Causative Microorganisms Isolated from Patients with Intra-Abdominal Infections and Their Drug Resistance Profiles: An 11-Year (2011-2021) Single-Center Retrospective Study / 生物医学与环境科学（英文）

OBJECTIVE@#To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections (IAIs).@*METHODS@#A total of 2,926 bacterial and fungal strains were identified in samples collected from 1,679 patients with IAIs at the Peking Union Medical College Hospital between 2011 and 2021. Pathogenic bacteria and fungi were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing (AST) was performed using the VITEK 2 compact system and the Kirby-Bauer method. AST results were interpreted based on the M100-Ed31 clinical breakpoints of the Clinical and Laboratory Standards Institute.@*RESULTS@#Of the 2,926 strains identified, 49.2%, 40.8%, and 9.5% were gram-negative bacteria, gram-positive bacteria, and fungi, respectively. Escherichia coli was the most prevalent pathogen in intensive care unit (ICU) and non-ICU patients; however, a significant decrease was observed in the isolation of E. coli between 2011 and 2021. Specifically, significant decreases were observed between 2011 and 2021 in the levels of extended-spectrum β-lactamase (ESBL)-producing E. coli (from 76.9% to 14.3%) and Klebsiella pneumoniae (from 45.8% to 4.8%). Polymicrobial infections, particularly those involving co-infection with gram-positive and gram-negative bacteria, were commonly observed in IAI patients. Moreover, Candida albicans was more commonly isolated from hospital-associated IAI samples, while Staphylococcus epidermidis had a higher ratio in community-associated IAIs. Additionally, AST results revealed that most antimicrobial agents performed better in non-ESBL-producers than in ESBL-producers, while the overall resistance rates (56.9%-76.8%) of Acinetobacter baumanmii were higher against all antimicrobial agents than those of other common gram-negative bacteria. Indeed, Enterococcus faecium, Enterococcus faecalis, S. epidermidis, and S. aureus were consistently found to be susceptible to vancomycin, teicoplanin, and linezolid. Similarly, C. albicans exhibited high susceptibility to all the tested antifungal drugs.@*CONCLUSION@#The distribution and antimicrobial susceptibility of the causative microorganisms from patients with IAIs were altered between 2011 and 2021. This finding is valuable for the implementation of evidence-based antimicrobial therapy and provides guidance for the control of hospital infections.

Características clínicas y microbiológicas de la infección intra-abdominal complicada en Colombia: un estudio multicéntrico / Clinical and microbiological characteristics of complicated intra-abdominal infection in Colombia: a multicenter study

Introducción: La infección intra-abdominal complicada adquirida en la comunidad (IIAc-AC) es una causa frecuente de abdomen agudo. Objetivo: Identificar el perfil clínico y microbiológico de la IIAc-AC en cuatro hospitales de Colombia. Métodos: Estudio descriptivo, prospectivo entre 07-2012 y 09-2014 en pacientes de 15 o más años con IIAc-AC. Se midieron las frecuencias de variables socio-demográficas, clínicas, diagnóstico, aislamientos y susceptibilidad antimicrobiana del primer cultivo obtenido asépticamente del sitio de infección. Resultados: 192 pacientes incluidos, 62% hombres, edad media 47,3 años; 38,4% con co-morbilidad, 13% hospitalizados en el último año y 9,4% recibieron antimicrobianos en los últimos seis meses. Fueron admitidos 44,3%, por apendicitis 17,7% por peritonitis y 16,7% por perforación intestinal. El 64,1% de las IIAc-AC fue moderada y tratada con ampicilina/sulbactam (SAM) y ertapenem. En 70,8% se aisló al menos un microorganismo en: 65,1% bacilos gramnegativos (80,0% Escherichia coli, 44,8% susceptible a piperacilina/tazobactam, 65,7% a SAM y 11,2% Klebsiella pneumoniae, 85% susceptibles a SAM) y en 16,7% especies grampositivas (28,1% Streptococcus grupo viridans). La mediana de hospitalización fue siete días y 15,1% fallecieron. Conclusión: Escherichia coli y K. pneumoniae en IIAc-AC son los principales microorganismos a cubrir en la terapia empírica y es necesario conocer la susceptibilidad antimicrobiana en cada región para seleccionar un tratamiento empírico adecuado.

Introduction: Complicated community-acquired intra-abdominal infections (CA-cIAI) are a common cause of acute abdomen. Objective: To identify the clinical and microbiology profile of CA-cIAI in four Colombian hospitals. Methods: This is a prospective, descriptive study, between 08-2012 and 09-2014, including patients with CA-cIAI > 15 years. Data collected included: socio-demographic, clinical, diagnosis, and isolates of the first culture obtained aseptically during surgery with antimicrobial susceptibility. Results: 192 patients were included, 62% men, median age 47.3 years. Co-morbidities were present in 38.4%, 13% had been hospitalized in the previous year 13%, and 9.4% had received antibiotics in the last 6 months; 44.3% were admitted for appendicitis, 17.7% for peritonitis and 16.7% for bowel perforation. CA-cIAI were assessed as moderate in 64.1% of the cases and were treated with ampicillin/sulbactam (SAM) and ertapenem. In 70.8% of cases a bacteria was isolated: 65.1% were gramnegative rods (80.0% Escherichia coli, 44.8% of them susceptible to pipercillin/tazobactam, 65.7% to SAM; 11.2 % were K.pneumoniae, 85% was susceptible for SAM; 16.7% were grampositive cocci (28.1% Streptococci viridans group). The median hospital stay was 7 days and 15.1% died. Conclusions: E. coli, K. pneumoniae and S. viridans were the main organisms to consider in an empiric therapy for CA-cIAI and it is important to know the local epidemiology in order to choose the right antibiotic.