The Virulence of S. marcescens Strains Isolated From Contaminated Blood Products Is Divergent in the C. elegans Infection Model

Bacterial contamination of platelet concentrates (PCs) can occur during blood donation or PC processing, necessitating routine screening to identify contaminated products in efforts to prevent adverse transfusion reactions in recipient patients. Serratia marcescens is a common bacterial contaminant, and its resilient nature coupled with genetic promiscuity imbue this environmental bacterium with resistance to disinfectants and antibiotics enhancing bacterial virulence. In this study, we aim to understand adaptive survival mechanisms through genetic characterization of two S. marcescens strains, CBS11 and CBS12, isolated from PCs by Canadian Blood Services. Genomic analyses of the two strains indicated that CBS11 has one chromosome and one plasmid (pAM01), whereas CBS12 has no plasmids. Phylogenetic analyses show that CBS11 and CBS12 are non-clonal strains, with CBS11 clustering closely with clinical strain CAV1492 and less so with environmental strain PWN146, and CBS12 clustering with a clinical strain AR_0027. Interestingly, pAM01 was most closely related to PWN146p1, a plasmid found in S. marcescens PWN146 strain associated with pinewood nematode Bursaphelenchus xylophilus. Lastly, the genomic diversity of CBS11 and CBS12 was not reflected in the antibiotic resistance profiles as they were remarkably similar to one another, but was reflected in the virulence phenotypes assessed in the Caenorhabditis elegans nematode infection model, with CBS11 being more virulent then CBS12. Taken together, we suggest that S. marcescens environmental isolates that feature evolutionary diverse genomics are better equipped to adapt and thrive in varied environments, such as that of PCs, and therefore is as much of a concern as multi-drug resistance for human infection potential.

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Nematotoxic activity from essential oils and their hydrocarbons and oxygen-containing molecules fractions against the pinewood nematode Bursaphelenchus xylophilus

Planta Medica ◽

10.1055/s-0034-1394795 ◽

2014 ◽

Vol 80 (16) ◽

Author(s):

P Barbosa ◽

AM Rodrigues ◽

JMS Faria ◽

LG Pedro ◽

JG Barroso ◽

...

Keyword(s):

Essential Oils ◽

Bursaphelenchus Xylophilus ◽

Pinewood Nematode

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Bxy‐fuca encoding α‐L‐fucosidase plays crucial roles in development and reproduction of the pathogenic pinewood nematode, Bursaphelenchus xylophilus

Pest Management Science ◽

10.1002/ps.5497 ◽

2019 ◽

Vol 76 (1) ◽

pp. 205-214 ◽

Cited By ~ 2

Author(s):

Jia Tang ◽

Ruoqing Ma ◽

Najie Zhu ◽

Kai Guo ◽

Yiqing Guo ◽

...

Keyword(s):

Bursaphelenchus Xylophilus ◽

Pinewood Nematode

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Characterizing and Evaluating the Zoonotic Potential of Novel Viruses Discovered in Vampire Bats

Viruses ◽

10.3390/v13020252 ◽

2021 ◽

Vol 13 (2) ◽

pp. 252

Author(s):

Laura M. Bergner ◽

Nardus Mollentze ◽

Richard J. Orton ◽

Carlos Tello ◽

Alice Broos ◽

...

Keyword(s):

Machine Learning ◽

Phylogenetic Analyses ◽

Human Infection ◽

Machine Learning Algorithms ◽

Zoonotic Potential ◽

Metagenomic Sequencing ◽

Learning Models ◽

Sequencing Data ◽

Vampire Bats ◽

Machine Learning Models

The contemporary surge in metagenomic sequencing has transformed knowledge of viral diversity in wildlife. However, evaluating which newly discovered viruses pose sufficient risk of infecting humans to merit detailed laboratory characterization and surveillance remains largely speculative. Machine learning algorithms have been developed to address this imbalance by ranking the relative likelihood of human infection based on viral genome sequences, but are not yet routinely applied to viruses at the time of their discovery. Here, we characterized viral genomes detected through metagenomic sequencing of feces and saliva from common vampire bats (Desmodus rotundus) and used these data as a case study in evaluating zoonotic potential using molecular sequencing data. Of 58 detected viral families, including 17 which infect mammals, the only known zoonosis detected was rabies virus; however, additional genomes were detected from the families Hepeviridae, Coronaviridae, Reoviridae, Astroviridae and Picornaviridae, all of which contain human-infecting species. In phylogenetic analyses, novel vampire bat viruses most frequently grouped with other bat viruses that are not currently known to infect humans. In agreement, machine learning models built from only phylogenetic information ranked all novel viruses similarly, yielding little insight into zoonotic potential. In contrast, genome composition-based machine learning models estimated different levels of zoonotic potential, even for closely related viruses, categorizing one out of four detected hepeviruses and two out of three picornaviruses as having high priority for further research. We highlight the value of evaluating zoonotic potential beyond ad hoc consideration of phylogeny and provide surveillance recommendations for novel viruses in a wildlife host which has frequent contact with humans and domestic animals.

