Whole genome sequence analysis of the first reported isolate of Salmonella Agona carrying blaCTX-M-55 gene in Brazil

This study analyzes the genomic findings of the first report of Salmonella isolate carrying the blaCTX-M-55 gene, recovered from a bacteremic patient from Brazil. A bacterial isolate positive for the blaCTX-M-55 gene was submitted to antimicrobial susceptibility testing by disk diffusion and epsilometric test. Whole genome sequencing was performed using Illumina technology. Conjugation assay was performed; plasmid sizes determined by S1-PFGE and plasmid content were investigated by hybrid assembly after MinION long reads sequencing. Isolate 288_18 was identified as sequence type ST13, resistant to ampicillin, cefotaxime, ceftazidime, cefepime, ceftriaxone, and aztreonam. A transferable IncFII plasmid sized approximately 67 kb was found to carry the blaTEM-1 and blaCTX-M-55 in a module consisting of IS26-blaTEM-1B-WbuC-blaCTX-M-55-IS26. In addition, an 117 kb IncI1plasmid was also identified in the 288_18 isolate, but without additional resistance genes. To the best of our knowledge, this is the first report of blaCTX-M-55 in Salmonella isolated from human infection in Brazil. The occurrence of blaCTX-M-55 in the IncFII epidemic plasmid in a relevant clinical human isolate of Salmonella Agona underscores the urgent need for enhanced and effective continuous surveillance for controlling its dissemination.

Resistencia a colistina en aislados de Klebsiella pneumoniae resistente a carbapenémicos en un hospital pediátrico de Corrientes / Colistin resistance in carbapenem-resistant Klebsiella pneumoniae isolates from a pediatric hospital from Corrientes, Argentina

INTRODUCCIÓN: Existe un incremento de las infecciones por Klebsiella pneumoniae resistente a carbapenémicos (KPRC) en la población pediátrica y los datos epidemiológicos son limitados. OBJETIVOS: Conocer la frecuencia de KPRC en pacientes pediátricos, determinar la actividad in vitro de colistina y detectar el gen mcr-1 en dichos aislados. MATERIALES Y MÉTODOS: Se estudiaron 220 aislados de K. pneumoniae en un hospital pediátrico durante los años 2018 y 2019. La susceptibilidad antimicrobiana se determinó por microdilución en caldo según CLSI y EUCAST. Los genes blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48 y mcr-1 se analizaron mediante reacción de polimerasa en cadena (RPC). RESULTADOS: El 9,5% (n: 21) de los aislados fueron caracterizados como KPRC, donde se observó una resistencia a colistina de 47,6% (10/21) con valores de CIM50 de 2 μg/mL y CIM90 de > 4 μg/mL. En todos los aislados de KPRC se caracterizó el gen blaKPC y no se detectó el gen mcr-1. El perfil de resistencia observado en otros antimicrobianos fue el siguiente: gentamicina 100% (n: 21), ciprofloxacina 100% (n: 21), cotrimoxazol 100% (n: 21) y amikacina 19% (n: 4). Se observó 100% de sensibilidad a tigeciclina y ceftazidima/avibactam. CONCLUSIÓN: Este estudio demuestra un valor significativo de la resistencia a colistina en comparación a ceftazidima/avibactam y tigeciclina.

BACKGROUND: There is an increase of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections in the pediatric population and epidemiological data are limited. Aim: To calculate the frequency of CRKP in pediatric patients, to determine the in vitro activity of colistin and to detect the presence of mcr-1 gene in said isolates. METHODS: 220 isolates of K. pneumoniae were studied in a pediatric hospital between January 2018 and December 2019. Antimicrobial susceptibility was determined by microdilution in broth according to guidelines of CLSI and EUCAST. The genes blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48 and mcr-1 were detected by polymerase chain reaction (PCR). RESULTS: 9.5% (n: 21) of the isolates were characterized as CRKP, where was observed a resistance to colistin of 47.6% (10/21) with values of MIC50 of 2 μg/mL and MIC90 of ≥ 4 μg/mL. In 100% of CRKP strains the blaKPC gene was detected and the mcr-1 gene was not found. The resistance profile to other antimicrobials was as follow: gentamicin 100% (n: 21), trimethoprim/sulfamethoxazole 100% (n: 21), ciprofloxacin 100% (n: 21), amikacin 19% (n: 4). All of the isolates were sensitive to ceftazidime/avibactam and tigecycline. CONCLUSION: This study demonstrates a significant value of resistance to colistin in pediatric patients compared to other last line antimicrobial such as ceftazidime/avibactam and tigecycline.

Caracterização molecular e fenotípica de Klebsiella spp. produtoras de NDM / Molecular and phenotypic characterization of Klebsiella spp. NDM producers

