ABSTRACT In order to describe the genomic characteristics related to antimicrobial resistance and comparative genomics of diarrheagenic Escherichia coli (DEC), 14 DEC isolates from the strain collection of the Instituto Nacional de Salud (INS) were subjected to genome sequencing. We used bioinformatic procedures to analyze the obtained sequences in order to look for microbial resistance genes and genetic regions related to pathotypes and phylogroups. Several antimicrobial resistance determinants were detected, but the production of beta-lactamases and mutations associated to quinolone resistance were the most relevant. Additionally, we observed isolates of the same pathotype grouped in different phylogroups. The comparative genomics analysis showed a greater number of orthologous genes in isolates from the same pathotype and phylogroup. In conclusion, DEC isolates from Lima, Peru, showed resistance to multiple drugs; likewise, molecular and phylogenetic diversity was observed in several pathotypes and phylogroups.

RESUMEN Con el objetivo de describir las características genómicas relacionadas con la resistencia antimicrobiana y genómica comparativa de Escherichia coli diarreogénica (DEC), se sometieron a secuenciamiento genómico catorce aislamientos de DEC del banco de cepas del Instituto Nacional de Salud (INS). Las secuencias obtenidas se analizaron mediante procedimientos bioinformáticos a fin de buscar genes de resistencia microbiana y regiones genéticas relacionadas con patotipos y filogrupos. Se detectaron diversos determinantes de resistencia antimicrobiana, se destaca la producción de betalactamasas y mutaciones asociadas a la resistencia a quinolonas. Además, se observaron aislamientos de un mismo patotipo agrupados en distintos filogrupos. El análisis de genómica comparativa mostró un mayor número de genes ortólogos en aislamientos que pertenecían al mismo patotipo y filogrupo. Sobre la base de lo estudiado, los aislamientos de DEC en Lima, Perú, presentan resistencia a múltiples fármacos, y se detectaron varios patotipos y filogrupos con diversidad molecular y filogenética.

ABSTRACT In order to describe the genomic characteristics related to antimicrobial resistance and comparative genomics of diarrheagenic Escherichia coli (DEC), 14 DEC isolates from the strain collection of the Instituto Nacional de Salud (INS) were subjected to genome sequencing. We used bioinformatic procedures to analyze the obtained sequences in order to look for microbial resistance genes and genetic regions related to pathotypes and phylogroups. Several antimicrobial resistance determinants were detected, but the production of beta-lactamases and mutations associated to quinolone resistance were the most relevant. Additionally, we observed isolates of the same pathotype grouped in different phylogroups. The comparative genomics analysis showed a greater number of orthologous genes in isolates from the same pathotype and phylogroup. In conclusion, DEC isolates from Lima, Peru, showed resistance to multiple drugs; likewise, molecular and phylogenetic diversity was observed in several pathotypes and phylogroups.

RESUMEN Con el objetivo de describir las características genómicas relacionadas con la resistencia antimicrobiana y genómica comparativa de Escherichia coli diarreogénica (DEC), se sometieron a secuenciamiento genómico catorce aislamientos de DEC del banco de cepas del Instituto Nacional de Salud (INS). Las secuencias obtenidas se analizaron mediante procedimientos bioinformáticos a fin de buscar genes de resistencia microbiana y regiones genéticas relacionadas con patotipos y filogrupos. Se detectaron diversos determinantes de resistencia antimicrobiana, se destaca la producción de betalactamasas y mutaciones asociadas a la resistencia a quinolonas. Además, se observaron aislamientos de un mismo patotipo agrupados en distintos filogrupos. El análisis de genómica comparativa mostró un mayor número de genes ortólogos en aislamientos que pertenecían al mismo patotipo y filogrupo. Sobre la base de lo estudiado, los aislamientos de DEC en Lima, Perú, presentan resistencia a múltiples fármacos, y se detectaron varios patotipos y filogrupos con diversidad molecular y filogenética.

Abstract As part of the rhizosphere microbiota, actinomycetes interact with their host by releasing metabolites that positively influence their host’ growth. The main objective of this study was to evaluate the plant growth-promoting capacity of actinomycetes isolated from the rhizosphere of potato crops collected in the city of San Jeronimo, Andahuaylas, Peru. Forty-nine actinomycetes strains were isolated and screened for their capacity to solubilize phosphates, fix atmospheric nitrogen, produce indole acetic acid (IAA) and produce siderophores. Out of the total number of isolates, 33 (63.27%) solubilized phosphates, 42 (87.72%) fixed atmospheric nitrogen, 10 (20.41%) produced IAA and 18 (24.49%) were siderophore producers; strains AND 13 and AND 16 being the top performers. AND 13 was identified by 16S RNAr gene amplification as Streptomyces sp. The results indicate that actinomycetes can be considered as potential PGPR organisms and could be included in biofertilization programs of potato crops as an alternative to agrochemicals.

