Positron Emission Tomography-Computed Tomography and Magnetic Resonance Imaging Assessments in a Mouse Model of Implant-Related Bone and Joint Staphylococcus aureus Infection.

Osteomyelitis is an infection of the bone, associated with an inflammatory process. Imaging plays an important role in establishing the diagnosis and the most appropriate patient management. However, data are lacking regarding the use of preclinical molecular imaging techniques to assess osteomyelitis progression in experimental models. This study aimed to compare structural and molecular imaging to assess disease progression in a mouse model of implant-related bone and joint infections caused by Staphylococcus aureus. In SWISS mice, the right femur was implanted with a resorbable filament impregnated with S. aureus (infected group, n = 10) or sterile culture medium (uninfected group, n = 6). Eight animals (5 infected, 3 uninfected) were analyzed with magnetic resonance imaging (MRI) at 1, 2, and 3 weeks postintervention, and 8 mice were analyzed with [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)-computed tomography (CT) at 48 h and at 1, 2, and 3 weeks postintervention. In infected animals, CT showed bone lesion progression, mainly in the distal epiphysis, although some uninfected animals presented evident bone sequestra at 3 weeks. MRI showed a lesion in the articular area that persisted for 3 weeks in infected animals. This lesion was smaller and less evident in the uninfected group. At 48 h postintervention, FDG-PET showed higher joint uptake in the infected group than in the uninfected group (P = 0.025). Over time, the difference between groups increased. These results indicate that FDG-PET imaging was much more sensitive than MRI and CT for differentiating between infection and inflammation at early stages. FDG-PET clearly distinguished between infection and postsurgical bone healing (in uninfected animals) from 48 h to 3 weeks after implantation. IMPORTANCE Our results encourage future investigations on the utility of the model for testing different therapeutic procedures for osteomyelitis.We thank Yolanda Sierra, Alexandra de Francisco, and María de la Jara Felipe, from the Imaging Laboratory for Small Animals of the Instituto de Investigación Sanitaria, Gregorio Marañón, for their excellent work with animal preparation and imaging protocols. Additionally, we thank Daniel Calle, from the Advanced Imaging Unit of CNIC, for his help in imaging postprocessing. This study was partially supported by the Instituto de Salud Carlos III (grants PI20/ 01632 and PT20/00044), cofunded by the European Regional Development Fund (ERDF), A way to make Europe. This work was also supported by the Diagnosis and Treatment Follow-up of Severe Staphylococcal Infections with Anti-Staphylococcal Antibodies and Immune-PET project of the Grant Fundación BBVA a Equipos de Investigación Científica 2018, by the Fundación Ramón Areces, and by Comunidad de Madrid (S2022/BMD-7403 RENIM-CM). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN), and the Pro CNIC Foundation, and it is a Severo Ochoa Center of Excellence (grant CEX2020-001041-S, funded by MICIN/AEI/10.13039/501100011033).S

Integrating magnetic capabilities to intracellular chips for cell trapping

Current microtechnologies have shown plenty of room inside a living cell for silicon chips. Microchips as barcodes, biochemical sensors, mechanical sensors and even electrical devices have been internalized into living cells without interfering their cell viability. However, these technologies lack from the ability to trap and preconcentrate cells in a specific region, which are prerequisites for cell separation, purification and posterior studies with enhanced sensitivity. Magnetic manipulation of microobjects, which allows a non-contacting method, has become an attractive and promising technique at small scales. Here, we show intracellular Ni-based chips with magnetic capabilities to allow cell enrichment. As a proof of concept of the potential to integrate multiple functionalities on a single device of this technique, we combine coding and magnetic manipulation capabilities in a single device. Devices were found to be internalized by HeLa cells without interfering in their viability. We demonstrated the tagging of a subpopulation of cells and their subsequent magnetic trapping with internalized barcodes subjected to a force up to 2.57 pN (for magnet-cells distance of 4.9 mm). The work opens the venue for future intracellular chips that integrate multiple functionalities with the magnetic manipulation of cells

Parasites of the reintroduced Iberian Lynx (Lynx pardinus) and Sympatric Mesocarnivores in Extremadura, Spain

