Evaluation of a rapid immunochromatographic test for detection of distinct variants of Klebsiella pneumoniae carbapenemase (KPC) in Enterobacteriaceae

Capture ELISA for KPC Detection in Gram-Negative Bacilli: Development and Standardisation

The detection of KPC-type carbapenemases is necessary for guiding appropriate antibiotic therapy and the implementation of antimicrobial stewardship and infection control measures. Currently, few tests are capable of differentiating carbapenemase types, restricting the lab reports to their presence or not. The aim of this work was to raise antibodies and develop an ELISA test to detect KPC-2 and its D179 mutants. The ELISA-KPC test was designed using rabbit and mouse polyclonal antibodies. Four different protocols were tested to select the bacterial inoculum with the highest sensitivity and specificity rates. The standardisation procedure was performed using 109 previously characterised clinical isolates, showing 100% of sensitivity and 89% of specificity. The ELISA-KPC detected all isolates producing carbapenemases, including KPC variants displaying the ESBL phenotype such as KPC-33 and -66.

Recent Developments in Smart Food Packaging Focused on Biobased and Biodegradable Polymers

Food packaging has a crucial function in the modern food industry. New food packaging technologies seek to meet consumers and industrial's demands. Changes related to food production, sale practices and consumers' lifestyles, along with environmental awareness and the advance in new areas of knowledge (such as nanotechnology or biotechnology), act as driving forces to develop smart packages that can extend food shelf-life, keeping and supervising their innocuousness and quality and also taking care of the environment. This review describes the main concepts and types of active and intelligent food packaging, focusing on recent progress and new trends using biodegradable and biobased polymers. Numerous studies show the great possibilities of these materials. Future research needs to focus on some important aspects such as possibilities to scale-up, costs, regulatory aspects, and consumers' acceptance, to make these systems commercially viable.

Intelligent Packaging for Real-Time Monitoring of Food-Quality: Current and Future Developments

Food packaging encompasses the topical role of preserving food, hence, extending the shelf-life, while ensuring the highest quality and safety along the production chain as well as during storage. Intelligent food packaging further develops the functions of traditional packages by introducing the capability of continuously monitoring food quality during the whole chain to assess and reduce the insurgence of food-borne disease and food waste. To this purpose, several sensing systems based on different food quality indicators have been proposed in recent years, but commercial applications remain a challenge. This review provides a critical summary of responsive systems employed in the real-time monitoring of food quality and preservation state. First, food quality indicators are briefly presented, and subsequently, their exploitation to fabricate intelligent packaging based on responsive materials is discussed. Finally, current challenges and future trends are reviewed to highlight the importance of concentrating efforts on developing new functional solutions.

Rapid detection of total bacteria in foods using a poly-l-lysine-based lateral-flow assay

Food safety and freshness are evaluated according to microbiological load. To analyze this load rapidly, a poly-_l-lysine-based lateral-flow assay (PLFA) was developed. A total of 90 strains of bacteria that are often detected in spoiled foods, including Enterobacteriaceae, lactic acid bacteria, Pseudomonas, and Bacillus were detected using the PLFA. A positive signal was obtained when the bacterial concentration was ≥6 log₁₀ (cfu/test). A total of 36 fresh foods (meats, pastries, lettuces, cabbages, radishes, and sprouts) and corresponding spoiled foods were cultured for 0, 3, 6, and 9 h to investigate how many hours were required for microbial detection using PLFA. The higher the number of bacteria in a food, the shorter was the culture time required for PLFA-positive results to be obtained, so the distinction between fresh and spoiled food could be made based on the time taken for the culture to become PLFA-positive. The coefficient of determination of the least squares regression between the time to become PLFA-positive and the initial log₁₀ (cfu/g) bacterial count for the food was 0.9888. The test time for the PLFA, including pretreatment, was approximately 15-30 min. This novel method will enable the detection of total bacteria on the food processing site.

First report of Klebsiella quasipneumoniae harboring bla KPC-2 in Saudi Arabia

Background

Nosocomial infections caused by multi-drug resistant Enterobacteriaceae are a global public health threat that ought to be promptly identified, reported, and addressed accurately. Many carbapenem-resistant Enterobacteriaceae-associated genes have been identified in Saudi Arabia but not the endemic Klebsiella pneumoniae carbapenemases (KPCs), which are encoded by bla_KPC-type genes. KPCs are known for their exceptional spreading potential.

Methods

We collected n = 286 multi-drug resistant (MDR) Klebsiella spp. isolates as part of screening for resistant patterns from a tertiary hospital in Saudi Arabia between 2014 and 2018. Antimicrobial susceptibility testing was carried out using both VITEK II and the broth microdilution of all collected isolates. Detection of resistance-conferring genes was carried out using Illumina whole-genome shotgun sequencing and PacBio SMRT sequencing protocols.

Results

A Carbapenem-resistant Enterobacteriaceae (CRE) Klebsiella quasipneumoniae subsp. similipneumoniae strain was identified as a novel ST-3510 carrying a bla_KPC-2 carbapenemase encoding gene. The isolate, designated as NGKPC-421, was obtained from shotgun Whole Genome Sequencing (WGS) surveillance of 286 MDR Klebsiella spp. clinical isolates. The NGKPC-421 isolate was collected from a septic patient in late 2017 and was initially misidentified as K. pneumoniae. The sequencing and assembly of the NGKPC-421 genome resulted in the identification of a putative ~ 39.4 kb IncX6 plasmid harboring a bla_KPC-2 gene, flanked by transposable elements (ISKpn6-bla_KPC-2–ISKpn27).

Conclusion

This is the first identification of a KPC-2-producing CRE in the Gulf region. The impact on this finding is of major concern to the public health in Saudi Arabia, considering that it is the religious epicenter with a continuous mass influx of pilgrims from across the world. Our study strongly highlights the importance of implementing rapid sequencing-based technologies in clinical microbiology for precise taxonomic classification and monitoring of antimicrobial resistance patterns.

Filipe CD, Didar TF. Intelligent Food Packaging: A Review of Smart Sensing Technologies for Monitoring Food Quality

Food safety is a major factor affecting public health and the well-being of society. A possible solution to control food-borne illnesses is through real-time monitoring of the food quality throughout the food supply chain. The development of emerging technologies, such as active and intelligent packaging, has been greatly accelerated in recent years, with a focus on informing consumers about food quality. Advances in the fields of sensors and biosensors has enabled the development of new materials, devices, and multifunctional sensing systems to monitor the quality of food. In this Review, we place the focus on an in-depth summary of the recent technological advances that hold the potential for being incorporated into food packaging to ensure food quality, safety, or monitoring of spoilage. These advanced sensing systems usually target monitoring gas production, humidity, temperature, and microorganisms' growth within packaged food. The implementation of portable and simple-to-use hand-held devices is also discussed in this Review. We highlight the mechanical and optical properties of current materials and systems, along with various limitations associated with each device. The technologies discussed here hold great potential for applications in food packaging and bring us one step closer to enable real-time monitoring of food throughout the supply chain.