Infection of Populus tremuloldes by Hypoxylon mammatum ascospores through Saperda inornata gails

1995 ◽  
Vol 25 (5) ◽  
pp. 813-816 ◽  
Author(s):  
Michael E. Ostry ◽  
Neil A. Anderson
Keyword(s):  
Infection Rate ◽  
Natural Infection ◽  
Sterile Water ◽  
Elapsed Time ◽  
Hypoxylon Mammatum ◽  
Canker Development

Branch galls resulting from oviposition wounds made by Saperdainornata Say on Populustremuloides Michx. were studied in relation to inoculation with Hypoxylonmammatum (Wahlenberg) J.H. Miller ascospores. The natural infection rate of galls in an aspen plantation in central Minnesota averaged 1.6% (range 0.8–2.6%) during a 4-year period. However, when S. inornata galls were inoculated with ascospores during a 3-year period, 9.1% (range 6.5–2.6%) of the branches became infected. When galls were inoculated with sterile water, 3.3% of the branches became infected, perhaps indicating that inoculum already was present in the galls. The average elapsed time from ascospore inoculation until the development of hypoxylon canker symptoms was 26 months. These results provide the first demonstration of canker development following inoculation of natural wounds on aspen with H. mammatum ascospores.

A Study of the Sandfly Population in Endemic Foci of Infantile Kala-azar in Italy

1931 ◽  
Vol 22 (1) ◽  
pp. 105-113 ◽  
Author(s):  
S. Adler ◽  
O. Theodor
Keyword(s):  
Visceral Leishmaniasis ◽  
Infection Rate ◽  
Natural Infection ◽  
Kala Azar

The sandflies of the two largest Italian foci of visceral leishmaniasis, Naples and Catania, were studied.The following species were found : P. papatasii, P. perniciosus, P. sergenti, P. vesuvianus, sp. n., P. parroti var. italicus var. n.P. papatasii and P. perniciosus are the commonest sandflies in the areas examined.Out of 1,547 ♀♀ dissected none showed a natural infection with Leishmania.P. papatasii was infected with Italian strains of L. infantum by feeding on cultures through membranes. The infection rate was low, but in contrast to Indian strains of L. donovani in the same sandfly, the infection once established did not die out.

scholarly journals Investigation on Prevalence of Sparganum mansoni Infection in Wild Frogs on Hainan Island of China

2020 ◽  
Author(s):  
Ruijia Fu ◽  
Pei Liang ◽  
Gang LU ◽  
Jinbao Gu ◽  
Dayong Wang
Keyword(s):  
South China Sea ◽  
Infection Rate ◽  
South China ◽  
Natural Infection ◽  
Hainan Island ◽  
Open Wound ◽  
Potential Threat ◽  
Local Populations ◽  
Food Borne ◽  
The Mainland Of China

Abstract Background: Sparganosis is a serious food-borne parasitic zoonosis, which is mainly caused by ingesting or open-wound contact of the frog flesh infected by Sparganum mansoni, or even by intake of the water contaminated by the parasite. The purpose of the study was to explore the prevalence of sparganum infection in wild frogs distributed throughout the Hainan Island, which is the largest island of the mainland of China and located at the northwest of the South China Sea, and to analyze the risk in local populations to suffer from sparganosis.Methods: From 2018 to 2020, wild frogs were collected from rural ponds, rivers and farmlands in different cities and counties throughout the Hainan Island. After weighing and marking of the frogs, the sparganums were examined and isolated. The sites of the parasite and the number of infections of each frog were recorded and analyzed by statistics analysis.Results: A total of 1556 of wild frogs were examined and isolated. 201 wild frogs were found to be infected by sparganum, and the natural infection rate of sparganum in wild frogs was 12.92% (201/1556). There were 612 sparganums found in the frogs, and the average was 3.04 per frog, while the highest infection rate of wild frogs was in Baoting, up to 32.93% (27/82). The infection rate of sparganum in wild frogs in the central region of Hainan Island is higher than other regions. Most sparganums were located in the hind legs of frog, and the number of the sparganum infection in the frogs was not related to the species and weight of the frogs.Conclusions: On Hainan Island, sparganum infection in wild frogs is relatively common, and constitutes a potential threat to human. Effective measures should be taken to control the incidence of sparganosis.

