiol Rep ; 9(4): 357-373, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28418094

RESUMO

The health of sharks, like all organisms, is linked to their microbiome. At the skin interface, sharks have dermal denticles that protrude above the mucus, which may affect the types of microbes that occur here. We characterized the microbiome from the skin of the common thresher shark (Alopias vulpinus) to investigate the structure and composition of the skin microbiome. On average 618 812 (80.9% ± S.D. 0.44%) reads per metagenomic library contained open reading frames; of those, between 7.6% and 12.8% matched known protein sequences. Genera distinguishing the A. vulpinus microbiome from the water column included, Pseudoalteromonas (12.8% ± 4.7 of sequences), Erythrobacter (5. 3% ± 0.5) and Idiomarina (4.2% ± 1.2) and distinguishing gene pathways included, cobalt, zinc and cadmium resistance (2.2% ± 0.1); iron acquisition (1.2% ± 0.1) and ton/tol transport (1.3% ± 0.08). Taxonomic community overlap (100 - dissimilarity index) was greater in the skin microbiome (77.6), relative to the water column microbiome (70.6) and a reference host-associated microbiome (algae: 71.5). We conclude the A. vulpinus skin microbiome is influenced by filtering processes, including biochemical and biophysical components of the shark skin and result in a structured microbiome.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Microbiota , Tubarões/microbiologia , Pele/microbiologia , Animais , Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodiversidade , Metagenômica , Fases de Leitura Aberta , Filogenia
8.
Nat Prod Res ; 31(9): 985-989, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-26186097

RESUMO

Four quinolinones (1-4; 1 is a new compound) were isolated from the static fermentation culture of a shark gill-derived fungus Penicillium polonicum AP2T1. In addition, five new quinolinone derivatives (5-9) and also 1 were obtained in a trimethylsilyldiazomethane-induced methylation reaction of 4. Their structures were elucidated by spectroscopic analyses. In bioassays, compounds 7 and 5 with lactim structures moderately inhibited the proliferation of human cancer cell line HCT116 (wild-type) with IC50-24 h of 8.4 µg/mL and 30.7 µg/mL, respectively; the other compounds displayed weaker inhibition. The p53 gene may play some role in their action as suggested by their much weakened activity towards p53-knockout HCT116 cell line. Besides, 6 and 8 exhibited moderate or weak toxicity to brine shrimp larvae, and 3, 4, 8 and 9 showed weak inhibition against Staphylococcus aureus. It is the first report on elucidation of new compounds with origin of shark-derived fungi.


Assuntos
Brânquias/microbiologia , Penicillium/metabolismo , Quinolonas/isolamento & purificação , Tubarões/microbiologia , Animais , Artemia/efeitos dos fármacos , Humanos , Quinolonas/química , Quinolonas/farmacologia , Staphylococcus aureus/efeitos dos fármacos
9.
Antonie Van Leeuwenhoek ; 109(12): 1593-1603, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27566710

RESUMO

A novel Gram-stain negative, non-motile, moderately halophilic, facultatively anaerobic and spherical bacterium designated strain SS9T was isolated from the gill homogenate of a shark. Cells of SS9T were observed to be 0.8-1.2 µm in diameter. The strain was found to grow optimally at 33 °C, pH 7.0-8.0 and in the presence of 6.0 % (w/v) NaCl. On the basis of 16S rRNA gene phylogeny, strain SS9T can be affiliated with the family Halomonadaceae and is closely related to Chromohalobacter marismortui NBRC 103155T (95.6 % sequence similarity), Halomonas ilicicola SP8T (95.6 %) and Chromohalobacter salexigens DSM 3043T (95.5 %). Multilocus sequence analysis of strain SS9T using the housekeeping genes 16S rRNA, 23S rRNA, gyrB, rpoD and secA revealed the strain's distinct phylogenetic position, separate from other known genera of the family Halomonadaceae. Strain SS9T was found to contain ubiquinone-9 (Q-9) as the predominant ubiquinone and C18:1 ω7c, C16:0 and summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH) as the major fatty acids. The major polar lipids of strain SS9T were identified as phosphatidylglycerol and phosphatidylethanolamine. The DNA G + C content of strain SS9T was determined to be 60.4 mol%. It is evident from phylogenetic, genotypic, phenotypic and chemotaxonomic results that strain SS9T represents a novel species in a new genus, for which the name Pistricoccus aurantiacus gen. nov., sp. nov. is proposed. The type strain is SS9T (=KCTC 42586T = MCCC 1H00111T).