O perfil de resistência, que algumas das espécies do complexo Klebsiella pneumoniae podem expressar, representa uma grande ameaça à saúde humana, particularmente quando resistentes aos carbapenêmicos, que são amplamente utilizados no tratamento de infecções graves em pacientes hospitalizados. O principal mecanismo de resistência aos carbapenêmicos é a produção de carbapenemases, particularmente dos tipos KPC e NDM. Um dos compostos desenvolvidos para o tratamento de infecções causadas por cepas produtoras de KPC é a combinação ceftazidimaavibactam (CAZ-AVI), mas que não tem atividade inibitória sobre metalo-betalactamases, a exemplo das NDMs. Os objetivos deste trabalho foram determinar a frequência das espécies do complexo K. pneumoniae e da coprodução de KPC, avaliar a clonalidade dos isolados, a sensibilidade ao aztreonam-avibactam (ATM-AVI), o desempenho do disco de meropenem (MEM) com inibidores para detecção de coprodução de NDM e KPC e desenvolver um teste de triagem para prever a sensibilidade ao ATM-AVI. Um total de 113 isolados do complexo K. pneumoniae produtoras de NDM ou coprodutoras de NDM e KPC, provenientes da coleção de bactérias do Grupo Fleury, coletadas períodos pré e pós início do uso de CAZ-AVI no Brasil, foram utilizadas neste estudo. A identificação da espécie e a presença dos genes blaNDM e blaKPC foi confirmada por PCR multiplex. A clonalidade dos isolados foi avaliada por eletroforese em campos pulsados (PFGE) após clivagem com XbaI. A produção de carbapenemases foi confirmada utilizando-se o teste Blue Carba. O desempenho dos discos de meropenem e CAZ-AVI contendo um ou mais inibidores de carbapenemases foi comparado com o teste molecular. A pré-difusão combinada foi realizada pré-incubando-se o ágar não inoculado com disco de CAZ-AVI, e a seguir aplicando-se o inóculo bacteriano e um disco de ATM após remover o disco de CAZ-AVI. Após incubação, os halos foram aferidos e correlacionados com a concentração inibitória mínima para ATM-AVI. As CIMs para ATM e ATM-AVI foram determinadas segundo o EUCAST. A identificação das espécies por PCR evidenciou as seguintes frequências: K. pneumoniae 75,2% (n=85); K. quasipneumoniae 16,8% (n=19), e K. variicola 8% (n=9). Uma fração de 12,4% (n=14) dos isolados apresentaram os genes blaNDM e blaKPC e 87,6% (n=99) apenas blaNDM. A análise dos perfis de PFGE de K. pneumoniae evidenciou a presença de cinco grupos clonais predominantes. Isolados do principal grupo clonal Ap (n=15) foram detectados nas cidades de São Paulo e Porto Alegre durante todo o período analisado. O grupo clonal Lp foi detectado nas cidades de São Paulo e Recife em 2019. Os dois principais grupos clonais no período pré-CAZ-AVI continham maior número de isolados do que aqueles no período de uso do CAZ-AVI. Os perfis de PFGE de K. quasipneumoniae evidenciaram quatro grupos clonais predominantes, e presentes apenas no estado de São Paulo, com persistência do grupo clonal Aq desde 2017. Quanto à K. variicola, foram observados dois grupos clonais predominantes Av e Bv, o primeiro presente apenas em São Paulo desde 2018 e o segundo em Porto Alegre apenas em 2019. Calculando-se a diferença entre os diâmetros de halo do disco MEM contendo EDTA e ácido fenilborônico (AFB) e o maior dos halos obtidos para MEM com EDTA ou AFB, observou-se que todos os isolados com coexpressão de KPC e NDM apresentaram diferença ≥ 5 mm. Uma fração de 42,3% dos isolados positivos apenas para blaNDM apresentaram sensibilidade para ATM (CIM ≤ 4 mg/L). Todos os isolados testados apresentaram CIM para ATM-AVI ≤ 1/4 mg/L, sendo a CIM90 0,125/4 mg/l. No teste de pré-difusão combinada, o menor diâmetro de halo obtido foi de 23 mm. A espécie predominante na amostragem foi K. pneumoniae. A disseminação clonal, observada neste estudo, contrasta com a diversidade clonal descrita em outros locais do mundo para produtores de NDM, exceto Grécia e China. Considerando os pontos de corte atuais para ATM, é provável que haja resposta clínica adequada no uso de ATM-AVI no tratamento de infecções causadas por isolados produtores de NDM e coprodutores de KPC e NDM. Utilizando-se o valor de corte de ≤ 5 mm para a diferença entre halos de inibição, de MEM com AFB e EDTA e o segundo maior halo com inibidor, a sensibilidade foi de 100% e a especificidade foi de 96,1,0%. O método de pré-difusão com CAZ-AVI e ATM é um método simples e o diâmetro ≥ 23 mm tem excelente correlação com a CIM para ATM-AVI ≤ 1/4 mg/L

The resistance profile, which some species of the Klebsiella pneumoniae complex may express, represent a great threat to human health, particularly when resistant to carbapenems, which are widely used in the treatment of severe infections in hospitalized patients. The main mechanism of resistance to carbapenems is the production of carbapenemases, particularly KPCs and NDMs. One of the compounds developed for the treatment of infections caused by KPC-producing strains is the combination ceftazidime-avibactam (CAZ-AVI), but which has no inhibitory activity on metallobetalactamases, as is the case for NDMs. The objectives of this work were to determine the frequency of K. pneumoniae complex species and KPC co-production, evaluate the clonality of isolates, the susceptibility to aztreonam-avibactam (ATM-AVI), the performance of meropenem (MEM) disks with inhibitors for detecting NDM co-production and KPC and develop a screening test to predict sensitivity to ATM-AVI. A total of 113 NDM-producing or NDM and KPC co-producing K. pneumoniae complexes, from the Fleury Group's bacteria collection, collected in the pre- and post-starting periods of CAZ-AVI use in Brazil, were used in this study. Species identification and the presence of the blaNDM and blaKPC genes were confirmed by multiplex PCR. The clonality of the isolates was evaluated by pulsed field electrophoresis (PFGE) after cleavage with XbaI. Carbapenemase production was confirmed using the Blue Carba test. The performance of MEM and CAZ-AVI disks containing one or more carbapenemase inhibitors was compared with the molecular test. Combined pre-diffusion was performed by preincubating the uninoculated agar with a CAZ-AVI disk, and then applying the bacterial inoculum and na ATM disk after removal of the CAZ-AVI disk. After incubation, halos were measured and correlated with the minimum inhibitory concentration (MIC) for ATM-AVI. ATM and ATM-AVI MICs were determined according to EUCAST. The identification of species by PCR evidenced the following frequencies: K. pneumoniae 75.2% (n=85); K. quasipneumoniae 16.8% (n=19), and K. variicola 8% (n=9). A fraction of 12.4% (n=14) of the isolates had the blaNDM and blaKPC genes and 87.6% (n=99) had only blaNDM. The analysis of the PFGE profiles of K. pneumoniae evidenced the presence of five predominant clonal groups. Isolates from the main clonal group Ap (n=16) were detected in the cities of São Paulo and Porto Alegre throughout the analyzed period. The clonal group Lp was detected in the cities of São Paulo and Recife 2019. The PFGE profiles of K. quasipneumoniae showed four predominant clonal groups, present only in the state of São Paulo, with persistence of the clonal group Aq since 2017. As for K. variicola, two predominant clonal groups Av and Bv were observed, the first present only in São Paulo since 2018 and the second in Porto Alegre only in 2019. Calculating the difference between the inhibition zone diameters of the MEM disk containing EDTA and phenylboronic acid (AFB) and the largest of the inhibition zone diameters obtained for MEM with EDTA or AFB, it was observed that all isolates with co-expression of KPC and NDM showed a difference 5 ≥mm. A fraction of 42.3% of isolates positive only for blaNDM showed sensitivity to ATM (MIC ≤ 4 mg/L). All tested isolates presented MIC for ATM-AVI ≤ 1/4 mg/L, being the MIC90 0.125/4 mg/l. In the combined pre-diffusion test, the smallest inhibition zone diameter obtained was 23 mm. The predominant species in the sample was K. pneumoniae, but a significant fraction of the other species in the complex was also observed in the sample. The clonal spread observed in this study contrasts with the clonal diversity described elsewhere in the world for NDM-producing isolates, except Greece and China. Considering the current cut-off points for ATM, it is likely that there is an adequate clinical response in the use of ATM-AVI in infections caused by NDM-producing and KPC-NDM co-producing isolates in Brazil. Using the cutoff value of 5 mm for the difference between inhibition zones, of MEM with AFB and EDTA and the second largest zone of MEM with inhibitor, the sensitivity was 100% and the specificity was 96.1%. The pre-diffusion method with CAZ-AVI and ATM is a simple method and the diameter ≥ 23 mm has excellent correlation with the MIC for ATM-AVI ≤ 1/4 mg/L

