Detection of porcine circovirus 2, porcine parvovirus 1, and torque teno sus virus k2a in wild boars from northeastern Patagonia, Argentina.

Wild boars can act as a reservoir of pathogenic viruses that affect the pig industry. Here, we assessed the presence of porcine circovirus 2, porcine parvovirus 1, and torque teno sus virus k2a in wild boars in northeastern Patagonia (Argentina). Total DNA was extracted from the tonsils of 27 animals (collected between early 2016 and mid-2019) and used to prepare sample pools, which were subjected to viral detection through two-round PCR assays. Sequencing of the amplification products and phylogenetic analysis confirmed the occurrence of all of the aforementioned infectious agents.

SARS-CoV-2 surveillance in untreated wastewater: detection of viral RNA in a low-resource community in Buenos Aires, Argentina.

OBJECTIVE: To measure SARS-CoV-2 RNA in sewage in a low-resource community in order to determine if it can be considered as an estimator of changes in the prevalence of COVID-19 in the population. METHODS: In this descriptive observational study we collected samples of surface waters contaminated with sewage and optimized a method of purification of viral RNA using PEG concentration. We determined the amount of genetic material by quantitative real-time PCR using the CDC method for SARS-CoV-2 detection. RESULTS: We quantified viral RNA in surface waters contaminated with sewage of a low resource community and determined that temporal trends of SARS-CoV-2 in wastewater samples mirrored trends in COVID-19 active cases. CONCLUSIONS: Measuring of SARS-CoV-2 RNA in sewage can be applied in low-resource communities without connection to sewers as an estimator of changes in the prevalence of COVID-19.

Molecular detection of Porcine cytomegalovirus (PCMV) in wild boars from Northeastern Patagonia, Argentina.

Porcine cytomegalovirus (PCMV) is a recognized pathogen of domestic swine that is widely distributed around the world. PCMV is the etiological agent of inclusion body rhinitis and has also been associated with other diseases that cause substantial losses in swine production. Wild boar populations can act as reservoirs of numerous infectious agents that affect pig livestock, including PCMV. The aim of this work was to assess the circulation of this virus in free-living wild boars that inhabit Northeastern Patagonia (Buenos Aires and Río Negro Provinces), Argentina. Nested-PCR assays were conducted to evaluate the presence of PCMV in samples of tonsil tissue collected from 62 wild boar individuals. It was found that the overall rate of infection was about 56%, with significant higher values (almost 90%) in the age group corresponding to piglets (animals less than 6 months old). In addition, a seasonal variation was observed in the PCMV detection rate, with an increase during the transition from summer to autumn. In conclusion, this study confirmed that wild boars are major carriers and dispersal agents of PCMV in Northeastern Patagonia, which raises the necessity to evaluate the extent to which this virus affects local livestock production.

Specific diagnostic method for St. Louis encephalitis virus using a non-structural protein as the antigen.

St. Louis encephalitis virus (SLEV) is a mosquito-borne re-emerging flavivirus in Argentina. It is currently necessary to develop specific serological tests that can efficiently discriminate the flaviviruses that circulate in our country. The immunoassays to diagnose SLEV lack specificity because they are based on the detection of structural viral proteins and the human immunoglobulins produced during infection against these proteins cross-react with other flaviviruses. Here, we describe an enzyme-immunoassay designed to detect human IgG antibodies specific to the viral non-structural protein NS5. The results indicate that NS5 is a promising antigen useful to discriminate SLEV from other circulating flaviviruses.

Development and standardization of an enzyme-linked inmunosorbent for the detection of orthohantavirus infection in Argentina based on its bacterial-expressed nucleocapside protein.

We conducted a development and standardization of an IgG ELISA assay for serological detection of human orthohantavirus infections using the recombinant antigen rLECH13 produced in bacterial and derived from the LECHV. The evaluation and standardization were carried out by analyzing serum samples from a total of 50 patients with confirmed Hantavirus Pulmonary Syndrome (HPS) diagnosis through the reference technique, 50 negative sera, and 53 patients with other medical conditions. The data from the assay analysis showed a diagnostic sensitivity value of 95% and a diagnostic specificity of 80%. The high sensitivity of this novel assay leads us to conclude that rLECH13 is a feasible option for use in the immunodiagnostic of orthohantavirus infection. Additionally, it is crucial to have an antigen that can be produced under conditions that do not require highly complex laboratories. Furthermore, the new assay is cost-effective, reproducible, and demonstrates excellent performance.

Torque teno sus virus k2a (TTSuVk2a) in wild boars from northeastern Patagonia, Argentina.

