Slide 1.

 

Antimicrobial Sensitivity Patterns of UK

Chicken E. Coli Isolates.

 

 

David G S Burch

 

Octagon Services Ltd, UK.

 

 

 

Slide 2.

 

Introduction

 

 

Slide 3 & 4.

 

Disease slides – normal and Colisepticaemia – severe systemic/septicaemic disease, following mycoplasmal and viral infections especially TRT in turkeys.

 

Slide 5.

 

Materials

 

Data on E. coli isolates from chickens supplied by two centres:-

 

  1. Veterinary Laboratories Agency, Lasswade, Scotland

286 isolates for 1999

 

  1. VLA, Shrewsbury, England

198 isolates up to October 1999

 

From clinical cases that may have received prior treatment

Sensitivity disc method with 13mm zone of inhibition the break point.

 

 

 

 

 

Slide 6.

 

Antimicrobial sensitivity pattern (%) of UK chicken E. coli isolates

 

Antimicrobial

(Disc Conc. mg)

 Lasswade

(n = 286)

 Shrewsbury

(n =198)

Overall

(n = 484)
Apramycin (15) 98 98 98
Neomycin (10) 79 89 83
Spectinomycin (25) - 88 88
Linco/spectin (150)* 91 - 91
Amoxycillin (2) 15 - 15
Ampicillin (10) - 62 62
Doxycycline (30) 56 - 56
Tetracycline (10) 46 61 52
Trimeth/Sulpha (25) 72 82 76
Enrofloxacin (5) 99 98 99
Difloxacin (10)** 95 - 95

*Lincomycin/spectinomycin – 239 isolates

** Difloxacin – 71 isolates

 

 

Slide 7.

 

Disc strength in comparison with serum levels (mg/ml) in broilers

 

Antimicrobial Disc Strength (mg) Dose (mg/kg) C. max. (mg/ml) Steady State or 12hours (mg/ml)
Apramycin 15 43 - 0.04
Spectinomycin 25 33 0.05 <0.05
Amoxycillin 2 10 160 >15
Doxycycline 30 20 55 7
Chlortetracycline 10 25 0.35 0.14
Chlortetracycline 10 50 0.7 0.1
Trimethoprim / 25 9 0.24 0.11
Sulfadiazine 25 45 14.7 6.8
Enrofloxacin 5 10 1.9 0.52
Difloxacin 10 10 0.7 -
Danofloxacin - 5 0.5 0.12

 

 

 

 

 

 

 

 

 

 

Slide 8.

 

Comparative sensitivity (%) with other avian E. coli studies

 

Country UK UK EU (slaughter) Canada USA (Turkeys)
Year Isolated 1999 1986-91 1995 1993 1995
No. Isolates 484 274 1154 294 1204

Antimicrobial

          
Apramycin 98 - - 97 -
Neomycin 83 84 94 50 13
Spectinomycin 88 - - 38 54
Ampicillin 62 84 66 58 67
Tetracycline 52 48 55 11 -
Trimeth/Sulpha 76 85 64 78 87
Enrofloxacin 99 - 97 99 99

Sources (Wray et al, 1993; Scheer et al, 1997; Laperle et al, 1996; Salmon and Watts, 2000)

 

 

Slide 9.

 

Comparative sensitivity (%) of E. coli and salmonella in the UK

 

Antimicrobial E. coli, 1999 Salmonella, 1998 (n = 1240)*
Apramycin 98 99
Neomycin 83 99
Ampicillin 62 81
Tetracycline 52 78
Trimeth/Sulpha 76 89
Enrofloxacin 99 -
Nalidixic Acid - 92 (S. typhimurium, chick 95; turkey 29.

*Source (VLA, 1999)

 

 

Slide 10.

 

Conclusions

 

  1. There is still a high level of sensitivity to the fluoroquinolones in the UK.
  2. The use of Nalidixic acid should be replaced – confuses issue
  3. Apramycin is consistently active – gut active mainly
  4. There is a need to standardize discs and methods
  5. Amoxycillin at 2mg was too low
  6. RUMA guidelines are having an effect in the UK – plus supermarkets.
  7. Future monitoring / surveillance – salmonella successful – others? E.coli and Campylobacter started in 1999.
  8. Future active monitoring – develop baselines – actions? – Ban, suspend or formularies? Action / control in the ROW?