Geostatistical analysis of biomarkers of genotoxicity in cattle, Bos taurus and Bos taurus x Bos indicus, sentinels near industrial facilities

Identification of Genomic Instability in Cows Infected with BVD Virus

An important factor for dairy cattle farmers is the profitability of cattle rearing, which is influenced by the animals' health and reproductive parameters, as well as their genomic stability and integrity. Bovine viral diarrhea (BVD) negatively affects the health of dairy cattle and causes reproductive problems. The aim of the study was to identify genomic instability in cows with reproductive disorders following infection with the BVD virus. The material for analysis was peripheral blood from Holstein-Friesian cows with reproductive problems, which had tested positive for BVD, and from healthy cows with no reproductive problems, which had tested negative for BVD. Three cytogenetic tests were used: the sister chromatid exchange assay, fragile sites assay, and comet assay. Statistically significant differences were noted between the groups and between the individual cows in the average frequency of damage. The assays were good biomarkers of genomic stability and enabled the identification of individuals with an increased frequency of damage to genetic material that posed a negative impact on their health. The assays can be used to prevent disease during its course and evaluate the genetic resistance of animals. This is especially important for the breeder, both for economic and breeding reasons. Of the three assays, the comet assay proved to be the most sensitive for identifying DNA damage in the animals.

Biomonitoring of the hematological, biochemical and genotoxic effects of the mixture cypermethrin plus chlorpyrifos applications in bovines

External antiparasitic agents applied in bovine production represent a risk to consumers of meat products, especially if the conditions of their use are not strictly respected. The post-mortem control of residues in meat is an activity that must be updated and reinforced by the biomonitoring of live animals and the use of analytical tools to help identifying signs of early warning risks. The objective of the present study was to carry out a pre-slaughter biomonitoring approach in Aberdeen Angus cattle and crosses (n = 12) with the application of a commercial formulation of cypermethrin plus chlorpyrifos. This was performed with a single therapeutic dose applied on the backs of the cattle, through hematological, enzymatic, as well as hepatic and renal function analysis in plasma, and then quantifying the genotoxic effect on lymphocytes. Analytical measurements of plasma concentrations of cypermethrin plus chlorpyrifos at 24 h were negative and therefore a low absorption of the compounds was assumed. Measurement of acetyl cholinesterase showed no inhibition after exposure. The concentration of urea increased between 24 h and 168 h post application of the formulation, without showing any kidney damage. The rest of the parameters analyzed did not show any variations. This evaluation of hematological and biochemical effects and of cytokinesis-block micronucleus cytome assay in bovines is proposed as a pre-slaughter control of biomonitoring of the health status of animals, with a focus on food safety for meat consumers.

Evaluating geostatistical modeling of exceedance probability as the first step in disease cluster investigations: very low birth weights near toxic Texas sites

BACKGROUND

The first step in evaluating potential geographic clusters of disease calls for an evaluation of the disease risk comparing the risk in a defined location to the risk in neighboring locations. Environmental exposures, however, represent continuous exposure levels across space not an exposure with a distinct boundary. The objectives of the current study were to adapt, apply and evaluate a geostatistical approach for identifying disease clusters.

METHODS

The exceedance probability for very low birth weight (VLBW; < 1.5 kg) infants was mapped using an Intrinsic Conditional Autoregressive model. The data were applied to a 20 by 20 grid of 1 km2 pixels centered on each of the 13 National Priority List Superfund Sites in Harris County, Texas.

RESULTS

Large clusters of VLBW were identified in close proximity to four of the 13 Superfund Sites. Three of the Superfund Sites, associated with disease clusters, were located close together in central Houston and these sites may have been surrounded by a single, confluent disease cluster.

CONCLUSIONS

Geostatistical modeling of the exceedance probability for very low birth weights identified disease clusters of varying size, shape and statistical certainty near Superfund Sites in Harris County, Texas. The approach offers considerable potential as the first step for investigating potential disease clusters.