RESUMEN
We investigated the phenotypic and molecular characteristics of Extended-Spectrum-ß-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae clinical isolates from four health-care institutions in Hermosillo, Sonora, Mexico. ESBL-producing isolates were collected from February to August 2016. The prevalence of ESBL-producing E. coli and K. pneumoniae was 11.9 and 8.7%, respectively. High dissemination of resistance to ciprofloxacin (88%), trimethoprim/sulfamethoxazole (72%) and aminoglycosides (59%) were detected, as well as susceptibility to meropenem, amikacin and tigecycline. The ESBL found variants were CTX-M-1 (88%) and CTX-M-9 (5%). The plasmid-mediated quinolone resistance (PMQR) gene aac(6´)-Ib-cr was identified in 62% of a representative sample, whereas the qnrB and qnrS genes were detected in 49% of the isolates. PFGE analyses detected many unrelated clones among the hospital or community isolates. A constant programme of epidemiological surveillance is recommended to understand the dynamics of bacterial resistance to both cephalosporin as well as the fluoroquinolone family of antibiotics.
Asunto(s)
Escherichia coli/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , beta-Lactamasas/biosíntesis , Farmacorresistencia Bacteriana Múltiple/genética , Farmacorresistencia Bacteriana Múltiple/fisiología , Escherichia coli/aislamiento & purificación , Humanos , Klebsiella pneumoniae/aislamiento & purificación , México , Pruebas de Sensibilidad Microbiana , FenotipoRESUMEN
Cluster BG of the actinobacteriophage was formed upon discovery of five novel bacteriophages isolated by enrichment from their host, Streptomyces griseus subsp. griseus strain ATCC 10137. Four members of this cluster (BabyGotBac, Maih, TP1605, and YDN12) share over 89% average nucleotide identity, while the other (Xkcd426) has only 72% similarity to other cluster members.
RESUMEN
The acquisition of ß-lactamases, such as class B metallo-ß-lactamases, in Pseudomonas aeruginosa is detrimental to antimicrobial therapy in hospitalized patients. In Mexico, metallo-ß-lactamase IMP-15 has been found to be encoded on the In95 class 1 integron in a major clone of P. aeruginosa. In this work, we describe the variability of this class 1 integron in an epidemic clone of carbapenem-resistant P. aeruginosa clinical isolates highly related to isolates previously described in Mexico.
Asunto(s)
Enfermedades Endémicas , Variación Genética , Integrones/genética , Infecciones por Pseudomonas/epidemiología , Pseudomonas aeruginosa/enzimología , beta-Lactamasas/genética , Antibacterianos/farmacología , Carbapenémicos/farmacología , Electroforesis en Gel de Campo Pulsado , Humanos , Imipenem/farmacología , México/epidemiología , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/aislamiento & purificación , Análisis de Secuencia de ADN , Resistencia betalactámica/genéticaRESUMEN
BACKGROUND AND AIMS: Carbapenem resistance in Pseudomonas aeruginosa may be due to the presence of metallo-beta-lactamases (MbetaL). The genes that encode these enzymes can be located in association with aminoglycoside-modifying enzymes on class 1 integrons. This study describes the bla(IMP-18) class 1 integron array (In169) from a carbapenem-resistant P. aeruginosa clinical isolate obtained at the Centro Medico Nacional La Raza (CMNR) in Mexico City and compares it to other bla(IMP)-type producers. METHODS: Twenty six multiresistant P. aeruginosa clinical isolates were recovered between June and December 2004 and tested by MicroScan and CLSI agar dilution methods. The MbetaL production was screened by a disk approximation test and MbetaL Etest strips, whereas MbetaL genes and integrons were detected using PCR primers. DNA sequence analysis was carried out by BLAST, and epidemiological typing was performed by pulsed-field gel electrophoresis (PFGE). A Southern hybridization analysis was performed with a bla(IMP) specific DNA probe. RESULTS: Nine of 26 P. aeruginosa isolates were imipenem-resistant with unique PFGE patterns (no clonal relation), and only one strain (5106) was positive for MbetaL production, corresponding to the IMP-type. The class 1 integron encoding the MbetaL was characterized: it contained the IMP-18, two copies of aadA2 and OXA-2 genes, corresponding to a new class 1 integron array, denoted In169. P. aeruginosa isolate 5106 is genetically related to bla(IMP-18) positive P. aeruginosa isolate from a distant hospital (Hospital Infantil de Morelia). CONCLUSION: This report is the first to describe the bla(IMP-18) in two genetically related isolates from two different institutions.