Biochemical studies on the production of neuraminidase by environmental isolates of<i>Vibrio cholerae</i>non-O1 from Bulgaria

Еneva, Rumyana; Engibarov, Stephan; Abrashev, Radoslav; Abrashev, I

doi:10.1139/w11-042

Cited by 11 publications

(6 citation statements)

References 16 publications

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“…Two of the reference strains used in the antibacterial activity assay, Escherichia coli NBIMCC 3397 and Pseudomonas aeruginosa NBIMCC 1390, were purchased from the National Bank for Industrial Microorganisms and Cell Cultures, Bulgaria. Klebsiella pneumoniae G31 (NBIMCC 8650) and Vibrio cholerae non-O1 strain V13 (NBIMCC 8715) were isolated and identified previously and deposited in the same culture collection [ 40 , 41 ].…”

Section: Methodsmentioning

confidence: 99%

New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

et al. 2021

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Bacillus licheniformis is a soil bacterium with many industrial applications. In addition to enzymes, platform chemicals, antibiotics and phytohormones, the species produces exopolysaccharides (EPSs) of various biological activities. This study revealed that Bulgarian isolate B. licheniformis 24 produced EPSs consisting of galactose, glucose and mannose with substrate-dependent ratio. From glucose, B. licheniformis 24 secreted EPS1, consisting of 54% galactose, 39% glucose and 7% mannose. From fructose, the strain formed EPS2, containing 51% glucose, 30% mannose and 19% galactose. Batch cultivation in flasks yielded 2.2–2.6 g/L EPS1 and 1.90–2.11 g/L EPS2. Four to five times higher yields of EPS were obtained from both substrates during batch and fed-batch processes in a fermenter at 37.8 °C, pH 6.2 and aeration 3.68 vvm. The batch process with 200 g/L of starting substrates received 9.64 g/L EPS1 and 6.29 g/L EPS2, reaching maximum values at the 33rd and 24th h, respectively. Fed-batch fermentation resulted in the highest yields, 12.61 g/L EPS1 and 7.03 g/L EPS2. In all processes, EPSs were produced only in the exponential growth phase. Both EPSs exhibited antioxidant activity, but EPS2 was much more potent in this regard, reaching 811 μM Vitamin C Equivalent Antioxidant Capacity (versus 135 μM for EPS1). EPS1 displayed antibacterial activity against a non-O1 strain of Vibrio cholerae.

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Section: Methodsmentioning

confidence: 99%

New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

et al. 2021

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“…It was described previously that bacterial sialidases optimal temperature was in the range of 35 to 40°C (22). In Vibrio cholerae non-O1 and Arcanobacterium pyrogenes the neuraminidase enzyme was found to be thermo-tolerant and was found to be stable up to 55 to 60°C (23,24). The optimal pH in V. cholerae non-O1 was 5.4, however, the SA was found to be stable at pH 8.2 (24).…”

Section: Characterization Of Sialidase Enzyme In L Monocytogenesmentioning

confidence: 97%

“…In Vibrio cholerae non-O1 and Arcanobacterium pyrogenes the neuraminidase enzyme was found to be thermo-tolerant and was found to be stable up to 55 to 60°C (23,24). The optimal pH in V. cholerae non-O1 was 5.4, however, the SA was found to be stable at pH 8.2 (24). The sialidase enzyme was found to be quite diverse and different molecular mass was observed.…”

Section: Characterization Of Sialidase Enzyme In L Monocytogenesmentioning

confidence: 98%

Optimization and Molecular Detection of Neuraminidase Gene in Listeria Monocytogenes