Assuntos
Halomonadaceae/isolamento & purificação , Tubarões/microbiologia , Animais , China , Halomonadaceae/classificação , Halomonadaceae/genética , Tipagem Molecular , Filogenia , RNA Bacteriano , RNA Ribossômico 16S/genética
10.
Artigo em Inglês | MEDLINE | ID: mdl-26239220

RESUMO

Few investigations have studied digestive enzyme activities in the alimentary tracts of sharks to gain insight into how these organisms digest their meals. In this study, we examined the activity levels of proteases, carbohydrases, and lipase in the pancreas, and along the anterior intestine, spiral intestine, and colon of the bonnethead shark, Sphyrna tiburo. We then interpreted our data in the context of a rate-yield continuum to discern this shark's digestive strategy. Our data show anticipated decreasing patterns in the activities of pancreatic enzymes moving posteriorly along the gut, but also show mid spiral intestine peaks in aminopeptidase and lipase activities, which support the spiral intestine as the main site of absorption in bonnetheads. Interestingly, we observed spikes in the activity levels of N-acetyl-ß-D-glucosaminidase and ß-glucosidase in the bonnethead colon, and these chitin- and cellulose-degrading enzymes, respectively, are likely of microbial origin in this distal gut region. Taken in the context of intake and relatively long transit times of food through the gut, the colonic spikes in N-acetyl-ß-D-glucosaminidase and ß-glucosidase activities suggest that bonnetheads take a yield-maximizing strategy to the digestive process, with some reliance on microbial digestion in their hindguts. This is one of the first studies to examine digestive enzyme activities along the gut of any shark, and importantly, the data match with previous observations that sharks take an extended time to digest their meals (consistent with a yield-maximizing digestive strategy) and that the spiral intestine is the primary site of absorption in sharks.


Assuntos
Digestão/fisiologia , Sistema Digestório/metabolismo , Microbiota/fisiologia , Tubarões/fisiologia , Acetilglucosaminidase/metabolismo , Aminopeptidases/metabolismo , Animais , Metabolismo dos Carboidratos , Colo/enzimologia , Colo/metabolismo , Colo/microbiologia , Sistema Digestório/enzimologia , Sistema Digestório/microbiologia , Mucosa Intestinal/metabolismo , Intestinos/enzimologia , Intestinos/microbiologia , Lipase/metabolismo , Pâncreas/enzimologia , Pâncreas/metabolismo , Peptídeo Hidrolases/metabolismo , Tubarões/metabolismo , Tubarões/microbiologia , Fatores de Tempo , beta-Glucosidase/metabolismo
11.
Mycoses ; 58(7): 422-31, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26095191

RESUMO

Fusarium species are environmental saprophytic fungi. Among the many Fusarium species, members of the Fusarium solani species complex (FSSC) are the most prevalent and virulent in causing human and animal infections. In this study, we describe the first case of fatal FSSC infection in a black spotted stingray and three concomitant infections in scalloped hammerhead sharks. In the stingray, cutaneous lesions were characterised by ulcers and haemorrhage of the ventral pectoral fin, or 'ray', especially around the head; while cutaneous lesions in the sharks were characterised by ulcers, haemorrhage, as well as white and purulent exudates at the cephalic canals of the cephalofoil and lateral line. Histological sections of the cutaneous lesions revealed slender (1-4 µm in diameter), branching, septate fungal hyphae. Internal transcribed spacer region and 28S nrDNA sequencing of the fungal isolates from the fish showed two isolates were F. keratoplasticum (FSSC 2) and the other two were FSSC 12. Environmental investigation revealed the FSSC strains isolated from water and biofilms in tanks that housed the elasmobranchs were also F. keratoplasticum and FSSC 12. Fusarium is associated with major infections in elasmobranchs and FSSC 12 is an emerging cause of infections in marine animals. DNA sequencing is so far the most reliable method for accurate identification of Fusarium species.


Assuntos
Elasmobrânquios/microbiologia , Doenças dos Peixes/microbiologia , Fusariose/veterinária , Fusarium/isolamento & purificação , Tubarões/microbiologia , Pele/microbiologia , Animais , Evolução Fatal , Fusariose/microbiologia , Fusarium/classificação , Fusarium/genética , Humanos , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Filogenia , Análise de Sequência de DNA , Pele/ultraestrutura
12.
Probiotics Antimicrob Proteins ; 7(2): 157-63, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25740801

