Human consumption of rumen flukes of cattle in India

The practice of eating rumen flukes of cattle by a section of people living in Meghalaya, a north eastern State of India, is reported in this communication. Economically backward, some rural people belonging to Khasi, Jaintia, Garo, and Karbi tribes of Christian and Nepali communities who eat beef are accustomed to consuming cooked flukes during breakfast, meals, and also along with rice beer or alcohol. Inspection of the rumens of cattle during slaughter indicated a prevalence of flukes belonging to Cotylophoron, Paramphistomum, Calicophoron, Gastrothylax, and Fischoederius genera in 74% cases, and their collection from rumen ranged approximately from 50 g to 600 g. Biochemical analysis of flukes found 12.60% total protein, 0.78% fat, and 0.87% ash on fresh weight basis. High prevalence of flukes, easy visualization in rumen, their bulk collection, presence of nutritive value, absence of any ill effect, and lack of imminent danger of transmissibility are believed to be the rationales influencing their consumption by people. It is suggested that dietary benefits obtained from flukes might contribute to the energy transfer and inclusion in the food web.

[Investigation on infection sources of schistosomiasis in mountainous regions, Nanjian County, Yunnan Province]

OBJECTIVE

To understand the types of schisotsome infection sources and their roles in schistosomiasis transmission in mountainous endemic regions in Yunnan Province, so as to provide the evidence for implementing the comprehensive control measures based on infection source control.

METHODS

Two villages of typical mountainous regions in Nanjian County were chosen for field investigation. The Oncomelania hupensis snail status was surveyed by the methods of systematic and environmental sampling. The infections of schistosomiasis were surveyed in residents with the indirect haemagglutination and the hatching method, in livestock with the hatching method and in wild animals with the anatomical method and the hatching method. The distribution and pollution status of wild faeces were investigated in the snail environments nearby villages or with livestock frequent activities. The positives of schistosomiasis in wild faeces were tested with the hatching method. The pollution index of wild feces was calculated.

RESULTS

A total of 533.56 hm2 were investigated in two villages, and the area with snails was 16.52 hm2. The rate of frame with snails was 1.03%, the average density of snails was 0.07 snails/0.1 m2, and no positive snails were found. The positive rate of blood examinations of population was 1.61%, but no persons were positive with the hatching method. The infection rates were 0.90%, and 0.62% in cattle and equus, respectively, and there were no positives in other livestock. Totally 472 piles of wild feces of 6 species (human, cattle, equus, goat, pig and dog) distributed in the investigation areas, and among them, the densities of wild feces of cattle, equus, and dog were 7.2, 4.3 piles/hm2, and 2.1 piles/hm2 respectively, being relatively higher than others. The hatching positive rates of wild faeces of cattle, equus, and dog were 2.27% (3/132), 2.63% (2/76), and 3.70% (1/27), respectively. The relative pollution indexes of wild faeces of cattle, equus, and dog were 80.68%, 15.89%, and 3.43%, respectively.

CONCLUSIONS

After schistosomiasis transmission is controlled, the potential epidemic factors still remain in the mountainous endemic regions of schistosomiasis in Yunnan Province. The cattle are still the most infection source of schistosomiasis, but equus and dog as infection sources should be not neglected. We should extend the investigation and monitor scope of the infection sources, and carry out scientific and feasible control technique and management measures.

[Endemic status of schistosomiasis in People's Republic of China in 2012]

This report showed the endemic status of schistosomiasis in P. R. China at national level in 2012. By the end of 2012, the total number of schistosomiasis japonica cases were estimated to be 240597, with a decrease of 16.12% compared with that in 2011. Meanwhile, thirteen acute cases were reported. Compared with 2011, 10.34% more advanced schistosomiasis patients were treated (22988) in 2012. Nationally, around 368741.67 hm2 were found to be infested with Oncomelania hupensis snails by the end of 2012, among which 46.71 hm2 were newly reported. Moreover, 1 189829 cattle were estimated to be raised in epidemic regions with 0.52% of them being infected with Schistosoma japonicum, which experienced a reduction of 23.53% compared with that in 2011.

