Intra-Species Diversity and Panmictic Structure of Cryptosporidium parvum Populations in Cattle Farms in Northern Spain

The intra-herd and intra-host genetic variability of 123 Cryptosporidium parvum isolates was investigated using a multilocus fragment typing approach with eleven variable-number tandem-repeat (VNTR) loci and the GP60 gene. Isolates were collected from intensively farmed diarrheic pre-weaned calves originating from 31 dairy farms in three adjoining regions in northern Spain (País Vasco, Cantabria and Asturias). The multilocus tool demonstrated an acceptable typeability, with 104/123 samples amplifying at all twelve loci. The ML2, TP14, GP60 and the previously un-described minisatellite at locus cgd2_3850 were the most discriminatory markers, while others may be dismissed as monomorphic (MSB) or less informative (CP47, ML1 and the novel minisatellites at loci Cgd1_3670 and Cgd6_3940). The 12-satellite typing tool provided a Hunter-Gaston index (HGDI) of 0.987 (95% CI, 0.982-0.992), and differentiated a total of 70 multilocus subtypes (MLTs). The inclusion of only the four most discriminatory markers dramatically reduced the number of MLTs (n: 44) but hardly reduced the HGDI value. A total of 54 MLTs were distinctive for individual farms, indicating that cryptosporidiosis is an endemic condition on most cattle farms. However, a high rate of mixed infections was detected, suggesting frequent meiotic recombination. Namely, multiple MLTs were seen in most farms where several specimens were analyzed (90.5%), with up to 9 MLTs being found on one farm, and individual specimens with mixed populations being reported on 11/29 farms. Bayesian Structure analysis showed that over 35% of isolates had mixed ancestry and analysis of evolutionary descent using the eBURST algorithm detected a high rate (21.4%) of MLTs appearing as singletons, indicating a high degree of genetic divergence. Linkage analysis found evidence of linkage equilibrium and an overall panmictic structure within the C. parvum population in this discrete geographical area.

Nellore cattle (Bos indicus) and ticks within the Brazilian Pantanal: ecological relationships

Pantanal is a huge floodplain mostly in Brazil, and its main economic activity is extensive cattle raising, in farms characterized by an extremely wildlife-rich environment. We herein describe tick infestations of cattle and of the natural environment in Pantanal of Nhecolândia in Brazil, at areas with and without cattle during both dry and wet seasons. Environmental sampling resulted in three tick species: Amblyomma sculptum (423 nymphs and 518 adults), Amblyomma parvum (7 nymphs and 129 adults), Amblyomma ovale (3 adults) as well as three clusters and two individuals of Amblyomma sp. larvae. A significantly higher number of adult A. sculptum ticks was found in areas with cattle in the wet season. From 106 examinations of bovines 1710 ticks from three species were collected: Rhipicephalus microplus (55.7% of the total), A. sculptum (38%) and A. parvum (4.1%), as well as 32 Amblyomma sp. larvae. A significant similarity was found between Amblyomma tick fauna from environment and on cattle during both seasons. All A. sculptum females on bovines were flat whereas many of A. parvum females and A. sculptum nymphs were engorging. Although R. microplus was the most abundant tick species on cattle, overall highest tick prevalence on bovines in the dry season was of A. sculptum nymphs. Lack of R. microplus in environmental sampling, relationship between cattle and increase in adult A. sculptum numbers in the environment as well as suitability of bovine for the various tick species are discussed.

Exploring the Gastrointestinal "Nemabiome": Deep Amplicon Sequencing to Quantify the Species Composition of Parasitic Nematode Communities

