An unusual presentation of hemoglobin SD Punjab in a Saudi Arabian adult

HbDPunjab is an uncommon variant hemoglobin that does not result in significant pathology when inherited as a homozygous disorder. When inherited with other hemoglobinopathies, it may result in varying disease phenotypes. HbSDPunjab has been rarely reported in Saudi Arabia, coexisting with alpha or beta thalassemia. In this report, we discuss the case of a 39 years old male who presented with severe anemia and renal injury and was later diagnosed with HbSDPunjab through electropheresis and genetic testing

Safety and Immunogenicity of Multimeric-001 (M-001) Followed by Seasonal Quadrivalent Inactivated Influenza Vaccine in Young Adults – a Randomized Clinical Trial

BACKGROUND: The continuing evolution of influenza viruses poses a challenge to vaccine prevention, highlighting the need for a universal influenza vaccine. We evaluated the safety and immunogenicity of one such candidate, Multimeric-001 (M-001), when used as a priming vaccine prior to administration of quadrivalent inactivated influenza vaccine (IIV4). METHODS: Healthy adults 18 to 49 years of age were enrolled in a phase 2 randomized, double-blind placebo-controlled trial. Participants received two doses of either 1.0-mg M-001 or saline placebo (60 per study arm) on Days 1 and 22 followed by a single dose of IIV4 on about Day 172. Safety, reactogenicity, cellular immune responses and influenza hemagglutination inhibition (HAI) and microneutralization (MN) were assessed. RESULTS: The M-001 vaccine was safe and had an acceptable reactogenicity profile. Injection site tenderness (39% post-dose 1, 29% post-dose 2) was the most common reaction after M-001 administration. Polyfunctional CD4+ T cell responses (perforin-negative, CD107α-negative, TNF-α+, IFN-γ+, with or without IL-2) to the pool of M-001 peptides increased significantly from baseline to two weeks after the second dose of M-001, and this increase persisted through Day 172. However, there was no enhancement of HAI or MN antibody responses among M-001 recipients following IIV4 administration. CONCLUSIONS: M-001 administration induced a subset of polyfunctional CD4+ T cells that persisted through 6 months of follow-up, but it did not improve HAI or MN antibody responses to IIV4. (clinicaltrials.gov NCT03058692)

Heat Resistance Mediated by a New Plasmid Encoded Clp ATPase, ClpK, as a Possible Novel Mechanism for Nosocomial Persistence of Klebsiella pneumoniae

Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. We have characterized a K. pneumoniae strain responsible for a series of critical infections in an intensive care unit over a two-year period. The strain was found to be remarkably thermotolerant providing a conceivable explanation of its persistence in the hospital environment. This marked phenotype is mediated by a novel type of Clp ATPase, designated ClpK. The clpK gene is encoded by a conjugative plasmid and we find that the clpK gene alone renders an otherwise sensitive E. coli strain resistant to lethal heat shock. Furthermore, one third of a collection of nosocomial K. pneumoniae isolates carry clpK and exhibit a heat resistant phenotype. The discovery of ClpK as a plasmid encoded factor and its profound impact on thermal stress survival sheds new light on the biological relevance of Clp ATPases in acquired environmental fitness and highlights the challenges of mobile genetic elements in fighting nosocomial infections

Relative Effectiveness and Immunogenicity of Quadrivalent Recombinant Influenza Vaccine Versus Egg-Based Inactivated Influenza Vaccine Among Adults Aged 18-64 Years: Results and Experience From a Randomized, Double-Blind Trial.

