Ceftazidima/avibactam frente a otros antimicrobianos para el tratamiento de bacteriemias por Enterobacterales productores de carbapenemasa KPC: datos de la vida real en un hospital universitario de Argentina

Introducción: Las bacteriemias por Enterobacterales productores de carbapenemasa KPC (EPC-KPC) presentan una mortalidad elevada y opciones terapéuticas limitadas. Objetivos: Describir y comparar la evolución de los pacientes con bacteriemia por EPC-KPC tratados con ceftazidima/avibactam (CA) frente a otros antimicrobianos (OA). Pacientes y Métodos: Estudio prospectivo y retrospectivo de casos y controles. Se incluyeron pacientes adultos con bacteriemia por EPC-KPC, con una proporción entre casos tratados con CA y controles tratados con OA. de 1:2. Se analizaron variables clínicas, epidemiológicas y de evolución. Resultados: Se incluyeron 48 pacientes (16 CA y 32 OA). Los casos se encontraban más frecuentemente neutropénicos (50 vs.16%, p = 0,012); asimismo, presentaron medianas de score de APACHE II más altas y de score de Pitt más bajas. El 65% de la cohorte total presentó un foco clínico y Klebsiellapneumoniae fue el microorganismo más frecuentemente aislado. Los casos recibieron una mayor proporción de tratamiento antimicrobiano empírico adecuado (81 vs. 53%, p = 0,05). La antibioterapia dirigida en casos y controles fue combinada en 38 y 91%, p = 0,009. Los casos presentaron menor mortalidad al día 7 y al día 30 relacionada a infección (0 vs. 22%, p = 0,04 y 0 vs. 34%, p = 0,008). Solo los controles desarrollaron shock, ingresaron a la unidad de cuidados intensivos y presentaron bacteriemia de brecha. Conclusión: CA mostró beneficio clínico frente a OA para el tratamiento de pacientes con bacteriemia por EPC-KPC.

Background: KPC-producing Enterobacterales bacteremia (KPCCPE) is associated with a high mortality rate and limited therapeutic options. Aim: To describe and compare the outcome of patients with KPC-CPE bacteremia treated with ceftazidime/avibactam (CA) versus other antibiotics (OA). Methods: Prospective and retrospective cases and control study performed in adult patients with KPC-CPE bacteremia, with a 1:2 ratio between cases treated with CA. and controls treated with OA. Clinical, epidemiological, and outcome variables were analyzed. Results: Forty-eight patients (16 CA and 32 OA) were included. Cases were more frequently neutropenic (50 vs. 16%, p = 0.012), presented higher median APACHE II score and lower Pitt score. Of the total cohort, 65% had a clinical source, and Klebsiella pneumoniae was the most frequently isolated microorganism. Cases received more adequate empirical antibiotic treatment (81 vs. 53%, p = 0.05). Targeted antibiotic therapy in cases and controls was combined in 38 and 91%, p = 0.009. Cases had a lower 7-day mortality and 30-day infection-related mortality (0 vs. 22%, p = 0.04 and 0 vs. 34%, p = 0.008). Only controls developed shock, were admitted to the intensive care unit, and had breakthrough bacteremia. Conclusion: CA. showed clinical benefit over OA in the treatment of patients with EPC-KPC bacteremia.

Uso de ceftazidima-avibactam en una recién nacida prematura con infección urinaria bacteriémica por Klebsiella pneumoniae productora de carbapenemasa

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.

Meningitis por Aeromonas complejo hydrophila productora de carbapenemasa: a propósito de un caso / Meningitis due to carbapenemase-producing Aeromonas hydrophila: a case report

Se describe una presentación clínica inusual de infección por Aeromonas complejo hydrophila y se destaca la importancia del correcto diagnóstico microbiológico para adecuar el tratamiento. Paciente de 6 años consultó por fiebre y drenaje de líquido serohemático de herida quirúrgica por antecedente de craneotomía con duroplastia la semana previa. Laboratorio con parámetros normales y tomografía computada sin cambios relevantes. Punción lumbar: leucocitos 91/mm3, proteínas 89 mg/dl, glucosa 36 mg/dl. Comenzó tratamiento con vancomicina y ceftazidima. Cultivo de líquido cefalorraquídeo: bacilo gramnegativo, oxidasa positivo, fermentador de glucosa. Se rotó a meropenem. A las 72 horas, se informó, por método difusión y Vitek2, Aeromonas complejo hydrophila: sensible a trimetoprimasulfametoxazol, ciprofloxacina, cefotaxima y meropenem. Se realizó método Blue Carba para detección de carbapenemasas con resultado positivo. Se rotó a trimetoprima-sulfametoxazol. Completó 21 días de tratamiento con evolución clínica favorable

Here we describe an unusual clinical presentation of infection due to Aeromonas hydrophila and underline the importance of a correct microbiological diagnosis for an adequate treatment. A 6-year-old patient with a history of craniotomy with duraplasty the week before consulted for fever and drainage of serosanguineous fluid from the surgical wound. The laboratory parameters were normal and the computed tomography scan showed no relevant changes. Lumbar puncture: leukocytes: 91/mm3; proteins: 89 mg/dL; glucose: 36 mg/dL. Treatment with vancomycin and ceftazidime was started. Cerebrospinal fluid culture: oxidase-positive, glucose-fermenting Gram-negative bacillus. Treatment was changed to meropenem. At 72 hours, using a diffusion method and Vitek 2, it was reported as Aeromonas hydrophila sensitive to trimethoprim-sulfamethoxazole, ciprofloxacin, cefotaxime, and meropenem. The Blue-Carba method was performed to detect carbapenemases; the result was positive. Treatment was changed to trimethoprimsulfamethoxazole. The patient completed 21 days of treatment with a favorable clinical course.

Molecular epidemiology of clinical isolation of carbapenem-resistant Enterobacterales and application of carbapenemase inhibitor enhancement test / 中南大学学报(医学版)

OBJECTIVES@#The prevalence of carbapenem-resistant Enterobacterales (CRE) presents a significant challenge in clinical anti-infective treatment. This study aims to investigate drug resistance and the molecular epidemiological characteristics of CRE in our area. Additionally, we seek to evaluate practicality of utilizing carbapenemase inhibitor enhancement test in clinical laboratory.@*METHODS@#Non-repeated CREs isolated from clinical specimens at Xiangya Hospital, Central South University, were collected. Minimum inhibitory concentration (MIC) combined with Kirby-Bauer (KB) assay was used to detect the drug susceptibility of the strains, and 13 carbapenemase-producing genes were detected by PCR. The phenotype of 126 strains of carbapenemase-producing Enterobacterales identified by PCR was detected by the carbapenemase inhibitor enhancement test to understand the agreement between the method and the gold standard PCR results.@*RESULTS@#Among 704 CRE strains examined, we observed significant drug resistance in 501 strains dentified as carbapenemase-producing Enterobacterales (CPE). Klebsiella pneumoniae was the predominant CPE strain, followed by Enterobacter cloacae and Escherichia coli. A total of 9 carbapenemase types were detected, including Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron- encoded metallo-β-lactamases (VIM), imipenemase (IMP), oxacillinase-48 (OXA-48), and rare imipenem-hydrolyzing β-lactamase (IMI), adelaide imipenemase (AIM), Bicêtre carbapenemase (BIC), and guiana extended-spectrum β-lactamase (GES). The detection rate of KPC serine carbapenemase was 61.7% (309/501). The carbapenemase inhibitor enhancement test exhibited a 100% consistency rate for the strains producing Class A serine carbapenemase and/or Class B metallo-β-lactamases.@*CONCLUSIONS@#CRE strains in Changsha, Hunan, China, are wide distribution and exhibit carbapenemase production. The main mechanism of carbapenem resistance in these bacterias is predominatly attributed to the production of KPC serine carbapenemase. The presence of GES and IMI genes carried by Enterobacterales has been detected for the first time in this region. The carbapenemase inhibitor enhancement test has been proven to be an accurate method for detecting CRE producing Class A serine carbapenemase and/or Class B metallo-β-lactamases. This method offers simpicity of operation and ease of results interpretation, making it weel-suited meeting the clinical microbiology laboratory's reguirements for the detection of serine carbapenemase and metallo-β-lactamases.

NDM-beta-lactamase-1: Where do we stand?

Multidrug-resistant (MDR) Gram-negative bacilli (GNB) have been playing havoc in the field of nosocomial as well as community-acquired infections. Of particular concern are the carbapenem-resistant GNBs, belonging to Enterobacteriaceae and encoding for New Delhi metallo-beta-lactamase-1 (NDM-1) gene. These strains spread rapidly and horizontally in the population, thus exhibiting MDR traits as these can harbour several resistance encoding genes to almost all antimicrobial groups. Several predisposing factors are responsible towards its spread, viz. excessive antibiotic usage, improper aseptic conditions by healthcare workers, lack of awareness, abruptly discontinuing medication course, alternative medications and vector-borne factors contributing to the unchecked harbouring of these super bugs in India. Thus, a bugle call has already been sounded worldwide especially in India, where the country has taken serious cognizance to build up strategy via implementation of several national programs to combat antimicrobial resistance covering human, animal, agriculture and environmental aspects. As there is an exponential rise in variants of NDM-1 harbouring strains, molecular epidemiological investigations of these strains using genotyping techniques are of paramount importance for a better understanding of this rampant spread and curbing resistance thereafter. This review explores the urgent need to develop a cost-effective, rapid molecular assay, viz. the loop-mediated isothermal amplification method for field detection of MBL harbouring bacterial strains, especially NDM-1 and its variants, thus targeting specific carbapenemase genes at a grass root level even to the remote and rural regions of the country.

Genomic epidemiology analysis of Enterobacter hormaechei subsp. hoffmannii / 中华检验医学杂志

Objectives:To investigate the genetic characteristics of the blaNDM-1-carrying plasmid of the multidrug resistant Enterobacter hormaechei subsp. hoffmannii clinical isolate C37, and constructing a phylogenetic tree of the 66 publicly available genomes of the Enterobacter hormaechei subsp. hoffmannii to explore its global epidemic situation. Methods:Carbapenem-resistant Enterobacter cloacae complex (CRECC) strains isolated from the First Affiliated Hospital of Sun Yat-sen University from August 2014 to August 2021 were collected. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rDNA Sanger sequencing were used for species identification. Micro broth dilution method was used for antibacterial susceptibility test. The polymerase chain reaction (PCR) was used to detect the β-lactamase resistance gene and plasmid-mediated quinolone resistance (PMQR) gene carried by the C37 strain. The conjugation experiment was used to confirm the conjugative metastasis of the resistance genes in C37 strain. Whole genome of the C37 strain was sequenced. Core genome was extracted and the phylogenetic analysis of 66 publicly available Enterobacter hormaechei subsp. hoffmannii was performed. Results:Enterobacter hormaechei subsp. hoffmannii C37 strain is resistant to third-generation cephalosporins, carbapenems, aminoglycosides and quinolones, and carries blaACT-5, blaNDM-1, qnrA1, aac(6′)-Ib-cr, oqxAB, fosA, dfrA15 and other resistance genes, as well as IncX3, IncX4, IncFIB and IncFII plasmids. Multilocus sequence typing (MLST) analysis showed that C37 strain belongs to the ST78 type of Enterobacter cloacae complex (ECC). Conclusions:ST78 type Enterobacter hormaechei subsp. hoffmannii is closely related to the spread of carbapenem resistance genes. It is a potential high-risk clone to spread carbapenem resistance genes. The prevalence and trends of ST78 type Enterobacter hormaechei subsp. Hoffmannii should be monitored.

Enterobacterales productores de carbapenemasas en sifones de lavamanos de una Unidad de Paciente Crítico

Resumen Introducción: Enterobacterales productores de carbapenemasas (EPC) son una importante causa de infecciones asociadas a la atención en salud (IAAS). El principal reservorio de EPC lo constituyen pacientes infectados y colonizados, sin embargo, también se han identificado reservorios ambientales. Objetivo: Detectar la presencia de EPC en los sifones de lavamanos de la unidad de cuidados críticos de pacientes quemados adultos (UPC QMD) y unidad de cuidados críticos de pacientes pediátricos crónicos (UCEP). Método: Se recolectaron cuatro muestras de sifones de los lavamanos ubicados en el interior de las unidades de pacientes en UCEP y 10 de UPC QMD. A las muestras se les realizó estudio fenotípico y molecular para detección de carbapenemasas en el Instituto de Salud Pública de Chile. Resultados: En los sifones estudiados de UCEP no se aislaron cepas de EPC. En UPC QMD, 50% de los sifones estudiados se aislaron cepas de EPC. Conclusiones: En UPC QMD se objetivó la presencia de EPC en una alta proporción de los sifones de lavamanos testeados, lo que demuestra un reservorio ambiental de bacterias multi-resistentes.

Abstract Introduction: Carbapenemase-producing Enterobacterales (CPE) are an important cause of health care associated infections (HAI). The main reservoir is constituted by infected and colonized patients; however, environmental reservoirs have also been identified. Objective: To detect the presence of CPE in the sink traps of the critical care unit for adult burn patients (UPC QMD) and the critical care unit for chronic pediatric patients (UCEP). Material and Method: Four samples of trap were collected from the sinks located inside the patient units at PICU and 10 at UPC QMD. The samples underwent a phenotypic and molecular study for the detection of carbapenemases at the Institute of Public Health of Chile. Results: In the UCEP no EPC strains were isolated. In UPC QMD, CPE was detected in 50% of the traps. Conclusions: In UPC QMD, the presence of CPE was observed in a high proportion of the tested sinks traps, which shows an environmental reservoir of multi-resistant bacteria.

Occurrence of extended-spectrum beta-lactamase (ESBL) and carbapenemases among ampicillin-resistant enterobacteriales recovered from a municipal raw sewage in Minas Gerais, Brazil

SUMMARY Introduction: The capacity of resistance to ß-lactam among enterobacteriales is notable, mainly into water environment. Herein, many species of this family have the ability to carrier and produce ß-lactamases enzymes, such as extended-spectrum ß-lactamases (ESBLs) and carbapenemases. However, contrary to clinical settings, where the distribution of resistant bacteria is well documented, the evidence of resistant pathogens in the domestic sewage has been little explored, especially in Brazil. Thus, we aimed to investigate the occurrence of ESBL and carbapenemases between ampicillin-resistant enterobacteriales recovered from a municipal raw sewage in Minas Gerais, Brazil. Methods: Enterobacteriales were isolated from sewage samples on MacConkey agar supplemented with ampicillin. Species identification was performed by biochemical and morphological methods and the resistance profile determined by the Kirby-Bauer test. The production of ESBL and carbapenemase was investigated in all isolates by phenotypic tests. Results and discussion: A total of 45 species of enterobacteriales resistant to ampicillin were recovered (37 Escherichia coli, four Klebsiella pneumoniae, and one Klebsiella oxytoca, Citrobacter freundii and Pantoea agglomerans). Most isolates showed a high ß-lactam susceptibility profile (14/45, 31.1 %), however E. coli with decreased susceptibility to imipenem was detected (2/37; 2.7 %). ESBL-positive isolates were mostly identified as E. coli (10/45; 22.2 %), but no isolates were positive carbapenemase. Conclusion: Domestic sewage is an important source of ß-lactams resistant determinants in Brazil.

Introdução: a capacidade de resistência aos beta-lactâmicos entre enterobacteriales é notável, principalmente no ambiente aquático. Nessa direção, muitas espécies desta família têm a capacidade de transportar e produzir enzimas ß-lactamases, especialmente a ß-lactamases de espectro estendido (ESBL) e as carbapenemases. Porém, ao contrário do cenário clínico, onde a distribuição de bactérias resistentes é bem documentada, as evidências de patógenos resistentes no esgoto doméstico têm sido pouco exploradas, principalmente no Brasil. Assim, objetivamos investigar a ocorrência de ESBL e carbapenemases entre enterobacteriales resistentes à ampicilina recuperadas de um esgoto bruto municipal em Minas Gerais, Brasil. Métodos: enterobacteriales foram isoladas de amostras de esgoto em ágar MacConkey suplementado com ampicilina. A identificação das espécies foi realizada por métodos bioquímicos e morfológicos e o perfil de resistência determinado pelo teste de Kirby-Bauer. A produção de ESBL e carbapenemase foi investigada em todos os isolados por testes fenotípicos. Resultados e discussão: foram recuperadas 45 isolados de enterobacteriales resistentes à ampicilina (37 Escherichia coli, quatro Klebsiella pneumoniae e uma Klebsiella oxytoca, Citrobacter freundii e Pantoea agglomerans). A maioria dos isolados apresentou um perfil de alta susceptibilidade aos ß-lactâmicos (14/45, 31,1 %), porém E. coli com susceptibilidade diminuída ao imipenem foi detectada (2/37; 2,7 %). Os isolados ESBL-positivos foram identificados principalmente como E. coli (10/45; 22,2 %), mas nenhum isolado foi positivo para a carbapenemase. Conclusão: o esgoto doméstico é uma importante fonte de determinantes de resistência aos ß-lactâmicos no Brasil.

Introducción: la capacidad de resistencia a betalactámicos entre enterobacteriales es notable, principalmente en el medio acuático. En este sentido, muchas especies de esta familia tienen la capacidad de transportar y producir enzimas ß-lactamasas, especialmente ß-lactamasas de espectro extendido (BLEE) y carbapenemasas. Sin embargo, en contraste con el escenario clínico, donde la distribución de bacterias resistentes está bien documentada, la evidencia de patógenos resistentes en las aguas residuales domésticas ha sido poco explorada, especialmente en Brasil. Por lo tanto, nuestro objetivo es investigar la ocurrencia de BLEE y carbapenemasas entre enterobacteriales resistentes a ampicilina recuperadas de un alcantarillado municipal sin tratar en Minas Gerais, Brasil. Métodos: se aislaron enterobacteriales de muestras de aguas residuales en agar MacConkey suplementado con ampicilina. La identificación de las especies se realizó mediante métodos bioquímicos y morfológicos y el perfil de resistencia se determinó mediante la prueba de Kirby-Bauer. La producción de BLEE y carbapenemasa se investigó en todos los aislamientos mediante pruebas fenotípicas. Resultados y discusión: se recuperaron 45 aislamientos de enterobacteriales resistentes a ampicilina (37 Escherichia coli, cuatro Klebsiella pneumoniae y una Klebsiella oxytoca, Citrobacter freundii y Pantoea agglomerans). La mayoría de los aislamientos tenían un perfil de susceptibilidad alto a los (3-lactámicos (14/45, 31,1 %), pero se detectó E. coli con susceptibilidad reducida al imipenem (2/37; 2,7 %). Los aislamientos positivos para BLEE se identificaron principalmente como E. coli (10/45; 22,2 %), pero ningún aislado fue positivo para carbapenemasa. Conclusión: las aguas residuales domésticas son una fuente importante de determinantes de la resistencia a los ß-lactámicos en Brasil.

Primer reporte de Enterobacterales dobles productores de carbapenemasas en hospitales de Paraguay. Año 2021

RESUMEN Las carbapenemasas se encuentran ampliamente distribuidas en nuestro país, tanto en bacilos gramnegativos fermentadores como no fermentadores. Durante 2021, se ha reportado incremento de cepas con estas enzimas. Con el objetivo de evaluar la doble producción de carbapenemasas en Enterobacterales y comunicar su circulación, fue puesta a punto una PCR convencional múltiple. Estudio retrospectivo en 128 aislamientos provenientes de 20 centros colaboradores de la Red Nacional de Vigilancia de la RAM (Capital, Central e interior del país), remitidos al LCSP entre febrero y setiembre de 2021, para confirmación y genotipificación de carbapenemasas. Se realizaron pruebas fenotípicas y colorimétricas con sustratos específicos, y pruebas genotípicas (PCR convencional múltiple) para la detección simultánea de varios genes de resistencia (bla NDM, bla KPC, bla OXA-48-like, bla IMP y bla VIM). De los 128 aislamientos estudiados, 107 correspondieron a Klebsiella pneumoniae, 14 a Enterobacter cloacae complex, entre otros; aislados en mayor frecuencia de muestras de orina (30%), respiratorias (30%), sangre y catéter (24%). Los genes de resistencia a los carbapenemes detectados fueron: bla NDM (77,3%), bla KPC (17,2%); siendo confirmada la doble producción de carbapenemasas en 7 aislamientos (5,5%) provenientes de 4 centros diferentes de la capital de país y uno de Central; 6 de ellas (K. pneumoniae) con bla NDM+bla KPC y 1 (E. cloacae complex) con bla NDM+bla OXA-48-like; confirmando circulación de Enterobacterales dobles productores de carbapenemasas en el país (KPC+NDM y OXA+NDM); hallazgos que obligan a proveer de capacidades de detección, de manera a que se puedan tomar medidas oportunas y eficaces de contención y control.

ABSTRACT Carbapenemases are widely distributed in our country, both in fermenting and non-fermenting gram-negative bacilli. During 2021, an increase in strains with these enzymes has been reported. In order to evaluate the double production of carbapenemases in Enterobacterales and communicate their circulation, a multiple conventional PCR was set up. Retrospective study carried out in 128 isolates from 20 collaborating centers of the National AMR Surveillance Network (Capital, Central and interior of the country), sent to the LCSP between February and September 2021, for confirmation and genotyping of carbapenemases. Phenotypic and colorimetric tests were performed with specific substrates, as well as genotypic tests (multiple conventional PCR) for the simultaneous detection of several resistance genes (blaNDM, blaKPC, blaOXA-48-like, blaIMP and blaVIM). Of the 128 isolates studied, 107 corresponded to Klebsiella pneumoniae, 14 to Enterobacter cloacae complex, among others; isolated in higher frequency from urine (30%), respiratory (30%), blood and catheter (24%) samples. The genes for resistance to carbapenems detected were: blaNDM (77.3%), blaKPC (17.2%); the double production of carbapenemases was confirmed in 7 isolates (5.5%) from 4 different centers in the capital of the country and one in Central; 6 of them (K. pneumoniae) with blaNDM + blaKPC and 1 (E. cloacae complex) with blaNDM + blaOXA-48-like; confirming circulation of double Enterobacterales producers of carbapenemases in the country (KPC + NDM and OXA + NDM); findings that require the provision of detection capabilities, so that timely and effective containment and control measures can be taken.

Mecanismos de resistencia en aislados clínicos de Klebsiella pneumoniae

Resumen La bacteria Klebsiella pneumoniae es la causante de infecciones intrahospitalarias multirresistentes, posee diversos mecanismos de resistencia como la producción de enzimas betalactamasas cuya acción afecta a los antibióticos betalactámicos. Objetivo: Caracterizar los mecanismos de resistencia presentes en aislados clínicos con Klebsiella pneumoniae identificados mediante métodos fenotípicos en el Hospital Monte Sinai desde enero de 2018 hasta agosto de 2020. Materiales y métodos: Estudio positivista con un enfoque cuantitativo de corte transversal descriptivo de diseño documental. La población estuvo conformada por 274 datos de aislados clínicos identificados con Klebsiella pneumoniae. Los cuales conformaron la totalidad de la muestra con un muestreo por cobertura total. Mismos que fueron recopilados de fuentes secundarias ingresados en la base de datos del departamento de Microbiología. Para el análisis se utilizó estadística descriptiva. Resultados: Klebsiella pneumoniae mostró mayor frecuencia en el año 2020 con el 35%. Se identificó al mecanismo de resistencia BLEE con el 27,7% y carbapenemasas tipo KPC con el 7.7 %, con mayor presencia en el sexo masculino. Presentó una mayor resistencia a Penicilinas, una sensibilidad moderada a Cefalosporinas, Aminoglucósidos, Quinolonas y una alta sensibilidad a los Carbapenémicos, Tigeciclina y Colistina. Los aislados se clasificaron como multidrogorresistentes, con mayor frecuencia en Urocultivo, Aspirado bronquial, Líquido corporal, Punta de Catéter y Hemocultivo en áreas de Hospitalización, UCI y Neonatología. Conclusiones: Los mecanismos de resistencia de K. pneumoniae a los antibióticos son un hallazgo común en ambientes hospitalarios independientemente de sexo, servicio hospitalario o tipo de muestra, convirtiéndose en un problema de salud pública.

Abstract The bacterium Klebsiella pneumoniae is the cause of multiresistant intrahospital infections, it has various resistance mechanisms such as the production of beta-lactamase enzymes whose action affects beta-lactam antibiotics. Objective: To characterize the resistance mechanisms present in clinical isolates with Klebsiella pneumoniae identified by phenotypic methods at Monte Sinai Hospital from January 2018 to August 2020. Materials and methods: Positivist study with a descriptive cross-sectional quantitative approach to documentary design. The population consisted of 274 data from clinical isolates identified with Klebsiella pneumoniae. Which made up the entire sample with a total coverage sampling. The same ones that were collected from secondary sources entered in the database of the Microbiology department. Descriptive statistics were used for the analysis. Results: Klebsiella pneumoniae showed a higher frequency in 2020 with 35%. The ESBL resistance mechanism was identified with 27.7% and KPC-type carbapenemases with 7.7%, with a higher presence in males. It presented a greater resistance to Penicillins, a moderate sensitivity to Cephalosporins, Aminoglycosides, Quinolones and a high sensitivity to Carbapenems, Tigecycline and Colistin. The isolates were classified as multidrug resistant, more frequently in Urine culture, Bronchial aspirate, Body fluid, Catheter Tip and Blood culture in Hospitalization, ICU and Neonatology areas. Conclusions: The resistance mechanisms of K. pneumoniae to antibiotics are a common finding in hospital settings regardless of sex, hospital service or type of sample, becoming a public health problem.

Resumo A bactéria Klebsiella pneumoniae é causa de infecções intra-hospitalares multirresistentes, possui diversos mecanismos de resistência como a produção de enzimas beta-lactamase cuja ação afeta os antibióticos beta-lactâmicos. Objetivo: Caracterizar os mecanismos de resistência presentes em isolados clínicos de Klebsiella pneumoniae identificados por métodos fenotípicos no Hospital Monte Sinai de janeiro de 2018 a agosto de 2020. Materiais e métodos: Estudo positivista com abordagem quantitativa transversal descritiva do design documental. A população consistia em 274 dados de isolados clínicos identificados com Klebsiella pneumoniae. O que constituiu toda a amostra com uma amostra de cobertura total. Os mesmos que foram coletados em fontes secundárias e cadastrados no banco de dados do departamento de Microbiologia. Estatísticas descritivas foram utilizadas para a análise. Resultados: Klebsiella pneumoniae apresentou maior frequência em 2020 com 35%. O mecanismo de resistência a ESBL foi identificado com 27,7% e carbapenemases do tipo KPC com 7,7%, com maior presença no sexo masculino. Apresentou maior resistência às Penicilinas, sensibilidade moderada às Cefalosporinas, Aminoglicosídeos, Quinolonas e alta sensibilidade aos Carbapenêmicos, Tigeciclina e Colistina. Os isolados foram classificados como multirresistentes, com maior frequência em Urocultura, Aspirado Brônquico, Fluido Corporal, Ponta de Cateter e Hemocultura em Hospitalização, UTI e Neonatologia. Conclusões: Os mecanismos de resistência de K. pneumoniae aos antibióticos são um achado comum em ambientes hospitalares independentemente do sexo, serviço hospitalar ou tipo de amostra, tornando-se um problema de saúde pública.

Primer aislado de Pseudomonas aeruginosa productora de Sao Paulo metalo-beta-lactamasa (SPM-1) en un paciente chileno / First isolate of SPM-1- producing Pseudomonas aeruginosa (Sao Paulo metallo-beta-lactamase) in a Chilean patient

Resumen Las enzimas VIM, IMP, y NDM son carbapenemasas de tipo metalo-beta-lactamasas (MBLs) que se encuentran ampliamente distribuidas en el mundo. La SPM-1 (Sao Paulo metalo-beta-lactamasa) es una MBL que fue descrita en Pseudomonas aeruginosa en Sao Paulo (Brasil) en 2002. Comunicamos por primera vez la presencia de SPM-1 en Chile, en un aislado de P aeruginosa resistente a meropenem e imipenem, detectado en un cultivo rectal de vigilancia de carbapenemasas desde un paciente internado en nuestra institución. La secuencia del producto de la RPC fue 100% idéntica a la secuencia de SPM-1 reportada en Brasil. El paciente tenía antecedentes de una angioplastía realizada en Brasil en 2004-2005. Como consecuencia de este hallazgo, la detección de SPM mediante RPC será incorporada a la búsqueda de rutina de carbapenemasas en P aeruginosa.

Abstract VIM, IMP, and NDM carbapenemases are metallo-beta-lactamases (MBLs) that are widely distributed throughout the world. SPM-1 (Sao Paulo metallo-beta-lactamase) is an MBL that was described in Pseudomonas aeruginosa in Sao Paulo (Brazil) in 2002. We report for the first time the presence of SPM-1 in Chile, in an isolate of P aeruginosa resistant to meropenem and imipenem, detected in a carbapenemase surveillance rectal swab culture, in a patient admitted to our institution. The sequence of the PCR product was 100% identical to the sequence of SPM-1 reported in Brazil. The patient had a history of an angioplasty performed in Brazil in 2004-2005. As a consequence of this finding, the detection of SPM by PCR will be incorporated into the routine screening for carbapenemases in P aeruginosa.

Caracterización molecular de carbapenemasas en bacilos gramnegativos circulantes en hospitales de Paraguay. Primer cuatrimestre 2021 / Molecular characterization of carbapenemases in Gram-negative bacilli circulating in hospitals of Paraguay. First quarter of 2021

La resistencia a los antimicrobianos (RAM), representa un grave problema por el uso indiscriminado de antimicrobianos de amplio espectro. En nuestro país, durante el primer cuatrimestre del año, se observó un aumento inusual en el número de aislamiento de gérmenes multirresistentes, sobre todo de bacilos gramnegativos, los cuales fueron remitidos al laboratorio de referencia con el objetivo de caracterizar los genes de resistencia a los carbapenemes. Estudio observacional y prospectivo de corte transversal en 456 aislamientos de bacilos gramnegativos provenientes de 11 centros colaboradores de la Red Nacional de Vigilancia de la RAM, remitidos al Laboratorio Central de Salud Pública entre enero y abril de 2021, para la detección molecular (reacción en cadena de la polimerasa múltiple) de los genes de resistencia enzimática bla OXA-51, bla OXA-23, bla OXA-24, bla OXA-48, bla OXA-58, bla NDM, bla KPC, bla IMP, bla VIM. Trescientos sesenta correspondieron a bacilos gramnegativos no fermentadores: 346 Acinetobacter baumannii y 14 Pseudomonas aeruginosa; 96 fueron miembros de Enterobacterales, siendo prevalente Klebsiella pneumoniae (81). Todos los aislamientos de Acinetobacter baumannii resultaron ser productores de carbapenemasas: OXA-23 (94%), NDM (4%), NMD+OXA-58 (2%); en Pseudomonas aeruginosa, 7 de los 14 aislamientos (50%) fueron portadores de metalobetalactamasa del genotipo NDM (100%). Los genotipos NDM (92%) y KPC (8%) fueron confirmados en Enterobacterales. La resistencia plasmídica a carbapenemes es endémica en nuestro país, siendo prevalentes los genotipos OXA-23 en Acinetobacter baumannii y NDM en Pseudomonas aeruginosa y Enterobacterales

