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Resumen Introducción. El manejo adecuado de la tuberculosis multirresistente es una estrategia priorizada para el control de la tuberculosis en el mundo. Objetivo. Evaluar las diferencias entre las características demográficas y clínicas, y los indicadores programáticos de los pacientes con diagnóstico confirmado de tuberculosis pulmonar resistente a rifampicina o multirresistente en Buenaventura, frente a la cohorte de los demás municipios del Valle del Cauca entre 2013 y 2016. Materiales y métodos. Se desarrolló un estudio analítico de cohortes para comparar los registros de pacientes mayores de 15 años con tuberculosis multirresistente, del Programa de Tuberculosis de Buenaventura (con ácido paraaminosalicílico), frente a los demás municipios del Valle del Cauca (sin ácido paraaminosalicílico). Resultados. Se registraron 99 casos con una mediana de edad de 40 años (RIC = 26 - 53); en Buenaventura, el 56 % eran mujeres; en los demás municipios, predominaron los hombres (67 %); el 95 % de los evaluados tenía aseguramiento en salud. La comorbilidad más frecuente fue diabetes (14 %). Las reacciones adversas a medicamentos antituberculosos en Buenaventura fueron 1,3 veces más frecuentes que en los demás municipios (OR = 2,3; IC95 %: 0,993 - 5,568; p = 0,04). En Buenaventura falleció el 5 % de los casos frente al 15 % reportado en los demás municipios. No hubo fracasos con el tratamiento en Buenaventura, pero se reportó un 35 % de pérdida del seguimiento. El éxito del tratamiento fue mayor en Buenaventura en el 56 %. Conclusión. El programa fortalecido de Buenaventura presentó mejores resultados programáticos que los demás municipios del Valle del Cauca. El acceso a pruebas moleculares, la disponibilidad de tratamientos acortados y el seguimiento continuo para identificar reacciones adversas a medicamentos antituberculosos son un derrotero para todos los programas de control.
Abstract Introduction. Proper management of multidrug-resistant tuberculosis is a prioritized strategy for tuberculosis control worldwide. Objective. To evaluate differences concerning demographic and clinical characteristics and programmatic indicators of Buenaventura patient cohort with confirmed diagnosis of multidrug-resistant tuberculosis, compared to those of the other municipalities from Valle del Cauca, Colombia, 2013-2016. Materials and methods. We conducted an analytical cohort study to compare records of patients older than 15 years with multidrug-resistant tuberculosis included in the Programa de Tuberculosis de Buenaventura (with para-aminosalicylic acid) versus the other municipalities of Valle del Cauca (without para-aminosalicylic). Results. Ninety-nine cases were recorded with a median age of 40 years (IQR = 26 - 53); in Buenaventura, 56% of the patients were women, while in the other municipalities, men predominated with 67%; 95% had health insurance. The most common comorbidity was diabetes (14%). Adverse reactions to antituberculosis medications in Buenaventura were 1.3 times more frequent than in the other municipalities (OR = 2.3; 95% CI = 0.993 - 5.568; p = 0.04). In Buenaventura, the mortality rate was 5% compared to the 15% reported in the other municipalities. Treatment failures were not reported in Buenaventura, but 35% did not continue with the follow-up. Treatment success was higher in Buenaventura (56 %). Conclusion. A strengthened program in Buenaventura presented better programmatic results than those from the other municipalities of Valle del Cauca. Access to molecular tests, availability of shortened treatments, and continuous monitoring to identify adverse reactions to antituberculosis medications are routes for all other control programs.
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Abstract Introduction: The presence of secondary infections in critically ill patients and antibiotic resistance are often determining factors in the clinical evolution of these patients. Objective: To describe the pathogens isolated in blood cultures and tracheal secretion cultures in ICU patients with COVID-19 and to evaluate the association between the presence of secondary infections and 60-day mortality. Methods: Retrospective analytical cohort study conducted in 273 adults admitted to the ICU with COVID-19 at the Subred Integrada de Servicios de Salud del Sur - Hospital El Tunal, Bogotá, Colombia between April and December 2020. Data from records of blood or tracheal secretion cultures were collected. A bivariate analysis was performed using a Cox proportional-hazards regression model to assess the association between the development of secondary infections and 60-day mortality. Results: At least one positive blood culture was reported in 96/511 patients (18.8%). Of the 214 blood cultures performed within 48 hours after ICU admission, 7.7% were positive. A total of 127 germs were isolated from blood cultures - mostly gram-negative bacteria (61.4%) - followed by fungi (25.2%). Additionally, 39.5% were multidrug-resistant, and carbapenem resistance was the most common antibiotic resistance pattern (33.3% of all gram-negative bacteria isolates). Finally, in this cohort, the presence of secondary infections was not associated with 60-day mortality (HR: 1.012, 95%CI: 0.7211.420; p= 0.946). Conclusions: Although the prevalence of superinfection was moderately high, the prevalence of coinfection was low. Gram-negative bacteria were predominant, and almost one third of the germs were multidrug-resistant.
