Antimicrobial resistance of heterotrophic marine bacteria isolated from seawater and sands of recreational beaches with different organic pollution levels in southeastern Brazil: evidences of resistance dissemination

The aim of this study was to describe and compare the succession of intertidal benthic communities in two areas at Guanabara Bay, RJ, Brazil: Urca, an area submitted to moderated organic pollution and Catalão, an extremely polluted area. Three transects in each area were scraped one month before the beginning of this study in order to evaluate the recruitment (recruitment-treatments). Three other transects were monitored without manipulation (monitoring treatments). Species composition and relative abundance were evaluated monthly between September and December, 2000. A total of 26 species was found at Urca and 13 at Catalão. The percent cover of the most abundant organisms was not similar between treatments at Urca after four months, while in Catalão, the similarity was 72% in the second month. The faster community development and recovery at the most polluted area was probably related to the existence of simple and resilient communities in more impacted areas.

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Environmental Risk Assessment of Organic Pollution on Wastewater on Industrial Parks in Bien Hoa City

Thu Dau Mot University Journal of Science ◽

10.37550/tdmu.ejs/2020.04.086 ◽

2020 ◽

pp. 422-434

Keyword(s):

Environmental Risk ◽

Wastewater Treatment Plants ◽

Risk Index ◽

Organic Pollution ◽

Industrial Park ◽

Pollution Levels ◽

Industrial Parks ◽

Wastewater Quality ◽

P 16 ◽

Total P

Bien Hoa City is an urban area of Dong Nai province located in the Southern key economic region. Currently, Bien Hoa City has 6 industrial parks in operation with large daily wastewater flow, causing environmental risks, especially from organic pollutants. The study applied the Nemerow risk index and the geographic information systems (GIS). The results showed that the industrial parks were mainly organic pollution levels including N-total, P-total, and Ammonium. The level of environmental risk from organic pollution was recorded in range of medium to very high levels, the ranked in descending order: Agtex Long Binh Industrial Park (P = 24)> Amata Industrial Park (P = 16)> Bien Hoa 2 Industrial Park ( P = 10),> Tam Phuoc Industrial Park (P = 5)> Loteco Industrial Park (P = 3). The results of the study provided good information for the management and improvement of wastewater quality in the industrial wastewater treatment plants of the industrial parks in Bien Hoa City.

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Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

Iheringia Série Zoologia ◽

10.1590/s0073-47212010000400003 ◽

2010 ◽

Vol 100 (4) ◽

pp. 291-300 ◽

Cited By ~ 7

Author(s):

Augusto Oliveira ◽

Marcos Callisto

Keyword(s):

Water Quality ◽

Organic Pollution ◽

Southeastern Brazil ◽

Functional Feeding Groups ◽

Average Score ◽

Macroinvertebrate Communities ◽

Forest Fragment ◽

Freshwater Habitats ◽

Disturbed Systems ◽

Belo Horizonte

The objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "Reserva Particular do Patrimônio Natural" (RPPN) Mata Samuel de Paula and its surroundings, in the municipality of Nova Lima near the city of Belo Horizonte, Minas Gerais State, southeastern Brazil. This region has been strongly modified by human activities including mining and urbanization. Samples were collected in the field every three months between August 2004 and November 2005, totaling six samplings in the rainy and dry seasons. This assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. However, according to the Biological Monitoring Work Party (BMWP) and the Average Score Per Taxon (ASPT) indices, all sampling sites had excellent water quality. A total of 14,952 organisms was collected, belonging to 155 taxa (148 Insecta, two Annelida, one Bivalvia, one Decapoda, one Planariidae, one Hydracarina, and one Entognatha). The most abundant benthic groups were Chironomidae (47.9%), Simuliidae (12.3%), Bivalvia (7.5%), Decapoda (6.1%), Oligochaeta (5.2%), Polycentropodidae (3.7%), Hydropsychidae (2.5%), Calamoceratidae (1.8%), Ceratopogonidae (1.7%), and Libellulidae (1.2%). The assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. The RPPN Mata Samuel de Paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.

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Application of water quality biological indices using diatoms as bioindicators in the Gravataí river, RS, Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842011000500015 ◽

2011 ◽

Vol 71 (4) ◽

pp. 949-959 ◽

Cited By ~ 15

Author(s):

SE. Salomoni ◽

O. Rocha ◽

G. Hermany ◽

EA. Lobo

Keyword(s):

