Artículos (Microbiología)

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Antimicrobial susceptibility trends and evolution of isolates with extended spectrum β-lactamases among Gram-negative organisms recovered during the SMART study in Spain (2011-2015)
(Sociedad Española de Quimioterapia, 2018) Cantón, Rafael; Loza, Elena; Aznar Martín, Javier; Barrón Adúriz, Rubén; Calvo, Jorge; Castillo, F. Javier; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología
Introduction. The SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study monitors antimicrobial susceptibility and extended spectrum β-lactamases (ESBLs) in Gram-negative bacilli recovered from intra-abdominal infections (IAI). Material and methods. Antimicrobial susceptibility of 5,343 isolates from IAI recovered in 11 centres during the 2011-2015 SMART-Spain program was analysed by standard microdilution (EUCAST criteria) and compared with that from 2002-2010. ESBLs were phenotypically detected. Results. Escherichia coli, the most common isolate, significantly decreased in community acquired IAI (60.9% 2002-2010 vs. 56.1% 2011-2015, P=0.0003). It was followed in prevalence by Klebsiella pneumoniae that increased both in the community (8.9% vs. 10.8%, P=0.016) and nosocomial (9.2% vs. 10.8%, P=0.029) IAI and P. aeruginosa, which significantly increased in community acquired IAI (5.6% vs. 8.0%, P=0.0003). ESBLs were more prevalent in K. pneumoniae (16.3%) than in E. coli (9.5%) of nosocomial origin and were more frequently isolated from elderly patients (>60 years). Considering all Enterobacteriaceae, ertapenem (92.3-100%) and amikacin (95.5%-100%) were the most active antimicrobials. Ertapenem activity, unlike amoxicillinclavulanate or piperacillin-tazobactam, remained virtually unchanged in ESBL (100%) and non-ESBL (98.8%) E. coli producers. Its activity decreased in ESBL-K. pneumoniae (74.7%) but was higher than that of amoxicillin-clavulanate (14.0%) and piperacillin-tazobactam (24.0%). Interestingly, ertapenem susceptibility was maintained in >60% of ESBL isolates that were resistant to amoxicillin-clavulanate, piperacillin-tazobactam or fluoroquinolones. Conclusions. SMART-Spain results support current guidelines which include ertapenem as empiric treatment in mild-moderate community-acquired IAI, particularly with ESBL producers. These recommendations will need to be updated with the recently introduction of new antimicrobials.
Evolution of the Quorum network and the mobilome (plasmids and bacteriophages) in clinical strains of Acinetobacter baumannii during a decade
(Nature Research, 2018-02-06) López, M.; Rueda, A.; Florido, J.P.; Blasco, L.; Fernández-García, L.; Trastoy, R.; Pascual Hernández, Álvaro; Tomas, M.; Universidad de Sevilla. Departamento de Microbiología; Instituto de Salud Carlos III; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Gobierno de España; Xunta de Galicia
In this study, we compared eighteen clinical strains of A. baumannii belonging to the ST-2 clone and isolated from patients in the same intensive care unit (ICU) in 2000 (9 strains referred to collectively as Ab_GEIH-2000) and 2010 (9 strains referred to collectively as Ab_GEIH-2010), during the GEIH-REIPI project (Umbrella BioProject PRJNA422585). We observed two main molecular differences between the Ab_GEIH-2010 and the Ab_GEIH-2000 collections, acquired over the course of the decade long sampling interval and involving the mobilome: i) a plasmid harbouring genes for blaOXA 24/40 ß-lactamase and abKA/abkB proteins of a toxin-antitoxin system; and ii) two temperate bacteriophages, Ab105-1ϕ (63 proteins) and Ab105-2ϕ (93 proteins), containing important viral defence proteins. Moreover, all Ab_GEIH-2010 strains contained a Quorum functional network of Quorum Sensing (QS) and Quorum Quenching (QQ) mechanisms, including a new QQ enzyme, AidA, which acts as a bacterial defence mechanism against the exogenous 3-oxo-C12-HSL. Interestingly, the infective capacity of the bacteriophages isolated in this study (Ab105-1ϕ and Ab105-2ϕ) was higher in the Ab_GEIH-2010 strains (carrying a functional Quorum network) than in the Ab_GEIH-2000 strains (carrying a deficient Quorum network), in which the bacteriophages showed little or no infectivity. This is the first study about the evolution of the Quorum network and the mobilome in clinical strains of Acinetobacter baumannii during a decade.