Parasitic helminth infections have a considerable impact on global human health as well as animal welfare and production. Although co-infection with multiple parasite species within a host is common, there is a dearth of tools with which to study the composition of these complex parasite communities. Helminth species vary in their pathogenicity, epidemiology and drug sensitivity and the interactions that occur between co-infecting species and their hosts are poorly understood. We describe the first application of deep amplicon sequencing to study parasitic nematode communities as well as introduce the concept of the gastro-intestinal “nemabiome”. The approach is analogous to 16S rDNA deep sequencing used to explore microbial communities, but utilizes the nematode ITS-2 rDNA locus instead. Gastro-intestinal parasites of cattle were used to develop the concept, as this host has many well-defined gastro-intestinal nematode species that commonly occur as complex co-infections. Further, the availability of pure mono-parasite populations from experimentally infected cattle allowed us to prepare mock parasite communities to determine, and correct for, species representation biases in the sequence data. We demonstrate that, once these biases have been corrected, accurate relative quantitation of gastro-intestinal parasitic nematode communities in cattle fecal samples can be achieved. We have validated the accuracy of the method applied to field-samples by comparing the results of detailed morphological examination of L3 larvae populations with those of the sequencing assay. The results illustrate the insights that can be gained into the species composition of parasite communities, using grazing cattle in the mid-west USA as an example. However, both the technical approach and the concept of the ‘nemabiome’ have a wide range of potential applications in human and veterinary medicine. These include investigations of host-parasite and parasite-parasite interactions during co-infection, parasite epidemiology, parasite ecology and the response of parasite populations to both drug treatments and control programs.

Molecular and Parasitological Survey of Bovine Piroplasms in the Black Sea Region, Including the First Report of Babesiosis Associated with Babesia divergens in Turkey

Clinical cases of babesiosis were evaluated, and the frequency of bovine Babesia and Theileria parasites was determined in cattle. Blood samples and thin blood smears were collected from 23 cattle exhibiting clinical signs of babesiosis. In addition, tick and blood samples were collected from 100 apparently healthy cattle cograzing from the same area. Egg masses obtained from fully engorged female ticks were included. DNA isolated from blood and tick samples was screened for Babesia and Theileria by reverse line blot assay. Piroplasms compatible with Babesia spp. were observed microscopically for symptomatic cattle as circular, oval, elongated, or pear-shaped bodies. Parasitemia ranged from 0.08 to 0.9% for Babesia bovis, 2.5 to 15.4% for Babesia bigemina, and 7.4% for Babesia divergens. Reverse line blot showed positivity in 13 (13%) of the sampled clinically normal cattle and revealed the presence of three Babesia species. Babesia bovis was the most prevalent (9/100, 9%), followed by Babesia occultans (3/100, 3%) and B. bigemina (1/100, 1%). One animal infected with B. bigemina was also infected with B. bovis. The single animal infected with B. divergens showed symptoms of babesiosis. Ticks were identified as Rhipicephalus annulatus, Rhipicephalus turanicus, and Ixodes ricinus. One female R. annulatus and its egg mass were infected with B. bigemina. Neither Theileria annulata nor Theileria buffeli/orientalis infections were observed in cattle or ticks. This is the first report of clinical babesiosis caused by B. divergens in cattle from Turkey.

Comparisons of antifeedancy and spatial repellency of three natural product repellents against horn flies, Haematobia irritans (Diptera: Muscidae)

BACKGROUND

Horn flies are among the most important biting fly pests of cattle in the United States. Horn fly management is largely dependent upon pesticides, which ultimately leads to the rapid development of insecticide resistance. Alternative control strategies, including repellents, have shown promising results in reducing fly biting. In the present study, we examined the efficacy and longevity of recently identified natural product repellents against horn flies.

RESULTS

Catnip oil, geraniol and C8910 acids reduced horn fly feeding in a laboratory bioassay and also exhibited spatial repellency in the olfactometer. Residual activity was observed for up to 3 days in laboratory assays; however, 24 h of residual effectiveness was observed from the two repellents when applied on cattle in the field. The limited residual effectiveness was correlated with the high volatility of the major active repellent compounds.

CONCLUSION

All three natural product repellents effectively repel biting horn flies, exhibiting both feeding deterrence and spatial repellency. They may be used for developing an effective push-pull strategy with a slow release matrix that can prolong their effectiveness for horn fly management.

[Effect of schistosomiasis control in Jingzhou City from 2009 to 2013]

OBJECTIVE

To evaluate the effect of schistosomiasis control in Jingzhou City of Hubei Province from 2009 to 2013, so as to provide the reference for the establishment of control strategy in the future.

METHODS

The annual reports on schistosomiasis control from 2009 to 2013 in nine counties (cities, districts) in Jingzhou City were collected and analyzed sta- tistically.

