Cull guinea pigs: carcass and non-carcass traits in males and females compared to their fattening counterparts.

Culling of guinea pigs can provide a large number of animals per year for meat production, but little information is available in the scientific literature on the carcass characteristics and non-carcass components of these animals. The objective of this study was to evaluate the carcass and non-carcass characteristics of cull guinea pigs in comparison to their fattening counterparts. Forty-eight fattening (3 months-age, 24 females and 24 males) and forty-eight cull (14 months-age, 24 females and 24 males) guinea pigs were slaughtered and carcass yield, linear measurements, tissular composition, and non-carcass components were evaluated. In general, cull guinea pigs had higher carcass, tissue, and non-carcass component weights. Cull male and both female guinea pig groups had similar carcass yields. Cull animals had higher carcass and hind leg lengths, lumbar and thoracic circumferences, and carcass compactness than their young counterparts. However, a sex effect was found for leg compactness depending on whether they were fattened or cull. Tissue percentages values were similar between fattening and culling animals of the same sex. However, females had a higher percentage of fat tissue than males. Fattening females had the best muscle to bone ratio, followed by cull males. The non-carcass elements were more represented in fattening animals than in culls, probably due to an allometric growth of the viscera in relation to the rest of the body. In commercial and cooking terms, this information is valuable for producers and researchers who need to understand the factors that influence carcass characteristics of guinea pigs.

[Primary immune thrombocytopenia linked to the ingestion of guinea pigs (Cavia porcellus) causality or coincidence?] / Trombocitopenia inmune primaria vinculada a la ingesta de cuy (Cavia porcellus). ¿casualidad o coincidencia?

The guinea pig in Ecuador is synonymous with our ancestral gastronomy and cultural tradition, but because of the diet rich in L-canavanine (alfalfa) that they receive; could limit its consumption in patients with primary immune thrombocytopenia (ITP). Ingestion of alfalfa in humans can cause kidney failure and lupus-like syndrome. The John Hopkins Lupus Center recommends avoiding it in the diet of patients with Systemic Lupus Erythematosus (SLE), as it aggravates inflammation by stimulating immune activity (flares). We present two cases of patients with ITP linked to guinea pig ingestion. It is probable

El cuy en el Ecuador es sinónimo de nuestra gastronomía ancestral y de tradición cultural, pero por la alimentación rica en L-canavanina (alfalfa) que reciben; podría limitar su consumo en pacientes con trombocitopenia inmune primaria (PTI). La ingesta de alfalfa en humanos puede propiciar insuficiencia renal y síndrome lupus-like.  El centro de Lupus John Hopkins recomiendan evitarla en la dieta de los pacientes con Lupus Eritematoso Sistémico (LES), al agravar la inflamación por estimulación de la actividad inmune (flares). Presentamos dos casos de pacientes con PTI vinculados con la ingesta de cuy.  ¿Es probable?

Analysis and 3D Imaging of Morphometric - Mineral Structure Changes in Skulls of Male and Female Guinea Pigs During and After Developmental Period

SUMMARY: Even though morphometric and mineral studies related to the guinea pig (Cavia porcellus) skull have been carried out, this study is the first attempt to evaluate all developmental stages of male and female guinea pigs. This study aims to this study is to create 3D modeling of CT images obtained from the skulls of male and female guinea pigs during the developmental period (prepuberty and the period between puberty and adulthood) and following periods (young adulthood and old adulthood), to analyze some biometric bone data such as volume, surface area and length, and to assess the developmental analysis of the mineral matter change in their skulls. The CT-scanned skulls were transferred to 3D Slicer (5.0.2), which is used for 3D modeling. The surface area and volume were calculated by measuring the measurement points on the models. In addition, the XRF device was used to show elemental ratio changes during different developmental stages. According to metric measurements, a gradual increase was observed during the life period. The metric measurements of the skull bone had a higher measurement value in male guinea pigs than in their female counterparts. While Ca/P ratio increased up to the third group and partially decreased in the fourth group in males, it gradually increased from the first group to the fourth group in females. This study revealed that puberty, adulthood and sex were effective in the physical and chemical characterization of skull bone structure in guinea pigs.

