RESUMEN
The aim of this study was to screen sixteen meso-1 semi-synthetic derivatives bearing ether, esther, carbamate, phosphate or aminoether functional groups against five cancer cell lines: MCF-7 (breast), A549 (lung), HepG2 (liver), HeLa (cervix), and DU145 (prostate) at 25â µM using the MTT assay. Results from the screening showed that two derivatives had the lowest percentage of cell viability at 25â µM, the aminoether derivative meso-11 and the esther derivative meso-20 against A549 (44.15±0.78 %) and MCF-7 (41.60±0.92 %), respectively. Then, it was determined the IC50 value of each compound against their most sensitive cancer cell line. Results showed that aminoether derivative meso-11 showed potent cytotoxicity against A549 (IC50 =17.11±2.11â µM), whereas it resulted more cytotoxic against the LL-47 lung normal cell line (IC50 =9.49±1.19â µM) having a Selective Index (SI) of 0.55. On the other hand, the esther derivative meso-20 exhibited potent activity against MCF-7 (IC50 =18.20±1.98â µM), whereas it displayed moderate cytotoxicity against the MCF-10 breast normal cell line (IC50 =41.22±2.17â µM) with a SI of 2.2. Finally, studies on the mechanism of action of meso-20 indicated disruption of MCF-7 plasma membrane inâ vitro and the AMPK activation in silico.
Asunto(s)
Antineoplásicos , Guayacol/análogos & derivados , Lignanos , Masculino , Humanos , Relación Estructura-Actividad , Ensayos de Selección de Medicamentos Antitumorales , Antineoplásicos/farmacología , Lignanos/farmacología , Proliferación Celular , Estructura Molecular , Simulación del Acoplamiento Molecular , Línea Celular Tumoral , Células MCF-7RESUMEN
Although fetal death is now understood to be a severe outcome of congenital Zika syndrome, the role of viral genetics is still unclear. We sequenced Zika virus (ZIKV) from a rhesus macaque fetus that died after inoculation and identified a single intrahost substitution, M1404I, in the ZIKV polyprotein, located in nonstructural protein 2B (NS2B). Targeted sequencing flanking position 1404 in 9 additional macaque mothers and their fetuses identified M1404I at a subconsensus frequency in the majority (5 of 9, 56%) of animals and some of their fetuses. Despite its repeated presence in pregnant macaques, M1404I has occurred rarely in humans since 2015. Since the primary ZIKV transmission cycle is human-mosquito-human, mutations in one host must be retained in the alternate host to be perpetuated. We hypothesized that ZIKV I1404 increases viral fitness in nonpregnant macaques and pregnant mice but is less efficiently transmitted by vectors, explaining its low frequency in humans during outbreaks. By examining competitive fitness relative to that of ZIKV M1404, we observed that ZIKV I1404 produced lower viremias in nonpregnant macaques and was a weaker competitor in tissues. In pregnant wild-type mice, ZIKV I1404 increased the magnitude and rate of placental infection and conferred fetal infection, in contrast to ZIKV M1404, which was not detected in fetuses. Although infection and dissemination rates were not different, Aedes aegypti mosquitoes transmitted ZIKV I1404 more poorly than ZIKV M1404. Our data highlight the complexity of arbovirus mutation-fitness dynamics and suggest that intrahost ZIKV mutations capable of augmenting fitness in pregnant vertebrates may not necessarily spread efficiently via mosquitoes during epidemics.IMPORTANCE Although Zika virus infection of pregnant women can result in congenital Zika syndrome, the factors that cause the syndrome in some but not all infected mothers are still unclear. We identified a mutation that was present in some ZIKV genomes in experimentally inoculated pregnant rhesus macaques and their fetuses. Although we did not find an association between the presence of the mutation and fetal death, we performed additional studies with ZIKV with the mutation in nonpregnant macaques, pregnant mice, and mosquitoes. We observed that the mutation increased the ability of the virus to infect mouse fetuses but decreased its capacity to produce high levels of virus in the blood of nonpregnant macaques and to be transmitted by mosquitoes. This study shows that mutations in mosquito-borne viruses like ZIKV that increase fitness in pregnant vertebrates may not spread in outbreaks when they compromise transmission via mosquitoes and fitness in nonpregnant hosts.
