Anastomotic leak in colorectal cancer surgery: Contribution of gut microbiota and prediction approaches.

AIM: To monitor prospectively the occurrence of colorectal anastomotic leakage (CAL) in patients with colon cancer undergoing resectional surgery, characterizing the microbiota in both faeces and mucosal biopsies of anastomosis. In a second stage, we investigated the ability to predict CAL using machine learning models based on clinical data and microbiota composition. METHOD: A total of 111 patients were included, from whom a faecal sample was obtained, as well as biopsy samples from proximal and distal sites in the healthy margins of the tumour piece. The microorganisms present in the samples were investigated using microbial culture and 16S rDNA massive sequencing. Collagenase and protease production was determined, as well as the presence of genes responsible for expressing enzymes with these activities. Machine learning analyses were developed using clinical and microbiological data. RESULTS: The incidence of CAL was 9.0%, and CAL was associated with collagenase/protease-producing Enterococcus. Significant differences were found in the microbiota composition of proximal and distal biopsy samples, but not in faecal samples, among patients who developed CAL. Clinical predictors of CAL were 5-day C-reactive protein and heart disease, whereas 3-day C-reactive protein and diabetes were negative predictors. CONCLUSION: Biopsy samples from surgical margins, rather than faecal samples, are the most appropriate samples for exploring the contribution of the intestinal microbiota to CAL. Enterococci are only enriched in the anastomosis after surgery, and their collagenases and proteases are involved in the degradation of the anastomotic scar.

Cefiderocol resistance genomics in sequential chronic Pseudomonas aeruginosa isolates from cystic fibrosis patients.

OBJECTIVE: To evaluate the activity of cefiderocol against sequential P. aeruginosa isolates from chronically-infected cystic fibrosis patients as well as to investigate the potential mechanisms involved in resistance through whole genome sequencing. METHODS: Three sequential P. aeruginosa isolates from each of 50 chronically-colonized cystic fibrosis patients were studied. MICs for novel and classical antipseudomonal agents were determined by broth microdilution and whole genome sequences (n = 150) were obtained to investigate the presence of mutations within a set of chromosomal genes involved in P. aeruginosa antibiotic resistance (n = 40) and iron uptake (n = 120). RESULTS: Cefiderocol showed the lowest MIC50/90 values and its susceptibility rate was comparable to other novel antipseudomonal agents. Clinical resistance was documented in 9 isolates from 6 patients. Resistance genes associated with a statistically significant increase in cefiderocol MICs included ampC, pmrAB, galU, fusA1 and those coding the penicillin-binding proteins PBP2 and PBP3. Likewise, mutations within several genes participating in different iron-uptake systems were found to be significantly associated with resistance, including genes participating in the pyochelin and pyoverdin biosynthesis and several tonB-dependent receptors. Mutator and small colony variants isolates were also associated with increased cefiderocol MICs. DISCUSSION: Cefiderocol resistance is modulated by a complex mutational resistome, potentially conferring cross-resistance to novel beta-lactam beta-lactamase combinations, as well as an extended list of mutated iron-uptake genes. Monitoring the acquisition of mutations in all these genes will be helpful to guide treatments and mitigate the emergence and spread of resistance to this novel antibiotic.

Impacto de un programa de vigilancia activa y medidas de control de infecciones sobre la incidencia de bacilos gram negativos resistentes a carbapenems en una unidad de cuidados intensivos

Resumen Las infecciones hospitalarias causadas por bacilos gram negativos resistentes a carbapenems (BGNCR) están asociadas al aumento de morbimortalidad y gasto sanitario. La identificación mediante cultivos de vigilancia y las medidas de control de infecciones permiten reducir su diseminación. El objetivo del estudio fue evaluar el impacto de un programa de vigilancia integrado a protocolos de control de infecciones sobre la incidencia de BGNCR y conocer su epidemiología molecular en una unidad de cuidados intensivos. Se realizaron auditorías seguidas de un programa de cultivo de vigilancia activa y caracterización molecular de BGNCR, antes y después de la implementación de programas de prevención y control de infecciones. El screening microbiológico se realizó en medios cromogénicos; la caracterización molecular de p-lactamasas (blaKPC, bla0XA-48-like, blaVIM, blaiMP, blaNDM, blaSHV y blaCTx-M) por PCR y la tipificación molecular por PFGE y MLST para Klebsiella pneumoniae. El protocolo desarrollado permitió reducir la colonización global de 16,92% al 9,67%. La diseminación de K. pneumoniae fue a expensas de diversos clones portadores de KPC-2 asociada a BLEE SHV-2 y CTX-M-15, y distribuidos en varios secuenciotipos (ST17, ST13, ST2256, ST353); no se observó persistencia de un clon particular y ningún aislamiento presentó factores de virulencia asociados a hipervi-rulencia. Los aislamientos de Acinetobacter baumannii fueron mayoritariamente productores de IMP-1. El análisis PFGE individualizó 3 clusters, asumiendo que la diseminación fue clonal.

