Influence of cyclic di-GMP metabolism to T3SS expression, biofilm formation and symbiosis efficiency in Mesorhizobium japonicum MAFF303099.

A link between the T3SS and inhibition of swimming motility by the transcriptional regulator TtsI in Mesorhizobium japonicum MAFF303099 has been previously reported. Here, we show that mutants in T3SS components display impaired biofilm formation capacity, indicating that a functional T3SS, or at least pili formation, is required for this process. As a first approach to the cdiG regulation network in this bacterium, we started a study of the second messenger cdiG by overexpressing or by deleting some genes encoding cdiG metabolizing enzymes. Overexpression of two putative PDEs as well as deletion of various DGCs led to reduced biofilm formation on glass tubes. Mutation of dgc9509 also affected negatively the nodulation and symbiosis efficiency on Lotus plants, which can be related to the observed reduction in adhesion to plant roots. Results from transcriptional nopX- and ttsI-promoter-lacZ fusions suggested that cdiG negatively regulates T3SS expression in M. japonicum MAFF303099.

Progestogens for maintenance tocolysis in symptomatic women. A systematic review and meta-analysis.

OBJECTIVE: Prevention of preterm birth (PTB) with progestogens after an episode of threatened preterm labour is still controversial. As different progestogens have distinct molecular structures and biological effects, we conducted a systematic review and pairwise meta-analysis to investigate the individual role played by 17-alpha-hydroxyprogesterone caproate (17-HP), vaginal progesterone (Vaginal P) and oral progesterone (Oral P). METHODS: The search was performed in MEDLINE, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials (CENTRAL) up to 31 October 2021. Published RCTs comparing progestogens to placebo or no treatment for maintenance tocolysis were considered. We included women with singleton gestations, excluding quasi-randomized trials, studies on women with preterm premature rupture of membrane, or receiving maintenance tocolysis with other drugs. Primary outcomes were preterm birth (PTB) < 37 weeks' and < 34 weeks'. We assessed risk of bias and evaluated certainty of evidence with the GRADE approach. RESULTS: Seventeen RCTs including 2152 women with singleton gestations were included. Twelve studies tested vaginal P, five 17-HP, and only 1 oral P. PTB < 34 weeks' did not differ among women receiving vaginal P (RR 1.21, 95%CI 0.91 to 1.61, 1077 participants, moderate certainty of evidence), or oral P (RR 0.89, 95%CI 0.38 to 2.10, 90 participants, low certainty of evidence) as opposed to placebo. Instead, 17-HP significantly reduced the outcome (RR 0.72, 95% CI 0.54 to 0.95, 450 participants, moderate certainty of evidence). PTB < 37 weeks' did not differ among women receiving vaginal P (RR 0.95, 95%CI 0.72 to 1.26, 8 studies, 1231 participants, moderate certainty of evidence) or 17-HP (RR 0.86, 95%CI 0.60 to 1.21, 450 participants, low certainty of evidence) when compared to placebo/no treatment. Instead, oral P significantly reduced the outcome (RR 0.58, 95% CI 0.36 to 0.93, 90 participants, low certainty of evidence). CONCLUSIONS: With a moderate certainty of evidence, 17-HP prevents PTB < 34 weeks' gestation among women that remained undelivered after an episode of threatened preterm labour. However, data are insufficient to generate recommendations in clinical practice. In the same women, both 17-HP and vaginal P are ineffective in the prevention of PTB < 37 weeks'.

Legume-rhizobium dance: an agricultural tool that could be improved?

The specific interaction between rhizobia and legume roots leads to the development of a highly regulated process called nodulation, by which the atmospheric nitrogen is converted into an assimilable plant nutrient. This capacity is the basis for the use of bacterial inoculants for field crop cultivation. Legume plants have acquired tools that allow the entry of compatible bacteria. Likewise, plants can impose sanctions against the maintenance of nodules occupied by rhizobia with low nitrogen-fixing capacity. At the same time, bacteria must overcome different obstacles posed first by the environment and then by the legume. The present review describes the mechanisms involved in the regulation of the entire legume-rhizobium symbiotic process and the strategies and tools of bacteria for reaching the nitrogen-fixing state inside the nodule. Also, we revised different approaches to improve the nodulation process for a better crop yield.

