Last twenty-years activity of cardiovascular tissue banking in Barcelona

The Barcelona Tissue Bank was established from the merge of two previous multi-tissue banks. Potential donors are screened by Donor Center staff and multi-tissue retrieval is performed by specialized own teams. Tissue processing and preservation is performed in clean room facilities by specialised personnel. After quality control of both donor and all tissues results, the heart valves and vascular segments are stored until medical request. The aim of this report is to present the cardiovascular tissue activity and retrospectively evaluate the outcomes of the changes performed in last 20 years. Cardiovascular tissue from 4088 donors was received, specifically 3115 hearts and 2095 vascular segments were processed and evaluated. A total of 48% of the aortic valves, 68% of the pulmonary valves and 75% of the vascular segments were suitable for transplant. The main reason for discarding tissue was macroscopic morphology followed by microbiological results, for both valves and arteries. Altogether, 4360 tissues were distributed for transplantation: 2032 (47%) vascular segments, 1545 (35%) pulmonary valves and 781 (18%) aortic valves. The most common indication for aortic valve surgery was the treatment of endocarditis, while for pulmonary valves, it was congenital malformation reconstruction. Vascular segments were mainly used for reconstruction after ischemia. During this period, a number of changes were made with the goal of enhancing tissue quality, safety and efficacy. These improvements were achieved through the use of a new antibiotic cocktail, increasing of donor age criteria and changing the microbiological control strategy.

Mancha3D Code: Multipurpose Advanced Nonideal MHD Code for High-Resolution Simulations in Astrophysics

The Mancha3D code is a versatile tool for numerical simulations of magnetohydrodynamic (MHD) processes in solar/stellar atmospheres. The code includes nonideal physics derived from plasma partial ionization, a realistic equation of state and radiative transfer, which allows performing high-quality realistic simulations of magnetoconvection, as well as idealized simulations of particular processes, such as wave propagation, instabilities or energetic events. The paper summarizes the equations and methods used in the Mancha3D (Multifluid (-purpose -physics -dimensional) Advanced Non-ideal MHD Code for High resolution simulations in Astrophysics 3D) code. It also describes its numerical stability and parallel performance and efficiency. The code is based on a finite difference discretization and a memory-saving Runge-Kutta (RK) scheme. It handles nonideal effects through super-time-stepping and Hall diffusion schemes, and takes into account thermal conduction by solving an additional hyperbolic equation for the heat flux. The code is easily configurable to perform different kinds of simulations. Several examples of the code usage are given. It is demonstrated that splitting variables into equilibrium and perturbation parts is essential for simulations of wave propagation in a static background. A perfectly matched layer (PML) boundary condition built into the code greatly facilitates a nonreflective open boundary implementation. Spatial filtering is an important numerical remedy to eliminate grid-size perturbations enhancing the code stability. Parallel performance analysis reveals that the code is strongly memory bound, which is a natural consequence of the numerical techniques used, such as split variables and PML boundary conditions. Both strong and weak scalings show adequate performance up to several thousands of processors (CPUs).

Radiotherapy for Metastatic Spinal Cord Compression with Increased Doses: Final Results of the RAMSES-01 Trial

PURPOSE/OBJECTIVE(S)

To investigate the outcomes of precision-radiotherapy (RT) with 15 × 2.633 Gy (EQD2 = 41.6 Gy for tumor cell kill, α/β = 10 Gy) or 18 × 2.333 Gy (EQD2 = 43.2 Gy) in patients with metastatic spinal cord compression (MSCC) and favorable survival prognoses (>35 points on a validated survival score). In addition, these patients were compared to a historical control group of patients with favorable prognoses treated with 10 × 3 Gy (EQD2 = 32.5 Gy).

