Dispersion of sneeze droplets in a meat facility indoor environment - Without partitions.

Spreading patterns of the coronavirus disease (COVID-19) showed that infected and asymptotic carriers both played critical role in escalating transmission of virus leading to global pandemic. Indoor environments of restaurants, classrooms, hospitals, offices, large assemblies, and industrial installations are susceptible to virus outbreak. Industrial facilities such as fabrication rooms of meat processing plants, which are laden with moisture and fat in indoor air are the most sensitive spaces. Fabrication room workers standing next to each other are exposed to the risk of long-range viral droplets transmission within the facility. An asymptomatic carrier may transmit the virus unintentionally to fellow workers through sporadic sneezing leading to community spread. A novel Computational Fluid Dynamics (CFD) model of a fabrication room with typical interior (stationary objects) was prepared and investigated. Study was conducted to identify indoor airflow patterns, droplets spreading patterns, leading droplets removal mechanism, locations causing maximum spread of droplets, and infection index for workers along with stationary objects in reference to seven sneeze locations covering the entire room. The role of condensers, exhaust fans and leakage of indoor air through large and small openings to other rooms was investigated. This comprehensive study presents flow scenarios in the facility and helps identify locations that are potentially at lower or higher risk for exposure to COVID-19. The results presented in this study are suitable for future engineering analyses aimed at redesigning public spaces and common areas to minimize the spread of aerosols and droplets that may contain pathogens.

Integration of biophysical photosynthetic parameters into one photochemical index for early detection of Tobacco Mosaic Virus infection in pepper plants.

Photosynthesis in host plants is significantly reduced by many virus families. The early detection of viral infection before the onset of visual symptoms in both directly and systemically infected leaves is critical in crop protection. Viral pathogens cause a variety of symptoms through modifications of chloroplast structure and function and the response of the photochemistry process is immediate. Therefore, chlorophyll fluorescence monitoring has been extensively investigated the last two decades as a tool for timely assessment of pathogenic threats. Alternatively, the analysis of Chla fluorescence transients offers several interlinked parameters which describe the fate of excitation energy round and through the photosystems. Additionally, OJIP fluorescence transients and leaf reflectance spectra methodologies serve for rapid screening of large number of samples. The objective of the present study was to achieve early detection of viral infection, integrating the multiparametric information of the Chla fluorescence transients and of the leaf reflectance spectra into one photochemical performance index. Infection decreased the maximum quantum yield of PSII (FV/FM), the effective quantum yield of PSII (ΦPSII), the CO2 assimilation rate (A) and the stomatal conductance (gs) in the studied TMV-pepper plant pathosystem, while non-photochemical quenching (NPQ) increased. Some parameters from the OJIP transients and the leaf reflectance spectra were significantly affected 24 h after infection, while others modified three to five days later. Similar results were obtained from systemically infected leaves but with one to three days hysteresis compared to inoculated leaves. Differences between healthy and infected leaves were marginal during the first 24 h post infection. The Integrated Biomarker Response tool was used to create a photochemical infection index (PINFI) which integrates the partial effects of infection on each fluorescence and reflectance index. The PINFI, which to the best of our knowledge is the first photochemical infection index created by the IBR method, discriminated reliably between the infected and healthy leaves of pepper plants from the first 24 h after infection with the TMV.

Apigenin effect against Leishmania tropica amastigotes in vitro.

Cutaneous Leishmaniasis is a current public health problem in Syria. It causes different skin lesions that vary in their severity from spontaneously heal lesions to permanent deformity ones. However, the used treatments have many disadvantages as their high toxicity and many side effects. Flavonoids including Apigenin reported to have many anti parasitic properties. As well as their preference as potential therapeutic alternatives in the treatment of Leishmaniasis due to its low side effects and toxicity. This study aims to evaluate the efficacy of Apigenin against L.tropica amastigotes in vitro using Leishmania-Macrophage Interaction Assay. Our study demonstrated the possibility of efficacy of Apigenin against L.tropica amastigotes since Apigenin reduced the infection index at IC50 60.44 µM and this requires subsequent studies in humans and using Apigenin as a candidate for the chemotherapeutic treatment against Leishmaniasis.

