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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