Gram Positive Cocci

Gram--Positive Cocci Gram Prof Dr Prof. Dr. Asem Shehabi Faculty of Medicine University of Jordan

Gram--psitive cocci Gram ƒ Micrococcaceae Mi f il F family.. Facultative lt ti A Anaerobic bi Gram--positive cocci .. includes the following Gram Genera/Groups: .. Arranged in Irregular Clusters ƒ Staphylococcus Staphylococcus.. ..Catalase+ve Catalase+ve ƒ Streptococci Streptococci.. .. Arranged in Diplococci or Chain of Cocci.. Cocci Catalase Catalase--ve ƒ Enterococci Enterococci.. .. Arranged in Diplococci & Short Chain CatalaseChain.. Catalase-ve e ƒ The Two Common Staphylococcus species are: S. S aureus.. S. S epidermidis id idi are common iin skin, nose, oral cavity. other body sites.

Stapylococci--Streptococci Stapylococci

Pathogenicity of S. S aureus ƒ More invasive & pathogenic than other Staph. species capsule,, cell wall antigenic structure ƒ Contains capsule Polysaccharides.. Protein A A.. .. Production Specific Enzymes y & ExoExo- & Enterotoxins Enterotoxins.. .. Food Poisoning g Coagulase & Clumping factor +ve +ve.. .. Both converted prothrombin into fibrin & fibrinogen .. Deposit fibrin during infection.. Hyaluronidase Hyaluronidase.. .. Spreading factor, Leukocidin.. Leukocidin .. destroy WBCs.. formation of pus and acne ƒ A common cause of skin abscess ..wounds, sepsis/ bacteremia sinusitis bacteremia, sinusitis, conjunctivitis pneumonia pneumonia, meningitis, osteomyelitis, any body sites.

S. S epidermidis ƒ Less pathogenic.. part body normal flora.. coagulase ve.. opportunistic pathogen.. Bacteremia.. Skin abscess. ƒ Diagnosis: Collect specimens ..Culture & identification of isolates by gramgram-stain, catalase & coagulase test, susceptibility test.. ƒ Most S. aureus strains.. Less S. epidermidis are resistant to all BB-lactams.. Increase rate of isolation Methicillin/Oxacillin--resistant S. aureus (MRSA).. All Methicillin/Oxacillin still till susceptible tibl tto vancomycin vancomycin. i . ƒ Micrococcus species: common on skin.. coagulase ve.. opportunistic t i ti pathogen.. th IImmunoImmuno-compromised i d patients.. mostly susceptible to B B--Lactams.

Streptococci--1 Streptococci ƒ Viridans Streptococci Group: Group: Alpha Alpha--hemolytic/ Non Non-Hemolytic.. y Normal respiratory p y flora.. Oral cavity.. y opportunistic pathogen, Dental caries, Sepsis, Localized oral abscesses.. Common Endocarditis ƒ Beta B t -hemolytic Betah l ti Streptococci St t i Group: Group G : Serogroups S A A, B, C, D, F, G.. Cell wall specific carbohydrates.. Respiratory flora flora.. Healthy Carries Carries..Population Population ƒ Group A Hemolytic Streptococci ( S. pyogens): pyogens): Most invasive & Pathogenic Pathogenic.. Virulence Factors Factors.. Cell Wall antigens/ M Proteins.. Many Extracellular Enzymes.. y Hemolysins, y , 80 Specific p subtypes yp , Pyrogenic /Erythrogenic Toxin.. Superficial skin infection.. Scarlet fever.. Children

Beta-Hemolytic Betay StreptococcisStreptococcis p Susceptible for Bacitracin

Streptococci--2 Streptococci ƒ Group A streptococcal infections affect all ages g with p peak incidence at 5-15 y years of age.. g Acute Sore throat/ Pharyngitis, Skin infection, Sepsis, Otitis media, Sinusitis, Meningitis.. Less Ad lt Adults ƒ Complications: A) Rheumatic Fever.. i fl inflammatory di disease affecting ff i primarily i il the h heart and joints. B) Glomerulonephritis.. imm ne comple immune complex disease of the kidne kidney ƒ Group B Streptococci: Common in vaginal t t Purperal tract.. P l Sepsis, S i Neonatal N t lM Meningitis, i iti Fatal ..Urinary Tract Infection.

Streptococci--3 Streptococci ƒ Streptococci pneumonia: Capsule.. Capsule polysacharides 85 Serotypes.. Healthy Carriers ƒ Common cause of bacterial p pneumonia.. more common in the very young and the very old persons. ƒ Common cause of meningitis, Sinusitis, Otitis Media, B t Bacteremia.. i Young Y children.. hild IImunocompromised i d persons.. up 50 50% % S. pneumonia RR-Penicillin. ƒ S. S pneumoniae can be differentiated from S.viridans S viridans, which is also alpha hemolytic, using an Optochin test, ƒ Enterococcus: E. fecalis, E. faecium.. Common Intestine HumanHuman-Animal.. opportunistic pathogen.. Urinary Tract Infect., Wound, Rare Sepsis, E d Endocarditis.. diti

S. p pneumoniae - Susceptible p to Optochin in Lab test

Enterococcus species ƒ GramGram-positive diplococci..short strept. Chains. Common intestinal tract human human, animals animals.. resistance to environmental conditions.. and many antibiotics ..cephalosporines and gy aminoglycosides ƒ Common cause of urinary tract infections. Sepsis nosocomial infections in associated Sepsis..nosocomial with underlying diseases. ƒ Treatment: combination of antibiotics