Novas variantes de KPC em isolados do Complexo Klebsiella pneumoniae resistentes à ceftazidima-avibactam / New KPC variants in ceftazidime-avibactam-resistant K. pneumoniae Complex isolates

O Complexo K. pneumoniae (C-Kp) é o principal grupo de bacilos Gram-negativos responsáveis por infecções nosocomiais graves em todo o mundo e o tratamento empírico dessas infecções usualmente inclui os carbapenêmicos. O principal mecanismo de resistência a essa classe de antimicrobianos é a expressão de carbapenemases, e no Brasil, mais frequentemente as do tipo KPC. Em março de 2019 a ceftazidima-avibactam foi disponibilizada para uso clínico no Brasil, sendo amplamente utilizada no tratamento infecções causadas por bacilos gram-negativos produtores de KPC. Diversos países já relataram a presença de K. pneumoniae produtores de KPC resistentes à ceftazidima-avibactam. No entanto, há poucos relatos dessa ocorrência no Brasil. O objetivo deste trabalho foi caracterizar genotipicamente e fenotipicamente isolados do C-Kp produtores de KPC, resistentes à ceftazidima-avibactam. No período de julho/2019 a julho/2021, 46 isolados do C-Kp, um por paciente, foram detectados em diferentes sítios de infecção ou culturas de vigilância de pacientes internados em hospitais privados de seis estados brasileiros. Os isolados tiveram seu genoma completo sequenciado nas plataformas MiSeq e MinION para determinação da variante alélica de blaKPC e avaliação do seu contexto genético. As taxas de resistência ao ertapenem e à ceftazidima-avibactam foram calculadas a partir de banco de dados. A clonalidade dos isolados foi avaliada por PFGE e MLST. A localização plasmidial do gene blaKPC foi confirmada por conjugação e/ou transformação. A concentração inibitória mínima (CIM) para betalactâmicos foi determinada por microdiluição em caldo segundo o BrCAST. Ensaios imunocromatográficos, NG-Test CARBA-5 e O.K.N.V.I. RESIST-5, foram avaliados quanto à sua performance na detecção de variantes KPC. A taxa de resistência ao ertapenem entre isolados do C-Kp aumentou 15,6% em 2019 para 27,3% em 2021. A taxa de resistência à ceftazidima-avibactam entre isolados do C-Kp resistentes ao ertapenem aumentou de 4,2% em 2019 para 17,2% em 2021. Onze isolados apresentaram novas variantes de KPC designadas KPC-103 a KPC-108 e KPC-139 a KPC-143. Os demais isolados apresentavam variantes de KPC já descritas, sendo a KPC-33 a variante mais frequente (36%). Quinze grupos clonais foram identificados, sendo que a maioria dos isolados pertencia ao ST11. O grupo clonal A foi o mais numeroso e pertencia ao ST258. A principal variante detectada nesse grupo foi a KPC-33. Diferentes grupos de incompatibilidade foram identificados em plasmídeos alberguando blaKPC, sendo os grupos IncN (n=12) e IncF, com replicons FII(K)-FIB (n=11), os grupos mais frequentes, seguido de InX3-IncU (n=9) e IncQ1 (n=1). Dos 46 isolados resistentes à ceftazidima-avibactam, 36 foram capazes de transferir o gene blaKPC para cepas receptoras. A maioria dos isolados foi sensível dose padrão ou sensível aumentabdo exposição ao meropenem e apresentaram redução significativa da CIM quando o avibactam foi adicionado ao aztreonam. O NG-Test CARBA-5 detectou 12 das 24 variantes testadas enquanto que o O.K.N.V.I. RESIST-5 detectou apenas nove variantes. A grande diversidade de variantes KPC, e a predominância do grupo clonal ST11, e da KPC- 33 retratam um cenário preocupante no Brasil

The K. pneumoniae Complex (C-Kp) is the main group of gram-negative bacilli responsible for serious nosocomial infections worldwide and the empirical treatment of these infections usually includes carbapenems. The main mechanism of resistance to this class of antimicrobials is the expression of carbapenemases, and in Brazil, more frequently the KPC type. In March 2019, ceftazidime-avibactam was available for clinical use in Brazil, being widely used to treat infections caused by KPC-producing gram-negative bacilli. Several countries have already reported the presence of KPC-producing K. pneumoniae resistant to ceftazidime-avibactam; however, there are few reports of this occurrence in Brazil. This work aimed to genotypically and phenotypically characterize KPC-producing C-Kp isolates resistant to ceftazidimeavibactam. From July 2019 to July 2021, 46 C-Kp isolates, one per patient, were detected in different sites of infection or surveillance cultures from patients admitted to private hospitals in six Brazilian states. The isolates had their complete genome sequenced on the MiSeq and MinION platforms to determine the allelic variant of blaKPC and evaluate its genetic context. Resistance rates to ertapenem and ceftazidime-avibactam were calculated from a database. The clonality of the isolates was evaluated by PFGE and MLST. The plasmid location of the blaKPC gene was confirmed by conjugation and/or transformation. The minimal inhibitory concentrations for beta-lactams were determined by broth microdilution according to BrCAST. Immunochromatographic assays, NG-Test CARBA-5 and O.K.N.V.I. RESIST-5, were evaluated for its performance in detecting KPC variants. The resistance rate to ertapenem among C-Kp isolates increased from 15.6% in 2019 to 27.3% in 2021. The resistance rate to ceftazidime-avibactam among ertapenem-resistant C-Kp isolates increased from 4.2% in 2019 to 17.2% in 2021. Eleven isolates showed new KPC variants designated KPC-103 to KPC-108 and KPC-139 to KPC-143. The remaining isolates presented previously described KPC variants, with KPC-33 being the most common variant (36%). Fifteen clonal groups were identified, with most isolates belonging to ST11. Different incompatibility groups were identified in plasmids harboring blaKPC, with the IncN (n=12) and IncF groups, with FII(K)-FIB(n=11) replicons, being the most frequent groups, followed by InX3-IncU (n= 9) and IncQ1 (n=1). All IncX3-IncU plasmids were approximately 46 kb in size and were identified among isolates belonging to the largest identified clonal group (A) and ST258. The main variant detected in this group was KPC-33. Of the 46 ceftazidime-avibactam-resistant isolates, 36 were able to transfer the blaKPC gene to recipient strains. Most isolates were susceptible standard dose or susceptible increased exposure to meropenem and showed a significant decrease in MIC when avibactam was added to aztreonam. The NG-Test CARBA-5 was able to detect 12 of the 24 variants evaluated while the O.K.N.V.I. RESIST-5 detected only nine variants. The great diversity of KPC variants, the predominance of the ST11 clonal group, and KPC-33 portray a worrying scenario in Brazil

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 / Ceftazidime/avibactam versus other antibiotics for the treatment of KPC carbapenemase-producing Enterobacterales bacteremia: real-life data from a university hospital in 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 / 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.

Utilización de antibióticos restringidos en la práctica clínica: ceftolozano/tazobactam, ceftazidima/avibactam, ceftarolina y dalbavancina / Use of restricted antibiotics in clinical practice: ceftolozane/tazobactam, ceftazidime/avibactam, ceftaroline and dalbavancin

Objetivo: Evaluar la utilización en la práctica clínica de cuatro antibióticos de amplio espectro o innovadores: ceftolozano/tazobactam, ceftazidima/avibactam, ceftarolina y dalbavancina. Métodos: Estudio retrospectivo en que se han recogido datos de los pacientes que han recibido dichos antibióticos entre julio de 2018 y junio de 2019 en un hospital terciario. Se recogen las condiciones de uso y los resultados en efectividad a los 30 días para dalbavancina, y para el resto de antimicrobianos a los 3-5 días del inicio, a los 14 y a los 30 días para determinar mortalidad. Resultados: Se recogieron datos de 51 pacientes, con una mediana de edad de 63 años. La infección más comúnmente tratada fue neumonía (41,2%). Tres pacientes (5,9%) recibieron la terapia en estudio como primera línea y 43 (84,3%) recibieron antibióticos concomitantes. En el 66,7% de las infecciones se había aislado previamente un microorganismo sensible. En el 19,6% de los casos el cultivo fue negativo. En el grupo dalbavancina, el 75% de los pacientes se curaron a los 30 días. En el resto de antimicrobianos, el tratamiento resultó efectivo a los 3-5 días en el 65,1%. El 51,2% se curaron a los 14 días y un 30,2% fallecieron a los 30 días. Conclusiones: Los resultados de efectividad resultan comparables a estudios publicados con diseños similares. Se detecta la importancia de fomentar un uso adecuado de los antibióticos, como tratamientos dirigidos o empíricos en casos de riesgo de resistencias, priorizando su desescalada. Es esencial la implantación de equipos multidisciplinares PROA. (AU)

Objective: To evaluate the use in clinical practice of four recently marketed antibiotics: ceftolozane/tazobactam, ceftazidime/avibactam, ceftaroline, and dalbavancin. Methods: Retrospective study in which data have been collected from patients who have received these antibiotics between July 2018 and June 2019, in a third-level hospital. The conditions of use and the results in clinical efficacy measured in three periods have been studied: 3-5 days after the start of treatment, 14 days and 30 days to determine mortality. Results: Data were collected from a total of 51 patients, with a median age of 63 years. The most commonly treated infection was pneumonia (41.2%). Three patients (5.9%) received study therapy as the first line of treatment and 43 (84.3%) received concomitant antibiotics. In 66.7% of the infections, a sensitive microorganism to the antibiotic under study had been previously isolated. In 19.6% of the cases, the culture was negative. In the dalbavancin group, 75% of the pacients cured at day 30. In the other groups, the treatment was effective at 3-5 days in 65.1% of the cases. 51.2% experienced clinical cure at 14 days and 30.2% died at 30 days. Conclusions: The effectiveness results are comparable to published studies with similar designs. The importance of promoting an adequate use of antibiotics is detected, as directed or empirical treatments in cases of risk of resistance, prioritizing their de-escalation. The implementation of multidisciplinary PROA teams is essential. (AU)

Mecanismos de resistencia bacteriana frente a ceftazidima avibactam. Revisión Sistemática / Mechanisms of bacterial resistance against ceftazidime avibactam. Systematic Review / Mecanismos de resistência bacteriana contra ceftazidima avibactam. Revisão sistemática

La resistencia a los antibióticos representa una problemática a nivel mundial determinada por la capacidad que poseen las bacterias para desarrollar mecanismos de resistencia que les permitan adaptarse y sobrevivir en el entorno en el que se desenvuelven. La combinación ceftazidima-avibactam (CAZ/AVI) desde su aprobación en 2015 por la Food and Drug Administration (FDA) ha demostrado ser muy eficiente frente a bacilos Gram negativos productores de carbapenemasas, pero al igual que otras estrategias frente a bacterias multirresistentes no está exenta del desarrollo de mecanismos de resistencia. Métodos. Se realizó una revisión sistemática de la literatura en las bases de datos Web of Science, PubMed y Scopus siguiendo la metodología PRISMA, se incluyeron 29 artículos en los que se reportó la resistencia a CAZ/AVI en aislados clínicos. Resultados. los mecanismos de resistencia más relevantes fueron las mutaciones en el gen blaKPC en la posición 179 (D179Y) en el bucle conservado omega estimulada por la exposición previa a CAZ/AVI, generando de esta forma nuevas variantes como blaKPC-31 y blaKPC-33. Conclusiones. la evidente presencia de mecanismos de resistencia a CAZ/AVI a pesar de ser una combinación de uso relativamente reciente hace un llamado al uso adecuado de esta combinación.

