THE IntIPstQ-like INTEGRASE RECOMBINATION SITES (attCSITES)ARE POORLY ASSOCIATED TO attCsFROM ANTIMICROBIAL RESISTANCE GENE CASSETTES OF CLASS 1 INTEGRONS.

CENTRÓN DANIELA; ALONSO FERNANDO; QUIROGA PAULA; GAMBINO ANAHÍ

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

Reunión Conjunta 2017

Pseudomonas stutzeri is a naturally competent gram-negative species widely distributed in the environment, also described as an opportunistic pathogen and integron carrier. Such characteristics make P. stutzeri a promising organism for the study of lateral genetic transfer (LGT) mechanisms. In order to study the diversity of the attC recombination sites associated with IntIPstQ-like and its contribution to multidrug resistant integrons we performed a search for sequences with an identity >65% with IntIPstQ integrase. Sequences were analyzed with INTEGRON FINDER to detect: C-In (complete integrons, Integrase+attC), CALINs (clusters of attC sites lacking integron-integrases) and In0 (Integrase only). Sequence and phylogenetic analysis of IntIPstQ were made to establish its relationship with other integron integrases. We also carried out a phylogenetic analysis of the obtained attC sites and the ones of the main antibiotic resistance gene cassettes (ARGC). 20 sequences belonging to Pseudomonas, Halothiobacillus, Azotobacter, Methylibium, Thioalkalivibrio were analyzed in which 15 C-In, 25 CALINs and 4 In0 were identified. IntIPstQ was found more related to IntI2, evidencing the tetrad RHRY conserved in most cases, and 50% of the strains showed an ALAR motif. A total of 285 attC sites were found, 170 located in C-In and 115 in CALINs. The length of attC sites was between 42 and 132bp, being the most frequent of 76bp. Most attC sites from ARGCs were found in 3 main subclusters related to attCs from Halothiobacillus sp., Azotobacter and Methylibium. Only attCqnrVC1 was found among attC sites from Pseudomonas. Taken together, our results suggest that the genus Pseudomonas is not an active reservoir of attC sites that circulate by the mechanisms of the LGT in the genetic platform of class 1 integrons, although IntIPstQ-related integrases with attCs sites belonging to other clusters are part of the resistome of ARGCs