Publications by authors named "Ramamurthy T"

Background: Public health is seriously threatened by transmission of zoonotic infection through the food chain. Factors like increasing population, deforestation, high demand for animal protein, and trade of sub-clinically infected animals are the main causes of the spread of infections from asymptomatic animals to humans. Despite several national programs like (The Clean India Mission) prevention of open defecation and water, sanitation, and hygiene (WASH), the incidence of diarrhoeal diseases remains high in India.

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Pasteurization is a process that eliminates microorganisms and minimizes nutrient loss in fruit juices, thus extending their shelf life. It is effective for juices with a pH range of 3.5-4.

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Background: Traditional and fermented foods are widely consumed by the ethnic population of Northeast India. These foods are not only very nutritious, easily available, and reasonably priced, but also boost immunity and protect from various seasonal infections and have been reported through several investigations. However, pathogens transmitted by these foods have never been reported.

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Article Synopsis
  • - Food safety is a serious global issue, especially in India’s North-East region, where fermented foods have led to numerous diarrheal outbreaks, but there is a lack of systematic data on foodborne pathogens.
  • - The research aims to create an integrated surveillance system to monitor enteric pathogens in humans, food animals, and the environment, improving outbreak investigations in North-East India.
  • - The Indian Council of Medical Research (ICMR) is leading a study to gather data through laboratory surveillance at various locations, utilizing a centralized digital database for better management and analysis of foodborne diseases.
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  • Food and waterborne illnesses are a major public health concern in India, often linked to large gatherings and poor food handling practices, as seen in an acute diarrheal disease outbreak at a birthday party in rural Assam.
  • The investigation involved collecting demographic data, illness details, rectal swabs, and water samples, revealing that 25 people were affected, with Shigella sonnei identified as the pathogen responsible for the outbreak.
  • The study highlighted a significant association between illness and the consumption of chicken curry, indicating a high attack rate and resistance of the pathogen to several antibiotics, while the water quality was deemed safe.
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  • Polymethylmethacrylate (PMMA) is commonly used for dentures but can lead to infections like denture stomatitis due to microbial growth; enhancing its antimicrobial properties is vital for better patient health.
  • Chitosan, a natural biopolymer with antimicrobial qualities, was added to heat-polymerized PMMA in varying concentrations (0%, 5%, 10%, 15%) to investigate its effectiveness against oral pathogens.
  • The study found that chitosan-reinforced PMMA samples exhibited significantly improved antimicrobial effectiveness compared to conventional PMMA, indicating a promising approach to reduce microbial colonization in dentures.
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Robust digital infrastructure is vital and the need of the hour, especially in the healthcare sector, for real-time data generation, analysis, and quick decision-making. Food- and water-borne illnesses represent a prominent cause of morbidity and mortality worldwide. India, a developing nation with diverse cultures and food practices, poses a high risk of food-borne diseases and outbreaks, yet is often underreported and ineffectively researched.

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Background: Foodborne and waterborne diseases and outbreaks are a neglected public health issue worldwide. In developing countries, diarrheal disease caused by foodborne and waterborne infections is a major cause of ill health. There is a lack of information on foodborne pathogens, their transmission routes, outbreaks, and related mortalities, due to the absence of a robust disease surveillance system and adequately equipped laboratories.

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Age-stratified path analyses modeled associations between enteric pathogen reservoirs, transmission pathways and height-for-age z-scores (HAZ) to identify determinants of childhood growth in the Kolkata, India site of the Global Enteric Multicenter Study (GEMS). Models tested direct associations of potential pathogen reservoirs with HAZ at 60-day follow-up in separate moderate and severe diarrhea (MSD) case and control cohorts or indirectly when mediated by enteric infections. In the MSD cohort, rotavirus and typical EPEC (tEPEC) infections among children 0-11 months of age and ST-ETEC infections among children 12-23 months of age were associated with lower HAZ.

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Introduction An acute gastrointestinal illness outbreak was reported in a higher educational institution among students and faculties in East Sikkim, India, from January to February 2023. The investigation was conducted to identify the source of the infection and causative pathogens and prevent the spread of the outbreak. Methods We defined a case as three or more loose stools in 24 hours, abdominal pain, or vomiting with the onset of symptoms between January 16 and February 16, 2023.

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Food and waterborne outbreaks are a neglected public health problem in India. However, it is important to identify the source of infection and the causative pathogen to curb the outbreak quickly and minimize mortality and morbidity. A retrospective descriptive study was conducted with a line list of 130 diarrheal cases.

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Background: Quantitative molecular assays are increasingly used for detection of enteric viruses.

Methods: We compared the clinical severity using the modified Vesikari score (mVS) of enteric viruses detected by conventional assays (enzyme immunoassays [EIAs] for rotavirus and adenovirus 40/41 and conventional polymerase chain reaction for astrovirus, sapovirus, and norovirus) and a quantitative molecular assay (TaqMan Array Card [TAC]) among children aged 0-59 months in the Global Enteric Multicenter Study. For rotavirus and adenovirus 40/41, we compared severity between EIA-positive and TAC-positive cases assigned etiologies using different cycle threshold (Ct) cutoffs.