RESULTS

The estimated number of schistosomiasis patients in Jingzhou City dropped from 78 903 in 2009 to 28 034 in 2013, with a reduction rate of 63.37%. The schistosome infection rate of residents dropped from 2.21% in 2009 to 0.65% in 2013, which showed an exponential decline trend (y = 3.196e(-0.317x)). The number of cattle with schistosomiasis decreased from 2 132 in 2009 to 0 in 2013, and the infection rate of cattle dropped from 1.87% in 2009 to 0% in 2013. Only 2 cases with acute infection of schistosome were found in 2009, and no schistosome infected snails were found out in 2 consecutive years, 2012 and 2013.

CONCLUSIONS

The endemic level of schistosomiasis in Jingzhou City has decreased significantly. In order to consolidate the achievement of control, the comprehensive strategy including infection source control, snail control with mol- luscicides and snail surveillance should be implemented.

The Differential Expression of Immune Genes between Water Buffalo and Yellow Cattle Determines Species-Specific Susceptibility to Schistosoma japonicum Infection

Water buffalo are less susceptible to Schistosoma japonicum infection than yellow cattle. The factors that affect such differences in susceptibility remain unknown. A Bos taurus genome-wide gene chip was used to analyze gene expression profiles in the peripheral blood of water buffalo and yellow cattle pre- and post-infection with S. japonicum. This study showed that most of the identified differentially expressed genes (DEGs) between water buffalo and yellow cattle pre- and post-infection were involved in immune-related processes, and the expression level of immune genes was lower in water buffalo. The unique DEGs (390) in yellow cattle were mainly associated with inflammation pathways, while the unique DEGs (2,114) in water buffalo were mainly associated with immune-related factors. The 83 common DEGs may be the essential response genes during S. japonicum infection, the highest two gene ontology (GO) functions were associated with the regulation of fibrinolysis. The pathway enrichment analysis showed that the DEGs constituted similar immune-related pathways pre- and post-infection between the two hosts. This first analysis of the transcriptional profiles of natural hosts has enabled us to gain new insights into the mechanisms that govern their susceptibility or resistance to S. japonicum infections.

Seasonal variation in coat characteristics, tick loads, cortisol levels, some physiological parameters and temperature humidity index on Nguni cows raised in low- and high-input farms

Seasonal variations in hair length, tick loads, cortisol levels, haematological parameters (HP) and temperature humidity index (THI) in Nguni cows of different colours raised in two low-input farms, and a commercial stud was determined. The sites were chosen based on their production systems, climatic characteristics and geographical locations. Zazulwana and Komga are low-input, humid-coastal areas, while Honeydale is a high-input, dry-inland Nguni stud farm. A total of 103 cows, grouped according to parity, location and coat colour, were used in the study. The effects of location, coat colour, hair length and season were used to determine tick loads on different body parts, cortisol levels and HP in blood from Nguni cows. Highest tick loads were recorded under the tail and the lowest on the head of each of the animals (P < 0.05). Zazulwana cows recorded the highest tick loads under the tails of all the cows used in the study from the three farms (P < 0.05). High tick loads were recorded for cows with long hairs. Hair lengths were longest during the winter season in the coastal areas of Zazulwana and Honeydale (P < 0.05). White and brown-white patched cows had significantly longer (P < 0.05) hair strands than those having a combination of red, black and white colour. Cortisol and THI were significantly lower (P < 0.05) in summer season. Red blood cells, haematoglobin, haematocrit, mean cell volumes, white blood cells, neutrophils, lymphocytes, eosinophils and basophils were significantly different (P < 0.05) as some associated with age across all seasons and correlated to THI. It was concluded that the location, coat colour and season had effects on hair length, cortisol levels, THI, HP and tick loads on different body parts and heat stress in Nguni cows.

A comparison of phenotypic traits related to trypanotolerance in five west african cattle breeds highlights the value of shorthorn taurine breeds

BACKGROUND

Animal African Trypanosomosis particularly affects cattle and dramatically impairs livestock development in sub-Saharan Africa. African Zebu (AFZ) or European taurine breeds usually die of the disease in the absence of treatment, whereas West African taurine breeds (AFT), considered trypanotolerant, are able to control the pathogenic effects of trypanosomosis. Up to now, only one AFT breed, the longhorn N'Dama (NDA), has been largely studied and is considered as the reference trypanotolerant breed. Shorthorn taurine trypanotolerance has never been properly assessed and compared to NDA and AFZ breeds.

