Prevalence and infection risk factors of bovine Eimeria in China: a systematic review and meta-analysis

Melatonin Treatment at Dry-off Reduces Postpartum Shedding of Coccidia in Primiparous Dairy Cows and Their Calves

Coccidiosis is a protozoan disease that causes diarrhea in cattle. This study examines the impact of treating pregnant cows at dry-off with melatonin on postpartum coccidia excretion in dams and their calves. The study population comprised 106 primiparous lactating dairy cows: 53 controls and 53 receiving melatonin on days 220-226 of gestation, plus 99 calves: 52 born from control and 47 from treated dams. Feces samples were collected from each dam on gestation days 220-226 and on days 10-16 and 30-36 postpartum; and from each calf on days 10-16 and 30-36 of age. Postpartum rates of high excretion of oocysts per gram (OPG) (feces counts > 5000) were significantly lower (p < 0.01) in treated than control dams. Low excretion rates of OPG (<2000) were significantly higher (p < 0.01) in the melatonin treatment than control groups in dams on days 30-36 of lactation and in calves at 10-16 and 30-36 days of life. In conclusion, melatonin treatment in lactating cows at dry-off reduced coccidia shedding in dams and their calves during the early postpartum period.

Molecular Identification and Survey of Cyclospora spp. in Cattle in Shanxi Province, North China

To date, more than 20 species in the genus Cyclospora have been reported. Among them, Cyclospora cayetanensis has been recognized as the causative agent of human cyclosporiasis, which is characterized by severe intestinal injury and prolonged diarrhea in patients with immune dysfunction. The presence of C. cayetanensis in cattle has been confirmed. To date, however, no surveillance data are available on the occurrence and prevalence of Cyclospora spp. in cattle in Shanxi Province, North China. In the present study, a total of 761 fecal samples collected from cattle in three representative counties (Qi, Jishan, and Shanyin) in this Province were examined for Cyclospora spp. by using a polymerase-chain-reaction-restriction-fragment-length polymorphism (PCR-RFLP) test based on the nuclear small subunit ribosomal RNA (SSU rRNA) gene. The prevalence of Cyclospora spp. in cattle was 2.1%, and region, age, sex, and breed were not identified to be risk factors. Molecular evolutionary analysis based on the SSU rRNA sequences revealed that all 12 of the isolates were relatively distant from the human pathogen C. cayetanensis; seven isolates were grouped with Cyclospora colobi, whereas the others were grouped with cattle Cyclospora spp. reported previously. Though C. cayetanensis was not detected in cattle in the present study, more investigations should be performed in human populations, other animal species, or cattle from other regions of Shanxi Province and other environmental sources from the One Health perspective.

Eimeria zuernii (Eimeriidae: Coccidia): mitochondrial genome and genetic diversity in the Chinese yak

BACKGROUND

Coccidiosis caused by Eimeria zuernii (Eimeriidae: Coccidia) represents a significant economic threat to the bovine industry. Understanding the evolutionary and genetic biology of E. zuernii can assist in new interaction developments for the prevention and control of this protozoosis.

METHODS

We defined the evolutionary and genetic characteristics of E. zuernii by sequencing the complete mitogenome and analyzing the genetic diversity and population structure of 51 isolates collected from eight yak breeding parks in China.

RESULTS

The 6176-bp mitogenome of E. zuernii was linear and encoded typical mitochondrial contents of apicomplexan parasites, including three protein-coding genes [PCGs; cytochrome c oxidase subunits I and III (cox1 and cox3), and cytochrome b (cytb)], seven fragmented small subunit (SSU) and 12 fragmented large subunit (LSU) rRNAs. Genome-wide comparative and evolutionary analyses showed cytb and cox3 to be the most and least conserved Eimeria PCGs, respectively, and placed E. zuernii more closely related to Eimeria mephitidis than other Eimeria species. Furthermore, cox1-based genetic structure defined 24 haplotypes of E. zuernii with high haplotype diversities and low nucleotide diversities across eight geographic populations, supporting a low genetic structure and rapid evolutionary rate as well as a previous expansion event among E. zuernii populations.