Antibiotic resistance represents a worldwide problem determined by the ability of batteries to develop resistance mechanisms that allow them to adapt and survive in the environment in which they operate. Since its approval in 2015 by the Food and Drug Administration (FDA), the ceftazidime-avibactam (CAZ/AVI) combination has proven to be very efficient against Gram-negative bacilli that produce carbapenemase, but like other strategies against multiresistant bacteria, it is not exempt from the development of resistance mechanisms. Methods. a systematic review of the literature was carried out in the Web of Science, PubMed and Scopus databases following the PRISMA methodology, including 29 articles in which resistance to CAZ/AVI was reported in clinical isolates. Results. The most relevant resistance mechanisms were mutations in the blaKPC gene at position 179 (D179Y) in the conserved omega loop, stimulated by previous exposure to CAZ/AVI, thus generating new variants such as blaKPC-31 and blaKPC-33. Conclusions. The evident presence of resistance mechanisms to CAZ/AVI, despite being a combination of relatively recent use, calls for the appropriate use of this combination.

A resistência aos antibióticos representa um problema mundial determinado pela capacidade das bactérias desenvolverem mecanismos de resistência que lhes permitem adaptar-se e sobreviver no ambiente em que operam. Desde sua aprovação em 2015 pela Food and Drug Administration (FDA), a combinação ceftazidima-avibactam (CAZ/AVI) tem se mostrado muito eficiente contra bacilos Gram-negativos produtores de carbapenemases, mas como outras estratégias contra bactérias multirresistentes, é não isentos do desenvolvimento de mecanismos de resistência. Métodos. Foi realizada uma revisão sistemática da literatura nas bases de dados Web of Science, PubMed e Scopus seguindo a metodologia PRISMA, incluindo 29 artigos nos quais foi relatada resistência ao CAZ/AVI em isolados clínicos. Resultados. Os mecanismos de resistência mais relevantes foram mutações no gene blaKPC na posição 179 (D179Y) na alça ômega conservada, estimuladas pela exposição prévia ao CAZ/AVI, gerando novas variantes como blaKPC-31 e blaKPC-31. 33. Conclusões. A evidente presença de mecanismos de resistência ao CAZ/AVI, apesar de ser uma combinação de uso relativamente recente, exige o uso adequado dessa combinação.

Costo-efectividad de ceftazidima/avibactam versus colistin + meropenem en el tratamiento de infecciones por enterobacterias resistentes a carbapenémicos en Chile / Cost-effectiveness of ceftazidime/avibactam versus colistin + meropenem for treatment of carbapenemic-resistant enterobacteria infections in Chile

INTRODUCCIÓN: Ceftazidima-avibactam (C/A), ha demostrado reducir las tasas de mortalidad y el riesgo de nefrotoxicidad, comparado con colistin, la terapia convencional. OBJETIVO: Estimar la costo-efectividad de C/A versus colistin + meropenem en el tratamiento de infecciones por Enterobacteriaceae resistentes a carbapenémicos (ERC) en Chile. MATERIAL Y MÉTODOS: Se adaptó un modelo económico tipo árbol de decisión. Se utilizó la perspectiva del pagador público, un horizonte de tiempo de 30 días con extrapolación a la expectativa de vida. La información clínica se derivó de un estudio observacional. Los costos de los medicamentos y de atención corresponden a reportes locales. Los resultados se expresan como razón de costo-efectividad incremental (RCEI) por año de vida ganado (AVG) y por año de vida ajustado por calidad (AVAC) en pesos chilenos y en dólares estadounidenses (US$ 1,00 = $792,2218). RESULTADOS: Se obtuvieron 8,65 y 6,48 AVGs y 6,44 y 4,27 AVACs, para C/A y colistin + meropenem, respectivamente. La RCEI estimada de C/A fue $940.488 (US$1.187,2) por AVG y $938.715 (US$1.184,9) por AVAC. DISCUSIÓN: Dada la falta de publicaciones o evidencia, el modelo se basa en un estudio observacional. C/A reduciría la proporción de muertes e incrementaría los AVG y los AVAC, resultando en una alternativa costo-efectiva versus colistin + meropenem para ERC.

