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Plasmids play a fundamental role in the evolution of bacteria by allowing them to adapt to different environments and acquire, through horizontal transfer, genes that confer resistance to different classes of antibiotics. Using the available in vitro and in silico plasmid typing systems, we analyzed a set of isolates and public genomes of K. variicolato study its plasmid diversity. The resistome, the plasmid multilocus sequence typing (pMLST), and molecular epidemiology using the MLST system were also studied. A high frequency of IncF plasmids from human isolates but lower frequency from plant isolates were found in our strain collection. In silico detection revealed 297 incompatibility (Inc) groups, but the IncFIBK(216/297) predominated in plasmids from human and environmental samples, followed by IncFIIK(89/297) and IncFIA/FIA(HI1) (75/297). These Inc groups were associated with clinically important ESBL (CTX-M-15), carbapenemases (KPC-2 and NDM-1), and colistin-resistant genes which were associated with major sequence types (ST): ST60, ST20, and ST10. In silico MOB typing showed 76% (311/404) of the genomes contained one or more of the six relaxase families with MOBFbeing most abundant. We identified untypeable plasmids carrying blaKPC-2, blaIMP-1, and blaSHV-187but for which a relaxase was found; this may suggest that novel plasmid structures could be emerging in this bacterial species. The plasmid content in K. variicolahas limited diversity, predominantly composed of IncFIBKplasmids dispersed in different STs. Plasmid detection using the replicon and MOB typing scheme provide a broader context of the plasmids in K. variicola. This study showed that whole-sequence-based typing provides current insights of the prevalence of plasmid types and their association with antimicrobial resistant genes in K. variicolaobtained from humans and environmental niches.

A survey of entomopathogenic nematodes was conducted in sugar cane crops in a total of 14 soils, and positive results were obtained for strain MC5-2014 in the municipality of Tepalcingo, Morelos, in soil with a sandy loam texture and a pH of 6.4. Species determination was performed via morphological and morphometric techniques by searching for a tubular stoma with a swollen cylindrical pharyngeal body and a metacorpus in the basal part. The range of body length (L) was 750 to 1200 μm in females and 720 to 910 μm in males, while the corresponding maximum widths (W) of the body were 30 to 60 μm and 20 to 30 μm, respectively. Males exhibited bursa with a 1 + 1 + 3 + 3 distribution of papillae, and females exhibited a vulva located at the mid-body. For molecular identification, the ITS region of ribosomal DNA was used. Virulence tests (LC50) were conducted with Galleria mellonella, and a value of 4.732 was obtained for infective juveniles (IJs). Taking taxonomic and molecular characteristics into account, the isolate was determined to be Oscheius myriophila. The isolation of this strain represents the first geographic report of O. myriophilain Mexico, and it should be noted that the cultivation of sugar cane occurs with constant application of insecticides, herbicides, fungicides, and fertilizers as well as harvesting activities such as burning of the crop for harvest. The O. myriophilaisolate has the potential to be used in the future as a method of biological control in our country.