A simple smartphone-assisted paper-based colorimetric biosensor for the detection of urea adulteration in milk based on an environment-friendly pH-sensitive nanocomposite.

Urea is a common milk adulterant that falsely increases its protein content. Excessive consumption of urea is harmful to the kidney, liver, and gastrointestinal system. The conventional methods for urea detection in milk are time-consuming, costly, and require highly skilled operators. So, there is an increasing demand for the development of rapid, convenient, and cost-efficient methods for the detection of urea adulteration in milk. Herein, we report a novel colorimetric paper-based urea biosensor, consisting of a novel environment-friendly nanocomposite of halloysite nanotubes (HNT), that urease enzyme and an anthocyanin-rich extract, as a natural pH indicator are simultaneously immobilized into its internal and external surfaces. The biosensing mechanism of this biosensor is based on anthocyanin color change, which occurs due to urease-mediated hydrolysis of urea and pH increment of the environment. The colorimetric signal of this biosensor is measured through smartphone-assisted analysis of the mean RGB (Red-Green-Blue) intensity of samples and is capable of detecting urea with a detection limit of 0.2 mM, and a linear range from 0.5 to 100 mM. This biosensor has demonstrated promising results for the detection of urea in milk samples, in the presence of other milk adulterants and interferents.

Evolutionary analysis and quality assessment of ζ-carbonic anhydrase sequences from environmental microbiome.

Carbonic anhydrase (CA) is one of the most vital enzymes in living cells. This study has been performed due to the significance of this metalloenzyme for life and the novelty of some CA families like ζ-CA to evaluate evolutionary processes and quality check their sequences. In this study, bioinformatics methods revealed the presence of ζ-CA in some eukaryotic and prokaryotic microorganisms. Notably, it has not been previously reported in prokaryotes. The coexistence of ß- and ζ-CAs in some microorganisms is also a novel finding as well. Also, our analysis identified several CA proteins with 6-14 amino acid intervals between histidine and cysteine in the second highly conserved motif, which can be classified as the novel ζ-CA subfamily members that emerged under the Zn deficiency of aquatic ecosystems and selection pressure in these environments. There is also a possibility that the achieved results are rooted in the contamination of samples from the environmental microbiome genome with genomes of diatom species and the occurrence of errors was observed in the DNA sequencing outcomes. Combining of all results from evolutionary analysis to quality control of ζ-CA DNA sequences is the incentive motivation to explore more the hidden aspects of ζ-CAs.

Toward waterborne protozoa detection using sensing technologies.

Drought and limited sufficient water resources will be the main challenges for humankind during the coming years. The lack of water resources for washing, bathing, and drinking increases the use of contaminated water and the risk of waterborne diseases. A considerable number of waterborne outbreaks are due to protozoan parasites that may remain active/alive in harsh environmental conditions. Therefore, a regular monitoring program of water resources using sensitive techniques is needed to decrease the risk of waterborne outbreaks. Wellorganized point-of-care (POC) systems with enough sensitivity and specificity is the holy grail of research for monitoring platforms. In this review, we comprehensively gathered and discussed rapid, selective, and easy-to-use biosensor and nanobiosensor technologies, developed for the early detection of common waterborne protozoa.

Free-living amoebae in an oil refinery wastewater treatment facility.

