Antimicrobial activity of biogenically produced spherical Se-nanomaterials embedded in organic material against Pseudomonas aeruginosa and\ua0Staphylococcus aureus strains on hydroxyapatite-coated surfaces

In an effort to prevent the formation of pathogenic biofilms on hydroxyapatite (HA)-based clinical devices and surfaces, we present a study evaluating the antimicrobial efficacy of Spherical biogenic Se-Nanostructures Embedded in Organic material (Bio Se-NEMO-S) produced by Bacillus mycoides SelTE01 in comparison with two different chemical selenium nanoparticle (SeNP) classes. These nanomaterials have been studied as potential antimicrobials for eradication of established HA-grown biofilms, for preventing biofilm formation on HA-coated surfaces and for inhibition of planktonic cell growth of Pseudomonas aeruginosa NCTC 12934 and Staphylococcus aureus ATCC 25923. Bio Se-NEMO resulted more efficacious than those chemically produced in all tested scenarios. Bio Se-NEMO produced by B.\ua0mycoides SelTE01 after 6 or 24\ua0h of Na2 SeO3 exposure show the same effective antibiofilm activity towards both P.\ua0aeruginosa and S.\ua0aureus strains at 0.078\ua0mg\ua0ml(-1) (Bio Se-NEMO6 ) and 0.3125\ua0mg\ua0ml(-1) (Bio Se-NEMO24 ). Meanwhile, chemically synthesized SeNPs at the highest tested concentration (2.5\ua0mg\ua0ml(-1) ) have moderate antimicrobial activity. The confocal laser scanning micrographs demonstrate that the majority of the P.\ua0aeruginosa and S.\ua0aureus cells exposed to biogenic SeNPs within the biofilm are killed or eradicated. Bio Se-NEMO therefore displayed good antimicrobial activity towards HA-grown biofilms and planktonic cells, becoming possible candidates as new antimicrobials

Global distribution of Leptospira serovar isolations and detections from animal host species: A systematic review and online database

Objectives Leptospira, the spirochaete causing leptospirosis, can be classified into >250 antigenically distinct serovars. Although knowledge of the animal host species and geographic distribution of Leptospira serovars is critical to understand the human and animal epidemiology of leptospirosis, current data are fragmented. We aimed to systematically review, the literature on animal host species and geographic distribution of Leptospira serovars to examine associations between serovars with animal host species and regions and to identify geographic regions in need of study. Methods Nine library databases were searched from inception through 9 March 2023 using keywords including Leptospira, animal, and a list of serovars. We sought reports of detection of Leptospira, from any animal, characterised by cross agglutinin absorption test, monoclonal antibody typing, serum factor analysis, or pulsed-field gel electrophoresis to identify the serovar. Results We included 409 reports, published from 1927 through 2022, yielding data on 154 Leptospira serovars. The reports included data from 66 (26.5%) of 249 countries. Detections were from 144 animal host species including 135 (93.8%) from the class Mammalia, 5 (3.5%) from Amphibia, 3 (2.1%) from Reptilia, and 1 (0.7%) from Arachnida. Across the animal host species, Leptospira serovars that were detected in the largest number of animal species included Grippotyphosa (n = 39), Icterohaemorrhagiae (n = 29), Pomona (n = 28), Australis (n = 25), and Ballum (n = 25). Of serovars, 76 were detected in a single animal host species. We created an online database to identify animal host species for each serovar by country. Conclusions We found that many countries have few or no Leptospira serovars detected from animal host species and that many serovars were detected from a single animal species. Our study highlights the importance of efforts to identify animal host species of leptospirosis, especially in places with a high incidence of human leptospirosis. We provide an updated resource for leptospirosis researchers

Aerobic Growth of Rhodococcus aetherivorans BCP1 Using Selected Naphthenic Acids as the Sole Carbon and Energy Sources

