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PURPOSE: This study aimed to evaluate the therapeutic effect of an ethanol extract of Ocimum basilicum L. (EEOb) aerial parts against Ehrlich's experimental tumor (EET) in mice. METHODS: Swiss mice were divided into two groups (control and treated; n = 6). On day 21, all mice were inoculated subcutaneously with 2 × 106 (0.05 mL) EET cells in the left paw for solid tumor development. This study lasted 28 days. Treatment began 24 hours after inoculation with EET. Measurements of dorsoplantar thickness were used to assess tumor growth. The paw pad was collected for histopathological analysis and stained using the argyrophilic nucleolar organizing regions (AgNOR) technique and immunohistochemistry for proliferating cell nuclear antigen, Bcl-2 and Bax. RESULTS: The treatment of animals with EEOb at 100 mg/kg intraperitoneally was able to reduce the growth (Control = 3.7 ± 0.1 mm vs. EEOb = 5.7 ± 0.2 mm) and the number of AgNORs of solid Ehrlich tumor. The antitumor effect of EEOb was associated with the induction of apoptosis of tumoral cell, as suggested by the reduction of the content of Bcl-2 induced by extract. CONCLUSIONS: The study demonstrated that daily administration of EEOb is able to reduce the growth of EET by induce apoptosis of tumoral cells.

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The urgent global health challenge posed by methicillin-resistant Staphylococcus aureus (MRSA) infections demands effective solutions. Antimicrobial peptides (AMPs) represent promising tools of research of new antibacterial agents and LyeTx I mn∆K, a short synthetic peptide based on the Lycosa erythrognatha spider venom, is a good representative. This study focused on analyzing the antimicrobial activities of LyeTx I mn∆K, including minimum inhibitory and bactericidal concentrations, synergy and resensitization assays, lysis activity, the effect on biofilm, and the bacterial death curve in MRSA. Additionally, its characterization was conducted through isothermal titration calorimetry, dynamic light scattering, calcein release, and finally, efficacy in a mice wound model. The peptide demonstrates remarkable efficacy against planktonic cells (MIC 8-16 µM) and biofilms (>30% of inhibition) of MRSA, and outperforms vancomycin in terms of rapid bactericidal action and anti-biofilm effects. The mechanism involves significant membrane damage. Interactions with bacterial model membranes, including those with lysylphosphatidylglycerol (LysylPOPG) modifications, highlight the versatility and selectivity of this compound. Also, the peptide has the ability to sensitize resistant bacteria to conventional antibiotics, showing potential for combinatory therapy. Furthermore, using an in vivo model, this study showed that a formulated gel containing the peptide proved superior to vancomycin in treating MRSA-induced wounds in mice. Together, the results highlight LyeTx I mnΔK as a promising prototype for the development of effective therapeutic strategies against superficial MRSA infections.

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INTRODUCTION: Active targeting of tumors by nanomaterials favors early diagnosis and the reduction of harsh side effects of chemotherapeuticals. METHOD: We synthesized magnetic nanoparticles (64 nm; -40 mV) suspended in a magnetic fluid (MF) and decorated them with anti-carcinoembryonic antigen (MFCEA; 144 nm; -39 mV). MF and MFCEA nanoparticles were successfully radiolabeled with technetium-99m (99mTc) and intravenously injected in CEA-positive 4T1 tumor-bearing mice to perform biodistribution studies. Both 99mTc-MF and 99mTc-MFCEA had marked uptake by the liver and spleen, and the renal uptake of 99mTc-MFCEA was higher than that observed for 99mTc-MF at 20h. At 1 and 5 hours, the urinary excretion was higher for 99mTc-MF than for 99mTc-MFCEA. RESULTS: These data suggest that anti-CEA decoration might be responsible for a delay in renal clearance. Regarding the tumor, 99mTc-MFCEA showed tumor uptake nearly two times higher than that observed for 99mTc-MFCEA. Similarly, the target-nontarget ratio was higher with 99mTc-MFCEA when compared to the group that received the 99mTc-MF. CONCLUSION: These data validated the ability of active tumor targeting by the as-developed antiCEA loaded nanoparticles and are very promising results for the future development of a nanodevice for the management of breast cancer and other types of CEA-positive tumors.

