Bacteriocin and its effect against skin pathogens

Introduction

Skin is an important organ that represents thefirst line of defense against the externalenvironment. Some microorganisms arepathogenic but some are usually present on theskin does not causing damages but duringadverse condition like immunosuppressantphases the organisms develop infections in thehost (Hall and Dorsch, 2002). Some of such caseslike; Primary cutaneous aspergillosis usuallyinvolves site of injury, at or near intravenouscatheter sites, occlusive dressings, burns, orsurgery (Walsh and Groll, 1999). Secondaryinfections infect the underlying structures or fromwide spread blood borne seeding of the skin.Superficial infections including keratitis,otomycosis are commonly caused by Penicilliumsp., Malassezia sp. are another example ofnormal skin flora colonizes as commensals andduring adverse conditions develops diseases atthe head, neck dermatitis, and malasseziafolliculitis (Gupta and Kohli, 2004). 

Fusarium sp. Causes infections in patients inconditions like hematologic malignant or bonemarrow transplant (Nucci and Anaissie, 2007).Candida nail infections occur in patients withchronic mucocutaneous candidiasis caused byCandida albicans, they invade the entire nailplates (Kirkpatrick, 2001). Staphylococcus aureusis a major cause of bacterial skin infectionsnamely, abscesses in boils, furuncles, Cellulitis(Prendiville, 1989). Streptococcus pyogens arealso bacterial species causing infections in thesuperficial keratin layer called impetigo, thesuperficial epidermis layer-erysipelas, thesubcutaneous tissue layer-cellulitis, fascia callednecrotizing fasciitis or in the muscle-myositis,myonecrosis (Stevens and Bryant, 2017).Klebsiella causes surgical wound infections, theyusually enters through break in the skin andgradually leads to soft tissue infections(Paterson and Bonomo, 2005).

Balanced skin is crucial for maintaining healthyskin functioning; but changes in the skinmicrobes are associated with skin diseases suchas those caused by Candida albicans, Aspergillus,Malassezia furfur, Fusarium, Penicillium,Staphylococcus aureus, Streptococcus pyogens,and Klebsiella sp. Lactobacilli are probioticbelonging to the group of lactic acid bacteria;they are Gram-positive, non-sporulating,anaerobic or facultative anaerobic rods. They arecommonly present in dairy products, soil, lakes,and the intestinal tract of humans and animals.They possess antagonistic activity against variouspathogenic microorganisms (Salminen et al.,2004). In the present study, the Lactobacillus sp.from dairy products like milk, curd, and yogurtare isolated; then bacteriocin is extracted from itand checked their efficacy against fungal andbacterial pathogens using the technique of KirbyBauer disc diffusion method (Aasen and Moretro,2018). Bacteriocins are low molecular weightpeptides secreted by the bacterial cells to killsensitive cells present in the same ecosystemcompeting for food and other nutrients.Bacteriocins, along with their native antibacterialproperty, also exhibit additional antiviral andantifungal properties nowadays (Riley and Wertz,2002). The dairy samples (milk, curd, yogurt)were collected in sterile containers from differentplaces of Vandithavalam, Palakkad, Kerala. Thesamples were analyzed microbiologically,identified, and confirmed by biochemical tests.The study aimed to extract bacteriocin fromLactobacillus sp. and to see whether its effectagainst the mentioned microorganism.