Antimicrobial resistance patterns and plasmid profiles of Staphylococcus aureus isolated from milk and meat.
OBJECTIVE
To determine the frequency of resistance of Staphylococcus aureus to various antimicrobial agents, and the relationship between antimicrobial resistance of the isolates and carriage of plasmids.


METHODS
A random sampling of milk and meat samples was carried out.


METHODS
Milk was collected from various dairy co-operative societies in Nairobi and Kiambu districts. Minced meat samples were purchased from various outlets in the city of Nairobi.


METHODS
Ninety six Staphylococcus aureus isolates from milk (seventy five isolates) and minced meat (twenty one isolates) samples.


METHODS
Plasmid profiles and antimicrobial susceptibility tests to ampicillin, lincomycin, penicillin, erythromycin, methicillin, minocycline, cotrimoxazole and chloramphenicol.


RESULTS
Seventy one per cent of the isolates carried between one and six plasmids of molecular sizes ranging from 0.1 to 14.5 kilobases. High frequency of resistance was observed with lincomycin (67.7%), penicillin (66.7%) and cotrimoxazole (51%). A high percentage (76%) of isolates were susceptible to minocycline followed by erythromycin (57.3%). Most (80.2%) of isolates were multiply resistant to between two and six antibiotics.


CONCLUSIONS
Most Staphylococcus aureus isolates were multiply resistant to various antimicrobial agents, but there was no apparent relationship between carriage of plasmids and antimicrobial resistance. Milk and meat may contain resistant Staphylococcus aureus posing a potential risk to consumers.
Ombui
J N
JN
Department of Public Health, Pharmacology and Toxicology, College of Agriculture and Veterinary Services, University of Nairobi, P O Box 29053, Nairobi, Kenya.
Kimotho
A M
AM
Nduhiu
J G
JG
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D024881:Drug Resistance, Bacterial; D007630:Kenya; D008460:Meat / Q000382:microbiology*; D008892:Milk / Q000382:microbiology*; D010957:Plasmids / Q000187:drug effects* / Q000302:isolation & purification*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents