Photorhabdus antumapuensis sp. nov., a novel symbiotic bacterial species associated with Heterorhabditis atacamensis entomopathogenic nematodes.

One motile, Gram-negative, non-spore-forming and rod-shaped symbiotic bacterium, strain UCH-936T, was isolated from Heterorhabditis atacamensis nematodes. Results of biochemical, physiological, molecular and genomic analyses suggest that it represents a new species, which we propose to name Photorhabdus antumapuensis sp. nov. Digital DNA-DNA hybridization shows that strain UCH-936T is more closely related to Photorhabdus kleinii DSM 23513T, but shares solely 50.5 % similarity, which is below the 70% cut-off value that delimits species boundaries in bacteria. Phylogenetic reconstructions using whole-genome sequences show that strain UCH-936T forms a unique clade, suggesting its novel and distinct taxonomic status again. Similarly, comparative genomic analyses shows that the virulence factor flagella-related gene fleR, the type IV pili-related gene pilL and the vibriobactin-related gene vibE are present in the genome of strain UCH-936T but absent in the genomes of its closest relatives. Biochemically and physiologically, UCH-936T differs also from all closely related Photorhabdus species. Therefore, Photorhabdus antumapuensis sp. nov. is proposed as a new species with the type strain UCH-936T (CCCT 21.06T=CCM 9188T=CCOS 1991T).

Entomopathogenic nematology in Latin America: A brief history, current research and future prospects.

Since the 1980s, research into entomopathogenic nematodes (EPNs) in Latin America has produced many remarkable discoveries. In fact, 16 out of the 117 recognized species of EPNs have been recovered and described in the subcontinent, with many more endemic species and/or strains remaining to be discovered and identified. In addition, from an applied perspective, numerous technological innovations have been accomplished in relation to their implementation in biocontrol. EPNs have been evaluated against over 170 species of agricultural and urban insects, mites, and plant-parasitic nematodes under laboratory and field conditions. While much success has been recorded, many accomplishments remain obscure, due to their publication in non-English journals, thesis dissertations, conference proceedings, and other non-readily available sources. The present review provides a brief history of EPNs in Latin America, including current findings and future perspectives.

First Report of Heterorhabditis amazonensis from Venezuela and Characterization of Three Populations.

During a survey in western Venezuela in 2011, three new populations of Heterorhabditis amazonensis (LPV081, LPV156, and LPV498) were isolated. Some differences were found in terms of morphometry compared with the original description; however, the distance from the anterior end to the excretory pore is the most variable character; significantly shorter in all infective juveniles and in other developmental stages depending on the population. According to a Principal Component Analysis, LPV498 possesses more differences in morphometric characteristics and can be separated from the other two. Those intraspecific differences could be attributed to the geographic origin of the nematode. Molecular studies of ITS regions demonstrated that the sequences of the Venezuelan strains were identical to those of the type species originally isolated in the Brazilian Amazonian forest. This is an interesting fact because in several studies on heterorhabditids, intraspecific variability has been recorded. Herein, we present the first report of H. amazonensis in Venezuela and the characterization of three populations of this species.

Steinernema goweni n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Zulia State, Venezuela.

A nematode from the genus Steinernema was isolated in Zulia state (North-western, Venezuela). Morphological, morphometric and molecular studies indicated that this nematode belongs to the "bicornutum" group and is described herein as Steinernema goweni n. sp. Steinernema goweni n. sp. is characterised by morphometrics of its infective juveniles, with body length 640 (531-719) µm, pharynx length of 119 (109-126) µm, tail of 67 (59-89) µm, c ratio = 9 (6-11) and E% = 77 (48-94). First generation male specimens can be recognised by the shape and size of spicules (55 (50-57) µm long) and gubernaculum (35 (30-40) µm long), and %D value 42 (28-59), which is at the lower limit within the "bicornutum" group. The number of genital papillae in males is also distinctive for S. goweni n. sp. presenting up to 27 (13 pairs + 1) papillae in 15% of specimens. The phasmids can be seen in scanning electron microscopy in all stages, characters not previously reported within the "bicornutum" group. Phylogenetic analyses of the "bicornutum" group based on both ITS and D2D3 regions showed a clear separation of S. goweni n. sp. from the other species. In both analyses S. goweni n. sp. formed a strongly supported group of American species.