Yersinia Pestis

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Joseph B Hinnebusch - One of the best experts on this subject based on the ideXlab platform.

  • molecular and genetic mechanisms that mediate transmission of Yersinia Pestis by fleas
    Biomolecules, 2021
    Co-Authors: Joseph B Hinnebusch, Clayton O Jarrett, David M Bland
    Abstract:

    The ability to cause plague in mammals represents only half of the life history of Yersinia Pestis. It is also able to colonize and produce a transmissible infection in the digestive tract of the flea, its insect host. Parallel to studies of the molecular mechanisms by which Y. Pestis is able to overcome the immune response of its mammalian hosts, disseminate, and produce septicemia, studies of Y. Pestis–flea interactions have led to the identification and characterization of important factors that lead to transmission by flea bite. Y. Pestis adapts to the unique conditions in the flea gut by altering its metabolic physiology in ways that promote biofilm development, a common strategy by which bacteria cope with a nutrient-limited environment. Biofilm localization to the flea foregut disrupts normal fluid dynamics of blood feeding, resulting in regurgitative transmission. Many of the important genes, regulatory pathways, and molecules required for this process have been identified and are reviewed here.

  • intravital confocal microscopy of dermal innate immune responses to flea transmitted Yersinia Pestis
    Methods of Molecular Biology, 2019
    Co-Authors: Jeffrey G Shannon, Joseph B Hinnebusch
    Abstract:

    The technique known as intravital microscopy (IVM), when used in conjunction with transgenic mice expressing fluorescent proteins in various cell populations, is a powerful tool with the potential to provide new insights into host-pathogen interactions in infectious disease pathogenesis in vivo. Yersinia Pestis, the causative agent of plague, is typically deposited in a host's skin during feeding of an infected flea. IVM has been used to characterize the innate immune response to Y. Pestis in the skin and identify differences between the responses to needle-inoculated and flea-transmitted bacteria that would have been difficult, if not impossible, to detect by other means. Here we describe techniques used to image the neutrophil response to flea-transmitted Y. Pestis in the dermis of live mice using conventional confocal microscopy.

  • fleaing the plague adaptations of Yersinia Pestis to its insect vector that lead to transmission
    Annual Review of Microbiology, 2017
    Co-Authors: Joseph B Hinnebusch, Clayton O Jarrett, David M Bland
    Abstract:

    Interest in arthropod-borne pathogens focuses primarily on how they cause disease in humans. How they produce a transmissible infection in their arthropod host is just as critical to their life cycle, however. Yersinia Pestis adopts a unique life stage in the digestive tract of its flea vector, characterized by rapid formation of a bacterial biofilm that is enveloped in a complex extracellular polymeric substance. Localization and adherence of the biofilm to the flea foregut is essential for transmission. Here, we review the molecular and genetic mechanisms of these processes and present a comparative evaluation and updated model of two related transmission mechanisms.

  • correction comparative ability of oropsylla montana and xenopsylla cheopis fleas to transmit Yersinia Pestis by two different mechanisms
    PLOS Neglected Tropical Diseases, 2017
    Co-Authors: Joseph B Hinnebusch, David M Bland, Christopher F Bosio, Clayton O Jarrett
    Abstract:

    Background Transmission of Yersinia Pestis by flea bite can occur by two mechanisms. After taking a blood meal from a bacteremic mammal, fleas have the potential to transmit the very next time they feed. This early-phase transmission resembles mechanical transmission in some respects, but the mechanism is unknown. Thereafter, transmission occurs after Yersinia Pestis forms a biofilm in the proventricular valve in the flea foregut. The biofilm can impede and sometimes completely block the ingestion of blood, resulting in regurgitative transmission of bacteria into the bite site. In this study, we compared the relative efficiency of the two modes of transmission for Xenopsylla cheopis, a flea known to become completely blocked at a high rate, and Oropsylla montana, a flea that has been considered to rarely develop proventricular blockage. Methodology/Principal findings Fleas that took an infectious blood meal containing Y. Pestis were maintained and monitored for four weeks for infection and proventricular blockage. The number of Y. Pestis transmitted by groups of fleas by the two modes of transmission was also determined. O. montana readily developed complete proventricular blockage, and large numbers of Y. Pestis were transmitted by that mechanism both by it and by X. cheopis, a flea known to block at a high rate. In contrast, few bacteria were transmitted in the early phase by either species. Conclusions A model system incorporating standardized experimental conditions and viability controls was developed to more reliably compare the infection, proventricular blockage and transmission dynamics of different flea vectors, and was used to resolve a long-standing uncertainty concerning the vector competence of O. montana. Both X. cheopis and O. montana are fully capable of transmitting Y. Pestis by the proventricular biofilm-dependent mechanism.

