Evidence that staphylococcal superantigens promote within-patient bacterial persistence following post-operative surgical site infection.

is a predominant cause of post-operative surgical site infections and persistent bacteremia. Here, we describe a patient who experienced three episodes of infection over a period of 4 months following a total knee arthroplasty. The initial bloodstream isolate (SAB-0429) was a clonal complex 5 (CC5) and methicillin-resistant (MRSA), whereas two subsequent isolates (SAB-0485 and SAB-0495) were CC5 isolates but methicillin-sensitive .

Structural analysis of extracellular ATP-independent chaperones of streptococcal species and protein substrate interactions.

Unlabelled: During infection, bacterial pathogens rely on secreted virulence factors to manipulate the host cell. However, in gram-positive bacteria, the molecular mechanisms underlying the folding and activity of these virulence factors after membrane translocation are not clear. Here, we solved the protein structures of two secreted parvulin and two secreted cyclophilin-like peptidyl-prolyl isomerase (PPIase) ATP-independent chaperones found in gram-positive streptococcal species.

Proinflammatory synergy between protease and superantigen streptococcal pyogenic exotoxins.

Streptococcal pyogenic exotoxins (Spe proteins) secreted by (group A , GAS) are responsible for scarlet fever and streptococcal toxic shock syndrome. Most Spes are superantigens that cause excessive inflammation by activating large numbers of T cells. However, Streptococcal pyogenic exotoxin B (SpeB) is an exception, which is pro-inflammatory through its protease activity.

Cells that survive acute SARS-CoV-2 infection contribute to inflammation and lung regeneration in mice.

Unlabelled: Post-acute sequelae of COVID-19 involves several organs, but its basis remains poorly understood. Some infected cells in mice survive the acute infection and persist for extended periods in the respiratory tract but not in other tissues. Here, we describe two experimental models of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection to assess the effect of viral virulence on previously infected cells.

VopX, a novel T3SS effector, modulates host actin dynamics.

Unlabelled: Pathogenic strains cause cholera using different mechanisms. O1 and O139 serogroup strains use the toxin-co-regulated pilus (TCP) and cholera toxin (CT) for intestinal colonization and to promote secretory diarrhea, while non-O1/non-O139 serogroup strains are typically non-toxigenic and use alternate virulence factors to cause a clinically similar disease. An O39 serogroup, TCP/CT-negative strain, named AM-19226, uses a type III secretion system (T3SS) to translocate more than 10 effector proteins into the host cell cytosol.

Pathogen genomic surveillance and the AI revolution.

The unprecedented sequencing efforts during the COVID-19 pandemic paved the way for genomic surveillance to become a powerful tool for monitoring the evolution of circulating viruses. Herein, we discuss how a state-of-the-art artificial intelligence approach called protein language models (pLMs) can be used for effectively analyzing pathogen genomic data. We highlight examples of pLMs applied to predicting viral properties and evolution and lay out a framework for integrating pLMs into genomic surveillance pipelines.

Virus-like particle-based vaccines targeting the mosquito salivary protein TRIO.

Malaria is a highly lethal infectious disease caused by parasites. These parasites are transmitted to vertebrate hosts when mosquitoes of the genus probe for a blood meal. Sporozoites, the infectious stage of , transit to the liver within hours of injection into the dermis.

LitR and its quorum-sensing regulators modulate biofilm formation by .

Quorum sensing controls numerous processes ranging from the production of virulence factors to biofilm formation. Biofilms, communities of bacteria that are attached to one another and/or a surface, are common in nature, and when they form, they can produce a quorum of bacteria. One model system to study biofilms is the bacterium , which forms a biofilm that promotes the colonization of its symbiotic host.

Metagenome-assembled genomes (MAGs) of the emerging pathogen from enrichment of coastal seawater, sediment, and algae at St. John's Island, Singapore.

Coastal water, sediment, and algae samples were collected from St. John's Island, Singapore, and enriched in either broth or agar. Metagenomic sequencing was carried out on DNA from these enrichments and analyzed.

Update on the evolving landscape of pneumococcal capsule types: new discoveries and way forward.

SUMMARY (the "pneumococcus") is a significant human pathogen. The key determinant of pneumococcal fitness and virulence is its ability to produce a protective polysaccharide (PS) capsule, and anti-capsule antibodies mediate serotype-specific opsonophagocytic killing of bacteria. Notably, immunization with pneumococcal conjugate vaccines (PCVs) has effectively reduced the burden of disease caused by serotypes included in vaccines but has also spurred a relative upsurge in the prevalence of non-vaccine serotypes.

Influenza A virus NS2 protein acts on vRNA-resident polymerase to drive the transcription to replication switch.

The heterotrimeric RNA-dependent RNA polymerase (RdRp) of influenza A virus catalyzes viral RNA transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA) by adopting different conformations. A switch from transcription to replication occurs at a relatively late stage of infection. We recently reported that the viral NS2 protein, expressed at later stages from a spliced transcript of the NS segment messenger RNA (mRNA), inhibits transcription, promotes replication and plays a key role in the transcription-to-replication switch.

Transcriptional signature of CD56 NK cells predicts favourable prognosis in bladder cancer.

Human natural killer (NK) cells can be sub-divided into two functional subsets but the clinical significance of these CD56 and CD56 NK cells in anti-tumour immunity remains largely unexplored. We determined the relative abundances of gene signatures for CD56 and CD56 NK cells along with 3 stromal and 18 other immune cell types in the patient tumour transcriptomes from the cancer genome atlas bladder cancer dataset (TCGA-BLCA). Using this computational approach, CD56 NK cells were predicted to be the more abundant tumour-infiltrating NK subset which was also associated with improved patient prognosis.

