Microscopical anatomy of the peripheral nervous system: An essential notion for understanding the pathophysiology of very early classic Guillain-Barré syndrome.

The aim of this paper is to analyze the pathophysiological mechanisms acting in very early classic Guillain-Barré syndrome (GBS) (≤4 days of symptomatic onset). In this inaugural period, both in GBS and its animal model, experimental autoimmune neuritis, the outstanding pathological feature is inflammatory edema predominating in proximal nerve trunks, particularly spinal nerves, and possibly in preterminal nerve segments. Nerve trunks external to the subarachnoid angle possess epi- perineurium that is relatively inelastic and of low compliance. Here such edema can increase endoneurial fluid pressure that, when sufficiently critical, may stretch the perineurium and constrict transperineurial microcirculation, compromising blood flow and producing the potential for ischemic nerve injury, whose consequence is rapid partial or complete loss of nerve excitability. These histopathological features correlate well with electrophysiological and imaging findings reported in early GBS stages. Spinal nerve edema and ischemia help to understand the pattern of Wallerian-like degeneration observed in the axonal form of GBS, predominating in motor spinal roots at their exit from the dura matter (spinal nerves) with centrifugal distribution in more distant motor nerve trunks, and centripetal extension to the distal portion of intrathecal roots. The similarity of initial pathogenic mechanisms between demyelinating and axonal forms of GBS explains why an early increase of serum biomarkers of axonal damage is detected in both forms. In conclusion, knowledge of the microscopic anatomy of the peripheral nervous system is an essential step for a reliable understanding of pathophysiological mechanisms operating in the early phase of any classic GBS subtype.

Unraveling Complexity: Acute Intermittent Porphyria Complicated by Rhabdomyolysis and Acute Pancreatitis.

Acute intermittent porphyria (AIP) is a rare autosomal dominant disorder characterized by defective porphyrin metabolism in the blood. It manifests through variable clinical features, among these are abdominal pain, nausea, vomiting, peripheral neuropathy, and seizure. The diverse presentation of AIP poses substantial diagnostic challenges due to its potential to mimic other medical conditions, delaying early recognition and intervention. Management strategies of AIP involve a multifaceted approach, focusing on symptom relief and attack cessation. Early recognition and intervention are pivotal in optimizing patient outcomes, highlighting the importance of heightened clinical suspicion and precise diagnostic pathways. We present a unique case of a 34-year-old female who presented to the emergency department with severe abdominal pain, oliguria, and progressive sensory and motor deficits. Despite exhibiting hallmark symptoms suggestive of AIP, the absence of distinctive "attack periods" added complexity to the diagnostic process, requiring the exclusion of other medical conditions with similar overlapping symptoms.

Molecular Basis of Antimicrobial Resistance in Group B Streptococcus Clinical Isolates from Saudi Arabia.

Published data on the molecular mechanisms underlying antimicrobial resistance in Group B Streptococcus (GBS) isolates from Saudi Arabia are lacking. Here, we aimed to determine the genetic basis of resistance to relevant antibiotics in a collection of GBS clinical isolates (n = 204) recovered from colonized adults or infected patients and expressing serotypes Ia, Ib, II, III, V, and VI. Initial susceptibility testing revealed resistance to tetracycline (76.47%, n = 156/204), erythromycin (36.76%, n = 75/204), clindamycin (25.49%, n = 52/204), levofloxacin (6.37%, n = 13/204), and gentamicin (2.45%, n = 5/204). Primers designed for the detection of known resistance determinants in GBS identified the presence of erm(A), erm(B), mef(A), and/or lsa(C) genes at the origin of resistance to macrolides and/or clindamycin. Of these, erm(B) and erm(A) were associated with the cMLSB (n = 46) and iMLSB (n = 28) phenotypes, respectively, while mef(A) was linked to the M phenotype (n = 1) and lsa(C) was present in isolates with the L phenotype (n = 8). Resistance to tetracycline was mainly mediated by tet(M) alone (n = 112) or in combination with tet(O) (n = 10); the remaining isolates carried tet(O) (n = 29), tet(L) (n = 2), or both (n = 3). Isolates resistant to gentamicin (n = 5) carried aac(6')-Ie-aph(2')-Ia, and those exhibiting resistance to levofloxacin (n = 13) had alterations in GyrA and/or ParC. Most isolates with the erm gene (93.24%, n = 69/74) also had the tet gene and were therefore resistant to erythromycin, clindamycin, and tetracycline. Overall, there were no clear associations between serotypes and resistance genotypes except for the presence of erm(B) in serotype Ib isolates. Dissemination of antibiotic resistance genes across different serotypes represents a public health concern that requires further surveillance and appropriate antibiotic use in clinical practice.