[Surveillance of schistosomiasis endemic situation in Jingzhou City in 2011]

OBJECTIVE

To understand the endemic situation of schistosomiasis in monitoring sites of Jingzhou City in 2011.

METHODS

According to the monitoring scheme of the schistosomiasis in Hubei Province, the schistosomiasis endemic situation in human, farm cattle and Oncomelania snails were investigated in 64 monitoring sites of Jingzhou City in 2011 and the results were analyzed statistically.

RESULTS

In the 64 monitoring sites, the average schistosome infection rate of residents was 1.48%, and the rate in residents aged 50 years or over was highest. There was no case of acute schistosomiasis infection. There were 170 cases of advanced schistosomiasis. The average infection rate of farm cattle was 1.38%. Among the 3 034.03 hm2 area with snails, the area with schistosome infected snails was 25.65 hm2. The average density of living snails was 0.74 snails/0.1 m2, while the average density of infected snails was 0.000 6 snails/0.1 m2. The infection rate of snails was 0.08%.

CONCLUSION

The endemic situation of schistosomiasis in Jingzhou City in 2011 is relatively stable, but the infection rate of farm cattle is higher. Therefore, the preventive measures still should be enhanced.

Advances in the diagnosis of key gastrointestinal nematode infections of livestock, with an emphasis on small ruminants

Parasitic nematodes (roundworms) of livestock have major economic impact globally. In spite of the diseases caused by these nematodes and some advances in the design of new therapeutic agents (anthelmintics) and attempts to develop vaccines against some of them, there has been limited progress in the establishment of practical diagnostic techniques. The specific and sensitive diagnosis of gastrointestinal nematode infections of livestock underpins effective disease control, which is highly relevant now that anthelmintic resistance (AR) is a major problem. Traditional diagnostic techniques have major constraints, in terms of sensitivity and specificity. The purpose of this article is to provide a brief background on gastrointestinal nematodes (Strongylida) of livestock and their control; to summarize conventional methods used for the diagnosis and discuss their constraints; to review key molecular-diagnostic methods and recent progress in the development of advanced amplification-based and sequencing technologies, and their implications for epidemiological investigations and the control of parasitic diseases.

Prevalence and genetic characterization of Cryptosporidium in yaks in Qinghai Province of China

The objective of this study was to determine the prevalence, species and subtypes of Cryptosporidium infecting yaks in the Qinghai Province of Northwestern China. The prevalence of Cryptosporidium spp. was detected by microscopy and nested-PCR. A total of 586 fecal samples were collected from yaks in 6 counties, of which 142 (24.2%) samples tested positive for Cryptosporidium. The small subunit (SSU) rRNA gene of fifty-five samples were amplified and sequenced successfully and demonstrated that Cryptosporidium bovis (31/55, 56.4%) was the most common species, followed by C. parvum (16/55, 29.1%) and C. ryanae (5/55, 9.0%). Mixed infections of C. parvum and C. bovis (n = 2), C. ryanae and C. bovis (n = 1) were also detected. All three species were found in yaks ranging in age from <1 year, 1–2 years, to >2 years. Cryptosporidium was most commonly detected in spring (28.4%), followed by summer (20.9%), then winter (17.5%). Cryptosporidium parvum positive samples were subtyped using the 60 kDa glycoprotein (gp60) gene. Subtypes IIaA15G2R1 (n = 8), IIaA16G2R1 (n = 2), IIaA14G1R1 (n = 1), IIaA14G2R1 (n = 1) and IIaA16G3R1 (n = 1) were detected. All of these subtypes are zoonotic, and may pose a potential threat to human health.

Movement of male Dermacentor andersoni (Acari: Ixodidae) among cattle

Movement of male Dermacentor andersoni (Stiles) was examined among 54 pairs of artificially infested donor and recipient cattle during a 3-yr period. The number of males declined at a rate independent of the initial level of infestation, while the rate of decline of females on the donor animals tended to increase with initial infestation level. Male tick movement to recipient cattle was observed in 26 of 54 (48%) of the animal pairs, but varied among years and trials. Movement tended to be greater during April compared with May and June. The daily probability of movement averaged (SD) 0.067 (0.082), and the number of males moving per day averaged (SD) 0.083 (0.228). Logistic and Poisson regression models were developed and indicated that movement was determined by interactions between the number of males on the donor animals, differences in the number of females on the donor and recipient cattle, temperature, and female age. These models can be used to incorporate movement into tick population models.