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The jelleine family is a group of four peptides (jelleines I-IV) originally isolated from the royal jelly of honey bee (Apis mellifera), but later detected in some honey samples. These oligopeptides are composed of 8-9 amino acid residues, positively charged (+2 to +3 at pH 7.2), including 38-50% of hydrophobic residues and a carboxamide C-terminus. Jelleines, generated by processing of the C-terminal region of major royal jelly proteins 1 (MRJP-1), play an important biological role in royal jelly conservation as well as in protecting bee larvae from potential pathogens. Therefore, these molecules present numerous benefits for human health, including therapeutic purposes as shown in preclinical studies. In this review, we aimed to evaluate the biological effects of jelleines in addition to characterising their toxicities and stabilities. Jelleines I-III have promising antimicrobial activity and low toxicity (LD50 > 1000 mg/Kg). However, jelleine-IV has not shown relevant biological potential. Jelleine-I, but not the other analogues, also has antiparasitic, healing, and pro-coagulant activities in addition to indirectly modulating tumor cell growth and controlling the inflammatory process. Although it is sensitive to hydrolysis by proteases, the addition of halogens increases the chemical stability of these molecules. Thus, these results suggest that jelleines, especially jelleine-I, are a potential target for the development of new, effective and safe therapeutic molecules for clinical use.

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ABSTRACT Purpose: This study aimed to evaluate the therapeutic effect of an ethanol extract of Ocimum basilicum L. (EEOb) aerial parts against Ehrlich's experimental tumor (EET) in mice. Methods: Swiss mice were divided into two groups (control and treated; n = 6). On day 21, all mice were inoculated subcutaneously with 2 × 106 (0.05 mL) EET cells in the left paw for solid tumor development. This study lasted 28 days. Treatment began 24 hours after inoculation with EET. Measurements of dorsoplantar thickness were used to assess tumor growth. The paw pad was collected for histopathological analysis and stained using the argyrophilic nucleolar organizing regions (AgNOR) technique and immunohistochemistry for proliferating cell nuclear antigen, Bcl-2 and Bax. Results: The treatment of animals with EEOb at 100 mg/kg intraperitoneally was able to reduce the growth (Control = 3.7 ± 0.1 mm vs. EEOb = 5.7 ± 0.2 mm) and the number of AgNORs of solid Ehrlich tumor. The antitumor effect of EEOb was associated with the induction of apoptosis of tumoral cell, as suggested by the reduction of the content of Bcl-2 induced by extract. Conclusions: The study demonstrated that daily administration of EEOb is able to reduce the growth of EET by induce apoptosis of tumoral cells.

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Infections caused by multidrug-resistant Acinetobacter baumannii (MDR-Ab) have become a public health emergency. Due to the small therapeutic arsenal available to treat these infections, health agencies have highlighted the importance of developing new antimicrobials against MDR-Ab. In this context, antimicrobial peptides (AMPs) stand out, and animal venoms are a rich source of these compounds. Here, we aimed to summarize the current knowledge on the use of animal venom-derived AMPs in the treatment of MDR-Ab infections in vivo. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The eight studies included in this review identified the antibacterial activity of eleven different AMPs against MDR-Ab. Most of the studied AMPs originated from arthropod venoms. In addition, all AMPs are positively charged and rich in lysine residues. In vivo assays showed that the use of these compounds reduces MDR-Ab-induced lethality and bacterial load in invasive (bacteremia and pneumonia) and superficial (wounds) infection models. Moreover, animal venom-derived AMPs have pleiotropic effects, such as pro-healing, anti-inflammatory, and antioxidant activities, that help treat infections. Animal venom-derived AMPs are a potential source of prototype molecules for the development of new therapeutic agents against MDR-Ab.

