Natural Infection Rates Research Articles

Improved growth rate and disease resistance in olive flounder, Paralichthys olivaceus, by probiotic Lactococcus lactis WFLU12 isolated from wild marine fish

The use of probiotics is a strategy employed to improve host health status and to prevent infectious diseases. The current study was aimed at investigating the diversity of lactic acid bacteria (LAB) and Bacillus species in the gastrointestinal tracts of wild marine fishes, as well as the beneficial effects of Lactococcus lactis WFLU12 as a host-derived probiotics in olive flounder. In marine fishes, wild olive flounder and rock bream were shown to be good sources of LAB and Bacillus isolation, respectively. Some isolates, including the strain WFLU12, have shown stronger inhibitory activity against various aquatic bacterial pathogens and more tolerance to low pH and bile acids compared to some strains isolated from sources other than marine. Lc. lactis WFLU12 was found to confer to olive flounder protection against streptococcosis caused by Streptococcus parauberis through competitive exclusion and increased innate immune responses. Interestingly, the natural infection rate in the probiotic fed group (33%=10/30) was significantly lower than that in the control group (60%=18/30). None of the nisin Z and colicin V-producing probiotic-fed fish were naturally infected by S. parauberis during the feeding period. In addition, more importantly, this promising probiotic strain significantly promoted fish growth along with better feed conversion and specific growth rate. This study demonstrates that the use of host-derived probiotics can offer a significant advantage in terms of optimum survival and function in the gastrointestinal tract of the intended host. Statement of relevanceIn this study, host-derived probiotic strain outperforms elimination of pathogen through competitive exclusion in the gastrointestinal tract and increased innate immune responses. More importantly, this promising probiotic strain significantly promoted fish growth along with better feed conversion. This study will provide insight into how optimal probiotics should be selected and developed. It might facilitate the replacement of commercial fish probiotic products originated from terrestrial sources with host-derived probiotics in the near future.

Correlation between infection rate of triatominies and Chagas Disease in Southwest of Bahia, Brazil: a warning sign?

Chagas disease, caused by the Trypanosoma cruzi, has a wide distribution in South America, and its main method of control is the elimination of triatomines. It is presented here the geographic distribution and the rate of natural infection by T. cruzi of triatomines collected and evaluated from 2008 to 2013 in southwest of Bahia. Triatomines were captured in the intradomiciliary and peridomiciliary areas of five cities located in the southwest of Bahia state, identified, and analyzed for the presence of trypanosomatids in their feces. During the study period the number of patients suspected for acute Chagas disease was recovered from the Notifiable Diseases Information System (SINAN). 8966 triatomines were captured and identified as belonging to eight species. Twenty-six presented themselves infected, being Triatoma sordida the most abundant and with the highest percentage of infection by T. cruzi. Tremedal was the city with the highest number of cases of acute Chagas' disease reported to SINAN. All cities showed triatomines infected with T. cruzi, so there is considerable risk of vectorial transmission of Chagas disease in the southwestern Bahia state, evidencing the need for vector transmission control programs and preventive surveillance measures.

New sex-determination system inthe genus Panstrongylus (Hemiptera: Reduviidae) revealed by chromosomal analysis of Panstrongylus lutzi.

BackgroundPanstrongylus lutzi (Neiva & Pinto, 1923) is a triatomine species native to Caatinga habitats in north-eastern Brazil. It is considered an important vector of Chagas disease in this region, presenting high rates of natural infection with Trypanosoma cruzi Chagas, 1909, and readily invading houses by flight. This study describes a previously unknown chromosomal sex system in the genus Panstrongylus based on P. lutzi.MethodsFifth-instar and male adults of P. lutzi originating from municipality of Várzea Alegre, Ceará (Brazil) were analysed. Chromosomal analyses of male meiotic process were done by Giemsa staining.ResultsChromosomal analyses of male meiosis reveal a diploid chromosome number of 24 chromosomes (20 autosomes plus X1X2X3Y). During meiotic prophase I, the sex chromosomes remained close together, forming four heteropycnotic chromocenters in zygotene, and a single chromocenter in pachytene and diplotene. Still at the diplotene stage, each one of the ten autosomal bivalents showed an evident chiasma. In metaphase I, the four sex chromosomes appeared clearly separated. The three X chromosomes were the smallest of the complement and isopycnotic with respect to the Y chromosome. Two bivalents appear larger, whereas the other eight showed no significant difference in size.ConclusionKaryotype analysis of P. lutzi revealed a new sex system in the genus Panstrongylus. This result is of utmost importance to karyosystematics of P. lutzi, and demonstrates the need for further studies of this type in the subfamily Triatominae.

