Advancements in Immunology and Microbiology Research: A Comprehensive Exploration of Key Areas.

Immunology and microbiology research has witnessed remarkable growth and innovation globally, playing a pivotal role in advancing our understanding of immune mechanisms, disease pathogenesis, and therapeutic interventions. This manuscript presents a comprehensive exploration of the key areas in immunology research, spanning from the utilisation of bacterial proteins as antibody reagents to the intricate realms of clinical immunology and disease management. The utilisation of bacterial immunoglobulin-binding proteins (IBPs), including protein A (SpA), protein G (SpG), and protein L (SpL), has revolutionised serological diagnostics, showing promise in early disease detection and precision medicine. Microbiological studies have shed light on antimicrobial resistance patterns, particularly the emergence of extended-spectrum beta-lactamases (ESBLs), guiding antimicrobial stewardship programmes and informing therapeutic strategies. Clinical immunology research has elucidated the molecular pathways underlying immune-mediated disorders, resulting in tailored management strategies for conditions such as severe combined immunodeficiency (SCID), neuropsychiatric systemic lupus erythematosus (NPSLE), etc. Additionally, significant efforts in vaccine development against tuberculosis and HIV are highlighted, underscoring the ongoing global pursuit of effective preventive measures against these infectious diseases. In summary, immunology and microbiology research have provided significant contributions to global healthcare, fostering collaboration, innovation, and improved patient outcomes.

Increasing community prevalence of extended-spectrum beta-lactamase-producing Escherichia coli in urine is associated with increasing district-level antibiotic consumption.

This study aimed to analyze ESBL-producing Escherichia coli prevalence in urine samples collected between 2011-2019 in Curitiba, a large city in Brazil, and relating it to antibiotic consumption and sanitary conditions. This is a longitudinal study correlating prevalence of ESBL-producing E. coli isolates from urine samples with district-level antibiotic consumption and sociodemographic data during 2011-2019. E. coli isolates were tested for antibiotic susceptibility and ESBL by an automated method. Statistical analysis applied linear regressions, pooled ordinary least squares, and fixed effects models for districts or years. The Chow and Hausman tests indicated that the fixed effects model for individual districts fitted best. Chi-square test was used for qualitative variables (statistical significance was set when P < 0.05). Among the 886 535 urine sample cultures, 9.9% of isolates were ESBL-producing E. coli. Their prevalence increased from 4.7% in 2012 to 19.3% in 2019 (P < 0.0001; R2 = 0.922). This progressive increase correlated with age (P = 0.007; R2 = 0.8725) and male gender (P < 0.001) and increased antibiotic consumption (P = 0.0386; R2 = 0.47). The fixed effects model showed that district influences ESBL prevalence and that antibiotic consumption explains 20%-30% of this variation, with an increase of one defined daily dose accounting for an increase of 0.02084 percentage points of ESBL. The increasing prevalence of ESBL-producing E. coli can, to a considerable extent, be explained by increasing antibiotic consumption.

Occurrence of Antimicrobial-Resistant Bacteria in Intestinal Contents of Wild Marine Fish in Chile.

Antimicrobial-resistant bacteria (ARB) from the intestinal contents of wild fish may have a relevant ecological significance and could be used as indicators of antimicrobial-resistance dissemination in natural bacterial populations in water bodies impacted by urban contamination. Thus, the occurrence of ARB in the intestinal contents of pelagic and demersal wild fishes captured in anthropogenic-impacted Coquimbo Bay in Chile was studied. Culturable counts of total and antimicrobial-resistant bacteria were determined by a spread plate method using Trypticase soy agar and R2A media, both alone and supplemented with the antimicrobials amoxicillin, streptomycin, florfenicol, oxytetracycline and ciprofloxacin, respectively. Heterotrophic plate counts of pelagic and demersal fishes ranged from 1.72 × 106 CFU g-1 to 3.62 × 109 CFU g-1, showing variable proportions of antimicrobial resistance. Representative antimicrobial-resistant isolates were identified by 16S rRNA gene sequencing, and isolates (74) from pelagic fishes mainly belonged to Pseudomonas (50.0%) and Shewanella (17.6%) genera, whereas isolates (68) from demersal fishes mainly belonged to Vibrio (33.8%) and Pseudomonas (26.5%) genera. Antimicrobial-resistant isolates were tested for susceptibility to 12 antimicrobials by an agar disk diffusion method, showing highest resistance to streptomycin (85.2%) and amoxicillin (64.8%), and lowest resistance to oxytetracycline (23.2%) and ciprofloxacin (0.7%). Only furazolidone and trimethoprim/sulfamethoxazole were statistically different (p < 0.05) in comparisons between isolates from pelagic and demersal wild fishes. Furthermore, an important number of these isolates carried plasmids (53.5%) and produced Extended-Spectrum-ß-lactamases (ESBL) (16.9%), whereas the detection of Metallo-ß-Lactamases and class 1-integron was rare. This study provides evidence that wild fish are important reservoirs and spreading-vehicles of ARB, carrying plasmids and producing ESBLs in Chilean marine environments.

Resistencia antimicrobiana de Enterobacterias causante de infección del tracto urinario en pacientes ambulatorios / Antimicrobial resistance of Enterobacteriaceae causing urinary tract infection in ambulatory patients / Resistência antimicrobiana de Enterobacteriaceae causadora de infecção do trato urinário em pacientes ambulatoriais

Las infecciones del tracto urinario son consideradas un problema de salud a nivel hospitalario y comunitario por el aumento de bacterias resistentes a los antibióticos. Objetivo: Analizar el patrón de susceptibilidad y resistencia antimicrobiana de Enterobacterias causante de infección del tracto urinario. Métodos: Se aplicó una investigación descriptiva de diseño documental. La población fue de 672 registros de urocultivos positivos, recopilados de la base de datos del Laboratorio San Pablo en el periodo 2021-2022. Para su tabulación y análisis los datos obtenidos fueron procesados en el Software SPSS versión 25.0. Resultados: Las ITU se presentan con mayor frecuencia en el género femenino 86,5%. El grupo etario con más afección es la edad adulta 50,4%. El agente etiológico con mayor incidencia fue Escherichia coli 75,74%, Citrobacter Freundii 8,93%, Klebsiella spp 6,10%. La producción de BLEE como mecanismo de resistencia predominaron en las cepas de E.coli y Klebsiella spp. Se encontró un mayor porcentaje de resistencia para Ampicilina y SXT. Los antibióticos con mejor sensibilidad destacaron nitrofurantoína, fosfomicina. Conclusión: La especie con mayor aislamiento, implicada en la etiología de infecciones urinarias sigue siendo E.coli con una sensibilidad alta para nitrofurantoína y fosfomicina.