MATERIALS/METHODS

In a multi-center phase 2 study (RAMSES-01), patients with MSCC and favorable survival prognoses receiving 15 × 2.633 Gy or 18 × 2.333 Gy of precision-RT alone (no upfront surgery) were mainly evaluated for local progression-free survival (LPFS), defined as no deterioration of motor function during RT and no in-field recurrence of MSCC following RT, at 12 months (primary endpoint). Secondary endpoints included improvement of motor and sensory functions, post-RT ambulatory status, relief of pain and distress, toxicity, and survival (OS). The maximum relative doses allowed to the spinal cord were 101.5 % of the prescribed dose for 18 × 2.333 Gy and 101.2% for 15 × 2.633 Gy, respectively (both representing an EQD2 of 46.6 Gy for myelopathy, α/β = 2 Gy). In addition, the RAMSES-cohort was compared to a historical control group (N = 266) irradiated with 10 × 3 Gy (propensity score adjusted Cox regression).

RESULTS

In the RAMSES-cohort, 50 (of 62 planned) patients were evaluable for LPFS and included in the analyses. Since OS was worse than expected, a new survival score was developed, which was more precise in predicting OS than a previous tool. As a consequence, the RAMSES-trial, which was based on the previous score, was terminated. In the 50 patients included so far, 12-month rates of LPFS and OS were 97.6% and 69.9%, respectively. Improvement of motor function occurred in 28 patients (56.0%), and 47 patients (94.0%) were ambulatory following RT. Within 3 months following RT, 12 of 21 patients (57.2%) with pre-RT sensory deficits improved, 38 of 45 patients (84.4%) with pre-RT pain experienced at least partial relief, and 39 of 50 patients (78.0%) reported relief of distress. Ten of 50 patients (20.0%) experienced grade 2 toxicities (mainly esophagitis/dysphagia) and another two patients (4.0%) grade 3 toxicities (1 diarrhea, 1 esophagitis). After propensity score adjustment, the RAMSES-cohort showed significantly better LPFS than the control group (hazard ratio = 0.125, 95% confidence interval = 0.016 - 0.962, p = 0.046) and a strong trend regarding improvement of motor function (hazard ratio = 1.943, 95% confidence interval = 0.981 - 3.850, p = 0.057). Post-RT ambulatory rates (p = 0.56) and OS rates (p = 0.62) were not significantly different.

CONCLUSION

Precision-RT with 15 × 2.633 Gy or 18 × 2.333 Gy was sufficiently well tolerated and resulted in significantly better long-term LPFS than 10 × 3 Gy in patients with MSCC and favorable survival prognoses. Thus, the dose-fractionation regimens of the RAMSES-01 trial appear preferable for these patients.

Layperson Perception of Symptoms Caused by the Sinuses

OBJECTIVE

To assess the perceived symptoms caused by the sinuses as defined by otolaryngology patients and clinicians.

STUDY DESIGN

Multi-institutional cross-sectional study.

SETTING

Six academic outpatient otolaryngology practices.

METHODS

We performed a multi-institutional, cross-sectional study using a semantics-based questionnaire. Consecutive patients were enrolled at 6 academic otolaryngology centers from June 2020 to May 2021. The primary outcome examined patient and provider definitions for the symptoms caused by the sinuses from a list of 28 proposed terms covering 6 general categories. These data were also collected from otolaryngology faculty at the same institutions.

RESULTS

Responses were obtained from 451 patients (54% female, mean age 48.3 years) and 29 otolaryngologists (38% female, mean age 37.4 years). Patients selected a median of 12 terms, compared to 8.5 for otolaryngologists. Among patients, the most frequently selected symptom domains were mucus (419, 92.9%), airflow (412, 91.4%), and pain (389, 86.3%). Compared to clinicians, patients more frequently selected symptoms related to the ear (difference, 48.3%; 95% confidence interval [CI], 34.8%-59.3%), throat (difference, 35.7%, 95% CI, 22.0%-47.5%), systemic (difference, 34.4%, 95% CI, 21.2%-46.0%), mucus (difference, 20.5%, 95% CI, 10.2%-30.6%), and airflow domains (difference, 19.0%, 95% CI, 8.4%-29.3%). Multiple domains were selected by 98% of patients and 79% of providers.

