Extracellular enzyme profiling of<i>Stenotrophomonas maltophilia</i>clinical isolates

Thomas, R. Brent; Hamat, Rukman Awang; Neela, Vasanthakumari

doi:10.4161/viru.27724

Cited by 31 publications

(18 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aforementioned, only 19 clinical isolates formed a hazy zone with different diameter of the zone, suggestive that not all strains are capable of twitching motility. Regarding environmental isolates, a study reported that LMG959 showed a zone of twitching under normal growth condition [27], but we did not observe in our study. Instead, LMG10879 exhibited twitching with an average zone of 23.00 mm in both normal and iron-depleted conditions.…”

Section: Discussioncontrasting

confidence: 99%

“…The flagella filaments of S. maltophilia are composed of a 38-kDa subunit, SM FliC , and appeared to be similar to Serratia marcescens (78.6%), Escherichia coli, Proteus mirabilis, Shigella sonnei (71.4%), and Pseudomonas aeruginosa (57.2%) [26]. Numerous studies have reported the correlation between S. maltophilia's motility and biofilm formation on abiotic surfaces, and its capability of invading host epithelial cells under normal nutritional condition [18,[27][28][29][30]. Iron depletion in S. maltophilia was found to be associated with biofilm formation, extracellular polymeric substances (EPS) production, oxidative stress response, outer membrane proteins (OMPs) regulation, quorum sensing, siderophore production, and expression of iron acquisition systems [31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches

Kalidasan

Neela

2020

Virulence

View full text Add to dashboard Cite

This study investigates the twitching ability of 28 clinical and five environmental strains of S. maltophilia grown under iron-depleted condition through in-silico, phenotypic and proteomics approaches. Rapid Annotations using Subsystem Technology (RAST) analysis revealed the presence of 21 targets of type IV pilus shared across S. maltophilia strains K279a, R551-3, D457 and JV3. The macroscopic twitching assay showed that only clinical isolates produced a zone of twitching with a mean of 22.00 mm under normal and 25.00 mm under iron-depleted conditions. (p = 0.002). Environmental isolates did not show any significant twitching activity in both conditions tested. Isobaric Tags for Relative and Absolute Quantification (ITRAQ) analysis showed altered expression of twitching motility protein PilT (99.08-fold change), flagellar biosynthesis protein FliC (20.14-fold change), and fimbrial protein (0.70-fold change) in response to iron-depleted condition. Most of the strains that have the ability to twitch under the normal condition, exhibit enhanced twitching during iron limitation. ARTICLE HISTORY

show abstract

Section: Discussioncontrasting

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches

Kalidasan

Neela

2020

Virulence

View full text Add to dashboard Cite

show abstract

“…All isolates were previously identified as S. maltophilia using standard biochemical assays, API 20 NE (bioMerieux, Marcy-l’Étoile, France) and confirmed by the VITEK ® Mass Spectrometry System [ 25 , 26 ]. Besides this, the isolates were morphologically identified by culture characteristics on Columbia agar with 5% sheep blood (Isolac, Selangor, Malaysia) and Gram morphology.…”

Section: Methodsmentioning

confidence: 99%

Putative Iron Acquisition Systems in Stenotrophomonas maltophilia

et al. 2018

View full text Add to dashboard Cite

Iron has been shown to regulate biofilm formation, oxidative stress response and several pathogenic mechanisms in Stenotrophomonas maltophilia. Thus, the present study is aimed at identifying various iron acquisition systems and iron sources utilized during iron starvation in S. maltophilia. The annotations of the complete genome of strains K279a, R551-3, D457 and JV3 through Rapid Annotations using Subsystems Technology (RAST) revealed two putative subsystems to be involved in iron acquisition: the iron siderophore sensor and receptor system and the heme, hemin uptake and utilization systems/hemin transport system. Screening for these acquisition systems in S. maltophilia showed the presence of all tested functional genes in clinical isolates, but only a few in environmental isolates. NanoString nCounter Elements technology, applied to determine the expression pattern of the genes under iron-depleted condition, showed significant expression for FeSR (6.15-fold), HmuT (12.21-fold), Hup (5.46-fold), ETFb (2.28-fold), TonB (2.03-fold) and Fur (3.30-fold). The isolates, when further screened for the production and chemical nature of siderophores using CAS agar diffusion (CASAD) and Arnows’s colorimetric assay, revealed S. maltophilia to produce catechol-type siderophore. Siderophore production was also tested through liquid CAS assay and was found to be greater in the clinical isolate (30.8%) compared to environmental isolates (4%). Both clinical and environmental isolates utilized hemoglobin, hemin, transferrin and lactoferrin as iron sources. All data put together indicates that S. maltophilia utilizes siderophore-mediated and heme-mediated systems for iron acquisition during iron starvation. These data need to be further confirmed through several knockout studies.

show abstract

“…Cultures (5 μL) were spotted on nutrient gelatin plates and cultivated at 37°C for 24 h. Then, 2–3 mL acid mercuric chloride was added to the plates and color development was assessed after 5 min. Cells capable of liquefying gelatin, were identified by a transparent halo around the bacterial lawn ( Frazier, 1926 ; Mcdade and Weaver, 1959 ; Thomas et al, 2014 ).…”

Section: Methodsmentioning

confidence: 99%

Riemerella anatipestifer Type IX Secretion System Is Required for Virulence and Gelatinase Secretion

Guo

et al. 2017

Front. Microbiol.

View full text Add to dashboard Cite

Riemerella anatipestifer (RA), a major causative agent of septicemia anserum exsudativa in domesticated ducklings, has a protein secretion system known as the type IX secretion system (T9SS). It is unknown whether the T9SS contributes to the virulence of RA through secretion of factors associated with pathogenesis. To answer this question, we constructed an RA mutant deficient in sprT, which encodes a core protein of the T9SS. Deletion of sprT yielded cells that failed to digest gelatin, an effect that was rescued via complementation by a plasmid encoding wild-type sprT. Complement-mediated killing was significantly increased in the deletion mutant, suggesting that proteins secreted by the T9SS are necessary for complement evasion in RA. Liquid chromatography-tandem mass spectrometry analysis revealed that RAYM_01812 and RAYM_04099 proteins containing a subtilisin-like serine protease domain and exhibiting extracellular gelatinase activity were secreted by the T9SS. Animal experiments demonstrated that the virulence of mutant strain ΔsprT strain was attenuated by 42,000-fold relative to wild-type RA-YM. Immunization with the ΔsprT protected ducks from challenge with RA-YM, suggesting that the former can be used as a live attenuated vaccine. These results indicate that the T9SS is functional in RA and contributes to its virulence by exporting key proteins. In addition, subtilisin-like serine proteases which are important virulence factors that interact with complement proteins may enable RA to evade immune surveillance in the avian innate immune system.

show abstract

Extracellular enzyme profiling ofStenotrophomonas maltophiliaclinical isolates

Cited by 31 publications

References 43 publications

Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches

Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches

Putative Iron Acquisition Systems in Stenotrophomonas maltophilia

Riemerella anatipestifer Type IX Secretion System Is Required for Virulence and Gelatinase Secretion

Contact Info

Product

Resources

About