  • Comparative Ability of Oropsylla montana and Xenopsylla cheopis Fleas to Transmit Yersinia Pestis by Two Different Mechanisms.
    Public Library of Science (PLoS), 2017
    Co-Authors: Joseph B Hinnebusch, David M Bland, Christopher F Bosio, Clayton O Jarrett
    Abstract:

    BACKGROUND:Transmission of Yersinia Pestis by flea bite can occur by two mechanisms. After taking a blood meal from a bacteremic mammal, fleas have the potential to transmit the very next time they feed. This early-phase transmission resembles mechanical transmission in some respects, but the mechanism is unknown. Thereafter, transmission occurs after Yersinia Pestis forms a biofilm in the proventricular valve in the flea foregut. The biofilm can impede and sometimes completely block the ingestion of blood, resulting in regurgitative transmission of bacteria into the bite site. In this study, we compared the relative efficiency of the two modes of transmission for Xenopsylla cheopis, a flea known to become completely blocked at a high rate, and Oropsylla montana, a flea that has been considered to rarely develop proventricular blockage. METHODOLOGY/PRINCIPAL FINDINGS:Fleas that took an infectious blood meal containing Y. Pestis were maintained and monitored for four weeks for infection and proventricular blockage. The number of Y. Pestis transmitted by groups of fleas by the two modes of transmission was also determined. O. montana readily developed complete proventricular blockage, and large numbers of Y. Pestis were transmitted by that mechanism both by it and by X. cheopis, a flea known to block at a high rate. In contrast, few bacteria were transmitted in the early phase by either species. CONCLUSIONS:A model system incorporating standardized experimental conditions and viability controls was developed to more reliably compare the infection, proventricular blockage and transmission dynamics of different flea vectors, and was used to resolve a long-standing uncertainty concerning the vector competence of O. montana. Both X. cheopis and O. montana are fully capable of transmitting Y. Pestis by the proventricular biofilm-dependent mechanism

Didier Raoult - One of the best experts on this subject based on the ideXlab platform.

  • Yersinia Pestis the natural history of plague
    Clinical Microbiology Reviews, 2020
    Co-Authors: Remi Barbieri, Didier Raoult, Michel Signoli, Stefan Tzortzis, Dominique Cheve, Caroline Costedoat, Gerard Aboudharam, Michel Drancourt
    Abstract:

    SUMMARY The Gram-negative bacterium Yersinia Pestis is responsible for deadly plague, a zoonotic disease established in stable foci in the Americas, Africa, and Eurasia. Its persistence in the environment relies on the subtle balance between Y. Pestis-contaminated soils, burrowing and nonburrowing mammals exhibiting variable degrees of plague susceptibility, and their associated fleas. Transmission from one host to another relies mainly on infected flea bites, inducing typical painful, enlarged lymph nodes referred to as buboes, followed by septicemic dissemination of the pathogen. In contrast, droplet inhalation after close contact with infected mammals induces primary pneumonic plague. Finally, the rarely reported consumption of contaminated raw meat causes pharyngeal and gastrointestinal plague. Point-of-care diagnosis, early antibiotic treatment, and confinement measures contribute to outbreak control despite residual mortality. Mandatory primary prevention relies on the active surveillance of established plague foci and ectoparasite control. Plague is acknowledged to have infected human populations for at least 5,000 years in Eurasia. Y. Pestis genomes recovered from affected archaeological sites have suggested clonal evolution from a common ancestor shared with the closely related enteric pathogen Yersinia pseudotuberculosis and have indicated that ymt gene acquisition during the Bronze Age conferred Y. Pestis with ectoparasite transmissibility while maintaining its enteric transmissibility. Three historic pandemics, starting in 541 AD and continuing until today, have been described. At present, the third pandemic has become largely quiescent, with hundreds of human cases being reported mainly in a few impoverished African countries, where zoonotic plague is mostly transmitted to people by rodent-associated flea bites.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa
    2016
    Co-Authors: Hamza Leulmi, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Didier Raoult
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. Methodology/Principal findings: Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1 % (2/199), and an uncultured Bartonella sp. was detected in 34.7 % (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10 % (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65 % (13/20) of Ctenocephalides felis strongylus, 71.4 % (5/7) of Ctenocephalides canis and 25 % (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5 % (13/23) of Ct. f. felis from Kinshasa, in 26.3 % (10/38) of Ct. f. felis and 9 % (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2 % (5/ 26) of Ct. f. strongylus and 4.7 % (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3 % (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8 % (1/26) of Ct. f. strongylus and 10 % (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Conclusion: Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rura