CONCLUSION

Semantic differences exist between patients and clinicians regarding the symptoms caused by the sinus with patients having a broader range of perceived symptoms. These differences may provide clues to improve communication between otolaryngologists and their patients.

Changes of CD3+CD56+ γδ T cell number and apoptosis during hospital admission are related to mortality in septic patients

Immunoparalysis and apoptosis of T cells are serious problems for the evolution of septic patients. We aimed to relate changes in the number of αβ and γδ T cells during hospital stay to the poor evolution of sepsis. In this prospective study, we recruited a total of 92 septic patients from the Emergency and Intensive Care Departments of two Hospitals, according to the latest criteria for the definition and management of sepsis. According to the severity of the septic process, there was a progressive decrease in T cells, being much more intense in γδ T cells. This decrease recovered in surviving patients, but CD3+CD56+ γδ T cells continued to decreased during hospital stay in non-surviving patients. Apoptosis increased in sepsis. Cell death of CD3+CD56+ γδ T cells progressively increased according to the severity of sepsis, especially in non-surviving patients.

Evaluation of adverse outcomes in patients with Troponinemia without significant coronary artery disease; a proposal application of the ACTION-ICU Score

Purpose

Elevated troponin in absence of significant coronary artery disease is a frequent situation that is associated with increased mortality. Criteria to estimate complications in these patients are not defined. The aim of this study was to evaluate the predictive capacity of the ACTION-ICU score, a scale designed to predict likelihood of complication requiring ICU care for patients with NSTEMI, to define risk of complications in patients with elevated troponin without significant coronary artery disease.

Methods

A retrospective study of patients with elevated troponin and no significant coronary artery disease were selected to apply the ACTION-ICU Score to predict likelihood of complications. Complications were defined as cardiac arrest development, shock, high-grade atrioventricular block, respiratory failure, stroke, or death during the index hospitalization. ROC Curves were created to determine the predictive power.

Results

1221 patients were screened, of them 181 presented elevated troponin without significant coronary artery disease; age median 65 year (IQR 56–75 years), female 48,1%. Of 181 patients, 73.5% were admitted to ICU based on physician criteria. Only 13.3% of patients presented a complication. A score greater than 5 was present in 33.7% of the patients, of which 5,5% presented a complication. ROC to predict complications was 0,75 (95% CI: 0,65–0,86). Best cut off point was >6 points, sensitivity 70.83%, specificity 72.08%, LR+ 2.54, LR− 0.4.

Conclusions

In patients with elevated troponin and no significant coronary artery disease, the ACTION-ICU Score was a predictive scale for the development of complications with adequate accuracy. The best cut-off point for this classification in patients with elevated troponin in absence of significant coronary artery disease was >6.

Funding Acknowledgement

Type of funding sources: None. ROC Curve of ACTION-ICU score >6 points

Histological and molecular characterization of human aortic stenosis: a matter of sex

Introduction

Aortic stenosis (AS) is the most common heart valve disease and it is strongly prevalent with elderly. AS is a progressive, degenerative disease associated with fibrosis and calcification of the valve leaflets. Surgical valve replacement is the only treatment available. Molecular, cellular and interstitial events activate multifactorial and complex cues with a significant contribution by valve interstitial cells (VICs). Despite male sex is a risk factor for developing AS, there is scant information on sex-specific differences in aortic valve (AV) biology or pathology.

Purpose

The aim of our study was to analyse sex-specific differences in aortic valves from AS patients.

Methods

185 patients with severe AS undergoing surgical valve replacement were recruited. 149 AVs (66 women; 83 men) were used for ex vivo analyses. Human VICs were isolated from 36 AVs (12 women; 24 men) for in vitro experiments. AVs structure were evaluated by haematoxylin-eosin, Movat, Alizarin Red, Congo red and Alcian blue/Sirius Red staining and immunohistochemistry. Western blot, ELISA and zymography were used for molecular biology studies.

