Occurrence of blaNDM-1, blaNDM-5, blaNDM-7, and blaKPC-2 genes in clinical isolates of enterobacterales with high genetic variability, from colonization and infection in patients with or without COVID-19, from a hospital in Brazil.

AIMS: This study aimed to investigate the presence of beta-lactams resistance genes and the clonal relationship of clinical isolates of Enterobacterales obtained from patients with and without COVID-19, in a hospital in northeastern Brazil. METHODS AND RESULTS: The study analyzed 45 carbapenem-resistant clinical isolates using enterobacterial repetitive intergenic consensus (ERIC-PCR), PCR, and amplicon sequencing to detect resistance genes (blaKPC, blaGES, blaNDM, blaVIM, and blaIMP). The main species were Klebsiella pneumoniae, Serratia marcescens, and Proteus mirabilis. Detected genes included blaNDM (46.66%), blaKPC (35.55%), and both (17.79%). ERIC-PCR showed multiclonal dissemination and high genetic variability. The main resistance gene was blaNDM, including blaNDM-5 and blaNDM-7. CONCLUSIONS: The presence of Enterobacterales carrying blaKPC and blaNDM in this study, particularly K. pneumoniae, in infections and colonizations of patients with COVID-19 and non-COVID-19, highlights genetic variability and resistance to carbapenems observed in multiple species of this order.

Preliminary snapshot reveals a relationship between multidrug-resistance and biofilm production among enterobacteriaceae isolated from fecal samples of farm-raised poultry in ceará, Brazil.

Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for ß-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of ß-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC ß-lactamase and extended-spectrum ß-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.

Seven-day antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients: toward a new paradigm.

PURPOSE: Data on short courses of antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients are limited. The aim of the study was to describe and compare the frequency of bacteremia relapse, 30-day overall and infection-related mortality, Clostridiodes difficile infection and length of hospital stay since bacteremia among those who received antibiotic therapy for 7 or 14 days. METHODS: This is a multicenter, prospective, observational cohort study in adult high-risk neutropenic patients with hematologic malignancies or hematopoietic stem cell transplant and monomicrobial Enterobacterales bacteremia. They received appropriate empirical antibiotic therapy, had a clinical response within 7 days, and infection source control. Clinical, epidemiological and outcomes variables were compared based on 7 or 14 days of AT. RESULTS: Two hundred patients were included (100, 7-day antibiotic therapy; 100, 14-day antibiotic therapy). Escherichia coli was the pathogen most frequently isolated (47.5%), followed by Klebsiella sp. (40.5%). Among those patients that received 7-day vs. 14-day antibiotic course, a clinical source of bacteremia was found in 54% vs. 57% (p = 0.66), multidrug-resistant Enterobacterales isolates in 28% vs. 30% (p = 0.75), and 40% vs. 47% (p = 0.31) received combined empirical antibiotic therapy. Overall mortality was 3% vs. 1% (p = 0.62), in no case related to infection; bacteremia relapse was 7% vs. 2% (p = 0.17), and length of hospital stay since bacteremia had a median of 9 days (IQR: 7-15) vs. 14 days (IQR: 13-22) (p = < 0.001). CONCLUSIONS: These data suggest that seven-day antibiotic therapy might be adequate for patients with high-risk neutropenia and Enterobacterales bacteremia, who receive appropriate empirical therapy, with clinical response and infection source control.

Rapid colorimetric polymyxin B microelution directly from positive blood bottles: because patients with serious infections should not have to wait for results of culture-based methodologies.

