Background: Lactiplantibacillus plantarum can inhibit the growth of multidrug-resistant organisms (MDROs) and modulate the gut microbiome. However, data on hematopoietic stem cell transplantation (HSCT) are scarce. Aim: In an observational study, we assessed the impact of L. plantarum on the modulation of the gut microbiome in HSCT patients colonized by MDROs. Methods: Participants were allocated to an intervention group (IG = 22) who received capsules of L. plantarum (5 × 10⁹ CFU) twice per day until the onset of neutropenia or a control group (CG = 20). The V4 region of the 16S bacterial rRNA gene was sequenced in 87 stool samples from a subset of 33 patients (IG = 20 and CG = 13). The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) program was used to predict metagenome functions. Results: L. plantarum demonstrated an average 86% (±11%) drug-target engagement at 43 (±29) days of consumption and was deemed safe, well-tolerated, and associated with an increase in the abundance of the Lactobacillales (p < 0.05). A significant increase in Lactococcus and a reduction in Turicibacter (p < 0.05) were identified on the second week of L. plantarum use. Although Enterococcus abundance had a greater rise in the CG (p = 0.07), there were no significant differences concerning the Gram-negative MDROs. No serious adverse effects were reported in the IG. We observed a greater, non-significant pyruvate fermentation to propanoate I (p = 0.193) relative abundance in the IG compared with the CG. L. plantarum use was safe and tolerable by HSCT patients. Conclusions: While L. plantarum is safe and may impact Enterococcus and Turicibacter abundance, it showed no impact on Gram-negative MDRO abundance in HSCT patients.

Background/Objectives. Autism spectrum disorder (ASD) has been associated with microbiome alterations, but the relative contribution of environmental and individual factors remains unclear. This study explored oral and gut microbiome profiles in environmentally matched dizygotic triplets discordant for ASD. Materials and Methods. Triplets in the 5-9 year age range, including one child with ASD and two neurotypical siblings, underwent standardized oral examination. Oral tongue-dorsum and rectal swab samples were analyzed by 16S rRNA sequencing. Taxonomic composition and beta diversity were evaluated descriptively. Results. Dominant bacterial phyla were broadly similar across siblings, but oral microbial profiles showed greater interindividual variation. The participant with ASD had the highest dental biofilm accumulation, predominance of Streptococcus, and reduced representation of several secondary genera. One neurotypical sibling with mild gingival inflammation showed greater representation of Fusobacterium, Prevotella, and Leptotrichia. Beta diversity demonstrated clearer interindividual separation among oral than gut samples. Conclusions. Individual-specific factors may influence microbiome patterns even under highly similar environmental and dietary conditions. These findings support further investigation of the oral microbiome as a complementary component of ASD microbiome research.

This study aimed to investigate the microbial community structure and the presence of Antibiotic-Resistant Bacteria (ARB), Antibiotic Resistance Genes (ARGs), and antimicrobial residues in an urban stream adjacent to an informal settlement in Brazil. Water samples collected during the winter of 2021 (n = 7) were analysed using culture-dependent and -independent methods. Microbial community structure was assessed by 16S rRNA sequencing, while bacterial isolates were characterized by Chlorhexidine Minimum Inhibitory Concentration (CHX-MIC) and whole-genome sequencing. Free carbapenemase ARGs were screened by conventional PCR and selected antimicrobial residues were quantified by UHPLC-MS/MS. The bacterial community was dominated by phyla Firmicutes, Bacteroidota, Proteobacteria, Campylobacterota, Actinobacteriota, and Patescibacteria. Abundant (> 5%) families included Ruminococcaceae, Prevotellaceae, Moraxellaceae, and Arcobacteraceae, associated with faecal contamination and antimicrobial resistance. Urban stream bacterial isolates (31/66) belonged mainly to the genera Aeromonas, Citrobacter, Escherichia, Serratia, Chryseobacterium, Elizabethkingia with a high percentage of phenotypic resistance to third-generation cephalosporin and carbapenems. WGS of some isolates (16/31) revealed the co-production of ESBL and carbapenemase ARGs as well as Inc-type plasmids, efflux pumps and virulence genes. CHX-MICs ranged from 0.5 to 128 mg/L, with Klebsiella pneumoniae and Serratia marcescens showing the highest values and harboring qac genes and IncHI2 plasmids, respectively. Azithromycin, ceftriaxone, levofloxacin, and chlorhexidine were detected at up to 2.39, 1.18, 0.14, and 0.43 mg/L, respectively. Notably, ceftriaxone-positive water samples also contained ARB and free ARGs (bla_NDM, bla_KPC, bla_VIM). These findings highlight urban streams as reservoirs of ARB, ARGs, and antimicrobial residues, stressing the urgent need for local water treatment to mitigate antimicrobial resistance and public health risks.

