Reactivation of hidden-latent infection after doxycycline and streptomycin treatment in mice.

Brucellosis has therapeutic challenges due to 3%-15% relapses/therapeutic failures (R/TF) after antibiotic treatment. Therefore, determining the antibiotic concentration in tissues, the physiopathological parameters, and the R/TF after treatment is relevant. After exploring different antibiotic quantities, we found that a combined dose of 100 µg/g of doxycycline (for 45 days) and 7.

Unveiling the fungal color palette: pigment analysis of species complex and clinical isolates.

Fungal species in the , such as spp. (), are etiologic agents of hyalohyphomycosis capable of producing violaceous or yellowish pigments under certain conditions, while spp. () are agents of phaeohyphomycosis and typically produce melanin in their cell walls.

Determination of streptomycin and doxycycline using LC/MS towards an effective treatment against an experimental Brucella abortus infection in mice.

Herein we described a versatile liquid chromatographic method for detection and quantification of the total levels of two antimicrobials [i.e., streptomycin (STM) and doxycycline (DOX)], in mice plasma and selected tissues, with the aid of a single quadrupole as a detection method.

Nitrogen/protein and one-step moisture and ash examination in foodstuffs: Validation case analysis using automated combustion and thermogravimetry determination under ISO/IEC 17025 guidelines.

Method validation within food science is a not only paramount to assess method certainty and ensure the quality of the results, but a pennant in analytical chemistry. Proximate analysis is an indispensable requirement for food characterization. To improve proximate analysis, automated protein and thermogravimetric methods were validated according to international guidelines (including ISO 17025) and acceptance criteria of results based on certified reference materials and participation within international recognized proficiency schemes.

Microbiological Safety and Presence of Major Mycotoxins in Animal Feed for Laboratory Animals in a Developing Country: The Case of Costa Rica.

Safety and quality of compound feed for experimental animals in Costa Rica is unknown. Some contaminants, such as spp. and mycotoxins, could elicit confounding effects in laboratory animals used for biomedical research.

Selected Instrumental Techniques Applied in Food and Feed: Quality, Safety and Adulteration Analysis.

This review presents an overall glance at selected instrumental analytical techniques and methods used in food analysis, focusing on their primary food science research applications. The methods described represent approaches that have already been developed or are currently being implemented in our laboratories. Some techniques are widespread and well known and hence we will focus only in very specific examples, whilst the relatively less common techniques applied in food science are covered in a wider fashion.

Total and resistant starch from foodstuff for animal and human consumption in Costa Rica.

Starchy ingredients are a key source of carbohydrates and have an essential role in a healthy diet. Starch amount in foodstuffs is paramount as it allows diet professionals to base their formulations on scientific data. Herein, the total (TS) and resistant starch (RS) content, in a selection of typical starchy foods available on the Costa Rican market, for both human and animal consumption, is reported.

Simultaneous LC/MS Analysis of Carotenoids and Fat-Soluble Vitamins in Costa Rican Avocados ( Mill.).

Avocado (a fruit that represents a billion-dollar industry) has become a relevant crop in global trade. The benefits of eating avocados have also been thoroughly described as they contain important nutrients needed to ensure biological functions. For example, avocados contain considerable amounts of vitamins and other phytonutrients, such as carotenoids (e.

Pet Food Quality Assurance and Safety and Quality Assurance Survey within the Costa Rican Pet Food Industry.

Costa Rican animal feed production is continually growing, with approximately 1,238,243 metric tons produced in 2018. Production-wise, pet cat and dog food are in fifth place (about 41,635 metric tons per year) amongst animal feeds, and it supplies up to 90% of the national market. Pet food production has increased as a response to the increase in the population of dogs and cats in Costa Rica, where 50.

Effect of the veterinary ionophore monensin on the structure and activity of a tropical soil bacterial community.

Monensin (MON) is a coccidiostat used as a growth promoter that can reach the environment through fertilization with manure from farm animals. To verify whether field-relevant concentrations of this drug negatively influence the structure and activity of tropical soil bacteria, plate counts, CO efflux measurements, phospholipid fatty acids (PLFA) and community-level physiological profiling (CLPP) profiles were obtained for soil microcosms exposed to 1 or 10 mg kg of MON across 11 days. Although 53% (1 mg kg) to 40% (10 mg kg) of the MON concentrations added to the microcosms dissipated within 5 days, a subtle concentration-dependent decrease in the number of culturable bacteria (<1 log CFU g), reduced (-20 to -30%) or exacerbated (+25%) soil CO effluxes, a marked shift of non-bacterial fatty acids, and altered respiration of amines (1.

Mycotoxins at the Start of the Food Chain in Costa Rica: Analysis of Six Toxins and Ochratoxin A between 2013 and 2017 in Animal Feed and Aflatoxin M in Dairy Products.

Mycotoxins are secondary metabolites, produced by fungi of genera , and (among others), which produce adverse health effects on humans and animals (carcinogenic, teratogenic and immunosuppressive). In addition, mycotoxins negatively affect the productive parameters of livestock (e.g.

Total starch in animal feeds and silages based on the chromatographic determination of glucose.

Starch is an important nutrient in animal feed, and so its analysis is of considerable concern as it is one of the most relevant energy containing fractions. Method AOAC 996.11 was modified to exchange the enzymometric and colorimetric step full approach to a simpler HPLC amine-based column one.