Aunque se han realizado estudios morfométricos y de minerales relacionados con el cráneo del cobayo (Cavia porcellus), esta investigación es el primer intento de evaluar las etapas de desarrollo de cobayos machos y hembras. El objetivo de este estudio fue crear un modelado 3D de imágenes de tomografía computarizada obtenidas de los cráneos de cobayos machos y hembras durante el período de desarrollo (prepubertad y el período entre la pubertad y la edad adulta) y los períodos siguientes (edad adulta joven y edad adulta mayor), para analizar algunos datos biométricos de los huesos, como el volumen, la superficie y la longitud, y además, analizar el cambio de materia mineral en sus cráneos durante el desarrollo. Los cráneos escaneados se transfirieron a 3D Slicer (5.0.2), que se utiliza para el modelado 3D. El área de superficie y el volumen se calcularon midiendo los puntos de medición en los modelos. Además, se utilizó el dispositivo XRF para mostrar los cambios en las proporciones elementales durante diferentes etapas de desarrollo. Según mediciones métricas, se observó un aumento gradual durante el período de vida. Las medidas métricas del hueso del cráneo tuvieron un valor de medición más alto en los cobayos machos que en las hembras. Mientras que la relación Ca/P aumentó hasta el tercer grupo y disminuyó parcialmente en el cuarto grupo en los machos y aumentó gradualmente del primer grupo al cuarto grupo en las hembras. Este estudio reveló que la pubertad, la edad adulta y el sexo fueron efectivos en la caracterización física y química de la estructura ósea del cráneo en cobayos.

Egg Yolk-Supplemented Tris-Citric Acid Extender Improves the Prefreezing and Post-Thaw Sperm Quality Indices of Guinea Pig (Cavia porcellus) Epididymal Spermatozoa.

This study aimed to assess the suitability of egg yolk (EY) supplementation to a tris-citric acid-based extender on cryosurvival of guinea pig (Cavia porcellus) epididymal spermatozoa. Two synthetic-based extenders, tris-citric acid-glucose plus 20% EY (TCG-EY) and tris-citric acid-fructose (TCF) both with 5% glycerol, were compared. Thirty-two epididymides were recovered from 16 adult guinea pig males by gonadectomy, and then the sperm samples were retrieved by retrograde flushing using TCG-EY and TCF extenders for left or right epididymis, respectively. TCG-EY and TCF sperm samples were frozen in static liquid nitrogen vapors through a two-step cooling procedure. Before freezing, the percentage of progressive sperm motility and sperm with intact plasma and acrosome membranes from TCG-EY sperm samples were higher (p < 0.05) than those diluted with TCF. Post-thaw sperm kinematic variables and membrane integrity were drastically reduced (p < 0.001) compared with prefreezing samples, regardless of extender type. The post-thaw plasmatic and acrosome membrane integrity from TCG-EY sperm samples was higher (p < 0.05) than those from TCF samples. Except for the length, the morphometric head dimensions of sperm diluted with TCG-EY or TCF did not vary (p > 0.05) after the freezing-thawing process compared with the prefreezing samples. In conclusion, despite greater cell cryoinjury with both extenders, the EY supplementation exerted greater cell membrane protection before and after the freezing-thawing process. This research shows an in-depth analysis of guinea pig sperm cryopreservation; however, more studies are recommended.

Monitoramento sanitário de colônias de cobaias e coelhos: principais agentes infecciosos

The quality of animals used in research is a fundamental aspect that directly influences the validity and reproducibility of results. Additionally, animal quality also plays an important role in research ethics, contributing to the reduction of the number of animals required in studies and minimizing unnecessary suffering. To ensure an adequate quality standard, it is vital to implement comprehensive programs of sanitary monitoring. These programs primarily aim to prevent biological contamination through animals, biological materials, insects, people, and equipment. Furthermore, it is crucial to have knowledge of the sanitary standard both of the environment and of the animals already present in the animal facility, in order to avoid collective outbreaks of diseases and ensure the safety of both animals and researchers. Considering that laboratory animals can be asymptomatic carriers of pathogens, sanitary control becomes even more challenging. Therefore, it is crucial to develop effective strategies to detect, prevent, and control the spread of infectious agents in the research environment. In this context, this study aims to provide a comprehensive review of the sanitary control of animals used in research. This literature review will cover detailed information, recommendations, and specific methodologies for parasitological, bacteriological, and virological monitoring in the breeding of guinea pigs and rabbits. This information is essential to ensure the integrity of scientific studies, the safety of animals, and the validity of research results.

