Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil / Características microbiológicas de infecções da corrente sanguínea em hospital de referência no nordeste do Brasil

Abstract Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Resumo A cultura sanguínea de rotina é usada para a detecção de infecções na corrente sanguínea por bactérias aeróbias e anaeróbias e por leveduras patogênicas comuns. Estudo retrospectivo realizado em hospital público de Maceió-AL, por meio da coleta de dados de todos os prontuários com culturas sanguíneas positivas. Das 2.107 culturas sanguíneas realizadas, 17% foram positivas com Staphylococcus coagulase negativo (51,14%), seguido por Staphylococcus aureus (11,21%) e Klebsiella pneumoniae (6,32%). As bactérias Gram-positiva predominaram entre as culturas de sangue positivas, destacando-se o grupo das Staphylococcus coagulase-negativo. Enquanto as bactérias Gram-negativas apresentaram um número maior de espécies entre as culturas de sangue positivas.

Pandemia de COVID-19 y evolución de la resistencia a antimicrobianos en bacilos Gram negativos / COVID-19 pandemic and evolution of antimicrobial resistance in Gram negative bacilli

Introducción: La emergencia y diseminación de la re-sistencia a antimicrobianos está vinculada en parte al abuso y/o mal uso de los mismos. La propagación del SARS-CoV-2 implicó un mayor consumo de antibióticos. El objetivo de este trabajo fue analizar los mecanismos de resistencia a betalactámicos (MRB) en bacilos Gram negativos (BGN) y la resistencia a amikacina (R AKN) en Acinetobacter baumannii.Métodos: Se realizó un estudio retrospectivo descriptivo de 2863 muestras con aislamientos de BGN remitidas al sector de Bacteriología del hospital de mayo 2019 a abril 2022. Se definieron tres períodos: mayo 2019-abril 2020 (P0), mayo 2020-abril 2021 (P1) y mayo 2021-abril 2022 (P2).Resultados: En P0 se halló un 15% de MRB. En P1, un 17,7% y en P2, un 21%. La combinación de BLEE+MBL se encontró en un aislamiento de P0, en dos de P1 y en 13 de P2. KPC+MBL se halló en nueve aislamientos de P2. La R AKN en A. baumannii fue de 20,8% en P0, 29,8% en P1 y 42,7% en P2.Conclusiones: Hubo un aumento significativo de aisla-mientos de BGN con MRB. BLEE fue el MRB más frecuente y Klebsiella sp. el microorganismo con MRB aislado con mayor frecuencia. En P2 se observó un aumento de aisla-mientos con combinación de MRB. Se observó diferencia significativa en la R AKN en A. baumannii entre P0 y P2. Con la pandemia de COVID-19 aumentó la cantidad de BGN con MRB y la R AKN en A. baumannii

Introduction: emergency and disemination of antimicrobial resistance is partly linked to abusive or wrong usage of them. The spread of SARS-CoV-2 implied a rise in antibiotics consumption. The aim of this study was to analize the mechanisms of resistance to beta lactams (MRB) in Gram negative bacilli (BGN) and amikacin resistance (R AKN) in Acinetobacter baumannii.Methods: a retrospective, descriptive study was made on 2863 samples with BGN isolates which were remitted to the bacteriology laboratory from May 2019 to April 2022. 3 periods were defined: May 2019 - April 2020 (P0). May 2020 - April 2021 (P1) and May 2021 - April 2022 (P2).Results: in P0, 15% had MRB. In P1, 17,7% and in P2, 21%. Combination of BLEE+MBL was found in 1 isolate of P0, in 2 of P1 and in 13 of P2. KPC+MBL was found in 9 isolates of P2. R AKN in A. baumannii was 20.8% in P0, 29.8% in P1 and 42.7% in P2.Conclusion: there was a significant increase in BGN isolates with MRB. BLEE was the most frequent MRB and Klebsiella sp. the most frequently isolated microorganism with MRB. A significant difference was observed in R AKN in A. baumanii between P0 and P2. After COVID-19 pandemic, there was an increase in the number of BGN with MRB and in R AKN in A. baumannii

Evaluación de la formación de biopelículas en aislamientos bacterianos y fúngicos por el método semicuantitativo de microtitulación con cristal violeta y el cualitativo de agar con rojo Congo / Assessment of biofilms formation of bacterial and fungal isolates using qualitative Congo red agar and semiquantitative crystal violet microtiter methods