[Diagnosis value of serum infection index for early infection of patients undergoing posterior cervical expansive open-door laminoplasty].

OBJECTIVE: To investigate the diagnosis value of white blood cell (WBC) count, C-reactive protein (CRP), serum procalcitonin (PCT) and erythrocyte sedimentation rate (ESR) levels for early infection after posterior cervical expansive open-door laminoplasty. Discover, prevent, and treat postoperative infections promptly. METHODS: The clinical data of 120 patients with early fever after posterior cervical laminoplasty from January 2010 to April 2019 were retrospectively analyzed. According to the results of bacteriological culture of wound exudate, the patients were divided into infected group(53 cases) and non-infected group(67 cases). In infection group, there were 32 males and 21 females, aged from 48 to 63 years old, with an average of(52.28±6.36) years. In non-infected group, there were 37 males and 30 females, aged from 46 to 62 years old, with an average of(51.63±5.82) years. According to the postoperative infection types, the patients in infection group were divided into 30 cases of deep surgical site infection group and 23 cases of superficial surgical site infection group. In deep surgical site infection group, there were 19 males and 11 females, aged from 50 to 63 years old with an average of (53.16±5.62) years. In superficial surgical site infection group, there were 13 males and 10 females, aged from 48 to 61 years old with an average of (52.15±5.68) years. WBC count, CRP, PCT and ESR serum infection indexes were compared between groups and within groups before and after surgery. The serum infective index data of 120 patients were collected and the sensitivity and specificity of the serum infectious index were used to diagnose the infection. Accuracy assessment of early infection diagnosis of WBC count, CRP, PCT and ESR serum infection indexes by plotting the receiver operating characteristic(ROC) curve with 1-specificity as the abscissa and sensitivity as the ordinate. RESULTS: There were no significant difference in WBC count, CRP, PCT and ESR serum infection indexes between infected group and non-infected group before operation(P>0.05). Postoperative WBC count, CRP, PCT and ESR infection indexes in infection group were higher than in non-infected group(P<0.05). Among patients with postoperative infection, WBC count, CRP, PCT and ESR serum infection index levels were significantly different in the different postoperative infection types (P<0.05). In non-infected group, WBC count, CRP, PCT and ESR serum infection indexes showed an overall trend of rising first and then falling. The area under curve (AUC) of WBC count infection index was 0.637(P<0.05). The AUC of CRP infection index was 0.792 (P<0.05). The AUC of PCT infection index was 0.774 (P<0.05). The AUC of ESR infection index was 0.783(P<0.05). CONCLUSIONS: WBC count, CRP, PCT and ESR serum infection indexes can be used for the diagnosis of early infection after posterior cervical expansive open-door laminoplasty. In addition, the comprehensive analysis of the changes of the four infection indexes can be used for the identification of different postoperative infection types. WBC count index is less accurate for early infection diagnosis, and CRP, PCT, and ESR indexes are more accurate for early infection diagnosis. In general, CRP, PCT and ESR serum infection indexes have important clinical significance for the diagnosis of early infection after posterior cervical open-door laminoplasty, which helps clinicians to detect early postoperative infection as early as possible to facilitate subsequent treatment.

CD100/Sema4D Increases Macrophage Infection by Leishmania (Leishmania) amazonensis in a CD72 Dependent Manner.

Leishmaniasis is caused by trypanosomatid protozoa of the genus Leishmania, which infect preferentially macrophages. The disease affects 12 million people worldwide, who may present cutaneous, mucocutaneous or visceral forms. Several factors influence the form and severity of the disease, and the main ones are the Leishmania species and the host immune response. CD100 is a membrane bound protein that can also be shed. It was first identified in T lymphocytes and latter shown to be induced in macrophages by inflammatory stimuli. The soluble CD100 (sCD100) reduces migration and expression of inflammatory cytokines in human monocytes and dendritic cells, as well as the intake of oxidized low-density lipoprotein (oxLDL) by human macrophages. Considering the importance of macrophages in Leishmania infection and the potential role of sCD100 in the modulation of macrophage phagocytosis and activation, we analyzed the expression and distribution of CD100 in murine macrophages and the effects of sCD100 on macrophage infection by Leishmania (Leishmania) amazonensis. Here we show that CD100 expression in murine macrophages increases after infection with Leishmania. sCD100 augments infection and phagocytosis of Leishmania (L.) amazonensis promastigotes by macrophages, an effect dependent on macrophage CD72 receptor. Besides, sCD100 enhances phagocytosis of zymosan particles and infection by Trypanosoma cruzi.

