Fecal samples of 53 white face monkeys (Cebus capucinus) from some sites of Costa Rica were studied for blood and intestinal parasites. Animals were anesthetized with darts containing Telazol, blood and fecal samples were collected and all the material was studied in the laboratory. For blood parasites, Giemsa stain and Knott concentration was performed. Intestinal parasites were studied by direct examination in 0,85% saline solution and a Iodine solution. Haematoxylin stain was used for better protozoa identification. Strongyloides sp, hookworms, acanthocephalid eggs and other nematodes, as well as Tritrichomonas sp (more frequent) and other protozoa were found. The presence of at least one parasites was observed in 33.3% to 100% of the fecal samples with an average of 73.6%. There was not any correlation between sex and infection rate, but the presence of parasite was higher in heavier (older) animals. Microfilarias were the only blood organism detected.The reasons for these high infection rates could be explained for feed diversity, contaminated soil and water contact and sociability of these animals, among other factors.

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Aims:  To investigate amino acid and dipeptide utilization by Lactobacillus plantarum N4 isolated from orange peel, in a nutritionally depleted medium based on MRS (Mann, Rogosa, Sharpe). Methods and Results:  In MRS with 0·1 g l−1 of meat extract and without peptone and yeast extract, growth increased when essential and stimulatory amino acids and nonessential amino acid were added to the medium. Replacement of the essential amino acid, leucine, and the nonessential amino acid, glycine, by leucyl‐leucine (Leu‐Leu) and/or glycyl‐glycine (Gly‐Gly) significantly enhanced growth. Essential amino acids were mainly consumed and the dipeptides were almost completely used at the end of growth. Leucine and glycine accumulated internally from the peptides were higher than from the free amino acids. Glucose utilization increased in the media containing dipeptides compared with the medium containing free amino acids. Conclusions:  In a N‐depleted medium, Leu‐Leu and/or Gly‐Gly were more effective than the respective amino acids in supporting growth of the micro‐organism. The more efficient internal accumulation of glycine and especially leucine from dipeptides confirmed the ability of the strain to assimilate mainly complex nitrogen molecules rather than simple ones. Significance and Impact of the Study:  The ability of Lact. plantarum N4 to efficiently use dipeptides could contribute to spoilage development in the natural medium of the organism, orange juice.

Background: The intrinsic sensitivity limitations of basic parasitological methods, along with the particular biological characteristics of parasites, make these methods ineffective to differentiate morphologically indistinguishable species. Molecular detection and characterization techniques could be used to overcome these problems. The purpose of this work was to standardize molecular polymerase chain reaction (PCR) techniques, described in the literature, for the detection and molecular characterization of intestinal protozoa and other pathogens in humans. Methods: DNA was extracted from human or animal feces, previously washed or cultured in Boeck Drbohlav's Modified Medium. DNA extraction was performed with Machery-Nagel extraction kits. The standardization of the PCR, nested-PCR or RFLP techniques was carried out according to the literature. For each molecular technique performed, the sensitivity of the test was determined based on the minimun quantity required of DNA (sensitivity A) and the minimum quantity of life forms that the test detected (sensitivity B). Results: Sensitivity A was 10 fg for G. duodenalis , 12.5 pg for Entamoeba histolytica or Entamoeba dispar , 50 fg for Cryptosporidium spp., 225 pg for Cyclospora spp. and 800 fg or 8 fg for Blastocystis spp. after performing a 1780 bp PCR or 310 bp nested PCR, respectively. The sensitivity B was 100 cysts for G. duodenalis, 500 cysts for E. histolytica or E. dispar , 1000 oocysts for Cyclospora spp. and 3600 or four vegetatives forms for PCR or nested PCR of Blastocystis spp., respectively. Conclusions: The molecular detection of protozoa and chromist was achieved and the molecular characterization allowed the genotyping of some of the parasites such as Giardia duodenalis , Cryptosporidium spp., and Blastocystis spp. This study summarizes the molecular techniques for epidemiological studies in humans and animals, and helps in the investigation of their transmission sources in countries where intestinal parasites are a public health problem.

We investigated the dominant lactic acid bacteria (LAB) from grape juice and commencement of malolactic fermentation (MLF) samples of a cellar located in Argentina and assessment of its β-glucosidase activity and butter aroma compounds production. LAB number found in grape juice (approximately log 10 3.3) was lower than that obtained in the MLF samples. Oenococcus oeni was predominant, accounting for 68% of the 81 LAB isolated. Majority of whole cells derived from O. oeni cultures at the end of the exponential growth showed detectable β-glucosidase activity. Contrarily, the highest proportion of them did not produce diacetyl, acetoin, and 2,3-butylene glycol. A direct relation between both properties among the O. oeni strains could not be established. In the selected MS25 strain, l-malic acid was compatible with good enzyme activity and was partially able to annul the negative influence of the low pH (3.8). In different conditions, the aroma compounds were lower than 4 mg/ml, especially at pH 3.8 and in presence of l-malic acid (2.5 g/l). This strain could have adequate characteristics for potential use in winemaking. Finally, the assessment of both biochemical properties in O. oeni should be considered as a quality criterion for selecting starter cultures for the improvement of the wines aroma.