Diagnóstico microbiológico de las infecciones intraabdominales García-Sánchez, José Elías; García-García, M. Inmaculada; García-Garrote, Fernando ...
Enfermedades infecciosas y microbiología clínica,
April 2013, Letnik:
31, Številka:
4
Journal Article
Recenzirano
Resumen Las infecciones intraabdominales constituyen un amplio y diverso grupo de procesos intra y retroperitoneales que incluyen infecciones no complicadas, en las que el proceso infeccioso se ...limita al órgano o tejido de origen (apendicitis, diverticulitis, colecistitis…), y complicadas, cuando la infección se extiende y afecta al peritoneo desencadenando cuadros generales, como las peritonitis difusas, o localizados, como los abscesos intraabdominales. La mayoría se produce por perforación o inflamación de la pared intestinal, a partir de la flora gastrointestinal, y por tanto son infecciones polimicrobianas y mixtas, con predominio de bacterias anaerobias. El diagnóstico microbiológico es esencial para conocer la etiología y sobre todo la sensibilidad, en especial de las infecciones nosocomiales o comunitarias en pacientes de riesgo por el incremento de resistencia bacteriana, multirresistencia e implicación fúngica. A pesar de los avances en el diagnóstico microbiológico, en el caso de las infecciones intraabdominales sigue siendo directo, basándose en las tinciones y cultivos, y el progreso más notable es la introducción de la espectrometría de masas (MALDI-TOF) en la identificación de los patógenos implicados. De forma general se indican las recomendaciones sobre la recogida, transporte y procesamiento microbiológico de las muestras clínicas. Se comenta la etiopatogenia, la clínica y el diagnóstico microbiológico de las peritonitis primarias, secundarias y terciarias y de la peritonitis (y otras infecciones) asociada a diálisis peritoneal, de los abscesos intraabdominales (intraperitoneales, viscerales y retroperitoneales), infecciones de las vías biliares, apendicitis y diverticulitis.
Susceptibility testing of Eikenella corrodens is usually performed by a Mueller-Hinton sheep blood agar dilution (AD) method. However, this method is impractical for testing only a few strains. We ...compared AD with the broth microdilution method using Haemophilus test medium (HTM) in order to determine the susceptibility of 36 clinical isolates of E. corrodens to eight antimicrobial agents. MICs obtained by the HTM method yielded 95.5 and 84% agreement (within 2 and 1 log2 dilutions, respectively) with those obtained by AD. The HTM method with incubation in CO2 for 48 h was highly reproducible and constitutes an easy alternative for antimicrobial susceptibility testing of E. corrodens.
Abstract The present study was carried out to evaluate the prevalence of the clonal subgroup O16:H5-ST131 and the H 30 and H 30-Rx subclones among E. coli isolates causing extraintestinal infections ...and to know their virulence potential. The ST131 clonal group accounted for 490 (16%) of the 2995 isolates obtained from clinical samples in five Spanish hospitals during the study period (2005–2012). Among those 490 ST131 isolates, 456 belonged to serotype O25b:H4, 27 to O16:H5 and seven were O-non-typeable:H4 (ONT:H4). All 27 O16:H5 isolates showed fimH 41, whereas fimH 30 and fimH 22 alleles were the most frequently detected among O25b:H4 isolates. The majority (381/490; 78%) of ST131 isolates belonged to H 30 subclone, and 302 of 381 (79%) H 30 isolates belonged to the H 30-Rx subclone. Of the 27 O16:H5 isolates, 48% produced CTX-M-14; however, none produced CTX-M-15. In contrast, 46% of O25b:H4 isolates produced CTX-M-15 while only 2% produced CTX-M-14. More than a half of the O16:H5 isolates (56%) showed the ExPEC status which was significantly more prevalent within O25b:H4 isolates (81%) ( P < 0.01), especially among H 30-Rx (97%) isolates. In the present study, a modified virotype scheme was applied within which approximately half (52%) of the O16:H5 isolates showed the C1 specific virotype. Despite their low virulence-gene score (mean of virulence genes 6.4 versus 8.5 in O25b:H4 isolates), six out of the 10 O16:H5 isolates assayed showed high virulence in the mouse model of sepsis (killed 90–100% of mice challenged). Furthermore, four O16:H5 isolates of virotypes A and C1, carrying K2 variant of group II capsule, showed lethality at 24 h. Thus, certain O16:H5 fimH 41 isolates show a similar in vivo virulence to that reported with the highly virulent O25b:H4 H 30-Rx isolates (Mora et al., PLOS ONE 2014, e87025), supporting their potential virulence for humans.
