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1.
Andreia Albuquerque Hélder Cardoso Dolores Pinheiro Guilherme Macedo 《Gastroenterologia y hepatologia》2013
Bacteremia due to Vibrio cholerae non-O1 and non-O139 is a rare condition and potentially fatal. We report a case of bacteremia due to V. cholerae non-O1 and non-O139 in a Portuguese male with Hepatitis C cirrhosis, admitted due to acute diarrhea, after consuming shrimp. He had no recent travels. To our knowledge, this is the first reported case of bacteremia due to V. cholerae non-O1 and non-O139 in Portugal. 相似文献
2.
M. Kamruzzaman S. M. Nashir Udden D. Ewen Cameron Stephen B. Calderwood G. Balakrish Nair John J. Mekalanos Shah M. Faruque 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(4):1588-1593
The factors that enhance the waterborne spread of bacterial epidemics and sustain the pathogens in nature are unclear. The epidemic diarrheal disease cholera caused by Vibrio cholerae spreads through water contaminated with the pathogen. However, the bacteria exist in water mostly as clumps of cells, which resist cultivation by standard techniques but revive into fully virulent form in the intestinal milieu. These conditionally viable environmental cells (CVEC), alternatively called viable but nonculturable cells, presumably play a crucial role in cholera epidemiology. However, the precise mechanism causing the transition of V. cholerae to the CVEC form and this form''s significance in the biology of the pathogen are unknown. Here we show that this process involves biofilm formation that is dependent on quorum sensing, a regulatory response that is controlled by cell density. V. cholerae strains carrying mutations in genes required for quorum sensing and biofilm formation displayed altered CVEC formation in environmental water following intestinal infections. Analysis of naturally occurring V. cholerae CVEC showed that organisms that adopt this quiescent physiological state typically exist as clumps of cells that comprise a single clone closely related to isolates causing the most recent local cholera epidemic. These results support a model of cholera transmission in which in vivo-formed biofilms convert to CVEC upon the introduction of cholera stools into environmental water. Our data further suggest that a temporary loss of quorum sensing due to dilution of extracellular autoinducers confers a selective advantage to communities of V. cholerae by blocking quorum-mediated regulatory responses that would break down biofilms and thus interfere with CVEC formation. 相似文献
3.
Jongsik Chun Christopher J. Grim Nur A. Hasan Je Hee Lee Seon Young Choi Bradd J. Haley Elisa Taviani Yoon-Seong Jeon Dong Wook Kim Jae-Hak Lee Thomas S. Brettin David C. Bruce Jean F. Challacombe J. Chris Detter Cliff S. Han A. Christine Munk Olga Chertkov Linda Meincke Elizabeth Saunders Ronald A. Walters Anwar Huq G. Balakrish Nair Rita R. Colwell 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(36):15442-15447
Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the sixth and the current seventh pandemics, respectively. Cholera researchers continually face newly emerging and reemerging pathogenic clones carrying diverse combinations of phenotypic and genotypic properties, which significantly hampered control of the disease. To elucidate evolutionary mechanisms governing genetic diversity of pandemic V. cholerae, we compared the genome sequences of 23 V. cholerae strains isolated from a variety of sources over the past 98 years. The genome-based phylogeny revealed 12 distinct V. cholerae lineages, of which one comprises both O1 classical and El Tor biotypes. All seventh pandemic clones share nearly identical gene content. Using analogy to influenza virology, we define the transition from sixth to seventh pandemic strains as a “shift” between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages. In contrast, transition among clones during the present pandemic period is characterized as a “drift” between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V. cholerae O139 and V. cholerae O1 El Tor hybrid clones. Based on the comparative genomics it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to define pathogenic V. cholerae clones. 相似文献
4.
5.
