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The main mechanism that causes resistance to carbapenem, one of the most potent antibiotic available, in Enterobacterales bacterial isolates, is due to Klebsiella pneumoniae carbapenemase (KPC) production by the bacterium. KPC is spread worldwide, requiring laboratories to be capable of identifying this enzyme, however some methods can be expensive for small laboratories, especially in developing countries. Therefore, the development of methods with low cost of reagents for the detection of KPC enzyme is necessary. The objective of this study was to evaluate the detection of KPC enzyme by MALDI-TOF MS from inactivated bacteria impregnated in filter paper. A total of 129 Enterobacterales isolates were impregnated in filter paper, and after 7 days at room temperature, they were subjected to a protein extraction protocol and spectra acquisition, in triplicates, by MALDI-TOF MS. The spectra were evaluated and KPC was identified according to the presence of a peak of 28,712.62 ± 27.80 m/z. Considering the presence of the KPC peak in at least one spectrum of the triplicates, this method presented 60.8% sensitivity and 96.4% specificity. However, considering the presence of KPC peak in at least two spectra of the triplicate, a specificity of 100% was achieved. The detection of KPC enzyme from inactivated bacteria impregnated in filter paper can be used as a method to confirm the presence of KPC, which could be very significant for small laboratories with limited resources., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Paper-based nucleic acid testing techniques are increasingly in demand. Hence, we have developed a simple and cheap paper fluidic device to detect multiple gene targets in Leptospira. Fluidic channels of the penta-clover device are drawn using a correction pen on Whatman filter paper 1. The fluid blocks the pores of the paper, avoiding leakage and ensuring the equal flow of sample to the reaction pads. The target genes are amplified by performing Loop-Mediated Isothermal Amplification (LAMP) with dry reaction components. Thecolor change of leuco crystal violetallows real-time monitoring of a positive amplification. The difference in color intensity is captured with a smartphone and analyzed using image processing software. The device amplifies the target within 15 min, detects the pathogen at a concentration as low as 50 attogram μL -1 , detects Leptospira in blood samples without prior treatment and differentiates the Leptospira species even after 21 days of storage at room temperature., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The paper and pulp industry (PPI) produces high quantities of solid and liquid discharge and is regarded as the most polluting industry in the world causing adverse effects to environments and human beings. Hence changes in the way PPI sludge and waste materials are treated is urgently required. Nearly, 10 million tons of waste is generated per year, however PPI waste is enriched with many organic chemicalscontaining a high percentage of lignin, cellulose, and hemicellulose which can be used as valuable raw materials for the production of bioenergy and value-added chemicals. Pretreatment of complex lignocellulosic materials of PPI waste is difficult because of the cellulose crystallinity and lignin barrier. At present most of this waste is recycled in a conventional treatment approach through biological and chemical processes, incurring high cost and low returns. Henceefficient pretreatment techniques are required by which complete conversion of PPI waste is possible. Therefore, the present chapter provides the scope of integration of pretreatment methods through which bioenergy recovery is possible during the PPI waste treatment. Detailed information is presented on the various pre-treatment techniques (chemical, mechanical, enzymatic and biological) in order to increase the efficiency of PPI waste treatment and energy recovery from PPI waste. Along with acid and alkali based efficient chemical treatment process, physical methods (i.e. shearing, high-pressure homogenization, etc.), biochemical techniques (whole cell-based and enzyme-based) and finally biological techniques (e.g. aerobic and anaerobic treatment) are discussed. During each of the treatment processes, scope of energy recovery and bottlenecks of the processes were elaborated. The review thus provides systemic insight into developing efficient pretreatment processes which could increase carbon recovery and treatment efficiency of PPI waste., (Copyright © 2019. Published by Elsevier B.V.)

Cholera is now considered to be endemic in Haiti, often with increased incidence during rainy seasons. The challenge of cholera surveillance is exacerbated by the cost of sample collection and laboratory analysis. A diagnostic tool is needed that is low cost, easy-to-use, and able to detect and quantify Vibrio cholerae accurately in water samples within 18-24h, and perform reliably in remote settings lacking laboratory infrastructure and skilled staff. The two main objectives of this study were to develop and evaluate a new culture medium embedded in a new diagnostic tool (PAD for paper based analytical device) for detecting Vibrio cholerae from water samples collected in Haiti. The intent is to provide guidance for corrective action, such as chlorination, for water positive for V. cholerae epidemic strains. For detecting Vibrio cholerae, a new chromogenic medium was designed and evaluated as an alternative to thiosulfate citrate bile salts sucrose (TCBS) agar for testing raw water samples. Sensitivity and specificity of the medium were assessed using both raw and spiked water samples. The Vibrio cholerae chromogenic medium was proved to be highly selective against most of the cultivable bacteria in the water samples, without loss of sensitivity in detection of V. cholerae. Thus, reliability of this new culture medium for detection of V. cholerae in the presence of other Vibrio species in water samples offers a significant advantage. A new paper based device containing the new chromogenic medium previously evaluated was compared with reference methods for detecting V. cholerae from spiked water sample. The microbiological PAD specifications were evaluated in Haiti. More precisely, a total of 185 water samples were collected at five sites in Haiti, June 2014 and again in June 2015. With this new tool, three V. cholerae O1 and 17 V. cholerae non-O1/O139 strains were isolated. The presence of virulence-associated and regulatory genes, including ctxA, zot, ace, and toxR, was confirmed using multiplex PCR. The three V. cholerae O1 isolates were positive for three of the four virulence-associated and regulatory genes. Twelve of the V. cholerae non-O1/O139 isolates were found to carry toxR, but none were ctxA+, zot+, or ace+. However, six of the V. cholerae non-O1/O139 isolates were resistant to penicillin, ampicillin, trimethoprim/sulfamethoxazole, nalidixic acid, and ciprofloxacin. The paper based analytical device (PAD) provides advantages in that standard culture methods employing agar plates are not required. Also, intermediary isolation steps were not required, including transfer to selective growth media, hence these steps being omitted reduced time to results. Furthermore, experienced technical skills also were not required. Thus, PAD is well suited for resource-limited settings., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Host DNA may adversely affect metagenomic studies focusing on the prokaryotic microbiota. This study compared the levels of host DNA in subgingival plaque collected by paper points and curette, using quantitative PCR. Lower proportions of host DNA and higher proportions of bacterial DNA were recovered from samples collected with curettes., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A method has been developed for the analysis of (14)CO(2) evolution from the mineralization of (14)C-labelled organic compounds in soil samples. The new method is less space demanding and substantially cuts down laborious manual work compared to the traditional incubation bottle method used. Furthermore, the use of scintillation cocktail is largely reduced with the new method. In the new method, (14)CO(2) is trapped in filter paper held in the lid of a 20 ml glass vial by surface tension. The trapping solution used is Ca(OH)(2), which fixates CO(2) in the filter paper and the analysis of trapped (14)CO(2) is done using the Cyclone trade mark Storage Phosphor system. The lids are placed in a 32 well holder and exposed to a phosphor screen prior to scanning in a Cyclone trade mark scanner. The new filter method has been tested and compared to results obtained using the traditional method. The results show good agreement but due to a smaller capacity for CO(2) with the filter method compared to the traditional method, the interval between sampling has to be shorter using the filter method when the CO(2) development is high. The detection limits for the filter method is higher compared to the traditional method. With the filter method, the level of radioactivity has to exceed 300 dpm before detection is possible, while the same limit for the traditional method is around 30 dpm. On the other hand, the gas trapping faster and the efficiency is higher with the filter method.