18S rRNA gene sequencing for environmental aflatoxigenic fungi and risk of hepatic carcinoma among exposed workers

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Vol. 57; no. 3; pp. 174 - 182
• Main Authors: Saad-Hussein, Amal, Soliman, Kawther M., Moubarz, Gehan
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 2022; Taylor & Francis Ltd
• Subjects: 18S rRNA gene sequence; aflatoxin; Aflatoxins; Airborne wastes; alpha fetoprotein; Aspergillus; Cancer; DNA sequencing; Exposure; Fungi; Gene polymorphism; Gene sequencing; Genotypes; Glutathione; glutathione S-transferases gene polymorphism; GSTT1 protein; Health risks; Hepatocellular carcinoma; Liver; Liver cancer; Occupational exposure; Polymerase chain reaction; Polymorphism; Restriction fragment length polymorphism; Ribonucleic acid; Risk; RNA; rRNA 18S; Wastewater; Wastewater treatment; Wastewater treatment plants; Water treatment; Water treatment plants; glutathione S-transferases gene polymorphism; Aspergillus; aflatoxin; alpha fetoprotein; 18S rRNA gene sequence
• ISSN: 1093-4529; 1532-4117
• DOI: 10.1080/10934529.2022.2046428

Aspergillus exposure causes an increase in aflatoxin (AF) levels among exposed workers thereby increasing their risk of developing hepatocellular carcinoma (HCC). This study attempted to determine the presence of airborne aflatoxigenic fungi in environment of waste water treatment plant (WWTP); and study the hepatic cancer risks among exposed workers, emphasizing the role of glutathione S-transferases (GST) gene polymorphism protecting against the risk of hepatic cancer development due to exposure to AFs. The study isolated and identified different Aspergillus species producing AFs in air samples from WWTP sites using 18S ribosomal ribonucleic acid (18S rRNA) gene sequencing technique. GST gene polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A significant increase in blood AF levels was found among WWTP exposed workers. The occurrence of GSTT1& M1 gene polymorphism in 6% of the workers was accompanied by significant decrease in the levels of AFs and alpha fetoprotein (AFP). In conclusion, Aspergillus-producing AFs were found in air of WWTP. Continuous exposure to AF-producing fungi caused elevated AF-levels in exposed workers. However only workers with heterozygous GSTT1& M1 genotypes can detoxify AFs, thereby decreasing the risk of HCC development among exposed workers.