A qualidade dos animais utilizados na pesquisa é um aspecto fundamental que influencia diretamente a validade e a reprodutibilidade dos resultados. Além disso, a qualidade dos animais também desempenha um papel importante na ética da pesquisa, contribuindo para a redução do número de animais necessários nos estudos e minimizando o sofrimento desnecessário. Para assegurar um padrão de qualidade adequado, é vital implementar programas abrangentes de monitoramento sanitário. Esses programas visam primordialmente prevenir a contaminação biológica de animais, materiais biológicos, pessoas e equipamentos. Além disso, é fundamental conhecer o padrão sanitário do ambiente e dos animais, a fim de evitar a disseminação de doenças, assegurar a eficiência das barreiras sanitárias e os aspectos de biossegurança. Considerando que os animais de laboratório podem ser portadores assintomáticos de patógenos, o controle sanitário torna-se ainda mais desafiador. Portanto, é fundamental desenvolver estratégias eficazes para detectar, prevenir e controlar a disseminação de agentes infecciosos no ambiente de pesquisa. Nesse contexto, este trabalho visa fornecer um guia de consulta sobre o controle sanitário de cobaias e coelhos utilizados em pesquisas científicas, que abordará informações detalhadas dos patógenos que acometem estas espécies, recomendações e metodologias específicas para o monitoramento parasitológico, bacteriológico e virológico. Este trabalho apresenta-se como um importante guia de consulta para técnicos em bioterismo, pesquisadores, e profissionais envolvidos com a ciência em animais de laboratório, por apresentar informações essenciais para garantir a integridade dos estudos científicos, a segurança dos animais e a validade dos resultados da pesquisa.

Cavia porcellus (Rodentia: Caviidae) as host for Ctenocephalides felis felis (Siphonaptera: Pulicidae) in artificially infestation.

The number of guinea pigs is increasing as pet and their domestication necessitates the study of their pathology and emerging diseases. This study aimed to evaluate guinea pigs' capacity to be infested by Ctenocephalides felis felis fleas, as it is a common parasite among pets that causes irritation, stress, and transmission of other pathogens. Seventeen guinea pigs were infested with C. felis felis. After 48 hours, the animals were combed, and the number of fleas was determined. Guinea pigs had a very low recovery (average of 5%), leading us to conclude that they are not good hosts for this species, despite some literature citing it as an accidental host if infested along with dogs or cats.

Os porquinhos-da-índia como animal de estimação têm aumentado cada vez mais, e, sua domesticação trouxe a necessidade de estudos sobre suas patologias e doenças emergentes. Este estudo teve como objetivo avaliar a capacidade de infestação dos porquinhos-da-índia pela pulga Ctenocephalides felis felis, ectoparasita comum entre os animais domésticos que causa irritação, estresse e transmissão de outros patógenos. Dezessete animais foram infestados com C. felis felis. Após 48 horas, os animais foram penteados e o número de pulgas determinado. Os porquinhos-da-índia tiveram uma recuperação muito baixa (média de 5%), levando-nos a concluir que estes não são bons hospedeiros para essa espécie de pulga, apesar de algumas literaturas os citarem como hospedeiro acidental se conviverem juntamente com cães ou gatos infestados.

Masticatory Myositis in a Guinea Pig (Cavia porcellus): A Case Report.

Masticatory myositis is an autoimmune neuromuscular disorder that affects the muscles of mastication. The affected individual has difficulties in opening or closing the mouth, pain, and swelling in the acute phase, and significant atrophy of the affected musculature in the chronic phase. A guinea pig (Cavia porcellus) with a history of chronic hyporexia, recurrent cheek teeth overgrowth, and loss of facial silhouette, was suspected of having masticatory myositis. The disease was confirmed by computed tomography and histopathological examination of muscle fragments. The patient was treated with a protocol involving corticosteroids and gabapentin, and occlusal correction procedures.

Cross-protection of commercial vaccines against Chilean swine influenza A virus using the guinea pig model as a surrogate.