Free Living Amoebae (FLA) are ubiquitous microorganisms reported from harsh environmental conditions. Oil refinery facilities consume vast volumes of water during their processes, generating a large amount of wastewater. The present study aimed to evaluate the wastewater treatment process in an oil refinery wastewater treatment facility (ORWWTF) for the presence of FLA. Water samples were collected from an oil refinery wastewater (ORWW) for nine months. After recording physical-chemical features, samples were cultivated onto non-nutrient agar (NNA). The discriminative fragments of the ribosomal RNA (rRNA) gene were amplified and sequenced to characterize the isolated FLA. Phylogenetic tree, and network analysis were employed to evaluate genetic relationships. The thermo- and osmotolerant tests were performed on the isolated FLA. Twenty-five (32.9%) samples were positive for FLA cultivation. Acanthamoeba spp., Vahlkampfiids, and Vermamoeba spp. were detected, of which Acanthamoeba species were predominant. There was no statistical correlation between pH, NH3, PO4, H2S, and TDS with the presence of FLA. A statistical correlation between the presence of FLA and the type of wastewater treatment plants (WWTPs) was significant (P-value = 0.011). All Acanthamoeba spp. isolates belonged to the genotypes T4 (17/21; 80.95%) and T11 (4/21; 19.05%). Vahlkampfiids were Naegleria spp., (7/10; 70%), Tetramitus aberdonicus (1/10; 10%), Learamoeba spp., (1/10; 10%), and Vahlkampfia spp., (1/10; 10%). All three Vermamoeba spp. were V. vermiformis. The ORWW contains toxic materials, and a few microorganisms can stay active in these environments. This is the first study which isolates FLA from such super harsh conditions. For the first time, T. aberdonicus, and Learamoeba spp., were isolated from oily wastewater. Our findings signify the concern due to the distribution of potentially pathogenic FLA to downstream lands via treated wastewater that may be released after treatment processing.

Lack of association between VEGF -2578C/A polymorphism and risk of colorectal cancer in an Iranian population.

AIM: Here, we evaluated the VEGF gene -2578C/A polymorphism as a potential susceptibility factor in colorectal cancer (CRC) occurrence amongst Iranian CRC patients. BACKGROUND: Vascular endothelial growth factor (VEGF) is a key regulatory factor in angiogenesis which plays essential roles in the development of malignancy in colorectal cancer (CRC), as the third most prevalent cancer worldwide. METHODS: VEGF -2578C/A polymorphism was evaluated in 200 CRC patients and 200 healthy control subjects via restriction fragment length polymorphism analysis. RESULTS: The frequencies of CC, AC and AA genotypes among CRC patients were 22.5%, 51% and 26.5%, respectively, with their respective genotype frequencies at 16%, 54% and 30% in control cohorts (P=0.247). The A allele frequency among the case group was 52% and for control group, it was 57%. C allele frequency in case and control groups was 48% and 43%, respectively (p=0.156). No significant association was observed (p=0.990) between this polymorphism and CRC stage. CONCLUSION: Our findings provide limited support for the hypothesis that the -2578C/A VEGF are associated with increased risk of colorectal cancer in Iranian colorectal cancer patients and suggest instead that meta data studies, which have previously relied upon populations definitions such as 'Asian', should more specifically take into account country of origin when associating prognostic value to a given genotype.

Association between variants of the autophagy related gene ATG16L1 in inflammatory bowel diseases and clinical statues.

AIM: In the present study, two main variants of ATG16L1 gene, rs2241880 T300A and rs2241879 C/T, were evaluated in IBD patients as well as in remission and flareup phase across an Iranian population for the first time. BACKGROUND: Inflammatory bowel disease (IBD) has found increasing global incidence and prevalence in recent years especially among pediatrics. ATG16L1 is the major gene that regulates autophagy pathway. The autophagy pathway also affects dysbiosis. METHODS: Genomic DNA was isolated from peripheral blood samples following salting out extraction method. The genotypes of ATG16L1 polymorphisms rs2241880 T300A and rs2241879 C/T were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: In this case control study, a total of 101 IBD patients (75 ulcerative colitis (UC) and 26 Crohn's disease (CD)) and 99 healthy controls were evaluated. In the present study, a significant association was found between rs2241879 single nucleotide polymorphism on ATG16L1 gene and increased risk of IBD among an Iranian population (P=0.01). There was no statistically significant relationship between rs2241880 and IBD risk (P= 0.42). The effect on these two variants was investigated in relapse and flareup phase which was not significant either, but in CD, rs2241879 and rs2241880 were difference in the relapse phase. CONCLUSION: The results showed that ATG16L1 gene rs2241879 has a significant relationship with increased risk of IBD among an Iranian population. Individuals with C allele showed a significant relationship with 1.68-fold increased risk of IBD (P=0.01; adjusted OR=1.68; 95% CI=1.13-2.50).