Short-term microbial release during rain events from on-site sewers and cattle in a surface water source

The protection of drinking water from pathogens such as Cryptosporidium and Giardia requires an understanding of the short-term microbial release from faecal contamination sources in the catchment. Flow-weighted samples were collected during two rainfall events in a stream draining an area with on-site sewers and during two rainfall events in surface runoff from a bovine cattle pasture. Samples were analysed for human (BacH) and ruminant (BacR) Bacteroidales genetic markers through quantitative polymerase chain reaction (qPCR) and for sorbitol-fermenting bifidobacteria through culturing as a complement to traditional faecal indicator bacteria, somatic coliphages and the parasitic protozoa Cryptosporidium spp. and Giardia spp. analysed by standard methods. Significant positive correlations were observed between BacH, Escherichia coli, intestinal enterococci, sulphite-reducing Clostridia, turbidity, conductivity and UV254 in the stream contaminated by on-site sewers. For the cattle pasture, no correlation was found between any of the genetic markers and the other parameters. Although parasitic protozoa were not detected, the analysis for genetic markers provided baseline data on the short-term faecal contamination due to these potential sources of parasites. Background levels of BacH and BacR makers in soil emphasise the need to including soil reference samples in qPCR-based analyses for Bacteroidales genetic markers.

Genetic diversity and geographic population structure of bovine Neospora caninum determined by microsatellite genotyping analysis

The cyst-forming protozoan parasite Neosporacaninum is one of the main causes of bovine abortion worldwide and is of great economic importance in the cattle industry. Recent studies have revealed extensive genetic variation among N. caninum isolates based on microsatellite sequences (MSs). MSs may be suitable molecular markers for inferring the diversity of parasite populations, molecular epidemiology and the basis for phenotypic variations in N. caninum, which have been poorly defined. In this study, we evaluated nine MS markers using a panel of 11 N. caninum-derived reference isolates from around the world and 96 N. caninum bovine clinical samples and one ovine clinical sample collected from four countries on two continents, including Spain, Argentina, Germany and Scotland, over a 10-year period. These markers were used as molecular tools to investigate the genetic diversity, geographic distribution and population structure of N. caninum. Multilocus microsatellite genotyping based on 7 loci demonstrated high levels of genetic diversity in the samples from all of the different countries, with 96 microsatellite multilocus genotypes (MLGs) identified from 108 N. caninum samples. Geographic sub-structuring was present in the country populations according to pairwise F_ST. Principal component analysis (PCA) and Neighbor Joining tree topologies also suggested MLG segregation partially associated with geographical origin. An analysis of the MLG relationships, using eBURST, confirmed that the close genetic relationship observed between the Spanish and Argentinean populations may be the result of parasite migration (i.e., the introduction of novel MLGs from Spain to South America) due to cattle movement. The eBURST relationships also revealed genetically different clusters associated with the abortion. The presence of linkage disequilibrium, the co-existence of specific MLGs to individual farms and eBURST MLG relationships suggest a predominant clonal propagation for Spanish N. caninum MLGs in cattle.

The detection and PCR-based characterization of the parasites causing trypanosomiasis in water-buffalo herds in Venezuela