  • detection of rickettsia felis rickettsia typhi bartonella species and Yersinia Pestis in fleas siphonaptera from africa
    PLOS Neglected Tropical Diseases, 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa
    PLoS Neglected Tropical Diseases, 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. Methodology/Principal findings: Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/ 26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Conclusion: Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. Pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa.
    Public Library of Science (PLoS), 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    UNLABELLED:Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. METHODOLOGY/PRINCIPAL FINDINGS:Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. CONCLUSION:Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. Pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high

Philippe Parola - One of the best experts on this subject based on the ideXlab platform.

  • detection of rickettsia felis rickettsia typhi bartonella species and Yersinia Pestis in fleas siphonaptera from africa
    PLOS Neglected Tropical Diseases, 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa
    PLoS Neglected Tropical Diseases, 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. Methodology/Principal findings: Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/ 26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Conclusion: Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. Pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa.
    Public Library of Science (PLoS), 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    UNLABELLED:Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. METHODOLOGY/PRINCIPAL FINDINGS:Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. CONCLUSION:Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. Pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high

Clayton O Jarrett - One of the best experts on this subject based on the ideXlab platform.

  • molecular and genetic mechanisms that mediate transmission of Yersinia Pestis by fleas
    Biomolecules, 2021
    Co-Authors: Joseph B Hinnebusch, Clayton O Jarrett, David M Bland
    Abstract:

    The ability to cause plague in mammals represents only half of the life history of Yersinia Pestis. It is also able to colonize and produce a transmissible infection in the digestive tract of the flea, its insect host. Parallel to studies of the molecular mechanisms by which Y. Pestis is able to overcome the immune response of its mammalian hosts, disseminate, and produce septicemia, studies of Y. Pestis–flea interactions have led to the identification and characterization of important factors that lead to transmission by flea bite. Y. Pestis adapts to the unique conditions in the flea gut by altering its metabolic physiology in ways that promote biofilm development, a common strategy by which bacteria cope with a nutrient-limited environment. Biofilm localization to the flea foregut disrupts normal fluid dynamics of blood feeding, resulting in regurgitative transmission. Many of the important genes, regulatory pathways, and molecules required for this process have been identified and are reviewed here.

  • fleaing the plague adaptations of Yersinia Pestis to its insect vector that lead to transmission
    Annual Review of Microbiology, 2017
    Co-Authors: Joseph B Hinnebusch, Clayton O Jarrett, David M Bland
    Abstract:

    Interest in arthropod-borne pathogens focuses primarily on how they cause disease in humans. How they produce a transmissible infection in their arthropod host is just as critical to their life cycle, however. Yersinia Pestis adopts a unique life stage in the digestive tract of its flea vector, characterized by rapid formation of a bacterial biofilm that is enveloped in a complex extracellular polymeric substance. Localization and adherence of the biofilm to the flea foregut is essential for transmission. Here, we review the molecular and genetic mechanisms of these processes and present a comparative evaluation and updated model of two related transmission mechanisms.