Water Quality ◽

Analytical Techniques ◽

Organic Pollution ◽

Metropolitan Region ◽

Biological Indices ◽

Pollution Levels ◽

Intensive Farming ◽

Thermotolerant Coliforms ◽

Species Tolerance ◽

Physical And Chemical

The Gravataí river situated in the metropolitan region of Porto Alegre has an area of approximately 2.020 km² and provides public water supply to about 500,000 inhabitants in 5 municipalities (latitude 29° 45'-30° 12' S; longitude 50° 27'-51° 12' W). The river basin has two regions with distinctive characteristics of occupation: the upper course shows intensive farming and the lower course presents urban and industrial uses. In this context, the aim of this study was to evaluate the water quality in the Gravataí River (RS, Brazil) by using physical, chemical and microbiological variables, and the water quality biological indices (WQBI) formulated for southern Brazilian rivers based on epilithic diatom communities as indicators. For comparison purposes, a local WQBI, called the Gravataí WQBI, was also used where species were given new saprobic values (s) and indicative values (vi) according to their occurrence and abundance in the river, using multivariate analytical techniques. The biological samples were taken every three months at six stations along the Gravataí River between September 2000 and August 2002. The results of the physical and chemical analyses of the water indicated a pollution gradient down the river, from the headwaters to the mouth, detected mainly by considering a significant decrease in the concentration of dissolved oxygen and turbidity, as well as a significant increase in BOD5, total nitrogen, ortho-phosphate and thermotolerant coliforms. Comparing the results obtained, differences were found regarding the predominant pollution levels as higher in the Gravataí WQBI, although both corroborated a tendency for the contamination gradient to increase from the headwaters to the mouth. Given the local anthropic changes, it is of great importance to continue the study of diatom species tolerance to organic pollution and eutrophication in different lotic systems of the region.

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Copy-out-paste-in transposition of a Tn6283-like integrative element assists interspecies antimicrobial resistance gene transfer from Vibrio alfacsensis

10.1101/2021.06.22.449512 ◽

2021 ◽

Author(s):

Lisa Nonaka ◽

Michiaki Masuda ◽

Hirokazu Yano

Keyword(s):

Gene Transfer ◽

Antimicrobial Resistance ◽

Marine Bacteria ◽

Donor Site ◽

Conjugative Plasmid ◽

Health Concern ◽

Donor Strain ◽

Resistance Level ◽

Ampicillin Resistance ◽

Antimicrobial Resistance Gene

The exchange of antimicrobial resistance (AMR) genes between aquaculture and terrestrial microbial populations has emerged as a serious public health concern. However, the nature of the mobile genetic elements in marine bacteria is poorly documented. To gain insight into the genetic mechanisms underlying AMR gene transfer from marine bacteria, we mated a multi-drug resistant Vibrio alfacsensis strain with an Escherichia coli strain, and then determined the complete genome sequences of the donor strain and multidrug-resistant transconjugants. Sequence analysis revealed a conjugative plasmid of the MOBH family in the donor strain, which was integrated into the chromosome of the recipient. The plasmid backbone in the transconjugant chromosome was flanked by two copies of a 7.1 kb integrative element, designated Tn 6945, harboring a beta-lactamase gene that conferred ampicillin resistance to the host cell. Use of a recA mutant E. coli strain as the recipient yielded a transconjugant showing ampicillin resistance but not multidrug resistance, suggesting the involvement of homologous recombination in plasmid integration into the chromosome. Polymerase chain reaction experiments revealed that Tn 6945 generates a circular copy without generating an empty donor site, suggesting that it moves via a copy-out-paste-in mode, as previously reported for Tn 6283. Transposition of the integrative element into multiple loci in the recipient chromosome increased the resistance level of the transconjugants. Overall, these results suggest that Tn 6283-like copy-out integrative elements and conjugative plasmids additively spread AMR genes among marine bacteria and contribute to the emergence of isolates with high-level resistance through amplification of AMR genes.

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The leaf breakdown of Picramnia sellowii (Picramniales: Picramniaceae) as index of anthropic disturbances in tropical streams

Brazilian Journal of Biology ◽

10.1590/1519-6984.00414 ◽

2015 ◽

Vol 75 (4) ◽

pp. 846-853 ◽

Cited By ~ 10

Author(s):

M. P. Lopes ◽

R. T. Martins ◽

L. S. Silveira ◽

R. G. Alves

Keyword(s):

Aquatic Ecosystems ◽

Riparian Vegetation ◽

Fungal Biomass ◽

Organic Pollution ◽

Southeastern Brazil ◽

Leaf Breakdown ◽

Breakdown Rate ◽

Litter Bags ◽

Tropical Regions ◽

Negative Effect

Abstract There are few studies in tropical regions exploring the use of leaf breakdown process as a functional tool to assess anthropic disturbance on aquatic ecosystems. We assessed the effects of water pollution due to human activities on the leaf breakdown rate of Picramnia sellowii in streams of the southeastern Brazil. The experiment was carried out for 60 days in three reference streams and three streams impaired by organic pollution and absence of riparian vegetation. Three litter bags were incubated in each stream containing 3 ± 0.05 g of P. sellowii leaves. The reference streams presented higher values of dissolved oxygen and lower values of nutrients, turbidity, electrical conductivity, total impermeable area and water temperature. The leaf breakdown rate (k) differed significantly between the reference (k = 0.014 ± 0.003 d–1) and impaired streams (k = 0.005 ± 0.001 d–1). The leaves incubated in the reference streams contained greater fungal biomass (measured as ergosterol concentration) and abundance of invertebrates, as well as greater presence of shredders, with k values being related to the biomass of these organisms. Overall, there were clear differences between the leaf mass loss in the reference and impaired streams. These results reinforce the negative effect of urbanization on leaf breakdown and fungal and shredder biomass.

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