Increased Blood Monocytic Myeloid Derived Suppressor Cells but Low Regulatory T Lymphocytes in Patients with Mild COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may produce a systemic disease, the coronavirus disease-19 (COVID-19), with high morbidity and mortality. Even though we do not fully understand the interaction of innate and adaptive immunity in the control and complications of the viral infection, it is well recognized that SARS-CoV-2 induces an immunodepression that impairs the elimination of the virus and favors its rapid dissemination in the organism. Even less is known about the possible participation of inhibitory cells of the innate immune system, such as the myeloid-derived suppressor cells (MDSCs), or the adaptive immune system, such as the T regulatory cells (Tregs). That is why we aimed to study blood levels of MDSCs, as well as lymphocyte subpopulations, including Tregs, and activated (OX-40+) and inhibited (PD-1) T lymphocytes in patients with mild COVID-19 in comparison with data obtained from control donors. We have found that 20 hospitalized patients with COVID-19 and no health history of immunosuppression had a significant increase in the number of peripheral monocytic MDSCs (M-MDSC), but a decrease in Tregs, as well as an increase in the number of inhibited or exhausted T cells, whereas the number of activated T cells was significantly decreased compared with that from 20 healthy controls. Moreover, there was a significant negative correlation (r = 0.496) between the number of M-MDSC and the number of activated T cells. Therefore, M-MDSC rather than Tregs may contribute to the immunosuppression observed in patients with COVID-19.

Development and validation of a laboratory-based risk score to predict the occurrence of critical illness in hospitalized patients with COVID-19.

BACKGROUND: Early identification of patients with COVID-19 who may develop critical illness is of great importance. METHODS: In this study a retrospective cohort of 264 COVID-19 cases admitted at Macarena University was used for development and internal validation of a risk score to predict the occurrence of critical illness in hospitalized patients with COVID-19. Backward stepwise logistic regression was used to derive the model, including clinical and laboratory variables predictive of critical illness. Internal validation of the final model used bootstrapped samples and the model scoring derived from the coefficients. External validation was performed in a cohort of 154 cases admitted at Valme and Virgen del Rocio University Hospital. RESULTS: A total of 62 (23.5%) patients developed a critical illness during their hospitalization stay, 21 (8.0%) patients needed invasive ventilation, 34 (12.9%) were admitted at the ICU and the overall mortality was of 14.8% (39 cases). 5 variables were included in the final model: age >59.5 years (OR: 3.11;95%CI 1.39-6.97), abnormal CRP results (OR: 5.76;95%CI 2.32-14.30), abnormal lymphocytes count (OR: 3.252;95%CI 1.56-6.77), abnormal CK results (OR: 3.38;95%CI 1.59-7.20) and abnormal creatinine (OR: 3.30;95%CI 1.42-7.68). The AUC of this model was 0.850 with sensitivity of 65% and specificity of 87% and the IDI and NRI were 0.1744 and 0.2785, respectively. The validation indicated a good discrimination for the external population. CONCLUSIONS: Biomarkers add prognostic information in COVID-19 patients. Our risk-score provides an easy to use tool to identify patients who are likely to develop critical illness during their hospital stay.

Escherichia coli O25b: H4/ST131 es prevalente en España y con frecuencia no se encuentra asociado a resistencia a quinolonas o producción de beta-lactamasas de espectro ampliado (BLEE) / No disponible

Introducción Recientemente, y de forma simultánea en 3 continentes, ha emergido un grupo clonal de E. coli multirresistente y productor de CTX-M-15. Por el momento, se dispone de pocos estudios que analicen de forma apropiada la prevalencia real de este linaje. Métodos En un estudio prospectivo en el sur de España, realizado con todos los aislados clínicos de E. coli recuperados en Sevilla durante 30 semanas en 2010, se realizó el despistaje de ST131 mediante PCR para O25b/pabB3/B23. Los enzimas BLEE fueron caracterizados mediante PCR y posterior secuenciación. La relación genética de los aislados fue estudiada mediante PFGE con XbaI. Resultados la prevalencia de este grupo clonal resultó ser del 12,5% de todos los aislados de E. coli y únicamente 37 (6,8% de los aislados ST131) eran productores de BLEE. Se caracterizaron 25 aislados ST131 productores de BLEE y la mayoría (96%) producían CTX-M-15. Los aislados ST131 eran con más frecuencia resistentes a amoxicilina/clavulánico, aminoglicósidos y fluorquinolonas tanto en el grupo de productores de BLEE como en el de no productores. En el análisis mediante XbaI PFGE, realizado a 88 aislados ST131, se observaron 3 pulsotipos, que incluían ≥4 aislados cada uno (25% de todos los aislados ST131 tipados) y 11 pulsotipos, que contenían 2-3 aislados cada uno. Tres de los 14 pulsotipos de este grupo clonal incluían aislados sensibles y resistentes al ácido nalidíxico y 5 pulsotipos incluían productores y no productores de BLEE. Conclusiones Los hallazgos de este estudio sugieren que O25b/ST131 es un clon prevalente en nuestra área y la prevalencia de BLEE en el referido clon es idéntica a la que se encuentra en la totalidad de los aislados de la especie. Algunos pulsotipos dentro del clon muestran una expansión mayor que podría ser explicada en parte por la adquisición de genes codificantes de BLEEs o resistencia a quinolonas (AU)

