Cintya de Oliveira Souza

Antimicrobial-resistant Pseudomonas aeruginosa and Acinetobacter baumannii are major One Health threats, yet the environmental distribution of their epidemic lineages in Brazil remains poorly characterized. This systematic review aimed to synthesize evidence on the clonal diversity, antimicrobial resistance, and geographic distribution of molecularly typed P. aeruginosa and A. baumannii recovered from Brazilian aquatic environments. Searches were conducted in PubMed/MEDLINE, Scopus, Web of Science, SciELO, and LILACS/BVS, following PRISMA 2020. Eleven studies published between 2015 and 2026 were included, comprising 66 unique molecularly typed environmental isolates: 59 P. aeruginosa and seven A. baumannii. Among P. aeruginosa, 24 sequence types (STs) were identified, including the recognized high-risk clones ST244, ST277, and ST235. Four A. baumannii isolates belonged to ST79/International Clone 5, while ST1278, ST3355, and ST744 represented additional lineages. Clinically relevant resistance determinants included blaSPM-1, blaVIM-2, blaKPC-2, and blaOXA-23. Evidence was geographically concentrated and frequently based on selective molecular characterization. Brazilian aquatic environments therefore harbor both established high-risk clones and diverse additional resistant lineages within a One Health framework.

Vertical transmission of sexually transmitted infections remains a public health concern, particularly in socially vulnerable settings. Although Brazil has achieved the elimination of mother‐to‐child transmission of HIV, syphilis during pregnancy continues to pose significant challenges, especially in the northern region. This cross‐sectional study aimed to estimate the prevalence of HIV and syphilis and identify associated factors among pregnant women receiving prenatal care in Belém, Pará, Brazil. Between April and June 2021, 398 pregnant women were interviewed using a structured clinical–epidemiological questionnaire and underwent laboratory testing. HIV diagnosis was established using fourth‐generation serological assays with immunoblot confirmation, and syphilis diagnosis was based on nontreponemal testing followed by treponemal confirmation. Descriptive analyses were performed, followed by bivariate analyses using Fisher’s exact test, chi‐square test with Monte Carlo simulation, and Mann–Whitney U test, and Poisson regression with robust variance was applied to estimate prevalence ratios for syphilis. The prevalence of syphilis was 6.36%, and HIV prevalence was 1.01%. Psychoactive substance use was the only variable independently associated with syphilis positivity, while other sociodemographic and behavioral factors showed descriptive trends without statistical significance, and no significant associations were observed for HIV infection. These findings indicate that persistent social and behavioral vulnerabilities, particularly psychoactive substance use, contribute to ongoing syphilis transmission during pregnancy, underscoring the importance of integrating substance use screening, targeted counseling, and harm‐reduction strategies into prenatal care to advance efforts toward eliminating vertical transmission of sexually transmitted infections.

Background: Class B carbapenemases confer high-level resistance to carbapenems in Klebsiella pneumoniae. In Brazil, data on the national burden and geographic distribution of these genes among clinical K. pneumoniae isolates are sporadic. We performed a systematic review and meta-analysis to estimate the prevalence of MβL genes in Brazilian clinical K. pneumoniae. Methods: We searched SciELO, PubMed, ScienceDirect and LILACS for original studies published between 2006 and 2024 reporting molecular detection of MβL in clinical K. pneumoniae isolates from Brazil. Articles were independently screened, along with the extracted data and appraised study quality using Joanna Briggs Institute checklists. A random-effects meta-analysis estimated the pooled prevalence of MβL producers and assessed heterogeneity and publication bias. Results: Fifteen studies including 3.533 clinical K. pneumoniae isolates met inclusion criteria. Overall, 402 isolates (11.4%) harbored MβL genes, yielding a pooled prevalence of 44.6%. Subgroup analysis demonstrated highest prevalence in the Southeast. bla_NDM was the dominant variant (present in 14/15 studies), with bla_VIM and bla_IMP rarely detected. Meta-regression revealed an inverse association between sample size and reported prevalence, and no significant publication bias was observed. Conclusions: MβLs, particularly NDM, are widespread in Brazilian clinical K. pneumoniae but show marked regional heterogeneity driven by differences in study design, laboratory capacity, and outbreak dynamics. Urgent expansion of standardized and multicenter molecular surveillance, including allele-specific detection, and strengthened laboratory infrastructure are needed and may inform targeted infection-control and antimicrobial-stewardship interventions.

