Antibiotic-resistance <it>Staphylococcus aureus</it> isolated from cow’s milk in the Hawassa area, South Ethiopia

• Main Authors: Daka Deresse, G/silassie Solomon, Yihdego Dawit
• Format: Article
• Language: English
• Published: BMC 2012-09-01
• Series: Annals of Clinical Microbiology and Antimicrobials
• Subjects: Antibiotics; S. aureus; Milk
• Online Access: http://www.ann-clinmicrob.com/content/11/1/26

<p>Abstract</p> <p>Background</p> <p>Quarter milk samples from cows were examined to determine the prevalence of <it>Staphylococcus aureus</it> (SA) and different antibiotic resistant pattern were determined in a cross-sectional study design.</p> <p>Objective</p> <p>The objective of this study was to isolate <it>Staphylococcus aureus</it> from samples of cow’s milk obtained from Hawassa area and to determine their antibiotic susceptibility patterns.</p> <p>Method</p> <p>A total of 160 milk (CCP1-CCP5) samples were collected and screened for the presence of <it>S. aureus</it>. Gram staining, oxidase, catalase, DNase, haemolysis and coagulase tests were employed for bacterial identification.</p> <p>Results</p> <p>All the samples were contaminated with <it>S. aureus</it>. A total of 78 <it>S. aureus</it> isolates were obtained during this study. The levels of contamination with <it>S. aureus</it> 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 <it>S. aureus</it> 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.</p> <p>Conclusion</p> <p>The proportion of isolates resistant to CIP, TMP-SMZ, CRO, AC, E and V were low compared to AP, PG and Ox. <it>S. aureus</it> is normally resident in humans; therefore, the <it>S. aureus</it> 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.</p>