scholarly journals Investigation of natural infection by Leishmania in sandflies of Paraná State, Southern Brazil

2008 ◽  
Vol 51 (3) ◽  
pp. 483-491 ◽  
Author(s):  
Regiane Bertin de Lima Scodro ◽  
Kárin Rosi Reinhold-Castro ◽  
Alessandra de Cassia Dias-Sversutti ◽  
Herintha Coeto Neitzke-Abreu ◽  
Norberto de Assis Membrive ◽  
...  
Keyword(s):  
Infection Rate ◽  
Natural Infection ◽  
Southern Brazil ◽  
Light Traps ◽  
Endemic Areas

The purpose of this work was to verify the occurrence of Leishmania in naturally infected sandflies. The insects were collected with Falcão, Shannon and HP light-traps, in Doutor Camargo and Maringá municipalities between November 2004 and October 2005. Of the 11,033 sandflies collected in Doutor Camargo, 2,133 surviving females were dissected, particularly those of the Nyssomyia neivai species (86.87%). In Maringá, 136 sandflies were collected, of which 79 N. whitmani females and 1 Migonemyia migonei female were dissected. The dissected insects were identified and stored in the pools of 10 specimens. The PCR was carried out on 1,190 females of N. neivai and 190 of N. whitmani from Doutor Camargo, and on 30 of N. whitmani from Maringá, using the primers MP1L/MP3H. The natural infection by Leishmania in sandflies was not confirmed by either of the methods used. The results suggested the low natural infection rate of sandflies by Leishmania in these areas, corroborating other studies carried out in endemic areas of ACL.

Studies on Trypanosoma avium Danilewsky 1885 I. Incidence in some birds of Hertfordshire

Parasitology ◽  
1956 ◽  
Vol 46 (3-4) ◽  
pp. 308-320 ◽  
Author(s):  
J. R. Baker
Keyword(s):  
Bone Marrow ◽  
Infection Rate ◽  
Peripheral Blood ◽  
Natural Infection ◽  
Peripheral Circulation ◽  
First Year ◽  
Corvus Frugilegus ◽  
Time Of Year

1. A survey of 227 rooks (Corvus frugilegus frugilegus L.) and seventy jackdaws (C. monedula spermologus Vieill.) was conducted in Hertfordshire. The birds were examined by means of cultures of their peripheral blood, or (in the case of eleven rooks and one jackdaw only) bone-marrow, on N.N.N. medium. Twenty-seven rooks (11·9%) and six jackdaws (8·6%) were found to be infected.Some of the rooks were examined at a time of year when the trypanosomes are not present in the peripheral circulation; other rooks were examined in the first year of their life before adults of Ornithomyia avicularia (the vector of this parasite) were present. Ignoring birds of these two groups, twenty-six out of seventy-eight (33·3 %) adult rooks were found to be infected. This value probably approximates to the natural infection rate among adult rooks (and perhaps jackdaws).2. The trypanosome in question is a large spindle-shaped form, measuring an average of 48·2µ in length (excluding flagellum) and 5·5µ in width. There is a tapering aflagellar region extending 14·1µ (on the average) beyond the kineto-plast. This trypanosome is assigned to the species T. avium Danilewsky, 1885.

