Avaliação do potencial biotecnológico de Streptomyces isolados de processo de compostagem

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Ação de antissépticos e desinfetantes de uso doméstico sobre Enterococcus sp. isolados do arroio Dilúvio, RS, Brasil

Located in downtown Porto Alegre, Rio Grande do Sul state, southern Brazil, the Dilúvio stream receives waste and domestic sewage inflow daily from several districts of the city. If not properly treated, such wastewater can be the source of different microorganisms like enterococci. In the present study, the activity of household disinfectants and antiseptics was tested against microorganisms isolated from such wastewater. Fifteen disinfectants and six antiseptic products were tested against 28 enterococci isolated from Dilúvio stream by the disk diffusion method. Products showing anti-enterococci activity were subjected to the minimum inhibitory concentration method, which was obtained by diluting products in 50% to 1.563% for 24 and 48 h of exposure. Of the 21 tested products, 13 disinfectants and five antiseptics showed activity against enterococci isolated from the Dilúvio stream. Although most products proved to be efficient when pure (100%), many had their antimicrobial activity efficiency reduced already in the first dilution (50%) and in the 24-h exposure time. Exposure period revealed to be an important factor for bacterial growth, since the time of permanence of compounds may influence the capacity of bacteria to grow. Our study demonstrated that most tested household disinfectants and antiseptics proved to be efficient in controlling antimicrobial-susceptible and -resistant enterococci strains isolated from the Dilúvio stream. O arroio Dilúvio, localizado em uma área central de Porto Alegre, recebe diariamente lixo e esgoto doméstico de vários bairros da cidade, que sem o tratamento adequado poderão ser fonte de diferentes microrganismos, entre eles destacam-se os enterococos resistência antimicrobianos que já foram isolados do arroio. A ausência de dados sobre a atividade de desinfetantes e antissépticos de uso doméstico frente aos microrganismos isolados de águas residuais justifica o presente estudo. Foram testados 15 produtos desinfetantes e seis produtos antissépticos frente a 28 enterococos isolados do arroio Dilúvio. A atividade dos produtos selecionados foi verificada através do método de difusão em disco. Os produtos com atividade frente aos enterococos foram submetidos ao método de concentração inibitória mínima, obtida pela diluição dos produtos em 50% até 1,563%, por 24 e 48 h de exposição. Dos 21 produtos testados, 13 desinfetantes e a cinco antissépticos apresentaram atividade contra os enterococos isolados do arrio Dilúvio. Apesar da maioria dos produtos mostraram-se eficiente quanto aplicado puro (100%), muitos tiveram a eficiência de sua atividade antimicrobiana reduzida já na primeira diluição do produto, de 50%, e no tempo de exposição de 24 horas. O período de exposição mostrou-se um fator importante frente ao crescimento bacteriano, já que o tempo de permanência de um composto pode influenciar essa capacidade de crescimento das bactérias. Como conclusão, o presente estudo demonstrou que os desinfetantes e antissépticos domésticos testados, em sua grande maioria, mostraram-se eficientes no controle cepas de enterococos susceptível e resistente a antimicrobianos isolados do arroio Dilúvio.

Multidrug resistance in Enterococci isolated from wild pampas foxes (Lycalopex gymnocercus) and Geoffroy's Cats (Leopardus geoffroyi) in the Brazilian pampa biome

Enterococci are ubiquitous microorganisms present in various environments and within the gastrointestinal tracts of humans and other animals. Notably, fecal enterococci are suitable indicators for monitoring antimicrobial resistance dissemination. Resistant bacterial strains recovered from the fecal samples of wild animals can highlight important aspects of environmental disturbances. In this report, we investigated antimicrobial susceptibility as well as resistance and virulence genes in fecal enterococci isolated from wild Pampas foxes (Lycalopex gymnocercus) (n = 5) and Geoffroy's cats (Leopardus geoffroyi) (n = 4) in the Brazilian Pampa biome. Enterococci were isolated from eight out of nine fecal samples and Enterococcus faecalis was identified in both animals. However, E. faecium and E. durans were only detected in Pampas foxes, while E. hirae was only detected in Geoffroy's cats. Antimicrobial susceptibility analysis showed resistance to rifampicin (94%), erythromycin (72.6%), ciprofloxacin/norfloxacin (40%), streptomycin (38%), and tetracycline (26%). The high frequency of multidrug-resistant enterococci (66%) isolated in this study is a matter of concern since these are wild animals with no history of therapeutic antibiotic exposure. The tetM/tetL and msrC/ermB genes were detected in most tetracycline- and erythromycin-resistant enterococci, respectively. The gelE, ace, agg, esp, and clyA virulence genes were also detected in enterococci. In conclusion, our data suggest that habitat fragmentation and anthropogenic activities in the Pampa biome may contribute to high frequencies of multidrug-resistant enterococci in the gut communities of wild Pampas foxes and Geoffroy's cats. To the best of the authors' knowledge, this is the first report of antimicrobial-resistant enterococci in the Pampa biome

