Explore the vast range of titles available.

Limnoperna fortunei, the golden mussel, is a bivalve mollusc native to Southeast Asia, which was introduced to South America via ballast water from commercial cargo ships from China and South Korea. In Brazil, the golden mussel is considered an invasive species, which has caused enormous economic and environmental damage. This is mainly due to the obstruction of pipes carrying water for the cooling systems within hydroelectric power plants. The presence of this invasive species also negatively impacts native fauna and flora. Early detection and rapid response during the early stages of infestation for this invasive species is essential to effectively control populations and prevent new infestations from forming. Techniques within molecular biology allow for more efficient detection of the golden mussel in all stages of development. In addition, the analysis of the genome, transcriptome and proteome of this species makes it possible to identify targets of biotechnological interest, which may be useful for the control of the golden mussel or for the generation of products of technological innovation. This review presents an overview of molecular studies involving this species and the perspectives on the prevention, control and combat of the golden mussel using these approaches.

Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L−1) and NaDCC (1.5 mg L−1) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time.

Among the invasive species known to occur in South America is the bivalve mollusc Limnoperna fortunei, whose presence is linked to several environmental and economic problems. Early detection and mitigation actions are needed to limit its impact in the remaining L. fortunei-free areas. PCR-based molecular methods have become the gold standard methodology for L. fortunei detection. However, PCR-based methods require complex logistics from field sampling to laboratory processing. Thus, the use of methods that can be directly applied in the field can speed up the detection process. This work aimed to establish, for the first time, the loop-mediated isothermal amplification (LAMP) method for the detection of L. fortunei, with perspectives for in situ application. A set of primers designed for LAMP was tested for amplification of DNA from L. fortunei adult tissues and environmental samples containing bivalve larvae. The test showed a limit of detection as low as 0.01 ng of DNA obtained from adult tissue samples and a minimum reaction time of 60 min. The set of primers used seems to be specific for L. fortunei, since there was no cross-amplification with other bivalve or invasive molluscs that co-occur with the golden mussel in the same environment. The LAMP technique also proved to be efficient in amplifying DNA derived from L. fortunei larvae, demonstrating it to be a robust method regarding potential environmental reaction inhibitors. Although the results obtained here were acquired under controlled laboratory conditions, the LAMP method is a promising tool to integrate L. fortunei invasion monitoring protocols.

Wastewater treatment plants (WWTPs) represent an important reservoir of antibiotic resistance determinants. Although many studies have been conducted to evaluate resistance profiles in Enterobacteriaceae isolates from this setting, the dynamics of this phenomenon are poorly known to the bacterium Pseudomonas aeruginosa. Here we aimed to evaluate the resistance profiles and the production of AmpC β-lactamase in P. aeruginosa isolates from a domestic full-scale WWTP. Samples of the raw sewage and effluent were collected and the bacterium P. aeruginosa was isolated on cetrimide agar. Susceptibility to β-lactams, fluoroquinolones and aminoglycosides was evaluated by the disc diffusion method, and the presence of AmpC β-lactamase was investigated phenotypically and by molecular method. We recovered 27 isolates of P. aeruginosa. Of these, 81.5% were susceptible to all antimicrobials tested. However, a considerable rate of resistance to carbapenems (11%) was found among the isolates. Twenty-two isolates were positive in the phenotypic test for inducible AmpC β-lactamase but the blaampc gene was only identified in four isolates, suggesting the presence of other independent resistance mechanisms besides this β-lactamase. In summary, we have shown that P. aeruginosa isolates from a domestic WWTP represents a potential reservoir of blaampC genes and other resistance determinants, including those that result in low susceptibility to carbapenems and aminoglycosides.

Introduction Freshwater ecosystems provide propitious conditions for the acquisition and spread of antibiotic resistance genes (ARGs), and integrons play an important role in this process. Material and methods In the present study, the diversity of putative environmental integron-cassettes, as well as their potential bacterial hosts in the Velhas River (Brazil), was explored through intI-attC and 16S rRNA amplicons deep sequencing. Results and discussion ORFs related to different biological processes were observed, from DNA integration to oxidation-reduction. ARGs-cassettes were mainly associated with class 1 mobile integrons carried by pathogenic Gammaproteobacteria, and possibly sedentary chromosomal integrons hosted by Proteobacteria and Actinobacteria. Two putative novel ARG-cassettes homologs to fosB3 and novA were detected. Regarding 16SrRNA gene analysis, taxonomic and functional profiles unveiled Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria as dominant phyla. Betaproteobacteria, Alphaproteobacteria, and Actinobacteria classes were the main contributors for KEGG orthologs associated with resistance. Conclusions Overall, these results provide new information about environmental integrons as a source of resistance determinants outside clinical settings and the bacterial community in the Velhas River.

