A novel Microbacterium strain SRS2 promotes the growth of Arabidopsis and MicroTom (S. lycopersicum) under normal and salt stress conditions.

MAIN CONCLUSION: Microbacterium strain SRS2 promotes growth and induces salt stress resistance in Arabidopsis and MicroTom in various growth substrates via the induction of the ABA pathway. Soil salinity reduces plant growth and development and thereby decreases the value and productivity of soils. Plant growth-promoting rhizobacteria (PGPR) have been shown to support plant growth such as in salt stress conditions. Here, Microbacterium strain SRS2, isolated from the root endosphere of tomato, was tested for its capability to help plants cope with salt stress. In a salt tolerance assay, SRS2 grew well up to medium levels of NaCl, but the growth was inhibited at high salt concentrations. SRS2 inoculation led to increased biomass of Arabidopsis and MicroTom tomato in various growth substrates, in the presence and in the absence of high NaCl concentrations. Whole-genome analysis revealed that the strain contains several genes involved in osmoregulation and reactive oxygen species (ROS) scavenging, which could potentially explain the observed growth promotion. Additionally, we also investigated via qRT-PCR, promoter::GUS and mutant analyses whether the abscisic acid (ABA)-dependent or -independent pathways for tolerance against salt stress were involved in the model plant, Arabidopsis. Especially in salt stress conditions, the plant growth-promotion effect of SRS2 was lost in aba1, abi4-102, abi3, and abi5-1 mutant lines. Furthermore, ABA genes related to salt stress in SRS2-inoculated plants were transiently upregulated compared to mock under salt stress conditions. Additionally, SRS2-inoculated ABI4::GUS and ABI5::GUS plants were slightly more activated compared to the uninoculated control under salt stress conditions. Together, these assays show that SRS2 promotes growth in normal and in salt stress conditions, the latter possibly via the induction of ABA-dependent and -independent pathways.

Oncologic and Fertility Outcomes After Simple Trachelectomy in Women With Early Cervical Cancer.

STUDY OBJECTIVE: This study aimed to present our case series of patients with early-stage cervical cancer undergoing simple trachelectomy (ST). Currently, radical trachelectomy is considered the most appropriate fertility-preserving procedure for the treatment of early-stage cervical cancer. However, there is increasing debate on the appropriate radicality of the surgery to preserve oncologic safety. DESIGN: Descriptive retrospective analysis of patient records and evaluation of questionnaires. SETTING: 2 gynecologic oncologic centers, surgeries performed by one surgical team. PATIENTS: 36 women with early-stage cervical cancer undergoing ST. INTERVENTIONS: Laparoscopic assisted simple vaginal trachelectomy. MEASUREMENTS: Demographic, histologic, fertility, and follow-up data of all patients who underwent ST between April 2007 and July 2021 were prospectively recorded and retrospectively analyzed. MAIN RESULTS: A total of 36 women (mean age: 28 years) underwent ST of whom 81% were nulliparous. Indications for ST were multifocal International Federation of Gynecology and Obstetrics stage IA1 (n = 30), stage IA1 L1 (n = 1), stage IA2 (n = 2), and stage IB1 (n = 3). Mandatory staging procedure was laparoscopic pelvic lymphadenectomy, including bilateral sentinel biopsy in 92% of the cases and systematic in 8%. Residual tumor was histologically confirmed in 8 specimens (22%); 18 women (50%) were seeking parenthood, and 13 succeeded (72%). There were 16 live births, all on term, with a median fetal weight of 3110 grams (2330-4420). One patient had a medical abortion owing to fetal congenital malformation. One pregnancy is ongoing. After a median follow-up of 91.5 months (9-174), all women are alive with no evidence of disease. CONCLUSION: ST represents a de-escalation compared with radical trachelectomy and provides excellent oncologic results with an outstanding fertility rate and obstetric outcome for patients with early cervical cancer. However, clear indications for this tailored fertility-preserving surgery have to be defined in well-designed trials.

Salinity and host drive Ulva-associated bacterial communities across the Atlantic-Baltic Sea gradient.