METHODOLOGY/PRINCIPAL FINDINGS

This study compared the trypanotolerant/susceptible phenotype of five West African local breeds that differ in their demographic history. Thirty-six individuals belonging to the longhorn taurine NDA breed, two shorthorn taurine Lagune (LAG) and Baoulé (BAO) breeds, the Zebu Fulani (ZFU) and the Borgou (BOR), an admixed breed between AFT and AFZ, were infected by Trypanosoma congolense IL1180. All the cattle were genetically characterized using dense SNP markers, and parameters linked to parasitaemia, anaemia and leukocytes were analysed using synthetic variables and mixed models. We showed that LAG, followed by NDA and BAO, displayed the best control of anaemia. ZFU showed the greatest anaemia and the BOR breed had an intermediate value, as expected from its admixed origin. Large differences in leukocyte counts were also observed, with higher leukocytosis for AFT. Nevertheless, no differences in parasitaemia were found, except a tendency to take longer to display detectable parasites in ZFU.

CONCLUSIONS

We demonstrated that LAG and BAO are as trypanotolerant as NDA. This study highlights the value of shorthorn taurine breeds, which display strong local adaptation to trypanosomosis. Thanks to further analyses based on comparisons of the genome or transcriptome of the breeds, these results open up the way for better knowledge of host-pathogen interactions and, furthermore, for identifying key biological pathways.

Ethnoveterinary plants and practices used for ecto-parasite control in semi-arid smallholder farming areas of Zimbabwe

BACKGROUND

The inclusion of traditional plant-based ecto-parasite control methods in primary health care of livestock is increasingly becoming an important intervention for improving livestock productivity in resource-challenged smallholder farming areas. In this study, commonly used plants used for the control of cattle ticks and other pests were identified through a survey in four semi-arid districts of Zimbabwe.

METHODS

A standard structured questionnaire with details of demographics, socioeconomic status of households, livestock parasites, control practices and list of ethnoveterinary plants used was used to interview 233 knowledgeable smallholder farmers in four districts. Focus group discussions with community members further provided insights on how the plants were being used and other issues surrounding ecto-parasite control and indigenous knowledge systems in the study areas.

RESULTS

The older generation (>40 years) of the respondents were knowledgeable about ethnoveterinary plants and practices. Overall, 51 plant species were reportedly effective against cattle ticks and other livestock parasites. The most frequently mentioned plants were in descending order, Cissus quadrangularis (30.1%), Lippia javanica (19.6%), Psydrax livida (14.9%) and Aloe sp (14.9%). Most of the plant materials were prepared by crushing and soaking in water and spraying the extract on animals. Despite the knowledge of these useful pesticidal plants, the preferred animal health care for cattle and other highly ranked livestock species is still the use of commercial acaricides. Cattle dipping services were reported sporadic by 48% of the respondents. Traditional knowledge and plants are considered only as an alternative in the absence of conventional synthetic products.

CONCLUSIONS

Livestock farming communities know of plant species used for livestock ecto-parasite control. The plant species are mostly used to complement commercial products. More work, is required to confirm the acaricidal properties claimed by the farmers in order to optimize and promote sustainable use of these plants.

[Monitoring of sentinel mice and risk assessment of schistosomiasis transmission in key regions of Yunnan Province in 2014]

OBJECTIVE

To establish and perfect the surveillance and forecast system of schistosomiasis, and timely discover the suspicious high risk environments for preventing the human and livestock from schistosomiasis.

METHODS

Eight villages of three counties were selected as survey points. Then, the surveillance and forecast of sentinel mice were carried out in the key water regions. The recovered sentinel mice were dissected in laboratory. The sentinel mouse serum antibodies against schistosome were detected by ELISA, the suspicious water contacts of residents and livestock were investigated and the results were analyzed, and the epidemic risk was assessed.

RESULTS

Totally 300 sentinel mice were placed, the recovery rate was 94.67%, and the mortality rate was 8.80%. There were no mice with positive serum antibodies against schistosome, and the results of the dissection of all the sentinel mice were negative. The humans who contacted with the suspicious water were mainly villagers, students, children and fishermen by washing hands and feet, washing vegetables, harvesting, fishing and swimming. The Oncomelania hupensis snail areas, human infection rates, and cattle infection rates were obviously declined in recent 3 years. However, the epidemic risks still existed.