Exploring the "Two-Hit" Phenomenon of Guillain-Barré Syndrome Following Respiratory Syncytial Virus and Influenza Vaccinations.

Guillain-Barré syndrome (GBS) is a neurological disorder characterized by peripheral, autoimmune-mediated demyelinating polyneuropathy, which can cause muscle weakness and paralysis. While most cases are triggered by respiratory or gastrointestinal infections, vaccinations have also been linked to GBS pathogenesis. The association of the influenza vaccine and GBS, notably prevalent during the 1976 United States swine flu pandemic, has significantly decreased with contemporary seasonal influenza vaccines. At the same time, cases of GBS have been reported with newer vaccines, like the recently approved respiratory syncytial virus (RSV) vaccines. However, their exact relationship with autoimmune demyelinating polyneuropathy remains unknown. In this report, we present a case of a 60-year-old man who developed GBS two weeks after receiving the new Pfizer's RSV vaccine in conjunction with the influenza vaccine for the first time.

A Neuropathy Mimic: Statin-Induced Myopathy Presenting as Guillain-Barré Syndrome.

Statins are widely used to manage dyslipidemia and prevent cardiovascular diseases due to their effectiveness and general safety profile. However, they can sometimes cause severe muscle-related adverse effects, presenting diagnostic challenges when symptoms overlap with other conditions. This case report describes a middle-aged woman who presented to the emergency department with bilateral lower limb weakness, initially suggesting Guillain-Barré syndrome (GBS). Despite her history of low-grade fever and diarrhea, primary and secondary surveys, including electrocardiogram, blood gas analysis, and nerve conduction studies, showed no definitive signs of GBS. The patient had a recent history of percutaneous transluminal coronary angioplasty and was on dual antiplatelet therapy and rosuvastatin. Elevated creatine kinase levels and exclusion of other differential diagnoses led to the diagnosis of statin-induced myopathy, a rare but severe adverse effect of statins. The patient was treated with intravenous fluids, cessation of statins, and sessions of hemodialysis and plasmapheresis, resulting in significant improvement and eventual recovery of muscle power and neurological function. This case highlights the importance of recognizing statin-induced myopathy in patients with muscle weakness and emphasizes the need for thorough clinical evaluation to differentiate it from other conditions such as GBS. Further research is warranted to understand the pathophysiology of statin myopathy and identify at-risk populations.

Maternal Streptococcus agalactiae colonization in Europe: data from the multi-center DEVANI study.

INTRODUCTION: Despite national guidelines and use of intrapartum antibiotic prophylaxis (IAP), Streptococcus agalactiae (group B streptococci (GBS)) is still a leading cause of morbidity and mortality in newborns in Europe and the United States. The European DEVANI (Design of a Vaccine Against Neonatal Infections) program assessed the neonatal GBS infection burden in Europe, the clinical characteristics of colonized women and microbiological data of GBS strains in colonized women and their infants with early-onset disease (EOD). METHODS: Overall, 1083 pregnant women with a GBS-positive culture result from eight European countries were included in the study. Clinical obstetrical information was collected by a standardized questionnaire. GBS strains were characterized by serological and molecular methods. RESULTS: Among GBS carriers included in this study after testing positive for GBS by vaginal or recto-vaginal sampling, 13.4% had at least one additional obstetrical risk factor for EOD. The five most common capsular types (i.e., Ia, Ib, II, III and V) comprised ~ 93% of GBS carried. Of the colonized women, 77.8% received any IAP, and in 49.5% the IAP was considered appropriate. In our cohort, nine neonates presented with GBS early-onset disease (EOD) with significant regional heterogeneity. CONCLUSIONS: Screening methods and IAP rates need to be harmonized across Europe in order to reduce the rates of EOD. The epidemiological data from eight different European countries provides important information for the development of a successful GBS vaccine.

