blood culture

Genetic characteristics of antimicrobial resistance mechanisms in Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii isolated from blood and cerebrospinal fluid of children

Objective. To assess antimicrobial susceptibility, presence of resistance genes and determine the phenotypic groups of K. pneumoniae, P. aeruginosa and A. baumannii isolated from blood and cerebrospinal fluid of children with nosocomial infections in intensive care units from 2014 to 2020. Materials and Methods. Minimum inhibitory concentrations of antibiotics were determined using the serial broth microdilution method. The identification of genes encoding the production of carbapenemases was carried out using hybridization fluorescence detection.

Genetic diversity of vancomycinresistant Enterococcus faecium isolated from blood culture in patients with hematological malignancies

Objective. To study the genetic diversity of vancomycin-resistant Enterococcus faecium (VR-E. faecium) isolated from the blood culture in patients with hematological malignancies by multilocus sequence typing (MLST). Materials and Methods. VR-E. faecium isolated from the blood culture in hematological patients in 6 hospitals of 4 Russian cities (2003–2019) were evaluated. Susceptibility to vancomycin was tested by the broth microdilution method (CLSI, 2018). Vancomycin-resistance genes (vanA, vanB) were identified by polymerase chain reaction.

Detection of acquired carbapenemase genes among Acinetobacter baumannii isolated from blood culture in patients with hematological malignancies

Objective. To evaluate the prevalence of acquired carbapenemase genes among A. baumannii isolates collected from blood culture in patients with hematological malignancies. Materials and Methods. This prospective multicenter study included A. baumannii isolated from blood culture in hematological patients in 7 Russian hospitals (2003–2015). Minimum inhibitory concentrations (MICs) of meropenem and imipenem were determined by broth microdilution method (CLSI, 2017). All A. baumannii isolates were tested by multiplex real-time PCR for presence of acquired carbapenemase genes (blaOXA-23-like, blaOXA-24⁄40-like, blaOXA-58-like, blaNDM-like, blaVIM-like and blaIMP-like).

The results of identification of bacteria from positive blood cultures using MALDI-TOF mass spectrometry

Objective. To evaluate the results of accelerated identification of microorganisms isolated from positive hemocultures obtained from patients of various departments of a large multi-profile hospital by MALDI-TOF MS and to compare them with classical cultural methods. Materials and Methods. In the period from 2017 to 2018, the study included 109 positive blood cultures from 73 patients from UIA GKB number 40 at the age of 1 to 83 years. Blood samples were taken in aseptic conditions from 2 peripheral veins according to the standard protocol in 12 departments of the health facility.

Molecular characterization of extended-spectrum beta-lactamase-producing Enterobacterales isolates collected from blood culture in patients with hematological malignancies

Objective. The objective of the study was to evaluate the prevalance of genes blaTEM, blaSHV and blaCTX-M among extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales isolates collected from blood culture in patients with hematological malignancies. Materials and methods. The prospective multicenter study included Enterobacterales isolates collected from blood culture in hematological patients from 10 Russian hospitals (2003-2015). The isolates were screened for ESBLs by the phenotypic methods (CLSI 2017). Genes encoding TEM, SHV and CTX-M were detected using polymerase chain reaction (PCR) by specific primers.

Accelerated Techniques of Pathogen Identification from Positive Blood Cultures by MALDI-TOF Mass Spectrometry

Objective. To assess pathogen identification from positive blood cultures by MALDI-TOF mass spectrometry. Materials and Methods. At the first stage, an in vitro study using MALDI-TOF MS and including 11 pathogen species (K. pneumoniae, E. coli, P. aeruginosa, A. baumannii, S. aureus, S. epidermidis, S. haemolyticus, E. faecalis, E. faecium, C. albicans, C. parapsilosis) was performed. This study involved hourly attempts to identify the above listed pathogens by MALDI-TOF MS (Vitek MS, bioMerieux) during incubation until their correct identification.