Introduction A multiresistant CTX-M-15-producing clonal group of Escherichia coli isolates, namely O25b:H4/ST131, has recently emerged in three continents. At this moment, appropriate studies to assess the real prevalence of this successful lineage are still scarce. Methods In a prospective study in the south of Spain, among all clinical E. coli isolates recovered in Seville during a 30 week period in 2010, ST131 was screened by using PCR for O25b/pabB3/B23 traits. ESBL enzymes were characterized by PCR and sequencing. Genetic relatedness was performed by XbaI PFGE. Results This clonal group was found to be prevalent (12.5% of all E. coli isolates), and only 37 (6.8% of ST131 isolates) were ESBL producers. Among 25 characterized ESBL-producing ST131 isolates, 96% harbored CTX-M-15. ST131 isolates were more frequently resistant to amoxicillin/clavulanate, aminoglycosides and fluoroquinolones in both ESBL and non-ESBL producers groups. XbaI PFGE performed on 88 ST131 isolates showed three pulsotypes, which included ≥4 isolates each (25% of all typed ST131 isolates), and 11 pulsotypes, which contained 2–3 isolates each. Three of 14 pulsotypes of this clonal group included both nalidixic acid-resistant and susceptible isolates, and five pulsotypes included both ESBL and non-ESBL producers. Conclusions Our findings suggest that O25b/ST131 is a prevalent clone in our area, and the observed prevalence of ESBL-producers within this clone is similar to that found in the total isolates of this species. Certain pulsotypes among ST131 clone that showed a greater expansion, and ESBL genes acquisition or quinolone resistance could explain part of this prevalence (AU)

Escherichia coli O25b:H4/ST131 are prevalent in Spain and are often not associated with ESBL or quinolone resistance.

INTRODUCTION: A multiresistant CTX-M-15-producing clonal group of Escherichia coli isolates, namely O25b:H4/ST131, has recently emerged in three continents. At this moment, appropriate studies to assess the real prevalence of this successful lineage are still scarce. METHODS: In a prospective study in the south of Spain, among all clinical E. coli isolates recovered in Seville during a 30 week period in 2010, ST131 was screened by using PCR for O25b/pabB3/B23 traits. ESBL enzymes were characterized by PCR and sequencing. Genetic relatedness was performed by XbaI PFGE. RESULTS: This clonal group was found to be prevalent (12.5% of all E. coli isolates), and only 37 (6.8% of ST131 isolates) were ESBL producers. Among 25 characterized ESBL-producing ST131 isolates, 96% harbored CTX-M-15. ST131 isolates were more frequently resistant to amoxicillin/clavulanate, aminoglycosides and fluoroquinolones in both ESBL and non-ESBL producers groups. XbaI PFGE performed on 88 ST131 isolates showed three pulsotypes, which included ≥4 isolates each (25% of all typed ST131 isolates), and 11 pulsotypes, which contained 2-3 isolates each. Three of 14 pulsotypes of this clonal group included both nalidixic acid-resistant and susceptible isolates, and five pulsotypes included both ESBL and non-ESBL producers. CONCLUSIONS: Our findings suggest that O25b/ST131 is a prevalent clone in our area, and the observed prevalence of ESBL-producers within this clone is similar to that found in the total isolates of this species. Certain pulsotypes among ST131 clone that showed a greater expansion, and ESBL genes acquisition or quinolone resistance could explain part of this prevalence.

[Microbiological characterisation of Listeria monocytogenes isolates from human cases in Andalusia]. / Caracterización microbiológica de los aislados de Listeria monocytogenes procedentes de casos humanos en Andalucía.

OBJECTIVE: The aim of this study was to perform a retrospective study by genotyping 154 isolates from human listeriosis cases occurred in the region of Andalusia (southern Spain) in the period 2005-2009. MATERIAL AND METHODS: Serotyping was performed for 1 and 4 somatic antigens using commercial Listeria antisera, and by multiplex-PCR serogrouping according to the method described by Doumith et al. (2004). The antimicrobial susceptibility was performed by Epsilon test and interpreted by CLSI criteria. PFGE was performed according to the PulseNet protocol with the ApaI enzyme. The similarity of PFGE profiles was evaluated using the Bionumerics software. The multiplex PCR protocol described by Chen and Knabel (2007) was used for the identification of isolates belonging to L. monocytogenes ECI, ECII, and ECIII epidemic clones. RESULTS: The 154 isolates were grouped into four serotypes: 4b [94 (61%)] strains, 1/2b [30 (19%)] strains, 1/2a [27 (18%)] strains, and 1/2c [3 (2%)] strains, with 100% of susceptibility to ampicillin and cotrimoxazole. A further sixty-two ApaI distinct pulsotypes were recognized. Thirty-seven isolates (24%) showed unique ApaI pulsotypes, and the remaining 117 strains (76%) were assigned to 25 ApaI clusters (60% in clusters of more than two isolates). The EC markers were found in 62 (40.3%) of the L. monocytogenes isolates tested. The ECI marker was present in 43 (46.2%) 4b serotype isolates, ECII in 10 (10.7%) 4b serotype isolates, and ECIII in 9 (33,3%) 1/2a serotype isolates. DISCUSSION: A large proportion of the human listeriosis cases under investigation could be grouped into molecular subtype clusters, and our cases could be related to international food-borne outbreaks.