Naphthenic acids (NAs) are an important group of toxic organic compounds naturally occurring in hydrocarbon deposits. This work shows that Rhodococcus aetherivorans BCP1 cells not only utilize a mixture of eight different NAs (8XNAs) for growth but they are also capable of marked degradation of two model NAs, cyclohexanecarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) when supplied at concentrations from 50 to 500 mgL-1. The growth curves of BCP1 on 8XNAs, CHCA, and CPCA showed an initial lag phase not present in growth on glucose, which presumably was related to the toxic effects of NAs on the cell membrane permeability. BCP1 cell adaptation responses that allowed survival on NAs included changes in cell morphology, production of intracellular bodies and changes in fatty acid composition. Transmission electron microscopy (TEM) analysis of BCP1 cells grown on CHCA or CPCA showed a slight reduction in the cell size, the production of EPS-like material and intracellular electron-transparent and electron-dense inclusion bodies. The electron-transparent inclusions increased in the amount and size in NA-grown BCP1 cells under nitrogen limiting conditions and contained storage lipids as suggested by cell staining with the lipophilic Nile Blue A dye. Lipidomic analyses revealed significant changes with increases of methyl-branched (MBFA) and polyunsaturated fatty acids (PUFA) examining the fatty acid composition of NAs-growing BCP1 cells. PUFA biosynthesis is not usual in bacteria and, together with MBFA, can influence structural and functional processes with resulting effects on cell vitality. Finally, through the use of RT (Reverse Transcription)-qPCR, a gene cluster (chcpca) was found to be transcriptionally induced during the growth on CHCA and CPCA. Based on the expression and bioinformatics results, the predicted products of the chcpca gene cluster are proposed to be involved in aerobic NA degradation in R. aetherivorans BCP1. This study provides first insights into the genetic and metabolic mechanisms allowing a Rhodococcus strain to aerobically degrade NAs

Data_Sheet_1.pdf

<p>Naphthenic acids (NAs) are an important group of toxic organic compounds naturally occurring in hydrocarbon deposits. This work shows that Rhodococcus aetherivorans BCP1 cells not only utilize a mixture of eight different NAs (8XNAs) for growth but they are also capable of marked degradation of two model NAs, cyclohexanecarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) when supplied at concentrations from 50 to 500 mgL^-1. The growth curves of BCP1 on 8XNAs, CHCA, and CPCA showed an initial lag phase not present in growth on glucose, which presumably was related to the toxic effects of NAs on the cell membrane permeability. BCP1 cell adaptation responses that allowed survival on NAs included changes in cell morphology, production of intracellular bodies and changes in fatty acid composition. Transmission electron microscopy (TEM) analysis of BCP1 cells grown on CHCA or CPCA showed a slight reduction in the cell size, the production of EPS-like material and intracellular electron-transparent and electron-dense inclusion bodies. The electron-transparent inclusions increased in the amount and size in NA-grown BCP1 cells under nitrogen limiting conditions and contained storage lipids as suggested by cell staining with the lipophilic Nile Blue A dye. Lipidomic analyses revealed significant changes with increases of methyl-branched (MBFA) and polyunsaturated fatty acids (PUFA) examining the fatty acid composition of NAs-growing BCP1 cells. PUFA biosynthesis is not usual in bacteria and, together with MBFA, can influence structural and functional processes with resulting effects on cell vitality. Finally, through the use of RT (Reverse Transcription)-qPCR, a gene cluster (chcpca) was found to be transcriptionally induced during the growth on CHCA and CPCA. Based on the expression and bioinformatics results, the predicted products of the chcpca gene cluster are proposed to be involved in aerobic NA degradation in R. aetherivorans BCP1. This study provides first insights into the genetic and metabolic mechanisms allowing a Rhodococcus strain to aerobically degrade NAs.</p

Virulent Brucella nosferati infecting Desmodus rotundus has emerging potential due to the broad foraging range of its bat host for humans and wild and domestic animals