CONCLUSIONS

To our knowledge, this is the first study presenting the phylogeny, genetic diversity, and population structure of the yak E. zuernii, and such information, together with its mitogenomic data, should contribute to a better understanding of the genetic and evolutionary biological studies of apicomplexan parasites in bovines.

Faecal prevalence and histopathological evaluation of coccidiosis in bovine calves

Bovine coccidiois, caused by Eimeria spp. is widely prevalent around the globe and responsible for huge economic losses by causing morbidity and mortality among young calves. The present study was designed to evaluate the prevalence as well as to evaluate histopathological alterations associated with it. The faecal samples were collected from 700 bovine calves upto two month of age from August 2019 to July 2021 and screened for Eimeria oocycts. The intestinal tissue samples of 37 calves were also collected which died during the study period after showing symptoms of diarrhea and examined for histological lesions. The faecal prevalence of Eimeria observed in our study was 2.29% (16/700) while in tissue samples only two out of 37 were found positive for Eimeria infection. Tissue sections revealed various stages of Eimeria gametogony, variable congestion, haemorrhage, and necrosis along with cryptic dilatation and mononuclear cell infiltration. Coccidia was not found to be associated with season, age and sex of calf. Bovine coccidiosis was found to be endemic with low prevalence but severe onset characterized by moderate to severe congestion and inflammatory reaction mainly in the ileum and caecum.

Prevalence and risk factors of coccidiosis in calves from Veracruz, México

The objectives of the present study were: (1) to determine the prevalence of Eimeria spp. sporulated oocysts in calves from 26 Municipalities in the Central Zone of the State of Veracruz, Mexico, (2) to identify the Eimeria spp. infecting calves, and (3) to identify the risk factors associated with the presence of Eimeria spp. in tropical cattle. A total of 930 individual fecal samples were analyzed by using the McMaster technique; then, oocysts were maintained in 2.5% potassium dichromate to allow sporulation. The general prevalence of calves with Eimeria spp. oocysts was 39.7% (370/930). Of a total of 10 identified species, Eimeria canadensis was the most observed, followed by Eimeria bovis and Eimeria zuernii. The statistical analysis showed an association between the age of the calves (5 to 9 months), the presence of other animals, the physiographic regions and the restricted type of husbandry with the presence of Eimeria spp. in calves (P<0.05). Protective risk factors, such as: routine coprological analysis was also associated with a decrease in infection. These data demonstrate the presence of coccidia in cattle from the State of Veracruz, additionally to the necessary measures that must be taken to control this parasitosis.

Development of a multiplex polymerase chain reaction technique for detection and discrimination of Eimeria spp. in cattle in Indonesia

Background and Aim: Bovine eimeriosis is a disease caused by apicomplexan parasites of the genus Eimeria. It is one of the most important and widespread bovine illnesses in the world. Some of the identified species of bovine eimeriosis have morphologically similar oocysts that are difficult to differentiate. For the identification of particular Eimeria spp., diagnostic laboratories are increasingly turning to DNA-based technology. This study aims to develop a multiplex polymerase chain reaction (mPCR) technique based on the internal transcribed spacer-1 (ITS-1) gene for the simultaneous identification of pathogenic Eimeria spp. in cattle from Sulawesi Island, Indonesia. Materials and Methods: Genomic DNA was extracted by the DNAzol reagent from the purified Eimeria oocysts. Species-specific primers targeting the ITS-1 region were used to amplify the distinct Eimeria spp. Results: Using PCR ITS-1, this study showed that 36 of 120 fecal samples (30%) were infected by Eimeria spp. The multiplex PCR assay allowed for the simultaneous identification of six major Eimeria spp. in a single-tube reaction. The proportion of mixed Eimeria spp. infections was 100% (36/36). The maximum number of Eimeria spp. was five, and the minimum number was two. Conclusion: Identification of six pathogenic Eimeria spp. in cattle was successfully carried out by nested multiplex PCR using ITS-1 gene. In the future, a procedure to detect pathogenic Eimeria spp. in one tube reaction will offer economical and save diagnostic time.