Characterization of putative virulence factors of Serratia marcescens strain SEN for pathogenesis in Spodoptera litura

Aggarwal, Chetana; Paul, Sangeeta; Tripathi, Vishwas; Paul, Bishwajeet; Khan, Mohammad Zafar

doi:10.1016/j.jip.2016.12.004

Cited by 38 publications

(29 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…S. marcescens strains were also evaluated for the presence of toxin genes Shl A and phl A, and all but the Sm 40 strain carried these genes. Our findings are in agreement with other studies that reported the presence these genes in S. marcescens (strain SEN) ( Aggarwal et al, 2017 ). Flh DC has been proposed as a regulator controlling flagellum biogenesis, biofilm formation, cell septation and expression of virulence factors during swarming ( Givskov et al, 1995 ; Fraser and Hughes, 1999 ; Chilcott and Hughes, 2000 ; Lin et al, 2010 ).…”

Section: Discussionsupporting

confidence: 94%

“…Many bacteria produce virulence factors as hydrolytic enzymes and toxins that enable host invasion, bacterial proliferation and inhibit host defense mechanisms, sometimes resulting in host death ( Aggarwal et al, 2017 ). S. marcescens strains were also evaluated for the presence of toxin genes Shl A and phl A, and all but the Sm 40 strain carried these genes.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

et al. 2020

View full text Add to dashboard Cite

Serratia marcescens has emerged as an important opportunistic pathogen responsible for nosocomial and severe infections. Here, we determined phenotypic and molecular characteristics of 54 S. marcescens isolates obtained from patient samples from intensive-care-unit (ICU) and neonatal intensive-care-unit (NIUC) of a Brazilian tertiary hospital. All isolates were resistant to beta-lactam group antibiotics, and 92.6% (50/54) were not susceptible to tigecycline. Furthermore, 96.3% showed intrinsic resistance to polymyxin E (colistin), a last-resort antibiotic for the treatment of infections caused by MDR (multidrug-resistant) Gram-negative bacteria. In contrast, high susceptibility to other antibiotics such as fluoroquinolones (81.5%), and to aminoglycosides (as gentamicin 81.5%, and amikacin 85.2%) was found. Of all isolates, 24.1% were classified as MDR. The presence of resistance and virulence genes were examined by PCR and sequencing. All isolates carried KPC-carbapenemase (bla KPC) and extended spectrum beta-lactamase bla TEM genes, 14.8% carried bla OXA−1 , and 16.7% carried bla CTX−M−1group genes, suggesting that bacterial resistance to β-lactam antibiotics found may be associated with these genes. The genes SdeB/HasF and SdeY/HasF that are associated with efflux pump mediated drug extrusion to fluoroquinolones and tigecycline, respectively, were found in 88.9%. The aac(6)-Ib-cr variant gene that can simultaneously induce resistance to aminoglycoside and fluoroquinolone was present in 24.1% of the isolates. Notably, the virulence genes to (i) pore-forming toxin (ShlA); (ii) phospholipase with hemolytic and cytolytic activities (PhlA); (iii) flagellar transcriptional regulator (FlhD); and (iv) positive regulator of prodigiosin and serratamolide production (PigP) were present in 98.2%. The genetic relationship among the isolates determined by ERIC-PCR demonstrated that the vast majority of isolates were grouped in a single cluster with 86.4% genetic similarity. In addition, many isolates showed 100% genetic similarity to each other, suggesting that the S. marcescens that circulate in this ICU are closely related. Our results suggest that the antimicrobial resistance to many drugs

show abstract

Section: Discussionsupporting

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Foregut and hindgut of termite are lined with chitinous cuticle, but it is absent in the midgut, which is lined by peritrophic membrane, a matrix of secreted protein fibrils, proteoglycans and glycoproteins function as physical and immunological protection [ 34 ]. Serratia marcescens lethality to insect hosts has been shown to have proteolytic and chitinolytic virulence factors that degrade the peritrophic membrane [ 35 ]. The zone of transition from cuticular lining to peritrophic membrane may present a vulnerability to infection which can be exploited by certain bacteria.…”

