Determinação do agente microbiano, perfil de resistência antimicrobiana e produção de biofilme em úlceras de membros inferiores em pacientes com sequelas de hanseníase e outras doenças crônicas / Determination of the microbial agent, antimicrobial resistance profile and biofilm production in lower limb ulcers in patients with leprosy sequelae and other chronic diseases

Úlceras crônicas são definidas quando o processo de reparação do tecido excede o período de 3 meses, dificultando sua cicatrização. Sua etiologia pode ser multifatorial, como a ocorrência de traumas e consequência de patologias, como hanseníase, hipertensão e diabetes. As úlceras abrigam diversos microrganismos colonizadores e residentes que podem tornar-se potenciais agravantes a sua condição clínica, visto sua capacidade de formação de biofilmes e resistência antimicrobiana, diminuindo a eficácia da terapêutica. O objetivo deste trabalho foi determinar os agentes microbianos presentes em úlceras de pacientes com doenças crônicas atendidos no ambulatório de feridas do Instituto Lauro de Souza Lima, avaliar a susceptibilidade antimicrobiana destes isolados e sua capacidade de produção de biofilme, bem como comparar os resultados evidenciados por swab e biópsia e correlacionar os resultados microbiológicos com dados clínicos dos pacientes. Foram coletadas amostras de exsudato por swab e biópsia de úlceras crônicas dos participantes com doenças crônicas. As amostras foram semeadas em ágar sangue, manitol, cetrimide e MacCnkey para posterior identificação microbiana. Também foi desempenhada a determinação da susceptibilidade aos antimicrobianos e capacidade de produção de biofilme dos isolados identificados por swab e biópsia. Foram identificados 47 microrganismos no total, sendo 26 (55%) isolados presentes no swab e 21 (45%) em biópsia. P. aeruginosa, P. mirabilis e S. aureus foram as bactérias comumente prevalentes em ambos os materiais de coleta, com predomínio de P. aeruginosa. Apenas 16 (36%) das bactérias demonstraram capacidade de produzir biofilme, com destaque para o grupo dos gram-positivos (92%) que também exibiram alto perfil de susceptibilidade frente linezolida e vancomicina. Meropenem foi o único fármaco a mostrar eficácia frente as cepas de P. aeruginosa presentes, enquanto o grupo das enterobactérias apresentaram menor resposta frente a amoxicilina com ácido clavulânico. Swab e biópsia apresentaram uma concordância geral de 60%, semelhante ao observado por outros estudos. Tais diferenças podem se dar devido à presença de colonizadores. A cobertura de zinco e bota de Unna foi correlacionada à ausência de sinais flogísticos de infecção. Os dados sociodemográficos mostram prevalência de indíviduos com baixa escolaridade e idade acima de 60 anos. O swab é menos invasivo e mais utilizado devido sua facilidade e baixo custo em relação a biópsia; contudo, deve ser considerado com mais cautela na análise dos resultados microbiológicos.

Chronic wounds are defined when the tissue repair process exceeds the period of 3 months, making it difficult to heal. Its etiology can be multifactorial, such as the occurrence of trauma and consequences of pathologies, such as leprosy, hypertension, and diabetes mellitus. Ulcers harbor several colonizing and resident microorganisms that can become potential aggravating factors for their clinical condition, given their ability to form biofilms and their antimicrobial resistance, decreasing the therapeutic efficacy. This study aimed to determine the microbial agents present in ulcers of patients with chronic conditions treated at the wound clinic of the Instituto Lauro de Souza Lima, to evaluate their antimicrobial susceptibility and ability to produce biofilm, as well as to compare the results evidenced by swab and biopsy and correlate the microbiological results with clinical data of the patients. Exudate samples were collected by swab and biopsy of leg ulcers from participants with chronic diseases. Samples were seeded on sheep blood agar, mannitol, cetrimide and MacConkey agar for subsequent microbial identification. The determination of antimicrobial susceptibility and biofilm production capacity of isolates identified by swab and biopsy was also performed. A total of 47 microorganisms were identified, 26 (55%) of which were isolated from the swab and 21 (45%) from the biopsy. P. aeruginosa, P. mirabilis and S. aureus were the commonly prevalent bacteria in both collection materials, with predominance of P. aeruginosa. Only 16 (36%) bacteria demonstrated the ability to produce biofilm, with emphasis on the gram-positive group (92%) that also exhibited a high profile of susceptibility to linezolid and vancomycin. Meropenem was the only drug to show efficacy against the strains of P. aeruginosa present, while the group of enterobacteria showed less response against amoxicillin with clavulanic acid. Swab and biopsy showed an overall agreement of 60%, similar to that observed by other studies. Such differences may occur due to the presence of colonizers. Zinc coating and Unna boot correlated with the absence of phlogistic signs of infection. Sociodemographic data show a prevalence of individuals with low education and aged over 60 years. The swab is less invasive and more used due to its ease and low cost compared to biopsy; however, it should be considered with more caution in the analysis of microbiological results

Mycobacterium Biofilms.

The genus Mycobacterium includes human pathogens (Mycobacterium tuberculosis and Mycobacterium leprae) and environmental organisms known as non-tuberculous mycobacteria (NTM) that, when associated with biomaterials and chronic disease, can cause human infections. A common pathogenic factor of mycobacteria is the formation of biofilms. Various molecules are involved in this process, including glycopeptidolipids, shorter-chain mycolic acids, and GroEL1 chaperone. Nutrients, ions, and carbon sources influence bacterial behavior and have a regulatory role in biofilm formation. The ultrastructure of mycobacterial biofilms can be studied by confocal laser scanning microscopy, a technique that reveals different phenotypic characteristics. Cording is associated with NTM pathogenicity, and is also considered an important property of M. tuberculosis strains. Mycobacterial biofilms are more resistant to environmental aggressions and disinfectants than the planktonic form. Biofilm-forming mycobacteria have been reported in many environmental studies, especially in water systems. NTM cause respiratory disease in patients with underlying diseases, such as old tuberculosis scars, bronchiectasis, and cystic fibrosis. Pathogens can be either slowly growing mycobacteria, such as Mycobacterium avium complex, or rapidly growing species, such as Mycobacterium abscessus. Another important biofilm-related group of infections are those associated with biomaterials, and in this setting the most frequently isolated organisms are rapidly growing mycobacteria. M. tuberculosis can develop a biofilm which plays a role in the process of casseous necrosis and cavity formation in lung tissue. M. tuberculosis also develops biofilms on clinical biomaterials. Biofilm development is an important factor for antimicrobial resistance, as it affords protection against antibiotics that are normally active against the same bacteria in the planktonic state. This antibiotic resistance of biofilm-forming microorganisms may result in treatment failure, and biofilms have to be physically eradicated to resolve the infection. New strategies with potential antibiofilm molecules that improve treatment efficacy have been developed. A novel antibiofilm approach focuses on Methylobacterium sp. An understanding of biofilm is essential for the appropriate management of patients with many NTM diseases, while the recent discovery of M. tuberculosis biofilms opens a new research field.