Isolation and antimicrobial resistance patterns of Methicillin‐resistant Staphylococcus aureus from raw cow's milk in dairy farms of Wolaita Sodo Town, Southwest, Ethiopia

Abstract Staphylococcus aureus is a pathogenic bacterium‐contaminating milk and milk products causing food poisoning primarily due to its enterotoxins. A cross‐sectional study was conducted from November 2021 to June 2022 in Wolaita Sodo Town, to detect Methicillin‐resistant Staphylococcus aureus (MRSA) in raw cow's milk and assess their resistance levels to different antimicrobials. Purposive sampling was used to select 34 dairy farms. Accordingly, 419 raw milk samples from the farm and collection centers were collected. Isolates of S. aureus showing resistance to Cefoxitin were classified as MRSA. From the total 419 samples, 22.19% (93/419) were contaminated with S. aureus in dairy cows. The prevalence of S. aureus in raw milk, bulk milk from the farm, and bulk tank milk from the collection centers was 16.9%, 2.1%, and 3.1%, respectively. The risk of S. aureus contamination in dairy farm owners and milkers who do not take food safety training was 5.303 times higher than the risk of S. aureus contamination in dairy farm owners and milkers who take food safety training. The risk of S. aureus contamination in dairy farms kept under poor management system was 7.34 times more than that of dairy farms kept under good management. The cefoxitin disk diffusion method was used to detect MRSA, 57.14% being resistant to Cefoxitin in total while approximately 87.5% were sensitive to Sulfamethoxazole‐trimethoprim and Gentamycin, while Erythromycin registered 75%, Ciprofloxacin 62.5%, Chloramphenicol 62.5%, and Tetracycline 25%. This study revealed that MRSA exhibited a notable multidrug resistance pattern, encompassing resistance to multiple drugs, with a prevalence of 75%. Significantly, the hands of milkers and the milking containers emerged as pivotal sources of contamination. This underscores the crucial importance of maintaining stringent hygienic practices during the milking process, with particular emphasis on thorough cleaning and decontamination of utensils.


