Publications by authors named "Bernard Arulanandam"

Multi-drug-resistant (MDR) is an opportunistic pathogen associated with hospital-acquired infections. Due to its environmental persistence, virulence, and limited treatment options, this organism causes both increased patient mortality and incurred healthcare costs. Thus, prophylactic vaccination could be ideal for intervention against MDR infection in susceptible populations.

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In view of a conspicuous absence of any cross-country study linking obesity and COVID-19 mortality, we conduct an empirical analysis of plausible associations between COVID-19 mortality and the proportion of obese in the adult population distributed across 142 countries around the globe. We observe a statistically significant positive association between COVID-19 mortality and the proportion of obese in adult populations spanning 142 countries. This association holds across countries belonging to different income groups and is not sensitive to a population's median age, proportion of the elderly, and/or proportion of females.

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Background: Genital Chlamydia trachomatis infection is the most common bacterial sexual transmitted disease that causes severe complications including pelvic inflammatory disease, ectopic pregnancy, and infertility in females. The Pgp3 protein encoded by C. trachomatis plasmid has been speculated to be an important player in chlamydial pathogenesis.

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Genital Chlamydia trachomatis infection remains a major health issue as it causes severe complications including pelvic inflammatory disease, ectopic pregnancy and infertility in females as a result of infection-associated chronic inflammation. Podoplanin, a transmembrane receptor, has been previously reported on inflammatory macrophages. Thus, strategies that specifically target podoplanin might be able to reduce local inflammation.

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is a nosocomic opportunistic Gram-negative bacteria known for its extensive drug-resistant phenotype. hospital-acquired infections are major contributors to increased costs and mortality observed during the COVID-19 pandemic. With few effective antimicrobials available for treatment of this pathogen, immune-based therapy becomes an attractive strategy to combat multi-drug resistant infection.

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Fetuin-A is an acute phase glycoprotein shown to counter in a regulatory manner proinflammatory cytokine production to maintain homeostasis during inflammation. We report here that in wild-type mice 12 days after (Cm) intranasal challenge, fetuin-A content in the lungs decreased 46%, while INF- increased 44%, consistent with a negative regulatory role of fetuin-A in inflammation. Importantly, the observed increased IFN- production was abrogated in fetuin-A-deficient AHSG mice suggesting that IFN- induction following Cm infection is fetuin-A dependent.

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Understanding the immune response to SARS-CoV-2 is important for development of effective diagnostics and vaccines. We report here a broad antibody response to SARS-CoV-2 spike protein receptor binding domain (RBD) in 100 convalescent patient plasma samples. Antibody isotypes IgA, IgM, and IgG exhibited significantly higher anti-RBD titers when compared to SARS-CoV-2 negative controls.

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is a Gram-negative bacterium responsible for many hospital-acquired infections including ventilator-associated pneumonia and sepsis. We have previously identified thioredoxin A protein (TrxA) as a virulence factor with a multitude of functions including reduction of protein disulfides. TrxA plays an important role in resistance to oxidative stress facilitating host immune evasion in part by alteration of type IV pili and cell surface hydrophobicity.

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Objectives: The objective is to study the role, if any, of excess body weight in COVID-19 mortality.

Study Design: This is a cross-country study of plausible associations between COVID-19 mortality and the proportion of overweight among adults, controlling for age, gender, and income.

Methods: Parametric and non-parametric regression analysis.

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Chlamydia is known to both ascend to the upper genital tract and spread to the gastrointestinal tract following intravaginal inoculation. Gastrointestinal Chlamydia was recently reported to promote chlamydial pathogenicity in the genital tract since mice intravaginally inoculated with an attenuated Chlamydia strain, which alone failed to develop pathology in the genital tract, were restored to develop hydrosalpinx by intragastric coinoculation with wild-type Chlamydia. Gastrointestinal Chlamydia promoted hydrosalpinx via an indirect mechanism since Chlamydia in the gut did not directly spread to the genital tract lumen.

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Genomic sequence analysis of Acinetobacter baumannii revealed the presence of a putative Acid Phosphatase (AcpA; EC 3.1.3.

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Previously, our laboratory established the role of small, noncoding RNA species, microRNA (miRNA) including miR-135a in anti-chlamydial immunity in infected hosts. We report here chlamydial infection results in decreased miR-135a expression in mouse genital tissue and a fibroblast cell line. Several chemokine and chemokine receptor genes (including CXCL10, CCR5) associated with chlamydial pathogenesis were identified to contain putative miR-135a binding sequence(s) in the 3' untranslated region.

