The forgotten habitats in conservation: early successional vegetation

Conservation efforts in terrestrial environments have focused on preserving patches of natural habitats and restoring disturbed habitats, with the main goal of transforming them into forests or habitats that resemble the original conditions. This approach tends to overlook the importance of conserving early successional vegetation (e.g., riverside vegetation, natural regeneration, young secondary forests), which often includes a large number of species (e.g., plants and animals) associated with or restricted to these habitats. In this paper we want to bring to attention the importance of preserving early successional vegetation, and to encourage scientists to investigate, e.g., the diversity, distribution, and species interactions occurring in these habitats. To address these goals, we focus on two main objectives: (1) to identify the common types of early successional vegetation in the Costa Rican Central Valley; and (2) to use some case studies to draw attention to the importance that such areas have as reservoirs of a large portion of the diversity unique to early successional stages. We first include an example to show the diversity of plants in small forest patches immersed in a large urbanized area. We provide general information on the insects that occur in early successional vegetation in urban areas, and in further detail examples of butterflies. Additionally, we provide examples of birds and mammals that are restricted to early successional vegetation, and how the reduction of this vegetation type affects species conservation. Finally, we encourage scientists to investigate these early successional habitats, particularly those species exclusive to early successional stages. Special attention should be paid to endemic species and those with a restricted distribution. Information of this type will make conservation of the diversity contained in these habitats possible.Los hábitats olvidados en conservación: la vegetación de estados sucesionales tempranos. Los esfuerzos de conservación en ambientes terrestres se han centrado principalmente en la preservación de ambientes naturales y la restauración de diferentes hábitats, con la meta principal de transformar estos ambientes en bosques maduros o hábitats que asemejen las condiciones originales. Este enfoque tiende a pasar por alto la importancia de conservar la vegetación de estados de regeneración temprana (e.g., vegetación riparia, regeneración natural, bosque secundario joven), la cual incluye un gran número de especies (e.g., plantas y animales) asociadas o restringidas a estos hábitats. Con este artículo queremos llamar la atención sobre la importancia de preservar áreas cubiertas con vegetación de sucesión temprana, e instar a científicos y naturalistas a investigar, e.g., la diversidad, distribución, e interacciones entre las especies presentes en estos ambientes. Para apoyar esta meta, nos enfocamos en dos objetivos principales: (1) identificar los tipos más comunes de vegetación pionera en el Valle Central de Costa Rica; y (2) utilizar algunos casos de estudio para llamar la atención sobre la importancia que tales áreas tienen como reservorio de gran parte de la diversidad, mucha de la cual es única de los estados de sucesión temprana. Primero se incluye un ejemplo particular en el cual se muestra la diversidad de plantas en pequeños fragmentos de bosque y matorral inmersos en una gran área urbanizada. Después se presenta una revisión general de los insectos que habitan en la vegetación de sucesión temprana en áreas urbanas, para luego discutir en mayor detalle ejemplos de mariposas. Además, proporcionamos ejemplos de especies de aves y mamíferos que están restringidos a vegetación de sucesión temprana, y cómo la reducción de este ambiente afecta su conservación. Finalmente, instamos a los científicos de diferentes áreas a investigar los diversos procesos ecológicos e interacciones biológicas inherentes a los estados de regeneración temprana. Especial atención requieren aquellas especies exclusivas o endémicas de estos ambientes. Sin esta información es imposible conservar la diversidad de estos hábitats.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Experimental infection of Artibeus lituratus bats and no detection of Zika virus in neotropical bats from French Guiana, Peru, and Costa Rica suggests a limited role of bats in Zika transmission

