Grampositive bacteria 2008

Classification of Gr+ bacteria (I part)

• Tribe: Actinobacteria• Class: Actinobacteria

– Order: Actinomycetales– F.: Micrococcace– F: Corynebacteriaeceae– F: Mycobacteriaceae– F: Nocardiaeace

Classification of Gr+ bacteria (II part)

• Class : Bacilli– Order : Bacillales– F.: Bacillaceae– F.: Listeriaceae– F.: Staphylococcaceae– Order: Lactobacillales– F.: Lactobacillaceae– F.: Enterococcaceae– F.: Streptococcaceae

Class: Actinobacteria

• Order : Actinomycetales

• F: Micrococcaceae

G+ cocci

• F: Micrococcaceae (catalase +)

• Genera: – Micrococccus (M.luteus)

• Kocuria (K.rosea)

• Dermacoccus

Class: Bacilli

• Order Bacillales

• F. Staphylococcace

• Order Lactobacillales

• F: Streptococcaceae

• F.:Enterococcaceae

• F.:Lactobacillaceae

Staphylococcus• Coagulase positive staphylococci (CPS)

• Toxins:– hemolysines (alpha, beta, gama, delta)– enterotoxines– exfoliative toxin

• Coagulase negative staphylococci (CNS)

Staphylococcal species

• CPS– S.aureus– S.intermedius, S.pseudointermedius– S.hyicus subsp. hyicus

• CNS– S.epidermidis– S.chromoges S.sciuri

Antibiotic rezistence in S.aureus

• Resistant isolates– 90% - penicillins

– 4O%- macrolides/. linkosamides

• MRSA- methicillin rezistant S.aureus

• Aditional penicilline binding proteins PBP are produced ´ with low avidity to betalactams

Antibiotic rezistence in S.pseudointermedius

• MRSP isolates from dogs in Sweden

• mecA gene

• Isolates from post operative wound infections

Antibiotic rezistence in S.intermedius

• Multiresistant strains. Clindamycin erytromycine,streptomycine, tetracycline and enrofloxacin

Streptococcus

Pyogennic haemolytic streptococcoci S.pyogenes (ser. group A) human infections

– S.agalactiae (ser. group B) cattle, man , pig– S.equi (group C)– S. equi subsp. – S.canis (group G)

• Other non-haemolytic streptococci: S.suis

New species S.suis

• S.suis decribed (1987) and validated (1992)

• Major host: pig• Pathogenicity for pigs and humans

• Habitat: tonzils • About 35 serovars is recognised (1-35)

• Patogenic and nonpatogenic strains

Pathogenic serotypes of S. suis

• Pig • Serotype 1

• Serotype1/2

• Serotype 2

• Srotype 3

• Serotype 4

• Serotype 7

• Serotype 8

• Serotype 9

• Serotype 16

• Man• Serotype 2

Factors associated with patogenicity and virulence

• Capsule (polysacharide)

• Adherence

• Receptors for IgG a albumins

• Hemolyzin (suilysin)

• Virulent proteins (MRP, EF, MRP*, EF*)

• Other proteins (heat shock protein)

• Genes responsible for virulence are known

Disease in pigs and humans

• Meningitis (serotype 2)

• Endocarditis

• Bronchopneumonia only in pigs

• (Poly) Arthritis (serotype 1) only in pigs

Enterococcus

• Habitat: intestine of animals

• E. faecium• E.faecalis• Vancomycine rezistence enterococci (VRE) from

broilers• VRE - nosocomial (hospital) infection in humans • E. hirae

Lactococcus

• Starter cultures

• L.lactis

• L.cremoris

• L.rafinolactis

Grampositive rods forming endospores

• Aerobic/facultatively anaerobic: – The genus Bacillus

• Anaerobic: – The genus Clostridium

Genus Bacillus

• Group of B.cereus:

• B.anthracis

• B.cereus*

• B.thuringiensis*

• B.mycoides

• B.pseudomycoides

• Group of B.subtilis

B.anthracis

• Anthrax in domestic animals (cattle and sheep)– septisemia

• Anthrax in man in 3 forms:– cutaneneous– gastrointestinal – pulmonary

Anthrax treatment

• 1. Antibiotics:– humans: ciprofloxacin (fluorochinolone)

