Direct, rapid antimicrobial susceptibility test from positive blood cultures based on microscopic imaging analysis

Abstract

For the timely treatment of patients with infections in bloodstream and cerebrospinal fluid, a rapid antimicrobial susceptibility test (AST) is urgently needed. Here, we describe a direct and rapid antimicrobial susceptibility testing (dRAST) system, which can determine the antimicrobial susceptibility of bacteria from a positive blood culture bottle (PBCB) in six hours. The positive blood culture sample is directly mixed with agarose and inoculated into a micropatterned plastic microchip with lyophilized antibiotic agents. Using microscopic detection of bacterial colony formation in agarose, the total time to result from a PBCB for dRAST was only six hours for a wide range of bacterial concentrations in PBCBs. The results from the dRAST system were consistent with the results from a standard AST, broth microdilution test. In tests of clinical isolates (n = 206) composed of 16 Gram-negative species and seven Gram-positive species, the dRAST system was accurate compared to the standard broth microdilution test, with rates of 91.11% (2613/2868) categorical agreement, 6.69% (192/2868) minor error, 2.72% (50/1837) major error and 1.45% (13/896) very major error. Thus, the dRAST system can be used to rapidly identify appropriate antimicrobial agents for the treatment of blood stream infection (BSI) and antibiotic-resistant strain infections.

Clinical Evaluation of QMAC-dRAST for Direct and Rapid Antimicrobial Susceptibility Test with Gram-Positive Cocci from Positive Blood Culture Bottles

“…The QMAC-dRAST results were available within 6 hours after inoculation into the QMAC-dRAST GP panel, which were concordant with previous research [13].…”

“…The QMAC-dRAST system detects the response of individual bacteria to antimicrobials by time-lapse microscopic observation and image analysis of micro-colony formation at the various concentrations of antimicrobial agents [13].…”

“…The QMAC-dRAST (Quantamatrix Inc., Seoul, Republic of Korea) system has been introduced in the clinical microbiology laboratory for expedite treatment of bloodstream infection and antibiotic-resistant strain infections via a direct inoculation of PBC [13]. This system determines the antimicrobial susceptibility of bacteria within six hours without performing any additional separation processes and inoculum size measurement [13][14][15].…”

Identification and antimicrobial susceptibility testing of Gram-positive and Gram-negative bacteria from positive blood cultures using the Accelerate Pheno™ system

“…Time-lapse microscopic imaging of bacterial colony formation in the presence of an antimicrobial agent has been suggested as a novel approach to ascertain AST directly from the positive blood culture bottles [8]. The Accelerate Pheno™ system (Accelerate Diagnostics Inc., Tucson, AZ, USA) employs this technique in a fully automated system.…”

Métodos rápidos para avaliação da susceptibilidade antimicrobiana em bacilos Gram-negativos

“…A redução no tempo para o diagnóstico de infecções, identificação do agente infeccioso e tratamento do paciente, principalmente aqueles com infecções sistêmicas e causadas por microrganismos resistentes, é fundamental para a diminuição da mortalidade e do tempo de permanência do paciente no hospital (BARENFANGER;KACICH, 1999;CHANDRASEKARAN et al, 2018;CHOI et al, 2017;DOERN et al, 1994;INGLIS;EKELUND, 2019;MACHEN;WANG, 2014;PEREZ et al, 2013;TRENHOLME et al, 1989 Em microbiologia clínica, a citometria de fluxo pode ser utilizada em análises de detecção direta, testes sorológicos e testes de susceptibilidade de bactérias, fungos, parasitas e vírus (ALVAREZ-BARRIENTOS et al, 2000). Há na literatura diversos trabalhos que aplicam a metodologia de diversas maneiras para os diferentes microrganismos, principalmente em testes de susceptibilidade (Tabela 2) (BARBOSA et al, 2014;FREDRICKS et al, 2006; PINA-VAZ, C.;…”