Impact of SARS-CoV-2 vaccination and of seasonal variations on the innate immune inflammatory response.

Introduction: The innate immune response is an important first checkpoint in the evolution of an infection. Although adaptive immunity is generally considered the immune component that retains antigenic memory, innate immune responses can also be affected by previous stimulations. This study evaluated the impact of vaccination on innate cell activation by TLR7/8 agonist R848, as well as seasonal variations.

A Rare Case of Facial Arteriovenous Malformation in a 3-Year-Old Female.

Arteriovenous malformation (AVM) is a rare congenital vascular anomaly involving abnormal artery-vein connections that bypass the capillary system. AVMs are particularly uncommon in young children. A 3-year-old girl presented with a painless, progressively enlarging left cheek swelling since birth.

Changes in CD4+CD25HIGH T cells and TGFβ1 levels in different stages of adult-onset type 1 diabetes.

Background: Previous studies suggested an important role of impairments in T cell subsets in different stages during type 1 diabetes (T1D) development, while data regarding CD25high T cells and transforming growth factor b1 (TGFβ1), both T regulatory associated, remains controversial. We analyzed the level of (a) CD25high T cells (b) TGFβ1 in 17 first-degree relatives of patients with T1D in stage 1 (FDRs1) (GADA+, IA-2+); 34 FDRs in stage 0 (FDRs0) (GADA, IA-2); 24 recent-onset T1D in insulin-requiring state (IRS); 10 patients in clinical remission (CR); 18 healthy, unrelated controls (CTR).

Methods: T cell subsets were characterized by two-color immunofluorescence staining and flow cytometry; TGFβ1 was determined by ELISA, GADA, and IA-2 by RIA.

T cell immune evasion by SARS-CoV-2 JN.1 escapees targeting two cytotoxic T cell epitope hotspots.

Although antibody escape is observed in emerging severe acute respiratory syndrome coronavirus 2 variants, T cell escape, especially after the global circulation of BA.2.86/JN.

A practical approach to investigating nosocomial acquisition of Aspergillus.

Invasive mould disease (IMD) has a high mortality in immunosuppressed patients. Invasive aspergillosis (IA) is the most common IMD. A guideline for preventing IA has been published jointly by the Centers for Diseases Control and Prevention, the Infectious Disease Society of America, and the American Society of Blood and Marrow Transplantation.

Cell-free assays reveal that the HIV-1 capsid protects reverse transcripts from cGAS immune sensing.

Retroviruses can be detected by the innate immune sensor cyclic GMP-AMP synthase (cGAS), which recognizes reverse-transcribed DNA and activates an antiviral response. However, the extent to which HIV-1 shields its genome from cGAS recognition remains unclear. To study this process in mechanistic detail, we reconstituted reverse transcription, genome release, and innate immune sensing of HIV-1 in a cell-free system.

Bacterial vaginosis is associated with transcriptomic changes but not higher concentrations of cervical leukocytes in a study of women at high risk for HIV acquisition.

Background: The association between bacterial vaginosis (BV) and increased HIV acquisition risk may be related to concentrations of HIV-susceptible immune cells in the cervix.

Methods: Participants (31 with BV and 30 with normal microbiota) underwent cervical biopsy at a single visit. Immune cells were quantified and sorted using flow cytometry (N=55), localization assessed by immunofluorescence (N=16), and function determined by bulk RNA sequencing (RNA-seq) of live CD45+ cells (N=21).

Seroprevalence and Risk Factors of Anaplasma marginale in Water Buffaloes in Nile Delta of Egypt.

Purpose: Bovine anaplasmosis is a major tick-borne disease in ruminants, resulting in significant economic loss for the dairy sector. This study aimed to evaluate the seroprevalence of Anaplasma marginale (A. marginale) in buffaloes in three governorates in Nile Delta of Egypt.

The circulating plasma microRNA signature in human visceral leishmaniasis.

Visceral leishmaniasis (VL) is a vector-borne disease caused by the obligate intracellular protozoan in India. VL can be complicated by post-kala-azar dermal leishmaniasis (PKDL), a macular or nodular rash that develops in 10%-20% of patients after treatment of VL in India. Patients with PKDL are infectious to sand flies, promoting further transmission of the parasite.

Restoring cefepime activity against multidrug-resistant KPC-producing by combination with boronic acid inhibitors, MB076 and S02030.

Foremost in the design of new β-lactamase inhibitors (BLIs) are the boronic acid transition state inhibitors (BATSIs). Two highly potent BATSIs being developed are S02030 and MB076 strategically designed to be active against cephalosporinases and carbapenemases, especially KPC. When combined with cefepime, S02030 and MB076 demonstrated potent antimicrobial activity against laboratory and clinical strains of expressing a variety of class A and class C β-lactamases, including and .

Positive feedback regulation between RpoS and BosR in the Lyme disease pathogen.

In , the causative agent of Lyme disease, differential gene expression is primarily governed by the alternative sigma factor RpoS (σ). Understanding the regulation of RpoS is crucial for elucidating how is maintained throughout its enzootic cycle. Our recent studies have shown that the homolog of Fur/PerR repressor/activator BosR functions as an RNA-binding protein that controls the mRNA stability.