Blue Light Potentiates Antibiotics in Bacteria via Parallel Pathways of Hydroxyl Radical Production and Enhanced Antibiotic Uptake.

In the age of antimicrobial resistance, the urgency by which novel therapeutic approaches need to be introduced into the clinical pipeline has reached critical levels. Antimicrobial blue light (aBL), as an alternative approach, has demonstrated promise as a stand-alone therapeutic method, albeit with a limited window of antimicrobial activity. Work by others indicates that treatment with antibiotics increases the production of reactive oxygen species (ROS) which may, in part, contribute to the bactericidal effects of antibiotics. These findings suggest that there may be potential for synergistic interactions with aBL, that similarly generates ROS. Therefore, in this study, the mechanism of aBL is investigated, and the potential for aBL to synergistically promote antibiotic activity is similarly evaluated. Furthermore, the translatability of using aBL and chloramphenicol in combination within a mouse model of Acinetobacter baumanii burn infection is assessed. It is concluded that porphyrins and hydroxyl radicals driven by "free iron" are paramount to the effectiveness of aBL; and aBL is effective at promoting multiple antibiotics in different multidrug-resistant bacteria. Moreover, rROS up-regulation, and promoted antibiotic uptake are observed during aBL+antibiotic exposure. Lastly, aBL combined with chloramphenicol appears to be both effective and safe for the treatment of A. baumannii burn infection. In conclusion, aBL may be a useful adjunct therapy to antibiotics to potentiate their action.

Genomic analysis of multidrug-resistant CTX-M-15-positive Klebsiella pneumoniae belonging to the highly successful ST15 clone isolated from a dog with chronic otitis.

BACKGROUND: Extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae have been increasingly reported worldwide as a frequent cause of human and animal infections. K. pneumoniae belonging to the K24 capsular serotype and sequence type (ST) ST15 has been considered a global successful clone responsible for the spread of the blaCTX-M-15 gene. OBJECTIVE: To report the draft genome sequence of a multidrug-resistant CTX-M-15-positive K. pneumoniae K24-ST15 strain (L3KP1), which was isolated from a dog with chronic otitis. METHODS: Genomic DNA was extracted and sequenced using Illumina NextSeq platform. De novo assembly was performed by SPAdes and in silico prediction accomplished by curated bioinformatics tools. RESULTS: The genome size was calculated at 5 642 348 bp, with a GC content of 57.11%, and comprising 5601 total genes, 52 tRNAs, 8 rRNAs, 9 ncRNAs and 105 pseudogenes. The K. pneumoniae L3KP1 strain belonged to ST15 and carried the yersiniabactin biosynthetic gene cluster [ybt 10 (YbST28) in the integrative conjugative element ICEKp4], and the KL24 locus encoding capsular serotype K24. Besides the blaCTX-M-15 ESBL gene, other clinically important resistance genes to ß-lactams, aminoglycosides, fosfomycin, macrolides, phenicol, quinolones, sulfonamides, tetracyclines and trimethoprim were detected. Additionally, heavy metals and disinfectant resistance genes were also identified. CONCLUSION: This draft genome might be useful for comparative genomic analyses of the international clone of K. pneumoniae K24-ST15-CTX-M-15. In addition, information presented in this study also shed light on the urgent need to monitor ESBL-producing K. pneumoniae in veterinary hospitals.

Pomegranate extracts on larval inhibition of Haemonchus spp and Cooperia spp obtained from cattle / Extratos de romã sobre inibição larval de Haemonchus spp e Cooperia spp provenientes de bovinos

Consumers increasingly demand natural food and absent of toxic waste and medicated. The aim of this study was to evaluate the aqueous extract of dried and in natura stem from pomegranate on the larval inhibition of Haemonchus spp. and Cooperia spp. obtained from cattle. Dried and in natura aqueous extract from pomegranate stem (AEPS), negative control (autoclaved distilled water) and positive control (levamisole hydrochloride 0.05 mg / mL) were evaluated. Four mL of each treatment were used, and the results were evaluated in triplicate by egg counts per gram of feces (EPG), larval culture and counting of the larvae. The mean of the larvae that developed per gram of feces was submitted to logarithimic transformation log. (X + 10). The EPG had an average value of 3.620 eggs, identified in larval culture from Haemonchus spp. and Cooperia spp. Dried AEPS presented, by the reduction of larvae, effectiveness of 92.29% for Haemonchus spp. and 96.97% for Cooperia spp. In natura, this extract showed 80% of efficacy against Cooperia larvae, being considered moderately effective; however, for Haemonchus spp. this extract was not effective. These results are specially important for organic and agroecological systems of production, that not allow the use of chemical parasiticides. In conclusion, the use of dried AEPS showed potential anthelmintic and may represent important natural therapeutic option.

