Deciphering the Tangible Spatio-Temporal Spread of a 25-Year Tuberculosis Outbreak Boosted by Social Determinants.

Outbreak strains of Mycobacterium tuberculosis are promising candidates as targets in the search for intrinsic determinants of transmissibility, as they are responsible for many cases with sustained transmission; however, the use of low-resolution typing methods and restricted geographical investigations represent flaws in assessing the success of long-lived outbreak strains. We can now address the nature of outbreak strains by combining large genomic data sets and phylodynamic approaches. We retrospectively sequenced the whole genome of representative samples assigned to an outbreak circulating in the Canary Islands (the GC strain) since 1993, which accounts for ~20% of local tuberculosis cases. We selected a panel of specific single nucleotide polymorphism (SNP) markers for an in-silico search for additional outbreak-related sequences within publicly available tuberculosis genomic data. Using this information, we inferred the origin, spread, and epidemiological parameters of the GC strain. Our approach allowed us to accurately trace the historical and more recent dispersion of the GC strain. We provide evidence of a highly successful nature within the Canarian archipelago but limited expansion abroad. Estimation of epidemiological parameters from genomic data disagree with a distinctive biology of the GC strain. With the increasing availability of genomic data allowing for the accurate inference of strain spread and critical epidemiological parameters, we can now revisit the link between Mycobacterium tuberculosis genotypes and transmission, as is routinely carried out for SARS-CoV-2 variants of concern. We demonstrate that social determinants rather than intrinsically higher bacterial transmissibility better explain the success of the GC strain. Importantly, our approach can be used to trace and characterize strains of interest worldwide. IMPORTANCE Infectious disease outbreaks represent a significant problem for public health. Tracing outbreak expansion and understanding the main factors behind emergence and persistence remain critical to effective disease control. Our study allows researchers and public health authorities to use Whole-Genome Sequencing-based methods to trace outbreaks, and shows how available epidemiological information helps to evaluate the factors underpinning outbreak persistence. Taking advantage of all the freely available information placed in public repositories, researchers can accurately establish the expansion of an outbreak beyond original boundaries, and determine the potential risk of a strain to inform health authorities which, in turn, can define target strategies to mitigate expansion and persistence. Finally, we show the need to evaluate strain transmissibility in different geographic contexts to unequivocally associate spread to local or pathogenic factors, an important lesson taken from genomic surveillance of SARS-CoV-2.

[Clostridioides difficile toxin B gen amplification cycle threshold as a predictor of severity]. / Umbral del ciclo de amplificación del gen de la toxina B de Clostridioides difficile como predictor de gravedad.

BACKGROUND: Clostridioides dfficile infection (CDI) is the main cause of nosocomial diarrhea, generally associated with the use of antibiotics. This infection can cause uncomplicated diarrhea to pseudomembranous colitis or toxic megacolon. Recent studies have attempted to relate the threshold cycle (Ct) value of RT-PCR with mortality, as a fast, simple, objective and efficient method. AIM: To evaluate Ct as a predictor of poor outcome in patients with C. dfficile disease with/without clinical signs of severity. METHODS: We carried out a retrospective study between January 2015 and December 2018, including all patients in the reference area of the Hospital Universitario de Canarias in Tenerife (396,483 inhabitants) in patients with clinical criteria of severity and patients without clinical severity criteria (according to the guide for the clinical practice of CDI of the Society of Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of North America (IDSA). RESULTS: A total of 202 CDI episodes were diagnosed. 77.7% (n = 157) presented clinical severity criteria. The presence of ulcerative colitis (p < 0.001), fever (p < 0.001), leukocytosis (p < 0.001), neutrophilia (p < 0.001), creatininemia (p = 0.005) were presented as risk factors for the development of severe CDI (S-CDI). Female sex, institutionalization, previous admission and death were described more frequently in the group with S-CDI, not finding significant differences. We found no differences with respect to the days of previous stay, or of post-CDI stay, although in the latter, the mean was higher in the case of S-CDI patients. No significant differences were found in terms of Ct in both groups; being only one point lower in patients with severity criteria (Ct = 26.1) than without severity criteria (Ct = 27.4) (p = 0.326). Conclusión: Based on the results of our study, it has not been possible to systematically implement the Ct value as a predictor of severity to the clinical report, and it is not possible to extrapolate this predictive variable from S-CDI and standardize the Ct value as a predictor of severity. CONCLUSION: Basándonos en los resultados de nuestro estudio, no ha sido posible la implementación sistemática del valor Ct como predictor de gravedad al informe clínico, no siendo posible extrapolar esta variable predictora de enfermedad por C difficile-G y estandarizar el valor Ct como factor predictor de gravedad.