Impacto da unitarização de ceftazidima + avibactam em um hospital público universitário durante a pandemia de COVID-19 / Impact of ceftazidime + avibactam unitarization in a university public hospital during the COVID-19 pandemic

Introdução: A pandemia de COVID-19 fez aumentar a demanda de medicamentos utilizados em hospitais, como a Ceftazidima + Avibactam. Nesse contexto, a Central de Misturas Intravenosas (CMIV) de um hospital público universitário passou a unitarizar as doses prescritas. O objetivo deste trabalho foi avaliar o impacto da unitarização no consumo deste antibacteriano de alto custo em um hospital público universitário. Métodos: Trata-se de uma análise farmacoeconômica de custos diretos, sobre a utilização de frascos-ampola de Ceftazidima + Avibactam no período de 01/07/2020 a 31/05/2021. Foram unitarizadas todas as doses que correspondiam a uma fração da dose total do frasco-ampola, em Cabine de Segurança Biológica classe II B2. Os frascos-ampola foram utilizados à exaustão, através do compartilhamento e organização dos horários de manipulação. Resultados: O número total de preparos realizados pela CMIV do referido hospital no período foi de 837. O consumo projetado sem a centralização dos preparos seria de 837 (um frasco por dose). Entretanto, o consumo real foi de 437 frascos. A eficiência de unitarização foi de 101%, com economia real de 400 frascos (R$ 244.832,00) para a instituição. Conclusão: A pandemia de COVID-19 sobrecarregou os sistemas de saúde do mundo todo, sendo que a atuação farmacêutica foi fundamental para garantir o acesso aos medicamentos essenciais. A CMIV assumiu a unitarização da Ceftazidima + Avibactam, antibiótico em risco de desabastecimento, gerando um consumo 47,8% menor, contribuindo para o acesso deste medicamento de forma ininterrupta durante os 11 meses avaliados na referida instituição.

Introduction: COVID-19 pandemic has increased the demand for drugs used in hospitals, such as Ceftazidime + Avibactam. In this context, the Central of Intravenous Admixtures (CMIV) of a public university hospital started to unitarize the prescribed doses. The objective of this study was to evaluate the impact of unitarization on the consumption of this high-cost antibacterial in a public university hospital. Methods: This is a pharmacoeconomic analysis of direct costs, on the Ceftazidime + Avibactam vials use, in the period from 07/01/2020 to 05/31/2021. All doses that corresponded to a fraction of the entire vial were unitarized in a Class II B2 Biological Safety Cabin. The vials were used to exhaustion, by sharing them, and organizing the manipulation schedules. Results: The total number of preparations made by the CMIV of that hospital in the period was 837 doses. The projected consumption would be 837 vials (one vial per dose). However, the actual consumption was 437 vials. The unitarization efficiency was of 101%, with real savings of 400 vials (R$ 244,832.00) for the institution. Conclusion: COVID-19 pandemic has overburdened health systems around the world, and pharmaceutical actions have been fundamental to guaranteeing access to essential medicines. CMIV took over the unitarization of Ceftazidime + Avibactam, an antibiotic at risk of shortages, leading to a 47.8% lower consumption, contributing to uninterrupted access to this drug during the 11 months evaluated at that institution.

Pioderma gangrenoso ampollar como forma de presentación de leucemia mieloide agudo: informe de un caso / Acute myeloid leukemia presented in the form of bullous pyoderma gangrenosum: a case report

El pioderma gangrenoso ampollar es una variedad infrecuente de pioderma gangrenoso, que se asocia en el 50-70% de los casos con trastornos oncohematológicos. Se comunica el caso de una paciente de 59 años, que consultó por fiebre y ampollas purpúricas de rápida progresión, con compromiso cutáneo mucoso. Con sospecha de una enfermedad neutrofílica, ampollar, o infección por gérmenes oportunistas, se realizó biopsia de piel para estudio histopatológico, inmunofluorescencia directa y cultivo. Los cultivos y la inmunofluorescencia directa fueron negativos, y la anatomía patológica reveló un denso infiltrado inflamatorio con predominio neutrofílico en dermis. Ante el diagnóstico de pioderma gangrenoso ampollar, se realizó una punción-aspiración de médula ósea cuyo resultado fue compatible con leucemia mieloide aguda. Se instauró tratamiento con corticosteroides sistémicos, a pesar de lo cual la paciente evolucionó desfavorablemente y falleció a los 15 días de su ingreso hospitalario. Este caso ilustra la asociación de esta enfermedad cutánea con trastornos oncohematológicos y el mal pronóstico que esto implica a corto plazo. (AU)

