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Wound healing in DFU (diabetic foot ulcer) has prolonged inflammation phase and defective granulation tissue formation. LL-37 has antimicrobial property, induces angiogenesis, and keratinocyte migration and proliferation. This study analyzes the efficacy of LL-37 cream in enhancing wound healing rate and decreasing the levels of IL-1α, TNF-α, and the number of aerobic bacteria colonization in DFU with mild infection. This study was conducted from January 2020 to June 2021 in Jakarta. Subjects were instructed to apply either LL-37 cream or placebo cream twice a week for 4 weeks. Wounds were measured on days 7, 14, 21, and 28 and processed with ImageJ. The levels of LL-37, IL-1α, and TNF-α from wound fluid were measured using ELISA. The number of aerobic bacteria colonization was counted from the isolate grown in culture. The levels of LL-37 in DFU at baseline were equally low in both groups which were 1.07 (0.37-4.96) ng/mg protein in the LL-37 group and 1.11 (0.24-2.09) ng/mg protein in the placebo group. The increase in granulation index was consistently greater in the LL-37 group on days 7, 14, 21, and 28 (p = 0.031, 0.009, 0.006, and 0.037, respectively). The levels of IL-1α and TNF-α increased in both groups on days 14 and 21 (p > 0.05). The decrease in the number of aerobic bacteria colonization was greater in the LL-37 group on days 7, 14 and 21, but greater in the placebo group on day 28 (p > 0.05). In conclusion, LL-37 cream enhanced the healing rate of DFU with mild infection, but did not decrease the levels of IL-1α and TNF-α and the number of aerobic bacteria colonization. This trial is registered at ClinicalTrials.gov, number NCT04098562.

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Achlorophyllous, mycoheterotrophic plants often have an elaborate mycorrhizal colonization pattern, allowing a sustained benefit from external fungal root penetrations. The present study reveals the root anatomy and mycorrhizal pattern of eight mycoheterotrophic Thismia spp. (Thismiaceae), all of which show separate tissue compartments segregating different hyphal shapes of the mycorrhizal colonization, as there are intact straight, coiled and peculiarly knotted hyphae as well as degenerated clumps of hyphal material. Those tissue compartments in Thismia roots potentially comprise exo-, meso- and endoepidermae, and exo-, meso- and endocortices, although not all species develop all these root layers. Differences in details among species according to anatomy (number of root layers, cell sizes and shapes) and colonization pattern (hyphal shapes within cells) are striking and can be discussed as an evolutionary series towards increasing mycorrhizal complexity which roughly parallels the recently established phylogeny of Thismia. We suggest functional explanations for why the distinct elements of the associations can contribute to the mycorrhizal advantage for the plants and, thus, we emphasize the relevance of structural traits for mycorrhizae.

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Many aspects regarding the role of lipopeptides (LPs) in bacterial interaction with plants are not clear yet. Of particular interest is the LP family of surfactin, immunogenic molecules involved in induced systemic resistance (ISR) and the bacterial colonization of plant surfaces. We hypothesize that the concentration of surfactin produced by a strain correlates directly with its ability to colonize and persist on different plant surfaces, which conditions its capacity to trigger ISR. We used two Bacillus velezensis strains (BBC023 and BBC047), whose antagonistic potential in vitro is practically identical, but not on plant surfaces. The surfactin production of BBC047 is 1/3 higher than that of BBC023. Population density and SEM images revealed stable biofilms of BBC047 on leaves and roots, activating ISR on both plant surfaces. Despite its lower surfactin production, strain BBC023 assembled stable biofilms on roots and activated ISR. However, on leaves only isolated, unstructured populations were observed, which could not activate ISR. Thus, the ability of a strain to effectively colonize a plant surface is not only determined through its production of surfactin. Multiple aspects, such as environmental stressors or compensation mechanisms may influence the process. Finally, the importance of surfactin lies in its impacts on biofilm formation and stable colonization, which finally enables its activity as an elicitor of ISR.