The green seaweed Ulva is a model system to study seaweed-bacteria interactions, but the impact of environmental drivers on the dynamics of these interactions is little understood. In this study, we investigated the stability and variability of the seaweed-associated bacteria across the Atlantic-Baltic Sea salinity gradient. We characterized the bacterial communities of 15 Ulva sensu lato species along 2,000 km of coastline in a total of 481 samples. Our results demonstrate that the Ulva-associated bacterial composition was strongly structured by both salinity and host species (together explaining between 34% and 91% of the variation in the abundance of the different bacterial genera). The largest shift in the bacterial consortia coincided with the horohalinicum (5-8 PSU, known as the transition zone from freshwater to marine conditions). Low-salinity communities especially contained high relative abundances of Luteolibacter, Cyanobium, Pirellula, Lacihabitans and an uncultured Spirosomaceae, whereas high-salinity communities were predominantly enriched in Litorimonas, Leucothrix, Sulfurovum, Algibacter and Dokdonia. We identified a small taxonomic core community (consisting of Paracoccus, Sulfitobacter and an uncultured Rhodobacteraceae), which together contributed to 14% of the reads per sample, on average. Additional core taxa followed a gradient model, as more core taxa were shared between neighbouring salinity ranges than between ranges at opposite ends of the Atlantic-Baltic Sea gradient. Our results contradict earlier statements that Ulva-associated bacterial communities are taxonomically highly variable across individuals and largely stochastically defined. Characteristic bacterial communities associated with distinct salinity regions may therefore facilitate the host's adaptation across the environmental gradient.

Fertility sparing therapy in women with lymph node negative cervical cancer >2cm - oncologic and fertility outcomes of neoadjuvant chemotherapy followed by radical vaginal trachelectomy.

OBJECTIVE: Simple or radical trachelectomy are accepted fertility sparing therapies for patients diagnosed with cervical cancer ≤2 cm. In patients with larger tumors a fertility sparing concept is considered experimental. The aim of our study is to present oncological and fertility outcomes of laparoscopic pelvic lymphadenectomy followed by neoadjuvant chemotherapy and subsequent radical vaginal trachelectomy. These procedures were performed in two centers in patients diagnosed with cervical cancer of diameter >2 cm. METHOD: We retrospectively analyzed the demographic, histological, fertility and follow-up data of all patients with cervical cancer assessed as stage IB2, IB3 or IIA1 under the International Federation of Gynecology and Obstetrics (FIGO) 2018 system. These patients had undergone pelvic lymphadenectomy, followed by neoadjuvant chemotherapy and radical vaginal trachelectomy between February 2006 and June 2020 at Charité University Berlin and Asklepios Hospital, Hamburg. RESULTS: A total of 31 patients (mean age 29.5 years, range; 26-40) underwent neoadjuvant chemotherapy followed by radical vaginal trachelectomy in case of proven tumor-free lymph nodes. Twenty-six (84%) of these patients were nulliparous. Across all 31 patients, the initial tumor stages were FIGO 2018 stage IB2 (n=27), IB3 (n=3) and IIA1 (n=1).Lymphadenectomy was completed in all but one patient (sentinel) with a median of 33 (range; 11-47) pelvic lymph nodes. The neoadjuvant chemotherapy regimen was two cycles of paclitaxel, ifosfamide and cisplatin in 17 patients; three cycles of paclitaxel, ifosfamide and cisplatin in eight patients; two cycles of paclitaxel and cisplatin in four patients; two cylces cisplatin monoagent in one patient; and two cycles of paclitaxel and cisplatin followed by two cycles of paclitaxel, ifosfamide and cisplatin in one patient. Residual tumor was histologically confirmed in 17 specimens (55%). The median residual tumor size following neoadjuvant chemotherapy was 12 mm (range; 1-60). Fertility could be preserved in 27 patients (87%); two patients underwent adjuvant chemoradiation after radical vaginal trachelectomy due to high-risk histological features; two other patients underwent radical hysterectomy with adjuvant chemoradiation therapy following neoadjuvant chemotherapy. Of 18 (67%) patients seeking motherhood, 13 became pregnant (72%). There were 12 live births in 10 women, with a median fetal weight of 2490 grams (range; 1640-3560) and five miscarriages. After a median follow-up of 94.5 months (range; 6-183) three recurrences (11.1%) were detected, one patient (3.7%) died of the disease. CONCLUSION: Neoadjuvant chemotherapy followed by radical vaginal trachelectomy may be offered to patients seeking motherhood with cervical cancer >2 cm and histopathologically tumor-free lymph nodes, the rate of healthy baby pregnancy on discharge was 10/18 women (55%). This fertility-preserving strategy is associated with higher recurrence and death compared with what was published in the literature for women undergoing radical vaginal trachelectomy for tumors up to 2 cm.

