Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Study on Presence of Borrelia persica in Soft Ticks in Western Iran
A Barmaki,J Rafinejad,H Vatandoost,Z Telmadarraiy
Iranian Journal of Arthropod-Borne Diseases , 2010,
Abstract: "nAbstract "nBackground: A molecular survey was conducted to investigate the presence of pathogenic Borrelia persica species caus-ing the tick borne relapsing fever (TBRF) in Takistan district Qazvin Province, western Iran. "nMethods: A number of 1021 soft ticks were collected from 31 villages including previously reported infected and none-infected TBRF cases and individually examined for the presence of B. persica DNA by conventional PCR target-ing the 16S rRNA. "nResults: A total of 1021 soft ticks of three species of Ornithodouros tholozani (120: 11.75%), O. lahorensis (461: 45.15%) and Argas persicus (440: 43.1%) were collected and tested against Borrelia infection. Soft ticks were more preva-lent (67%) in infected areas than none infected areas. The rate O. tholozani in infected areas was much greater (29 times) than none infected areas. Ninety seven percent of soft ticks in none infected areas were of O. tholozani. Six-teen (16.7%) ticks of tested (n=95) O. tholozani were infected with B. persica. Three (1.3%) out of 205 soft ticks of O. lahorensis were positive for Borrelia sp., and no infection was observed in A. persicus. TaqI RFLP analysis and se-quence analysis of the positive PCR products showed the presence of B. persica. The RFLP analysis showed that the positive ticks of O. lahorensis were infected with unknown Borrelia species. "nConclusion: This study showed that although there were no TBRF cases in Takisan, but still infected O. tholozani, the known vector of TBRF, presented in the region. Control measures needs to be fulfilled in Thakisan. "n "nKeywords: Borrelia persica, tick borne relapsing fever (TBRF), PCR-RFLP, Takistan, Iran
Detection of Borrelia persica Infection in Ornithodoros Tholo Zani Using PCR Targeting RRS Gene and Xenodiagnosis
J Rafinejad,N Choubdar,MA Oshaghi,N Piazak
Iranian Journal of Public Health , 2011,
Abstract: Background: Relapsing fever caused by Borrelia persica, is an acute tick-borne disease which is transmitted by soft ticks of Ornithodoros tholozani to human.Methods: Value of PCR and xenodiagnosis for detection of B. persica in O. tholozani ticks was compared. Sixty-four Bor-relia-free ticks were fed on infected guinea pigs and used for the experiments. For xenodiagnosis, a group of 32 ticks in subsequent blood meal were fed on sterile guinea pigs and the indication of B. persica in the animal blood was tested 5-14 days later by dark-field microscopy. For PCR, all 64 ticks were subjected to PCR against B. persica rrs gene (16S-rDNA). Also sensitivity of PCR in terms of minimum detectable number of spirochetes as well as the effects of tick sex and post digestion was tested.Results: PCR revealed B.persica DNA in 98.4% ticks, in which B. persica were found in 25.0% by xenodiagnosis. PCR was enough sensitive to give positive results for DNA of 1 spirochete. PCR success rates were similar for male or female ticks. Course of time did not affect the efficacy of PCR and similar results were observed for ticks of immediately fed, semi- or completely gravid or completely digested blood ones.Conclusion: Our results indicate that due to very low specificity and time consuming, xenodiagnosis is not a useful method whereas PCR method has advantages for study the Borrelia prevalence in ticks.
Distribution of Soft Ticks and Their Natural Infection with Borrelia in a Focus of Relapsing Fever in Iran
Z Aghighi,M Assmar,N Piazak,E Javadian
Iranian Journal of Arthropod-Borne Diseases , 2007,
Abstract: Tick-borne diseases such as relapsing fever and Crimean-Congo Hemorrhagic Fever (CCHF) are of public health impor tance in Iran. There are 471 reported cases of relapsing fever in 2003, according to the Ministry of Health of Iran.The num ber of cases has been increased in recent years. Its distribution is more or less prevalent in different parts of Iran. The aim of this study was to find out the fauna and natural infection of soft ticks with Borrelia in Qazvin Province, during their sea sonal activity. The province covers 15821 km2 between 48-45 to 50-50 east of Greenwich Meridian of longitude and 35-37 to 36-45 north latitude of the equator. For this purpose a field study was carried out in the region. A total of 54 villages from 19 districts were selected ran domly and ticks were collected from their habitats according to the standard method. A total of 3197 Argasidae ticks were collected from human dwellings, poultry and animal shelters. They belonged to Argas and Or nithodoros genera which 36.8% were Argas persicus, 4% A. reflexus, 6.4% O. canestrini, 45.5% O. lahorensis and 7.3% O. tholozani. It should be noted that 12 ticks of O. erraticus were collected from 12 rodents borrows. We found that 8.82 % of O. tholozani ticks were infected with Borrelia persica and half of the O. erraticus were infected with Borrelia microti. All the people who are in volved with veterinary activities should be aware of disease transmission by the ticks. In the endemic area of the disease tick control is recommended.
