-
Immunology Letters Dec 2017Hemocyanin is an important multifunctional non-specific immune molecule. In this study, we purified lectin binding and non-lectin binding hemocyanin from Litopenaeus...
Hemocyanin is an important multifunctional non-specific immune molecule. In this study, we purified lectin binding and non-lectin binding hemocyanin from Litopenaeus vannamei using Concanavalin A (ConA) lectin affinity chromatography (designated HMC-C and HMC-NC, respectively). Analysis of the carbohydrate content showed that HMC-C had about 20 times as much carbohydrate as HMC-NC. 54 and 42 peaks were observed in HMC-C and HMC-NC by HPLC, which reduced to 49 and 6 peaks, respectively, when digested with trypsin and repurified with ConA lectin column. Further, the agglutinative activity of HMC-C against two pathogenic bacteria, Vibrio alginolyticus and Vibrio fluvialis, was about 8-fold and 4-fold, respectively, to that of HMC-NC. While the antibacterial activity of HMC-NC was about 30% lower compared with HMC-C. Similarly, when HMC was deglycosylated using O-glycosidase, its agglutinative activity reduced about 4-8 fold. Most importantly, when shrimps were challenged with V. alginolyticus or V. fluvialis, the glycan content of hemocyanin increased dramatically and remained high at the earlier time points (24-72h) post infection, only decreasing after 96 hpi. Taken together, these results suggest that hemocyanin glycosylation plays an important role in its antibacterial properties.
Topics: Agglutination; Animals; Anti-Bacterial Agents; Cells, Cultured; Glycoside Hydrolases; Glycosylation; Hemocyanins; Immunity, Innate; Penaeidae; Trypsin; Vibrio Infections; Vibrio alginolyticus
PubMed: 29051089
DOI: 10.1016/j.imlet.2017.10.008 -
Scientific Reports Sep 2017Vibrio fluvialis is recognized as an emerging pathogen. However, not much is known about the mechanism of its pathogenesis, and its adaptation to a special niche such as...
Vibrio fluvialis is recognized as an emerging pathogen. However, not much is known about the mechanism of its pathogenesis, and its adaptation to a special niche such as the gall bladder. Here we describe two V. fluvialis strains that cause acute cholecystitis. It is noteworthy that both strains were susceptible to all antibiotics tested, which is in contrast to previous studies, suggesting substantial genetic diversity among V. fluvialis isolates. In agreement with their survival and growth in the gall bladder, the genomes of strains 12605 and 3663 contain a considerable number of genes that confer resistance to bile, including toxR, omp U, tolC, cmeABC, rlpB, yrbK, rpoS, damX and gltK. Furthermore, integrative and conjugative elements (ICEs), virulence factors and prophage regions were also detected in strains 12605 and 3663, reflecting their flexibility in recombination during the evolution of pathogenicity. Comparative analysis of nine available genomes of V. fluvialis revealed a core genome consisting of 3,147 genes. Our results highlight the association of V. fluvialis with a rare disease profile and shed light on the evolution of pathogenesis and niche adaptation of V. fluvialis.
Topics: Bacterial Proteins; Bile; Female; Genome, Bacterial; Humans; Male; Species Specificity; Vibrio; Virulence; Virulence Factors
PubMed: 28928424
DOI: 10.1038/s41598-017-12304-8 -
BioMed Research International 2017Thirty-one mercury-resistant bacterial strains were isolated from the effluent discharge sites of the SIPCOT industrial area. Among them, only one strain (CASKS5) was...
Thirty-one mercury-resistant bacterial strains were isolated from the effluent discharge sites of the SIPCOT industrial area. Among them, only one strain (CASKS5) was selected for further investigation due to its high minimum inhibitory concentration of mercury and low antibiotic susceptibility. In accordance with 16S ribosomal RNA gene sequences, the strain CASKS5 was identified as . The mercury-removal capacity of was analyzed at four different concentrations (100, 150, 200, and 250 g/ml). Efficient bioremediation was observed at a level of 250 g/ml with the removal of 60% of mercury ions. The interesting outcome of this study was that the strain had a high bioremediation efficiency but had a low antibiotic resistance. Hence, could be successfully used as a strain for the ecofriendly removal of mercury.