Munirul Alam Shah Manzur Rashed Shahnewaj Bin Mannan Tarequl Islam Marcial Leonardo Lizarraga-Partida Gabriela Delgado Rosario Morales-Espinosa Jose Luis Mendez Armando Navarro Haruo Watanabe Makoto Ohnishi Nur A. Hasan Anwar Huq R. Bradley Sack Rita R. Colwell Alejandro Cravioto 《Proceedings of the National Academy of Sciences of the United States of America》2014,111(27):9917-9922
6.
Tatsuo Inoue Satoshi Kitai Sousuke Hayaishi Masatoshi Kudo 《Clinical journal of gastroenterology》2012,5(6):383-387
We describe a case of non-O1/ non-O139?Vibrio cholerae septicemia in a 65-year-old male patient with alcoholic liver cirrhosis. He was admitted due to septic shock from non-O1/ non-O139 V. cholerae. An intravenous empiric antibiotic, ceftriaxone sodium hydrate, was administered together with amikacin sulfate, gamma globulin and dopamine. He was discharged feeling well 17?days after admission. Poor host defense mechanisms as seen in cirrhotic patients seem to be a determinant for systemic infection of non-O1/ non-O139 V. cholerae. Such patients should be warned and educated against eating raw or undercooked seafood to avoid the occurrence of non-O1/non-O139 V. cholerae septicemia. 相似文献
7.
Maria Teresa Nascimento Silva José Valfrido Santana Gérson Bragagnoli Alexandre Magno da Nóbrega Marinho Elizabeth Malague?o 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(5):451-454
There is a clear need to perform epidemiological studies to find the
true prevalence of Entamoeba histolytica around the world. The
evaluation of this prevalence has been hindered by the existence of two
different species which are morphologically identical, but genetically
different, namely E. histolytica, which causes amebiasis, and
E. dispar, which is non-pathogenic. In Brazil, the
E. dispar has been detected in communities in the
Southeastern (SE) and Northeastern (NE) regions with poor
sanitation. However, individuals infected with E. histolytica
have been identified in other regions. There is an absence of reports on the
prevalence of these parasites in the state of Paraíba, which also has areas
with poor sanitary conditions where a high prevalence of the E.
histolytica/E. dispar complex has been detected in children
from urban slums. The present study evaluated the prevalence of E.
histolytica and E. dispar in 1,195 asymptomatic
children between two and 10 years of age, living in a sprawling urban slum in
Campina Grande, in the state of Paraíba, in Northeastern Brazil. These
children were examined and their feces samples were analyzed microscopically. A
total of 553 children tested positive for the E. histolytica/E.
dispar complex, and 456 of the positive samples were tested with
the E. histolytica II® ELISA kit. All 456 samples were
negative for the presence of the adhesin E. histolytica
specific antigen. The evidence suggests that in this community E.
histolytica is absent and E. dispar is the
dominant species. 相似文献
8.
S. M. Nayeemul Bari M. Kamruzzaman Roky M. Mohiuddin M. Kamruzzaman John J. Mekalanos Shah M. Faruque 《Proceedings of the National Academy of Sciences of the United States of America》2013,110(24):9926-9931
Cholera epidemics have long been known to spread through water contaminated with human fecal material containing the toxigenic bacterium Vibrio cholerae. However, detection of V. cholerae in water is complicated by the existence of a dormant state in which the organism remains viable, but resists cultivation on routine bacteriological media. Growth in the mammalian intestine has been reported to trigger “resuscitation” of such dormant cells, and these studies have prompted the search for resuscitation factors. Although some positive reports have emerged from these investigations, the precise molecular signals that activate dormant V. cholerae have remained elusive. Quorum-sensing autoinducers are small molecules that ordinarily regulate bacterial gene expression in response to cell density or interspecies bacterial interactions. We have found that isolation of pathogenic clones of V. cholerae from surface waters in Bangladesh is dramatically improved by using enrichment media containing autoinducers either expressed from cloned synthase genes or prepared by chemical synthesis. These results may contribute to averting future disasters by providing a strategy for early detection of V. cholerae in surface waters that have been contaminated with the stools of cholera patients or asymptomatic infected human carriers. 相似文献
9.
