An
            <i>in vivo</i>
            expression technology screen for
            <i>Vibrio cholerae</i>
            genes expressed in human volunteers

Lombardo, Mary Jane; Michalski, Jane; Martinez-Wilson, Hector; Morin, Cara; Hilton, Tamara; Osório, Carlos; Nataro, James P.; Tacket, Carol O.; Camilli, Andrew; Kaper, James B.

doi:10.1073/pnas.0705636104

Cited by 79 publications

(79 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…J. BACTERIOL. activated in the host environment (27), suggesting that these genes may be involved in survival in the human intestine. To test whether vciB plays a role in in vivo growth, a competition assay using infant mice was performed.…”

mentioning

confidence: 99%

Vibrio choleraeVciB Promotes Iron Uptake via Ferrous Iron Transporters

et al. 2008

View full text Add to dashboard Cite

Vibrio cholerae uses a variety of strategies for obtaining iron in its diverse environments. In this study we report the identification of a novel iron utilization protein in V. cholerae, VciB. The vciB gene and its linked gene, vciA, were isolated in a screen for V. cholerae genes that permitted growth of an Escherichia coli siderophore mutant in low-iron medium. The vciAB operon encodes a predicted TonB-dependent outer membrane receptor, VciA, and a putative inner membrane protein, VciB. VciB, but not VciA, was required for growth stimulation of E. coli and Shigella flexneri strains in low-iron medium. Consistent with these findings, TonB was not needed for VciB-mediated growth. No growth enhancement was seen when vciB was expressed in an E. coli or S. flexneri strain defective for the ferrous iron transporter Feo. Supplying the E. coli feo mutant with a plasmid encoding either E. coli or V. cholerae Feo, or the S. flexneri ferrous iron transport system Sit, restored VciB-mediated growth; however, no stimulation was seen when either of the ferric uptake systems V. cholerae Fbp and Haemophilus influenzae Hit was expressed. These data indicate that VciB functions by promoting iron uptake via a ferrous, but not ferric, iron transport system. VciB-dependent iron accumulation via Feo was demonstrated directly in iron transport assays using radiolabeled iron. A V. cholerae vciB mutant did not exhibit any growth defects in either in vitro or in vivo assays, possibly due to the presence of other systems with overlapping functions in this pathogen.

show abstract

mentioning

confidence: 99%

Vibrio choleraeVciB Promotes Iron Uptake via Ferrous Iron Transporters

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Recently, microarray expression profiling and in vivo expression technology have been used to elucidate the genes that are expressed by V. cholerae directly in the human host environment (1,17,19,20). These studies have identified a number of candidate genes that are preferentially expressed during human infection.…”

Section: Discussionmentioning

confidence: 99%

Proteomic Analysis of Vibrio cholerae in Human Stool

et al. 2008

View full text Add to dashboard Cite

An effective vaccine for Vibrio choleraeis not yet available for use in the developing world, where the burden of cholera disease is highest. Characterizing the proteins that are expressed by V. cholerae in the human host environment may provide insight into the pathogenesis of cholera and assist with the development of an improved vaccine. We analyzed the V. cholerae proteins present in the stools of 32 patients with clinical cholera. The V. cholerae outer membrane porin, OmpU, was identified in all of the human stool samples, and many V. cholerae proteins were repeatedly identified in separate patient samples. The majority of V. cholerae proteins identified in human stool are involved in protein synthesis and energy metabolism. A number of proteins involved in the pathogenesis of cholera, including the A and B subunits of cholera toxin and the toxincoregulated pilus, were identified in human stool. In a subset of stool specimens, we also assessed which in vivo expressed V. cholerae proteins were recognized uniquely by convalescent-phase as opposed to acute-phase serum from cholera patients. We identified a number of these in vivo expressed proteins as immunogenic during human infection. To our knowledge, this is the first characterization of the proteome of a pathogenic bacteria recovered from a natural host.Vibrio cholerae is a gram-negative bacillus that exists within an aquatic reservoir and that can cause severe, dehydrating, and occasionally fatal diarrhea in humans (11). Strains of V. cholerae are differentiated serologically by the O side chain of lipopolysaccharide, and the majority of toxigenic strains belong to serogroup O1 or O139. V. cholerae O1 occurs in two biotypes, classical and El Tor, which differ in biochemical characteristics and phage susceptibility. Since 1817, there have been seven cholera pandemics during which disease has spread from the Indian subcontinent across Asia, Europe, Africa, and the Western Hemisphere. The disease is also endemic in floodprone regions of South Asia, such as Bangladesh, where seasonal outbreaks typically occur in the spring and fall. The ongoing seventh pandemic of cholera is due to the O1 El Tor biotype of V. cholerae, and more than 100,000 diarrheal deaths per year are attributed to infection with this organism. Although a number of cholera vaccines have been developed over the past 100 years, an effective vaccine is not yet available for use in the developing world, where the burden of disease is highest (21).Humans are the only known host and reservoir for V. cholerae outside its aquatic environment, and an important limitation to the development and testing of cholera vaccines has been the lack of an optimal animal model of infection. It is consequently of great interest to understand which virulence factors are expressed by the organism directly in the human host environment, since in vivo expressed antigens of V. cholerae may represent targets of protective human immune responses. The capacity to perform such research has been facilitated by the sequen...

show abstract

“…Evidence that iron transport genes are expressed during infection has been obtained by using animal models or experimental infections of humans. Lombardo et al (176) used in vivo expression technology (IVET) to determine the V. cholerae genes expressed during infection of human volunteers or in an infant mouse model. fhuC, encoding the ATPase of the hydroxamate transport system, was identified in both infected humans and the mouse model.…”

Section: Iron Acquisition Within the Hostmentioning

confidence: 99%

Vibrio Iron Transport: Evolutionary Adaptation to Life in Multiple Environments

Payne

Mey

Wyckoff

2016

Microbiol Mol Biol Rev

View full text Add to dashboard Cite

SUMMARYIron is an essential element forVibriospp., but the acquisition of iron is complicated by its tendency to form insoluble ferric complexes in nature and its association with high-affinity iron-binding proteins in the host. Vibrios occupy a variety of different niches, and each of these niches presents particular challenges for acquiring sufficient iron.Vibriospecies have evolved a wide array of iron transport systems that allow the bacteria to compete for this essential element in each of its habitats. These systems include the secretion and uptake of high-affinity iron-binding compounds (siderophores) as well as transport systems for iron bound to host complexes. Transporters for ferric and ferrous iron not complexed to siderophores are also common toVibriospecies. Some of the genes encoding these systems show evidence of horizontal transmission, and the ability to acquire and incorporate additional iron transport systems may have allowedVibriospecies to more rapidly adapt to new environmental niches. While too little iron prevents growth of the bacteria, too much can be lethal. The appropriate balance is maintained in vibrios through complex regulatory networks involving transcriptional repressors and activators and small RNAs (sRNAs) that act posttranscriptionally. Examination of the number and variety of iron transport systems found inVibriospp. offers insights into how this group of bacteria has adapted to such a wide range of habitats.

show abstract

An in vivo expression technology screen for Vibrio cholerae genes expressed in human volunteers

Cited by 79 publications

References 40 publications

Vibrio choleraeVciB Promotes Iron Uptake via Ferrous Iron Transporters

Vibrio choleraeVciB Promotes Iron Uptake via Ferrous Iron Transporters

Proteomic Analysis of Vibrio cholerae in Human Stool

Vibrio Iron Transport: Evolutionary Adaptation to Life in Multiple Environments

Contact Info

Product

Resources

About