Relationship between Tolerance and Persistence Mechanisms in Acinetobacter baumannii Strains with AbkAB Toxin-Antitoxin System
(American Society for Microbiology, 2018-04-26) Fernández García, Laura; Fernández Cuenca, Felipe Manuel; Blasco, Lucía; López Rojas, Rafael; Ambroa, Antón; López, María; Pascual Hernández, Álvaro; Bou, Germán; Tomás, María; Universidad de Sevilla. Departamento de Microbiología; Instituto de Salud Carlos III; Consejo Superior de Investigaciones Científicas (CSIC); Grupo de Estudio sobre Mecanismos de Acción y Resistencia a los Antimicrobianos, GEMARA (SEIMC); Xunta de Galicia
The molecular mechanisms of tolerance and persistence associated with several compounds in Acinetobacter baumannii clinical isolates are unknown. Using transcriptomic and phenotypic studies, we found a link between mechanisms of bacterial tolerance to chlorhexidine and the development of persistence in the presence of imipenem in an A. baumannii strain belonging to clinical clone ST-2 (OXA-24 β-lactamase and AbkAB toxin-antitoxin [TA] system carried in a plasmid). Interestingly, the strain A. baumannii ATCC 17978 (AbkAB TA system from plasmid) showed persistence in the presence of imipenem and chlorhexidine.
Quorum sensing network in clinical strains of A. baumannii: AidA is a new quorum quenching enzyme
(Public Library of Science, 2017-03-22) López, María; Mayer, Celia; Fernández García, Laura; Blasco, Lucía; Muras, Andrea; Martín Ruiz, Federico; Bou, German; Otero, Ana; Tomás, María; Pachón Díaz, Jerónimo; Pascual Hernández, Álvaro; Rodríguez-Baño, Jesús; Cisneros, José Miguel; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina; Instituto de Salud Carlos III; Consejo Superior de Investigaciones Científicas (CSIC); Gobierno de España; Xunta de Galicia
Acinetobacter baumannii is an important pathogen that causes nosocomial infections generally associated with high mortality and morbidity in Intensive Care Units (ICUs). Currently, little is known about the Quorum Sensing (QS)/Quorum Quenching (QQ) systems of this pathogen. We analyzed these mechanisms in seven clinical isolates of A. baumannii. Microarray analysis of one of these clinical isolates, Ab1 (A. baumannii ST-2_clon_2010), previously cultured in the presence of 3-oxo-C12-HSL (a QS signalling molecule) revealed a putative QQ enzyme (α/ß hydrolase gene, AidA). This QQ enzyme was present in all non-motile clinical isolates (67% of which were isolated from the respiratory tract) cultured in nutrient depleted LB medium. Interestingly, this gene was not located in the genome of the only motile clinical strain growing in this medium (A. baumannii strain Ab421_GEIH-2010 [Ab7], isolated from a blood sample). The AidA protein expressed in E. coli showed QQ activity. Finally, we observed downregulation of the AidA protein (QQ system attenuation) in the presence of H2O2 (ROS stress). In conclusion, most of the A. baumannii clinical strains were not surface motile (84%) and were of respiratory origin (67%). Only the pilT gene was involved in surface motility and related to the QS system. Finally, a new QQ enzyme (α/ß hydrolase gene, AidA protein) was detected in these strains.