| Background and justification
In less developed nations, the primary reason for illness and fatalities is attributed to contaminations transmitted through food.These illnesses stem from shifts in dietary habits, large-scale food service operations, inappropriate storage practices, and insufficient adherence to hygiene protocols.Consequently, these factors contribute to 600 million instances of illness and 33 million deaths globally (Mekibib et al., 2010).S. aureus case fatality rates are 0.03% (Mekibib et al., 2010) in poor countries like Ethiopia, where milk production and other dairy products are mostly prepared under unclean situations and the consumption of raw milk and under cooked milk and milk products is common.
Pathogenic microorganisms in milk may be sourced from the cow itself, the human hand, or the environment (Abera et al., 2013).
Milk and its derivatives are prone to microbial contamination due to their nutrient-rich composition, creating an optimal environment for the proliferation of various microorganisms.Contamination can occur through multiple origins, such as Staphylococcus aureus contamination in the mammary gland or inadequate hygienic practices like coughing, sneezing, and insufficient handwashing during the handling of milk, milk storage, and milking processes.In this context, human-related factors play a great role in contamination, as the bacteria; in this case, the bacteria inhabit the nasal passages of humans (Abunna et al., 2016).
Staphylococcus aureus is an adaptable pathogen of animals and humans that causes a wide array of diseases.It occurs in different locations on dairy farms and many studies recommended that the transmission of S. aureus between humans and cows is possible.Mostly transmission occurs at the milking time through contaminated milking machines, clothes, and the hands of milkers or machine operators (Radostis et al., 2007).Dairy farms serve as significant repositories for S. aureus pathogens.This S. aureus can move in the farm via infected and noninfected cows, farm workers, and the environment, and there is a risk that it may sporadically transfer to bulk tank milk, presenting a public health concern for consumers (Haran et al., 2012).S. aureus is a leading pathogen causing many serious diseases in dairy and healthcare surroundings (Mekibib et al., 2010).In the last few decades, Staphylococcal food poisoning has been reported as the third cause of foodborne illnesses in the world (Mekibib et al., 2010).
Additionally, the presence of antibiotic-resistant strains of S. aureus poses a significant challenge for both veterinary and healthcare professionals, and dairy cattle producers, due to its adverse impact on treatment efficacy.This bacterium produces various exoproteins that enhance its capacity to invade the mammary gland, including membrane-damaging hemolysin toxins (alpha, beta, gamma, and delta), and leukocidin.Among these, alpha and beta hemolysins play a crucial role in the development of intramammary contaminations.Staphylococcal protein A, a membrane-bound exoprotein, is particularly notable for its well-known capability to bind to the fragment crystallizable (Fc) region of immunoglobulins found in most mammalian species (Radostis et al., 2007).
Several studies in Ethiopia indicated that S. aureus is associated with approximately 40% of mastitic cases in cows, as reported by many authors (Abera et al., 2013;Dego & Tarake, 2003;Koye et al., 2008;Shibeshi et al., 2002).In a study conducted by Sori et al. (2005), the prevalence of S. aureus causing mastitis was found to be 44%, with Staphylococcus epidermidis accounting for 14.93% of cases.Given the high prevalence of subclinical mastitis in Ethiopia, the potential public health risks of zoonotic pathogens become a significant concern, particularly with the common practice of consuming raw milk from apparently healthy cows (CSA, 2001).
Reports highlight increasing resistance among S. aureus isolates to multiple antibiotics.Despite the availability of various antibiotics, cases of S. aureus mastitis often exhibit poor responsiveness to drug treatments, leading to substantial losses in the global dairy industry (Normanno et al., 2007).The notable capacity of S. aureus to develop drug resistance has resulted in the emergence of Methicillin-resistant S. aureus (MRSA).Traditionally, Penicillin and its derivatives, including Methicillin, were used to treat S. aureus contaminations.However, resistance has arisen due to an alternative Penicillin-binding protein, PBP2a, encoded by the mecA gene located in the Staphylococcal cassette chromosome (SCCmec) mobile genetic element (Vanderhaeghen et al., 2010).
The various groups exhibit differences in their susceptibility to antibiotics, the location and size of the chromosomal cassette (SCCmec), and the presence of the Panton-Valentine leukocidin gene (PVL) (Joshi et al., 2014).The inappropriate use of antimicrobials in dairy farms, whether for therapeutic or for preventive purposes, has the potential to foster resistance mechanisms in S. aureus, hastening the emergence of multidrug resistant strains like MRSA.And, due to lateral gene transfer, the prevalence of antibiotic-resistant genes in the Staphylococcus species is a major problem, as these resistant bacterial strains can be carried from animals to humans (Lubna et al., 2023).Inadequate awareness and unhygienic practices, such as the consumption of raw milk or insufficient use of personal protective equipment (PPE) and handwashing, may elevate the risk of occupational exposure to MRSA.The threat of MRSA associated with dairy farms could extend to public health if these strains gain entry into milk or spread environmentally through contaminated air, water, or manure to populations residing in proximity to dairy farms (Elmonir et al., 2019).While comprehensive studies on antimicrobial resistance (AMR) in Ethiopia are lacking, available reports strongly suggest that it is an emerging issue deserving attention as a public health concern (DACA, 2009;Gebre-Sealsssie, 2007).Although there is limited information on the public health impact of Methicillin-resistant Staphylococcus aureus (MRSA) associated with food-producing animals in Ethiopia, various reports in the veterinary field highlight the common occurrence of S. aureus resistance to antimicrobials in different regions of the country (Abera et al., 2013;Daka et al., 2012;Sori et al., 2011).
Asmelash Tassew et al. (2016) reveal that approximately 47.2% of S. aureus from milk exhibit resistance to Cefoxitin, with 45.3% demonstrating resistance to four antibiotic disks (penicillin G, ampicillin, cefoxitin, and erythromycin).However, there are limited data on the antimicrobial resistance patterns of S. aureus and MRSA in raw milk specifically from Wolaita Sodo Town.Therefore, this study aims to assess the antibiotic response profile of MRSA to understand the extent of resistance in the study area.

