Antibiotic resistance profiles on pathogenic bacteria in the Brazilian environments

Multivariate statistical analysis of surface water quality in the capibaribe river (Pernambuco state, Northeast Brazil): Contributions to water management

Assessing the quality of surface waters is essential for identifying changes in freshwater ecosystems and supporting the planning/proposing of measures to mitigate polluting sources. However, many studies involving the identification of pathogenic bacteria and/or their resistance profile to antimicrobial agents need a more holistic approach to conditioning or modulating factors. Thus, we apply different multivariate statistical techniques to the data set from the Capibaribe River's surface water, one of the most important in the Northeast of Brazil. Our data, taken together, suggest that the waters of the Capibaribe River have been suffering impacts associated with different human activities. Due to its flow crossing a large urban area, different sources are contributing to the contamination/pollution of its aquatic ecosystem, whose multivariate analysis allowed us to identify site-dependent characteristics that reflect the degree and type of human influence. The study of physical-chemical and chemical parameters reveals the influence of the high load of effluents (industrial and domestic) on the chemical and microbiological quality of the waters sampled at the SS4 site. On the other hand, the antimicrobial resistance profile of the isolates evaluated, especially at SS1, SS2, and SS3 sites, provides a comprehensive sample of the "resistome" present in the fecal content of thousands of people living in the region surrounding the Capibaribe River. The presence of enterobacteria in water indicates contamination of fecal origin. It represents a public health problem since the waters of the Capibaribe River can be a source of dissemination and persistence of bacteria resistant to humans and the environment. In conclusion, our study provides a more comprehensive understanding of the relationships between surface water, basic sanitation, antibiotic exposure, bacterial gene transfer, and human colonization, whether in the context of the region studied or other locations.

The Impact of Urban Pollution on Plasmid-Mediated Resistance Acquisition in Enterobacteria from a Tropical River

Background: The exposure of environmental bacteria to contaminants in aquatic ecosystems accelerates the dissemination of antibiotic-resistance genes (ARGs) through horizontal gene transfer (HGT). Methods: In this study, we sampled three locations along a contamination gradient of a polluted river, focusing on isolating Enterobacteria from the surface waters to investigate the relationship between urban pollution and antibiotic resistance. The genomes of 15 isolates (5 per site) were sequenced to identify plasmid-borne ARGs and their association with resistance phenotypes. Results: Isolates from the site with the highest contamination (Site 3) showeda larger number of ARGs, plasmids, and resistance phenotypes. Notably, one of the isolates analyzed, E. coli A231-12, exhibited phenotypic resistance to seven antibiotics, presumably conferred by a single plasmid carrying 12 ARGs. Comparative analysis of this plasmid revealed its close evolutionary relationship with another IncH plasmid hosted by Salmonella enterica, underscoring its high ARG burden in the aquatic environment. Other plasmids identified in our isolates carried sul and dfrA genes, conferring resistance to trimethoprim/sulfamethoxazole, a commonly prescribed antibiotic combination in clinical settings. Conclusions: These results highlight the critical need to expand research on the link between pollution and plasmid-mediated antimicrobial resistance in aquatic ecosystems, which can act as reservoirs of ARGs.

Hospital sewage in Brazil: a reservoir of multidrug-resistant carbapenemase-producing Enterobacteriaceae

The One Health concept recognizes that human health is clearly linked to the health of animals and the environment. Infections caused by bacteria resistant to carbapenem antibiotics have become a major challenge in hospitals due to limited therapeutic options and consequent increase in mortality. In this study, we investigated the presence of carbapenem-resistant Enterobacteriaceae in 84 effluent samples (42 from hospital and 42 from non-hospital) from Campo Grande, midwest Brazil. First, sewage samples were inoculated in a selective culture medium. Bacteria with reduced susceptibility to meropenem and ertapenem were then identified and their antimicrobial susceptibility was determined using the Vitek-2 system. The blaKPC genes were detected using PCR and further confirmed by sequencing. Carbapenem-resistant Enterobacteriaceae (CRE) were identified in both hospital (n=32) and non-hospital effluent (n=16), with the most common being Klebsiella pneumoniae and of the Enterobacter cloacae complex species. This is the first study to indicate the presence of the blaKPC-2 gene in carbapenem-resistant Enterobacteriaceae, classified as a critical priority by the WHO, in hospital sewage in this region. The dissemination of carbapenem antibiotic-resistant genes may be associated with clinical pathogens. Under favorable conditions and microbial loads, resistant bacteria and antimicrobial-resistance genes found in hospital sewage can disseminate into the environment, causing health problems. Therefore, sewage treatment regulations should be implemented to minimize the transfer of antimicrobial resistance from hospitals.

Multifunctional assessment of copper-doped ZnO nanoparticles synthesized via gliding arc discharge plasma technique: antioxidant, antibacterial, and photocatalytic performance

