Brucella canis is an intracellular pathogen that induces a lower proinflammatory response than smooth zoonotic counterparts.

Canine brucellosis caused by Brucella canis is a disease of dogs and a zoonotic risk. B. canis harbors most of the virulence determinants defined for the genus, but its pathogenic strategy remains unclear since it has not been demonstrated that this natural rough bacterium is an intracellular pathogen. Studies of B. canis outbreaks in kennel facilities indicated that infected dogs displaying clinical signs did not present hematological alterations. A virulent B. canis strain isolated from those outbreaks readily replicated in different organs of mice for a protracted period. However, the levels of tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-12 in serum were close to background levels. Furthermore, B. canis induced lower levels of gamma interferon, less inflammation of the spleen, and a reduced number of granulomas in the liver in mice than did B. abortus. When the interaction of B. canis with cells was studied ex vivo, two patterns were observed, a predominant scattered cell-associated pattern of nonviable bacteria and an infrequent intracellular replicative pattern of viable bacteria in a perinuclear location. The second pattern, responsible for the increase in intracellular multiplication, was dependent on the type IV secretion system VirB and was seen only if the inoculum used for cell infections was in early exponential phase. Intracellular replicative B. canis followed an intracellular trafficking route undistinguishable from that of B. abortus. Although B. canis induces a lower proinflammatory response and has a stealthier replication cycle, it still displays the pathogenic properties of the genus and the ability to persist in infected organs based on the ability to multiply intracellularly.

Novel genotype of Ehrlichia canis detected in samples of human blood bank donors in Costa Rica.

This study focuses on the detection and identification of DNA and antibodies to Ehrlichia spp. in samples of blood bank donors in Costa Rica using molecular and serological techniques. Presence of Ehrlichia canis was determined in 10 (3.6%) out of 280 blood samples using polymerase chain reaction (PCR) targeting the ehrlichial dsb conserved gene. Analysis of the ehrlichial trp36 polymorphic gene in these 10 samples revealed substantial polymorphism among the E. canis genotypes, including divergent tandem repeat sequences. Nucleotide sequences of dsb and trp36 amplicons revealed a novel genotype of E. canis in blood bank donors from Costa Rica. Indirect immunofluorescence assay (IFA) detected antibodies in 35 (35%) of 100 serum samples evaluated. Thirty samples showed low endpoint titers (64-256) to E. canis, whereas five sera yielded high endpoint titers (1024-8192); these five samples were also E. canis-PCR positive. These findings represent the first report of the presence of E. canis in humans in Central America.

Parámetros sanguíneos y perfil de hormonas reproductivas de hembras de Choloepus hoffmanni en cautiverio / Blood parameters and reproductive hormone profile of female Choloepus hoffmanni in captivity

Resumen El uso de técnicas no invasivas ni estresantes para determinar perfiles hormonales, como la medición de esteroides fecales, ha incrementado la comprensión de la fisiología reproductiva en animales silvestres. Debido a la escasa información con respecto a perfiles hormonales reproductivos del perezoso de dos dedos, Choloepus hoffmani, se realizó un estudio en hembras en cautiverio en el centro de rescate "Sloth Sanctuary" (Cahuita, Limón, Costa Rica) con el fin de determinar (i) la confiabilidad de la extracción de progesterona y estradiol en heces, y su cuantificación en el analizador AIA-360®, (ii) evaluar los parámetros sanguíneos en esta especie y (iii) establecer si existe una correlación entre los esteroides plasmáticos y fecales. El estudio se realizó en un periodo de tres meses, durante noviembre de 2013 a enero de 2014, con un total de 208 muestras de heces provenientes de cinco hembras sexualmente maduras, con peso promedio de 6.32 kg. El promedio de las concentraciones medianas en las heces de las cinco hembras fue 124.21 ng/g para progesterona y 1 708.95 pg/g de estradiol. En plasma, los valores de mediana fueron 1.26 ng/mL con un mínimo de 0.32 ng/mL y 12.84 ng/mL como valor máximo; los valores plasmáticos de estrógeno se encontraron por debajo del límite de detección del equipo (25 pg/mL). Aunque no se encontró una correlación estadísticamente significativa entre la progesterona plasmática y la fecal, nuestros datos sugieren que los eventos plasmáticos se reflejan en heces durante los dos días posteriores. Asimismo, los niveles de progesterona se mantuvieron elevados durante la primera mitad de noviembre, y posteriormente mostraron una reducción importante en todas las hembras. Nuestros resultados demuestran que las extracciones en heces y su medición en el AIA-360® permiten la detección y el seguimiento de variaciones hormonales en C. hoffmani, aunque no remplaza las mediciones plasmáticas para determinar valores absolutos.