External quality assessment of HIV-1 DNA quantification assays used in the clinical setting in Italy.

Total cell-associated HIV-1 DNA is a surrogate marker of the HIV-1 reservoir, however, certified systems for its quantification are not available. The Italian HIV DNA Network was launched to validate HIV-1 DNA quantification methods in use at University and Hospital labs. A quality control panel including HIV-1 DNA standards, reconstructed blood samples (RBSs) and DNA from different HIV-1 subtypes was blindly tested by 12 participating labs by quantitative real-time PCR (n = 6), droplet digital PCR (n = 3) or both (n = 3). The median 95% hit rate was 4.6 (3.7-5.5) copies per test and linearity in the tested range was excellent (R2 = 1.000 [1.000-1.000]). The median values obtained across labs were 3,370 (2,287-4,245), 445 (299-498), 59 (40-81) and 7 (6-11) HIV-1 DNA copies, for the 3,584, 448, 56 and 7-copy standards, respectively. With RBSs, measured values were within twofold with respect to the median in two thirds of cases. HIV-1 subtypes were missed (CRF01_AE by 3 labs) or underestimated by > 1 log (subtypes A, C, D, F by one lab; CRF01_AE by one lab; CRF02_AG by one lab). The overall performance was excellent with HIV-1 DNA standards, however detection of different HIV-1 subtypes must be improved.

Umbral del ciclo de amplificación del gen de la toxina B de Clostridioides difficile como predictor de gravedad / Clostridioides difficile toxin B gen amplification cycle threshold as a predictor of severity

INTRODUCCIÓN: La infección por Clostridioides dfficile (ICD) es la principal causa de diarrea nosocomial, generalmente asociada al consumo de antimicrobianos. Esta infección puede causar desde diarrea no complicada hasta colitis pseudomembranosa o megacolon tóxico. Estudios recientes han intentado relacionar el valor el ciclo umbral (Ct) de la RT-PCR con la mortalidad, como un método rápido, sencillo, objetivo y eficaz. OBJETIVO: Evaluar el Ct como predictor de mala evolución en pacientes con y sin criterio clínico de dicha gravedad. PACIENTES Y MÉTODOS: Realizamos un estudio retrospectivo entre enero 2015 y diciembre 2018, incluyendo todos los pacientes del área de referencia del Hospital Universitario de Canarias en Tenerife (396.483 habitantes) en pacientes con criterios clínicos de gravedad (de acuerdo a la Guía para la Práctica Clínica de la enfermedad por C. dfficile de la Sociedad de Epidemiología del Cuidado de la Salud de América (SHEA) y la Sociedad de Enfermedades Infecciosas de Norteamérica (IDSA) y pacientes sin criterios clínicos de gravedad evaluando el Ct como predictor de mala evolución. RESULTADOS: Se diagnosticó un total de 202 episodios de ICD. El 77,7% (n = 157) presentó criterios clínicos de gravedad. La presencia de colitis ulcerosa (p < 0,001), fiebre (p < 0,001), leucocitosis (p < 0,001), neutrofilia (p < 0,001), creatininemia (p = 0,005) se presentaron como factores de riesgo para el desarrollo de ICD grave. El sexo femenino, la institucionalización, el ingreso previo y el exitus se describieron con mayor frecuencia en el grupo con ICD-G, no encontrando diferencias significativas. No encontramos diferencias respecto a los días de estancia previa, o de estancia post-ICD, aunque en este último, la media fue mayor en el caso de los pacientes con ICD-G. No se encontraron diferencias significativas en cuanto al Ct en ambos grupos; siendo sólo un punto menor en pacientes con criterio de gravedad (Ct = 26,1) que sin criterios de gravedad (Ct = 27,4) (p = 0,326).