  • correction comparative ability of oropsylla montana and xenopsylla cheopis fleas to transmit Yersinia Pestis by two different mechanisms
    PLOS Neglected Tropical Diseases, 2017
    Co-Authors: Joseph B Hinnebusch, David M Bland, Christopher F Bosio, Clayton O Jarrett
    Abstract:

    Background Transmission of Yersinia Pestis by flea bite can occur by two mechanisms. After taking a blood meal from a bacteremic mammal, fleas have the potential to transmit the very next time they feed. This early-phase transmission resembles mechanical transmission in some respects, but the mechanism is unknown. Thereafter, transmission occurs after Yersinia Pestis forms a biofilm in the proventricular valve in the flea foregut. The biofilm can impede and sometimes completely block the ingestion of blood, resulting in regurgitative transmission of bacteria into the bite site. In this study, we compared the relative efficiency of the two modes of transmission for Xenopsylla cheopis, a flea known to become completely blocked at a high rate, and Oropsylla montana, a flea that has been considered to rarely develop proventricular blockage. Methodology/Principal findings Fleas that took an infectious blood meal containing Y. Pestis were maintained and monitored for four weeks for infection and proventricular blockage. The number of Y. Pestis transmitted by groups of fleas by the two modes of transmission was also determined. O. montana readily developed complete proventricular blockage, and large numbers of Y. Pestis were transmitted by that mechanism both by it and by X. cheopis, a flea known to block at a high rate. In contrast, few bacteria were transmitted in the early phase by either species. Conclusions A model system incorporating standardized experimental conditions and viability controls was developed to more reliably compare the infection, proventricular blockage and transmission dynamics of different flea vectors, and was used to resolve a long-standing uncertainty concerning the vector competence of O. montana. Both X. cheopis and O. montana are fully capable of transmitting Y. Pestis by the proventricular biofilm-dependent mechanism.

  • Comparative Ability of Oropsylla montana and Xenopsylla cheopis Fleas to Transmit Yersinia Pestis by Two Different Mechanisms.
    Public Library of Science (PLoS), 2017
    Co-Authors: Joseph B Hinnebusch, David M Bland, Christopher F Bosio, Clayton O Jarrett
    Abstract:

    BACKGROUND:Transmission of Yersinia Pestis by flea bite can occur by two mechanisms. After taking a blood meal from a bacteremic mammal, fleas have the potential to transmit the very next time they feed. This early-phase transmission resembles mechanical transmission in some respects, but the mechanism is unknown. Thereafter, transmission occurs after Yersinia Pestis forms a biofilm in the proventricular valve in the flea foregut. The biofilm can impede and sometimes completely block the ingestion of blood, resulting in regurgitative transmission of bacteria into the bite site. In this study, we compared the relative efficiency of the two modes of transmission for Xenopsylla cheopis, a flea known to become completely blocked at a high rate, and Oropsylla montana, a flea that has been considered to rarely develop proventricular blockage. METHODOLOGY/PRINCIPAL FINDINGS:Fleas that took an infectious blood meal containing Y. Pestis were maintained and monitored for four weeks for infection and proventricular blockage. The number of Y. Pestis transmitted by groups of fleas by the two modes of transmission was also determined. O. montana readily developed complete proventricular blockage, and large numbers of Y. Pestis were transmitted by that mechanism both by it and by X. cheopis, a flea known to block at a high rate. In contrast, few bacteria were transmitted in the early phase by either species. CONCLUSIONS:A model system incorporating standardized experimental conditions and viability controls was developed to more reliably compare the infection, proventricular blockage and transmission dynamics of different flea vectors, and was used to resolve a long-standing uncertainty concerning the vector competence of O. montana. Both X. cheopis and O. montana are fully capable of transmitting Y. Pestis by the proventricular biofilm-dependent mechanism

  • retracing the evolutionary path that led to flea borne transmission of Yersinia Pestis
    Cell Host & Microbe, 2014
    Co-Authors: Yicheng Sun, Christopher F Bosio, Clayton O Jarrett, Joseph B Hinnebusch
    Abstract:

    Summary Yersinia Pestis is an arthropod-borne bacterial pathogen that evolved recently from Yersinia pseudotuberculosis , an enteric pathogen transmitted via the fecal-oral route. This radical ecological transition can be attributed to a few discrete genetic changes from a still-extant recent ancestor, thus providing a tractable case study in pathogen evolution and emergence. Here, we determined the genetic and mechanistic basis of the evolutionary adaptation of Y. Pestis to flea-borne transmission. Remarkably, only four minor changes in the bacterial progenitor, representing one gene gain and three gene losses, enabled transmission by flea vectors. All three loss-of-function mutations enhanced cyclic-di-GMP-mediated bacterial biofilm formation in the flea foregut, which greatly increased transmissibility. Our results suggest a step-wise evolutionary model in which Y. Pestis emerged as a flea-borne clone, with each genetic change incrementally reinforcing the transmission cycle. The model conforms well to the ecological theory of adaptive radiation.

