Antibiotic-resistant bacteria are a key problem currently facing the world. Therefore, there is a great need to develop specific methods to selectively identify drug-resistant bacteria. It has been found that one of their main defense mechanisms for developing antibiotic resistance is the production of resistant enzymes such as β-lactamases (Blas). For drug-resistant bacteria, we need not only to investigate novel antibiotics that target Blas, but also to develop new enzyme assays to identify superbugs.

Identification of Superbugs by resistant enzymes detection services

Some pathogenic bacteria have developed significant resistance to antibiotics due to the progressive development of drug-resistant enzymes. Blas are hydrolytic enzymes that destroy antibiotics further rendering the drugs ineffective. Nearly 3000 Blas have been identified. Depending on the type of substrate, these enzymes can be classified as penicillinases, cephalosporinases, ultra-broad-spectrum β-lactamases and carbapenemases. As these types of enzymes continue to emerge, methods for selective and specific detection of enzymes have been developed and have become important diagnostic tools for the detection and monitoring of drug-resistant bacteria.

Fig. 1 Hydrolysis reaction of β-lactamases with antibiotics. (Ding Y, et al., 2021)

Detection Services of Superbugs by Resistant Enzymes

Our assays for Blas include the following.

Phenotypic assays

We can provide susceptibility testing of bacterial samples to Blas-like antibiotics. This includes agar diffusion tests, minimum inhibitory concentration assays, etc. This can help to some extent in detecting the type and severity of bacterial resistance.

Genetic assays

We mainly provide PCR to detect quantitative expression of bacterial resistance genes, and detection of drug-resistant enzyme genes with high accuracy and sensitivity by mass spectrometry and other methods.

Small molecule probe assays

We offer small molecule probes as research tools for specific enzyme analysis. Based mainly on the hydrolytic properties of Blas and antibiotics, we design and screen Blas-specific probes, and detect them by the characteristic changes of the probes after hydrolysis. Especially for the less studied carbapenemases, which are mostly superbugs resistance-inducing causes, we design probes that specifically recognize carbapenemases based on carbapenem parent nuclei.

Types of Detection Probes

• Different specificity probes. According to the evolution of Blas, so specific detection probes have to be designed for different types of enzymes. This allows rapid and sensitive detection of different drug resistant bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Enterobacter cloacae, etc.
• Bacterial covalent labeling probes. When the probe is hydrolyzed by the enzyme, it tends to spread out from the drug-resistant bacteria. Therefore, it is difficult to achieve real-time monitoring of drug-resistant bacteria. Probes that use covalently labeled proteins to localize to the surface of bacteria and specifically identify drug-resistant enzymes can improve the efficiency of identification of drug-resistant bacteria.
• Bacterial disease model probes. Enzyme identification probes are designed with the ultimate goal of diagnosing bacterial diseases and guiding therapy. Probes designed to combine biological models of various infections and diseases caused by ESBLs, carbapenemases, and other drug resistance can be applied in research to diagnose diseases and evaluate therapeutic efficacy.