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Antibiotics (Basel, Switzerland) Feb 2021Cyadox has potential use as an antimicrobial agent in animals. However, its pharmacodynamic properties have not been systematically studied yet. In this study, the in...
Cyadox has potential use as an antimicrobial agent in animals. However, its pharmacodynamic properties have not been systematically studied yet. In this study, the in vitro antibacterial activities of cyadox were assayed, and the antibacterial efficacy of cyadox against facultative anaerobes was also determined under anaerobic conditions. It was shown that and (MIC = 0.25 and 1 μg/mL) from pigs, and from poultry, , spp., and from fish were highly susceptible to cyadox (MIC= 1 and 8 μg/mL). However, has no killing effect for drug tolerance. Under in vitro anaerobic conditions, the antibacterial activity of cyadox against most facultative anaerobes was considerably enhanced Under anaerobic conditions for the facultative anaerobes, susceptible bacteria were , . (including , , , , and , excluding ), , spp. (including , , and ), , , , , , and (MICs were 0.25~8 μg/mL, MBCs were 1-64 μg/mL). Intermediate bacteria were spp. (including and ), , and spp. (MICs mainly were 8~32 μg/mL, MBCs were 16~128 μg/mL). This study firstly showed that cyadox had strong antibacterial activity and had the potential to be used as a single drug in the treatment of bacterial infectious diseases.
PubMed: 33546407
DOI: 10.3390/antibiotics10020153 -
Microbiology (Reading, England) Nov 2020the aetiological agent of cholera, possesses multiple iron acquisition systems, including those for the transport of siderophores. How these systems benefit in...
the aetiological agent of cholera, possesses multiple iron acquisition systems, including those for the transport of siderophores. How these systems benefit in low-iron, polymicrobial communities in environmental settings or during infection remains poorly understood. Here, we demonstrate that in iron-limiting conditions, co-culture of with a number of individual siderophore-producing microbes significantly promoted growth . We further show that in the host environment with low iron, colonizes better in adult mice in the presence of the siderophore-producing commensal . Taken together, our results suggest that in aquatic reservoirs or during infection, may overcome environmental and host iron restriction by hijacking siderophores from other microbes.
Topics: Animals; Bacterial Outer Membrane Proteins; Coculture Techniques; Enterobactin; Escherichia coli; Gastrointestinal Microbiome; Iron Deficiencies; Mice; Microbial Viability; Receptors, Cell Surface; Seawater; Siderophores; Vibrio cholerae
PubMed: 33074088
DOI: 10.1099/mic.0.000975 -
Frontiers in Microbiology 2020Agarose-oligosaccharide production from agar degradation by agarase exhibits lots of advantages and good application prospects. In this study, a novel agar-degrading...
Agarose-oligosaccharide production from agar degradation by agarase exhibits lots of advantages and good application prospects. In this study, a novel agar-degrading bacterium sp. A8 was isolated from a red algae in the South China Sea. The whole genome sequencing with comparative genomic and secretomic analysis were used to better understand its genetic components about agar degradation. This strain exhibited good agarase production in artificial seawater after culture optimization. The complete genome (4.88 Mb) of this strain comprised two circular chromosomes (3.19 and 1.69 Mb) containing 4,572 protein-coding genes, 108 tRNA genes and 31 rRNA genes. This strain was identified as A8 by comparative genomic analysis based on genome phylogenetic tree and average nucleotide identity (ANI) similarity. Different from other 20 similar strains including three strains of the same species, A8 possessed unique agar degradation ability with four β-agarases (GH50) and one α-1,3-L-NA2 hydrolase (GH117) due to the horizontal gene transfer. Secretomic analysis showed that only β-agarase (gene 3152) was abundantly expressed in the secretome of A8. This agarase had a good substrate specificity and wide work conditions in complex environments, suggesting its potential application for agarose-oligosaccharide production.