Results

AVs from men presented increased inflammatory infiltrates (CD68 and CD45 positive cells) as compared to women. Complementarily, AVs from men exhibited higher levels of the inflammatory molecules interleukin (IL)-6 and IL-1b and RANTES. In line with these results, oxidative stress markers (eNOS, myeloperoxidase, malondialdehyde and nitrotyrosine) were upregulated in male AVs. Concerning, fibrosis, increased levels of collagen type I, fibronectin and syndecan-1 were found in AVs from men. Extracellular matrix (ECM) remodelling was characterized by reduced metalloproteinase-1 expression and increased tissue inhibitor of metalloproteinase-2 expression in male AVs. Importantly, calcification and osteogenic markers (bone morphogenetic protein-9, periostin, osteocalcin and Sox-9) was greatly enhanced in men AVs as compared to women. These findings were confirmed in isolated VICs. At baseline, male VICs presented higher myofibroblast-like phenotype than female VICs. In line with our ex vivo results, male VICs exhibited increased inflammatory, oxidative stress, fibrotic and osteogenic differentiation markers.

Conclusions

Our results suggest that the mechanisms driving the AV pathogenesis could be different in men and women patients with the same AS severity. Male AVs and isolated VICs presented more inflammation, oxidative stress, fibrosis and ECM remodelling including extensive calcification as compared to female. A better knowledge of the pathophysiological pathways in AVs and VICs will allow developing sex-specific options for AS treatment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III

P–787 Impact of delaying ART to promote weight loss: a large multicentre study accounting for the combined effect of female/male age and body mass index (BMI)

Study question

Is postponing the start of ART (to promote a reduction in female BMI) beneficial for cumulative live birth rates (CLBR) when accounting for the female/male ageing this delay will cause?

Summary answer

Postponing ART treatment in one year to promote female weight loss could be detrimental in women of advanced maternal age (AMA, >35 years-old).

What is known already

Overweight/obese couples are frequently encouraged to lose weight prior to infertility treatment to enhance ART outcomes. However, a meaningful weight loss is often difficult to achieve for these couples, frequently taking at least one year to accomplish. Given that both female and male ageing are also important for ART success, we were interested in understanding the combined impact on CLBR of BMI reduction and ageing following a one-year delay.

Study design, size, duration

A retrospective study including patients performing their first ART cycle using autologous gametes between 2013–2018 in one of 39 participating ART centres. Only GnRH antagonist cycles were included (n = 14260). CLBR was the primary outcome. Secondary outcomes included time-to-pregnancy, birthweight and gestational age.

Participants/materials, setting, methods

Patients were subdivided according to female BMI (Kg/m2) in either underweight (<18.5), normal-weight (18.5–24.9), overweight (BMI 25.0–29.9 kg/m2) and obese (≥30 kg/m2). Meaningful and extreme weight loss were defined as a reduction from obesity to either overweight or normal-weight, respectively. We performed multivariable regression analysis to account for potential confounding.

Main results and the role of chance

Overweight (36.8%) and obese (33.0%) women had significantly lower CLBR when compared to the underweight (42.6%) and normal-weight (41.4%). When assessing the confounder-adjusted net-effect of male/female age and BMI, the predicted benefit of promoting a meaningful BMI reduction was lower than the estimated hindrance due to male/female ageing as soon as women reached AMA (n = 8365, 58.6%). This absence of benefit was especially important in women >38 years-old, in which even extreme weight-loss did not compensate for the age-related reduction in CLBR caused by the one-year delay. Moreover, male weight-loss failed to provide any additional benefit when accounted for in the regression models. Finally, obesity was also associated with a modest but statistically significant one-month delay in time-to-pregnancy and a 96.1 g (95% confidence interval: 39.9–152.4) increase in birth weight. The diagram of predicted outcomes presented in this study may serve as a useful tool to counsel patients before treatment, namely when recommending treatment postponement to promote short-term (i.e. 3–6 months) or long-term (i.e. 1 year) weight loss.