Bullous pyoderma gangrenosum is an infrequent type of pyoderma gangrenosum, associated with onco hematological diseases in 50-70% of cases. We present the case of a 59-year-old patient with fever and mucocutaneous hemorrhagic bullous of rapid progression. A biopsy for histopathology, direct immunofluorescence (DIF) and skin culture was made, considering the possibility of neutrophilic dermatoses, bullous dermatosis or an opportunistic infection. The results of both the culture and the DIF were negative. The histopathological examination of the specimen revealed a dense dermal polymorphic infiltrate composed primarily of neutrophils. Considering bullous pyoderma gangrenosum as a potential diagnosis, a bone-marrow biopsy was performed. This study revealed an acute myeloid leukemia. Although systemic corticosteroid therapy was begun, the patient presented an unfavorable evolution that led to her death 15 days after her admission at the hospital. This case shows the association between bullous pyoderma gangrenosum and onco hematological diseases. In addition, it highlights the poor prognosis related to these diseases in the short term. (AU)

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.

Actividad antimicrobiana de ceftolozano-tazobactam y ceftazidima-avibactam contra bacilos gramnegativos clínicamente relevantes aislados en México / Ceftolozane/tazobactam and ceftazidime/avibactam antimicrobial activity against clinically relevant gram-negative bacilli isolated in Mexico

Resumen Introducción: Existe poca información acerca de la efectividad de las combinaciones ceftolozano/tazobactam y ceftazidima/avibactam en cepas clínicamente relevantes aisladas en México. Objetivo: Determinar el perfil antimicrobiano de ambos antibióticos en nuestra comunidad. Método: El presente estudio de investigación fue prospectivo, descriptivo y transversal. Se incluyeron cepas clínicamente relevantes aisladas a partir de cultivos de cepa pura durante el periodo de agosto de 2018 a enero de 2019 en Mexicali, Baja California, México. Resultados: Se analizaron 74 cepas de enterobacterias y 19 cepas de Pseudomonas aeruginosa; el porcentaje de sensibilidad de ceftazidima/avibactam fue de 100 % contra enterobacterias y de 72.7 % contra Pseudomonas aeruginosa; el porcentaje de sensibilidad de ceftolozano/tazobactam fue de 90.5 % para enterobacterias y de 72.7 % para Pseudomonas aeruginosa. Conclusiones: Las combinaciones ceftolozano/tazobactam y ceftazidima/avibactam ofrecen buena sensibilidad antimicrobiana in vitro, tanto contra enterobacterias productoras de betalactamasas de espectro extendido como contra Pseudomonas aeruginosa. Se requieren más datos para valorar la respuesta clínica en pacientes que reciben esas combinaciones de antibióticos.

Abstract Introduction: There is limited information on the effectiveness of ceftolozane/tazobactam and ceftazidime/avibactam combinations on clinically relevant strains isolated in Mexico. Objective: To determine the antimicrobial profile of both antibiotic combinations in our community. Method: The present research study was prospective, descriptive and cross-sectional. Clinically relevant strains isolated from pure-strain cultures were included during the period from August 2018 to January 2019 in Mexicali, Baja California, Mexico. Results: 74 enterobacteriaceae and 19 Pseudomonas aeruginosa strains were analyzed; the percentage of sensitivity of ceftazidime/avibactam was 100 % for enterobacteriaceae and 72.7 % for Pseudomonas aeruginosa; the percentage of sensitivity of ceftolozane/tazobactam for enterobacteriaceae was 90.5 % and 72.7 % for Pseudomonas aeruginosa. Conclusions: The ceftolozane/tazobactam and ceftazidime/avibactam combinations offer good antimicrobial sensitivity in vitro, both for ESBL-producing enterobacteriaceae and Pseudomonas aeruginosa. More data are required to assess clinical response in patients receiving these antibiotic combinations.

Bacterias Gram negativas resistentes a carbapenemicos en Colombia: un desafío continuo al sistema de salud: [Editorial] / Carbapenem resistant Gram negative bacteria in Colombia: a continuous challenge for the health system: [Editorial]

En Colombia, los Enterobacterales (Escherichia coli, Klebsiella spp y Enterobacter spp) ocupan los primeros lugares en la epidemiología de las infecciones asociadas a la atención en salud (IAAS) y de las adquiridas en comunidad. Estas bacterias pueden desarrollar resistencia a carbapenemicos (Ertapenem, Imipenem, Meropenem y Doripenem) por una combinación de mecanismos que incluye la producción de enzimas hidrolíticas (como las betalactamasas de espectro extendido o BLEEs, las cefalosporinasas AmpC y las carbapenemasas) y las mutaciones en proteínas de la membrana externa. Desde su aparición en 1996, las carbapenemasas han sido las enzimas más temidas. Klebsiella pneumoniae carbapenemase (KPC) Verona integron-mediated metallo- ß-lactamase (VIM), New Delhi metallo-ß-lactamase (NDM), Imipenemase (IMP) y oxacillinase-48-like carbapenemase (OXA-48) han sido las más estudiadas por su diseminación y alta mortalidad. En 2006 se reportó por primera vez la presencia de carbapenemasas en Colombia correspondiente a una KPC-24 . Desde entonces, varios reportes de diversas enzimas han sido publicados por grupos de investigación y por el Instituto Nacional de Salud (INS) en cuyo último informe 66% de los Enterobacterales resistentes a carbapenémicos expresan KPC, 23% expresan NDM y 6% expresan VIM. Llama la atención un 12% de aislamientos sin carbapenemasas detectables.