Zaida Araujo Sietze Brandes Elena Pinelli María A. Bochichio Andrea Palacios Albina Wide Bruno Rivas-Santiago Juan Carlos Jiménez 《Revista do Instituto de Medicina Tropical de S?o Paulo》2015,57(1):47-55
The present study aimed at measuring seropositivities for infection by
Ascaris suum and Toxocara canis using the
excretory/secretory (E/S) antigens from Ascaris suum (AES) and
Toxocara canis (TES) within an indigenous population. In
addition, quantification of cytokine expressions in peripheral blood cells was
determined. A total of 50 Warao indigenous were included; of which 43 were adults and
seven children. In adults, 44.1% were seropositive for both parasites; whereas
children had only seropositivity to one or the other helminth. For ascariosis, the
percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%,
respectively. While that for toxocariosis, the percentage of TES seropositivity in
adults and children was low; 9.3% and 14.3%, respectively. The percentage of
seronegativity was comparable for AES and TES antigens in adults (27.9%) and children
(28.6%). When positive sera were analyzed by Western blotting technique using AES
antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the
TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9,
98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that
Blastocystis hominis, Hymenolepis nana and
Entamoeba coli were the most commonly observed intestinal
parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and
IL-4 expressions showed that there was only a significant increased expression of
IL-4 in indigenous with TES seropositivity (p < 0.002).
Ascaris and Toxocara seropositivity was
prevalent among Warao indigenous. 相似文献
10.
Lasaro Teixeira FERREIRA Aparecida Helena de Souza GOMES Vera Lucia PEREIRA-CHIOCCOLA 《Revista do Instituto de Medicina Tropical de S?o Paulo》2015,57(3):257-262
Introduction:
American tegumentary leishmaniasis (ATL) can be caused by Leishmania (Viannia) braziliensis complex. The evolution of ATL initially results in lesions and can develop into disseminated or diffuse forms. The genetic diversity of L. (V.) braziliensis in some endemic areas of Brazil has been poorly studied, such as in the state of São Paulo. This study analyzed the genetic diversity of L. (V.) braziliensis isolates collected from patients and dogs with LTA from the state of São Paulo.Methods:
Leishmaniasis diagnosis was determined by PCR. The 132 biopsies were collected in different regions of Sao Paulo State, Brazil (36 municipalities). The genetic characterization of L. (V.) braziliensis isolates was tested by RFLP-PCR using DNA extracted from biopsies. The primer set amplified a specific region of Leishmania internal transcribed spacers of the ribosomal DNA locus.Results:
Of the 132 samples, 52 (40%) were completely genotyped by RFLP-PCR (44 from human patients and eight from dogs). The results showed nine distinct patterns. The majority of the genotyped samples were from Sorocaba (30), and the others were distributed among 14 other municipalities. The first pattern was more frequent (29 samples), followed by pattern 2 (nine samples) and pattern 3 (three samples). Patterns 4, 6, 7, 8 and 9 were composed of two samples each and pattern 5 of one sample.Conclusion:
These results suggest that polymorphic strains of L. (V.) braziliensis circulate in the state of São Paulo. These data agree with studies from other regions of Brazil, showing great variability among the natural populations of endemic foci. 相似文献11.