PURPOSE: To evaluate the performance of the rapid colorimetric polymyxin B microelution (RCPEm) in determining polymyxin B resistance directly from Enterobacterales-positive blood cultures. METHODS: A set volume of positive blood culture bottles (diluted 1:10) was inoculated into a glucose-broth-phenol red solution (NP solution), where a polymyxin B disk was previously eluted (final concentration of 3 µg/mL). Test was read each 1 h for up to 4 h. Color change from red/orange to yellow indicated resistant isolates. Results were compared to the reference method, broth microdilution (BMD), performed from colonies grown on solid media from the same blood culture bottle. RESULTS: One hundred fifty-two Enterobacterales-positive blood cultures were evaluated, 22.4% (34/152) of them resistant to polymyxin B (including 6.6% with borderline MICs). When performing directly from positive blood cultures (RCPEm-BC), specificity and sensitivity were 99.1% and 94.1%, respectively. Of note, 79.4% (27/34) of truly resistant isolates required 3 h of incubation, compared to the 18 ± 2 h incubation that microtiter plates of BMD demand before reading can be performed. CONCLUSIONS: RCPEm directly from blood cultures has great potential to be part of the routine of clinical microbiology laboratories to establish polymyxin B susceptibility, impacting outcome of patients with bloodstream infections caused by carbapenem-resistant Enterobacterales.

Emergence of NDM-producing Enterobacterales infections in companion animals from Argentina.

Antimicrobial resistance is considered one of the most critical threat for both human and animal health. Recently, reports of infection or colonization by carbapenemase-producing Enterobacterales in companion animals had been described. This study report the first molecular characterization of NDM-producing Enterobacterales causing infections in companion animals from Argentina. Nineteen out of 3662 Enterobacterales isolates analyzed between October 2021 and July 2022 were resistant to carbapenemes by VITEK2C and disk diffusion method, and suspected to be carbapenemase-producers. Ten isolates were recovered from canine and nine from feline animals. Isolates were identified as K. pneumoniae (n = 9), E. coli (n = 6) and E. cloacae complex (n = 4), and all of them presented positive synergy among EDTA and carbapenems disks, mCIM/eCIM indicative of metallo-carbapenemase production and were also positive by PCR for blaNDM gene. NDM variants were determined by Sanger sequencing method. All 19 isolates were resistant to ß-lactams and aminoglycosides but remained susceptible to colistin (100%), tigecycline (95%), fosfomycin (84%), nitrofurantoin (63%), minocycline (58%), chloramphenicol (42%), doxycycline (21%), enrofloxacin (5%), ciprofloxacin (5%) and trimethoprim/sulfamethoxazole (5%). Almost all isolates (17/19) co-harbored blaCTX-M plus blaCMY, one harbored blaCTX-M alone and the remaining blaCMY. E. coli and E. cloacae complex isolates harbored blaCTX-M-1/15 or blaCTX-M-2 groups, while all K. pneumoniae harbored only blaCTX-M-1/15 genes. All E. coli and E. cloacae complex isolates harbored blaNDM-1, while in K. pneumoniae blaNDM-1 (n = 6), blaNDM-5 (n = 2), and blaNDM-1 plus blaNDM-5 (n = 1) were confirmed. MLST analysis revealed the following sequence types by species, K. pneumoniae: ST15 (n = 5), ST273 (n = 2), ST11, and ST29; E. coli: ST162 (n = 3), ST457, ST224, and ST1196; E. cloacae complex: ST171, ST286, ST544 and ST61. To the best of our knowledge, this is the first description of NDM-producing E. cloacae complex isolates recovered from cats. Even though different species and clones were observed, it is remarkable the finding of some major clones among K. pneumoniae and E. coli, as well as the circulation of NDM as the main carbapenemase. Surveillance in companion pets is needed to detect the spread of carbapenem-resistant Enterobacterales and to alert about the dissemination of these pathogens among pets and humans.

Resistance phenotype and virulence potential of Leclercia adecarboxylata strains isolated from different sources.

Introduction. Leclercia adecarboxylata is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted L. adecarboxylata as an emerging pathogen harbouring virulence and resistance determinants.Gap statement. Little information exists on virulence and resistance determinants in L. adecarboxylata strains isolated from environmental, food, and clinical samples.Aim. To determine the presence of resistance and virulence determinants and plasmid features in L. adecarboxylata strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship.Results. All strains tested showed resistance to ß-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of L. adecarboxylata, the resistance phenotype was only observed in 50 % of the strains; bla TEM was the most prevalent BLEE gene (70 %), while the quinolone qnrB gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains.Conclusions. L. adecarboxylata is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.

KPC-2-producing Enterobacterales from ready-to-eat food to hospitalized patients.

