Conjunctival habronemiasis in a square‐lipped rhinoceros (Ceratotherium simum)

A captive female square‐lipped rhinoceros born in 1993 had been showing intermittent signs of bilateral conjunctivitis and conjunctival proliferation since 1998. Periodic improvement was noted, especially in winter, but overall the condition had deteriorated over the years. Treatment with various topical, intralesional, and systemic antibiotics and glucocorticosteroids was largely ineffective, as were repeated dewormings. No primary cause for these lesions was found in biopsies taken in 2000 and 2006, although a severe infiltrate of numerous eosinophils was observed in the latter. As the condition worsened, secondary corneal changes were noted, and eventually vision was lost due to proliferative conjunctival tissue. Aggressive resection of the proliferating tissue in 2013 restored vision and submitted biopsies yielded a diagnosis of severe allergic conjunctivitis, eosinophilic granuloma, and habronematid (Habronema or Draschia) larval infection. As no other rhinoceros in the herd was affected, including two calves born to the patient who were in close contact with their mother, it was concluded the presentation was most likely due to a hypersensitivity reaction to the dead or dying larvae. Fly repellent is now regularly applied around the eye of this rhinoceros, and a protective face mask has been fitted. Ongoing periodic relapses are treated with oral ivermectin, topical antibiotics, and steroids.     

Evaluation of different fractions of the organic matter of peat on tetracycline retention in environmental conditions: in vitro studies

Purpose

Due to the modernization of the agro-industrial sector, compounds with different toxicity and effects on human health and animal have been used and consequently affecting the environment. Among them, tetracycline (TC) stands out as one of the antibiotics most commonly used worldwide. This study evaluated the TC interaction with different fractions of peat in natura and humic substances, humic acid, fulvic acid, and humin.

Materials and methods

The different fractions of the organic matter were characterized by organic matter content, elemental analysis, spectroscopic analysis (E₄/E₆), and nuclear magnetic resonance of carbon 13 (NMR ¹³C), and the interaction between TC and different fractions of organic matter was made by fluorescence spectrometry. We used the tangential ultra-filtration system for determining the complexation capability of humic substances (HSs), fulvic acids (FA), humic acids (HA), and humin (HUM) from peat with TC. Finally, we evaluated sorption kinetic experiments between TC and peat in natura.

Results and discussion

The peat samples, humic substances, FAs, HAs, and HUM were characterized by organic matter (OM), atomic ratio (H/C and C/O) calculated from elemental analysis data, functional groups quantified by NMR ¹³C data, and E₄/E₆ ratio, and the results show significant differences in the structural characteristics of the fractions of OM influenced by the type of microorganisms and environmental factors associated with this decomposition. Data analysis revealed the strongest interaction between HUM and TC (59.19 mg g^?1), followed by interaction between HS and TC (43.36 mg g^?1 HS). In the sorption studies, these conditions showed the best model to describe the system under consideration using the Freundlich model.

Conclusions

The results showed that the different fractions of the OM extracted from peat show different contributions that affect the bioavailability of contaminants to the environment.

     

Preliminary characterization of Escherichia coli isolated from pigs with diarrhoea in Venezuela

The aetiology of neonatal porcine diarrhoea was studied in 15 different herds located in the north-western region of Venezuela. Of 56 strains of Escherichia coli analyzed, 16 (28.6%) were shown to produce heat-stable (STa) enterotoxin, as detected by infant mouse assay. Only four of these STa+ isolates also possessed the K88 pilus antigen, two were 987P+ and none possessed the K99 antigen, leaving 10 STa+ samples in which no pilus antigen was identified. Among the 40 STa negative samples were six K88+ specimens, one K99+, four 987P+, one which reacted as K88+ + K99+ and one K88+ + 987P+. Considering as pathogenic any strain showing at least one of the characters studied, pathogenic E. coli were detected with an overall frequency of 42.9%, being more prevalent during the second week of life. An electrophoretic analysis of the plasmid content of the field isolates of E. coli, revealed the presence of numerous species of extrachromosomal DNA, although no direction association could be made between a particular plasmid and any of the pathogenic characteristics identified. Results of Southern blot analysis indicate that the STa enterotoxin was preferentially encoded within an endemic plasmid of 4.9 Md. Other plasmids present in the E. coli isolates could be related to antibiotic resistance. With the exception of one strain, all E. coli isolates were resistant to more than one of the nine drugs tested; multiresistant E. coli were frequently isolated, including four strains which were resistant to seven antibiotics.     

Kinetics and Adsorption Isotherms of Bisphenol A, Estrone, 17β-Estradiol, and 17α-Ethinylestradiol in Tropical Sediment Samples

The sorption of four endocrine disruptors, bisphenol A (BPA), estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) in tropical sediment samples was studied in batch mode under different conditions of pH, time, and sediment amount. Data obtained from sorption experiments using the endocrine disruptors (EDs) and sediments containing different amounts of organic matter showed that there was a greater interaction between the EDs and organic matter (OM) present in the sediment, particularly at lower pH values. The pseudosecond order kinetics model successfully explained the interaction between the EDs and the sediment samples. The theoretical and experimentally obtained q _e values were similar, and k values were smaller for higher SOM contents. The k _F values, obtained from the Freundlich isotherms, varied in the ranges 4.2–7.4 × 10⁻² (higher OM sediment sample, S₂) and 1.7 × 10⁻³–3.1 × 10⁻² (lower OM sediment sample, S₁), the latter case indicating an interaction with the sediment that increased in the order: EE2 > > E2 > E1 > BPA. These results demonstrate that the availability of endocrine disruptors may be directly related to the presence of organic material in sediment samples. Studies of this kind provide an important means of understanding the mobility, transport, and/or reactivity of this type of emergent contaminant in aquatic systems.     

