Methicillin-resistant Staphylococcus aureus (MRSA) on Belgian pig farms

Transcription

1 Methicillinresistant Staphylococcus aureus (MRSA) on Belgian pig farms Dewaele I., De Man I., Stael A., Delputte P., Butaye P., Vlaemynck G., Herman L., Heyndrickx M., Rasschaert G. 1

2 ILVO: Institute for Agricultural and Fisheries Research, Unit Technology and Food KATHO: Catholic University College SouthWest Flanders, Department HIVB CODA: Veterinary and Agrochemical Research Centre 2

3 1. Introduction: MRSA 3 types MRSA: 1. Hospitalacquired MRSA (HAMRSA) Hospitals and nursing homes Multiresistant 2. Communityacquired MRSA (CAMRSA) Unrelated to HAMRSA Not resistant to many different antibiotics PVL toxin 3

4 3. Pig related or animalrelated MRSA The Netherlands (Voss et al., 2005; de Neeling et al., 2007) Belgium (MedVetTask Force, 2007) 44% of the pigs were MRSA carriers 68% of all pig farms were MRSA positive 50% of all MRSA positive farms at least one human carrier 4

5 2. Aim of the study 1) MRSA carriage of the pigs : age related? 2) MRSA contamination of the pen environment? 3) best sampling site to determine the MRSA carriage of the pigs? 4) antibiotic resistance profile? 5

6 3. Materials and Methods I. Sampling 3 Belgian pig farms (1 open en 2 closed) sampled twice sampling: 7 pigs from each age group nares skin rectum perineum environment floor wall ventillation drinking nipples air Pig farmer and family nose swab 6

7 II. Isolation Swabs: Enrichment BHI + 7,5% NaCl ; 22h 37 C Selective chromogenic agar ChromID MRSA (BioMérieux) ; 24h 37 C Based on colony morphology Air samples: Selective chromogenic agar ORSAB (Oxoid) ; 24h 37 C Based on colony morphology 7

8 III. Identification MRSA Multiplex PCR: 3 genes meca methicillin resistance, PBP2a nuc Staphylococcus aureus specific, thermonuclease 16S rdna genus specific, control 16S rdna meca nuc 750 bp 533 bp 279 bp Strandén et al. (2003), Maes et al. (2002) 8

9 IV. Antimicrobial resistance profile Antibiogram according CLSI (disk diffusion) Neosensitabs (Rosco) ; 24h at 30 C gentamicin tobramycin kanamycin erythromycin tylosin ciprofloxacin tetracycline sulphonamid rifampicin mupirocin linezolid fucidin trimethoprim chloramphenicol lincomycin quinupristin/dalfopristin 9

10 4. Results 1) MRSA carriage of the pigs : age related? 2) MRSA contamination of the pen environment? 10

11 AGES (weeks) 14 w 48 w 812 w 1216 w 1620 w 2328 w sows FARM 1 pigs 79 % 87 % 97 % stable 67 % 78 % 67 % % air 75 % 25 % 5 FARM 2 Pig farmer and his wife: MRSA + pigs 5 59 % stable air 5 5 FARM 3 pigs 36 % 71 % 36 % stable 67 % 67 % air N.D. N.D. N.D. N.D. N.D. N.D. N.D. 11

12 3) best sampling site to determine the MRSA carriage of the pigs? nares perineum skin rectum nares + perineum nares + skin nares + rectum skin + perineum skin + rectum perineum + rectum total sensitivity % CI (lower upper level)

13 4) antibiotic resistance profile? Antibiotic resistance % Farm 1 Farm 2 gentamicin kanamycin tobramycin tetracycline erythromycin tylosin ciprofloxacin sulfonamide trimethoprim chloramphenicol fucidin lincomycin linezolid mupirocin rifampicine quinupristin/dalfopristin

14 5. Conclusions 1. Pig farms in Belgium: a reservoir of MRSA 2. Pigs are colonized already at young age 3. Younger animals are more frequently colonized with MRSA than older animals 4. The air and dust in the stables can play an important role in the spread of MRSA to the environment 5. MRSA positive pigs carry MRSA mainly in the nares 6. Antibiotic resistance profile differs a lot between two farms 14

15 6. Future research Antimicrobial resistance profile of third farm Molecular typing of the strains AB profile linking to AB use New project Other farms age of colonization younger animals more frequently colonized? 15

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