Microfouling can have significant economic impacts for hydroelectric power plants. However, knowledge concerning the composition and metabolism of microbial biofilm in cooling systems remains scarce. We examined the metagenome present in a cooling system, comprising a filter (F) and heat exchanger (HE), in the Nova Ponte hydroelectric power plant in Brazil, to identify bacteria and pathways that could be targeted to monitor and control biofilm formation. Our data revealed that the microfouling sample from heat exchanger 1 (HEM1), with porous consistency, presented enriched bacterial members not frequently described as biofilm formers in cooling systems, besides it has been shown to be an autoinducer repression pathway. Furthermore, the microfouling sample from heat exchanger 2 (HEM2), with gelatinous consistency, seemed to be an established biofilm, containing enriched bacterial groups such as Desulfotomaculum and Crenothrix and autoinducers, with biotechnological relevance in industrial biofilms. The results demonstrate that biofilm composition will vary depending on different abiotic conditions and the antifouling strategy used, including type of compound, concentration, and frequency of use. Therefore, all these variables must be evaluated when a power plant is affected by microbial slime in the cooling system. Our findings could help to define strategies for efficient and ecofriendly measures to contain microfouling in power plants.

Iron (Fe) is the fourth most abundant element on the planet, and iron-oxidising bacteria (FeOB) play an important role in the biogeochemical cycle of this metal in nature. FeOB stands out as Fe oxidisers in microaerophilic environments, and new members of this group have been increasingly discussed in the literature, even though their isolation can still be challenging. Among these bacteria is the Gallionellaceae family, mainly composed of neutrophilic FeOB, highlighting Gallionella ferruginea , and nitrite-oxidiser genera. In the previous metagenomic study of the biofilm and sediments of the cooling system from the Irapé hydroelectric power plant (HPP-Irapé), 5% of the total bacteria sequences were related to Gallionellaceae, being 99% unclassified at genus level. Thus, in the present study, a phylogenetic tree based on this family was constructed, in order to search for shared and unique Gallionellaceae signatures in a deep phylogenetic level affiliation and correlated them with geomorphologic characteristics. The results revealed that Gallionella and Ferrigenium were ubiquitous reflecting their ability to adapt to various locations in the power plant. The cave was considered a hotspot for neutrophilic FeOB since it harboured most of the Gallionellaceae diversity. Microscopic biosignatures were detected only in the CS1 sample, which presented abundance of the stalk-forming Ferriphaselus and of the sheath-forming Crenothrix . Further studies are required to provide more detailed insights on Gallionellaceae distribution and diversity patterns in hydroelectric power plants, particularly its biotechnological potential in this industry.

Limnoperna fortunei, known as the golden mussel, is an invasive bivalve in South America responsible for economic damages in hydroelectric plants due to its ability to attach and grow on the walls of water pipes and tubes. Chemical compounds are often used to control golden mussel infestations in water systems. Here, we investigated the effects of two biocides—MXD-100 ™ and sodium dichloroisocyanurate (NaDCC)—through the assessment of morphological and gene-expression alterations in the gills. Both biocides were able to modulate the expression of defensive genes and morphological changes. Yet, it seems that NaDCC needs continuous exposure to control golden mussel infestation, whereas MXD-100™ can inflict severe damage to the mussels in as little as 24 h. Our results can be used to enhance control strategies for managing mussel growth in water systems, simultaneously reducing the environmental impact associated with costly and harmful chemical releases. Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L[sup.−1]) and NaDCC (1.5 mg L[sup.−1]) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time.