Resumen Introducción: La presencia de infecciones secundarias en pacientes críticos y la resistencia a los antibióticos suelen ser factores determinantes en la evolución clínica de estos pacientes. Objetivo: Describir los patógenos aislados en cultivos de sangre y de secreciones traqueales en pacientes de la UCI con COVID-19 y evaluar la relación entre la presencia de infecciones secundarias y la mortalidad a 60 días. Métodos: Estudio de cohorte analítico retrospectivo realizado en 273 adultos ingresados a la UCI con COVID-19 de la Subred Integrada de Servicios de Salud del Sur - Hospital El Tunal, Bogotá, Colombia entre abril y diciembre de 2020. Se obtuvieron los datos de los registros de cultivos en sangre y en secreciones de la tráquea. Se llevó a cabo un análisis bivariado mediante un modelo de riesgos proporcionales o regresión de Cox para evaluar la relación entre el desarrollo de infecciones secundarias y la mortalidad a 60 días. Resultados: Se reportó al menos un cultivo en sangre positivo en 96/511 (18.8%). De los 214 cultivos de sangre realizados dentro de las 48 horas siguientes al ingreso a la UCI, 7,7% resultaron positivos. Se aislaron en total 127 gérmenes en los cultivos en sangre, en su mayoría bacterias gramnegativas (61,4%) - seguido de hongos (25,2%). Adicionalmente, 39.5% fueron multirresistentes, siendo la resistencia los carbapenémicos el patrón de resistencia a los antibióticos más frecuente (33,3% de todos los aislados de bacterias gramnegativas). Finalmente, la presencia de infecciones secundarias en esta cohorte no se asoció con mortalidad a 60 días (HR: 1,012, IC 95%: 0,721-1,420; p= 0,946). Conclusiones: A pesar de que la prevalencia de super infecciones fue moderadamente alta, la prevalencia de coinfección fue baja. Las bacterias gramnegativas fueron las predominantes y casi un tercio de los gérmenes eran multirresistentes.
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Slaughterhouses produce huge volumes of effluents throughout the production chain that, when discharged untreated into bodies of water, can become a source of environmental contamination. This is particularly worrisome if these effluents are used for irrigation since they increase contamination levels and spread pathogens and resistance determinants to humans and animals. Therefore, in this study, we assessed antimicrobial resistance in bacteria isolated from inlet water, equalization wastewater tanks, treatment plant wastewater, and treated wastewater in slaughterhouse facilities in Rio de Janeiro, Brazil. Four samples were collected at each of the collection points, between June 2021 and July 2022. Following bacterial isolation and identification, the samples were analyzed for antimicrobial resistance using the disk diffusion method to test aminoglycoside, beta-lactam, and fluoroquinolone antimicrobials. A total of 229 bacteria were isolated, with 74 isolates selected from the genera Citrobacter (12), Enterobacter (14), Klebsiella (35), Serratia (5), and Pseudomonas (8). Inlet water had the lowest number of isolates and was the only point with gentamicin-resistant isolates. Raw effluent from the equalization tank showed the highest number of isolated bacteria and resistance levels, followed by treated wastewater and the treatment plant. Across all samples, a high rate of cefoxitin-resistance was observed among the isolated bacteria. Klebsiella pneumoniae stood out as the species that demonstrated the greatest resistance to a variety of antimicrobials. These results highlight the importance of water quality monitoring in mitigating public health and environmental risks and high antimicrobial resistance levels.
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Solid organ transplant (SOT) recipients are particularly susceptible to infections caused by multidrug-resistant organisms (MDRO) and are often the first to be affected by an emerging resistant pathogen. Unfortunately, their prevalence and impact on morbidity and mortality according to the type of graft is not systematically reported from high-as well as from low and middle-income countries (HIC and LMIC). Thus, epidemiology on MDRO in SOT recipients could be subjected to reporting bias. In addition, screening practices and diagnostic resources may vary between countries, as well as the availability of new drugs. In this review, we aimed to depict the burden of main Gram-negative MDRO in SOT patients across HIC and LMIC and to provide an overview of current diagnostic and therapeutic resources.