Influenza A virus poses a significant threat to public health and the swine industry. Vaccination is the primary measure for controlling the disease, but the effectiveness of vaccines can vary depending on the antigenic match between vaccine strains and circulating strains. In Chile, H1N1pdm09 and other lineages H1N2 and H3N2 have been detected in pigs, which are genetically distinct from the strains included in commercial vaccines. This study aimed to evaluate the cross-protection by commercial vaccines against strains circulating in Chile using the guinea pig model. For this study, four circulating strains [A/swine/Chile/H1A-7/2014(H1N2), A/swine/Chile/H1B-2/2014(H1N2), A/swine/Chile/H1P-12/2015(H1N1), and A/swine/Chile/H3-2/2015(H3N2)] were selected. Guinea pigs were divided into vaccinated and control groups. The vaccinated animals received either a multivalent antigenically heterologous or monovalent homologous vaccine, while the control animals remained unvaccinated. Following vaccination, all animals were intranasally challenged, and nasal wash samples were collected at different time points post-infection. The results showed that the homologous monovalent vaccine-induced hemagglutinin-specific antibodies against the Chilean pandemic H1N1pdm09 strain. However, the commercial heterologous multivalent vaccine failed to induce hemagglutinin-specific antibody titers against the H1N2 and H3N2 challenge strains. Furthermore, the homologous monovalent vaccine significantly reduced the duration of viral shedding and viral titers specifically against the Chilean pandemic H1N1pdm09 strain and heterologous multivalent vaccine only partial. These findings highlight the importance of regularly updating vaccine strains to match the circulating field strains for effective control of swine influenza. Further research is needed to develop vaccines that confer broader protection against diverse strains of swine influenza A virus.

Healing Effect of a Nano-Functionalized Medical-Grade Honey for the Treatment of Infected Wounds.

Based on the qualities of Ulmo honey (Eucryphia cordifolia), a medical-grade honey (Ulmoplus®) has been developed. Relevant to this, the use of copper represents an emerging therapy for the treatment of wounds. Therefore, the aim of this study was to see how this medical-grade honey with copper nanoparticles (CuNPs) helped to heal infected or non-infected wounds. Twenty-four guinea pigs (Cavia porcellus) were divided into four groups for phase 1 (without and with infection, U + F1 and U + F2), and two groups for phase 2 (selected formulation, without and with infection, U + F2NI and U + F2I). Bacteriological and histopathological studies, collagen fibers content evaluation, and stereological analysis were performed. The selected formulation displayed the same antibacterial potency as Ulmoplus®, indicating that this medical-grade honey by itself can be used as an antibacterial agent. However, the evaluation of collagen content demonstrated a significant increase in fibroblast and type III collagen fibers for infected and uninfected groups, which correlated with the histopathological study. Therefore, it is correct to affirm that adding CuNPs to Ulmoplus® improved the maturation of collagen fibers. Finally, polymorphonuclear cells presented similar values between experimental groups, which would indicate that the formulation under study was able to regulate the inflammatory process despite their infectious condition.

Morphological and morphometric study of the superior vestibular nerve trunk in guinea pigs.

The guinea pig has been chosen as a research model for otologic or neuropathic studies due to the relative ease of the cochlea, cochlear nerve, and vestibular nerve dissection. Little data have been reported on the normality of these nerves. The vestibular nerve is composed of the superior vestibular, inferior vestibular, and branch nerves. This study aimed to study the microscopic anatomy of the superior vestibular nerve (SVN) of guinea pigs using light microscopy and to search for normality patterns for use in experimental models in basic otologic research. We used eight male albino guinea pigs (Cavia porcellus, English strain), weighing between 400 and 500 g. After anesthetizing, the animals were perfused with a fixative solution of 2.5% glutaraldehyde. Dissection was performed by the access method to the temporal bone, coming to the rock and exposing the cochlea and vestibular nerve. The NVS fragments were removed, postfixed in osmium tetroxide, and embedded in the epoxy plastic resin Poly/Bed 812® (Polysciences Inc., Warrington, PA). Semi-thin transverse serial sections (0.5 µm) were made using a microtome MT6000-XL, RMC, Inc. and stained with toluidine blue. Morphology and morphometry were described and evaluated using the KS 400 application (Kontron 2.0, EchingBei, Munich, Germany) by macro, a computer program specially designed and developed for the study of the VIII nerve. The SVN was found to be devoid of epineurium, with only a thin conjunctive tissue layer. The myelin sheath of guinea pigs is relatively thin compared to the sensory and motor nerves found in mammals. The average fascicular area SVN was 0.19 ± 0.05 mm2 , with the largest area found to be 0.24 mm2 and the lowest was 0.12 mm2 . The average number of fibers was 5,753.00 ± 538 fibers. The density of myelinated fibers reached 32,316.08 ± 11,375.29 fibers/mm2 . Its diameter ranged from 1.0 to 9 µm and its peak was 3 µm. The measured results confirm the results of another study, indicating that the methodology is appropriate and reproducible. These findings are important for the evaluation of injured nerves in experimental models of peripheral neuropathy and basic ear disease.

