Frecuencia de E. coli y Klebsiella spp productoras de betalactamasas en cultivos procesados en un laboratorio clínico / Frequency of E. coli and betalactamase-producing Klebsiella spp in cultures processed in a clinical laboratory / Frequência de E. coli e Klebsiella spp produtoras de betalactamase em culturas processadas em laboratório clínico

Introducción: la resistencia antibiótica en bacterias patógenas como Escherichia coli y Klebsiella spp. productoras de betalactamasas, han surgido como un problema global de salud pública. Su presencia, se asocia con infecciones intrahospitalarias y comunitarias, aumentando la morbilidad y la mortalidad de los pacientes. Objetivo: determinar la frecuencia de E.coli y Klebsiella spp productoras de betalactamasas en cultivos procesados en un laboratorio clínico. Métodos: se realizó un estudio descriptivo de diseño documental. La muestra estuvo constituida por un total de 1465 resultados de cultivos positivos para Escherichia coli o Klebsiella spp. en el periodo 2022. Para la recolección de la información, se tuvo acceso a la base de datos anonimizada del laboratorio en una hoja de Excel para su posterior análisis. Los datos fueron tabulados en SPSS versión 25. Resultados: el análisis de bacterias productoras de BLEE mostró una positividad del 22,3% en E. coli y 46,1% en Klebsiella spp. E. coli presentó mayor frecuencia de negativos (77,7%) en comparación con Klebsiella spp. La presencia de E. coli fue más común en muestras de orina (90,6%) y en otras muestras como esputo y heridas cutáneas (21,3%). Se evaluaron 8 antibióticos, y se destacó la alta sensibilidad para amikacina (AK) (99,6% y 98,0%) y elevada resistencia ampicilina (AM) (91,5% y 100%) en ambas especies. Ciprofloxacino (CIP) y Trimetropin/Sulfametoxazol (STX) mostraron relativa frecuencia mayor de resistencia. Conclusión: los resultados muestran una alta frecuencia de bacterias productoras de BLEE en E. coli y Klebsiella spp., con una mayor prevalencia en Klebsiella spp. Además, la resistencia a AM, CIP y STX destaca la importancia de una gestión adecuada de la resistencia antimicrobiana.

Introduction: antibiotic resistance in pathogenic bacteria such as Escherichia coli and Klebsiella spp. producing beta-lactamases has emerged as a global public health problem. Their presence has been associated with both hospital-acquired and community-acquired infections, leading to increased morbidity and mortality in patients. Objective: to determine the frequency of betalactamase-producing E. coli and Klebsiella spp. in cultures processed in a clinical laboratory. Methods: a descriptive documentary design study was conducted. The sample consisted of a total of 1465 positive culture results for Escherichia coli or Klebsiella spp. in the year 2022. Data collection involved accessing the laboratory's anonymized database in an Excel sheet for subsequent analysis. The data were tabulated in SPSS version 25. Results: the analysis of ESBL-producing bacteria showed a positivity of 22.3% in E. coli and 46.1% in Klebsiella spp. E. coli showed a higher frequency of negatives (77.7%) compared to Klebsiella spp. The presence of E. coli was more common in urine samples (90.6%) and in other samples such as sputum and skin wounds (21.3%). Eight antibiotics were evaluated, with high sensitivity noted for amikacin (AK) (99.6% and 98.0%) and high resistance for ampicillin (AM) (91.5% and 100%) in both species. Ciprofloxacin (CIP) and Trimethoprim/Sulfamethoxazole (STX) showed a relatively higher frequency of resistance. Conclusion: the results show a high frequency of ESBL-producing bacteria in E. coli and Klebsiella spp., with a higher prevalence in Klebsiella spp. Furthermore, the resistance to AM, CIP, and STX highlights the importance of proper management of antimicrobial resistance.

Introdução: a resistência antibiótica em bactérias patogênicas como Escherichia coli e Klebsiella spp., produtoras de beta-lactamases, emergiu como um problema de saúde pública global. Sua presença tem sido associada a infecções hospitalares e comunitárias, aumentando a morbidade e a mortalidade dos pacientes. Objetivo: determinar a frequência de E. coli e Klebsiella spp. produtoras de betalactamase em culturas processadas em laboratório clínico. Métodos: foi realizado um estudo descritivo de design documental. A amostra consistiu em um total de 1465 resultados de cultura positiva para Escherichia coli ou Klebsiella spp. no ano de 2022. A coleta de dados envolveu o acesso ao banco de dados anonimizado do laboratório em uma planilha do Excel para análise subsequente. Os dados foram tabulados na versão 25 do SPSS. Resultados: a análise de bactérias produtoras de BLEE mostrou uma positividade de 22,3% em E. coli e 46,1% em Klebsiella spp. E. coli apresentou uma frequência maior de resultados negativos (77,7%) em comparação com Klebsiella spp. A presença de E. coli foi mais comum em amostras de urina (90,6%) e em outras amostras, como escarro e feridas na pele (21,3%). Foram avaliados oito antibióticos, com alta sensibilidade observada para amicacina (AK) (99,6% e 98,0%) e alta resistência para ampicilina (AM) (91,5% e 100%) em ambas as espécies. Ciprofloxacina (CIP) e Trimetoprima/Sulfametoxazol (STX) mostraram uma frequência relativamente maior de resistência. Conclusão: os resultados mostram uma alta frequência de bactérias produtoras de BLEE em E. coli e Klebsiella spp., com uma maior prevalência em Klebsiella spp. Além disso, a resistência a AM, CIP e STX destaca a importância da adequada gestão da resistência antimicrobiana.