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Farmacorresistência Bacteriana Múltipla , Transplante de Órgãos , Humanos , Transplante de Órgãos/efeitos adversos , Transplantados , Antibacterianos/uso terapêutico , Prevalência , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Países em DesenvolvimentoRESUMO
Cronobacter spp. are bacterial pathogens isolated from a wide variety of foods. This study aims at evaluating the occurrence of Cronobacter spp. in low water activity functional food samples, detect the presence of virulence genes, and determine the antibiotic susceptibility of strains. From 105 samples, 38 (36.2%) were contaminated with Cronobacter spp. The species identified by polymerase chain reaction (PCR) and sequencing analyses (rpoB and fusA genes, respectively) were C. sakazakii (60.3%), C. dublinensis (25.4%), C. turincensis (9.5%), and C. malonaticus (4.8%). Nineteen fusA alleles were identified, including four new alleles. The virulence genes were identified by PCR and all isolates were positive for ompX and sodA genes, 60.3% to cpa gene, and 58.7% to hly gene. Using the disk diffusion method, antibiotic susceptibility to twelve antibiotics was assessed twice, separated by a 19-month period. In the first test, the isolates showed diverse antibiotic susceptibility profiles, with nineteen isolates (30.2%) being multi-drug resistant (resistant to three or more antibiotic classes), in the second, the isolates were susceptible to all antibiotics. Cronobacter spp. in functional foods demonstrates the need for continued investigation of this pathogen in foods, and further research is needed to clarify the loss of resistance of Cronobacter strains.
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Antibacterianos , Cronobacter , Alimento Funcional , Testes de Sensibilidade Microbiana , Cronobacter/genética , Cronobacter/efeitos dos fármacos , Cronobacter/isolamento & purificação , Cronobacter/classificação , Brasil , Antibacterianos/farmacologia , Microbiologia de Alimentos , Fatores de Virulência/genética , Proteínas de Bactérias/genética , Contaminação de Alimentos/análise , Água , Farmacorresistência Bacteriana/genéticaRESUMO
The rise of antibiotic-resistant bacterial strains represents an important challenge for global health, underscoring the critical need for innovative strategies to confront this threat. Natural products and their derivatives have emerged as a promising reservoir for drug discovery. The social amoeba Dictyostelium discoideum is a potent model organism in this effort. Employing this invertebrate model, we introduce a novel perspective to investigate natural plant extracts in search of molecules with potential antivirulence activity. Our work established an easy-scalable developmental assay targeting a virulent strain of Klebsiella pneumoniae, with Helenium aromaticum as the representative plant. The main objective was to identify tentative compounds from the Helenium aromaticum extract that attenuate the virulence of K. pneumoniae virulence without inducing cytotoxic effects on amoeba cells. Notably, the methanolic root extract of H. aromaticum fulfilled these prerequisites compared to the dichloromethane extract. Using UHPLC Q/Orbitrap/ESI/MS/MS, 63 compounds were tentatively identified in both extracts, 47 in the methanolic and 29 in the dichloromethane, with 13 compounds in common. This research underscores the potential of employing D. discoideum-assisted pharmacognosy to discover new antivirulence agents against multidrug-resistant pathogens.
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Enterococci spp. are Gram-positive bacteria that cause mild to severe infections, many associated with the oral cavity, such as periapical infections and healthcare-associated infections (HAIs). Many of these infections become serious diseases that are difficult to resolve, specifically when multidrug-resistant (MDR) strains cause them. In recent years, the number of MDR strains of Enterococcus spp. has increased significantly. This increased prevalence of MDR strains produces significant pressure to generate more antimicrobial therapies, but there is a decline in the production of new antibiotics, driving the development of complementary therapies, such as photodynamic therapy (PDT). PDT combines a photosensitizer agent (PS), light, and oxygen to cause photooxidative stress in bacterial cells. PDT can eradicate Enterococcus spp. contaminations, improve the classic cleaning processes, and eradicate the bacteria in dental pieces. PDT's effectiveness can be improved with nanoparticles that function as carriers. Our work aims to describe the advances in PDT against Enterococcus spp. as a complement to antibiotic therapy, focusing on infections by Enterococcus faecium and Enterococcus faecalis, dental hygiene, and using nanoparticles to improve the antimicrobial effect. A systematic bibliographic search without a meta-analysis was conducted on various databases, using inclusion and exclusion criteria to identify the most relevant research. Of the 193 non-redundant articles found, 65 were selected for a systematic review, from which a summary table was created and a manual description was made. Photodynamic therapy for treating E. faecium and E. faecalis is a widely studied area, with promising results concerning bactericidal effectiveness and reductions in biofilm formation, particularly in regard to dental hygiene. Because most of the studies were conducted in vitro or ex vivo, the results indicated that there were not sufficient data to initiate clinical trials for safety and efficacy studies on humans.