Response to Bile Salts in Clinical Strains of Acinetobacter baumannii Lacking the AdeABC Efflux Pump: Virulence Associated with Quorum Sensing
(Frontiers Media, 2017-05-09) López, María; Blasco, Lucía; Gato, Eva; Pérez, Astrid; Fernández García, Laura; Martínez Martínez, Luis; Rodríguez-Baño, Jesús; Pascual Hernández, Álvaro; Garnacho Montero, José; Pachón Díaz, Jerónimo; Cisneros, José Miguel; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina
Introduction: Acinetobacter baumannii is an opportunistic nosocomial pathogen associated with multiple infections. This pathogen usually colonizes (first stage of microbial infection) host tissues that are in contact with the external environment. As one of the sites of entry in human hosts is the gastrointestinal tract, the pathogen must be capable of tolerating bile salts. However, studies analyzing the molecular characteristics involved in the response to bile salts in clinical strains of A. baumannii are scarce. Material and Methods: Microbiological and transcriptional studies (arrays and RT-PCR) in the response to bile salts were carried out in isogenic (A. baumanni ΔadeB ATCC 17978 and A. baumannii ΔadeL ATCC 17978) and clinical strains from clone ST79/PFGE-HUI-1 which is characterized by lacking the AdeABC efflux pump and by overexpression the AdeFGH efflux pump. Results and Discussion: In presence of bile salts, in addition to the glutamate/aspartate transporter were found overexpressed in A. baumannii ΔadeB ATCC 17978, the virulence factors (surface motility, biofilm, and Type VI Secretion System) which are associated with activation of the Quorum Sensing system. Overexpression of these factors was confirmed in clinical strains of clone ST79/PFGE-HUI-1. Conclusions: This the first study about the adaptive response to bile salts investigating the molecular and microbiological characteristics in response to bile salts of an isogenic model of A. baumannii ATCC 17978 and clinical isolates of A. baumannii (clinical strains of ST79/PFGE-HUI-1) lacking the main RND efflux pump (AdeABC). Clinical isolates of A. baumannii lacking the AdeABC efflux pump (clone ST79/PFGE-HUI-1) displayed a new clinical profile (increased invasiveness) possibly associated with the response to stress conditions (such as the presence of bile salts).
Genome Sequence of Airborne Acinetobacter sp. Strain 5-2Ac02 in the Hospital Environment, Close to the Species of Acinetobacter towneri
(American Society for Microbiology, 2016-12-08) Barbosa, Beathriz; Fernández García, Laura; Gato, Eva; López, María; Blasco, Lucía; Leão, Robson Souza; Pascual Hernández, Álvaro; Tomás, María; Universidad de Sevilla. Departamento de Microbiología; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Xunta de Galicia; Instituto de Salud Carlos III; Gobierno de España
Acinetobacter spp. are found in 53% of air colonization samples from the hospital environment. In this work, we sequenced all the genome of airborne Acinetobacter sp. strain 5-2Ac02. We found important features at the genomic level in regards to the rhizome. By phylogenetic analysis, A. towneri was the species most closely related to Acinetobacter sp. 5-2Ac02.