Research Areas: MicrobiologyABSTRACT - The Iberian lynx (Lynx pardinus) is one of the most endangered felid species in the world. Conservation efforts have increased its population size and distribution and reinforced their genetic diversity through captive breeding and reintroduction programmes. Among several threats that the Iberian lynx faces, infectious and parasitic diseases have underlined effects on the health of their newly reintroduced populations, being essential to identify the primary sources of these agents and assess populations health status. To achieve this, 79 fresh faecal samples from Iberian lynx and sympatric mesocarnivores were collected in the reintroduction area of Extremadura, Spain. Samples were submitted to copromicroscopic analyses to assess parasite diversity, prevalence, and mean intensity of parasite burden. Overall, 19 (24.1%, ±15.1–35.0) samples were positive for at least one enteric parasite species. Parasite diversity and prevalence were higher in the Iberian lynx (43.8%) compared with the others mesocarnivores under study (e.g., the red fox Vulpes vulpes and the Egyptian mongoose Herpestes ichneumon). Ancylostomatidae and Toxocara cati were the most prevalent (15.6%) parasites. Obtained results revealed that Iberian lynx role as predator control might have reduced parasite cross-transmission between this felid and mesocarnivores due to their decreasing abundances. Surveillance programs must include regular monitoring of this endangered felid, comprising mesocarnivores, but also domestic/feral and wild cat communities.info:eu-repo/semantics/publishedVersio

Parasites of the Reintroduced Iberian Lynx (Lynx pardinus) and Sympatric Mesocarnivores in Extremadura, Spain.

The Iberian lynx (Lynx pardinus) is one of the most endangered felid species in the world. Conservation efforts have increased its population size and distribution and reinforced their genetic diversity through captive breeding and reintroduction programmes. Among several threats that the Iberian lynx faces, infectious and parasitic diseases have underlined effects on the health of their newly reintroduced populations, being essential to identify the primary sources of these agents and assess populations health status. To achieve this, 79 fresh faecal samples from Iberian lynx and sympatric mesocarnivores were collected in the reintroduction area of Extremadura, Spain. Samples were submitted to copromicroscopic analyses to assess parasite diversity, prevalence, and mean intensity of parasite burden. Overall, 19 (24.1%, ±15.1-35.0) samples were positive for at least one enteric parasite species. Parasite diversity and prevalence were higher in the Iberian lynx (43.8%) compared with the others mesocarnivores under study (e.g., the red fox Vulpes vulpes and the Egyptian mongoose Herpestes ichneumon). Ancylostomatidae and Toxocara cati were the most prevalent (15.6%) parasites. Obtained results revealed that Iberian lynx role as predator control might have reduced parasite cross-transmission between this felid and mesocarnivores due to their decreasing abundances. Surveillance programs must include regular monitoring of this endangered felid, comprising mesocarnivores, but also domestic/feral and wild cat communities.This research was funded by the European Union through its LIFE project Life + IBERLINCE (LIFE + 10NAT/ES/570) “Recuperación de la distribución histórica del lince ibérico (Lynx pardinus) en España y Portugal”. R. T. Torres is funded by national funds (OE), through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July. Thanks are due to FCT/MCTES for the financial support to CESAM (UIDP/50017/2020 + UIDB/50017/2020) and CIISA Project UIDB/00276/2020 through national funds.S

A survey of zoonotic pathogens carried by house mouse and black rat populations in Yucatan, Mexico

The house mouse (Mus musculus) and the black rat (Rattus rattus) are reservoir hosts for zoonotic pathogens, several of which cause neglected tropical diseases (NTDs). Studies of the prevalence of these NTD-causing zoonotic pathogens, in house mice and black rats from tropical residential areas are scarce. Three hundred and two house mice and 161 black rats were trapped in 2013 from two urban neighbourhoods and a rural village in Yucatan, Mexico, and subsequently tested for Trypanosoma cruzi, Hymenolepis diminuta and Leptospira interrogans. Using the polymerase chain reaction we detected T. cruzi DNA in the hearts of 4.9% (8/165) and 6.2% (7/113) of house mice and black rats, respectively. We applied the sedimentation technique to detect eggs of H. diminuta in 0.5% (1/182) and 14.2% (15/106) of house mice and black rats, respectively. Through the immunofluorescent imprint method, L. interrogans was identified in 0.9% (1/106) of rat kidney impressions. Our results suggest that the black rat could be an important reservoir for T. cruzi and H. diminuta in the studied sites. Further studies examining seasonal and geographical patterns could increase our knowledge on the epidemiology of these pathogens in Mexico and the risk to public health posed by rodents.Centro de Estudios Parasitológicos y de Vectore

Alteraciones morfológicas en el tracto respiratorio de ratas wistar inducidas por vapores de la raíz de hierba del zorrillo (Petiveria alliacea) del Suroeste de México = Morphologic Alterations in the Respiratory Tract of Wistar Rats Induced by Steams of the Root of Hierba del Zorrillo (Petiveria alliacea) from Southwest of Mexico