BACKGROUND: Immunogenicity studies suggest that recombinant influenza vaccine (RIV) may provide better protection against influenza than standard-dose inactivated influenza vaccines (SD IIV). This randomized trial evaluated the relative vaccine effectiveness (VE) and immunogenicity of RIV versus SD IIV in frontline workers and students aged 18-64 years. METHODS: Participants were randomized to receive RIV or SD IIV and followed for reverse-transcription polymerase chain reaction (RT-PCR)-confirmed influenza during the 2022-2023 influenza season. Sera were collected from a subset of participants before and at 1 and 6 months postvaccination and tested by hemagglutination inhibition for A/H1N1, A/H3N2, B/Yamagata, and B/Victoria and against cell-grown vaccine reference viruses for A/H1N1 and A/H3N2. RESULTS: Overall, 3988 participants were enrolled and vaccinated (25% of the trial sample size goal); RT-PCR-confirmed influenza occurred in 20 of 1963 RIV recipients and 28 of 1964 SD IIV recipients. Relative VE was 29% (95% confidence interval [CI], -26% to 60%). In the immunogenicity substudy (n = 118), the geometric mean titer ratio (GMTR) comparing RIV to SD IIV at 1 month was 2.3 (95% CI, 1.4-3.7) for cell-grown A/H1N1, 2.1 (95% CI, 1.3-3.4) for cell-grown A/H3N2, 1.1 (95% CI, .7-1.6) for B/Victoria, and 1.4 (95% CI, .9-2.0) for B/Yamagata. At 6 months, GMTRs were \u3e1 against A/H1N1, A/H3N2, and B/Yamagata. CONCLUSIONS: Relative VE of RIV compared to SD IIV did not reach statistical significance, but RIV elicited more robust humoral immune responses to 2 of 4 vaccine viruses at 1 month and 3 of 4 viruses at 6 months after vaccination, suggesting possible improved and sustained immune protection from RIV

Immunoproteomics Analysis of the Murine Antibody Response to Vaccination with an Improved Francisella tularensis Live Vaccine Strain (LVS)

Background: Francisella tularensis subspecies tularensis is the causative agent of a spectrum of diseases collectively known as tularemia. An attenuated live vaccine strain (LVS) has been shown to be efficacious in humans, but safety concerns have prevented its licensure by the FDA. Recently, F. tularensis LVS has been produced under Current Good Manufacturing Practice (CGMP guidelines). Little is known about the immunogenicity of this new vaccine preparation in comparison with extensive studies conducted with laboratory passaged strains of LVS. Thus, the aim of the current work was to evaluate the repertoire of antibodies produced in mouse strains vaccinated with the new LVS vaccine preparation. Methodology/Principal Findings: In the current study, we used an immunoproteomics approach to examine the repertoire of antibodies induced following successful immunization of BALB/c versus unsuccessful vaccination of C57BL/6 mice with the new preparation of F. tularensis LVS. Successful vaccination of BALB/c mice elicited antibodies to nine identified proteins that were not recognized by antisera from vaccinated but unprotected C57BL/6 mice. In addition, the CGMP formulation of LVS stimulated a greater repertoire of antibodies following vaccination compared to vaccination with laboratory passaged ATCC LVS strain. A total of 15 immunoreactive proteins were identified in both studies, however, 16 immunoreactive proteins were uniquely reactive with sera from the new formulation of LVS. Conclusions/Significance: This is the first report characterising the antibody based immune response of the new formulation of LVS in the widely used murine model of tularemia. Using two mouse strains, we show that successfully vaccinated mice can be distinguished from unsuccessfully vaccinated mice based upon the repertoire of antibodies generated. This opens the door towards downselection of antigens for incorporation into tularemia subunit vaccines. In addition, this work also highlights differences in the humoral immune response to vaccination with the commonly used laboratory LVS strain and the new vaccine formulation of LVS.Peer reviewed: YesNRC publication: Ye

Lipopolysaccharide O1 Antigen Contributes to the Virulence in Klebsiella pneumoniae Causing Pyogenic Liver Abscess

Klebsiella pneumoniae is the common cause of a global emerging infectious disease, community-acquired pyogenic liver abscess (PLA). Capsular polysaccharide (CPS) and lipopolysaccharide (LPS) are critical for this microorganism's ability to spread through the blood and to cause sepsis. While CPS type K1 is an important virulence factor in K. pneumoniae causing PLA, the role of LPS in PLA is not clear. Here, we characterize the role of LPS O antigen in the pathogenesis of K. pneumoniae causing PLA. NTUH-K2044 is a LPS O1 clinical strain; the presence of the O antigen was shown via the presence of 1,3-galactan in the LPS, and of sequences that align with the wb gene cluster, known to produce O-antigen. Serologic analysis of K. pneumoniae clinical isolates demonstrated that the O1 serotype was more prevalent in PLA strains than that in non-tissue-invasive strains (38/42 vs. 9/32, P<0.0001). O1 serotype isolates had a higher frequency of serum resistance, and mutation of the O1 antigen changed serum resistance in K. pneumoniae. A PLA-causing strain of CPS capsular type K2 and LPS serotype O1 (i.e., O1:K2 PLA strain) deleted for the O1 synthesizing genes was profoundly attenuated in virulence, as demonstrated in separate mouse models of septicemia and liver abscess. Immunization of mice with the K2044 magA-mutant (K1− O1) against LPS O1 provided protection against infection with an O1:K2 PLA strain, but not against infection with an O1:K1 PLA strain. Our findings indicate that the O1 antigen of PLA-associated K. pneumoniae contributes to virulence by conveying resistance to serum killing, promoting bacterial dissemination to and colonization of internal organs after the onset of bacteremia, and could be a useful vaccine candidate against infection by an O1:K2 PLA strain