In Colombia, Enterobacteriaceae (Escherichia coli, Klebsiella spp and Enterobacter spp) occupy the first places in the epidemiology of healthcare-associated infections (HAI) and community-acquired infections. These bacteria can develop resistance to carbapenemics (Ertapenem, Imipenem, Meropenem and Doripenem) by a combination of mechanisms including the production of hydrolytic enzymes (such as extended-spectrum beta-lactamases or BLEEs, AmpC cephalosporinases and carbapenemases) and mutations in outer membrane proteins. Since their emergence in 1996, carbapenemases have been the most feared enzymes. Klebsiella pneumoniae carbapenemase (KPC) Verona integron-mediated metallo- ß-lactamase (VIM), New Delhi metallo-ß-lactamase (NDM), Imipenemase (IMP) and oxacillinase-48-like carbapenemase (OXA-48) have been the most studied because of their dissemination and high mortality. In 2006, the presence of carbapenemases in Colombia corresponding to a KPC-24 was reported for the first time. Since then, several reports of various enzymes have been published by research groups and by the National Institute of Health (INS) in whose last report 66% of carbapenem-resistant Enterobacteriaceae express KPC, 23% express NDM and 6% express VIM. It is noteworthy that 12% of isolates had no detectable carbapenemases.

Nuevos antibióticos en la era de la multiresistencia: revisión sobre ceftolozano/tazobactam y ceftazidima/avibactam / New antibiotics in the multiresistance era: review about ceftolozane/tazobactam and ceftazidime/avibactamISSN 2314-3193. Actualizaciones en sida e infectología. Buenos Aires. noviembre 2020. volumen 28. número 103: 57-71

En los últimos años se han desarrollado nuevos antimicrobianos destinados a combatir infecciones causadas por microorganismos multirresistentes a drogas (MDR), incluyendo combinaciones entre agentes ß-lactámicos (BL) e inhibidores de ß-lactamasas (IBL). En nuestro país se encuentran disponibles dos nuevas combinaciones de BL/IBL: ceftolozano/tazobactam (C/T) y ceftazidima/avibactam (CAZ/AVI). La adición de tazobactam a ceftolozano incrementa la actividad in vitro contra microorganismos productores de BL de espectro extendido (BLEE), por lo que la combinación presenta una potente actividad intrínseca frente a P. aeruginosa. Por su parte, CAZ/AVI conserva las características que definen el perfil de actividad de ceftazidima, por lo que con el agregado de avibactam presenta una potente actividad inhibidora frente a las BLEE y carbapenemasas (KPC, ß-lactamasas de clase C y algunas de clase D). Se presenta a continuación una revisión de la evidencia publicada. A partir de la misma, y considerando la situación actual de tasas crecientes de resistencia antimicrobiana, particularmente en bacilos Gram negativos, se considera que el uso de C/T o CAZ/AVI constituye una excelente alternativa para el manejo de infecciones graves causadas por microorganismos multirresistentes. Sin embargo, su utilización en forma empírica no es recomendable, salvo en situaciones puntuales y estrictamente seleccionadas, y en el contexto un programa de uso racional de antibióticos, bajo el control por parte del equipo de infectología responsable

In recent years, new antimicrobials have been developed to combat infections caused by multidrug-resistant microorganism (MDR), including combinations between ß-lactam agents (BL) and ß-lactamase inhibitors (IBL). Two new combinations of BL / IBL are available in our country: ceftolozano / tazobactam (C / T) and ceftazidime / avibactam (CAZ / AVI). The addition of tazobactam to ceftolozano increases in vitro activity against microorganisms producing extended spectrum BL (ESBL), so the combination has a potent intrinsic activity against P. aeruginosa. For its part, CAZ / AVI retains the characteristics that define the activity profile of ceftazidime, to which with the addition of avibactam it presents a potent inhibitory activity against ESBL and carbapenemases (KPC, ß-lactamases of class C and some of class D). A review of the published evidence is presented below. Based on this, and considering the current situation of increasing rates of antimicrobial resistance, particularly in Gram-negative bacilli, we consider that the use of C/T or CAZ/AVI is an excellent alternative for the management of serious infections caused by multi-resistant microorganisms. However, its use empirically is not recommended, except in specific and strictly selected situations, and in the context of a program for the rational use of antibiotics, under the control of the responsible infectious disease team

Carbapenemase-producing Enterobacteriaceae: A diagnostic, epidemiological and therapeutic challenge / Enterobacteriaceae productoras de carbapenemasas: Un reto diagnóstico, epidemiológico y terapéutico

The global spread of carbapenemase-producing Enterobacteriaceae (CPE) has become a public health problem. Not all CPE are resistant to carbapenems creating a diagnostic and therapeutic challenge. Furthermore, as resistance to carbapenems can also be mediated by other β-lactamases combined with defects in membrane permeability, their detection can be difficult by microbiology laboratories that lack molecular tools, which may limit and often delay the correct antibiotic selection. There is only limited evidence regarding infection control measures to contain the spread of CPE. However, recomendations have been published from the World Health Organization (WHO) and the European Prevention Center and Disease Control (ECDC). Because of the lack of randomized control trials, treatment regimens are mostly based on observational clinical studies. Several of those studies have reported that combination therapy with two or more in vitro-active agents including a carbapenem is superior to monotherapy. On the other hand, a new β-lactamase inhibitor in combination with ceftazidime has shown clinical efficacy Against KPC and some OXA-type producing Enterobacteriaceae

La diseminación global de las Enterobacteriaceae productoras de carbapenemasas (EPC) se ha convertido en un problema de salud pública. No todas las EPC son resistentes a los carbapenémicos, por lo que representan un reto diagnóstico y terapéutico. Adicionalmente, como la resistencia a los carbapenémicos puede ser mediada por otras β-lactamasas en combinación con cambios de la permeabilidad de la membrana plasmática, su detección puede ser difícil en laboratorios de microbiología que no cuentan con técnicas de diagnóstico molecular, lo que puede restringir y frecuentemente retrasar el inicio de la terapia antimicrobiana adecuada. La evidencia respecto a las medidas para la contención de las EPC es escasa. Sin embargo, existen recomendaciones por parte de la Organización Mundial de la Salud y del European Prevention Center and Disease Control (ECDC). Debido a la ausencia de estudios controlados y aleatorizados, los esquemas terapéuticos se basan en estudios clínicos observacionales. Varios de estos estudios han reportado mejores resultados con la terapia combinada de dos o más agentes activos in vitro, incluyendo a los carbapenémicos, en comparación con la monoterapia. Por otra parte, un nuevo inhibidor de β-lactamasas en combinación con ceftazidime, ha mostrado eficacia clínica contra infecciones por Enterobacteriaceae productoras de KPC y algunas carbapenemasas de tipo OXA.