Liquid Chromatography Analysis of Common Nutritional Components, in Feed and Food.

Food and feed laboratories share several similarities when facing the implementation of liquid-chromatographic analysis. Using the experience acquired over the years, through application chemistry in food and feed research, selected analytes of relevance for both areas were discussed. This review focused on the common obstacles and peculiarities that each analyte offers (during the sample treatment or the chromatographic separation) throughout the implementation of said methods.

Two alternative chromatography methods assisted by the sulfonic acid moeity for the determination of furosine in milk.

-(2-(2-Furanyl-2-oxoethyl))-l-lysine (furosine) is a deteriorative reaction product that is produced during heat treatment and storage of milk. This compound affects the quality of commercial dairy products. Accurate determination of furosine is necessary as it may serve as a measure of the degree of protein degradation in dairy products.

A straightforward LC approach using an amine column and single quad mass detector to determine choline chloride in feed additives and feeds.

Considering choline (ChCl) as an essential ingredient for animals and that it is administered through feed, we developed an easy, accurate, and sensitive method for its analysis. The method is straightforward, derivatization-free and has no secondary chromatographic interactions. •We demonstrated that the method can be used for quality control for feeds and feed additives containing choline chloride•We report a simple chromatographic method which takes advantage of the hydroxyl moiety present in ChCl and a MS detector.

Tetracyclines in Food and Feedingstuffs: From Regulation to Analytical Methods, Bacterial Resistance, and Environmental and Health Implications.

Antibiotics are widely used as growth promoters in animal husbandry; among them, the tetracyclines are a chemical group of relevance, due to their wide use in agriculture, surpassing in quantities applied almost every other antibiotic family. Seeing the considerable amounts of tetracyclines used worldwide, monitoring of these antibiotics is paramount. Advances must be made in the analysis of antibiotics to assess correct usage and dosage of tetracyclines in food and feedstuffs and possible residues in pertinent environmental samples.

Vigilance for Salmonella in Feedstuffs Available in Costa Rica: Prevalence, Serotyping and Tetracycline Resistance of Isolates Obtained from 2009 to 2014.

Relevant epidemiological information is provided in this report for Salmonella based on data obtained from a Costa Rican surveillance program for animal feeds. In addition to prevalence, a description in terms of serotypes and tetracycline (TET) resistance of the isolates is included. A total of 1725 feed and feed ingredients samples were analyzed during 2009 and 2014, from which 110 Salmonella strains were recovered (76 from poultry, 23 from meat and bone meal [MBM], 3 from pet foods, and 8 from other feed).

Detection of aflatoxin M1 in milk, cheese and sour cream samples from Costa Rica using enzyme-assisted extraction and HPLC.

Aflatoxins are toxic fungal metabolites, which can be found in feed. Aflatoxin M1 (AFM1) is excreted into milk when ruminants ingest aflatoxin B1 contaminated feedstuffs. Due to its carcinogenic potential, contamination of milk and dairy products with AFM1 may pose a risk for consumers.

Unravelling a vicious circle: animal feed marketed in Costa Rica contains irregular concentrations of tetracyclines and abundant oxytetracycline-resistant Gram-positive bacteria.

Diverse tetracyclines are used to prevent and control bacterial infections in livestock and farmed fish. These drugs are administered through the diet, but farmers seldom check whether feed contains antibiotic-resistant bacteria that may colonise their crops or transfer their resistance traits to species of veterinary relevance. To examine whether antibiotic dosage defines the abundance of antibiotic-resistant bacteria in animal feed, we determined the concentration of parental compounds and epimers of oxytetracycline (OTC), doxycycline, tetracycline and chlortetracycline, as well as the abundance and resistance level of OTC-resistant bacteria in samples of fish (n = 21), poultry (n = 21), swine (n = 21), and shrimp feed (n = 21) marketed in Costa Rica.

Tetracycline and 4-epitetracycline modified the in vitro catabolic activity and structure of a sediment microbial community from a tropical tilapia farm idiosyncratically.

Aquaculture farmers commonly add tetracycline to fish feed or to their ponds to prevent or treat bacterial infections in their crops. To assess the short-term effect of tetracycline (TET) and of one of its reversible epimers, 4-epitetracycline (ETC), on the function and structure of a sediment microbial community from a tropical tilapia farm, we contrasted community-level physiological profiles (CLPP) and phospholipid fatty acid profiles (PLFA) obtained from microcosms exposed for 12 days to 5, 10, 50, or 75 mg kg(-1)of these antibiotics. Notwithstanding that the concentration of the antibiotics during the experiment decreased between 13-100% (TET) or 16-61% (ETC), both compounds provoked opposing metabolic responses that did not revert.

A novel green chemistry method for nonaqueous extraction and high-performance liquid chromatography detection of first-, second-, and third-generation tetracyclines, 4-epitetracycline, and tylosin in animal feeds.

Although tetracyclines and macrolides are common additives for animal nutrition, methods for their simultaneous determination in animal feeds are nonexistent. By coupling an organic extraction and solid-phase extraction cleanup to a high-performance liquid chromatography separation and a nonaqueous postcolumn derivatization, we succeeded in detecting from 0.2 to 24.