Introducción. El 65 % de las infecciones humanas son producidas por bacterias o levaduras, cuya capacidad de formar biopelículas las hace más resistentes a los antimicrobianos y antifúngicos. Objetivo. Determinar la capacidad de formación de biopelículas en aislamientos bacterianos y fúngicos por medio de los métodos cuantitativo de microtitulación con cristal violeta y cualitativo de cultivo en agar con rojo Congo. Materiales y métodos. Con el método cuantitativo, se utilizaron los medios de cultivo infusión cerebro-corazón, tripticasa de soya y Müeller-Hinton para aislamientos bacterianos; para levaduras, se usaron caldo infusión cerebro-corazón y Sabouraud dextrosa. Para el método cualitativo de cultivo en agar, se utilizaron los mismos medios de cultivo más una solución con 3 % de rojo Congo y 10 % de dextrosa. Cómo método de referencia, se utilizó la propuesta de Stepanovic et al. Resultados. Se evaluaron 103 aislamientos bacterianos y 108 de levaduras. No es recomendable sustituir el caldo infusión cerebro-corazón por los caldos tripticasa de soya y Müeller-Hinton en el método cuantitativo, para evaluar la formación de biopelículas en los aislamientos bacterianos. El medio Sabouraud dextrosa, en caldo y agar, puede sustituir al de infusión de cerebro-corazón para evaluar la formación de biopelículas en levaduras, tanto por el método cuantitativo como por el cualitativo. Conclusión. El estudio de las biopelículas en el laboratorio de microbiología, a partir del método cualitativo de cultivo en agar con rojo Congo, es un procedimiento sencillo, rápido y de bajo costo, que proporciona información útil para el diagnóstico y la terapéutica de infecciones persistentes causadas por bacterias y levaduras.

Introduction. Sixty-five percent of human infections are caused by bacteria or yeasts able to form biofilms. This feature makes them more resistant to antimicrobials and antifungals. Objective. To determine biofilm formation capacity of bacterial and fungal isolates by quantitative crystal violet microtiter and qualitative Congo red agar methods. Materials and methods. Brain-heart infusion, trypticase soy broth and Müeller-Hinton culture media were used in bacterial isolates for the quantitative method; brain-heart infusion broth and Sabouraud dextrose were used for yeasts. The same culture media plus 3% Congo red and 10% dextrose were used to apply the qualitative method in agar. The proposal by Stepanovic, et al. was used as a reference method. Results. We evaluated 103 bacterial isolates and 108 yeasts isolates. We did not recommend substitute brain-heart infusion broth for trypticase soy and Müeller-Hinton broths for biofilm formation assessment in bacterial isolates using the quantitative method. Sabouraud dextrose medium, both broth and agar, can replace brain-heart infusion to assess biofilm formation in yeasts, quantitatively and qualitatively. Conclusion. The study of biofilms in the microbiology laboratory, using Congo red agar qualitative method, is a simple, fast, and inexpensive procedure that provides precise information for the diagnosis and treatment of persistent infections caused by bacteria and yeasts.

A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies / 中华血液学杂志

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Distribution and Drug Sensitivity Analysis of Pathogenic Bacteria Isolated from Patients in Hematology Department / 中国实验血液学杂志

OBJECTIVE@#To investigate the distribution and drug sensitivity of pathogenic bacteria isolated from patients in hematology department, in order to provide evidence for rational use of antibiotics in clinic.@*METHODS@#The distribution of pathogenic bacteria and drug sensitivity data of patients in the hematology department of The First Affiliated Hospital of Nanjing Medical University from 2015 to 2020 were retrospectively analyzed, and the pathogens isolated from different specimen types were compared.@*RESULTS@#A total of 2 029 strains of pathogenic bacteria were isolated from 1 501 patients in the hematology department from 2015 to 2020, and 62.2% of which were Gram-negative bacilli, mainly Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii. Gram-positive coccus accounted for 18.8%, mainly Coagulase-negative staphylococcus (CoNS) and Staphylococcus aureus. Fungi (17.4%) were mainly candida. The 2 029 strains were mainly isolated from respiratory tract (35.1%), blood (31.8%) and urine (19.2%) specimens. Gram-negative bacilli were the main pathogenic bacteria in different specimen types (>60%). K. pneumoniae, S. maltophilia and A. baumannii were the most common pathogens in respiratory specimens, E. coli, CoNS, K. pneumoniae and P. aeruginosa were common in blood samples, and E. coli and Enterococcus were most common in urine samples. Enterobacteriaceae had the highest susceptibility to amikacin and carbapenems (>90.0%), followed by piperacillin/tazobactam. P. aeruginosa strains had high sensitivity to antibiotics except aztreonam (<50.0%). The susceptibility of A. baumannii to multiple antibiotics was less than 70.0%. The antimicrobial resistance rates of E. coli and K. pneumoniae in respiratory tract specimens were higher than those in blood specimens and urine specimens.@*CONCLUSION@#Gram-negative bacilli are the main pathogenic bacteria isolated from patients in hematology department. The distribution of pathogens is different in different types of specimens, and the sensitivity of each strain to antibiotics is different. The rational use of antibiotics should be based on different parts of infection to prevent the occurrence of drug resistance.