"Distribution of Soft Ticks and Their Infection with Borrelia in Hamadan Province, Iran"
H Vatandoost,A Ghaderi,E Javadian,AH Zahir Nia
Iranian Journal of Public Health , 2003,
Abstract: Tick-borne diseases like tick-borne relapsing fever are a public health problem in Iran. Its occurrence is more prevalent in north part of country. In order to determine the distribution of soft ticks, Argasidae, and their infection with Borrelia species in Hamadan province, 53 villages were selected randomly. A total of 4805 ticks were collected directly from human dwellings, poultries, and animal shelters. They belong to the genus Argas and Ornithodoros, among which 52.3% were Argas persicus, 2.6% A. reflexus, 2% Ornithodoros canestrinni, 41.4% O. lahorensis, and 1.77% O.tholozani . The most prevalent species was A.persicus and the least one O. lahorensis. Examination of ticks revealed that O.tholozani was infected with Borrelia persica. Infection rate and disease prevalence is coincident in the region. The results will be discussed in more details in terms of preventive measures.
Endemic Foci of the Tick-Borne Relapsing Fever Spirochete Borrelia crocidurae in Mali, West Africa, and the Potential for Human Infection  [PDF]
Tom G. Schwan ,Jennifer M. Anderson,Job E. Lopez,Robert J. Fischer,Sandra J. Raffel,Brandi N. McCoy,David Safronetz,Nafomon Sogoba,Ousmane Ma?ga,Sékou F. Traoré
PLOS Neglected Tropical Diseases , 2012, DOI: 10.1371/journal.pntd.0001924
Abstract: Background Tick-borne relapsing fever spirochetes are maintained in endemic foci that involve a diversity of small mammals and argasid ticks in the genus Ornithodoros. Most epidemiological studies of tick-borne relapsing fever in West Africa caused by Borrelia crocidurae have been conducted in Senegal. The risk for humans to acquire relapsing fever in Mali is uncertain, as only a few human cases have been identified. Given the high incidence of malaria in Mali, and the potential to confuse the clinical diagnosis of these two diseases, we initiated studies to determine if there were endemic foci of relapsing fever spirochetes that could pose a risk for human infection. Methodology/Principal Findings We investigated 20 villages across southern Mali for the presence of relapsing fever spirochetes. Small mammals were captured, thin blood smears were examined microscopically for spirochetes, and serum samples were tested for antibodies to relapsing fever spirochetes. Ornithodoros sonrai ticks were collected and examined for spirochetal infection. In total, 11.0% of the 663 rodents and 14.3% of the 63 shrews tested were seropositive and 2.2% of the animals had active spirochete infections when captured. In the Bandiagara region, the prevalence of infection was higher with 35% of the animals seropositive and 10% infected. Here also Ornithodoros sonrai were abundant and 17.3% of 278 individual ticks tested were infected with Borrelia crocidurae. Fifteen isolates of B. crocidurae were established and characterized by multi-locus sequence typing. Conclusions/Significance The potential for human tick-borne relapsing fever exists in many areas of southern Mali.
Inactivation of Genes for Antigenic Variation in the Relapsing Fever Spirochete Borrelia hermsii Reduces Infectivity in Mice and Transmission by Ticks  [PDF]
Sandra J. Raffel,James M. Battisti,Robert J. Fischer,Tom G. Schwan
PLOS Pathogens , 2014, DOI: doi/10.1371/journal.ppat.1004056
Abstract: Borrelia hermsii, a causative agent of relapsing fever of humans in western North America, is maintained in enzootic cycles that include small mammals and the tick vector Ornithodoros hermsi. In mammals, the spirochetes repeatedly evade the host’s acquired immune response by undergoing antigenic variation of the variable major proteins (Vmps) produced on their outer surface. This mechanism prolongs spirochete circulation in blood, which increases the potential for acquisition by fast-feeding ticks and therefore perpetuation of the spirochete in nature. Antigenic variation also underlies the relapsing disease observed when humans are infected. However, most spirochetes switch off the bloodstream Vmp and produce a different outer surface protein, the variable tick protein (Vtp), during persistent infection in the tick salivary glands. Thus the production of Vmps in mammalian blood versus Vtp in ticks is a dominant feature of the spirochete’s alternating life cycle. We constructed two mutants, one which was unable to produce a Vmp and the other was unable to produce Vtp. The mutant lacking a Vmp constitutively produced Vtp, was attenuated in mice, produced lower cell densities in blood, and was unable to relapse in animals after its initial spirochetemia. This mutant also colonized ticks and was infectious by tick-bite, but remained attenuated compared to wild-type and reconstituted spirochetes. The mutant lacking Vtp also colonized ticks but produced neither Vtp nor a Vmp in tick salivary glands, which rendered the spirochete noninfectious by tick bite. Thus the ability of B. hermsii to produce Vmps prolonged its survival in blood, while the synthesis of Vtp was essential for mammalian infection by the bite of its tick vector.