Understanding the transmission dynamics of Leishmania donovani to provide robust evidence for interventions to eliminate visceral leishmaniasis in Bihar, India.

Visceral Leishmaniasis (VL) is a neglected vector-borne disease. In India, it is transmitted to humans by Leishmania donovani-infected Phlebotomus argentipes sand flies. In 2005, VL was targeted for elimination by the governments of India, Nepal and Bangladesh by 2015. The elimination strategy consists of rapid case detection, treatment of VL cases and vector control using indoor residual spraying (IRS). However, to achieve sustained elimination of VL, an appropriate post elimination surveillance programme should be designed, and crucial knowledge gaps in vector bionomics, human infection and transmission need to be addressed. This review examines the outstanding knowledge gaps, specifically in the context of Bihar State, India.The knowledge gaps in vector bionomics that will be of immediate benefit to current control operations include better estimates of human biting rates and natural infection rates of P. argentipes, with L. donovani, and how these vary spatially, temporally and in response to IRS. The relative importance of indoor and outdoor transmission, and how P. argentipes disperse, are also unknown. With respect to human transmission it is important to use a range of diagnostic tools to distinguish individuals in endemic communities into those who: 1) are to going to progress to clinical VL, 2) are immune/refractory to infection and 3) have had past exposure to sand flies.It is crucial to keep in mind that close to elimination, and post-elimination, VL cases will become infrequent, so it is vital to define what the surveillance programme should target and how it should be designed to prevent resurgence. Therefore, a better understanding of the transmission dynamics of VL, in particular of how rates of infection in humans and sand flies vary as functions of each other, is required to guide VL elimination efforts and ensure sustained elimination in the Indian subcontinent. By collecting contemporary entomological and human data in the same geographical locations, more precise epidemiological models can be produced. The suite of data collected can also be used to inform the national programme if supplementary vector control tools, in addition to IRS, are required to address the issues of people sleeping outside.

Assessment of the FasciMol-ELISA in the detection of the trematode Fasciola hepatica in field-collected Galba cubensis: a novel tool for the malacological survey of fasciolosis transmission.

BackgroundFasciolosis is one of the food-borne neglected trematodioses that has reemerged as a human disease while its effects on domestic animal health remains of significant economic consideration. Being snail-borne disease, the accurate and time-saving epidemiological surveillance of the transmission foci where infected lymnaeid snails occur could be essential to effectively focus or redirect control strategies. For this purpose, the first monoclonal antibody-based immunoenzymatic assay to detect Fasciola hepatica-infected snails (FasciMol-ELISA) was recently developed and showed a high sensitivity and specificity when tested in an experimental F. hepatica – Galba cubensis system.MethodsHere, we surveyed populations of G. cubensis occurring in western Cuba for the assessment of the FasciMol-ELISA in determining natural F. hepatica infection in this intermediate host. A multiplex PCR, previously developed to detect F. hepatica in G. cubensis, was used for sample classification. Snail dissection method was also employed as screening technique. A Χ2 test and a Kappa index were calculated to evaluate the positivity and the level of agreement between the FasciMol-ELISA and the snail dissection methods with the multiplex PCR, respectively.ResultsGalba cubensis was found in nine out of 12 sampled localities of which four were positive for F. hepatica infection as detected by both immunoenzymatic and PCR-based assays. The overall prevalence was higher than the natural infection rates previously reported for Cuban G. cubensis (range from 4.1 to 7.42 % depending on the screening method). No significant differences were found between FasciMol-ELISA and multiplex PCR when determining parasite positivity (Χ2 = 6.283; P = 0.0981) whereas an excellent agreement was also noted (Kappa = 0.8224).ConclusionsOur results demonstrate the importance of malacological surveys in assessing parasite transmission risk and constitute an alert on the need of accurate measures to control fasciolosis in western Cuba. The sensitivity and specificity of the FasciMol-ELISA as well as its time-saving capacity and the easy of performing the determination of a large number of samples, point at this assay as a novel tool suitable for large-scale monitoring of natural snails populations. To our knowledge, this is the first study that explores natural infection by F. hepatica in field-occurring lymnaeid snails using an immunoenzymatic assay.