Unilateral Vocal Cord Paralysis in a Patient with Anti-Galactocerebroside Antibodies: A Case Report.

Anti-galactocerebroside (Gal-C) antibodies are present in patients with conditions such as Guillain-Barré syndrome and mycoplasma pneumonia. We report a rare case of left vocal cord paralysis in a patient with anti-Gal-C IgG antibodies that improved after administeration of antivirals and steroids.

Genome-Wide Association Studies and QTL Mapping Reveal a New Locus Associated with Resistance to Bacterial Pustule Caused by Xanthomonas citri pv. glycines in Soybean.

Bacterial pustule (BP), caused by Xanthomonas citri pv. glycines, is an important disease that, under favorable conditions, can drastically affect soybean production. We performed a genome-wide association study (GWAS) with a panel containing Brazilian and American cultivars, which were screened qualitatively and quantitatively against two Brazilian X. citri isolates (IBS 333 and IBS 327). The panel was genotyped using a genotyping by sequencing (GBS) approach, and we identified two main new regions in soybeans associated with X. citri resistance on chromosomes 6 (IBS 333) and 18 (IBS 327), different from the traditional rxp gene located on chromosome 17. The region on chromosome 6 was also detected by QTL mapping using a biparental cross between Williams 82 (R) and PI 416937 (S), showing that Williams 82 has another recessive resistance gene besides rxp, which was also detected in nine BP-resistant ancestors of the Brazilian cultivars (including CNS, S-100), based on haplotype analysis. Furthermore, we identified additional SNPs in strong LD (0.8) with peak SNPs by exploring variation available in WGS (whole genome sequencing) data among 31 soybean accessions. In these regions in strong LD, two candidate resistance genes were identified (Glyma.06g311000 and Glyma.18g025100) for chromosomes 6 and 18, respectively. Therefore, our results allowed the identification of new chromosomal regions in soybeans associated with BP disease, which could be useful for marker-assisted selection and will enable a reduction in time and cost for the development of resistant cultivars.

Group B streptococcus colonization in pregnancy and neonatal outcomes: a three-year monocentric retrospective study during and after the COVID-19 pandemic.

