Jayaprakash Nattamai Subramanian

Bacteria are historically known to cause a disproportionate number of deaths because of infectious diseases worldwide. Annually, 55 million deaths are accounted for because of bacterial infections, out of which approximately 3 million deaths are because of diarrhoea and dysentery. Shigellosis is an infectious disease caused by Shigella species, and it targets the intestinal tract. It is characterised by acute diarrhoea mixed with blood. The oral antibiotics recommended for shigellosis are ciprofloxacin and azithromycin, with ciprofloxacin as the first-line treatment. Recently, Shigella species have shown a rapid increase in resistance to these antibiotics, which is leading to overdose and prolonged treatment for the same. There is a need of the hour to find a potential substitute for antibiotics. Many alternatives, such as antimicrobial peptides, plant-based substances, bacteriophages, and probiotics, have shown promise compared to antibiotics. This paper focuses on the isolation and characterization of bacteriophages against Shigella dysenteriae. Bacteriophages are viruses that kill bacteria and are very specific to their host. They require host machinery to replicate; therefore, there is very little chance of developing resistance in bacteria against phage. The paper describes screening and isolation of phages from environmental samples against Shigella dysenteriae, followed by optimization studies and their characterization, such as host range, burst size and one-step growth curve. Morphological characterization using transmission electron microscopy (TEM) and whole genome sequencing has been performed, indicating that the phage belongs to the Myoviridae family and has a genome size of 38kbp.

Tuberculosis (TB) is a highly infectious disease caused by Mycobacterium tuberculosis. The World Health Organization (WHO) has reported more than 8 million new or relapse TB cases and 1.25 million deaths in 2023. Even though the global End TB strategy implemented by WHO has reduced the TB incidence rate between the years 2015 and 2023 up to 8.3%, TB remains one of the leading infectious causes of death worldwide. Active tuberculosis can affect any part of the body, and the clinical symptoms include fever, weight loss, and night sweats, whereas latent TB does not show any clinical symptoms. One of the significant concerns regarding the control of TB is the reservoir nature of latent tuberculosis. The Bacillus Calmette-Guerin (BCG) vaccine helps control TB and is still used globally to combat it. Currently, two methods are primarily used to identify tuberculosis infection: the Tuberculin Skin Test (TST) and the Interferon-Gamma Release Assay (IGRA). A significant disadvantage of these two methods is the inability to differentiate between latent and active tuberculosis. Accurate and timely diagnosis of TB is essential for effective management, mainly due to the emergence of multidrug-resistant strains. Specific biomarkers are required to evaluate tuberculosis infection, and novel biomarkers are needed to develop new diagnostic methods for tuberculosis. This article presents a brief review of recent developments in TB diagnostics, covering immunological, molecular, and monoclonal antibody-based platforms. The review also discusses the emerging role of artificial intelligence and deep machine learning platforms as complementary diagnostic tools.

Objective: Antibiotic resistance is one of the major causes of the increase in bacterial infections worldwilde. This is why it is the need of an hour to look for an alternative treatment; bacteriophage therapy is one of the most potent. Phages have been and still are being isolated against Shigella species but many of them remain uncultured and uncharacterized. Our study focuses on whole genome data sequence for bacteriophage isolated against Shigella dysenteriae. Data description: Bacteriophage VIT_AJPSC was isolated from cow shed drainage sample against Shigella dysenteriae. Phage genome is linear, double stranded and 38,898 bp long. A total 38 Coding sequences (CDS) were annotated and GC content was found to be 57%. TEM analysis showed that phage VIT_AJPSC has a icosahedral-shaped head, a contractile neck and tail region, a characteristic feature of Myoviridae family.

The World Health Organization (WHO) has set forth a global call for eradicating malaria, caused majorly by the protozoan parasites Plasmodium falciparum and Plasmodium vivax. The lack of diagnostic biomarkers for P. vivax, especially those that differentiate the parasite from P. falciparum, significantly hinders P. vivax elimination. Here, we show that P. vivax tryptophan-rich antigen (PvTRAg) can be a diagnostic biomarker for diagnosing P. vivax in malaria patients. We report that polyclonal antibodies against purified PvTRAg protein show interactions with purified PvTRAg and native PvTRAg using Western blots and indirect enzyme-linked immunosorbent assay (ELISA). We also developed an antibody-antigen-based qualitative assay using biolayer interferometry (BLI) to detect vivax infection using plasma samples from patients with different febrile diseases and healthy controls. The polyclonal anti-PvTRAg antibodies were used to capture free native PvTRAg from the patient plasma samples using BLI, providing a new expansion range to make the assay quick, accurate, sensitive, and high-throughput. The data presented in this report provides a proof of concept for PvTRAg, a new antigen, for developing a diagnostic assay for P. vivax identification and differentiation from the rest of the Plasmodium species and, at a later stage, translating the BLI assay into affordable, point-of-care formats to make it more accessible.

In the present study, monoclonal antibodies (MAbs) against recombinant histidine-rich protein (rHRP3) were developed and assessed for their potential in detection of Plasmodium falciparum HRP3. Hybridomas were obtained by fusion of Sp2/0 mouse myeloma cells and spleen cells from the mouse immunized with purified rHRP3. Three MAbs (IgG1 isotype) specific to rHRP3 were established and characterized by enzyme-linked immunosorbent assay (ELISA) and immunoblotting for sensitivity and specificity. Purification of MAbs from hybridoma cell culture supernatant and PAbs from rabbit anti-serum were carried out using Phenylpropylamine (PPA) HyperCel ^™ sorbent. The MAbs were able to detect rHRP3 and the HRP3 from P. falciparum spent medium. Sandwich ELISA was developed to quantify HRP3 in the spent medium of P. falciparum culture. The generated MAbs could be potentially used in immuno-based diagnostic systems for the detection of P. falciparum HRP.

Monoclonal antibodies (MAbs) have diverse applications in diagnostics and therapeutics. The recent advancement in hybridoma technology for large‐scale production of MAbs in bioreactors demands rapid and efficient purification methods. Conventional affinity purification systems have drawbacks of low flow rates and denaturation of antibodies owing to harsh elution conditions. Here, we attempted purification of MAbs by use of a high‐throughput metal–chelate methacrylate monolithic system. Monolithic macroporous convective interaction media–iminodiacetate (CIM‐IDA) disks immobilized with four different metal ions (Cu²⁺, Ni²⁺, Zn²⁺ and Co²⁺) were used and evaluated for purification of anti‐human serum albumin IgG1 mouse MAbs from cell culture supernatant after precipitation with 50% ammonium sulfate. Elution with 10 mM imidazole in the equilibration buffer (25 mM MMA = MOPS (Morpholino propane sulfonic acid) + MES (Morpholino ethane sulfonic acid) + Acetate + 0.5 M NaCl, pH 7.4) resulted in a purification of 25.7 ± 2.9‐fold and 32.5 ± 2.6‐fold in experiments done using Zn²⁺ and Co²⁺ metal ions, respectively. The highest recovery of 85.4 ± 1.0% was obtained with a CIM‐IDA‐Zn(II) column. SDS–PAGE, ELISA and immuno‐blot showed that the antibodies recovered were pure, with high antigen‐binding efficiency. Thus, metal chelate CIM monoliths could be a potential alternative to conventional systems for fast and efficient purification of MAbs from the complex cell culture supernatant. Copyright © 2012 John Wiley & Sons, Ltd.