Antimicrobial resistance (AMR) represents a serious problem due to the indiscriminate use of broad-spectrum antimicrobials. During the first quarter of the year, an unusual increase in the number of isolation multi-resistant germs, especially gram-negative bacilli was observed, specially of Gram-negative bacilli which were referred to the reference laboratory in order to characterize the carbapenems resistance genes. Observational and prospective cross-sectional study in 456 isolates of Gram-negative bacilli from 11 collaborating centers of the National AMR Surveillance Network, referred to the Central Public Health Laboratory (LCSP) between January and April 2021, for molecular detection (multiple polymerase chain reaction) targeting the enzymatic resistance genes: bla OXA-51, bla OXA-23, bla OXA-24, bla OXA-48, bla OXA-58, bla NDM, bla KPC, bla IMP, bla VIM. Of the 456 isolates studied, 360 corresponded to non-fermenting Gram-negative bacilli, of which 346 were confirmed as Acinetobacter baumannii and 14 Pseudomonas aeruginosa; 96 were Enterobacterales, being Klebsiella pneumoniae (81) the most prevalent. All isolates of Acinetobacter baumannii carried genes encoding carbapenemases, being the OXA-23 (94%) followed by NDM (4%) and NDM +OXA-58 (2%). In Pseudomonas aeruginosa strains, 7 of the 14 isolates (50%) were carriers of NDM metallobetalactamase (100%). No carbapenemase gene was detected in the remaining 7. In all Enterobacterales strains, the presence of carbapenemases of the NDM (92%) and KPC (8%) genotypes were confirmed. Plasmid resistance to carbapenems is endemic in our country, being the OXA-23 genotypes prevalent in Acinetobacter baumannii and NDM in Pseudomonas aeruginosa and Enterobacterales

Resistencia a antibióticos de relevancia clínica en un hospital de Corrientes / Resistance to antibiotics of clinical relevance in a hospital of Corrientes city

Resumen Las bacterias productoras de carbapenemasas están involucradas en infecciones y colonizaciones y se asocian a elevada morbimortalidad. Su identificación facilita el diseño y la implementación de intervenciones dirigidas a reducir el riesgo de infecciones y óbitos. El objetivo de este estudio fue determinar la prevalencia de microorganismos productores de carbapenemasas en el principal hospital público de la ciudad de Corrientes, Argentina, y determinar sus perfiles de susceptibilidad a antibióticos comúnmente usados en la práctica clínica. Fueron incluidos 674 muestras clínicas provenientes del mismo número de adultos de las diferentes unidades de internación del Hospital Escuela Gral. José Francisco de San Martín durante el período septiembre-diciembre 2018. La identificación de las bacterias se realizó mediante pruebas bioquímicas manua les y la susceptibilidad a los antimicrobianos se evaluó según las recomendaciones del Clinical and Laboratory Standars Institute. Fueron identificadas 115 bacterias productoras de carbapenemasas de tipo KPC (90, 78%), OXA-ACI (24, 21%) y OXA-163 (~1%). De los 56 (49%) microorganismos involucrados en infecciones, la mayoría de las del tipo KPC (n=32; 57%) mostró sensibilidad solo a amikacina (27/32; 84%), mientras que la mayoría de las del tipo OXA-ACI (n=24; 43%) solo frente a minociclina (17/24; 71%) y colistina (19/24; 79%). En todas las unidades de hospitalización investigadas se comprobó la presencia de microorganismos productores de carbapenemasas y alta frecuencia de resistencia a antimicrobianos de uso habitual en la práctica clínica. Esta información es relevante para adecuar los esquemas terapéuticos y las medidas higiénico-sanitarias a la realidad local.

Abstract Carbapenemase-producing bacteria are involved in infections and colonizations and associated with high morbidity and mortality. Their identification facilitates the design and implementation of interventions aimed at reducing the risk of infections and deaths. The objective of this study was to determine the prevalence of carbapenemase-producing microorganisms in the main public hospital in the city of Corrientes, Argentina, and to determine their susceptibil ity to antibiotics commonly used in clinical practice. We analyzed 674 clinical samples from the same number of adults admitted to different inpatient units of the Hospital Escuela Gral. José Francisco de San Martín during the period September-December 2018. The bacterial identification was carried out through manual biochemical tests and the susceptibility to antimicrobials was evaluated according to the recommendations of the Clinical and Laboratory Standards Institute. We identified 115 carbapenemase-producing bacteria of the following types: KPC (90, 78%), OXA-ACI (24, 21%) and OXA-163 (~1%). Among the microorganisms involved in infections (n = 56; 49%), most of those of the KPC type (n = 32; 57%) showed sensitivity only against amikacin (27/32; 84%), while most of those of the OXA-ACI type ( 24; 43%) showed significant sensitivity only against minocycline (17/24; 71%) and colistin (n = 19/24; 79%). This study demonstrated the presence of carbapenemase-producing microorgan isms in all the investigated hospital units and a high frequency of resistance to antimicrobials commonly used in clinical practice. This information is relevant to adapt the therapeutic schemes and hygienic-sanitary measures to the local reality.

Percepciones del enfermero en el cuidado del paciente con aislamiento de contacto infectado por Klebsiella Pneumoniae carbapenemasa / Perceptions of the nurse in the care of the patient with isolation of contact infected by Klebsiella Pneumoniae carbapenemase

La percepción como concepto es el proceso mediante el cual la conciencia integra los estímulos sensoriales sobre objetos, hechos o situaciones y los transforma en experiencia útil. El presente trabajo fue una investigación cualitativa de tipo fenomenológico, cuyo objetivo principal es analizar cuáles son las percepciones del enfermero en el cuidado del paciente con aislamiento de contacto infectado por Klebsiella Pneumoniae Carbapenemasa. Los participantes fueron los enfermeros del internado general y de la unidad de terapia intensiva. El análisis de datos se realizó a través de la transcripción de las entrevistas resaltando puntos fuertes y relacionándolos entre ellos para poder obtener dimensiones y características comunes. Los participantes firmaron un consentimiento informado en donde se les solicito permiso para la grabación. Los hallazgos se organizaron en 3 dimensiones: percepción emocional del enfermero que se expresa en el miedo, la incertidumbre y la necesidad de conocimiento, el apoyo entre colegas como medio para afrontar las emociones y la igualdad y comprensión a la hora de brindar cuidado al paciente aislado por Klebsiella Pneumoniae carbapenemasa. Percepción empática que se evidencia en la empatía del personal de enfermería frente al paciente con aislamiento de contacto por Klebsiella Pneumoniae carbapenemasa. Comportamiento en la relación enfermero-paciente expresa la importancia del conocimiento y evidencia como el actuar de enfermería mejora a través de la adquisición del mismo logrando mejora en la calidad de atención brindando seguridad y confianza, no solo al paciente, sino a su propio equipo. Conclusión: Los servicios de enfermería necesitan brindar un acompañamiento con orientación desde un primer momento al enfermero que brinda cuidado al paciente con aislamiento por Klebsiella Pneumoniae carbapenemasa[AU]