Methicillin-resistant Staphylococcus aureus (MRSA) catheter-related bacteraemia in haemodialysis patients
(BioMed Central, 2015-10-30) Cuervo, Guillermo; Camoez, Mariana; Shaw, Evelyn; Domínguez, María Ángeles; Gasch, Oriol; Padilla, Belén; Rodríguez-Baño, Jesús; Lepe Jiménez, José Antonio; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Medicina; Universidad de Sevilla. Departamento de Microbiología; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Instituto de Salud Carlos III
Background The aim of the study was to determine clinical and microbiological differences between patients with methicillin-resistant Staphylococcus aureus (MRSA) catheter-related bacteraemia (CRB) undergoing or not undergoing haemodialysis, and to compare outcomes. Methods Prospective multicentre study conducted at 21 Spanish hospitals of patients with MRSA bacteraemia diagnosed between June 2008 and December 2009. Patients with MRSA-CRB were selected. Data of patients on haemodialysis (HD-CRB) and those not on haemodialysis (non-HD-CRB) were compared. Results Among 579 episodes of MRSA bacteraemia, 218 (37.7 %) were CRB. Thirty-four (15.6 %) were HD-CRB and 184 (84.4 %) non-HD-CRB. All HD-CRB patients acquired the infection at dialysis centres, while in 85.3 % of the non-HD-CRB group the infection was nosocomial (p < .001). There were no differences in age, gender or severity of bacteraemia (Pitt score); comorbidities (Charlson score ≥ 4) were higher in the HD-CRB group than in the non-HD-CRB group (73.5 % vs. 46.2 %, p = .003). Although there were no differences in VAN-MIC ≥1.5 mg/L according to microdilution, using the E-test a higher rate of VAN-MIC ≥1.5 mg/L was observed in HD-CRB than in non-HD-CRB patients (63.3 % vs. 44.1 %, p = .051). Vancomycin was more frequently administered in the HD-CRB group than in the non-HD-CRB group (82.3 % vs. 42.4 %, p = <.001) and therefore the appropriate empirical therapy was significantly higher in HD-CRB group (91.2 % vs. 73.9 %, p = .029). There were no differences with regard to catheter removal (79.4 % vs. 84.2 %, p = .555, respectively). No significant differences in mortality rate were observed between both groups (Overall mortality: 11.8 % vs. 27.2 %, p = .081, respectively), but there was a trend towards a higher recurrence rate in HD-CRB group (8.8 % vs. 2.2 %, p = .076). Conclusions In our multicentre study, ambulatory patients in chronic haemodialysis represented a significant proportion of cases of MRSA catheter-related bacteraemia. Although haemodialysis patients with MRSA catheter-related bacteraemia had significantly more comorbidities and higher proportion of strains with reduced vancomycin susceptibility than non-haemodialysis patients, overall mortality between both groups was similar.
Sensibilidad de microorganismos gramnegativos de infecciones intraabdominales y evolución de los aislados con β-lactamasas de espectro extendido en el estudio smart en españa (2002-2010)
(Sociedad Española de Quimioterapia, 2011) Cantón, Rafael; Loza, Elena; Aznar Martín, Javier; Calvo, Jorge; Cercenado, Emilia; Cisterna, Ramón; González Romo, Fernando; López Hontangas, José Luis; Rubio Calvo, Carmen; Suárez Barrenechea, Ana Isabel; Tubau, Fe; Weber, Irene; Yuste, Patricia; Cavanillas, Rafael; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
Introducción. El estudio SMART (Study for Monitoring Antimicrobial Resistance Trends) tiene como objetivo monitorizar la sensibilidad a los antimicrobianos de los microorganismos gramnegativos aislados en la infección intraabdominal, con especial seguimiento de los que producen β-lactamasas de espectro extendido (BLEE). Material y métodos. Se han analizado por microdulución los datos de sensibilidad de 8.869 aislados recogidos en el estudio SMART en España entre 2002 y 2010 en el que han participado 16 centros. Resultados. Escherichia coli fue el patógeno más frecuente (60,9% en la infección intraabdominal adquirida en la comunidad y 49,9% en la nosocomial) seguido de Klebsiella pneumoniae (8,9% vs 9,2%). Pseudomonas aeruginosa fue más habitual en la infección nosocomial (5,6% comunitaria y 8,6% nosocomial). La frecuencia de aislados con BLEE fue: E. coli 8,7%, K. pneumoniae 8,4%, Klebsiella oxytoca 1,4% y Proteus mirabilis 1,6%. En los pacientes de mayor edad aumentó la proporción global de aislados con BLEE (6,8% en pacientes >60 años). Ertapenem y meropenem fueron los antimicrobianos más activos en el conjunto de las enterobacterias (rango de sensibilidad con criterios EUCAST, 89-100%) y también entre los aislados con BLEE (95,5-100%). La actividad de amoxicilina/ácido clavulánico y piperacilina/tazobactam fue considerablemente inferior, en particular en los aislados con BLEE. Ertapenem mantuvo una buena actividad (sensibilidad >95%) en los productores de BLEE resistentes a amoxicilina/ácido clavulánico, piperacilina/tazobactam o fluoroquinolonas. Conclusiones. Los datos de sensibilidad del estudio SMART en España avalan las guías terapéuticas actuales de infección intraabdominal que sitúan al ertapenem como tratamiento empírico de elección, teniendo en cuenta sobre todo la elevada frecuencia de aislados con BLEE en nuestro medio.