Bacteremia due to Roseomonas spp Vasallo, Francisco J.; Alcalá, Luis; Cercenado, Emilia ...
Clinical microbiology and infection,
February 1998, Letnik:
4, Številka:
2
Journal Article
CTX-M enzymes, mainly CTX-M-14 and CTX-M-15, have emerged as the most prevalent extended-spectrum β-lactamase (ESBL) type produced by in Spain, with successful dissemination of clonal group ...O25b:H4-B2-ST131 producing CTX-M-15 within the hospital and community settings. However, until now CTX-M-14-producing in Spain had been shown to belong to a wide variety of serotypes with no predominance of a certain clonal group. In the present study, 654 strains positive for ESBL production obtained between 2005 and 2008 from inpatients and outpatients of four hospitals in Galicia, northwest Spain, were analysed. The strains were characterised with regard to ESBL enzymes, serotype, virulence genes, phylogenetic group, multilocus sequence type, and pulsed-field gel electrophoresis of I-digested DNA. As a result, the emergence of certain clonal groups of extraintestinal pathogenic producing CTX-M-14 has been detected in this geographic area, including O1:HNM-D-ST59, O15:H1-D-ST393/ST1394, O20:H34/HNM-D-ST354, O25b:H4-B2-ST131 and ONT:H21,42-B1-ST101. These five clonal groups showed a high virulence potential as they harboured more than eight virulence factors, which could explain their successful dissemination.
Having shown that the Xeral-Calde Hospital in Lugo (Spain) has been concerned by Escherichia coli clone O25:H4-ST131 producing CTX-M-15 (Nicolas-Chanoine et al. J Antimicrob Chemother 2008; 61: ...273-81), the present study was carried out to evaluate the prevalence of this clone among the extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates and also to molecularly characterize the E. coli isolates producing ESBL other than CTX-M-15.
In the first part of this study, 105 ESBL-producing E. coli isolates (February 2006 to March 2007) were characterized with regard to ESBL enzymes, serotypes, virulence genes, phylogenetic groups, multilocus sequence typing (MLST) and PFGE. In the second part of this study, 249 ESBL-producing E. coli isolates (April 2007 to May 2008) were investigated only for the detection of clone O25b:H4-ST131 producing CTX-M-15 using a triplex PCR developed in this study and based on the detection of the new operon afa FM955459 and the targets rfbO25b and 3' end of the bla(CTX-M-15) gene.
Of the 105 ESBL-producing E. coli isolates, 60 (57.1%) were positive for CTX-M-14, 23 (21.9%) for CTX-M-15, 10 (9.5%) for SHV-12 and 7 (6.7%) for CTX-M-32. Serotypes, virulence genes, phylogenetic groups and molecular typing by PFGE demonstrated high homogeneity within those producing CTX-M-15 and high diversity within E. coli producing CTX-M-14 and other ESBLs. By PFGE, CTX-M-15-producing E. coli isolates O25b:H4 belonging to the phylogenetic group B2 and MLST profile ST131 were grouped in the same cluster. The epidemic strain of clone O25b:H4-ST131 represented 23.1%, 22.5% and 20.0% of all ESBL-producing E. coli isolated in 2006, 2007 and 2008, respectively.
CTX-M-type ESBLs, primarily CTX-M-14 and CTX-M-15, have emerged as the predominant types of ESBL produced by E. coli isolates in Lugo. In view of the reported findings, long-term care facilities for elderly people may represent a significant reservoir for E. coli clone O25b:H4-ST131 producing CTX-M-15. The triplex PCR developed in this work will be useful for rapid and simple detection of this clone.
PDF