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Viruses are obligate intracellular parasites, and host cell entry is the first step in the viral life cycle. The SARS-CoV-2 (COVID-19) entry process into susceptible host tissue cells is complex requiring (1) attachment of the virus via the conserved spike (S) protein receptor-binding motif (RBM) to the host cell angiotensin-converting-enzyme 2 (ACE2) receptor, (2) S protein proteolytic processing, and (3) membrane fusion. Spike protein processing occurs at two cleavage sites, i.

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The obligate intracellular bacterium can colonize the mouse colon for a long period, but a gamma interferon (IFN-γ)-susceptible mutant clone fails to do so. Nevertheless, the mutant's colonization is rescued in mice deficient in interleukin-7 receptor (IL-7R) (lacking both lymphocytes and innate lymphoid cells [ILCs]) or IFN-γ but not in mice lacking recombination-activated gene 1 (Rag1 mice) (lacking adaptive immunity lymphocytes), indicating a critical role of ILC-derived IFN-γ in regulating chlamydial colonization. In the current study, we have used an adoptive transfer approach for further characterizing the responsible ILCs.

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Our laboratory has investigated the role of an evolutionarily conserved RNA species called microRNAs (miRs) in regulation of anti-chlamydial protective immunity. MiRs including miR-155 expressed in specific immune effector cells are critical for antigen specific protective immunity and IFN-γ production. Using miR-155 deficient mice, and a murine pulmonary model for chlamydial infection, we report here 1) the effect of host miR-155 on bacterial burden, and 2) identify probable immune genes regulated by miR-155.

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, a Gram-negative coccobacillus, has become a prevalent nosocomial health threat affecting the majority of hospitals both in the U.S. and around the globe.

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Article Synopsis
  • The cryptic plasmid plays a critical role in how chlamydia colonizes different areas of the gastrointestinal tract, enhancing its ability to become infectious.
  • In experiments, plasmid-positive strains were able to produce infectious particles throughout the GI tract, while plasmid-deficient strains struggled to do so, especially in the small intestine, where they showed a noninfectious status.
  • The dependence on the plasmid for effective colonization increased with time and varied across different gut regions, suggesting that the plasmid aids chlamydia's adaptation and fitness through distinct mechanisms.
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The cervical microbiota constitutes an important protective barrier against the invasion of pathogenic microorganisms. A disruption of microbiota within the cervical milieu has been suggested to be a driving factor of sexually transmitted infections. These include Chlamydia trachomatis which frequently causes serious reproductive sequelae such as infertility in women.

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Although manual enumeration of inclusion forming units is the most widely accepted means of quantification in the field, it is both time consuming and subject to inherent investigator bias. We report here a rapid, ., minutes .

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The increasing number of new cases of infection worldwide may be attributed to the pathogen's ability to evade various host immune responses. Summarized here are means of evasion utilized by enabling survival in a hostile host environment. The pathogen's persistence involves a myriad of molecular interactions manifested in a variety of ways, .

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The Gram-negative pathogen, Acinetobacter baumannii has emerged as a global nosocomial health threat affecting the majority of hospitals in the U.S. and abroad.

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Introduction: Due to high risk of septic transfusion reactions arising from bacterial contamination, US Food and Drug Administration regulations currently limit platelet storage to 5 days at room temperature (RT). However, blood culturing methods can take up to 7 days to detect bacteria, allowing transfusion of potentially contaminated units. Thus, cold storage (CS) may be a viable means of extending shelf life and improving safety.

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The genital tract pathogen is frequently detected in the gastrointestinal tract, but the host immunity that regulates chlamydial colonization in the gut remains unclear. In a -C57 mouse model, chlamydial organisms are cleared from the genital tract in ∼4 weeks, but the genital organisms can spread to the gastrointestinal tract. We found that the gastrointestinal chlamydial organisms were cleared from the small intestine by day 28, paralleling their infection course in the genital tract, but persisted in the large intestine for long periods.

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We have identified recombinant human cystatins 9 (rCST9) and C (rCSTC) as a combination immunotherapeutic treatment against multidrug-resistant (MDR) New Delhi metallo-β-lactamase-1 (NDM-1)-producing We evaluated the lasting protection of rCST9/rCSTC treatment against MDR NDM-1 pneumonia. Results showed that rCST9/rCSTC treatment modulated endogenous serum biomarkers, cystatins 9 and C and amyloid A, associated with poor patient outcomes and provided prophylactic and long-term protection in a murine model of pneumonia.

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Background: Persistent inflammation caused by Chlamydia trachomatis in the female genital compartment represents one of the major causes of pelvic inflammatory disease (PID), ectopic pregnancy and infertility in females. Here, we examined the pro-inflammatory cytokine response following stimulation with three different types of C. trachomatis antigens, viz.

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