Plant-Derivatives Small Molecules with Antibacterial Activity

The vegetal world constitutes the main factory of chemical products, in particular secondary metabolites like phenols, phenolic acids, terpenoids, and alkaloids. Many of these compounds are small molecules with antibacterial activity, although very few are actually in the market as antibiotics for clinical practice or as food preservers. The path from the detection of antibacterial activity in a plant extract to the practical application of the active(s) compound(s) is long, and goes through their identification, purification, in vitro and in vivo analysis of their biological and pharmacological properties, and validation in clinical trials. This review presents an update of the main contributions published on the subject, focusing on the compounds that showed activity against multidrug-resistant relevant bacterial human pathogens, paying attention to their mechanisms of action and synergism with classical antibiotics

Phenotypic and molecular characterization of resistance to macrolides and Lincosamides in Corynebacterium striatum clinical strains isolated from Tunisia

Objectives: In this study we investigated the susceptibility profiles against macrolides and lincosamides of 85 C. striatum strains isolated at a clinical centre in Sousse (Tunisia). Methods: The strains were identified by the routine biochemical assays and then confirmed by Vitek-Maldi-Tof-MS. MIC?s of erythromycin and clindamycin were determined using the microdilution method. The detection of erm(X), erm(B), msr(A), mph(A) and mef(A-E) resistance genes was performed by PCR. The strains were typed by PFGE using XbaI. Results: Sixty-nine (81.17%) strains were resistant to erythromycin, 58 (67.44%) strains were resistant to clindamycin. There was a high correlation between the resistance to erythromycin and clindamycin and the presence of erm(X) gene in 85.50% and 89.65% respectively. The erm(B) gene was detected in 21(24.70%) strains whereas, no others genes were detected in our strains collection. By PFGE, the 85 strains belonged to 18 different clones. Conclusion: erm(X) is implicated in macrolide resistance for almost all the Corynebacterium strains analyzed in our study. Other resistance genes like erm(B) must also be implicated in this resistance, although its presence seems to be unusual in previously reported studies

In vitro Antibacterial Effects of Salvia sclarea, Eucalyptus Globulus and Eugenia Caryophyllata Essential oils Against Multidrug Resistant Corynebacterium spp Clinical Isolates

Objectives: Multidrug resistant Corynebacterium species are increasingly reported as the ethiological agent of various clinical infections. Thus, the purpose of this research was to evaluate the in vitro antimicrobial activity of three essential oils Salvia sclarea, Eucalyptus globulus and Eugenia caryophyllata against Corynebacterium species. Methods: Twenty-four multidrug resistant strains including C. striatum, C. amycolatum, C. urealyticum, C. aurimucosum, C. imitans, and C. jeikeium were used in the study. Inhibition diameter zone, minimum inhibitory concentration and minimum bactericide concentration of these oils were determined using agar disc diffusion method and microdilution method. Tigecycline was used as positive control. Results: Our study showed that Eugenia caryophyllata had the best activity. Eucalyptus globulus extract exhibited a moderate activity and Salvia sclarea was inactive against all the species tested. We found that C. amycolatum was more resistant to the essential oils than other species. On the other hand, tigecycline was effective on the majority of the strains (37.5%), but his action was lower than Eugenia caryophyllata oil. Conclusion: These results support the use of clove oil as a natural alternative to treat infections caused by multidrug resistant corynebacteria

Método de diagnóstico molecular para la detección e identificación de Rhodococcus equi.