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Characterization of Salmonella serotypes prevalent in asymptomatic people and patients

BMC Infectious Diseases ◽

10.1186/s12879-021-06340-z ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Haiyan Xu ◽

Weibing Zhang ◽

Kai Zhang ◽

Yue Zhang ◽

Zhenyu Wang ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Asymptomatic Infection ◽

Resistance Rate ◽

Human Infection ◽

The Other ◽

Resistance Testing ◽

Multi Drug Resistance ◽

Discriminative Ability ◽

Source Of Infection ◽

The Difference

Abstract Background Infection with Salmonella enterica usually results in diarrhea, fever, and abdominal cramps, but some people become asymptomatic or chronic carrier as a source of infection for others. This study aimed to analyze the difference in serotype, antimicrobial resistance, and genetic profiles between Salmonella strains isolated from patients and those from asymptomatic people in Nantong city, China. Methods A total of 88 Salmonella strains were collected from patients and asymptomatic people from 2017 to 2018. Serotyping, antimicrobial susceptibility testing, and PFGE analysis were performed to analyze the characteristics of these strains. Results Twenty serotypes belonging to 8 serogroups were identified in the 88 Salmonella strains. S. Typhimurium remained to be the predominant serotype in strains from both patients and asymptomatic people. Among the 27 strains from patients, S. Enteritidis and S. Rissen were shown as the other two major serotypes, while S. London, S. Derby, and S. Meleagridis were demonstrated as the other significant serotypes among the 61 strains from asymptomatic people. Antimicrobial resistance testing revealed that 84.1% of strains from both resources were multi-drug resistant. PFGE displayed a highly discriminative ability to differentiate strains belonging to S. Derby, S. Typhimurium, etc., but could not efficiently differentiate serotypes like S. Enteritidis. Conclusions This study’s results demonstrated that S. Typhimurium could cause human infection in both symptomatic and asymptomatic state; S. London, S. Derby, and S. Meleagridis usually cause asymptomatic infection, while S. Enteritidis infection mainly results in human diseases. The high multi-drug resistance rate detected in the antimicrobial resistance and diverse PFGE profiles of these strains implied that the strains were isolated from different sources, and the increased surveillance of Salmonella from both patients and asymptomatic people should be taken to control the disease.

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Genetic characteristics of Bursaphelenchus xylophilus third-stage dispersal juveniles

Scientific Reports ◽

10.1038/s41598-021-82343-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Qiaoli Chen ◽

Ruizhi Zhang ◽

Danlei Li ◽

Feng Wang

Keyword(s):

Fat Metabolism ◽

Bursaphelenchus Xylophilus ◽

Pinewood Nematode ◽

Genetic Characteristics ◽

Highest Weight ◽

Homologous Genes ◽

Third Stage ◽

Highly Correlated ◽

Oil Red O Staining ◽

Oil Red O

AbstractThe third-stage dispersal juvenile (DJ3) of pinewood nematode (PWN) is highly associated with low-temperature survival and spread of the nematode. Oil-Red-O staining showed that its lipid content was significantly higher compared with other PWN stages. Weighted gene coexpression network analysis identified that genes in the pink module were highly related to DJ3 induced in the laboratory (DJ3-lab). These genes were arranged according to their gene significance (GS) to DJ3-lab. Of the top 30 genes with the highest GS, seven were found to be highly homologous to the cysteine protease family cathepsin 1 (CATH1). The top 30 genes with the highest weight value to each of the seven genes in the pink module were selected, and finally 35 genes were obtained. Between these seven CATH1 homologous genes and their 35 highly related genes, 15 were related to fat metabolism or autophagy. These autophagy-related genes were also found to be highly correlated with other genes in the pink module, suggesting that autophagy might be involved in the mechanism of longevity in DJ3 and the formation of DJ3 by regulating genes related to fat metabolism.

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Chitosan increases Pinus pinaster tolerance to the pinewood nematode (Bursaphelenchus xylophilus) by promoting plant antioxidative metabolism

Scientific Reports ◽

10.1038/s41598-021-83445-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Marta Nunes da Silva ◽

Carla S. Santos ◽

Ana Cruz ◽

Adrián López-Villamor ◽

Marta W. Vasconcelos

Keyword(s):