Limitations, reasons for caution

Caution is recommended when extrapolating these results into everyday practice owing to the retrospective nature of the study and the fact that only GnRH antagonist cycles were included.

Wider implications of the findings: Patients are frequently confronted with the dilemma to either postpone treatment (and promote weight loss) or start treatment immediately (to avoid further ageing). Our results seem to show that women in AMA may have hindered CLBR if recommended to delay treatment even if the desired weight loss is ultimately achieved.

Trial registration number

Not applicable

Wastewater effluents cause microbial community shifts and change trophic status

Widespread wastewater pollution is one of the greatest challenges threatening the sustainable management of rivers globally. Understanding microbial responses to gradients in environmental stressors, such as wastewater pollution, is crucial to identify thresholds of community change and to develop management strategies that protect ecosystem integrity. This study used multiple lines of empirical evidence, including a novel combination of microbial ecotoxicology methods in the laboratory and field to link pressure-stressor-response relationships. Specifically, community-based whole effluent toxicity (WET) testing and environmental genomics were integrated to determine real-world community interactions, shifts and functional change in response to wastewater pollution. Here we show that wastewater effluents above moderate (>10%) concentrations caused consistent significant shifts in bacterial community structure and function. These thresholds of community shifts were also linked to changes in the trophic state of receiving waters in terms of nutrient concentrations. Differences in the community responses along the effluent concentration gradient were primarily driven by two globally relevant bacterial indicator taxa, namely Malikia spp. (Burkholderiales) and hgcI_clade (Frankiales). Species replacement occurred above moderate effluent concentrations with abundances of Malikia spp. increasing, while abundances of hgcI_clade decreased. The responses of Malikia spp. and hgcI_clade matched gene patterns associated with globally important nitrogen cycling pathways, such as denitrification and nitrogen fixation, which linked the core individual taxa to putative function and ecosystem processes, rarely achieved in previous studies. This study has identified potential indicators of change in trophic status and the functional consequences of wastewater pollution. These findings have immediate implications for both the management of environmental stressors and protection of aquatic ecosystems.

Reactive astrogliosis in the dentate gyrus of mice exposed to active volcanic environments

Air pollution has been associated with neuroinflammatory processes and is considered a risk factor for the development of neurodegenerative diseases. Volcanic environments are considered a natural source of air pollution. However, the effects of natural source air pollution on the central nervous system (CNS) have not been reported, despite the fact that up to 10% of the world's population lives near a historically active volcano. In order to assess the response of the CNS to such exposure, our study was conducted in the island of Sao Miguel (Azores, Portugal) in two different areas: Furnas, which is volcanically active one, and compared to Rabo de Peixe, a reference site without manifestations of active volcanism using Mus musculus as a bioindicator species. To evaluate the state of the astroglial population in the dentate gyrus in both samples, the number of astrocytes was determined using immunofluorescence methods (anti-GFAP and anti-GS). In addition, the astrocytic branches in that hippocampal area were examined. Our results showed an increase in GFAP+ astrocytes and a reduction in GS+ astrocytes in Furnas-exposed mice compared to animals from Rabo de Peixe. In addition, astrocytes in the dentate gyrus of chronically exposed animals exhibited longer branches compared to those residing at the reference site. Thus, reactive astrogliosis and astrocyte dysfunction are found in mice living in an active volcanic environment.

Comparative in silico design and validation of GPS™ CoVID-19 dtec-RT-qPCR test

AIMS

Providing a ready-to-use reverse transcriptase qPCR (RT-qPCR) method fully validated to detect the SARS-CoV-2 with a higher exclusivity than this shown by early published RT-qPCR designs.