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The Asian house rat (AHR), Rattus tanezumi, has recently invaded the northern half of China. The AHR is a highly adaptive rat species that has also successfully conquered the Qinghai-Tibet Plateau (QTP) and replaced the brown rat (BR), R. norvegicus, at the edge of the QTP. Here, we assembled a draft genome of the AHR and explored the mechanisms of its northward invasion and the genetic basis underlying plateau adaptation in this species. Population genomic analyses revealed that the northwardly invasive AHRs consisted of two independent and genetically distinct populations which might result from multiple independent primary invasion events. One invasive population exhibited reduced genetic diversity and distinct population structure compared with its source population, while the other displayed preserved genetic polymorphisms and little genetic differentiation from its source population. Genes involved in G-protein coupled receptors and carbohydrate metabolism may contribute to the local adaptation of northern AHRs. In particular, RTN4 was identified as a key gene for AHRs in the QTP that favours adaptation to high-altitude hypoxia. Coincidently, the physiological performance and transcriptome profiles of hypoxia-exposed rats both showed better hypoxia adaptation in AHRs than in BRs that failed to colonize the heart of the QTP, which may have facilitated the replacement of the BR population by the invading AHRs at the edge of the QTP. This study provides profound insights into the multiple origins of the northwardly invasive AHR and the great tolerance to hypoxia in this species.

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Achlorophyllous, mycoheterotrophic plants depend on their mycorrhizal fungi for 100% of their carbon supply. Hence, there is strong evolutionary pressure towards a well-organized functioning of the association from the plant's perspective. Members of the mycoheterotrophic genus Afrothismia have evolved elaborate fungal colonization patterns allowing a sustained benefit from external fungal penetration events. On the basis of anatomical details of the root-shoot systems of A. korupensis and A. hydra, we elucidate an evolutionary progression between the comparatively simple mycorrhizal pattern in A. gesnerioides and the so far most complex mycorrhiza in A. saingei. We detected two major advancements: (1) two species, A. korupensis and A. saingei, use the fungus itself as energy storage, replacing starch depositions used by A. gesnerioides and A. hydra, and (2) the morphological complexity of hyphal forms in plant tissue compartments increases from A. gesnerioides to A. saingei. We discuss the omitting of starch metabolism as well as the morpho-anatomical differences as an evolutionary fine-tuning of the compartmented mycorrhizal organization in Afrothismia. Our results support the idea of a taxonomic distinction between Afrothismia and other Thismiaceae.

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Numerous reports have shown that various rhizobia can interact with non-host plant species, improving mineral nutrition and promoting plant growth. To further investigate the effects of such non-host interactions on root development and functions, we inoculated Arabidopsis thaliana with the model nitrogen fixing rhizobacterium Mesorhizobium loti (strain MAFF303099). In vitro, we show that root colonization by M. loti remains epiphytic and that M. loti cells preferentially grow at sites where primary and secondary roots intersect. Besides resulting in an increase in shoot biomass production, colonization leads to transient inhibition of primary root growth, strong promotion of root hair elongation and increased apoplasmic acidification in periphery cells of a sizeable part of the root system. Using auxin mutants, axr1-3 and aux1-100, we show that a plant auxin pathway plays a major role in inhibiting root growth but not in promoting root hair elongation, indicating that root developmental responses involve several distinct pathways. Finally, using a split root device, we demonstrate that root colonization by M. loti, as well as by the bona fide plant growth promoting rhizobacteria Azospirillum brasilense and Pseudomonas, affect root development via local transduction pathways restricted to the colonised regions of the root system.

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Aspergillus terreus is a common soil saprophyte. After Aspergillus fumigatus and Scedosporium apiospermum it ranks third amongst the filamentous fungi colonizing the airways of patients with cystic fibrosis. In this context, the clinical presentation of A. terreus infection mainly corresponds to allergic broncho-pulmonary aspergillosis. In the work presented here, we studied colonization patterns of A. terreus in CF patients by genotyping using nine short tandem repeat markers. A total of 115 clinical isolates from respiratory secretions collected from five French CF patients were studied. The number of isolates varied from 15 to 39 per patient, and the duration of the follow-up period ranged from 2 months to 7.5 years. Seventeen genotypes were identified, corresponding to three distinct colonization patterns. The first colonization pattern consisted of a chronic colonization by one dominant genotype associated with few other genotypes found only incidentally. The second colonization pattern consisted of a prolonged colonization by two distinct genotypes detected simultaneously. The last pattern was characterized by multiple different genotypes that were present only transiently. These results demonstrate the importance of genotyping clinical isolates before making conclusions about chronic colonization of the airways in CF patients in the case of repeated isolation of the fungus.

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Campylobacter is the most common bacterial food-borne pathogen worldwide. Poultry and specifically chicken and raw chicken meat is the main source for human Campylobacter infection. Whilst being colonized by Campylobacter spp. chicken in contrast to human, do scarcely develop pathological lesions. The immune mechanisms controlling Campylobacter colonization and infection in chickens are still not clear. Previous studies and our investigations indicate that the ability to colonize the chicken varies significantly not only between Campylobacter strains but also depending on the original source of the infecting isolate. The data provides circumstantial evidence that early immune mechanisms in the gut may play an important role in the fate of Campylobacter in the host.