The first report of porcine parvovirus 7 (PPV7) in Colombia demonstrates the presence of variants associated with modifications at the level of the VP2-capsid protein.

There are a wide variety of porcine parvoviruses (PPVs) referred to as PPV1 to PPV7. The latter was discovered in 2016 and later reported in some countries in America, Asia, and Europe. PPV7 as a pathogenic agent or coinfection with other pathogens causing disease has not yet been determined. In the present study, we report the identification of PPV7 for the first time in Colombia, where it was found retrospectively since 2015 in 40% of the provinces that make up the country (13/32), and the virus was ratified for 2018 in 4/5 provinces evaluated. Additionally, partial sequencing (nucleotides 380 to 4000) was performed of four Colombian strains completely covering the VP2 and NS1 viral genes. A sequence identity greater than 99% was found when comparing them with reference strains from the USA and China. In three of the four Colombian strains, an insertion of 15 nucleotides (five amino acids) was found in the PPV7-VP2 capsid protein (540-5554 nt; 180-184 aa). Based on this insertion, the VP2 phylogenetic analysis exhibited two well-differentiated evolutionarily related groups. To evaluate the impact of this insertion on the structure of the PPV7-VP2 capsid protein, the secondary structure of two different Colombian strains was predicted, and it was determined that the insertion is located in the coil region and not involved in significant changes in the structure of the protein. The 3D structure of the PPV7-VP2 capsid protein was determined by threading and homology modeling, and it was shown that the insertion did not imply a change in the shape of the protein. Additionally, it was determined that the insertion is not involved in suppressing a potential B cell epitope, although the increase in length of the epitope could affect the interaction with molecules that allow a specific immune response.

First detection of porcine circovirus type 3 in Colombia and the complete genome sequence demonstrates the circulation of PCV3a1 and PCV3a2.

Porcine circovirus 3 (PCV3) was recently discovered and is a new species of the genus circovirus. Clinically, it is associated with absence of symptoms or with different clinical syndromes. It has been reported in different countries of America, Europe and Asia. Last year, in Colombia, some farms have reported symptoms similar to those caused by PCV2. Samples were taken from two farms located in the centre of the country, and the presence of PCV3 was determined by PCR in two samples, one from a pool of sera and another from mesenteric lymph node. The strains were fully sequenced (GenBank accession numbers MH327784 and MH327785) and classified into subgroups a1 and a2. According to this classification and its analysis, strain a2 is located within the group called "Linker" that may be evolving towards group "b". In addition to the above, the two Colombian strains were compared with 104 strains reported in the GenBank database. The phylogenetic tree obtained grouped according to the classification of subgroups a1, a2, b1 and b2. It was found that subgroups a1 and a2 were well grouped when comparing whole genomes, but the same was not observed with the strains of group "b". In the latter, no subgroups were evidenced when comparing complete genomes. It is suggested that a new classification of PCV3 subgroups should be proposed, based on whole genome sequences. This is the first report of PCV3 in Colombia and its complete genome sequence.

Caracterización molecular de cepas colombianas de Salmonella spp. a través del RFLP-IS 200m / Molecular characterizacion of Colombian stumps of Salmonella spp. through the RFLP-IS200

Las técnicas moleculares empleadas para el análisis de ADN cromosomal como el RFLP IS200 han demostrado ser eficientes para resolver relaciones filogenéticas y epidemiológicas entre las cepas de Salmonella spp., aisladas de aves y humanos. El presente estudio tuvo como objetivo determinar si la IS200 estaba presente en las cepas de Salmonella aisladas de aves de corral y de humanos para establecer una posible cadena de transmisión entre ambos. El análisis filogenético de las cepas de Salmonella mostró 13 perfiles de IS200 que exhibieron de 1 a 11 copias de la secuencia de inserción, localizadas en un rango entre 13 y 1.71kb. El trabajo permitió concluir que IS200 es un marcador molecular eficiente, sensible y específico, útil para realizar estudios epidemiológicos ya que discriminó entre cepas de diferentes orígenes y comprobó que existe una relación clonal entre las cepas aviares y humanas. Los resultados obtenidos muestran la necesidad de implementar medidas sanitarias que conlleven a que en la producción se minimicen las condiciones que favorezcan la propagación de Salmonella entre las aves