Antibiotic-resistance Staphylococcus aureus isolated from cow's milk in the Hawassa area, South Ethiopia.
BACKGROUND
Quarter milk samples from cows were examined to determine the prevalence of Staphylococcus aureus (SA) and different antibiotic resistant pattern were determined in a cross-sectional study design.


OBJECTIVE
The objective of this study was to isolate Staphylococcus aureus from samples of cow's milk obtained from Hawassa area and to determine their antibiotic susceptibility patterns.


METHODS
A total of 160 milk (CCP1-CCP5) samples were collected and screened for the presence of S. aureus. Gram staining, oxidase, catalase, DNase, haemolysis and coagulase tests were employed for bacterial identification.


RESULTS
All the samples were contaminated with S. aureus. A total of 78 S. aureus isolates were obtained during this study. The levels of contamination with S. aureus were higher in milk obtained from CCP1, CCP2, CCP3, CCP4 and CCP5 at Hawassa area farms (18.0%, 25.6%, 27.0%, 21.8% and 7.7%) respectively. A large percentage of the S. aureus isolates (25.6% and 27.0%) were from CCP2 and CCP3. All strains were resistant to Penicillin G (PG) (10 μg), Ampicillin (AP) (10 μg), Amoxicillin-Clavulanic acid (AC) (30 μg), Ciprofloxacin (CIP) (5 μg), Erythromycin (E) (15 μg), Ceftriaxone (CRO) (30 μg), Trimethoprime-Sulfamethoxazole (TMP-SMZ) (25 μg) Oxacillin (Ox) (1 μg) and Vancomycin (V) (30 μg), 67.9%, 70.9%, 30.9%, 0%, 32.1%, 23.1%, 7.7%, 60.3% and 38.5% respectively.


CONCLUSIONS
The proportion of isolates resistant to CIP, TMP-SMZ, CRO, AC, E and V were low compared to AP, PG and Ox. S. aureus is normally resident in humans; therefore, the S. aureus present in the cow's milk may have resulted from transmission between the two species, emphasizing the need to improve sanitary conditions in the milking environment.
Hawassa University College of Medicine and Health sciences, Hawassa, Ethiopia. drsdk200@gmail.com
Deresse
D
Daka
Addis Ababa University College of Medicine, Addis Ababa, Ethiopia. solomongst@yahoo.com
Solomon
S
G/Silassie
Hawassa University College of Medicine and Health sciences, Hawassa, Ethiopia. dawitbgm@gmail.com
Dawit
D
Yihdego
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques; D002417:Cattle; D003430:Cross-Sectional Studies; D018562:Disease Transmission, Infectious; D024881:Drug Resistance, Bacterial; D005002:Ethiopia; D006801:Humans; D008892:Milk / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000635:transmission / Q000662:veterinary; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents