Bacterial Strains Isolated from Stingless Bee Workers Inhibit the Growth of Apis mellifera Pathogens.

Apis mellifera bees are an important resource for the local economy of various regions in Argentina and the maintenance of natural ecosystems. In recent years, different alternatives have been investigated to avoid the reduction or loss of colonies caused by pathogens and parasites such as Ascosphaera apis, Aspergillus flavus, and Paenibacillus larvae. We focused on bacterial strains isolated from the intestine of native stingless bees, to elucidate their antagonistic effect on diseases of A. mellifera colonies. For this purpose, worker bees of the species Tetragonisca fiebrigi, Plebeia spp., and Scaptotrigona jujuyensis were captured from the entrance to tree hives and transported to the laboratory, where their intestines were extracted. Twenty bacterial colonies were isolated from the intestines, and those capable of inhibiting enterobacteria in vitro and producing organic acids, proteases, and chitinases were selected. Four genera, Levilactobacillus, Acetobacter, Lactiplantibacillus, and Pantoea, were selected and identified by the molecular marker that codes for the 16S rRNA gene. For inhibition assays, cell suspensions and cell-free suspensions were performed. All treatments showed significant antibacterial effects, in comparison with the controls, against P. larvae and antifungal effects against A. apis and A. flavus. However, the mechanisms by which these bacteria inhibit the growth of these pathogens were not studied.

Fungal microbiota isolated from native stingless bee species inhibited pathogens of Apis mellifera.

Social bees can establish interactions with microorganisms to keep their colonies free of pathogens and parasites by developing different protection strategies. We explored the fungal microbiota isolated from three species of stingless bees, Tetragonisca fiebrigi, Plebeias sp., and Scaptotrigona jujuyensis, and its potential ability to suppress pathogenic microorganisms of A. mellifera, namely Paenibacillus larvae, Ascosphaera apis and Aspergillus flavus, which were tested and evaluated. Six filamentous fungal strains, Trametes hirsuta, Alternaria alternata, Curvularia spicifera, Skeletocutis sp., Alternaria tenuissima, Monascus spp., as well as the yeast Wickerhamomyces anomalus, were selected for trials and isolated from the heads of foraging bees. The fungal strains were identified by macroscopic and microscopic taxonomic characteristics and by sequencing of the ITS1-5.8S-ITS2 region of ribosomal DNA. All fungal strains inhibited these pathogens of A. mellifera. We also evaluated the effect of the secondary metabolites extracted with and without ethanol. Both metabolites showed antimicrobial properties, and our results suggest that fungi isolated from stingless bees produce bioactive compounds with antibacterial and antifungal effects that could be used to treat Apis mellifera colony diseases and maintain colony health.

Low-cost homemade cocktails for enzymatic conversion of sugarcane and cassava bagasses.

The agricultural industries generate lignocellulosic wastes that can be modified by fungi to generate high value-added products. This work aimed to analyze the efficiency and the cost-effectiveness of the bioconversion of sugarcane and cassava bagasses using low-cost homemade enzymatic cocktails from Aspergillus niger LBM 134. Both bagasses were pretreated with a soft alkaline solution without any loss of polysaccharides. After the hydrolysis, a 28% of conversion to glucose and 42% to xylose were reached in the hydrolysis of sugarcane bagasse while an 80% of saccharification yield, in the hydrolysis of cassava bagasse using the homemade enzymes. Furthermore, a more disorganised surface and no starch granules were observed in the sugarcane and cassava bagasses, respectively. The bioethanol yield from sugarcane and casava bagasses was predicted to be 4.16 mg mL-1 and 2.57 mg mL-1, respectively. A comparison of the cost of the homemade and the commercial enzymes was carried out. Similar hydrolysis percentages were achieved employing any enzyme; however, it was 1000-2000 times less expensive using the homemade cocktails than using the commercial enzymes. Therefore, the cost of obtaining glucose from bagasses was most expensive when applying the commercial enzymes. Moreover, the hydrolysis of the cassava bagasse was most efficient with the homemade cocktails. The importance and novelty of this work lie in the similar performance and the lower cost of the homemade cocktails from the fungus A. niger LBM 134 compared with the commercial enzymes on the hydrolysis of the sugarcane and cassava bagasses.