An analysis of the cecum microbiome of three breeds of the guinea pig: Andina, Inti, and Peru.

This study investigated the effect of host genetics on the structure and composition of the cecum microbiota of three breeds of guinea pigs: Andina, Inti, and Peru. Fifteen guinea pigs were distributed into three groups according to their breed: Andina (5), Inti (5), and Peru (5). We discovered that four main phyla were shared between the three breeds: Bacteroidota, Firmicutes, Spirochaetota, and Synergistota. Although there were no significant differences in the alpha and beta diversity analysis, we found that the Linear discriminant analysis effect size and the heat tree analysis showed significant differences between the abundance of several taxa present in the cecum microbiome of the three breeds. These results suggest that host genetics could be a factor in the structure and composition of the guinea pig cecum microbiome. In addition, we found unique genera for each breed that have fermentation capacity and, therefore can be analyzed in further studies to determine if there is a functional relationship between them and the breed and its industrial profile.

Outbreak of leishmaniasis caused by Leishmania enriettii in guinea pigs (Cavia porcellus) / Surto de leishmaniose causada por Leishmania enriettii em cobaias (Cavia porcellus)

We describe an outbreak of leishmaniasis in seven guinea pigs (Cavia porcellus) in which nodular ulcerated skin lesions of varying sizes were observed in the nasal cavity, upper lip, pinnae, vulva, and periarticular region of the limbs. Cytologic exam of collected samples of the lesions in the auricle of one of the animals revealed macrophages containing parasitophorous vacuoles of approximately 4.0μm in diameter in their cytoplasm with morphology suggestive of Leishmania sp. Although skin lesions spontaneously regressed in two of the Guinea pigs, only one survived. All six animals that died were necropsied. Grossly, all animals showed bloody nodular cutaneous lesions with crusts. One of the guinea pigs had distended dark red and firm lungs. Histopathology of the skin lesions revealed histiocytic interstitial acanthotic dermatitis associated with a myriad of Leishmania organisms within macrophages cytoplasm. In the lung, the lesions were characteristic of broncho-interstitial pneumonia with focal infiltrates of neutrophils, epithelioid macrophages, and multinucleated giant cells containing 2µm basophilic amastigotes with morphology compatible with Leishmania spp. A focal granulomatous lesion ,associated with the causal agent in the lung is a novel description of leishmaniasis in guinea pigs caused by L. enriettii. The polymerase chain reaction (PCR) technique with mini-exon primer performed in samples of lesions from two affected guinea pigs was positive and equal to the reference strain, identifying Leishmania enriettii. The cytological, macroscopic, and histological lesions associated with the PCR technique allowed the diagnosis of leishmaniasis and the identification of the specie L. enriettii.