Abstract Hospital-acquired infections caused by carbapenem-resistant Gram-negative bacteria (CRGNB) have been increasingly reported worldwide and are associated with high rates of mortality especially in intensive care units(ICUs). Early identification through rectal surveillance cultures and implementation of infection control measures(ICM) including contact precautions, staff education on cleaning and hand hygiene may reduce the spread of these microorganisms. The aim of this work was to assess the impact of enhanced ICM on CRGNB colonization and to describe the molecular epidemiology of these bacteria in a polyvalent ICU in a tertiary level hospital. A prospective study including audits and active surveillance culture program, with molecular characterization, was conducted before and after the implementation of prevention programs and infection control measures. Microbiological screening was performed in chromogenic media; PCR targeting p-lactamases genes (ó/qkpc, óíQndm, blaviM and blaoxA-48, blasHv and ó/qctx-m), molecular typing by PFGE; and MLST in K. pneumoniae were performed. CRGNB colonization was reduced from 16.92% to 9.67% upon implementing the infection control measures. In K. pneumoniae the most frequent carbapenemase type was KPC-2 associated with SHV-2 and CTX-M-15, and was disseminated in various STs (ST17, ST13, ST2256, ST353); there was no persistence of particular clones and virulence factors showed no association with hypervirulence. IMP-1 carbapenemase predominated in A. baumannii and the PFGE analysis individualized 3 clusters, assuming that the dissemination in the ICU was clonal. The early detection of patients colo-nized with CRBGN by using epidemiological surveillance cultures and the implementation of prophylactic measures are key to reducing the incidence of these microorganisms.

Core Microbiota in Central Lung Cancer With Streptococcal Enrichment as a Possible Diagnostic Marker / Núcleo de microbiota en el cáncer de pulmón central con enriquecimiento estreptocócico como posible marcador de diagnóstico

Background: Dysbiosis in lung cancer has been underexplored. The aim of this study was to define the bacterial and fungal microbiota of the bronchi in central lung cancer and to compare it with that of the oral and intestinal compartments. Methods: Twenty-five patients with central lung cancer and sixteen controls without antimicrobial intake during the previous month were recruited. Bacterial and fungal distribution was determined by massive sequencing of bronchial biopsies and saliva and faecal samples. Complex computational analysis was performed to define the core lung microbiota. Results: Affected and contralateral bronchi of patients have almost identical microbiota dominated by Streptococcus, whereas Pseudomonas was the dominant genera in controls. Oral and pulmonary ecosystems were significantly more similar in patients, probably due to microaspirations. Streptococcal abundance in the bronchi differentiated patients from controls according to a ROC curve analysis (90.9% sensitivity, 83.3% specificity, AUC=0.897). The saliva of patients characteristically showed a greater abundance of Streptococcus, Rothia, Gemella and Lactobacillus. The mycobiome of controls (Candida) was significantly different from that of patients (Malassezia). Cancer patients’ bronchial mycobiome was similar to their saliva, but different from their contralateral bronchi. Conclusions: The central lung cancer microbiome shows high levels of Streptococcus, and differs significantly in its composition from that of control subjects. Changes are not restricted to tumour tissue, and seem to be the consequence of microaspirations from the oral cavity. These findings could be useful in the screening and even diagnosis of this disease. (AU)

Antecedentes: La disbiosis en cáncer pulmonar no ha sido suficientemente estudiada. Los objetivos de este estudio fueron definir la microbiota bacteriana y fúngica de bronquios con cáncer central de pulmón, y compararla con la del compartimento intestinal en heces y saliva. Métodos: Se reclutaron 25 pacientes con cáncer central de pulmón y 16 controles sin exposición antibiótica durante el mes anterior. Se determinó la composición de bacterias y hongos en biopsias de bronquio, saliva y heces. Se realizó un análisis computacional para definir el núcleo de microbiota del pulmón. Resultados: Los bronquios afectados y contralaterales de pacientes presentaron una microbiota similar dominada por Streptococcus, mientras que Pseudomonas destacó en los controles. Los ecosistemas orales y pulmonares fueron significativamente más parecidos en pacientes, probablemente debido a microaspiraciones. La abundancia bronquial de estreptococos permitió diferenciar a los pacientes de los controles mediante una curva ROC (90,9% de sensibilidad, 83,3% de especificidad, AUC=0,897). La saliva de los pacientes presentó mayor abundancia de Streptococcus, Rothia, Gemella y Lactobacillus. El micobioma de los controles (Candida) fue significativamente diferente al de los pacientes (Malassezia), con los bronquios afectados por el cáncer similares a su saliva, pero diferentes de sus bronquios contralaterales. Conclusiones: En el cáncer de pulmón central hay enriquecimiento de Streptococcus, y su composición es significativamente diferente de sujetos control. Las alteraciones no se limitan al tejido tumoral, y parecen ser consecuencia de microaspiraciones desde la cavidad oral. Estos hallazgos podrían ser útiles para la detección e incluso el diagnóstico de esta patología. (AU)