The usefulness of PCR-based assays for detecting trypanosomiasis in water buffaloes and other livestock was explored, under field conditions, in Venezuela. The sensitivity and specificity of the assays, which were based on established primer pairs (21-mer/22-mer and ILO1264/ILO1265), were evaluated, partly by comparison with the results of parasitological tests (stained bloodsmears and microhaematocrit centrifugation) and immunological assays (IFAT) run in parallel. The optimised PCR-based assays showed a sensitivity of 10 pg DNA. The use of the 21-mer/22-mer primer pair gave a test that was specific for species in the subgenus Trypanozoon (including Trypanosoma evansi), whereas use of ILO1264/ILO1265 produced a test that was specific for T. vivax. The results of a hybridization assay using T. evansi-DNA and T. vivax-DNA probes indicated no cross-hybridization between the T. evansi and T. vivax PCR products.The results of the bloodsmear examinations, microhaematocrit centrifugations (MHC) and IFAT indicated that 23 (6.7%), 39 (11.4%) and 135 (39.5%) of the 342 blood samples investigated (including 316 from water buffaloes) contained trypanosomes, respectively. The results of the PCR-based assays indicated that 68 (19.9%) of the same blood samples contained T. vivax (or at least T. vivax DNA), and that none contained T. evansi or any other member of the subgenus Trypanozoon. For the detection of trypanosomes, the assay therefore appeared almost twice as sensitive as the MHC. These results are the first on the molecular characterization of the trypanosomes infecting water buffaloes in Venezuela. When the results of the MHC (which is the most practical, and frequently used, alternative detection method) were used as the gold standard, the PCR-based assay for T. vivax was found to have 100% sensitivity, 90.4% specificity, a positive predictive value of 0.57, a positive likelihood ratio of 10.45, and a negative likelihood ratio of 0.00. The assay therefore appears a reasonable choice for detecting T. vivax in the mammalian livestock of Venezuela and elsewhere.

A new species of Tunga (Siphonaptera: Tungidae) parasitizing cattle from Brazil

Tunga hexalobulata (Siphonaptera: Tungidae), new species oftungid sand flea belonging to the penetrans group, is described with illustrations of adult female parasitizing Bos indicus (L., 1758) from Brazil. It differs from the 12 other known species of Tunginae by the presence of six anterior humps in the neosome. It also can be differentiated from other species of the penetrans group by lesser size of the neosome, presence of three posterodorsally bristles in antennal segment II, and the extension of the posterior arm of the preoral internal sclerotization.

Prevalence of Ehrlichia ruminantium in adult Amblyomma variegatum collected from cattle in Cameroon

Ehrlichia ruminantium, the etiologic agent of the economically important disease heartwater, is an obligate intracellular bacterium transmitted by ticks of the genus Amblyomma, particularly A. hebraeum and A. variegatum. Although serologic and microscopic evidence of the presence of heartwater have been reported in ruminants in Cameroon, knowledge of E. ruminantium infection in the tick vector, A. variegatum, is lacking. In order to determine the infectivity of A. variegatum ticks by E. ruminantium, we analysed 500 un-engorged A. variegatum ticks collected by hand-picking from predilection sites from 182 cattle [115 ticks from 82 cattle at Société de Développement et d'Exploitation des Productions Animales (SODEPA) Dumbo ranch (SDR) and 385 ticks from 100 cattle at the Upper Farms ranch (UFR)] by amplification of the open reading frame (ORF) 2 of the pCS20 region of E. ruminantium. PCR amplification of the 279 bp fragment of the pCS20 region detected E. ruminantium DNA in 142 (28.4 %) of the 500 ticks with a higher infection rate (47/115; 40.9 %) observed in ticks from SDR and 24.7 % (95/385) of ticks collected from cattle at UFR. Twenty five randomly selected PCR products were sequenced and results indicated that some of the isolates shared homology with one another and to sequences of E. ruminantium in the GenBank. This report represents the first molecular evidence of E. ruminantium infection in A. variegatum ticks in Cameroon and suggests possible exposure of cattle to this pathogen in our environment.

Understanding the genetic, demographical and/or ecological processes at play in invasions: lessons from the southern cattle tick Rhipicephalus microplus (Acari: Ixodidae)

The southern cattle tick, Rhipicephalus microplus, is the ixodid species causing the largest economic losses in tropical agrosystems because of its recurrent invasive success, explosive demography on bovine herds, vector competence for diverse pathogens and frequent development of acaricide resistance. Its ecology and the physiological bases of the acaricide resistances it developed, as well as alternative tick control measures, have been intensively studied for decades. By contrast, the tick population genetic structure and its remarkable ability to quickly adapt to new environments have not yet received much attention. We investigated such issues using population genetics analyses in the recently invaded island New Caledonia. In this paper we aim to describe some guidelines for acarologists willing to investigate the processes at play in Acari invasions. Particular emphasis is given to the accuracy of sampling designs and sampling scales for population genetics to be actually informative on the demographical processes of the species (i.e., its mating rules, the determinants of population limits, population sizes, the relationships between genetic exchanges and geographical distances and relevant ecological factors).