Caracterización molecular y detección de genes blaCTX-M grupos 1 y 9 en Klebsiella pneumoniae resistentes a ceftazidima, en un hospital de San José de Cúcuta, Colombia / Molecular characterization and detection of genes blaCTX-M groups 1 and 9 in Klebsiella pneumoniae resistant to ceftazidime, in a hospital in San José de Cúcuta, Colombia

Resumen Introducción: La expresión de β-lactamasas CTX-M pertenecientes a los grupos 1 y 9 en Klebsiella pneumoniae produce grados altos de resistencia a ceftazidima, y presentan una amplia distribución mundial. Objetivo: Identificar y caracterizar los genes blaCTX-M-Grupo1 y blaCTX-M-Grupo9 en aislados de K. pneumoniae resistentes a ceftazidima en un hospital de San José de Cúcuta, Colombia. Material y Método: Se diseñaron partidores para la identificación de K. pneumoniae y los genes blaCTX-M mediante reacción de polimerasa en cadena (RPC). Posteriormente se realizó el análisis de la relación genética de estos aislados por medio de la RPC basada en secuencias repetitivas (RPC-REP). Resultados: Treinta y ocho por ciento de los 24 aislados identificados por RPC como K. pneumoniae presentaron los genes blaCTX-M-3, blaCTX-M-15 y blaCTX-M-32 (Grupo CTX-M-1) y 42% los genes blaCTX-M14, blaCTX-M-24 y blaCTX-M-27 (Grupo CTX-M-9). El análisis filogenético agrupó los aislados de K. pneumoniae en cuatro clusters, mostrando correlación en los clusters I, II y IV, al comparar los perfiles genéticos con el tipo de muestra y grupo de genes. Discusión: Se encontró una frecuencia similar de los genes blaCTX-M-Grupo1 y blaCTX-M-Grupo 9 en aislados de K. pneumoniae resistentes a ceftazidima. La correlación entre la RPC-REP con los grupos de CTX-M y el tipo de muestra reveló la presencia de tres patrones clonales.

Background: The expression of CTX-M β-lactamases belonging to groups 1 and 9 in Klebsiella pneumoniae produces high levels of resistance to ceftazidime, and they have a wide distribution worldwide. Aim: To identify and characterize the blaCTX-M-Group1 and blaCTX-M-Group9 genes in K. pneumoniae isolates resistant to ceftazidime in a hospital in San José de Cúcuta, Colombia. Material and Methods: Primers were designed for the identification of K. pneumoniae and blaCTX-M genes by PCR. Subsequently, the genetic relationship of these isolates was analyzed by REP-PCR. Results: A 38% of the 24 isolates identified by PCR as K. pneumoniae showed blaCTX-M-3. blaCTX-M-15 y blaCTX-M-32 genes (Group CTX-M-1) and 42% blaCTX-M14. blaCTX-M-24 y blaCTX-M-27 genes (Group CTX-M-9). The phylogenetic analysis grouped the K. pneumoniae isolates into 4 clusters, showing correlation in clusters I, II and IV, when comparing the genetic profiles with the type of sample and group of genes. Discussion: We found a similar frequency of blaCTX-M-Group 1 and blaCTX-M-Group 9 genes in isolates of K. pneumoniae resistant to ceftazidime. The correlation between the REP-PCR with the CTX-M groups and the type of sample revealed the presence of three clonal patterns.

Tailoring antimicrobials in febrile neutropenia: using faster diagnostic and communication tools to improve treatment in the era of extensively resistant pathogens

ABSTRACT Febrile Neutropenia represents a medical emergency and the use of appropriate antimicrobial therapy is essential for a better outcome. Although being time-consuming, conventional cultures and antimicrobial susceptibility tests remain the golden standard practices for microbiology identification. Final reports are typically available within several days. Faster diagnostic tools, such as species identification trough Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) and molecular techniques might help to shorten time to diagnostic and also guide definitive therapy in this scenario. Here we present a case in which the use of a diagnostic molecular workflow combining MALDI-TOF and real-time PCR for relevant genes codifying antibiotic resistant integrated with instant communication report, led to a tailored and more appropriate treatment in a patient presenting with febrile neutropenia.

Efficacy and safety of ceftazidime-avibactam in the treatment of complicated intra-abdominal infections (CIAIs) and complicated urinary tract infections (CUTIs): A meta-analysis of randomized controlled trials