Description of microbial diversity associated with ticks Hyalomma dromedarii (Acari: Ixodidae) isolated from camels in Hail region (Saudi Arabia) using massive sequencing of 16S rDNA.

Ticks are blood feeder able to transmit a wide diversity of microbes including pathogens. Therefore, it is of our interest to detect the diversity of microorganisms residing within ticks using massive sequencing of 16S rDNA. In this study, 200 adult ticks were collected from healthy camels in two localities from Hail province (Saudi Arabia). The analysis showed high microbial diversity dominated by the two domains (Archaea and Bacteria) associated with Hyalomma dromedarii from both regions. Proteobacteria (61.3%) and Firmicutes (31.2%) dominated the ticks from the Al Khotha region. While, the microbiome of ticks from the Al Gayed region was dominated by Proteobacteria (81.2%) and Firmicutes (9.2%). Twenty-three families were identified in the DNA-pool from the Al Gayed region, and was dominated by Pseudomonadaceae (45.37%), and Marinobacteraceae (14.39%) families. Francisellaceae (46%), Staphylococcaceae (24.26%) dominated the microbiome of the ticks collected from Al Gayed region. Thus, the genera Pseudomonas, Francisella, Proteus, Marinobacter, Glutamicibacter, Pedobacter, and Staphylococcus are largely distributed in the two identified microbiomes. This study concluded that ticks collected from the studied localities contained a wide range of microbial communities. These data have a great veterinary and medical importance in near future.

Antibiotic prescription patterns in Spanish cystic fibrosis patients: results from a national multicenter study / Patrones de prescripción de antimicrobianos en pacientes españoles con fibrosis quística: resultados de un estudio multicéntrico nacional

Objective: Information about antibiotic prescription patterns for cystic fibrosis (CF) patients and, specifically, about inhaled treatment strategies for their management is lacking in Spain due to the absence of a national patient registry. In this study we present data about antibiotic prescription in the Spanish CF context that were obtained in a multicenter study, being inhaled treatment strategies the special focus of this work. Methods: Twenty-four specialized CF units (12 adult, 12 pediatric) from 17 tertiary-care hospitals covering all Spanish Autonomous Communities provided sputa and clinical data from 15 consecutive patients. Data about antibiotic and non-antibiotic therapies prescribed to these patients during the year prior inclusion (2013) were retrospectively collected. Results: The multicenter study included 341 CF patients from all age groups and clinical status. The prevalence of oral, inhaled and intravenous therapies was 89% (n = 302), 80% (n = 273) and 31% (n = 105), respectively. The most prevalent oral agents were ciprofloxacin (n = 177, 59%), cotrimoxazole (n = 109, 36%) and amoxicillin-clavulanate (n = 99, 33%), whereas ceftazidime (n = 53, 50%), to bramycin (n = 43, 41%) and meropenem (n = 41, 49%) were the most prevalent intravenous ones. Two or more different inhaled antibiotics were administered to 67 patients (24%), 51 of them receiving 2 drugs continuously in alternating schemes. Nebulization of intravenous specific antibiotics was common (n = 39) and, in some cases, was used for maintenance purposes. Conclusions: These results show that the treatment of CF patients is evolving more rapidly than clinical consensus guidelines. Clinical trials evaluating new specific inhaled combinations and new alternative treatment regimens of the existing ones are needed (AU)