Advances in genomics of multi-drug resistant Stenotrophomonas / 生物工程学报

Stenotrophomonas species are non-fermentative Gram-negative bacteria that are widely distributed in environment and are highly resistant to numerous antibiotics. Thus, Stenotrophomonas serves as a reservoir of genes encoding antimicrobial resistance (AMR). The detection rate of Stenotrophomonas is rapidly increasing alongside their strengthening intrinsic ability to tolerate a variety of clinical antibiotics. This review illustrated the current genomics advances of antibiotic resistant Stenotrophomonas, highlighting the importance of precise identification and sequence editing. In addition, AMR diversity and transferability have been assessed by the developed bioinformatics tools. However, the working models of AMR in Stenotrophomonas are cryptic and urgently required to be determined. Comparative genomics is envisioned to facilitate the prevention and control of AMR, as well as to gain insights into bacterial adaptability and drug development.

Bioactive properties of Persea lingue Ness (Lauraceae) fruit and leaf extracts / Propriedades bioativas de extratos de folhas e frutos de Persea lingue Ness (Lauraceae)

Abstract Persea lingue Ness is a tree species that lives mainly in temperate forests of south-central Chile. Its leaves are used in ethnomedicine, the fruit is a drupe similar to that of the avocado and has not been studied. The aim of this study was to determine the cytotoxicity in leukemia cell and antibacterial activity, along with some chemical content characteristics of P. lingue fruit and leaf extracts. The antibacterial activity was determined by the inhibition of bacterial growth in liquid medium assay against Gram-positive and Gram-negative bacteria. The leukemia cell lines Kasumi-1 and Jurkat were used to evaluate the cytotoxic activity by using propidium iodide and AlamarBlue assays. Total phenolic, flavonoid, condensed tannin, alkaloid and lipid contents were evaluated in the fruit and in the leaf extracts. The antioxidant activity of both extracts were also elavaluated. Leaf extract presented the highest content of total phenols, condensed tannins and flavonoids, and also the highest antioxidant activity. While the fruit extract has a higher amount of lipids and alkaloids and the high antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium and Micrococcus luteus. The leaf extract only showed activity against M. luteus. Concerning the cytotoxic activity, only the fruit extract showed cytotoxicity against the cell lines Jurkat and Kasumi-1. P. lingue fruit extract is a potential source of biologically active molecules for the development of new drugs to be used in some types of leukemia, as well as antibacterial agent.

Resumo Persea lingue Ness é uma árvore que vive principalmente na floresta temperada do centro-sul do Chile. As folhas são usadas na etnomedicina. O fruto é uma drupa similar ao abacate e que nunca foi pesquisada anteriormente. O objetivo deste estudo foi o de avaliar a citotoxicidade em células leucêmicas e as atividades antibacterianas, assim como algumas características químicas do extrato de fruto e da folha do P. lingue. As atividades antibacterianas foram determinadas pelo método da inibição do crescimento bacteriano em meio líquido empregando-se bactérias Gram-positivas e Gram-negativas. As linhagens celulares leucêmicas, Kasumi-1 e Jurkat foram usadas para avaliar a atividade citotóxica em ensaios empregando-se iodeto de propídio e AlamarBlue. Foram avaliados os teores totais de fenóis, flavonóides, taninos condensados, alcalóides e lipídeos presentes nos extratos das folhas e dos frutos. As atividades antioxidantes de ambos os extratos também foram avaliadas. O extrato das folhas foi o que apresentou o maior conteúdo de fenóis, taninos condensados e flavonóides totais e a maior atividade antioxidante. Já o extrato de fruto apresentou a maior quantidade de lipídios e alcaloides e a melhor atividade antibacteriana contra Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium e Micrococcus luteus. Já o extrato das folhas apresentou apenas atividade contra M. luteus. Em relação à atividade citotóxica, apenas o extrato do fruto apresentou citotoxicidade contra as linhagens celulares Jurkat e Kasumi-1. Em resumo, o extrato do fruto de P. lingue é uma potencial fonte de moléculas com atividade biológica para o desenvolvimento de novos fármacos a serem utilizados em alguns tipos de leucemia, bem como agente antibacteriano.

Temporal association between antibiotic use and resistance in Gram-negative bacteria / Associação temporal entre o uso de antibióticos e resistência em bactérias gram-negativas

Abstract The β-lactam/lactamase inhibitors (BLBLIs) combination drugs are considered an effective alternative to carbapenems. However, there is a growing concern that the increased use of BLBLIs may lead to increased resistance. This study determined the temporal association between the consumption of BLBLI and the antimicrobial resistance in Gram-negative bacteria. In this retrospective study, electronic data on the Gram-negative bacterial isolates, including A. baumannii, P. aeruginosa, E. coli, and K. pneumoniae from in-patients and susceptibility testing results were retrieved from the medical records of the clinical laboratory. A linear regression and cross-correlation analysis were performed on the acquired data. Increasing trends (p<0.05) in the consumption of BIBLI and carbapenem with a median use of 27.68 and 34.46 DDD/1000 PD per quarter were observed, respectively. A decreased trend (p=0.023) in the consumption of fluoroquinolones with a median use of 29.13 DDD/1000 PD per quarter was observed. The resistance rate of K. pneumoniae was synchronized with the BIBLI and carbapenem consumptions with a correlation coefficient of 0.893 (p=0.012) and 0.951 (p=0.016), respectively. The cross-correlation analysis against the consumption of BIBLI and meropenem resistant K. pneumoniae was peaked at 0-quarter lag (r=951, p=0.016). There was an increasing trend in the consumption of BLBLI and carbapenems. The increasing trend in the rates of resistance to piperacillin/tazobactam, in line with the increasing consumption of BLBLI, suggests that BLBLI has to be used with caution and cannot be directly considered as a long-term alternative to carbapenems.