Urinary tract infections are considered a health problem at hospital and community level due to the increase of antibiotic resistant bacteria. Objective: To analyze the pattern of susceptibility and antimicrobial resistance of Enterobacteriaceae causing urinary tract infection. Methods: A descriptive research of documentary design was applied. The population was 672 records of positive urine cultures, collected from the San Pablo Laboratory database in the period 2021-2022. For tabulation and analysis, the data obtained were processed in SPSS software version 25.0. Results: UTIs occur more frequently in females 86.5%. The age group with the highest incidence was adulthood 50.4%. The etiological agent with the highest incidence was Escherichia coli 75.74%, Citrobacter Freundii 8.93%, Klebsiella spp 6.10%. The production of BLEE as a mechanism of resistance predominated in the strains of E.coli and Klebsiella spp. A higher percentage of resistance was found for Ampicillin and SXT. The antibiotics with the best sensitivity were nitrofurantoin and fosfomycin. Conclusion: The species with the highest isolation, implicated in the etiology of urinary tract infections, continues to be E.coli with a high sensitivity to nitrofurantoin and fosfomycin.

As infecções do trato urinário são consideradas um problema de saúde a nível hospitalar e comunitário devido ao aumento de bactérias resistentes aos antibióticos. Objetivo: Analisar o padrão de suscetibilidade e resistência antimicrobiana das Enterobacteriaceae causadoras de infecções do trato urinário. Métodos: Foi aplicada uma metodologia de investigação documental descritiva. A população foi de 672 registros de culturas de urina positivas, coletados do banco de dados do Laboratório San Pablo no período de 2021-2022. Para tabulação e análise, os dados obtidos foram processados no software SPSS versão 25.0 Resultados: As ITUs ocorreram com maior frequência no sexo feminino 86,5%. A faixa etária com maior incidência foi a adulta 50,4%. O agente etiológico com maior incidência foi a Escherichia coli 75,74%, Citrobacter Freundii 8,93%, Klebsiella spp 6,10%. A produção de BLEE como mecanismo de resistência predominou em E. coli e Klebsiella spp. Foi encontrada uma maior percentagem de resistência para a ampicilina e o SXT. Os antibióticos com melhor sensibilidade foram a nitrofurantoína e a fosfomicina. Conclusão: A espécie com maior isolamento, implicada na etiologia das infecções do trato urinário, continua a ser a E. coli com uma elevada sensibilidade à nitrofurantoína e à fosfomicina.

Structural basis of metallo-ß-lactamase resistance to taniborbactam.

The design of inhibitors against metallo-ß-lactamases (MBLs), the largest family of carbapenemases, has been a strategic goal in designing novel antimicrobial therapies. In this regard, the development of bicyclic boronates, such as taniborbactam (TAN) and xeruborbactam, is a major achievement that may help in overcoming the threat of MBL-producing and carbapenem-resistant Gram-negative pathogens. Of concern, a recent report has shown that New Delhi MBL-9 (NDM-9) escapes the inhibitory action of TAN by a single amino acid substitution with respect to New Delhi MBL-1 (NDM-1), the most widely disseminated MBL. Here, we report a docking and computational analysis that identifies that "escape variants" against TAN can arise by disruption of the electrostatic interaction of negative charges in the active site loops of MBLs with the N-(2-aminoethyl)cyclohexylamine side chain of TAN. These changes result in non-productive binding modes of TAN that preclude reaction with the MBLs, a phenomenon that is not restricted to NDM-9. This analysis demonstrates that single amino acid substitutions in non-essential residues in MBL loops can unexpectedly elicit resistance to TAN.

Perfil de resistencia antimicrobiana de Escherichia coli y Klebsiella pneumoniae en pacientes que acudieron al Hospital de Norte durante diciembre 2022 - abril 2023

Introducción: Las infecciones causadas por bacterias resistentes a múltiples antibióticos son un problema mundial. El objetivo de la presente investigación fue determinar el perfil de resistencia antimicrobiana de Escherichia coli y Klebsiella pneumoniae en pacientes que acudieron al Hospital del Norte, Cochabamba - Bolivia. Método: La población estuvo conformada por 134 pacientes. Se incluyeron muestras de orina, esputo, punta de catéter, aspirado traqueal, secreción vaginal, líquido abdominal, absceso, secreción faríngea y secreción escrotal, provenientes de pacientes de ambos sexos y que fueron atendidos entre los meses de diciembre 2022 - abril 2023. El aislamiento e identificación de bacterias se realizó en Agar, Sangre, Mac Conkey, Eosina Azul de Metileno (EMB), pruebas bioquímicas y determinación de resistencia y sensibilidad antibiótica in vitro utilizando el método de disco difusión en agar. Resultados: Los microorganismos que se aislaron con mayor prevalencia fue Escherichia coli con 93,3 %, seguido por Klebsiella pneumoniae con 6,7 %. Ambos microorganismos presentaron mecanismos de resistencia de tipo betalactamasas de espectro extendido (BLEE), betalactamasas de espectro ampliado (BLEA) y serin-betalactamasas (AMPc). Conclusión: La bacteria más aislada fue la Escherichia coli productora de BLEE, BLEA y AMPc, con mayor frecuencia en el sexo femenino. Presentando multirresistencia a los antibióticos cefazolina, ácido Nalidíxico, ciprofloxacina, ampicilina y gentamicina. Y K. pneumoniae presento multirresistencia a cefazolina, ciprofloxacina, ampicilina, cefotaxima y gentamicina.