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BACKGROUND: There was a reported increase in the antimicrobial consumption in hospitals during the COVID-19 pandemic, accompanied by an increase in infections due to multidrug-resistant (MDR) bacteria. METHODS: This retrospective time series study from intensive care units in Buenos Aires examined changes in antibiotic consumption (defined daily doses/1000 patients/day), the incidence of Gram-negative bacilli (GNB) and the mechanism of resistance. Antibiotics were categorised into group 1 (agents against MDR GNB) and group 2 (agents against non-MDR infections). Bacteriological samples included respiratory samples and blood cultures. Periods were divided into pre-pandemic (July 2019 to March 2020) and pandemic (April 2020 to March 2022). Correlation coefficients (r) were analysed and the Mann-Whitney test was performed to compare both periods. RESULTS: During the study period, GNB incidence, group 1 antibiotic consumption and resistance mechanisms increased, whereas antibiotics decreased in group 2. A significant positive correlation was seen between the consumption of antibiotics in group 1 and the incidence of GNB (r = 0.63; P < 0.001) and resistance (r = 0.52; P = 0.002). Significant differences were found between pre-pandemic and pandemic periods regarding the medians of group 1 consumption (520 [408-570] vs. 753 [495-851] DDD/1000 patients/day; P = 0.029), incidence of GNB (12 [10-13] vs. 43 [25-52.5] cases/month; P < 0.001) and resistance mechanisms (5 [4-8] vs. 17 [10-25] cases/month; P < 0.001), extended-spectrum beta lactamases (2 [1-2] vs. 6 [3-8] cases/month; P < 0.001) and metallo-beta-lactamases (0 [0-0] vs. 6 [1.75-8.5] cases/month; P < 0.001). CONCLUSION: During the COVID-19 pandemic, the rise in GNB incidence and the amount of resistance mechanisms significantly correlated with the increase in consumption of agents against MDR strains.
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Antibacterianos , COVID-19 , Bactérias Gram-Negativas , Unidades de Terapia Intensiva , Humanos , COVID-19/epidemiologia , Estudos Retrospectivos , Antibacterianos/uso terapêutico , Incidência , Argentina/epidemiologia , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , SARS-CoV-2/efeitos dos fármacos , Farmacorresistência Bacteriana MúltiplaRESUMO
Introducción: La implementación de un método diagnóstico adecuado y eficiente es crucial para la detección temprana de la tuberculosis. Esto no solo permite un control efectivo de la enfermedad para evitar su transmisión y progresión hacia estadios más graves, además previene el desarrollo de resistencia a los fármacos en los pacientes.Objetivo: Evaluar la utilidad de la prueba molecular GeneXpert MTB/RIF en el diag-nóstico de Mycobacterium tuberculosis complex, en comparación con la bacilos-copia, utilizando el cultivo como referencia.Material y Métodos: Se realizó un estudio descriptivo, observacional y no expe-rimental de corte transversal, se incluyeron 253 muestras de pacientes de ambos sexos y de variados rangos de edad, que fueron evaluadas mediante baciloscopia, GeneXpert MTB/RIF y cultivo. El estudio se centró en muestras procesadas en un Hospital público de la ciudad de Quito durante el período de enero de 2021 a mayo de 2022Resultados: La prueba molecular GeneXpert MTB/RIF mostró una sensibilidad del 94,7% y una especificidad del 93,9% para el diagnóstico de Mycobacterium tu-berculosis complex. Además, se identificó un caso de resistencia a la rifampicina.Conclusión: Este estudio confirma la eficacia de la prueba molecular GeneXpert MTB/RIF sobre la baciloscopia para el diagnóstico oportuno de Mycobacterium tu-berculosis complex. Sin embargo, es esencial considerar las diversas condiciones de las muestras y pacientes para optimizar la precisión diagnóstica
Introduction: Implementing an appropriate and efficient diagnostic method is cru-cial for the early detection of tuberculosis. This not only allows for effective control of the disease to prevent its transmission and progression to more severe stages but also prevents the development of drug resistance in patients.Objective: To evaluate the utility of the GeneXpert MTB/RIF molecular test in diag-nosing Mycobacterium tuberculosis complex, compared to sputum smear micros-copy, using culture as the reference. Material and Methods: A descriptive, observational, and non-experimental cross-sectional study was conducted, including 253 samples from patients of both sexes and various age ranges, which were assessed using sputum smear micros-copy, GeneXpert MTB/RIF, and culture. The study focused on samples processed at a Quito Ìs Public Hospital during the period from January 2021 to May 2022.Results: The GeneXpert MTB/RIF molecular test showed a sensitivity of 94.7% and a specificity of 93.9% for the diagnosis of Mycobacterium tuberculosis com-plex. Additionally, a case of resistance to rifampicin was identified.Conclusion: This study confirms the effectiveness of the GeneXpert MTB/RIF mo-lecular test over sputum smear microscopy for the timely diagnosis of tuberculosis. However, it is essential to consider the diverse conditions of the samples and pa-tients to optimize diagnostic accuracy
