Rapid identification of drug-type strains in Cannabis sativa using loop-mediated isothermal amplification assay

Identifying a suspect powder as a cannabis concentrate through chemical analysis and DNA testing

PURPOSE

Cannabis is regulated in many countries, and cannabis products are diversifying, which can hinder identification. Here, we report the seizure of a powder sample with a cannabis-like odor in a spice bottle labeled "nutmeg" and identification of the sample by chemical testing and cannabis DNA testing.

METHODS

The sample was observed under a microscope, extracted with methanol, and analyzed by gas chromatography-mass spectrometry (GC-MS). The chemical profile of the seized powder was compared with that of nutmeg samples. Gas chromatography-flame ionization detection was used to estimate the total Δ9-tetrahydrocannabinol (Δ9-THC) concentration in the sample. A commercially available cannabis DNA testing kit was used to confirm the presence of cannabis plant DNA in the seized sample.

RESULTS

The characteristics of cannabis in the seized powder were difficult to determine through microscopic observation alone. GC-MS analysis identified β-caryophyllene (an aromatic component of cannabis) and five cannabinoids unique to cannabis, including Δ9-THC. No common compounds were identified in the seized powder or nutmeg samples. The total Δ9-THC concentration in the sample was very high (approximately 47% by weight). Cannabis DNA testing confirmed that the seized powder contained cannabis.

CONCLUSIONS

The seized powder was found to be a processed product made from a finely pulverized resin-like cannabis concentrate. Our results indicate that combined chemical and DNA analysis should help identify cannabis-related samples in various forms.

Rapid identification of drug-type and fiber-type cannabis by allele specific duplex PCR

Cannabis is classified into two types: drug-type cannabis, which is abused worldwide, and fiber-type cannabis, which is used for industrial purposes. The two types are a result of differences in the sequences of tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS) genes. In the present study, we aimed to establish a PCR-based method to distinguish between drug-type and fiber-type cannabis by detecting the differences in the sequences of THCAS and CBDAS. We constructed a single-plex PCR targeting active THCAS, and observed drug-type cannabis-specific amplification when using 10pg to 1ng of DNA; however, amplification was also observed in fiber-type cannabis when the DNA content reached 10ng. Similarly, single-plex PCR targeting active CBDAS showed fiber-type cannabis-specific amplification in 100pg of DNA, as well as in >1ng of drug-type cannabis DNA. Therefore, when an allele-specific duplex PCR system was constructed, in which both primer sets were mixed at an appropriate ratio, unintended nonspecific amplification was suppressed and amplicons of different sizes were observed between the drug-type and fiber-type cannabis, using DNA samples in the range of 1pg to 10ng. When the constructed duplex PCR was performed on DNA extracted from various cannabis seed samples, it was possible to distinguish between the drug-type and the fiber-type as well as detect a hybrid-type with both active THCAS and active CBDAS and a special type with neither. The identification method developed in the present study can quickly and accurately distinguish between drug-type and fiber-type cannabis, and is expected to be used for various purposes such as the detection of genetic contamination of industrial hemp as well as forensic examination of cannabis-related cases.

Rapid Detection to Differentiate Hypervirulent Klebsiella pneumoniae (hvKp) From Classical K. pneumoniae by Identifying peg-344 With Loop-Mediated Isothermal Amplication (LAMP)

Objectives

To establish a rapid molecular diagnostics of hvKp using the peg-344 loop-mediated isothermal amplification technique (LAMP).

Methods

In all, 28 K. pneumoniae strains isolated from the blood of patients were used for the peg-344 LAMP. K. pneumoniae NTUH-K2044 and K. pneumoniae ATCC700603 were used as positive control and negative control, respectively. For comparison, all the results were detected in a polymerase chain reaction (PCR), which was considered the gold standard for the detection of the gene. Mouse lethality assay, and Serum killing assay were also used to determine the virulence phenotype of K. pneumoniae.

Results

We determined the specificity and sensitivity of the primers for peg-344 detection in the LAMP reactions. This LAMP assay was able to specifically differentiate hvKp from classical K. pneumoniae (cKp) at 65°C, which was 100-fold more sensitive than a PCR assay for peg-344 detection. The virulence phenotype of K. pneumoniae detected by LAMP was as precise as by Mouse lethality assay and Serum killing assay.

Conclusion

The LAMP assay is easy to perform and rapid. Therefore, it can be routinely applied to differentiate hvKp from cKp in the clinical laboratory.

CelB is a suitable marker for rapid and specific identification of Klebsiella pneumoniae by the loop-mediated isothermal amplification (LAMP) assay

Klebsiella pneumoniae belongs to Enterobacteriaceae, which is the commonest bacterium causing nosocomial respiratory tract infection. It ranks second in bacteremia and urinary tract infection in gram-negative bacteria. Therefore, the rapid and accurate identification of K. pneumoniae was of great significance for the guide of clinical medication, and timely treatment of patients. The purpose of this study was to establish a rapid and sensitive molecular detection method for K. pneumoniae based on loop-mediated isothermal amplification (LAMP) technology. Firstly, local BLAST and NCBI BLAST were used to analyze the genome of K. pneumoniae. According to the principle of interspecific and intraspecific specificity, CelB (GenBank ID 11847805) was selected as the specific gene. Then, the LAMP and PCR identification systems were established with this target gene. Thirty-six clinical isolates of K. pneumoniae and 50 non-K. pneumoniae were used for the specific evaluation, and both LAMP and PCR could specifically distinguish K. pneumoniae from non-K. pneumoniae. A 10-fold series diluted positive plasmids and simulated infected blood samples were used as the templates in the sensitivity assay, and the results showed that the sensitivity could reach 1 copy/reaction. In summary, a rapid, specific, and sensitive LAMP method was established to detect K. pneumoniae in clinics.