Abstract In wild animal species, the use of non-invasive and non-stressful procedures to determine hormone profiles, such as fecal steroid measurements, has considerably increased the comprehension of their reproductive physiology. Since there is limited information related to the reproductive hormone profiles of the two-toed sloth, Choloepus hoffmani, a study was conducted in captive specimens at the "Sloth Sanctuary" (Cahuita, Limón, Costa Rica), in order to determine: (i) the reliability of the fecal progesterone and estrogen extraction and its quantification with an AIA-360® analyzer, (ii) assess blood parameters in this species and (iii) evaluate if there is a correlation between fecal and plasmatic steroids. The study was performed over a three-month period, from November, 2013 to January, 2014, with a total amount of 208 fecal samples collected from five sexually mature females weighing 6.32 kg in average. The average of the median concentrations of progesterone in feces of the five females was 124.21 ng/g, and 1 708.95 pg/g for estrogen. The average minimal and maximal values were 50.96 ng/g and 1 057.46 ng/g for progesterone and, 1 191.77 pg/g and 2 159.24 pg/g for estradiol. In plasma, progesterone median values were 1.26 ng/mL, showing a minimum of 0.32 ng/mL and 12.84 ng/mL as maximum values. The plasmatic estrogen levels were below the detection limit of the equipment (25 pg/mL). Although there was no strong statistical correlation between the fecal and plasmatic progesterone fluctuations, our data suggests that the plasmatic events are mostly reflected in feces two days afterwards. Also, the levels of progesterone were elevated during the first half of November and, subsequently, showed a successive and important reduction in all the females tested. Finally, our results demonstrated that fecal steroid extractions and their measurement in a AIA-360®, allowed the successful detection and represents an alternative non-invasive determination of hormone profiles in C. hoffmani. Rev. Biol. Trop. 66(1): 280-292. Epub 2018 March 01.

Strongyloides stercoralis en pacientes psiquiátricos / Strongyloides stercoralis in psychiatric patients

Strongyloides stercoralis es un parásito intestinal, cuya prevalencia es usualmente subestimada en Costa Rica, porque se emplea sólo el examen directo de las muestras de heces; mientras que, para S. stercoralis es necesario emplear métodos más sensibles, como el Baermann o el cultivo en agar. En otros países se ha considerado a los pacientes psiquiátricos como un grupo de riesgo para esta parasitosis; por lo que estudiamos un grupo de pacientes (n=108)y del personal (n=71) del Hospital Nacional Psiquiátrico, analizado mediante una modificación del método de Baermann y el examen directo estándar. Los parásitos más frecuentes fueron Endolimax nana (20 por ciento), Entamoeba coli (16 por ciento), Giardia duodenalis (4 por ciento) y dos casos de S. stercoralis, uno del grupo de pacientes y el otro del personal. Este informe corrobora la importancia del método de Baermann, porque los dos casos de S. stercoralis spp., encontrados, además de dos de Trichuris spp. y otros dos de uncinarias solo fueron detectados por el método de Baermann. Adicionalmente, la prevalencia global de parásitos intestinales encontrada fue un 10 por ciento superior a la prevalencia informada para el país en la encuestra nacional de 1996. Los datos presentados corroboran un grupo de alto riesgo para los parásitos intestinales y cualquier otro agente transmitido por contaminación fecal.

Strongyloides stercoralis is an intestinal parasite, which prevalence is usually underestimated in Costa Rica, because the stool samples are analyzed only by direct fecal smears; where as, for S. stercoralis analysis is necessary to use more sensible methods; such as the Baermann or agar culture methods. In other countries the psychiatric patients are considered as a risk group for this parasite. For this reason, a group of patients (n=108) and personal (n=71) from the National Hospital of Psychiatric were studied using a modification of the Baermann method and the standard direct fecal analysis. The most frequent parasites found were Endolimax nana (20%), Entamoeba coli (16%), Giardia duodenalis (4%), and two cases of S. stercoralis were diagnosed, one from the patients and the other in the staff. This report stresses the importance of the use of Baermann method, because the two cases of S. stercoralis found and other two cases of Trichuris and another two of hookworms were diagnosed only with this method. The global prevalence of intestinal parasites of the psychiatric patients was 30%, a 10% higher than the prevalence described for the country, according to the national survey from 1996. Our data corroborate that the psychiatric patients represent a high-risk group for intestinal parasites and also to any other agent transmitted by fecal contamination.