Toxoplasma gondii is a highly prevalent zoonotic parasite in Brazil capable of infecting mammals and birds. The increase in the urban populations of pets and the narrowing of the human–animal relationship can facilitate the transmission of important public health zoonoses, such as toxoplasmosis. This study aimed to evaluate the frequency and spatial distribution of T. gondii infection and its risk factors in domiciled dogs and cats attended at the Jorge Vaitsman Institute, Rio de Janeiro. Serum samples from 400 dogs and 272 cats were evaluated by an indirect fluorescent antibody test (IFAT) for IgG anti- T. gondii antibodies. Epidemiological questionnaires were used to interview the animals’ owners to identify risk factors for infection. Of the total, 34% (136/400) of dogs and 8.1% (22/272) of cats had anti- T. gondii antibodies. Breed (OR: 2.10–95%, CI 1.27–3.46) was a risk factor for dogs, while sex (OR: 3.40–95%, CI 1.10–10.52) and homemade food consumption (OR: 8.49–95%, CI 2.48–29.05) were risk factors for cats. Offal consumption was considered a risk factor for both species evaluated (OR: 2.74–95%, CI 1.38–5.43 for dogs; OR: 7.66–95%, CI 1.24–47.29 for cats). The spatial analysis showed that T. gondii seropositive animals were widely distributed in the metropolitan region of Rio de Janeiro state, with a concentration observed mainly in the west and north zones of Rio de Janeiro city. The results emphasize the importance of adopting prophylactic measures to control T. gondii transmission in domiciled dogs and cats in Rio de Janeiro, contributing positively to public health. Toxoplasma gondii est un parasite zoonotique très répandu au Brésil, capable d’infecter les mammifères et les oiseaux. L’augmentation des populations urbaines d’animaux de compagnie et le rétrécissement de la relation homme-animal peuvent faciliter la transmission de zoonoses importantes pour la santé publique, telles que la toxoplasmose. Cette étude visait à évaluer la fréquence et la distribution spatiale de l’infection à T. gondii et ses facteurs de risque chez les chiens et les chats domiciliés qui ont fréquenté l’Institut Jorge Vaitsman de Rio de Janeiro. Des échantillons de sérum de 400 chiens et 272 chats ont été évalués par un test d’immunofluorescence indirecte (IFAT) pour les anticorps IgG anti- T. gondii . Des questionnaires épidémiologiques ont été appliqués aux propriétaires des animaux pour identifier les facteurs de risque d’infection. Sur le total, 34 % (136/400) des chiens et 8,1 % (22/272) des chats avaient des anticorps anti- T. gondii . La race (OR : 2,10-95 %, IC 1,27-3,46) était un facteur de risque pour les chiens, tandis que le sexe (OR : 3,40-95 %, IC 1,10-10,52) et la consommation d’aliments faits maison (OR : 8,49-95 % IC 2,48-29,05) l’étaient pour les chats. La consommation d’abats a été considérée comme un facteur de risque pour les deux espèces évaluées (OR : 2,74-95 %, IC 1,38-5,43 pour les chiens; OR : 7,66-95 %, IC 1,24-47,29 pour les chats). L’analyse spatiale a montré que les animaux séropositifs pour T. gondii étaient largement répartis dans la région métropolitaine de l’État de Rio de Janeiro, avec une concentration observée principalement dans les zones ouest et nord de la ville de Rio de Janeiro. Les résultats soulignent l’importance d’adopter des mesures prophylactiques pour contrôler la transmission de T. gondii chez les chiens et les chats domiciliés à Rio de Janeiro, contribuant positivement à la santé publique.

Background Since the novel coronavirus disease outbreak, over 179.7 million people have been infected by SARS-CoV-2 worldwide, including the population living in dengue-endemic regions, particularly Latin America and Southeast Asia, raising concern about the impact of possible co-infections. Methods Thirteen SARS-CoV-2/DENV co-infection cases reported in Midwestern Brazil between April and September of 2020 are described. Information was gathered from hospital medical records regarding the most relevant clinical and laboratory findings, diagnostic process, therapeutic interventions, together with clinician-assessed outcomes and follow-up. Results Of the 13 cases, seven patients presented Acute Undifferentiated Febrile Syndrome and six had pre-existing co-morbidities, such as diabetes, hypertension and hypopituitarism. Two patients were pregnant. The most common symptoms and clinical signs reported at first evaluation were myalgia, fever and dyspnea. In six cases, the initial diagnosis was dengue fever, which delayed the diagnosis of concomitant infections. The most frequently applied therapeutic interventions were antibiotics and analgesics. In total, four patients were hospitalized. None of them were transferred to the intensive care unit or died. Clinical improvement was verified in all patients after a maximum of 21 days. Conclusions The cases reported here highlight the challenges in differential diagnosis and the importance of considering concomitant infections, especially to improve clinical management and possible prevention measures. Failure to consider a SARS-CoV-2/DENV co-infection may impact both individual and community levels, especially in endemic areas.