Author summaryIn previous works in 2008-2009, we found the presence of antibodies against flaviviruses, and viral RNA was detected in Neotropical chiropterans in Mexico, which led us to support the hypothesis that these animals could be reservoirs of flaviviruses. As controversial opinions have been exposed and based on a previous (2019) experimental ZIKV infection experiment conducted at Colorado State University using adult Artibeus males from a captive colony, in this work, we also experimentally infected adult Artibeus males complementarily adding females and using wild-caught animals instead of laboratory bats. We also monitored a diverse range of natural bat populations in Latin America for the presence of viral RNA against ZIKV in blood. A plaque reduction seroneutralization test was used for the detection of antibodies against ZIKV. Similar to the previous work, we found histopathological alterations in male testicles but also in the ovaries and oviducts of females, as well as gliosis and multifocal necrosis in pyramidal neurons and Purkinge cells of inoculated animals. Only two urine samples from inoculated animals showed viral RNA. Additionally, leukopenia and lymphoid follicular splenic hyperplasia were evidenced. In contrast to what was reported, no neutralizing antibodies against ZIKV were detected in any sample. Viral RNA within the blood was not present in any of the 2056 bat samples collected in French Guiana, Peru and Costa Rica and proceeding from 34 bat genera. These results together suggest that bats are not efficient amplifiers or reservoirs of ZIKV and might not have an important role in ZIKV transmission dynamics. Bats are important natural reservoir hosts of a diverse range of viruses that can be transmitted to humans and have been suggested to play an important role in the Zika virus (ZIKV) transmission cycle. However, the exact role of these animals as reservoirs for flaviviruses is still controversial. To further expand our understanding of the role of bats in the ZIKV transmission cycle in Latin America, we carried out an experimental infection in wild-caught Artibeus lituratus bats and sampled several free-living neotropical bats across three countries of the region. Experimental ZIKV infection was performed in wild-caught adult bats (4 females and 5 males). The most relevant findings were hemorrhages in the bladder, stomach and patagium. Significant histological findings included inflammatory infiltrate consisting of a predominance of neutrophils and lymphocytes, in addition to degeneration in the reproductive tract of males and females. This suggests that bat reproduction might be at some level affected by ZIKV. Leukopenia was also observed in some inoculated animals. Hemorrhages, genital alterations, and leukopenia are suggested to be caused by ZIKV; however, since these were wild-caught bats, we cannot exclude other agents. Detection of ZIKV by qPCR was observed at low concentrations in only two urine samples in two inoculated animals. All other animals and tissues tested were negative. Finally, no virus-neutralizing antibodies were found in any animal. To determine ZIKV infection in nature, the blood of a total of 2056 bats was sampled for ZIKV detection by qPCR. Most of the sampled individuals belonged to the genus Pteronotus sp. (23%), followed by the species Carollia sp. (17%), Anoura sp. (14%), and Molossus sp. (13.7%). No sample of any tested species was positive for ZIKV by qPCR. These results together suggest that bats are not efficient amplifiers or reservoirs of ZIKV and may not have an important role in ZIKV transmission dynamics

Background and common lesions in the female reproductive organs of giant anteaters (Myrmecophaga tridactyla)

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species in South America and is considered endangered or near extinction in Central America. Therefore, studies describing the reproductive characteristics of this species are pivotal for its conservation. Thus, this study aimed to provide a morphological description of the female reproductive tissues of this species. We collected tissue samples from six female giant anteaters and performed gross, morphological, and histochemical analyses. Five adult subjects and one juvenile were included in the study. In the ovary, classifications were made according to the follicle and oocyte sizes: primordial, primary, secondary, early antral, or antral. Typical follicles with a single oocyte surrounded by a simple or stratified layer of cubic epithelium, atretic follicles, corpora lutea, corpora albicans, and ovarian cysts were also observed. No ovarian lesions were observed. By contrast, endometritis, metritis, mucometra, and endometrial cysts were identified in the uterus. Uterine alterations in these subjects were frequent and could affect reproduction

Serological Positivity against Selected Flaviviruses and Alphaviruses in Free-Ranging Bats and Birds from Costa Rica Evidence Exposure to Arboviruses Seldom Reported Locally in Humans

Arboviruses have two ecological transmission cycles: sylvatic and urban. For some, the sylvatic cycle has not been thoroughly described in America. To study the role of wildlife in a putative sylvatic cycle, we sampled free-ranging bats and birds in two arbovirus endemic locations and analyzed them using molecular, serological, and histological methods. No current infection was detected, and no significant arbovirus-associated histological changes were observed. Neutralizing antibodies were detected against selected arboviruses. In bats, positivity in 34.95% for DENV-1, 16.26% for DENV-2, 5.69% for DENV-3, 4.87% for DENV-4, 2.43% for WNV, 4.87% for SLEV, 0.81% for YFV, 7.31% for EEEV, and 0.81% for VEEV was found. Antibodies against ZIKV were not detected. In birds, PRNT results were positive against WNV in 0.80%, SLEV in 5.64%, EEEV in 8.4%, and VEEV in 5.63%. An additional retrospective PRNT analysis was performed using bat samples from three additional DENV endemic sites resulting in a 3.27% prevalence for WNV and 1.63% for SLEV. Interestingly, one sample resulted unequivocally WNV positive confirmed by serum titration. These results suggest that free-ranging bats and birds are exposed to not currently reported hyperendemic-human infecting Flavivirus and Alphavirus; however, their role as reservoirs or hosts is still undetermined

