PART 1: CLINICAL BACTERIOLOGY LECTURE [M2.L1. GRAM + COCCI]

Who are the Gram-Positive Cocci?

Staphylococcaceae, Micrococcaceae, Streptococcaceae

Staphye means?

Bunch of grapes

What are the color of Staphylococcus when viewed in the microscope?

Purple

NON-MOTILE or MOTILE. Staphylococcus

Non-motile

Staphylococcus are halophilic at what percentage of NaCl?

7\.5%

POSTIVE OR NEGATIVE. Catalase of Staphylococcus

POSITIVE

POSTIVE OR NEGATIVE. Modified oxidase of Staphylococcus

Negative

Staphylococcus are ______ to 0.04 units of _________

Resistant; bacitracin

__**TRUE or FALSE.**__ **Staphylococcus** are known to be **Glucose oxidizers.**

FALSE

__**TRUE or FALSE.**__ *Staphylococcus aureus, Staphylococcus albus*, as well as *Staphylococcus haemolyticus* are known to be **chromogenic**

FALSE

“Aureus” means?

Gold

The color of the colonies of *S. albus*

Porcelain white

Micrococcus are known to be Glucose __________

Oxidizers

__**TRUE OR FALSE.**__ **Micrococcus** are modified oxidase **positive**

TRUE

Micrococcus are _____________ to 0.04 units of ____________

Susceptible; bacitracin

Which of the medically-important Staphylococcus spp. is the only **coagulase positive**

Staphylococcus aureus

__**TRUE or FALSE.**__ The **5 medically-important staphylococcus spp**. are *S. aureus, S. lugdunensis, S. epidermidis, S. saprophyticus, and S. hyicus*

FALSE

This animal pathogen is **coagulase positive** and is **very rarely** recovered among humans.

Staphylococcus intermedius

The **most virulent** species of Staphylococci

Staphylococcus aureus

Enzyme that clots plasma

Coagulase

Can cause lysis of clot

Fibrinolysin/Staphylokinase

Lysis of clot

Fibrinolysis

Acts on lipids present in the skin

Lipase

Hydrolyzes hyaluronic acid present in connective tissues allowing spread of bacteria

Hyaluronidase/Duran Reynal Factor

This acts to hydrolyze DNA

DNAse/Deoxyribonuclease/Thermonuclease

Present in bacterial cell wall and has protective effect against IgG

Protein A

Can cause hemolysis/destruction of RBC

Hemolysin

Causes non-specific membrane toxicity

Alpha and delta

Beta hemolytic pattern is enhances is the culture media is incubated at ___________ after which is at ____________

37 degree Celsius; 4 degree Celsius

Causes lysis of WBC

Gamma/Leukocidin/Panton Valentine

This is associated with food poisoning

Enterotoxin

New name of Enterotoxin F

Toxic Shock Syndrome Toxin 1 or Pyrogenic Exotoxin C

_________ is known to cause Staphylococcal scalded skin syndrome/Reiter’s syndrome. It is also associated with ___________

Epidermolytic toxin/Exfoliative toxin/Exfoliatin; Bullous impetigo

Staphylococcus aureus are generally resistant against penicillin because they have an enzyme called?

Beta lactamase

What does beta-lactamase destroy in penicillin?

Beta-lactam ring

S. aureus us the normal flora of?

Anterior nares and nasopharynx

This is a disease that is caused by the bacteria itself

Non-toxin Mediated Disease

This is a disease caused by the toxin produced by S. aureus

Toxin-Mediated Disease

**Which of the following are not part of the Non-Toxin Mediated Diseases:**

\
A. Skin, Soft tissue and wound infections

B. Meningitis

C. Staphylococcal pseudomembraneous enterocolitis

D. UTI

E. Scalded Skin Syndrome

\
LETTER ONLY

C and E

Pus filled mild inflammation of hair follicles or oil glands

Folliculitis

Extension of folliculitis

Furuncle/Oils

Multiple furuncle

Carbuncle

Large fluid filled lesions that is caused by S. aureus

Bullous impetigo

Non-bullous impetigo/impetigo contagiosa is caused by?

Streptococcus pyogenes

__**Bullous impetigo or Non-bullous impetigo**__. Which is known to be more contagious?

Non-bullous impetigo

Inflammation of the oil gland on the edge of the eyelid

Stye

Associated with open skull fracture

Meningitis

Associated with open bone fracture

Osteomyelitis

Food poisoning that is associated with Enterotoxin A, B, and D

Staphylococcal food-poisoning

Food poisoning that is associated with Enterotoxin B

Staphylococcal pseudomembraneous enterocolitis

This is manifested in having high grade fever, scarltiniform rashes as well as hypotension

Toxic Shock Syndrome

__**TRUE OR FALSE.**__ Epidermolytic toxin is associated with the use of high absorbent tampons

FALSE

Manifested as having erythema/redness and exfoliative dematitis

Scalded Skin Syndrome/Reiter’s syndrome

What is the M/C cause of wound infection?