Objetivos: Existen actualmente pocos datos acerca de las pautas de tratamiento antimicrobiano administradas a los pacientes con fibrosis quística (FQ) en España, sobre todo en lo que se refiere a la antibioterapia inhalada. Esta escasez de conocimiento se debe principalmente a la ausencia de un registro nacional de datos de pacientes. En 2013 se llevó a cabo el primer estudio multicéntrico español focalizado en la microbiología de la FQ. En este trabajo presentamos los patrones de prescripción de antimicrobianos administrados durante un año a los pacientes incluidos en dicho estudio. Métodos: Se contó con la participación de 24 unidades de FQ (12 de adultos y 12 de pediatría) procedentes de 17 hospitales españoles. Cada unidad reclutó a 15 pacientes de manera consecutiva, que aportaron muestras respiratorias y datos clínicos. Se recogieron de manera retrospectiva los tratamientos antibióticos y no antibióticos administrados a estos pacientes durante el año previo a su inclusión en el estudio. Resultados: Se incluyeron 341 pacientes con FQ de todos los rangos de edad y de gravedad clínica. La prevalencia de antibioterapia oral, inhalada e intravenosa fue del 89% (n = 302), 80% (n = 273) y 31% (n = 105), respectivamente. Los fármacos administrados con mayor frecuencia por vía oral fueron ciprofloxacino (n = 177, 59%), cotrimoxazol (n = 109, 36%) y amoxicilina-cla- vulánico (n = 99, 33%), siendo ceftazidima (n = 53, 50%), tobramicina (n = 43, 41%) y meropenem (n = 41, 49%) los más frecuentes por vía intravenosa. Se administraron dos o más antibióticos por vía inhalada a 67 pacientes (24%), habiendo recibido 51 de ellos 2 antibióticos simultáneamente de manera rotatoria. La nebulización de antibióticos con formulación intravenosa fue una práctica común (n = 39) y, en algunos casos, se utilizó durante un tiempo prolongado como terapia de mantenimiento. Conclusiones: Los esquemas de tratamiento observados en este estudio demuestran que la terapia antibiótica de la FQ evoluciona más rápidamente que las recomendaciones reflejadas en las guías clínicas. Es necesario evaluar estos nuevos esquemas con estudios clínicos, así como con otros fármacos inhalados de reciente aparición y su papel en los esquemas existentes (AU)

Antimicrobial-resistant Escherichia coli and Enterococcus spp. isolated from Miranda donkey (Equus asinus): an old problem from a new source with a different approach.

PURPOSE: The Miranda donkey (Equus asinus) is an endangeredasinine from Miranda do Douro region, located in the north east of Portugal. We studied the antimicrobial resistance and virulence genes in Escherichia coli and Enterococcus spp. isolates from these animals. METHODOLOGY: In March 2014, a total of 66 faecal samples were recovered from independent animals. Antibiotic resistance was determined by the disc diffusion method. Carriage of genes coding for antibiotic-resistant and virulent factors was analysed by PCR. RESULTS: A total of 66 E. coli and 41 enterococcal isolates were detected, with Enterococcus faecium (61 %) and Enterococcus hirae (24 %) being the most prevalent species. For enterococcal isolates, high percentages of resistance rates to tetracycline (68.3 %), quinupristin/dalfopristin (51.2 %) and ciprofloxacin (48.8 %) were observed. The genes erm(A) and/or erm(B), tet(M) and/or tet(L), vat(D) and/or vat(E) and aph(3')-IIIa were also found. The most frequent virulence gene detected was gel(E), followed by ace, cpd and hyl. Escherichia coli isolates were highly resistant to streptomycin (78 %), whereas 39 % of them exhibited resistance to aminoglycosides and tetracycline. Genes sul1 and/or sul2 were detected in 66.7 % of trimethoprim/sulfamethoxazole-resistant isolates. The virulence genes detected were fim(A) (46 %) and cnf1 (27 %). CONCLUSION: To the best of our knowledge, this is the first report showing antibiotic resistance among Escherichiacoli and Enterococcus spp. isolates from the Miranda donkey in Portugal, indicating possible antibiotic-resistant bacterial reservoirs. However, the detection of these resistances presents a low risk for other animals and human beings in that rural area.

First description of late recurrence of catheter-associated bacteraemia due to Cellulosimicrobium cellulans / Primer caso de bacteriemia asociada a catéter con recurrencia tardía debido a Cellulosimicrobium cellulans

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Screening in a Lactobacillus delbrueckii subsp. bulgaricus Collection to select a strain able to survive to the human intestinal tract / Estudio de una colección de Lactobacillus delbrueckii subsp. bulgaricus y selección de una cepa capaz de sobrevivir en el tracto digestivo humano

