98 Pakistan Veterinary Journal ISSN: 0253-8318 (PRINT), 2074-7764 (ONLINE) Accessible at: www.pvj.com.pk Prevalence and Antibiotics Resistance of Staphylococcus aureus Isolates Isolated from Raw Milk Obtained from Small-Scale Dairy Farms in Penang, Malaysia Ahamed Kamal Shamila-Syuhada 1 , Gulam Rusul 1, *, Wan Abdullah Wan-Nadiah 2 and Li-Oon Chuah 1 1 Food Technology Division; 2 Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia (USM), 11800 Penang, Malaysia *Corresponding author: gulam@usm.my ARTICLE HISTORY (15-371) ABSTRACT Received: Revised: Accepted: Online available: Aug 15, 2015 October 06, 2015 October 12, 2015 January 11, 2016 The study was carried out to determine the prevalence and antibiotics resistance of S. aureus in raw milk samples obtained from dairy farms in Penang, Malaysia. A total of 60 samples were examined and all the samples examined were positive for S. aureus with counts ranging from 2.88 to 3.41 log cfu/mL. Milk samples obtained from different farms had similar S. aureus counts (P>0.05). All the isolates examined were susceptible to gentamycin, kanamycin, chloramphenicol and ciprofloxacin. S. aureus isolates were resistant to penicillin (23.3%), ampicillin (23.3%), trimethoprim (18.3%), cefoxitin (15.0%), linezolid (11.7%), clindamycin (10.0%), erythromycin (8.3%) and tetracycline (5.0%). 28.3% of the isolates were resistant to at least one antibiotic with MAR index ranging from 0.08 to 0.67. The following genes, blaZ, ermA and tetK were detected in 9, 5 and 1 isolate/s of S. aureus respectively. Presence of high S. aureus counts and antibiotic resistant strains of S. aureus might pose a health hazard if milk is not pasteurized adequately and prolonged storage of milk after milking at ambient temperature might further aggravate the problem. ©2015 PVJ. All rights reserved Key words: Antibiotics susceptibility Raw milk Resistance gene S. aureus To Cite This Article: Shamila-Syuhada AK, Rusul G, Wan-Nadiah WA and Chuah LO, 2016. Prevalence and antibiotics resistance of Staphylococcus aureus isolates isolated from raw milk obtained from small-scale dairy farms in Penang, Malaysia. Pak Vet J, 36(1): 98-102. INTRODUCTION Staphylococcus aureus is a common microorganism found in raw milk and has been associated with food poisoning due to consumption of raw milk and contaminated dairy products Presence of S. aureus in milk can be due to poor hygiene practices of milk handlers because S. aureus is naturally present on the hands, nasal cavity and skin of human (Jorgensen et al., 2005; Popov et al., 2014). Other than milk handlers and farm workers, the cow itself can be a source of S. aureus, especially if it is suffering from clinical or subclinical mastitis or having skin lesions (Lammers et al., 2001; Bradley, 2002). In Malaysia, most dairy farms are small where milking is done by hand and this might increase the risk of direct human contact with the raw milk. When cow is sick, suffering from clinical or subclinical mastitis or having skin lesions such as boils the cow should be isolated to prevent it from infecting other cows in the farm and also to avoid the milk from being mixed together with milk from healthy cows (Bradley, 2002). However, this is not routinely practice in Malaysia, especially on small scale dairy farms, since animal health is not given priority and the cattle are not regularly check by veterinarian. Moreover the dairy farmers are ignorant of good farm practices. Antimicrobial agents are normally administered to livestock animals such as cattle to treat microbial infections (Jamali et al., 2015). Antimicrobial agents such as penicillin, tetracycline, oxacillin, erythromycin, cefazolin, clindamycin and tobramycin are used for treatment of bovine mastitis (Lammers et al., 2001; Goa et al., 2012; Jamali et al., 2014). Prolonged use of antimicrobial agents may lead to the emergence of antimicrobial resistant bacterial strains which is a serious concern not only in animal health but also more importantly to human health. Presence of antimicrobial resistant genes in Staphylococcus species is also of great concern since resistance genes can be transferred between staphylococcal species through lateral transfer and these pathogens harboring resistant genes can be transferred to humans from animals (Walther and Perreten, 2007). In Staphylococcus species, mecA (methacillim), blaZ (penicillin) tetM/tetK (tetracycline), ermA/ermC RESEARCH ARTICLE