Torque teno sus virus k2a (TTSuVk2a) is a member of the family Anelloviridae that can establish persistent infections in both domestic pigs and wild boars. Its association with diseases has not been precisely elucidated, and it is often considered only as a commensal virus. This infectious agent has been reported in herds throughout the world. In this study, we investigated the detection rate and diversity of TTSuVk2a in free-living wild boars from northeastern Patagonia, Argentina. Total DNA was extracted from tonsil samples of 50 animals, nested PCR assays were carried out, and infection was verified in 60% of the cases. Sequence analysis of the viral non-coding region revealed distinct phylogenetic groups. These clusters showed contrasting patterns of spatial distribution, which presented statistically significant differences when evaluating spatial aggregation. In turn, the sequences were compared with those available in the database to find that the clusters were distinguished by having similarity with TTSuVk2a variants of different geographic origin. The results suggested that Patagonian wild boar populations are bearers of diverse viral strains of Asian, European, and South American provenance.

A rapid and simple protocol for concentration of SARS-CoV-2 from sewage.

The aim of this study was to set up a simple protocol to concentrate SARS-CoV-2 from sewage, which can be implemented in laboratories with minimal equipment resources. The method avoids the need for extensive purification steps and reduces the concentration of potential inhibitors of RT-qPCR contained in sewage. The concentration method consists of a single step, in which a small volume (40 mL) of sewage sample is incubated with polyaluminum chloride (PAC)(0.00045 N Al3+ final concentration). Virus particles adsorbed to the precipitate are collected by low-speed centrifugation, after which the recovered pellet is resuspended with a saline buffer. PAC-concentrated samples are stable for at least one week at 4 °C. Therefore, they may be sent refrigerated to a diagnosis center for RNA extraction and RT-qPCR for SARS-CoV-2 RNA detection if the lab does not have such capabilities. The PAC concentration method produced an average shift of 4.5-units in quantification cycle (Cq) values compared to non-concentrated samples, indicating a 25-fold increase in detection sensitivity. The lower detection limit corresponded approximately to 100 viral copies per ml. Kappa index indicated substantial agreement between PAC and polyethylene glycol (PEG) precipitation protocols (k = 0.688, CI 0.457-0.919). This low-cost concentration protocol could be useful to aid in the monitoring of community circulation of SARS-CoV-2, especially in low- and middle-income countries, which do not have massive access to support from specialized labs for sewage surveillance.

Molecular detection of Porcine cytomegalovirus (PCMV) in wild boars from Northeastern Patagonia, Argentina / Detección molecular de citomegalovirus porcino (PCMV) en jabalíes del noreste de la Patagonia argentina

ABSTRACT Porcine cytomegalovirus(PCMV) is a recognized pathogen of domestic swine that is widely distributed around the world. PCMV is the etiological agent of inclusion body rhinitis and has also been associated with other diseases that cause substantial losses in swine production. Wild boar populations can act as reservoirs of numerous infectious agents that affect pig livestock, including PCMV. The aim of this work was to assess the circulation of this virus in free-living wild boars that inhabit Northeastern Patagonia (Buenos Aires and Río Negro Provinces), Argentina. Nested-PCR assays were conducted to evaluate the presence of PCMV in samples of tonsil tissue collected from 62 wild boar individuals. It was found that the overall rate of infection was about 56%, with significant higher values (almost 90%) in the age group corresponding to piglets (animals less than 6 months old). In addition, a seasonal variation was observed in the PCMV detection rate, with an increase during the transition from summer to autumn. In conclusion, this study confirmed that wild boars are major carriers and dispersal agents of PCMV in Northeastern Patagonia, which raises the necessity to evaluate the extent to which this virus affects local livestock production.

RESUMEN El citomegalovirus porcino (CMVP) es un reconocido patógeno de los cerdos domésticos y cuenta con una amplia distribución mundial. Es el agente etiológico de la rinitis por cuerpos de inclusión y también se lo ha asociado con otras enfermedades que causan pérdidas sustanciales en la producción porcina. Las poblaciones de jabalíes pueden actuar como reservorios de numerosos agentes infecciosos que afectan al ganado porcino, incluido el CMVP. El objetivo de este trabajo fue evaluar la circulación de este virus en jabalíes de vida libre que habitan en la región noreste de la Patagonia argentina, en las provincias de Buenos Aires y Río Negro. Se realizaron ensayos de PCR anidada para evaluar la presencia de CMVP en muestras de tejido de amígdalas tomadas de 62 jabalíes. Se encontró que la tasa general de infección fue de aproximadamente el 56%, con valores significativamente más altos (casi el 90%) en el grupo de edad correspondiente a los lechones (animales con menos de 6meses). Además, se observó una variación estacional en la tasa de detección de CMVP, con un incremento durante la transición de verano a otoño. En conclusión, este estudio confirmó que los jabalíes son importantes portadores y agentes de dispersión del CMVP en el noreste patagónico, lo cual plantea la necesidad de evaluar en qué medida este virus afecta la producción ganadera local.