Abstract. Putra GDS, Khairullah AR, Effendi MH, Lazuardi M, Kurniawan SC, Afnani DA, Silaen OSM, Waruwu YKK, Millannia SK, Widodo A, Ramadhani S, Farizqi MTI, Riwu KHP. 2023. Detection of multidrug-resistant (MDR) Staphylococcus aureus isolated from dairies milk in Medowo Village of Kediri District, Indonesia. Biodiversitas 24: 423-430. Bacterial resistance has emerged as a major concern in dairy farms in Indonesia due to the pervasive usage of antibiotics. Furthermore, no specific research has been done to explain the prevalence of Staphylococcus aureus in isolated milk from dairy cows in Kediri, particularly in Medowo Village, and their antibiotic resistance. Moreover, to control the emergence of diseases in humans brought on by dairy cow's milk or infections transmitted through milk, additional research on the prevalence and resistance of bacteria in dairy farms in the Kediri district is urgently required. In Medowo, the Village Kandangan of District, Kediri Regency, Indonesia, 100 dairy cow's milk samples were taken from farms in numerous hamlets. The Kirby-Bauer method performed an antibiotic sensitivity test using disk diffusion. The sensitivity test was attached with antibiotic discs on tetracycline, penicillin, gentamicin, erythromycin, and cefoxitin. According to sample evaluation results, S. aureus was detected in 94 (94%) of the 100 isolated milk samples based on morphological culture features, Gram staining, and biochemical assays. According to the profile of antibiotic resistance derived from the findings of the S. aureus antibiotic resistance test, 23 isolates (24.47%) were proven to be multidrug-resistant (MDR) because they were resistant to three to four classes of antibiotics. The use of antibiotics typically rises in response to an increase in the prevalence of disease in cattle, which could lead to higher levels of antibiotic residue in milk and possibly higher levels of bacterial resistance to antibiotics. Therefore, dairy farming requires methods for prudently and correctly employing antibiotics.

Abstract. Khairullah AR, Kurniawan SC, Sudjarwo SA, Effendi MH, Afnani DA, Silaen OSM, Putra GDS, Riwu KHP, Widodo A, Ramandinianto SC. 2023. Detection of multidrug-resistant  Staphylococcus aureus and coagulase-negative staphylococci in cow milk and hands of farmers in East Java, Indonesia. Biodiversitas 24: 658-664. Cow milk is a nutrient-dense food containing various nutrients, i.e., carbohydrates, fat, and protein. However, it can potentially spread several pathogenic bacteria, such as staphylococci. Staphylococci cause public health problems. Staphylococcal strains were divided into two groups based on coagulase characteristics, namely coagulase-positive and coagulase-negative staphylococci (CoNS). Coagulase-positive was represented by Staphylococcus aureus. S. aureus and CoNS can become resistant to several antibiotics, known as multidrug resistance (MDR) bacteria. S. aureus and CoNS bacteria are known as causal agents in human infections. This study aims to identify the presence of multidrug resistance S. aureus and CoNS bacteria in several dairy farms in East Java, Indonesia. We collected 332 milk and 125 swab samples from the hand of farmers from several dairy farms in Probolinggo, Tulungagung, and Blitar of East Java, Indonesia. The collected S. aureus and CoNS were tested for antibiotic susceptibility using the disc diffusion method. The antibiotic used were cefoxitin, erythromycin, gentamicin, tetracycline, and oxacillin. The results of isolation and identification based on morphological and biochemical characteristics showed that out of 457 samples, 291 samples (63.68%) were positive for S. aureus, and 166 samples (36.32%) were positive for CoNs. There were 15 S. aureus isolates (5.15%) and 7 CoNS isolates (4.22%) confirmed as MDR; therefore, it is confirmed that S. aureus and CoNS resistance to various drugs was very high in the province of East Java. Intensive livestock systems, high livestock densities, and excessive use of antibiotics in modern dairy systems may predispose the developing growth of MDR S. aureus and CoNS infections. In conclusion, the results of this study indicate the presence of very high multidrug resistant S. aureus and CoNS in the East Java provinces. MDR bacteria can be prevented from spreading by improving biosecurity, hygiene in the milking process, and regular health care for animals and dairy workers.