Objectives: Genetic diversity and resistance of Lactobacillus bulgaricus sbsp. delbrueckii collection with 100 isolates from different home-made yogurt in rural Bulgarian areas were determined. Methods: The strain K98 was the most resistant to bile salts and low pH. Survival and effects on short chain fatty acids production were tested in 20 healthy volunteers. High genetic diversity was observed in the L. bulgaricus collection by RAPD, whereas the ability of tolerate high deoxycholic acid concentrations, and different acid pHs was variable. The strain K98 was selected and used to prepare a homemade yogurt which was administered to 20 healthy volunteers (500 ml/day during 15d). A basal faecal sample and another after yogurt intake were recovered. Results: DGGE experiments, using both universal and Lactic Acid Bacteria (LAB) primers, demonstrated no significant changes in the qualitative composition of gut microbiota. A band corresponding to L. bulgaricus was observed in all 20 samples. Viable L. bulgaricus K98 strain was only recovered in one volunteer. After yogurt intake we found an increase of LAB and Clostridium perfringens, and a decrease of Bacteroides-Prevotella-Porphyromonas. In addition, increases of acetic, butyric and 2-hydroxybutyric acids in faeces were detected. Conclusions: Genetic diversity of L. delbrueckii subsp. bulgaricus especie is high We have isolated a probiotic resistant strain to bile and high acidity, L. delbrueckii subsp. bulgaricus-K98. Qualitative and quantitative changes in the intestinal microbiota are found after ingestion of a homemade yogurt containing this strain, with a concomitant increase in faecal SCFA. Our findings support the interest in developing further studies providing different amounts of L. delbrueckii subsp. bulgaricus-K98, and should evaluate its clinical effects in human disease (AU)

Objetivos: Se determinaron la diversidad genética y la resistencia de una colección de más de 100 cepas de Lactobacillus bulgaricus subespecie delbrueckii, aisladas de diferentes yogures caseros de las áreas rurales de Bulgaria. Métodos: La cepa K98 fue la más resistente a las sales biliares y al pH bajo. La supervivencia y los efectos sobre la producción de ácidos grasos de cadena corta se evaluó en 20 voluntarios sanos. Se observó una alta diversidad genética en la colección de L. bulgaricus mediante RAPD, mientras que la capacidad de tolerar concentraciones altas del ácido desoxicólico y de diferentes niveles de pH fue variable. Se seleccionó la cepa K98 y se usó para preparar un yogur casero que se administró a los 20 voluntarios (500 ml/día durante 15 días). Se recogieron muestras fecales basales y tras la ingesta del yogur. Resultados: Los experimentos DGGE, empleando cebadores universales y para bacterias ácidolácticas (BAL) demostraron que no hubo cambios significativos en la composición cualitativa de la composición de la microflora intestinal. Se observó una banda correspondiente a L. bulgaricus en las 20 muestras. Sólo se recuperó una cepa viable de L. bulgaricus K98 en un único voluntario. Tras la ingesta de yogur, hallamos un aumento de BAL y de Clostridium perfringens y una disminución de Bacteroides-Prevotella-Porphyromonas. Además, se detectó un aumento en las heces de los ácidos acético, butírico y 2-hidroxibutírico. Conclusiones: La diversidad genética de L. delbrueckii subespecie bulgaricus es alta. Hemos aislado una cepa probiótica resistente a la bilis y a la acidez elevada, L. delbrueckii subesp. bulgaricus-K98. Se hallaron cambios cualitativos y cuantitativos en la microflora intestinal tras la ingesta de yogur casero que contenía esta cepa, con un aumento concomitante en las heces de AGCC. Nuestros hallazgos apoyan el interés por desarrollar estudios futuros con cantidades variables de L. delbrueckii subesp. bulgaricus-K98, y que evalúen sus efectos clínicos en la enfermedad humana (AU)

Streptococcus bovis, situación taxonómica, relevancia clínica y sensibilidad antimicrobiana / Streptococcus bovis, taxonomic status, clinical relevance and antimicrobial susceptibility

Streptococcus bovis constituye un grupo de cocos grampositivos anaerobios facultativos que incluye diferentes especies relacionadas genéticamente. Tradicionalmente, según sus diferencias bioquímicas se han clasificado en S. bovis biotipo I (fermentación de manitol), S. bovis biotipo II/1 (manitol negativo y β-glucuronidasa negativa) y biotipo II/2 (manitol negativo y β-glucuronidasa positiva). En las últimas décadas y tras la aplicación de las técnicas de microbiología molecular se ha demostrado que S. bovis biotipo I corresponde a Streptococcus gallolyticus subsp. gallolyticus, que el biotipo II/1 es Streptococcus infantarius subsp. infantarius, posteriormente renombrado como Streptococcus lutetiensis, y el biotipo II/2 se corresponde con S. gallolyticus subsp. pasteurianus, conocido habitualmente como Streptococcus pasteurianus. Aunque en la actualidad esta nomenclatura está muy aceptada en el ámbito taxonómico, en la práctica clínica habitual no está totalmente integrada. Es importante una correcta identificación porque hay una elevada asociación entre bacteriemia, endocarditis y/o cáncer de colon con las diferentes subespecies. En general, S. bovis presenta mayor sensibilidad a los antimicrobianos que otros estreptococos, aunque se han descrito porcentajes de resistencia elevados a los macrólidos y a las tetraciclinas

