typhoid purification

The hemolysin (HlyE) protein of Salmonella enterica serovar Typhi was reported to be antigenic. This work describes the cloning, expression, and purification of a hexahistidine-tagged HlyE protein under native conditions. Immunoblot analysis and a competitive enzyme-linked immunosorbent assay using sera from typhoid patients showed the presence of HlyE-specific antibodies in circulation.

BACKGROUND: Salmonella Typhi is a pathogenic bacterium that causes a number of infectious diseases such as gastroenteritis and typhoid fever. In this study, an antigenic (34 kDa) protein was identified, purified, and characterized from outer membrane of Salmonella typhi. METHODS: Immunoblot analysis was used to screen antigenic proteins from outer membrane of Salmonella Typhi. Proteins from outer membrane were isolated and resolved on SDS-PAGE. In immunoblot analysis, four proteins with the following molecular weights of 60 kDa, 54 kDa, 34 kDa, and 26 kDa were identified as highly antigenic against the serum of patients suffering from typhoid fever...

Salmonella enterica subsp. Typhi (S. Typhi) Vi antigen capsular polysaccharide (Vi-CPS) is a licensed vaccine against typhoid fever. As there is no animal model for S. Typhi fever to evaluate the protective efficacy of the Vi-CPS vaccine, a serum bactericidal assay (SBA) is the recommended 'gold standard' to evaluate its potency. Vi-CPS was extracted from S. Typhi Ty6S (CSBPI-B191) using a modified Gotschlich method. Purified Vi-CPS (50 µg) was injected intramuscularly into three groups of five rabbits; group 2 received an additional booster dose of 50 µg Vi-CPS on day 15 and group 3 received two additional boosters on days 15 and 30...

Unsafe drinking water continues to burden developing countries despite improvements in clean water delivery and sanitation, in response to Millennium Development Goal 7. Salmonella serotype Typhi and Vibrio cholerae bacteria can contaminate drinking water, causing waterborne typhoid fever and cholera, respectively. Household water treatment (HWT) systems are widely promoted to consumers in developing countries but it is difficult to establish their benefits to the population for specific disease reduction. This research uses a laboratory assessment of halogenated chlorine beads treating contaminated water to inform a quantitative microbial risk assessment (QMRA) of S...

Infection with Salmonella enterica serovar Typhi in humans causes the life-threatening disease typhoid fever. In the laboratory, typhoid fever can be modeled through the inoculation of susceptible mice with Salmonella enterica serovar Typhimurium. Using this murine model, we previously characterized the interactions between Salmonella Typhimurium and host cells in the gallbladder and showed that this pathogen can successfully invade gallbladder epithelial cells and proliferate. Additionally, we showed that Salmonella Typhimurium can use bile phospholipids to grow at high rates...

A conjugate vaccine for Salmonella enterica serovar Typhi was produced by chemically linking Vi, purified from Citrobacter, to the non-toxic mutant diphtheria toxin CRM(197) via an adipic dihydrazide spacer using N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide coupling chemistry. The polysaccharide purification process was developed based on Vi precipitation from culture supernatant with cetyl trimethylammonium bromide (CTAB), solubilization of the CTA-polysaccharide salt with ethanol followed by exchange of the CTA(+) counter ion with Na(+)...

We evaluated the robustness of loop-mediated isothermal amplification (LAMP) of DNA for bacterial diagnostic applications. Salmonella enterica serovar Typhi was used as the target organism and compared with a real-time quantitative PCR (qPCR) for testing assay performance and reproducibly, as well as the impact of pH and temperature stability. This isothermal amplification method appeared to be particularly robust across 2 pH units (7.3-9.3) and temperature values (57-67 °C). The detection limit was comparable to that observed using optimized home-brew qPCR assays...

The quality of drinking water in the United States has continued to improve over the past 40 years. The formation of the U.S. Environmental Protection Agency (USEPA) in 1971, the passage of the initial Safe Drinking Water Act (SDWA, PL 93-523) in 1974, and the passage of the 1996 SDWA Amendments (PL 104-208) represent significant progress in drinking water quality. While the widespread adoption of filtration and disinfection in the early 1900s virtually eliminated waterborne typhoid fever, some residual risks still remained 40 years ago...