BACKGROUND: Ceftazidime-avibactam (C/A), has shown reduction in mortality rates and risk of nephrotoxicity, compared to colistin, conventional therapy. AIM: To estimate the cost-effectiveness of C/A versus colistin + meropenem in the treatment of infections due to carbapenem-resistant Enterobacteriaceae (CRE) in Chile. METHODS: An economic decision tree type model was adapted. The perspective of the public payer was used with a time horizon of 30 days and extrapolation to life expectancy. The clinical information was derived from an observational study. Medication and care costs correspond to local reports. The results are expressed as incremental cost-effectiveness ratio (ICER) per life year gained (LYG) and per quality adjusted life year (QALY) in Chilean pesos and US dollars (US$ 1.00 = $792.2218). RESULTS: 8.65 and 6.48 LYGs and 6.44 and 4.27 QALYs were obtained, for C/A and colistin + meropenem, respectively. The estimated ICER for C/A was $940,488 (US$1,187.2) per AVG and $938,715 (US$1,184.9) per QALY. DISCUSSION: Given the lack of publications or evidence, the model is based on an observational study. C/A would reduce the death rate and increase LYGs and QALYs, resulting in a cost-effective alternative vs. colistin + meropenem for CRE.

Clinical characteristics and prognosis of infections caused by OXA-48 carbapenemase-producing Enterobacteriaceae in patients treated with ceftazidime-avibactam.

BACKGROUND: Ceftazidime-avibactam has in vitro activity against Gram-negative bacilli that produce Class A, C and some D ß-lactamases, and has been successfully used in the treatment of infections caused by cephalosporin and carbapenem-resistant Enterobacteriaceae. However, actual experience in the treatment of OXA-48 carbapenemase-producing Enterobacteriaceae (CPE) is limited. OBJECTIVE: To review the characteristics and prognosis of OXA-48 CPE infections treated with ceftazidime-avibactam since introduction of the drug to the current centre during the period October 2014 to December 2016. METHODS: Retrospective assessment of episodes of infection caused by OXA-48 CPE treated with ceftazidime-avibactam, analysing data collected from infection diagnosis until 90 days after the end of treatment. RESULTS: Twenty-four episodes were analysed. Ceftazidime-avibactam was given as the initial definitive treatment in 15 (62.5%) and as salvage therapy in nine (37.5%). Intraabdominal (seven, 29%), urinary (six, 25%) and respiratory (five, 21%) were the most common sources. The 30-day and 90-day mortality rates were 8.3% and 20.8%, respectively. Clinical cure at 30 days was achieved in 62.5% of episodes. Four (16.7%) patients had adverse events, two of them were related to impaired renal function. Among patients who finished the treatment with ceftazidime-avibactam, seven (35%) were diagnosed with infection recurrence within 90 days of the end of treatment. CONCLUSIONS: From experience, ceftazidime-avibactam is an effective drug for treating infections due to OXA-48 CPE. From these results a better safety profile than the current best available therapy could be expected.

Lumbar arthrodesis infection by multi-resistant Klebsiella pneumoniae, successfully treated with implant retention and ceftazidime/avibactam. / Infección de artrodesis lumbar por Klebsiella pneumoniae multirresistente, exitosamente tratada con retención del implante y ceftazidima/avibactam.

There are increasingly more patients with prosthetic implants (orthopaedic prostheses, lumbar instruments, osteosynthesis material). In the last decade, infections caused by carbapenem resistant Enterobacteriaceae have increased (bacteriaemia, abscesses, urinary tract infections...) with great difficulty in treatment and important associated comorbidity. We present the first case of infection of a lumbar instrumentation by Klebsiella pneumoniae producing carbapenemase D, OXA-48 type, and successfully treated.