Comparison of immunohistochemistry, electron microscopy, and direct fluorescent antibody test for the detection of bovine coronavirus

Telocytes response to cardiac growth induced by resistance exercise training and endurance exercise training in adult male rats

Telocytes are interstitial cells found in different tissues, including cardiac stem cell niches. The purpose of this study was to investigate the response of the telocytes to the cardiac growth that occurs in response to resistance and endurance exercise trainings using rats distributed into control, endurance, and resistance training groups. Results revealed that the ratio of heart weight to body weight, cardiomycyte number, cardiomyocyte area, thickness of the left ventricular wall were significantly higher in the training groups compared to the control group. We observed increment in the cardiomyocytes surface area and thickness of the left ventricular wall in the resistance-training group than endurance-training group. We conclude that both resistance and endurance exercise trainings will lead to an increased number of cardiac telocytes, consequently, promote activity of the cardiac stem cells, and results in physiological cardiac growth, and this response does not seem to depend on the type of exercise.

Prevalence of bovine coronavirus in cattle in China: A systematic review and meta-analysis

Bovine coronavirus (BCoV) is one of the important pathogens that cause calf diarrhea (CD), winter dysentery (WD), and the bovine respiratory disease complex (BRDC), and spreads worldwide. An infection of BCoV in cattle can lead to death of young animals, stunted growth, reduced milk production, and milk quality, thus bringing serious economic losses to the bovine industry. Therefore, it is necessary to prevent and control the spread of BCoV. Here, a systematic review and meta-analysis was conducted to assess the prevalence of BCoV in cattle in China before 2022. A total of 57 articles regarding the prevalence of BCoV in cattle in China were collected from five databases (PubMed, ScienceDirect, CNKI, VIP, and Wan Fang). Based on the inclusion criteria, a total of 15,838 samples were included, and 6,136 were positive cases. The overall prevalence of BCoV was 30.8%, with the highest prevalence rate (60.5%) identified in South China and the lowest prevalence (15.6%) identified in Central China. We also analyzed other subgroup information, included sampling years, sample sources, detection methods, breeding methods, age, type of cattle, presence of diarrhea, and geographic and climatic factors. The results indicated that BCoV was widely prevalent in China. Among all subgroups, the sample sources, detection methods, breeding methods, and presence or absence of diarrheal might be potential risk factors responsible for BCoV prevalence. It is recommended to strengthen the detection of BCoV in cattle, in order to effectively control the spread of BCoV.

Epidemiological survey on equine cryptosporidium and giardia infections in Italy and molecular characterization of isolates

Cryptosporidium and Giardia are two of the most common enteric pathogens of domestic and wild animals and humans. However, little is known on the prevalence, clinical manifestations and economic and zoonotic significance of these infections in horses. This study was undertaken to investigate the prevalence, excretion patterns and risk factors related to the faecal shedding of Cryptosporidium oocysts and Giardia cysts in horses and the zoonotic potential of species/genotypes isolated. The survey was performed on 120 foals and 30 broodmares reared in five Italian farms. Foals were divided in four homogeneous groups of 30 animals each (age classes: 0-2, 2-4, 4-8, >8 weeks). Three sequential faecal samples were collected from each animal and analysed by three techniques: direct fluorescent antibody test (DFA), faecal flotation (FF) and stained faecal smears (SFS). The DFA results showed a prevalence of 8% for Cryptosporidium and of 13.33% for Giardia; the prevalence values obtained by FF and SFS were lower and in poor agreement with DFA results. Giardia and Cryptosporidium infections were more common in foals (23.33% and 26.66% respectively) and higher excretions were observed in the youngest foals. Distribution of Cryptosporidium prevalence was statistically related to farms (P < 0.01), age of animals (P < 0.01), but was unrelated to the presence of diarrhoea. In the case of Giardia, the prevalence was only related to age (P < 0.01). Pattern sheddings were related to intestinal diseases and horse age (P < 0.01). Risk factors for shedding included residence farms and age older than 8 weeks for both parasites. All DFA-positive faecal samples were submitted to DNA extraction and PCR to determine Giardia and Cryptosporidium species/genotypes. Sequence analysis of the COWP gene of Cryptosporidium and of the SSU-rRNA gene of Giardia revealed that they were identical to each other and identified Cryptosporidium parvum and Giardia duodenalis assemblage E. The potential role of infected horses in zoonotic transmission of Cryptosporidium was supported by the findings of this study.