Topics: Biodegradation, Environmental; Mercury; RNA, Bacterial; RNA, Ribosomal, 16S; Vibrio; Water Pollutants, Chemical
PubMed: 28626761
DOI: 10.1155/2017/6509648 -
Frontiers in Microbiology 2017is an emerging foodborne pathogen of increasing public health concern. The mechanism(s) that contribute to the bacterial survival and disease are still poorly...
is an emerging foodborne pathogen of increasing public health concern. The mechanism(s) that contribute to the bacterial survival and disease are still poorly understood. In other bacterial species, type VI secretion systems (T6SSs) are known to contribute to bacterial pathogenicity by exerting toxic effects on host cells or competing bacterial species. In this study, we characterized the genetic organization and prevalence of two T6SS gene clusters (VflT6SS1 and VflT6SS2) in . VflT6SS2 harbors three "orphan" modules and was more prevalent than VflT6SS1 in our isolates. We showed that VflT6SS2 is functionally active under low (25°C) and warm (30°C) temperatures by detecting the secretion of a T6SS substrate, Hcp. This finding suggests that VflT6SS2 may play an important role in the survival of the bacterium in the aquatic environment. The secretion of Hcp is growth phase-dependent and occurs in a narrow range of the growth phase (OD from 1.0 to 2.0). Osmolarity also regulates the function of VflT6SS2, as evidenced by our finding that increasing salinity (from 170 to 855 mM of NaCl) and exposure to high osmolarity KCl, sucrose, trehalose, or mannitol (equivalent to 340 mM of NaCl) induced significant secretion of Hcp under growth at 30°C. Furthermore, we found that although VflT6SS2 was inactive at a higher temperature (37°C), it became activated at this temperature if higher salinity conditions were present (from 513 to 855 mM of NaCl), indicating that it may be able to function under certain conditions in the infected host. Finally, we showed that the functional expression of VflT6SS2 is associated with anti-bacterial activity. This activity is Hcp-dependent and requires , a transcriptional regulator of T6SS. In sum, our study demonstrates that VflT6SS2 provides with an enhanced competitive fitness in the marine environment, and its activity is regulated by environmental signals, such as temperature and osmolarity.
PubMed: 28424671
DOI: 10.3389/fmicb.2017.00528 -
Journal of Food Science and Technology Apr 2017This study examined the antibacterial activity of on multiple antibiotic resistant (MAR) and isolated from shrimps. The ethanol extract of antibacterial properties...
This study examined the antibacterial activity of on multiple antibiotic resistant (MAR) and isolated from shrimps. The ethanol extract of antibacterial properties was assessed using the agar diffusion method. Survival of test organisms in shrimp meat using different concentrations of was done using standard method. The quantitative and qualitative phytochemical tests of extract were determined. The ethanol extract had antimicrobial activities on the test organisms showing 20.00 ± 0.0 and 23.00 ± 0.0 mm zone of inhibition on and respectively. completely decreased microbial load of and in 150 and 60 min, respectively. The phytochemical screening for the ethanol extract reported phenol, alkaloids, tannin, saponin, anthraquinone flavonoid and cardiac glycoside as 51.76, 26.60, 6.76, 54.33, 30.35 89.65 and 18.23 mg/100 g, respectively. This study reveals the antibacterial property of on the MAR species.
PubMed: 28416870
DOI: 10.1007/s13197-017-2543-6 -
Journal of Zoo and Wildlife Medicine :... Mar 2017Between September 2001 and March 2013, 62 bacterial cultures (37 aerobic and 25 anaerobic) were performed on 37 blood samples from 23 Antillean manatees ( Trichechus...
