Didzis Elferts

Dr. Didzis Elferts

Latvian State Forest Research Institute "Silava", Salaspils, Salaspils Novads, Latvia
orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2018 in Ecological Indicators
Verified
Journal Article
Open access
Sandra PoikaneSandra Poikane
Sandra Poikane
RPRob Portielje
Rob Portielje
LDLuc Denys
Luc Denys
Didzis ElfertsDidzis Elferts
Didzis Elferts
MKMartyn Kelly
Martyn Kelly
MBMarcel S. van Den Berg
Marcel S. van Den Berg
• We harmonised nine macrophyte-based approaches for assessing lake ecological status. • We established relationships between the common view and nutrient concentrations. • Submerged vegetation decrease and free-floating plants increase along the status gradient. • We describe indicator taxa for ‘good’ and ‘less than good’ ecological status. • We establish a ‘guiding image’ of the macrophyte community at ‘good’ ecological status.

1 January 2017 in Journal of Experimental Biology
Verified
Journal Article
Open access
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Indrikis KramsIndrikis Krams
Indrikis Krams
SKSanita Kecko
Sanita Kecko
PJPriit Jõers
Priit Jõers
GTGiedrius Trakimas
Giedrius Trakimas
Didzis ElfertsDidzis Elferts
Didzis Elferts
TKTatjana Krama
Tatjana Krama
Communities of symbiotic microorganisms that colonize the gastrointestinal tract play an important role in food digestion and protection against opportunistic microbes. Diet diversity increases the number of symbionts in the intestines, a benefit that is considered to impose no cost for the host organism. However, less is known about the possible immunological investments that hosts have to make in order to control the infections caused by symbiont populations that increase because of diet diversity. Using taxonomical composition analysis of the 16S rRNA V3 region, we show that enterococci are the dominating group of bacteria in the midgut of the larvae of the greater wax moth (Galleria mellonella). We found that the number of colony-forming units of enterococci and expressions of certain immunity-related antimicrobial peptide (AMP) genes such as Gallerimycin, Gloverin, 6-tox, Cecropin-D and Galiomicin increased in response to a more diverse diet, which in turn decreased the encapsulation response of the larvae. Treatment with antibiotics significantly lowered the expression of all AMP genes. Diet and antibiotic treatment interaction did not affect the expression of Gloverin and Galiomicin AMP genes, but significantly influenced the expression of Gallerimycin, 6-tox and Cecropin-D. Taken together, our results suggest that diet diversity influences microbiome diversity and AMP gene expression, ultimately affecting an organism9s capacity to mount an immune response. Elevated basal levels of immunity-related genes (Gloverin and Galiomicin) might act as a prophylactic against opportunistic infections and as a mechanism that controls the gut symbionts. This would indicate that a diverse diet imposes higher immunity costs on organisms.

8 April 2020 in Forests
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Journal Article
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OKOskars Krisans
Oskars Krisans
RMRoberts Matisons
Roberts Matisons
SRSteffen Rust
Steffen Rust
Natalija BurnevicaNatalija Burnevica
Natalija Burnevica
LBLauma Brūna
Lauma Brūna
AJAris Jansons
Aris Jansons
Storms are the main abiotic disturbance in European forests, effects of which are expected to intensify in the future, hence the importance of forest stand stability is increasing. The predisposition of Norway spruce to wind damage appears to be enhanced by pathogens such as Heterobasidion spp., which reduce stability of individual trees. However, detailed information about the effects of the root rot on the stability of individual trees across diverse soil types is still lacking. The aim of the study was to assess the effect of root rot on the individual tree stability of Norway spruce growing on drained peat and mineral soils. In total, 77 Norway spruce trees (age 50–80 years) growing in four stands were tested under static loading. The presence of Heterobasidion spp. had a significant negative effect on the bending moment at primary and secondary failure of the tested trees irrespectively of soil type. This suggests increased legacy effects (e.g., susceptibility to pathogens and pests due to fractured roots and altered water uptake) of storms. Damaged trees act as weak spots increasing the susceptibility of stands to wind damage, thus forming a negative feedback loop and contributing to an ongoing decline in vitality of Norway spruce stands following storms in the study region in the future. Accordingly, the results support the importance of timely identification of the decayed trees, lowering stand density and/or shortening rotation period as the measures to counteract the increasing effects of storms on Norway spruce stands.

1 January 2016 in Journal of Sea Research
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Journal Article
Closed access
DUDidzis Ustups
Didzis Ustups
UBU. Bergström
U. Bergström
AFA.B. Florin
A.B. Florin
EKE. Kruze
E. Kruze
DZD. Zilniece
D. Zilniece
DUD. Uzars
D. Uzars

1 February 2018 in Agriculture, Ecosystems & Environment
Verified
Journal Article
Closed access
IVIvo Vinogradovs
Ivo Vinogradovs
ONOļģerts Nikodemus
Oļģerts Nikodemus
Didzis ElfertsDidzis Elferts
Didzis Elferts
Guntis BrumelisGuntis Brumelis
Guntis Brumelis

6 July 2021 in Pathogens
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Journal Article
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Margarita TerentjevaMargarita Terentjeva
Margarita Terentjeva
ŽŠŽanete Šteingolde
Žanete Šteingolde
IMIrena Meistere
Irena Meistere
Didzis ElfertsDidzis Elferts
Didzis Elferts
JAJelena Avsejenko
Jelena Avsejenko
Aivars BerzinsAivars Berzins
Aivars Berzins
Listeria spp. is a diverse genus of Gram-positive bacteria commonly present in the environment while L. monocytogenes and L. ivanovii are well known human and ruminant pathogens. The aim of the present study was to reveal the prevalence and genetic diversity of L. monocytogenes and other Listeria spp. and to identify the factors related to the abundance of pathogen at cattle farms. A total of 521 animal and environmental samples from 27 meat and dairy cattle farms were investigated and the genetic diversity of L. monocytogenes isolates was studied with WGS. The prevalence of Listeria was 58.9%, while of L. monocytogenes it was −11%. The highest prevalence of L. monocytogenes was found in the environment—soil samples near to manure storage (93%), mixed feed from the feeding trough and hay (29%), water samples from farms drinking trough (28%) and cattle feces (28%). Clonal complexes (CC) of CC37 (30%), CC11 (20%) and CC18 (17%) (all IIa serogroup) were predominant L. monocytogenes clones. CC18, CC37 and CC8 were isolated from case farms and CC37, CC11 and CC18 from farms without listeriosis history. Only one hypervirulent CC4 (1%) was isolated from the case farm. Sequence types (STs) were not associated with the isolation source, except for ST7, which was significantly associated with soil (p < 0.05). The contamination of soil, feeding tables and troughs with L. monocytogenes was associated with an increased prevalence of L. monocytogenes at farms. Our study indicates the importance of hygienic practice in the prevention of the dissemination of L. monocytogenes in the cattle farm environment.