Fungi and Mould Biomedical Science PDF

Fungi and Mould Biomedical science Benjamin Tighe Intended Learning Outcomes By the end of this sessions students should be able to: Di3eren5ate a yeast from a mould Iden5fy fungal commensal :ora and their loca5on  multicelled...

Fungi and Mould Biomedical science Benjamin Tighe Intended Learning Outcomes By the end of this sessions students should be able to: Di3eren5ate a yeast from a mould Iden5fy fungal commensal :ora and their loca5on  multicelled Single called or Features of Fungi I yeast Fungi are eukaryotic Most important fungus relevant to dentistry is Candida. Fungi present in 2 structural forms 1. Yeast 2. Mould Dimorphic (can exist as both) wardebstance cells contain fungi · nucleus orsands contains Chitin · · cl war Yeast (complete the table in your Fungi Workbook) CharacterisCcs of Yeasts Form Cell type Habitat Appearance Hyphae Spore Colour Oxygen Health risks Yeast (complete the table in your Fungi Workbook) CharacterisCcs of Yeasts Form Grow as large single cells. Cell type Unicellular Habitat Very common – on fruit, stomach of mammals oral cavity and vaginal areas Appearance White and thready. Usually oval in shape. Hyphae Yeasts do not have true hyphae. Instead, they form mul5cellular structures called pseudo-hyphae. Spore Yeast is a not a sporing species of fungi. Colour Yeasts are less colourful compared to moulds (colourless). Collec5vely yellow creamy colour Oxygen Yeast can grow in aerobic as well as in anaerobic condi5ons. Health risks It can cause infec5on in individuals with compromised immune systems.  Shapes Shape of Fungi Different shapped. - or bas Stick together reproduction and Sexual Reproduced a sexually of Release spores  -- Yeasts Often seen to have lateral projections – daughter cells Splits of from mother cell to produce next generation – ‘budding’ Some reproduce by binary fission Pseudohyphae (chains of elongated budding cells) Candida forms pseudohyphae in the oral cavity Moulds (complete the table in your Fungi Workbook) CharacterisCcs of Moulds Form Cell type Habitat Appearance Hyphae Spore Colour Oxygen Health risks Moulds (complete the table in your Fungi Workbook) CharacterisCcs of Moulds Form Grow as mul5ple tubular branches Cell type Mul5cellular Habitat Typically found in damp, dark or humid areas. Appearance Mould has a :u3y appearance and can be found in several shapes Hyphae Have microscopic Slaments called hyphae Spore Mould is a sporing fungus Colour Are very colorful and maybe orange, green, black, brown, pink or purple. Oxygen Grows only in aerobic condi5ons Health risks Usually allergic reac5ons and respiratory problems.  fillaments fungi Moulds chitin ou wall has a Multicellular threads called hyphae Hypha contain cytoplasm and organelles Mycelium is a mass of hyphae that forms mould colony Reproduce through spores asexual or sexual IdenCfy fungal commensal Hora and their locaCon and fungi that live on the ski and mucosal surfaces of the body 4 interact with the immune system. · Skin - candida albicans · mouth malassezia aut ·  oral Fungal commensal Flora - cavity That microgranism Lives mal s untilacta Fungi in the body human. Introduction This handbook is to be used in conjunction with your lecture and powerpoint on Fungi. You will need to complete the workbook to meet the intended learning outcomes: By the end of this sessions students should be able to: Differentiate a yeast from a mould Identify the position of fungal commensal flora and their location 2 Characteristics of Yeasts Spherical, egg shaped and filamentous Form Large singled celled Eukaryotic, single celled Cell type Unicellular Widely distributed and occur in substances rich in sugars such as milk, Habitat surfaces of fruit and in flower hector, oral cavity , vagina Oval in shape , white and threads Appearance Yeasts don’t have true hyphae. Instead they form mulicellular structures Hyphae called peseudo hyphae Yeast is not a sporting species of fungi Spore White,cream,pink Colour Anaerobes. Can survive with or without oxygen Oxygen Overgrowth of yeast fungi can cause candidiasis in areas such as Vagina, Health mouth, throat ,esophgus risks  Characteristics of Moulds Long branched filaments Form Grow as multiple tubular branches Mulicellular Cell type Moist places such as soil , plants and dead or decaying matter. Habitat Dark damp areas Fuzzy appearance which canHOSPITAL be white, grey, blue,green, orange,black, Appearance EASTMAN brown EDUCATION DENTAL CENTRE Yes Hyphae DENTAL HYGIENE & YesDENTAL THERAPY Spore Range from red to green to black Colour Yes need oxygen to survive Oxygen Allergic reactions ,respiratory problems , irritation of the eyes,nose and Health throat , sinus congestion risks 2 How would you define commensal oral microflora? The community of microorganisms that live in the mouth including bacteria, fungus, viruses and sometimes Protozoa that play an important role in Maintaing oral health. Where else will you find fungi present as part of normal commensal microflora? Skin Gut Mouth 2 FUNGAL INFECTIONS (associated with Fungal Infections lecture) By the end of the session students should be able Describe the diseases caused by Candida albicans and the host predisposing factors to these diseases. ▪ List the pathogenicity factors of Candida albicans and indicate their role in the infective process. Identify the host predisposing factors to cryptococosis, the main pathogenicity factors of Cryptococcus neoformans and their role in infection. Outline the predisposing factors, relevant pathogenicity factors and their role in the infective process for: dermatophyte infection, aspergillosis, zygomycosis Candida albicans Conditions Superficial A yeast infection caused by the fungus Candida albicans that affects the skin. Mucosal (Thrush) Overgrowth of Candida in the mouth. Causing mouth to feel cottony , white coating on tongue, white spots and loss of taste. Skin infection Most commonly found in areas of skin that rubs together. Nappy rash Bright red , shiny rash with clear patches and red dots with pus like bumps Candidal Paronychia Skin infection of the nail folds Mucocutaneous Involves skin and the oral and/or vaginal mucosae. Rare condition associated impacted host immune response. Systemic (deep candidiasis) Resulting from candidaemia (Candida in the blood). Location can b endocardium, meninges, bones, kidney. Untreated disseminated is fatal Susceptible patients are – organ transplant, heart surgery, long term steroid therapy.  EASTMAN DENTAL HOSPITAL EDUCATION CENTRE DENTAL HYGIENE & DENTAL THERAPY Predisposing Factors to Candida Read the article in Moodle Candidiasis: Predisposing Factors, Prevention, Diagnosis and Alternative Treatment Nata´lia Martins Isabel C. F. R. Ferreira Lillian Barros So´nia Silva Mariana Henriques Anotate below the section associated on Predisposing factors page 227 -229. Predisposing factors are factors that can controtribute to Candida infection occurring more commonly. Theses include; Decreased digestive secretions Nutrients deficiency Impaired immune system Underlying disease states Impaired liver function Drugs and prolonged antibiotics use Altered Bowel flora Systemic Fungal Infections Cryptococcus Caused By Breathing in spores from the yeast like fungus cryptococcus. Habitat Found in soil Pathogenicity Spores inhaled and deposited in lungs where they can germinate and cause disease. Transmission Inhalation Impact on host Fever, headache, malaise, neck stiffness and can lead to meningitis, lung infection Fatal if it involves the central nervous system Treatment Anti fungal medication for at least six months such as fluconazole or flucytosine Aspergillosis Caused By Breathing in spores of mold aspergillus Habitat Plants, decaying matter, soil, air, in/on aminals , freshwater and marine habitats Pathogenicity Via the inhalation of airborne conidiophores and deposition in the bronchioles or alveola space Transmission Inhalation , not spread between humans Impact on host Allergic reaction, bleeding in the lungs, localised infections , endocarditis, EASTMAN DENTAL HOSPITAL endophthalitis EDUCATION CENTRE , gastrointestinal issues and cerebral DENTAL aspergillosis HYGIENE & DENTAL THERAPY Treatment Corticosteroids, anti fungal medication via mouth or intravenously. Zygomycosis Caused By Fungi called zygomycota found in soil, fallen leaves , compost, animal poo and air Habitat Soil, fallen leaves , animal poo, air Pathogenicity Breathing in the spores Transmission Inhalation , ingestion of contaminated food , inoculation of spores through trauma or contaminated instruments Impact on host Rhinocerebral and pulmonary disease. Treatment Anti fungal medication Sometimes surgery is needed to remove  infected tissue. 2 Introduction to Oral Candidiasis Picture Name Short notes Acute Fungal infection pseudomembranous causing white spot candidiasis patches in the mouth. Treated with anti fungal mouth gel Chronic hyperplastic Rare form of oral candidasis candidisis Denture stomatis Chronic inflammatory Chronic atrophic condition caused by candidasis dentures.  skin condition Angular cheliitis affecting the corners of your mouth. It can be painful, cause cracked sores. People often confuse angular cheilitis with cold sores. 2