Asunto(s)
Mutación , Complicaciones Infecciosas del Embarazo/virología , Infección por el Virus Zika/virología , Virus Zika/genética , Aedes/virología , Animales , Chlorocebus aethiops , Brotes de Enfermedades , Femenino , Humanos , Macaca mulatta , Masculino , Ratones , Ratones Endogámicos C57BL , Mosquitos Vectores/virología , Embarazo , Células Vero , Proteínas no Estructurales Virales , Viremia , Virus Zika/crecimiento & desarrolloRESUMEN
Despite initial data suggesting positive treatment outcomes for adolescent eating disorder day-hospital programmes (DHPs), existing studies have included limited follow-up, small samples, and a focus on restricting-type eating disorders. To address these gaps, we explored naturalistic outcomes for an adolescent eating disorders DHP. Adolescent participants (N = 265) completed measurements at treatment admission, discharge (n = 170), and various lengths of follow-up (n = 126; Mfollow up = 278.87 days). Results from multilevel models indicated significant increases in body weight for the anorexia nervosa group throughout treatment and maintenance of increased body weight from discharge to follow-up. In bulimic spectrum disorders, binge eating and purging significantly decreased from intake to discharge and did not change from discharge to follow-up. Across the entire sample, eating disorder symptoms decreased from intake to discharge and did not change from discharge to follow-up. Further, anxiety and depression decreased over the course of treatment and continued to decrease over the follow-up period. The current investigation represents the first study to explore longitudinal DHP outcomes within adolescent bulimic spectrum eating disorders. Our findings also highlight many challenges inherent in conducting naturalistic research; it is critical that the field continue to develop solutions to the barriers inherent in conducting longitudinal research on eating disorder treatment.
Asunto(s)
Centros de Día/métodos , Trastornos de Alimentación y de la Ingestión de Alimentos/terapia , Adolescente , Femenino , Humanos , Masculino , Resultado del TratamientoRESUMEN
OBJECTIVE: The objective of this study was to review the current eating disorders outcome literature after residential or partial hospitalization programme (PHP) treatment. METHOD: Articles were identified through a systematic search of PubMed and PsycINFO. RESULTS: Twenty-two PHP and six residential treatment studies reported response at discharge and tended to find improvement. Fewer studies (nine PHP and three residential) reported outcome at some interval after discharge from treatment. These tended to find sustained improvement. A substantial proportion of patients were lost to follow-up, particularly for residential treatment. Only two follow-up studies used controlled trials; both showed efficacy for PHP compared with inpatient treatment with regard to maintaining symptom remission. CONCLUSIONS: Improvement at discharge may not predict long-term outcome. Long-term follow-up studies were confounded by high dropout rates. While higher levels of care may be essential for reversing malnutrition, there remains a lack of controlled trials showing long-term efficacy, particularly for residential treatment settings. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.
Asunto(s)
Centros de Día , Trastornos de Alimentación y de la Ingestión de Alimentos/terapia , Hospitalización , Alta del Paciente , Pacientes Desistentes del Tratamiento , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Resultado del TratamientoRESUMEN
Dialectical behavior therapy (DBT) and family-based treatment (FBT) are two evidence-based interventions that have been applied in the treatment of bulimia nervosa (BN) in adolescents. While DBT focuses on providing skills for coping with emotion dysregulation that often co-occurs with BN, FBT targets the normalization of eating patterns. The purpose of the current article is to introduce an integration of both treatments to provide a more comprehensive approach that targets the full scope of the disorder. We provide a review of the conceptual similarities and differences between FBT-BN and DBT along with strategies to guide a blended treatment approach. Given the strengths and limitations of either independent treatment, DBT and FBT-BN complement one another and together can address the range of symptoms and behaviors typically seen in adolescent BN.