Epidemic Characteristics of Foot and Mouth Disease on the Buffaloes and Cows in Lang Son Province, Vietnam

From 2011 to 2015, in Lang Son province, Vietnam, foot and mouth disease (FMD) occurred in 11 districts and town. The virus causing FMD on the cattle in Lang Son belonged to type O and type A. While type Asia 1 virus had occurred in some other provinces in Vietnam, it was not found in Lang Son. FMD epidemic in Lang Son province had no regularity. In one district, the epidemic occurred continuously in two or three years (e.g. in Binh Gia and Van Quan districts) while in some others, it occurred only once (e.g. Cao Loc district and Lang Son city). On average, 1.26% of the buffaloes and cows were infected with FMD per year. Precisely, 1.39% of the buffaloes and 0.75% of the cows were infected. FMD on the buffaloes and cows in Lang Son was under the influence of (i) the weather and climate conditions (especially the years with extremely cold winter), (ii) the seasonal agricultural practice in the locality (during the time of the year when the cattle were used for ploughing and pulling carts for the crops, their health was relatively declined), and (iii) the results of vaccination in early Autumn – Winter season (the smaller the number of cattle vaccinated, the higher the number of cattle infected). These influences were clearly observed in 2011 with the highest number of cattle infected (8,929 infected cattle, accounting for 5.3% of the herds, whereas the average rate of infection in the whole five studied years was 1.26%). The sources of FMD were identified as mainly came from the infected cattle which had been medically treated and clear of the symptoms, yet still carried and shed the virus to the environment. On average, the rate of natural virus infection on the cattle in Lang Son was 33.23%. Of which, the rate was highest in the following districts: Bac Son (66.66%), Van Quan (50%), Trang Dinh (32.88%) and Binh Gia (28.57%). After being injected with FMD vaccine (Aftovax Bivalent, with 2 types of O and A), 100% of the cattle had immune response. 30 days after vaccination, the rate of protection varied from 86.6% to 100%. Six months after the first vaccination shot, a second one must be done for the vaccination to be effective.

Health care workers in Pearl River Delta Area of China are not vaccinated adequately against hepatitis B: a retrospective cohort study.

BackgroundsHealth-care workers’ (HCWs) exposure to bodily fluids puts them at risk of hepatitis B virus HBV infection. This study investigated HBV vaccination practices and outcomes in HCWs and assessed postvaccination seroprotection across HCWs in different departments.MethodsA survey of HCWs in a Chinese public general hospital was carried out with a retrospective cohort of 1420 hospital HCWs (458 males and 962 females). HBV vaccination status (10-μg/dose used) was investigated in the cohort from vaccination records from the period of 1988 to 2008. Blood samples were collected and tested for hepatitis B surface antigen (HBsAg) and HBV antibodies (anti-HBs).ResultsThe overall vaccination (complete course) and HBsAg carrier rates among HCWs were 40.42 % (574/1420) and 6.13 % (87/1420), respectively. Vaccination rates differed by department, with HCWs in internal medicine (39.5 %) and emergency (42.0 %) departments having particularly low rates. The natural infection rate was 7.53 % (107/1420) among HCWs. HCWs in the department of infectious diseases (vaccination rate, 57.8 %) had the highest rate of antibody produced by natural infection (88.2 %).ConclusionThe vaccination rate was a disappointingly low among HCWs in Pearl River Delta Area of China. HCWs working in infectious diseases departments and technicians were at particularly likely to have been infected with HBV. A concerted effort is needed to bring vaccination rates up among Chinese HCWs in Pearl River Delta Area of southern China.