Staphylococcus aureus

Non-toxin mediated diseases are what type of infection?

Pyogenic/ suppurative infection

This bacteria is associated with nosocomial bacteremia, nosocomial UTI, as well as endocarditis

Staphylococcus epidermidis

It is the normal flora of the skin

Staphylococcus epidermidis

What are 2 most common Coagulase-Negative Staphylococcus

Staphylococcus epidermidis and Staphylococcus saprophyticus

Staphylococcus epidermidis has a slime layer which is made up of?

Polygamma DL-glutamic acid

This is associated with UTI among sexually active young females

Staphylococcus saprophyticus

S. saprophyticus is the normal flora or?

Female genitalia and perineum

This is the 2nd leading cause of cystitis among women

Staphylococcus saprophyticus

Associated with endocarditis, septicemia, meningitis, and UTI

Staphylococcus lugdunensis and Staphylococcus haemolyticus

Staphylococcus lugdunensis and Staphylococcus haemolyticus has what type of gene that makes them resistant to **methicillin, oxacillin, nafcillin**

Mec A Gene

These are rarely implicated with human infections

Micrococcus species

Micrococcus species is the normal flora of?

Human skin, mucosa, and oropharynx

TRUE or FALSE. Micrococcus are strict aerobe which requires them to have 50% oxygen

FALSE

All micrococcus species are strict aerobe except for?

Micrococcus kristinae (Kocuria kristinae)

Micrococcus species are inherently resistant to what drugs?

Furazolidone and lysostaphin

Best temp to grow S. aureus is at?

37 degree celsius

Pigment production of S. aureus is best when it is incubated at what degrees?

20-25 degree celsius

GRAM STAIN. Staphylococci are gram positive cocci in?

Cluster/singly/pairs

GRAM STAIN. Micrococcus are gram positive cocci in?

Tetrads

What is the reagent for catalase testing

3% Hydrogen Peroxide

With catalase test, hydroden peroxide is broken down into?

H2O and O2

Positive in catalase test produces?

Bubbling formation/effervescence

Positive in catalase test indicates what bacteria present?

Staphylococcus or Micrococcus

Negative reaction for catalase indicates what bacteria present?

Streptococcus

In performing catalase testing, where should you NEVER get colonies from?

Blood Agar Plate (5% Sheep’s Agar Blood)

Blood Agar Plate has a component wherein it can mimic the action of catalase which can cause false positive staphylococcus/micrococcus

Pseudoperoxidase

Other strains of Staphylococcus aureus does not possess this type of coagulase

a. Cell bound

b. Free coagulase

c. Extracellular coagulase

d. Clumping factor

e. Staphylocoagulase

LETTER ONLY

A and D

To detect the presence of cell bound, the coagulase test we use is ___________ which is a type of SCREENING coagulase test

Slide coagulase test

Positive in clumping factor indicates what bacteria present?

Staphylococcus aureus

In preparing screening coagulase test, what is the ONLY anticoagulant that should be used?

EDTA

All Staphylococcus aureus possess this type of coagulase

a. Staphylocoagulase

b. Free coagulase

c. Clumping factor

d. Extracellular coagulase

e. Cell bound

LETTER ONLY

A, B, D

To detect the presence of free coagulase, the coagulase test we use is ________, which is the CONFIRMATORY coagulase test

Tube Coagulase Test

Negative reaction for free coagulase indicates the presence of which bacteria?

CoNS/Micrococcus

Mannitol Salt Agar is a selective media for?

Staphylococcus and Micrococcus

Mannitol Salt Agar is a differential media for?

Staphylococcus aureus from other species of Staphylococcus

Mannitol in MSA is considered as?

Carbohydrate

pH indicator of MSA is?

Phenol red

Color of media in MSA is?

Pink/Reddish pink

If the pH of the culture media becomes acidic , it will turn?

Yellow

S. aureus or CoNS. Which bacteria is mannitol fermenter?

S. aureus

In S. aureus, the media will change from color __________ due to acidity

Red to yellow

S. aureus or CoNS. Which bacteria is non mannitol fermenter?

CoNS

Which bacteria is halophilic, non-mannitol fermenters; The media remains the same because they are non-mannitol fermenters

CoNS and Micrococcus species

Media used in DNase

DNAse agar

Which indicator in DNase shows the clear zone surrounding the colonies

Methyl green

Which indicator in DNase shows the pink zone surrounding the colonies

Toluidine blue