Resumo Os medicamentos combinados de β-lactâmicos / inibidores da lactamase (BLBLIs) são considerados uma alternativa eficaz aos carbapenêmicos. No entanto, existe uma preocupação crescente de que o aumento do uso de BLBLIs pode levar ao aumento da resistência. Este estudo determinou a associação temporal entre o consumo de BLBLI e a resistência antimicrobiana em bactérias gram-negativas. Neste estudo retrospectivo, os dados eletrônicos sobre as bactérias gram-negativas isoladas, incluindo A. baumannii, P. aeruginosa, E. coli e K. pneumoniae de pacientes internados e os resultados dos testes de suscetibilidade foram recuperados dos registros médicos do laboratório clínico. Uma regressão linear e análise de correlação cruzada foram realizadas nos dados adquiridos. Foram observadas tendências crescentes (p < 0,05) no consumo de BIBLI e carbapenem com uma mediana de uso de 27,68 e 34,46 DDD/1000 PD por trimestre, respectivamente. Foi observada uma tendência de diminuição (p = 0,023) no consumo de fluoroquinolonas com uma mediana de uso de 29,13 DDD/1000 PD por trimestre. A taxa de resistência de K. pneumoniae foi sincronizada com os consumos de BIBLI e carbapenem com coeficiente de correlação de 0,893 (p = 0,012) e 0,951 (p = 0,016), respectivamente. A análise de correlação cruzada contra o consumo de BIBLI e K. pneumoniae resistente ao meropenem atingiu o pico no intervalo de 0 quarto (r = 951, p = 0,016). Houve uma tendência de aumento no consumo de BLBLI e carbapenêmicos. A tendência crescente nas taxas de resistência a piperacilina/tazobactam, em linha com o consumo crescente de BLBLI, sugere que BLBLI deve ser usado com cautela e não pode ser considerado diretamente como alternativa de longo prazo aos carbapenêmicos.

Distribution and Drug Resistance of Pathogens in Oral Mucositis Associated with Chemotherapy in Patients with Malignant Hematopathy / 中国实验血液学杂志

OBJECTIVE@#To analyze the distribution and drug resistance of pathogens in oral mucositis associated with chemotherapy in hospitalized patients with malignant hematopathy, so as to provide scientific evidences for rational selection of antibiotics and infection prevention and control.@*METHODS@#From July 2020 to June 2022, 167 patients with malignant hematopathy were treated with chemical drugs in the Department of Hematology, Hainan Hospital, and secretions from oral mucosal infected wounds were collected. VITEK2 COMPECT automatic microbial identification system (BioMerieux, France) and bacterial susceptibility card (BioMerieux) were used for bacterial identification and drug susceptibility tests.@*RESULTS@#A total of 352 strains of pathogens were isolated from 167 patients, among which 220 strains of Gram-positive bacteria, 118 strains of Gram-negative bacteria and 14 strains of fungi, accounted for 62.50%, 33.52% and 3.98%, respectively. The Gram-positive bacteria was mainly Staphylococcus and Streptococcus, while Gram-negative bacteria was mainly Klebsiella and Proteus. The resistance of main Gram-positive bacteria to vancomycin, ciprofloxacin and gentamicin was low, and the resistance to penicillin, cefuroxime, ampicillin, cefotaxime, erythromycin and levofloxacin was high. The main Gram-negative bacteria had low resistance to gentamicin, imipenem and penicillin, but high resistance to levofloxacin, cefotaxime, cefuroxime, ampicillin and vancomycin. The clinical data of oral mucositis patients with oral ulcer (severe) and without oral ulcer (mild) were compared, and it was found that there were statistically significant differences in poor oral hygiene, diabetes, sleep duration less than 8 hours per night between two groups (P<0.05).@*CONCLUSION@#Gram-positive bacteria is the main pathogen of oral mucositis in patients with malignant hematopathy after chemotherapy. It is sensitive to glycopeptide antibiotics and aminoglycosides antibiotics. Poor oral hygiene, diabetes and sleep duration less than 8 hours per night are risk factors for oral mucositis with oral ulcer (severe).

Gonococcal arthritis in a healthy adult. Is it that possible?

A case report is presented of a 50-year-old woman who was seen in Accident and Emergency because of pain in the lumbar area. She was subsequently diagnosed with septic arthritis of the left hip due to being Neisseria gonorrhoeae positive for beta-lactamase. She responded to treatment with ceftriaxone, but later required a total hip replacement.