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Humanos , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Tuberculose/diagnóstico , Técnicas de Diagnóstico Molecular , DiagnósticoRESUMO
Klebsiella pneumoniae strains are globally associated with a plethora of opportunistic and severe human infections and are known to spread genes conferring antimicrobial resistance. Some strains harbor virulence determinants that enable them to cause serious disease in any patient, both in the hospital and in the community. The aim of this study was to determine the frequency of antimicrobial resistance and virulence traits (by gene detection and string test) among 83 K. pneumoniae isolates obtained from patient cultures of a scholar tertiary hospital in the Midwestern Brazil (Brasília, DF). Antimicrobial susceptibility analysis showed that 94% (78/83) of the isolates presented one of the following resistance profiles: resistant (R, 39), multidrug-resistant (MDR, 29), or extensively drug-resistant (XDR, 10). Several MDR and XDR strains harbored multiple virulence genes and displayed hypermucoviscous phenotype. These characteristics were observed among isolates obtained throughout all the sample collection period (2013 - 2017). The K2 serotype gene, a molecular marker of hypervirulence, was detected in three isolates, one of which classified as XDR. Sequence typing revealed the occurrence of isolates belonged to high-risk (ST13) and multiple resistance-spreading clones (ST105). Thus, our findings showed the occurrence of virulent potential isolates that also presented MDR/XDR phenotypes from 2013 to 2015. This study also indicates the probable convergence of virulence and resistance since at least 2013 in Brazil.
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Antibacterianos , Farmacorresistência Bacteriana Múltipla , Infecções por Klebsiella , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária , Fatores de Virulência , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/patogenicidade , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/classificação , Brasil , Centros de Atenção Terciária/estatística & dados numéricos , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Antibacterianos/farmacologia , Virulência/genética , Fatores de Virulência/genéticaRESUMO
Introduction: Nosocomial infectious ventriculitis caused by multidrug-resistant (MDR) Gram-negative bacilli associated with external ventricular drainage (EVD) placement poses a significant mortality burden and hospital costs. Objectives: This study aims to analyze the characteristics, ventriculitis evolution, treatment, and outcomes of patients with ventriculitis due to MDR Gram-negative bacilli associated with EVD placement. Methods: A retrospective cohort study focusing on patients with nosocomial infection caused by MDR Gram-negative bacilli while on EVD was conducted from 2019 to 2022. Medical, laboratory, and microbiological records were collected. The antibiotic resistance of the Gram-negative bacilli isolated in the cerebrospinal fluid (CSF) of patients was analyzed. The risk factors were identified using univariate risk models and were analyzed using survival curves (Cox regression). An adjusted Cox proportional hazards model was also constructed. Results: Among 530 patients with suspected EVD-associated ventriculitis, 64 patients with isolation of Gram-negative bacilli in CSF were included. The estimated mortality was 78.12%. Hemorrhages (intracranial, subarachnoid, and intraventricular) were observed in 69.8% of patients. Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequently isolated bacilli. In the univariate analysis, significant risk factors for mortality included arterial hypertension, a Glasgow Coma Scale (GCS) score of ≤ 8, invasive mechanical ventilation (IMV) upon hospital admission and during hospitalization, septic shock, and ineffective treatment. The adjusted Cox proportional hazards model revealed that septic shock (HR = 3.3, 95% CI = 1.5-7.2; p = 0.003) and ineffective treatment (HR = 3.2, 1.6-6.5, 0.001) were significant predictors. A high resistance to carbapenems was found for A. baumannii (91.3%) and P. aeruginosa (80.0%). Low resistance to colistin was found for A. baumannii (4.8%) and P. aeruginosa (12.5%). Conclusion: Ineffective treatment was an independent hazard factor for death in patients with ventriculitis caused by MDR Gram-negative bacilli associated with EVD.
