Tick-borne microorganisms in Amblyomma tigrinum (Acari: Ixodidae) from the Patagonian region of Argentina.

This study presents the results of the molecular detection of tick-borne microorganisms in Amblyomma tigrinum Koch collected near the city of Viedma, Río Negro, Argentina. Ticks were collected in their non-parasitic stage, on pet dogs and on Lycalopex gymnocercus (Pampa fox). Also, six tick samples from humans were analyzed. All ticks were morphologically identified to species level and genomic DNA was extracted. The DNA samples were examined by end point PCR assays to amplified DNA of Anaplasma sp., Babesia sp., Ehrlichia sp., Rickettsia sp. and Theileria sp. Although all tested DNA samples from the collected ticks resulted negative to the detection of Piroplasmida and Rickettsia spp., 16 samples (16.5%, including all hosts) were positive in the 16S rDNA gene PCR that detects bacteria from the Anaplasmataceae family. Phylogenetic analysis of seven obtained partial sequences resulted in the identification of three bacteria: two Ehrlichia spp. (related to Ehrlichia sp. strain Iberá and strain Viedma) and Candidatus Anaplasma boleense. The latter finding represents the first detection of this novel Candidatus species in A. tigrinum. Based on the results of this study, it must be assumed that the diversity of bacteria of the Anaplasmataceae family in Argentina is greater than previously thought, and that these bacteria can infect a wide range of domestic and wild animals.

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.

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.

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.

Tuberculosis in Wild Pigs from Argentina.

Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex (MTC) and non-tuberculous Mycobacteria (NTM), may infect wild and domestic mammals, including humans. Although cattle are the main hosts and spreaders of M. bovis, many wildlife hosts play an important role worldwide. In Argentina, wild boar and domestic pigs are considered important links in mammalian tuberculosis (mTB) transmission. The aim of this work was to investigate the presence of M. bovis in wild pigs from different regions of Argentina, to characterize isolates of M. bovis obtained, and to compare those with other previously found in vertebrate hosts. A total of 311 samples from wild pigs were obtained, and bacteriological culture, molecular identification and genotyping were performed, obtaining 63 isolates (34 MTC and 29 NTM). Twelve M. bovis spoligotypes were detected. Our findings suggest that wild pigs have a prominent role as reservoirs of mTB in Argentina, based on an estimated prevalence of 11.2 ± 1.8% (95% CI 8.0-14.8) for MTC and the frequency distribution of spoligotypes shared by cattle (75%), domestic pigs (58%) and wildlife (50%). Argentina has a typical scenario where cattle and pigs are farm-raised extensively, sharing the environment with wildlife, creating conditions for effective transmission of mTB in the wildlife-livestock-human interface.

Monitoring macroplastic ingestion by birds and marine mammals in northeastern Patagonia, Argentina.

Plastic debris is of particular concern due to its abundance, and its persistence in the environment. In Argentina, the impact of plastic debris has been documented with a significant increase during the last years. However, evidence of debris ingestion remains low compared to other regions of the world. Between 2020 and 2022, one of the twenty-three individuals analyzed in this study (seven species: five birds and two marine mammals) had ingested plastic debris. A single macroplastic piece was found in the Great Grebe (Podiceps major). It was a hardy yellow elastic band that appears to be a packaging band in agreement with the debris category with the greatest number of reports. This study is a contribution to the few records of plastic ingestion in birds, on the east coast of South America.

Molecular Detection of Candidatus Rickettsia andeanae and Ehrlichia sp. in Amblyomma pseudoconcolor Aragão, 1908 (Acari: Ixodidae) from the Argentinian Patagonia.

This study presents the molecular detection of Candidatus Rickettsia andeanae and Ehrlichia sp. in Amblyomma pseudoconcolor Aragão, 1908 (Acari: Ixodidae) collected on a large hairy armadillo (Chaetophractus villosus (Desmarest, 1804)). On 12 October 2020, a specimen of C. villosus was found dead on the road in Río Negro province, Argentina. Molecular detection of Rickettsia and Ehrlichia agents was performed amplifying the gltA and 16S rRNA gene, respectively. One tick, determined morphologically and genetically as A. pseudoconcolor, was collected on C. villosus. The rickettsial agent detected in A. pseudoconcolor was identified as Candidatus Rickettsia andeanae. The Ehrlichia sp. strain showed high sequence similarity to different uncultured Ehrlichia sp. detected in horses, capybaras and Ixodes ornithorhynchi from Nicaragua, Brazil and Australia, respectively. The results of this study and previous findings suggest that A. pseudoconcolor may be a potential vector of some Rickettsia and Ehrlichia bacteria of unknown pathogenicity.

Serological survey suggests circulation of coronavirus on wild Suina from Argentina, 2014-2017.