Presentamos el caso de una mujer de 50 arios, sin antecedentes de importancia, a quien se le diagnosticó inicialmente lumbago e infección de vías urinarias. Por persistencia del dolor y limitación de la movilidad en la cadera izquierda se inicia el estudio de artritis séptica, que fue provocada por Neisseria gonorrhoeae betalactamasa positiva, sensible a tratamiento con ceftriaxona, con posterior deterioro articular, el cual requirió reemplazo total de cadera.

Meningite bacteriana: uma revisão / Bacterial meningitis: a review

A meningite bacteriana é uma inflamação das leptomeninges que envolvem o Sistema Nervoso Central. Essa patologia, que possui diversos agentes etiológicos, apresenta-se na forma de síndrome, com quadro clínico grave. Entre as principais bactérias que causam a meningite, estão a Neisseria meningitis e Streptococcus pneumoniae. A transmissão ocorre através das vias aéreas por meio de gotículas, sendo a corrente sanguínea a principal rota para as bactérias chegarem à barreira hematoencefálica e, a partir dessa, até as meninges. Atualmente existem vários métodos de diagnóstico precisos, onde a cultura de líquido cefalorraquidiano (LCR) é o método padrão ouro. Ademais, a melhora na qualidade do tratamento com beta-lactâmicos e a maior possibilidade de prevenção, devido à elevação do número e da eficácia de vacinas, vem contribuindo para redução dos casos da doença e de sua gravidade. Porém, apesar desses avanços, ainda há um elevado número de mortalidades e sequelas causadas por essa síndrome.

Bacterial meningitis is an inflammation of the leptomeninges that surround the Central Nervous System. This pathology, which has several etiological agents, is presented as a syndrome with a severe clinical scenario. The main bacteria causing meningitis include Neisseria meningitis and Streptococcus pneumoniae. It can be transmitted by droplets through the airways, with the bacteria using the bloodstream as the main route to reach the blood-brain barrier, and from there to the meninges. There are currently several accurate diagnostic methods, with CSF culture being the gold standard. In addition, the improvement in the quality of beta-lactam treatment and the greater possibility of prevention due to the increased number and effectiveness of vaccines have contributed to reducing the number of cases and severity of the disease. Nevertheless, despite these advances, this syndrome still presents a high number of mortalities and sequelae.

Mapa Microbiológico - 2020 del Instituto de Hematología e Inmunología de Cuba / Microbiological Map

Introducción: Los mapas microbiológicos se consideran un marcador epidemiológico pues resumen estadísticamente las bacterias circulantes y su comportamiento frente a los antibióticos en uso. Permiten establecer una política de antibióticos que garantiza el uso más racional de los antimicrobianos y disminuye el riesgo de resistencia bacteriana. Objetivos: Identificar las bacterias aisladas con mayor frecuencia a partir de cultivos microbiológicos de pacientes hospitalizados en el Instituto de Hematología e Inmunología durante el año 2020 y determinar la resistencia de las bacterias más frecuentes a los antimicrobianos ensayados, con vista a establecer el primer mapa microbiológico de la institución. Métodos: Se realizó un estudio de corte transversal que incluyó los cultivos de pacientes hospitalizados durante el año 2020. La identificación bacteriana se realizó según métodos convencionales y para determinar los perfiles de resistencia se empleó el método de Bauer-Kirby. Resultados: El hemocultivo fue el estudio microbiológico más indicado con una positividad de 32,80 por ciento. Predominaron las bacterias Gram negativas (81,71 por ciento), siendo las más identificadas Pseudomonas spp., Enterobacter spp., Klebsiella spp. y Escherichia coli. Entre las bacterias Gram positivas predominó Staphylococcus spp. coagulasa negativa. Se obtuvieron elevados porcentajes de resistencia frente a casi todos los antimicrobianos evaluados. Conclusiones: La realización del mapa microbiológico de la institución permite actualizar la política de uso de los antimicrobianos al identificar a los bacilos Gram negativos, con elevados porcentajes de resistencia, como los principales agentes etiológicos de las infecciones registradas en este centro de salud durante el año 2020(AU)

Introduction: Microbiological maps are considered an epidemiological marker as statistically summarize circulating bacteria and their behavior against antibiotics in use. They allow establishing an antibiotic policy that guarantees the most rational use of antimicrobials and decreases the risk of bacterial resistance. Objectives: Identify the isolated bacteria with more frequency from microbiological crops of hospitalized patients in the Institute of Hematology and Immunology during the year 2020 and determine the resistance of the most frequent bacteria to the antimicrobials tested, with a view to establishing the first microbiological map of the institution. Methods: An observational, descriptive, cross-sectional study was performed that included cultures of patients hospitalized during the year 2020. Bacterial identification was carried out according to conventional methods and to determine the resistance profiles was used by the Bauer-Kirby method. Results: The blood culture was the most indicated microbiological study with 32.80 percent positivity. The Gram negative bacteria predominated (81.71percent), being the most identified Pseudomona spp., Enterobacter spp., Klebsiella spp. and Escherichia coli. Among the Gram positive bacteria predominate Staphylococcus spp. coagulase negative. High percentages of resistance were obtained in front of almost all antimicrobials evaluated. Conclusions: The completion of the institutional microbiological map allows updating the antimicrobial use policy by identifying the Gram negative bacilli, with high percentages of resistance, as the main etiological agents of the infections registered in this health center during 2020(AU)