Mapeando en tiempos de la COVID-19 / Mapping out in COVID-19 times

Introducción y objetivos: La COVID-19 hace evidente la urgencia de crear un sistema equitativo en el acceso a la salud. Así, se decide realizar un enfoque salutogénico basado en los activos para la salud. Para ello, se pretende identificar los principales problemas de salud de nuestra comunidad y conocer los recursos comunitarios disponibles, con el fin de establecer alianzas y proyectos futuros de colaboración. Métodos: Inicialmente, el Grupo Promotor (GP) hace el diagnóstico de salud y delimita el área de intervención. Una vez ubicados los activos por internet, se representan en el mapa. Se elige la entrevista individual como técnica de recogida de información. Cuando la situación epidemiológica lo permite, se organiza una reunión con los representantes de los recursos comunitarios, donde se analizan los resultados y se identifican los problemas más emergentes. Resultados: A lo largo de 7 meses, se hicieron 16 entrevistas con distintos representantes sociales de la comunidad Los principales problemas encontrados fueron desempleo, migración, prostitución, adicción y suicidio. La mayoría de las actividades comunitarias se han visto interrumpidas durante el confinamiento por la COVID-19, aunque han surgido nuevas iniciativas. Conclusión/discusión: El mapeo de recursos comunitarios y diagnóstico en salud aporta una visión real de la comunidad. Además, implica a sus representantes, profesionales y ciudadanía en la búsqueda de soluciones, desarrollando mejores condiciones de vida. (AU)

Introduction and objectives. COVID-19 reveals the urgency of creating an equitable system in access to healthcare. Thus, it has been decided to perform a salutogenic approach based on health assets. For that to be accomplished, it is intended to identify our community’s main health problems and to ascertain the available community resources to establish alliances and future collaboration projects. Methodology. Initially, the Promoter Group (PG) performs the health diagnosis and defines the area of intervention. Once the assets are found on the internet, they are placed on the map. The data collection technique chosen was the individual interview. When the epidemiological situation enables this, a meeting is organized with the representatives of the community resources, where the results are analyzed and the most emerging problems are identified. Results. Over seven months, 16 interviews were held with different social representatives of the community. The fundamental problems detected were unemployment, migration, prostitution, addiction and suicide. Most community activities were interrupted during the COVID-19 lockdown, although new initiatives have arisen. Conclusion/Discussion. Asset mapping and diagnosis in health provides an actual vision of the Community. Furthermore, it involves its representatives, professionals and citizens in the search for solutions, providing a better quality of life. (AU)

Sexual expression involving people with dementia living in long-term care facilities: Staff's reactions.

This study aims to explore and compare the reaction of long-term care staff towards situations of sexual intercourse in which one or both partners have dementia. Participants were 538 staff members at 28 Portuguese long-term care facilities. Data were collected using a printed questionnaire with seven vignettes with situations related to the sexuality of LTCF residents. In this study, three of these vignettes were analysed with situations in which residents were having relationships in their bedrooms: (1) one male resident and one female resident; (2) two residents with dementia; (3) two residents, one of them with dementia. For each of the vignettes, participants are asked what they think their 'colleagues' would do in each vignette, i.e. 'What do you think most of your colleagues would do?' The results revealed that when sexual relationships involved both partners living with dementia, the most selected reaction was 'Comment on what happened with supervision or direction', which may suggest that the situation was perceived as difficult or problematic. The most restrictive reactions were most often chosen when only one partner had dementia. This study suggests the need to improve and provide training, so that staff have knowledge and strategies that allow people living with dementia to preserve their sexual rights in long-term care facilities.

Exploring Agaricomycetes from the Paranaense rainforest (Misiones, Argentina) as an unconventional source of fibrinolytic enzymes.

Fungal fibrinolytic enzymes, secreted by some Agaricomycetes, are recognized as important thrombolytic agents due to their ability to rapidly dissolve thromboembolic clots. The present work evaluated fibrinolytic and proteolytic secretion abilities of 35 Agaricomycetes isolates from the Paranaense rainforest (Misiones, Argentina). We detected proteolytic activity in 40% of the strains while nine strains showed fibrinolytic activity. Schizophyllum commune LBM 026, Schizophyllum commune LBM 223, and Hornodermoporus martius LBM 224 exhibited the highest levels of fibrinolytic activity. Fibrin zymography from S. commune LBM 026 and LBM 223 showed an enzyme of 27.5 kDa, while H. martius LBM 224 presented an enzyme of 29 kDa. The evaluation of the enzymatic stability of culture supernatant of these strains revealed that the fibrinolytic activity was highly stable over a wide temperature and pH range. Long-term stability of fibrinolytic activity at physiological conditions evidenced that the strains had a half-life of at least 72 h. Fibrinolytic enzymes produced by S. commune LBM 026 and LBM 223 were inhibited in the presence of EDTA indicating that they are metalloproteases. This work reveals the potential of S. commune LBM 026, S. commune LBM 223, and H. martius LBM 224 as an unconventional source of thrombolytic agents.

Aspergillus niger LBM 134 isolated from rotten wood and its potential cellulolytic ability.

Aspergillus is a genus of filamentous and cosmopolitan fungi that includes important species for medical mycology, food, basic research and agro-industry areas. Aspergillus section Nigri are efficient producers of hydrolytic enzymes such as cellulases that are employed in the cellulose conversion. Hence, the search of new cellulolytic isolates and their correct identification is important for carrying out safe biotechnological processes. This study aimed to characterise the cellulolytic potential of Aspergillus sp. LBM 134, isolated from the Paranaense rainforest (Argentina) and to identify the isolate through a polyphasic approach. The fungus was identified as Aspergillus niger and its cellulolytic potential was evaluated by using Congo red technique and fluorescence plate assays for carboxymethyl cellulase, ß-glucosidase and cellobiohydrolase, respectively. All three cellulase activities were positive; this bio-prospective positioned A. niger LBM 134 as a promising alternative for industries that require organisms capable of carrying out cellulosic biomass processing.

Proteomic insight on the polychlorinated biphenyl degrading mechanism of Pleurotus pulmonarius LBM 105.

White-rot fungi are well known bioremediation agents capable of removing recalcitrant xenobiotics. However, the molecular mechanism involved in this process is not well understood. The aim of the present study was to compare the proteomic profiles of Pleurotus pulmonarius LBM 105 in presence and absence of a mixture of polychlorinated biphenyls. Cultures of the fungus were spiked with a mixture of Aroclors and cultivated for 28 days. This strain achieved a peak of PCBs-removal of 65.50 ± 8.09% after 21 days. The ecotoxicological assays showed a toxicity reduction of 46.47%. Based on these findings, a proteomic study was carried out and it was proven that the oxidative metabolism was highly affected. Two proteins that have a function at the transcriptional level and related to the oxidative metabolism, the glyceraldehyde-3-phosphate dehydrogenase and the basal transcription factor 3, presented an increase in their quantity in PCBs presence. Several oxidases and reductases were highly induced, presenting the short chain reductases, aldo/keto reductases, laccases and versatile peroxidases as the enzymes with the most notorious changes. These results indicate a complex response of the fungal metabolism towards these pollutants, which includes a transcriptional response to the oxidative stress and a modification of the intra- and extra-cellular enzymatic profile.

Evaluation of bioremediation strategies for treating recalcitrant halo-organic pollutants in soil environments.

The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyls (PCBs) in soil, mimicking three strategies: (a) mycoaugmentation: by the addition of Trametes sanguinea and Pleurotus sajor-caju co-cultures immobilized on sugarcane bagasse; (b) biostimulation: by supplementation of sugarcane bagasse; and (c) natural attenuation: no amendments. The experiments were done in microcosms using Ultisol soil. Remediation effectiveness was assessed based on pollutants content, soil characteristics, and ecotoxicological tests. Biostimulation and mycoaugmentation demonstrated the highest PCBs-removal (approx. 90%) with a significant toxicity reduction at 90 d. The studied strains were able to survive during the incubation period in non-sterilized soil. Laccase, manganese-peroxidase and endoxylanase activities increased significantly in co-cultures after 60 d. Sugarcane bagasse demonstrated to be not only a suitable support for fungal immobilization but also an efficient substrate for fungal colonization of PCBs-contaminated soils. Mycoaugmentation and biostimulation with sugarcane bagasse improved oxidable organic matter and phosphorous contents as well as dehydrogenase activity in soil. Therefore, biostimulation with sugarcane bagasse and mycoaugmentation applying dual white-rot fungal cultures constitute two efficient bioremediation alternatives to restore PCBs-contaminated soils.

Secretomic analysis of cheap enzymatic cocktails of Aspergillus niger LBM 134 grown on cassava bagasse and sugarcane bagasse.

Currently, agroindustrial wastes are little used for generating value-added products; hence, their use of these waste to produce enzymatic cocktails for the conversion of lignocellulosic biomass to fermentable sugars is a very interesting alternative in the second-generation bioethanol process. The Ascomycota fungus Aspergillus niger LBM 134 produces hydrolytic enzymes in large proportions. In this work, A. niger LBM 134 was grown on sugarcane and cassava bagasses under optimized conditions. To identify the extracellular enzymes involved in the degradation of these agroindustrial wastes, the secretomes of the culture supernatants of the fungus were analyzed and validated by biochemical assays of the enzymatic activities. A. niger LBM 134 secreted higher quantities of xylanases and accessory hemicellulases when it grew on sugarcane bagasse, whereas more cellulases, amylases, and pectinases were secreted when it grew on cassava bagasse. These findings suggest two promising enzyme cocktails for the hydrolysis of lignocellulose carbohydrate polymers to fermentable sugars. These bioinformatic analysis were functional validates through enzymatic biochemical assays that confirm the biotechnological potential of A. niger LBM 134 for the bioconversion of hemicellulosic substrates such as sugarcane and cassava bagasses.

Assessing the ability of white-rot fungi to tolerate polychlorinated biphenyls using predictive mycology.

The aim of the present study was to assess the ability of different white-rot fungi to tolerate polychlorinated biphenyls (PCBs) using predictive mycology, by relating fungal growth inhibition to ligninolityc enzyme secretion. Fungal strains were grown in the presence of PCBs in solid media and their radial growth values were modelled through the Dantigny-logistic like function in order to estimate the time required by the fungal colonies to attain half their maximum diameter. The principal component analysis (PCA) revealed an inverse correlation between strain tolerance to PCBs and the laccase secretion over time, being laccase production closely associated with fungal growth capacity. Finally, a PCA was run to regroup and split between resistant and sensitive fungi. Simultaneously, a function associated with a model predicting the tolerance to PCBs was developed. Some of the assayed isolates showed a promising capacity to be applied in PCB bioremediation. Abbreviations: Polychlorinated biphenyls (PCBs), white-rot fungi (WRF).

Preliminary studies of new strains of Trametes sp. from Argentina for laccase production ability

Abstract Oxidative enzymes secreted by white rot fungi can be applied in several technological processes within the paper industry, biofuel production and bioremediation. The discovery of native strains from the biodiverse Misiones (Argentina) forest can provide useful enzymes for biotechnological purposes. In this work, we evaluated the laccase and manganese peroxidase secretion abilities of four newly discovered strains of Trametes sp. that are native to Misiones. In addition, the copper response and optimal pH and temperature for laccase activity in culture supernatants were determined.The selected strains produced variable amounts of laccase and MnP; when Cu2+ was added, both enzymes were significantly increased. Zymograms showed that two isoenzymes were increased in all strains in the presence of Cu2+. Strain B showed the greatest response to Cu2+ addition, whereas strain A was more stable at the optimal temperature and pH. Strain A showed interesting potential for future biotechnological approaches due to the superior thermo-stability of its secreted enzymes.

Preliminary studies of new strains of Trametes sp. from Argentina for laccase production ability.

Oxidative enzymes secreted by white rot fungi can be applied in several technological processes within the paper industry, biofuel production and bioremediation. The discovery of native strains from the biodiverse Misiones (Argentina) forest can provide useful enzymes for biotechnological purposes. In this work, we evaluated the laccase and manganese peroxidase secretion abilities of four newly discovered strains of Trametes sp. that are native to Misiones. In addition, the copper response and optimal pH and temperature for laccase activity in culture supernatants were determined. The selected strains produced variable amounts of laccase and MnP; when Cu(2+) was added, both enzymes were significantly increased. Zymograms showed that two isoenzymes were increased in all strains in the presence of Cu(2+). Strain B showed the greatest response to Cu(2+) addition, whereas strain A was more stable at the optimal temperature and pH. Strain A showed interesting potential for future biotechnological approaches due to the superior thermo-stability of its secreted enzymes.