Edna Cleide Mendes Muricy Romilda Aparecida Lemes Sidney Bombarda Lucilaine Ferrazoli Erica Chimara 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(5):397-401
New methodologies were developed for the identification of
Nocardia but the initial diagnosis still requires a fast
and accurate method, mainly due to the similarity to
Mycobacterium, both clinical and bacteriologically. Growth
on Löwenstein-Jensen (LJ) medium, presence of acid-fast bacilli
through Ziehl-Neelsen staining, and colony morphology can be confusing aspects
between Nocardia and Mycobacterium. This study
describes the occurrence of Nocardia spp. in a
mycobacterial-reference laboratory, observing the main difficulties in
differentiating Nocardia spp. from
Mycobacterium spp., and correlating isolates with
nocardiosis cases. Laboratory records for the period between 2008 and 2012 were
analyzed, and the isolates identified as Nocardia sp. or as
non-acid-fast filamentous bacilli were selected. Epidemiological and
bacteriological data were analyzed as well. Thirty-three isolates identified as
Nocardia sp. and 22 as non-acid-fast bacilli were selected
for this study, and represented 0.12% of isolates during the study period.
The presumptive identification was based on macroscopic and microscopic
morphology, resistance to lysozyme and restriction profiles using the
PRA-hsp65 method. Nocardia spp. can grow
on media for mycobacteria isolation (LJ and BBL MGIT™) and
microscopy and colony morphology are very similar to some mycobacteria species.
Seventeen patients (54.8%) were reported and treated for
tuberculosis, but presented signs and symptoms of nocardiosis. It was concluded
that the occurrence of Nocardia sp. during the study period was
0.12%. Isolates with characteristics of filamentous bacilli, forming aerial
hyphae, with colonies that may be pigmented, rough and without the BstEII
digestion pattern in PRA-hsp65 method are suggestive of
Nocardia spp. For a mycobacterial routine laboratory, a
flow for the presumptive identification of Nocardia is
essential, allowing the use of more accurate techniques for the correct
identification, proper treatment and better quality of life for patients. 相似文献
12.
Verónica Casmo Gerito Augusto Rassul Nala Acácio Sabonete Filipe Anibal Carvalho-Costa 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(3):219-224
This study aims to assess the association between schistosomiasis and
hookworm infection with hemoglobin levels of schoolchildren in northern Mozambique.
Through a cross-sectional survey, 1,015 children from five to 12 years old in the
provinces of Nampula, Cabo Delgado and Niassa were studied. Hookworm infection and
urinary schistosomiasis were diagnosed, through Ritchie and filtration methods, with
a prevalence of 31.3% and 59.1%, respectively. Hemoglobin levels were obtained with a
portable photometer (Hemocue®). The average hemoglobin concentration was
10.8 ± 1.42 g/dL, and 62.1% of the children presented levels below 11.5 g/dL, of
which 11.8% of the total number of children had hemoglobin levels below 9 g/dL. A
multiple linear regression analysis demonstrated negative interactions between
hemoglobin levels and ancylostomiasis, this being restricted to the province of Cabo
Delgado (β = -0.55; p < 0.001) where an independent interaction
between hemoglobin levels and urinary schistosomiasis was also observed (β = -0.35;
p = 0.016). The logistical regression model indicated that
hookworm infection represents a predictor of mild (OR = 1.87; 95% CI = 1.17-3.00) and
moderate/severe anemia (OR = 2.71; 95% CI = 1.50 - 4.89). We concluded that, in the
province of Cabo Delgado, hookworm and Schistosoma haematobium
infections negatively influence hemoglobin levels in schoolchildren. Periodical
deworming should be considered in the region. Health education and improvements in
sanitary infrastructure could achieve long-term and sustainable reductions in
soil-transmitted helminthiases and schistosomiasis prevalence rates. 相似文献
13.
Cláudia Torres Codeço 《BMC infectious diseases》2001,1(1):1-14
Background
In the last decades, attention to cholera epidemiology increased, as cholera epidemics became a worldwide health problem. Detailed investigation of V. cholerae interactions with its host and with other organisms in the environment suggests that cholera dynamics is much more complex than previously thought. Here, I formulate a mathematical model of cholera epidemiology that incorporates an environmental reservoir of V. cholerae. The objective is to explore the role of the aquatic reservoir on the persistence of endemic cholera as well as to define minimum conditions for the development of epidemic and endemic cholera. 相似文献14.
15.