Absceso hepático en Cali, Colombia / Liver abscess in Cali, Colombia

INTRODUCCIÓN: El absceso hepático (AH) es el tipo mas común de abscesos viscerales. Se estima que el perfil epidemiológico de esta enfermedad ha cambiado con el aumento de la resistencia de los microorganismos y el uso de nuevos medicamentos. OBJETIVO: Describir las características demográficas y clínicas de los pacientes hospitalizados con diagnóstico de AH en un hospital universitario del suroccidente colombiano. MÉTODOS: Se realizó un estudio observacional retrospectivo, en la Fundación Valle del Lili, Cali, Colombia. Se incluyeron pacientes mayores de 18 años con diagnóstico de AH hospitalizados entre 2011-2020. RESULTADOS: Se incluyeron 182 pacientes. La mediana de edad fUe 56 años (rango intercuartílico, 45-67) y 62,1% fueron hombres. El microrganismo mas común fue Klebsiella pneumoniae (17,6%). La mayoría requirió drenaje percutáneo (58,2%). El 58,8% tuvo un absceso único y 54,4% fue manejado en cuidados intensivos. El 7,1% de los pacientes falleció. Al comparar los casos que fueron manejados en cuidados intensivos vs. aquellos que no lo fueron, hubo más hepatomegalia (28,3 vs. 11,0%, p = 0,004), derrame pleural derecho (48,5 vs. 28,1%, p = 0,010), cirugía (42,4 vs. 13,4%, p < 0,001), falla terapéutica (22,2 vs. 7,3%, p = 0,007) y muerte (12,1 vs. 1,2%, p = 0,005) en los atendidos en UCI. CONCLUSIÓN: Las Enterobacterales son la principal causa de AH en nuestra población. La mortalidad ha disminuido, pero la hospitalización en cuidados intensivos sigue siendo alta.

BACKGROUND: Liver abscess (LA) is the most common type of visceral abscess. It is estimated that the epidemiological profile of this disease has changed with the increase in resistance and the use of new drugs. AIM: To describe the demographic and clinical characteristics of hospitalized patients with a diagnosis of LA in a university hospital in the southwestern region of Colombia. METHODS: A. retrospective observational study was conducted at Fundación Valle del Lili, Cali, Colombia. Patients older than 18 years with a diagnosis of LA hospitalized between 2011-2020 were included. RESULTS: A total of 182 patients were included. The median age was 56 years (interquartile range, 45-67) and 62.1% were men. The most common microorganism was Klebsiella pneumoniae (17.6%). The majority required percutaneous drainage (58.2%). A 58.8% had a single abscess and 54.4% were treated in ICU. A 7.1% of the patients died. When comparing cases treated in the ICU vs. those who did not, there was more hepatomegaly (28.3 vs. 11.0%, p = 0.004), right pleural effusion (48.5 vs. 28.1%, p = 0.010), surgery (42.4 vs. 13.4%, p < 0.001), therapeutic failure (22.2 vs. 7.3%, p = 0.007) and death (12.1 vs. 1.2%, p = 0.005) in patients treated in ICU. CONCLUSION: Enterobacterales are the main cause of LA in our population. Mortality has decreased, but intensive care hospitalization remains high.

Effect of N-acetyl cysteine, rifampicin, and ozone on biofilm formation in pan-resistant Klebsiella pneumoniae: an experimental study

ABSTRACT BACKGROUND: To the best of our knowledge, this is the first study to evaluate the effectiveness of specific concentrations of antibiofilm agents, such as N-acetyl cysteine (NAC), rifampicin, and ozone, for the treatment of pan-resistant Klebsiella pneumoniae (PRKp). OBJECTIVES: We evaluated the effectiveness of antibiofilm agents, such as NAC, rifampicin, and ozone, on biofilm formation in PRKp at 2, 6, 24, and 72 h. DESIGN AND SETTING: This single-center experimental study was conducted on June 15, 2017, and July 15, 2018, at Istanbul Faculty of Medicine, Istanbul University, Turkey. METHODS: Biofilm formation and the efficacy of these agents on the biofilm layer were demonstrated using colony counting and laser-screened confocal microscopy. RESULTS: NAC at a final concentration of 2 μg/mL was administered to bacteria that formed biofilms (24 h), and no significant decrease was detected in the bacterial counts of all isolates (all P > 0.05). Rifampicin with a final concentration of 0.1 μg/mL was administered to bacteria that formed biofilm (24 h), and no significant decrease was detected in bacterial count (all P > 0.05). Notably, ozonated water of even 4.78 mg/L concentration for 72 h decreased the bacterial count by ≥ 2 log10. CONCLUSION: Different approaches are needed for treating PRKp isolates. We demonstrate that PRKp isolates can be successfully treated with higher concentrations of ozone.

Sepsis probada a Klebsiella oxytoca en un recién nacido

La sepsis neonatal constituye una de las principales causas de muertes neonatales en los países en desarrollo, con datos que estiman más de un millón de muertes en todo el mundo cada año. Se persigue presentar un caso, dada la infrecuencia de la sepsis neonatal tardía por Klebsiella oxytoca. Se trata de una paciente femenina, pretérmino y de bajo peso al nacer, que a los 17 días de vida comenzó con deterioro de su estado clínico dado por hipoactividad, palidez cutánea, succión morosa e incremento de la circunferencia abdominal, acompañados de disfunción hematológica severa dada por anemia, trombocitopenia y neutropenia, que requirió varias transfusiones con hemoderivados y terapéutica antimicrobiana combinada (primero con meronem y amikacina, luego con ciprofloxacina y vancomicina). Se trató también con antifúngicos, diuréticos, drogas vasoactivas, ventilación mecánica y eritropoyetina. Se interconsultó con Cardiología e Infectología pediátricas. Tuvo finalmente una evolución satisfactoria, con lactancia materna efectiva. El incremento de la sepsis en neonatos hospitalizados y la resistencia bacteriana son problemas de salud pública. Es importante reconocer los factores de riesgo para la sepsis en este grupo de pacientes, para su tratamiento oportuno.

Neonatal sepsis is one of the main causes of neonatal deaths in developing countries, with data estimating more than one million deaths around the world every year. The aim is to present case a case, given the infrequency of late neonatal sepsis by Klebsiella oxytoca. This is the case of a pre-term female patient, with low weight at birth, who at 17 days of birth began with deterioration of her clinical status due to hypo-activity, skin paleness, morose suction and increase in abdominal circumference, accompanied by severe hematological dysfunction given by anemia, thrombocytopenia and neutropenia, which required several transfusions with blood products and combined antimicrobial therapeutic (first with meronem and amikacin, then with ciprofloxacin and vancomycin). She was also treated antifungals, diuretics, vasoactive drugs, mechanical ventilation and erythropoietin. She was consulted with Pediatric Cardiology and Infectious diseases. Finally she had a satisfactory evolution, with effective maternal breastfeeding. Sepsis increase in hospitalized neonates and bacterial resistance are public health problems. It is important to recognize the risk factors for sepsis in this group of patients, for their timely treatment.