CONCLUSION

Although schistosomiasis transmission was effectively controlled in the three counties, the comprehensive control measures still should be strengthened.

Use of multiplexed tandem PCR to estimate the prevalence and intensity of Theileria orientalis infections in cattle

This study employed a semi-quantitative, multiplexed tandem PCR (MT-PCR) to assess the prevalence and infection intensity of four genotypes (buffeli, chitose, ikeda and type 5) of Theileria orientalis in cattle in Australia. Genomic DNA samples from blood samples (n=448) collected from 27 to 32 dairy cows from each of 15 dairy herds with a history of recent theileriosis outbreaks (Group 1), and from blood samples available from 24 cows with or without oriental theileriosis (Group 2) were tested using MT-PCR. Results revealed that all four genotypes were present in Group 1 cattle; genotype buffeli had the highest prevalence (80.5%), followed by genotypes ikeda (71.4%), chitose (38.6%) and type 5 (20.3%). Genotype ikeda had the highest average infection intensity in the cattle (relating to 55,277 DNA copies), followed by buffeli, chitose and type 5 (6354-51,648 copies). For Group 2, results indicated that genotype ikeda had a significantly higher average intensity of infection than buffeli in symptomatic cattle (P<0.001), and symptomatic cattle had a higher intensity of ikeda than asymptomatic cattle (P=0.004). Future studies should assess the utility of the present MT-PCR assay as a diagnostic and epidemiological tool in other parts of Australasia and the world.

Use of Ivermectin as Endoparasiticide in Tropical Cattle Herds Generates Resistance in Gastrointestinal Nematodes and the Tick Rhipicephalus microplus (Acari: Ixodidae)

The objective of the present study was to determine simultaneously the status of resistance against ivermectin (IVM) in gastrointestinal nematodes (GIN) and Rhipicephalus microplus (Canestrini, 1888) ticks in 12 cattle farms where IVM was used for the control of GIN in the Mexican tropics. Six farms had frequent use of IVM (≥ 4 times per year) and six farms had low frequency of IVM use (1-2 times per year). The fecal egg count reduction test and the larval immersion test were used to determine the resistant status of GIN and R. microplus against IVM, respectively. The results indicated that 100% of the surveyed farms had IVM-resistant GIN (reduction % from 0 to 67%). The genera involved were Haemonchus, Cooperia, Ostertagia, Trichostrongylus, and Oesophagostomum. Although the IVM was never used for the control of ticks, 50% of the surveyed farms presented GIN and R. microplus simultaneously resistant to IVM. Furthermore, two R. microplus populations showed high resistance ratio (RR) to IVM (farm TAT: RR50% = 7 and RR99% = 40.1; and farm SLS: RR50% = 2.4; RR99% = 11.0). A high frequency of IVM use (≥ 4 times per year) seemed to promote IVM resistance amongst R. microplus ticks compared with the farms with low frequency of IVM use (1-2 times per year; 66.6 vs. 25.0%, respectively). However, the number of surveyed farms was insufficient to show clear statistical inferences (odds ratio = 6.00; 95% CI = 0.341-105.5). The use of IVM for the control of GIN promoted simultaneously the development of IVM resistance in the GIN and R. microplus populations of the cattle herds surveyed.

Do Size and Insecticide Treatment Matter? Evaluation of Different Nets against Phlebotomus argentipes, the Vector of Visceral Leishmaniasis in Nepal

In the Indian subcontinent, Leishmania donovani, the parasite causing visceral leishmaniasis (VL) is transmitted by the sand fly vector Phlebotomus argentipes. Long lasting insecticide treated nets (LN) have been postulated as alternative or complement to Indoor Residual Spraying but there are few field studies evaluating the entomological efficacy of different nets against this vector. We conducted two crossover trials in a VL endemic area in Nepal to compare the barrier effect of (1) LN with different mesh sizes (156 holes/inch2 vs 625 holes/inch2) and (2) alpha-cypermethrin treated LN and untreated nets having the same mesh size (156 holes/inch2). Each crossover trial had two arms consisting of a sequence of two different nets for 8 nights. We used 10 cattle sheds per trial. A cow placed under the net was used as bait. CDC light traps placed inside the nets were used to evaluate the number of P. argentipes crossing the net barrier. Negative binomial generalized estimating equation (GEE) population-averaged models adjusted by night and sequence were used to estimate the barrier effect of the different nets. The crossover trials conducted in a rural village in Morang district (South-eastern Nepal) demonstrated that reducing the size of the holes in treated nets (625 holes/inch2) increased the barrier effect of LN by 77% (95% confidence interval (CI): 56%-88%) compared with treated nets with larger holes (156 holes/inch2). Treating nets with alpha-cypermethrin reduced the number of P. argentipes captured inside the nets by 77% (95% CI: 27%-93%) compared with untreated nets. The effectiveness and acceptability of finer mesh pyrethroid treated LN should be tested for VL prevention in a randomized controlled trial.

