COAGULASE +VE COAGULASE -VE

1. Always Pathogenic

2. Eg: S. Aureus

1. Often contaminants in culture.

2. Can be pathogenic in situations like

Indwelling Prosthetic devices

Plastic Vascular Catheters

3. Eg: S. Epidermis,

S. Hemolyticus

Tests to differentiate S. AureusTests to differentiate S. Aureus

• Coagulase Production

• Rapid Test : Latex Assay

Coagulase + VeCoagulase + VeA. Eg: S.Aureus

B. CARRIER: Skin, Nasopharynx, Vagina

C. INFECTIONS:

SKIN

DEEP: Endocarditis, Meningitis, Arthritis, Pneumonia, Sepsis, MOF

TOXIN MEDIATED:

Food poisoning

Toxic Shock Syndrome

Scalded Skin Syndrome

Coagulase - VeCoagulase - VeA. Eg : S. Epidermis

B. CARRIER: Skin , Ear canal,GU Tract, Mucous membranes.

C. INFECTIONS

Indwelling Foreign body

Valves, Catheter, Pacemakers, Shunts, Grafts, IV Catheter.

UTI

Others : Post OP, Endocarditis

D. TREATMENT:

Vancomycin + Aminoglycoside

Surgical Removal

Folliculitis,Furunculosis& Recurrent FurunculosisFolliculitis,Furunculosis& Recurrent Furunculosis

FOLLICULITIS (Superficial Skin Infection)Staphylococcus, Pseudomonas

FURUNCULOSIS ( Inflamm.. Nodule around hair follicle)

EXTENSIVE CELLULITIS

BACTRAEMIA

Hyper Immunoglobunaemia E SyndromeHyper Immunoglobunaemia E Syndrome

• Primary immunodeficiency disease with high IgE titre.

• Chronic Staphylococcal infections ( Furunculosis).

• Rx of Chronic Furunculosis : - Avoid strong irritants

- Role of Vitamin C ?

- 2 % Mupirocin – Intra nasal 5 days every month for 1 year

- Oral Rifampicin + Pencillinase resistant penicillin

• 1940 : Pencillin

• 1960 : Methicillin, Oxacillin

• 1961 : MRSA Identified

• 1970 & Later : Hospital Acquired MRSA

• 1990 : VISA ( Vancomycin Intermediate S. Aureus)

Seen in Hemodialysis Patients on prolonged vancomycin Rx.

Responds to Cotrimoxazole, Linezolid, Streptogramins.

• 2002 : VRSA

Sensitive to same drug as VISA and Tetracycline.

What Are TheseWhat Are These ? ?

1. MRSA ( Methicillin Resistant S. Aureus)

- Resistant to all Beta Lactam Antibiotics

(Pencillin, Cephalosporin, Carbepenem)

DOC : Vancomycin

DOC in deep infection : Vancomycin + Aminoglycoside, Rifampicin Cotrimoxazole

MRSA as a Nosocomial pathogenMRSA as a Nosocomial pathogen

• In Tertiary Care Hospitals

• Rapid Detection

• Prompt Implementation of barrier precautions

• Eradication of Nasal discharge in patients / Carriers using Intra nasal muciporin

2. MSSA (Methicillin Sensitive S. Aureus)

A. DOC : Nafcillin, Oxacillin

B. If Allergy to Pencillin : 1st Gen Cephalosporin's : Caphazolin. C. If Allergy to all Beta Lactams : Vancomycin / Clindamycin / Macrolides

3. GRSA (Glycopeptide Resistant S. Aureus)

MIC > 32 mcg/ml of V

4. VRE (Vancomycin Resistant Enterococci)

STREPTOGRAMINSSTREPTOGRAMINS• MOA : Complex with Bacterial Ribosome's to

inhibit Protein synthesis.

• Useful against VRE, VISA, VRSA Strep. Pneumoniae when vancomycin can’t be

tolerated.

• Eg : Quinupristin, Dalfopristin

DRUG RESISTANCE IN DRUG RESISTANCE IN STAPHYLOCOCCISTAPHYLOCOCCI

• Beta Lactamase

• Methicillin resistant

• Plasmid Mediated Drug inactivation.

• Chromosomal Linked

Decreased activity to penicillin binding protein

• Plasmid Mediated

VIRULENCE OF MRSA & MSSAVIRULENCE OF MRSA & MSSA• Both are equally capable of producing life

threatening infections (Endocarditis, Pneumonia, Bactraemia).

• Source may be carrier• Mortality is up to 50% .• Drugs useful : Vancomycin, Linezolid, Quinopristin,

Dalfopristin, Daptomycin, Ciprofloxacin, Cotrimoxazole

STERPTOCOCCISTERPTOCOCCI

• Gram + Ve

• Catalase – Ve

• Grow in Pairs/ Chains

CLASSIFICATIONCLASSIFICATIONPatterns of Hemolysis in Blood Agar (Alpha, Beta, Gamma)

Antigenic differences in Cell Wall carbohydrates (A to H J K to V) in LANCEFIELD scheme for beta hemolytic streptococci

Biochemical Reactions

Growth Characteristics

BASED ON

DISEASESDISEASES

• Group A S. Pyogenes

Non Suppurative

• Pharyngitis, Tonsillitis, Scarlet fever, pneumonia, Septicemia, Necrotizing Fascitis.