Infection Rate by Trypanosoma cruzi and Biased Vertebrate Host Selection in the Triatoma dimidiata (Hemiptera: Reduvidae) Species Complex.

Chagas disease is a vector-borne disease, caused by the protozoan parasite Trypanosoma cruzi and transmitted by hematophagous insects. Triatoma dimidiata (Hemiptera: Reduvidae (Latreille 1811)) is one of the main vectors, and recent molecular studies indicate that it is a species complex, with potentially different vectorial competences. We investigated the differences in natural T. cruzi infection rate within T. dimidiata complex in Yucatan, Mexico. ITS-2 hybrid bugs had a twofold higher infection rate than ITS-2 Groups 2 and 3 bugs, and this pattern was consistent over time and in several villages. To test if T. dimidiata ITS-2 hybrid bugs could feed more frequently on T. cruzi-infected hosts, we evaluated their host-seeking behavior in a dual-choice chamber. Group 2 and 3 bugs were equally attracted to T. cruzi-infected or uninfected mice. On the contrary, ITS-2 hybrid bugs reached three times more frequently the T. cruzi-infected mouse, compared to the uninfected one, indicating a significant bias toward an infected host. This behavior may explain in part their higher natural infection rate. Further studies should explore the complex and unique interactions among T. cruzi, triatomines vectors, and mammalian hosts, as this may led to new strategies to interfere with transmission cycles and improve Chagas disease control.

IMPORTÂNCIA DA DISTRIBUIÇÃO GEOGRÁFICA DOS VETORES DA DOENÇA DE CHAGAS EM PERNAMBUCO, BRASIL, EM 2012

Objectives: To underscore the importance of geographic distribution and behavior of vectors ofChagas disease in the state of Pernambuco. Methods: The material analyzed included 100% of theinsects infected with Trypanosoma spp., and 40% of negative insects, examined at the EndemicDisease Laboratory for taxonomic confirmation, searching for the parasite in feces of the insects,with Quality Control to confirm the diagnosis. Results: A total of 3,323 triatomines. Naturalinfection by trypanosomes was detected in 21.3% of the specimens. Triatoma brasiliensis wasthe most frequent intradomiciliary species (24.3%), outside the home Triatoma pseudomaculata(14.9%) and Panstrongylus megistus had a natural infection rate proportionally superior to the others(40.8%). Conclusion: The current knowledge of the geographical distribution of Chagas diseasevectors is important as a platform to integrate actions between health services, contributing to theentomological surveillance and control of the insects.

Effect of the physiognomy of Attalea butyracea (Arecoideae) on population density and age distribution of Rhodnius prolixus (Triatominae).

