pathogenic gram positive bacteria (4)

7/23/2019 Pathogenic Gram Positive Bacteria (4)

1/34

Pathogenic Gram Positive Bacteria

Part I

BIOM 1005/1905

Dr. Shivanthi Samarasinghe

: Microio!og" #ith Diseases " $a%onom"


2/34

&ims an' !eaning o(tcomes

Aims:to !earn more ao(t me'ica!!"im)ortant Gram*)ositive acteria.

Learning outcomes:&fteratten'ing the !ect(re "o( sho(!' ea!e to name e%am)!es of Gram*)ositive organisms+ their structure,pathogenicity, disease theycause, Diagnosis, Treatment and

Prevention.


3/34

Gram*Positive Bacteria

Characteristics Stain )(r)!e #hen Gram

staine'.

,ontains thic- )e)ti'og!"can

ce!! #a!! str(ct(re.

Base' on the common)h"!ogen" an' ce!! #a!!str(ct(re+ G ve+ can 'ivi'e'into

non*s)ore*forming acteria.

ce!!s that !ac- ce!! #a!!.

s)ore*forming acteria.

Gram*)ositivece!! #a!! str(ct(reRef: Broc-+ Bio!og"

of Microorganisms


4/34

Gram Staine'Gram*Positive Bacteria

Reference: Gram stains were produced y !"#$%&&' and %(&'

student group &), in their $icroscopy practica*

Bacillus subtilis Kocuria rhizophilia B.subtilis s)ore staining


5/34

Staphylococcus

Ref: Microio!og" #ith Diseases " $a%onom"


6/34

Staphylococcus

Memers of ever" h(mans

microiota.

,an e o))ort(nistic )athogens.

-tructure and Physio*ogy

ac(!tative anaeroes

onmoti!e

-ynthesie cata*ase Sa!t*to!erant2 $o!erate sa!t on h(man s-in

$o!erant ra'iation+ an' heat

Staphylococcus.Gra)e!i-e str(ct(reRef: Microio!og" #ithDiseases " $a%onom"


7/34

$#o s)ecies common!" associate' #ith'iseases in h(mans+

Staphylococcus aureus

More vir(!ent strain3ariet" of con'itions 'e)en'ing on

site of infection.

Staphylococcus epidermidis

orma! microiota of h(man s-in

O))ort(nistic )athogen.

Staphylococcus


8/34

Infections res(!t #hen microes reacho'"s )h"sica! arriers.

4ntr" of on!" a fe# h(n're' acteria canres(!t in 'isease.

Pathogenicit" res(!ts from three feat(res

Str(ct(res that ena!e it to eva'e)hagoc"tosis.

Pro'(ction of en"mes 6heamo!"sins+coag(!ase7.

Pro'(ction of to%ins.

Pathogenicity/0ow

microes causeinfection1


9/34

Pathogenicity ofStaphylococcus

-tructura* defenses

against phagocytosis

Pro'(ceCoagu*ase2 ,onverts

8rinogen into 8rin mo!ec(!es+

2irin c*ots hi'e the acteria

from )hagoc"tic ce!!s.

S"nthesie )o!"sacchari'e s*ime

*ayers 3capsu*es4+Inhiit

)hagoc"tosis+ faci!itate

attachment of Staphylococcusto

s(rfaces

,oag(!ase !ea'sto 8rin formation+an' 8rin #a!!so infection.

-tructure of a oi*


10/34

-taphy*ococca* Diseases 5oninvasive disease

oo' )oisoning D(e to ingestion of enteroto%in*contaminate'

foo'.

Cutaneous diseases 3ario(s s-in con'itions.

-ca*ded s6in syndromeRe''ening of the s-in

O(ter !a"er of s-in )ee!s o in sheets.

"mpetigoRe''ene' )atches of s-in ecome)(ss*8!!e' an' event(a!!" cr(st ov

Ref: Microio!og"#ithDiseases "

$a%onom"


11/34

-taphy*ococca* Diseases

To7ic8shoc6 syndrome Some Staphylococcusstrains )ro'(ce $SS

to%in

$SS to%in asore' into the !oo'

Pro'(ces fever+ vomiting+ rash+ !o#!oo' )ress(re

To7ic8shoc6syndrome

eta! infection invo!ves noton!" re' rash (t interna!organs as #e!!.