[Clinical diagnosis and treatment in an outbreak of Fasciola gigantica infection in Yunnan Province]

OBJECTIVE

To carry out clinical diagnosis and treatment of Fasciola gigantica infection during an outbreak in Yunnan Province.

METHODS

Data on epidemiology, diagnosis and treatment were collected from 27 patients. A questionnaire survey to the patients and partial villagers was carried out including history of raw food-eating and pet-raising. Animal feces were collected and examined by precipitation method and eggs incubation method. Cattle from two patients families were dissected to find Fasciola infection. Serum samples from patients, family members, and villagers were detected. Possible intermediate snails were collected from the vicinity of streams and ponds in 15 villages where patients lived.

RESULTS

The earliest onset of symptoms among the patients was on March 10, 2011 and the last case was on January 10, 2012. The clinical manifestations were mainly fever with unknown reason, decreasing hemoglobin, increasing eosinophils, and hepatosplenomegaly. No parasite eggs were found in feces. Antibodies against F. gigantica were positive by ELISA in 23 patients. Fasciola eggs were then found in 4 patients' feces on February 16, 2012. F. gigantica eggs and adults were found in the hepatobiliary system of dissected cattle. Triclabendazole [10 mg/(kg x d) x2 d] was administered orally for the patients and the clinical symptoms eased. Snails including Physa acuta, Radix swinhoei and Galba pervia were collected and cercariae were found in only one snail.

CONCLUSION

An outbreak of F. gigantica infection has been confirmed and the diagnosed cases effectively treated with triclabendazole.

[Detection of immunity and antioxidant indexes in dairy cows infected with Cryptosporidium]

OBJECTIVE

To detect the immune status and antioxidant system indexes of cows infected with Cryptosporidium.

METHODS

Fecal samples of 325 dairy cows were collected at a farm in Anhui and examined by floating saturated solution. 7 positive cows and 7 negative cows from the farm were selected as infection group and non-infection group, respectively. Blood samples were taken from cow's jugular vein before feeding in the morning. 19 indexes of total protein (TP), albumin (ALB), IgG, IgM, IgA, phagocytic rate of white blood cells, T lymphocyte transformation rate, IL-2, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), NO, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), glucose (GLU), triglyceride (TG), Cl-, and Ca2+ were tested, respectively.

RESULTS

The infection rate of 325 cows was 31.7% (103/325). The Cryptosporidium was identified as C. andersoni according to the morphology and size of oocysts. Compared with the non-infection group, there was no significant difference in the concentration of TP, ALB, IgM, IgA, GSH-Px, ALT, AST, ALP and Cl- (P > 0.05). The concentration of MDA and NO in the infection group increased by 59.9% and 28.1% (P < 0.05 or 0.01), and that of IgG, SOD, GLU, TG, Ca2+, IL-2 and the activities of T lymphocyte transformation rate, phagocytic rate of white blood cells decreased by 32.9%, 11.1%, 18.6%, 78.9%, 14.5%, 7.0%, 22.0%, and 20.2%, respectively (P < 0.05).

CONCLUSION

The change of antioxidant and immune indexes shows that the capability of eliminating free radicals and the immune function have decreased in the Cryptosporidium andersoni-infected cows.