PubMed: 32849481
DOI: 10.3389/fmicb.2020.01934 -
Veterinary World Jun 2020bacteria are autochthonous inhabitants of aquatic and marine environments. Certain strains are responsible for important seafood-borne outbreaks in developed nations....
BACKGROUND AND AIM
bacteria are autochthonous inhabitants of aquatic and marine environments. Certain strains are responsible for important seafood-borne outbreaks in developed nations. The aim of this study was to investigate the occurrence of spp. along the Algerian Mediterranean coast in several samples of two prominent wild and farmed marine fishes, and .
MATERIALS AND METHODS
A total of 350 (n=280 farmed and n=70 wild) and 340 (n=250 farmed and n=90 wild) were sampled among three different locations along the Algerian Mediterranean coastal area. The samples were processed for research according to the ISO methods. Isolated colonies were identified utilizing biochemical tests and consecutively confirmed with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, combined with polymerase chain reaction (PCR) analysis when appropriate, or confirmed with PCR analysis alone.
RESULTS
A total of 42 spp. were detected only among the farmed fishes. Taking into account, all 690 fishes sampled, the incidence of spp. was 6.08% (with peaks up to 7.92%) among the total number of farmed fishes. Overall, 25 strains were isolated from and 17 strains were isolated from . The isolated strains belonged to four different species and were represented as follows: (n=20), (n=15), (n=5), and (n=2). The incidence of was higher in places characterized by greater levels of anthropogenic contamination of seawater.
CONCLUSION
Considering the growing production and consequent rising consumption of farmed fish in Algeria, the reported incidence of and the presence of potentially pathogenic strains of such as cause particular concern for food safety matters. Even if innovative and natural techniques are desired in aquaculture, proper hygiene and manufacturing practices are essential for the correct management of infection risk in farmed fishes at both industrial and domestic levels.
PubMed: 32801574
DOI: 10.14202/vetworld.2020.1199-1208 -
Engineering in Life Sciences Oct 2019The increasing demand for freshwater and the continued depletion of available resources has led to a deepening global water crisis. Significant water consumption...
The increasing demand for freshwater and the continued depletion of available resources has led to a deepening global water crisis. Significant water consumption required by many biotechnological processes contributes to both the environmental and economic cost of this problem. Relatively few biocatalytic processes have been developed to utilize the more abundant supply of seawater, with seawater composition and salinity limiting its use with many mesophilic enzymes. We recently reported a salt tolerant ω-transaminase enzyme, Ad2-TAm, isolated from the genome of a halophilic bacterium, sp. CSM-2, from a Triassic period salt mine. In this study we aimed to demonstrate its applicability to biocatalytic reactions carried out in a seawater-based medium. Ad2-TAm was examined for its ability to aminate the industrially relevant substrate, furfural, in both seawater and freshwater-based reaction systems. Furfural was aminated with 53.6% conversion in a buffered seawater system, displaying improved function versus freshwater. Ad2-TAm outperformed the commonly employed commercial ω-TAms from and , both of which showed decreased conversion in seawater. Given the increasingly precarious availability of global freshwater, such applications of enzymes from halophiles have the ability to reduce demand for freshwater in large-scale industrial processes, delivering considerable environmental and economic benefits.
PubMed: 32624965
DOI: 10.1002/elsc.201900053 -
Open Forum Infectious Diseases Jun 2020is a foodborne pathogen known to cause a cholera-like gastroenteritis syndrome. Here we report the first case of liver abscess and bacteremia presumed to be from...
is a foodborne pathogen known to cause a cholera-like gastroenteritis syndrome. Here we report the first case of liver abscess and bacteremia presumed to be from sashimi, a Japanese raw seafood delicacy. We also provide a literature review of reported cases of extra-intestinal diseases including bacteremia.
PubMed: 32587879
DOI: 10.1093/ofid/ofaa212 -
Microbial Ecology Aug 2020It is now recognized that some diseases of aquatic animals are attributed to polymicrobial pathogens infection. Thus, the traditional view of "one pathogen, one disease"...