Ref: Microio!og" #ithDiseases "

$a%onom"


12/34

Staphylococcus DiseaseDiagnosis, Treatment, and Prevention

Diagnosis

Detect Gram*)ositive acteria in gra)e!i-e

arrangements.

erments s(gar mannito!+ t(rns re' to "e!!o#

'eferentia! me'ia )!ate.

Treatment

Methici!!in+ 3ancom"cin (se' to treat MRS& infections.

Prevention

an' antise)sis im)ortant to )revent nosocomia!

infections.


13/34

Streptococcus

ac(!tative anaeroes. ,occi arrange' in )airs or chains.

Often categorie' ase' on ;ance8e!'c!assi8cation

Divi'e' into serot")es ase' onacterias antigens

Lance9e*d groups A and ! inc*ude

the signi8cant h(man )athogens

. pyogens S. pneumonia


14/34

Stre)tococca! Gro()ing test < o# 'oes this #or-=Streptococci are often 'ivi'e' into imm(no!ogica! gro()s2

&+B+,+D+ an' G ase' on the )resence of ce!! #a!!

antigens.Late7 agg*utination test:&ntio'" coate' ea's c!(m) together in the )resence of

the a))ro)riate stre)tococca! antigen 6o.>7.


15/34

Streptococcus

aemo!"tic reaction on

!oo' agar (se' tos('ivi'e the gen(s.

?haemo!"sis2 !arge one of

com)!ete !"sis: S. pyogens

@*haemo!"sis2 )artia! !"sis+co!onies #ith greenish or

ro#nish one.

S. pyogens S. pneumonia

? haemo!"sis*S. pyoge


16/34

Streptococcus pyogenes

Pathogenicit" "a!(roni'ase en"me: aci!itates the s)rea' of

Streptococcusthro(gh tiss(es

P"rogenic to%ins: ,an stim(!ate fever+ rash+ an'shoc-

Stre)to!"sins: ;"se re' !oo' ce!!s

4)i'emio!og"$")ica!!" infects the )har"n% or s-in

Often ca(ses 'isease #hen norma! microiota are'e)!ete'

S)rea's via res)irator" 'ro)!ets


17/34

Streptococcus pyogenes diseases:

Pharyngitis 3strepthroat4

InAammation of the )har"n%

-car*et fever ,an occ(r fo!!o#ing stre)tococca!

)har"ngitis infections

,hest rash 'eve!o)s that s)rea's

across the o'"

5ecrotiing fasciitis Streptococcusenter the o'" an'

s)rea' a!ong the fascia/m(sse! tiss(e

Secrete en"mes an' to%ins that

'estro" tiss(e


18/34

Diagnosis an' treatment Diagnosis

S-in infections 'iagnose' " the

)resence of Gram*)ositive acteria in

short chains or )airs

Ra)i' stre) test (se' to 'iagnose

res)irator" infections

Treatment and Prevention

Penici!!in+ Methici!!in+ 3ancom"cin is

eective for most Staphylococcus(t

ineective against MRS&

an' antise sis im ortant to revent

h ! i h


19/34

$he M"co)!asmas2 Bacteria that!ac- ce!! #a!!

Sma!!est free*!iving microes M"co)!asma ce!!s are )!eomor)hic

6cocc(s an' 8!aments7

Re(ire vario(s gro#th factors from a

host or s())!ie' in !aorator" me'ia ,an co!onie the m(co(s memranes

of the res)irator" an' (rinar" tracts

&ssociate' #ith )ne(monia an'

(rinar" tract infections

On!" a fe# s)ecies ca(se signi8cant

h(man 'isease

Mycoplasma mycoide

Co*onies of Mycoplasm

On agar fried-egg19


20/34

Mycobacterium

on*en'os)ore*forming )athogen

,e!! #a!! contains a #a%" !i)i' ca!!e'm"co!ic aci'2 I'enti8e' " &ci'*aststain 6re' co!o(r7

(ni(e characteristics S!o# gro#th

Protection from !"sis after )hagoc"tosis

,a)acit" for intrace!!(!ar gro#th

Resistance to Gram staining+ 'etergents+


21/34

$(erc(!osis Res)irator" 'isease ca(se' "

Mycobacterium tuberculosis.