Nuevo medio sólido para el crecimiento de Borrelia persica y Borrelia microti
Revista Cubana de Medicina Tropical , 1996,
Abstract: se describe un nuevo medio sólido para la rápida detección de borrelia persica y borrelia microti. corrientemente el cultivo y aislamiento de borrelia demora alrededor de 21 días. el examen serológico más frecuentemente realizado demora menos tiempo pero está asociado con resultados falsos positivos relativamente altos. sin embargo, nuestro nuevo medio sólido reduce el tiempo de cultivo a 72 horas, lo que permite un rápido diagnóstico de la enfermedad causada por borrelia persica y borrelia microti y el inicio temprano del tratamiento en estos pacientes.
Nuevo medio sólido para el crecimiento de Borrelia persica y Borrelia microti  [cached]
Revista Cubana de Medicina Tropical , 1996,
Abstract: Se describe un nuevo medio sólido para la rápida detección de Borrelia persica y Borrelia microti. Corrientemente el cultivo y aislamiento de Borrelia demora alrededor de 21 días. El examen serológico más frecuentemente realizado demora menos tiempo pero está asociado con resultados falsos positivos relativamente altos. Sin embargo, nuestro nuevo medio sólido reduce el tiempo de cultivo a 72 horas, lo que permite un rápido diagnóstico de la enfermedad causada por Borrelia persica y Borrelia microti y el inicio temprano del tratamiento en estos pacientes.
The Influence of Training System on Employees’ Hard Skills in the Palestinian National Authority
Mohammed Y. A. Alsabbah, Hazril Izwar Ibrahim
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1103854
The purpose of this study is to report the influence of a training system on improving employee hard skills. The motive of this study is to investigate the implementation of training system in public organisations. The paper uses a survey questionnaire to collect data from the Palestinian National Authority ministries. One hypothesis was formulated to guide the study. Individual-level analyses from a sample of 399 employees from Palestinian National Authority ministries indicate that training systems have a positive effect on employees’ hard skills. The theoretical contribution of this study is to demonstrate the value of training systems on employee hard skills. It further confirms the importance of addressing the relationship between organizational practice and employee outcomes, and accordingly the results will contribute the HRM literature. From a practical standpoint, the findings encourage careful consideration of the training system used in the Palestinian National Authority and support the utility of the framework to inform future studies.
Identification of Borrelia Species after Creation of an In-House MALDI-TOF MS Database  [PDF]
Adriana Calderaro, Chiara Gorrini, Giovanna Piccolo, Sara Montecchini, Mirko Buttrini, Sabina Rossi, Maddalena Piergianni, Maria Cristina Arcangeletti, Flora De Conto, Carlo Chezzi, Maria Cristina Medici
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0088895
Abstract: Lyme borreliosis (LB) is a multisystemic disease caused by Borrelia burgdorferi sensu lato (sl) complex transmitted to humans by Ixodes ticks. B. burgdorferi sl complex, currently comprising at least 19 genospecies, includes the main pathogenic species responsible for human disease in Europe: B. burgdorferi sensu stricto (ss), B. afzelii, and B. garinii. In this study, for the first time, MALDI-TOF MS was applied to Borrelia spp., supplementing the existing database, limited to the species B. burgdorferi ss, B. spielmanii and B. garinii, with the species B. afzelii, in order to enable the identification of all the species potentially implicated in LB in Europe. Moreover, we supplemented the database also with B. hermsii, which is the primary cause of tick-borne relapsing fever in western North America, B. japonica, circulating in Asia, and another reference strain of B. burgdorferi ss (B31 strain). The dendrogram obtained by analyzing the protein profiles of the different Borrelia species reflected Borrelia taxonomy, showing that all the species included in the Borrelia sl complex clustered in a unique branch, while Borrelia hermsii clustered separately. In conclusion, in this study MALDI-TOF MS proved a useful tool suitable for identification of Borrelia spp. both for diagnostic purpose and epidemiological surveillance.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.