Introduction: Infections caused by bacteria resistant to multiple antibiotics are a worldwide problem. The objective of this research was to determine the antimicrobial resistance profile of Escherichia coli and Klebsiella pneumoniae in patients who attended the Hospital del Norte, Cochabamba, Bolivia. Method: The population consisted of 134 patients. Samples of urine, sputum, catheter tip, tracheal aspirate, vaginal secretion, abdominal fluid, abscess, pharyngeal secretion, and scrotal secretion were included, coming from patients of both sexes who were attended between the months of December 2022 and April 2023. Isolation and identification of bacteria were carried out in Agar, blood, Mac Conkey, Eosin Methylene Blue (EMB), biochemical tests and determination of antibiotic resistance and sensitivity in vitro using the agar diffusion disk method. Results: The microorganisms that were isolated with the highest prevalence were Escherichia coli with 93.3%, followed by Klebsiella pneumoniae with 6.7%. Both microorganisms presented extended-spectrum beta-lactamase (ESBL), extended-spectrum beta-lactamase (ESBL) and serine-beta-lactamase (cAMP) resistance mechanisms. Conclusion: The most isolated bacterium was Escherichia coli, which produced ESBL, ESBL and cAMP, more frequently in females. Presenting multi-resistance to the antibiotics cefazolin, nalidixic acid, ciprofloxacin, ampicillin and gentamicin. And K. pneumoniae presented multiresistance to cefazolin, ciprofloxacin, ampicillin, cefotaxime and gentamicin.

Introdução: As infecções causadas por bactérias resistentes a múltiplos antibióticos são um problema mundial. O objetivo desta pesquisa foi determinar o perfil de resistência antimicrobiana de Escherichia coli e Klebsiella pneumoniae em pacientes atendidos no Hospital del Norte, Cochabamba - Bolívia. Método: A população foi composta por 134 pacientes. Foram incluídas amostras de urina, escarro, ponta de cateter, aspirado traqueal, secreção vaginal, líquido abdominal, abscesso, secreção faríngea e secreção escrotal, provenientes de pacientes de ambos os sexos e que foram atendidos entre os meses de dezembro de 2022 a abril de 2023. Isolamento e a identificação da bactéria foi realizada em Ágar, Sangue, Mac Conkey, Eosina Azul de Metileno (EMB), testes bioquímicos e determinação de resistência e sensibilidade a antibióticos in vitro pelo método do disco de difusão em ágar. Resultados: Os microrganismos isolados com maior prevalência foram Escherichia coli com 93,3%, seguido de Klebsiella pneumoniae com 6,7%. Ambos os microrganismos apresentaram mecanismos de resistência à beta-lactamase de espectro estendido (ESBL), beta-lactamase de espectro estendido (ESBL) e serina-beta-lactamase (cAMP). Conclusão: A bactéria mais isolada foi a Escherichia coli, que produziu ESBL, ESBL e cAMP, com maior frequência no sexo feminino. Apresentando multirresistência aos antibióticos cefazolina, ácido nalidíxico, ciprofloxacina, ampicilina e gentamicina. E K. pneumoniae apresentou multirresistência a cefazolina, ciprofloxacina, ampicilina, cefotaxima e gentamicina.

Characterization of extended spectrum ß-lactamases in Colombian clinical isolates of non-typhoidal Salmonella enterica between 1997 and 2022 / Caracterización de ß-lactamasas de espectro extendido en aislamientos clínicos colombianos de Salmonella enterica no tifoidea de 1997 a 2022.

Introduction. Salmonella spp. is a zoonotic pathogen transmitted to humans through contaminated water or food. The presence of extended-spectrum ß-lactamases is a growing public health problem because these enzymes are resistant to third and fourth generation cephalosporins. Objective. To characterize extended-spectrum ß-lactamases in Salmonella spp. isolates received by the acute diarrheal disease/foodborne disease surveillance program of the Grupo de Microbiología of the Instituto Nacional de Salud. Materials and methods. A total of 444 Salmonella spp. isolates, resistant to at least one of the cephalosporins, were obtained between January 1997 and June 2022. The extendedspectrum ß-lactamases phenotype was identified by the double disk test. DNA extraction was carried out by the boiling method, and the blaCTX-M, blaSHV, and blaTEM genes were amplified by PCR. Results. All the isolates were positive for the extended-spectrum ß-lactamases test. The genes identified were: blaCTX-M + blaTEM (n=200), blaCTX-M (n=177), blaSHV (n=16), blaSHV + blaCTX-M (n=6), blaTEM (n=13) and blaSHV + blaCTX-M + blaTEM (n=3). Twenty-six isolates were negative for the evaluated genes. Positive extended-spectrum ß-lactamases isolates were identified in Bogotá and 21 departments: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusion. Resistance to third generation cephalosporins in Salmonella spp. isolates was mainly caused by blaCTX-M. Isolates were resistant to ampicillin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole (44 %; 197/444). The most frequent extended-spectrum ß-lactamases-expressing serotypes were Salmonella Typhimurium and Salmonella Infantis.

Introducción. Salmonella spp. es un agente patógeno zoonótico transmitido al humano por el agua o los alimentos contaminados. La presencia de ß-lactamasas de espectro extendido es un creciente problema para la salud pública debido a que estas enzimas confieren resistencia contra las cefalosporinas de tercera y cuarta generación. Objetivo. Caracterizar las ß-lactamasas de espectro extendido en aislamientos de Salmonella spp. recibidos por el programa de vigilancia de enfermedad diarreica aguda o enfermedad transmitida por alimentos del Grupo de Microbiología del Instituto Nacional de Salud. Materiales y métodos. Entre enero de 1997 y junio de 2022, se recibieron 444 aislamientos de Salmonella spp. resistentes, por lo menos, a una de las cefalosporinas de tercera generación. El fenotipo de las ß-lactamasas de espectro extendido se identificó con la prueba de doble disco. El ADN se extrajo por ebullición y mediante PCR se amplificaron los genes blaCTX-M, blaSHV y blaTEM. Resultados. Todos los aislamientos fueron positivos para la prueba de ß-lactamasas de espectro extendido. Los resultados de la amplificación por PCR fueron: blaCTX-M + blaTEM (n=200), blaCTX-M (n=177), blaSHV (n=16), blaSHV + blaCTX-M (n=6), blaTEM (n=13) y blaSHV + blaCTX-M + blaTEM (n=3). Del total, 26 aislamientos fueron negativos para los genes evaluados. Los aislamientos positivos para ß-lactamasas de espectro extendido se identificaron en Bogotá y en 21 departamentos: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusión. La resistencia a las cefalosporinas de tercera generación en aislamientos de Salmonella spp. fue generada principalmente por blaCTX-M. El 44 % (197/444) de los aislamientos presentó resistencia a ampicilina, tetraciclina, cloranfenicol y trimetoprimsulfametoxazol Los serotipos portadores de ß-lactamasas de espectro extendido más frecuentes fueron S. Typhimurium y S. Infantis.

[Gram-negative bacteria of critical priority in ICU patients from a tertiary care hospital]. / Bacterias Gram-negativas de prioridad crítica en pacientes de las UCI de un hospital de tercer nivel.

Background: Intensive care units (ICU) are the epicenter of antimicrobial resistance (AMR), and patients' infections are mainly caused by Gram-negative bacteria (GNB). Objective: To describe the frequency and trends in AMR of GNB deriving from the clinical samples of ICU patients at a tertiary care hospital in Mérida, Yucatán. Material and methods: Study which included the review of laboratory reports of all bacteriological samples collected from patients admitted to neonatal, pediatric and adult ICU from January 1 2019 to December 31 2021. Results: 433 GNB isolates were recovered, with Klebsiella pneumoniae being the most predominant isolate (n = 117; 27.02%). The majority of GNB were recovered from bronchial secretions (n = 163). Overall, GNB showed high resistance rates to ampicillin (89.48%), ampicillin/sulbactam (66.85%), cephalosporins (58.52-93.81%), tobramycin (58.06%), and tetracycline (61.73%). Among GNB, 73.90% and 68.53% exhibited multidrug-resistant, and highly resistant microorganisms' profiles, respectively, and 47.54% of Acinetobacter baumannii exhibited an extensively drug-resistant profile. A total of 80.33% of A. baumannii was carbapenem-resistant, and 83.76% of K. pneumoniae strains were ESBL-producing. Conclusion: Our data could be helpful to improve the empirical therapy and the infection-control program.

Introducción: las unidades de cuidados intensivos (UCI) son el epicentro de la resistencia a los antimicrobianos (RAM) y las infecciones en estas áreas son causadas principalmente por bacterias Gram-negativas (BGN). Objetivo: describir la frecuencia y los patrones de RAM en BGN aisladas de muestras clínicas de pacientes de las UCI de un hospital de tercer nivel en Mérida, Yucatán. Material y métodos: estudio que incluyó la revisión de los reportes de laboratorio de las muestras bacteriológicas obtenidas de pacientes ingresados en las UCI neonatal, pediátrica y adulta del 1 de enero de 2019 al 31 de diciembre de 2021. Resultados: se identificaron 433 BGN y Klebsiella pneumoniae fue el patógeno más prevalente (n = 117; 27.02%). La mayoría de las BGN aisladas se obtuvieron de secreciones bronquiales (n = 163). En general, las BGN mostraron altas tasas de resistencia a ampicilina (89.48%), ampicilina/sulbactam (66.85%), cefalosporinas (58.52-93.81%), tobramicina (58.06%) y tetraciclina (61.73%). El 73.90% y el 68.53% de las BGN exhibieron perfiles multidrogorresistentes y microorganismos altamente resistentes a fármacos, respectivamente, y 47.54% de los aislamientos de Acinetobacter baumannii mostró perfil de drogorresistencia extendida. El 80.33% de los A. baumannii fue resistente a carbapenémicos y el 83.76% de las K. pneumoniae fueron productoras de BLEE. Conclusión: nuestros datos podrían mejorar la terapia antimicrobiana empírica y el programa de control de infecciones.

Caracterización de ß-lactamasas de espectro extendido en aislamientos clínicos colombianos de Salmonella enterica no tifoidea de 1997 a 2022 / Characterization of extended spectrum ß-lactamases in Colombian clinical isolates of non-typhoidal Salmonella enterica between 1997 and 2022

Introducción. Salmonella spp. es un agente patógeno zoonótico transmitido al humano por el agua o los alimentos contaminados. La presencia de ß-lactamasas de espectro extendido es un creciente problema para la salud pública debido a que estas enzimas confieren resistencia contra las cefalosporinas de tercera y cuarta generación. Objetivo. Caracterizar las ß-lactamasas de espectro extendido en aislamientos de Salmonella spp. recibidos por el programa de vigilancia de enfermedad diarreica aguda o enfermedad transmitida por alimentos del Grupo de Microbiología del Instituto Nacional de Salud. Materiales y métodos. Entre enero de 1997 y junio de 2022, se recibieron 444 aislamientos de Salmonella spp. resistentes, por lo menos, a una de las cefalosporinas de tercera generación. El fenotipo de las ß-lactamasas de espectro extendido se identificó con la prueba de doble disco. El ADN se extrajo por ebullición y mediante PCR se amplificaron los genes bla CTX-M, bla SHVy : ' a ILM. Resultados. Todos los aislamientos fueron positivos para la prueba de ß-lactamasas de espectro extendido. Los resultados de la amplificación por PCR fueron: bla CTX-M + bla TLM (n=200), bla CTX-M (n=177), bla SHV(n=16), bla SHV + bla CTX-M (n=6), bla TLM (n=13) y bla SHV + bla CTX-M + bla TLM (n=3). Del total, 26 aislamientos fueron negativos para los genes evaluados. Los aislamientos positivos para ß-lactamasas de espectro extendido se identificaron en Bogotá y en 21 departamentos: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusión. La resistencia a las cefalosporinas de tercera generación en aislamientos de Salmonella spp. fue generada principalmente por bla CTX-M. El 44 % (197/444) de los aislamientos presentó resistencia a ampicilina, tetraciclina, cloranfenicol y trimetoprim- sulfametoxazol Los serotipos portadores de ß-lactamasas de espectro extendido más frecuentes fueron S. Typhimurium y S. Infantis.

