Comparative Study of Genetic and Antibacterial Profiles of Nigerian Indigenous and Exotic Varieties of Garlic (Allium sativum)

Abstract

Extracts and isolated compounds of Allium sativum (garlic) have been found to be of health benefit. The study was aimed at assessing the effects of crude garlic extracts on urinopathogens of pregnant women, as well as to compare the antibacterial and genetic profiles of Nigerian indigenous and exotic varieties of garlic. Biodata and urine samples were collected from two hundred (200) healthy pregnant women attending antenatal clinics. The urine samples were subjected to urinalysis and bacteriological investigations. The subjects were 20 - 43 (31.03 ± 1.46) years old, with modal age 25-30 years. Urinalysis of subjects’ urine samples showed no nitrituria, haematuria and bilirubinuria. However, glucosuria (1.5%), ketonuria (3%), leukocyturia (15%) and proteinuria (24%) were detected. Bacterial loads of the urine samples range from 0 to 1100 (with mean value of 315.72) cfu/mL, an indication of non-urinary tract infection bacteriuria. Bacteria isolated from the urine samples were: Escherichia coli, Klebsiella pneumoniae, Klebsiella variicola, Enterobacter cloacae, Pseudomonas aeruginosa, Proteus mirabilis, Citrobacter freundii, Corynebacterium accolens, Actinomyces urogenitalis, Luteococcus sanguinis and Bacillus cereus among others. The bacterial isolates showed high prevalence of multidrug resistant bacteria, with resistance to 2-8 drugs. The filtrates of crushed and centrifuged bulbs of both the indigenous and exotic varieties of garlic produced high antibacterial activities, while both ethanolic and methanolic extracts of garlic did not produce antibacterial activity. The indigenous variety showed higher antibacterial activities and protein qualities than the exotic variety, with both varieties showing genetic diversity. In conclusion, the Nigerian indigenous garlic was found to be of high antibacterial and protein qualities; and for maximal health benefit garlic needs to be chewed or crushed and consumed directly.