METHODS AND RESULTS

The specificity of the GPS™ CoVID-19 dtec-RT-qPCR test by analysis of sequence alignments was approached and compared with other RT-qPCR designs. The GPS™ CoVID-19 dtec-RT-qPCR test was validated following criteria of UNE/EN ISO 17025:2005 and ISO/IEC 15189:2012. Diagnostic validation was achieved by two independent reference laboratories, the Instituto de Salud Carlos III, (Madrid, Spain), the Public Health England (Colindale, London, UK), and received the label CE-IVD. The GPS design showed the highest exclusivity and passed all parameters of validation with strict acceptance criteria. Results from reference laboratories 100% correlated with these obtained by using reference methods and showed 100% of diagnostic sensitivity and specificity.

CONCLUSIONS

The CE-IVD GPS™ CoVID-19 dtec-RT-qPCR test, available worldwide with full analytical and diagnostic validation, is the more exclusive for SARS-CoV-2 by far.

SIGNIFICANCE AND IMPACT OF THE STUDY

Considering the CoVID-19 pandemic status, the exclusivity of RT-qPCR tests is crucial to avoid false positives due to related coronaviruses. This work provides of a highly specific and validated RT-qPCR method for detection of SARS-CoV-2, which represents a case of efficient transfer of technology successfully used since the pandemic was declared.

Nature (Hole or Electron) of Charge-Transfer Ability of Substituted Cyclopyrenylene Hoop-Shaped Compounds

We theoretically investigate here by means of DFT methods how the selective substitution in cyclic organic nanorings composed of pyrene units may promote semiconducting properties, analyzing the energy needed for a hole- or electron-transfer accommodation as a function of the substitution pattern and the system size (i.e., number of pyrene units). We choose to study both [3]Cyclo-2,7-pyrenylene ([3]CPY) and [4]Cyclo-2,7-pyrenylene ([4]CPY) compounds, the latter already synthesized, with substituents other than hydrogen acting in ipso and ortho positions, as well as the effect of the per-substitution. As substituents, we selected a set of electroactive halogen atoms (F, Cl, and Br) and groups (CN) to disclose structure-property relationships allowing thus to anticipate the use of these systems as organic molecular semiconductors.

Analysis of mismatch repair (MMR) proteins expression in a series of malignant pleural mesothelioma (MPM) patients

BACKGROUND

Promising results have been reported with immune checkpoint inhibitors (ICI) in a small proportion of MPM patients. MMR deficiency (dMMR) has been well described in several malignancies and was approved as a biomarker for anti-PD-1 inhibitors. Next generation sequencing (NGS) data demonstrated that 2% of MPM harbor microsatellite instability. The aim of this study is to characterize MMR by immunohistochemistry (IHC) in a series of MPM including a subset of patients treated with immunotherapy.

METHODS

Tumors of 159 MPM p diagnosed between 2002 and 2017 were reviewed. Formalin-fixed, paraffin-embedded tissue was stained for MLH1, MSH2, MSH6 and PMS2 and tumors were classified as dMMR (MMR protein expression negative) and MMR intact (all MMR proteins positively expressed). We retrospectively collected clinical outcomes under standard chemotherapy and experimental immunotherapy in the entire cohort.

RESULTS

MMR protein expression was analyzed in 158 samples with enough tissue and was positive in all of the cases. Twenty two patients received ICI with anti-CTLA4 or anti-PD-1 blockade in clinical trials, 58% had a response or stable disease for more than 6 m, with median progression-free survival (PFS) of 5.7 m (2.1-26.1 m). The median overall survival (mOS) in all population was 15 months (m) (13.5-18.8 m). In a multivariable model factors associated to improved mOS were PS 0, neutrophil-lymphocyte ratio (NLR) < 5 and epithelioid histology (p < 0.001).

CONCLUSIONS

In our series we were unable to identify any MPM patient with dMMR by IHC. Further studies are needed to elucidate potential predictive biomarkers of ICI benefit in MPM.

