Post-COVID-19 neurocandidiasis.

Associated with a significant morbidity and mortality, neurocandidiasis affects severely immunocompromised patients, especially if recently treated with antibiotics or corticosteroids. We present the case of a 70-year-old man admitted to an intensive care unit due to a Sars-Cov-2 pneumonia, with fever, coma, and multifocal neurological deficits reported 13 days after extubation. After isolation of Candida albicans in both urine and blood cultures and a brain MRI with multiple gadolinium-enhanced ring lesions, a diagnosis of neurocandidiasis was assumed and aggressive antifungal therapy started. During treatment, the patient developed a hospital-acquired pneumonia with fatal outcome.

Depression after stroke.

Stroke treatment has dramatically improved in recent decades. However, although new treatments have reduced its mortality and the severity of its physical and cognitive sequelae, many people still have incapacitating disabilities following a stroke. Depression is the most common psychiatric disorder following stroke; it is important to recognise and treat as it limits motor and cognitive rehabilitation. Antidepressant medication is an effective treatment and can improve adherence to clinically recommended physical and cognitive tasks, thereby enhancing functional remodelling of neuronal pathways and improving rehabilitation outcomes.

Mechanisms protecting host cells against bacterial pore-forming toxins.

Pore-forming toxins (PFTs) are key virulence determinants produced and secreted by a variety of human bacterial pathogens. They disrupt the plasma membrane (PM) by generating stable protein pores, which allow uncontrolled exchanges between the extracellular and intracellular milieus, dramatically disturbing cellular homeostasis. In recent years, many advances were made regarding the characterization of conserved repair mechanisms that allow eukaryotic cells to recover from mechanical disruption of the PM membrane. However, the specificities of the cell recovery pathways that protect host cells against PFT-induced damage remain remarkably elusive. During bacterial infections, the coordinated action of such cell recovery processes defines the outcome of infected cells and is, thus, critical for our understanding of bacterial pathogenesis. Here, we review the cellular pathways reported to be involved in the response to bacterial PFTs and discuss their impact in single-cell recovery and infection.

Stathmin recruits tubulin to Listeria monocytogenes-induced actin comets and promotes bacterial dissemination.

The tubulin cytoskeleton is one of the main components of the cytoarchitecture and is involved in several cellular functions. Here, we examine the interplay between Listeria monocytogenes (Lm) and the tubulin cytoskeleton upon cellular infection. We show that non-polymeric tubulin is present throughout Lm actin comet tails and, to a less extent, in actin clouds. Moreover, we demonstrate that stathmin, a regulator of microtubule dynamics, is also found in these Lm-associated actin structures and is required for tubulin recruitment. Depletion of host stathmin results in longer comets containing less F-actin, which may be correlated with higher levels of inactive cofilin in the comet, thus suggesting a defect on local F-actin dynamics. In addition, intracellular bacterial speed is significantly reduced in stathmin-depleted cells, revealing the importance of stathmin/tubulin in intracellular Lm motility. In agreement, the area of infection foci and the total bacterial loads are also significantly reduced in stathmin-depleted cells. Collectively, our results demonstrate that stathmin promotes efficient cellular infection, possibly through tubulin recruitment and control of actin dynamics at Lm-polymerized actin structures.

MouR controls the expression of the Listeria monocytogenes Agr system and mediates virulence.

The foodborne pathogen Listeria monocytogenes (Lm) causes invasive infection in susceptible animals and humans. To survive and proliferate within hosts, this facultative intracellular pathogen tightly coordinates the expression of a complex regulatory network that controls the expression of virulence factors. Here, we identified and characterized MouR, a novel virulence regulator of Lm. Through RNA-seq transcriptomic analysis, we determined the MouR regulon and demonstrated how MouR positively controls the expression of the Agr quorum sensing system (agrBDCA) of Lm. The MouR three-dimensional structure revealed a dimeric DNA-binding transcription factor belonging to the VanR class of the GntR superfamily of regulatory proteins. We also showed that by directly binding to the agr promoter region, MouR ultimately modulates chitinase activity and biofilm formation. Importantly, we demonstrated by in vitro cell invasion assays and in vivo mice infections the role of MouR in Lm virulence.