Foodstuffs are a well-documented source of multidrug-resistant bacteria, and hospitalized patients are usually susceptible to hospital infections owing to their immune status. Therefore, this study aimed to investigate the presence of beta-lactamase-producing Enterobacterales in ready-to-eat foods consumed by hospitalized patients. For this purpose, 51 vegetable and meat samples were collected over 2 months and analyzed. Enterobacterales isolates were identified and subjected to antimicrobial susceptibility testing, followed by beta-lactamase gene screening, pH tolerance assays, and whole-genome sequencing (WGS). Isolates harboring genes encoding extended-spectrum beta-lactamases, cephalosporinases, or carbapenemases were detected, and all isolates tolerated pH levels similar to those in the human gastrointestinal tract. The blaKPC-2 carriers were characterized by WGS and lineages closely related to those causing human infections were identified. These results showed that dietary intake is an alternative route for the transmission of antimicrobial-resistant bacteria, which must be considered when designing effective strategies for infection control.

Antimicrobial resistance of Enterobacteriaceae and Staphylococcus spp. isolated from raw cow's milk from healthy, clinical and subclinical mastitis udders.

Mastitis is the most common disease of dairy cattle and can be manifested in clinical and subclinical forms. The overuse of antimicrobials in the treatment and prevention of mastitis favours antimicrobial resistance and milk can be a potential route of dissemination. This study aimed to evaluate the biological quality of bulk tank milk (BTM) and the microbiological quality and signs of mastitis of freshly milked raw milk. In addition, to evaluate antimicrobial resistance in Enterobacteriaceae and Staphylococcus spp. isolated from freshly milked raw milk. None of the farms were within the official Brazilian biological quality limits for BTM. Freshly milked raw milk with signs of clinical (CMM), subclinical (SCMM) and no signs (MFM) of mastitis were detected in 6.67%, 27.62% and 65.71% samples, respectively. Most samples of freshly milked raw milk showed acceptable microbiological quality, when evaluating the indicators total coliforms (78.10%), Escherichia coli (88.57%) and Staphylococcus aureus (100%). Klebsiella oxytoca and S. aureus were the most prevalent microorganisms in SCMM and MFM samples. Antimicrobial resistance and multidrug resistance (MDR) were observed in 65.12% and 13.95% of Enterobacteriaceae and 84.31% and 5.88% of Staphylococcus spp., respectively, isolated from both SCMM and MFM samples. Enterobacteriaceae resistant to third-generation cephalosporin (3GCR) (6.98%) and carbapenems (CRE) (6.98%) and methicillin-resistant S. aureus (MRSA) (4.88%) were observed. Antimicrobial-resistant bacteria can spread resistance genes to previously susceptible bacteria. This is a problem that affects animal, human and environmental health and should be evaluated within the one-health concept.

In vitro activity of ceftazidime-avibactam against gram-negative bacteria in patients with bacteremia and skin and soft-tissue infections in Colombia 2019-2021.

OBJECTIVES: Ceftazidime-avibactam (CAZ-AVI) is an option for infections caused by MDR gram-negative bacilli. In this study, we aimed to analyze the in vitro antimicrobial activity of CAZ-AVI and other antimicrobial agents against gram-negative bacilli that were collected in Colombia between 2019 and 2021 from patients with bacteremia and skin and soft-tissue infections (SSTIs). METHODS: A total of 600 Enterobacterales and 259 P. aeruginosa strains were analyzed. The phenotypic resistance of isolates, particularly non-susceptibility to meropenem, multidrug-resistant (MDR) isolates, and difficult-to-treat (DTR) P. aeruginosa, was evaluated according to CLSI breakpoints. RESULTS: Enterobacterales had the most susceptibility to CAZ-AVI (96.5 %) and tigecycline (95 %). Tigecycline and CAZ-AVI were the antimicrobial agents with the most in vitro activity against carbapenem-resistant Enterobacterales (CRE). CAZ-AVI was the antimicrobial treatment with the most activity against P. aeruginosa. CONCLUSIONS: Tigecycline and CAZ-AVI were the antimicrobial agents with the most activity against CRE and MDR Enterobacterales. For P. aeruginosa, CAZ-AVI was the antimicrobial treatment with the most in vitro activity.