Método de diagnóstico molecular para la detección e identificación de Rhodococcus equi el cual se refiere a un procedimiento de análisis molecular, por PCR, que permite la detección e identificación de Rhodococcus equi, un microorganismo de interés en patología animal y humana, a partir de aislamientos obtenidos en el laboratorio y/o muestras clínicas. El método se fundamenta en una reacción de amplificación que utiliza unos cebadores específicos para esta bacteria, basados en la secuencia del gen choE, codificante para la colesterol oxidasa. El procedimiento discrimina Rhodococcus equi de otras bacterias próximas, como micobacterias y otros actinomicetos patógenos. El procedimiento permite reconocer cualquier aislamiento de Rhodococcus equi con independencia de su origen, presenta una especificidad del 100%, es muy sensible y su ejecución es muy rápida.Solicitud: 200200012 (03.01.2002)Nº Pub. de Solicitud: ES2222061A1 (16.01.2005)Nº de Patente: ES2222061B2 (01.02.2006

Analysis of Phenotypic and Genotypic Susceptibility to Clarithromycin and Amikacin of Mycobacterium abscessus Complex Strains Isolated from Cystic Fibrosis Patients

Mycobacterium; Amikacin; ClarithromycinMicobacteria; Amikacina; ClaritromicinaMicobacteri; Amikacina; ClaritromicinaMycobacterium abscessus complex infections are ever on the rise. To curb their increasing evolution, we performed an in-depth study of 43 clinical isolates of cystic fibrosis patients obtained from 2009 to 2020. We identified their subspecies, uncovered their genotypic resistance profiles, characterised their antibiotic-resistant genes, and assessed their phenotypic antibiotic susceptibilities. The phenotypic and genotypic methods showed total agreement in terms of resistance to clarithromycin and amikacin. Of the 43 clinical strains, 28 belonged to M. abscessus subsp. abscessus (65.1%), 13 to M. abscessus subsp. massiliense (30.2%), and 2 to M. abscessus subsp. bolletii (4.6%). The resistant rates for clarithromycin and amikacin, the two main drugs against M. abscessus complex pulmonary infections, were 64.2% and 14.2%, respectively. We found three strains of M. abscessus subsp. abscessus that showed heteroresistance in the rrl and rrs genes, and these strains also presented double-resistance since they were macrolide- and aminoglycoside-resistant. M. abscessus subsp. abscessus showed a high minimum inhibitory concentration (MIC) and a resistant percentage larger than or equal to 88% to cefoxitin, ciprofloxacin, moxifloxacin, doxycycline, imipenem, and trimethoprim-sulfamethoxazole. These results show a panorama of the high resistance of Mycobacterium abscessus complex to current drugs for cystic fibrosis patients. Thus, other treatment methods are urgently needed.This research received funding from the Fundació Hospital Universitari Vall Hebron—Institut de Recerca

The COVID-19 Diagnostic Technology Landscape: Efficient Data Sharing Drives Diagnostic Development

Work at the Brazilian groups was partially funded by grants fromMCTIC, CNPq, CAPES, and FAPESB. LP was recipient of a research fellowship from CNPq

Antimicrobial Resistance Determinants in Genomes and Plasmids from Acinetobacter baumannii Clinical Isolates

Acinetobacter baumannii is a Gram-negative coccoid rod species, clinically relevant as a human pathogen, included in the ESKAPE group. Carbapenem-resistant A. baumannii (CRAB) areconsidered by the Worl Health Organization (WHO) as a critical priority pathogen for the research and development of new antibiotics. Some of the most relevant features of this pathogen are its intrinsic multidrug resistance and its ability to acquire rapid and effective new resistant determinants against last-resort clinical antibiotics, mostly from other ESKAPE species. The presence of plasmids and mobile genetic elements in their genomes contributes to the acquisition of new antimicrobial resistance determinants. However, although A. baumannii has arisen as an important human pathogen, information about these elements is still not well understood. Current genomic analysis availability has increased our ability to understand the microevolution of bacterial pathogens, including point mutations, genetic dissemination, genomic stability, and pan- and core-genome compositions. In this work, we deeply studied the genomes of four clinical strains from our hospital, and the reference strain ATCC®19606TM, which have shown a remarkable ability to survive and maintain their effective capacity when subjected to long-term stress conditions. With that, our aim was presenting a detailed analysis of their genomes, including antibiotic resistance determinants and plasmid composition.This research was funded by ‘Plan Nacional de I+D+i and Instituto de Salud Carlos III (Fondo de Investigaciones Sanitarias PI16/01103 to J.R.-V.), Subdirección General de Redes y Centros de Investigación Cooperativa, Spanish Ministry of Economy and Competitiveness, Spanish Network for Research in Infectious Diseases (REIPI RD12/0015) and (REIPI RD16/0016) co-financed by the European Development Regional Fund “A way to achieve Europe” ERDF and Ministerio de Ciencia e Innovación, Acciones de dinamización «Redes de Investigación» RED2018-102469-T