Endoplasmic reticulum chaperone Gp96 controls actomyosin dynamics and protects against pore-forming toxins.

During infection, plasma membrane (PM) blebs protect host cells against bacterial pore-forming toxins (PFTs), but were also proposed to promote pathogen dissemination. However, the details and impact of blebbing regulation during infection remained unclear. Here, we identify the endoplasmic reticulum chaperone Gp96 as a novel regulator of PFT-induced blebbing. Gp96 interacts with non-muscle myosin heavy chain IIA (NMHCIIA) and controls its activity and remodelling, which is required for appropriate coordination of bleb formation and retraction. This mechanism involves NMHCIIA-Gp96 interaction and their recruitment to PM blebs and strongly resembles retraction of uropod-like structures from polarized migrating cells, a process that also promotes NMHCIIA-Gp96 association. Consistently, Gp96 and NMHCIIA not only protect the PM integrity from listeriolysin O (LLO) during infection by Listeria monocytogenes but also affect cytoskeletal organization and cell migration. Finally, we validate the association between Gp96 and NMHCIIA in vivo and show that Gp96 is required to protect hosts from LLO-dependent killing.

l-Rhamnosylation of wall teichoic acids promotes efficient surface association of Listeria monocytogenes virulence factors InlB and Ami through interaction with GW domains.

Wall teichoic acids (WTAs) are important surface glycopolymers involved in various physiological processes occurring in the Gram-positive cell envelope. We previously showed that the decoration of Listeria monocytogenes (Lm) WTAs with l-rhamnose conferred resistance against antimicrobial peptides. Here, we show that WTA l-rhamnosylation also contributes to physiological levels of autolysis in Lm through a mechanism that requires efficient association of Ami, a virulence-promoting autolysin belonging to the GW protein family, to the bacterial cell surface. Importantly, WTA l-rhamnosylation also controls the surface association of another GW protein, the invasin internalin B (InlB), that promotes Lm invasion of host cells. Whereas WTA N-acetylglucosaminylation is not a prerequisite for GW protein surface association, lipoteichoic acids appear to also play a role in the surface anchoring of InlB. Strikingly, while the GW domains of Ami, InlB and Auto (another autolysin contributing to cell invasion and virulence) are sufficient to mediate surface association, this is not the case for the GW domains of the remaining six uncharacterized Lm GW proteins. Overall, we reveal WTA l-rhamnosylation as a bacterial surface modification mechanism that contributes to Lm physiology and pathogenesis by controlling the surface association of GW proteins involved in autolysis and infection.

Scavenger Receptors: Promiscuous Players during Microbial Pathogenesis.

Innate immunity is the most broadly effective host defense, being essential to clear the majority of microbial infections. Scavenger Receptors comprise a family of sensors expressed in a multitude of host cells, whose dual role during microbial pathogenesis gained importance over recent years. SRs regulate the recruitment of immune cells and control both host inflammatory response and bacterial load. In turn, pathogens have evolved different strategies to overcome immune response, avoid recognition by SRs and exploit them to favor infection. Here, we discuss the most relevant findings regarding the interplay between SRs and pathogens, discussing how these multifunctional proteins recognize a panoply of ligands and act as bacterial phagocytic receptors.

The electroclinical spectrum, etiologies, treatment and outcome of nonconvulsive status epilepticus in the elderly.

