2014 CLSI M100-S24 Update Content

Author: Zhang Yawei, Wang Hui Source: Chinese Journal of Laboratory Medicine Establishing standardized operating procedures for pathogen identification and in vitro antimicrobial susceptibility testing is one of the fundamental requirements for strengthening the capacity of microbiology laboratories. It holds significant practical importance for optimizing clinical drug selection, enhancing the diagnosis and treatment of infectious diseases, and addressing the emergence of drug‑resistant pathogens. The antimicrobial susceptibility testing standards developed by the Clinical and Laboratory Standards Institute (CLSI) serve as a guiding document that laboratories in China are expected to follow. This article will interpret the newly introduced “dose‑dependent susceptibility (SD)” criteria for Enterobacteriaceae antimicrobial susceptibility testing in CLSI M100‑S24 (2014).

The Dilemma and Prospects of Severe MDR Gram-Negative Bacterial Infections in Critically Ill Patients

Qiu Haibo, Xu Jingyuan: Critical care medicine—Severe infections and septic shock are clinical syndromes caused by systemic infection, characterized by organ dysfunction, with mortality rates as high as 30% to 70%, making them the leading cause of death among critically ill patients in the ICU. In recent years, the widespread use of broad-spectrum antibiotics has led to a marked increase in severe infections caused by multidrug-resistant (MDR) Gram-negative bacteria, which have become a major threat to critically ill patients. Consequently, the development of standardized and effective therapeutic strategies has become an urgent priority. 1. The situation regarding MDR Gram-negative bacterial infections is grave; MDR Gram-negative bacteria have emerged as a significant challenge in the ICU.

Diagnostic Value of Blood Cultures in Bacteremia

Recently, at the thematic symposium of the Second Beijing–Hong Kong Infectious Disease Physicians Forum, Professor Wang Hui—Director of the Department of Laboratory Medicine at Peking University People’s Hospital, doctoral supervisor, advisor to the Antimicrobial Susceptibility Subcommittee of the Clinical and Laboratory Standards Institute (CLSI), and member of the Microbiology and Immunology Branch of the Chinese Medical Association as well as deputy leader of its Clinical Microbiology Group—delivered a presentation titled “The Clinical Significance of Blood Cultures in the Diagnosis and Management of Bacteremia.” Professor Wang began by noting that, with the widespread adoption of molecular techniques and biomarkers such as procalcitonin (PCT), clinicians often overlook the importance of submitting microbiological specimens. However, particularly in the case of bacteremia, the sensitivity of molecular methods and biomarkers…

How to assess and quantify the contamination rate of blood cultures

Blood bacterial culture is the gold standard for the clinical diagnosis of bacteremia, sepsis, septicemia, and septic shock; however, contamination of blood cultures is an unavoidable issue that poses significant challenges for both clinicians and laboratories. In light of this, how should laboratories evaluate and quantify blood culture contamination? Here is an analysis: Bacterial species: Only common skin and environmental flora, as well as opportunistic pathogens that are currently considered non‑pathogenic or only weakly pathogenic, should be regarded as potential contaminants. Based on published literature and the principles outlined above, we assess the likelihood of contamination for the following bacteria: CoNS (coagulase-negative staphylococci) and corynebacteria.