Estenosis laringotraqueal recurrente asociada a Klebsiella pneumoniae subsp. rhinoscleromatis / Recurrent laryngotracheal stenosis associated with Klebsiella pneumoniae subsp. rhinoscleromatis

Introducción: Klebsiella rhinoscleromatis (KR) es una enterobacteria asociada con formación de granulomatosis crónica. Cuando este microorganismo afecta el tracto respiratorio se denomina escleroma, afectando principalmente la cavidad nasal; puede comprometer nasofaringe, laringe, tráquea y bronquios. Caso clínico: paciente femenina con antecedente de laringotraqueítis crónica con diagnóstico de estenosis traqueal y aislamiento en cultivos de Klebsiella pneumoniae ssp rhinoscleromatis multisensible, sin compromiso nasosinusal o extralaríngeo. Discusión: el escleroma puede afectar todo el tracto respiratorio y se deben tener presentes factores de riesgo asociados, como condiciones de hacinamiento, inmunosupresión y sexo femenino. El pilar del tratamiento es médico, basado en antibióticos; adicionalmente, se reserva manejo quirúrgico en la etapa esclerótica, donde hay ausencia del fenómeno inflamatorio. Conclusión: el escleroma es una patología rara con una evolución crónica y compromiso principalmente en cavidad nasal, que requiere alta sospecha diagnóstica para realizar manejo oportuno.

Introduction: Klebsiella rhinoscleromatis (KR) is an enterobacterium associated with the formation of chronic granulomatosis. When this microorganism affects the respiratory tract, it is called scleroma, the nasal cavity is the main one affected; additionally, it can involve nasopharynx, larynx, trachea, and bronchi. Clinical case: female patient with a history of chronic laryngotracheitis, with diagnosis of tra-cheal stenosis and isolation in cultures of multisensitive Klebsiella pneumoniae ssp rhinoscleromatis, without nasosinusal or extralaryngeal involvement. Discussion: scleroma can affect the entire respiratory tract, so associated risk factors should be taken into account, mainly overcrowding, immunosuppression, and female sex, in whom it is more common. The mainstay of treatment is medical, based on antibio-tics; additionally, surgical management is reserved for sclerotic stage, when there is no inflammatory phenomenon. Conclusion: scleroma is a rare pathology, with a chronic evolution, with involvement mainly in the nasal cavity, which requires a high diagnostic suspicion for its timely management.

Construction of a risk prediction model for bloodstream infection induced by carbapenem-resistant Klebsiella pneumoniae / 中国药房

OBJECTIVE To construct a risk prediction model for bloodstream infection （BSI） induced by carbapenem-resistant Klebsiella pneumoniae （CRKP）. METHODS Retrospective analysis was conducted for clinical data from 253 patients with BSI induced by K. pneumoniae in the First Hospital of Qinhuangdao from January 2019 to June 2022. Patients admitted from January 2019 to December 2021 were selected as the model group （n＝223）， and patients admitted from January 2022 to June 2022 were selected as the validation group （n＝30）. The model group was divided into the CRKP subgroup （n＝56） and the carbapenem- sensitive K. pneumoniae （CSKP） subgroup （n＝167） based on whether CRKP was detected or not. The univariate and multivariate Logistic analyses were performed on basic information such as gender， age and comorbid underlying diseases in two subgroups of patients； independent risk factors were screened for CRKP-induced BSI， and a risk prediction model was constructed. The established model was verified with patients in the validation group as the target. RESULTS Admissioning to intensive care unit （ICU）， use of immunosuppressants， empirical use of carbapenems and empirical use of antibiotics against Gram-positive coccus were independent risk factors of CRKP-induced BSI （ORs were 3.749， 3.074， 2.909， 9.419， 95%CIs were 1.639-8.572， 1.292- 7.312， 1.180-7.717， 2.877-30.840， P＜0.05）. Based on this， a risk prediction model was established with a P value of 0.365. The AUC of the receiver operating characteristic （ROC） curve of the model was 0.848 [95%CI （0.779， 0.916）， P＜0.001]， and the critical score was 6.5. In the validation group， the overall accuracy of the prediction under the model was 86.67%， and the AUC of ROC curve was 0.926 [95%CI （0.809， 1.000]， P＜0.001]. CONCLUSIONS Admission to ICU， use of immunosuppressants， empirical use of carbapenems and empirical use of antibiotics against Gram-positive coccus are independent risk factors of CRKP- induced BSI. The CRKP-induced BSI risk prediction model based on the above factors has good prediction accuracy.

Caracterización de aislamientos de Klebsiella pneumoniae doble productores de carbapenemasas en un hospital universitario / Phenotypic and genotypic characterization of double carbapenemase producing Klebsiella pneumoniaeisolates in a University Hospital

La emergencia de aislamientos de Klebsiella pneumoniaedoble productores de carbapenemasas (KPC y NDM) es una de las consecuencias de la pandemia causada por SARS-CoV-2 que ha causado un impacto significativo en las tasas de resistencia a los antimicrobianos en las infecciones intrahospitalarias por esta enterobacteria. Estos aislamientos representan un desafío para los servicios de salud, por su detección y caracterización y posterior tratamiento. En este trabajo se describen los aislamientos portadores de KPC y NDM recuperados durante 2022 aislados de distintas muestras clínicas de pacientes internados en un hospital universitario de la Ciudad de Buenos Aires, se los caracteriza fenotípicamente y genotípicamente como portadores de ambas carbapenemasas y se destaca la excelente actividad in vitro de la combinación ceftazidima-avibactam y aztreonam en el tratamiento de estas infecciones en donde las alternativas terapéuticas estarían limitadas a antibióticos no ß-lactámicos con porcentajes de resistencia que superan el 70%