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The increase in the incidence of fungal infections associated with the limited therapeutic arsenal available and the increasing rate of resistance of pathogenic fungi reinforce the need for research of new antifungal agents. Thus, this study aims to evaluate the antifungal activity of the peptide LyeTx I mnΔK, a shortened analogue of the natural peptide LyeTx I derived from spider venom, against Candida species. LyeTx I mnΔK showed potent activity against Candida spp. with minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) between 4 and 32 µM. The peptide also completely inhibited the yeast-to-hypha transition (at 2 µM) and broke mature biofilms (67% reduction at 32 µM) of C. albicans. In addition, LyeTx I mnΔK did not induce resistance in C. albicans during 21 days of exposure. Therefore, the LyeTx I mnΔK is a promising prototype for the development of new antifungal agents.

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SUMMARY Introduction: Escherichia coli, a Gram-negative bacillus, is found in diverse environments and causes several human diseases, such as pneumonia and urinary tract infections. Aminoglycosides are antimicrobials that present high activity against Gram-negative species, including multidrug-resistant pathogens. However, the indiscriminate use of these compounds has selected resistant microorganisms, mainly due to the production of aminoglycoside-modifying enzymes (AME). Material and methods: The minimal inhibitory concentration of the aminoglycosides amikacin, gentamicin, and neomycin against clinical (CI, n = 52, only urinary) and domestic sewage (DS, n = 33) E. coli isolates was determined by the microdilution method, according to the European Committee on Antimicrobial Susceptibility Testing. The presence of AMEs among E. coli isolates was determined based on the susceptibility profile to amikacin, gentamicin, kanamycin, and tobramycin, according to Mancini et al. (2019). Results: Overall, 33.3% of the DS isolates and 100% of the CI isolates presented mechanisms of resistance to amikacin, gentamicin, or neomycin. The extended-spectrum beta-lactamase enzymes-producing isolates (23/27, 85%) showed mechanisms of resistance to gentamicin and/or neomycin and resistance to amikacin was simultaneously observed only in CI isolates. All DS isolates were considered wild-type-no AME, while APH (3') (14/52) and AAC (3') (10/52) enzymes were detected among CI isolates, one of which produces APH (3') and AAC (6')-I simultaneously. Conclusion: Resistance to aminoglycosides is present among E. coli isolates in Brazil, but to a lesser extent in environmental isolates. Besides, AMEs are frequent in CI isolates, and surveillance for antimicrobial resistance should be implemented to monitor aminoglycoside-resistant E. coli infections.

Introducción: Escherichia coli se encuentra en diversos ambientes y causa enfermedades humanas. Los aminoglucósidos son antimicrobianos que presentan actividad contra especies gramnegativas. Sin embargo, el uso indiscriminado de estos compuestos ha seleccionado microorganismos resistentes, principalmente debido a la producción de enzimas modificadoras de aminoglucósidos (AME). Material y métodos: La concentración mínima inhibitoria de aminoglucósidos frente a aislados de E.coli clínicos (CI, n = 52) y de aguas residuales sanitarias (DS, n = 33) se determinó mediante el método de microdilución, según la European Committee on Antimicrobial Susceptibility Testing. La presencia de AME se determinó con base en el perfil de susceptibilidad a amikacina, gentamicina, kanamicina y tobra-micina, según Mancini et al. (2019). Resultados: 33,3% de los aislados de DS y 100% de los CI presentaron resistencia a amikacina, gentamicina o neomicina. Los aislados productores de enzimas betalactamasas de espectro extendido (23/27, 85%) mostraron resistencia a gentamicina y/o neomicina y la resistencia a amikacina se observó simultáneamente solo en CI. Todos los aislados de DS se consideraron wild type sin AME, mientras que las enzimas APH (3') (14/52) y AAC (3') (10/52) se detectaron entre CI, uno de los cuales produce APH (3') y AAC (6')-I simultáneamente. Conclusión: La resistencia a los aminoglucósidos está presente entre los aislados de E. coli en Brasil, pero en menor grado en los aislados ambientales. Se debe implementar la vigilancia de la resistencia a los antimicrobianos para monitorear las infecciones por E. coli resistentes a los aminoglucósidos.

