Expression in Saccharomyces boulardii of recombinant Toxin-coregulated pilus A subunit (TcpA) of Vibrio cholerae O1

Cholera is endemic in over 50 countries with an estimated mortality of 100,000-120,000. Vaccination is considered the complementary key to prevent and control cholera; therefore, alternative vaccine preparations are needed. Toxin Co-regulated Pilus is part of the toxR virulence regulon, which is necessary for colonization in the intestinal mucosa. In order to express Vibrio cholerae TcpA protein in Saccharomyces boulardii, the expression plasmid pYES2 was constructed by inserting tcpA gene isolated from local Vibrio cholerae Eltor Inaba isolates. The new construct was transferred into Saccharomyces boulardii cells and the expression of tcpA gene was induced from the GAL1 promoter by adding galactose to the medium. The SDS-PAGE and Western blot analysis showed the presence of TcpA in yeast. These results showed that Saccharomyces boulardii is a promising host to express Vibrio cholerae toxin TcpA as the first step in attempt to produce an oral Vibrio cholerae vaccine(AU)

El cólera es endémico en más de 50 países. Se estima una mortalidad entre 100.000 - 120.000 debido a esta enfermedad. La vacunación se considera una medida complementaria para prevenir y controlar el cólera, por lo tanto, se necesitan preparaciones vacunales alternativas a las existentes. El Pili corregulado con la toxina, es parte del regulón de virulencia toxR, y es necesario para la colonización en la mucosa intestinal. Para expresar la proteína tcpA de Vibrio cholerae en Saccharomyces boulardii, se construyó el plásmido de expresión pYES2 insertando el gen tcpA obtenido a partir de aislamientos locales de Vibrio cholerae El Tor Inaba. La nueva construcción se transfirió a las células de Saccharomyces boulardii y se indujo la expresión del gen tcpA a partir del promotor GAL1 mediante la adición de galactosa al medio. El análisis mediante SDS-PAGE y Western blot demostró la presencia de TcpA en levaduras. Los resultados demostraron que Saccharomyces boulardii es un hospedero prometedor para expresar el gen tcpA de Vibrio cholerae como el primer paso en el intento de producir una vacuna oral contra Vibrio cholerae(AU)

Yemen OCV risk assessment

The Ministry of Public Health and Population [MoHP], Yemen, WHO and other partners conducted assessment to determine risk profile of governorates and districts for occurrence and spread of cholera in order to prioritize the high risk districts for use of oral cholera vaccine [OCV] as a preventive measure for prevention and control of cholera

OCV risk assessment in Sudan

In October 2017, the Federal Ministry of Health, Sudan, in collaboration with WHO and other partners conducted as-sessment to determine risk profile of states and localities for occurrence and spread of cholera in order to prioritize localities and special high risk groups for use of oral cholera vaccine [OCV] for prevention of the outbreak

Cholera Outbreak in Somalia

Somalia has been experiencing recurring outbreaks of cholera in the last few years. The current cholera outbreak started in November 2016 and is still ongoing. Since the beginning of the outbreak in early 2016, a cumulative total of 20 684 cases including 689 deaths have been reported so far [CFR=3.2%] from the country

Communications in public health emergencies

Recent experience with famine and cholera outbreak in Somalia has shown that communication, whether with affected communities, among public health response actors, or with the media, is a critical component of effective response to public health emergencies

Use of single dose OCV: New strate-gies for cholera control

Recent evidence has emerged on the effectiveness of single dose of oral cholera vaccine for outbreak response. This finding has generated interest in the control of cholera outbreaks in the epidemic belt of the Eastern Mediterranean Region

Cholera in Yemen: cases rise

Cholera outbreak in Yemen continues while cases increase in recent time. As of date, a total of 7,730 suspected cases including 82 relate deaths have been reported since the outbreak began during the first week of October [epidemiological week no 34]

Cholera vaccine: developmental strategies and problems.

Over a hundred years have elapsed since Vibrio cholerae, the etiological agent for the disease cholera, was discovered by Robert Koch. Ever since then serious efforts have been made to develop prophylactic measures to combat the disease without much success. Seven pandemics have so far been reported and cholera still remains a public health problem in developing countries. Several strategies have been adopted to develop vaccines against the disease and many of these vaccines have undergone field trials. During the last two decades, an enormous amount of information has accumulated regarding the organism V. cholerae, its virulence factors, including cholera toxin, and the molecular basis of its pathogenicity. In recent years, with the advent of recombinant DNA technology and major breakthroughs in molecular biology and immunology, a new dimension has been given to the design of vaccine strains. The second generation live oral vaccines will perhaps soon replace the long-used first generation parenterally administered killed whole cell vaccines which offered protection for not more than three months. All the recombinant vaccines tested so far produced adverse reactions in volunteers, although they provided varying degrees of protection upto about one year of surveillance. Parallel to the trials of live oral vaccines, combination vaccines comprising killed whole cells and purified B subunit of cholera toxin was also tried. These vaccines had minimal side-effects but the efficacy was not upto expectations. From the failure of each vaccine strain, new information had emerged and improved strategies were adopted.(ABSTRACT TRUNCATED AT 250 WORDS)