ABSTRACT During the period from 1995 to 2017, in order to determine the diversity of Vibrio parahaemolyticus pathogenic variants in Peru, 102 Peruvian genomes (97 from a hospital setting and 5 from an out-of-hospital setting) were analyzed using the multilocus typification scheme and BLASTn in the search for virulence genes. Fifteen different sequence types were identified. It was found that the ST3 genotype, which is found in the pandemic clone, was the most abundant, with 52% (n=53); followed by ST120, with 23.5% (n=24); and the CC345 clonal complex, with 11.8% (n=12). A total of 89 analyzed strains presented genes encoding the pathogenicity island VpaI-7 (87.3%), while 96 presented the tdh gene (94.1%), and 6 the trh gene (5.9%). The ST3 genotype was the predominant one during the evaluated period, this genotype was the cause of a major outbreak in Peru’s past history. Other pathogenic genotypes found represent a latent public health risk associated with seafood consumption.

RESUMEN Con el objetivo de determinar la diversidad de variantes patogénicas de Vibrio parahaemolyticus en el Perú durante el periodo 1995-2017, se analizaron 102 genomas peruanos (97 clínicos y 5 ambientales) empleando el esquema de tipificación multilocus y BLASTn para la búsqueda de genes de virulencia. Se identificaron 15 tipos de secuencia diferentes, encontrándose que el genotipo ST3, perteneciente al clon pandémico, fue el más abundante, con 52% (n=53); seguido por el ST120, con 23,5% (n=24); y el complejo clonal CC345, con 11,8% (n=12). Un total de 89 cepas analizadas presentaron genes que codifican la isla de patogenicidad VpaI-7 (87,3%), mientras que 96 presentaron el gen tdh (94,1%), y 6, el trh (5,9%). Durante el periodo evaluado, se resalta la predominancia del ST3, causante de un importante brote en el pasado del Perú, además de otros genotipos patógenos que representan un riesgo latente en salud pública asociado al consumo de alimentos marinos.

ABSTRACT During the period from 1995 to 2017, in order to determine the diversity of Vibrio parahaemolyticus pathogenic variants in Peru, 102 Peruvian genomes (97 from a hospital setting and 5 from an out-of-hospital setting) were analyzed using the multilocus typification scheme and BLASTn in the search for virulence genes. Fifteen different sequence types were identified. It was found that the ST3 genotype, which is found in the pandemic clone, was the most abundant, with 52% (n=53); followed by ST120, with 23.5% (n=24); and the CC345 clonal complex, with 11.8% (n=12). A total of 89 analyzed strains presented genes encoding the pathogenicity island VpaI-7 (87.3%), while 96 presented the tdh gene (94.1%), and 6 the trh gene (5.9%). The ST3 genotype was the predominant one during the evaluated period, this genotype was the cause of a major outbreak in Peru’s past history. Other pathogenic genotypes found represent a latent public health risk associated with seafood consumption.

RESUMEN Con el objetivo de determinar la diversidad de variantes patogénicas de Vibrio parahaemolyticus en el Perú durante el periodo 1995-2017, se analizaron 102 genomas peruanos (97 clínicos y 5 ambientales) empleando el esquema de tipificación multilocus y BLASTn para la búsqueda de genes de virulencia. Se identificaron 15 tipos de secuencia diferentes, encontrándose que el genotipo ST3, perteneciente al clon pandémico, fue el más abundante, con 52% (n=53); seguido por el ST120, con 23,5% (n=24); y el complejo clonal CC345, con 11,8% (n=12). Un total de 89 cepas analizadas presentaron genes que codifican la isla de patogenicidad VpaI-7 (87,3%), mientras que 96 presentaron el gen tdh (94,1%), y 6, el trh (5,9%). Durante el periodo evaluado, se resalta la predominancia del ST3, causante de un importante brote en el pasado del Perú, además de otros genotipos patógenos que representan un riesgo latente en salud pública asociado al consumo de alimentos marinos.

Abstract Potato (Solanum tuberosum L.) is the fourth most consumed food crop in the world, whose production in Peru is diminished due to phytosanitary problems and high costs of chemical fertilizers. In the present work, 32 actinomycetes isolated from the rhizosphere of organic native potato crops collected in the town of Cabana, Lucanas, Ayacucho, were characterized phenotypically and evaluated for their in vitro antagonistic capacity against Oomycete phytopathogen Phytophthora infestans. The characterization tests showed that 97% of the actinomycetes were able to assimilate glucose, sucrose, and mannitol; as well as producing extracellular enzymes like amylases (100%) and cellulases (50%). Furthermore, the growth in laboratory culture was better in the range of pH 5.5-8.5 and temperature 28-30 °C. From the tests of antagonism in oat agar (71.9%) and rye agar (31.2%), three strains were selected according to the native potato variety were selected as CAB10-J2 (Ccompis), CAB9-CA4 (Cuchipa-akan) and CAB5-F5 (Futis) with pathogen inhibition rates of 80.05, 77.47 and 37.5% respectively. The strains were identified by molecular tests as members of the genus Streptomyces and owners of polyketide synthase (PKS) genes. It is concluded that the rhizospheric actinomycetes of potato are producers of bioactive compounds capable of remarkably inhibiting the pathogen Phytophthora infestans, being able to be considered candidates in biological control programs of the "potato blight".

