Search

Alma López-García,1 Rosa del Carmen Rocha-Gracia,1 Elena Bello-López,1 Claudia Juárez-Zelocualtecalt,1 Yolanda Sáenz,2 Miguel Castañeda-Lucio,1 Liliana López-Pliego,1 María Cristina González-Vázquez,1 Carmen Torres,3 Teolincacihuatl Ayala-Nuñez,1 Guadalupe Jiménez-Flores,4 Margarita María de la Paz Arenas-Hernández,1 Patricia Lozano-Zarain1 1Benemérita Universidad Autónoma de Puebla, Instituto de Ciencias, Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Complejo de Ciencias, Ciudad Universitaria. Col San Manuel CP, Puebla, Mexico; 2Area de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain; 3Area Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain; 4Laboratorio de Análisis Clínicos, Sección de Microbiología, Hospital Regional Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Puebla, Mexico Purpose: Pseudomonas aeruginosa infections in hospitals constitute an important problem due to the increasing multidrug resistance (MDR) and carbapenems resistance. The knowledge of resistance mechanisms in Pseudomonas strains is an important issue for an adequate antimicrobial treatment. Therefore, the objective was to investigate other antimicrobial resistance mechanisms in MDR P. aeruginosa strains carrying blaIMP, make a partial plasmids characterization, and determine if modifications in oprD gene affect the expression of the OprD protein. Methodology: Susceptibility testing was performed by Kirby Baüer and by Minimum Inhibitory Concentration (presence/absence of efflux pump inhibitor); molecular typing by Pulsed-field gel electrophoresis (PFGE), resistance genotyping and integrons by PCR and sequencing; OprD expression by Western blot; plasmid characterization by MOB Typing Technique, molecular size by PFGE-S1; and blaIMP location by Southern blot. Results: Among the 59 studied P. aeruginosa isolates, 41 multidrug resistance and carbapenems resistance isolates were detected and classified in 38 different PFGE patterns. Thirteen strains carried blaIMP; 16 blaGES and four carried both genes. This study centered on the 17 strains harboring blaIMP. New variants of β-lactamases were identified (blaGES-32, blaIMP-56, blaIMP-62) inside of new arrangements of class 1 integrons. The presence of blaIMP gene was detected in two plasmids in the same strain. The participation of the OprD protein and efflux pumps in the resistance to carbapenems and quinolones is shown. No expression of the porin OprD due to stop codon or IS in the gene was found. Conclusions: This study shows the participation of different resistance mechanisms, which are reflected in the levels of MIC to carbapenems. This is the first report of the presence of three new variants of β-lactamases inside of new arrangements of class 1 integrons, as well as the presence of two plasmids carrying blaIMP in the same P. aeruginosa strain isolated in a Mexican hospital. Keywords: Pseudomonas aeruginosa, resistance mechanisms, plasmid, integrons

Manuel G Ballesteros-Monrreal, 1 Margarita MP Arenas-Hernández, 1 Yessica Enciso-Martínez, 2 Claudia F Martínez-de la Peña, 1 Rosa del C Rocha-Gracia, 1 Patricia Lozano-Zaraín, 1 Armando Navarro-Ocaña, 3 Ygnacio Martínez-Laguna, 1 Rafael de la Rosa-López 2 1Posgrado en Microbiología, Centro de Investigación en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria, Puebla, Pue, Mexico; 2Departamento de Ciencias Químico Biológicas y Agropecuarias, Universidad de Sonora Unidad Regional Norte, Caborca, Sonora, Mexico; 3Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de Mexico, MexicoCorrespondence: Margarita MP Arenas-HernándezEdificio IC-11, Ciudad Universitaria, Colonia San Manuel CP, Puebla 72570, MexicoTel/Fax +52 222 2295500 ext 2524Email maguie10@gmail.comBackground/Purpose: Uropathogenic E. coli (UPEC) is the main cause of urinary tract infection (UTI) and it is known that pregnant women have a higher risk for UTI. UPEC has a variety of virulence and antibiotic resistance factors that facilitate its pathogenic success and it is crucial to know which are the susceptibility patterns, Extended-Spectrum-β-Lactamase (ESBL) production, virulence genes, pathogenicity islands (PAI), phylogenetic groups and serotypes among strains isolated from pregnant and non-pregnant women.Methods: One hundred fifty UPEC strains were isolated from pregnant and non-pregnant women from two different Mexican states (Sonora and Puebla). Strains were analyzed using the Kirby-Bauer method for the determination of antibiotic susceptibility and ESBL. Virulence genes, PAIs and phylogenetic groups were determined using a multiplex PCR. Strains were serotyped by an agglutination assay. Blood agar and CAS agar were used for phenotypic assays.Results: 92.7% of UPEC strains showed multidrug-resistant (MDR), 6.7% extremely-resistant (XDR) and 0.6% pandrug-resistant (PDR). The highest resistance was determined to be for β-lactam antibiotics (> 72% in both states) and 44.5% of the UPEC strains were ESBL+. The predominant virulence genes found were fimH (100%), iucD (85%) and iha (60%). The strains isolated from pregnant women from Puebla presented a large percentage of genes associated with upper urinary tract infections. PAIs were found in 51% and 68% of the strains from Sonora and Puebla, respectively. All the strains were siderophores producers and 41.5% produced hemolysis. The serotypes found were diverse and belonged to phylogroups A, B2 and C.Conclusion: The UPEC strains from this study are MDR with tendency to XDR or PDR, they can cause upper UTIs and are serotypically and phylogenetically diverse, which supports the need to develop new strategies for UTI treatment in pregnant and non-pregnant Mexican women.Keywords: UPEC in pregnancy, antibiotic resistance, virulence profile, phylogenetic groups, multiplex PCR, serotype