Background: The global impact of the SARS-CoV-2 pandemic on antimicrobial resistance (AMR) patterns has been significant. In northern Brazil, Carbapenem-resistant Klebsiella pneumoniae (CRKP) are a major concern, with an observed shift from Klebsiella pneumoniae carbapenemase (KPC) to New Delhi metallo-β-lactamase (NDM) during the pandemic. Methods: This cross-sectional study analyzed 775 carbapenem-resistant K. pneumoniae isolates collected from 25 hospitals in the Brazilian Amazon Region (states of Pará and Acre) between 2018 and 2021. The isolates were tested for the presence of carbapenemase genes (bla_KPC, bla_NDM, bla_OXA-48, bla_IMP, bla_VIM, bla_AIM, bla_DIM, bla_GIM and bla_SIM). Results: Of the isolates analyzed, n = 653/775 (84%) were carbapenemase producers, with the most prevalent being bla_KPC n = 446/775 (57.5%) and bla_NDM n = 243/775 (31.4%). A significant increase in NDM producers was observed during the pandemic, rising from n = 1/250 (8.4%) pre-pandemic to n = 222/525 (42.3%) during the pandemic, while KPC producers declined from n = 172/250 (68.8%) to n = 274/525 (52.2%) (p < 0.001). Adult intensive care units (ICUs) were the primary source of isolates n = 357/775 (46%), with a notable increase in tracheal secretion and surveillance swab samples during the pandemic. Regression analysis confirmed a strong upward trend in the prevalence of bla_NDM (R² = 0.778). Conclusions: The shift from KPC to NDM producers in northern Brazil highlights an evolving AMR landscape, partly driven by the pandemic. Strengthened infection control measures, antimicrobial stewardship and continuous surveillance are essential to mitigate the spread of NDM-producing K. pneumoniae in settings with limited resources.

Staphylococcus aureus is associated with human infections, being a resistant bacterium involved in serious infections, and its virulence and resistance are linked to oxidative stress. In this study, we review the role of oxidative stress in the pathogenesis of this bacterium and its influence on immune system evasion, antibiotic resistance, and pharmacological targeting. S. aureus infection generates an intense inflammatory response in the host, evidenced by the activation of pro-inflammatory pathways, the exacerbated production of reactive oxygen species (ROS), and cellular oxidative stress. However, the bacterium develops protective mechanisms against damage, including the production of endogenous antioxidants, the formation of biofilms, and the regulation of redox metabolism, favoring pathogenicity and drug resistance. Resistance seems to be related to alterations in redox metabolism, which influences the sensitization of the immune system. Modulation of the redox response has emerged as a promising approach for developing new antibiotics and formulating more effective combination therapies to combat resistant infections. Natural compounds, including flavonoids, terpenes, and quinones, have demonstrated antibacterial properties by inducing oxidative stress in S. aureus. In summary, the involvement of oxidative stress is complex, with an increase in ROS in the infection and a reduction in immune system evasion and resistance, which could be an interesting therapeutic target.

Background: Globally, Pseudomonas aeruginosa is a high-priority opportunistic pathogen which displays several intrinsic and acquired antimicrobial resistance (AMR) mechanisms, leading to challenging treatments and mortality of patients. Moreover, its wide virulence arsenal, particularly the type III secretion system (T3SS) exoU⁺ virulotype, plays a crucial role in pathogenicity and poor outcome of infections. In depth insights into the molecular epidemiology of P. aeruginosa, especially the prevalence of high-risk clones (HRCs), are crucial for the comprehension of virulence and AMR features and their dissemination among distinct strains. This study aims to evaluate the prevalence and distribution of HRCs and non-HRCs among Brazilian isolates of P. aeruginosa. Methods: A systematic review and meta-analysis were conducted on studies published between 2011 and 2023, focusing on the prevalence of P. aeruginosa clones determined by multilocus sequence typing (MLST) in Brazil. Data were extracted from retrospective cross-sectional and case-control studies, encompassing clinical and non-clinical samples. The analysis included calculating the prevalence rates of various sequence types (STs) and assessing the regional variability in the distribution of HRCs and non-HRCs. Results: A total of 872 samples were analyzed within all studies, of which 298 (34.17%) were MLST typed, identifying 78 unique STs. HRCs accounted for 48.90% of the MLST-typed isolates, with ST277 being the most prevalent (100/298—33.55%), followed by ST244 (29/298—9.73%), ST235 (13/298—4.36%), ST111 (2/298—0.67%), and ST357 (2/298—0.67%). Significant regional variability was observed, with the Southeast region showing a high prevalence of ST277, while the North region shows a high prevalence of MLST-typed samples and HRCs. Conclusions: Finally, this systematic review and meta-analysis highlight the role of P. aeruginosa clones in critical issue of AMR in P. aeruginosa in Brazil and the need of integration of comprehensive data from individual studies.