Neisseria gonorrhoeae (NG) has become an increasing global health threat due to drug resistance and potentially invasive disease. In this study, we assessed the genotypic profile in both invasive and non-invasive NG strains from patients at University of Sao Paulo Faculty of Medicine Clinics Hospital, Brazil. We analyzed the NG genotypic profiles and clinical data from 25 patients hospitalized at Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (HC-FMUSP) from January 2017 to March 2020. A total of 25 isolates underwent whole genome sequencing, of which 10 (40%) were collected from sterile sites like blood and classified as invasive. Invasive and noninvasive specimens were clustered in 5 STs and 11 STs, respectively, sharing 3 STs in common. We identified resistance markers for macrolides (mtrR) in 40% of isolates and 92% exhibited at least one resistance marker for beta-lactams (penA, blaTEM-1B, or blaTEM-135), predominantly PBP1 and PBP2 alterations. Resistance genes blaTEM-1B (7%vs.50%, p=0.023) and tetM (13%vs.80%, p=0.002) were more frequently found in invasive disease isolates, always accompanied by the mobile genetic elements pJD4 and pEP5289, respectively. Associated with these elements were two toxin encoding genes (vapD and zeta1/2) previously described as possible virulence factors and resistance genes for beta-lactams and tetracyclines. Results revealed that invasive strains of NG are genotypically clustered and frequently harbor two plasmids which may be associated with invasive disease. Resistance markers for beta-lactam as PBP1 and PBP2 alterations warn against a future potential resistance to this class.

Gut colonization by multidrug resistant organisms(MDROs) is a risk factor for bloodstream infections(BSI) in the early phase of Hematopoietic Stem Cell Transplantation(HSCT). We evaluated, in an exploratory study, the impact of Lactobacillus plantarum on modulation of the gut microbiome in HSCT patients colonized by MDROs. Participants were allocated to an intervention group(IG=22) who received capsules of L. plantarum(5x109 CFU) twice a day until the onset of neutropenia and a control group(CG=20). The V4 region of the 16S bacterial rRNA gene in 93 stool samples from a subset of 33 patients was sequenced(IG=20 and CG=13). Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) (PICRUSt2) program was used for prediction of metagenome functions. L. plantarum had an average 86%(±11%) drug-target engagement at 43(±29) days of consumption and it was safe, tolerable and associated with an increase in the abundance of the Lactobacillales(p=0.004). A significant increase of Lactococcus and reduction of Turicibacter(p<0.05) were identified on the second-week of L. plantarum use. Although Enterococcus abundance had a greater rise in the CG (p=0,07), there were no significant differences concerning the gram-negative MDROs. No serious adverse effects was reported in the IG. . We observed greater non-significant pyruvate fermentation to propanoate I (p=0.193) relative abundance in the IG comparing with CG. L. plantarum use was safe and tolerable by HSCT patients. Although it may have impact on Enterococcus abundance and reduction of Turicibacter, it has not showed impact on Gram-Negative MDRO abundance in MDRO gram-negative colonized HSCT patients.

Introduction : The oral cavity is an important site for the entry and multiplication of respiratory viruses, and the immune system and oral microbiome act as antiviral barriers. Data regarding oral microbiome and COVID-19 is scarce. Therefore, a prospective cohort was conducted at the Hospital das Clínicas of FMUSP to evaluate the frequency of oral lesions associated with COVID-19 and the diversity of the oral microbiome on disease severity. Methods : Oral samples from SARS-CoV-2 positive patients were collected. After DNA extraction from the whole saliva samples, sequencing of the 16S rRNA gene using the Ion Torrent PGM platform was performed. Alpha and beta diversity analyses were conducted using the R program. Clinical data from electronic medical records were collected and multiple logistic regression model was constructed to assess the association between oral microbiome diversity and COVID-19 severity (oxygen therapy, mechanical ventilation). Results : The study included a total of 115 samples from 125 patients, 14 had oral lesions, the majority were female (54.8%), with a mean age of 55.4 years old. Around 59.1% of patients were in intensive care units(ICUs), 87.2% were using antibiotics, and 18.3% died. The most frequently antibiotics used were third-generation cephalosporins(35.7%), piperacillin/tazobactam(27%), and glycopeptides(21.7%). In general, the most abundant phyla were Firmicutes , Proteobacteria , and Bacteroidetes , representing 86.3% of the oral microbiome. Oral microbiome diversity analysis revealed statistical differences in COVID-19 severity (Shannon p=0.05), presence of oral lesions Shannon p=0.05), antibiotic use(Shannon p=0.04), and oxygen therapy Observed p=0.04). Differential abundance analysis identified specific taxa related to each variable, such as Prevotella in severe patients and Staphylococcus in individuals with oral lesions. Multivariable logistic regression pointed out that the SARS-CoV-2 PCR positive on the oral cavity and the age (above 60 years) were risk factors for disease severity. Conclusion : Despite the small number of participants with oral cavity lesions, we found significant differences in the microbial communities, particularly in the genus Staphylococcus d associated with oral lesions. Although the abundance of Prevotella was associated with severity of COVID-19 on the microbiome analysis, the multivariate model showed that only age and RT-PCR positive for SARS-CoV-2 on the oral cavity were independent risk factors for severity.