Hallazgos histopatológicos asociados a la presencia de arbovirus (chikungunya, zika, dengue, virus del nilo occidental) en murciélagos y aves silvestres en ambientes rurales domiciliares y peridomiciliares

Los arbovirus son virus transmitidos por vectores artrópodos. En Costa Rica, circulan algunos como el Dengue, Zika, Chikungunya y Nilo occidental. Los arbovirus poseen dos ciclos ecológicos diferentes para lograr mantenerse en el ambiente, a saber: selvático y urbano. El ciclo selvático del Dengue, Zika y Chikungunya sólo se ha descrito entre primates no humanos y artrópodos en África y Asia, sin embargo, no se ha descrito aún en América. El ciclo selvático del Virus del Nilo Occidental involucra las aves silvestres. La presencia de estos arbovirus se ha descrito en vertebrados; no obstante, no se ha logrado demostrar la presencia de lesiones patológicas en los animales silvestres infectados por estos arbovirus. Mediante el uso de la técnica de la reacción en cadena de la polimerasa con transcriptasa reversa (RT-PCR) y técnicas para la detección de anticuerpos, como el PRNT (plaque reduction neutralization test, por sus siglas en inglés) se determinó la posible presencia de estos virus en aves y murciélagos silvestres en dos zonas endémicas a arbovirosis del país (Santa Cruz y Talamanca). Además, se realizó un estudio histopatológico complementario extensivo con el objetivo de describir los hallazgos histopatológicos asociados con la presencia de los arbovirus en los animales silvestres. Se colectaron en total 140 aves y 144 murciélagos de las zonas. Se determinó la presencia de anticuerpos neutralizantes en murciélagos contra DENV-1 en el 34.95% (43/123), DENV-2 en el 16.26% (20/123), DENV-3 en el 5.69% (7/123), DENV-4 en el 4.87% (6/123), YFV en un 0.81% (1/123), WNV en 2.43% (3/123), SLEV en un 4.87% (6/123), EEEV en 7.31% (9/123) y VEEV en 0.81% (1/123). No se identificaron anticuerpos neutralizantes contra ZIKV. En el caso de las aves, se determinaron anticuerpos neutralizantes contra WNV en 0.80% (1/124), SLEV en 2.41% (3/124), EEEV en 8.4% (6/71) y VEEV en el 5.63% (4/71). No se encontraron lesiones histopatológicas específicas asociadas a la seropositividad por flavivirus. Además, los resultados de los RT-PCR fueron negativos. Con base en esto hay evidencia de exposición a Flavivirus y Alfavirus en murciélagos y aves silvestres en Costa Rica, sin embargo, no fue posible evidenciar la presencia de lesiones histopatológicas asociadas.Arbovirus are arthropod borne viruses. In Costa Rica, Dengue, Zika, Chikungunya Virus and West Nile Virus have been reported. Arbovirus have two ecologic transmission cycles, sylvatic and urban. Dengue, Zika and Chikungunya sylvatic cycle has been described only between nonhuman primates and mosquitoes from Africa and Asia. It has not been yet described in America. The sylvatic cycle of West Nile Virus involves free-ranging birds. The presence of these viruses has been described in vertebrates; however histological lesions associated with their infection have not been yet described in wild animals. Using reverse transcriptase polymerase chain reaction (RT-PCR) and plaque reduction neutralizing tests (PRNT), evidence of these viruses in wild bats and birds from two arbovirus endemic locations in Costa Rica (Santa Cruz and Talamanca) was determined. Also, a complementary full tissue histological analysis was performed to establish histological lesions associated with them. A total of 140 birds and 144 bats were collected. Neutralizing antibodies were detected against Dengue (DENV 1-4), Zika Virus (ZIKV), Yellow Fever Virus (YFV), West Nile Virus (WNV), Saint Louis Encephalitis Virus (SLEV), Eastern Equine Encephalitis Virus (EEEV) and Venezuelan Encephalitis Virus (VEEV). In bats, 34.95% (43/123) for DENV-1, 16.26% (20/123) for DENV-2, 5.69% (7/123) for DENV-3, 4.87% (6/123) for DENV-4, 2.43% (3/123) for WNV, 4.87% (6/123) for SLEV, 0,81% (1/123) for YFV, 7.31% (9/123) for EEEV and 0.81% (1/123) for VEEV were found. Antibodies to ZIKV were not found. In birds, PRNT resulted positive against WNV in 0.80% (1/124), SLEV in 5.64% (7/124), EEEV in 8.4% (6/71) and VEEV in 5.63% (4/71). No significant specific histological findings were observed. Results for RT-PCR were also negative. These results demonstrate that free-ranging bats and birds are exposed to Flavivirus and Alphavirus, however there is no presence of associated histological lesions.UCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Salud::Maestría Académica en Microbiologí