Section: Discussionmentioning

confidence: 99%

Septicaemia of subterranean termites Coptotermes curvignathus caused by disturbance of bacteria isolated from termite gut and its foraging pathways

et al. 2020

View full text Add to dashboard Cite

Microbial pathogens continue to attract a great deal of attention to manage the termite population. Every bacterium has its own mode of action and in fact, the mechanisms used by bacteria to attack termites remain elusive at the moment. Hence, the objective of this study was to evaluate the susceptibility of subterranean termites Coptotermes curvignathus to opportunistic pathogens using culturable aerobic bacteria isolated from the termite gut and its foraging pathways. Bacterial suspensions were prepared in concentrations of 10 3 , 10 6 and 10 9 colony-forming units (CFU) ml −1 and introduced to the termites via oral-contact and physical contact treatment. The data show that contact method acted slower and gave lower mortality, compared to the oral-contact method. Coptotermes curvignathus were highly susceptible to Serratia marcescens and Pseudomonas aeruginosa . Serratia marcescens showed the highest mortality percentage of 68% and 54% at bacterial concentration of 10 9 CFU ml −1 via oral-contact and contact method, respectively. Serratia marcescens was also defined as the bacteria with the highest ability to induce the high mortality of C. curvignathus with the lowest concentration of bacterial suspension at a given time under laboratory condition. The results of this study indicate that P. aeruginosa and S. marcescens in particular may be attractive candidates worth further examination as a possible biocontrol agent against C. curvignathus in the field and to evaluate environmental and ecological risks of the biocontrol.

show abstract

“…These results showed that the insect gut is a barrier for orally bacterial infection, and as soon as the bacteria have reached the insect haemocoel, it can surpass the insect immune system and kill the insect host. A variety of toxins and extracellular degradative enzymes, such as protease, lipase, carbohydrase and chitinase, have been reported to be secreted by S. marcescens that allow this bacterium to completely degrade and exploit whole body of host (Aggarwal, Paul, Tripathi, Paul, & Khan, ; Benedik & Strych, ; Castagnola & Stock, ). The presence of these virulence factors could assist the S. marcescens isolate to infect the insects, particularly through feeding infection as the bacterium must persist in the gut of insects and cross the intestinal barrier to reach the haemocoel.…”

Section: Discussionmentioning

confidence: 99%

Isolation and characterization of a Serratia marcescens with insecticidal activity from Polyphylla olivieri (Col.: Scarabaeidae)

Bidari

Shams-Bakhsh

Mehrabadi

2017

J Applied Entomology

View full text Add to dashboard Cite

Members of the genus Serratia are known for their abilities to infect insects. In this study, a red-pigmented S. marcescens was isolated and characterized from the infected larvae of Polyphylla olivieri using bacterial cultivation, phylogenetic analysis as well as bioassays against larvae of the two insect pests, Plodia interpunctella and Ephestia kuehniella. Comparative 16S rRNA and groEL gene sequence BLAST analyses strongly suggested that the isolated strain should be placed in the genus Serratia, sharing high sequence similarities with several strain of S. marcescens associated with insects.Phylogenetic analysis placed the isolated bacterium with other S. marcescens bacteria in a clade with high bootstrapping values. To assess pathogenicity of the S. marcescens isolate, the bacterial cells were either injected into the haemolymph of the fifth-instar larvae or added to the diets of insects. Survival curves of the control insects and those challenged with six different concentrations of S. marcescens showed that the S. marcescens isolate significantly reduced survival rates of the larvae. The LC 50 s of the bacterium on P. interpunctella and E. kuehniella were 1992.26 and 1.09 × 10 4 (CFU/μl) for injection bioassays at 6 h post-injection, and 4.48 × 10 4 and 1.96 × 10 5 (CFU/10 μl)for feeding bioassays at 24 h post-feeding, respectively. Injection of the bacterial culture supernatant into the larvae led to continuous bleeding from the site of injection, while injection of heat-treated culture supernatant of the bacterium did not cause continuous bleeding. Together, our results showed the possibility of using this S. marcescens isolate in microbial control of the insect pests after addressing the safety concerns. Moreover, it might be considered as a source of useful bioactive molecules and genes with application in insect control and biotechnology via developing insectresistant plants.

show abstract

Characterization of putative virulence factors of Serratia marcescens strain SEN for pathogenesis in Spodoptera litura

Cited by 38 publications

References 38 publications

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

Characterization of KPC-Producing Serratia marcescens in an Intensive Care Unit of a Brazilian Tertiary Hospital

Septicaemia of subterranean termites Coptotermes curvignathus caused by disturbance of bacteria isolated from termite gut and its foraging pathways

Isolation and characterization of a Serratia marcescens with insecticidal activity from Polyphylla olivieri (Col.: Scarabaeidae)

Contact Info

Product

Resources

About