Exploring Peracetic Acid and Acidic pH Tolerance of Antibiotic Resistant Non-typhoidal Salmonella and Enterococcus faecium from Diverse Epidemiological and Genetic Backgrounds

Acid stress poses a common challenge for bacteria in diverse environments by the presence of inorganic (e.g., mammals stomach) or organic acids (e.g., feed additives; acid-based disinfectants). Limited knowledge exists regarding acid-tolerant strains of specific serotypes, clonal lineages, or sources in human/animal pathogens, namely non-typhoidal Salmonella enterica (NTS) and Enterococcus faecium (Efm). This study evaluated acidic pH and peracetic acid (PAA) susceptibility of Efm (n=72) and NTS (n=60) from diverse epidemiological/genetic backgrounds, and with multiple antibiotic resistance profiles. Efm minimum growth/survival-pH was 4,5-5/3-4 and for NTS 4,0-4,5/3,5-4,0. Among Efm, only those of clade-non-A1 (non-hospital associated) or food chain demonstrated greater tolerance to acidic pH compared to clade-A1 (hospital-associated clones) or clinical isolates (P&lt;0.05). MDR (multidrug-resistant) NTS survived better to acidic pH (P&lt;0.05). The MICPAA/MBCPAA was 70-120/80-150mg/L for Efm and 50-70/60-100mg/L for NTS. Efm-clade-A1 or MDR strains exhibited higher PAA tolerance than clade-non-A1 or non-MDR ones (P&lt;0.05). Higher tolerance was found in non-MDR and clinical NTS than in food chain isolates (P&lt;0.05), but not between different serogroups. This unique study identifies specific NTS or Efm populations more tolerant to acidic pH or PAA, emphasizing the need for further research to tailor control measures of public health and food safety within a One Health framework.</jats:p

Enterococcus spp. from chicken meat collected 20 years apart overcome multiple stresses occurring in the poultry production chain : Antibiotics, copper and acids

Poultry meat has been a vehicle of antibiotic resistant bacteria and genes. Yet, the diversity of selective pressures associated with their maintenance in the poultry-production chain remains poorly explored. We evaluated the susceptibility of Enterococcus spp. from chicken meat collected 20 years apart to antibiotics, metals, acidic pH and peracetic acid-PAA. Contemporary chicken-meat samples (n = 53 batches, each including a pool of neck skin from 10 single carcasses) were collected in a slaughterhouse facility using PAA as disinfectant (March-August 2018, North of Portugal). Broilers were raised in intensive farms (n = 29) using CuSO4 and organic acids as feed additives. Data were compared with that of 67 samples recovered in the same region during 1999-2001. All 2018 samples had multidrug resistant-MDR isolates, with >45 % carrying Enterococcus faecalis, Enterococcus faecium or Enterococcus gallinarum resistant to tetracycline, erythromycin, ampicillin, quinupristin-dalfopristin, ciprofloxa-cin, chloramphenicol or aminoglycosides. Resistance rates were similar (P > 0.05) to those of 1999-2001 samples for all but five antibiotics. The decrease of samples carrying vancomycin-resistant isolates from 46 % to % between 1999-2001 and 2018 was the most striking difference. Isolates from both periods were similarly susceptible to acid pH [minimum-growth pH (4.5-5.0), minimum-survival pH (3.0-4.0)] and to PAA (MIC90 = 100-120 mg/L/MBC90 = 140-160 mg/L; below concentrations used in slaughterhouse). Copper tolerance genes (tcrB and/or cueO) were respectively detected in 21 % and 4 % of 2018 and 1999-2001 samples. The tcrB gene was only detected in E. faecalis (MICCuSO4 > 12 mM), and their genomes were compared with other international ones of chicken origin (PATRIC database), revealing a polyclonal population and a plasmid or chromosomal location for tcrB. The tcrB plasmids shared diverse genetic modules, including multiple antimicrobial resistance genes (e.g. to tetracyclines, chloramphenicol, macrolide-lincosamide-streptogramin B-MLSB, aminoglycosides, bacitracin, coccidiostats). When in chromosome, the tcrB gene was co-located closely to merA (mercury) genes. Chicken meat remains an important vehicle of MDR Enterococcus spp. able to survive under diverse stresses (e.g. copper, acid) potentially contributing to these bacteria maintenance and flux among animal-environment -humans.Peer reviewe