The emergence of double-carbapenemase (KPC and NDM) producing Klebsiella pneumoniae isolates is one of the consequences derived from the SARS CoV-2 pandemic, which has caused significant impact on the antimicrobial resistance rates in hospital acquired infections. These isolates represent a real challenge for Health Services due to their difficult detection and characterization and subsequent treatment. In the present work we describe the double carbapenemase producing isolates recovered during the year 2022 from clinical samples belonging to hospitalized patients at a University Hospital in Buenos Aires city, we report their phenotypic and genotypic characterization and the excellent "in vitro" activity of the ceftazidime-avibactam-aztreonam combination in the treatment of infections in which the therapeutical options are restricted to non ß- lactamic antimicrobials which hold resistance rates higher than 70%

Respuesta de procalcitonina ante co-infección e infección secundaria por bacterias multirresistentes en pacientes COVID -19 / Procalcitonin response in co-infection and secondary infection by multidrug resistant bacteria in COVID -19 patients

INTRODUCCIÓN. La procalcitonina, es un biomarcador que puede usarse como apoyo diagnóstico en infecciones bacterianas y la monitorización del tratamiento antibiótico, sobre todo en pacientes con sepsis. De ahí que, fue utilizado durante la pandemia COVID-19 OBJETIVO. Determinar los valores de procalcitonina en pacientes con COVID-19 y definir una p osible correlación entre su incremento y vinculación en coinfección o infección secundaria por Klebsiella pneumoniae y Pseudomonas aeruginosa con multidrogo resistencia y resistencia extendida a los antibióticos. MATERIALES Y MÉTODOS. Estudio retrospectivo observacional, descriptivo transversal, realizado del 1 de mayo al 31 de octubre del 2020 en el Hospital de Especialidades Carlos Andrade Marín sobre 7028 pacientes adultos, hospitalizados, con diagnóstico de COVID-19, y resultados de procalcitonina, cuyas muestras de secreción traqueal y/o hemocultivo presentaron desarrollo de Klebsiella pneumoniae y Pseudomonas aeruginosa. Su análisis estadístico fue desarrollado mediante la prueba Chi Cuadrado de Pearson. RESULTADOS. Se recibieron 861 muestras de hemocultivo y 391 de secreción traqueal, obteniéndose: 32% aislamientos de Klebsiella pneumoniae y Pseudomonas aeruginosa multidrogo y extremadamente resistente. Entre los pacientes COVID-19 que fallecieron, 34,4% mostraron incrementos de procalcitonina. Al contrario, entre los pacientes que sobrevivieron sólo en 8,8% se observó incrementos de procalcitonina evidenciándose un vínculo entre el incremento de procalcitonina y mortalidad. CONCLUSIONES. No existe diferencia en relación al incremento en los valores de procalcitonina en pacientes COVID-19 con co-infección o infección secundaria por Klebsiella pneumoniae y Pseudomonas aeruginosa multidrogo y extremadamente resistente y los valores de procalcitonina en pacientes con coinfección e infección secundaria con otro tipo de aislamientos bacterianos.

INTRODUCTION. Procalcitonin is a biomarker that can be used as a diagnostic support in bacterial infections and the monitoring of antibiotic treatment, especially in patients with sepsis. Hence, it was used during the COVID-19 pandemic OBJECTIVE. To determine the values of procalcitonin in patients with COVID-19 and to define a possible correlation between its increase and linkage in co-infection or secondary infection by Klebsiella pneumoniae and Pseudomonas aeruginosa with multidrug resistance and extended resistance to antibiotics. MATERIALS AND METHODS. Retrospective observational, descriptive cross-sectional study, conducted from May 1 to October 31, 2020 at the Hospital de Especialidades Carlos Andrade Marín on 7028 adult patients, hospitalized, with diagnosis of COVID-19, and procalcitonin results, whose tracheal secretion and/or blood culture samples presented development of Klebsiella pneumoniae and Pseudomonas aeruginosa. Their statistical analysis was developed using Pearson's Chi-squared test. RESULTS. We received 861 blood culture and 391 tracheal secretion samples, obtaining: 32% isolates of Klebsiella pneumoniae and multidrug-resistant and extremely resistant Pseudomonas aeruginosa. Among the COVID-19 patients who died, 34.4% showed increased procalcitonin levels. On the contrary, among patients who survived, only 8.8% showed increased procalcitonin levels, showing a link between increased procalcitonin levels and mortality. CONCLUSIONS. There is no difference in relation to the increase in procalcitonin values in COVID-19 patients with co-infection or secondary infection by Klebsiella pneumoniae and multidrug-resistant and extremely resistant Pseudomonas aeruginosa and procalcitonin values in patients with co-infection and secondary infection with other types of bacterial isolates.

Uso de ceftazidima-avibactam en una recién nacida prematura con infección urinaria bacteriémica por Klebsiella pneumoniae productora de carbapenemasa / Use of ceftazidime-avibactam in a preterm infant with urinary tract infection with bacteremia caused by carbapenemase-producing Klebsiella pneumoniae

Los recién nacidos tienen un alto riesgo de morbimortalidad asociada a infecciones durante su estancia en unidades de cuidado intensivo neonatal, a lo que se asocia un aumento progresivo de infecciones por microorganismos multi-resistentes que requiere el uso de nuevos antimicrobianos. Presentamos el caso de una recién nacida de pretérmino de 36 semanas que cursó con una infección del tracto urinario bacteriémica por Klebsiella pneumoniae productora de carbapenemasa tratada de forma efectiva con 14 días de cefazi- dima-avibactam, sin efectos adversos observados. Según nuestro conocimiento, este es el primer caso reportado en nuestro país del uso de este antimicrobiano en población neonatal. Se necesita más información sobre la eficacia y seguridad de ceftazidima-avibactam en este grupo de pacientes.

Neonates are high risk patients regarding morbimortality secondary to infections during their neonatal intensive care unit stay, which is associated to a progressive increase in the report of multidrug resistant organism infections, that require the use of new antimicrobial. We report the case of a 36-week preterm with an urinary tract infection with bacteriemia caused by carbapenemase- producing Klebsiella pneumoniae treated effectively with 14 day of ceftazidime-avibactam, without observed adverse effects. To our knowledge, this is the first case report in our country of the use of this antibiotic in neonatal population. More information is needed regarding efficacy and safety of ceftazidime-avibactam in this group of patients.