Análisis comparativo de la actividad antimicrobiana de secreciones y excreciones larvarias de Calliphora vicina y Sarconesiopsis magellanica (Diptera: Calliphoridae) / A comparative analysis of Calliphora vicina and Sarconesiopsis magellanica (Diptera: Calliphoridae) larval secretions and excretions antimicrobial activity

Introducción. La creciente resistencia bacteriana a los antibióticos representa una amenaza mundial de salud pública. Las excreciones y secreciones larvarias derivadas de moscas necrófagas de la familia Calliphoridae podrían configurar una fuente promisoria para contrarrestar sus efectos. Objetivo. Comparar la actividad antimicrobiana de las excreciones y secreciones larvarias nativas, y de las mayores y menores de 10 kDa de Calliphora vicina y Sarconesiopsis magellanica (Diptera: Calliphoridae). Materiales y métodos. El bioensayo se hizo a partir de la técnica de turbidimetría y en el caso de las excreciones y secreciones menores de 10 kDa se determinó la concentración inhibitoria mínima (CIM). Resultados. Las excreciones y secreciones nativas y las menores de 10 kDa de C. vicina y S. magellanica, evidenciaron una potente actividad antibacteriana contra tres cepas de Staphylococcus aureus y cuatro bacterias Gram negativas, siendo las menores de 10 kDa más efectivas que las nativas en las dos especies de moscas evaluadas. Además, las menores de 10 kDa presentaron la misma efectividad, aunque en las pruebas de CIM se observó que las de S. magellanica fueron más potentes en todas las bacterias evaluadas, excepto contra la cepa de S. aureus ATCC 25923. Las mayores de 10 kDa no inhibieron el crecimiento bacteriano. Conclusión. Los resultados validaron, en general, que estas sustancias son fuente importante para el aislamiento y la caracterización de agentes antimicrobianos.

Introduction: The growing resistance to antibiotics worldwide represents a global threat to public health. The larval excretions and secretions derived from necrophagous flies from the Calliphoridae family could represent a promising source for counteracting their effects. Objective: To compare the antimicrobial activity of Calliphora vicina and Sarconesiopsis magellanica (Diptera: Calliphoridae) native excretions and secretions and those weighing more than 10 kDa and less. Materials and methods: We used the turbidimetry technique for the bioassay; we determined the minimum inhibitory concentration (MIC) for excretions and secretions weighing less than 10 kDa. Results: Calliphora vicina and S. magellanica native excretions and secretions and those weighing less than 10 kDa exhibited potent antibacterial activity against three Staphylococcus aureus strains and four Gram-negative bacteria; those weighing less than 10 kDa were more effective than the native ones in the two species of flies evaluated here. Furthermore, excretions and secretions weighing less than 10 kDa had the same effectiveness, except in the MIC trials where S. magellanica excretions and secretions weighing less than 10 kDa were more potent against all the bacteria evaluated, except for S. aureus ATCC 25923. Excretions and secretions weighing more than 10 kDa did not inhibit bacterial growth. Conclusions: These results potentially validate these substances as an important source for isolating and characterizing antimicrobial agents.

Comparação do mecanismo de heterorresistência em Serratia marcescens por time kill curve frente ao meropeném / Comparison of heteroresistance mechanism in Serratia marcescens by time kill curve against meropenem

Serratia marcescens pertence à Família Enterobacteriaceae, é Gram-negativa e anaeróbica facultativa, sendo bem distribuída na natureza; pode ser isolada como saprófita do solo e da água. Possui um significado clínico relevante, pois acarreta infecções nosocomiais e pulmonares em determinados setores da saúde, como unidades neonatais, maternidades e UTIs, além de sepse, meningite, choque endotóxico e infecções do trato urinário. O intuito desse estudo foi analisar o mecanismo de heterorresistência em linhagens sensíveis de Serratia marcescens diante das concentrações testadas de meropeném. As linhagens SR1 e SR2 apresentaram perfil heterorresistente, ao passo que a SR6 demonstrou ser não heterorresistente, com CIM elevado (32µg/mL). Os isolados de Serratia marcescens são suscetíveis ao meropenem, por testes de sensibilidade padrão, mas contêm subpopulações resistentes ao mesmo.

Serratia marcescens belongs to the Enterobacteriaceae family, it is optional anaerobic gram-negative, being well distributed in nature and it might be isolated as saprophytic from soil and water. It has a meaningful clinical significance, because it causes nosocomial and lung infections in certain healthcare sectors, such as neonatal units, maternity units and UTIs; septicemia, meningitis, endotoxin shock and urinary tract infections. The aim of this study was to analyze the mechanism of heteroresistance in susceptible strains of Serratia marcescens in the presence of the tested concentration of meropenem. The lineages SR1 and SR2 presented heteroresistant profile, while the SR6 showed to be nonheterorresistente, with CIM (32 µg/mL). The Isolates of Serratia marcescens are susceptible to meropenem, by standard sensitivity testing, but there are subpopulations resistant to it.