Ghazaei

2018

Int J Infect

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Background: Listeria monocytogenes is one of the human pathogenic microbes causing Listerosis and is usually found as a contaminant in many foods and dairy samples. Neuraminidases (NAs) plays a key role in many pathogenic bacteria and has the ability to block sialic acid (a virulence factor) that targets mucosal surfaces. Objectives: In the current study, NA or sialidase-producing Listeria monocytogenes were screened from different milk samples of cow. Methods: Listeria monocytogenes was identified by morphological, biochemical, and hlyA gene polymerase chain reaction (PCR) assay. Furthermore, molecular detection of 432 bp amplicon of sialidase enzyme (Neuraminidase) gene in the native isolates was noted. Results: The prevalence of Listeria species was found to be around 4.16%. Sialidase enzyme was found to be produced in high amounts in isolated L. monocytogenes. Furthermore, NA was purified by ammonium sulphate precipitation and gel filtration techniques. The partially purified sialidase enzyme possessed a molecular mass of 27.0 ± 1 with an isoelectric point of 7.6. The optimum pH and temperature were 4.6 to 8.2 and 30 to 35°C, respectively. The enzyme had no effect on metal ions, such as Mn +2 , Zn +2 , and Ca +2 , whereas Hg +2 and Al +3 had potentially acted as inhibitors. Conclusions: This study suggests that the sialidase of L. monocytogenes plays a significant role in its pathogenesis.

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“…However, high occurrences of the nanH gene were present in intestinal samples of the aquatic products collected in the Guangming Aquatic Product Base in Shanghai in November 2020. Microaerophilic environments in the intestinal epithelium and sediment lake mud may benefit the survival of V. cholerae (9). Occurrences of V. cholerae isolates of clinical and environmental origins carrying the target genes have been reported (4,13).…”

Section: Discussionmentioning

confidence: 99%

“…It has been reported that the zot gene encodes a zonula occludens toxin that increases transcellular ion transport and contributes to diarrhea in cholera, whereas the ace gene encodes an accessory cholera enterotoxin that disturbs small-intestinal tight junction permeability (11,18,20). In addition, previous studies have indicated that a cri gene is an important virulence-related gene required for toxin-linked cryptic plasmid replication in V. cholerae (26), whereas a nanH gene encodes a neuraminidase that is a key factor in the infectious process of many viruses and pathogenic bacteria (9). Thus, monitoring of these virulence-related genes of V. cholerae is imperative for assuring food safety and human health.…”

mentioning

confidence: 99%

Rapid and Visualized Detection of Virulence-Related Genes of Vibrio cholerae in Water and Aquatic Products by Loop-Mediated Isothermal Amplification

Chen

Liang

Alali

et al. 2022

Journal of Food Protection

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Vibrio cholerae can cause pandemic cholera in humans. The bacterium resides in aquatic environments worldwide. Continuous testing of V. cholerae contamination in water and aquatic products is imperative for food safety control and human health. In this study, a rapid and visualized method was developed for the first time based on loop-mediated isothermal amplification (LAMP) for detection of the important virulence-related genes ace, zot, cri, and nanH for toxins and the infectious process of V. cholerae. Three pairs of molecular probes targeting each of these genes were designed and synthesized. The one-step LAMP reaction was conducted at 65°C for 40 min. Positive results were inspected by the production of a light green color under visible light or green fluorescence under UV light (302 nm). Limit of detection of the LAMP method ranged from 1.85 to 2.06 pg per reaction of genomic DNA or 2.50 × 100 to 4.00 × 102 CFU per reaction for target genes of cell culture of V. cholerae, which was more sensitive than standard PCR. Inclusivity and exclusivity of the LAMP method were 100% for all target genes. The method showed similar high efficiency to a certain extent in rapid testing of spiked or collected specimens of water and aquatic products. Target genes were detected by absence from all water samples from various sources. However, high occurrences of the nanH gene were observed in intestinal samples derived from four species of fish and one species of shellfish, indicating a risk of potentially toxic V. cholerae in commonly consumed aquatic products. The results in this study provide a potential tool for rapid and visualized detection of V. cholerae in water and aquatic products. HIGHLIGHTS

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Biochemical studies on the production of neuraminidase by environmental isolates ofVibrio choleraenon-O1 from Bulgaria

Cited by 11 publications

References 16 publications

New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

Optimization and Molecular Detection of Neuraminidase Gene in Listeria Monocytogenes

Rapid and Visualized Detection of Virulence-Related Genes of Vibrio cholerae in Water and Aquatic Products by Loop-Mediated Isothermal Amplification

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