Microbial community and physicochemical characterization of kombuchas produced and marketed in Brazil

Kombucha has recently become popular in the Brazilian beverage market as a healthy alternative to soft drinks. However, little is known about the microbial composition and physicochemical characteristics of products available on the market. To investigate the microbial profile of kombuchas, high-throughput sequencing of the 16S rRNA and ITS genes, in samples belonging to six brands was utilized. In addition, the drinks were characterized based on the physicochemical parameters of pH, total acidity and alcohol content. Through the metagenetic analysis, the most abundant prokaryotic species identified were Liquorilactobacillus nagelii, Oenococcus oeni, Komagataeibacter rhaeticus, Liquorilactobacillus ghanensis, Gluconobacter oxydans, Komagataeibacter saccharivorans, Acetobacter peroxydans and Pantoea stewartii, while the mainly eukaryotic species were Dekkera bruxellensis, Dekkera anomala, Saccharomyces cerevisiae and Lanchancea fermentati. Interestingly, we identified six different oligotypes of D. bruxellensis, showing a wide diversity of strains belonging to this species. The results obtained for the physicochemical analyses, within the shelf life of the products, presented a range between 2.88 ± 0.06 and 3.43 ± 0.04 of pH, values between 1.80 ± 0.59 and 4.86 ± 0.72 for the total titratable acidity and 1.03 ± 0.24 to 2.54 ± 0.39 referring to alcohol content, demonstrating significant differences between brand. In addition, all samples had alcohol content above 0.5%, resulting in the classification of alcoholic beverages, which need proper labelling. The data generated in this work helped to understand the composition of the kombuchas available in the Brazilian market, as well as in the development of the identity and quality standard of the drink

Evaluating Sardinella brasiliensis quality indicators through the quantification of histamine and bacterial communities

Primarily formed by the microbial decarboxylation of the amino acid histidine, histamine is the leading global cause of food poisoning from fish consumption worldwide. In the present work, the quality of 12 fresh and 12 frozen marketed sardines (Sardinella brasiliensis) were evaluated for histamine concentration using Highperformance Liquid Chromatography with Diode-Array Detection (HPLC-DAD), while the detection and quantification of histamine-producing bacteria were performed via quantitative Polymerase Chain Reaction (qPCR), and the microbiota composition of sardines was assessed through amplification of the 16S rRNA gene using highthroughput sequencing (HTS). According to the results obtained by HPLC-DAD, histamine concentration ranged from 226.14 to 583.87 mg kg 1. The histidine decarboxylase (hdc) genes from gram-negative bacteria (Morganella morganii, and Enterobacter aerogenes) were identified. The most abundant microorganisms present in fresh sardines belong to the genera Macrococcus spp., Acinetobacter spp., and Pseudomonas spp., while the genera Phyllobacterium spp., Pseudomonas spp., and Acinetobacter spp. were most abundant in frozen sardines

Evaluation of enterotoxins and antimicrobial resistance in microorganisms isolated from raw sheep milk and cheese : ensuring the microbiological safety of these products in southern Brazil

This study emphasizes the importance of monitoring the microbiological quality of animal products, such as raw sheep’s milk and cheese, to ensure food safety. In Brazil, there is currently no legislation governing the quality of sheep’s milk and its derivatives. Therefore, this study aimed to evaluate: (i) the hygienic-sanitary quality of raw sheep’s milk and cheese produced in southern Brazil; (ii) the presence of enterotoxins and Staphylococcus spp. in these products; and (iii) the susceptibility of the isolated Staphylococcus spp. to antimicrobial drugs and the presence of resistance genes. A total of 35 samples of sheep’s milk and cheese were examined. The microbiological quality and presence of enterotoxins were accessed using Petrifilm and VIDAS SET2 methods, respectively. Antimicrobial susceptibility tests were conducted using VITEK 2 equipment and the disc diffusion method. The presence of resistance genes tet(L), sul1, sul2, ermB, tetM, AAC(6)’, tetW, and strA were evaluated through PCR. In total, 39 Staphylococcus spp. were obtained. The resistance genes tetM, ermB, strA, tetL, sul1, AAC(6)’, and sul2 were detected in 82%, 59%, 36%, 28%, 23%, 3%, and 3% of isolates, respectively. The findings revealed that both raw sheep’s milk and cheese contained Staphylococcus spp. that exhibited resistance to antimicrobial drugs and harbored resistance genes. These results underscore the immediate need for specific legislation in Brazil to regulate the production and sale of these product

Effect of live Eimeria vaccination or salinomycin on growth and immune status in broiler chickens receiving in-feed inclusion of gelatin and vitamin E