Summary Objective: The aim of this study was to assess the efficacy and safety of ceftazidime-avibactam in the treatment of complicated intra-abdominal infections (CIAIs) and complicated urinary tract infections (CUTIs) with meta-analysis method. Method: We included six randomized clinical trials identified from Medline, Embase, Cochrane Library, "ISRCTN Register" and "ClinicalTrials.gov" which compared ceftazidime-avibactam with comparison group. The meta-analysis was performed using Review Manager software version 5.3. Results: Ceftazidime-avibactam versus active comparisons demonstrated a statistically significant higher rate of microbiological response success on microbiological evaluable populations at the test-of-cure visit (95CI 1.10-2.38, p=0.02) and late-follow-up visit (95CI 1.09-2.23, p=0.02) for the treatment of CUTIs. Ceftazidime-avibactam versus active comparisons demonstrated a statistically significant higher rate of microbiological response success on EME populations at the test-of-cure visit (95CI 1.08-4.27, p=0.03) and late-follow-up visit (OR=1.75, 95CI 1.33-2.29, p<0.0001) for the treatment of CUTIs. Similar results were obtained at the late-follow-up visit (OR = 1.58, 95CI 1.26-1.97, p<0.0001) on microbiologically modified intent-to-treat (mMITT) populations for the treatment of CUTIs. We can find better eradication rates for E. coli and Klebsiella pneumoniae based on mMITT populations. In terms of AEs, SAEs and mortality, ceftazidime-avibactam had a safety and tolerability profile broadly similar to the comparison group. Conclusion: This meta-analysis provides evidence of the efficacy of ceftazidime-avibactam as a potential alternative for the treatment of patients with CUTIs, and CIAIs.

Determination of cefotaxime, cefoperazone, ceftazidime and cefadroxil using surface plasmon resonance band of silver nanoparticles

The aim of this work is to evaluate simple, sensitive, effective and validated procedures for the determination of cefotaxime, cefoperazone, ceftazidime and cefadroxil. In this study, the methods based on the ability of the cited drugs to reduce Ag+ ions to silver nanoparticles (Ag-NPs) in the presence of Polyvinyl Pyrrolidone (PVP) as a stabilizing agent producing very intense surface plasmon resonance peak of Ag-NPs (λmax. = 410-430 nm). The plasmon absorbance of the Ag-NPs allows the quantitative spectrophotometric determination of the cited drugs. The calibration curves are linear with concentration ranges of 0.4-3.2, 1-8, 0.5-4.0 and 1.5-9.0 µg/mL for cefotaxime, cefoperazone, ceftazidime and cefadroxil, respectively. Apparent molar absorptivity, detection and quantitative limits are calculated. Applications of the proposed methods to representative pharmaceutical formulations are successfully presented. The extracellular synthesis of nanoparticles is fast, and the method doesn't require various elaborate treatments and tedious extraction procedures.

Nuevas cefalosporinas / New cephalosporins

Resumen La resistencia bacteriana se ha incrementado en América Latina y el mundo, por lo que se requiere investigación y creación de nuevos antimicrobianos capaces de erradicar a los microorganismos resistentes. Se realizó una revisión acerca de nuevas cefalosporinas y sus combinaciones con un inhibidor de β-lactamasas, recopilando información de espectro, farmacocinética, farmacodinamia y estudios clínicos de las indicaciones actuales para ceftarolina, ceftazidima/avibactam y ceftolozano/tazobactam. La primera, con actividad frente a Staphylococcus aureus y Staphylococcus coagulasa negativa sensibles y resistentes a meticilina, y contra Streptococcus pneumoniae resistente a penicilina; por lo tanto, aprobada para uso en neumonía bacteriana adquirida en comunidad e infecciones bacterianas de piel y tejidos blandos. Entre las nuevas combinaciones, ceftazidima, una cefalosporina de tercera generación con actividad anti-pseudomonas, asociada a avibactam, un inhibidor de β-lactamasas, ha demostrado efectividad en el tratamiento de infecciones abdominales e infecciones urinarias complicadas. Por último, la combinación ceftolozano y el conocido tazobactam presenta acción comparable a la combinación de ceftazidima y avibactam por su actividad contra bacilos gramnegativos y, en combinación con metronidazol no presenta inferioridad a meropenem en infecciones intra-abdominales. Se presentan los estudios clínicos y las potenciales indicaciones y escenarios de uso de estas cefalosporinas.

Bacterial resistance has increased in Latin America and the world, making research and creation of new antimicrobials capable of eradicating resistant microorganisms essential. A review of new cephalosporins and their combinations with a beta-lactamase inhibitor was conducted, collecting data on the spectrum, pharmacokinetic and pharmacodynamic profile and clinical studies of the current indications for ceftaroline, and the combinations ceftazidime with avibactam and ceftolozane with tazobactam. The first one has activity against methicillin-resistant Staphylococcus aureus and coagulase negative Staphylococcus (SCoN) and against penicillin-resistant Streptococcus pneumoniae, therefore approved for use in community-acquired pneumonia and acute bacterial skin and skin structure infections. Among the new combinations, ceftazidime, a third generation cephalosporin with antipseudomonal activity, associated with avibactam, a betalactamase inhibitor, has been shown to be effective in the treatment of abdominal infections and complicated urinary infections. Finally, the combination of ceftolozane with tazobactam has comparable action to ceftazidime with avibactam due to its activity against Gram negative rods, and in combination with metronidazole they do not present inferiority to meropenem in intra-abdominal infections. The clinical studies are presented, as well as the potential indications and clinical scenarios for their use of this cephalosporins.

Isolation, enumeration, molecular identification and probiotic potential evaluation of lactic acid bacteria isolated from sheep milk

Lactic acid bacteria species were molecularly identified in milk from Lacaune, Santa Inês and crossbred sheep breeds and their in vitro probiotic potential was evaluated. The species identified were Enterococcus faecium (56.25%), E. durans (31.25%) and E. casseliflavus (12.5%). No other lactic acid bacteria species, such as lactobacilli, was identified. Most of the isolated enterococci were resistant to gastric pH (2.0) and to 0.3% oxgall. All tested enterococci were resistant to ceftazidime, oxacillin and streptomycin and sensible to clindamycin, erythromycin and penicillin. The resistance to ciprofloxacin, gentamicin, tetracycline and vancomycin varied among tested species. All tested enterococci strongly inhibited (P<0.05) Escherichia coli and Listeria monocytogenes, moderately inhibited E. faecalis and Staphylococcus aureus and did not inhibit Pseudomonas aeruginosa, Salmonella enterica var. Typhimurium and also one E. durans sample isolated from sheep milk. Four samples of E. faecium, one of E. durans and one of E. casseliflavus presented the best probiotic potential...