SUMÁRIO Introdução: Escherichia coli é encontrada em vários ambientes e causa doenças em humanos. Os aminoglicosídeos são antimicrobianos que exibem atividade contra espécies Gram-negativas. No entanto, o uso indiscriminado desses compostos tem selecionado microrganismos resistentes, principalmente devido à produção de enzimas modificadoras de aminoglicosídeos (EMA). Material e métodos: A concentração inibitória mínima de aminoglicosídeos contra isolados de E. coli recuperadas de amostras clínicas (IC, n=52) e de águas residuais sanitárias (AR, n=33) foi determinada pelo método de microdiluição, de acordo com o European Committee on Antimicrobial Susceptibility Testing. A presença de EMA foi determinada com base no perfil de suscetibilidade à amicacina, gentamicina, canamicina e tobramicina, de acordo com Mancini et al. (2019). Resultados: 33,3% dos ARS e 100% dos ICs apresentaram resistência à amicacina, gentamicina ou neomicina. Os isolados produtores de enzima beta-lactamase de espectro estendido (23/27, 85%) mostraram resistência à gentamicina e/ou neomicina e resistência à amicacina foi observada simultaneamente apenas em um IC. Todos os ARs foram considerados de tipo selvagem sem EMA, enquanto as enzimas APH (3') (14/52) e AAC (3') (10/52) foram detectadas entre os ICs, um dos quais produz APH (3') e AAC (6')-I simultaneamente. Conclusão: A resistência aos aminoglicosídeos está presente entre isolados clínicos de E. coli no Brasil, mas em menor grau em isolados ambientais. Assim a vigilância da resistência antimicrobiana deve ser implementada para monitorar infecções por E. coli resistentes aos aminoglicosídeos.

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Introdução: Acinetobacter baumanni é um cocobacilo Gram negativo responsável por elevadas taxas de infecções relacionadas à assistência à saúde (IRAS). Apresenta alto nível de resistência intrínseca a antimicrobianos, além da capacidade de adquirir resistência a carbapenêmicos e polimixinas. Ainda, A. baumannii possui habilidade para produzir biofilmes em superfícies abióticas e bióticas, o que favorece a infecção de pacientes gravemente enfermos internados em unidades de terapia intensiva (UTI). Deve ser ressaltado que bactérias envolvidas em biofilmes apresentam maior resistência aos antimicrobianos, atribuída a fatores bioqúmicos, moleculares e as condições dos hospedeiros, o que dificulta o tratamento dessas infecções. Objetivos: Avaliar a produção de biofilme por isolados de A. baumannii recuperados de pacientes internados em UTIs, bem como operfil de susceptibilidade a antimicrobianos (aminoglicosídeos, tigeciclina, carbapenêmicos e polimixinas) entre esses isolados. Métodos: Foi realizada uma revisão sistemática de acordo com os critérios Prisma nos bancos de dados Pubmed/Medline, Scopus, Lilacs, Scielo, e Web of Science. Resultados: Foram incluídos um total de 12 artigos que avaliaram 1006 isolados clínicos de A. baumannii, os quais todos foram resistentes aos carbapenê-micos. No entanto, a maioria dos isolados permaneceu sensível as polimixinas B e E(94,46%). A porcentagem dos isolados produtores de biofilme foi alta (96,3%), e neste estudo não fica clara a relação entre a habilidade de produzir biofilmes e a resistência aos antimicrobianos analisados. Conclusão: Mais estudos devem ser conduzidos para monitorar a resistência aos antimicrobianos em A. baumannii, sobretudo em produtores de biofilme, visto que o manejo terapêutico das infecções ocasionadas por essas linhagens torna-se mais complexo e desafiador.