BACKGROUND: Group B Streptococcus (GBS) is a major cause of sepsis and meningitis in newborns. The Centers for Disease Control and Prevention (CDC) recommends to pregnant women, between 35 and 37 weeks of gestation, universal vaginal-rectal screening for GBS colonization, aimed at intrapartum antibiotic prophylaxis (IAP). The latter is the only currently available and highly effective method against early onset GBS neonatal infections. Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, the preventive measures implemented to mitigate the effects of SARS-CoV-2 infection led to the reduction in the access to many health facilities and services, including the obstetric and perinatal ones. The purpose of the present study was to evaluate the prevalence of maternal GBS colonization, as well as use of IAP and incidence of episodes of neonatal GBS infection when antibiotic prophylaxis has not been carried out in colonized and/or at risk subjects, in a population of pregnant women during (years 2020-2021) and after (year 2022) the COVID-19 pandemic, also with the aim to establish possible epidemiological and clinical differences in the two subjects' groups. METHODS: We retrospectively analyzed the clinical data of pregnant women admitted to, and delivering, at the Gynaecology and Obstetrics Unit, Department of Sciences for Health Promotion and Mother and Child Care, of the University Hospital of Palermo, Italy, from 01.01.2020 to 31.12.2022. For each of them, we recorded pertinent socio-demographic information, clinical data related to pregnancy, delivery and peripartum, and specifically execution and status of vaginal and rectal swab test for GBS detection, along with eventual administration and modality of IAP. The neonatal outcome was investigated in all cases at risk (positive maternal swabs status for GBS, either vaginal or rectal, with or without/incomplete IAP, preterm labor and/or delivery, premature rupture of membranes ≥ 18 h, previous pregnancy ended with neonatal early onset GBS disease [EOD], urine culture positive for GBS in any trimester of current gestation, intrapartum temperature ≥ 38 °C and/or any clinical/laboratory signs of suspected chorioamnionitis). The data concerning mothers and neonates at risk, observed during the pandemic (years 2020-2021), were compared with those of both subjects' groups with overlapping risk factors recorded in the following period (year 2022). The chi squared test has been applied in order to find out the relationship between pregnant women with GBS colonization receiving IAP and outcome of their neonates. RESULTS: The total source population of the study consisted of 2109 pregnant women, in addition to their 2144 newborns. Our analysis, however, focused on women and neonates with risk factors. The vaginal-rectal swab for GBS was performed in 1559 (73.92%) individuals. The test resulted positive in 178 cases overall (11.42% of those undergoing the screening). Amongst our whole sample of 2109 subjects, 298 women had an indication for IAP (vaginal and/or rectal GBS colonization, previous pregnancy ended with neonatal GBS EOD, urine culture positive for GBS in any trimester of current gestation, and unknown GBS status at labor onset with at least any among delivery at < 37 weeks' gestation, amniotic membranes rupture ≥ 18 h and/or intrapartum temperature ≥ 38.0 °C), and 64 (21.48%) received adequate treatment; for 23 (7.72%) it was inadequate/incomplete, while 211 (70.8%) did not receive IAP despite maternal GBS colonization and/or the presence of any of the above mentioned risk factors. Comparing the frequency of performing vaginal-rectal swabs in the women admitted in the two time periods, the quote of those screened out of the total in the pandemic period (years 2020-2021) was higher than that of those undergoing GBS screening out of the total admitted in the year 2022 (75.65% vs. 70.38%, p = 0.009), while a greater number (not statistically significant, p = 0.12) of adequate and complete IAP was conducted in 2022, than in the previous biennium (26.36 vs. 18.62%). During the whole 3 years study period, as expected, none of the newborns of mothers with GBS colonization and/or risk factors receiving IAP developed EOD. Conversely, 13 neonates with EOD, out of 179 (7.3%) born to mothers with risk factors, were observed: 3 among these patients' mothers performed incomplete IAP, while the other 10 did not receive IAP. Neither cases of neonatal meningitis, nor deaths were observed. The incidence rate in the full triennium under investigation, estimated as the ratio between the number of babies developing the disease out of the total of 2144 newborns, was 6.06‰; among those born to mothers with risk factors, if comparing the two time periods, the incidence was 8.06% in the pandemic biennium, while 5.45% in the following year, evidencing thus no statistical significance (p = 0.53). CONCLUSIONS: The present study revealed in our Department an increased prevalence of pregnant women screened for, and colonized by GBS, in the last decade. However, an overall still low frequency of vaginal-rectal swabs performed for GBS, and low number of adequate and complete IAP despite the presence of risk factors have been found, which did not notably change during the two time periods. Moreover, significant EOD incidence rates have been reported among children of mothers carrying risk factors, although also in this case no statistically significant differences have been observed during and after the pandemic. Such data seem to be in contrast to those reported during the COVID-19, showing a decrease in the access to health facilities and increased mortality/morbidity rates also due to the restrictive measures adopted to mitigate the effects of the pandemic. These findings might be explained by the presence within the same metropolitan area of our Department of a COVID hospital and birthing center, which all the patients with SARS-CoV-2 infection referred to, and likely leading to a weaker concern of getting sick perceived by our patients. Although IAP is an easy procedure to implement, however adherence and uniformity in the management protocols are still not optimal. Therefore, the prophylactic measures adopted to date cannot be considered fully satisfactory, and should be improved. Better skills integration and obstetrical-neonatological collaboration, in addition to new effective preventive tools, like vaccines able to prevent invasive disease, may allow further reduction in morbidity and mortality rates related to GBS perinatal infection.

Complex Neurological Sequelae: Axonal Guillain-Barré Syndrome Post COVID-19 in a Young Patient.