Bovine coronavirus associated syndromes

Bovine coronaviruses, like other animal coronaviruses, have a predilection for intestinal and respiratory tracts. The viruses responsible for enteric and respiratory symptoms are closely related antigenically and genetically. Only 4 bovine coronavirus isolates have been completely sequenced and thus, the information about the genetics of the virus is still limited. This article reviews the clinical syndromes associated with bovine coronavirus, including pneumonia in calves and adult cattle, calf diarrhea, and winter dysentery; diagnostic methods; prevention using vaccination; and treatment, with adjunctive immunotherapy.

Cross-protection against a human enteric coronavirus and a virulent bovine enteric coronavirus in gnotobiotic calves

A group 2 human coronavirus designated HECV-4408 was isolated from a child with acute diarrhea and is antigenically and genetically more closely related to bovine coronavirus (BCoV) than to human coronavirus OC43 (X. M. Zhang, W. Herbst, K. G. Kousoulas, and J. Storz, J. Med. Virol. 44:152-161, 1994). To determine whether HECV-4408 infects gnotobiotic calves and induces cross-protective immunity against the virulent enteric BCoV DB2 strain, gnotobiotic calves (n = 4) were orally inoculated with HECV-4408 and then challenged with BCoV DB2 at postinoculation day (PID) 21. All calves inoculated with HECV-4408 developed diarrhea at PID 3 to 4 lasting 5 to 9 days. Fecal and nasal virus shedding were first detected by reverse transcription-PCR at PID 3 to 4 and at PID 2 to 4, respectively. After challenge with bovine coronavirus, no diarrhea or virus shedding was detected in calves inoculated with HECV-4408, but a mock-inoculated calf developed diarrhea and fecal and nasal shedding. Fecal immunoglobulin A (IgA) and serum IgG antibodies were first detected at PID 7 and PID 14, respectively. At postchallenge day 7, serum IgG and fecal IgA antibody titers remained the same or increased only twofold compared to prechallenge titers. An additional two gnotobiotic calves were inoculated with HECV-4408 and euthanized at PID 5. Moderate villous atrophy was observed in the small intestines, and viral antigen was detected in villous enterocytes of the small and large intestines by immunohistochemistry. These results support and extend the previous report that HECV-4408 is likely a variant of bovine coronavirus. They confirm its infectivity for calves and complete cross-protection against a bovine coronavirus (DB2 strain) showing 98.2% amino acid identity to HECV-4408 in the S protein.

Detection and isolation of coronavirus from feces of three herds of feedlot cattle during outbreaks of winter dysentery-like disease

Clinical signs of a winter dysentery-like syndrome in 6- to 9-month-old cattle in 3 feedlots included acute onset of diarrhea with high morbidity and low mortality, respiratory tract problems that included dyspnea, coughing, and nasal discharge, and high rectal temperatures. Bovine coronavirus was detected by use of an ELISA and immune electron microscopy in fecal and nasal swab samples and by immunohistochemical analysis of intestinal sections collected from calves during necropsy. Bovine coronavirus should be considered in the differential diagnoses for diseases that cause acute onset of bloody diarrhea in feedlot cattle.

Production, characterization, and uses of monoclonal antibodies against recombinant nucleoprotein of elk coronavirus

This is the first report of the production of monoclonal antibodies against elk coronavirus. The nucleoprotein gene of elk coronavirus was amplified by PCR and was cloned and expressed in a prokaryotic expression vector. Recombinant nucleocapsid protein was used to immunize mice for the production of hybridomas. Twelve hybridomas that produced monoclonal antibodies against the nucleocapsid protein of elk coronavirus were selected by an indirect fluorescent-antibody test, an enzyme-linked immunosorbent assay, and a Western blot assay. Ten of the monoclonal antibodies were of the immunoglobulin G1 (IgG1) isotype, one was IgG2a, and one was IgM. All had kappa light chains. By immunohistochemistry four monoclonal antibodies detected bovine coronavirus and elk coronavirus in formalin-fixed intestinal tissues. Antinucleoprotein monoclonal antibodies were found to be better at ruminant coronavirus detection than the anti-spike protein monoclonal antibodies. Because nucleoprotein is a more abundant antigen than spike protein in infected cells, this was not an unexpected finding.