Phenolic Compounds ◽

Pinus Pinaster ◽

Plant Defence ◽

Pine Wilt Disease ◽

Bursaphelenchus Xylophilus ◽

Nematode Population ◽

Post Inoculation ◽

Pinewood Nematode ◽

Plant Tolerance ◽

The Moment

AbstractThe pine wilt disease (PWD), for which no effective treatment is available at the moment, is a constant threat to Pinus spp. plantations worldwide, being responsible for significant economic and environmental losses every year. It has been demonstrated that elicitation with chitosan increases plant tolerance to the pinewood nematode (PWN) Bursaphelenchus xylophilus, the causal agent of the PWD, but the biochemical and genetic aspects underlying this response have not been explored. To understand the influence of chitosan in Pinus pinaster tolerance against PWN, a low-molecular-weight (327 kDa) chitosan was applied to mock- and PWN-inoculated plants. Nematode population, malondialdehyde (MDA), catalase, carotenoids, anthocyanins, phenolic compounds, lignin and gene expression related to oxidative stress (thioredoxin 1, TRX) and plant defence (defensin, DEF, and a-farnesene synthase, AFS), were analysed at 1, 7, 14, 21 and 28 days post-inoculation (dpi). At 28 dpi, PWN-infected plants elicited with chitosan showed a sixfold lower nematode population when compared to non-elicited plants. Higher levels of MDA, catalase, carotenoids, anthocyanins, phenolic compounds, and lignin were detected in chitosan-elicited plants following infection. The expression levels of DEF gene were higher in elicited plants, while TRX and AFS expression was lower, possibly due to the disease containment-effect of chitosan. Combined, we conclude that chitosan induces pine defences against PWD via modulation of metabolic and transcriptomic mechanisms related with plant antioxidant system.

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In Silico Screening of Agonist and Antagonist Natural Compounds from Reported Essential Oils against Bursaphelenchus xylophilus

Chemistry Proceedings ◽

10.3390/ecsoc-24-08386 ◽

2020 ◽

Vol 3 (1) ◽

pp. 31

Author(s):

Jorge M. S. Faria ◽

Ana Margarida Rodrigues ◽

Pedro Barbosa ◽

Manuel Mota

Keyword(s):

Essential Oils ◽

Pine Wilt Disease ◽

Natural Compounds ◽

Bursaphelenchus Xylophilus ◽

Pinewood Nematode ◽

Highly Active ◽

Bibliographic Data ◽

Agonist And Antagonist ◽

Containment Strategy ◽

Detailed Chemical

Chemical control has been the most effective and reliable containment strategy in integrated pest management of pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus. Yet, large spectrum nematicides can be dangerous to human health and the environment. Essential oils (EOs) are safer sustainable alternatives, being composed of highly active natural compounds. A survey of bibliographic data on the detailed chemical composition and activity of the EOs used against the PWN allowed pinpointing monoterpenes as the main source of structures with agonist or antagonist properties. Transversal EO data treatment can identify potential highly active anti-PWN compounds.

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Satellite DNA as a target for TaqMan real-time PCR detection of the pinewood nematode, Bursaphelenchus xylophilus

Molecular Plant Pathology ◽

10.1111/j.1364-3703.2007.00434.x ◽

2007 ◽

Vol 8 (6) ◽

pp. 803-809 ◽

Cited By ~ 42

Author(s):

CECILE FRANÇOIS ◽

CHANTAL CASTAGNONE ◽

NEIL BOONHAM ◽

JENNY TOMLINSON ◽

REBECCA LAWSON ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Satellite Dna ◽

Bursaphelenchus Xylophilus ◽

Pcr Detection ◽

Pinewood Nematode

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Molecular and biochemical characterization of an endo-β-1,3-glucanase from the pinewood nematode Bursaphelenchus xylophilus acquired by horizontal gene transfer from bacteria

Biochemical Journal ◽

10.1042/bj20042042 ◽

2005 ◽

Vol 389 (1) ◽

pp. 117-125 ◽

Cited By ~ 86

Author(s):

Taisei KIKUCHI ◽

Hajime SHIBUYA ◽

John T. JONES

Keyword(s):

Gene Transfer ◽

Horizontal Gene Transfer ◽

Biochemical Characterization ◽

Glycosyl Hydrolase ◽

Functional Characterization ◽

Nematode Species ◽

Bursaphelenchus Xylophilus ◽

Pinewood Nematode ◽

Sequence Comparisons

We report the cloning and functional characterization of an endo-β-1,3-glucanase from the pinewood nematode Bursaphelenchus xylophilus acquired by horizontal gene transfer from bacteria. This is the first gene of this type from any nematode species. We show that a similar cDNA is also present in another closely related species B. mucronatus, but that similar sequences are not present in any other nematode studied to date. The B. xylophilus gene is expressed solely in the oesophageal gland cells of the nematode and the protein is present in the nematode's secretions. The deduced amino acid sequence of the gene is very similar to glycosyl hydrolase family 16 proteins. The recombinant protein, expressed in Escherichia coli, preferentially hydrolysed the β-1,3-glucan laminarin, and had very low levels of activity on β-1,3-1,4-glucan, lichenan and barley β-glucan. Laminarin was degraded in an endoglucanase mode by the enzyme. The optimal temperature and pH for activity of the recombinant enzyme were 65 °C and pH 4.9. The protein is probably important in allowing the nematodes to feed on fungi. Sequence comparisons suggest that the gene encoding the endo-β-1,3-glucanase was acquired by horizontal gene transfer from bacteria. B. xylophilus therefore contains genes that have been acquired by this process from both bacteria and fungi. These findings support the idea that multiple independent horizontal gene transfer events have helped in shaping the evolution of several different life strategies in nematodes.

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