Guillain-Barré syndrome (GBS) encompasses a spectrum of immune-mediated neuropathies, with axonal GBS representing a less common yet often severe subtype. This variant directly damages peripheral nerve axons, resulting in rapid and profound muscle weakness and sensory deficits. Axonal GBS has similar clinical features to the demyelinating form but is generally more severe with a less favorable prognosis. Here, we present a case of axonal GBS in a 46-year-old female following a mild COVID-19 infection, highlighting the diagnostic challenges and the importance of tailored therapeutic approaches and multidisciplinary care in managing this condition.

Group B Streptococcus Infections in Non-Pregnant Adults, Italy, 2015-2019.

Group B Streptococcus (GBS, Streptococcus agalactiae) is a pathogen of increasing importance in adults. Severe and invasive cases in non-pregnant adults were collected during the period 2015-2019 by voluntary-based surveillance. In total, 108 GBS strains were phenotypically and genotypically characterized for the serotype, antimicrobial resistance, pili, surface protein genes, and the hyper-virulent adhesin hvgA. Patients were divided into two age groups: adults (18-64 years; n = 32) and older adults (≥65 years; n = 72). The average age was 70.8 years, with a male/female ratio of 1.7. Most isolates were recovered from cases of bacteremia (blood, n = 93), and a higher frequency of invasive GBS infections (iGBS) was found among older adults (66.7%). Serotype III was the most frequent (n = 41, 38%), followed by type Ia and type V (n = 20 each, 18.5%). Serotypes Ia, Ib, II, III, IV, and V accounted for all but one isolates (99.1%). The iGBS isolates were universally susceptible to penicillin, while the prevalence of resistance to clindamycin, erythromycin, tetracycline, and high-level gentamicin resistance was 26.8%, 24.1%, 85.2%, and 5.5%, respectively, with the predominance of the erm(B) gene for macrolide resistance and the tet(M) gene for tetracycline resistance. The associations between the serotypes/antimicrobial resistance/virulence traits underlined the increasing importance of serotype III and its contribution to antimicrobial resistance as well as the steady increase over time of serotype IV. This nationwide study confirmed the need for monitoring the GBS epidemiology in non-pregnant adults through continuous surveillance of GBS infections.

Genome-Wide Analysis of Fruit Color and Carotenoid Content in Capsicum Core Collection.

This study investigated carotenoid content and fruit color variation in 306 pepper accessions from diverse Capsicum species. Red-fruited accessions were predominant (245 accessions), followed by orange (35) and yellow (20). Carotenoid profiles varied significantly across accessions, with capsanthin showing the highest mean concentration (239.12 µg/g), followed by ß-cryptoxanthin (63.70 µg/g) and zeaxanthin (63.25 µg/g). Total carotenoid content ranged from 7.09 to 2566.67 µg/g, emphasizing the diversity within the dataset. Correlation analysis revealed complex relationships between carotenoids, with strong positive correlations observed between total carotenoids and capsanthin (r = 0.94 ***), ß-cryptoxanthin (r = 0.87 ***), and zeaxanthin (r = 0.84 ***). Principal component analysis (PCA) identified two distinct carotenoid groups, accounting for 67.6% of the total variance. A genome-wide association study (GWAS) identified 91 significant single nucleotide polymorphisms (SNPs) associated with fruit color (15 SNPs) and carotenoid content (76 SNPs). These SNPs were distributed across all chromosomes, with varying numbers on each. Among individual carotenoids, α-carotene was associated with 28 SNPs, while other carotenoids showed different numbers of associated SNPs. Candidate genes encoding diverse proteins were identified near significant SNPs, potentially contributing to fruit color variation and carotenoid accumulation. These included pentatricopeptide repeat-containing proteins, mitochondrial proton/calcium exchangers, E3 ubiquitin-protein ligase SINAT2, histone-lysine N-methyltransferase, sucrose synthase, and various enzymes involved in metabolic processes. Seven SNPs exhibited pleiotropic effects on multiple carotenoids, particularly ß-cryptoxanthin and capsanthin. The findings of this study provide insights into the genetic architecture of carotenoid biosynthesis and fruit color in peppers, offering valuable resources for targeted breeding programs aimed at enhancing the nutritional and sensory attributes of pepper varieties.