Descrevemos um surto de leishmaniose em sete cobaias (Cavia porcellus), com lesões cutâneas nodulares ulceradas de tamanhos variados observadas na cavidade nasal, lábio superior, pavilhões auriculares, vulva e região periarticular dos membros. No exame citológico foram encontrados macrófagos contendo vacúolos parasitóforos no citoplasma de aproximadamente 4.0μm em diâmetro com morfologia sugestiva de Leishmania sp. Apesar de regressão espontânea das lesões cutâneas terem ocorrido em duas das sete cobaias, apenas um sobreviveu. Seis dos sete animais afetados morreram e foram necropsiados. Macroscopicamente, todos os animais apresentaram lesões cutâneas nodulares, crostosas e sanguinolentas. Uma das cobaias tinha pulmões vermelho-escuros, distendidos e firmes. A histopatologia das lesões cutâneas revelou dermatite acantótica intersticial histiocítica associada a miríades de organismos de Leishmania no citoplasma de macrófagos. Nos pulmões as lesões eram características de pneumonia bronco-intersticial com infiltrado focal de neutrófilos, eosinófilos, macrófagos epitelioides e células gigantes multinucleadas contendo amastigotas basofílicos de 2µm com morfologia compatível com Leishmania spp. Lesões granulomatosas focais associadas ao agente no pulmão são um achado inédito na leishmaniose causada por L. enriettii em cobaias. A técnica de reação em cadeia da polimerase (PCR) com primer mini-exon realizada em amostras de lesões de duas cobaias afetadas foi positiva, identificando Leishmania enriettii. Os aspectos macroscópicos, citológicos, e histológicos associados à técnica da (PCR), permitiram o diagnóstico da leishmaniose e a identificação da espécie L. enriettii.

Comparative analysis of fasting effects on the cecum microbiome in three guinea pig breeds: Andina, Inti, and Peru.

Guinea pigs have historically been used as a food source and are also an important model for studying the human intestines. Fasting is the act of temporarily stopping the intake of food. This process can alter the microbiota of various animals. This study is the first to investigate the impact of fasting on the cecum microbiome of three guinea pig breeds. We investigated the impact of fasting on the microbiome population structure in the cecum of three guinea pig breeds. This was done by sequencing and analyzing the V4 hypervariable region of the 16S rRNA gene in bacterial communities found in cecum mucosa samples. To achieve this, we established two treatment groups (fasting and fed), for each of the three guinea pig breeds: Andina, Inti, and Peru. The study involved twenty-eight guinea pigs, which were divided into the following groups: Andina-fed (five), Andina-fasting (five), Inti-fed (four), Inti-fasting (five), Peru-fed (five), and Peru-fasting (four). The results indicated a significant difference in beta diversity between the treatment groups for the Peru breed (P-value = 0.049), but not for the treatment groups of the Andina and Inti breeds. The dominant phyla across all groups were Firmicutes and Bacteroidetes. We observed variations in the abundance of different taxa in the cecum microbiota when comparing the treatment groups for each breed. Additionally, there was a higher number of unique taxa observed in the fasting groups compared to the fed groups. We discovered that the genus Victivallis was the only one present in all fasting groups across all breeds. Despite the findings, the resilience of the gut microbiome was not challenged in all three breeds, which can lead to disruptive changes that may affect the overall maintenance of the cecum microbiome. Based on the observed differences in the treatment groups of the Peru breed, it can be suggested that fasting has a greater impact on this particular breed.

Role of Guinea Pigs (Cavia porcellus) Raised as Livestock in Ecuadorian Andes as Reservoirs of Zoonotic Yeasts

Guinea pigs (Cavia porcellus) have been reared for centuries in the Andean region for ceremonial purposes or as the main ingredient of traditional foods. The animals are kept in close proximity of households and interact closely with humans; this also occurs in western countries, where guinea pigs are considered pets. Even though it is acknowledged that domestic animals carry pathogenic yeasts in their tissues and organs that can cause human diseases, almost nothing is known in the case of guinea pigs. In this work we used traditional microbiological approaches and molecular biology techniques to isolate, identify, and characterize potentially zoonotic yeasts colonizing the nasal duct of guinea pigs raised as livestock in Southern Ecuador (Cañar Province). Our results show that 44% of the 100 animals studied were colonized in their nasal mucosa by at least eleven yeast species, belonging to eight genera: Wickerhamomyces, Diutina, Meyerozyma, Candida, Pichia, Rhodotorula, Galactomyces, and Cryptococcus. Noticeably, several isolates were insensitive toward several antifungal drugs of therapeutic use, including fluconazole, voriconazole, itraconazole, and caspofungin. Together, our results emphasize the threat posed by these potentially zoonotic yeasts to the farmers, their families, the final consumers, and, in general, to public and animal health.

First serological and molecular detection of Toxoplasma gondii in guinea pigs (Cavia porcellus) used for human consumption in Nariño, Colombia, South America.