In this paper, undoped and copper-doped ZnO nanoparticles (NPs) were successfully synthesized using a gliding arc discharge (GAD) plasma technique, which is a sustainable, cost-effective, and scalable method. This method offers several advantages over traditional synthesis methods. The synthesized NPs were characterized by various techniques to understand their physicochemical properties. XRD analysis confirmed the presence of characteristic peaks of pure ZnO, while doped samples exhibited additional peaks corresponding to CuO crystal planes, indicating the successful incorporation of Cu into the lattice. As obvious, bare ZnO showed absorption peak at 378 nm corresponding to the band gap of 3.21 eV. The band gap of Cu-doped samples increased systematically, i.e., 3.35 eV for 2% Cu, 3.47 eV for 4% Cu, and 3.66 eV for 6% Cu. SEM images revealed aggregation and increase in particle size with the increasing in Cu concentration. EDAX analysis revealed a decrease in the weight percentage of oxygen and zinc with the increase in Cu concentration, suggesting structural changes within the lattice. Furthermore, the antibacterial activity against Gram-positive and Gram-negative bacteria, antioxidant activity, and photocatalytic activity against three different organic dyes such as Brilliant Cresyl Blue (BCB), Methylene Blue (MB), and Congo Red (CR) was studied. It is found that the photocatalytic activity of ZnO NPs varies with Cu concentration, leading to a decrease in its performance. The antibacterial activity of the NPs was also assessed, with undoped ZnO NPs showing dose-dependent effects against bacteria, while the Cu-doped ZnO NPs exhibited decreased efficacy. Interestingly, Cu doping significantly enhanced the antioxidant activity of the NPs compared to the undoped ZnO.

Pre-Harvest Food Safety Challenges in Food-Animal Production in Low- and Middle-Income Countries

Food safety remains a significant global public health concern, with the risk of unsafe food varying worldwide. The economies of several low- and middle-income countries (LMICs) heavily rely on livestock, posing a challenge to ensuring the production of safe food. This review discusses our understanding of pre-harvest critical issues related to food safety in LMICs, specifically focusing on animal-derived food. In LMICs, food safety regulations are weak and inadequately enforced, primarily concentrating on the formal market despite a substantial portion of the food sector being dominated by informal markets. Key critical issues at the farm level include animal health, a low level of good agriculture practices, and the misuse of antimicrobials. Effectively addressing foodborne diseases requires a comprehensive One Health framework. Unfortunately, the application of the One Health approach to tackle food safety issues is notably limited in LMICs. In conclusion, considering that most animal-source foods from LMICs are marketed through informal channels, food safety legislation and policies need to account for this context. Interventions aimed at reducing foodborne bacterial pathogens at the farm level should be scalable, and there should be strong advocacy for the proper implementation of pre-harvest interventions through a One Health approach.

Analyses of Extended-Spectrum-β-Lactamase, Metallo-β-Lactamase, and AmpC-β-Lactamase Producing Enterobacteriaceae from the Dairy Value Chain in India

The consumption of milk contaminated with antibiotic-resistant bacteria poses a significant health threat to humans. This study aimed to investigate the prevalence of Enterobacteriaceae producing β-lactamases (ESBL, MBL, and AmpC) in cow and buffalo milk samples from two Indian states, Haryana and Assam. A total of 401 milk samples were collected from dairy farmers and vendors in the specified districts. Microbiological assays, antibiotic susceptibility testing, and PCR-based genotyping were employed to analyze 421 Gram-negative bacterial isolates. The overall prevalence of β-lactamase genes was 10% (confidence interval (CI) (7-13)), with higher rates in Haryana (13%, CI (9-19)) compared to Assam (7%, CI (4-11)). The identified β-lactamase genes in isolates were blaCMY, blaMOX, blaFOX, blaEBC, and blaDHA, associated with AmpC production. Additionally, blaCTX-M1, blaSHV, and blaTEM were detected as ESBL producers, while blaVIM, blaIMP, blaSPM, blaSIM, and blaGIM were identified as MBL producers. Notably, Shigella spp. were the dominant β-lactamase producers among identified Enterobacteriaceae. This study highlights the presence of various prevalent β-lactamase genes in milk isolates, indicating the potential risk of antimicrobial-resistant bacteria in dairy products. The presence of β-lactam resistance raises concern as this could restrict antibiotic options for treatment. The discordance between genotypic and phenotypic methods emphasizes the necessity for comprehensive approaches that integrate both techniques to accurately assess antibiotic resistance. Urgent collaborative action incorporating rational and regulated use of antibiotics across the dairy value chain is required to address the global challenge of β-lactam resistance.

Anthropic Impact on the Critically Endangered Melanophryniscus admirabilis (Admirable Redbelly Toad): Evidence from the Presence of Multiresistant Enterobacteriaceae

Melanophryniscus admirabilis is a microendemic and critically endangered toad, known from a single population. This microendemic species inhabits a small fragment of the Atlantic Forest in South Brazil, an area significantly impacted by hydroelectric power plant projects, livestock farming, agricultural activities, biopiracy, and tourism. Given the exclusive and limited population of M. admirabilis, preserving and conserving this species is of utmost importance in Brazil. Research on this species primarily concentrates on its biology, ecology, and ecotoxicology. Currently, there is no knowledge about antimicrobial resistance (AMR) bacteria present in wild M. admirabilis, despite the potential for studying them to provide valuable insights into environmental pollution. To this end, Enterobacteriaceae species (n = 82) obtained from 15 wild M. admirabilis toads were subjected to the standard Kirby-Bauer disk diffusion method to test their AMR. The results showed that Enterobacteriaceae species had the highest antibiotic resistance to IPM (45.1%), CIP (39%), NIT (32.5%), AMP (31.3%), TET (18.3%), and FOX (17%). Of the tested species, 18 (21.9%) species tested were susceptible, 40 (48.8%) were resistant to 1 or 2 different antibiotic classes, and 24 (29.3%) were classified as multidrug-resistant. Overall, our findings suggest that the incidence of AMR in Enterobacteriaceae isolated from wild M. admirabilis is high, indicating environmental stress caused by anthropic pollution in their habit.