This experiment determined if 2% of gelatin, to improve the levels of proline and glycine in the diet, and 70 mg/kg of vitamin E supplementation would relieve the impaired performance of male Cobb broilers vaccinated for coccidiosis. Half of the chicks were vaccinated via water (live oocysts), while the other half received medication (salinomycin) in the feed until 35 d of age. The effects of coccidiosis vaccine on performance and mRNA levels of genes involved in mucin synthesis, cytokines, trefoil family factor-2 (TFF2), and metabolic processes (CD36) in the jejunum of broilers were measured. Vaccination negatively affected performance in the first 21 d; however, the inclusion of gelatin and vitamin E reduced this negative response. Additionally, supplementation with these nutrients led to an improvement in broilers receiving the coccidiostat (P < 0.05). From 21 to 35 d, birds treated with gelatin and coccidiosis vaccine experienced better body weight gain than birds without gelatin and vitamin E (P < 0.05). Vaccinated chickens had decreased body weight and decreased anti-inflammatory cytokine expression. Fur- thermore, they had increased inflammatory cytokine expression, mucin 2 expression, and TFF2 compared to salinomycin-fed broilers (P < 0.05). Transcripts for IL- 1B, IFN-y, MUC2, TFF2 were decreased while mRNAs for IL-4 and IL-10 increased in salinomycin-fed broilers compared to vaccinated broilers (P < 0.05). In conclusion, broilers vaccinated against coccidiosis increase their pro-inflammatory immune status and mucin expression compared to broilers receiving salinomycin. These events may contribute to lower performance in vaccinated broiler chicks. Moreover, vitamin E and gelatin can minimize the vaccine’s negative immune effects and promote better performance

Fecal bacterial communities of wild black capuchin monkeys (Sapajus nigritus) from the Atlantic Forest biome in Southern Brazil are divergent from those of other non-human primates

Gut microbiota are influenced by factors such as diet, habitat, and social contact, which directly affect the host's health. Studies related to gut microbiota in non-human primates are increasing worldwide. However, little remains known about the gut bacterial composition in wild Brazilian monkeys. Therefore, we studied the fecal microbiota composition of wild black capuchin monkey (Sapajus nigritus) (n=10) populations from two different Atlantic Forest biome fragments (five individuals per fragment) in south Brazil. The bacterial community was identified via the high-throughput sequencing and partial amplification of the 16S rRNA gene (V4 region) using an Ion Personal Genome Machine (PGMTM) System. In contrast to other studies involving monkey microbiota, which have generally reported the phyla Firmicutes and Bacteroidetes as predominant, black capuchin monkeys showed a high relative abundance of Proteobacteria (X= 80.54%), followed by Firmicutes (X= 12.14%), Actinobacteria (X= 4.60%), and Bacteriodetes (X= 1.31%). This observed particularity may have been influenced by anthropogenic actions related to the wild habitat and/or diet specific to the Brazilian biome's characteristics and/or monkey foraging behavior. Comparisons of species richness (Chao1) and diversity indices (Simpson and InvSimpson) showed no significant differences between the two groups of monkeys. Interestingly, PICRUSt2 analysis revealed that metabolic pathways present in the bacterial communities were associated with xenobiotic biodegradation and the biosynthesis of secondary metabolites, which may suggest positive effects on monkey health and conservation in this anthropogenic habitat. Infectious disease-associated microorganisms were also observed in the samples. The present study provides information about the bacterial population and metabolic functions present in fecal microbiota, which may contribute to a better understanding of the ecology and biology of black capuchin monkeys living in forest fragments within the Atlantic Forest biome in southern Brazil. Additionally, the present study demonstrates that the fecal bacterial communities of wild black capuchin monkeys in this area are divergent from those of other wild non-human primates

Changes in the ceca microbiota of broilers vaccinated for coccidiosis or supplemented with salinomycin

The objective of this study was to characterize differences in the cecal microbiota of chickens vaccinated for coccidiosis or receiving salinomycin in the diet. In this study, 140 male 1-day-old broiler chickens were divided in 2 groups: vaccine group (live vaccine) vaccinated at the first day and salinomycin group (125 ppm/kg since the first day until 35 d of age). Each treatment was composed for 7 replicates of 10 birds per pen. At 28 d, the cecal content of one bird per replicate was collected for microbiota analysis. The genetic sequencing was conducted by the Miseq Illumina platform. Vaccine group showed lower body weight, weight gain, and poorer feed conversion in the total period (P 0.05). The richness distribution in the salinomycin group was larger and more uniform than the vaccinated birds. Salinomycin group was related to the enrichment of Bacteroidetes, whereas Firmicutes and Proteobacteria phyla were in greater proportions in the vaccine group. The last phylum includes a wide variety of pathogenic bacteria. The vaccine did not decrease the species richness but decreased the percentage of Bacteroidetes, a phylum composed by genera that produce short-chain fatty acids improving intestinal health. Vaccine group also had higher Proteobacteria phylum, which may help explain its poorer performance