Gram-positive Cocci Lecture Notes PDF

Gram-positive cocci Mantana Jamklang School of Preclinical Sciences Institute of Science Suranaree University of technology Email: [email protected] 1 Major groups of medically important bacteria 2 ...

Gram-positive cocci Mantana Jamklang School of Preclinical Sciences Institute of Science Suranaree University of technology Email: [email protected] 1 Major groups of medically important bacteria 2  Scientific nomenclature Genus begins with a capital letter Species with a lower case Names of taxa species ~ ~ Genus Staphylococcus aureus Staphylococcus aureus Burkholderia (Pseudomonas) pseudomallei & Jan 3  Aerobic Gram-positive cocci 4  Gram-positive cocci As enzyme - ms + Catalase Staphylococcus spp. Micrococcus spp. Streptococcus spp. Enterococcus spp. Chain Chain Grapelike cluster Tetrad , Bac juras Bacsin& i 5  Staphylococcus spp. Gram-positive cocci in cluster Catalase-positive O G 6  assis Coagulase-negative staphylococci Coagulase-positive staphylococci plasmat staf O ↳niplasmas ne insosT - C Carotenoid pigment (staphyloxanthin)  inactivate microbicidal effect of - superoxides & reactive oxygen - species (ROS) within neutrophils Kornenav 7  Staphylococcus aureus usos 2 15712 Pyogenic bacteria (propensity to evoke acute neutrophilic inflammation & “pus”) - One of the most common causes of human infections Jenn dotraiacon iss un MRSA (methicillin-resistant S. aureus): healthcare-associated infections Grow on mannitol salt agar Habitat: humanOnose (30%) &G skin Transmission: hands idrionado ~ O Produce α-hemolysin Hemolysis 8  alls s does, S. aureus Virulent factors Bri cell Brin : Host diseisit - - ↳ B in Source: https://journals.plos.org/ 9 S. aureus sensmg Infections Diseases Soft tissue & skin infections Impetigo Folliculitis (boil) Furuncle Carbuncle Bullous impetigo Soft tissue and skin infections Pneumonia Vonnis Food poisoning 0-U151T0ES Osteomyelitis proondance a Staphylococcal scaled skin syndrome Pneumonia (SSSS) Toxic shock syndrome (TSS) Food poisoning produce toxin TSST-1 Toxic shock syndrome 10 S. aureus Food poisoning & diarrhea minothsio-7 Food contaminated by worker with staphylococci on hands Ess Food is left at room temperature. entertoxinsson (Reheating will eliminate staphylococci but not the toxins) - S C Food containing toxins is eaten netair In 1-6h, staphylococcal intoxication occurs 11  Coagulase-negative staphylococci 82 Sata + ~ Novobiocin-susceptible - - S. epidermidis S. saprophyticus amerJanss do , es Normal skin flora (90%) & mucosal surfaces produce extracellular slime Trinito ~ Opportunistic pathogen grnts Community-acquired urinary tract infections (UTI) endocarditis, catheter & shunt infection, in young women (but Escherichia coli is a much more F neonatal sepsis common cause) , obsto · n isz Note: Coagulase-negative staphylococcus ส่วนใหญ่ไม่ก่อโรค มักจะเป็ น contaminant 12 เชื้ อแกรมบวกในกลุ่ม staphylococci และ micrococci กลุม่ /ชนิด คุณสมบัตสิ ำคัญ โรคติดเชื้อที่สำคัญ แบคทีเรีย ปั จจัย/กลไกก่อโรค S. aureus -Gram-positive cocci in cluster -Soft tissue and skin infection -Coagulase -Food poisoning -staphyloxanthin -Osteomyelitis intrap -TSST-1 -Toxic shock syndrome S. epidermidis -Opportunistic pathogen -endocarditis, catheter & shunt infection S. saprophyticus -extracellular slime -Community-acquired urinary tract infections (UTI) Micrococcus -Tetrad -Opportunistic pathogen 13  Streptococcus spp. Gram-positive cocci (in chain) Catalase-negative Serological classification (Lancefield’s antibody) RBC Im B Beta-hemolysis a Alpha-hemolysis je Gamma-hemolysis (Complete)sure (Partial) (Non) S. pyogenes (gr. A) S. pneumoniae Streptococcus gr. D (Enterococci) S. agalactiae (gr. B) Viridans gr. streptococci (E. faecalis, E. faecium) Streptococcus gr. C,G Streptococcus gr. D (non-enterococci) 14  β-hemolysis streptococci Ꝋ Gr. A streptococcus(S. pyogenes) (GAS) Ꝋ Gr. B streptococcus (S. agalactiae) (GBS) inito I a jorsnut f ~ netration Colony - clear zone herysin jorsong RBL 15  β-hemolysis streptococci Streptococcus gr. A Streptococcus gr. B &S (S. pyogenes) (S. agalactiae) sergus hemlin & On an ⑳ hisPrin 16  - Streptococcus pyogenes (Gr. A streptococcus) Characteristics Habitat & Transmission Gram-positive cocci in chain Habitat: human throat & skin β-hemolytic colonies Transmission: respiratory droplets Bacitracin-sensitive Virulent factors Diseases adonisy Suppurative (pus-producing) pharyngitis (strep sore throat) and tonsillitis - Scarlet fever ni l Mastoiditis & sinusitis Otitis media ubunans C Wound infection (i.e cellulitis) Impetigo (a skin infection) - Complications Rheumatic fever Guionru Glomerulonephristis vimonly 17 https://wydaily.com/health  18 S. pyogenes Pharyngitis 51p0 Strep throat by β-hemolytic gr. A strep Abscesses on tonsils Complications: Scarlet fever & Toxic Shock Syndrome G Treatment: penicillin Strep throat Strep throat  65 d 19 S. pyogenes Scarlet fever Susu Sometimes occur after “Strep Throat” Strawberry tongue found in children (