Abstract Background The widespread Escherichia coli clone ST131 implicated in multidrug-resistant infections has been recently reported, the majority belonging to O25:H4 serotype and classified into five main virotypes in accordance with the virulence genes carried. Methods Pathogenicity Islands I and II (PAI-I and PAI-II) were determined using conventional PCR protocols from a set of four E. coli CTXR ST131 O25:H4/H30-Rx strains collected from healthy donors’ stool. The virulence genes patterns were also analyzed and compared them with the virotypes reported previously; then adherence, invasion, macrophage survival and biofilm formation assays were evaluated and AIEC pathotype genetic determinants were investigated. Findings Non-reported virulence patterns were found in our isolates, two of them carried satA, papA, papGII genes and the two-remaining isolates carried cnfI, iroN, satA, papA, papGII genes, and none of them belonged to classical ST131 virotypes, suggesting an endemic distribution of virulence genes and two new virotypes. The presence of PAI-I and PAI-II of Uropathogenic E. coli was determined in three of the four strains, furthermore adherence and invasion assays demonstrated higher degrees of attachment/invasion compared with the control strains. We also amplified intI1, insA and insB genes in all four samples. Interpretation The results indicate that these strains own non-reported virotypes suggesting endemic distribution of virulence genes, our four strains also belong to an AIEC pathotype, being this the first report of AIEC in México and the association of AIEC with healthy donors.

Uropathogenic Escherichia coli (UPEC) remains the main etiological agent of urinary tract infections affecting females and males. The draft genome sequence of three strains of UPEC isolated from senior citizens and pregnant women in the state of Puebla, Mexico, is reported here., Competing Interests: The authors declare no conflict of interest.

There is increased evidence demonstrating the association between Crohn's Disease (CD), a type of Inflammatory Bowel Disease (IBD), and non-diarrheagenic Adherent/Invasive Escherichia coli (AIEC) isolates. AIEC strains are phenotypically characterized by their adhesion, invasion and intra-macrophage survival capabilities. In the present study, the genomes of five AIEC strains isolated from individuals without IBD (four from healthy donors and one from peritoneal liquid) were sequenced and compared with AIEC prototype strains (LF82 and NRG857c), and with extra-intestinal uropathogenic strain (UPEC CFT073). Non-IBD-AIEC strains showed an Average Nucleotide Identity up to 98% compared with control strains. Blast identities of the five non-IBD-AIEC strains were higher when compared to AIEC and UPEC reference strains than with another E. coli pathotypes, suggesting a relationship between them. The SNPs phylogeny grouped the five non-IBD-AIEC strains in one separated cluster, which indicates the emergence of these strains apart from the AIEC group. Additionally, four genomic islands not previously reported in AIEC strains were identified. An incomplete Type VI secretion system was found in non-IBD-AIEC strains; however, the Type II secretion system was complete. Several groups of genes reported in AIEC strains were searched in the five non-IBD-AIEC strains, and the presence of fimA, fliC, fuhD, chuA, irp2 and cvaC were confirmed. Other virulence factors were detected in non-IBD-AIEC strains, which were absent in AIEC reference strains, including EhaG, non-fimbrial adhesin 1, PapG, F17D-G, YehA/D, FeuC, IucD, CbtA, VgrG-1, Cnf1 and HlyE. Based on the differences in virulence determinants and SNPs, it is plausible to suggest that non-IBD AIEC strains belong to a different pathotype., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2019 Elsevier Inc. All rights reserved.)