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Salmonella spp. and Escherichia coli are implicated in human and animal infections and require antimicrobial treatment in many situations. Faecal samples of healthy white-lipped peccaries (Pecari tajacu) (n = 30) and collared peccaries (Tayassu pecari ) (n = 60) obtained in three farms located in the Midwest Brazil. The antimicrobial profiles of commensal E. coli from P. tajacu and T. pecari from commercial herds in Brazil were isolated and analyzed and virulence genes were detected. Among 90 healthy animals, no Salmonella spp. were isolated. However, 30 samples (27%) tested positive for E. coli, with 18 isolates from P. tajacu and 12 from T. pecari, representing frequencies of 58.0% and 38.7%, respectively. Additionally, other Enterobacteriaceae family bacteria were detected but not included in this analysis. However, individual samples from 30 animals tested positive for E. coli, of which 16 were isolated from P. tajacu presenting multidrug resistance and six were isolated from T. pecari presenting a similar pattern. The E. coli virulence genes detected were papC (pilus-associated pyelonephritis) in five isolates, tsh (temperature-sensitive hemagglutinin) in one isolate, and eae (enteric attachment and effacement) in one isolate. The serum resistance gene, iss (increased serum survival), was detected in four isolates. An association between these genes and the presence of hemolysin was also observed in one isolate. Thus, T. pecari and P. tajacu are potential reservoirs of pathogenic and multidrug-resistant and E. coli. Faecal E. coli of healthy P. tajacu and T. pecari could act as a possible reservoir of antimicrobial resistance genes in environment.
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Antibacterianos , Artiodáctilos , Escherichia coli , Fezes , Salmonella , Fatores de Virulência , Animais , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Escherichia coli/classificação , Salmonella/genética , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Salmonella/patogenicidade , Salmonella/classificação , Brasil , Fatores de Virulência/genética , Antibacterianos/farmacologia , Fezes/microbiologia , Artiodáctilos/microbiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/epidemiologia , Salmonelose Animal/microbiologia , Virulência/genética , Prevalência , Farmacorresistência Bacteriana/genética , Testes de Sensibilidade MicrobianaRESUMO
Multidrug resistance in bacteria is a major challenge worldwide, increasing both mortality by infections and costs for the health systems. Therefore, it is of utmost importance to find new drugs against resistant bacteria. Beauvericin (BEA) is a mycotoxin produced by entomopathogenic and other fungi of the genus Fusarium. Our work determines the effect of BEA combined with antibiotics, which has not been previously explored. The combination analysis included different antibiotics against non-methicillin-resistant Staphylococcus aureus (NT-MRSA), methicillin-resistant Staphylococcus aureus (MRSA), and Salmonella typhimurium. BEA showed a synergy effect with oxacillin with a fractional inhibitory concentration index (FICI) = 0.373 and an additive effect in combination with lincomycin (FICI = 0.507) against MRSA. In contrast, it was an antagonist when combined with ciprofloxacin against S. typhimurium. We propose BEA as a molecule with the potential for the development of new therapies in combination with current antibiotics against multidrug-resistant bacteria.
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Antibacterianos , Depsipeptídeos , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Salmonella typhimurium , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Depsipeptídeos/farmacologia , Sinergismo Farmacológico , Farmacorresistência Bacteriana MúltiplaRESUMO
Pseudomonas aeruginosa (PA) is an important opportunistic pathogen that causes different infections on immunocompromised patients. Within PA accessory genome, differences in virulence, antibiotic resistance and biofilm formation have been described between strains, leading to the emergence of multidrug-resistant strains. The genome sequences of 17 strains isolated from patients with healthcare-associated infections in a Mexican hospital were genomically and phylogenetically analyzed and antibiotic resistance genes, virulence genes, and biofilm formation genes were detected. Fifteen of the 17 strains were resistant to at least two of the carbapenems meropenem, imipenem, and the monobactam aztreonam. The antibiotic resistance (mexA, mexB, and oprM) and the biofilm formation (pslA and pslD) genes were detected in all strains. Differences were found between strains in accessory genome size. The strains had different sequence types, and seven strains had sequence types associated with global high risk epidemic PA clones. All strains were represented in two groups among PA global strains. In the 17 strains, horizontally acquired resistance genes to aminoglycosides and beta-lactams were found, mainly, and between 230 and 240 genes that encode virulence factors. The strains under study were variable in terms of their accessory genome, antibiotic resistance, and virulence genes. With these characteristics, we provide information about the genomic diversity of clinically relevant PA strains.