Flemish soils contain rhizobia partners for Northwestern Europe-adapted soybean cultivars.

In Europe, soybean (Glycine max) used for food and feed has to be imported, causing negative socioeconomic and environmental impacts. To increase the local production, breeding generated varieties that grow in colder climates, but the yield using the commercial inoculants is not satisfactory in Belgium because of variable nodulation efficiencies. To look for indigenous nodulating strains possibly adapted to the local environment, we initiated a nodulation trap by growing early-maturing cultivars under natural and greenhouse conditions in 107 garden soils in Flanders. Nodules occurred in 18 and 21 soils in the garden and greenhouse experiments respectively. By combining 16S rRNA PCR on single isolates with HiSeq 16S metabarcoding on nodules, we found a large bacterial richness and diversity from different soils. Furthermore, using Oxford Nanopore Technologies sequencing of DNA from one nodule, we retrieved the entire genome of a Bradyrhizobium species, not previously isolated, but profusely present in that nodule. These data highlight the need of combining diverse identification techniques to capture the true nodule rhizobial community. Eight selected rhizobial isolates were subdivided by whole-genome analysis in three genera containing six genetically distinct species that, except for two, aligned with known type strains and were all able to nodulate soybean in the laboratory.

R othia mucilaginosa is an anti-inflammatory bacterium in the respiratory tract of patients with chronic lung disease.

BACKGROUND: Chronic airway inflammation is the main driver of pathogenesis in respiratory diseases such as severe asthma, chronic obstructive pulmonary disease, cystic fibrosis (CF) and bronchiectasis. While the role of common pathogens in airway inflammation is widely recognised, the influence of other microbiota members is still poorly understood. METHODS: We hypothesised that the lung microbiota contains bacteria with immunomodulatory activity which modulate net levels of immune activation by key respiratory pathogens. Therefore, we assessed the immunomodulatory effect of several members of the lung microbiota frequently reported as present in CF lower respiratory tract samples. RESULTS: We show that Rothia mucilaginosa, a common resident of the oral cavity that is also often detectable in the lower airways in chronic disease, has an inhibitory effect on pathogen- or lipopolysaccharide-induced pro-inflammatory responses, in vitro (three-dimensional cell culture model) and in vivo (mouse model). Furthermore, in a cohort of adults with bronchiectasis, the abundance of Rothia species was negatively correlated with pro-inflammatory markers (interleukin (IL)-8 and IL-1ß) and matrix metalloproteinase (MMP)-1, MMP-8 and MMP-9 in sputum. Mechanistic studies revealed that R. mucilaginosa inhibits NF-κB pathway activation by reducing the phosphorylation of IκBα and consequently the expression of NF-κB target genes. CONCLUSIONS: These findings indicate that the presence of R. mucilaginosa in the lower airways potentially mitigates inflammation, which could in turn influence the severity and progression of chronic respiratory disorders.

Bradyrhizobium campsiandrae sp. nov., a nitrogen-fixing bacterial strain isolated from a native leguminous tree from the Amazon adapted to flooded conditions.

The nitrogen-fixing bacterial strain UFLA 01-1174T was isolated from nodules of Campsiandra laurilifolia Benth. originating from the Amazon region, Brazil. Its taxonomic position was defined using a polyphasic approach. Analysis of the 16S rRNA gene placed the strain in the Bradyrhizobium genus, the closest species being B. guangdongense CCBAU 51649T and B. guangzhouense CCBAU 51670T, both with 99.8% similarity. Multilocus sequence analysis (MLSA) of recA, gyrB, glnII, rpoB, atpD, and dnaK indicated that UFLA 01-1174T is a new species, most closely related to B. stylosanthis BR 446T (94.4%) and B. manausense BR 3351T (93.7%). Average nucleotide identity (ANI) differentiated UFLA 01-1174T from the closest species with values lower than 90%. The G + C content in the DNA of UFLA 01-1174T is 63.6 mol%. Based on this data, we conclude that the strain represents a new species. The name proposed is Bradyrhizobium campsiandrae, with UFLA 01-1174T (= INPA 394BT = LMG 10099T) as type strain.

Bradyrhizobium uaiense sp. nov., a new highly efficient cowpea symbiont.