Antibacterial effectiveness of trans-cinnamaldehyde against foodborne Enterobacteriaceae and its adjuvant effect with gentamicin.

The Enterobacteriaceae family is recognized as a primary group of Gram-negative pathogens responsible for foodborne illnesses and is frequently associated with antibiotic resistance. The present study explores the natural-based compound trans-cinnamaldehyde (TC) against drug-resistant Enterobacteriaceae and its synergism with gentamicin (GEN) to address this issue. The research employs three strains of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, previously isolated from shrimp. The antibacterial activity was evaluated by the disk diffusion method, microdilution test, kinetics of growth, and time-kill curve. In addition, the synergistic effect between TC/GEN was investigated by checkerboard assay. All strains showed sensitivity to TC with an inhibition zone diameter > 35 mm. The TC showed inhibitory and bactericidal action in the most tested bacteria around 625 µg/mL. Sub-inhibitory amounts (1/2 and 1/4 MIC) of TC interfered with the growth kinetics by lag phase extension and decreased the log phase. Time-kill curves show a reduction of viable cells after the first hour of TC treatment at bactericidal concentrations. The synergistic effect between TC/GEN was observed for E. coli and E. cloacae strains with FICi ranging from 0.15 to 0.50. These findings, therefore, suggest TC as a promising alternative in the fight against drug-resistant Enterobacteriaceae that can cause foodborne illnesses.

Detection of Carbapenem Resistance in Enterobacterales Directly From Positive Blood Cultures Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry.

CONTEXT.­: Carbapenem-resistant Enterobacterales are disseminated worldwide and associated with infections with high rates of morbidity and mortality. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a useful tool for identification of pathogens directly from blood cultures in clinical microbiology laboratories. Furthermore, it has been applied for the detection of carbapenemase production, by evaluating carbapenem hydrolysis. OBJECTIVE.­: To determine meropenem hydrolysis to detect carbapenemase production directly from positive blood cultures, using logRQ to establish a quantitative measure of hydrolysis. DESIGN.­: We evaluated 100 Enterobacterales from positive blood cultures, with 81 carrying a carbapenemase gene (blaKPC, blaGES, blaNDM-1, blaIMP, blaVIM, and blaOXA-48-like), as determined by real-time multiplex polymerase chain reaction with high-resolution melting (HRM-qPCR). Bacterial proteins extracted from positive blood culture bottles were incubated in a meropenem solution (2-4 hours) followed by centrifugation for MALDI-TOF MS analysis. The intensity of peaks of the hydrolyzed and nonhydrolyzed forms were used to calculate the logRQ value. RESULTS.­: Overall, sensitivity was 86.8% and specificity, 89.5%. Of note, sensitivity varied depending on enzyme type. For blaKPC-positive isolates, sensitivity was 97.9%, while it reduced significantly for blaNDM-1 and blaOXA-48-like isolates: 62.5% (10 of 16) and 66.7% (6 of 9), respectively. Indeed, logRQ was higher in blaKPC-positive isolates (0.37-1.97) than in blaNDM-1 (-1.37 to 0.83) and blaOXA-48-like isolates (-1.08 to 1.79). CONCLUSIONS.­: This is an inexpensive and rapid test to identify carbapenemase activity directly from blood culture bottles, which contributes to early adequate antimicrobial therapy and implementation of infection control measures.

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.

Portrayal of Punica granatum L peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation / Retrato do extrato de casca de Punica granatum L por meio de cromatografia líquida de alto desempenho e avaliação da atividade antimicrobiana

ncreasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These [...].(AU)

A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia [...].(AU)

Portrayal of Punica granatum L peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation / Retrato do extrato de casca de Punica granatum L por meio de cromatografia líquida de alto desempenho e avaliação da atividade antimicrobiana

ncreasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These [...].

A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia [...].

In vitro activity of ceftazidime-avibactam against Enterobacterales and Pseudomonas aeruginosa isolates collected in Latin America as part of the ATLAS global surveillance program, 2017-2019.