BACKGROUND: Nonconvulsive status epilepticus (NCSE) in the elderly is particularly difficult to diagnose, mainly due to subtle clinical manifestations and associated comorbidities. The recently validated electroencephalography (EEG) diagnostic criteria for NCSE and the proposed operational classification of status epilepticus provide tools that can allow an earlier diagnosis and better management of NCSE in this age group, possibly contributing to reduce its high mortality. MATERIAL AND METHODS: we used these tools to identify and characterize a cohort of elderly (>60year-old) patients admitted at our institution in a 3-year period; the video-EEG and clinical files of the patients fulfilling EEG diagnostic criteria for NCSE were reviewed, being in this study described their electroclinical spectrum, etiologies, treatment, inhospital mortality, and status epilepticus severity score (STESS). RESULTS: Fourty patients (23 women; mean age 76.6years) were identified. Although dyscognitive NCSE associated with >2.5Hz of epileptiform discharges (ED) was the most frequent electroclinical phenotype, this was quite heterogeneous, ranging from patients with aura continua to patients in coma, associated with frequent ED or rhythmic slow activities. Acute symptomatic (45%) and multifactorial (27.5%) etiologies were the most common, and associated with the worst prognosis. There was a trend to use newer antiepileptic drugs in the early steps of NCSE treatment. The inhospital mortality was high (22.5%) and predicted by STESS scores ≥3. CONCLUSION: In the elderly, NCSE has heterogeneous electroclinical phenotypes and etiologies. In spite of the treatment limitations conditioned by the comorbidities, more aggressive treatments could be justified to reduce mortality in patients with high STESS scores.

Listeria monocytogenes CadC Regulates Cadmium Efflux and Fine-tunes Lipoprotein Localization to Escape the Host Immune Response and Promote Infection.

Listeria monocytogenes is a major intracellular human foodborne bacterial pathogen. We previously revealed L. monocytogenes cadC as highly expressed during mouse infection. Here we show that L. monocytogenes CadC is a sequence-specific, DNA-binding and cadmium-dependent regulator of CadA, an efflux pump conferring cadmium resistance. CadC but not CadA is required for L. monocytogenes infection in vivo. Interestingly, CadC also directly represses lspB, a gene encoding a lipoprotein signal peptidase whose expression appears detrimental for infection. lspB overexpression promotes the release of the LpeA lipoprotein to the extracellular medium, inducing tumor necrosis factor α and interleukin 6 expression, thus impairing L. monocytogenes survival in macrophages. We propose that L. monocytogenes uses CadC to repress lspB expression during infection to avoid LpeA exposure to the host immune system, diminishing inflammatory cytokine expression and promoting intramacrophagic survival and virulence. CadC appears as the first metal efflux pump regulator repurposed during infection to fine-tune lipoprotein processing and host responses.

L-Rhamnosylation of Listeria monocytogenes Wall Teichoic Acids Promotes Resistance to Antimicrobial Peptides by Delaying Interaction with the Membrane.

Listeria monocytogenes is an opportunistic Gram-positive bacterial pathogen responsible for listeriosis, a human foodborne disease. Its cell wall is densely decorated with wall teichoic acids (WTAs), a class of anionic glycopolymers that play key roles in bacterial physiology, including protection against the activity of antimicrobial peptides (AMPs). In other Gram-positive pathogens, WTA modification by amine-containing groups such as D-alanine was largely correlated with resistance to AMPs. However, in L. monocytogenes, where WTA modification is achieved solely via glycosylation, WTA-associated mechanisms of AMP resistance were unknown. Here, we show that the L-rhamnosylation of L. monocytogenes WTAs relies not only on the rmlACBD locus, which encodes the biosynthetic pathway for L-rhamnose, but also on rmlT encoding a putative rhamnosyltransferase. We demonstrate that this WTA tailoring mechanism promotes resistance to AMPs, unveiling a novel link between WTA glycosylation and bacterial resistance to host defense peptides. Using in vitro binding assays, fluorescence-based techniques and electron microscopy, we show that the presence of L-rhamnosylated WTAs at the surface of L. monocytogenes delays the crossing of the cell wall by AMPs and postpones their contact with the listerial membrane. We propose that WTA L-rhamnosylation promotes L. monocytogenes survival by decreasing the cell wall permeability to AMPs, thus hindering their access and detrimental interaction with the plasma membrane. Strikingly, we reveal a key contribution of WTA L-rhamnosylation for L. monocytogenes virulence in a mouse model of infection.

Prospective validation of an initial cholecystectomy strategy for patients at intermediate-risk of common bile duct stone.

BACKGROUND AND AIMS: Initial cholecystectomy for patients at intermediate risk of common bile duct (CBD) stones (including increased liver function tests but bilirubin <4 mg/dL and no cholangitis) showed shorter length of stay and fewer CBD investigations without increased morbidity compared with sequential CBD endoscopic assessment and subsequent cholecystectomy in a randomized controlled trial. The objectives were to prospectively validate these results in daily clinical practice and discuss current guidelines. METHODS: Initial cholecystectomy has become the standard management strategy at Geneva University Hospitals since July 2013 for patients at intermediate risk of CBD stones admitted with acute gallstone-related conditions. Between July 2013 and December 2014, length of stay, number of CBD investigations, and number of adverse events were recorded for these patients and compared with the data of the patients in the randomized controlled trial. RESULTS: Data for 161 consecutive newly assessed patients at intermediate risk of CBD stones confirmed shorter length of stay (7.6 vs 9.8 days; P < .001), fewer CBD investigations (0.8 vs 1.4 investigations per patient; P < .001), and similar adverse event rates (5.6% vs 14%, P = .14 including all adverse events; 3.1% vs 8%, P = .22 including only grade ≥III adverse events, defined by endoscopic/surgical reintervention or intensive care unit admission) compared with the previously reported group of patients who underwent preoperative CBD investigations. CONCLUSIONS: These data confirm that initial cholecystectomy results in a shorter length of stay without increased morbidity among patients at intermediate risk of CBD stones compared with sequential CBD assessment and subsequent cholecystectomy. This approach may change current guidelines.

Management of suspected common bile duct stones on cholangiogram during same-stay cholecystectomy for acute gallstone-related disease.

BACKGROUND: Recent data have suggested that upfront cholecystectomy should be performed even in the presence of moderately abnormal liver function tests (LFTs). As a consequence, more common bile duct (CBD) stones are discovered on intra-operative cholangiogram. We assessed the presentation and management of such patients to refine their management plan. METHODS: Adult patients (>16 years) with an acute gallstone-related disease who had undergone same-stay cholecystectomy from January 2013 to January 2015 were retrospectively assessed. We excluded patients with pre-operative endoscopic CBD exploration. RESULTS: Among the 612 patients with same-stay cholecystectomy, 399 patients were included in the study, and 213 were excluded because of a pre-operative CBD exploration. Fifty patients (12.5%) presented an image of CBD stone on the intra-operative cholangiogram. Such patients were younger (47 vs. 55 years, P = .01) and less likely to present with fever (1 vs. 11.7%, P = .04) or signs of cholecystitis on ultrasound (66 vs. 83.7%, P = .003). Admission LFTs were higher in patients with an image of a stone. Among the 50 patients with an image on cholangiogram, a stone was confirmed in 26 (52%). Most patients (n = 32) underwent post-operative assessment with endoscopic ultrasound (EUS). LFTs did not predict the presence of a confirmed stone. However, the absence of contrast passage into the duodenum was negatively associated with a confirmed stone (P = .08), and a filling defect was positively associated with one (P = .11). Most confirmed stones were successfully extracted by endoscopic retrograde cholangiopancreatogram (ERCP) (25/26, 96%), except in one patient who needed a per-cutaneous approach because of duodenal diverticuli. CONCLUSIONS: Same-stay cholecystectomy can (and should) be performed even in the presence of moderately abnormal liver function tests. The cholangiogram suspicion of a CBD stone is confirmed in only half of the patients (more often in the presence of a filling defect, and less often with the absence of contrast passage). All stones can be safely treated after surgery (most by ERCP).