Aims: The present study aimed to use a conventional and metagenomic approach to investigate the microbiological diversity of water bodies in a network of drainage channels and rivers located in the central area of the city of Belém, northern Brazil, which is considered one of the largest cities in the Brazilian Amazon. Methods and results: In eight of the analyzed points, both bacterial and viral microbiological indicators of environmental contamination—physical–chemical and metals—were assessed. The bacterial resistance genes, drug resistance mechanisms, and viral viability in the environment were also assessed. A total of 473 families of bacteria and 83 families of viruses were identified. Based on the analysis of metals, the levels of three metals (Cd, Fe, and Mn) were found to be above the recommended acceptable level by local legislation. The levels of the following three physicochemical parameters were also higher than recommended: biochemical oxygen demand, dissolved oxygen, and turbidity. Sixty-three bacterial resistance genes that conferred resistance to 13 different classes of antimicrobials were identified. Further, five mechanisms of antimicrobial resistance were identified and viral viability in the environment was confirmed. Conclusions: Intense human actions combined with a lack of public policies and poor environmental education of the population cause environmental degradation, especially in water bodies. Thus, urgent interventions are warranted to restore the quality of this precious and scarce asset worldwide.

To characterize a novel acquired MBL, BIM-1, in a Pseudomonas #2 (subgroup P. guariconensis) strain isolated from the Aurá river located in the Brazilian Amazon hydrographic basin. WGS using an Illumina^® MiSeq System was used to characterize the genome of Pseudomonas sp. IEC33019 strain. Southern blotting/hybridization assays were performed to confirm the location of the MBL-encoding gene, bla_BIM-1 (Belém Imipenemase). Antimicrobial susceptibility testing, cloning, and biochemical and phenotypic characterization were performed to determine BIM-1 kinetics. The IEC33019 strain showed high resistance rates to β-lactams, ciprofloxacin and aminoglycosides, being susceptible only to polymyxins and susceptible, increased exposure to aztreonam. WGS analysis revealed a novel acquired MBL-encoding gene, bla_BIM-1, found as a gene cassette inserted into a class 1 integron (In1326) that also carried qnrVC1 and aadA11e. In1326 was located in a complex transposon, Tn7122, carried by a 52.7 kb conjugative plasmid (pIEC33019) with a toxin/antitoxin system (vapB/vapC). BIM-1 belongs to the molecular subgroup B1 and shares 70.2% and 64.9% similarity with SIM-1 and IMP-1, respectively. Kinetics analysis of BIM-1 showed hydrolytic activity against all β-lactams tested. BIM-1 is a novel acquired MBL encoded by a gene carried by mobile genetic elements, which can be transferred to other Gram-negative bacilli (GNB). Because the IEC33019 strain was recovered from a river impacted by a populous metropolitan region with poor basic sanitation and served by limited potable freshwater, it would be important to establish the role of the BIM-1-producing GNB as nosocomial pathogens and/or as colonizers of the riverside population in this geographical region.

We field-assessed the accuracy, acceptability, and feasibility of the SD BIOLINE HIV/Syphilis Duo rapid diagnostic test in three groups: pregnant women, female sex workers (FSW), and men who have sex with men (MSM). Venous blood samples collected in the field were compared with the respective gold standard methods: SD BIOLINE HIV/Syphilis Duo Treponemal Test versus FTA-abs (Wama brand) treponemal laboratory test for syphilis, and SD BIOLINE HIV/Syphilis Duo Test versus the fourth generation Genscreen Ultra HIV Ag-Ag (Bio-Rad brand) laboratory test for HIV. From a total of 529 participants, 397 (75.1%) were pregnant women, 76 (14.3%) FSW and 56 (10.6%) MSM. Sensitivity and specificity parameters of HIV were 100.0% (95% CI: 82.35–100.0%) and 100.0% (95% CI: 99.28–100.0%), respectively. Sensitivity and specificity parameters found for TP antibody detection were 95.00% (95% CI: 87.69–98.62%) and 100.0% (95% CI: 98.18–100.0%), respectively. The SD BIOLINE HIV/Syphilis Duo Test showed high acceptability among participants (85.87%) and health professionals (85.51%), as well as easy usability by professionals (91.06%). The usability of the SD BIOLINE HIV/Syphilis Duo Test kit would not be a barrier to accessing rapid testing, if the product were incorporated into the list of health service supplies.

This study aimed to characterize a Klebsiella pneumoniae strain (KP411) recovered from the stool samples of poultry (Gallus gallus) in the Brazilian Amazon Region. The whole-genome sequencing of KP411 revealed the presence of an important arsenal of antimicrobial resistance genes to β-lactams (bla_CTX-M-14, bla_TEM-1B, bla_KPC-2, bla_SVH-11), aminoglycosides [aph(3″)- Ib, aph(6)-Id, aph(3′)-Ia], sulfonamides (sul1, sul2), quinolones (oqxAB), fosfomycin (fosA^KP), and macrolides [mph(A)]. Furthermore, our analyses revealed that the KP411 strain belongs to the ST258 clonal lineage, which is one of the main epidemic clones responsible for the dissemination of KPC-2 worldwide. Our data suggest that food-producing animals may act as reservoirs of multidrug-resistant K. pneumoniae belonging to the ST258 clone, and, consequently, contribute to their dissemination to humans and the environment.