Between September 2001 and March 2013, 62 bacterial cultures (37 aerobic and 25 anaerobic) were performed on 37 blood samples from 23 Antillean manatees ( Trichechus manatus manatus) that were kept in captivity at the Brazilian National Center for Research and Conservation of Aquatic Mammals (CMA) in Pernambuco (CMA-PE) and Alagoas (CMA-AL), Brazil. All of the animals sampled exhibited clinical signs at the time of sampling including abscesses (n = 8), debilitation and anorexia (n = 22), and profound lethargy-moribundity (n = 7). The 4 animals with profound lethargy-moribundity died shortly after sampling of unknown causes. Bacteria were isolated from 15/37 (40.5%) and aerobic blood cultures from 13/23 animals (56.5%). None of the anaerobic cultures were positive. Aeromonas caviae , Aeromonas hydrophila , Aeromonas sp., Escherichia coli , Leclercia adecarboxylata , Pantoea agglomerans , Pseudomonas aeruginosa , Pseudomonas stutzeri , Pseudomonas sp., Sphingomonas paucimobilis , coagulase-negative Staphylococcus, and Staphylococcus epidermidis were each found in only one animal; Staphylococcus spp. was found in two; and Vibrio fluvialis in four. Thirteen samples had only one bacteria isolated, one sample had two bacteria, and one sample had three bacteria isolated. Regarding sex, age group, and origin among the manatees examined, 54.5% (6/11) of the females, 58.3% (7/12) of the males, 40% (2/5) of the calves, 66.7% (8/12) of the juveniles, 50% (3/6) of the adults, 55.5% (10/18) at CMA-PE, and 60% (3/5) at CMA-AL were found to be positive for bacterial growth during at least one sampling time. All Antillean manatees were clinically ill. Regarding clinical signs, bacteria were found in 50% (11/22) of blood samples of the animals showing debilitation and anorexia, 1 of 8 (12.5%) of blood samples of the animals showing abscesses, and 3 of 7 (42.9%) of blood samples of the animals showing profound lethargy-moribundity.
Topics: Animals; Bacteremia; Bacteriological Techniques; Female; Male; Trichechus manatus
PubMed: 28363079
DOI: 10.1638/2015-0094.1 -
Revista Chilena de Infectologia :... Aug 2016
Topics: Humans; Polymerase Chain Reaction; Vibrio
PubMed: 27905630
DOI: 10.4067/S0716-10182016000400011 -
Emerging Infectious Diseases Oct 2016Carbapenems have been used for many years to treat severe nosocomial Enterobacteriaceae infections. The spread of resistance to these drugs among other bacterial...
Carbapenems have been used for many years to treat severe nosocomial Enterobacteriaceae infections. The spread of resistance to these drugs among other bacterial families is an emerging problem worldwide, mostly caused by New Delhi metallo-β-lactamase (NDM-1). We screened for the prevalence of NDM-1-expressing enteric pathogens from hospitalized patients with acute diarrhea in Kolkata, India, and identified 27 Vibrio fluvialis-harboring blaNDM-1 (NDM-VF) strains. These isolates were also resistant to all the tested antimicrobial drugs except doxycycline. The large plasmid of V. fluvialis harboring blaNDM-1 could be easily transferred to other enteric pathogens. Genes flanking the blaNDM-1 were found to be identical to the reported sequence from an Escherichia coli isolate. Analyses showed that the V. fluvialis possessing the NDM-VF region belonged to different clones. The pathogenicity of V. fluvialis to humans and its ubiquitous presence in the environment call for constant monitoring of this species for emerging antimicrobial drug resistance.
Topics: Anti-Bacterial Agents; Carbapenems; Conjugation, Genetic; Diarrhea; Drug Resistance, Multiple, Bacterial; Enterobacteriaceae; Enterobacteriaceae Infections; Escherichia coli; Gene Transfer, Horizontal; Humans; India; Microbial Sensitivity Tests; R Factors; Species Specificity; Vibrio; beta-Lactam Resistance; beta-Lactamases
PubMed: 27649032
DOI: 10.3201/eid2210.151612 -
Molecular Immunology Sep 2016Hemocyanin (HMC) is a multifunctional immune molecule present in mollusks and arthropods and functions as an important antigen non-specific immune protein. Our previous...