Streptococcus bovis is a large bacterial complex of facultative anaerobic Gram-positive cocci that includes distinct, genetically-related species. Traditionally, S. bovis was classified into three biotypes: I (mannitol fermentation-positive), II/1 (mannitol-negative and β-glucuronidase-negative), and II/2 (mannitol-negative and β-glucuronidase-positive). The introduction of molecular techniques in the last few decades has led to proposals for a genetic classification of this complex: S. bovis biotype I belongs to Streptococcus gallolyticus subsp. gallolyticus, S. bovis biotype II/1 is, in fact, Streptococcus infantarius subsp. infantarius, designated as Streptococcus lutetiensis, and S. bovis biotype II/2 is Streptococcus gallolyticus subsp. pasteurianus, commonly designated as Streptococcus pasteurianus. Although this modern taxonomy is currently accepted, many clinicians remain unfamiliar with these terms. The importance of correct identification lies in the strong association between bacteriemia, endocarditis and/or colon cancer and the various subspecies. In general, S. bovis is more susceptible to antimicrobial agents than other streptococci, but high levels of resistance to macrolides and tetracycline have been described

Tratamiento de mantenimiento con ampicilina inhalada en pacientes con fibrosis quística e infección pulmonar por Staphylococcus aureus sensible a meticilina / Maintenance Treatment With Inhaled Ampicillin in Patients With Cystic Fibrosis and Lung Infection Due to Methicillin-Sensitive Staphylococcus aureus

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Sharing of bacterial strains between breast milk and infant feces.

In previous years, it has been shown that human milk is a potential source of bacteria for the infant gut. The results of this work confirm the presence of the same specific bacterial strains of Bifidobacterium, Lactobacillus, and Staphylococcus in breast milk and infant fecal samples. The identity of bacteria isolated from breast milk and infant feces from 20 mother-infant pairs was investigated at the strain level. DNA from Staphylococcus, Lactobacillus, and Bifidobacterium was detected by qRTi-PCR in nearly all samples analyzed. These samples were cultured on different agar media. One colony representative of each morphology was selected and identified at the species level combining classical tests and molecular techniques (PCR, RAPD, PFGE, and/or MLST genotyping). Breast milk and infant feces from 19 mother-infant pairs shared different Staphylococcus, Lactobacillus, and/or Bifidobacterium species and strains. Significantly, 2 mother-infant pairs shared 4 bacterial strains although most pairs shared 2. These results confirm that breast milk and infant feces from mother-infant pairs share the same strain(s), indicating that breastfeeding could contribute to the bacterial transfer from the mother to the infant and, therefore, to the infant gut colonization.

Reidentification of Streptococcus bovis isolates causing bacteremia according to the new taxonomy criteria: still an issue?

All Streptococcus bovis blood culture isolates recovered from January 2003 to January 2010 (n = 52) at the Hospital Universitario Ramón y Cajal were reidentified on the basis of their genetic traits using new taxonomic criteria. Initial identification was performed by the semiautomatic Wider system (Fco. Soria-Melguizo, Spain) and the API 20 Strep system (bioMérieux, France). All isolates were reidentified by PCR amplification and sequencing of both the 16S rRNA and sodA genes and by mass spectrometry using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS; Bruker, Germany). Results of 16S rRNA/sodA gene sequencing were as follows: Streptococcus gallolyticus subsp. gallolyticus, 14/14 (number of isolates identified by 16S rRNA/number of isolates identified by sodA gene sequencing); Streptococcus gallolyticus subsp. pasteurianus, 24/24; Streptococcus spp., 7/0; Streptococcus infantarius subsp. infantarius, 0/2; Streptococcus lutetiensis, 0/5; Leuconostoc mesenteroides, 4/0; and Lactococcus lactis, 3/3. MALDI-TOF MS identified 27 S. gallolyticus isolates but not at the subspecies level, 4 L. mesenteroides isolates, 3 L. lactis isolates, and 6 S. lutetiensis isolates, whereas 12 isolates rendered a nonreliable identification result. Pulsed-field gel electrophoresis grouped all S. gallolyticus subsp. gallolyticus isolates into 3 major clusters clearly different from those of the S. gallolyticus subsp. pasteurianus isolates, which, in turn, exhibited no clonal relationship. The percentages of resistance to the tested antimicrobials were 38% for erythromycin, 23% for fosfomycin, 10% for levofloxacin, 6% for tetracycline, and 4% for co-trimoxazole. The most frequent underlying diseases were hepatobiliary disorders (53%), endocarditis (17%), and malignancies (12%). We conclude that sequencing of the sodA gene was the most discriminatory method and that S. gallolyticus subsp. pasteurianus appears to have a higher genetic diversity than S. gallolyticus subsp. gallolyticus.