BackgroundRhodnius prolixus Stål, 1859 is one of the main vectors of Trypanosoma (Schyzotrypanum) cruzi Chagas, 1909. In its natural forest environment, this triatomine is mainly found in palm tree crowns, where it easily establishes and develops dense populations. The aim of this study was to evaluate the effect of the physiognomy and reproductive status of Attalea butyracea on the population relative density and age structure of R. prolixus and to determine the vector’s population stratification according to the vertical and horizontal profile of an A. butyracea forest.MethodsUsing live bait traps, 150 individuals of A. butyracea with different physiognomy and 40 individuals with similar physiognomy (crown size, number of leaves, palm tree height, diameter at breast height, reproductive status) were sampled for triatomines in Yopal, Casanare-Colombia. Temperature and relative humidity were measured in the crown of the palm tree. Entomological indices and natural infection rates were also determined.ResultsThe relative population density of R. prolixus on natural A. butyracea groves is associated with the palm’s height, number of leaves and crown volume. The young immature stages were present mostly at the crown’s base and the advanced immature stages and adults were present mostly at the crown of the palm tree. This distribution correlates with the temperature stability and relative humidity in the base and the fluctuation of both environmental variables in the palm’s crown. A higher density of R. prolixus was found as the palm tree height increased and as the distance of the palm with respect to the forest border decreased, especially towards anthropically intervened areas. A density index of 12.6 individuals per palm tree with an infestation index of 88.9% and a colonization index of 98.7% was observed. 85.2% was the infection index with T. cruzi.ConclusionThe physiognomy of palm trees affects the relative population density and the distribution of developmental stages of R. prolixus. Therefore, they constitute a risk factor for the potential migration of infected insects from wild environments towards residential environments and the subsequent epidemiological risk of transmission of T. cruzi to people.

Role of underappreciated vectors in malaria transmission in an endemic region of Bangladesh-India border.

BackgroundDespite the efforts of the National Malaria Control Programme, malaria remains as an important public health problem in Bangladesh, particularly in the south-eastern region bordering India. Successful malaria control strategies rely on a detailed understanding of the underlying causes of malaria transmission. Here, an entomological survey was conducted in a malaria endemic area of Bangladesh bordering India to investigate the Anopheles mosquito community and assess their Plasmodium infection status.MethodsMonthly entomological collections were undertaken from October 2010 to September 2011 in five villages in the Matiranga sub-district, Khagrachari district in Bangladesh, bordering the Indian State of Tripura. CDC miniature light traps were placed inside houses to collect adult Anopheles mosquitoes. Following morphological and molecular identification of the female Anopheles mosquitoes collected, they were screened for circumsporozoite proteins (CSP) of Plasmodium falciparum (Pf), Plasmodium vivax-210 (Pv-210) and Plasmodium vivax-247 (Pv-247), by ELISA to determine natural infection rates. Variation in Anopheles species composition, relative abundance and Plasmodium infection rates were analysed between sampled villages.ResultsA total of 2,027 female Anopheles were collected, belonging to 20 species. Anopheles nivipes was the most abundant species in our test villages during the peak malaria transmission season, and was observed sympatrically with An. philippinensis in the studied area. However, in the dry off-peak season, An. jeyporiensis was the most abundant species. Shannon’s diversity index was highest in October (2.12) and evenness was highest in May (0.91). The CSP ELISA positive rate overall was 0.44%. Anopheles karwari (n = 2), An. barbirostris s.l. (n = 1) and An. vagus (n = 1) were recorded positive for Pf. Anopheles kochi (n = 1) was positive for Pv-210 while An. umbrosus (n = 1), An. nivipes (n = 1) and An. kochi (n = 1) were positive for Pv-247. A mixed infection of Pf and Pv-247 was detected in An. barbirostris s.l..ConclusionHigh diversity of Anopheles species was observed in areas close to the international border where species that were underestimated for malaria transmission significantly outnumbered principal vector species and these may play a significantly heightened role in malaria transmission.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0803-8) contains supplementary material, which is available to authorized users.

Development of real time PCR to study experimental mixed infections of T. congolense Savannah and T. b. brucei in Glossina morsitans morsitans.

Tsetse flies are able to acquire mixed infections naturally or experimentally either simultaneously or sequentially. Traditionally, natural infection rates in tsetse flies are estimated by microscopic examination of different parts of the fly after dissection, together with the isolation of the parasite in vivo. However, until the advent of molecular techniques it was difficult to speciate trypanosomes infections and to quantify trypanosome numbers within tsetse flies. Although more expensive, qPCR allows the quantification of DNA and is less time consuming due to real time visualization and validation of the results. The current study evaluated the application of qPCR to quantify the infection load of tsetse flies with T. b. brucei and T. congolense savannah and to study the possibility of competition between the two species. The results revealed that the two qPCR reactions are of acceptable efficiency (99.1% and 95.6%, respectively), sensitivity and specificity and can be used for quantification of infection load with trypanosomes in experimentally infected Glossina morsitans morsitans. The mixed infection of laboratory Glossina species and quantification of the infection suggests the possibility that a form of competition exists between the isolates of T. b. brucei and T. congolense savannah that we used when they co-exist in the fly midgut.

