Abstract

Antimicrobial resistance (AMR) is a global threat that seriously affects public health, animal welfare, and the sustainability of food production systems. In the poultry sector, irrational use of antibiotics is a key factor contributing to the emergence of resistance. This study investigated the association between broiler farmers’ knowledge and their antibiotic usage practices with the resistance of Staphylococcus spp. in broiler chickens. The study employed a cross-sectional design and included 20 broiler farms located in Tabanan Regency, Indonesia. Knowledge and practices were assessed using structured questionnaires, while five tracheal swab samples were collected from randomly selected chickens on each farm. These samples were pooled and tested in the laboratory to identify Staphylococcus spp. and determine their susceptibility to amoxicillin, ciprofloxacin, erythromycin, and doxycycline. The antibiotic susceptibility test followed the guidelines of the Clinical and Laboratory Standards Institute (CLSI), and the associations between variables were examined using cubic regression analysis. Based on the scores obtained from the structured questionnaires, the majority of farmers demonstrated a moderate level of knowledge (65%) and a moderate level of antibiotic usage practices (60%). Laboratory testing revealed that Staphylococcus spp. isolates showed the highest resistance to amoxicillin (75%), followed by erythromycin (60%), doxycycline (55%), and ciprofloxacin (30%). The results showed that most farmers had moderate knowledge (65%) and practices (60%), with the highest resistance observed against amoxicillin (75%), followed by erythromycin (60%), doxycycline (55%), and ciprofloxacin (30%). A significant positive correlation was found between farmers’ knowledge scores and their antibiotic usage practice scores (r = 0.683, R² = 0.467), indicating that higher knowledge was associated with better practices; however, practices were not significantly associated with inhibition zone diameters. These findings suggested that low antibiotic literacy may lead to improper use, while bacterial resistance is also influenced by external factors such as environmental contamination, horizontal gene transfer, and centralized medication protocols in contract farming.