Infectivity of Chordodes nobilii larvae (Gordiida: Nematomorpha) / Infectividad de las larvas de Chordodes nobilii (Gordiida: Nematomorpha)

AbstractThe gordiids are freshwater representatives of the parasite phylum Nematomorpha that function as a link between aquatic and terrestrial ecosystems. In recent years, different ecotoxicologic studies have been made with the South-American gordiid species, Chordodes nobilii, that have demonstrated the capacity of this group to act as a bioindicator of contamination. Despite the Gordiida's ecologic relevance, further studies are still needed to elucidate different aspects of the biology of the class, and among those, the infective capacity, a parameter that can be evaluated by the infection index mean abundance (IIMA). A knowledge of the intrinsic variability in the infective capacity of C. nobilii would warrant priority in order to establish, the range of acceptable responses for normal or standard conditions in the laboratory, and, to compare the criteria among different assays. The objective of this study was to establish a baseline value for the infective capacity for C. nobilii larvae, under controlled laboratory conditions, by employing the IIMA as the evaluation parameter. To that end, we analyzed the infective capacity of C. nobilii larvae that had hatched from different strings of eggs laid in the laboratory by a total of 12 females. The C. nobilii adults were collected from streams within the Argentina Sauce Grande basin, between 2006 and 2009. Once in the laboratory, after mating, the females were placed in individual containers for oviposition. The egg strings obtained from each female were cut in 3 mm long segments; and when free larvae were observed, the segments (N= 90) were placed together with 30 Aedes aegypti larvae for evaluation of the gordiids' infective capacity. After 72 h, the mosquito larvae were observed by microscopy in order to quantify the C. nobilii larvae in body cavities. The IIMAs were calculated as the total number of C. nobilii larvae present divided by total number of A. aegypti larvae examined. For analysis of the IIMAs obtained, the data were grouped according to the female who made the original ovoposition. Our results enabled the corroboration of an ample range of responses in the infective capacity of this species, a characteristic that would normally be linked to the progenitors originating the hatch. Because this relationship prevents the establishment of a baseline for making comparisons among assays with gordiids, through the IIMA as a response parameter, we recommend expressing the IIMA values in each assay relative to their respective controls. These findings also provide evidence for the greater success in infections by certain members of the progeny over others. Finally, on the basis of the results obtained from this study, we stress the relevance of the use of the IIMA as a decisive aspect to be considered in different studies on the biology of Gordiida. Rev. Biol. Trop. 65 (1): 1-8. Epub 2017 March 01.