Introduction. Salmonella spp. is a zoonotic pathogen transmitted to humans through contaminated water or food. The presence of extended-spectrum ß-lactamases is a growing public health problem because these enzymes are resistant to third and fourth generation cephalosporins. Objective. To characterize extended-spectrum ß-lactamases in Salmonella spp. isolates received by the acute diarrheal disease/foodborne disease surveillance program of the Grupo de Microbiología of the Instituto Nacional de Salud. Materials and methods. A total of 444 Salmonella spp. isolates, resistant to at least one of the cephalosporins, were obtained between January 1997 and June 2022. The extended- spectrum ß-lactamases phenotype was identified by the double disk test. DNA extraction was carried out by the boiling method, and the bla CTX-M, bla SHV, and bla TLM genes were amplified by PCR. Results. All the isolates were positive for the extended-spectrum ß-lactamases test. The genes identified were: bla CTX-M + ba TLM (n=200), bla CTX-M (n=177), bla SHV(n=16), bla SHV + bla CTX-M (n=6), bla TLM (n=13) and bla SHV + bla CTX-M + bla TLM (n=3). Twenty-six isolates were negative for the evaluated genes. Positive extended-spectrum ß-lactamases isolates were identified in Bogotá and 21 departments: Chocó, Magdalena, Meta, Bolívar, Casanare, Cesar, Córdoba, Quindío, Atlántico, Tolima, Cauca, Cundinamarca, Huila, Boyacá, Caldas, Norte de Santander, Risaralda, Antioquia, Nariño, Santander y Valle del Cauca. Conclusion. Resistance to third generation cephalosporins in Salmonella spp. isolates was mainly caused by bla CTX-M. Isolates were resistant to ampicillin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole (44 %; 197/444). The most frequent extended-spectrum ß-lactamases-expressing serotypes were Salmonella Typhimurium and Salmonella Infantis.

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

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

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

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

High levels of antimicrobial resistance in Escherichia coli and Salmonella from poultry in Ecuador.

Objective: To describe antimicrobial resistance profiles of Escherichia coli and Salmonella spp. isolated from chicken carcasses and the antimicrobials commonly used in animals in Ecuador and provide information on antimicrobial resistance patterns for implementing evidence-based corrective measures. Methods: Meat samples were collected from chicken carcasses in 199 slaughterhouses across Ecuador as part of a national pilot study for monitoring antimicrobial resistance in agricultural sources in 2019. Samples were tested for E. coli and Salmonella spp. Sensitivity to 10 critically important and three highly important antimicrobials (from a human health perspective) was assessed. The country report submitted to the World Organization for Animal Health was accessed to extract the quantity of antimicrobials produced or imported for use in animals. Results: Of 383 samples, E. coli was isolated from 148 (39%) and Salmonella spp. from 20 (5%) samples. Ninety percent of the isolates were resistant to at least one critically important antimicrobial. Resistance was highest to erythromycin (E. coli 76%; Salmonella spp. 85%) and tetracycline (E. coli 71%; Salmonella spp. 90%). Critically or highly important antimicrobials (colistin, tetracycline, trimethoprim/sulfamethoxazole) formed the bulk (87%) of antimicrobials used in animals as per the World Organization for Animal Health report. Conclusions: High prevalence of antimicrobial resistance in poultry in Ecuador calls for the development of guidelines and regulations on the use of antimicrobials and for engagement with livestock producers. The existing surveillance system needs to be strengthened to improve the monitoring of antimicrobial use and evolving resistance patterns.

Molecular and Clinical Data of Antimicrobial Resistance in Microorganisms Producing Bacteremia in a Multicentric Cohort of Patients with Cancer in a Latin American Country.

Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1-0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.

Concern levels of beta-lactamase-producing Gram-negative bacilli in hospital wastewater: hotspot of antimicrobial resistance in Latin-America.

Hospital wastewater (HWW) discharges are among the main sources of antibiotic-resistant bacteria. This study detected a high frequency of beta-lactamase-producing Gram-negative Bacilli in HWW of different geographical regions of Colombia, even in the presence of the wastewater treatment plant, highlighting the importance of regulating these environments in developing countries.

High levels of antimicrobial resistance in Escherichia coli and Salmonella from poultry in Ecuador / Niveles elevados de resistencia antimicrobiana de las bacterias Escherichia coli y Salmonella en aves de corral en Ecuador / Altos níveis de resistência aos antimicrobianos em Escherichia coli e Salmonella de aves de criação no Equador

ABSTRACT Objective. To describe antimicrobial resistance profiles of Escherichia coli and Salmonella spp. isolated from chicken carcasses and the antimicrobials commonly used in animals in Ecuador and provide information on antimicrobial resistance patterns for implementing evidence-based corrective measures. Methods. Meat samples were collected from chicken carcasses in 199 slaughterhouses across Ecuador as part of a national pilot study for monitoring antimicrobial resistance in agricultural sources in 2019. Samples were tested for E. coli and Salmonella spp. Sensitivity to 10 critically important and three highly important antimicrobials (from a human health perspective) was assessed. The country report submitted to the World Organization for Animal Health was accessed to extract the quantity of antimicrobials produced or imported for use in animals. Results. Of 383 samples, E. coli was isolated from 148 (39%) and Salmonella spp. from 20 (5%) samples. Ninety percent of the isolates were resistant to at least one critically important antimicrobial. Resistance was highest to erythromycin (E. coli 76%; Salmonella spp. 85%) and tetracycline (E. coli 71%; Salmonella spp. 90%). Critically or highly important antimicrobials (colistin, tetracycline, trimethoprim/sulfamethoxazole) formed the bulk (87%) of antimicrobials used in animals as per the World Organization for Animal Health report. Conclusions. High prevalence of antimicrobial resistance in poultry in Ecuador calls for the development of guidelines and regulations on the use of antimicrobials and for engagement with livestock producers. The existing surveillance system needs to be strengthened to improve the monitoring of antimicrobial use and evolving resistance patterns.