Infección bronquial crónica: el problema de Pseudomonas aeruginosa / Chronic bronchial infection: the problem of Pseudomonas aeruginosa

La colonización patogénica broncopulmonar y las exacerbaciones que se derivan de ella constituyen las causasmás importantes del deterioro de la función pulmonar en los pacientes con bronquiectasias. Haemophilusinfluezae y Pseudomonas aeruginosa son los patógenos más frecuentes en estos pacientes. El efecto lesivo seproduce por el proceso de inflamación local y el círculo vicioso que se desarrolla por el estímulo antigénico, laliberación de mediadores de la inflamación, la presencia de neutrófilos, el aumento del inóculo bacteriano yla liberación de exoproductos bacterianos. Se ha demostrado que P. aeruginosa afecta a los pacientes con bronquiectasiascon peor calidad de vida, coloniza a los que tienen peor funcionalidad pulmonar y mayor númerode tratamientos antimicrobianos. En las bronquiectasias, al igual que en la enfermedad pulmonar obstructivacrónica (EPOC) o fibrosis quística, P. aeruginosa es capaz de colonizar crónicamente la mucosa respiratoria.Debido al nicho ecológico donde se sitúa P. aeruginosa y a la multitud de ciclos con antimicrobianos a los queson sometidos estos pacientes es fácil que se desarrollen resistencias a los antimicrobianos, favorecidas por laelevada proporción de variantes hipermutadoras que existen. Asimismo, hay que resaltar la forma natural decrecimiento en biopelículas de P. aeruginosa en la superficie mucosa y la contribución que ejerce para su persistencia.El tratamiento antimicrobiano en los pacientes con bronquiectasas con colonización por P.aeruginosa ha de basarse en antimicrobianos o asociaciones de éstos que no pierdan actividad al actuar sobrelas biopelículas(AU)

Pathogenic bronchopulmonary colonizations and the exacerbations produced are among the most importantcauses of reduced pulmonary function in patients with bronchiectasis. The most frequent pathogens in thesepatients are Haemophilus influenzae and Pseudomonas aeruginosa. Lesions are produced by the localinflammatory process and the vicious circle developed by antigen stimulation, the release of inflammatorymediators, the presence of neutrophils, the increase of bacterial inoculum and the release of bacterialexoproducts. P. aeruginosa has been demonstrated to affect the patients with bronchiectasis and poorestquality of life and to colonize those with the poorest pulmonary function and the highest number ofantimicrobial treatments. In bronchiectasis, as in chronic obstructive pulmonary disease (COPD) or cysticfibrosis, P. aeruginosa is able to colonize the respiratory mucosa chronically. Due to the ecological nicheoccupied by P. aeruginosa and the multitude of cycles with antimicrobial agents to which these patients aresubjected, the development of antimicrobial resistance is highly likely, encouraged by the high proportion ofhypermutation variants in existence. Likewise, P. aeruginosa naturally grows in the form of biofilms on themucosal surface, greatly contributing to its persistence. Antimicrobial treatment in patients withbronchiectasis and P. aeruginosa colonization should be based on antimicrobial agents, alone or incombination, that do not lose activity when acting on biofilms(AU)

[Antimicrobial susceptibility and genetic bases for resistance of infection-causing Enterococcus strains in Cuba]. / Susceptibilidad antimicrobiana y bases genéticas de la resistencia de cepas de Enterococcus causantes de infecciones en Cuba.

