A bstract: SARS-CoV-2 genetic material is detectable in the faeces of a considerable part of COVID-19 cases and hence, in the urban wastewater. This fact was confirmed early during the spread of the COVID-19 pandemic and prompted several studies that proposed monitoring its incidence by wastewater. This paper studies the fate of SARS-CoV-2 genetic material in wastewater treatment plants using RT-qPCR with a two-fold goal: i) to check the safety of the water effluent and also of the sludge produced and ii) based on the understanding of the virus particles fate, to identify the most suitable spots for detecting the incidence of COVID-19 and monitor its evolution. On the grounds of the affinity of enveloped virus towards biosolids, we hypothesized that the sludge line acts as a concentrator of SARS-CoV-2 genetic material. Sampling several spots in primary, secondary and sludge treatment at the Ourense (Spain) WWTP showed that, in effect, most of SARS-CoV-2 particles cannot be detected in the water effluent as they are retained by the sludge line. We identified the sludge thickener as a suitable spot for detecting SARS-CoV-2 particles thanks to its higher solids concentration (more virus particles) and longer residence time (less sensitive to dilution caused by precipitation). Although more studies will be needed for confirmation, these results contribute to clarify the role of WWTPs in COVID-19 mitigation.

Understanding the functional potential of the gut microbiota for carbapenem-resistant Enterobacterales (CRE) decolonisation is essential for developing novel non-antibiotic strategies to promote their clearance. In a previous study, we identified distinct taxonomic signatures associated with spontaneous CRE decolonisation (DeCol). Here, we aimed to determine whether these taxonomic differences were accompanied by differences in the predicted functional potential of the gut microbiota. Patients were identified from a database of individuals colonised with CRE. We performed Illumina shotgun metagenomic sequencing on 14 persistent CRE carriage (Col) and 23 DeCol patients with OXA-48-producing isolates. Bioinformatic analysis was performed using SqueezeMeta and differential abundance of functional and metabolic genes was assessed using DESeq2. Several antimicrobial resistance genes, including blaOXA-48, were underrepresented in DeCol patients. In contrast, DeCol patients showed an overrepresentation of genes associated with motility, regulated adhesion, short-chain fatty acid (SCFA)-related pathways and alternative carbohydrate metabolism. These orthologue enrichment patterns are consistent with functions previously linked to intestinal homeostasis in the literature. Conversely, Col patients exhibited an overrepresentation of genes associated with redox defence, biofilm formation and amino acid metabolism, suggesting distinct predicted functional profiles between persistent carriage and spontaneous decolonisation. Spontaneous CRE decolonisation was associated with distinct KEGG-based functional signatures and a lower abundance of antimicrobial resistance determinants. These functional profiles were consistent with the taxonomic differences previously identified in the same cohort and generate hypotheses regarding microbiome functions that may contribute to colonisation clearance. Because these findings are based on gene-content analysis, they reflect predicted functional potential rather than direct evidence of metabolic activity. Further multi-omics and experimental studies are required to validate these observations.

This study aimed to evaluate the effectiveness of oral amoxicillin/clavulanate (AMX‐CL) for the prevention of bacteremia following dental extractions. The study group (AMX‐CLG) comprised 40 adults requiring dental extractions under general anesthesia who were administered a prophylactic regimen of 1875/125 mg of AMX‐CL orally 1–2 h prior to the surgery. Venous blood samples were collected from each patient at baseline and at 30 s and 15 min after dental extractions. Samples were inoculated into BACTEC Plus culture bottles and processed in the BACTEC 9240. Conventional microbiological techniques were used for subcultures and further identification of the isolated bacteria. The results for the AMX‐CLG were compared with those of a control group (CG; no prophylaxis) and an amoxicillin group (AMXG; 2 g of amoxicillin orally), consisting of randomly selected patients from among those participating in two clinical trials that we have previously published. The prevalence of bacteremia in the CG, AMXG, and AMX‐CLG was 97%, 50%, and 15%, respectively, at 30 s after completing the extractions, and 67%, 10%, and 4% at 15 min, respectively, after the last extraction. The prevalence of bacteremia in the AMXG and the AMX‐CLG at 30 s and at 15 min after completing the extractions was significantly lower than that in the CG (p < 0.001 and p < 0.001, respectively; Fisher’s exact test). The prevalence of bacteremia in the AMX‐CLG at 30 s after completing the extractions was significantly lower than that in the AMXG (p < 0.001; Fisher’s exact test). Based in the results of this preliminary study, oral AMX‐CL could be an excellent option for preventing bacteremia secondary to dental procedures in patients at risk.

Introduction: The treatment of asymptomatic bacteriuria (AB) has been associated with increased in antibiotic resistance and Clostridioides difficile infection, without clinical benefit. One strategy to improve management is to incorporate a recommendation in the microbiological report. The aim of the study was to assess the impact of this intervention on antibiotic prescribing for AB. Methods: Potential cases of AB were identified, and the following comment was included in the microbiology report: “Assess according to clinical findings. In AB, no treatment is recommended”. Patient demographics, sample characteristics, reason for request, isolated microorganism, resistance profile, time to clinician’s review of the report, initiation of treatment and its causes, and repeat urine culture were collected. Factors associated with adherence to the recommendations were evaluated. Results: A total of 391 possible AB cases were identified. The majority of samples originated, from primary care (96%) and in women over 65 years of age (98%). Antibiotic treatment was initiated in 60% of cases, while the microbiological recommendation was followed in 40%. Factors associated with nonadherence to the recommendation included urine culture request prompted by foul-smelling or cloudy urine, and repeat culture. In contrast, urine cultures requested during routine health checks were more likely to be associate with adherence to the recommendation. Conclusions: The inclusion of a commentary in the microbiology report contributed to a reduction in antimicrobial prescription in AB. This intervention may be effective in optimising antibiotic prescribing practices and improving urine culture request management policies.