Total and infectious Cryptosporidium oocyst and total Giardia cyst concentrations from distinct agricultural and urban contamination sources in Eastern Canada

Cryptosporidium and Giardia (oo)cyst concentrations are frequently used for assessing drinking water safety. The widely used USEPA Method 1623 provides total counts of (oo)cysts, but may not be accurate for human health risk characterization, since it does not provide infectivity information. The total counts and infectious fraction of Cryptosporidium oocysts and the total counts of Giardia cysts were assessed in major fecal pollution sources. Fresh calf and cow feces, their manure, and the discharge point were sampled in a small rural sub-watershed (n = 20, 21, 10, 10). Median concentrations for total (oo)cysts were higher in calves (333 oocysts g(-1); 111 cysts g(-1)) than in cows (52 oocysts g(-1); 7 cysts g(-1)). Infectious oocysts were found in 17 (7%) of the samples and none were found in manure or at the discharge point. Urban sources were sampled in the influent and effluent (n = 19, 18) of two wastewater treatment plants. Peak concentrations were 533 oocysts L(-1) and 9,010 cysts L(-1) for influents and 89 oocysts L(-1) and 472 cysts L(-1) for effluents. Infectious oocyst fractions varied from below the detection limit to 7-22% in the effluent and influent respectively. These infectious fractions are significantly lower than those currently used for quantitative microbial risk assessment estimates.

Distribution and seasonal activity of tick species on cattle in the West Aegean region of Turkey

The aim of the present study was to determine the identity, seasonal activity and distribution of tick species of cattle in the West Aegean region of Turkey between June 2006 and May 2008. Nine villages within three provinces, viz. Manisa, Izmir and Aydin, were included in the study and a total of 75 animal barns were visited monthly for a period of 24 months and 443 cattle were examined for the presence of ticks. It was determined that 23% of cattle were infested with ticks. A total of 19,679 adult ticks were collected. The most abundant tick species was Hyalomma marginatum (33.5%) and H. excavatum (16.9%) in the study area. Seasonal appearance of the adult ticks varied among species. Adult ticks of the Hyalomma genus were present throughout the year, although in smaller numbers during the winter. Species of Rhipicephalus were detected in all seasons except autumn. Rhipicephalus (Boophilus) annulatus was identified in July and August, Haemaphysalis parva was detected during the autumn. Ixodes ricinus and Dermacentor marginatus were identified during spring, autumn and winter. The study demonstrated the presence of I. ricinus, D. marginatus, Hyalomma rufipes and Hae. parva for the first time in the West Aegean region of Turkey.

Genetic characterisation of Giardia duodenalis in dairy cattle in Brazil

The intestinal protozoan parasite Giardia duodenalis (Lambl, 1859) Kofoid & Christiansen, 1915 [syn. Giardia intestinalis and Giardia lamblia] has emerged as a widespread enteric pathogen in humans and domestic animals. In recent years, G. duodenalis has been found in cattle worldwide and longitudinal studies have reported cumulative prevalence of 100% in some herds. In the present study, we determined the prevalence and genetic characterisation of G. duodenalis in 200 dairy cattle from 10 dairy farms in São Paulo state, Brazil. All faecal specimens were screened for the presence of G. duodenalis using microscopy examination, enzyme immunoassay (EIA) and polymerase chain reaction (PCR). DNA was extracted from faecal samples and G. duodenalis were identified by amplification of the small subunit ribosomal (SSU-rDNA) and glutamate dehydrogenase (GDH) genes followed by restriction fragment length polymorphism (RFLP) or sequencing analysis. Giardia was identified in eight farm locations (80% prevalence). Overall, 15/200 (7.5%) animals were positive for infection, only one of which was a cow. Giardia duodenalis genotype E was present in 14 of the animals tested. Zoonotic genotype AI was present in one positive sample. Genotype E and genotype A represented 93% and 7% of G. duodenalis infections, respectively. This study demonstrates that G. duodenalis infection was prevalent in dairy calves in São Paulo state and that the non-zoonotic genotype E predominates in cattle in this region. Nevertheless, calves naturally infected in Brazil can shed Giardia cysts that can potentially infect humans, and thus, they may represent a public health risk.

[Endemic situation of schistosomiasis in Donggou Village, a surveillance site, in Huarong County from 2005 to 2010]

From 2005 to 2010, the infection rates of schistosomiasis among residents (above 6 years old) were 13.34%, 9.59%, 4.81%, 3.03%, 2.35% and 2.19%, respectively. The positive rates of schistosomiasis among domestic animals fluctuated from 2.50% to 25.92%. Oncomelania snails were not found inside embankment since 1980, yet a high density of infected snails was found at low and uneven areas outside embankment. The cattle were the main infectious source and we should strengthen the administration and control of cattle.