– cattle and sheep: penicillins

• 2. Specific antibodies (hyperimmune serum):– humans : very limited

– animals : very ofen in use

B.cereus

• toxinogenic B.cereus causes food poisoning in man:– 1) diarrhoeal syndrom– 2) emetic syndrom

• toxinogenic B.cereus as feed poisoning in pigs

Pathogenicity and virulence factors of toxinogenic B.cereus

Toxins/ enterotoxins

Nu of components

genes Food poisoning

Hemolysine BL (HBL)

3:B, L1, L2 protein hblA,hblB, hblC,hblD

yes Nonhemolytic ET (NHE)

3 protein NheA,nheB, nheC

yes Enterotoxin K 1 protein yes Enterotoxin T protein Enterotoxin FM protein Emetic toxin 1

peptide yes

Laboratory diagnostics of enterotoxigenic B.cereus

• Foodstaffs samples/ rectal swabs

• Cultivation on selective media

• Evidence of enterotoxins– BCET-REPLA for HBL toxin– ELISA for NHE

Resistance to antimicrobial agents in B.cereus

• Low susceptibility to penicillins and cephalosporins

Genus Clostridium -pathogenic species

• Neurotoxic species:– C.botulinum - botulism– C.tetani - tetanus

• Histotoxic species: C.peringens, C.chauvoei, C.novyi, C.septicum, C.sordelii….

• Enteric and Enterotoxemic species:– C.perfringens -nekrotic enteritis (poultry, calves,

piglets)– C.difficile - colitis (man, horse, pig, dog)

Taxons of inserte sedis

• F.: Erysipelothrichaceae– G.: Erysipelothrix– E. rhusiopathiae

Listeria

• Pathogenic species:

• L.monocytogenes

• L.ivanovii

• virulence factors :– (LLO, PLC, internalin)

L.monocytogenes

• Human food borne infection since 1988• Meningitis• Pregnant women- fetal infection- stillbirth

– Neonatal menigitis

• Animal listeriosis (sheep, cattle) – menigitis– abortions– mastitis

L.ivanovii

• Pathogen of sheep and other ruminants

Non pathogenic species

• L. innocua

• L. seeligeri

Erysipelothrix

• E. rhusiopathiae

• Habitat: tonsils of pigs

• In pigs:– septisemia– „ diamond skin diseases“ – urtcal form– artritis– endocarditis

E. rhusiopathiae

• In fowl turkeys (septicemia):, chickens

• In sheep (septicemia)

Corynebacterium

• C.pseudotuberculosis– In sheep and goats: caseous lymphadenitis

• Corynebacterium renale, C.cystitidis , C. pilosum: bladder and kidney infections

• Corynebacterium renale pyelonephritis in cows

Nocardioform bacteria

• Rhodococcus equi

• pyogranulomatos pneumonia in foals

• virulent strains– virulence plasmid – protein 18 kD Vap A and B

Mycobacteria

• G: Mycobacteriun • Patogenic species:

• M.tuberculosis complex (one species ?)M. tuberculosis subsp. hominis (H)M.bovisM.bovis subsp.capraeM.microti (vole- rodents)M.africanum (H)

• M.leprae – leprosy (H)

Rod Mycobacterium -oprotunic pathogens :

• M. avium-intracellulare complex • M.avium

– M.avium subsp. avium– M.avium subsp. paratuberculosis– M.avium subsp. silvaticum– M.avium subsp. hominissuis

• M.intracellulare

• M.kansasii• M.simiae• M.marinum• M.xenopi

Mycoplasma

• Cattle– M.bovis,M. bovigenitalium

• Pig– M.hyopneumonie, M.hyosynovie, M.hyorhinis

• Poultry– M.gallisepticum– M.synoviae– M.meleagridis

Mycoplasma hyopneumoniae

• Enzootic pneumonia in pigs– aerogenic infection– chronic respirtory desease

• Seroconversion after 2-4 weeks

• Diagnostics: only PCR , serology suitable as herd test

Mycoplasma haemosuis – new species

• (Eperythrozoon suis) extracellular parasite of erythrocytes in pigs – eperythrozoonosis

in piglets after weaning or in faterns

• M.haemosuis – non detecteble on media in vitro – PCR detection during last decade

M.haemosuis detected in

• Blood of newborne piglets

• Spleen of newborne piglets

M.haemosuis positive newborne piglets

• Clinical signs of low viability

• High mortality (30%) during 3 days

G+ bacteria

2008