Acinetobacter Baumannii Maintains Its Virulence After Long-Time Starvation

Acinetobacter baumannii is a cause of healthcare-associated infections. Although A. baumannii is an opportunistic pathogen, its infections are notoriously difficult to treat due to intrinsic and acquired antimicrobial resistance, often limiting effective therapeutic options. A. baumannii can survive for long periods in the hospital environment, particularly on inanimate surfaces. Such environments may act as a reservoir for cross-colonization and infection outbreaks and should be considered a substantial factor in infection control practices. Moreover, clothing of healthcare personnel and gadgets may play a role in the spread of nosocomial bacteria. A link between contamination of hospital surfaces and A. baumannii infections or between its persistence in the environment and its virulence has not yet been established. Bacteria under stress (i.e., long-term desiccation in hospital setting) could conserve factors that favor infection. To investigate whether desiccation and/or starvation may be involved in the ability of certain strains of A. baumannii to retain virulence factors, we have studied five well-characterized clinical isolates of A. baumannii for which survival times were determined under simulated hospital conditions. Despite a considerable reduction in the culturability over time (up to 88% depending on strain and the condition tested), some A. baumannii strains were able to maintain their ability to form biofilms after rehydration, addition of nutrients, and changing temperature. Also, after long-term desiccation, several clinical strains were able to grow in the presence of non-immune human serum as fine as their non-stressed homologs. Furthermore, we also show that the ability of bacterial strains to kill Galleria mellonella larvae does not change although A. baumannii cells were stressed by long-term starvation (up to 60 days). This means that A. baumannii can undergo a rapid adaptation to both the temperature shift and nutrients availability, conditions that can be easily found by bacteria in a new patient in the hospital setting.Research in our laboratory is supported by the Spanish Instituto de Salud Carlos III, Spain (grant PI16/01103 to José Ramos-Vivas) and the Plan Nacional de I+D+i 2008-2011 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD12/0015) - co-financed by European Development Regional Fund "A way to achieve Europe" ERDF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Procedimiento para la detección, identificación y tipado de Haemophilus parasuis (Sistema DITPAR).

Se refiere un procedimiento de análisis molecular, por PCR-RFLP, que permite la detección, identificación y tipificación de Haemophilus parasuis, un microorganismo de interés en patología porcina, a partir de muestras clínicas y/o de aislamientos obtenidos en el laboratorio. El método se fundamenta en las peculiaridades de los genes tbp en esta bacteria cuando se compara con otras próximas, como Actinobacillus suis y Actinobacillus pleuropneumoniae. El procedimiento discrimina H. parasuis de A. pleuropneumoniae; de igual modo también diferencia otros miembros, no patógenos, de la familia Pasteurellaceae, presentes en el aparato respiratorio del cerdo, como A. minor, A. porcinus y A. indolicus. El producto de la amplificación por PCR, sometido a restricción con distintas nucleasas (AvaI, TaqI y RsaI) permite clasificar los serotipos de H. parasuis en un total de 28 tipos genéticos diferentes, lo que representa una alternativa de mucho interés al sistema tradicional de tipificación serológica.Solicitud: 200100946 (19.04.2001)Nº Pub. de Solicitud: ES2205967A1 (01.05.2004)Nº de Patente: ES2205967B1 (16.07.2005

Whole-genome sequence of Acinetobacter pittii HUMV-6483 isolated from human urine

Acinetobacter pittii strain HUMV-6483 was obtained from urine from an adult patient. We report here its complete genome assembly using PacBio singlemolecule real-time sequencing, which resulted in a chromosome with 4.07 Mb and a circular contig of 112 kb. About 3,953 protein-coding genes are predicted from this assembly