$hree t")es of t(erc(!osis

Primary tuercu*osis

Res(!ts from the initia! infection #ith M.tuberculosis

-econdary or reactivated tuercu*osis

Reesta!ishment of active infection after

)erio' of 'ormanc"Disseminated tuercu*osis

Res(!ts #hen infection s)rea's thro(gho(tthe o'"

S"m)toms arise '(e to com)!ications at

the vario(s sites invo!ve'

&ci'*fast staine' M. tuberculosis

Deve*opment of tuercu*osis in


22/34

Deve*opment of tuercu*osis inthe *ungs.

Respiratory

droplets

Inhaledrespiratory

droplets

Respiratorybronchiole

Alveoli

Tubercle

Collagen fibers

Caseousnecrosis

Tubercle

Alveolus

Rupturedtubercle

Mycobacterium

Bronchiole

Blood vessel

Beginningof tubercle

Bronchiole

Macrophage

Alveolus

Blood vessel

Mycobacterium

1

2 3

4 5

Primary tuberculosis infection Secondary or reactivated tuberculosis


agnos s rea men an


23/34

agnos s+ rea men + an

)revention Diagnosis

$(erc(!in s-in test i'enti8es )ossi!ee%)os(re

,hest C ra"s i'entif" in'ivi'(a!s #ith

active 'isease

Treatment

,ommon antimicroia!s ineective

,omination thera)" (se' for

months to treat the 'isease Prevention

Imm(niation #ith B,G vaccine

#here $B is common.

Tubercles


24/34

S(mmar"/ o( !earne'

ao(tm)!es of Gram*)ositive organisms2ica! Gram )ositive an' Gram )ositive !ac-s ce!! #a!!o)!asmas

ir

ucture and physio*ogy,hogenicity,ease they cause,gnosis,

atment and Prevention.erent staining methods for di;erent gram p


25/34

2ina*


26/34

Reference

!roc6+ !io*ogy of$icroorganisms


27/34

-e*f Directed Learning

More ao(t

hogenic Gram*)ositive acteria:


28/34

Capsu*e

Streptococcuspneumoniae

Ref: Microio!og" #ithDiseases " $a%onom"


29/34

Streptococcus pneumoniae

,occi that most common!" form )airs

orm (n)igmente'+ a!)ha*hemo!"tic co!onies on!oo' agar

;ac-s ;ance8e!' antigens

Pathogenicity

Po!"sacchari'e ca)s(!e+ Protein a'hesin: me'iates

in'ing of ce!!s to e)ithe!ia! ce!!s of )har"n%


30/34

Pneumococca* diseases Pneumococca* pneumonia2 Most

common 'isease ca(se' " S.

pneumoniae

!acteremia and endocarditis2 S.

pneumoniaecan enter the !oo'thro(gh tiss(e 'amage

Pneumococca* meningitis2

Morta!it" rate higher than other

Streptococcuspneumoniae


31/34

Diagnosis+ treatment+ an' )revention

Streptococcus pneumoniae

Diagnosis

Gram stain of s)(t(m or !oo'

$reatment

Penici!!in

Resistant strains have emerge'

Prevention

3accine ma'e from )(ri8e'

ca)s(!ar materia!


32/34



33/34

Leprosy &!so referre' to as Fansens

'iseaseF ,a(se' " Mycobacterium leprae

Bacteria 'o not gro# in ce!!*free c(!t(re

$#o 'ierent forms of the 'isease

$(erc(!oi' !e)ros"

on)rogressive form of the'isease

D(e to a strong ce!!*me'iate'imm(ne res)onse

;e)romat(s !e)ros"

More vir(!ent form of the 'isease

D(e to a #ea- ce!!*me'iate'imm(ne res)onse

,ases are ecoming re!ative!" rare

$ransmitte' via )erson*to*)erson contact

or rea- in the s-in


34/34

Diagnosis+ treatment+ an')revention

Diagnosis

Base' on signs an' s"m)toms of'isease

$reatment,omination of antimicroia! 'r(gs

;ife!ong treatment is sometimesnee'e'

Prevention;imiting e%)os(re to the )athogen

B,G vaccine )rovi'es some )rotection

pathogenic gram positive bacteria (4)

Documents