Desmodus rotundus, vampire bats, transmit dangerous infections, and brucellosis is a hazardous zoonotic disease, two adversities that coexist in the subtropical and tropical areas of the American continent. Here, we report a 47.89% Brucella infection prevalence in a colony of vampire bats inhabiting the tropical rainforest of Costa Rica. The bacterium induced placentitis and fetal death in bats. Wide-range phenotypic and genotypic characterization placed the Brucella organisms as a new pathogenic species named Brucella nosferati sp. nov., isolated from bat tissues, including the salivary glands, suggesting feeding behavior might favor transmission to their prey. Overall analyses placed B. nosferati as the etiological agent of a reported canine brucellosis case, demonstrating its potential for infecting other hosts. To assess the putative prey hosts, we analyzed the intestinal contents of 14 infected and 23 non-infected bats by proteomics. A total of 54,508 peptides sorted into 7,203 unique peptides corresponding to 1,521 proteins were identified. Twenty-three wildlife and domestic taxa, including humans, were foraged by B. nosferati-infected D. rotundus, suggesting contact of this bacterium with a broad range of hosts. Our approach is appropriate for detecting, in a single study, the prey preferences of vampire bats in a diverse area, demonstrating its suitability for control strategies where vampire bats thrive.Desmodus rotundus, los murciélagos vampiro, transmiten infecciones peligrosas, y la brucelosis es una peligrosa enfermedad zoonótica, dos adversidades que coexisten en las zonas subtropicales y tropicales del continente americano. Aquí se informa de una prevalencia de infección por Brucella del 47,89% en una colonia de murciélagos vampiro que habitan la selva tropical de Costa Rica. La bacteria indujo placentitis y muerte fetal en los murciélagos. Una amplia caracterización fenotípica y genotípica situó a los organismos de Brucella como una nueva especie patógena denominada Brucella nosferati sp. nov., aislada de tejidos de murciélagos, incluidas las glándulas salivales, lo que sugiere que el comportamiento alimentario podría favorecer la transmisión a sus presas. Los análisis globales situaron a B. nosferati como agente etiológico de un caso de brucelosis canina notificado, lo que demuestra su potencial para infectar a otros hospedadores. Para evaluar los posibles huéspedes presa, analizamos mediante proteómica el contenido intestinal de 14 murciélagos infectados y 23 no infectados. Se identificó un total de 54.508 péptidos clasificados en 7.203 péptidos únicos correspondientes a 1.521 proteínas. D. rotundus infectado con B. nosferati se alimentó de veintitrés taxones de fauna silvestre y doméstica, incluidos los humanos, lo que sugiere el contacto de esta bacteria con una amplia gama de hospedadores. Nuestro enfoque es apropiado para detectar, en un solo estudio, las preferencias de presa de los murciélagos vampiro en una zona diversa, lo que demuestra su idoneidad para las estrategias de control donde prosperan los murciélagos vampiro. IMPORTANCIA: El descubrimiento de que una elevada proporción de murciélagos vampiro en una zona tropical está infectada con Brucella nosferati patógena y que los murciélagos se alimentan de seres humanos y muchos animales salvajes y domésticos es relevante desde la perspectiva de la prevención de enfermedades emergentes. En efecto, los murciélagos que albergan B. nosferati en sus glándulas salivales pueden transmitir esta bacteria patógena a otros huéspedes. Este potencial no es trivial ya que, además de la patogenicidad demostrada, esta bacteria posee todo el arsenal virulento necesario de los organismos Brucella peligrosos, incluidos los que son zoonóticos para el ser humano. Nuestro trabajo ha sentado las bases para futuras acciones de vigilancia en los programas de control de la brucelosis en los que prosperan estos murciélagos infectados. Además, nuestra estrategia para identificar el área de alimentación de los murciélagos puede adaptarse para explorar los hábitos alimentarios de diversos animales, incluidos los artrópodos vectores de enfermedades infecciosas, y por tanto ser de interés para un público más amplio, además de los expertos en Brucella y murciélagos.Universidad Nacional, Costa RicaEscuela de Medicina Veterinari