It is now recognized that some diseases of aquatic animals are attributed to polymicrobial pathogens infection. Thus, the traditional view of "one pathogen, one disease" might mislead the identification of multiple pathogens, which in turn impedes the design of probiotics. To address this gap, we explored polymicrobial pathogens based on the origin and timing of increased abundance over shrimp white feces syndrome (WFS) progression. OTU70848 Vibrio fluvialis, OTU35090 V. coralliilyticus, and OTU28721 V. tubiashii were identified as the primary colonizers, whose abundances increased only in individuals that eventually showed disease signs but were stable in healthy subjects over the same timeframe. Notably, the random Forest model revealed that the profiles of the three primary colonizers contributed an overall 91.4% of diagnosing accuracy of shrimp health status. Additionally, NetShift analysis quantified that the three primary colonizers were important "drivers" in the gut microbiotas from healthy to WFS shrimp. For these reasons, the primary colonizers were potential pathogens that contributed to the exacerbation of WFS. By this logic, we further identified a few "drivers" commensals in healthy individuals, such as OUT50531 Demequina sediminicola and OTU_74495 Ruegeria lacuscaerulensis, which directly antagonized the three primary colonizers. The predicted functional pathways involved in energy metabolism, genetic information processing, terpenoids and polyketides metabolism, lipid and amino acid metabolism significantly decreased in diseased shrimp compared with those in healthy cohorts, in concordant with the knowledge that the attenuations of these functional pathways increase shrimp sensitivity to pathogen infection. Collectively, we provide an ecological framework for inferring polymicrobial pathogens and designing antagonized probiotics by quantifying their changed "driver" feature that intimately links shrimp WFS progression. This approach might generalize to the exploring disease etiology for other aquatic animals.
Topics: Actinobacteria; Animals; Aquaculture; Bacteria; China; Gastrointestinal Microbiome; Penaeidae; Vibrio
PubMed: 32307553
DOI: 10.1007/s00248-020-01511-y -
Journal of Applied Microbiology Jul 2020The current study was conducted to determine the incidence, antibiotic resistance and virulence genes of Vibrio strains isolated from ready-to-eat shrimps in Edo and...
AIM
The current study was conducted to determine the incidence, antibiotic resistance and virulence genes of Vibrio strains isolated from ready-to-eat shrimps in Edo and Delta States, Nigeria.
METHODS AND RESULTS
A total of 1440 ready-to-eat shrimp samples were obtained from open markets from November 2016 to October 2017 and analysed using standard culture-based procedures. Overall, our result showed that the ready-to-eat shrimp samples had high mean aerobic mesophilic bacterial count between 3·543 and 7·489 log CFU per gram. Vibrio cell densities ranged between 0·663 and 6·761 log CFU per gram. From the total samples, 1343/1440 (93·3%) were positive for Vibrio species where 120 Vibrio isolates were randomly selected and confirmed using genus- and species-specific PCR approach. The PCR identification revealed the presence of Vibrio parahaemolyticus 46 (38·33%), Vibrio vulnificus 14 (11·67%), Vibrio fluvialis 12 (10%), Vibrio alginolyticus 8 (6·67%), Vibrio cholerae 2 (1·67%), Vibrio mimicus 10 (8·33%), Vibrio harveyi 3 (2·5%) and other Vibrio sp. 25 (20·83%). All Vibrio isolates were sensitive to colistin and gentamycin with varying percentage of resistance to other antibiotics used in the study. Multiple antibiotic-resistant (MAR) index ranged from 0·08 to 0·83. The tcp, tdh and trl virulence genes were identified in 95 (79·2%), 92 (76·7%) and 95 (79·2%) of the examined isolates respectively. Antibiotic-resistant genes also revealed the presence of class 1 integrase 75 (62·5%), sul2 87 (72·5%), strB 94 (78·3%) and catB3 68 (56·7%).