Asunto(s)
Terapia Conductista , Bulimia Nerviosa/terapia , Terapia Familiar , Adolescente , Conducta del Adolescente , Bulimia Nerviosa/psicología , Práctica Clínica Basada en la Evidencia , HumanosRESUMEN
Existing descriptions of the treatment of avoidant/restrictive food intake disorder (ARFID) at higher levels of care (HLOC) for eating disorders are limited, despite HLOC settings frequently serving patients with ARFID. The purpose of this commentary is to expand on the preliminary literature that describes pediatric ARFID treatment at HLOC by describing two specific components of our approach to treating pediatric ARFID that may not yet have traction in the current literature. Specifically, we highlight the utility of (1) treatment accommodations that appropriately account for patients' neurodevelopmental needs (e.g., executive functioning, sensory processing) and (2) the adjunctive use of Dialectical Behavior Therapy (DBT) elements within family-based pediatric ARFID treatment. We also describe necessary future directions for research in these domains to clarify if incorporating these considerations and approaches into pediatric ARFID treatment at HLOC does indeed improve treatment outcomes.
RESUMEN
Ross River virus (RRV) and Barmah Forest virus (BFV) are arthritogenic arthropod-borne viruses (arboviruses) that exhibit generalist host associations and share distributions in Australia and Papua New Guinea (PNG). Using stochastic mapping and discrete-trait phylogenetic analyses, we profiled the independent evolution of RRV and BFV signature mutations. Analysis of 186 RRV and 88 BFV genomes demonstrated their viral evolution trajectories have involved repeated selection of mutations, particularly in the nonstructural protein 1 (nsP1) and envelope 3 (E3) genes suggesting convergent evolution. Convergent mutations in the nsP1 genes of RRV (residues 248 and 441) and BFV (residues 297 and 447) may be involved with catalytic enzyme mechanisms and host membrane interactions during viral RNA replication and capping. Convergent E3 mutations (RRV site 59 and BFV site 57) may be associated with enzymatic furin activity and cleavage of E3 from protein precursors assisting viral maturation and infectivity. Given their requirement to replicate in disparate insect and vertebrate hosts, convergent evolution in RRV and BFV may represent a dynamic link between their requirement to selectively 'fine-tune' intracellular host interactions and viral replicative enzymatic processes. Despite evidence of evolutionary convergence, selection pressure analyses did not reveal any RRV or BFV amino acid sites under strong positive selection and only weak positive selection for nonstructural protein sites. These findings may indicate that their alphavirus ancestors were subject to positive selection events which predisposed ongoing pervasive convergent evolution, and this largely supports continued purifying selection in RRV and BFV populations during their replication in mosquito and vertebrate hosts.
RESUMEN
From 2011-2018, we conducted surveillance in marine mammals along the California coast for influenza A virus (IAV), frequently detecting anti-influenza antibodies and intermittently detecting IAV. In spring 2019, this pattern changed. Despite no change in surveillance intensity, we detected IAV RNA in 10 samples in March and April, mostly in nasal and rectal swabs from northern elephant seals (Mirounga angustirostris). Although virus isolation was unsuccessful, IAV sequenced from one northern elephant seal nasal swab showed close genetic identity with pandemic H1N1 IAV subclade 6B.1A.1 that was concurrently circulating in humans in the 2018/19 influenza season. This represents the first report of human A(H1N1)pdm09 IAV in northern elephant seals since 2010, suggesting IAV continues to spill over from humans to pinnipeds.
Asunto(s)
Caniformia , Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Humana , Phocidae , Animales , Humanos , Gripe Humana/epidemiología , California/epidemiologíaRESUMEN
Type II intestinal failure (IF-II) is a condition in which the gastrointestinal tract is compromised. Liver complications may occur because of the pathology and/or prolonged use of parenteral nutrition (PN); oxidative stress has been implicated as one of the causes. Lipid emulsions containing n-3 polyunsaturated fatty acids (PUFAs) have been proposed for the treatment. We aimed to evaluate the effect of 7-day n-3 PUFA supplementation on oxidative stress in IF-II patients receiving PN. This was a randomized, controlled, double-blinded, pilot trial of adult patients with IF-II, receiving either conventional PN (control) or PN enriched with n-3 PUFAs (intervention). Twenty patients were included (14 men, 49 ± 16.9 years), with the ANCOVA analysis the glucose (p = 0.003), and direct bilirubin (p = 0.001) levels reduced; whereas the high-density lipoprotein cholesterol (HDL-C) increased (p = 0.017). In the random-effect linear regression analysis, a reduction (p < 0.0001) in the malondialdehyde (MDA) level was found in the intervention group when the covariables age, HDL-C level, and alanine aminotransferase activity were considered. After 1 week of PN supplementation with n-3 PUFAs, the marker levels of some oxidative stress, blood lipids, and hepatic biomarkers improved in patients with IF-II.