Pre-treatment of canine plasma with heat, rather than acid, efficiently enhances Dirofilaria immitis antigen detection

Abstract Background The dissociation of antigen-antibody complexes has been utilized to enhance the accuracy of serological tests for infectious diseases, including Dirofilaria immitis. Currently, the antigen detected by available tests is primarily a glycoprotein found in the reproductive tract of female worms. However, this antigen can become inaccessible when bound to excessive circulating antibodies, leading to reduced test sensitivity and false-negative results. Acid and heat treatments of the sera or plasma have been established as reliable methods for inducing immune complex dissociation (ICD). Previous antigen testing for heartworm infection in dogs and cats has demonstrated that these treatments improve the diagnostic sensitivity without compromising specificity. This study aims to evaluate the performance of four distinct ICD methods in the detection of D. immitis antigen. Methods We utilized twofold serial dilutions of a well-characterized plasma (ranging from 1:2 to 1:4096) obtained from a D. immitis-infected dog to simulate the diverse antigen levels encountered in real-life infected dogs. The presence of antigen in the diluted samples, both without treatment and treated with four ICD protocols, was assessed in triplicate visually using DiroCHEK® by observing color changes. OD values were also obtained using the microplate reader SpectraMax® i Series-Spectramax Id3. A Factorial ANOVA test was conducted to compare the OD values between samples with and without treatments. Results The highest dilution at which color changes were observed was 1:128 for untreated samples and for samples subjected to acid treatments in ICD-3 and the hybrid ICD-4 protocol. In contrast, both heat treatment protocols (ICD-1 and ICD-2) exhibited color changes at a 512-fold dilution. The OD values in samples subjected to heat treatment were significantly higher than those in untreated samples, up to dilutions of 512-fold. Although OD values tended to be higher in samples subjected to acid treatment and the hybrid protocol compared to untreated samples up to a 128-fold dilution, this difference was not significant as the samples underwent further dilution. Conclusions Our findings affirm that heat treatments, rather than acid treatment, efficiently enhance the detection of D. immitis antigen by liberating the sequestered antigen from the immune complexes

Histopathological description of ocular and nervous lesions in domestic rabbits infected with Encephalitozoon cuniculi: an overview

Este artículo describe las lesiones, a nivel del sistema nervioso central y ojo, en conejos infectados con Encephalitozoon cuniculi. El análisis histopatológico, en conjunto con el uso de tinciones especiales de Ziehl-Neelsen y Gomori metamina-plata, es el método más sensible en el diagnóstico post mórtem. La presentación neurológica afecta a una gran mayoría de estos pacientes y se asocia a una encefalitis granulomatosa multifocal severa. En muchos de estos casos se puede observar esporas microsporidiales con tinciones especiales. La presentación ocular es menos frecuente que la nerviosa, se caracteriza por una uveítis facoclástica bilateral o unilateral.This paper describes ocular and central nervous system lesions of rabbits infected with Encephalitozoon cuniculi. The histopathological analysis, together with the use of special Ziehl-Neelsen and Gomori methenamine silver stains, is the most sensitive post-mortem diagnostic test. The neurologic lesion affects most of these patients and is related to severe multifocal granulomatous encephalitis. In many cases, microsporidial spores can be observed with the help of special stains. Ocular lesions are less frequent than nervous ones; they are characterized by a bilateral or unilateral phacoclastic uveitis

Histopathological description of ocular and nervous lesions in domestic rabbits infected with Encephalitozoon cuniculi : an overview.