Clinical Features of Infection in Newly Diagnosed Patients with Myelodysplastic Syndrome and Its Correlation with Curative Effect / 中国实验血液学杂志

OBJECTIVE@#To explore the characteristics of infection in patients with myelodysplastic syndromes (MDS), risk factors of serious infection, and their correlation with curative effect.@*METHODS@#The clinical data of 92 newly diagnosed MDS patients with nosocomial infection from January 2016 to June 2020 in our hospital were retrospectively analyzed.@*RESULTS@#A total of 306 courses of treatment were completed in 92 newly diagnosed MDS patients. The infection rate was the highest in the first course of treatment (84.8%, 78/92), and then decreased gradually. The top three infection sites were lung, upper respiratory tract, and gastrointestinal tract. A total of 90 strains of pathogenic bacteria were detected, of which 33.4% (30/90) were gram-negative bacilli, 23.3% (21/90) were gram-positive cocci, 23.3% (21/90) were fungi, and 20.0% (18/90) were viruses. The serious infection rate among 92 patients with MDS was 22.8% (21/92). Multivariate analysis showed that neutrophil deficiency>7 days (OR=10.875, 95%CI: 2.747-43.051, P=0.001) was an independent risk factor for serious infection in MDS patients. Compared with non-severe infection group, the total effective rate of severe infection group was lower (90.9% vs 63.6%, χ2=4.393, P<0.05).@*CONCLUSION@#The infection rate of MDS patients is high in the first course of treatment, and the most common infection site is the lung. Gram-negative bacteria is the most common pathogen. MDS patients with neutrophil deficiency>7 days have a high risk of serious infection and poor efficacy.

Clinical and microbiological characteristics of children with drowning-associated aspiration pneumonia / 中国当代儿科杂志

OBJECTIVES@#To study the clinical and microbiological characteristics of children with drowning-associated aspiration pneumonia, so as to provide a reference for empirical selection of antibacterial agents.@*METHODS@#A retrospective analysis was performed on the medical data of 185 children with drowning-associated aspiration pneumonia who were admitted to Children's Hospital of Chongqing Medical University from January 2010 to October 2020. According to the drowning environment, these children were divided into four groups: fecal group (n=44), freshwater group (n=69), swimming pool group (n=41), and contaminant water group (n=31). The clinical characteristics and pathogen detection results were reviewed and compared among the four groups.@*RESULTS@#The 185 children had an age of 4 months to 17 years (median 34 months). Sputum cultures were performed on 157 children, and 103 were tested positive (65.6%), with 87 strains of Gram-negative bacteria (68.5%), 37 strains of Gram-positive bacteria (29.1%), and 3 strains of fungi (2.4%). Gram-negative bacteria were the main pathogen in the fecal group and the contaminant water group, accounting for 88.2% (30/34) and 78.3% (18/23), respectively. The freshwater group had a significantly higher detection rate of Gram-positive bacteria than the fecal group (P<0.008), and the swimming pool group had an equal detection rate of Gram-negative bacteria and Gram-positive bacteria.@*CONCLUSIONS@#For pulmonary bacterial infection in children with drowning in feces or contaminant water, antibiotics against Gram-negative bacteria may be applied empirically, while for children with drowning in a swimming pool or freshwater, broad-spectrum antibiotics may be used as initial treatment, and subsequently the application of antibiotics may be adjusted according to the results of the drug sensitivity test.

Distribution and drug resistance profiles of pathogens causing bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia / 中国当代儿科杂志

OBJECTIVES@#To study the changes in the distribution and drug resistance profiles of pathogens causing bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia.@*METHODS@#The medical data were collected from the children with acute lymphoblastic leukemia who were admitted to the First Affiliated Hospital of Zhengzhou University between January 2015 and December 2020 and developed bloodstream infection after chemotherapy. The samples were divided into the first three years group and the next three years group according to the time of testing to investigate the differences in the distribution and drug resistance profiles of pathogens as time.@*RESULTS@#A total of 235 strains of pathogens were isolated, among which there were 159 Gram-negative strains (67.7%; mainly Escherichia coli and Klebsiella pneumoniae), 61 Gram-positive strains (26.0%; mainly Staphylococcus epidermidis), and 15 strains of fungi (6.4%; mainly Candida albicans). There were no significant differences between the first three years group and the next three years group in the detection rate of Gram-negative bacteria (68.8% vs 66.9%, P>0.05) or Gram-positive bacteria (29.2% vs 23.7%, P>0.05). Compared with the first three years group, the next three years group had significant increases in the detection rate of Streptococcus mitis (5.8% vs 0.0%, P<0.05) and fungi (9.4% vs 2.1%, P<0.05). There was no significant difference in the drug resistance rate of Gram-negative or Gram-positive bacteria between the two groups (P>0.05).@*CONCLUSIONS@#Enterobacteriaceae bacteria are the main pathogens of bloodstream infection after chemotherapy in children with acute lymphoblastic leukemia, while the detection rates of Streptococcus mitis and fungi tend to increase as time, which needs to be taken seriously in clinical practice.

