Contemporary microbiology and identification ofCorynebacteriaspp. causing infections in human

Abstract

Significance and Impact of the Study: The number of opportunistic infections caused by Corynebacteria is increasing due to increase in number of immunocompromised patients. New Corynebacterium species and new human infections, caused by this group of bacteria, has been described recently. However, identification of Corynebacteria is still a challenge despite application of sophisticated laboratory methods. In the study we present possibilities and limitations of various commercial systems for identification of Corynebacteria. AbstractThe Corynebacterium is a genus of bacteria of growing clinical importance. Progress in medicine results in growing population of immunocompromised patients and growing number of infections caused by opportunistic pathogens. A new infections caused by new Corynebacterium species and species previously regarded as commensal micro-organisms have been described. Parallel with changes in Corynebacteria infections, the microbiological laboratory diagnostic possibilities are changing. But identification of this group of bacteria to the species level remains difficult. In the paper, we present various manual, semiautomated and automated assays used in clinical laboratories for Corynebacterium identification, such as API Coryne, RapID CB Plus, BBL Crystal Gram Positive ID System, MICRONAUT-RPO, VITEK 2, BD Phoenix System, Sherlock Microbial ID System, MicroSeq Microbial Identification System, Biolog Microbial Identification Systems, MALDI-TOF MS systems, polymerase chain reaction (PCR)-based and sequencing-based assays. The presented assays are based on various properties, like biochemical tests, specific DNA sequences, composition of cellular fatty acids, protein profiles and have specific limitations.

Cystic neutrophilic granulomatous mastitis: an update

“…Through the development of more sophisticated molecular methods, pathogens can now be detected and identified directly from clinical samples. In MALDI-TOF MS, identification of microbes is through generation of characteristic peptide mass fingerprint spectra and comparing them to sequences of known organisms in the database 41. Due to the low cost, accuracy and speed, MALDI-TOF MS analysis is increasingly used routinely for Corynebacterium identification 42.…”

“…Several studies show that MALDI-TOF MS can accurately identify most Corynebacterium species to the genus (up to 99.5%) and species (up to 92.3%) levels 35 43 44. The gold standard for Corynebacterium species identification is through sequencing of rpoB gene and 16S rRNA gene 41. However, identification of Corynebacteria in formalin-fixed paraffin-embedded tissue can be technically challenging due to cross-linking and fragmentation of nucleic acids as well as low sensitivity of molecular methods for the detection of extremely rare organisms in tissue sections 16.…”

Antimicrobial Susceptibility Testing for Corynebacterium Species Isolated from Clinical Samples in Romania

“…The Corynebacterium genus currently numbers around 129 species and subspecies isolated from human, mammals, and environmental sources [1]. Many species are members of the normal skin and the upper respiratory tract microbiota and can produce infections, especially in immune-compromised or debilitated human patients [2].…”

“…To identify the species that belong to Corynebacterium genus, several types of methods are used: phenotypic, molecular, and mass spectrometry-based methods. Due to this variety of identifications possibilities, new species from the Corynebacterium genus have been isolated from clinical samples [1], such as the following that are presented below, the most frequent isolated species. Unfortunately studies about prevalence of the infections caused by these microorganisms, either in hospitalized patients or out-patients, are scarce.…”

Early prosthetic valve endocarditis caused by Corynebacterium amycolatum: the first case reported in Brazil

“…This setting keeps the identification of Corynebacteria difficult and limited to the species included into appropriate databases. In addition, misidentification due to matching with closest patterns among the database entries can happen [9].…”