Sensory Evaluation of Barley Chocolate Chip Cookies by Consumers with Different Demographic Background and Eating Patterns

Health organizations have recommended an increase in consumption of whole grains, total dietary fiber, and soluble fiber to help reduce the potential risk factor for the development of type‐2 diabetes, obesity, and cardiovascular disease, among others. The purpose of this project was to determine the sensory characteristics of chocolate chip (CC) cookies containing a high‐soluble fiber whole barley flour (HSFWB). Cookies with 0, 30, 50, and 70% HSFWB were evaluated for appearance, color, flavor, texture, and overall acceptability using a 9‐point hedonic scale. Forty‐nine students, faculty, and staff tested the cookies on three different days. Demographic and behavioral data on age, gender, ethnicity, frequency of eating CC cookies, daily effort to consume fiber (FD), consumption of reduced‐fat (RF) cookies, and texture preference (TP) of CC cookies were collected. The 50% HSFWB cookie could be potentially marketed among older consumers (22+), males, Hispanics, individuals who consume CC cookies at least once a week, those making a FD in their diet, persons who consume RF cookies, as well as those who have no TP for CC cookies. A response surface relating flavor and texture to overall acceptability produced almost equivalent results to the multivariate PLS results in terms of predicting overall acceptability, which facilitates analysis and interpretation.     

Interaction Study Between Humin and Phosphate: Possible Environmental Remediation for Domestic Wastewater

The increase in demand for food due to the rapid population growth in recent years has raised the use of fertilizers, particularly phosphate salts. This fact has contributed to the excess amount of phosphorus species in aquatic systems. This is due to the leaching of these species present in the fertilizers applied to the soil to aquatic environments and may lead to eutrophication in these environments. Substances capable of interacting with the phosphate in the aquatic environment are promising for the reduction on the environmental impact. The humin, an insoluble fraction of humic material, has potential for phosphate retention, behaving like a chelating resin. Thus, the purpose of this research was to study the interaction between humin and phosphate. The equilibrium time between humin and phosphate was 15 min, where hydrogenionic potential (pH) 4.0 was the most effective in the interaction process. In this pH, the humin retained 33% of phosphate added. The complexing capacity of the humin-phosphate system was 11.53 mg g^?1. The adsorption studies indicated that the system follows a kinetic pseudo-second-order model. The Freundlich model was the most suitable to describe the phosphate adsorption process in humin. To evaluate the humin application in real systems, humin was added to the domestic wastewater. Sixteen percent of the total phosphate was adsorbed by the humin. Based on these results, humin has the potential to phosphate retention in domestic wastewater and could be used as a chelating resin minimizing environmental impact.     

Cyanogenic Residues: Environmental Impacts,Complexation with Humic Substances,and Possible Application as Biofertilizer

Treated and untreated rice straw extensively exists in the soil. In order to elucidate its possible effect on the fate of organic pollutants, sorption of pyrene by rice straw and its main constituents (lignin, cellulose, and hemi-cellulose) were studied, as single solute and in the presence of other co-existing organic pollutants, phenanthrene (Phen), benzo[a]pyrene (BaP), phenol, and pentachlorophenol (PCP). Pyrene showed the greatest sorption on lignin with greater aromaticity and smaller polarity, and the sorption coefficient was almost two orders of magnitude greater than those on cellulose and hemi-cellulose. Bi-solute sorption results showed that Phen, BaP and PCP exhibited apparent competitive sorption with pyrene on the four sorbents; while the existence of phenol promoted the sorption of pyrene on rice straw and lignin but inhibited the sorption on cellulose and hemi-cellulose. For the two polycyclic aromatic hydrocarbon (PAH) co-solutes and PCP, hydrophobicity and molecular size played important roles in competition, suggesting the direct competition for hydrophobic sorption sites and pore blockage mechanisms. In contrast, the polar co-solute, phenol showed different effects on pyrene sorption onto the four sorbents, suggesting that multiple interactions between polar organic compounds and sorbents are involved in the sorption.     

Characterization of rotaviruses isolated from pigs with diarrhoea in Venezuela

The prevalence of porcine rotavirus infection was studied in 15 different herds located in the north-western region of Venezuela. The presence of rotavirus was studied by direct electron microscopy (EM) and by an enzyme-linked immunosorbent assay (ELISA). From 136 samples analyzed during the six months of the study (September 1983-February 1984), 38 (27.9%) were found to be positive for rotaviruses, with infection more common in animals that were 4-6 weeks old. Atypical rotaviruses were not detected in any of the samples examined. Most rotavirus positive specimens were subgrouped using specific monoclonal antibodies in an ELISA test. The majority of the samples (26 out of 38) were found to exhibit Subgroup I antigenicity. Only two specimens, collected from the same herd in two consecutive months, were found to belong to Subgroup II. To characterize further the circulating rotaviruses, electrophoretic analysis of the RNA genome was performed on samples selected from nine different herds. Great variability in the RNA electropherotypes was observed. No correlation was found between subgroup specificity and the migration of the two smaller segments (Genes 10 and 11), as has been described for human rotaviruses.