The extracellular vesicles from gram-positive bacteria: a review / 生物工程学报

Extracellular vesicles (EVs), also known as membrane vesicles, are vesicular bodies secreted by eukaryotic cells and bacteria. EVs can carry proteins, DNA, RNA, and various metabolites for the exchange and transmission of substances between cells. They play contents-dependent physiological functions, such as delivering nutrients, participating in immune response, and treating cancers. Currently, most studies focus on the exploration of vesicles secreted by eukaryotic cells and gram-negative bacteria, while few studies focus on gram-positive bacteria. This review summarized the production, content composition, physiological function, and engineering of EVs secreted by gram-positive bacteria, and prospected future perspectives in this area.

Cefiderocol: a novel siderophore cephalosporin against multi-drug resistant Gram-negative bacilli infections / 生物工程学报

Antimicrobial resistance is one of the critical public health issues in the world. There is an urgent need to develop effective broad-spectrum antibiotics to treat the infection of multi-drug resistant Gram-negative bacilli. Cefiderocol, developed by the Shionogi Inc. in Japan, is a new type of iron carrier cephalosporin antibiotics, which overcomes the drug resistance of Gram-negative bacilli due to the down-regulation of outer membrane pore protein and the up-regulation of efflux pump, and has good stability to serine- and metallo-carbapenemases. This drug has a broad spectrum and strong antibacterial activity against carbapenem-resistant Enterobacteriaceae (CRE), Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. Cefiderocol can be used to treat complex urinary tract infections (including pyelonephritis), hospital-acquired pneumonia, and ventilator-associated pneumonia. By summarizing the chemical structure, antibacterial mechanism, in vitro antibacterial activity, pharmacokinetics, pharmacodynamics, and clinical treatment of cefiderocol, this review shows the application potential of cefiderocol as a new iron carrier cephalosporin in the treatment of multi-drug resistant Gram-negative bacilli infections.

Use of MALDI-TOF for identification and surveillance of gram-negative bacteria in captive wild psittacines / Uso do MALDI-TOF para identificação e monitoramento de bactérias Gram-negativas em psitacídeos cativos

Microbiological studies of the sanitary and health status of psittacine birds that will be reintroduced is important in evaluating whether these animals act as carriers of pathogenic agents to other animals and humans. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a faster and more accurate method to identify bacteria than conventional microbiology methods. The aim of this study was to evaluate the health status of psittacines housed in captivity, by assessment of Gram-negative bacteria from fecal microbiota through MALDI- TOF MS identification. The results indicate high frequency of Gram-negative bacteria in feces (96.5%), especially from the Enterobacteriaceae family (88.7%). The most prevalent bacteria were Escherichia coli (39.0%), Proteus vulgaris (12.2%), Klebsiella spp. (12.1%) and Raoultella ornithinolytica (8.7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. and Escherichia hermannii were isolated with lower frequency. . All these agents are potentially pathogenic for parrots and can cause systemic infections in other animals and humans. These findings reinforce that MALDI- TOF MS proved to be a rapid and accurate method of identification of the microorganism and evaluation of the health status of psittacines, providing relevant data to assist decision-making regarding the sanitary protocols in wildlife centers, and possible future reintroduction of wild birds.

Estudos microbiológicos da sanidade de psitacídeos que serão reintroduzidos são importantes para avaliar se esses animais atuam como portadores de agentes patogênicos para outros animais e humanos. A espectrometria de massa por ionização/dessorção de matriz assistida por laser/tempo de vôo (MALDI-TOF MS) é um método mais rápido e preciso para identificar bactérias na comparação com métodos convencionais de microbiologia. O objetivo deste estudo foi avaliar o estado de saúde de psitacídeos cativos, identificando bactérias Gram-negativas da microbiota fecal por MALDI -TOF MS. Os resultados indicaram alta frequência de bactérias Gram-negativas nas fezes (96,5%), principalmente da família Enterobacteriaceae (88,7%). As mais prevalentes foram Escherichia coli (39,0%), Proteus vulgaris (12,2%), Klebsiella spp. (12,1%) e Raoultella ornithinolytica (8,7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. e Escherichia hermannii foram isolados com menor frequência. Todos esses agentes são potencialmente patogênicos para os papagaios e podem causar infecções sistêmicas em outros animais e seres humanos. Esses achados reforçam que o MALDI- TOF MS é um método rápido e preciso de identificação do microrganismo e avaliação do estado de saúde dos psitacídeos, fornecendo dados relevantes para auxiliar na tomada de decisões sobre os protocolos sanitários em centros de triagem de animais selvagens e sobre a possibilidade de reintrodução futura.