Ana A. Weil Yasmin Begum Fahima Chowdhury Ashraful I. Khan Daniel T. Leung Regina C. LaRocque Richelle C. Charles Edward T. Ryan Stephen B. Calderwood Firdausi Qadri Jason B. Harris 《The American journal of tropical medicine and hygiene》2014,91(4):738-742
Multiple Vibrio cholerae infections within the same household are common. Household contacts of patients with cholera were observed with daily clinical assessments and collection of rectal swab cultures for nine days after presentation of the index case. During the follow-up period, 71 (24%) of 294 household contacts developed a positive V. cholerae rectal swab, signifying bacterial shedding. The average length of bacterial shedding was 2.0 days (95% confidence interval 1.7–2.4). However, 16 (5%) of 294 contacts shed V. cholerae for ≥ 4 days. In a multivariate analysis, malnutrition was predictive of long-term shedding (odds ratio = 1.4, 95% confidence interval = 1.3–13, P = 0.02). High rates of V. cholerae infection and bacterial shedding among household contacts of cholera patients represent an opportunity for intervention to reduce V. cholerae transmission. 相似文献
16.
Herintha Coeto Neitzke-Abreu Kárin Rosi Reinhold-Castro Mateus Sabaini Venazzi Regiane Bertin de Lima Scodro Alessandra de Cassia Dias Thaís Gomes Verzignassi Silveira Ueslei Teodoro Maria Valdrinez Campana Lonardoni 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(5):391-395
Sandflies transmit pathogens of leishmaniasis. The natural infection
of sandflies by Leishmania (Viannia) was assessed in
municipalities, in the state of Paraná, in Southern Brazil. Sandflies were
collected with Falcão and Shannon traps. After dissection in search of
flagellates in digestive tubes and identification of the species, female
sandflies were submitted to the Multiplex Polymerase Chain Reaction
(multiplex PCR) for detection of the fragment of the kDNA of
Leishmania (Viannia) and the fragment from the
IVS6 cacophony gene region of the phlebotomine insects. The
analysis was performed in pools containing seven to 12 guts from females of the
same species. A total of 510 female sandflies were analyzed, including nine
Migonemyia migonei, 17 Pintomyia fischeri,
216 Nyssomyia neivai, and 268 Nyssomyia
whitmani. Although none of the females was found naturally infected
by flagellates through dissection, the fragment of DNA from Leishmania
(Viannia) was shown by multiplex PCR in one sample of
Ny. neivai (0.46%) and three samples of
Ny. whitmani (1.12%). It was concluded that
Ny. neivai and Ny. whitmani are
susceptible to Leishmania infection, and that multiplex PCR can
be used in epidemiological studies to detect the natural infection of the
sandfly vector, because of its sensitivity, specificity and feasibility. 相似文献
17.
Maria W. Steenland Gerard A. Joseph Mentor Ali Ber Lucien Nicole Freeman Marisa Hast Benjamin L. Nygren Eyal Leshem Stanley Juin Michele B. Parsons Deborah F. Talkington Eric D. Mintz John Vertefeuille S. Arunmozhi Balajee Jacques Boncy Mark A. Katz 《The American journal of tropical medicine and hygiene》2013,89(4):641-646
An outbreak of cholera began in Haiti in October of 2010. To understand the progression of epidemic cholera in Haiti, in April of 2012, we initiated laboratory-enhanced surveillance for diarrheal disease in four Haitian hospitals in three departments. At each site, we sampled up to 10 hospitalized patients each week with acute watery diarrhea. We tested 1,616 specimens collected from April 2, 2012 to March 28, 2013; 1,030 (63.7%) specimens yielded Vibrio cholerae, 13 (0.8%) specimens yielded Shigella, 6 (0.4%) specimens yielded Salmonella, and 63 (3.9%) specimens tested positive for rotavirus. Additionally, 13.5% of children < 5 years old tested positive for rotavirus. Of 1,030 V. cholerae isolates, 1,020 (99.0%) isolates were serotype Ogawa, 9 (0.9%) isolates were serotype Inaba, and 1 isolate was non-toxigenic V. cholerae O139. During 1 year of surveillance, toxigenic cholera continued to be the main cause of acute diarrhea in hospitalized patients, and rotavirus was an important cause of diarrhea-related hospitalizations in children. 相似文献
18.
