Article
Medicine, Research & Experimental
Shania Vij, Reena Thakur, Raghwendra Pratap Singh, Rashmi Kumar, Preeti Pathania, Varsha Gupta, Chander Raman Suri, Praveen Rishi
Summary: This study explored the protective response of dual immunization using two different antigenic entities against lethal challenge of typhoidal serovars in a murine model. The results showed that the combination of both entities improved mice survival and reduced bacterial burden in organs. Passive immunization studies further determined the protective efficacy of generated antibodies by different mechanisms.
Article
Microbiology
Jobin John Jacob, Agila K. Pragasam, Karthick Vasudevan, Aravind Velmurugan, Monisha Priya Teekaraman, Tharani Priya Thirumoorthy, Pallab Ray, Madhu Gupta, Arti Kapil, Sulochana Putil Bai, Savitha Nagaraj, Karnika Saigal, Temsunaro Rongsen Chandola, Maria Thomas, Ashish Bavdekar, Sheena Evelyn P. Ebenezer, Jayanthi Shastri, Anuradha R. De, Shantha Dutta, Anna Alexander, Roshine Mary Koshy, Dasaratha Jinka, Ashita Singh, Sunil Kumar Srivastava, Shalini Anandan, Gordon Dougan, Jacob M. John, Gagandeep M. Kang, Balaji Veeraraghavan, Ankur Mutreja
Summary: This study investigates the evolutionary trajectory and population structure of S. Paratyphi A isolates collected in India. The study finds that S. Paratyphi A accounted for 17.6% of enteric fever cases in India during the study period, and the isolates were highly susceptible to major antibiotics except for fluoroquinolones. Phylogenetic analysis reveals that S. Paratyphi A isolates in India belong to lineages A, C, and F, and genome degradation events and gene acquisitions or losses are important molecular events in the evolution of new lineages.
Article
Immunology
Yogesh Hooda, Arif Mohammad Tanmoy, Samir K. Saha, Senjuti Saha
Summary: In the past 2 years, more than 1000 Salmonella Paratyphi A isolates have been sequenced from South Asia. An open-access tool called Paratype has been developed to track genotypes and antimicrobial resistance. However, there is still limited genomic data available from sub-Saharan Africa, the Middle East, and South America.
OPEN FORUM INFECTIOUS DISEASES
(2023)
Article
Microbiology
Mohammad S. Sajib, Arif M. Tanmoy, Yogesh Hooda, Hafizur Rahman, Jason R. Andrews, Denise O. Garrett, Hubert P. Endtz, Samir K. Saha, Senjuti Saha
Summary: The rising prevalence of antimicrobial resistance in Salmonella enterica serovars Typhi and Paratyphi A, especially against azithromycin, has raised concerns about untreatable infections. Cases of azithromycin-resistant strains with a single point mutation (AcrB-R717Q/L) have been reported in South Asia. Genomic analysis confirmed the spontaneous emergence of this mutation in different genotypes, with a specific genotype predicted to have acquired the mutation in 2010. The development of a low-cost PCR tool for real-time detection of this mutation may aid in early intervention against pan-oral drug resistance.
Article
Immunology
G. Gasperini, R. Alfini, V Arato, F. Mancini, M. G. Aruta, P. Kanvatirth, D. Pickard, F. Necchi, A. Saul, O. Rossi, F. Micoli, P. Mastroeni
Summary: Researchers developed a novel GMMA vaccine through genetic engineering to display specific antigens on bacterial surfaces, inducing a strong antibody response. This vaccine candidate shows potential to provide immune protection against infections caused by different Salmonella serovars.
INFECTION AND IMMUNITY
(2021)
Article
Immunology
Ye Feng, Yi-Ching Chen, Rajendra Prasad Janapatla, Zeyu Wang, Ying-Jie Hsu, Chyi-Liang Chen, Cheng-Hsun Chiu
Summary: The genomic analysis in Taiwan showed a link to infections in South and Southeast Asia, as well as global circulation of typhoidal clones. Mutations at gyrA 83 aa were found in ciprofloxacin-resistant strains. Local transmission of international clones was also observed in the country.
JOURNAL OF MICROBIOLOGY IMMUNOLOGY AND INFECTION
(2022)
Article
Cell Biology
Elli Mylona, Julia Sanchez-Garrido, Trang Nguyen Hoang Thu, Sabina Dongol, Abhilasha Karkey, Stephen Baker, Avinash R. Shenoy, Gad Frankel
Summary: The study investigated the impact of Salmonella Paratyphi A on human macrophages, revealing that it induces a specific form of cell death through activation of multiple caspases. Furthermore, the very long O-antigen chains produced by SPtA interfere with bacterial interactions with epithelial cells and inhibit inflammasome-mediated macrophage cell death. The differential expression of FepE in SPtA and Salmonella Typhimurium leads to serovar-specific inflammasome modulation, suggesting distinct virulence mechanisms between the two strains.