The Antimicrobial Testing Leadership and Surveillance (ATLAS) global surveillance program collected clinical isolates of Enterobacterales (n = 8416) and Pseudomonas aeruginosa (n = 2521) from 41 medical centers in 10 Latin American countries from 2017 to 2019. In vitro activities of ceftazidime-avibactam and comparators were determined using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Overall, 98.1% of Enterobacterales and 86.9% of P. aeruginosa isolates were susceptible to ceftazidime-avibactam. When isolates were analyzed by country of origin, susceptibility to ceftazidime-avibactam for Enterobacterales ranged from 97.8% to 100% for nine of 10 countries (except Guatemala, 86.3% susceptible) and from 75.9% to 98.4% for P. aeruginosa in all 10 countries. For Enterobacterales, 100% of AmpC-positive, ESBL- and AmpC-positive, GES-type carbapenemase-positive, and OXA-48-like-positive isolates were ceftazidime-avibactam-susceptible as were 99.8%, 91.8%, and 74.7% of ESBL-positive, multidrug-resistant (MDR), and meropenem-nonsusceptible isolates. Among meropenem-nonsusceptible isolates of Enterobacterales, 24.4% (139/570) carried a metallo-ß-lactamase (MBL); 83.3% of the remaining meropenem-nonsusceptible isolates carried another class of carbapenemase and 99.4% of those isolates were ceftazidime-avibactam-susceptible. Among meropenem-non-susceptible isolates of P. aeruginosa (n = 835), 25.6% carried MBLs; no acquired ß-lactamase was identified in the majority of isolates (64.8%; 87.2% of those isolates were ceftazidime-avibactam-susceptible). Overall, clinical isolates of Enterobacterales collected in Latin America from 2017 to 2019 were highly susceptible to ceftazidime-avibactam, including isolates carrying ESBLs, AmpCs, and KPCs. Country-specific variation in susceptibility to ceftazidime-avibactam was more common among isolates of P. aeruginosa than Enterobacterales. The frequency of MBL-producers among Enterobacterales from Latin America was low (1.7% of all isolates; 146/8,416), but higher than reported in previous surveillance studies.

In vitro synergistic activity of aztreonam (AZT) plus novel and old ß-lactamase inhibitor combinations against metallo-ß-lactamase-producing AZT-resistant Enterobacterales.

The emergence of metallo-ß-lactamase (MBL)-producing Enterobacterales, mainly New Delhi metallo-ß-lactamase (NDM), represents a clinical threat due to the limited therapeutic alternatives. Aztreonam (AZT) is stable to MBLs, but most MBL-producing Enterobacterales isolates usually co-harbour other ß-lactamases that confer resistance to AZT and, consequently, its use is restricted in these isolates. We compared the ability of sulbactam (SUL), tazobactam (TAZ), clavulanic acid (CLA) and avibactam (AVI) to restore the AZT activity in MBL-producing AZT-resistant Enterobacterales isolates. A collection of 64 NDM-producing AZT-resistant Enterobacterales from five hospitals in Buenos Aires city, Argentina, were studied during the period July-December 2020. MICs were determined using the agar dilution method with Mueller-Hinton agar according to Clinical and Laboratory Standards Institute (CLSI) recommendations. AVI, SUL and TAZ were used at a fixed concentration of 4 mg l-1, whereas CLA was used at a fixed concentration of 2 mg l-1. A screening method based on disc diffusion to evaluate this synergy was also conducted. Detection of bla KPC, bla OXA, bla NDM, bla VIM, bla CTXM-1, bla PER-2 and bla CIT was performed by PCR. The AZT-AVI combination restored the AZT activity in 98.4 % of AZT-resistant strains, whereas CLA, TAZ and SUL did so in 70.3, 15.6 and 12.5 %, respectively, in isolates co-harbouring extended-spectrum ß-lactamases, but were inactive in isolates harbouring AmpC-type enzymes and/or KPC. The synergy screening test showed an excellent negative predictive value to confirm the absence of synergy, but positive results should be confirmed by a quantitative method. The excellent in vitro performance of the AZT-CLA combination represents a much more economical alternative to AZT-AVI, which could be of use in the treatment of MBL-producing, AZT-resistant Enterobacterales.