RESUMEN
Retinal ganglion cells initiating the magnocellular/Y-cell visual pathways respond nonlinearly to high spatial frequencies (SFs) and temporal frequencies (TFs). This nonlinearity is implicated in the processing of contrast modulation (CM) stimuli in cats and monkeys, but its contribution to human visual perception is not well understood. Here, we evaluate human psychophysical performance for CM stimuli, consisting of a high SF grating carrier whose contrast is modulated by a low SF sinewave envelope. Subjects reported the direction of motion of CM envelopes or luminance modulation (LM) gratings at different eccentricities. The performance on SF (for LMs) or carrier SF (for CMs) was measured for different TFs (LMs) or carrier TFs (CMs). The best performance for LMs was at lower TFs and SFs, decreasing systematically with eccentricity. However, performance with CMs was bandpass with carrier SF, largely independent of carrier TF, and at the highest carrier TF (20 Hz) decreased minimally with eccentricity. Since the nonlinear subunits of Y-cells respond better at higher TFs compared to the linear response components and respond best at higher SFs that are relatively independent of eccentricity, these results suggest that behavioral tasks employing CM stimuli might reveal nonlinear contributions of retinal Y-like cells to human perception.
Asunto(s)
Células Ganglionares de la Retina , Vías Visuales , Humanos , Gatos , Animales , Estimulación Luminosa/métodos , Sensibilidad de ContrasteRESUMEN
The globalization of mosquito-borne arboviral diseases has placed more than half of the human population at risk. Understanding arbovirus ecology, including the role individual mosquito species play in virus transmission cycles, is critical for limiting disease. Canonical virus-vector groupings, such as Aedes- or Culex-associated flaviviruses, have historically been defined using virus detection in field-collected mosquitoes, mosquito feeding patterns, and vector competence, which quantifies the intrinsic ability of a mosquito to become infected with and transmit a virus during a subsequent blood feed. Herein, we quantitatively synthesize data from 68 laboratory-based vector competence studies of 111 mosquito-virus pairings of Australian mosquito species and viruses of public health concern to further substantiate existing canonical vector-virus groupings and quantify variation within these groupings. Our synthesis reinforces current canonical vector-virus groupings but reveals substantial variation within them. While Aedes species were generally the most competent vectors of canonical "Aedes-associated flaviviruses" (such as dengue, Zika, and yellow fever viruses), there are some notable exceptions; for example, Aedes notoscriptus is an incompetent vector of dengue viruses. Culex spp. were the most competent vectors of many traditionally Culex-associated flaviviruses including West Nile, Japanese encephalitis and Murray Valley encephalitis viruses, although some Aedes spp. are also moderately competent vectors of these viruses. Conversely, many different mosquito genera were associated with the transmission of the arthritogenic alphaviruses, Ross River, Barmah Forest, and chikungunya viruses. We also confirm that vector competence is impacted by multiple barriers to infection and transmission within the mesenteron and salivary glands of the mosquito. Although these barriers represent important bottlenecks, species that were susceptible to infection with a virus were often likely to transmit it. Importantly, this synthesis provides essential information on what species need to be targeted in mosquito control programs.
Asunto(s)
Aedes , Virus Chikungunya , Culex , Flavivirus , Infección por el Virus Zika , Virus Zika , Animales , Australia , Humanos , Mosquitos VectoresRESUMEN
OBJECTIVE: Primary dysmenorrhea has a high prevalence among the student population. The objective of this study was to determine the prevalence of dysmenorrhea, its severity and its impact on academic performance in Mexican university students. METHODS: Cross-sectional study. An anonymous multiple-choice questionnaire was applied in class hours in the classrooms. The visual pain scale (VAS) was used for the measurement of pain. A descriptive and inferential analysis of the variables studied was carried out using the program SPSS® IBM. RESULTS: A total of 2154 (n=2154) students were surveyed. The average age of the women was 20.4 ±1.9years. The general prevalence of dysmenorrhea was 78.9%, with psychology students having the highest value (83.7%). The VAS mean pain score was of 64.0. The severity of menstrual pain in students was reported as mild in 9.0%, and moderate-severe in 91.0%. The VAS mean pain scores and intensity of pain of gerontology students were significantly higher than those reported by dentistry and medicine students (P<.05). Limitation of daily activities was reported in 90.4% of women, with medical students reporting the highest percentage (93.3%). Women reported school absenteeism in 37.0%, with medical students presenting the highest percentage (41.4%). The severity of menstrual pain as a risk factor (independent variable) positively influenced various dependent variables involved in students' academic performance (P<.05), including: stop doing their activities due to pain in 1 to 6 menstruations a year, minor concentration, absenteeism, low school performance, and lower grades during dysmenorrhea. CONCLUSION: A high prevalence of dysmenorrhea was observed and it is concluded that the severity of the symptomatology significantly interferes with the academic performance of the participants.
Asunto(s)
Rendimiento Académico , Estudiantes de Medicina , Adolescente , Adulto , Estudios Transversales , Dismenorrea/epidemiología , Dismenorrea/psicología , Femenino , Humanos , Universidades , Adulto JovenRESUMEN
In recent years, there has been increased interest in the study of pain in children and its treatment. It is known that when facing diagnostic and therapeutic procedures similar to those performed on adults, children either do not receive specific pain treatment or receive it on a significantly lower scale. However, recent research suggests a change in attitude and an improvement in the current treatment of children's pain. Although current knowledge demonstrates the falsity of many preconceived ideas about pain and its management, our results suggest that attitudinal change towards childhood pain remains slow and that real improvement in the training and practical application of the pediatrician who has to treat childhood pain is urgently needed. In this context, this manuscript has prepared standards and guidelines to improve pain management practices in a large number of national and international professional settings.
Asunto(s)
Dolor Asociado a Procedimientos Médicos , Adulto , Niño , Humanos , Dolor Asociado a Procedimientos Médicos/diagnóstico , Dolor Asociado a Procedimientos Médicos/terapiaRESUMEN
The dengue viruses (DENVs) occur throughout tropical and subtropical regions of the world where they infect 100s of millions of people annually. In Australia, the dengue receptive zone is confined to the northern state of Queensland where the principal vector Aedes aegypti (L.) is present. In the current study, two populations of Ae. aegypti from north Queensland were exposed to two urban outbreak strains and one sylvatic strain of dengue virus type 2 (DENV-2). The titer of virus required to infect 50% of mosquitoes was between 105 and 106 50% tissue culture infectious dose (TCID)50/ml and was influenced by the combination of the origin of Ae. aegypti population and virus strain. When exposed to infectious bloodmeal titers > 106 TCID50/ml, infection and dissemination rates were all > 50% and were significantly affected by the origin of the mosquito population but not by the strain of DENV-2. Replication of DENV-2 was also significantly affected by the mosquito population and the titer of the infectious bloodmeal that mosquitoes were exposed to. The results of this study are discussed in the context of DENV transmission dynamics in northern Australia and the relative fitness of the sylvatic virus strain in urban Ae. aegypti populations.
Asunto(s)
Aedes/virología , Virus del Dengue/fisiología , Mosquitos Vectores/virología , Animales , Femenino , QueenslandRESUMEN
BACKGROUND & AIMS: Intestinal Failure (IF) is a complex disease with huge impacts on our society due to complications. Therefore, in a developing country like Mexico without specialized IF clinics, health care professionals must provide evidence-based interventions for the IF patient. This study aims to achieve consensus on how to adapt the existing guidelines for IF to the local practices considering the available resources and local practices. METHODS: A three-round modified Delphi process was used to build consensus on the most important interventions for our IF patients. For each round, data was collected and consensus was defined as ≥80% of agreement for each item. Descriptive statistics were used to determine whether a consensus was achieved. RESULTS: Ten content experts completed the three-round modified Delphi survey. Consensus was achieved for 98% of the items related to the hospitalized patient, ambulatory care management, and drug therapy. Some of these items are not included in the ESPEN guidelines for IF, but we considered that they are relevant in our clinical practice, like the calculation of fluids for patients with very low body weight, screening for refeeding syndrome and the use of some conventional drugs to promote intestinal rehabilitation. CONCLUSIONS: Using a three-round modified Delphi process, consensus was achieved for nearly all items. This represents a starting point for the improvement of our local practices towards this complex disease, leading to better outcomes and the implementation of evidence-based protocolized interventions which can have an important impact due to the lack of access to some of the most novel pharmacological therapies like the glucagon-like-peptide (GLP-2) analog.
Asunto(s)
Países en Desarrollo , Terapia Nutricional , Consenso , Técnica Delphi , Humanos , Encuestas y CuestionariosRESUMEN
Traditional screening for arboviruses in mosquitoes requires a priori knowledge and the utilization of appropriate assays for their detection. Mosquitoes can also provide other valuable information, including unexpected or novel arboviruses, nonarboviral pathogens ingested from hosts they feed on, and their own genetic material. Metagenomic analysis using next-generation sequencing (NGS) is a rapidly advancing technology that allows us to potentially obtain all this information from a mosquito sample without any prior knowledge of virus, host, or vector. Moreover, it has been recently demonstrated that pathogens, including arboviruses and parasites, can be detected in mosquito excreta by molecular methods. In this study, we investigated whether RNA viruses could be detected in mosquito excreta by NGS. Excreta samples were collected from Aedes vigilax and Culex annulirostris experimentally exposed to either Ross River or West Nile viruses and from field mosquitoes collected across Queensland, Australia. Total RNA was extracted from the excreta samples, reverse transcribed to cDNA, and sequenced using the Illumina NextSeq 500 platform. Bioinformatic analyses from the generated reads demonstrate that mosquito excreta provide sufficient RNA for NGS, allowing the assembly of near-full-length viral genomes. We detected Australian Anopheles totivirus, Wuhan insect virus 33, and Hubei odonate virus 5 and identified seven potentially novel viruses closely related to members of the order Picornavirales (2/7) and to previously described, but unclassified, RNA viruses (5/7). Our results suggest that metagenomic analysis of mosquito excreta has great potential for virus discovery and for unbiased arbovirus surveillance in the near future.IMPORTANCE When a mosquito feeds on a host, it ingests not only its blood meal but also an assortment of microorganisms that are present in the blood, thus acting as an environmental sampler. By using specific tests, it is possible to detect arthropod-borne viruses (arboviruses) like dengue and West Nile viruses in mosquito excreta. Here, we explored the use of next-generation sequencing (NGS) for unbiased detection of RNA viruses present in excreta from experimentally infected and field-collected mosquitoes. We have demonstrated that mosquito excreta provide a suitable template for NGS and that it is possible to recover and assemble near-full-length genomes of both arboviruses and insect-borne viruses, including potentially novel ones. These results importantly show the direct practicality of the use of mosquito excreta for NGS, which in the future could be used for virus discovery, environmental virome sampling, and arbovirus surveillance.
Asunto(s)
Aedes/virología , Culex/virología , Heces/virología , Virus de Insectos/clasificación , Viroma/genética , Animales , Arbovirus/clasificación , Arbovirus/aislamiento & purificación , Australia , Genoma Viral , Secuenciación de Nucleótidos de Alto Rendimiento , Virus de Insectos/aislamiento & purificación , MetagenómicaRESUMEN
Mosquito-borne diseases are a major public health concern globally and early detection of pathogens is critical to implement vector management and control strategies. Existing methods for pathogen detection include screening sentinel animals for antibodies and analyzing mosquitoes for pathogen presence. While these methods are effective, they are also expensive, labor-intense, and logistically challenging. To address these limitations, a new method was developed whereby mosquito saliva is collected on honey-coated nucleic acid preservation cards which are analyzed by molecular assays for detection of pathogens. However, mosquitoes only expel small amounts of saliva when feeding on these cards, potentially leading to false negatives. Another bodily fluid that is expelled by mosquitoes in larger volumes than saliva is excreta, and recent laboratory experiments have demonstrated that a range of mosquito-borne pathogens can be detected in mosquito excreta. In the current study, we have modified light and passive mosquito traps to collect their excreta and assessed their efficacy in field evaluations. From these field-collections, we detected West Nile, Ross River, and Murray Valley encephalitis viruses. Our findings suggest that mosquito traps are easily modified to collect excreta and, that this system has the potential to enhance detection of pathogens.