High-risk clones of ESBL-producing Klebsiella pneumoniae colonizing ICU patients in Natal, northeastern Brazil / Clones de alto risco de Klebsiella pneumoniae produtores de ESBL colonizando pacientes de UTI em Natal, Nordeste do Brasil / Clones de alto riesgo de Klebsiella pneumoniae productores de BLEE que colonizan pacientes de UCI en Natal, noreste de Brasil

Background and objectives: colonization by extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae in Intensive Care Unit (ICU) patients is considered a risk factor for infections, and poses as a source of spreading these strains in hospital facilities. This study aimed to perform the genetic characterization of ESBL-producing K. pneumoniae isolates recovered from surveillance swabs in an ICU in northeastern Brazil. Methods: the isolates were recovered between 2018-2019 from the nasal, axillary, and rectal sites of 24 patients admitted to the ICU. Bacterial identification was performed by traditional biochemical tests. Antimicrobial susceptibility was assessed by disk diffusion, and ESBL phenotype was detected by double-disc synergy test. Polymerase chain reaction (PCR) for blaCTX-M, blaSHV, and blaTEM genes, PFGE, and MLST were carried out in representative isolates. Results: a total of 27 isolates were recovered from 18 patients (75%). The ESBL production was detected in 85% of isolates. Resistance to ciprofloxacin, sulfamethoxazole/trimethoprim and most of the ß-lactams tested was recurrent, except for carbapenems. The blaSHV, blaTEM, and blaCTX-M genes were found in high frequency, and the CTX-M-(1, 2 and 9) groups were identified. Seven sequence types (ST11, ST14, ST17, ST395, ST709, ST855, and ST3827) were described, most of them considered high-risk. Conclusion: these findings emphasize the potential threat of well-established high-risk clones in an ICU, and highlight the importance of monitoring these clones to prevent infections.(AU)

Justificativa e objetivos: a colonização por Klebsiella pneumoniae produtora de ß-lactamase de espectro estendido (ESBL) em pacientes de Unidade de Terapia Intensiva (UTI) é considerada um fator de risco para infecções, e representa uma fonte de disseminação dessas cepas em instalações hospitalares. Este estudo objetivou realizar a caracterização genética de isolados de K. pneumoniae produtores de ESBL recuperados de swabs de vigilância em uma UTI no Nordeste do Brasil. Métodos: os isolados foram recuperados entre 2018-2019 dos sítios nasal, axilar e retal de 24 pacientes internados na UTI. A identificação bacteriana foi realizada por testes bioquímicos tradicionais. A suscetibilidade antimicrobiana foi avaliada por disco-difusão, e o fenótipo ESBL foi detectado pelo teste de sinergia de duplo-disco. Polymerase chain reaction (PCR) para os genes blaCTX-M, blaSHV e blaTEM, PFGE e MLST foram realizados em isolados representativos. Resultados: foram recuperados 27 isolados de 18 pacientes (75%). A produção de ESBL foi detectada em 85% dos isolados. A resistência à ciprofloxacina, sulfametoxazol/trimetoprima e à maioria dos ß-lactâmicos testados foi recorrente, exceto para os carbapenêmicos. Os genes blaSHV, blaTEM e blaCTX-M foram encontrados em alta frequência, e os grupos CTX-M-(1, 2 e 9) foram identificados. Sete sequence types (ST11, ST14, ST17, ST395, ST709, ST855 e ST3827) foram descritos, a maioria deles considerados de alto risco. Conclusão: esses achados enfatizam a ameaça potencial de clones de alto risco bem estabelecidos em uma UTI, e destacam a importância do monitoramento desses clones para prevenir infecções.(AU)

Justificación y objetivos: la colonización por Klebsiella pneumoniae productora de ß-lactamasas de espectro extendido (BLEE) en pacientes de Unidades de Cuidados Intensivos (UCI) se considera un factor de riesgo para infecciones, y se presenta como una fuente de propagación de estas cepas en instalaciones hospitalarias. Este estudio tuvo como objetivo realizar la caracterización genética de aislamientos de K. pneumoniae productores de BLEE recuperados de hisopos de vigilancia en una UCI en el noreste de Brasil. Métodos: los aislamientos se recuperaron entre 2018-2019 de sitios nasales, axilares y rectales de 24 pacientes ingresados en la UCI. La identificación bacteriana se realizó mediante pruebas bioquímicas tradicionales. La susceptibilidad antimicrobiana se evaluó mediante difusión en disco, y el fenotipo BLEE se detectó mediante la prueba de sinergia de doble-disco. La polymerase chain reaction (PCR) para los genes blaCTX-M, blaSHV y blaTEM, PFGE y MLST se llevaron a cabo en aislamientos representativos. Resultados: se recuperaron 27 aislamientos de 18 pacientes (75%). La producción de ESBL se detectó en 85% de los aislamientos. La resistencia a ciprofloxacino, sulfametoxazol/trimetoprima y a la mayoría de los ß-lactámicos evaluados fue recurrente, excepto a los carbapenémicos. Los genes blaSHV, blaTEM y blaCTX-M se encontraron en alta frecuencia, y se identificaron los grupos CTX-M-(1, 2 y 9). Se describieron siete sequence types (ST11, ST14, ST17, ST395, ST709, ST855 y ST3827), la mayoría consideradas de alto riesgo. Conclusión: estos hallazgos enfatizan la amenaza potencial de los clones de alto riesgo bien establecidos en una UCI, y resaltan la importancia de monitorear estos clones para prevenir infecciones.(AU)

Caracterización de la utilización de colistín en un hospital de alta complejidad / Evaluation of colistin use in a highly complex hospital

RESUMEN: El aumento de la resistencia y la escasez de nuevos antibacterianos ha requerido la reintroducción de antiguos antimicrobianos entre ellos colistín. OBJETIVO: Caracterizar la utilización de colistín durante el año 2017 en un hospital universitario, mediante la descripción de los pacientes, los tratamientos, la microbiología asociada y efectos adversos. PACIENTES Y MÉTODOS: Trabajo observacional retrospectivo. Se revisaron los datos de todos los pacientes que recibieron colistín intravenoso (IV) por al menos 48 horas, durante el año 2017. RESULTADOS: Se incluyeron 53 pacientes, equivalentes a 91 tratamientos. El foco respiratorio fue el principal (46,2%). El 68,1% de los tratamientos fue iniciado en la UCI. La mayoría de los pacientes tenía una hospitalización reciente (83,5%), y presentaban uso previo de antibacterianos (89%). Los dos patógenos mayoritariamente identificados fueron Pseudomonas aeruginosa y Klebsiella spp. El consumo promedio de colistín fue de 2,4 DDD/100 camas/día. El servicio que más consumió colistín fue la UCI, con 45,5 DDD/100 camas/día, usando generalmente la dosis de 3 MUI cada 8 horas IV y con una baja utilización de dosis de carga. CONCLUSIÓN: Colistín corresponde a un antimicrobiano de uso restringido a infecciones sospechadas o confirmadas por agentes bacterianos multi resistentes. En esta serie, su uso inicial fue principalmente empírico, en pacientes con factores de riesgo para resistencia antibacteriana; se usó en forma asociada a otros antimicrobianos, siendo el foco principal el respiratorio.