[Endemic cryptosporidiosis--underdiagnosed disease in Finland]

Acute diarrhea caused by Cryptosporidium-protozoan is rarely diagnosed in Finland. The infection is usually self-limited and does not require antimicrobial treatment. Cryptosporidiosis, like other intestinal parasite infections, is mostly associated with travelling, but may also cause large waterborne epidemics. Contact with infected calves may be a source of cryptosporidiosis also in Finland. Cryptosporidiosis should be considered in patients suffering from severe or long-lasting watery diarrhea. We describe three cases of cryptosporidiosis, originating from infected calves. These cases show that verification of the etiology of human cryptosporidiosis associated with calves may be difficult and demands collaboration of clinicians, laboratories and veterinarians.

Cytoskeleton remodeling and alterations in smooth muscle contractility in the bovine jejunum during nematode infection

Gastrointestinal nematodes of the genus Cooperia are arguably the most important parasites of cattle. The bovine jejunal transcriptome was characterized in response to Cooperia oncophora infection using RNA-seq technology. Approximately 71% of the 25,670 bovine genes were detected in the jejunal transcriptome. However, 16,552 genes were expressed in all samples tested, probably representing the core component of the transcriptome. Twenty of the most abundant genes accounted for 12.7% of the sequences from the transcriptome. A 164-h infection seemingly induced a minor change in the transcriptome (162 genes). Additionally, a total of 162,412 splice junctions were identified. Among them, 1,164 appeared unique to 1 of the 2 groups: 868 splice junctions were observed only in infected animals, while 278 were only present in all 4 control animals. Biological functions associated with muscle contraction were predominant Gene Ontology terms enriched in the genes differentially expressed by infection. The primary function of two of the four regulatory networks impacted was related to skeletal and muscular systems. A total of 34 pathways were significantly impacted by infection. Several pathways were directly related to host immune responses, such as acute phase response, leukocyte extravasation, and antigen presentation, consistent with previous findings. Calcium signaling and actin cytoskeleton signaling were among the pathways most significantly impacted by infection in the bovine jejunum. Together, these data suggest that smooth muscle hypercontractility may be initiated as a result of a primary C. oncophora infection, which may represent a mechanism for host responses in the jejunum during nematode infection.

Predicting risk habitats for the transmission of the small liver fluke, Dicrocoelium dendriticum to grazing ruminants

A multiple regression model was used to analyse if the structure of vegetation and soil patches in grazed units (pastures) can be used as explanatory variables to predict the prevalence of Dicrocoelium dendriticum, a common parasite of cattle and sheep, in grazing cattle stocks on the Baltic island of Öland in southern Sweden. The scale dependency was evaluated by comparing three levels of spatial resolution of patches. Prevalence data were obtained from slaughtered animals. Our models predict that the prevalence of D. dendriticum increases in grazed areas with woody vegetation, whereas moist and wet areas decrease parasite prevalence. The predictive power of the statistical models increased with increasing level of patch resolution. Approximately 42% of the variation in parasite prevalence (angular transformation) was explained by the areal proportion of vegetation types (4th-root-transformed). Based on the results obtained, we believe that our model strategy provides a rational and systematic tool to identify habitats that carry risk for D. dendriticum infection of ruminants, and that it can be applied to other parasites with similar life cycles such as Fasciola hepatica.

Control of tick populations by spraying Metarhizium anisopliae conidia on cattle under field conditions