Petiveria alliacea, es conocida con diferentes nombres según el lugar donde se le encuentre. Estudios con hojas, tallo, raíz o extractos describen múltiples usos medicinales. Sin embargo, son pocos los que describen efectos tóxicos. En este estudio se evaluó el efecto morfológico de los vapores de la raíz de P. alliacea sobre el tracto respiratorio de ratas Wistar. Se emplearon 15 ratas divididas en 5 grupos (n=3): control absoluto, 0, 5, 15 y 30 minutos post-exposición (grupos I-V, respectivamente). Las ratas se sacrificaron y se colectaron muestras representativas del tracto respiratorio que posteriormente se procesaron por la técnica histológica convencional, hasta su inclusión en bloques de parafina. Los cortes histológicos se tiñeron con H-E, tricrómico de Masson y azul de toluidina. En tráquea, bronquiolos y pulmón de las ratas de los grupos I y II se observó una histología normal. En la tráquea de los grupos III, IV y V se identificaron áreas variables de hiperplasia en el epitelio, zonas desprovistas de cilios, signos de aumento en la secreción de las células caliciformes y áreas desprovistas de epitelio que se incrementaron con el tiempo. En la lámina propia se observó congestión vascular e infiltrado mononuclear que incrementó con el tiempo. En los bronquiolos de los grupos III y IV se observó activación de las células de Clara, áreas desprovistas de epitelio, y células mononucleares en la luz bronquiolar. En el grupo V se observaron características histológicas normales. En pulmón de los grupos III y IV se identificó engrosamiento de tabiques alveolares, incremento de las fibras de colágena, congestión y extravasación capilar, además de exudado intralveolar. En el grupo V se observó aparente reversión de algunas alteraciones morfológicas de los grupos previos, aunque otras alteraciones persisten. No se observaron diferencias en el número de las células cebadas

New host, geographical records, and factors affecting the prevalence of helminths infection from synanthropic rodents in Yucatán, Mexico

The aim of this paper was to study the occurrence of helminths in Mus musculus and Rattus rattus from urban, suburban and rural settlements in Yucatán, Mexico; and to analyse the host factors (e.g. sex) related to helminths' distribution. Helminths in a total of 279 rodents were surveyed by visual examination of the liver for metacestodes and faecal examination for helminth eggs using the formalin-ethyl acetate sedimentation technique. The cestodes Hydatigera taeniaeformis (metacestodes detected in the liver) and Hymenolepis diminuta, and the nematodes Aspiculuris sp., Nippostrongylus brasiliensis, Syphacia muris, Syphacia obvelata, and Trichuris muris were identified. In M. musculus, the prevalence of infection with T. muris and H. taeniaeformis was higher in the rural village compared to those in the suburban neighbourhood. For R. rattus, a higher prevalence of infection with H. diminuta was found in the urban site compared to that in the suburban site. This study reports the occurrence of H. diminuta among rodents living in close proximity to humans, representing a potential public health risk. In addition, this survey increases our understanding of dynamic transmission among intestinal helminths recorded in Yucatán, Mexico.Centro de Estudios Parasitológicos y de Vectore

Population Characteristics of Rattus rattus and Mus musculus present in rural communities in Yucatán, México

The aim of this study was to describe the abundance, weight and body length structures, and reproductive and health status of the black rat Rattus rattus and the house mouse Mus musculus from Yucatán, México. Rodents were trapped from May to September 2016 in rural households in the communities Xkalakdzonot (XKA) and Paraíso (PAR). A total of 236 M. musculus and 127 R. rattus were trapped over 3880 trap-nights. In XKA, R. rattus was more abundant than M. musculus, whereas in PAR, M. musculus was notably dominant over R. rattus. The sex ratio was 1:1 in both rodent species. Rattus rattus in classes 40.1?80 g and 120?139 mm were more abundant, whereas M. musculus in classes 8.1?12 g and 70?79 mm were more abundant. Mus musculus had similar weight, body length and reproductive and health parameters between communities. The majority of specimens of trapped rodents had a good body condition and few individuals had wounds. The information generated in this study is basic for understanding the ecology of commensal rodents, the dynamics of rodent-associated zoonosis transmission, and to design of integrated control programs for rodents.Fil: Panti May, Jesús Alonso. Universidad Autonoma de Yucatan; MéxicoFil: Gurubel González, Yessica M.. Universidad Autonoma de Yucatan; MéxicoFil: Palomo Arjona, Eduardo E.. Universidad Autonoma de Yucatan; MéxicoFil: Cetina Trejo, Rosy C.. Universidad Autonoma de Yucatan; MéxicoFil: Machain Williams, Carlos. Universidad Autonoma de Yucatan; MéxicoFil: Robles, Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Hernández Betancourt, Silvia F.. Universidad Autonoma de Yucatan; Méxic