Potato crops are affected by a great number of pathogens that decrease their quality and productivity. One way of controlling these phytopathogens is through the use of antagonistic microorganisms, especially those isolated from the microbial community located in the rhizosphere. In this study, 49 strains of actinomycetes were isolated and their antagonist capacity against phytopathogens that affect Solanum tuberosum was assessed. 26.5% showed antagonist activity against Pectobacterium carotovorum, 69.4% against Fusarium sp., 44.9% against Lasiodiplodia sp., 55.1% against Rhizoctonia solani and 46.9% against Phytophthora infestans. Cultures of two selected actinomycetes (AND 12 and AND 24) were treated with ethyl acetate, dichloromethane, hexane and butanol, whose crude extracts showed antimicrobial activity, being the most important the extract obtained with ethyl acetate due to its greater spectrum of inhibitory activity. The selected strains were identified by phylogenetic analysis of the 16S rRNA gene as members of the genus Streptomyces. Due to their antagonist capacity demonstrated in the present study, rhizospheric actinomycetes could be considered as potential candidates to be used in pathogen control programs that affect potatoes.

El cultivo de la papa se ve afectado por una gran cantidad de patógenos que disminuyen su calidad y productividad. Uno de los métodos de control de estos fitopatógenos es mediante el uso de microorganismos antagonistas, en especial aquellos que se aíslan de la comunidad microbiana presente en la rizósfera. En este trabajo, se aislaron 49 cepas de actinomicetos y se evaluaron sus capacidades antagonistas frente a fitopatógenos que afectan a Solanum tuberosum. El 26.5% presentó capacidad antagónica frente a Pectobacterium carotovorum, el 69.4% a Fusarium sp., el 44.9% a Lasiodiplodia sp., el 55.1% a Rhizoctonia solani y el 46.9% a Phytophthora infestans. Cultivos de dos actinomicetos seleccionados (AND 12 y AND 24) fueron tratados con acetato de etilo, diclorometano, hexano y butanol, cuyos extractos crudos mostraron actividad antimicrobiana, siendo el extracto obtenido con acetato de etilo el más importante por presentar mayor espectro de actividad inhibitoria. Las cepas seleccionadas se identificaron por análisis filogenético del gen del ARNr 16S como miembros del género Streptomyces. Los actinomicetos rizosféricos, por su probada capacidad antagonista demostrada en el presente estudio, podrían ser considerados como potenciales candidatos a ser utilizados en programas de control de patógenos que afectan a la papa.

The aim of this study was to determine the prevalence, average intensity and mean abundance of ectoparasites in domestic pigeons (Columba livia). A total of 29 specimens were analyzed (17 males and 12 females). External surface of head, neck, chest, back and wings were examined, determining that 93.1% (14.9 ± 15.8 of total mean abundance) of pigeons were infected with one or more ectoparasites. All males and 83.3% of females were parasitized. Seven species of ectoparasites were identified, where five correspond to Order Mallophaga (Columbicola columbae [82.8%], Menopon gallinae [48.3%] Goniodes gigas [31%], Menacanthus stramineus [17.2%] and Lipeurus caponis [6.9%]), one to Order Diptera (Pseudolynchia canariensis [10.3%]), and one to Order Siphonapetra (Echidnophaga gallinacea [3.4%]). The largest number of mallophagans was found on the feathers of the wings and chest. Among associations, the monoparasitism was present in 28%, biparasitism in 28%, triparasitism in 34% and tetraparasitism in 3% of the pigeons. C. columbae was the most prevalent ectoparasite (82.8%). Besides, Menacanthus stramineus and Lipeurus caponis are reported for the first time as ectoparasites of Columba livia in Peru

El objetivo del presente trabajo fue determinar la prevalencia, intensidad media y abundancia media de ectoparásitos en palomas domésticas (Columba livia) comercializadas en un mercado de la ciudad de Lima, Perú. Se analizaron 29 ejemplares (17 machos y 12 hembras). Se inspeccionó la superficie externa de la cabeza, cuello, pecho, dorso y alas, determinando que el 93.1% (14.9 ± 15.8 de abundancia media total) de las palomas estuvieron infestadas con uno o más ectoparásitos; asimismo, el 100 de los machos y 83.3% de las hembras estuvieron parasitados. Se identificaron siete especies de ectoparásitos, de los cuales cinco corresponden al Orden Mallophaga (Columbicola columbae [82.8%], Menopon gallinae [48.3%] Goniodes gigas [31%], Menacanthus stramineus [17.2%] y Lipeurus caponis [6.9%]), uno al Orden Diptera (Pseudolynchia canariensis [10.3%]), y uno al Orden Siphonapetra (Echidnophaga gallinacea [3.4%]). El mayor número de malófagos fue encontrado sobre las plumas de las alas y el pecho. En las asociaciones de parásitos, se encontró 28% de monoparasitismo, 28% de biparasitismo, 34% de triparasitismo y 3% de tetraparasitismo. C. columbae fue el ectoparásito con mayor prevalencia (82.8%). Además, se reporta por primera vez a Menacanthus stramineus y Lipeurus caponis como ectoparásitos de C. livia en el Perú