Effect of L-arginine supplementation in pregnant women with chronic hypertension and previous placenta vascular disorders receiving Aspirin prophylaxis: a randomized control trial.

BACKGROUND: The aim of the study is to evaluate the effects of supplementation with Arginine (L-Arg) 3g, (together with Magnesium (Mg) 350 mg and Salicilate (Sal) 100 mg) on maternal blood pressure (BP), uterine artery doppler PI and neonatal outcomes in women with high-risk pregnancy for chronic hypertension (CH) and other previous placenta vascular disorders (PVD) already treated with low dose of aspirin (LDA), as recommended by guidelines. METHODS: We enrolled women affected by CH and other previous PVD referred to the High-Risk Clinic of the Department of Maternal and Child's Health at the University Hospital of Modena and Reggio Emilia from September 2017 to June 2019. The study design was a controlled, randomized trial of oral supplementation of L-Arg 3g (together with Mg 350 mg and Sal extract 100 mg) + LDA 100 mg/day versus only LDA 100 mg/day. Inclusion criteria were: singleton pregnancy; diagnosis of chronic hypertension, previous preeclampsia <34 weeks, previous intrauterine growth restriction (IUGR) <10th centile or previous stillbirth (SB) related to placenta vascular disorders; gestational age <14 weeks. Each woman was enrolled between 12-14 weeks gestation and underwent 24-hour ambulatory BP monitoring with an automatic device (SpaceLab 92710, Critikon, WA), repeated at 18-20th and 24-26th weeks. Moreover Uterine artery Doppler ultrasound evaluation including PI were performed at 18-20 weeks gestation and repeated at 24-26th weeks. Pregnancy outcomes data were collected in a password protected database. RESULTS: Seventy-nine women agreed to participate in the study. No significant differences between the demographic characteristics in the two groups were found at enrolment (Group LDA + L-Arg: 30 patients versus Group LDA: 49 patients). In the LDA-L-Arg group there is no significant increase in both systolic (127.22±12.02 and 132.75±7.51 mmHg, P=0.002) and diastolic (75.85±8.53 and 83.63±6.05 mmHg, P=0.0000) BP values at 24-26 weeks reveled in the LDA group. The value of the uterine artery Doppler median PI>95th centile at 24-26 weeks show a significant reduction in the LDA+L-Arg group respect the LDA group (seven women, 23.3% vs. 21 women, 42.9%; P=0.04). A significantly lower percentage of women received new antihypertensive drugs in the LDA+ L-Arg group than the LDA group (6.7% vs. 24.5%) (P=0.02). There was neither statistically significant difference in perinatal outcomes between the two groups, except for trend of significance. CONCLUSIONS: Although we found only trends of improvements of perinatal outcomes in LDA+L-Arg group, considering the promising results on BP values, uterine artery PI and the low need to start a new antihypertensive treatment, thus the resulting impact in reducing pregnancy medicalization, number of maternal-fetal well-being monitoring visits and the need of induction of labor, we believe that further studies should be performed to enlarge our observation and clarify the role of L-Arg 3g supplementation as a protective integration in high-risk pregnancies already in prophylaxis with LDA.

Management of suspected COVID-19 patients in a low prevalence region.

The spread of the SARS-CoV-2 infection among population has imposed a re-organization of healthcare services, aiming at stratifying patients and dedicating specific areas where patients with suspected COVID-related respiratory disease could receive the necessary health care assistance while waiting for the confirmation of the diagnosis of COVID-19 disease. In this scenario, the pathway defined as a "grey zone" is strongly advocated. We describe the application of rules and pathways in a regional context with low diffusion of the infection among the general population in the attempt to provide the best care to respiratory patients with suspected COVID-19. To date, this process has avoided the worst-case scenario of intra-hospital epidemic outbreak.