Characterizatio of the oxidative enzyme potental in wild white rot fungi fromm the subtropical forest of misiones (Argentina) / Caracterización del potencial enzimático oxidativo de cepas nativas de hongos de pudrición blanca de la selva subtropical de Misiones (Argentina)

This research aimed to evaluate the potential of several native white rot fungi (WRF) isolated from subtropical environments of Misiones (Argentina) to produce different ligninolytic enzymes. Coriolus versicolor f. antarcticus BAFC 266, Pycnoporus sanguineus BAFC 2126 and Phlebia brevispora BAFC 633 showed the highest phenoloxidase activity. Ganoderma applanatum strain E, P. sanguineus BAFC 2126 and P. brevispora BAFC 633 revealed marked laccase and peroxidase activity. C. versicolor f. antarcticus, G. applanatum (strain A) and Trametes villosa, gave high positive reactions with 2,6-dimethoxyphenol oxidation at the lowest tested pH. C. versicolor f. antarcticus, G. applanatum strains D and F, T. elegans BAFC 2127and T. villosa, showed the highest manganese peroxidase activity. C. versicolor f. antarcticus also produced the highest lignin peroxidase activity. Tyrosinase activity was mostly evident in G. applanatum strains (D and F) and Phanerochaete chrysosporium HHB 11741. Kraft liquor decolorization results were variable and depended on the fungus and the liquor concentration. Some fungi with moderate ligninolytic activity showed high decolorization rates (e.g. Pleurotus sajor-caju and Steccherinium sp. BAFC 1171) indicating the significance of additional approach to evaluate a potential biotechnological application.

El objetivo de este trabajo fue evaluar el potencial para producir enzimas ligninolíticas de diversas cepas de hongos de pudrición blanca, nativas de la Provincia de Misiones (Argentina). Coriolus versicolor v. antarcticus BAFC 266, Pycnoporus sanguineus BAFC 2126 y Phlebia brevispora BAFC 633 mostraron un gran potencial para producir fenoloxidasas. En Ganoderma applanatum cepa E, P. sanguineus BAFC 2126 y P. brevispora BAFC 633 se observó una marcada actividad lacasa y peroxidasa. C. versicolor v. antarcticus. G. applanatum (cepa A) y Trametes villosa, mostraron una reacción oxidativa altamente positiva sobre 2,6-dimetoxifenol a pH 4. C. versicolor v. antarcticus, G. applanatum (cepas D y F), T. elegans BAFC 2127 y T. villosa, mostraron una alta actividad manganeso peroxidasa y solo C. versicolor v. antarcticus mostró una alta actividad de lignino peroxidasa. La actividad tirosinasa fue evidente en las cepas D y F de G. applanatum y en Phanerochaete chrysosporium HHB 11741. La decoloración del licor negro Kraft reveló una actividad ligninolítica variable para las diferentes cepas estudiadas dependiendo de la concentración utilizada. Algunos hongos mostraron una moderada actividad ligninolítica con grandes halos de decoloración (p.e. Pleurotus sajor-caju y Steccherinium sp. BAFC 1171) indicando un significativo potencial para el aprovechamiento biotecnológico de estas cepas.

Effect of chemical and metallic compounds on biomass, mRNA levels and laccase activity of Phlebia brevispora BAFC 633.

Nine aromatic compounds (caffeic acid, syringaldehyde, vanillic acid, guaiacol, vanillin, sinapic acid, syringol, syringic acid and ferulic acid) and four metallic compounds (CuSO4, AgNO3, MnSO4, and CaCl2) were tested for their ability to increase laccase (Lac) activity in the ligninolytic basidiomycete Phlebia brevispora BAFC 633. The addition of syringaldehyde, syringol, guaiacol, sinapic acid, vanillin, ferulic acid and CuSO4 showed a positive effect on fungal growth; however, it decreased dramatically with the addition of AgNO3 and did not undergo changes in the presence of CaCl2 or MnSO4. Lac activity increased with the addition of all the compounds tested, depending on the concentration and the day of culture. P. brevispora BAFC 633 produced two isoenzymes, a constitutively expressed of 60 kDa and another of 75 kDa expressed upon induction by sinapic acid, MnSO4 or CuSO4. Lac secretion capacity of P. brevispora BAFC 633 can be increased 27 times higher than the control with the highest levels detected in the presence of 0.3 mM CuSO4 at day 14. The action is affected at pre-transcriptional level regulating at the onset of the process, however it does not rule out the effect at the post-transcriptional and post-translational levels, for which is necessary to deepen in the knowledge of all possible regulation points of gene expression.

Dissemination of information on visceral leishmaniasis from schoolchildren to their families: a sustainable model for controlling the disease.