BACKGROUND: The increase in resistance and the shortage of new antibiotics has led to the reintroduction of old antimicrobials such as colistin. AIM: To evaluate the use of colistin during 2017 in a university hospital, through the characterization of patients and treatment, associated microbiology, response to treatment and adverse effects. METHODS: Retrospective observational design. The data of all patients who received colistin for at least 48 hours during the year 2017 were reviewed. RESULTS: 55 patients were included, equivalent to 144 treatments. The respiratory focus was the main one (57.9%). 64% of the treatments began in the ICU, while 7% in the ward. Most of the patients has a recent hospitalization (86.8%) and has previous use of antibiotics (90.4%). The two main pathogens identified were Pseudomonas aeruginosa and Klebsiella spp. In 87.1% of the cases with microbiological justifications for the use of colistin, a favorable response was obtained. The average consumption of colistin was 2.4 DDD/100 beds/day. The department that consumed the most colistin was the ICU, with 45,5 DDD/100 beds/day, generally using a dose of 3 MIU every 8 hours IV and with low use of loading doses. CONCLUSION: Colistin corresponds to an antibiotic whose use is restricted to infections suspected or confirmed by multi-resistant bacterial agents. Its initial use in this serie was mainly empirical, in patients with risk factors for antibiotics resistance, it was used in association with other antimicrobials, being the respiratory the main infectious focus.

Six-Year Surveillance of Acquired Bloodstream Infection in a Pediatric Intensive Care Unit in Israel

Objectives: We studied the profile of bloodstream infections (BSI) in the pediatric intensive care unit (PICU) and identified predictors of mortality. Methods: The study collected data from hospital records for children younger than 18-years who developed BSI during their PICU stay between 2014 and 2019. Results: In 114 patients, 136 PICU-acquired BSIs with 152 pathogens were documented. The incidence of BSI was 47.12/1000 PICU admissions and 7.95/1000 PICU hospital days. Gram-negative rods accounted for 75% of isolates, Gram-positive cocci accounted for 21.7% of isolates, and fungi accounted for 3.3% of isolated pathogens. ICU mortality was observed in 25 (21.9%) patients with a BSI compared to 94 (3.1%) patients without a BSI (P<0.001). Hemodynamic instability (P=0.014, OR 4.10, 95%CI 1.33-12.66), higher blood urea nitrogen (BUN) (P=0.044), and lower albumin levels (P=0.029) were associated with increased risk of ICU mortality. Conclusion: BSI in the PICU is associated with increased mortality. Early identification and management of risk factors independently associated with poor clinical outcomes in these patients should be aimed to ensure improved survival.

Evaluation of the combination treatments with intravenous fosfomycin for carbapenem-resistant Klebsiella pneumoniae

SUMMARY OBJECTIVE: The aim of this study was to evaluate the combination treatments with intravenous fosfomycin for carbapenem-resistant Klebsiella pneumoniae infections in a tertiary-care center. METHODS: Between December 24, 2018 and November 21, 2022, adult patients diagnosed with bloodstream infection or ventilator-associated pneumonia due to culture-confirmed carbapenem-resistant Klebsiella pneumoniae in the anesthesiology and reanimation intensive care units were investigated retrospectively. RESULTS: There were a total of 62 patients fulfilling the study inclusion criteria. No significant difference was recorded in 14- and 30-day mortality among different types of combination regimens such as fosfomycin plus one or two antibiotic combinations. Hypokalemia (OR:5.651, 95%CI 1.019-31.330, p=0.048) was found to be a significant risk factor for 14-day mortality, whereas SOFA score at the time of diagnosis (OR:1.497, 95%CI 1.103-2.032, p=0.010) and CVVHF treatment (OR:6.409, 95%CI 1.395-29.433, p=0.017) were associated with 30-day mortality in multivariate analysis. CONCLUSION: In our study, high mortality rates were found in patients with bloodstream infection or ventilator-associated pneumonia due to carbapenem-resistant Klebsiella pneumoniae, and no significant difference was recorded in 14- and 30-day mortality among different types of combination regimens such as fosfomycin plus one or two antibiotic combinations.

Colistin resistance in Escherichia coli and Klebsiella pneumoniae in humans and backyard animals in Ecuador / Resistencia a la colistina de las bacterias Escherichia coli y Klebsiella pneumoniae en humanos y animales de granja en Ecuador / Resistência à colistina em Escherichia coli e Klebsiella pneumoniae em humanos e animais de quintal no Equador

ABSTRACT Objective. Colistin is an antibiotic of last resort for treating serious Gram-negative bacterial infections. However, the misuse of colistin, especially as an animal growth promoter, has contributed to increasing antimicrobial resistance, mediated mainly through plasmid transfer of the mcr-1 gene. This study assessed the prevalence of phenotypic and molecular colistin resistance in Escherichia coli and Klebsiella pneumoniae in Ecuador in healthy humans and their chickens and pigs. Methods. Fecal samples were collected from humans and their chickens and pigs in two rural coastal and Amazon regions between April and August 2020. Gram-negative bacteria were isolated and identified using conventional techniques. Phenotypic resistance was determined using the broth microdilution technique, and the mcr-1 gene was detected using conventional polymerase chain reaction. Results. A total of 438 fecal samples were obtained from 137 humans, 147 pigs and 154 chickens. The prevalence of E. coli isolates was 86.3% (378/438) and K. pneumoniae, 37.4% (164/438). Overall, the mcr-1 gene was found in 90% (340/378) of E. coli isolates, with higher prevalences found in isolates from coastal regions (96.5%, 191/198), humans (95.6%, 111/116) and chickens (91.8%, 123/134); for K. pneumoniae, the gene was found in 19.5% (32/164) of isolates, with equal distribution between regions and hosts. Only four isolates, two E. coli and two K. pneumoniae, showed phenotypic resistance: mcr-1 was present in both E. coli strains but absent in the K. pneumoniae strains. Conclusions. Despite a low prevalence of phenotypic resistance to colistin, the high prevalence of the mcr-1 gene in E. coli is of concern. Ecuador's ban on using colistin in animal husbandry must be enforced, and continual monitoring of the situation should be implemented.