Consumption of undercooked meat is one of the main transmission routes for Toxoplasma gondii worldwide. In the South American Andes, the guinea pig (Cavia porcellus) is a domestic rodent representing one of the main sources of animal proteins for indigenous communities. Although T. gondii infects a wide range of rodents worldwide, the natural impact of the infection on guinea pig populations is still unknown. Our study conducted in guinea pigs that were bred in traditional systems located in the village of José María Hernández (Nariño, Colombia) revealed the presence of T. gondii antibodies in 33.3% (23 out of 69) guinea pigs evaluated, with a cut-off point of 25 for the modified direct agglutination test. Conventional PCR detection of the T. gondii-specific RE fragment (529 bp) in 207 collected tissues demonstrated the presence of T. gondii DNA in several organs, including the brain (16/69), muscle (12/69), and heart (4/69), with an overall molecular detection frequency of 27.5% (19 out of 69 guinea pigs). This is the first report of natural infection of guinea pigs with T. gondii, demonstrating their potential epidemiological role in transmitting the infection to autochthonous populations.

Morphoidentification of intestinal nematodes in guinea pigs (Cavia porcellus) from Cajamarca City, Peru.

The research objective was to identify helminths in guinea pigs from processing centers in the city of Cajamarca, determining the frequency, morphometric characteristics, parasite gender, and location. The diagnosis of intestinal parasites was made by examining and opening the postmortem gastrointestinal tract and the morphometric characteristics were determined using a millimetric ruler, micrometric eyepiece, microscope, and stereoscope. At the end of the investigation, a frequency of 76% of nematodes was found, which according to morphometry correspond to Paraspidodera uncinata (74%), Capillaria spp. (18%), and Trichuris spp. (14%); according to location 18% were found in the small intestine (Capillaria spp. 18%), 72% in the cecum (58% correspond only to P. uncinata, 3% to Trichuris spp. and 11% to a mixed infection between both) and 23% in the colon (P. uncinata); no parasites were found in liver or stomach. Nematodes in guinea pigs from Cajamarca is high, with a greater presence of P. uncinata, located in the cecum and colon.

Genomic Characterization of Salmonella Typhimurium Isolated from Guinea Pigs with Salmonellosis in Lima, Peru.

Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) is one of the most important foodborne pathogens that infect humans globally. The gastrointestinal tracts of animals like pigs, poultry or cattle are the main reservoirs of Salmonella serotypes. Guinea pig meat is an important protein source for Andean countries, but this animal is commonly infected by S. Typhimurium, producing high mortality rates and generating economic losses. Despite its impact on human health, food security, and economy, there is no genomic information about the S. Typhimurium responsible for the guinea pig infections in Peru. Here, we sequence and characterize 11 S. Typhimurium genomes isolated from guinea pigs from four farms in Lima-Peru. We were able to identify two genetic clusters (HC100_9460 and HC100_9757) distinguishable at the H100 level of the Hierarchical Clustering of Core Genome Multi-Locus Sequence Typing (HierCC-cgMLST) scheme with an average of 608 SNPs of distance. All sequences belonged to sequence type 19 (ST19) and HC100_9460 isolates were typed in silico as monophasic variants (1,4,[5],12:i:-) lacking the fljA and fljB genes. Phylogenomic analysis showed that human isolates from Peru were located within the same genetic clusters as guinea pig isolates, suggesting that these lineages can infect both hosts. We identified a genetic antimicrobial resistance cassette carrying the ant(3)-Ia, dfrA15, qacE, and sul1 genes associated with transposons TnAs3 and IS21 within an IncI1 plasmid in one guinea pig isolate, while antimicrobial resistance genes (ARGs) for ß-lactam (blaCTX-M-65) and colistin (mcr-1) resistance were detected in Peruvian human-derived isolates. The presence of a virulence plasmid highly similar to the pSLT plasmid (LT2 reference strain) containing the spvRABCD operon was found in all guinea pig isolates. Finally, seven phage sequences (STGP_Φ1 to STGP_Φ7) were identified in guinea pig isolates, distributed according to the genetic lineage (H50 clusters level) and forming part of the specific gene content of each cluster. This study presents, for the first time, the genomic characteristics of S. Typhimurium isolated from guinea pigs in South America, showing particular diversity and genetic elements (plasmids and prophages) that require special attention and also broader studies in different periods of time and locations to determine their impact on human health.

Molecular dynamics simulations of human L-asparaginase1: Insights into structural determinants of enzymatic activity.

