Role of enterotoxigenic Escherichia coli prophage in spreading antibiotic resistance in a porcine-derived environment

Enterotoxigenic Escherichia coli (ETEC) cause acute secretory diarrhoea in pigs, posing a great economic loss to the swine industry. This study analysed the prevalence and genetic characteristics of prophages from 132 ETEC isolates from symptomatic pigs to determine their potential for spreading antibiotic resistance. A total of 1105 potential prophages were identified, and the distribution of the genome size showed three ‘overlapping’ trends. Similarity matrix comparison showed that prophages correlated with the ETEC lineage distribution, and further identification of these prophages corroborated the lineage specificity. In total, 1206 antibiotic resistance genes (ARGs) of 52 different categories were identified in 132 ETEC strains; among these, 2.65% (32/1206) of ARGs were found to be carried by prophages. Analysis of flanking sequences showed that almost all the ARGs could be grouped into two types: ‘bla_TEM-1B’ and ‘classic class 1 integron (IntI1)’. They co-occurred with a strictly conserved recombinase and transposon Tn3 family but with a difference: the ‘bla_TEM-1B type’ prophages exhibited a classic Tn2 transposon structure with 100% sequence identity, whereas the ‘IntI1 type’ co-occurred with the TnAs2 transposon with only 84% sequence identity. These results imply that ARGs might be pervasive in natural bacterial populations through transmission by transposable bacteriophages.     

New species of Parapharyngodon (Nematoda: Pharyngodonidae) parasite of Osteocephalus taurinus (Anura: Hylidae) from Northern Brazilian Amazon Region

Systematic Parasitology - Parapharyngodon spp. are nematodes parasites of amphibian and reptiles worldwide distributed. Of 55 valid species, only 11 are known for the Neotropical realm, and six...     

The influence of incubation periods on photosynthesis-irradiance curves

In phytoplankton primary production studies, samples for the determination of photosynthesis versus irradiance relationship (P-I) are usually incubated at several irradiance levels during a fixed time period, commonly 2-4 h. However, it is not clear if the use of this fixed incubation time is appropriate to study the P-I relationship in any given ecosystem. The aim of this work was to study the influence of incubation time on the P-I relationship in natural phytoplankton populations from three different coastal ecosystems: an open coastal area, an estuary, and a coastal lagoon. Physical and chemical variables, phytoplankton biomass, species composition, and P-I curves were analysed. The results showed that, in the coastal area and in the estuary, P-I relationships were time dependent, whereas in the coastal lagoon different incubation periods produced the same P-I curve. An underestimation of daily primary production, ranging from 13% to 42.5%, was calculated when data from standard incubation times (2-4 h) were used in ecosystems where P-I curves present a dynamic time-dependent behaviour. This work suggests that the response of the P-I curves to the incubation time varies with the characteristics of the ecosystem and is related to the light regime to which phytoplankton cells are adapted.     

No Evidence of SARS-CoV-2 Infection in Neotropical Primates Sampled During COVID-19 Pandemic in Minas Gerais and Rio Grande do Sul,Brazil

EcoHealth - In 2019, a new coronavirus disease (COVID-19) was detected in China. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was capable to infect domestic and captive mammals like...     

Hypercaloric diet and chronic stress desynchronizes the temporal pattern of rats’ insulin release

This study evaluated the effects of the association between obesity and chronic stress on the temporal pattern of serum levels of biochemical and hormonal markers. Obesity model was achieved by hypercaloric diet exposure. Wistar rats were divided into four groups: standard chow (C), hypercaloric diet (HD), stress + standard chow (S), and stress + hypercaloric diet (SHD) and analysed at three time points: ZT0, ZT12 and ZT18. Chronic stress was performed 1 h/per day, 5 days/per week, during 80 days. The presence of temporal pattern in naïve animals’ insulin release was accomplished. Hypercaloric diet induced obesity, increasing rats’ insulin and glucose levels; while chronic stress reduced insulin levels. There were interactions between chronic stress and obesity in serum insulin and glucose levels; and between time points and obesity in insulin levels. In conclusion, long exposure to hypercaloric diet and chronic stress were able to desynchronize temporal pattern of insulin release, contributing to the pathophysiology of obesity and its complications.     

Constraints on tree seedling establishment after fires: passing the germination bottlenecks

• Persistence and colonization by tree species in an environment following a fire depends on the effects on seed germination and seedling development. We used seeds of Kielmeyera coriacea and Qualea parviflora as a model to test the effects of high temperatures on germination and initial development of tree seedlings.
• We exposed the seeds to heat flow (70, 100, 130, 150 or 170 °C) for 2 or 5 min and compared the germination with that of unheated seeds (control). Seedlings were then harvested after 3, 7 or 15 days to evaluate aerial and root mass, root:shoot ratio, presence of cotyledon opening, true leaves, and secondary roots.
• We found no effect on germination for seeds exposed to temperatures ≥150 °C. However, germination was significantly reduced for seeds exposed to 100 °C for both 2 and 5 min. The mass of 15-day-old K. coriacea seedlings was smaller when seeds were heated at 70 °C for 5 min or at temperatures higher or equal to 100 °C. Qualea parviflora seedlings did not show any difference in mass, but there were marginal differences in the presence of roots and the opening of cotyledons. Kielmeyera coriacea seedlings allocated biomass faster than Q. parviflora.
• High temperatures affect both quantity and quality of germinable seeds, as well as biomass allocation during initial seedling development. These factors may explain the decrease in seedlings observed after fire, suggesting a bottleneck effect that influences population dynamics and species persistence in systems with frequent fires.

     

Sporotrichosis After Tattooing Caused by Sporothrix brasiliensis

Sporotrichosis is a subcutaneous mycosis caused by pathogenic species of the genus Sporothrix. Since 1998, the number of cases of sporotrichosis due to Sporothrix brasiliensis has grown significantly in Rio de Janeiro, Brazil. Nearly all cases are related to cats as the main source of fungal infection. We report two cases of sporotrichosis following tattoos, a transmission form of S. brasiliensis not yet reported. The first patient, a 22-year-old female, had cutaneous sporotrichosis, fixed form, over a tattoo in her lumbar region. The lesion appeared 12 weeks after she was tattooed. The second patient, a 27-year-old female, had a lymphocutaneous sporotrichosis over a forearm tattoo. The lesion appeared two weeks after she was tattooed. In both cases there was no history of contact with cats or other plausible source of infection. The present study highlights that other non-zoonotic forms of transmission of S. brasiliensis may occur in endemic areas.

     

Anti-glycation effect and the α-amylase,lipase, and α-glycosidase inhibition properties of a polyphenolic fraction derived from citrus wastes

Abstract

The advanced glycation end products (AGEs) constitute a wide variety of substances synthesized from interactions between amino groups of proteins and reducing sugars, which excess induces pathogenesis of chronic diseases. Brazil is the major producer of citrus, a low-cost source of hesperidin, which is a polyphenol recognized for its capacity to inhibit AGEs formation. This is the first work to evaluate the effects of a polyphenolic fraction derived from citrus wastes on the antiglycation and on the inhibition properties of digestive enzymes on the possibility to process these wastes in high value-added products. At concentrations of 10, 15 and 20?mg/mL inhibition of AGEs was higher than 60%. The extracts were able to inhibit by 76% the activity of pancreatic lipase and by 98% the activity of α-glucosidase. For the α-amylase the inhibition capacity was lower than 50%. Strong correlation was obtained among anti-glycation with polyphenolic content and antioxidant capacity.