Espécies de bactérias ácido-lácticas foram identificadas em nível molecular em leite das raças ovinas Lacaune, Santa Inês e suas mestiças, e o seu potencial probiótico in vitro foi avaliado. As espécies identificadas foram Enterococcus faecium (56,25%), E. durans (31,25%) e E. casseliflavus (12,5%). Nenhuma outra espécie de bactéria ácido-láctica, como Lactobacillus sp., foi identificada. A maioria dos enterococos isolados foi resistente ao pH gástrico (2.0) e a 0,3% de oxgall. Todos os enterococos testados foram resistentes à ceftazidima, oxacilina e estreptomicina e sensíveis à clindamicina, eritromicina e penicilina. A resistência à ciprofloxacina, gentamicina, tetraciclina e vancomicina variou entre as amostras. Todos os enterococos testados inibiram fortemente (P<0,05) Escherichia coli e Listeria monocytogenes, inibiram moderadamente E. faecalis e Staphylococcus aureus e não inibiram Pseudomonas aeruginosa, Salmonella enterica var. Typhimurium e uma amostra de E. durans isolada de leite de ovelha. Quatro amostras de E. faecium, uma de E. durans e uma de E. casseliflavus apresentaram o melhor potencial probiótico...

Imipenem-resistant Acinetobacter baumannii carrying the ISAba1-bla OXA-23, 51 and ISAba1-bla ADC-7 genes in Monteria, Colombia

The purpose of this study was to identify the genes coding for resistance to ceftazidime and imipenem and describe the molecular epidemiology of A. baumannii strains isolated from a clinical center in Colombia. Twenty isolates of imipenem-resistant A. baumannii from an equal number of patients with nosocomial infections were obtained. Primers were used to amplify genes bla IMP, bla VIM, bla OXA-23, bla OXA-24, bla OXA-58, bla OXA-51 and bla ADC-7. To detect insertion sequences ISAba1/bla OXA-23, ISAba1/bla OXA-51 and ISAba1/bla ADC-7, mapping by PCR using combinations of reverse primers ISAba1 and reverse primers of bla OXA-23, bla OXA-51 and bla ADC-7 were used. The amplification products were purified and cloned into PCR 2.1-TOPO vector and transformed into chemically competent Escherichia coli TOP10. These amplicons were then sequenced. PFGE was performed on DNA of A. baumannii isolates digested with ApaI. Results. The DNA profiles obtained included 9 clusters with, four 2-7 isolates per profile, and 5 single-isolate profiles. Of the 20 isolates resistant to imipenem, 15 carried bla OXA-23 gene, 4 contained ISAba1 upstream of bla OXA-51 gene, and 6 contained ISAba1 upstream of bla OXA-23 gene. Eighteen of these isolates carried the bla ADC-7 gene, with 9 of the isolates having ISAba1 located upstream of this gene. This is the first report of the ISAba1 /ADC-7 associated with OXAs genes in A. baumannii isolates from Colombia.

Ceftazidima en infusión continua en infecciones por Pseudomona aeruginosa / Ceftazidime in continuous infusion on infections by Pseudomona aeruginosa

La ceftazidima es un antimicrobiano perteneciente a la familia de las cefalosporinas de la tercera generación, está indicada en el tratamiento de infecciones bacterianas graves, simples o mixtas, su administración en infusión continua permite optimizar la concentración del antibiótico al mantenerse por encima de su concentración mínima inhibitoria.Objetivo: evaluar el uso de la ceftazidima en infusión continua en infecciones intrahospitalarias por Pseudomona aeruginosa.Método: se realizó un estudio de casos y controles sobre el uso de la ceftazidima en infusión continua y a dosis intermitentes, a pacientes ingresados con diagnóstico confirmado de infección por Pseudomonas aeruginosa en las salas de Cuidados Intermedios Polivalente y Unidad de Trauma, del Hospital Universitario Manuel Ascunce de Camagüey, desde marzo de 2009 a marzo de 2010. La muestra no probabilística estuvo constituida por 84 pacientes con infección documentada por Pseudomona aeruginosa y que recibieron tratamiento con ceftazidima, 42 casos e igual número de controles.Resultados: el 49 por ciento del total de la muestra tuvieron 60 y más años, la diabetes mellitus como comorbilidad asociada se presentó en 52 pacientes, la evolución favorable correspondió a 34 pacientes de los que se les administró la ceftazidima en infusión continua.Conclusiones: la infección por Pseudomona aeruginosa fue más frecuente en pacientes mayores de 60 años y la comorbilidad asociada fue la diabetes mellitus. La administración de ceftazidima en infusión continua mostró mejores resultados que la administración a dosis intermitentes

Ceftazidime is an antimicrobial belonging to the third generation cephalosporin’s family, it is indicated in the treatment of serious, simple or mixed bacterial infections, and its administration in continuous infusion allows optimizing the concentration of antibiotic to keep above their minimum inhibitory concentration.Objective: to evaluate the use of ceftazidime in continuous infusion in nosocomial infections by Pseudomona aeruginosa.Method: a case-control study was carried out on the use of ceftazidime in continuous infusion and intermittent doses, in patients admitted with a confirmed diagnostic of infection by Pseudomona aeruginosa in the Polyvalent Intermediate Care Unit and Trauma Unit rooms, at the University Hospital Manuel Ascunce, from March 2009 to March 2010. Nonrandom sample consisted of 84 patients with infection by Pseudomona aeruginosa and received treatment with ceftazidime 42 cases and an equal number of controls.Results: the 49 percent of the total sample had 60 years and older, diabetes mellitus as associated comorbidity presented in 52 patients, favorable evolution corresponded to 34 patients which ceftazidime in continuous infusion was administered.Conclusions: the infectionby Pseudomona aeruginosa was more frequent in patients older than 60 years and associated comorbidity was diabetes mellitus. Ceftazidime administration in continuous infusion showed better results than intermittent dose administration