Molecular identification, risk factor assessment, and phylogenetic analysis of tick-borne pathogens in symptomatic and asymptomatic cattle from South-Eastern Iran.

Tick-borne pathogens (TBPs) represent a substantial threat to cattle globally, exerting adverse impacts on production, health, and economic viability. This study delves into the prevalence and implications of TTBPs in cattle sourced from resource-limited smallholder livestock farms situated in southeastern Iran, proximate to Afghanistan and Pakistan. Blood and tick specimens were systematically collected from a cohort of 230 cattle, comprising 150 asymptomatic and 80 symptomatic individuals. Genomic DNA isolated from blood samples underwent rigorous examination for the presence of key TBPs, including Anaplasma marginale, A. phagocytophilum, A. bovis, A. centrale, Babesia bigemina, and Theileria annulata, utilizing multiple genetic markers. Nucleotide sequence analysis facilitated the reconstruction of phylogenetic relationships. The study also evaluated various potential risk factors, such as clinical status, gender, age, breed, tick infestation, and management practices, to elucidate their associations with TTBPs. Among the cattle cohort, a staggering 87.8% (202/230) tested positive for at least one pathogen. Prevalence statistics encompassed A. marginale (72.2%), T. annulata (68.3%), A. phagocytophilum/A. platys-like complex (66.1%), A. centrale (16.7%), B. bigemina (10.0%), and A. bovis (6.1%). Remarkably, mixed infections involving two, three, and four pathogens were detected in 23%, 52.1%, and 2.2% of animals, respectively. Notably, all asymptomatic cattle were positive for at least one TBP. Tick infestation was observed in 62.2% (143/230) of cattle, predominantly caused by Hyalomma anatolicum (82.5%), Rhipicephalus (Boophilus) annulatus (13.1%), and R. sanguineus sensu lato (4.4%). Risk factors linked to TBPs encompassed tick infestation, older age, and crossbred animals. Clinical presentations among symptomatic cattle encompassed fever, anemia, weight loss, anorexia, jaundice, and enlarged superficial lymph nodes. This study underscores the pivotal role of asymptomatic carriers in the propagation of TTBPs within endemic regions. Furthermore, it emphasizes the potential for the implementation of molecular diagnostics to unmask subclinical infections, thereby affording the opportunity for targeted interventions aimed at ameliorating the burden of TTBPs in resource-constrained smallholder dairy farms.

Epidemiological study on Anaplasma phagocytophilum in cattle: Molecular prevalence and risk factors assessment in different ecological zones in Iran.

Anaplasma phagocytophilum is a tick-borne pathogen affecting humans and domestic animals worldwide. This study aimed to determine the molecular epidemiology and its associated risk factors of A. phagocytophilum infection in cattle in four ecological zones of Iran. A multi-stage stratified random sampling method was utilized during 2017-2018. A total of 1851 blood samples from 320 cattle farms were collected and examined using specific nested polymerase chain reaction (nPCR) based on the 16S rRNA gene. The overall prevalence of A. phagocytophilum was 15.5% (286/1851) by using nPCR. All four zones were A. phagocytophilum positive, the presence of A. phagocytophilum DNA was detected in eight out of nine tested provinces. Univariable analysis of risk factors indicated that climate, altitude, longitude, latitude, season, farm-type, feeding method, hygiene of the farm, tick infestation, use of acaricides by the farmer, distance from other farms, contact with wild animals, race, sex, and milk yield were significant determinants (P < 0.05) for A. phagocytophilum infection. The multivariable analysis determined that longitude, latitude, season, feeding method, and hygiene of the farm remained as significant risk factors for A. phagocytophilum infection (P < 0.05). Specific (SaTScan) cluster analysis identified two high risks and four low risks statistically significant clusters for A. phagocytophilum infection amongst the study areas (P < 0.001). Phylogenetic analysis indicated that A. phagocytophilum 16S rRNA isolates were 96-99% identical to sequences deposited in the GenBank. To the best of our knowledge, this is the first comprehensive molecular study on the epidemiology and risk factors analysis of A. phagocytophilum infection in cattle in different climatic zones of Iran. Further investigations are necessary to be performed regarding the tick vectors, reservoir animals, and the zoonotic potential of the A. phagocytophilum in the endemic region of Iran.

Seroprevalence and risk factors assessment of the three main infectious agents associated with abortion in dairy cattle in Isfahan province, Iran.

This study aimed to determine the seroprevalence and identify the risk factors associated with Neospora caninum, Bovine herpesvirus type 1 (BHV-1), and Bovine viral diarrhea virus (BVDV) infection on industrial Holstein dairy cattle farms in Isfahan province, Central Iran. Blood samples were taken from 216 apparently healthy cattle from 16 randomly selected Holstein dairy farms in the North, South, East, and West of Isfahan in the summer of 2017. The antibodies to N. caninum, BHV-1, and BVDV were detected using a commercially available ELISA kit. The overall seroprevalence for N. caninum, BHV-1, and BVDV was 19%, 72.2%, and 52.8%, respectively. The significant major risk factors of BHV-1 in cattle were identified as farm direction, age groups, parity, and milk yield by the univariate analysis (p < 0.05). The significant major risk factors of BVDV in cattle were identified as age groups, parity, milk yield, and stage of pregnancy (p < 0.05). The only significant major risk factor of N. caninum was farm direction (p < 0.05). A significant association of concurrent infection with BVDV and BHV-1 has shown in the current study (p < 0.05). This study is the first to report the risk factors for N. caninum, BHV-1, and BVDV infection in the central part of Iran and allows us to conclude that these agents are widely distributed in this region.

Echocardiographic assessment of cardiac structural and functional indices in broiler chickens treated with silver nanoparticles.

270 Ross broiler chickens of twenty days old were housed in 18-floor pens in a completely randomized design with six treatment groups and three replicate groups and fifteen chicks per each pen. The treatment groups (1-6) consisted of 0, 10, 20, 30, 50, and 70 ppm of nanocide in drinking water, respectively. At 26 days of age, 3 chickens were selected randomly for echocardiography using a 7.5 MHz linear probe, and the left ventricular internal diameter at the end of diastole (LVIDd), left ventricular internal diameter at the end of systole (LVIDs), left ventricular fractional shortening (LVFS), ejection fraction (EF), stroke volume (SV), interventricular septum thickness at the end of systole (IVSTs), and interventricular septum thickness at the end of diastole (IVSTd) were evaluated. LVIDd and LVIDs in group six were of higher rate than other groups and showed statistically significant differences with groups two, three, and four (P < 0.05). LVFS, percentage of EF, and IVSTd were minimum in group six and had significant difference with other groups (P < 0.05). The results of this study showed that prescription of high dosage of nanocide leads to cardiovascular problems with decrease in myocardial contractility and increase in the internal diameter of left ventricle.