ResumenLos gordiidos son representantes dulceacuícolas del Phylum parásito Nematomorpha que actúan como un enlace entre ecosistemas acuáticos y terrestres. En años recientes, diferentes estudios ecotoxicológicos se han desarrollado con una especie sudamericana de gordiido, C. nobilii, que ha demostrado la capacidad de este grupo de actuar como bioindicador de contaminación. A pesar de su evidente importancia ecológica, aún se necesitan realizar estudios para dilucidar distintos aspectos de su biología, entre estos, la capacidad infectiva, un parámetro que puede evaluarse utilizando el Índice de Infección Abundancia Media (IIMA). El conocimiento de la variabilidad intrínseca en la capacidad infectiva de C. nobilii merece prioridad con el objeto de establecer el ámbito de respuesta aceptable para condiciones normales o estándar en el laboratorio, y que permita comparar los resultados entre distintos ensayos. El objetivo de este estudio es establecer la línea de base de la capacidad infectiva del gordiido C. nobilii en condiciones controladas de laboratorio, empleando el IIMA como parámetro de evaluación. Con este fin, se analizó la capacidad infectiva de larvas de C. nobilii que eclosionaron de diferentes cordones de huevos depositados por un total de 12 hembras, mantenidas en laboratorio. Los adultos de C. nobilii fueron recolectados de arroyos de la cuenca argentina Sauce Grande, entre 2006 y 2009. Una vez en el laboratorio, después de la cópula, las hembras se ubicaron en recipientes individuales a la espera de la oviposición. Los cordones de huevos obtenidos de cada hembra se cortaron en segmentos de 3 mm de longitud; y cuando las larvas libres fueron observadas al microscopio, los segmentos (N= 90) fueron ubicados junto con 30 larvas de Aedes aegypti para evaluar la capacidad infectiva del gordiido. Después de 72 h, las larvas del mosquito fueron observadas al microscopio para contabilizar las larvas de C. nobilii en las cavidades corporales. El IIMA fue calculado como el número total de larvas de C. nobilii presentes dividido entre el número total de larvas de A. aegypti examinadas. Para el análisis de los IIMAs obtenidos, los datos fueron agrupados de acuerdo a la hembra que hizo la oviposición. Nuestros resultados permiten corroborar un amplio rango de respuesta en la capacidad infectiva de esta especie, que estaría vinculada al origen de la camada. Debido a que no se pudo establecer una línea de base para realizar comparaciones entre estudios en los gordiidos utilizando el IIMA como parámetro de respuesta, se aconseja relativizar los valores de los IIMAs a sus respectivos controles. Estos resultados también pusieron en evidencia la ventaja en el éxito de infección de algunas progenies sobre las restantes. Finalmente, con base en los resultados obtenidos a partir de este estudio se plantea la importancia del uso del IIMA como punto final a considerar en distintos estudios sobre la biología de los gordiida.

Analysis of laboratory animal pathogen infection indexes in Shanghai area / 中国实验动物学报

Objective To more intuitively understand the quality control for laboratory animals and further achie-ving a more scientific and reasonable management of laboratory animals, the infection index as evaluation criteria was intro-duced. Then the best way to calculate infection index was explored in order to more scientifically reflect the infection status of laboratory animals. Methods Infection index, also called the degree of infection, is a qualitative indicator of monito-ring laboratory animal quality. After arranging, analyzing, processing and gathering the data from laboratory animal quality monitoring, the index reflects synthetically the pathogen infection status or trend of a particularly investigated experimental animal population or the development of certain experimental animals. Results In general, the pathogen infection index of mice was slightly decreased, while the pathogen infection index of rats roughly increased year by year. In comparing infec-tion index by different pathogens, the parasite infection index of mice was found to be higher than bacteria and virus infec-tion indexes, while the bacteria infection index of rats was higher than parasite infection index and virus ones. Conclusions The infection index model intuitively reflects the quality control status of laboratory animals. The analysis also reveals that the parasite monitoring of the mice and the bacteria detection of rat needs to be reinforcement. In addition, the index of infection reveals that the pathogen infection of mice is well under control, while that of rats tends to be more serious year by year.

New scenarios of Trypanosoma cruzi transmission in the Orinoco region of Colombia

Rhodnius prolixus, a blood-sucking triatomine with domiciliary anthropophilic habits, is the main vector of Chagas disease. The current paradigm of Trypanosoma cruzi transmission in Columbia includes a sylvatic and domiciliary cycle co-existing with domestic and sylvatic populations of reservoirs. The aim of this study is to evaluate the population densities and relative abundance of triatomines and mammals that may be involved in the sylvatic cycle of Chagas disease to clarify the epidemiological scenario in an endemic area in the province of Casanare. Insect vectors on Attalea butyracea palms were captured using both manual searches and bait traps. The capture of mammals was performed using Sherman and Tomahawk traps. We report an infestation index of 88.5% in 148 palms and an index of T. cruzi natural infection of 60.2% in 269 dissected insects and 11.9% in 160 captured mammals. High population densities of triatomines were observed in the sylvatic environment and there was a high relative abundance of reservoirs in the area, suggesting a stable enzootic cycle. We found no evidence of insect domiciliation. Taken together, these observations suggest that eco-epidemiological factors shape the transmission dynamics of T. cruzi, creating diverse scenarios of disease transmission.