Os consumidores têm exigido cada vez mais alimentos naturais e ausentes de resíduos medicamentosos. O objetivo deste estudo foi avaliar o extrato aquoso de caule de romã seco e in natura, sobre a inibição larval de Haemonchus spp. e Cooperia spp. provenientes de bovinos. Foram avaliados extrato aquoso de caule de romã (EACR) seca e in natura, controle negativo (água destilada autoclavada) e controle positivo (cloridrato de levamisol 0,05 mg/mL). Foram utilizados quatro mL de cada tratamento, e os resultados foram avaliados em triplicata, por meio de contagem de ovos por grama de fezes (OPG), cultura de larvas e contagem das larvas. A média de larvas desenvolvidas por grama de fezes foi submetida à transformação logarítmica Log. (x+10). A contagem de OPG apresentou valor médio de 3.620 ovos, sendo identificadas na cultura de larvas de Haemonchus e Cooperia. EACR seca apresentou por meio da redução de larvas, eficácia efetiva de 92,29% para Haemonchus e 96,97% para Cooperia. In natura, este extrato apresentou 80% de eficácia sobre larvas de Cooperia, sendo considerado moderadamente efetivo, porém, para Haemonchus o mesmo não foi efetivo. Esses resultados são especialmente importantes para os sistemas orgânicos e agroecológicos de produção, que não permitem a utilização de parasiticidas químicos. Concluiu-se que a utilização de EACR seca apresentou potencial anti-helmíntico, podendo representar importante opção terapêutica natural.

Atividade antimicrobiana in vitro de extrato de Punica granatum L. sobre Staphylococcus aureus isolado em leite bovino / Antimicrobial activity in vitro of extracts of Punica granatum L. over Staphylococcus aureus isolated in bovine milk

Mastite bovina é considerada principal doença causadora de grandes perdas econômicas nos rebanhos leiteiros. Antimicrobianos químicos promovem resistência farmacológica, resíduos no alimento e contaminação ambiental. Este estudo objetivou verificar a atividade antibacteriana, in vitro, do extrato de romã em Staphylococcus aureus isolado de leite bovino, avaliar sua atividade antioxidante, e quantificar teores de fenóis e flavonoides totais nos diferentes extratos utilizados. Utilizou-se para tanto extratos aquosos da casca do fruto (EAC) e folhas (EAF), secos e in natura de romã. Adicionalmente, avaliou-se atividade antioxidante (AA%), teores de fenóis e flavonóides totais. Amostras de leite foram semeadas, incubadas, e as colônias de Staphylococcus aureus foram ajustadas a 1,0x106 UFC/mL ao padrão nº6 da escala de MacFarland. A sensibilidade dos isolados microbianos foi determinada, em quintuplicata, pela técnica de difusão em discos. A Concentração Inibitória Mínima foi determinada pelo halo de inibição superior a 15 mm. Os resultados foram avaliados pelo método ANOVA, teste de Tukey 5%, utilizando-se o programa SISVAR 5.3 - DEX/UFLA. EACseco inibiu crescimento bacteriano a partir de 3%. EAFseco, EACin natura e EAFin natura, só apresentaram esta atividade a partir de 15%, 20% e 30% respectivamente. A ação antioxidante do EACseco foi verificada a partir de 75µg/mL, com valores correspondentes a 14,2%, atingindo um platô de 65,9% na concentração de 250µg/mL. Entretanto, essa atividade não foi correlacionada aos teores de fenóis totais e flavonoides. Provavelmente outras substâncias alcalóides, podem ter sido responsáveis por esta atividade. Conclui-se que os extratos de Punica granatum L., principalmente aquele obtido pela casca do fruto seco, demonstraram atividade inibitória sobre S. aureus, evidenciando a potencialidade de seu uso para o controle da mastite bovina.

Bovine mastitis is considered important disease causing major economic losses in dairy herds. Antimicrobial drug can promote resistance, chemical residues in food and environmental contamination. The purpose of this study was to evaluate the antibacterial activity in vitro of pomegranate extract on Staphylococcus aureus isolated from bovine milk, evaluate its antioxidant activity, and quantify levels of total phenols and fravonoides of the different extracts used. Aqueous extracts were used in nature and dry, from the peel of the fruit (EAC) and leaves (EAF). Additionally, it was evaluated the antioxidant activity (AA%), total phenols and flavonoids. Milk samples were inoculated, incubated, and the colonies were characterized as Staphylococcus aureus were adjusted to 1.0x106 UFC/mL in the 6 standard of the MacFarland scale. The sensitivity of the microbial isolates were determined in quintuplicate, in disk diffusion test. The minimum inhibitory concentration was determined by visible inhibition zone greater than 15mm. The results were evaluated by ANOVA, Tukey 5%, using the program SISVAR 5.3 - DEX / UFLA. Results implied that the aqueous extract from the bark of dried fruit was capable of inhibiting bacterial growth at concentrations of 3%. The other treatments only showed this activity, from the concentrations of 15%, 20% and 30% for dry EAF, in nature EAC and in nature EAF, respectively. Regarding the action antioxidant of dry EAC, was not correlated with total phenols and flavonoids. Probably other alkaloids substances present in the extract studied, may have been responsible for this activity. It is concluded that extracts of Punica granatum L., especially those obtained by the shell of the fruit, showed inhibitory activity against S. aureus, indicating your use potential for the control of bovine mastitis.