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Carbapenêmicos , Infecções por Pseudomonas , Humanos , Aztreonam , Pseudomonas aeruginosa/genética , Antibacterianos , Hospitais , Genômica , Atenção à Saúde , Testes de Sensibilidade MicrobianaRESUMO
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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Samples from a dairy cattle waste-fed anaerobic digester were collected across seasons to assess sanitary safety for biofertilizer use. Isolated enterobacteria (suggestive of Escherichia coli) were tested for susceptibility to biocides, antimicrobials, and biofilm-forming capability. Results revealed a decrease in total bacteria, coliforms, and enterobacteria in biofertilizer compared to the effluent. Among 488 isolates, 98.12 % exhibited high biofilm formation. Biofertilizer isolates exhibited a similar biofilm formation capability as effluent isolates in summer, but greater propensity in winter. Resistance to biocides and antimicrobials varied, with tetracycline resistance reaching 19 %. Of the isolates, 25 were multidrug-resistant (MDR), with 64 % resistant to three drugs. Positive correlations were observed between MDR and increased biofilm formation capacity in both samples, while there was negative correlation between MDR and increased biocide resistance. A higher number of MDR bacteria were found in biofertilizer compared to the effluent, revealing the persistence of E. coli resistance, posing challenges to food safety and public health.
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Anti-Infecciosos , Desinfetantes , Saúde Única , Animais , Bovinos , Escherichia coli , Enterobacteriaceae , Virulência , Anaerobiose , Águas Residuárias , Antibacterianos , Desinfetantes/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Objective: The antimicrobial activities of the synergistic combination of carvacrol and polymyxin B against polymyxin-resistant Klebsiella pneumoniae were evaluated. Methods: The methods employed checkerboard assays to investigate synergism, biofilm inhibition assessment and membrane integrity assay. In addition, the study included in vivo evaluation using a mouse infection model. Results: The checkerboard method evaluated 48 combinations, with 23 indicating synergistic action. Among these, carvacrol 10 mg/kg plus polymyxin B 2 mg/kg exhibited in vivo antimicrobial activity in a mouse model of infection, resulting in increased survival and a significant decrease in bacterial load in the blood. Conclusion: Polymyxin in synergy with carvacrol represents a promising alternative to be explored in the development of new antimicrobials.
In this study, we wanted to find a new way to fight a bacteria called Klebsiella pneumoniae, which is not easily killed by medication. We mixed two drugs, carvacrol and polymyxin B, to see if they would work together to fight the bacteria. We found that the mixed treatment helped to kill the bacteria. We also tried this mixed treatment in sick mice, and they got better. Our study shows that this mixed treatment might be a new way to fight bacteria that are hard to kill with regular drugs. Next, we hope to learn more about how it works.
Assuntos
Anti-Infecciosos , Cimenos , Polimixina B , Polimixina B/farmacologia , Antibacterianos/farmacologia , Klebsiella pneumoniae , Polimixinas , Sinergismo Farmacológico , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: During the COVID-19 pandemic, health service practices underwent significant changes, impacting the occurrence of health care-associated infections (HAIs). This study presents the epidemiology of bacterial infections and compares clinical data on nosocomial infections in hospitalized patients before and during the pandemic. METHODS: A unicentric, observational, retrospective cohort study was conducted with descriptive analyses on the microorganism identification and resistance profile. Patient's clinical data who had hospital-acquired infection (HAI), during their hospitalization in a tertiary hospital before and during the COVID-19 pandemic was compared by descriptive and inferential analyses. RESULTS: A total of 1,581 bacteria were isolated from 1,183 hospitalized patients. Among patients coinfected with COVID-19, there was a statistically significant increase in HAI-related deaths (P < .001) and HAI caused by multidrug-resistant organisms (P < .001), mainly by Acinetobacter baumannii and Staphylococcus aureus. A higher odds ratio of HAI-related deaths compared to the prepandemic period was observed (odds ratio 6.98 [95% confidence interval 3.97-12.64]). CONCLUSIONS: The higher incidence of multidrug-resistant bacteria and increased deaths due to HAI, especially in patients with COVID-19 coinfection, might be related to various factors such as increased workload, broad-spectrum antibiotic use, and limited resources. The pandemic has changed the profile of circulating bacteria and antimicrobial resistance. Prevention strategies should be considered to reduce the impact of these infections.