Immunotherapeutic maintenance treatment with toll-like receptor 9 agonist lefitolimod in patients with extensive-stage small-cell lung cancer: results from the exploratory, controlled, randomized, international phase II IMPULSE study

Background

The immune surveillance reactivator lefitolimod (MGN1703), a DNA-based TLR9 agonist, might foster innate and adaptive immune response and thus improve immune-mediated control of residual cancer disease. The IMPULSE phase II study evaluated the efficacy and safety of lefitolimod as maintenance treatment in extensive-stage small-cell lung cancer (ES-SCLC) after objective response to first-line chemotherapy, an indication with a high unmet medical need and stagnant treatment improvement in the last decades.

Patients and methods

103 patients with ES-SCLC and objective tumor response (as per RECIST 1.1) following four cycles of platinum-based first-line induction therapy were randomized to receive either lefitolimod maintenance therapy or local standard of care at a ratio of 3 : 2 until progression or unacceptable toxicity.

Results

From 103 patients enrolled, 62 were randomized to lefitolimod, 41 to the control arm. Patient demographics and response patterns to first-line therapy were balanced. Lefitolimod exhibited a favorable safety profile and pharmacodynamic assessment confirmed the mode-of-action showing a clear activation of monocytes and production of interferon-gamma-induced protein 10 (IP-10). While in the intent-to-treat (ITT) population no relevant effect of lefitolimod on progression-free and overall survival (OS) could be observed, two predefined patient subgroups indicated promising results, favoring lefitolimod with respect to OS: in patients with a low frequency of activated CD86⁺ B cells (hazard ratio, HR 0.53, 95% CI: 0.26–1.08; n = 38 of 88 analyzed) and in patients with reported chronic obstructive pulmonary disease (COPD) (HR 0.48, 95% CI: 0.20–1.17, n = 25 of 103).

Conclusions

The IMPULSE study showed no relevant effect of lefitolimod on the main efficacy end point OS in the ITT, but (1) the expected pharmacodynamic response to lefitolimod, (2) positive OS efficacy signals in two predefined subgroups and (3) a favorable safety profile. These data support further exploration of lefitolimod in SCLC.

Short communication: Molecular characterization and antimicrobial resistance of pathogenic Escherichia coli isolated from raw milk and Minas Frescal cheeses in Brazil

The aim of this study was to quantify, identify, evaluate antimicrobial resistance, and characterize the virulence factors of enteropathogenic (EPEC), Shiga-toxigenic (STEC), and enterohemorrhagic (EHEC) Escherichia coli in raw milk (RM) and legal (LMFC) and illegal (IMFC) Minas Frescal cheeses in southern and northeast Brazil. Illegal cheeses are those made without official inspection service or sanitary surveillance. We evaluated samples of RM produced in Paraná (southern) and Maranhão (northeast) States, LMFC produced using pasteurized milk in inspected industries, and IMFC potentially produced with raw milk. Mean total coliform counts were 8.4 × 10⁴ cfu/mL for RM, 1.4 × 10⁷ cfu/mL for LMFC, and 2.9 × 10⁷ cfu/mL for IMFC. Mean E. coli counts were 2.4 × 10³ cfu/mL for RM, 1.9 × 10² cfu/mL for LMFC, and 1.1 × 10⁵ cfu/mL for IMFC. Among the 205 E. coli isolates from RM, 9.75% were identified as EPEC, mainly (90%) in samples from Paraná. Of the total isolates from the cheese samples, 97.4% (n = 111) came from IMFC, of which 1.8 and 2.7% were identified as EPEC and STEC, respectively; no EHEC was detected. The phylogenetic group A (60%) and typical EPEC (68%) predominated, which confirms the possible human origin of pathogenic isolates in RM and IMFC. Of these, 50% were resistant to at least one antibiotic, and streptomycin was the antimicrobial with the highest number (8) of EPEC and STEC resistant isolates. This study reports the first isolation of serogroup O28ac in Brazilian milk. We found no predominance of a specific serogroup of EPEC or STEC in milk or cheese or clonal isolates in the same sample, indicating different origins of the contamination in these products, presumably mostly related to poor hygienic handling.