Urinary Incontinence in Chronic Obstructive Pulmonary Disease: A Common Co-morbidity or a Typical Adverse Effect?

Urinary incontinence (UI) is defined as a loss of bladder control and is characterized by the complaint of any involuntary leakage of urine. Evidence suggests that the prevalence of UI is higher in subjects with chronic obstructive pulmonary disease (COPD) than in age-matched controls in both sexes. UI is classified as stress, urge, and mixed, and has a considerable impact on quality of life. However, the prevalence of UI in individuals with COPD is mostly unexplored in clinical research and often underestimated in clinical practice. Interestingly, although the involuntary leakage of a small amount of urine during coughing (e.g., stress UI) is among the most plausible causes of UI in patients with COPD, its importance has been questioned by some researchers. Moreover, UI as a respiratory drug-related adverse effect is largely overlooked; only a few randomized controlled trials have reported the presence of urinary symptoms, mainly as urinary retention due to anticholinergic agents. In this narrative review, we explored whether, and to what extent, UI occurs in COPD individuals, and what the proposed actions to improve this condition are. We found that the association between UI and COPD is largely unexplored, mostly because UI tends to be attributed to older age. We infer that the prevalence of UI in individuals with chronic respiratory symptoms is often underestimated in clinical practice. The misinterpretation of urinary symptoms as related to the respiratory condition can delay diagnostic and therapeutic approaches. The use of simple self-administered questionnaires to assess the presence of UI is encouraged.

Two Rieske Fe/S Proteins and TAT System in Mesorhizobium loti MAFF303099: Differential Regulation and Roles on Nodulation.

Mesorhizobium loti MAFF303099 is a rhizobial strain that nodulates Lotus spp. A M. loti MAFF303099 mutant strain affected in the tatC gene was generated. This strain presented an altered protein secretion level to the culture supernatant and also a higher sensitivity to SDS. Its nodulation phenotype on Lotus showed the induction of small and colorless nodules, and in a larger number than those induced by the wild-type strain. In addition, these nodules presented defects in the degree of occupation by rhizobia. Two Rieske Fe/S proteins, encoded by the mll2707 and mlr0970 genes, were predicted as potential Tat substrates in M. loti MAFF303099. The transcriptional expression of mll2707 and mlr0970 genes was analyzed under different oxygen growth conditions. The mll2707 gene was expressed constitutively, while the expression of the mlr0970 gene was only detected under anaerobic and microaerophilic in vitro conditions. Both genes were down-regulated in the tatC mutant strain. mll2707 and mlr0970 mRNAs from the wild-type strain were detected in nodules. Using a translational reporter peptide fusion, we found that the Mll2707 protein was only detectable in the wild-type strain. On the other hand, although Mlr0970 protein was detected in wild-type and tatC mutant strains, its association with the membrane was favored in the wild-type strain. The tatC and the mll2707 mutant strains were affected in the cytochrome c oxidase activity. These results confirm that Mll2707 is required for cytochrome c-dependent respiration and that Tat functionality is required for the correct activity of Mll2707. The mll2707 mutant strain showed a nodulation phenotype similar to the tatC mutant strain, although it presented only a slight difference in comparison with wild-type strain in terms of nodule occupation. No defective phenotype was observed in the nodulation with the mlr0970 mutant strain. These results indicate that, of the two Rieske Fe/S proteins coded by M. loti MAFF303099, only Mll2707 expression is required for the induction of effective nodules, and that the functionality of the Tat system is necessary not only for the correct function of this protein, but also for some other protein required in an earlier stage of the nodulation process.

The transcriptional factor TtsI is involved in a negative regulation of swimming motility in Mesorhizobium loti MAFF303099.