Conidia of the entomopathogenic fungus, Metarhizium anisopliae, in oil/water formulation (1 × 10(8) conidia/ml) were sprayed at 3 weekly intervals on Rhipicephalus evertsi evertsi and Rhipicephalus (Boophilus) decoloratus ticks while feeding on Afrikana bulls grazing in paddocks for a period of 1 year. The fungus reduced the on-host tick populations by 83% 3 month after commencement of the experiment. The formulation by itself had only minimal effect on the tick population. Tick populations and fungal efficacy were highest at the peaks of rainfall and relative humidity or soon thereafter. Fed and unfed adult R. e. evertsi and R. (B.) decoloratus collected at the end of the experiment from the fungus-sprayed and from the control cattle and incubated in the laboratory exhibited a mortality of 93% in oil formulated conidia and 14% in oil control. The corresponding mortality in R. (B.) decoloratus was 100% in fungus and 11% in oil control. Ticks on the fungus-sprayed groups had significantly higher mortality (P < 0.05) than on the control groups. Furthermore, no significant difference (P < 0.05) was observed in fungus-induced mortality between the two tick species. Mortalities induced by Triton X-100 (0.05%), sunflower oil (20%) and water alone were low, suggesting that they were non-toxic to ticks at the concentrations used and no significant difference was observed among them. No physical or behavioral abnormalities were observed in the fungus-sprayed cattle at any time during the course of the experiment. All groups of cattle gained weights during the experimental period.

Spatial variation of tick abundance and seroconversion rates of indigenous cattle to Anaplasma marginale, Babesia bigemina and Theileria parva infections in Uganda

Tick abundance and seroconversion rates of 640 indigenous cattle in a mixed crop-livestock system in Uganda were investigated in a 14 months longitudinal study. Up to 100% of the cattle in Buyimini, Kubo, Nanjeho, Ojilai and Sitengo villages (high tick challenge zone) were consistently infested with Rhipicephalus appendiculatus, whereas on average 50% of the cattle in Bunghaji, Hitunga and Magoje villages (low tick challenge zone) were inconsistently infested. Likewise, up to 50% of the cattle in Buyimini, Kubo, Nanjeho, Ojilai and Sitengo villages were consistently infested with R. (Boophilus) decoloratus ticks, while on average 30% of the cattle in Bunghaji, Hitunga and Magoje were inconsistently infested. Seroconversion rates of cattle to Anaplasma marginale infection under low tick challenge were higher than those under high tick challenge, but the reverse was true for Babesia bigemina infection. For Theileria parva infection, seroconversion rates of cattle older than 6 months under low tick challenge were significantly higher than those under high tick challenge (P < 0.05). However, the likelihood of occurrence of theileriosis cases among calves (0-6 m) under high tick challenge was 6 times (Odds ratio = 5.82 [1.30-36.37]) higher than under low tick challenge. The high density of anti-tick plants Lantana camara and Ocimum suave that were widespread in villages with low tick challenge, among other factors, was probably the cause for unfavourable tick survival.

Metagenome plasticity of the bovine abomasal microbiota in immune animals in response to Ostertagia ostertagi infection

Infections in cattle by the abomasal nematode Ostertagia ostertagi result in impaired gastrointestinal function. Six partially immune animals were developed using multiple drug-attenuated infections, and these animals displayed reduced worm burdens and a slightly elevated abomasal pH upon reinfection. In this study, we characterized the abomasal microbiota in response to reinfection using metagenomic tools. Compared to uninfected controls, infection did not induce a significant change in the microbial community composition in immune animals. 16S rRNA gene-based phylogenetic analysis identified 15 phyla in the bovine abomasal microbiota with Bacteroidetes (60.5%), Firmicutes (27.1%), Proteobacteria (7.2%), Spirochates (2.9%), and Fibrobacteres (1.5%) being the most predominant. The number of prokaryotic genera and operational taxonomic units (OTU) identified in the abomasal microbial community was 70.8±19.8 (mean ± SD) and 90.3±2.9, respectively. However, the core microbiome comprised of 32 genera and 72 OTU. Infection seemingly had a minimal impact on the abomasal microbial diversity at a genus level in immune animals. Proteins predicted from whole genome shotgun (WGS) DNA sequences were assigned to 5,408 Pfam and 3,381 COG families, demonstrating dazzling arrays of functional diversity in bovine abomasal microbial communities. However, none of COG functional classes were significantly impacted by infection. Our results demonstrate that immune animals may develop abilities to maintain proper stability of their abomasal microbial ecosystem. A minimal disruption in the bovine abomasal microbiota by reinfection may contribute equally to the restoration of gastric function in immune animals.