Summary: perception as a concept is the process by which consciousness integrates sensory stimuli on objects, events or situations and transforms them into useful experience. The present work was a qualitative phenomenological investigation, the main objective of which is to analyze the perceptions of the nurse in the care of the patient with contact isolation infected by Klebsiella Pneumoniae Carbapenemasa. The participants were the nurses from the general boarding school and the intensive care unit. The data analysis was carried out through the transcription of the interviews, highlighting strong points nd relating them to each other in order to obtain common dimensions and characteristics. The participants signed an informed consent requesting permission for the recording. The findings were organized in 3 dimensions: emotional perception of the nurse that is expressed in fear, uncertainty and the need for knowledge, support among colleagues as a means to face emotions, and equality and understanding when providing care to the patient. isolated by Klebsiella Pneumoniae carbapenemasa. Empathic perception that is evidenced in the empathy of the nursing staff towards the patient with contact isolation due to Klebsiella Pneumoniae carbapenemase. Behavior in the nurse-patient relationship expresses the importance of knowledge and evidence of how nursing actions improve through the acquisition of it, achieving an improvement in the quality of care, providing security and confidence, not only to the patient, but to their own team. Conclusion: Nursing services need to provide guidance with guidance from the first moment to the nurse who provides care to the patient with Klebsiella Pneumoniae carbapenemasa isolation[AU]

A percepção como conceito é o processo pelo qual a consciência integra estímulos sensoriais em objetos, eventos ou situações e os transforma em experiências úteis. O presente trabalho foi uma investigação qualitativa fenomenológica, cujo objetivo principal é analisar as percepções do enfermeiro no cuidado ao paciente com isolamento de contato infectado por Klebsiella Pneumoniae Carbapenemasa. Os participantes foram os enfermeiros do internato geral e da unidade de terapia intensiva. A análise dos dados foi realizada por meio da transcrição das entrevistas, destacando os pontos fortes e relacionando-os entre si a fim de obter dimensões e características comuns. Os participantes assinaram um termo de consentimento livre e esclarecido solicitando permissão para a gravação. Os achados foram organizados em 3 dimensões: percepção emocional do enfermeiro que se expressa no medo, incerteza e necessidade de conhecimento, apoio entre os colegas como forma de enfrentar as emoções e igualdade e compreensão no cuidado ao paciente. Isolado por Klebsiella Pneumoniae carbapenemasa. Percepção empática que se evidencia na empatia da equipe de enfermagem para com o paciente com isolamento de contato por Klebsiella Pneumoniae carbapenemase. O comportamento na relação enfermeiro-paciente expressa a importância do conhecimento e da evidência de como a ação de enfermagem se aprimora por meio de sua aquisição, alcançando uma melhoria na qualidade da assistência, proporcionando segurança e confiança, não só ao paciente, mas à própria equipe. Conclusão: Os serviços de enfermagem precisam fornecer orientações com orientações desde o primeiro momento ao enfermeiro que presta cuidados ao paciente com isolamento de Klebsiella Pneumoniae carbapenemasa[AU]

Detección fenotípica y genotípica de la producción de carbapenemasas tipo NDM-1 y KPC en enterobacterias aisladas en un laboratorio clínico en Maracay, Venezuela / Phenotypic and genotypic detection of the production of carbapenemases type NDM-1 and KPC in isolated Enterobacteriaceae in a clinical laboratory in Maracay, Venezuela

INTRODUCCIÓN: La producción de beta-lactamasas capaces de hidrolizar a los carbapenémicos es uno de los mecanismos de resistencia más preocupantes porque eliminan la última opción terapéutica frente a los microorganismos multi-resistentes. OBJETIVO: Determinar la producción de carbapenemasas tipo KPC y NDM-1, empleando métodos fenotípicos y genotípicos, en enterobacterias aisladas en un laboratorio clínico de la ciudad de Maracay, Venezuela. MÉTODOS: Se determinó la producción de carbapenemasas mediante métodos fenotípicos (según algoritmo de Malbrán) y genotípicos (amplificación de los genes blaNDM-1 y blaKPC por RPC) en enterobacterias aisladas en un laboratorio clínico durante el período marzo-agosto 2018. RESULTADOS: Se identificaron 605 enterobacterias de diferentes especies, siendo Escherichia coli la cepa con mayor porcentaje de aislamiento (61,3%), seguida por Klebsiella pneumoniae (14,9%). Diez y seis enterobacterias (2,64%) fueron positivas para la producción de carbapenemasas: 13 cepas de K. pneumoniae y tres del complejo Enterobacter cloacae. La RPC demostró que 14 cepas (87,5%) contienen el gen blaNDM-1 y dos (12,5%) el gen blaKPC; se observó 100% de concordancia entre la determinación fenotípica y la RPC para ambos grupos de enzimas. CONCLUSIONES: Los resultados mostraron mayor incidencia de la metalo-beta-lactamasa tipo NDM-1, reconocida como una alarma epidemiológica debido a que su rápida diseminación dificulta su control, por lo que la identificación del tipo de enzima permitiría establecer estrategias de manejo y control más certeras con la finalidad de erradicar a dichos patógenos.

BACKGROUND: The production of carbapenem-hydrolyzing beta-lactamases is one of the most concerning resistance mechanisms since it eliminates the last therapeutic option against multidrug resistant microorganisms. AIM: To determine the production of KPC and NDM-1 type carbapenemases, using phenotypic and genotypic methods, in isolated enterobacteria in a clinical laboratory in the city of Maracay, Venezuela. METHODS: The production of carbapenemases was determined by phenotypic (according to the Malbrán algorithm) and genotypic methods (amplification of the blaNDM-1 and blaKPC genes by PCR) in clinical isolates of Enterobacteriaceae during the period March-August 2018. RESULTS: 605 Enterobacteriaceae of different species were identified, being Escherichia coli the strain with the highest percentage of isolation (61.3%), followed by Klebsiella pneumoniae (14.9%). Sixteen strains (2.64%) were positive for carbapenemases production: 13 strains of K. pneumoniae and three of the Enterobacter cloacae complex. PCR showed that 14 strains (87.5%) carry the blaNDM-1 gene and two strains (12.5%) the blaKPC gene; 100% agreement was observed between phenotypic determination and PCR for both groups of enzymes. CONCLUSIONS: The results of this study showed a higher incidence of metallo-beta-lactamase type NDM-1, which rapid dissemination and consequently difficult control has been cause of epidemiological alert. The identification of the type of enzyme would allow establishing more accurate management and control strategies in order to eradicate these pathogens.

Molecular epidemiology and drug resistance of Acinetobacter baumannii isolated from a regional hospital in the Brazilian Amazon region

Abstract INTRODUCTION: In this study, we report a clonal dissemination of carbapenem resistant Acinetobacter baumannii isolates due to the acquisition of blaOXA-23 in a regional hospital located in Brazilian Amazon Region. METHODS: The isolates were identified by MALDI-TOF and the carbapenemase-encoding genes were detected by multiplex-PCR. The genetic similarity was investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: Only 10 (55.6%) isolates harbored the gene bla OXA-23. PFGE analysis revealed that these isolates belong to a single clone. CONCLUSIONS: This dissemination strategy indicates the need for surveillance, adoption of control procedures defined in guidelines, and the careful administration of antimicrobials should be reinforced.

First report of a blaNDM-resistant gene in a Klebsiella aerogenes clinical isolate from Brazil

Abstract INTRODUCTION: Carbapenemase-resistant enterobacteria that produce the bla NDM gene are found worldwide. However, this is the first report of blaNDM in Klebsiella aerogenes in Brazil. METHODS: The identification of bacterial species was performed using anautomated system and confirmed by biochemical tests, 16S rRNA gene sequencing, and detection of resistance genes. RESULTS: The clinical isolate showed minimum inhibitory concentration resistance to meropenem and polymyxin B at 8mg/L and 4mg/L, respectively. Only the blaNDM gene was detected. CONCLUSIONS: The current report of the blaNDM gene in isolated MDR enterobacteria indicates that this gene can spread silently in a hospital setting.

Resistance and transmission mechanisms of carbapenem-resistant Enterobacterales / 中华微生物学和免疫学杂志

Objective:To investigate the resistance and transmission mechanism of carbapenem-resistant Enterobacterales (CRE), so as to provide the scientific evidence for the treatment and prevention of CRE infection.Methods:Seventy-six isolates of CRE isolated from Shaoxing Second Hospital between May 2016 and August 2018 were included. The isolates were re-identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The minimum inhibitory concentrations (MICs) of colistin, tigecycline, ceftazidime-avibactam, fosfomycin and other antibacterial drugs were determined using broth microdilution or agar dilution methods. PCR and sequencing analysis were performed to detect carbapenemase encoding genes ( blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48). Pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to analyze homology of strains. S1-PFGE combined with Southern blot hybridization were used to locate the carbapenamase genes. Filter mating test were performed to determine the horizontal transfer ability of plasmids harboring carbapenamase genes. Results:Among the 76 isolates of CRE, 51 isolates were Klebsiella pneumoniae; 10 isolates were Escherichia coli; 15 isolates were other Enterobacterales. The 76 CREs were mainly isolated from urine, sputum and blood samples. The distribution rate of ICU was the highest (55.26%). The 76 CREs showed low resistance rates (0%, 1.33%, 18.42%) to colistin, tigecycline and ceftazidime-avibactam. The resistance rates to amikacin and fosfomycin were <45%, and the resistance rates to other drugs were >97%. The detection rate of KPC-2 carbapenemase was the highest (85.33%). The ST11 CRKP producing KPC-2 carbapenemase accounted for the highest proportion (62.75%), mainly distributed in the ICU (62.50%). Southern blot hybridization showed that blaKPC-2 was mainly located on a plasmid about 90 kb (39/63). Filter mating test showed that blaKPC, blaNDM and blaIMP could be transferred horizontally to recipient bacteria through plasmids. Conclusions:The 76 CRE isolates were only susceptible to a few antibacterial drugs, such as colistin, tigecycline and ceftazidime-avibactam. The production of KPC-2 carbapenemase was the main reason for the resistance of Enterobacterales to carbapenems. KPC-2 carbapenemase-producing ST11 Klebsiella pneumoniae was the main epidemic clone of carbapenem-resistant Klebsiella pneumoniae (CRKP). The 90 kb size plasmid was the main plasmid encoding blaKPC-2 gene. Carbapenemase genes can be transferred horizontally through plasmids. The hospital should strengthen prevention of nosocomial infections to control the clonal prevalence of CRE.

Molecular biological characteristics of carbapenem-resistant Enterobacteriaceae in Shanghai / 上海预防医学

Objective:To investigate the antimicrobial resistance characteristics of carbapenem-resistant Enterobacteriaceae （CRE） isolated from outpatients with diarrhea in Shanghai， and provide support for surveillance， prevention and control of CRE. Methods:A total of 800 fecal swabs of the outpatients with diarrhea were collected from 23 sentinel hospitals for diarrhea pathogen surveillance in Shanghai from January 2018 to December 2019. The drug-resistant strains were isolated using MacConkey plates containing 1 μg/μL meropenem. The collected strains were identified preliminarily by the VITEK-2 Compact system and VITEK mass spectrometry. The minimum inhibitory concentration （MIC） of the strain was determined by the broth microdilution method. The multi-locus sequence typing （MLST） method and pulsed-field gel electrophoresis （PFGE） were used to analyze the homology of drug-resistant strains. The transferability of the resistance gene was investigated by a junction experiment. High-throughput sequencing was used to characterize the isolates. Results:Seven non-repetitive CRE isolates were multi-drug resistant carbapenem-resistant Escherichia coli （CREC） strains that produce New Delhi metallo-β-lactamase （NDM） with resistance to several commonly used antibiotics in clinical therapy. The molecular typing results showed that the CRE strains had different sequence types， and diverse PFGE patterns. The stains were all positive for blaNDM genes， including blaNDM-5 and blaNDM-13， with blaNDM-5 as the main type. The carbapenem-resistant genes could be transferred to EC600 by conjugation. Conclusion:The intestinal carbapenem-resistant strains in this study are all NDM-producing Escherichia coli. The isolates carried blaNDM and other resistance genes. The MLST analysis showed that they belonged to different cloning types. Antimicrobial resistance genes could be horizontally transferred to EC600 by conjugation.

Antimicrobial-resistant enterobacteria in surface waters with fecal contamination from urban and rural communities

Abstract INTRODUCTION: Inadequate wastewater treatment and fecal contamination have a strong environmental impact on antimicrobial resistance (AMR). This study evaluated the profile of AMR enterobacteria and fecal contamination from four surface waters: Jiquiriça-Brejões River and Cabrito, Tororó, and Abaeté Lagoons. METHODS: We analyzed AMR β-lactamase genes using the polymerase chain reaction method and fecal contamination using Coliscan®. RESULTS: We found high levels of fecal contamination, β-lactamase producers, and AMR genes (blaOXA-48, blaSPM, and blaVIM) in all waterbodies. CONCLUSIONS: Poor sanitation evidenced by fecal contamination and human activities around these surface waters contributed to the distribution and increase in AMR enterobacteria.