RESUMEN Objetivo. Describir los perfiles de resistencia antimicrobiana de las bacterias Escherichia coli y Salmonella spp. aisladas en carne de pollo y los antimicrobianos comúnmente empleados en animales en Ecuador, así como proporcionar información sobre los patrones de resistencia a los antimicrobianos para poner en marcha medidas correctivas basadas en la evidencia. Métodos. Se recogieron muestras de carne de pollo en 199 mataderos de todo Ecuador en el marco de un estudio piloto nacional para monitorear la resistencia a los antimicrobianos en fuentes agrícolas en el 2019. Se analizaron las muestras en busca de E. coli y Salmonella spp. Se evaluó la sensibilidad a diez antimicrobianos de importancia crítica y tres muy importantes (para la salud humana). Se accedió al informe de país presentado ante la Organización Mundial de Sanidad Animal para obtener la cantidad de antimicrobianos producidos o importados para su uso en animales. Resultados. De 383 muestras, se aisló E. coli en 148 (39%) y Salmonella spp. en 20 (5%). En total, 90% de las cepas aisladas fueron resistentes a al menos un antimicrobiano de importancia crítica. Hubo una mayor resistencia a la eritromicina (E. coli: 76%; Salmonella spp.: 85%) y a la tetraciclina (E. coli: 71%; Salmonella spp.: 90%). Los antimicrobianos de importancia crítica o muy importantes (colistina, tetraciclina, trimetoprima/sulfametoxazol) constituyeron la mayor parte (87%) de los antimicrobianos empleados en animales según el informe de la Organización Mundial de Sanidad Animal. Conclusiones. Debido a la alta prevalencia de la resistencia a los antimicrobianos en las aves de corral en Ecuador, son imprescindibles la elaboración de directrices y regulaciones sobre el uso de antimicrobianos y el compromiso con los productores pecuarios. Es necesario fortalecer el sistema de vigilancia existente para mejorar el seguimiento del uso de antimicrobianos y de la evolución de los patrones de resistencia.

RESUMO Objetivo. Descrever perfis de resistência aos antimicrobianos em Escherichia coli e Salmonella spp. isoladas de carcaças de frango e os antimicrobianos comumente usados em animais no Equador e fornecer informações sobre padrões de resistência aos antimicrobianos para implementar medidas corretivas baseadas em evidências. Métodos. Foram coletadas amostras de carne de carcaças de frango em 199 abatedouros em todo o Equador como parte de um estudo piloto nacional para monitorar a resistência aos antimicrobianos de origem agrícola em 2019. Foram testadas amostras de E. coli e Salmonella spp. Foi avaliada a sensibilidade a 10 agentes antimicrobianos de importância crítica e três agentes antimicrobianos muito importantes (do ponto de vista da saúde humana). O relatório do país apresentado à Organização Mundial de Saúde Animal foi acessado para extrair a quantidade de antimicrobianos produzidos ou importados para uso em animais. Resultados. De 383 amostras, E. coli foi isolada em 148 (39%) e Salmonella spp. em 20 (5%). Noventa por cento dos isolados foram resistentes a pelo menos um antimicrobiano de importância crítica. A resistência foi maior à eritromicina (E. coli, 76%; Salmonella spp., 85%) e à tetraciclina (E. coli, 71%; Salmonella spp., 90%). Antimicrobianos de importância crítica ou muito importantes (colistina, tetraciclina, trimetoprim/sulfametoxazol) responderam pela maior parte (87%) dos antimicrobianos utilizados em animais, conforme o relatório da Organização Mundial de Saúde Animal. Conclusões. A alta prevalência de resistência aos antimicrobianos na avicultura no Equador exige o desenvolvimento de diretrizes e regulamentos sobre o uso de antimicrobianos e o envolvimento com os produtores de gado e avícolas. O sistema de vigilância existente precisa ser reforçado para melhorar o monitoramento do uso de antimicrobianos e a evolução dos padrões de resistência.

Prognosis of Extended-Spectrum-Beta-Lactamase-Producing Agents in Emphysematous Pyelonephritis-Results from a Large, Multicenter Series.

BACKGROUND: Emphysematous pyelonephritis (EPN) is a necrotizing infection of the kidney and surrounding tissues with significant mortality. We aimed to assess the clinical factors and their influence on prognosis in patients being managed for EPN with and without ESBL-producing bacteria and to identify if those with EPN due to ESBL infections fared any different. METHODS: A retrospective analysis was performed on patients with EPN diagnosis from 22 centers across 11 countries (between 2013 and 2020). Demographics, clinical presentation, biochemical parameters, radiological features, microbiological characteristics, and therapeutic management were assessed. Univariable and multivariable analyses were performed to determine the independent variables associated with ESBL pathogens. A comparison of ESBL and non-ESBL mortality was performed evaluating treatment modality. RESULTS: A total of 570 patients were included. Median (IQR) age was 57 (47-65) years. Among urine cultures, the most common isolated pathogen was Escherichia coli (62.2%). ESBL-producing agents were present in 291/556 urine cultures (52.3%). In multivariable analysis, thrombocytopenia (OR 1.616 95% CI 1.081-2.413, p = 0.019), and Huang-Tseng type 4 (OR 1.948 95% CI 1.005-3.778, p= 0.048) were independent predictors of ESBL pathogens. Patients with Huang-Tseng Scale type 1 had 55% less chance of having ESBL-producing pathogens (OR 1.616 95% CI 1.081-2.413, p = 0.019). Early nephrectomy (OR 2.3, p = 0.029) and delayed nephrectomy (OR 2.4, p = 0.015) were associated with increased mortality in patients with ESBL infections. Conservative/minimally invasive management reported an inverse association with mortality (OR 0.314, p = 0.001). CONCLUSIONS: ESBL bacteria in EPN were not significantly associated with mortality in EPN. However, ESBL infections were associated with poor prognosis when patients underwent nephrectomy compared conservative/minimally invasive management.