Asunto(s)
Arbovirus/aislamiento & purificación , Culicidae/virología , Animales , Heces/virología , Femenino , Control de MosquitosRESUMEN
Arbovirus surveillance is crucial for the implementation of vector-borne disease control measures. Recently, it has been demonstrated that mosquitoes with a disseminated arbovirus infection excrete viral RNA, which can be detected by molecular methods. Thereby, mosquito excreta has been proposed as a sample type that could be utilized for arbovirus surveillance. In this study, we evaluated if West Nile virus (Kunjin strain, WNVKUN) RNA in Culex annulirostris Skuse (Diptera: Culicidae) excreta deposited on different substrates could be detected after storage for up to 2 wk at tropical conditions of high heat and humidity. No significant drop in relative quantity of WNVKUN RNA (determined by comparison of Ct values) in excreta deposited on Flinders Associate Technologies (FTA) cards was observed over 14 d, suggesting that RNA was stable for that time. There was no significant difference in relative quantity of WNVKUN RNA in excreta deposited on FTA cards or polycarbonate substrates after 24 h. However, after 7 and 14 d, there was a significant decline in the relative quantity of viral RNA in the excreta stored on polycarbonate substrates. For incorporation in arbovirus surveillance programs, we recommend the use of polycarbonate substrates for excreta collection in mosquito traps deployed overnight, and the integration of FTA cards in traps serviced weekly or fortnightly. Polycarbonate substrates facilitate the collection of the majority of excreta from a trap, and while FTA cards offer limited area coverage, they enable preservation of viral RNA in tropical conditions for extended periods of time.
Asunto(s)
Culicidae/virología , Heces/virología , ARN Viral/análisis , Virus del Nilo Occidental/aislamiento & purificación , AnimalesRESUMEN
BACKGROUND: Malaria is the most important vector-borne disease in the world. Epidemiological and ecological studies of malaria traditionally utilize detection of Plasmodium sporozoites in whole mosquitoes or salivary glands by microscopy or serological or molecular assays. However, these methods are labor-intensive, and can over- or underestimate mosquito transmission potential. To overcome these limitations, alternative sample types have been evaluated for the study of malaria. It was recently shown that Plasmodium could be detected in saliva expectorated on honey-soaked cards by Anopheles stephensi, providing a better estimate of transmission risk. We evaluated whether excretion of Plasmodium falciparum nucleic acid by An. stephensi correlates with expectoration of parasites in saliva, thus providing an additional sample type for estimating transmission potential. Mosquitoes were exposed to infectious blood meals containing cultured gametocytes, and excreta collected at different time points post-exposure. Saliva was collected on honey-soaked filter paper cards, and salivary glands were dissected and examined microscopically for sporozoites. Excreta and saliva samples were tested by real time polymerase chain reaction (RT-rtPCR). RESULTS: Plasmodium falciparum RNA was detected in mosquito excreta as early as four days after ingesting a bloodmeal containing gametocytes. Once sporogony (the development of sporozoites) occurred, P. falciparum RNA was detected concurrently in both excreta and saliva samples. In the majority of cases, no difference was observed between the Ct values obtained from matched excreta and saliva samples, suggesting that both samples provide equally sensitive results. A positive association was observed between the molecular detection of the parasites in both samples and the proportion of mosquitoes with sporozoites in their salivary glands from each container. No distinguishable parasites were observed when excreta samples were stained and microscopically analyzed. CONCLUSIONS: Mosquito saliva and excreta are easily collected and are promising for surveillance of malaria-causing parasites, especially in low transmission settings or in places where arboviruses co-circulate.