Swine coronaviruses affecting pigs have been studied sporadically in wildlife. In Argentina, epidemiological surveillance of TGEV/PRCV is conducted only in domestic pigs. The aim was to assess the prevalence of TGEV/PRCV in wild Suina. Antibodies against these diseases in wild boar and captive collared peccary were surveyed by ELISA. Antibodies against TGEV were found in three collared peccaries (n = 87). No TGEV/PRCV antibodies were detected in wild boar (n = 160). Preventive measures should be conducted in contact nodes where the transmission of agents may increase. Epidemiological surveillance in wildlife populations and in captive animals before their reintroduction should be attempted.

Reprint of: A review on Trichinella infection in South America.

Trichinella spp. causes human trichinellosis by means of the consumption of raw or inadequately treated meat from domestic or game animals. In the Americas, as well as in other continents, Trichinella infection is a health issue for humans and has a negative impact on the pork meat market, generated by people's fear of becoming infected with the parasite. The distribution of human cases and the sources of this disease in humans and animals were analysed in this report, which summarizes the information available regarding Trichinella infection in animals and humans in South America. Within South America, human infection with Trichinella was documented in Argentina and Chile during the period 2005-2019. Trichinellosis is endemic in these countries for, with human cases and foci in domestic and wild animals. In Argentina, human cases occur throughout the country, with foci found in pigs and wild animals. In Argentina, during the period 2012-2018, the number of suspected human cases reached 6,662. T. spiralis was identified in one South American sea lion (Otaria flavescens) from Patagonia, Argentina, for the first time in the region in 2018. In Chile, 258 human cases of trichinellosis were confirmed during the period 2005-2015; out of those 258 cases, most samples which tested positive for Trichinella spp. (29.5 %) were detected in the Metropolitan district (Santiago de Chile and outskirts), and 17.4 % in The Lake district. Regarding age brackets, people between 30-49 years of age showed the most cases (40.1 %). In Brazil, the infection is absent in domestic species but it has been found in wild boars (Sus scrofa) but limited to one or more region of the country. Within the animal species destined for food in South America, those that showed higher parasitical loads were pigs and wild boars, while armadillos (Chaetophractus villosus) and peccaries (Tayassu tajacu) showed very low Trichinella spp. larvae loads (0.04-0.1 larvae/g). Antibodies against Trichinella spp. have been detected in pigs from Ecuador and Bolivia. In Bolivia, antibodies were also found in humans. Peru, Colombia and Uruguay have no documented presence of Trichinella spp. in animals and humans. There is insufficient information regarding the presence of Trichinella spp. in domestic and wild animals, as well as in humans, since only a very limited number of surveys have been carried out. No papers with information on Trichinella spp. circulating in animals or humans have been published regarding the situation in Guyana, Surinam, French Guiana, Venezuela and Paraguay. Considering the growth of the guinea pig meat market in the Andean region, and the high prevalence of the disease reported in free range pigs and wild boars, as well as other game animal species, it is important to focus on the role of biosecurity and risk management, while improving meat market regulations, and detection of infection prior to consumption, in order to reduce the risk of transmission of this zoonotic disease to humans.

Epidemiology of Pig Tuberculosis in Argentina.

Bovine tuberculosis (bTB) is a disease caused mainly by the Mycobacterium bovis and that is endemic to livestock populations in most Latin American countries. Traditionally, bTB control programs are costly and targeted to cattle, largely disregarding other species such as swine and wildlife. According to official services, in Argentina disease prevalence in pigs is comparable to that observed in cattle, suggesting the need for efficient control programs to manage the disease in both species. Additionally, extensive farming systems, which are commonly practiced in Argentina, allow the interaction between livestock and wildlife such as wild boar (Sus scrofa), which is considered a natural host of the disease. Here, we evaluated the bTB pigs- cattle interface, studying the dynamics of M. bovis isolates in the pig population and identifying farm-level epidemiological variables associated with the disease confirmation at slaughterhouses. Additionally, to assess the potential multi-host systems in the transmission of bTB, the molecular characterization of wild boar mycobacterial strains was included in the study, as this interaction has not been previously evaluated in this region. Multivariable logistic regression models were used to assess the association between farm-level epidemiological variables (location, farm size, and co-existence with cattle and goats) and bTB confirmation in pig tuberculosis-like lesions samples. Results showed that when cattle were present, the odds of bTB in pigs decreased 0.3 or 0.6% for every additional sow when cattle were present or absent in the farm, respectively. Pigs shared 60% (18/30) of the genotypes with cattle and wild boar, suggesting transmission at the interface between pigs and cattle and highlighting the potential role of wild boar in bTB maintenance. These results provide novel information about the molecular diversity of M. bovis strains in pigs in Argentina and proposes the potential relevance of a multi-host system in the epidemiology of bTB in the region. The statistical models presented here may be used in the design of a low cost, abattoir-based surveillance program for bTB in the pig industry in Argentina, with potential extension to other settings with similar epidemiological conditions.