• Acute Rheumatic Fever

Acute Glomerular nephritis

• Group B :

• Strep. Pneumoniae

• Serious Neonatal Infections

( Meningitis, Sepsis), Female pelvic Infection.

• Pneumonia, Otitis Media, Sinusitis, Meningitis, Bactraemia.

• Enterococcus Faecalis

• Anaerobic Streptococci (pepto streptococcus)

• Endocarditis, UTI

• Peritonitis, Dental infections, Liver abscess, PID

*All Streptococci cause Septicemia

Streptococcus PyogenesStreptococcus Pyogenes

• Pyogenic Exotoxins: A, B, C

A – Toxic Shock Syndrome

M Protein

- Major Virulence Antigen

- Makes the bacterium resistant to phagocytosis

Necrotizing FascitisNecrotizing Fascitis• Produced by Strep. Pyogenes “Flesh eating Bacteria”

PAIN

NECROTIZING SKIN & SUB CUTANEOUS TISSUE

FRANK GANGRENE SEVERE SEPSIS

SEPTIC SHOCK, MULTI ORGAN FAILURE,

DICDEATH

TYPESTYPES

• Polymicrobial ( Enterobacteriacae and

Anaerobes)

• Seen Commonly following surgery in DM, HIV

• Pure growth of Strep. Pyogenes.

• Cutaneous findings do not correlate with extent of the disease

• Seen following Anesthesia of skin, Nerve damage, Vascular blockade

TYPE I TYPE II

DifferentialsDifferentials

1. Clostridia : Anaerobic Cellulitis, Myonecrosis

2. Staph Aureus + Strepto : Progressive bacterial synergistic gangrene.

3. Anaerobic Streptococci : Myonecrosis

4. Group A Streptococci : Myositis with out abscess

Treatment of NFTreatment of NF

A. High dose Penicillin IV

B. Penicillin Allergy : Cephalosporin, Vancomycin, Clindamycin

Toxic Shock SyndromeToxic Shock Syndrome

• Streptococcal TSS :

- Group A Streptococcus ( pyogenic exotoxin A)

- Initially influenza like illness.

- 50 % has features of NF

- Faint rash followed by multisystem involvement and MOF

Rx :

Fluid restriction.

BenzylPencillin + Clindamycin

• Staphylococcal TSS - F > M (9:1) - Vaginal Colonization of Staph. Aureus - TSS Toxin 1 is responsible for systemic manifestations.

Fever + Rash (localised erythema in Flexural Areas)

Rapidly Progressive (Erythroderma Desquamatum)

Multisystem Involvement

TreatmentTreatment

SPECIFIC Rx SUPPORTIVE Rx

1.Flucloxacillin, Vancomycin 2.Avoid Tampon Use

1.Haemodynamic Monitoring2. Supportive Care

ENTEROCOCCIENTEROCOCCIINFECTIONS INDUCED

COMMON

UTI, Bactraemia, Endocarditis, Intra abdominal & Pelvic infections.

UNCOMMON

Soft tissue, Meningitis, Neonatal sepsis, Pneumonia

Treating Enterococcal InfectionsTreating Enterococcal Infections• UTI

Penicillin, Ampicillin, Vancomycin, Quinolones, Nitrofurantoin.

• ENDOCARDITIS / BACTRAEMIA Penicillin/ Ampicillin + Amino glycoside

Vanomycin + Amino glycoside

• INTRA ABDOMINAL/ PELVIC INFECTIONS Ampicillin / Penicillin + Aminoglycoside

Vancomycin Resistant EnterococusVancomycin Resistant Enterococus

• Action: Inhibits cell wall synthesis by binding to cell wall precursors.

• Resistance to Vancomycin By producing Cell Wall precursors with less affinity

to Vancomycin.• E. Faecium – VRE

It is also resistant to Tobramycin

Bactericidal of Choice : Gentamicin

• RESISTANCE TO GENTAMYCIN By altering the molecule (G) by phosphorylation and

Acetylating.

• INFECTIONS Hospitalized patients, Device related.

• LESSONS

1. Infection Control Measures

2. Avoid Excessive antibiotic use especially Vancomycin

Treatment of VRETreatment of VRE

• Device Removal

• Surgical Debridgment of Source

• UTI : Nitrofurantoin, Amoxicillin, Fluroquinolone, Linezolid, Daptomycin, Otrivancin, Daflopristin.

LINEZOLIDLINEZOLID

• Acts on VRE, MRSA, GRSA, Penicillin Resistant Strep. Pneumoniae.

• S/E : Thrombocytopenia (25%), Reversible Bone marrow Toxicity