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

2014 ◽  
Vol 109 (7) ◽  
pp. 899-904 ◽  
Author(s):  
Veruska Nogueira de Brito ◽  
Arleana do Bom Parto Ferreira de Almeida ◽  
Luciano Nakazato ◽  
Rosemere Duarte ◽  
Cladson de Oliveira Souza ◽  
...  
Keyword(s):  
Infection Rate ◽  
Feeding Habits ◽  
Natural Infection ◽  
Mato Grosso

BEAUVERIA BASSIANA CHARACTERIZATION AND EFFICACY GRASSHOPPER /ANGARACRIS

2015 ◽  
Vol 13 (2) ◽  
pp. 96-100
Author(s):  
Kh Otgonjargal ◽  
S Sugar ◽  
E Bazarragchaa ◽  
N Enkhbold ◽  
B Battur
Keyword(s):  
Beauveria Bassiana ◽  
Infection Rate ◽  
Natural Infection ◽  
The Body ◽  
Insect Host ◽  
Local Strains ◽  
As Species ◽  
Agricultural Sciences ◽  
Scar Primers

The B. bassiana is a fungus of manyarthropods, including more than 200 species of insects and acaridae. When spores of the fungus come into contact with the body of an insect host, they germinate, enter the body, and grow inside, eventually killing the insect. Two local strains, including B. bassiana-G07, which was isolated from grasshopper Oedaleusasiaticus, died on natural infection, and B. bassiana-G10, which was isolated from grasshopper Caliptomus abbreviates, died of soil borne infection, were detected and it was identified as species B. bassiana by PCR. SCAR primers OPB9 F/R677 and OPA15 F/R441 was specific to of B. bassiana. The highest infection rate by B. bassiana-G07and mortality was observed in variants of both concentrations 2.1 x 108 conidia/ml, 2.1 x 109 conidia/ml; where mortality reached 86.3-100%.Mongolian Journal of Agricultural Sciences Vol.13(2) 2014: 96-100

Natural Infection Rate of Known Tomato Chlorosis Virus-Susceptible Hosts and the Influence of the Host Plant on the Virus Relationship With Bemisia tabaci MEAM1

Plant Disease ◽  
2020 ◽  
Author(s):  
Arnaldo Esquivel-Fariña ◽  
Jorge Alberto Marques Rezende ◽  
William M. Wintermantel ◽  
Laura Jenkins Hladky ◽  
Daiana Bampi
Keyword(s):  
Infection Rate ◽  
Bemisia Tabaci ◽  
Host Plants ◽  
Natural Infection ◽  
Sao Paulo ◽  
Cultivated Plants ◽  
São Paulo ◽  
Susceptible Host ◽  
External Sources ◽  
Tomato Chlorosis Virus

Tomato chlorosis virus (ToCV; genus Crinivirus, family Closteroviridae) was identified in tomato crops in the state of São Paulo, Brazil in 2006. Management strategies to control external sources of inoculum are necessary, because chemical control of the whitefly vector Bemisia tabaci MEAM1 has not efficiently prevented virus infections and no commercial tomato cultivars or hybrids are resistant to this crinivirus. We first evaluated the natural infection rate of some known wild and cultivated ToCV-susceptible hosts and their attractiveness for B. tabaci MEAM1 oviposition. Physalis angulata was the most susceptible to natural infection in all six exposures in 2018 and 2019. No plants of Capsicum annuum (cv. Dahra) or Chenopodium album became infected. Solanum melongena (cv. Napoli) had only two infected plants of 60 exposed. C. annuum and C. album were the least preferred, and Nicotiana tabacum and S. melongena were the most preferred for whitefly oviposition. In addition, from 2016 to 2019, we surveyed different tomato crops and the surrounding vegetation to identify ToCV in weeds and cultivated plants in the region of Sumaré, São Paulo state. Only Solanum americanum, vila vila (S. sisymbriifolium) and C. album were found naturally infected, with incidences of 18%, 20% and 1.4%, respectively. Finally, we estimated the ToCV titer (isolates ToCV-FL, USA and ToCV-SP, Brazil) by RT-qPCR in different ToCV-susceptible host plants and evaluated the relationship between virus acquisition and transmission by B. tabaci MEAM1. The results clearly showed significant differences in ToCV concentrations in the tissues of ToCV-susceptible host plants, which appeared to be influenced by the virus isolate. The concentration of the virus in plant tissues, in turn, directly influenced the ToCV-B. tabaci MEAM1 relationship and subsequent transmission to tomato plants. To minimize or prevent the damage from the tomato yellowing disease through management of external sources of ToCV, it is necessary to correctly identify the potentially important ToCV-susceptible hosts in the vicinity of new plantings.

scholarly journals Lockdowns and the COVID-19 pandemic: What is the endgame?