Molecular epidemiology of cefotaxime-resistant but ceftazidime-susceptible Enterobacterales and evaluation of the in vitro bactericidal activity of ceftazidime and cefepime.

Extended-spectrum ß-lactamases' (ESBLs) production is the main resistance mechanism to third-generation cephalosporins (TGCs) in gram-negative bacilli. In Argentina, there is a high prevalence of cefotaximase-type ESBLs (CTX-M). For this reason, dissociated resistance phenotype (DRP) displaying a profile of resistance to cefotaxime (CTX) and susceptibility to ceftazidime (CAZ) might be detected. The aims of this study were to determine the prevalence of DRP in Enterobacterales clinical isolates, to characterize the mechanisms responsible for this phenotype and to evaluate the in vitro behaviour against different antibiotics. Sixty Enterobacterales resistant to any TGC were studied, and among them, 25% displayed a DRP. The ß-lactamases associated with DRP were 5/11 CTX-M-2, 4/11 CTX-M-14, 1/11 CTX-M-15 and 1/11 CMY-2 in E. coli, 2/3 CTX-M-2 and 1/3 CMY-2 in P. mirabilis and 1/1 CTX-M-14 in K. pneumoniae. Furthermore, CTX-M-2 and CTX-M-14 were related with DRP in both wild-type isolates and the corresponding transconjugants. Time-kill experiments showed CAZ bactericidal activity on CTX-M-2-and CTX-M-14-producing strains and bacterial regrowth in those CMY-2 producers. An opposite behaviour was evident when cefepime (FEP) was used. However, CAZ and gentamicin combination showed a synergistic effect against the CMY-2 producers. We concluded that Enterobacterales with DRP responded differently to CAZ or FEP depending on the type of ß-lactamase they possess, suggesting that these cephalosporins could be a therapeutic option. Therefore, the characterization of the involved resistance mechanism might contribute to define the appropriate antibiotic treatment.

Eficacia y seguridad de ceftazidima-avibactam para el tratamiento de pacientes adultos con neumonía intrahospitalaria asociada a ventilación mecánica causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina / Efficacy and safety of ceftazidime-avibactam for the treatment of adult patients with hospital-acquired pneumonia associated with mechanical ventilation caused by colistin-resistant gram-negative carbapenemase-producing bacteria

