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![Staphylococci
• Staphylococcus was first identified in
1880 in Aberdeen, United Kingdom, by
the surgeon Sir Alexander Ogston in pus
from a surgical abscess in a knee joint.
[1] This name was later appended to
Staphylococcus aureus by Rosenbach
• Main types
– Staph aureus – coagulase positive
– Staph epidermidis, staph hemolyticus, staph
saphrophyticus – coagulase negative
Dr. Ashish Jawarkar
10](https://image.slidesharecdn.com/lec16-140105014208-phpapp01/85/staphylococci-10-320.jpg)
Uploaded byAshish Jawarkar
staphylococci
The document provides a detailed overview of gram-positive bacteria, specifically focusing on staphylococci and their characteristics, classification, morphology, and pathogenicity. It explains the gram staining process, the growth conditions, and the biochemical properties of staphylococci, including their resistance to antibiotics and associated diseases. Additionally, it discusses the laboratory diagnosis and treatment options for infections caused by these bacteria.
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staphylococci
- 1. SYSTEMIC MICROBIOLOGY BACTERIOLOGY Dr. AshishV. Jawarkar M.D.
- 2. GRAM POSITIVE BACTERIA STAPHYLOCOCCUS Dr.Ashish Jawarkar 2
- 3. Introduction Bacteria consist ofonly a single cell Bacteria fall into a category of life called the Prokaryotes There are thousands of species of bacteria, but all of them are basically one of three different shapes. Dr. Ashish Jawarkar 3
- 4. Classification of Bacteria Untilrecently classification has done on the basis of such traits as: shape bacilli : rod-shaped cocci : spherical spirilla : curved walls In clusters : actinomyces Dr. Ashish Jawarkar 4
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- 8. Classification of Bacteria TheGram stain is named after the 19th century Danish bacteriologist who developed it. The bacterial cells are first stained with a purple dye called crystal violet. Then the preparation is treated with alcohol or acetone. This washes the stain out of gram-negative cells. To see them now requires the use of a counterstain of a different color (e.g., the pink of safranin). Bacteria that are not decolorized by the alcohol/acetone wash are gram-positive Dr. Ashish Jawarkar 8
- 9. Gram Positive bacteria •Staphylococci and streptococci constitute the main group of medically important gram positive bacteria • There are also bacilli that are pathogenic such as Anthrax and the Clostridia group. These are also spore forming organisms • There are also some other gram positive rods such as Listeria, Lactobacillus,and Cornybacterium Dr. Ashish Jawarkar diptheria 9
- 10. Staphylococci • Staphylococcus wasfirst identified in 1880 in Aberdeen, United Kingdom, by the surgeon Sir Alexander Ogston in pus from a surgical abscess in a knee joint. [1] This name was later appended to Staphylococcus aureus by Rosenbach • Main types – Staph aureus – coagulase positive – Staph epidermidis, staph hemolyticus, staph saphrophyticus – coagulase negative Dr. Ashish Jawarkar 10
- 11. Description headings foreach bacteria Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 11
- 12. Staphylococci Morphology • Staphylococci staindark purple with the gram stain. • Staphylococci are arranged in grape like clusters • Because they divide in three planes with daughter cells remaining in close proximity Dr. Ashish Jawarkar 12
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- 15. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 15
- 16. Growth characteristics • Growon ordinary media like nutrient agar • Temperature 10-42 degree • Produce golden yellow pigment Dr. Ashish Jawarkar 16
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- 18. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 18
- 19. Staphylococci biochemical reactions • Themost virulent form of staphylococcus, SA also secretes coagulase, that causes citrated plasma to clot. These are referred to as coagulase positive • There are other staph that do not have this ability and are labeled coagulase negative Dr. Ashish Jawarkar 19
- 20. Coagulase test • Slidemethod or tube method • In tube method – we add culture of staphylococci and rabbit plasma • Look for clot formation Dr. Ashish Jawarkar 20
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- 22. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 22
- 23. Resistance • Resistant todrying – can remain in dried pus for 3-6 months • resistant forms to penicillin have emerged – Produce penicillinase which inactivates penicillin – Change surface receptors for penicillin – Develop tolerance to penicillin – bacteria inactivated, not killed Dr. Ashish Jawarkar 23
- 24. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 24
- 25. Pathogenicity • Cell surfaceprotein – protein A – antiphagocytic property • Clumping factor – surface protein – responsible for slide coagulase test • Produce enzyme coagulase • Produce toxins – Hemolytic toxins (leucocidins) – Enterotoxin – causes food poisoning – vomitting, diarrhoea etc – Toxic shock syndrome toxin – produces hypotension and rash – Epidermolytic toxin – causes STAPHYLOCOCCAL SCALDED SKIN SYNDROME (ssss) Dr. Ashish Jawarkar 25
- 26. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 26
- 27. Staphylococcus aureus epidemiology • Carriedby 20-40 % of healthy individuals in their mouth or on their skin • It also found in their nasal mucosa • Vagina – increased risk of TSS during menstruation • Umbilical stump infected during birth • Fomites carry staphylococci for months • Nosocomial infections by MRSA Dr. Ashish Jawarkar 27
- 28. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 28
- 29. Diseases caused bystaphylococci Dr. Ashish Jawarkar 29
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- 34. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 34
- 35. Lab diagnosis • Specimento be collected – – – – Skin – pus Respiratory inf – sputum Food poisoning – stool For detection of carriers – nasal swab Dr. Ashish Jawarkar 35
- 36. Staining and microsocopy •Gram stained smears – Gram positive cocci in grape like clusters Dr. Ashish Jawarkar 36
- 37. Culture • Nutrient agar/bloodagar – Colonies with golden yellow pigment • Coagulase test Dr. Ashish Jawarkar 37
- 38. Antibiotic susceptibility testing •In case of suspected hospital acquired infection Dr. Ashish Jawarkar 38
- 39. Description headings foreach bacteria • • • • • • • • • Morphology Growth characteristics Biochemical reactions Resistance Pathogenicity and virulence Epidemiology Diseases caused Laboratory diagnosis Treatment Dr. Ashish Jawarkar 39
- 40. Treatment • Penicillin • Inresistant cases – cloxacillin • For MRSA - vancomycin Dr. Ashish Jawarkar 40
- 41. Coagulase negative staph S.epidermidis – stitch abcess, grows on implants S. saprophyticus – causes UTI Dr. Ashish Jawarkar 41
- 42. THANK YOU Dr. AshishJawarkar 42