2020 ◽  
pp. 140349482096129 ◽  
Author(s):  
Theodore Lytras ◽  
Sotirios Tsiodras
Keyword(s):  
Public Health ◽  
Infection Rate ◽  
Natural Infection ◽  
Herd Immunity ◽  
Social Costs ◽  
Surveillance Data ◽  
Negative Effects ◽  
Social Distancing

An overall long-term strategy for managing the coronavirus disease 2019 (COVID-19) pandemic is presented. This strategy will need to be maintained until herd immunity is achieved, hopefully through vaccination rather than natural infection. We suggest that a pure test-trace-isolate strategy is likely not practicable in most countries, and a degree of social distancing, ranging up to full lockdown, is the main public-health tool to mitigate the COVID-19 pandemic. Guided by reliable surveillance data, distancing should be continuously optimised down to the lowest sustainable level that guarantees a low and stable infection rate in order to balance its wide-ranging negative effects on public health. The qualitative mixture of social-distancing measures also needs to be carefully optimised in order to minimise social costs.

OnCulicoidesas a Vector ofOnchocerca gibsoni(Cleland & Johnston, 1910)

1938 ◽  
Vol 16 (3) ◽  
pp. 121-158 ◽  
Author(s):  
J. J. C. Buckley
Keyword(s):  
Infection Rate ◽  
Experimental Infection ◽  
Blood Meal ◽  
Natural Infection ◽  
Common Species ◽  
Intermediate Hosts ◽  
Small Areas ◽  
Negative Results ◽  
Large Numbers ◽  
The Difference

The problem of the vector ofOnchoccrca gibsoniwas investigated in Kuala Lumpur, F.M.S., where the parasite is endemic and a high percentage of cattle is infected.For reasons which are outlined, the experimental work was confined to species ofCulicoidesandLasioheleaof which 18, possibly more, species were found on cattle, some of them being found to bite cattle in very large numbers daily.The distribution of the microfilariae of 0.gibsoniin the skin of live cattle was found to be very irregular, even within small areas of skin. In transverse sections of skin the microfilariae appear to have a maximum concentration just under the epidermis at a depth of ·05 to ·2 mm.0·52% of 1,523Culicoides pungens, which were dissected soon after an infective blood meal, were found to have picked up the microfilariae. 0·96% of 1,670 of this species, dissected some days after an infective blood meal, were found to have developing or mature filarial larvae in the thorax or head. 0·35% of 3,734 of this species, were found to be naturally infected with filarial larvae in the thorax or head. The difference between the experimental infection rate and the natural infection rate is shown statistically to be significant and it is concluded thatC. pungensis an intermediate host ofO. gibsoni.Culicoides oxystoma,C. shorttiandC. orientaliswere also dissected in large numbers and were found to pick up the microfilariae ofO. gibsoni; in each of these species the experimental infection rate exceeded the natural infection rate, but the difference in none of these is significant. It is concluded however, from the results obtained and from the morphological similarity of the mature larvae found in these species with that inC. pungens, that these species are also intermediate hosts ofO. gibsoni.C. peregrinusandC. buckleyiare suspected but not proven intermediate hosts.C. anophelisand/orC. anophelisv. flavcscensandLasiohelea stimulanswere found to pick up the microfilariae but only partial development was found in them.C. sumatraeandC. raripalpisalso picked up the microfilariae but no development was found in them. The remaining species worked with were entirely negative. In view, however, of the very minute percentage of infection which occurs inCulicoidesspp. and the large numbers which must be dissected to obtain positive results, the negative results given by these less common species are not necessarily conclusive.

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