Evaluación del medio chromID ESBL para la detección de portadores de enterobacterias productoras de betalactamasas de espectro extendido
(Elsevier, 2011-07) Del Castillo, María Carmen; López Cerero, Lorena; Casal, Mar; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
El aumento de la prevalencia de infecciones causadas por enterobacterias productoras de betalactamasas de espectro extendido (BLEE), tanto en la comunidad como en el ámbito hospitalario, plantea la necesidad, en determinadas investigaciones epidemiológicas de brotes nosocomiales, de disponer de métodos rápidos para la detección de portadores de estos microorganismos.
Epidemiologia de las blees en la comunidad: un problema emergente
(Elsevier, 2007-10) López Cerero, Lorena; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Instituto de Biomedicina de Sevilla (IBIS); Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
La emergencia de infecciones comunitarias por Escherichia coli productora de betalactamasas de espectro extendido (BLEE) es un fenómeno nuevo y generalizado, coincidente con la irrupción de enzimas CTX-M, que en nuestro país comienza a partir del año 2000. Las enzimas que se observan con más frecuencia pertenecen a la familia CTX-M y en segundo lugar encontramos SHV-12. Estos aislados están implicados principalmente en infecciones urinarias y se asocian a factores de riesgo como el uso de sonda urinaria y de antibióticos previamente. Su epidemiología es compleja ya que se han descrito clones epidémicos que afectaban a pacientes extra e intrahospitalarios, así como la detección de aislados no agrupados clonalmente y la diseminación horizontal de un grupo determinado de enzimas mediante elementos móviles. Existen portadores fecales en la comunidad, pero se desconoce actualmente el reservorio y las formas de transmisión, lo que supone una limitación para establecer medidas de control eficaces.
Extended-spectrum and CMY-type b-lactamase-producing Escherichia coli in clinical samples and retail meat from Pittsburgh, USA and Seville, Spain
(Elsevier, 2010-01) Doi, Yusuke; Paterson, David L.; Pascual Hernández, Álvaro; López Cerero, Lorena; Navarro, M. D.; Adams-Haduch, J. M.; Qureshi, Z. A.; Rodríguez-Baño, Jesús; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina; Instituto de Biomedicina de Sevilla (IBIS); Junta de Andalucía; Ministerio de Sanidad y Consumo. España; National Foundation of Infectious Diseases and the Infectious Diseases Society of America; National Institute of Allergy and Infectious Diseases; National Institutes of Health. United States; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
Infections due to Escherichia coli producing extended-spectrum β-lactamase (ESBL) or CMY-type β-lactamase (CMY) are increasingly observed in non-hospitalized patients. The origin of these organisms is uncertain, but retail meat contaminated with E. coli may be a source. In the present study, clinical information and strains collected from patients infected or colonized with ESBL-producing and CMY-producing E. coli at hospitals in Pittsburgh, USA and Seville, Spain were investigated. Retail meat purchased in these cities was also studied for the presence of these organisms. Twenty-five and 79 clinical cases with ESBL-producing E. coli and 22 cases and one case with CMY-producing E. coli were identified in Pittsburgh and Seville, respectively. Among them all, community-acquired and healthcareassociated cases together constituted 60% of the cases in Pittsburgh and 73% in Seville. Community-acquired cases were more common in Seville than in Pittsburgh (49% vs. 13%; p <0.001). ESBL-producing and CMY-producing E. coli isolates were commonly recovered from the local retail meat. In particular, 67% (8/12) of retail chickens in Seville and 85% (17/20) of those in Pittsburgh contained ESBLproducing and CMY-producing E. coli isolates, respectively. Among the ESBL-producing isolates, CTX-M and SHV were the most common ESBL types in both clinical and meat isolates. Approximately half of the ESBL-producing and CMY-producing E. coli isolates from meat belonged to phylogenetic groups associated with virulent extra-intestinal infections in humans. Community and healthcare environments are now significant reservoirs of ESBL-producing and CMY-producing E. coli. Retail meat is a potential source of these organisms.