Rapid Molecular Detection of Rifampicin Resistance Facilitates Early Diagnosis and Treatment of Multi-Drug Resistant Tuberculosis: Case Control Study

Multi-drug resistant tuberculosis (MDR-TB) is a major public health concern since diagnosis is often delayed, increasing the risk of spread to the community and health care workers. Treatment is prolonged, and the total cost of treating a single case is high. Diagnosis has traditionally relied upon clinical suspicion, based on risk factors and culture with sensitivity testing, a process that can take weeks or months. Rapid diagnostic molecular techniques have the potential to shorten the time to commencing appropriate therapy, but have not been put to the test under field conditions.This retrospective case-control study aimed to identify risk factors for MDR-TB, and analyse the impact of testing for rifampicin resistance using RNA polymerase B (rpoB) mutations as a surrogate for MDR-TB. Forty two MDR-TB cases and 84 fully sensitive TB controls were matched by date of diagnosis; and factors including demographics, clinical presentation, microbiology findings, management and outcome were analysed using their medical records. Conventionally recognised risk factors for MDR-TB were absent in almost half (43%) of the cases, and 15% of cases were asymptomatic. A significant number of MDR-TB cases were identified in new entrants to the country. Using rpoB mutation testing, the time to diagnosis of MDR-TB was dramatically shortened by a median of 6 weeks, allowing patients to be commenced on appropriate therapy a median of 51days earlier than those diagnosed by conventional culture and sensitivity testing.MDR-TB is frequently an unexpected finding, may be asymptomatic, and is particularly prevalent among TB infected new entrants to the country. Molecular resistance testing of all acid fast bacilli positive specimens has the potential to rapidly identify MDR-TB patients and commence them on appropriate therapy significantly earlier than by conventional methods

Zebrafish usp39 Mutation Leads to rb1 mRNA Splicing Defect and Pituitary Lineage Expansion

Loss of retinoblastoma (Rb) tumor suppressor function is associated with human malignancies. Molecular and genetic mechanisms responsible for tumorigenic Rb downregulation are not fully defined. Through a forward genetic screen and positional cloning, we identified and characterized a zebrafish ubiquitin specific peptidase 39 (usp39) mutation, the yeast and human homolog of which encodes a component of RNA splicing machinery. Zebrafish usp39 mutants exhibit microcephaly and adenohypophyseal cell lineage expansion without apparent changes in major hypothalamic hormonal and regulatory signals. Gene expression profiling of usp39 mutants revealed decreased rb1 and increased e2f4, rbl2 (p130), and cdkn1a (p21) expression. Rb1 mRNA overexpression, or antisense morpholino knockdown of e2f4, partially reversed embryonic pituitary expansion in usp39 mutants. Analysis of pre-mRNA splicing status of critical cell cycle regulators showed misspliced Rb1 pre-mRNA resulting in a premature stop codon. These studies unravel a novel mechanism for rb1 regulation by a neuronal mRNA splicing factor, usp39. Zebrafish usp39 regulates embryonic pituitary homeostasis by targeting rb1 and e2f4 expression, respectively, contributing to increased adenohypophyseal sensitivity to these altered cell cycle regulators. These results provide a mechanism for dysregulated rb1 and e2f4 pathways that may result in pituitary tumorigenesis

Differentiation of the Lateral Compartment of the Cochlea Requires a Temporally Restricted FGF20 Signal

FGF20 signaling in mice is required specifically for the differentiation of cochlear outer hair cells, the cells most often damaged during age-related hearing loss