CONCLUSION
Our findings revealed that the ready-to-eat shrimps may serve as potential reservoirs and medium in the dissemination of prospective MAR pathogens to the consumers and thus constitute a potential risk to public health.
SIGNIFICANCE AND IMPACT OF THE STUDY
The findings from this study represent the first comprehensive report of Vibrio isolates from ready-to-eat shrimps in Edo and Delta States, Nigeria. Incessant monitoring of Vibrio strains and their predisposition to antimicrobials is a necessity to guarantee seafood safety and guarantee the best treatment regimen for patients with gastroenteritis.
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Microbial; Genes, Bacterial; Microbial Sensitivity Tests; Nigeria; Shellfish; Vibrio; Virulence Factors
PubMed: 31977129
DOI: 10.1111/jam.14590 -
Angewandte Chemie (International Ed. in... Apr 2020Long-chain aliphatic amines such as (S,Z)-heptadec-9-en-7-amine and 9-aminoheptadecane were synthesized from ricinoleic acid and oleic acid, respectively, by whole-cell...
Long-chain aliphatic amines such as (S,Z)-heptadec-9-en-7-amine and 9-aminoheptadecane were synthesized from ricinoleic acid and oleic acid, respectively, by whole-cell cascade reactions using the combination of an alcohol dehydrogenase (ADH) from Micrococcus luteus, an engineered amine transaminase from Vibrio fluvialis (Vf-ATA), and a photoactivated decarboxylase from Chlorella variabilis NC64A (Cv-FAP) in a one-pot process. In addition, long chain aliphatic esters such as 10-(heptanoyloxy)dec-8-ene and octylnonanoate were prepared from ricinoleic acid and oleic acid, respectively, by using the combination of the ADH, a Baeyer-Villiger monooxygenase variant from Pseudomonas putida KT2440, and the Cv-FAP. The target compounds were produced at rates of up to 37 U g dry cells with conversions up to 90 %. Therefore, this study contributes to the preparation of industrially relevant long-chain aliphatic chiral amines and esters from renewable fatty acid resources.
Topics: Alcohol Dehydrogenase; Amines; Carboxy-Lyases; Chlorella; Esters; Micrococcus luteus; Molecular Structure; Oleic Acid; Photochemical Processes; Ricinoleic Acids
PubMed: 31957098
DOI: 10.1002/anie.201915108 -
Diseases of Aquatic Organisms Dec 2019Nanoparticles have multiple applications, among which is their use as antimicrobial agents in aquaculture. The objective of this work was to determine the antibacterial...
Nanoparticles have multiple applications, among which is their use as antimicrobial agents in aquaculture. The objective of this work was to determine the antibacterial effect of silver nanoparticles (AgNPs) against Vibrio fluvialis in cultured angelfish Pterophyllum scalare. AgNPs were synthetized through chemical reduction and characterized by UV-visible and infrared spectroscopy. Particle size ranged from 60 to 170.8 nm, and scanning electron microscopy revealed cubic and spherical forms. A minimal inhibitory concentration of 222.5 ppm was determined, as well as inhibition halos between 8.66 and 14.3 mm. Inhibition of V. fluvialis growth was observed upon contact with AgNPs. An 88% survival of infected fish was obtained when treated with AgNPs, in contrast to 100% mortality of fish that were not treated. No damage to internal or external organs was observed in fish exposed to AgNPs. We conclude that AgNPs exert an antimicrobial effect against V. fluvialis, and thus represent a new alternative to control diseases caused by this microorganism in P. scalare culture.
Topics: Animals; Anti-Bacterial Agents; Metal Nanoparticles; Microbial Sensitivity Tests; Plant Extracts; Silver; Spectroscopy, Fourier Transform Infrared; Vibrio
PubMed: 31802743
DOI: 10.3354/dao03423