Luciana Furlaneto-Maia Kátia Real Rocha Vera Lúcia Dias Siqueira Márcia Cristina Furlaneto 《Revista do Instituto de Medicina Tropical de S?o Paulo》2014,56(2):97-103
Enterococci are increasingly responsible for nosocomial infections
worldwide. This study was undertaken to compare the identification and
susceptibility profile using an automated MicrosScan system, PCR-based assay and
disk diffusion assay of Enterococcus spp. We evaluated 30
clinical isolates of Enterococcus spp. Isolates were identified
by MicrosScan system and PCR-based assay. The detection of antibiotic resistance
genes (vancomycin, gentamicin, tetracycline and erythromycin) was also
determined by PCR. Antimicrobial susceptibilities to vancomycin (30 µg),
gentamicin (120 µg), tetracycline (30 µg) and erythromycin (15 µg) were tested
by the automated system and disk diffusion method, and were interpreted
according to the criteria recommended in CLSI guidelines. Concerning
Enterococcus identification the general agreement between
data obtained by the PCR method and by the automatic system was 90.0% (27/30).
For all isolates of E. faecium and E. faecalis
we observed 100% agreement. Resistance frequencies were higher in E.
faecium than E. faecalis. The resistance rates
obtained were higher for erythromycin (86.7%), vancomycin (80.0%), tetracycline
(43.35) and gentamicin (33.3%). The correlation between disk diffusion and
automation revealed an agreement for the majority of the antibiotics with
category agreement rates of > 80%. The PCR-based assay, the
van(A) gene was detected in 100% of vancomycin resistant
enterococci. This assay is simple to conduct and reliable in the identification
of clinically relevant enterococci. The data obtained reinforced the need for an
improvement of the automated system to identify some enterococci. 相似文献
19.
Guillaume Constantin de Magny Raghu Murtugudde Mathew R. P. Sapiano Azhar Nizam Christopher W. Brown Antonio J. Busalacchi Mohammad Yunus G. Balakrish Nair Ana I. Gil Claudio F. Lanata John Calkins Byomkesh Manna Krishnan Rajendran Mihir Kumar Bhattacharya Anwar Huq R. Bradley Sack Rita R. Colwell 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(46):17676-17681
The causative agent of cholera, Vibrio cholerae, has been shown to be autochthonous to riverine, estuarine, and coastal waters along with its host, the copepod, a significant member of the zooplankton community. Temperature, salinity, rainfall and plankton have proven to be important factors in the ecology of V. cholerae, influencing the transmission of the disease in those regions of the world where the human population relies on untreated water as a source of drinking water. In this study, the pattern of cholera outbreaks during 1998–2006 in Kolkata, India, and Matlab, Bangladesh, and the earth observation data were analyzed with the objective of developing a prediction model for cholera. Satellite sensors were used to measure chlorophyll a concentration (CHL) and sea surface temperature (SST). In addition, rainfall data were obtained from both satellite and in situ gauge measurements. From the analyses, a statistically significant relationship between the time series for cholera in Kolkata, India, and CHL and rainfall anomalies was determined. A statistically significant one month lag was observed between CHL anomaly and number of cholera cases in Matlab, Bangladesh. From the results of the study, it is concluded that ocean and climate patterns are useful predictors of cholera epidemics, with the dynamics of endemic cholera being related to climate and/or changes in the aquatic ecosystem. When the ecology of V. cholerae is considered in predictive models, a robust early warning system for cholera in endemic regions of the world can be developed for public health planning and decision making. 相似文献