Antibiotic resistance problems in food animals Flashcards
Forklar MRSA og fortæl, hvordan man kan vide, at det er en MRSA.
Hvad hedder MRSA klonen ?
Hvad er risikofaktorer for livestock MRSA og at mennesker får det ?
Colonization vs temporary colonization
A Staphylococcus aureus, which has acquired the
mecA (or mecC) gene → resistance to all beta-lactams
When cefoxitin/(oxacillin) resistant, S. aureus should be
considered MRSA – beta-lactams must not be used
irrespective of susceptibility profile!
- MRSA confirmed by mecA PCR
- Often resistant to other antibiotic classes
Klonen: CC398!
- Risk factors
- Antibiotic use (tetracycline) and zink
- Poor hygiene (veal calves)
- Large size herd
- Purchase of animals from MRSA-positive farms
Human: Contact to farms with pigs or veal calves
LA-MRSA in animals:
• Colonization – not infection
LA-MRSA in humans: • Temporary colonization • Human-human transfer is rare • Low morbidity and mortality – but can cause serious infections
Kan MRSA være fødevarebåren ?
Det skyldes oftest kontakt med grise. 77% af grisene var positive ved slagter i 2012. De fleste MRSA fødevarebåren infektioner er fra importeret kød.
Forklar ESBL.
Transport ?
Indicator ?
ESBL-producing Enterobacteriaceae.
An enzyme, which can hydrolize all β-lactams except
carbapenems (+ inactivated by clavulanic acid)
Often plasmid-borne, so spreads easily between bacteria
primarily E. coli and Klebsiella spp but also in Salmonella and other species
ESBL-producing bacteria are often resistant to other antibiotic classes (on same plasmid)
Indicator: resistance to 3. generation cephalosporins, e.g.
cefpodoxime and cefotaxime
ESBL – how to combat the problem
Rational use of antibiotics (especially cephalosporins,
fluoroquinolones and amoxi/clav)
Hvor er ESBL problem størst
Poultry
Campylobacter
Hvad er de oftest resistente overfor ?
Agens og hvilken rammer oftest human ?
Macrolide- and
fluoroquinolone-resistant
Often a commensal in animals – but pathogenic in
humans
C. jejuni
• 90-95% af Campylobacter incidents in humans
• Widespread in many animals species, in particular
poultry
C. coli
• 5% of human Campylobacter cases
• Animals: primarily in pigs
Hvad er størst problem, campylobactor eller salmonella ?
Campylobactor
Treatment of Campylobacter infections
1,2 alternative choice
- Usually no treatment (self-limiting disease)
- Serious disease
- First choice: erythromycin (macrolide)
- Second choice: ciprofloxacin (fluoroquinolone)
- Alternatives: tetracyclines/gentamicin
Forklar antibiotika resistens i Campylobactor
Fluoroquinolone (FQ) resistance:
Point mutations important for DNA-replication → Target modification: FQ cannot bind and replication continues
Macrolide resistance
Point mutations, which are important for protein synthesis
→ Target modification: macrolides cannot bind and
protein synthesis continues
DEN ER MEST RESISTENT FOR FQ (EX ciprofloxacin) END MAKROLIDER (EX Erythromycin)
Forklar salmonella.
Agens ? Og i hvilken forbindelse får man hvilken agens ?
Gram-negative rod belonging to the Enterobacteriaceae
Salmonella enterica
- Humans
- Oral transfer, primarily through food
- S. Enteritidis: Egg, poultry meat
- S. Typhimurium: pork, poultry, beef
Hvad er Salmonella Typhimurium resistent overfor ?
ACSSuT
- Ampicillin
- Chloramfenikol
- Streptomycin
- Sulphonamide
- Tetracycline
Third-generation cephalosporins and fluoroquinolones are amongst last choice antibiotics for life-threatening
Salmonella infections in humans.
Take home message fra denne forelæsning
• Increasing occurrence of important resistant bacteria i
Danish production animals and meat:
• LA-MRSA
• Fluoroquinolone-resistant Campylobacter
• Multi-resistant Salmonella with the ASSuT phenotype
• ESBL E. coli in some animals
Hvordan nedsætter man ESBL E-coli hos svin som har virket ?
reduced after cephalosporin ban
Hvordan har man nedsat resistens med makrolide Campylobactor
after banning tylosin as growth promoter