This study describes two Bradyrhizobium strains, UFLA03-164T and UFLA03-153, which share more than 99% sequence similarity of the 16S rRNA with the type strains of 15 species in this genus. The concatenation of three housekeeping genes (recA, gyrB, and dnaK) indicated that both strains formed a single clade separate from known Bradyrhizobium species. B. viridifuturi, represented by SEMIA 690T, is the closest neighboring species (96.2%). Low (< 92%) average nucleotide identity (ANI) was observed between strain UFLA03-164T and any of the closest species on the phylogenetic trees based on concatenated housekeeping genes. The DNA G+C content of UFLA03-164T is 63.25%. Phenotypic characteristics were determined for both UFLA strains. Based on the data, the two strains represent a new species for which the name Bradyrhizobium uaiense is proposed, with UFLA03-164T (= LMG 31509T) as type strain.

Leeuwenhoekiella aestuarii sp. nov., isolated from salt-water sediment and first insights in the genomes of Leeuwenhoekiella species.

Four Gram-negative, aerobic, rod-shaped and yellow-orange pigmented bacteria (R-46770, R-48165T, R-50232 and R-50233) were isolated from intertidal sediment and water of the Westerschelde estuary between 2006 and 2012. Analysis of their 16S rRNA gene sequences revealed that the four strains form a separate cluster between validly described type strains of the genus Leeuwenhoekiella. DNA-DNA reassociation values of two representative strains (i.e. R-48165T and R-50232) of the new group with type strains of Leeuwenhoekiella species ranged from 18.7 to 56.6 %. A comparative genome analysis of the two strains and the type strains confirmed average nucleotide identity values from 75.6 to 94.4 %. The G+C contents of the genomic DNA of strains R-48165T and R-50232 were 37.80 and 37.83 mol%, respectively. The predominant cellular fatty acids of the four novel strains were summed feature 3 (i.e. C16 : 1ω7c and/or iso-C15 : 0 2-OH), iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The four new Leeuwenhoekiella-like strains grew with 0.5-12 % (w/v) NaCl, at pH 5.5-9.0 and displayed optimum growth between 20 and 30 °C. Based on the results of phenotypic, genomic, phylogenetic and chemotaxonomic analyses, the four new strains represent a novel species of the genus Leeuwenhoekiella for which the name Leeuwenhoekiella aestuarii sp. nov. is proposed. The type strain is LMG 30908T (=R-48165T=CECT 9775T=DSM 107866T). Genome analysis of type strains of the genus Leeuwenhoekiella revealed a large number of glycosyl hydrolases, peptidases and carboxyl esterases per Mb, whereas the number of transporters per Mb was low compared to other bacteria. This confirmed the environmental role of Leeuwenhoekiella species as (bio)polymer degraders, with a specialization on degrading proteins and high molecular weight compounds. Additionally, the presence of a large number of genes involved in gliding motility and surface adhesion, and large numbers of glycosyl transferases per Mb confirmed the importance of these features for Leeuwenhoekiella species.

Efficient Nitrogen-Fixing Bacteria Isolated from Soybean Nodules in the Semi-arid Region of Northeast Brazil are Classified as Bradyrhizobium brasilense (Symbiovar Sojae).

Soybean (Glycine max L.) is an important legume that greatly benefits from inoculation with nitrogen-fixing bacteria. In a previous study, five efficient nitrogen-fixing bacterial strains, isolated from nodules of soybean inoculated with soil from semi-arid region, Northeast Brazil, were identified as a new group within the genus Bradyrhizobium. The taxonomic status of these strains was evaluated in this study. The phylogenetic analysis of the 16S rRNA gene showed the high similarity of the five strains to Bradyrhizobium brasilense UFLA03-321T (100%), B. pachyrhizi PAC48T (100%), B. ripae WR4T (100%), B. elkanii USDA 76T (99.91%), and B. macuxiense BR 10303T (99.91%). However, multilocus sequence analysis of the housekeeping genes atpD, dnaK, gyrB, recA, and rpoB, average nucleotide identity, and digital DNA-DNA hybridization analyses supported the classification of the group as B. brasilense. Some phenotypic characteristics allowed differentiating the five strains and the type strain of B. brasilense from the two neighboring species (B. pachyrhizi PAC48T and B. elkanii USDA 76T). The nodC and nifH genes' analyses showed that these strains belong to symbiovar sojae, together with B. elkanii (USDA 76T) and B. ferriligni (CCBAU 51502T). The present results support the classification of these five strains as Bradyrhizobium brasilense (symbiovar sojae).