Risk factors for health care-associated infections by ESBL-producing germs in an intensive care unit of a public hospital in Bogotá D.C., Colombia / Factores de riesgo para infecciones asociadas a la atención en salud por gérmenes productores de BLEE en una unidad de cuidados intensivos de un hospital público en Bogotá D.C., Colombia

Abstract Introduction: Extended spectrum beta-lactamases (ESBL) produced by gram-negative bacteria have been associated with increased hospital morbidity and mortality, longer hospital stays, use of carbapenems, and higher health care costs. Few studies have assessed the risk factors for infection by ESBL-producing germs in intensive care units (ICU). Objective: To determine the risk factors for healthcare-associated infections (HAIs) by ESBL-producing Klebsiella pneumoniae and Escherichia coli in an ICU of a public tertiary care hospital and to assess the impact of this type of infection on mortality. Materials and methods: A case-control study with a 1:2 ratio (97 cases and 194 controls) was conducted in critically ill patients admitted to the ICU of a public tertiary care hospital in Bogotá D.C. (Colombia) between January 2016 and December 2019, and in which a HAI by ESBL-producing K. pneumoniae or E. coli (cases: n=97) or K. pneumoniae or E. coli with a normal antibiotic resistance pattern (controls: n=194) was documented. Bivariate analyses were performed using the chi-squared and the Mann-Whitney U tests. A logistic regression model was used in the multivariate analysis, and a two-tailed test was performed with the p-values obtained in the bivariate analyses. Results: ESBL-producing K. pneumoniae and E. coli isolates were identified in 57 (58.76%) and 40 (41.24%) patients, respectively. These isolates were obtained mainly from urine samples (30,92%), followed by peritoneal fluid (27.80%). In the multivariate analysis, the presence of urinary tract infection on admission to the ICU was identified as a risk factor (OR=5.63, 95%CI: 1.918-16.53;; p=0.002). The mortality rate was 28.17% (26.29% in the controls and 31.95% in the cases), but no significant difference was observed between groups (p=0.311). Conclusion: Urinary tract infection on admission to the ICU was a risk factor for HAIs by ESBL-producing K. pneumoniae or E. coli. Furthermore, no significant difference was observed between cases and controls in terms of mortality.

Resumen Introducción. Las betalactamasas de espectro extendido (BLEE) producidas por gérmenes gram negativos se han asociado con aumento de la morbilidad y mortalidad hospitalaria, mayor estancia hospitalaria, uso de carbapenémicos y mayores costos de atención en salud. Existen pocos trabajos que evalúen los factores de riesgo para infección por gérmenes productores de BLEE en unidades de cuidado intensivo (UCI). Objetivo. Determinar los factores de riesgo para el desarrollo de infecciones asociadas a la atención en salud (IAAS) por Klebsiella pneumoniae y Escherichia coli productoras de BLEE en una UCI de un hospital público de tercer nivel de atención y evaluar el impacto de este tipo de infección en la mortalidad. Materiales y métodos. Estudio de casos y controles con relación 1:2 realizado en pacientes críticamente enfermos admitidos entre enero de 2016 y diciembre de 2019 a la UCI de un hospital público de tercer nivel de Bogotá D.C., Colombia, y en los que se documentó una IAAS por K. pneumoniae o E. coli productoras de BLEE (casos; n=97) y por K. pneumoniae o E. coli con fenotipo de resistencia natural (controles; n=194). Se realizaron análisis bivariados mediante las pruebas de chi-cuadrado y U de Mann-Whitney. En el análisis multivariado se usó un modelo de regresión logística, con una prueba de dos colas con los valores p obtenidos en los análisis bivariados. Resultados. Se identificaron aislamientos de K. pneumoniae y de E. coli productoras de BLEE en 57 (58,76%) y 40 (41,24%) de los casos, respectivamente y estos aislamientos se obtuvieron principalmente de muestras de orina (30.92%), seguido de líquido peritoneal (27.83%). En el análisis multivariado, la presencia de infección de vías urinarias al ingreso a UCI fue identificada como factor de riesgo (OR=5.63, IC95%:1.918-16.527; p=0,002). La tasa de mortalidad fue del 28.17% (26.29% en los controles y 31.95% en los casos), pero no se observó una diferencia significativa entre grupos (p=0.311). Conclusión. La infección de vías urinarias al ingreso a la UCI fue un factor de riesgo para la IAAS por K. pneumoniae o E. coli productoras de BLEE. Además, no se observó una diferencia significativa entre los casos y controles en términos de mortalidad.

Resistencia antibiótica de Escherichia coli, según producción de beta lactamasas de espectro extendido, en urocultivos. Hospital III-1. Chiclayo, Perú 2020

Objetivo: determinar la resistencia antibiótica de Echerichia coli, en urocultivos, según produccion de BLEE, en pacientes hospitalizados. El estudio: Diseño descriptivo - retrospectivo. La identificación bacteriana se hizo con VITEK XL, la susceptibilidad, con las pautas del CLSI M100. 30 edicion. Hallazgos. E. coli BLEE positivo, presento resistencia de 0% a: Meropenem, ertapenem, tigeciclina y colistina. Piperacilina/tazobactam, nitrofurantoina, imipenem, amicacina con 16.7%, 6.2%, 5% y 1% respectivamente. E. Coli BLEE negativo, presento resistencia de 0% a: cefotaxima, cefuroxime, tigeciclina y piperacilina/tazobactam. Ceftriaxona, cefepime, gentamicina, cefazolina, ceftazidima, nitrofurantoina, meropenem, amicacina, imipenem y ertapenem con 14.7%, 13%, 13%, 10.7%, 9.7%, 9.1%, 9.1%, 8%, 5%, 2.7%, respectivamente. Conclusion: Meropenen, ertapenem, tigeciclina, colestina, piperacilina/tazobactam, nitrofurantoina, amicacina y imipenem, con resistencia menor de 20%, fueron los mismos, para E. coli BLEE positivo, y E. coli, sin considerar la produccion de BLEE.

ABSTRAC Objective: to determine the antibiotic resistance of Echerichia coli, in urine cultures, according to ESBL production, in hospitalized patients. The study: Descriptive-retrospective design. Bacterial identification was done with VITEK XL, susceptibility, with the CLSI M100 guidelines. 30 edition. Findings: E. coli ESBL positive, presented 0% resistance to: Meropenem, ertapenem, tigecycline and colistin. Piperacillin/tazobactam, nitrofurantoin, imipenem, amikacin with 16.7%, 6.2%, 5% and 1% respectively. E. Coli ESBL negative, presented 0% resistance to: cefotaxime, cefuroxime, tigecycline and piperacillin/tazobactam. Ceftriaxone, cefepime, gentamicin, cefazolin, ceftazidime, nitrofurantoin, meropenem, amikacin, imipenem, and ertapenem with 14.7%, 13%, 13%, 10.7%, 9.7%, 9.1%, 9.1%, 8%, 5%, 2.7%, respectively. Conclusion: Meropenen, ertapenem, tigecycline, cholesterol, piperacillin/tazobactam, nitrofurantoin, amikacin and imipenem, with less than 20% resistance, were the same for ESBL-positive E. coli, and E. coli, without considering ESBL production.