Mesorhizobium loti MAFF303099 has a functional Type III secretion system (T3SS) that is involved in the determination of competitiveness for legume nodulation. Here we demonstrate that the transcriptional factor TtsI, which positively regulates T3SS genes expression, is involved in a negative regulation of M. loti swimming motility in soft-agar. Conditions that induce T3SS expression affect flagella production. The same conditions also affect promoter activity of M. loti visN gene, a homolog to the positive regulator of flagellar genes that has been described in other rhizobia. Defects in T3SS complex assembly at membranes limited the negative regulation of motility by the expression of TtsI.

Maintenance of phenol hydroxylase genotypes at high diversity in bioreactors exposed to step increases in phenol loading.

To better understand how the composition of bacterial communities changes in response to different environmental conditions, we examined the influence of increasing phenol load on the distribution of the protein-coding functional gene of the largest subunit of phenol hydroxylase (LmPH) and of the 16S rRNA gene in lab-scale activated sludge reactors. LmPH diversity was assessed initially from a total of 124 clone sequences retrieved from two reactors exposed to a low (0.25 g L(-1)) and a high (2.5 g L(-1)) phenol concentration. The quantitative changes in the concentration of the eight detected genotypes accompanied changes in the phenol degradation rates, indicating a community structure-function relationship. Nonmetric dimensional analysis showed that LmPH genotypes and the denaturing gradient gel electrophoresis banding patterns clustered together by phenol concentration, rather than by reactor identity. Seven isolates, representing cultivated strains of each of the observed LmPH genotypes, exhibited a rather narrow range of physiological diversity, in terms of the growth rate and the kinetic parameters of the phenol-degrading activity. We suggest that lab-scale reactors support many ecological niches, which allow the maintenance of a high diversity of ecotypes through varying concentrations of phenol, but the ability of particular strains to become dominant members of the community under the different environmental conditions cannot be predicted easily solely from their phenol-degrading properties.

Intestinal permeability in preterm infants by feeding type: mother's milk versus formula.

BACKGROUND AND OBJECTIVE: Intestinal permeability in preterm infants represents a critical balance between absorption of nutritional agents and protection from dangerous pathogens. This study identified the relationship between feeding type (human milk and formula) and intestinal permeability as measured by lactulose to mannitol ratio in preterm infants in the first postnatal month. STUDY DESIGN: Sixty-two preterm (75%) demonstrated significantly lower intestinal permeability when compared to infants receiving minimal or no human milk (<25% or none) at postnatal days 7, 14, and 30 (p = 0.02, 0.02, and 0.047, respectively). When infants receiving any human milk were compared to infants receiving formula only, a significant difference existed at day 7 and day 14 but not for day 30 (p = 0.04, 0.02, and 0.15, respectively). With evaluation over the complete study period, exclusively formula-fed infants demonstrated a 2.8-fold higher composite median lactulose/mannitol ratio when compared with those who received any human milk. Infants who received >75% of enteral feeding as mother's milk demonstrated a 3.8-fold lower composite median ratio when compared to infants receiving <25% or no mother's milk. CONCLUSION: Preterm infant intestinal permeability was significantly decreased for those receiving human milk versus formula in a dose-related manner in the first postnatal month.

Quantitative assessment of phenol hydroxylase diversity in bioreactors using a functional gene analysis.

We describe a quantitative analysis of the genetic diversity of phenol-degrading potential in bacterial communities from laboratory-scale activated sludge. Genomic DNA extracted from activated sludge from two sequential batch reactors fed with synthetic sewage plus phenol was amplified using conserved primers for the major subunit of the phenol hydroxylase (LmPH) gene and used to generate clone libraries. Following phylogenetic analysis, 59 sequences containing a 470-bp fragment clustered into six distinct subgroups with a genetic distance of 8%, most likely representing ecologically relevant variants of the enzyme. Seven sets of primers were designed to target the six clusters and used to obtain quantitative information on the dynamics of LmPH gene diversity using real-time PCR assays throughout 9 months of bioreactors operation. Total LmPH gene copy number remained approximately steady in phenol-amended and control reactors. However, a significant increase in phenol-degrading activity in the phenol-amended sludge was accompanied by a parallel increase in LmPH gene diversity, suggesting that phenol degradation in the activated sludge depends on the combined activity of a number of redundant species.