Combining sequencing approaches to fully resolve a carbapenemase-encoding megaplasmid in a Pseudomonas shirazica clinical strain

ABSTRACTHorizontal transfer of plasmids plays a pivotal role in dissemination of antibiotic resistance genes and emergence of multidrug-resistant bacteria. Plasmid sequencing is thus paramount for accurate epidemiological tracking in hospitals and routine surveillance. Combining Nanopore and Illumina sequencing allowed full assembly of a carbapenemase-encoding megaplasmid carried by multidrug-resistant clinical isolate FFUP\_PS\_41. Average nucleotide identity analyses revealed that FFUP\_PS\_41 belongs to the recently proposed new species Pseudomonas shirazica, related to the P. putida phylogenetic group. FFUP\_PS\_41 harbours a 498,516-bp megaplasmid (pJBCL41) with limited similarity to publicly-available plasmids. pJBCL41 contains genes predicted to encode replication, conjugation, partitioning and maintenance functions and heavy metal resistance. The |aacA7|blaVIM-2|aacA4| cassette array (resistance to carbapenems and aminoglycosides) is located within a class 1 integron that is a defective Tn402 derivative. This transposon lies within a 50,273-bp region bound by Tn3-family 38-bp inverted repeats and flanked by 5-bp direct repeats (DR) that composes additional transposon fragments, five insertion sequences and a Tn3-Derived Inverted-Repeat Miniature Element. The hybrid Nanopore/Illumina approach allowed full resolution of a carbapenemase-encoding megaplasmid from P. shirazica. Identification of novel megaplasmids sheds new light on the evolutionary effects of gene transfer and the selective forces driving antibiotic resistance

Interactions between commensal <i>Enterococcus faecium</i> and <i>Enterococcus lactis</i> and clinical isolates of<i> Enterococcus faecium</i>

Enterococcus faecium (Efm) is a versatile pathogen, responsible for multidrug-resistant infections, especially in hospitalized immunocompromised patients. Its population structure has been characterized by diverse clades (A1, A2, and B (reclassified as E. lactis (Ela)), adapted to different environments, and distinguished by their resistomes and virulomes. These features only partially explain the predominance of clade A1 strains in nosocomial infections. We investigated in vitro interaction of 50 clinical isolates (clade A1 Efm) against 75 commensal faecal isolates from healthy humans (25 clade A2 Efm and 50 Ela). Only 36% of the commensal isolates inhibited clinical isolates, while 76% of the clinical isolates inhibited commensal isolates. The most apparent overall differences in inhibition patterns were presented between clades. The inhibitory activity was mainly mediated by secreted, proteinaceous, heat-stable compounds, likely indicating an involvement of bacteriocins. A custom-made database targeting 76 Bacillota bacteriocins was used to reveal bacteriocins in the genomes. Our systematic screening of the interactions between nosocomial and commensal Efm and Ela on a large scale suggests that, in a clinical setting, nosocomial strains not only have an advantage over commensal strains due to their possession of AMR genes, virulence factors, and resilience but also inhibit the growth of commensal strains