Whole Plastome Sequences of Two Drug-Type Cannabis: Insights Into the Use of Plastid in Forensic Analyses

DNA is one of the fastest growing tools in forensic sciences, increasing reliability in forensic reports and judgments. The use of DNA has increased in different areas of the forensic sciences, such as investigation of plant species, where plastid DNA has been used to elucidate and generate evidence in cases of traceability of genetically modified and controlled plants. Even with several advances and the practice of using DNA in forensic investigations, there are just few studies related to the identification of genetic tools for the characterization of drug and nondrug-types of Cannabis. Herein, the whole plastomes of two drug-type Cannabis are presented and have their structures compared with other Cannabis plastomes deposited in the GenBank, focusing in the forensic use of plastome sequences. The plastomes of Cannabis sativa "Brazuka" and of the hybrid Cannabis AK Royal Automatic presented general structure that does not differs from the reported for other C. sativa cultivars. A phylogenomic analyses grouped C. sativa "Brazuka" with the nondrug C. sativa cultivars, while the hybrid Cannabis AK Royal Automatic placed isolated, basal to this group. This suggests that the analysis of plastomes is useful toward genetic identification of hybrids in relation to C. sativa.

Rapid, specific, and sensitive detection of the ureR_1 gene in Klebsiella pneumoniae by loop-mediated isothermal amplification method

Klebsiella pneumoniae is one of the main pathogenic bacteria that causes nosocomial infections, such as pneumonia, urinary tract infection, and sepsis. Therefore, the rapid and accurate detection of K. pneumoniae is important for the timely treatment of infectious patients. This study aimed to establish a loop-mediated isothermal amplification (LAMP) method for the rapid and sensitive detection of K. pneumoniae-specific gene ureR_1 (Gene ID: 11847803). The ureR_1 gene was obtained through local and online BLAST, and the specific primers were designed for its detection. Positive reactions were observed on all 140 K. pneumoniae clinical isolates while all the 82 non-K. pneumoniae clinical isolates were negative. Plasmids with the specific gene and the mouse blood with K. pneumoniae were used for sensitivity analysis. The detection limit of the LAMP was 1 bacterium/reaction. The results showed that the LAMP targeted to ureR_1 is a fast, specific, sensitive, inexpensive, and suitable method for the detection of K. pneumoniae.

Development of simple and accurate detection systems for Cannabis sativa using DNA chromatography

In recent years, the need for analyzing cannabis DNA has increased in order to accommodate the various types of cannabis samples encountered in forensic investigation. This study was aimed to establish a simple and accurate cannabis DNA detection system using DNA chromatography. Two chromatography chip systems with different features were successfully developed. One system (the "four-line version") involves tetraplex PCR amplification, which could be used to detect cannabis DNA and distinguish between drug-type and fiber-type cannabis using the tetrahydrocannabinolic acid synthase gene sequence. The other system was the "three-line version" with triplex amplification, which was specialized to distinguish cannabis from other plants, and had a sensitivity (10fg DNA/reaction) that was 100 times greater than the four-line version. In both versions, no false positives were observed for 60 medicinal plants, and accurate detection could be performed for several simulated forensic samples such as cannabis leaves, buds, stems, roots, seeds, resin, and cannabis leaves blended 1/100 in tobacco. Detection could be performed by the naked eye and only a thermal cycler was required for operation. Thus, DNA chromatography systems for cannabis detection are expected to contribute to the analysis of cannabis DNA in forensic chemistry laboratories without extensive equipment.

Simple detection of bacterioplankton using a loop-mediated isothermal amplification (LAMP) assay: First practical approach to 72 cases of suspected drowning

We developed a novel molecular tool for assisting the diagnosis of death by drowning and evaluated its validity in forensic practical cases. Two novel sets of loop-mediated isothermal amplification (LAMP) primers were designed to detect either representative freshwater (Aeromonas) or marine (Vibrio, Photobacterium, Listonella) bacterioplankton (aquatic bacteria) in one tube using the LAMP technique. The assay involves only mixing template DNA with seven reagents and incubating at 64°C for 80min and does not require special or expensive equipment because detection is based on visual observation under natural light. The assay's excellent specificity was also demonstrated using 17 standard (control) strains and 124 other bacterial strains cultured from drowning and non-drowning victims in our previous studies. We then assayed 299 specimens (135 lung, 164 blood) from 72 victims, including 45 who had drowned in rivers, ditches, seas, and around estuaries. LAMP assay results could provide effective information to assist the diagnosis of death by drowning in practical cases. The LAMP assay would be useful for suspected drowning cases, as it is a less-laborious and less-expensive minimal test when death by drowning is sufficiently confirmed or negated from only autopsy findings and environmental data or when diatom testing is not performed due to logistic, personnel, or budgetary limitations. Moreover, the assay could serve as a simple additional test when the density of diatoms in the lungs is very low due to low density in the water.