Skin and mucosal human papillomavirus seroprevalence in persons with Fanconi Anemia.

Persons with Fanconi anemia (FA) are at risk for human papillomavirus (HPV)-associated cancers; however, their natural HPV exposure and infection rates are unknown as is the adequacy with which they mount antibodies to HPV vaccination. This study aimed to determine, in 62 persons with FA, the seroprevalence of skin and mucosal HPV types, the seroprevalence in individuals self-reporting a history of HPV vaccination, and the factors associated with HPV seropositivity. A bead Luminex assay was used to determine seropositivity for HPV1, -2, and -4 (low-risk skin), -6 and -11 (low-risk mucosal, included in one HPV vaccine), -16 and -18 (high-risk mucosal, included in both HPV vaccines), and -52 and -58 (high-risk mucosal). Health- and behavior-related questionnaires were completed. Type-specific seroprevalence estimates and participant characteristics associated with seroprevalence were calculated; 48% reported HPV vaccination. Type-specific seropositivity in unvaccinated persons ranged from 7 to 21% for skin HPV types and 7 to 38% for mucosal HPV types. Among the unvaccinated participants, adults versus children demonstrated increased HPV1, -6, -16, and -58 seroprevalence of 45% versus 6%, 64% versus 22%, 64% versus 17%, and 36% versus 0%, respectively (all P < 0.05). The vaccinated participants versus the nonvaccinated participants demonstrated increased seroprevalence of HPV6, -11, -16, and -18 of 92% versus 38%, 92% versus 24%, 96% versus 34%, and 75% versus 7%, respectively (all P < 0.0001). Our data demonstrate that the unvaccinated participants had serologic evidence of prior skin and mucosal HPV infections and that seroprevalence increased among adults; in self-reported vaccinees, seroprevalence of HPV vaccine types was 75 to 96%.

Urban schistosomiasis and associated determinant factors among school children in Bamako, Mali, West Africa.

BackgroundSchistosomiasis is classically described as a rural disease that occurs in areas with poor sanitary conditions. However, over recent decades, there has been an expansion of schistosomiasis foci towards urban areas faced with a rapid and disordered urbanization. In Bamako, Mali, the impact of environmental change on vector-borne diseases such as schistosomiasis is not well known. This study sought to identify the presence of schistosomiasis transmission hotspots in Bamako. Using this perspective, we aimed to describe the risk factors of the endemization and maintenance of schistosomiasis.Materials and methodsA cross-sectional study was carried out in the six municipalities (communes) in Bamako. Environmental information was obtained from earth observation satellites in order to maximize ecological contrasts. Twenty-nine blocks of 200 m x 200 m were identified. We selected a school inside or nearest to each block for urine and stool samples examination. The study cohort was school children aged between eight and 15 years. The Kato-Katz technique and filtration were used for Schistosoma mansoni and S. haematobium ova research in stools and urine, respectively. The schools and snail breeding sites were georeferenced. Four malacological surveys were conducted between October 2011 and February 2012. Bivariate analysis was used to identify independent predictors of being infected with schistosomiasis.ResultsThe prevalence rate of S. haematobium was 14.7% (n = 1,761) and that of S. mansoni 1.5% (n = 1,491). Overall, the urinary form was endemic in 76.6% of schools. The infection significantly varied between the municipalities (p < 0.001). It was also more prevalent on the left side of the Niger River than the right side (17.4% vs. 9.5% respectively; p < 0.001). The vicinity to snail breeding sites (OR = 3.677; 95% IC [2.765–4.889]; p < 10-3) and parents’ occupations (OR = 7.647; 95% IC [2.406–24.305]; p < 0.001) were the most important risk factors associated with S. haematobium infection exposure. Biomphalaria pfeifferi, Bulinus truncatus, and B. globosus were the intermediate hosts captured. The schistosome natural infection rates (SNIRs), which were low or nil in October and November, rose to 2.8% in January and 8.3% in February for B. pfeifferi and B. truncatus, respectively.ConclusionOur findings show that there is a high transmission risk for schistosomiasis in Bamako. Appropriate integrated control measures need to be introduced to control the transmission of this disease in the study area.Electronic supplementary materialThe online version of this article (doi:10.1186/2049-9957-4-4) contains supplementary material, which is available to authorized users.