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RESUMO Objetivo. A colistina é um antibiótico de último recurso para o tratamento de infecções graves por bactérias Gram-negativas. Entretanto, o uso indevido da colistina, principalmente como promotor de crescimento animal, tem contribuído para o aumento da resistência a antimicrobianos, principalmente por transferência horizontal do gene mcr-1 mediada por plasmídeos. Este estudo avaliou a prevalência de resistência fenotípica e molecular à colistina em Escherichia coli e Klebsiella pneumoniae no Equador em humanos hígidos e em galinhas e porcos por eles criados. Métodos. Entre abril e agosto de 2020, foram coletadas amostras de fezes de habitantes de duas regiões litorâneas e amazônicas do Equador e de galinhas e porcos por eles criados. Bactérias Gram-negativas foram isoladas e identificadas por meio de técnicas convencionais. A resistência fenotípica foi determinada pela técnica de microdiluição em caldo, e o gene mcr-1 foi detectado por reação em cadeia da polimerase convencional. Resultados. Foram obtidas 438 amostras fecais de 137 humanos, 147 suínos e 154 galinhas. A prevalência de isolados de E. coli foi de 86,3% (378/438), e de K. pneumoniae, 37,4% (164/438). Em geral, o gene mcr-1 foi encontrado em 90% (340/378) dos isolados de E. coli, com maiores prevalências encontradas em isolados de regiões litorâneas (96,5%, 191/198), humanos (95,6%, 111/116) e galinhas (91,8%, 123/134); para K. pneumoniae, o gene foi encontrado em 19,5% (32/164) dos isolados, com igual distribuição entre regiões e hospedeiros. Somente quatro isolados, dois de E. coli e dois de K. pneumoniae, demonstraram resistência fenotípica: o gene mcr-1 estava presente em ambas as cepas de E. coli, mas ausente nas de K. pneumoniae. Conclusões. Apesar da baixa prevalência de resistência fenotípica à colistina, a alta prevalência do gene mcr-1 em E. coli é preocupante. É preciso fiscalizar a proibição ao uso agropecuário de colistina no Equador e implementar o monitoramento contínuo da situação.

Endoftalmitis endógena por Klebsiella pneumoniae: reporte de 2 casos y revisión de literatura referente a K. pneumoniae hipermucoviscosa e hipermucovirulenta / Endogenous Klebsiella pneumoniae endophthalmitis: report of 2 cases and literature review regarding hypermucoviscous and hypermucovirulent K. pneumoniae

Objetivo: Reportar dos casos de endoftalmitis endógena por Klebsiella pneumoniae hipermucoviscosa y revisar las características clínicas de esta entidad que ha aumentado su prevalencia en países occidentales. Observaciones: Dos pacientes fueron diagnosticados con endoftalmitis endógena por K. pneumoniae con confirmación microbiológica de un origen abdominal, uno de ellos por un absceso hepático y el otro por un absceso renal. Ambos pacientes fueron sometidos a vitrectomía precoz, y a antibióticos intravítreos/intravenosos, no obstante uno requirió evisceración y el otro presentó una agudeza visual de percepción de luz. Conclusiones e importancia: K. pneumoniae es la primera causa de endoftalmitis endógena en Asia oriental, pero es poco frecuente en los países occidentales. Sin embargo su prevalencia en esta última población parece estar aumentando en asociación con las variantes hipermucoviscosas e hipervirulentas de este microorganismo. La detección temprana y el tratamiento temprano de esta enfermedad son fundamentales para preservar la anatomía del ojo.

Objective: To report two cases of hypermucoviscous Klebsiella pneumoniae endogenous endophthalmitis and to review the clinical characteristics of this aggressive disease whose prevalence appears to be increasing in western countries. Observations: Two patients were diagnosed with K. pneumoniae endogenous endophthalmitis with microbiological confirmation of an abdominal source, one from a hepatic abscess and the other with a renal abscess. Both patients underwent early vitrectomy, and intravitreal/intravenous antibiotics, nonetheless one required evisceration and the other presented a postoperative visual acuity of light perception. Conclusions and importance: K. pneumoniae is the first cause of endogenous endophthalmitis in eastern Asia, but it is rare in western countries. Nevertheless, its prevalence in the latter population appears to be increasing in association with the hypermucoviscous and hypervirulent variants of this microorganism. The early detection and early management of this disease are pivotal to preserve the anatomy of the eye.

A case report of brain abscess caused by carbapenem-resistant Klebsiella pneumoniae

ABSTRACT The treatment of infections caused by carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains is difficult due to the limited antimicrobial options and high mortality. There are many reports on intracranial infections caused by CR-Kp, but only a few on brain abscesses caused by CR-Kp. Here, we present a case of brain abscess caused by CR-Kp successfully treated with combined antibiotics. A 26-year-old male patient was admitted to our hospital due to high fever and headache. His past medical history includes a surgical intervention due to an acute subdural hematoma, performed at an external healthcare center. After the current diagnosis of cerebral abscess, he underwent two surgeries. During the procedure, multiple cerebral abscesses were drained and capsulotomies were performed under ultrasound guidance. The combination of meropenem and vancomycin was started. The contents of the abscesses were sent to the microbiology and pathology laboratory. On the 3 rd day of treatment, the medical team was informed that CR-Kp grew in an abscess culture. The patient's treatment was changed to meropenem + colistin + tigecycline. The patient developed electrolyte disturbances during the follow-up and this was considered an adverse effect of colistin. On the 41 st day of treatment, colistin was discontinued, fosfomycin was added, and meropenem and tigecycline were maintained. Treatment was discontinued on the 68 th day, when the patient was discharged. The general condition of the patient, who has been followed up for two years, is satisfactory. The treatment of CR-Kp infections should be individualized, and the pharmacokinetics and pharmacodynamics of antibiotics should be considered in each case.