Hamza Leulmi - One of the best experts on this subject based on the ideXlab platform.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa
    2016
    Co-Authors: Hamza Leulmi, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Didier Raoult
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. Methodology/Principal findings: Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1 % (2/199), and an uncultured Bartonella sp. was detected in 34.7 % (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10 % (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65 % (13/20) of Ctenocephalides felis strongylus, 71.4 % (5/7) of Ctenocephalides canis and 25 % (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5 % (13/23) of Ct. f. felis from Kinshasa, in 26.3 % (10/38) of Ct. f. felis and 9 % (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2 % (5/ 26) of Ct. f. strongylus and 4.7 % (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3 % (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8 % (1/26) of Ct. f. strongylus and 10 % (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Conclusion: Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rura

  • detection of rickettsia felis rickettsia typhi bartonella species and Yersinia Pestis in fleas siphonaptera from africa
    PLOS Neglected Tropical Diseases, 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa
    PLoS Neglected Tropical Diseases, 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. Methodology/Principal findings: Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/ 26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. Conclusion: Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. Pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high.

  • Detection of Rickettsia felis, Rickettsia typhi, Bartonella Species and Yersinia Pestis in Fleas (Siphonaptera) from Africa.
    Public Library of Science (PLoS), 2014
    Co-Authors: Hamza Leulmi, Didier Raoult, Cristina Socolovschi, Anne Laudisoit, Gualbert Houemenou, Bernard Davoust, Idir Bitam, Philippe Parola
    Abstract:

    UNLABELLED:Little is known about the presence/absence and prevalence of Rickettsia spp, Bartonella spp. and Yersinia Pestis in domestic and urban flea populations in tropical and subtropical African countries. METHODOLOGY/PRINCIPAL FINDINGS:Fleas collected in Benin, the United Republic of Tanzania and the Democratic Republic of the Congo were investigated for the presence and identity of Rickettsia spp., Bartonella spp. and Yersinia Pestis using two qPCR systems or qPCR and standard PCR. In Xenopsylla cheopis fleas collected from Cotonou (Benin), Rickettsia typhi was detected in 1% (2/199), and an uncultured Bartonella sp. was detected in 34.7% (69/199). In the Lushoto district (United Republic of Tanzania), R. typhi DNA was detected in 10% (2/20) of Xenopsylla brasiliensis, and Rickettsia felis was detected in 65% (13/20) of Ctenocephalides felis strongylus, 71.4% (5/7) of Ctenocephalides canis and 25% (5/20) of Ctenophthalmus calceatus calceatus. In the Democratic Republic of the Congo, R. felis was detected in 56.5% (13/23) of Ct. f. felis from Kinshasa, in 26.3% (10/38) of Ct. f. felis and 9% (1/11) of Leptopsylla aethiopica aethiopica from Ituri district and in 19.2% (5/26) of Ct. f. strongylus and 4.7% (1/21) of Echidnophaga gallinacea. Bartonella sp. was also detected in 36.3% (4/11) of L. a. aethiopica. Finally, in Ituri, Y. Pestis DNA was detected in 3.8% (1/26) of Ct. f. strongylus and 10% (3/30) of Pulex irritans from the villages of Wanyale and Zaa. CONCLUSION:Most flea-borne infections are neglected diseases which should be monitored systematically in domestic rural and urban human populations to assess their epidemiological and clinical relevance. Finally, the presence of Y. Pestis DNA in fleas captured in households was unexpected and raises a series of questions regarding the role of free fleas in the transmission of plague in rural Africa, especially in remote areas where the flea density in houses is high