Anopheles species composition explains differences in Plasmodium transmission in La Guajira, northern Colombia

Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil

Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.

Identification of Anaplasma specise in some anima sl from Xitianmu Mountain in Zh ejiang province

Objective To identify Anaplasma species circulating among livestock and rodents from Xitianmu Mountain area in Zhejiang province , Southeastern China and to analyze variations regarding to their 16S rRNA gene.Methods Samples of spleen, liver and blood were collected to extract DNAs .The 16S rRNA gene fragments of Anaplasma species were amplified by using a nested PCR and then sequenced .Ho-mology analysis was conducted by using BLAST program .The multiple sequence alignment and phylogenetic analyses comparing with the sequences of other Anaplasma species in GenBank were conducted by using MEGA 5.0 software.Results The 16S rRNA gene fragments of Anaplasma were detected in 1 cattle, 8 goats, 5 Rattus confucianus, 1 Apodemus agrarius, 1 Berylmys bowersi and 1 squirrel out of 129 animals. The natural infection rate of Anaplasma was 13.2% in animals from Xitianmu Mountain area in Zhejiang . The alignment and phylogenetic analyses indicated that there were at least four Anaplasma species prevalent in livestock and rodents from Xitianmu Mountain area , including Anaplasma phagocytophilum, Anaplasma marginale, Anaplasma centrale and Anaplasma bovis.Moreover, there was a variant that obviously differed from Anaplasmma bovis and other Anaplasma sp.in GenBank.Conclusion The Anaplasma infection was detected among livestock and rodents from Xitianmu Mountain area in Zhejiang province .A newly discovered variant in rodents was likely to be a novel species .More close attention should be paid to Anaplasma infec-tion among human in Xitianmu Mountain area . Key words: Anaplasma; Animal infection; Gene variation

Sarcocystis arieticanis (Apicomplexa: Sarcocystidae) infecting the heart muscles of the domestic sheep, Ovis aries (Artiodactyla: Bovidae), from K. S. A. on the basis of light and electron microscopic data.

In the present study, the heteroxenous life cycle of Sarcocystis species from three strains of the slaughtered sheep at Al-Azizia and Al-Saada abattoirs in Riyadh city, K.S.A., was studied. Muscle samples of the oesophagus, diaphragm, tongue, skeletal and heart muscles were examined. Varied natural infection rates in the muscles of the examined sheep strains were recorded as 83% in Niemy, 81.5% in Najdy and 90% in Sawakny sheep. Muscles of the diaphragm showed the highest infection level above all organs except Najdy sheep in which oesophagus has the highest rate. Also, the heart was the lowest infected organ (40% Niemy, 44% Najdy and 53% Sawakny). Microscopic sarcocysts of Sarcocystis arieticanis are easily identified in sections through the heart muscles of the domestic sheep Ovis aries (Artiodactyla: Bovidae). Cysts measured 38.5-64.4 μm (averaged 42.66 μm) in width and 62.4-173.6 μm (averaged 82.14 μm) in length. The validity of this species was confirmed by means of ultrastructural characteristics of the primary cyst wall (0.1-0.27 μm thick) which revealed the presence of irregularly shaped crowded and hairy-like projections underlined by a thin layer of ground substance. This layer consisted mainly of fine, dense homogenous granules enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. Several septa derived from the ground substance divided the cyst into compartments. The merozoites were banana-shaped and measured 12-16 μm in length with centrally or posteriorly located nuclei. Experimental infection of carnivores by feeding heavily infected sheep muscles revealed that the dog, Canis familiaris, is the only final host of the present Sarcocystis species. Gamogony, sporogonic stages and characteristics of sporulated oocysts were also investigated.