RESUMO

The bacterial isolates from Centroscyllium fabricii (deep sea shark) gut were screened for antagonistic activity by cross-streak method and disc diffusion assay. This study focuses on strain BTSS-3, which showed antimicrobial activity against pathogenic bacteria including Salmonella Typhimurium, Proteus vulgaris, Clostridium perfringens, Staphylococcus aureus, Bacillus cereus, Bacillus circulans, Bacillus macerans and Bacillus pumilus. BTSS3 was subjected to phenotypic characterization using biochemical tests, SEM imaging, exoenzyme profiling and antibiotic susceptibility tests. Comparative 16S rDNA gene sequence analysis indicated that this strain belonged to the genus Bacillus, with high (98%) similarity to 16S rDNA sequences of Bacillus amyloliquefaciens. The chemical nature of the antibacterial substance was identified by treatment with proteolytic enzymes. The antibacterial activity was reduced by the action of these enzymes pointing out its peptide nature. It was observed from the growth and production kinetics that the bacteriocin was produced in the eighth hour of incubation, i.e., during the mid-log growth phase of the bacteria.


Assuntos
Bacillus/isolamento & purificação , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Tubarões/microbiologia , Animais , Antibiose , Bacillus/classificação , Bacillus/fisiologia , Bacillus cereus/crescimento & desenvolvimento , Clostridium perfringens/crescimento & desenvolvimento , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Técnicas de Genotipagem , Testes de Sensibilidade Microbiana , Proteus vulgaris/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Salmonella typhimurium/crescimento & desenvolvimento , Análise de Sequência de DNA , Staphylococcus aureus/crescimento & desenvolvimento
13.
PLoS One ; 9(8): e104577, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25110948

RESUMO

Sharks possess a variety of pathogenic bacteria in their oral cavity that may potentially be transferred into humans during a bite. The aim of the presented study focused on the identification of the bacteria present in the mouths of live blacktip sharks, Carcharhinus limbatus, and the extent that these bacteria possess multi-drug resistance. Swabs were taken from the oral cavity of nineteen live blacktip sharks, which were subsequently released. The average fork length was 146 cm (±11), suggesting the blacktip sharks were mature adults at least 8 years old. All swabs underwent standard microbiological work-up with identification of organisms and reporting of antibiotic susceptibilities using an automated microbiology system. The oral samples revealed an average of 2.72 (±1.4) bacterial isolates per shark. Gram-negative bacteria, making up 61% of all bacterial isolates, were significantly (p<0.001) more common than gram-positive bacteria (39%). The most common organisms were Vibrio spp. (28%), various coagulase-negative Staphylococcus spp. (16%), and Pasteurella spp. (12%). The overall resistance rate was 12% for all antibiotics tested with nearly 43% of bacteria resistant to at least one antibiotic. Multi-drug resistance was seen in 4% of bacteria. No association between shark gender or fork length with bacterial density or antibiotic resistance was observed. Antibiotics with the highest overall susceptibility rates included fluoroquinolones, 3rd generation cephalosporins and sulfamethoxazole/trimethoprim. Recommended empiric antimicrobial therapy for adult blacktip shark bites should encompass either a fluoroquinolone or combination of a 3rd generation cephalosporin plus doxycycline.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Boca/microbiologia , Guias de Prática Clínica como Assunto , Tubarões/microbiologia , Animais , Farmacorresistência Bacteriana , Florida
14.
Int J Syst Evol Microbiol ; 64(Pt 7): 2204-2209, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24695056

RESUMO

A Gram-stain-negative, facultatively anaerobic, gliding, yellow-pigmented bacterium, designated SS12(T), was isolated from shark gill homogenate and characterized using a polyphasic approach. The strain was catalase-positive and oxidase-negative. Optimal growth occurred at 28-30 °C, pH 7.0-7.5 and in the presence of 2-4% (w/v) NaCl. The DNA G+C content was 40.0 mol%. The strain contained MK-7 as the prevailing menaquinone; iso-C15 : 0 and anteiso-C15 : 0 as the major cellular fatty acids; and phosphatidylethanolamine and an unknown lipid as the predominant polar lipids. Comparative analysis of 16S rRNA gene sequences demonstrated that the novel isolate showed the highest sequence similarity (94.68%) to Saccharicrinis fermentans DSM 9555(T) and the sequence similarities among the type strains of all other species studied were less than 92%. A phylogenetic tree, based on 16S rRNA gene sequences, showed that strain SS12(T) and Saccharicrinis fermentans DSM 9555(T) formed a distinct cluster within the family Marinilabiliaceae. On the basis of its phylogenetic position and phenotypic traits, strain SS12(T) represents a novel species of genus Saccharicrinis, for which the name Saccharicrinis carchari sp. nov. is proposed. The type strain is SS12(T) ( = CICC 10590(T) = DSM 27040(T)). Emended descriptions of the genus Saccharicrinis and Saccharicrinis fermentans are also provided.