CELLULAR MICROBIOLOGY
(2021)
Review
Microbiology
Durga P. Neupane, Hari P. Dulal, Jeongmin Song
Summary: Enteric fever is a life-threatening systemic febrile disease caused by Salmonella enterica serovars Typhi and Paratyphi. The current diagnostic methods have limitations, and identifying asymptomatic carriers remains challenging. Further research is needed to improve diagnostic tests and identify new biomarkers.
Article
Pediatrics
Valbona Selimaj Kontoni, Philippe Lepage, Marc Hainaut, Veronique Yvette Miendje Deyi, Wesley Maatheus, David Pace
Summary: Enteric fever in children presents with delayed diagnosis, serious clinical symptoms, and abnormal laboratory findings, with travel history being related to infection risk.
EUROPEAN JOURNAL OF PEDIATRICS
(2022)
Article
Infectious Diseases
Takashi Matono, Hidemasa Izumiya, Hidenobu Koga, Mitsuo Kaku, Makoto Ohnishi, Masatomo Morita
Summary: In 2015, there was an unusual increase in Salmonella Paratyphi A infection rate in Japanese travelers returning from Myanmar. Epidemiologic and molecular investigations revealed a close genetic relationship between the infections.
INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES
(2022)
Review
Microbiology
Amber J. Barton, Jennifer Hill, Christoph J. Blohmke, Andrew J. Pollard
Summary: The lack of vaccines against paratyphoid, multidrug resistance, and chronic carriage pose challenges for enteric fever elimination, despite the recent recommendation of conjugate vaccines for typhoid fever by WHO. Advances in in vitro and human challenge models in the past decade have enhanced understanding of enteric fever pathogenesis and have the potential to drive future developments in vaccines and antimicrobials.
FEMS MICROBIOLOGY REVIEWS
(2021)
Article
Genetics & Heredity
Marie Anne Chattaway, Amy Gentle, Satheesh Nair, Laura Tingley, Martin Day, Iman Mohamed, Claire Jenkins, Gauri Godbole
Summary: The study has shown an increase in the cases of Salmonella Typhi and S. Paratyphi A in England, mainly associated with travel to South Asia, leading to a review of clinical guidelines to address the emergence of multidrug-resistant and extensively drug resistant strains. Genomic surveillance has proven effective in monitoring trends in incidence, antimicrobial resistance, and travel patterns of typhoidal salmonellae.
MICROBIAL GENOMICS
(2021)
Review
Microbiology
Amber J. Barton, Jennifer Hill, Christoph J. Blohmke, Andrew J. Pollard
Summary: This review summarizes the advances in understanding the pathogenesis of enteric fever, including mechanisms of host restriction, intestinal invasion, interactions with innate immunity, and chronic carriage, and discusses how this knowledge may advance future vaccines and antimicrobials.
FEMS MICROBIOLOGY REVIEWS
(2021)
Review
Public, Environmental & Occupational Health
Abi Manesh, Eyal Meltzer, Celina Jin, Carl Britto, Divya Deodhar, Sneha Radha, Eli Schwartz, Priscilla Rupali
Summary: Enteric fever caused by Salmonella Typhi and Salmonella Paratyphi remains a significant infectious disease in Asia and Africa, with the highest prevalence reported in the Indian subcontinent. The emergence of widespread antimicrobial resistance has limited treatment options for travel-related EF, highlighting the importance of improving diagnosis, hygiene, and vaccination. Efforts to control typhoid include early detection of resistance, therapy with appropriate drugs, provision of safe drinking water, and vaccination among travellers and locals. improved vaccines against Salmonella Typhi and Salmonella Paratyphi A are needed to enhance control measures.
JOURNAL OF TRAVEL MEDICINE
(2021)
Article
Immunology
Laura B. Martin, Farhana Khanam, Firdausi Qadri, Ibrahim Khalil, Michael J. Sikorski, Stephen Baker
Summary: In Asia, there are 12 million annual cases of enteric fever caused by Salmonella enterica serovars Typhi (STy) and Paratyphi A (SPA), making a bivalent STy/SPA vaccine important. Several candidate vaccines for enteric fever control are close to entering clinical trials. The World Health Organization prioritizes the development of vaccines to protect young children and working-aged adults against both agents of enteric fever.