Identificación de enterobacterias multirresistentes a antibióticos en muestras de heces de lactantes residentes en Talara, Piura, Perú / Identification of multidrug-resistant enterobacteriaceae in fecal samples from infants residing in Talara, Piura, Peru Arturo

La colonización fecal en lactantes por bacterias resistentes a los antimicrobianos es un potencial riesgo para futuras terapias antibióticas. Nuestro objetivo fue determinar la frecuencia y características sociodemográficas de lactantes portadores fecales de enterobacterias resistentes a ciprofloxacina (PFRC) y sus genes de resistencia asociados. Analizamos muestras fecales de 41 niños lactantes residentes en el distrito de Talara-Piura, Perú, en 2019. Evaluamos la presencia de 3 genes de resistencia a quinolonas: aac(6')-Ib-cr, qnrB y oqxA y 2 de betalactamasas: bla CTX-M, bla PER-2.El 68% de lactantes fueron PFRC, Escherichia coli (83,3%) fue el más frecuente. El análisis genotípico detectó: oqxA (41,1%), qnrB (26,7%) y aac(6')-Ib-cr (20%) y al gen bla CTX-M en el 93,3% de los aislados con betalactamasas. La elevada frecuencia de PFRC nos alertan sobre el potencial riesgo en la pérdida de utilidad de esta familia antibiótica en el área de estudio.

Fecal colonization by antimicrobial-resistant bacteria in infants is a potential risk for future antibiotic therapy. We aimed to determine the sociodemographic characteristics and frequency of infants who were fecal carriers of ciprofloxacin-resistant enterobacteriaceae (FCCRE) and their associated resistance genes. We analyzed fecal samples from 41 infants from the district of Talara, Piura, Peru in 2019. The presence of 3 quinolone resistance genes was evaluated: aac(6')-Ib-cr, qnrB and oqxA as well as of 2 beta-lactamase genes: bla CTX-M,bla PER-2. We found that 68% of infants were FCCRE, Escherichia coli (83.3%) was the most frequent bacteria. The genotypic analysis detected: oqxA (41.1%), qnrB (26.7%), aac(6')-Ib-cr (20%) and the bla CTX-M gene (93.3%) of the isolates with beta-lactamases. The high frequency of FCCRE alerts us of the potential risk of this antibiotic family becoming less useful over time.

A case-control study of infections caused by Klebsiella pneumoniae producing New Delhi metallo-beta-lactamase-1: Predictors and outcomes.

Introduction: Infections caused by antimicrobial-resistant bacteria are a significant cause of death worldwide, and carbapenemase-producing bacteria are the principal agents. New Delhi metallo-beta-lactamase-1 producing Klebsiella pneumoniae (KP-NDM-1) is an extensively drug-resistant bacterium that has been previously reported in Mexico. Our aim was to conduct a case-control study to describe the risk factors associated with nosocomial infections caused by K. pneumoniae producing NDM-1 in a tertiary-care hospital in Mexico. Methods: A retrospective case-control study with patients hospitalized from January 2012 to February 2018 at the Hospital Civil de Guadalajara "Fray Antonio Alcalde" was designed. During this period, 139 patients with a culture that was positive for K. pneumoniae NDM-1 (cases) and 486 patients hospitalized in the same department and on the same date as the cases (controls) were included. Data were analyzed using SPSS v. 24, and logistic regression analysis was conducted to calculate the risk factors for KP-NDM-1 infection. Results: One hundred and thirty-nine case patients with a KP-NDM-1 isolate and 486 control patients were analyzed. In the case group, acute renal failure was a significant comorbidity, hospitalization days were extended, and significantly more deaths occurred. In a multivariate analysis of risk factors, the independent variables included the previous use of antibiotics (odds ratio, OR = 12.252), the use of a urinary catheter (OR = 5.985), the use of a central venous catheter (OR = 5.518), the use of mechanical ventilation (OR = 3.459), and the length of intensive care unit (ICU) stay (OR = 2.334) as predictors of infection with NDM-1 K. pneumoniae. Conclusion: In this study, the previous use of antibiotics, the use of a urinary catheter, the use of a central venous catheter, the use of mechanical ventilation, and ICU stay were shown to be predictors of infection with NDM-1 K. pneumoniae and were independent risk factors for infection with NDM-1 K. pneumoniae.

Different virulence genetic context of multidrug-resistant CTX-M- and KPC-producing Klebsiella pneumoniae isolated from cerebrospinal fluid.

Information regarding resistance and virulence traits of meningitis-causing enterobacteria in hospital environment remains scarce. The aim of this study was to characterize virulence and acquired resistance genes of carbapenem-resistant and/or 3rd to 4th generation cephalosporin-resistant Klebsiella pneumoniae isolated from the cerebrospinal fluid of inpatients. Antimicrobial susceptibility testing was performed by disk diffusion. The string test was performed to identify hypermucoviscous phenotype. Galleria mellonella infection model was used to evaluate the virulence profile of the isolates. Screening for virulence determinants and acquired resistance genes were performed by PCR. The blaCTX-M and/or blaKPC and/or rmtG were detected in all the isolates. Genetic virulence determinants, including mrkD, entB, iroD, fecIRA, uge, wabG, fimH, ureA, ybtS, and clb were detected in the majority of multidrug-resistant K. pneumoniae isolates. One isolate presented hypermucoviscous phenotype, and several isolates showed enhanced virulence in G. mellonella infection model. The combination of the virulence genes found here seems to support not only the known virulence genetic context among nosocomial infections-causing K. pneumoniae but also the role that clb and ybtS may play in K. pneumoniae virulence.