Comparative assessment of inoculum effects on the antimicrobial activity of amoxycillin-clavulanate and piperacillin-tazobactam with extended-spectrum beta-lactamase-producing and extended-spectrum beta-lactamase-non-producing Escherichia coli isolates
(Elsevier, 2010-02) López Cerero, Lorena; Picón, Eduardo; Morillo, E.; Hernández, J. R.; Docobo Pérez, Fernando; Pachón Díaz, Jerónimo; Rodríguez-Baño, Jesús; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina; Instituto de Biomedicina de Sevilla (IBIS); Instituto de Salud Carlos III; Junta de Andalucía; Ministerio de Sanidad y Consumo. España; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
A significant inoculum-size effect has been observed with piperacillin-tazobactam, and has been associated with β-lactamase production in extended-spectrum β-lactamase (ESBL) producers. This association has not been previously studied in the case of amoxycillin-clavulanate. Piperacillin-tazobactam and amoxycillin-clavulanate were compared, using high inocula of susceptible strains either harbouring ESBLs or not. Two non-ESBL-producing and 15 amoxycillin-clavulanate-susceptible and piperacillin-tazobactam-susceptible ESBL-producing Escherichia coli isolates, and their respective transconjugants, were tested in dilution susceptibility tests using standard and 100-fold higher inocula. Three ESBL-producing strains and E. coli ATCC 25922 were selected for time-kill studies using standard and high initial inocula. At high inocula, MICs of piperacillin increased >eight-fold for non-ESBL-producing strains, and MICs of piperacillin-tazobactam (8 : 1 ratio or with tazobactam fixed at 4 mg/L) increased>eight-fold for all ESBL-producing strains. However, amoxycillin MICs were not affected by a high inoculum with non-ESBL-producing strains, whereas the MICs of amoxycillin-clavulanate (2 : 1 and 4 : 1) increased ≤four-fold for ESBL producers, using the broth and agar dilution methods. In kinetic studies at a high inoculum, amoxycillin and amoxycillin-clavulanate were bactericidal against E. coli ATCC 25922, whereas piperacillin and piperacillin-tazobactam yielded decreases of <1 log10 CFU/mL. Similarly, at a high inoculum, only amoxycillin-clavulanate was able to maintain bactericidal rates of killing over 24 h against the ESBL-positive E. coli isolates. The stability of amoxycillin-clavulanate and the contrasting results obtained with piperacillin-tazobactam against high inocula of ESBL-non-producing and ESBL-producing E. coli strains appear to be related to aspects other than the amount of β-lactamase production.
Similarities between the genetic environments of blaCTX-M-15 in Escherichia coli from clinical and food samples from Spain and overseas travellers
(Oxford Academic, 2011-09) López Cerero, Lorena; Egea, P.; Rodríguez-Baño, Jesús; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina; Instituto de Biomedicina de Sevilla (IBIS); Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
The spread of E. coli producing CTX-M-15 is complex and diverse. The emergence of different pulsotypes of highly virulent B23 ST131 producing CTX-M-15 has contributed to international spread 5 co-transferred with blaOXA-1, blaTEM , tet(A), catB3 and aac(6′)-Ib, but, additionally, dissemination within group A strains with low virulence could also occur.