A review on Trichinella infection in South America.

Trichinella spp. causes human trichinellosis by means of the consumption of raw or inadequately treated meat from domestic or game animals. In the Americas, as well as in other continents, Trichinella infection is a health issue for humans and has a negative impact on the pork meat market, generated by people's fear of becoming infected with the parasite. The distribution of human cases and the sources of this disease in humans and animals were analysed in this report, which summarizes the information available regarding Trichinella infection in animals and humans in South America. Within South America, human infection with Trichinella was documented in Argentina and Chile during the period 2005-2019. Trichinellosis is endemic in these countries for, with human cases and foci in domestic and wild animals. In Argentina, human cases occur throughout the country, with foci found in pigs and wild animals. In Argentina, during the period 2012-2018, the number of suspected human cases reached 6,662. T. spiralis was identified in one South American sea lion (Otaria flavescens) from Patagonia, Argentina, for the first time in the region in 2018. In Chile, 258 human cases of trichinellosis were confirmed during the period 2005-2015; out of those 258 cases, most samples which tested positive for Trichinella spp. (29.5%) were detected in the Metropolitan district (Santiago de Chile and outskirts), and 17.4% in The Lake district. Regarding age brackets, people between 30-49 years of age showed the most cases (40.1%). In Brazil, the infection is absent in domestic species but it has been found in wild boars (Sus scrofa) but limited to one or more region of the country. Within the animal species destined for food in South America, those that showed higher parasitical loads were pigs and wild boars, while armadillos (Chaetophractus villosus) and peccaries (Tayassu tajacu) showed very low Trichinella spp. larvae loads (0.04 - 0.1 larvae/g). Antibodies against Trichinella spp. have been detected in pigs from Ecuador and Bolivia. In Bolivia, antibodies were also found in humans. Peru, Colombia and Uruguay have no documented presence of Trichinella spp. in animals and humans. There is insufficient information regarding the presence of Trichinella spp. in domestic and wild animals, as well as in humans, since only a very limited number of surveys have been carried out. No papers with information on Trichinella spp. circulating in animals or humans have been published regarding the situation in Guyana, Surinam, French Guiana, Venezuela and Paraguay. Considering the growth of the guinea pig meat market in the Andean region, and the high prevalence of the disease reported in free range pigs and wild boars, as well as other game animal species, it is important to focus on the role of biosecurity and risk management, while improving meat market regulations, and detection of infection prior to consumption, in order to reduce the risk of transmission of this zoonotic disease to humans.

New pieces in the transmission cycle of the hepatitis E virus in South America: first viral detection in wild boars from Argentina.

BACKGROUND: The hepatitis E virus (HEV) causes hepatitis worldwide. In Europe, wild boars are known to be viral reservoirs and sources of infection. In South America, there is a lack of information about HEV in these animals. METHODS: A total of 102 wild boar serum samples from Argentina (2014-2017) were studied for serological and molecular HEV detection. RESULTS: We obtained a seroprevalence of 19.6%, similar to that recently described in Uruguay (the only antecedent in South America). HEV ribonucleic acid (RNA) was amplified in two anti-HEV-positive samples. CONCLUSIONS: This is the first report of HEV circulation in wild boars from Argentina, adding evidence to the findings obtained in Uruguay indicating that wild boars could be viral reservoirs in South America.

Toxoplasma gondii and Trichinella infections in wild boars (Sus scrofa) from Northeastern Patagonia, Argentina.

Wild boar (Sus scrofa) was introduced in many countries of the world and is recognized as carrier of many infectious diseases. Wild game meat consumption is recognized as a source of transmission of Toxoplasma gondii and Trichinella spp. The aim of the present study was to evaluate the prevalence of antibodies to T. gondii and Trichinella spp. in free-range wild boars in Northeastern Argentine Patagonia. Between 2014 and 2018, 144 blood samples and 423 muscle samples from 423 carcasses were collected. To detect T. gondii IgG, 144 sera were processed by an immunofluorescent antibody test, and to detect anti-Trichinella IgG, 125 sera and 304 muscle juice samples were processed by ELISA. Detection of first stage larvae in muscle was performed by artificial digestion. A total of 423 wild boars muscle samples were negative to Trichinella spp. by artificial digestion. Antibodies to Trichinella spp. were detected in 2.4% (3/125) of serum samples and in 1.64% (5/304) of meat juice samples. Antibodies to T. gondii infection were detected in 12.5% (18/144) of the serum samples. This is the first study to reveal the presence of antibodies to T. gondii in wild boars from Argentina. The present results suggest that consumption of raw or undercooked wild boar meat could represent a potential source risk for toxoplasmosis in humans and that Trichinella spp. is infrequent and/or that it circulates in low burdens among wild boars in Northeastern Patagonia.

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.