Src-dependent tyrosine phosphorylation of non-muscle myosin heavy chain-IIA restricts Listeria monocytogenes cellular infection.

Bacterial pathogens often interfere with host tyrosine phosphorylation cascades to control host responses and cause infection. Given the role of tyrosine phosphorylation events in different human infections and our previous results showing the activation of the tyrosine kinase Src upon incubation of cells with Listeria monocytogenes, we searched for novel host proteins undergoing tyrosine phosphorylation upon L. monocytogenes infection. We identify the heavy chain of the non-muscle myosin IIA (NMHC-IIA) as being phosphorylated in a specific tyrosine residue in response to L. monocytogenes infection. We characterize this novel post-translational modification event and show that, upon L. monocytogenes infection, Src phosphorylates NMHC-IIA in a previously uncharacterized tyrosine residue (Tyr-158) located in its motor domain near the ATP-binding site. In addition, we found that other intracellular and extracellular bacterial pathogens trigger NMHC-IIA tyrosine phosphorylation. We demonstrate that NMHC-IIA limits intracellular levels of L. monocytogenes, and this is dependent on the phosphorylation of Tyr-158. Our data suggest a novel mechanism of regulation of NMHC-IIA activity relying on the phosphorylation of Tyr-158 by Src.

Prevalence and clinical aspects of CMV congenital Infection in a low-income population.

BACKGROUND: CMV is the most common cause of congenital infection in the whole world (0.2 to 2.2 %). That infection may be symptomatic or asymptomatic at birth and, although asymptomatic cases at birth are more common, some children may develop late sequelae, and require medical intervention. This study aimed to determine the prevalence of CMV congenital infections in children who were born in a public hospital in Ilhéus, Brazil, and to evaluate the clinical progression in infected newborns. METHODS: CMV congenital infection was determined by detecting viral DNA through nested PCR. RESULTS: The viral DNA was detected in 25 newborns, showing a prevalence of 1.19 % (25/2100) of CMV congenital infection. In regards to the risk factors from mothers, only the variables: age of mothers (p = 0.003), number of children (p = 0.011), and use of medications (p < 0.001) were associated with the congenital infection. Approximately 12 % of children presented symptoms. One death and two auditory alterations were detected during the monitored period. Only 50 % of children diagnosed attended their medical follow. CONCLUSIONS: The prevalence found confirms the findings from other studies which involved other poor populations. Two children presented impaired hearing during the monitored period; that was one of the main sequelae from the infection. It is noteworthy that there was low adherence to medical follow-up which may underestimate data on complications of the infection CMV. Late symptoms can be mistaken for other diseases or even go unnoticed.

Self-reported psychosocial factors among in vitro fertilization patients interviewed alone or with the partner.

The purpose of this study was to compare the sociodemographic and psychosocial characteristics reported by female in vitro fertilization (IVF) patients interviewed alone or with the partner in heterosexual couples. During 12 months (2011-2012), all patients undergoing IVF or intracytoplasmic sperm injection at one public reproductive medicine unit, in Portugal, were interviewed on the day of the diagnosis of pregnancy, being recruited 221 women interviewed with the partner and 92 interviewed alone. Interviewers collected data on sociodemographic and obstetric characteristics; and anxiety, depression, social support and partner relationship were collected by self-administered questionnaires. χ2 test was used to assess the independent association between the categorical variables and being interviewed alone or with the partner. For continuous variables, mean or median differences were compared by the t-test or the Mann-Whitney test, according to data distribution. No statistically significant differences were found in the self-reporting of depression, anxiety, social support and partner relationship or in sociodemographic and obstetric characteristics between women interviewed alone or with the partner. Although women interviewed alone were older and more frequently had children than women interviewed with the partner, no significant associations were observed. Thus, having a male partner present in the research setting during a self-administered questionnaire seems not to influence women's responses to psychosocial measures. Other outcomes and settings need to be evaluated to support evidence-based guidelines for research on infertility.