Acquired Tolerance in Apricot Plants that Stably Recovered from European Stone Fruit Yellows.

European stone fruit yellows (ESFY) is one of the most destructive phytoplasma diseases of plum, apricot, and peach in Europe. Conventional preventive defense strategies have been ineffective. Because apricot cultivars with innate-constitutive resistance against ESFY are not available, the aim of this more than 20-year-long study was to seek acquired resistance or tolerance. In the first experiment, we surveyed an orchard with seven apricot cultivars for 12 years in an area of northern Italy with a high rate of natural occurrence of ESFY. Of the diseased plants, a few (8.7%) became completely symptomless but retained the phytoplasma, as confirmed by polymerase chain reaction (PCR). In the second experiment, we grafted buds from two stably recovered plants and from two nonrecovered plants onto 'Rubira' peach. Over the next 9 years in an orchard with a high rate of natural infection, 93.0% of the "nonrecovered clones" became diseased but only 1.5% of the plants grafted with the two "recovered clones" developed ESFY symptoms. According to PCR analyses, all of the exposed test plants were ESFY-infected, whether they were derived from recovered or nonrecovered mothers. This could indicate that epigenetic changes occurred in recovered plants due to a graft-transmissible memory. Based on the results attained from the two described experiments, we propose that an acquired tolerance that occurred in stably recovered apricot trees was graft transmitted from two tolerant apricot clones. In contrast, we did not demonstrate a cross-protection process based on protectant avirulent phytoplasma strains that suppress severe strains.

Ecology of Rhodnius robustus Larrousse, 1927 (Hemiptera, Reduviidae, Triatominae) in Attalea palm trees of the Tapajós River Region (Pará State, Brazilian Amazon).

BackgroundThe rising number of acute cases of Chagas disease in the State of Pará, reported in the past two decades, has been associated, in part, with the ingestion of juice of local palm tree fruits, mainly açaí berry and bacaba. Near the study area, in Santarém, Pará State, an outbreak of Chagas disease has been notified and investigations suggest the consumption of bacaba juice as the main source of infection with T. cruzi. The purpose of this study is to assess the aspects associated to the ecology of Rhodnius robustus in palm trees of three communities of the Tapajós region, in the State of Pará, Brazil.MethodsPalm trees were cut down and dissected to search for triatomines. DNA from triatomines was extracted to investigate natural infection by Trypanosoma cruzi and T. rangeli. For statistical analyzes, data from infestation of palm trees, as well as the rates of natural infection by T. cruzi and T. rangeli were compared by Chi-square test. Triatomine density values were analyzed by the nonparametric Kruskal Wallis test and then comparisons between each pair of variables were made by the Mann–Whitney test assuming a confidence interval of 95%.ResultsWe dissected 136 palm trees, 60 at the end of the rainy period and 76 at the end of the dry period. Seventy-three of them (53.7%) were infested with triatomines and three species were found, namely: Rhodnius robustus, Rhodnius pictipes and Panstrongylus lignarius. We collected 743 triatomines, and R. robustus was predominant (n = 739). The identification of natural infection of the insects by trypanosomatids revealed that 125 triatomines were infected by T. cruzi, 69 by T. rangeli and 14 presented both parasites, indicating the presence of mixed infection in the same vector.ConclusionThe results suggest that São Tomé is the community with greater density of triatomines and infestation of palm trees; also, it demonstrates the existence of an intense sylvatic cycle in the region, which demands intensive surveillance to prevent human transmission.