linical challenges in Crohn s disease

Introduction: Crohn s disease is a chronic inflammatory disease from gastrointestinal tract. The increase in incidence and heterogeneity of this pathology, with different presentations and prognostics leads to a constant concern in developing and improving its classification and treatment. Objectives: To establish recommendations (based on level of evidence and recommendation grades) to 5 questions considered as the clinical challenges of the therapeutic approach in Crohn s disease. Methods: The methodology adopted by the working group DC2 (Desafios Clínicos na Doença de Crohn) was based on the selection of 5 questions, by voting, and establishing recommendations to each question proposed to each subgroup. Discussion and approval of reflexions and final recommendations was carried out in a consensus meeting. Conclusion: It has been possible to base conclusions about the questions under study on evidence, being recommended: 1) having Crohn s disease under 40 years old, structuring phenotype disease and anal disease are predictive factors of bad prognostic; 2) it is possible to consider suspension of biologics in patients with endoscopic remission and normal biomarkers; 3) patients with biochemical markers of disease activity (CRP and calprotectina) have more probability of relapse; 4) in failure of biologics it is essential to assure that treatment with the first drug was optimized: with infliximab it s demonstrated that either reduction of the administration range or increasing the dose allows to recover the response in the majority of patients; as for adalimumab, patients should change from bimonthly to weekly administrations; 5) in case of Crohn s disease with intestinal surgery, use of therapeutic to reduce postoperative recurrence is indicated, particularly immunosupressors and biologics

Crohn's disease in a southern European country: Montreal classification and clinical activity

BACKGROUND: Given the heterogeneous nature of Crohn's disease (CD), our aim was to apply the Montreal Classification to a large cohort of Portuguese patients with CD in order to identify potential predictive regarding the need for medical and/or surgical treatment. METHODS: A cross-sectional study was used based on data from an on-line registry of patients with CD. RESULTS: Of the 1692 patients with 5 or more years of disease, 747 (44%) were male and 945 (56%) female. On multivariate analysis the A2 group was an independent risk factor of the need for steroids (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1-2.3) and the A1 and A2 groups for immunosuppressants (OR 2.2; CI 1.2-3.8; OR 1.4; CI 1.0-2.0, respectively). An L3+L3(4) and L(4) location were risk factors for immunosuppression (OR 1.9; CI 1.5-2.4), whereas an L1 location was significantly associated with the need for abdominal surgery (P < 0.001). After 20 years of disease, less than 10% of patients persisted without steroids, immunosuppression, or surgery. The Montreal Classification allowed us to identify different groups of disease severity: A1 were more immunosuppressed without surgery, most of A2 patients were submitted to surgery, and 52% of L1+L1(4) patients were operated without immunosuppressants. CONCLUSIONS: Stratifying patients according to the Montreal Classification may prove useful in identifying different phenotypes with different therapies and severity. Most of our patients have severe disease

Public health risks associated with food‐borne parasites

Parasites are important food-borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe-focused ranking exercise, using multicriteria decision analysis, identified potentially food-borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food-borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well-established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T.gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures

Guidance on date marking and related food information: part 2 (food information)

A risk-based approach was used to develop guidance to be followed by food business operators (FBOs) when deciding on food information relating to storage conditions and/or time limits for consumption after opening a food package and thawing of frozen foods. After opening the package, contamination may occur, introducing new pathogens into the food and the intrinsic (e.g. pH and aw), extrinsic (e.g. temperature and gas atmosphere) and implicit (e.g. interactions with competing background microbiota) factors may change, affecting microbiological food safety. Setting a time limit for consumption after opening the package (secondary shelf-life) is complex in view of the many influencing factors and information gaps. A decision tree (DT) was developed to assist FBOs in deciding whether the time limit for consumption after opening, due to safety reasons, is potentially shorter than the initial ‘best before’ or ‘use by’ date of the product in its unopened package. For products where opening the package leads to a change of the type of pathogenic microorganisms present in the food and/or factors increasing their growth compared to the unopened product, a shorter time limit for consumption after opening would be appropriate. Freezing prevents the growth of pathogens, however, most pathogenic microorganisms may survive frozen storage, recover during thawing and then grow and/or produce toxins in the food, if conditions are favourable. Moreover, additional contamination may occur from hands, contact surfaces or contamination from other foods and utensils. Good practices for thawing should, from a food safety point of view, minimise growth of and contamination by pathogens between the food being thawed and other foods and/or contact surfaces, especially when removing the food from the package during thawing. Best practices for thawing foods are presented to support FBOs