A model for the dissemination of information on visceral leishmaniasis from schoolchildren to their families was evaluated in two schools in Caeté, Minas Gerais State, Brazil. Age ranged from 9 to 17 years in the two schools, one receiving the intervention (with 92 students) and the other serving as the control (96 students). All the students attended a class and received a pamphlet on visceral leishmaniasis. The intervention consisted of a homework assignment in which the student discussed the class content and pamphlet with a family member. Knowledge by family members (n = 100) on visceral leishmaniasis was evaluated with a pre and post-intervention questionnaire applied by a health agent, who also completed a form on hygiene around the household as observed during the home visit. A significant improvement was observed in knowledge and hygiene (e.g., sweeping of leaves, fruit, and branches from the yards) among the families that were exposed to the intervention (p < 0.05). The spread of information on visceral leishmaniasis by schoolchildren can contribute to measures for preventing the disease.

Dissemination of information on visceral leishmaniasis from schoolchildren to their families: a sustainable model for controlling the disease / Informação sobre leishmaniose visceral por escolares aos seus familiares: uma abordagem sustentável para o controle da doença

A model for the dissemination of information on visceral leishmaniasis from schoolchildren to their families was evaluated in two schools in Caeté, Minas Gerais State, Brazil. Age ranged from 9 to 17 years in the two schools, one receiving the intervention (with 92 students) and the other serving as the control (96 students). All the students attended a class and received a pamphlet on visceral leishmaniasis. The intervention consisted of a homework assignment in which the student discussed the class content and pamphlet with a family member. Knowledge by family members (n = 100) on visceral leishmaniasis was evaluated with a pre and post-intervention questionnaire applied by a health agent, who also completed a form on hygiene around the household as observed during the home visit. A significant improvement was observed in knowledge and hygiene (e.g., sweeping of leaves, fruit, and branches from the yards) among the families that were exposed to the intervention (p < 0.05). The spread of information on visceral leishmaniasis by schoolchildren can contribute to measures for preventing the disease.

Modelo de disseminação da informação sobre a leishmaniose visceral por escolares aos seus familiares foi avaliado em duas escolas no Município de Caeté, Minas Gerais, Brasil. Em ambas as escolas, intervenção (92 alunos) e controle (96 alunos), as idades dos alunos variaram de 9 a 17 anos. Todos assistiram a uma aula e receberam um panfleto sobre a doença. A intervenção consistiu de uma tarefa de casa, na qual o aluno discutia com o familiar o conteúdo da aula e do folheto. O conhecimento dos familiares (n = 100) sobre a leishmaniose visceral foi avaliado por meio de questionário antes e após a intervenção, aplicado por um agente de saúde, que também preenchia um formulário sobre as condições de limpeza no peridomicílio, no momento da visita. Observou-se melhora significativa do conhecimento sobre a enfermidade e da limpeza relacionada à retirada de folhas entre as famílias que receberam a intervenção (p < 0,05). A disseminação da informação sobre a leishmaniose visceral por escolares pode contribuir para as ações de prevenção da doença.

Absence of C1q leads to less neuropathology in transgenic mouse models of Alzheimer's disease.

C1q, the recognition component of the classical complement activation pathway, is a multifunctional protein known to be expressed in brain of Alzheimer's disease (AD) patients. To experimentally address the role of C1q in AD, a mouse model lacking C1q (APPQ-/-) was generated by crossing Tg2576 animals (APP) with C1q-deficient mice. The pathology of APPQ-/- was compared with that of APP mice and B6SJL controls at 3-16 months of age by immunohistochemistry and Western blot analysis. At younger ages (3-6 months), when no plaque pathology was present, no significant differences were seen in any of the neuronal or glial markers tested. At older ages (9-16 months), the APP and APPQ-/- mice developed comparable total amyloid and fibrillar beta-amyloid in frontal cortex and hippocampus; however, the level of activated glia surrounding the plaques was significantly lower in the APPQ-/- mice at 12 and 16 months. In addition, although Tg2576 mice showed a progressive decrease in synaptophysin and MAP2 in the CA3 area of hippocampus compared with control B6SJL at 9, 12, and 16 months, the APPQ-/- mice had significantly less of a decrease in these markers at 12 and 16 months. In a second murine model for AD containing transgenes for both APP and mutant presenilin 1 (APP/PS1), a similar reduction of pathology was seen in the APPPS1Q-/- mice. These data suggest that at ages when the fibrillar plaque pathology is present, C1q exerts a detrimental effect on neuronal integrity, most likely through the activation of the classical complement cascade and the enhancement of inflammation.