SUMMARY Introduction: Acinetobacter baumanni is a Gram-negative coccobacillus responsible for high rates of healthcare-related infections (HAI). It has a high level of intrinsic resistance to antimicrobials, in addition to the ability to acquire resistance to carbapenems and polymyxins. Furthermore, A. baumannii has the ability to produce biofilms on abiotic and biotic surfaces, which favors the infection of critically ill patients admitted to intensive care units (ICU). It should be noted that bacteria involved in biofilms have greater resistance to antimicrobials, attributed to biochemical and molecular factors and the conditions of the hosts, which makes the treatment of these infections difficult. Objectives: To evaluate the biofilm production by A. baumannii isolates recovered from ICU patients, as well as the antimicrobial susceptibility profile (aminoglycosides, tigecycline, carbapenems and polymyxins) among these isolates. Methods: A systematic review was performed according to PRISMA criteria in the PUBMED/MEDLINE, Scopus, LILACS, SciELO, and Web of Science databases. Results: A total of 12 articles that evaluated 1006 clinical isolates of A. baumannii, all of which were resistant to carbapenems, were included. However, most isolates remained sensitive to polymyxins B and E (94.46%). The percentage of biofilm-producing isolates was high (96.3%), and in this study the relationship between the ability to produce biofilms and resistance to the analyzed antimicrobials is not clear. Conclusion: More studies should be conducted to monitor antimicrobial resistance in A. baumannii, especially in biofilm producers, as the therapeutic management of infections caused by these strains becomes more complex and challenging.

Introducción: Acinetobacter baumanni es un cocobacilo gramnegativo responsable de altas tasas de infecciones relacionadas con la salud. Tiene un alto nivel de resistencia intrínseca a los antimicrobianos, además de la capacidad de adquirir resistencia a los carbapenémicos y polimixinas. Además, A. baumannii tiene la capacidad de producir biopelículas en superficies abióticas y bióticas, lo que favorece la infección de pacientes críticos ingresados en unidades de cuidados intensivos (UCI). Cabe señalar que las bacterias involucradas en biofilms tienen mayor resistencia a los antimicrobianos, atribuida a factores bioquímicos y moleculares y a las condiciones de los hospedadores, lo que dificulta el tratamiento de estas infecciones. Objetivos: Evaluar la producción de biofilm por aislamientos de A. baumannii recuperados de pacientes de UCI, así como el perfil de susceptibilidad antimicrobiana (amino-glucósidos, tigeciclina, carbapenémicos y polimixinas) entre estos aislamientos. Métodos: Se realizó una revisión sistemática según los criterios Prisma en las bases de datos Pubmed / Medline, Scopus, Lilacs, SciELO y Web of Science. Resultados: Se incluyeron un total de 12 artículos que evaluaron 1006 aislamientos clínicos de A. baumannii, todos ellos resistentes a carbapenémicos. Sin embargo, la mayoría de los aislados permanecieron sensibles a las polimixinas B y E (94,46%). El porcentaje de aislamientos productores de biopelículas fue alto (96,3%), y en este estudio no está clara la relación entre la capacidad de producir biopelículas y la resistencia a los antimicrobianos analizados. Conclusión: Se deben realizar más estudios para monitorear la resistencia a los antimicrobianos en A. baumannii, especialmente en productores de biopelículas, ya que el manejo terapéutico de las infecciones causadas por estas cepas se vuelve más complejo y desafiante.

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SUMMARY Introduction: Infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) is a health problem due to the limited therapeutic options available. This study was carried out to evaluate the main mechanisms of resistance of carbapenems in CRAB in the last 10 years in Brazil and to describe the susceptibility profile to tigecycline and polymyxins in these isolates. Material and methods: A systematic review was carried out according to Prisma in PUBMED/MEDLINE, Scopus, SciELO, Biblioteca Virtual de Saúde (BVS) and Cochrane Library. Data regarding enzyme resistance to carbapenems were evaluated by meta-analysis according to the random effect. Results: 21 articles were selected according to inclusion and exclusion criteria that evaluated 1096 CRAB. Most of the studies were carried out in the southern (33.3 %) and southeast (23.8 %) regions of Brazil (33.3 %) and in 2016 and 2018. According to the meta-analyzes, OXA-type carbapenemase was the main mechanism involved in the low susceptibility to carbapenems in CRAB (98%; 95% CI: 0.91, 0.99; I2 = 95%), with bla OXA-23-like (91 %; 95 % CI: 0.76; 0.97; I2 = 97 %) or bla OXA-51-like / ISAba1 (84 %; 95 % CI: 0.15, 0.99; I2 = 98 %) genes, followed by metallo-ß-lactamases (MBL) (12 %, 95 % CI: 0.09, 0.15, I2 = 99 %) and Klebsiella pneumoniae carbapenemase (KPC) (6 %, 95 % CI: 0.04; 0.08; I2 = 87 %). Conclusion: The included studies showed that susceptibility to colistin (99 %) and tigecy-cline (93 %) remains high and was not affected by carbapenem resistance.

