interaction of lectins with yersinia pestis strains.the ability of lectins to interact with yersinia pestis strains isolated from rodent fleas and human biological fluids, obtained from different geographic areas, was examined. lectins of canavalia ensiformis, ulex europaeus, phaseolus vulgaris, and triticum vulgaris, as well as a new autochthonous lectin of swartzia pickellii of undefined specificity, were used. most of the y. pestis strains did not agglutinate with u. europaeus or c. ensiformis lectin. however, p. vulgaris lectin agglutinated s ...19902091525
flea, rodent, and plague ecology at chuchupate campground, ventura county, california.chuchupate campground in ventura county, california, was closed to the public for 18 years (1982 to 2000) because of uncontrolled vector fleas and persistent plague antibody titers in rodents. the primary purpose of this study was to clarify the plague ecology of chuchupate campground by identifying involved rodents and their vector fleas and by determining many of their ecological parameters: abundance, flea and host preferences and diversities, and flea seasonality. rodents and fleas were iden ...200212125863
effect of deletion of the lpxm gene on virulence and vaccine potential of yersinia pestis in mice.yersinia pestis undergoes an obligate flea-rodent-flea enzootic life cycle. the rapidly fatal properties of y. pestis are responsible for the organism's sustained survival in natural plague foci. lipopolysaccharide (lps) plays several roles in y. pestis pathogenesis, prominent among them being resistance to host immune effectors and induction of a septic-shock state during the terminal phases of infection. lps is acylated with 4-6 fatty acids, the number varying with growth temperature and affec ...200717374882
[relations of the causative agents of plague and listeriosis during their simultaneous stay in the flea citellophilus tesquorum at different environmental temperatures].experiments were carried out to determine the persistence of a plague microbe with varying praline labeling (isolated in the central caucasian mountain focus of plague in the fleas citellophilus tesquorum of a mountain subspecies) in the contamination of the mixed culture of the plague microbe and listeria. inoculation of fleas with a suspension of a plague microbe and listeriae demonstrates the manifest signs of antagonism between both species of microorganisms. this is evidenced by the reducti ...200818368716
rodent and flea abundance fail to predict a plague epizootic in black-tailed prairie dogs.small rodents are purported to be enzootic hosts of yersinia pestis and may serve as sources of infection to prairie dogs or other epizootic hosts by direct or flea-mediated transmission. recent research has shown that small rodent species composition and small rodent flea assemblages are influenced by the presence of prairie dogs, with higher relative abundance of both small rodents and fleas at prairie dog colony sites compared to grasslands without prairie dogs. however, it is unclear if incr ...201020158331
seasonal and among-site variation in the occurrence and abundance of fleas on california ground squirrels (otospermophilus beecheyi).an improved understanding of the ecology of fleas on california ground squirrels, otospermophilus beecheyi, is warranted given the role of fleas in the transmission, and perhaps persistence, of the plague-causing bacterium yersinia pestis. we sampled o. beecheyi on a seasonal basis from three study sites, each representing a different land use type (preserve, pasture, and agriculture) in the san joaquin valley, ca. overall, the abundance of fleas on squirrels was greatest in spring at the preser ...201121635649
the fleas (siphonaptera) in iran: diversity, host range, and medical importance.flea-borne diseases have a wide distribution in the world. studies on the identity, abundance, distribution and seasonality of the potential vectors of pathogenic agents (e.g. yersinia pestis, francisella tularensis, and rickettsia felis) are necessary tools for controlling and preventing such diseases outbreaks. the improvements of diagnostic tools are partly responsible for an easier detection of otherwise unnoticed agents in the ectoparasitic fauna and as such a good taxonomical knowledge of ...201728068343
molecular survey of bartonella species and yersinia pestis in rodent fleas (siphonaptera) from chihuahua, mexico.rodent fleas from northwestern chihuahua, mexico, were analyzed for the presence of bartonella and yersinia pestis. in total, 760 fleas belonging to 10 species were tested with multiplex polymerase chain reaction analysis targeting the glta (338-bp) and pla genes (478-bp) of bartonella and y. pestis, respectively. although none was positive for y. pestis, 307 fleas were infected with bartonella spp., resulting in an overall prevalence of 40.4%. a logistic regression analysis indicated that the p ...201626576933
fast and simple detection of yersinia pestis applicable to field investigation of plague foci.yersinia pestis, the plague bacillus, has a rodent-flea-rodent life cycle but can also persist in the environment for various periods of time. there is now a convenient and effective test (f1-dipstick) for the rapid identification of y. pestis from human patient or rodent samples, but this test cannot be applied to environmental or flea materials because the f1 capsule is mostly produced at 37°c. the plasminogen activator (pla), a key virulence factor encoded by a y. pestis-specific plasmid, is ...201323383008
investigation of and response to 2 plague cases, yosemite national park, california, usa, august 2015, plague was diagnosed for 2 persons who had visited yosemite national park in california, usa. one case was septicemic and the other bubonic. subsequent environmental investigation identified probable locations of exposure for each patient and evidence of epizootic plague in other areas of the park. transmission of yersinia pestis was detected by testing rodent serum, fleas, and rodent carcasses. the environmental investigation and whole-genome multilocus sequence typing of y. pes ...201627870634
molecular history of plague.plague, a deadly zoonose caused by the bacterium yersinia pestis, has been firmly documented in 39 historical burial sites in eurasia that date from the bronze age to two historical pandemics spanning the 6th to 18th centuries. palaeomicrobiologic data, including gene and spacer sequences, whole genome sequences and protein data, confirmed that two historical pandemics swept over europe from probable asian sources and possible two-way-ticket journeys back from europe to asia. these investigation ...201627615720
physiology of yersinia pestis.this chapter outlines the physiology of yersinia pestis with emphasis on identifying unique functions required for tissue invasion and acute disease. these activities are opposed to often incompatible processes expressed by very closely related yersinia pseudotuberculosis, which causes localized gastrointestinal infection. gain of new information in y. pestis entailed lateral transfer of plasminogen activator and anti-phagocytic capsular antigen via the plasmids ppcp and pmt, respectively, and d ...201627722861
plague gives surprises in the first decade of the 21st century in the united states and worldwide.plague is an ancient disease caused by the bacterium yersinia pestis and transmitted by rodent flea bites that continues to surprise us with first-ever events. this review documents plague in human cases in the 1st decade of the 21st century and updates our knowledge of clinical manifestations, transmission during outbreaks, diagnostic testing, antimicrobial treatment, and vaccine development. in the united states, 57 persons were reported to have the disease, of which seven died. worldwide, 21, ...201324043686
serological and pcr investigation of yersinia pestis in potential reservoir hosts from a plague outbreak focus in zambia.plague is a bacterial zoonotic disease, caused by yersinia pestis. rodents are the natural hosts with fleas as the vehicle of disease transmission. domestic and wild dogs and cats have also been identified as possible disease hosts. in zambia, plague outbreaks have been reported in the southern and eastern regions in the last 20 years. based on these observations, y. pestis could possibly be endemically present in the area.201728754138
identification of risk factors associated with transmission of plague disease in eastern zambia.plague is a fatal, primarily rodent-flea-borne zoonotic disease caused by yersinia pestis. the identification of risk factors of plague was investigated through questionnaire interview and conducting focus group discussion (fgd) in sinda and nyimba of eastern zambia. a total of 104 questionnaires were administered to individual respondents and 20 groups consisting of 181 discussants, which comprised fgd team in this study. the study revealed that trapping, transportation, and preparation of rode ...201728722614
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