BACKGROUND: Clostridioides dfficile infection (CDI) is the main cause of nosocomial diarrhea, generally associated with the use of antibiotics. This infection can cause uncomplicated diarrhea to pseudomembranous colitis or toxic megacolon. Recent studies have attempted to relate the threshold cycle (Ct) value of RT-PCR with mortality, as a fast, simple, objective and efficient method. AIM: To evaluate Ct as a predictor of poor outcome in patients with C. dfficile disease with/without clinical signs of severity. METHODS: We carried out a retrospective study between January 2015 and December 2018, including all patients in the reference area of the Hospital Universitario de Canarias in Tenerife (396,483 inhabitants) in patients with clinical criteria of severity and patients without clinical severity criteria (according to the guide for the clinical practice of CDI of the Society of Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of North America (IDSA). RESULTS: A total of 202 CDI episodes were diagnosed. 77.7% (n = 157) presented clinical severity criteria. The presence of ulcerative colitis (p < 0.001), fever (p < 0.001), leukocytosis (p < 0.001), neutrophilia (p < 0.001), creatininemia (p = 0.005) were presented as risk factors for the development of severe CDI (S-CDI). Female sex, institutionalization, previous admission and death were described more frequently in the group with S-CDI, not finding significant differences. We found no differences with respect to the days of previous stay, or of post-CDI stay, although in the latter, the mean was higher in the case of S-CDI patients. No significant differences were found in terms of Ct in both groups; being only one point lower in patients with severity criteria (Ct = 26.1) than without severity criteria (Ct = 27.4) (p = 0.326). CONCLUSION: Based on the results of our study, it has not been possible to systematically implement the Ct value as a predictor of severity to the clinical report, and it is not possible to extrapolate this predictive variable from S-CDI and standardize the Ct value as a predictor of severity. Conclusion: Basándonos en los resultados de nuestro estudio, no ha sido posible la implementación sistemática del valor Ct como predictor de gravedad al informe clínico, no siendo posible extrapolar esta variable predictora de enfermedad por C difficile-G y estandarizar el valor Ct como factor predictor de gravedad.

High prevalence of carbapenem-resistant Klebsiella pneumoniae ST307 recovered from fecal samples in an Italian hospital.

Aim: This study reports the characterization of carbapenem-resistant colonizing strains of K. pneumoniae. Methods: 650 stool samples were screened for carbapenem-resistant K. pneumoniae (CR-Kp). All strains were characterized for antibiotic susceptibility, typing features, main carbapenemases and extended-spectrum ß-lactamases. The carbapenemase transferability was assessed by interspecific conjugation. Results: Eighteen CR-Kp were multidrug resistant, five were KPC producing. A predominance of ST307 isolates, constituting the predominant cluster by PFGE analysis, was identified (50% were KPC-2 producers). Conjugation data showed the co-transfer of blaKPC-2, blaTEM-1, blaOXA-1, blaCTX-M-15 in a single large pKPN3-like plasmid. Conclusion: Our data pointed out the diversity of colonizing K. pneumoniae strains compared with clinical ones. The predominance of ST307 strains suggested an increased spreading, even in our area, of this high-risk clone.

Lay abstract Carbapenem-resistant Klebsiella pneumoniae represents a major antibiotic resistance threat worldwide. These microorganisms are associated with high mortality and difficult-to-treat infections. Of particular interest is the production of carbapenemase, enzymes capable of inactivating life-saving drugs such as carbapenems. In the interaction with humans, K. pneumoniae plays different roles: commensal, opportunistic pathogen or true pathogen. Our study aimed to analyze the population of K. pneumoniae obtained from a fecal screening, since gut-colonizing strains are considered the common source of K. pneumoniae nosocomial infections. There are many differences between clinical and colonizing isolates, but the latter are much less characterized. The careful characterization of colonizing strains is crucial, in order to better understand how K. pneumoniae may change its role from commensal to pathogen.

Synergistic effect of antimicrobial peptide LL-37 and colistin combination against multidrug-resistant Escherichia coli isolates.

Overview: The global spread of antibiotic resistance represents a serious threat for public health. Aim: We evaluated the efficacy of the antimicrobial peptide LL-37 as antimicrobial agent against multidrug-resistant Escherichia coli. Results: LL-37 showed good activity against mcr-1 carrying, extended spectrum ß-lactamase- and carbapenemase-producing E. coli (minimum inhibitory concentration, MIC, from 16 to 64 mg/l). Checkerboard assays demonstrated synergistic effect of LL-37/colistin combination against all tested strains, further confirmed by time-kill and post antibiotic effect assays. MIC and sub-MIC concentrations of LL-37 were able to reduce biofilm formation. Conclusion: Our preliminary data indicated that LL-37/colistin combination was effective against multidrug-resistant E. coli strains and suggested a new possible clinical application.

Quantification of the HIV-1 total reservoir in the peripheral blood of naïve and treated patients by a standardised method derived from a commercial HIV-1 RNA quantification assay.

OBJECTIVES: HIV-1 DNA can persist in host cells, establishing a latent reservoir. This study was aimed to develop an extraction and amplification protocol for HIV-1 DNA quantification by modifying a quantitative commercial assay. METHODS: HIV-1 DNA was extracted on an Abbott m2000sp instrument, using an open-mode protocol. Two calibrators, spiked with a plasmid containing HIV-1 genome (103 and 105 cps/mL), were extracted and amplified to generate a master calibration curve. Precision, accuracy, linear dynamic range, limit of quantification (LOQ) and limit of detection (LOD) were determined. A cohort of patients, naïve or chronically infected, was analysed. RESULTS: Calibration curve was obtained from 42 replicates of standards (stds); precision was calculated (coefficients of variability [CVs] below 10%); accuracy was higher than 90%. Linearity covered the entire range tested (10-104 copies per reaction), and LOD (95%) was 12 copies per reaction. HIV-1 DNA was significantly higher (p < 0.0001) in drug-naïve (62) than in chronically treated patients (50), and proviral loads correlated with lymphocytes (p = 0.0002) and CD4+ (p < 0.0001) counts only in naïve patients. Both groups displayed a significant inverse correlation between CD4+ nadir and proviral loads. A significant correlation (p < 0.0001) between viraemia and HIV-1 reservoir was disclosed. No significant difference was obtained from the comparison between proviral loads on whole blood and peripheral blood mononuclear cells (PBMCs) from the same patient. CONCLUSIONS: The novelty of our approach relies on the selection of appropriate reference standard extracted and amplified as clinical specimens avoiding any underestimation of the reservoir. Results confirm HIV-1 DNA as a marker of disease progression, supporting the relationship between the width of latent reservoir and the immunological status of the patient.

Human leptospirosis in the Marche region: Over 10 years of surveillance.

We conducted a 10 years' retrospective study in 347 symptomatic individuals to assess the regional distribution of leptospirosis. A total of 173 individuals were diagnosed positive (49.8%): 11.5% were found positive to Leptospira by microscopic agglutination test positive, whereas 38.3% were found positive by microscopy analysis. The maximum peak of leptospirosis was reached in 2017 (n = 32). The most common serovars were Icterohaemorrhagiae and Poi.

Evaluation of the Ion AmpliSeq SARS-CoV-2 Research Panel by Massive Parallel Sequencing.

Deep knowledge of the genetic features of SARS-CoV-2 is essential to track the ongoing pandemic through different geographical areas and to design and develop early diagnostic procedures, therapeutic strategies, public health interventions, and vaccines. We describe protocols and first results of the Ion AmpliSeq™ SARS-CoV-2 Research Panel by a massively parallel sequencing (MPS) assay. The panel allows for targeted sequencing by overlapping amplicons, thereby providing specific, accurate, and high throughput analysis. A modified reverse transcription reaction, which consists of the use of a SARS-CoV-2 specific primers pool from the Ion AmpliSeq SARS-CoV-2 Research Panel, was assessed in order to promote viral RNA specific reverse transcription. The aim of this study was to evaluate the effectiveness of the Ion AmpliSeq™ SARS-CoV-2 Research Panel in sequencing the entire viral genome in different samples. SARS-CoV-2 sequence data were obtained from ten viral isolates and one nasopharyngeal swab from different patients. The ten isolate samples amplified with 12 PCR cycles displayed high mean depth values compared to those of the two isolates amplified with 20 PCR cycles. High mean depth values were also obtained for the nasopharyngeal swab processed by use of a target-specific reverse transcription. The relative depth of coverage (rDoC) analysis showed that when 12 PCR cycles were used, all target regions were amplified with high sequencing coverage, while in libraries amplified at 20 cycles, a poor uniformity of amplification, with absent or low coverage of many target regions, was observed. Our results show that the Ion AmpliSeq SARS-CoV-2 Research Panel can achieve rapid and high throughput SARS-CoV-2 whole genome sequencing from 10 ng of DNA-free viral RNA from isolates and from 1 ng of DNA-free viral RNA from a nasopharyngeal swab using 12 PCR cycles for library amplification. The modified RT-PCR protocol yielded superior results on the nasopharyngeal swab compared to the reverse transcription reaction set up according to the manufacturer's instructions.

SARS-CoV-2 infection in kidney transplant recipients: Experience of the italian marche region.

BACKGROUND: Infection related to Coronavirus-19 (CoV-2) is pandemic affecting more than 4 million people in 187 countries worldwide. By May 10, 2020, it caused more than 280 000 deaths all over the world. Preliminary data reported a high prevalence of CoV-2 infection and mortality due to severe acute respiratory syndrome related CoV-2 (SARS-CoV-2) in kidney-transplanted patients (KTRs). Nevertheless, the outcomes and the best treatments for SARS-CoV-2-affected KTRs remain unclear. METHODS: In this report, we describe the clinical data, the treatments, and the outcomes of 5 KTRs with SARS-CoV-2 admitted to our hospital in Ancona, Marche region, Italy, from March 17 to present. Due to the severity of SARS-CoV-2, immunosuppression with calcineurin inhibitors, antimetabolites, and mTOR-inhibitors were stopped at the admission. All KTRs were treated with low-dose steroids. 4/5 KTRs were treated with hydroxychloroquine. All KTRs received tocilizumab up to one dose. RESULTS: Overall, the incidence of SARS-CoV-2 in KTRs in the Marche region was 0.85%. 3/5 were admitted in ICU and intubated. One developed AKI with the need of CRRT with Cytosorb. At present, two patients died, two patients were discharged, and one is still inpatient in ICU. CONCLUSIONS: The critical evaluation of all cases suggests that the timing of the administration of tocilizumab, an interleukin-6 receptor antagonist, could be associated with a better efficacy when administered in concomitance to the drop of the oxygen saturation. Thus, in SARS-CoV-2-affected KTRs, a close biochemical and clinical monitoring should be set up to allow physicians to hit the virus in the right moment such as a sudden reduction of the oxygen saturation and/or a significant increase in the laboratory values such as D-dimer.

Antibacterial activity of novel dual bacterial DNA type II topoisomerase inhibitors.

In this study, a drug discovery programme that sought to identify novel dual bacterial topoisomerase II inhibitors (NBTIs) led to the selection of six optimized compounds. In enzymatic assays, the molecules showed equivalent dual-targeting activity against the DNA gyrase and topoisomerase IV enzymes of Staphylococcus aureus and Escherichia coli. Consistently, the compounds demonstrated potent activity in susceptibility tests against various Gram-positive and Gram-negative reference species, including ciprofloxacin-resistant strains. The activity of the compounds against clinical multidrug-resistant isolates of S. aureus, Clostridium difficile, Acinetobacter baumannii, Neisseria gonorrhoeae, E. coli and vancomycin-resistant Enterococcus spp. was also confirmed. Two compounds (1 and 2) were tested in time-kill and post-antibiotic effect (PAE) assays. Compound 1 was bactericidal against all tested reference strains and showed higher activity than ciprofloxacin, and compound 2 showed a prolonged PAE, even against the ciprofloxacin-resistant S. aureus BAA-1720 strain. Spontaneous development of resistance to both compounds was selected for in S. aureus at frequencies comparable to those obtained for quinolones and other NBTIs. S. aureus BAA-1720 mutants resistant to compounds 1 and 2 had single point mutations in gyrA or gyrB outside of the quinolone resistance-determining region (QRDR), confirming the distinct site of action of these NBTIs compared to that of quinolones. Overall, the very good antibacterial activity of the compounds and their optimizable in vitro safety and physicochemical profile may have relevant implications for the development of new broad-spectrum antibiotics.

Factores de riesgo en bacteriemias nosocomiales secundarias a ITU en un hospital terciario / Risk factors to secondary nosocomial bacteremia to UTI in a tertiary hospital

INTRODUCCIÓN: Las bacteriemias nosocomiales secundarias a infecciones del tracto urinario (BNS-ITU) ocurren en un 1-4% de los episodios y la mortalidad asociada puede aumentar hasta el 33%. Sin embargo, se conoce muy poco sobre la epidemiología de estas infecciones. La determinación de los factores de riesgo modificables para desarrollar este tipo de bacteriemias podría ayudar al control de la infección y reducir el gasto sanitario. MATERIAL Y MÉTODOS: Estudio de casos y controles de las BNS-ITU diagnosticadas en el Hospital Universitario de Canarias entre 2010-2014. Se recogieron las variables clínico-epidemiológicas y los factores de riesgo potenciales intrínsecos y extrínsecos. Se utilizó la regresión logística para estudiar las variables asociadas al desarrollo de BNS-ITU. RESULTADOS: Se estudiaron 178 episodios, 85 casos y 93 controles. La estancia media fue significativamente mayor en los casos; desde el ingreso hasta la bacteriemia (p< 0,003), como desde ésta hasta el alta (p< 0,005). La insuficiencia hepática (p< 0,091), el uso de ventilación mecánica (p < 0,001), de el catéter venoso central (p < 0,043) y la cirugía en el episodio (p< 0,001) se comportaron como factores de riesgo para la adquisición de BNS-ITU. CONCLUSIONES: Los dispositivos invasivos, como el catéter venoso central y la ventilación mecánica, que no había sido estudiada previamente; así como la cirugía en el episodio, que tampoco había sido estudiada, suponen factores de riesgo. Además, la BNS-ITU causa un aumento significativo de la estancia hospitalaria. Por ello, es necesario conocer los factores de riesgo para la aparición de estas infecciones, y así, prevenir su aparición y mejorar la seguridad de los pacientes hospitalizados

INTRODUCTION: Nosocomial bacteremia secondary to urinary tract infections (NBS-UTI) occur in 1-4% of episodes and the associated mortality can increase up to 33%. However, very little is known about the epidemiology of these infections. The determination of modifiable risk factors to develop this type of bacteremia could help to control the infection and reduce health costs. MATERIAL AND METHODS: Cases-control study of NBS-UTI diagnosed at the University Hospital of Canary Islands between 2010-2014. The clinical-epidemiological variables and the intrinsic and extrinsic potential risk factors were collected. Logistic regression was used to study the variables associated with the development of NBS-UTI. RESULTS: A total of 178 episodes were studied, 85 cases and 93 controls. The average stay was significantly greater in the cases; from admission to bacteremia (p <0.003), as well as from discharge to discharge (p <0.005). Hepatic insufficiency (p <0.091), the use of mechanical ventilation (p <0.001), the central venous catheter (p <0.043) and surgery in the episode (p <0.001) behaved as risk factors for the acquisition of NBS-ITU. CONCLUSION: Invasive devices, such as central venous catheter and mechanical ventilation, that had not previously been studied; as well as the surgery in the episode, which had not been studied either, suppose risk factors. In addition, NBS-ITU causes a significant increase in hospital stay. Therefore, it is necessary to know the risk factors for the appearance of these infections, and thus prevent their appearance and improve the safety of hospitalized patients

Onicomicosis por alga sin clorofila / Onychomycosis caused by algae without chlorophyll

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A Mycobacterium tuberculosis Beijing strain persists at high rates and extends its geographic boundaries 20 years after importation.

Transmission of Beijing Mycobacterium tuberculosis can be investigated based on genotypic analysis of clinical isolates. A Beijing strain began to spread on Gran Canaria Island, Spain, at the end of the last century. In 1996, only 3 years after its importation to the island, its frequency had increased to 27.1% of all the isolates. The strain was tracked during the following years, and the most recent data obtained corresponded to 2007-8, when its presence continued to be alarming (21%). In the current study, we updated data on the distribution of this strain 20 years (2013-2014) after it was first detected on the island and extended the analysis for the first time to all the mycobacteriology laboratories covering the population of the Canary Island archipelago. Rapid updating was enabled by means of 2 different strain-specific PCRs: one targeting a peculiar feature of the strain, which was identified based on an IS6110 copy mapping in the Rv2180c gene, and a newly defined strain-specific single nucleotide polymorphism, which was identified by whole-genome sequencing. The results showed that the strain has remained highly prevalent (20.90% of all isolates), has spread throughout the neighbouring islands, and has also reached high representativeness in them (11-32%).

Epidemiological study of secondary bloodstream infections: The forgotten issue.

OBJECTIVE: Secondary bacteraemia infections (SBI) are poorly studied. We analyse the epidemiology of nosocomial SBI, potential risk factors and mortality of affected patients. METHODS: Prospective study of patients with bacteraemia from 2009 to 2014 in a tertiary hospital. For each SBI was recorded: primary source of infection, aetiological agent, demographic data, intrinsic and extrinsic risk factors and mortality during the episode. RESULTS: 429/1918 episodes of Nosocomial Bacteraemia (NB) (22%) were SBI (average Incidence Density: 0.41% days of admission). Onco-hematological services had the highest Incidence Density of SBI. Surgical Site Infection-SBI (SSI-BSI) was the most frequent SBI (27%), followed by Urinary Tract Infection-SBI (UTI-BSI) (24%). Gram-negative bacteria were the most prevalent microorganism (61.1%). The median interval between SBI episodes to discharge was 37±59days. Mortality rate was 29%. These patients had many intrinsic and extrinsic risk factors such as urinary catheterization (68%), CVC (69%), Arterial hypertension (48%) and hospitalization in the six previous months (45%). Mean age was significantly higher in patients with UTI-BSI and SSI-BSI. Average stay from admission to the development of bacteraemia was statistically lower in patients with Intra-abdominal Infection bacteraemia (IAB-BSI). Patient with SSI-BSI had oncologic processes and had undergone for more Mechanical ventilation than UTI-SSBI and Respiratory Tract Infections Bacteraemia (RTI-BSI). The use of CVC was significantly higher in RTI-BSI. CONCLUSIONS: SBI accounts for almost a quarter of all NB. Patients has multiple comorbidities, increases hospital stay and mortality. It would be necessary to establish measures to rapidly diagnose and treat the primary infection, in order to prevent the onset of SBI.

¿Existe relación entre el ciclo umbral de la reacción en cadena de la polimerasa y el riesgo de infección grave por Clostridium difficile? / Is there a relationship between the polimerase chain reaction cycle threshold and the risk of severe Clostridium difficile infection?

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