Introducción: Las infecciones por Acinetobacter baumannii resistente a carbapenémicos (CRAB) es un problema de salud debido a las limitadas opciones terapéuticas disponibles. Este estudio se realizó para evaluar los principales mecanismos de resistencia de los carbapenémicos en CRAB en los últimos 10 años en Brasil y describir el perfil de susceptibilidad a tigeciclina y polimixinas en estos aislados. Material y métodos: Se realizó una revisión sistemática de acuerdo con Prisma en PUBMED/MEDLINE, Scopus, SciELO, Biblioteca Virtual de Saúde (BVS) y Cochrane Library. Los datos referentes a resistencia enzimática a los carbapenémicos se evaluaron mediante metaanálisis según el efecto aleatorio. Resultados: Se seleccionaron 21 artículos según criterios de inclusión y exclusión que evaluaron 1.096 CRAB. La mayoría de los estudios se llevaron a cabo en las regiones sur (33,3%) y sureste (23,8 %) de Brasil (33,3 %) y en los años 2016 y 2018. Según los metaanálisis, la carbapenemasa tipo OXA fue el principal mecanismo implicado en la baja susceptibilidad a los carbapenémicos en CRAB (98 %; IC 95 %: 0,91; 0,99; I² = 95 %), con bla OXA-23-like (91 %; 95 % CI: 0,76; 0,97; I² = 97 %) o bla OXA-51-like / ISAba1 (84 %; 95 % CI: 0,15; 0,99 ; I² = 98 %) genes, seguida de metalo-ß-lactamasas (MBL ) (12 %; IC95 %: 0,09; 0,15; I² = 99 %) y Klebsiella pneumoniae carbapenemase (KPC) (6 %; IC95 %: 0,04; 0,08; I² = 87 %). Conclusión: Los estudios incluidos mostraron que la susceptibilidad a la colistina (99 %) y tigeciclina (93 %) sigue siendo alta y no se ve afectada por la resistencia a los carbapenémicos.

Introdução: As infecções causadas por Acinetobacter baumannii resistente aos carbapenémicos (CRAB) são um problema de saúde devido às limitadas opções terapêuticas disponíveis. Este estudo foi realizado para avaliar os principais mecanismos de resistência aos carbapenêmicos em CRAB nos últimos 10 anos no Brasil e descrever o perfil de susceptibilidade à tigeciclina e às polimixinas nesses isolados. Material e métodos: Foi conduzida uma revisão sistemática segundo o Prisma nas bases de dados PUBMED/MEDLINE, Scopus, SciELO, Biblioteca Virtual de Saúde (BVS) e Biblioteca Cochrane. Os dados relativos à resistência enzimática aos carbapenêmicos foram avaliados por meta-análises de acordo com o efeito aleatório. Resultados: Foram selecionados 21 artigos de acordo com os critérios de inclusão e exclusão que avaliaram 1.096 CRAB. A maioria dos estudos foi realizada nas regiões Sul (33,3 %) e Sudeste (23,8 %) do Brasil e nos anos de 2016 e 2018. De acordo com as metanálises, a carbapenemase do tipo OXA foi o principal mecanismo envolvido na baixa susceptibilidade aos carbapenêmicos em CRAB (98 %; 95% IC: 0.91, 0.99; I² = 95 %), com bla OXA-23-like (91 %; 95 %; IC: 0,76; 0,97; I² = 97 %) ou bla OXA -51-like / ISAba1 (84 %; 95 % IC: 0.15, 0.99; I² = 98 %) genes, seguidos por metalo-ß-lactamases (MBL) (12 %, 95 % IC: 0,09, 0,15, I² = 99 %) e Klebsiella pneumoniae carbapenemase (KPC) (6 %, IC 95 %: 0,04; 0,08; I² = 87 %). Conclusão: Os estudos incluídos mostraram que a susceptibilidade à colistina (99 %) e tigeciclina (93 %) permanece alta e não foi afetada pela resistência aos carbapenêmicos.