Prevalence of Fasciola species in ruminants under extensive management system in Ibadan southwestern Nigeria

BACKGROUND

Fasciolosis is a zoonotic trematode of ruminants and a common parasite in cattle in Nigeria. With the increasing numbers of small household cattle herds kept under extensive management system as well as the more usual small ruminants, there is a possibility therefore that parasites common to these ruminants but better adapted to cattle such as Fasciola may also be on the increase within the small ruminant population as they graze freely over the same wide area and sometimes freely mix.

AIM

The aim of the study is to determine the prevalence of Fasciola spp in sheep, goats and cattle in Ibadan during the short wet season, (August-October 2011).

METHODS

Faecal samples were collected per rectum from 440 each of goats and sheep and 291 cattle. Helminth ova were recovered using sedimentation technique for faecal examination.

RESULTS

A total of 40 goats (9.1%), 53 sheep (12.0%) and 158 cattle (54.3%) were positive for Fasciola ova which reflects an increase in prevalence in small ruminants.

CONCLUSION

This implies that the entire Ibadan is endemic for Fasciola spp and small ruminants may serve as an important link in the epidemiology of Fasciola spp infection. More so, this has implications for the scavenging household animals which receive little or no medical attention and man that may acquire this trematode by inadvertently eating vegetables with encysted Fasciola metacercariae.

Molecular cloning and characterization of two novel autophagy-related genes belonging to the ATG8 family from the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Rhipicephalus (Boophilus) microplus is an obligate haematophagous arthropod and the major problem for cattle industry due to economic losses it causes. The parasite shows a remarkable adaptability to changing environmental conditions as well as an exceptional ability to survive long-term starvation. This ability has been related to a process of intracellular protein degradation called autophagy. This process in ticks is still poorly understood and only few autophagy-related (ATG) genes have been characterized. The aim of the present study was to examine the ESTs database, BmiGI, of R. microplus searching for ATG homologues. We predicted five putative ATG genes, ATG3, ATG4, ATG6 and two ATG8s. Further characterization led to the identification of RmATG8a and RmATG8b, homologues of GABARAP and MAP1LC3, respectively, and both of them belonging to the ATG8 family. PCR analyses showed that the expression level of RmATG8a and RmATG8b was higher in egg and larval stages when compared to ovary and midgut from adult ticks. This up-regulation coincides with the period in which ticks are in a starvation state, suggesting that autophagy is active in R. microplus.

Biting behaviour of Tabanidae on cattle in mountainous summer pastures, Pyrenees, France, and effects of weather variables

In France, during the summer, cattle in mountainous pastures can be highly exposed to tabanid bites. The persistent biting behaviour of tabanids not only causes disturbance, but is also responsible for transmitting diseases, such as bovine besnoitiosis. The purpose of this study was to better identify the level of tabanid annoyance on cattle by means of insect trapping and direct observation of cows. Tabanids were active during the entire daily observation period (10:00-16:00), except for Haematopota sp., which were less active in the morning. The tabanids collected in Nzi traps were generally representative of those that landed on cattle, except for Haematopota sp., as Nzi traps were not very effective for these species. The preferred feeding sites for most species appeared to be cow's legs or udder. Leg stamping was the defensive reaction most related to a tabanid alighting on a host. Generalized linear mixed models showed that the parameters associated with tabanid landings on hosts were related to weather and altitude, but not to landscape structure. Increased landings were mostly associated with the higher temperatures and lower wind speeds at midday, but some differences were observed between species. The results indicate that cattle-protection measures should be taken during the peak of tabanid abundance when climatic conditions favour intense biting activity. Nzi traps set close to livestock were very effective to catch tabanids and could help in reducing the annoyance caused by horse flies.