OBJECTIVE: To identify infection-causing Enterococcus species in Cuban hospitals and determine their susceptibility to antimicrobial drugs, as well as their resistance mechanisms. METHODS: A total of 687 Enterococcus isolates from 30 Cuban hospitals in nine provinces of the country were studied over the period 2000-2009. The species were identified using both the conventional method and the automatic API(®) system. The minimum inhibitory concentration was determined for 13 antimicrobial drugs following the standards recommended by the Clinical Laboratory and Standards Institute. The polymerase chain reaction technique was used to characterize the genes that were resistant to aminoglycosides, erythromycin, tetracycline, and glucopeptides. The presence of beta-lactamase was determined by the chromogenic cephalosporin test. RESULTS: The most prevalent species were Enterococcus faecalis (82.9%) and E. faecium (12.2%). Resistance to glucopeptides (1.0%) was mediated by the vanA and vanB genes. The strains resistant to ampicillin (6%) did not produce beta-lactamases. A high percentage of resistance to aminoglycosides was observed. Gentamicin (31.0%) and streptomycin and amikacin (29.1%) were mediated by the aac(6')Ie-aph(2")Ia, aph(3')-IIIa, ant(6)Ia, and ant(3")(9) genes. A correlation was found between resistance to tetracycline (56.0%) and presence of the tet(M) (75.1%) and tet(L) genes (7.0%), while resistance to erythromycin (34.1%) was due to the erm(B) gene (70.9%). CONCLUSIONS: Resistance to vancomycin is infrequent in Cuba, as opposed to a high level of resistance to aminoglycosides, which may be indicative of treatment failures. The microbiology laboratory is a cornerstone of Enterococcus infection surveillance, along with ongoing monitoring of the susceptibility of these infections to antimicrobial drugs at a time when resistance of this microorganism is on the rise.

Los complejos clonales de alto riesgo CC2 y CC9 están ampliamente representados en cepas hospitalarias de Enterococcus faecalis aisladas en España / High-risk clonal complexes CC2 and CC9 are widely distributed among Enterococcus faecalis hospital isolates recovered in Spain

Introducción. El desarrollo de un esquema de Multilocus sequence typing (MLST) para Enterococcus faecalis ha permitido conocer los primeros datos de su estructura poblacional y epidemiología global. Se ha detectado la dispersión en Europa y América de dos complejos clonales (CC) de alto riesgo denominados CC2 y CC9 que están especialmente adaptados al medio hospitalario. El objetivo de este trabajo ha sido definir la presencia de ambos CC en cepas de E. faecalis aisladas en España. Métodos. Se han caracterizado por MLST 81 cepas de E. faecalis aisladas de diversos orígenes y correspondientes a diferentes años y regiones españolas. Debido a su importancia clínica y epidemiológica se han incluido cepas representantes de cada uno de los brotes hospitalarios por E. faecalis resistente a vancomicina descritos en España. Resultados. En el medio hospitalario se detectó la dispersión de CC2 y CC9. En estos CC se han agrupado las cepas de E. faecalis resistentes a vancomicina causantes de los brotes hospitalarios en La Coruña, Palma de Mallorca y Valencia, así como cepas de origen hospitalario sensibles a la vancomicina. La utilización del índice de asociación (Ia), que estima el equilibrio de ligamiento en la población estudiada, reveló una estructura poblacional epidémica cuya variabilidad genética es debida a procesos de recombinación. Conclusión. En España se han detectado los CC de alto riesgo CC2 y CC9, que han evolucionado localmente de forma diferente en función de la carga genética del entorno. Las medidas de control de la infección deberían ir encaminadas a la detección de estos CC de alto riesgo, ya que su presencia en los hospitales podrían predecir tendencias futuras en cuanto a la adquisición de determinadas resistencias como es el caso de la vancomicina (AU)

Introduction. Our previously described multilocus sequence typing (MLST) scheme for Enterococcus faecalis has provided insight into the population structure and global epidemiology of this organism. Two high-risk complexes, CC2 and CC9, especially adapted to the hospital environment and widely distributed in Europe and America, were identified. The purpose of this study was to define the presence of CC2 and CC9 among E. faecalis strains isolated in Spain. Methods. A total of 81 E. faecalis isolates recovered from several sources and geographic areas of Spain were characterized using MLST. Because of their clinical and epidemiological interest, strains were included from each of the vancomycin-resistant E. faecalis hospital outbreaks described in Spain. Results. Among the isolates, CC2 and CC9 were detected in the hospital setting. Included in these CC were the vancomycin-resistant E. faecalis isolates causing hospital outbreaks in La Coruña, Palma de Mallorca and Valencia, as well as vancomycin-susceptible hospital isolates. The Index of Association (Ia), which measures linkage disequilibrium between alleles, revealed an epidemic population structure on a background of high recombination rates. Conclusions. High-risk complexes (CC2 and CC9) particularly adapted to the hospital environment were detected in Spain. Evolution of these CC in different areas depended on the local gene pool. Future infection control policies should be orientated to detect high-risk CC with the aim of predicting potential trends toward acquisition of specific resistance, such as to vancomycin (AU)