Antibacterial activity of GUAVA, Psidium guajava Linnaeus, leaf extracts on diarrhea-causing enteric bacteria isolated from Seabob shrimp, Xiphopenaeus kroyeri (Heller)

Abstract

SUMMARYGuava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.

Peels of Psidium Guajava Fruit Possess Antimicrobial Properties

“…This effect could be attributed to the structure of gram negative bacterial cell wall that provides a level of intrinsic resistance to certain hydrophilic substances and thus preventing the penetration of active materials in water extracts into the bacterial cell. This could provide an explanation for our results [10,21]. Inhibitory effects of acetone leaf extracts showed similar results to those of other studies [6,10,22].…”

“…This could provide an explanation for our results [10,21]. Inhibitory effects of acetone leaf extracts showed similar results to those of other studies [6,10,22].…”

“…Psidium guajava juice has also been used as a hypoglycemic agent [4]. Studies on the antimicrobial effect of guava have been carried mainly on extracts of leaves, shoots and barks, as well as seeds [5,6,7,8,9]such extracts have also been found to inhibit the growth of drug resistant microbes such as V. cholera [10]and to act synergistically with existing antibiotics to treat the pathogenic Staphylococcus aureus [11]as well as other food pathogens [5,6,7,11,12], or in improving oral hygiene and inhibiting biofilm formation by Streptococcus mutant [13].…”

Antibacterial effect (in vitro) of Moringa oleifera and Annona muricata against Gram positive and Gram negative bacteria

“…As shown by GONÇALVES et al 18 and NASCIMENTO et al 31 , S. aureus has been inhibited by extracts prepared from a variety of phanerogams. Likewise, VIEIRA et al 42 found S. aureus to be sensitive to guava leaf extracts in a study testing medicinal plants against bacteria causing diarrhea in children.…”

Phytopharmacological overview of Psidium guajava Linn.

“…30 The essential oil from leaf extract of P. guajava exhibited the inhibitory activity towards S. aureus and Salmonella species. 31 Pelegrini et al 32 isolated the peptide Pg-AMP1 from the seeds of P. guajava. Pg-AMP1 showed growth reduction in Klebsiella sp.…”