Early reports accounted for two main genotypes of Piscirickettsia salmonis, a fish pathogen and causative agent of piscirickettsiosis, placing the single isolate EM-90 apart from the prototypic LF-89 and related isolates. In this study, we provide evidence that, contrary to what has been supposed, the EM-90-like isolates are highly prevalent and disseminated across Chilean marine farms. Molecular analysis of 507 P. salmonis field isolates derived from main rearing areas, diverse hosts and collected over 6 years, revealed that nearly 50% of the entire collection were indeed typed as EM-90-like. Interestingly, these isolates showed a marked host preference, being recovered exclusively from Atlantic salmon (Salmo salar) samples. Although both strains produce undistinguishable pathological outcomes, differences regarding growth kinetics and susceptibility to the antibiotics and bactericidal action of serum could be identified. In sum, our results allow to conclude that the EM-90-like isolates represent an epidemiologically relevant group in the current situation of piscirickettsiosis. Based on the consistency between genotype and phenotype exhibited by this strain, we point out the need for genotypic studies that may be as important for the Chilean salmon industry as the continuous surveillance of antimicrobial susceptibility patterns.

Outbreaks caused by Piscirickettsia salmonis are one of the major threats to the sustainability of the Chilean salmon industry. We report here the annotated draft genomes of two P. salmonis isolates recovered from different salmonid species. A comparative analysis showed that the number of virulence-associated secretion systems constitutes a main genomic difference.

Dolphins are widespread in warm oceanic and coastal waters. They habitually frequent islands. In California, Chile, and other localities, prehistoric peoples targeted dolphins. Some communities specialised in their capture. Elsewhere, prehistoric human use of cetaceans is attributed to opportunistic exploitation of active or stranded animals. In Meso-and Central America, the scarcity of cetaceans in archaeological sites is inferred to reflect the difficulties of their capture at sea with available technology. An unrecorded regional pattern is evident on Pedro González Island in the Pearl Islands (Panama). Remains of bottlenose and common dolphins were found in a Preceramic midden ("Playa Don Bernardo" [PDB]) located in a reef-and mangrove-fringed bay. Eight 14 C-dates bracket the deposit between 6200 and 5600 calibrated years BP. The Preceramic strata, which are between 0.8 m and nearly 4 m deep, are capped by a pottery-bearing soil deposited after a 3000-yr. hiatus in occupation. Delphinid bones and teeth represent 8% of 3660 mammal specimens identified to Family in three small test cuts. These cuts represent only 0.7% of the estimated midden area. A minimum of fourteen dolphin individuals is inferred: 11 belong to common dolphin (Delphinus), two to bottlenose dolphin (Tursiops), and one, possibly, to harbour dolphin (cf Stenella). Several bones show evidence for cuts, scrapes and thermal alteration. Some modifications are anthropogenic. Dry season upwelling induces shoaling fish to enter bays in the Pearl Islands attracting their nektonic, avian and dolphin predators. Ecologically, Don Bernardo Bay suits the short-beaked common dolphin (Delphinus delphis) and the common bottlenose nose dolphin (Tursiops tuncatus) -the most likely species to be present on the basis of osteology and zoogeography. The opportunistic use of naturally beached dolphins is one hypothesis for their procurement at PDB. Another is intentional human interference: corralling and driving dolphins with watercraft when they entered Don Bernardo Bay to feed or under threat from shark attacks. Ethnographic evidence around the world is supportive. PDB's total subsistence strategy was multi-faceted, comprising exploiting dolphins and marine turtles, farming, marine shore collecting, marine coastal fishing, and hunting in island forests and secondary vegetation. The population included experienced seafarers. Among the exploited mammals, dolphins provided easily the largest quantities of edible tissues, fats and oils.Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

ResumenEntre los años 2007 y 2010 se desarrollaron reconocimientos pedestres acompañados de sondeos y pequeñas excavaciones en el Archipiélago de Las Perlas, Panamá. Las investigaciones más intensivas se realizaron en Isla Pedro González. Esta breve síntesis preliminar de la cronología de la ocupación prehispánica de esta isla se basa en dataciones radiocarbónicas. También incluye comparaciones tipológicas y cronométricas con dos regiones culturales: Gran Coclé hacia el Oeste, donde floreció una tradición de policromía particular entre 2500 y 450 cal a.P. y el área que se constituyó como la región cultural de Gran Darién a partir de 1200–800 cal a.P. El yacimiento más antiguo en Pedro González es precerámico (6200–5600 cal a.P.). Después de un largo hiato, esta isla fue colonizada por grupos alfareros para el 2350 cal a.P. Se plantea la existencia de cinco fases cerámicas basadas en los rangos a 2σ de las dataciones radiocarbónicas, las que se traslapan entre sí. Entre 2350 y 1450 a.P. la alfarería isleña refleja la trayectoria diacrónica de la cerámica en Gran Coclé con características propias que se extienden a zonas de tierra firme hacia el Norte, así como a islas cercanas a la costa como Taboguilla. Sin embargo, entre 1450 y 1200 cal a.P., las similitudes tipológicas con la Península de Azuero, Coclé y Playa Venado (en la costa Sur del área canalera) son tan marcadas que se asume que este área comprendió brevemente una misma zona de interacción cuya homogeneidad cultural pudo estar vinculada al comercio marítimo estimulado por la importancia de las conchas de arrecife, como Spondylus. La alfarería cambia abruptamente entre 1200 y 800 cal a.P., aludiendo a una nueva población o a un reajuste en las conexiones con tierra firme con un énfasis en el litoral Este de la Bahía de Panamá y el noroeste de Colombia.

Tenacibaculum-like bacilli have recently been isolated from diseased sea-reared Atlantic salmon in outbreaks that took place in the XI region (Región de Aysén) of Chile. Molecular typing identified the bacterium as Tenacibaculum dicentrarchi. Here, we report the complete genome sequence of the AY7486TD isolate recovered during those outbreaks.