Guidelines for the prevention of invasive mould diseases caused by filamentous fungi by the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC)
(Elsevier, 2011-04) Ruiz-Camps, Isabel; Aguado, J. M.; Almirante, Benito; Bouza, E.; Ferrer-Barbera, C. F.; Len, O.; López Cerero, Lorena; Cuenca-Estrella, M.; Universidad de Sevilla. Departamento de Microbiología; Instituto de Biomedicina de Sevilla (IBIS); European Union (UE); Instituto de Salud Carlos III; Ministerio de Educación y Cultura (MEC). España; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
Invasive fungal infections (IFIs) caused by filamentous fungi still have high rates of mortality, associated with difficulties in early detection of the infection and therapeutic limitations. Consequently, a useful approach is to prevent patients at risk of fungal infection from coming into contact with conidia of Aspergillus and other mould species. This document describes the recommendations for preventing IFI caused by filamentous fungi worked out by Spanish experts from different medical and professional fields. The article reviews the incidence of IFI in different risk populations, and questions related to environmental measures for prevention, control of hospital infections, additional procedures for prevention, prevention of IFI outside of hospital facilities and antifungal prophylaxis are also analysed.
Impact of changes in CLSI and EUCAST breakpoints for susceptibility in bloodstream infections due to extended-spectrum beta-lactamase-producing Escherichia coli
(Elsevier, 2012-09) Rodríguez-Baño, Jesús; Picón, Eduardo; Navarro, M. D.; López Cerero, Lorena; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Medicina; Universidad de Sevilla. Departamento de Microbiología; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Instituto de Salud Carlos III; Junta de Andalucía; Ministerio de Ciencia e Innovación; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
The impact of recent changes in and discrepancies between the breakpoints for cephalosporins and other antimicrobials, as determined by CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST), was analysed in patients with bloodstream infections caused by extended-spectrum β-lactamase (ESBL) producing Escherichia coli in Spain, was analysed. We studied a cohort of 191 episodes of bloodstream infection caused by ESBL-producing E. coli in 13 Spanish hospitals; the susceptibility of isolates to different antimicrobials was investigated by microdilution and interpreted according to recommendations established in 2009 and 2010 by CLSI, and in 2011 by EUCAST. Overall, 58.6% and 14.7% of isolates were susceptible to ceftazidime, and 35.1% and 14.7% to cefepime using the CLSI-2010 and EUCAST-2009/2011 recommendations, respectively (all isolates would have been considered resistant using the previous guidelines). Discrepancies between the CLSI-2010 and the EUCAST-2011 recommendations were statistically significant for other antimicrobials only in the case of amikacin (98.4% versus 75.9% of susceptible isolates; p <0.01). The results varied depending on the ESBL produced. No significant differences were found in the percentage of patients classified as receiving appropriate therapy, following the different recommendations. Four out of 11 patients treated with active cephalosporins according to CLSI-2010 guidelines died (all had severe sepsis or shock); these cases would have been considered resistant according to EUCAST-2011. In conclusion, by using current breakpoints, extended-spectrum cephalosporins would be regarded as active agents for treating a significant proportion of patients with bloodstream infections caused by ESBL-producing E. coli.
Performance of EUCAST and CLSI approaches for co-amoxiclav susceptibility testing conditions for clinical categorization of a collection of Escherichia coli isolates with characterized resistance phenotypes
(Oxford Academic, 2015-08) Díez-Aguilar, María; Morosini, María Isabel; López Cerero, Lorena; Pascual Hernández, Álvaro; Calvo, Jorge; Martínez Martínez, Luis; Marco, Francesc; Cantón, Rafael; Universidad de Sevilla. Departamento de Microbiología; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Ministerio de Economía y Competitividad (MINECO). España; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
Objectives: There are different methodological recommendations for in vitro testing of the co-amoxiclav combination. Performance of co-amoxiclav MIC testing for Escherichia coli by the standard ISO microdilution method (ISO 20776-1) was compared using EUCAST (fixed 2 mg/L clavulanate concentration) and CLSI (2 : 1 ratio) interpretive criteria. Methods: MICs were determined by broth microdilution using a 2 : 1 ratio and fixed clavulanate concentrations (2 and 4 mg/L) for 160 clinical E. coli isolates with characterized resistance mechanisms. Essential agreements, categorical agreements and relative errors were determined. Results: For all isolates, essential agreement between microdilution using 2 mg/L clavulanate and a 2 : 1 ratio was 25.6%. For ESBL-producing isolates, considering EUCAST breakpoints, 55% of isolates tested with 2 mg/L clavulanate were classified as resistant; conversely, 95% of isolates tested with 4 mg/L clavulanate were susceptible. When using CLSI breakpoints and a 2 : 1 ratio, 90% of isolates were susceptible and 10% were intermediate. Conclusions: Variation in the clavulanate concentration gave different susceptibility testing results, particularly among ESBL-producing E. coli isolates. The in vitro concentration of clavulanate that better correlates with clinical outcome is still under debate and should be established.