Este artículo describe las lesiones, a nivel del sistema nervioso central y ojo, en conejos infectados con Encephalitozoon cuniculi. El análisis histopatológico, en conjunto con el uso de tinciones especiales de Ziehl-Neelsen y Gomori metamina-plata, es el método más sensible en el diagnóstico post mórtem. La presentación neurológica afecta a una gran mayoría de estos pacientes y se asocia a una encefalitis granulomatosa multifocal severa. En muchos de estos casos se puede observar esporas microsporidiales con tinciones especiales. La presentación ocular es menos frecuente que la nerviosa, se caracteriza por una uveítis facoclástica bilateral o unilateral.This paper describes ocular and central nervous system lesions of rabbits infected with Encephalitozoon cuniculi. The histopathological analysis, together with the use of special Ziehl-Neelsen and Gomori methenamine silver stains, is the most sensitive post-mortem diagnostic test. The neurologic lesion affects most of these patients and is related to severe multifocal granulomatous encephalitis. In many cases, microsporidial spores can be observed with the help of special stains. Ocular lesions are less frequent than nervous ones; they are characterized by a bilateral or unilateral phacoclastic uveitis.Escuela de Medicina Veterinari

Extraosseous aneurysmal bone cyst in dogs: a report of two cases

During a routine check-up in a 6-year-old intact male Labrador Retriever and a 6-year-old intact male Boxer, a mass in their pelvic cavities was found. Both dogs were clinically healthy and did not display any clinical symptoms. The masses were surgically removed and sent to a pathology laboratory for analysis. The histopathological evaluation of both lesions diagnosis was: extraosseous aneurysmal bone cysts. This report describes the macroscopic and histopathological characteristics of the cysts in both patients.Durante una revisión de rutina en un Labrador Retriever macho intacto de 6 años y un Boxer macho intacto de 6 años, se encontró una masa en sus cavidades pélvicas. Ambos perros estaban clínicamente sanos y no presentaban ningún síntoma clínico. Las masas de Las masas fueron extirpadas quirúrgicamente y enviadas a un laboratorio de patología para su análisis. La evaluación histopatológica de ambas lesiones fue: quistes óseos aneurismáticos extraóseos. Este informe describe las características macroscópicas e histopatológicas de los quistes en ambos pacientes.Universidad Nacional, Costa RicaEscuela de Medicina Veterinari

Retroperitoneal extraskeletal osteosarcoma in a dog: a case report

Se presentó un perro, de raza mixta, no castrado, 15 años de edad, con hiporexia, constipación, letargia y dolor abdominal. En el examen físico, se identificó una masa intraabdominal. Las pruebas hematológicas evidenciaron anemia leve, normocítica y normocrómica y  leucocitosis a causa de neutrofilia. Los resultados de bioquímica sérica mostraron alteraciones del nitrógeno ureico sanguíneo, fosfatasa alcalina sérica y creatinina. En el ultrasonido, se detectó un nódulo en bazo. Las radiografías evidenciaron un área radiopaca en abdomen, cerca de las vértebras lumbares. Se realizó laparotomía exploratoria y se encontró dos masas retroperitoneales. Se realizó la eutanasia del paciente, debido al difícil abordaje quirúrgico. El análisis histopatológico e inmunohistoquímico de las masas fue concluyente de un osteosarcoma extraesquelético. Los osteosarcomas extraesqueléticos son tumores malignos, de origen mesenquimal infrecuentes, sin involucramiento primario de tejido óseo o periostio. La localización retroperitoneal de estos tumores pocas veces ha sido reportada.A 15-year-old not neutered mixed-breed dog was presented with hyporexia, constipation, lethargy and abdominal pain. An intra abdominal mass was identified during the physical examination. Mild normocytic and normochromic anemia and leukocytosis due to neutrophilia were detected in the complete blood count. Serum biochemistry results showed alterations in blood urea nitrogen, serum alkaline phosphatase, and creatinine. A splenic nodule was detected during the ultrasonographic examination, and radiographic findings showed a radiopaque area in the abdomen near the lumbar vertebrae. An exploratory laparotomy was done, and two retroperitoneal masses were found. Due to the difficult surgical approach euthanasia was elected. Histopathological and immunohistochemical evaluation of tissues was performed and the diagnosis of extraskeletal osteosarcoma was made. Extraskeletal osteosarcoma is an infrequent malign mesenchymal tumor without primary involvement of bone tissue or periosteum. Seldom has the retroperitoneal localization of this tumor been reported