French Guyana is located in South America, and it is confronted with an endemic situation where waterborne diseases are widespread, especially among those 30,000 people without access to drinking water. In 2007, two notices of the French High Council for Public Health were issued, one concerning vaccination against typhoid and the other on conditions for improving water supply in Guyana. The latter served as a basis for proposing and implementing actions to "improve water quality for those who did not have access to it"...

Brucellosis is a disease caused by Gram-negative, facultative, intracellular bacteria belonging to the genus Brucella. It is an emerging zoonosis, and an economically important infection of humans and livestock with a worldwide distribution. Human infection is known to occur through consumption of infected raw milk, milk products and undercooked or raw meat. Serodiagnosis of brucellosis is carried out by detection of antibodies generated against LPS or whole-cell bacterial extracts by ELISA or agglutination tests using colorimetry...

Porin proteins of Gram-negative bacteria are outer membrane proteins that act as receptors for bacteriophages and are involved in a variety of functions like solute transport, pathogenesis, and immunity. Salmonella enterica serovar Typhi (S. Typhi), a Gram-negative bacterium, is the causative agent of typhoid fever. Porins of S. Typhi have been shown to have a potential role in diagnostics and vaccination. In the present study, the major outer membrane proteins OmpF and OmpC from S. Typhi were cloned in pQE30UA vector and expressed in E...

Enteric fever is systemic illness caused by Salmonella Typhi and Salmonella Paratyphi A, B and C. It is believed to be a readily treatable illness by many clinicians in the developing world where it is endemic; however, with the emergence of drug resistance to fluoroquinolones, treatment is becoming increasingly difficult. While drugs such as cefixime, previously believed to be effective, have been proven otherwise, new agents such as gatifloxacin and azithromycin have proven to be promising. Re-emergence of chloramphenicol sensitive strains in previously resistant areas points towards the concept of antibiotic recycling, preserving the use of older antibiotics...

The purified alpha-amylase of Geobacillus thermoleovorans had a molecular mass of 26 kDa with a pI of 5.4, and it was optimally active at 100 degrees C and pH 8.0. The T 1/2 of alpha-amylase at 100 degrees C increased from 3.6 to 5.6 h in the presence of cholic acid. The activation energy and temperature quotient (Q 10) of the enzyme were 84.10 kJ/mol and 1.31, respectively. The activity of the enzyme was enhanced strongly by Co2+ and Fe2+; enhanced slightly by Ba2+, Mn2+, Ni2+, and Mg2+; inhibited strongly by Sn2+, Hg2+, and Pb2+, and inhibited slightly by EDTA, phenyl methyl sulfonyl fluoride, N-ethylmaleimide, and dithiothreitol...

Give the oyster a chance to cleanse itself and typhoid will be as preventable here as with domestic water supplies. This is the motif of this paper by Dr. Wells, who is no new hand at discussing shellfish problems. "It can be considered a conservation measure," he urges.

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No abstract text is available yet for this article.

A field survey was conducted on four slum, squatter and pavement dweller communities of Mumbai City, India with a total sample size of 1,070 households. Study revealed extremely low water consumption pattern averaging merely 30 l/c x d, no sewerage and safe excreta disposal facilities manifested by high occurrence of water-borne diseases. The annual diarrhoeal, typhoid and malaria cases were estimated to 614, 68 and 126 per thousand populations respectively. At point prevalence scale, at least 30% of all morbidity can be accounted for by water-related infections...

Transmission of pathogens with drinking water is a widespread problem, which affects not only the countries with low hygienic standards but the industrialized countries as well. The pathogens are excreted by man or animals and are picked up orally. Chlorination of drinking water has been introduced to the water supply in the beginning of the 19th century in order to stop the spreading of pathogens especially typhoid fever by drinking water. Despite the worldwide use of chlorine for disinfection of drinking water, water-mediated disease outbreaks occur again and again...