Characterization of an outbreak due to CTX-M-15-producing Klebsiella pneumoniae lacking the bla(OXA-48) gene belonging to clone ST405 in a neonatal unit in southern Spain
(Oxford Academic, 2016-08) Machuca, Jesús; López Cerero, Lorena; Fernández Cuenca, Felipe Manuel; Gracia Ahufinger, Irene; Ruiz Carrascoso, Guillermo; Rodríguez López, Fernando Carlos; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
In this study we characterize the first nosocomial out-break caused by MDR CTX-M-15-producing K. pneumoniae ST405 lacking the blaOXA-48 gene in a neonatal unit of a hospital in Cordoba (southern Spain).
Assessment of a phenotypic algorithm to detect plasmid-mediated quinolone resistance in Enterobacteriaceae
(Oxford Academic, 2016-03) Rodríguez Martínez, José Manuel; López Cerero, Lorena; Díaz de Alba, Paula; Chamizo López, Francisco Javier; Díaz de Alba, Paula; Chamizo López, Francisco Javier; Polo Padillo, Juan; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina Preventiva y Salud Pública; Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos; Universidad de Sevilla. CTS312: Análisis de la Demanda Sanitaria
Quinolone resistance in Gram-negative bacteria is the result of mutations in the quinolone resistance-determining region (QRDR) in chromosomally located genes encoding type II topoisomerases and, to a lesser extent, altered permeability. Plasmid-mediated quinolone resistance (PMQR) has also been reported as encoding different proteins: Qnr proteins, acetyltransferase AAC(6′)-Ib-cr variant and the QepA and OqxAB active efflux pumps.
Corrigendum to “The global threat of antimicrobial resistance: science for intervention” [New Microbes New Infect 6 (2015): 22–29]
(Elsevier, 0008-11) Roca, I.; Akova, M.; Baquero, F.; Carlet, J.; Cavaleri, M.; Coenen, S.; López Cerero, Lorena; Rodríguez-Baño, Jesús; Vila, J.; Universidad de Sevilla. Departamento de Microbiología; Universidad de Sevilla. Departamento de Medicina; Instituto de Biomedicina de Sevilla (IBIS); Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
The authors would like to apologise for any inconvenience caused.
Carbapenemase-Producing Gram-Negative Bacteria in Andalusia, Spain, 2014–2018
(U. S. Centers for Disease Control and Prevention, 2020-09) López Hernández, Inmaculada; Delgado Valverde, Mercedes; Fernández Cuenca, Felipe Manuel; López Cerero, Lorena; Machuca, Jesús; Pascual Hernández, Álvaro; Universidad de Sevilla. Departamento de Microbiología; Instituto de Biomedicina de Sevilla (IBIS); Universidad de Sevilla. CTS210: Resistencia a Antimicrobianos
The emergence and spread of carbapenemase-producing gram-negative bacteria is a major public health concern. We used data collected from microbiology laboratories as part of the PIRASOA program during 2014–2018 to study the epidemiology of carbapenemase-producing bacteria in Andalusia, Spain. Our findings highlight the importance of ongoing surveillance and epidemiologic studies for these bacteria.

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