SeqSNP-Based Targeted GBS Provides Insight into the Genetic Relationships among Global Collections of Brassica rapa ssp. oleifera (Turnip Rape).

Turnip rape is a multi-purpose crop cultivated in temperate regions. Due to its ability to fit into crop rotation systems and its role as a food and feed source, spring-type turnip rape cultivation is on the rise. To improve the crop's productivity and nutritional value, it is essential to understand its genetic diversity. In this study, 188 spring-type accessions were genotyped using SeqSNP, a targeted genotyping-by-sequencing method to determine genetic relationships between various groups and assess the potential effects of mutations within genes regulating major desirable traits. Single nucleotide polymorphism (SNP) alleles at six loci were predicted to have high effects on their corresponding genes' functions, whereas nine loci had country/region-specific alleles. A neighbor-joining cluster analysis revealed three major clusters (I to III). About 72% of cluster-I accessions were of Asian origin, whereas 88.5% of European accessions and all North American accessions were placed in cluster-II or cluster-III. A principal coordinate analysis explained 65.3% of the total genetic variation. An analysis of molecular variance revealed significant differentiation among different groups of accessions. Compared to Asian cultivars, European and North American cultivars share more genetic similarities. Hence, crossbreeding Asian and European cultivars may result in improved cultivars due to desirable allele recombination. Compared to landraces and wild populations, the cultivars had more genetic variation, indicating that breeding had not caused genetic erosion. There were no significant differences between Swedish turnip rape cultivars and the NordGen collection. Hence, crossbreeding with genetically distinct cultivars could enhance the gene pool's genetic diversity and facilitate superior cultivar development.

Neurolymphomatosis mimicking a Guillain-Barré syndrome triggered by COVID-19 vaccination.

Guillain-Barré syndrome (GBS) is an acute disorder of the peripheral nervous system, causing flaccid paralysis, areflexia, and variable sensory involvement. Proximal as well distal muscles of the limbs can be involved, and in most severe and advanced cases progresses to respiratory failure and death. GBS is considered an autoimmune disease, and at the basis of the attack at the peripheral nervous system different mechanisms have been recognized, in particular viral infections or other immune stimulations. Cranial nerve involvement in patients with diffuse large B-cell lymphoma (DLBCL) and primary central nervous system lymphoma are rare conditions that could present with similar clinical features. Here we present a case of a 36-year-old man hospitalized for acute polyradiculoneuritis of the cranial nerves and lumbar roots that arose a 14 days after severe acute respiratory syndrome COVID-19 2 (Sars-CoV-2) vaccination. Most of the main criteria for the diagnosis of GBS were met, including clinical and electrophysiological criteria. Albuminocytologic dissociation and high protein level in cerebrospinal fluid were also found. Therefore, the patient was treated with a cycle of intravenous immunoglobulin (IVIG) with notable improvement of symptoms and gradual recovery of motility. A five months later, following SARS-CoV-2 infection, the patient presented with worsening of neurological symptoms and was readmitted to the hospital. He underwent instrumental tests again and was treated with repeated cycles of IVIG and then with a cycle of plasmapheresis without any improvement. In the following 10 days he developed very serious conditions; he was transferred to intensive care unit and deceased after 6 days. The cause of the neurological syndrome was determined only after autoptic analysis, which revealed the presence of primary peripheral nervous system (PNS) DLBCL. The reported case highlights that GBS-like presentation always requires a careful differential diagnosis, and physicians should also consider the possibility of an occult cancer.

Perovskite Crystallization Control for Large, Oriented Grains with Residual Solvent Restrain via Hydrogen-Bonded Organic Frameworks.