Retrospective and spatial analysis tools for integrated surveillance of cystic echinococcosis and bovine cysticercosis in hypo-endemic areas

Cystic echinococcosis (CE) and bovine cysticercosis (BC) are two important parasitic zoonoses, whose prevalence varies among European countries. Few data are available on prevalence and geographic distribution of these two diseases in Veneto region in North-Eastern Italy, where they are generally perceived as minor public health problems. Available data from regional farms on cattle positive to CE and BC and slaughtered in the period 2006-2010 were analysed by spatial scan statistic using a Bernoulli probablility model. Out of 576 bovines testing positive to CE, 467 were found to be autochthonous cases. Three significant CE clusters were identified, the most likely one (P < 0.0001) located in the eastern part of the Veneto region. As for BC, two clusters were identified from 148 animals resting positive, 91 which were autochthonous. An epidemiological survey was conducted and the most likely CE cluster was centered, collecting faecal samples from 28 dogs living in the farms of the area. Out of five animals (all shepherd dogs) found positive for taenid eggs by copromicroscopy, one was confirmed positive for Echinoccus granulosus by means of polymerase chain reaction. The study demonstrates the usefulness of integration of slaughterhouse data and geographical coordinates of farms involved for effective surveillance of CE and BC. The reliability of the spatial analysis in the identification of clusters of EC cases was confirmed by the finding of one dog positive for E. granulosus.

Sequence analysis of cytb gene in Echinococcus granulosus from Western China

Echinococcus granulosus is the causative agent of cystic echinococcosis with medical and veterinary importance in China. Our main objective was to discuss the genotypes and genetic diversity of E. granulosus present in domestic animals and humans in western China. A total of 45 hydatid cyst samples were collected from sheep, humans, and a yak and subjected to an analysis of the sequences of mitochondrial cytochrome b (cytb) gene. The amplified PCR product for all samples was a 1,068 bp band. The phylogenetic analysis showed that all 45 samples were identified as E. granulosus (genotype G1). Ten haplotypes were detected among the samples, with the main haplotype being H1. The haplotype diversity was 0.626, while the nucleotide diversity was 0.001. These results suggested that genetic diversity was low among our samples collected from the west of China based on cytb gene analysis. These findings may provide more information on molecular characteristics of E. granulosus from this Chinese region.

Chemotaxis toward carbohydrates and peptides by mixed ruminal protozoa when fed, fasted, or incubated with polyunsaturated fatty acids

In contrast to the well-characterized chemotaxis and migratory behavior between the dorsal and ventral locations of the rumen by isotrichids, we hypothesized that chemotaxis toward soluble nutrients maintains entodiniomorphid protozoa in the particulate fraction. The objectives of these experiments were to compare the dose-responsive chemotaxis (1) toward different glucose concentrations when ruminal samples were harvested from fed versus fasted cows; (2) toward increasing concentrations of glucose compared with xylose when protozoa were harvested from a fed cow; (3) toward peptides of bacterial, protozoal, and soy origin; and (4) toward glucose when mixed ruminal protozoa were previously incubated for 0, 3, or 6h in the presence of emulsified polyunsaturated fatty acids (PUFA; Liposyn II, Hospira, Lake Forest, IL). In experiment 1, isotrichid protozoa decreased chemotaxis toward increasing glucose concentration when cows were fasted. Entodiniomorphids exhibited chemotaxis to similar concentrations of glucose as did isotrichids, but to a lesser magnitude of response. In experiment 2, xylose was chemotactic to both groups. Xylose might draw fibrolytic entodiniomorphid protozoa toward newly ingested feed. In contrast, even though isotrichids should not use xylose as an energy source, they were highly chemoattracted to xylose. In experiment 3, entodiniomorphids were not selectively chemoattracted toward bacterial or protozoal peptides compared with soy peptides. In experiment 4, despite isotrichid populations decreasing in abundance with increasing time of incubation in PUFA, chemotaxis to glucose remained unchanged. In contrast, entodiniomorphids recovered chemotaxis to glucose with increased time of PUFA incubation. Current results support isotrichid chemotaxis to sugars but also our hypothesis that a more moderate chemotaxis toward glucose and peptides explains how they swim in the fluid but pass from the rumen with the potentially digestible fraction of particulates.