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is a cholera-causing pathogen known to instigate severe contagious diarrhea that affects millions globally. Survival of vibrios depend on a combination of multicellular responses and adapt to changes that prevail in the environment. This process is achieved through a strong communication at the cellular level, the process has been recognized as quorum sensing (QS).

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Background: The primary aim of this study was to investigate the occurrence, characteristics, and antimicrobial resistance patterns of various Shigella serogroups isolated from patients with acute diarrhea of the Infectious Diseases Hospital in Kolkata from 2011-2019.

Principal Findings: During the study period, Shigella isolates were tested for their serogroups, antibiotic resistance pattern and virulence gene profiles. A total of 5.

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Background: Food safety is a critical factor in promoting public health and nutrition, especially in developing countries like India, which experience several foodborne disease outbreaks, often with multidrug-resistant pathogens. Therefore, implementing regular surveillance of enteric pathogens in the human-animal-environment interface is necessary to reduce the disease burden in the country.

Objective: To establish a network of laboratories for the identification of major food and waterborne pathogens prevailing in the northeast region of India through integrated surveillance of animal, food, human, and environment and investigate the antimicrobial susceptibility pattern of the pathogens of public health significance.

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Objectives: Recent advancement in understanding neurological disorders has revealed the involvement of dysbiosis of the gut microbiota in the pathophysiology of Parkinson's disease (PD). We sequenced microbial DNA using fecal samples collected from PD cases and healthy controls (HCs) to evaluate the role of gut microbiota.

Methods: Full-length bacterial 16S rRNA gene sequencing of fecal samples was performed using amplified polymerase chain reaction (PCR) products on the GridION Nanopore sequencer.

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We isolated a strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this organism, which was obtained by combining Illumina and Oxford Nanopore sequencing data.

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Microbes evolve rapidly by modifying their genomes through mutations or through the horizontal acquisition of mobile genetic elements (MGEs) linked with fitness traits such as antimicrobial resistance (AMR), virulence, and metabolic functions. We conducted a multicentric study in India and collected different clinical samples for decoding the genome sequences of bacterial pathogens associated with sepsis, urinary tract infections, and respiratory infections to understand the functional potency associated with AMR and its dynamics. Genomic analysis identified several acquired AMR genes (ARGs) that have a pathogen-specific signature.

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To characterize extensively drug-resistant from a patient with diarrhea. Antimicrobial susceptibility was tested by the disk diffusion method. The genome was sequenced to identify virulence, antibiotic resistance and prophages encoding genes.

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Antimicrobial resistance (AMR) in bacteria is an important global health problem affecting humans, animals, and the environment. AMR is considered as one of the major components in the "global one health". Misuse/overuse of antibiotics in any one of the segments can impact the integrity of the others.

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Article Synopsis
  • Cholera is a significant global health issue, and oral cholera vaccines (OCVs) are a key prevention strategy, with research suggesting the need to enhance their effectiveness against various cholera antigens beyond just O-antigen.
  • Patients recovering from cholera develop specific antibody responses that are crucial for immunity, highlighting the importance of targeting antigens like TCP and CT in OCV development.
  • Recent studies indicate that strains expressing the -139F allele can stimulate strong antibody responses in mice, making them promising candidates for improved inactivated OCVs that could lead to better protection against cholera.
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Diarrheal disease remains a great public health problem in many countries. Enteric infections caused by several viral, bacterial and parasitic species not only affect the host, but also alter the gut microbiome. The host physiology dictates the intestinal milieu and decides the composition and richness of gut microbiota, which forms a homeostatic ecosystem with numerous functions and provide protection against invading pathogens.

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  • Helicobacter pylori (H. pylori) is a common bacterium linked to chronic gastritis, peptic ulcers, and gastric cancer, with varying virulence and resistance factors, especially in India.
  • A study analyzed the genomes of 143 H. pylori strains from eastern and southern India, revealing distinct regional differences in antibiotic resistance and virulence genes.
  • Findings indicate lower resistance to amoxicillin and furazolidone in eastern strains, while resistance to metronidazole and clarithromycin is more prevalent; this suggests careful antibiotic use in eastern India and highlights the need for understanding local strain characteristics.
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Aims: The present study aimed to document the comparative analysis of differential hypervirulent features of Vibrio cholerae O1 strains isolated during 2018 from cholera endemic regions in Gujarat and Maharashtra (Western India) and West Bengal (Eastern India).

Methods And Results: A total of 87 V. cholerae O1 clinical strains from Western India and 48 from Eastern India were analysed for a number of biotypic and genotypic features followed by antimicrobial resistance (AMR) profile.

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