Void-free perovskite films with oriented large grains are considered good performance. However, contradictory requirements on solvent volatilization arise that the growth of large grains requires slow volatilization while the residual solvent problem, which leads to difficult-handled voids at buried interface, requires quick and complete volatilization. Currently, although grain boundary additives help reach large and oriented grains, the occupation of additives in the grain boundary volatilization channel may further deteriorate the residual solvent problem. Herein, porous structures with "switchable pore" nature are constructed based on flexible hydrogen-bonded (HOF-FJU-2) in perovskite grain boundaries to meet both contradictory requirements with achieving crystallization control and residual solvent restrain. The additive molecules prolongs the perovskite crystallization through the Pb-O bond and guides the growth of (100) facet based on its strong ordered accumulation trend. The pre-embedded porous structure opens up the solvent volatilization channel for complete volatilization in annealing stage and then switches to a closed pore state via phase transformation after the solvent completely leaves, preventing the intrusion of the external environment. Combined with theoretical calculations and in situ spectrum tests, the crystallization thermodynamics and dynamics are analyzed. As expected, the target device exhibits enhanced performance (improved from 22.14% to 24.18%) and stability.

Case Report: AMSAN variant of GBS complicating immediate postpartum period with severe dysautonomia leading to Posterior Reversible Encephalopathy Syndrome.

A 20's primiparous woman, following spontaneous expulsion of intrauterine death of the fetus at 30 weeks of gestation, presented on post-partum day 8 with acute onset flaccid quadriparesis and breathing difficulty, which had rapidly progressed to involve the legs on day 3 up to her upper limbs on post-partum day 5. Following examination, Guillain Barre Syndrome (GBS) with ascending diaphragmatic involvement was diagnosed, and plasma exchange was initiated. She developed raised blood pressure, headache, sudden onset visual loss with 2 episodes of generalized seizures on post-partum day 14. Brain MRI and clinical suspicion helped diagnose Posterior Reversible Encephalopathy Syndrome (PRES). The patient was treated with anticonvulsants and antihypertensive agents. She regained her vision over the next two days, completed the treatment for GBS, and made a good recovery with independence for advanced activities of daily living on follow-up.

Lipid lysination by MprF contributes to hemolytic pigment retention in group B Streptococcus.

Group B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis. A major virulence factor is a pigmented beta-haemolytic/cyto-lysin (ß-h/c) toxin with an ornithine rhamnolipid structure. We initially observed that absence of MprF enzyme altered pigmentation and haemolytic activity in GBS. Next, we showed that MprF-dependent lipid lysination contributes to the retention of the ornithine rhamnolipid within GBS membrane. Furthermore, cationic lipidation by MprF altered membrane properties contributing to resistance to the cyclic lipopeptide daptomycin and to acidic pH. This study highlights the importance of cationic lipids in cell envelope homeostasis and in modulating ß-h/c activity.

A group B streptococcal type VII-secreted LXG toxin mediates interbacterial competition and colonization of the murine female genital tract.

Group B Streptococcus (GBS) asymptomatically colonizes the vagina but can opportunistically ascend to the uterus and be transmitted vertically during pregnancy, resulting in neonatal pneumonia, bacteremia, and meningitis. GBS is a leading etiologic agent of neonatal infection and understanding the mechanisms by which GBS persists within the polymicrobial female genital mucosa has the potential to mitigate subsequent transmission and disease. Type VIIb secretion systems (T7SSb) are encoded by Bacillota and often mediate interbacterial competition using LXG toxins that contain conserved N-termini important for secretion and variable C-terminal toxin domains that confer diverse biochemical activities. Our recent work characterized a role for the GBS T7SSb in vaginal colonization and ascending infection but the mechanisms by which the T7SSb promotes GBS persistence in this polymicrobial niche remain unknown. Herein, we investigate the GBS T7SS in interbacterial competition and GBS niche establishment in the female genital tract. We demonstrate GBS T7SS-dependent inhibition of mucosal pathobiont Enterococcus faecalis both in vitro using predator-prey assays and in vivo in the murine genital tract and found that a GBS LXG protein encoded within the T7SS locus (herein named group B streptococcal LXG Toxin A) contributes to these phenotypes. We identify BltA as a T7SS substrate that is toxic to E. coli and S. aureus upon induction of intracellular expression along with associated chaperones. Finally, we show that BltA and its chaperones contribute to GBS vaginal colonization. Altogether, these data reveal a role for a novel T7b-secreted toxin in GBS mucosal persistence and competition.IMPORTANCECompetition between neighboring, non-kin bacteria is essential for microbial niche establishment in mucosal environments. Gram-positive bacteria encoding T7SSb have been shown to engage in competition through the export of LXG-motif-containing toxins, but these have not been characterized in group B Streptococcus (GBS), an opportunistic colonizer of the polymicrobial female genital tract. Here, we show a role for GBS T7SS in competition with mucosal pathobiont Enterococcus faecalis, both in vitro and in vivo. We further find that a GBS LXG protein contributing to this antagonism is exported by the T7SS and is intracellularly toxic to other bacteria; therefore, we have named this protein group B streptococcal LXG Toxin A (BltA). Finally, we show that BltA and its associated chaperones promote persistence within female genital tract tissues, in vivo. These data reveal previously unrecognized mechanisms by which GBS may compete with other mucosal opportunistic pathogens to persist within the female genital tract.