INTRODUCCIÓN: El presente dictamen expone la evaluación de la eficacia y seguridad de ceftazidima-avibactam (C-A) para el tratamiento de pacientes adultos con neumonía intrahospitalaria asociada a ventilación mecánica (NAVM) causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La neumonía intrahospitalaria es la principal causa de muerte por infecciones adquiridas en el hospital. Aproximadamente, el 80 % de las neumonías intrahospitalarias corresponden a neumonías intrahospitalarias asociadas a ventilador mecánico (NAVM) con una mortalidad que puede llegar al 76 %, cuando la infección es causada por patógenos de alto riesgo. Actualmente, existen patógenos gram negativos extremadamente resistentes que producen betalactamasas capaces de hidrolizar antibióticos carbapenémicos llamados bacterias gram negativas productoras de carbapenemasas. Hasta la fecha, existen pocas alternativas para el tratamiento de NAVM causada por bacterias productoras de carbapenemasas. Como opciones de última línea, se tienen esquemas basados en colistina más carbapenémicos. En EsSalud, estos pacientes tienen a su disposición esta combinación como última línea de tratamiento; sin embargo, algunos pacientes presentan infecciones resistentes a estos antibióticos, por lo cual no disponen de una alternativa terapéutica para controlar la infección. Así, los especialistas de EsSalud sugieren el uso de ceftazidima-avibactam (C-A) para el tratamiento de la NAVM por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La ceftazidima es una cefalosporina que inhibe la síntesis de la pared celular bacteriana, y el avibactam es un inhibidor de beta-lactamasa. Ambos son antibióticos cuya presentación en forma combinada ha sido aprobada por la Food and Drug Administration (FDA) y la European Medicines Agency (EMA) para el tratamiento de pacientes NAVM ocasionado por bacterias gram negativas. METODOLOGÍA: Se llevó a cabo una búsqueda bibliográfica exhaustiva con el objetivo de identificar la mejor evidencia sobre la eficacia y seguridad de C-A para el tratamiento de pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La búsqueda se inició con la revisión de la información sobre el uso del medicamento de acuerdo con entidades reguladoras como FDA, EMA, DIGEMID y la Organización Mundial de la Salud (OMS). La búsqueda bibliográfica se realizó en las bases de datos PubMed, The Cochrane Library y LILACS. Asimismo, se realizó una búsqueda manual dentro de las páginas web pertenecientes a grupos que realizan evaluación de tecnologías sanitarias y guías de práctica clínica (GPC) incluyendo la National Institute for Health and Care Excellence (NICE), Canadian Agency for Drugs and Technologies in Health (CADTH), Scottish Medicines Consortium (SMC), Scottish Intercollegiate Guidelines Network (SIGN), Institute for Clinical and Economic Review (ICER), El Instituto de Calidad y Eficiencia en la Atención de la Salud (IQWiG, por sus siglas en alemán), la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA), la OMS, el Ministerio de Salud del Perú (MINSA) y el Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI). Además, se realizó una búsqueda de GPC de las principales sociedades o instituciones especializadas en infectología, tales como: Infectious Diseases Society of America (IDSA), European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) y la Asociación Latinoamericana del Tórax (ALAT). Finalmente, se realizó una búsqueda en la página web de registro de ensayos clínicos (EC) www.clinicaltrials.gov, para identificar EC en curso o que no hayan sido publicados aún. RESULTADOS: Se llevó a cabo una búsqueda de evidencia científica relacionada al uso de C-A como tratamiento de pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La presente sinopsis describe la evidencia disponible según el tipo de publicación, siguiendo lo indicado en los criterios de elegibilidad (GPC, ETS, RS con o sin meta análisis o metaanálisis en red y estudios primarios) que se obtuvieron de la búsqueda sistemática y la búsqueda adicional realizada en PubMed. CONCLUSIONES:  El presente dictamen preliminar tuvo por objetivo evaluar la mejor evidencia disponible en torno a la eficacia y seguridad de C-A en comparación la mejor terapia de soporte (continuar con carbapenémicos, colistina u otros), como tratamiento de pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. No se identificaron GPC, ETS, RS o ECA que respondan a la pregunta PICO del presente dictamen. Tras ampliar los criterios de búsqueda y selección considerando los términos relacionados a la intervención y agentes gram negativos resistentes a carbapenémicos, se identificaron 4 estudios observacionales comparativos que incluían a la población de la pregunta PICO del presente dictamen. De los cuatro estudios incluidos, dos mostraron diferencia a favor de C-A en términos de mortalidad, tres reportaron respuesta clínica a favor de C-A y uno mostró mayor erradicación microbiológica a favor de C-A. Además, dos estudios que evaluaron seguridad estimaron que C-A tendría un mejor perfil de seguridad (menor daño renal) que otros antibióticos (entre ellos carbapenémicos y colistina). Debido al diseño y las limitaciones de estos estudios observacionales, no es posible establecer una relación causa-efecto entre el uso de C-A y los desenlaces evaluados. Sin embargo, sí nos ofrecen una descripción de la actividad antibacteriana y el perfil de seguridad de C-A. La NAVM es una enfermedad con alta mortalidad y los pacientes con NAVM por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina, no cuentan con una alternativa de tratamiento (vacío terapéutico) en EsSalud. La mejor terapia de soporte (continuar con carbapenémicos, colistina u otros disponibles en EsSalud), aumentaría el riesgo de desarrollar eventos adversos y resistencia bacteriana. Dicha resistencia bacteriana pone en riesgo a otros pacientes hospitalizados de adquirir infecciones resistentes, además incrementaría la estancia hospitalaria, los costos de atención y la mortalidad. Por lo expuesto, el IETSI aprueba el uso de C-A en pacientes pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina, como producto farmacéutico no incluido en el Petitorio Farmacológico de EsSalud. La vigencia del presente dictamen es de un año, según lo establecido en el Anexo N° 1 y la continuación de dicha aprobación estará sujeta a la evaluación de los resultados obtenidos y de mayor evidencia que pueda surgir en el tiempo.