Hemocyanin (HMC) is a multifunctional immune molecule present in mollusks and arthropods and functions as an important antigen non-specific immune protein. Our previous evidences demonstrated that Litopenaeus vannamei HMC might display extensive molecular diversities. In this study, bioinformatics analysis showed dozens of variant sequences of the HMC subunit with higher molecular weight from L. vannamei (LvHMC). Three variant fragments, named as LvHMCV1-3, which shared 85-99% nucleotide identity with that of the classical form of LvHMC (AJ250830.1), were cloned and characterized. Spatial expression profiles showed that LvHMCV1-3 had different tissue-specific distribution, which were affected by stimulation with six pathogenic bacteria, including Escherichia coli K12, Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio fluvialis, Streptococcus pyogenes and Staphylococcus aureus, with each variant fragment showing a specific stress pattern to different bacterial pathogens. Full length cDNA of LvHMCV3 was further cloned and characterized. The deduced amino acid sequence shared 92% identity with that of LvHMC, possessed a conserved structure characteristic of the HMC family and could be clustered into one branch along with other arthropod HMC in a phylogenetic tree. In addition, the recombinant protein of LvHMCV3 (rLvHMCV3) showed obvious agglutination activities against three aquaculture pathogenic bacteria including E. coli K12, V. parahaemolyticus and S.aureus at concentrations ranging from 31.25-62.5g/mL. It also showed obvious antibacterial activity against V. parahaemolyticus at concentrations 0.02-0.5mg/mL, and possessed the best inhibitive effects compared with those of rLvHMCV4 and rLvHMC. Co-injection of V. parahaemolyticus and rLvHMCV3 in L. vannamei showed significant decrease of the mortality rate at 24-72h after injection. Therefore, these studies suggested that L. vannamei had abundant HMC variants, which possessed obvious resistance to pathogenic infection and might specifically target on different pathogens in shrimp.
Topics: Amino Acid Sequence; Animals; Computational Biology; Genetic Variation; Hemocyanins; Penaeidae; Phylogeny; Polymerase Chain Reaction; Sequence Alignment
PubMed: 27497189
DOI: 10.1016/j.molimm.2016.07.017 -
Applied and Environmental Microbiology Jul 2016Many factors, such as the substrate and the growth phase, influence biosynthesis of secondary metabolites in microorganisms. Therefore, it is crucial to consider these...
UNLABELLED
Many factors, such as the substrate and the growth phase, influence biosynthesis of secondary metabolites in microorganisms. Therefore, it is crucial to consider these factors when establishing a bioprospecting strategy. Mimicking the conditions of the natural environment has been suggested as a means of inducing or influencing microbial secondary metabolite production. The purpose of the present study was to determine how the bioactivity of Vibrionaceae was influenced by carbon sources typical of their natural environment. We determined how mannose and chitin, compared to glucose, influenced the antibacterial activity of a collection of Vibrionaceae strains isolated because of their ability to produce antibacterial compounds but that in subsequent screenings seemed to have lost this ability. The numbers of bioactive isolates were 2- and 3.5-fold higher when strains were grown on mannose and chitin, respectively, than on glucose. As secondary metabolites are typically produced during late growth, potential producers were also allowed 1 to 2 days of growth before exposure to the pathogen. This strategy led to a 3-fold increase in the number of bioactive strains on glucose and an 8-fold increase on both chitin and mannose. We selected two bioactive strains belonging to species for which antibacterial activity had not previously been identified. Using ultrahigh-performance liquid chromatography-high-resolution mass spectrometry and bioassay-guided fractionation, we found that the siderophore fluvibactin was responsible for the antibacterial activity of Vibrio furnissii and Vibrio fluvialis These results suggest a role of chitin in the regulation of secondary metabolism in vibrios and demonstrate that considering bacterial ecophysiology during development of screening strategies will facilitate bioprospecting.
IMPORTANCE
A challenge in microbial natural product discovery is the elicitation of the biosynthetic gene clusters that are silent when microorganisms are grown under standard laboratory conditions. We hypothesized that, since the clusters are not lost during proliferation in the natural niche of the microorganisms, they must, under such conditions, be functional. Here, we demonstrate that an ecology-based approach in which the producer organism is allowed a temporal advantage and where growth conditions are mimicking the natural niche remarkably increases the number of Vibrionaceae strains producing antibacterial compounds.
Topics: Anti-Infective Agents; Biological Products; Carbon; Chitin; Glucose; Mannose; Secondary Metabolism; Vibrionaceae
PubMed: 27129958
DOI: 10.1128/AEM.00730-16