Assuntos
Bacteroidetes/classificação , Filogenia , Tubarões/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Brânquias/microbiologia , Dados de Sequência Molecular , Fosfatidiletanolaminas/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
15.
Int J Syst Evol Microbiol ; 64(Pt 5): 1690-1696, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24523447

RESUMO

The taxonomic characteristics of two bacterial strains, FH5T and SS4, isolated from enrichment cultures obtained from two distinct marine environments, were determined. These bacteria were Gram-stain-negative, facultatively anaerobic rods. Growth occurred at 20-40 °C (optimum, 28-32 °C), pH 5.5-9.0 (optimum, pH 7.0-7.5) and in the presence of 1-7% NaCl (optimum, 2-4%). The major cellular fatty acids were anteiso-C15:0 and iso-C15:0. Menaquinone 7 (MK-7) was the sole respiratory quinone. The major polar lipids were phosphatidylethanolamine, an unkown phospholipid and an unknown lipid. The DNA G+C contents of strains FH5T and SS4 were both determined to be 42.0 mol%. The results of DNA-DNA hybridization studies indicated that the FH5T and SS4 genomes share greater than 95% relatedness. The strains formed a distinct phyletic line within the class Bacteroidia, with less than 89.4% sequence similarity to their closest relatives with validly published names. On the basis of physiological and biochemical characteristics, 16S rRNA gene sequences and chemical properties, a novel genus and species, Draconibacterium orientale gen. nov., sp. nov., within the class Bacteroidia, are proposed, with strain FH5T (=DSM 25947T=CICC 10585T) as the type strain. In addition, a new family, Draconibacteriaceae fam. nov., is proposed to accommodate Draconibacterium gen. nov.


Assuntos
Bacteroidetes/classificação , Filogenia , Água do Mar/microbiologia , Tubarões/microbiologia , Animais , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Sedimentos Geológicos/microbiologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fosfatidiletanolaminas/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
17.
Fish Shellfish Immunol ; 34(5): 1223-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23403160

RESUMO

To assess non-cellular innate immune mechanisms that play a role in the antimicrobial defense of an organism several assay systems have been devised to screen for such factors. Most assays, however, have been developed to measure activity against clinical isolates of medical importance. There is scant information on methods optimal for assaying material from sharks and other marine fish for antimicrobial activity particularly against salt tolerant organisms that are likely to be encountered in the marine environment. We have modified and optimized agar diffusion and broth dilution assays for detection and quantification of antibacterial activity of shark leukocyte lysates. By replacing marine agar, typically used for marine organisms, with artificial sea water complete medium (SCM) enriched with tryptone and yeast extract has resulted in an improved inhibition zone assay that uses Planococcus citreus, a salt-tolerant organism as the target organism. Antibacterial activity is correlated to the size of zone of no bacterial growth around wells containing bioactive test sample. An alternative broth based microdilution growth assay uses the 96 well format and the antibacterial effect of the sample on growth of P. citreus, the target organism, is measured spectrophotometrically as percent inhibition of bacterial growth when compared to the growth of P. citreus grown in medium alone that represents 100% growth. The assay can also be used to titrate antibacterial activity and express the level of growth inhibition as a titer.


Assuntos
Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana/métodos , Planococáceas/efeitos dos fármacos , Tubarões/metabolismo , Animais , Tubarões/microbiologia
18.
J Zoo Wildl Med ; 41(1): 7-16, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20722248

RESUMO

Antibiotic resistance in bacteria is a growing problem in both human and veterinary medicine. Several studies documented the presence of resistant bacteria in humans, livestock, and domestic animals; however, limited research is available on the presence of antibiotic drug resistance in wildlife species. A cross-sectional study was conducted to estimate the prevalence of resistant bacteria collected from wild-caught, marine predatory fishes. Seven species of sharks and a single teleost species were opportunistically sampled from six different study sites in coastal Belize, coastal and nearshore waters of Louisiana, the Florida Keys, and Martha's Vineyard, Massachusetts. A total of 134 viable bacteria samples were isolated from the cloacal swabs of predatory fishes. Isolates were characterized by Gram-stain morphology and tested for resistance by using the Kirby-Bauer disc diffusion method. Thirteen drugs (penicillin G, piperacillin, ticarcillin, cefotaxime, ceftazidime, ceftiofur, amikacin, gentamicin, ciprofloxacin, enrofloxacin, doxycycline, chloramphenicol, and sulfamethoxazole) were selected for this study. Prevalence was calculated as the total number of isolates resistant to one or more drugs against the total number of samples in that study area or fish population. Sharks sampled in the Florida Keys exhibited the greatest resistance to a wide selection of drugs. Resistance to at least one drug was found in each of the six study sites and in all of the fish species sampled. Multidrug resistance was also documented in most of the study sites. Interspecific comparisons between redfish, Sciaenops ocellata, and sharks from Louisiana offshore waters (which represent species of the Carcharhinus genus) demonstrated a significantly higher prevalence in redfish, which may be because of the older age of the population. The findings of this study confirmed the presence of antibiotic-resistant bacteria in marine predatory fishes from multiple taxa and multiple geographic locations.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Perciformes/microbiologia , Tubarões/microbiologia , Animais , Bactérias/isolamento & purificação , Cloaca/microbiologia , Estudos Transversais , Farmacorresistência Bacteriana , Feminino , Masculino , Oceanos e Mares , Comportamento Predatório , Estados Unidos
19.
J Med Microbiol ; 59(Pt 8): 941-947, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20413619

RESUMO

The number of incidents involving sharks and humans at beaches in Recife, on the north-eastern Brazilian coast, is among the highest worldwide. In addition, wound infections in survivors are common; but the nature and risk of the aetiological agents is unknown. In the present study, 81 potential bacterial pathogens were identified in the oral cavity of sharks involved in attacks in Recife, and were subjected to antibiotic susceptibility tests using the standardized disc-diffusion method. The majority were enterobacteria such as Enterobacter spp., Citrobacter spp., Proteus spp., Providencia alcalifaciens, Escherichia coli, Moellerella wisconcensis and Leclercia adecarboxylata. Other Gram-negative bacteria included Vibrio spp., Burkholderia cepacia, Acinetobacter spp. and Pseudomonas spp. In addition, coagulase-positive and coagulase-negative Staphylococcus spp., Enterococcus spp. and Micrococcus spp. were identified, besides Streptococcus spp. from the viridans group. Resistance was especially found in the Proteus mirabilis and Citrobacter freundii, and ranged from 4 to 6 antibiotics out of the 13 tested. Gentamicin and vancomycin were the most effective against Gram-positive cocci strains, whereas levofloxacin was fully inhibitory against Gram-positive and Gram-negative bacteria. These data are discussed in light of a retrospective evaluation of the medical records of three shark victims treated at Restauração Hospital in Recife.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Biodiversidade , Boca/microbiologia , Tubarões/microbiologia , Adolescente , Animais , Brasil , Humanos , Masculino , Testes de Sensibilidade Microbiana
20.
Dis Aquat Organ ; 81(1): 13-38, 2008 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-18828560

RESUMO

Surveillance of zoonotic pathogens in marine birds and mammals in the Northwest Atlantic revealed a diversity of zoonotic agents. We found amplicons to sequences from Brucella spp., Leptospira spp., Giardia spp. and Cryptosporidium spp. in both marine mammals and birds. Avian influenza was detected in a harp seal and a herring gull. Routine aerobic and anaerobic culture showed a broad range of bacteria resistant to multiple antibiotics. Of 1460 isolates, 797 were tested for resistance, and 468 were resistant to one or more anti-microbials. 73% (341/468) were resistant to 1-4 drugs and 27% (128/468) resistant to 5-13 drugs. The high prevalence of resistance suggests that many of these isolates could have been acquired from medical and agricultural sources and inter-microbial gene transfer. Combining birds and mammals, 45% (63/141) of stranded and 8% (2/26) of by-caught animals in this study exhibited histopathological and/or gross pathological findings associated with the presence of these pathogens. Our findings indicate that marine mammals and birds in the Northwest Atlantic are reservoirs for potentially zoonotic pathogens, which they may transmit to beachgoers, fishermen and wildlife health personnel. Conversely, zoonotic pathogens found in marine vertebrates may have been acquired via contamination of coastal waters by sewage, run-off and agricultural and medical waste. In either case these animals are not limited by political boundaries and are therefore important indicators of regional and global ocean health.


Assuntos
Aves/microbiologia , Aves/parasitologia , Cetáceos/microbiologia , Cetáceos/parasitologia , Tubarões/microbiologia , Tubarões/parasitologia , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/parasitologia , Reservatórios de Doenças/veterinária , Vetores de Doenças , Eucariotos/classificação , Eucariotos/isolamento & purificação , Orthomyxoviridae/isolamento & purificação , Estações do Ano , Vírus/classificação , Vírus/isolamento & purificação
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