The l-asparaginase enzyme is used in cancer therapy, mainly acute lymphoid leukemia (ALL). Commercial enzymes (EcASNase2) cause adverse reactions during treatment, such as immunogenicity. A human enzyme could be a non-immunogenic substitute. However, no candidate was found showing efficient kinetic properties. HASNase1 is an l-asparaginase that comes from the N-terminal domain of a protein called 60 kDa-lysophospholipase and its 3D structure has not been resolved. HASNase1 is homologous to EcASNase1 and gpASNase1, and this last one has shown efficient kinetic properties. Homology modeling was used to find the 3D structure of hASNase1, so one could submit it to Molecular Dynamics (MD), in order to understand structural differences that lead to different catalytic efficiency compared to EcASNase2 and gpASNase1. The interaction potential between L-Asn and active site residues showed that the substrate can rotate in the site when Region1 is open. Region1 residues sequence favors deformations and movements as shown in MD. Region2-A is linear in gpASNase1, and it features a helix portion in hASNase1, which leaves the Tyr308 position projected to the active site ratifying its role in catalytic efficiency. Analysis of Lys188 orientation and movement showed the effect of positive cooperativity in hASNase1. It was found that the presence of Asn at the allosteric site helps, not only in Region1 stabilization, but also in Lys188 stabilization for the maintenance of the triad. Despite structural similarities in hASNase1, gpASNase1, and EcASNase2, there are differences in structural determinants that, in addition to allosterism, may explain the different kinetic properties.

Trichuris spp. in Animals, with Specific Reference to Neo-Tropical Rodents.

Trichuriasis is the clinical disease of animals infected with the parasite of the genus Trichuris. This review attempts to present information on Trichuris spp. infestation in neo-tropical rodents that are utilized for meat consumption by humans. Neo-tropical rodents utilized for meat production can be divided into two categories: those that have been domesticated, which include the guinea pig (Cavia porcellus), and those that are on the verge of domestication, such as the capybara (Hydrochoerus hydrochaeris), lappe (Cuniculus paca/Agouti paca), and agouti (Dasyprocta leporina). This document reviews the literature on the species of Trichuris that affects the rodents mentioned above, as well as the clinical signs observed. The literature obtained spans over sixty years, from 1951 to 2020. Trichuris spp. was found in these neo-tropical rodents mentioned. However, there is a dearth of information on the species of Trichuris that parasitize these animals. The capybara was the only rodent where some molecular techniques were used to identify a new species named T. cutillasae. In most cases, Trichuris spp. was found in combination with other endoparasites, and was found at a low prevalence in the lappe and guinea pig. The presence of Trichuris spp. ranged from 4.62-53.85% in the agouti, 4.21-10.00% in the lappe, 50% in the capybaras, and 1-31% in guinea pigs. Further work must be done towards molecular identification of various Trichuris spp. present in these rodents, as well as the clinical effect of infection on the performance of agouti, lappe, capybara, and guinea pigs.

Predictive model of stunting in the Central Andean region of Peru based on socioeconomic and agri-food determinants.

Objectives: A limitation in the design and monitoring of public health policies is the lack of conceptual models to explain their results. The objective of this study was to develop a predictive model of stunting in children under 5 years of age in the central Andean region of Peru, using socioeconomic and agro-productive predictors. Study design: Cross-sectional data of 380 families in 15 districts of the central region of Peru. WHO criteria were used to define stunting prediction model. Methods: An explanatory and predictive study of stunting in children was carried out considering causality criteria through Chi-square tests and bivariate logistic regression. Family food production, maternal education, breastfeeding practices and others determinant related to rural zone conditions were considered as explanatory variables in stunting of children under 5 years old. Three exhaustive models for predicted the presence of stunting was developed. Results: Stunting percentage was 40.3. To Hosmer and Lemeshow test, the best fit was the model that considered the level of maternal education, timely consumption of colostrum, birth weight and guinea pig rearing, having high reliability (P â€‹< â€‹0.05). Conclusions: A predictive model for early detection of stunting risk in rural areas of the Andean region was developed based on simple and easily applied indicators. Effective policies are required to improve the feeding practices of pregnant women, increase breastfeeding and promote guinea pig raising for self-consumption and improve the nutritional status of children.