Advances in researches of polymyxin resistance mechanism in Klebsiella pneumoniae / 中华检验医学杂志

In recent years, the carbapenem-resistant Klebsiella pneumoniae (CRKP) continues to significantly threaten public health. The limited therapeutic options are increasingly challenging for clinicians to reintroduce the polymyxin as last-resort drug, with the results that polymyxin resistance is not scarce in settings. The polymyxin resistance mechanism is diversified, mainly the modification of the lipopolysaccharide (LPS). In addition to phoPQ, pmrAB, crrAB and mgrB on chromosome, plasmid-carried mcr gene have been found to mediate the LPS modification. The mgrB gene variation plays an important role in polymyxin resistance. Above all, the aim of the current review is to discuss the mechanism of polymyxin resistance mechanism in Klebsiella pneumoniae provide insights for preventing this phenomenon.

Comparison of the diagnostic effect on different machine learning predictive model of imipenem sensitivity of Klebsiella pneumoniae based on MALDI-TOF MS / 中华检验医学杂志

Objective:Machine learning is not only an important branch of artificial intelligence, but also supporting technologies for bioinformatics analysis. In the presence work, four machine-learning-predictive model for the drug-sensitivity of Klebsiella pneumoniae to imipenem were established based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and the diagnostic effect of these methods was exmained. Methods:A retrospective study was performed and the data of MALDI-TOF-MS and imipenem sensitivity of a total number of 684 cases Klebsiella pneumoniae isolated from clinical specimens in the laboratory of microbiology department of Tianjin Haihe Hospital from 2019 January to 2020 December were collected. The mass spectrometry and imipenem sensitivity data of 70 cases identified as imipenem-sensitive and 70 resistant cases were simple randomly selected to establish the training set model; whereas 30 cases of sensitive and 30 cases of resistant cases were randomly selected to establish the test set model. Mass spectral peak data were subjected to Orthogonal Partial least squares Discriminant Analysis (OPLS-DA). The training set data model was established by machine learning least absolute shrinkage and selection operator (LASSO) algorithm, Logistic Regression (LR) algorithm, Support vector machines (SVM) algorithm, neural network (NN) algorithm. The area under the curve (AUC) and confusion matrix of training set and test set model were calculated and selected by Grid search and 10-fold Cross-validation respectively, the accuracy of the prediction model was verified by test set confusion matrix. Results:The R2Y and Q2 of OPLS-DA were 0.546 3 and 0.017 8. The AUC of the best training set and test set models were 1.000 0 and 0.858 1, 1.000 0 and 0.820 1, 0.940 8 and 0.756 1, 1.000 0 and 0.697 2 evaluated by LASSO, LR, SVM and NN model respectively. The accuracy of the model were 99% (69/70), 100% (70/70), 91% (64/70) and 100% (70/70) for prediction of drug resistance, 100% (70/70), 100% (70/70), 90% (63/70) and 100% (70/70) for drug sensitivity prediction, the correct rate were 99% (139/140), 100% (140/140), 91% (127/140) and 100% (140/140) in training set, the test set showed that the accuracy were 93% (28/30), 87% (26/30), 60% (18/30) and 60% (18/30) for prediction of drug resistance, 100% (30/30), 80% (24/30), 93% (28/30) and 67% (20/30) for drug sensitivity prediction, the correct rate were 97% (58/60), 83% (50/60), 77% (46/60) and 63% (38/60) by LASSO, LR, SVM and NN model respectively.Conclusion:The LASSO prediction model of Klebsiella pneumoniae sensitivity to imipenem established in this study has a high accuracy rate and has potential clinical decision support ability.

Mechanism of polymyxin resistance related to lipopolysaccharide modification in carbapenem-resistant Klebsiella pneumoniae / 中华微生物学和免疫学杂志

Objective:To investigate the mechanism of polymyxin resistance related to lipopolysaccharide modification in carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods:Plasmid-mediated drug resistance genes in seven CRKP strains were detected by conjugation assay and mcr gene detection. The expression of polymyxin resistance-related genes was measured using quantitative real-time PCR. The complete genomes of CRKP strains were sequenced. Silver staining and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) were performed to analyze the changes in lipopolysaccharide (LPS). Results:The seven CRKP strains were negative for mcr genes and the results of conjugation assay were also negative. Moreover, no mobile genetic elements related to drug resistance were detected. Compared with wild-type strain, all seven CRKP strains that were resistant to polymyxin showed increased expression of pmrA, pmrB and pmrC genes at the transcriptional level; six showed increased expression of phoP/ phoQ genes; three showed decreased expression of crrA/ crrB genes; four showed decreased expression of mgrB gene. The missense mutation sites in drug-resistant strains were mainly in KPHS_09430, KPHS_35900, KPHS_39520 and KPHS_52420. IS Kpn14 insertion sequence was detected in CRKP-6 strain. MALDI-TOF-MS reveals the modification of natural lipid A with L-Ara4N in CRKP LPS. Conclusions:LPS modification induced by chromosome-mediated mutation in the two-component regulatory system was the main molecular mechanism of polymyxin resistance in CRKP isolates in this study. Effects of the mutation in the two-component system on polymyxin resistance varied in different strains.

Programmed cell death induced by Klebsiella pneumoniae infection / 中华微生物学和免疫学杂志

Klebsiella pneumoniae can cause a variety of infectious diseases, especially in immunocompromised population. The emergence of multidrug-resistant hypervirulent Klebsiella pneumoniae has greatly limited the choice of treatment for Klebsiella pneumoniae infection, and the exploration of new treatment strategies is imminent. In the process of infection, there is a complex interaction between the programmed cell death of host cells and the invasion of Klebsiella pneumoniae. This paper mainly reviewed the research progress in several mechanisms of programmed cell death such as pyroptosis, apoptosis, necroptosis and autophagy caused by Klebsiella pneumoniae.