Assuntos
COVID-19 , Infecção Hospitalar , Centros de Atenção Terciária , Humanos , COVID-19/epidemiologia , Centros de Atenção Terciária/estatística & dados numéricos , Masculino , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Estudos Retrospectivos , Feminino , Pessoa de Meia-Idade , Idoso , SARS-CoV-2 , Adulto , Idoso de 80 Anos ou mais , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/efeitos dos fármacos , Pandemias , Estudos de Coortes , Farmacorresistência Bacteriana Múltipla , Hospitalização/estatística & dados numéricosRESUMO
BACKGROUND: Bacterial infections are increasingly difficult to combat, which makes them a threat to public health on a global level. Staphylococcus aureus is considered one of the main causes of infections in hospitals, as it has a variety of virulence factors, as well as is able to produce bacterial biofilms, which, consequently, bring numerous damages to public health as a result of increased resistance to conventional antibiotics and a longer hospital stay. Therefore, the use of compounds extracted from medicinal plants is a potential pharmaceutically acceptable target, as they do not have toxicity and the potential to disrupt biofilms produced by Staphylococcus aureus already evidenced, thus revealing their relevance to our study. OBJECTIVE: The objective of this work was to perform a critical analysis of a patent with natural extracts against bacterial biofilms found in the United States Patent and Trademark Office (USPTO) database, to map the possible bioactive compounds that may serve as potential future antimicrobial drugs. METHODS: A technological survey was carried out to verify existing patents using natural extracts with anti-biofilm potential. For this, it was searched with the keywords: Botanical extracts AND biofilms; which were performed in the United States Patent and Trademark Office (USPTO) database. Thus, the selected patent used a non-aqueous extract partitioned and vacuum-contracted, subsequently lyophilized for assays with antimicrobial potential. Because of this, a patent was analyzed regarding its chemistry, and biological activity, followed by a critical analysis of the technology proposed in the invention. RESULTS: When using the keywords Botanical extracts AND biofilms in the USPTO, it was possible to find twenty-two inventions; however, only four patents in the USPTO were in agreement with the proposal of the natural extract having antimicrobial activity and an anti-biofilm potential, of which two belonged to the same applicant with similar proposals. The key point of this invention was to enable the compounds of the Castanea sativa plant and its methods of obtaining the extract to present a significant antimicrobial action associated or not with antibiotics, promoting the development of new therapies against bacterial infections capable of disrupting biofilms. The invention developed a methodology for extracting Castanea sativa, in which pentacyclic triterpene compounds were found mostly in its leaves. Whereas for the extraction, the crude methanol extracts called extracts 224 from the ground leaves were made by maceration, filtered, combined, concentrated under pressure in rotary evaporators, and lyophilized. After that, they were resuspended in water and partitioned in succession with hexane, ethyl acetate, and butanol. The most active refined partition was the 224C extract with the solvent ethyl acetate, which was subjected to further fractionation using silica column chromatography. Resulting in the most refined extract, which was 224C-F2, capable of acting directly on the quorum sensing of bacteria, mainly Staphylococcus aureus, blocking the translation of RNAIII, including a series of exotoxins. Regarding the antimicrobial capacity against Staphylococcus aureus, it presented Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of 1.56 µg/mL-1 and > 100 µg/mL -1, respectively. CONCLUSION: Given the analyzed patent, it was possible to verify the importance of alternatives to reduce the impact of bacterial biofilms, which causes damage to industries in general and to health. From this, the invention analyzed has a promising proposal with antimicrobial potential focusing on the great impact of bacterial biofilms. Therefore, natural extracts with antibiofilmic potential can help to minimize the economic losses caused to health due to these multidrug-resistant microorganisms with different virulence mechanisms.
Assuntos
Acetatos , Anti-Infecciosos , Infecções Bacterianas , Humanos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Patentes como Assunto , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Bactérias , Testes de Sensibilidade Microbiana , BiofilmesRESUMO
Bloodstream infections (BSI) pose a substantial threat to the well-being and survival of patients undergoing hematopoietic stem cell transplantation (HSCT). Risk factors for these infections vary across the different post-HSCT phases. In the pre-engraftment period, patients are particularly susceptible to infection due to prolonged neutropenia, mucosal damage, and extensive use of central venous line (CVL). In the post-engraftment phase, the emergence of graft versus host diseases further compounds the risk. The epidemiology of these infections has undergone notable changes over the years due to multifactorial reasons, including the evolution of protocols that intensify immunosuppression. In this context, the emergence of multi-drug resistance (MDR) microorganisms can be a challenge due to the elevated risk of mortality in these vulnerable patients. Unfortunately, there is a lack of comprehensive data on this topic, particularly in pediatrics. This article aims to provide a summary of the epidemiology of BSI in the different post-transplant phases and the impact of MDR pathogens. Having knowledge about the local epidemiology of BSI can be instrumental in tailoring targeted therapies, leading to improved survival rates in HSCT recipients.