Vaccine patterns among older adults with Guillain-Barré syndrome and matched comparators, 2006-2019.

BACKGROUND: Some vaccines have a small risk of triggering Guillain-Barré syndrome (GBS), an autoimmune disorder where nerve damage leads to paralysis. There is a CDC precaution for patients whose GBS was associated with an influenza or tetanus toxoid-containing vaccine (GBS occurring within 42 days following vaccination). METHODS: We described vaccine patterns before and after a GBS diagnosis with a matched cohort design in a 20% random sample of fee-for-service Medicare enrollees. We defined the index date as an ICD-9-CM or ICD-10-CM GBS diagnosis code in the primary position of an inpatient claim. We matched each GBS patient to five non-GBS comparators on sex, exact age, racial and ethnic category, state of residence and the month of preventive health visits during baseline; used weighting to balance covariates; and measured frequency of vaccines received per 100 people during year before and after the index date using the weighted mean cumulative count (wMCC). RESULTS: We identified 1567 patients with a GBS diagnosis with at least 1 year of prior continuous enrollment in Medicare A and B that matched to five comparators each. The wMCCs in the 1 year before the index date were similar for both groups, with a wMCC of 74 vaccines/100 people in the GBS group (95% CI 71, 77). Within 1 year after the index date, patients with GBS had received 26 vaccines/100 people (95% CI 23, 28), which was 41 fewer vaccines than matched non-GBS comparators (95% CI -44, -38). Among GBS patients, 11% were diagnosed with GBS within 42 days after a vaccine. CONCLUSIONS: GBS diagnosis has a strong impact on reducing subsequent vaccination even though there is no warning or precaution about future vaccines for most patients diagnosed with GBS. These data suggest discordance between clinical practice and current vaccine recommendations.

The drought-induced plasticity of mineral nutrients contributes to drought tolerance discrimination in durum wheat.

Drought is a major challenge for the cultivation of durum wheat, a crucial crop for global food security. Plants respond to drought by adjusting their mineral nutrient profiles to cope with water scarcity, showing the importance of nutrient plasticity for plant acclimation and adaptation to diverse environments. Therefore, it is essential to understand the genetic basis of mineral nutrient profile plasticity in durum wheat under drought stress to select drought-tolerant varieties. The research study investigated the responses of different durum wheat genotypes to severe drought stress at the seedling stage. The study employed an ionomic, molecular, biochemical and physiological approach to shed light on distinct behaviors among different genotypes. The drought tolerance of SVEMS16, SVEVO, and BULEL was related to their capacity of maintaining or increasing nutrient's accumulation, while the limited nutrient acquisition capability of CRESO and S.CAP likely resulted in their susceptibility to drought. The study highlighted the importance of macronutrients such as SO42-, NO3-, PO43-, and K+ in stress resilience and identified variant-containing genes potentially influencing nutritional variations under drought. These findings provide valuable insights for further field studies to assess the drought tolerance of durum wheat genotypes across various growth stages, ultimately ensuring food security and sustainable production in the face of changing environmental conditions.