Impact of non-ionic surfactant on the long-term development of lab-scale-activated sludge bacterial communities.

The development of bacterial communities in replicate lab-scale-activated sludge reactors degrading a non-ionic surfactant was evaluated by statistical analysis of denaturing gradient gel electrophoresis (DGGE) fingerprints. Four sequential batch reactors were fed with synthetic sewage, two of which received, in addition, 0.01% of nonylphenol ethoxylates (NPE). The dynamic character of bacterial community structure was confirmed by the differences in species composition among replicate reactors. Measurement of similarities between reactors was obtained by pairwise similarity analysis using the Bray Curtis coefficient. The group of NPE-amended reactors exhibited the highest similarity values (Sjk=0.53+/-0.03), indicating that the bacterial community structure of NPE-amended reactors was better replicated than control reactors (Sjk=0.36+/-0.04). Replicate NPE-amended reactors taken at different times of operation clustered together, whereas analogous relations within the control reactor cluster were not observed. The DGGE pattern of isolates grown in conditioned media prepared with media taken at the end of the aeration cycle grouped separately from other conditioned and synthetic media regardless of the carbon source amendment, suggesting that NPE degradation residuals could have a role in the shaping of the community structure.

The effect of high-dose vitamin D supplementation on serum vitamin D levels and milk calcium concentration in lactating women and their infants.

OBJECTIVE: Improve vitamin D status in lactating women and their recipient infants, and measure breast milk calcium concentration [Ca] as a function of vitamin D regimen. DESIGN/METHODS: Fully breastfeeding mothers were randomized at 1 month postpartum to 2000 (n = 12) or 4000 (n = 13) IU/day vitamin D for 3 months to achieve optimal vitamin D status [serum 25(OH)D > or =32 ng/mL (80 nmol/L)]. Breast milk [Ca], maternal and infant serum 25(OH)D and serum Ca, and maternal urinary Ca/Cr ratio were measured monthly. RESULTS: Mothers were similar between groups for age, race, gestation, and birth weight. 25(OH)D increased from 1 to 4 months in both groups (mean +/- SD): +11.5 +/- 2.3 ng/mL for group 2000 (p = 0.002) and +14.4 +/- 3.0 ng/mL for group 4000 (p = 0.0008). The 4000 IU/day regimen was more effective in raising both maternal and infant serum levels and breast milk antirachitic activity than the 2000 IU/day regimen. Breast milk [Ca] fell with continued lactation through 4 months in the 2000 and 4000 IU groups. Decline in breast milk [Ca] was not associated with vitamin D dose (p = 0.73) or maternal 25(OH)D (p = 0.94). No mother or infant experienced vitamin D-related adverse events, and all laboratory parameters remained in the normal range. CONCLUSION: High-dose vitamin D was effective in increasing 25(OH)D levels in fully breastfeeding mothers to optimal levels without evidence of toxicity. Breast milk [Ca] and its decline in both groups during 1 to 4 months were independent of maternal vitamin D status and regimen. Both the mother and her infant attained improved vitamin D status and maintained normal [Ca].

Emisiones otoacústicas en recién nacidos con factores de riesgo auditivo / Otoacoustic emissions in newborns with auditory risk factors

La hipoacusia es un problema de gran importancia en la infancia por las consecuencias que puede tener en el desarrollo intelectual y social del niño si no es identificada y tratada en forma temprana. Se han identificado factores de riesgo para su aparición vinculados al embarazo y a la etapa neonatal. Se presentan los resultados de un trabajo realizado en el Centro Hospitalario Pereira Rossell en recién nacidos durante un período de seis meses. Se destaca la elevada prevalencia de factores de riesgo (8 por ciento) en la población estudiada, coexistiendo varios de ellos en los casos estudiados. Se encuentran emisiones otoacústicas alteradas en un alto porcentaje de la población con factores de riesgo (24 por ciento). Se propone un protocolo de estudio para los recién nacidos con factores de riesgo.