Cellular responses to Rhipicephalus microplus infestations in pre-sensitised cattle with differing phenotypes of infestation

The blue tick, Rhipicephalus microplus, threatens cattle production in most tropical and subtropical areas of the world. Delayed skin hypersensitivity reactions are thought to cause Nguni cattle to be more resistant to R. microplus than Bonsmara cattle yet the cellular mechanisms responsible for these differences have not been classified. Tick counts and inflammatory cell infiltrates in skin biopsies from feeding sites of adult R. microplus ticks were determined in 9-month-old Nguni and Bonsmara heifers to determine the cellular mechanisms responsible for tick immunity. Nguni heifers (1.7 ± 0.03) had lower (P < 0.05) tick counts than the Bonsmaras (2.0 ± 0.03). Parasitized sites in Nguni heifers had higher counts of basophils, mast and mononuclear cells than those in the Bonsmara heifers. Conversely, parasitized sites in Nguni heifers had lower neutrophil and eosinophil counts than those in the Bonsmara heifers. Tick count was negatively correlated with basophil and mast cell counts and positively correlated with eosinophil counts in both breeds. In the Bonsmara breed, tick count was positively correlated with mononuclear cell counts. Cellular responses to adult R. microplus infestations were different and correlated with differences in tick resistance in Nguni and Bonsmara cattle breeds. It is essential to further characterise the molecular composition of the inflammatory infiltrate elicited by adult R. microplus infestation to fully comprehend immunity to ticks in cattle.

A proline racemase based PCR for identification of Trypanosoma vivax in cattle blood

A study was conducted to develop a Trypanosoma vivax (T. vivax) specific PCR based on the T. vivax proline racemase (TvPRAC) gene. Forward and reverse primers were designed that bind at 764–783 bp and 983–1002 bp of the gene. To assess its specificity, TvPRAC PCR was conducted on DNA extracted from different haemotropic pathogens: T. vivax from Nigeria, Ethiopia and Venezuela, T. congolense Savannah type, T. brucei brucei, T. evansi, T. equiperdum, T. theileri, Theileria parva, Anaplasma marginale, Babesia bovis and Babesia bigemina and from bovine, goat, mouse, camel and human blood. The analytical sensitivity of the TvPRAC PCR was compared with that of the ITS-1 PCR and the 18S PCR-RFLP on a dilution series of T. vivax DNA in water. The diagnostic performance of the three PCRs was compared on 411 Ethiopian bovine blood specimens collected in a former study. TvPRAC PCR proved to be fully specific for T. vivax, irrespective of its geographical origin. Its analytical sensitivity was lower than that of ITS-1 PCR. On these bovine specimens, TvPRAC PCR detected 8.3% T. vivax infections while ITS-1 PCR and 18S PCR-RFLP detected respectively 22.6 and 6.1% T. vivax infections. The study demonstrates that a proline racemase based PCR could be used, preferably in combination with ITS-1 PCR, as a species-specific diagnostic test for T. vivax infections worldwide.

Measure post-bloodmeal dispersal of mosquitoes and duration of radioactivity by using the isotope ³²P

The radioactive isotope (32)P-labeled disodium phosphate (Na₂H(32)PO₄) was injected via the jugular vein into a cow kept in a shed in Maozhuang Village, Cao Township of Shanxian County, China. Over the following 5 d, mosquitoes feeding on the cow were captured at distances up to 400 m to determine dispersal distance. The duration of radioactivity in the cow and marked mosquitoes was 10 d. The results showed that after blood feeding, Anopheles sinensis and Culex tritaeniorhynchus temporarily rested in the cattle shed and then flew outdoors. In contrast, Culex pipiens pallens remained in the cattle shed after feeding. These findings confirmed that local An. sinensis and Cx. tritaeniorhynchus were partially endophilic and tended to rest out of doors, whereas Cx. pipiens pallens was endophilic. For marked An. sinensis and Cx. tritaeniorhynchus, there was a significant tendency for dispersal to be in a northeast and east direction, probably because of the presence of heavy shading by an agricultural field, a small river for mosquito oviposition sites, and locations downwind from the blood source. The furthest flight distances for An. sinensis and Cx. tritaeniorhynchus were 210 and 240 m; therefore, control of these mosquitoes should include resting places indoors and outdoors within a radius of 250 m from confirmed cases.