| Study area
The study was conducted from November 2021 to June 2022 in and around Wolaita Soddo town, located in Southern Ethiopia.
The Wolaita zone is positioned approximately 329 km south of Addis Ababa, ranging in altitude from 700 to 2950 m above sea level and covering a total land area of 4537.5 square kilometers.
Geographically, it is situated between 6°4′ N to 7°1′ N and 37°4′ E to 38°2′ E. The region experiences a mean annual rainfall between 450 and 1446 mm, with a bimodal distribution featuring a major rainy season from June to September and a shorter rainy season from February to April.The average annual temperatures in the area are recorded as 34.12°C max and 11.4°C min, respectively.The prevalent agricultural system is characterized by mixed croplivestock production.The estimated livestock population in the Wolaita zone includes 886,242 bovines, 117,274 ovines, 99,817 caprines, 41,603 equines, and 442,428 poultry.The zone comprises 12 Woredas (Districts).

| Study population
This study focused on milk samples collected from private, commercial, and governmental dairy farms from Wolaita Sodo Town.
This study had taken up a commitment to scientific inquiry and dedication to the ethical treatment of animals involved in our research endeavors.We prioritized the well-being of animals involved in our research.All measures were taken to ensure that animals are treated with the utmost care, respect, and consideration for their natural behaviors and needs.Housing, handling, and overall conditions were optimized to promote their physical and psychological welfare.

| Study design and sample type
A cross-sectional study was conducted from November 2021 to June 2022 to analyze, identify, and assess the antimicrobial susceptibility patterns of MRSA in dairy milks.The research involved obtaining samples from various sources, including raw milk, farm pooled milk, collection center pooled milk, milkers of dairy cows, and materials utilized in the milking process.Sampling days were randomly selected, and every sampled farm was visited twice during the study period.To facilitate the sampling process, a cooperation letter was dispatched to the authorities at Wolaita Sodo's livestock resource development office in advance, and an animal health technician was designated to assist with the sampling at each dairy farm.

| Sampling technique and sample size determination
The sample size was determined using Thrusfield (2018).Accordingly, a 95% confidence interval, 5% absolute precision, and an expected prevalence of 47%, as previously reported by Mekibib et al. (2010) were used.
Where Z = 1.96,N = sample size, P exp = expected prevalence, and D = absolute precision.Aligned with these specified criteria, an extensive collection effort resulted in the collection of a total of 419 milk samples originating from a network of 34 diverse dairy farms.
This encompassed the gathering of 382 individual raw milk samples, meticulously obtained from distinct cows within various farms, alongside 14 bulk tank milk samples sourced from different dairy establishments.Additionally, 23 pooled milk samples were meticulously acquired from designated collection centers, ensuring a nuanced and representative selection for thorough analysis.

| Sample collection and transportation
Approximately 382 milk samples were taken from lactating dairy cows in adherence to a previous procedure.The collection involved using sterile cotton swabs, screw-capped test tubes, peptone water, and wooden sticks to obtain 10-15 mL of milk from each sample.
A composite sample of pooled milk from the dairy farm was taken postmilking, combining the milk from all cows in a designated container.Similarly, samples from pooled milk at collection centers were gathered after consolidating milk sourced from various locations, with subsequent mixing and careful collection posthomogenization.
The collection times, either early morning or late afternoon, were determined by the convenience of the milkers, collection centers, and farm owners.The coded samples were then taken to the microbiology laboratory at the Wolaita Sodo University Teaching Referral Hospital for processing.
To begin with, 3-5 colonies from a pure culture were transferred into test tubes containing sterile saline, thoroughly mixed, and the suspension's turbidity was adjusted by comparing it with a 0.5 McFarland standard.
Subsequently, a Muller-Hinton agar plate was made ready, and a sterile cotton swab was immersed in the suspension, which was then spread across the surface of the Muller-Hinton agar plate.Antibiotic disks were placed on the agar plate using sterile forceps and pressed gently to ensure complete contact with the agar surface.After 24 h of incubation at 37°C under aerobic conditions, the plates were examined.

| Data management and statistical analysis
The data were encoded and inputted into a Microsoft Excel 2010 spreadsheet, where they underwent a thorough accuracy check.
Following validation, the data were transferred and processed using SPSS version 20 software for analysis.Descriptive analysis was employed to depict the results of the proportion analysis, where the proportion was determined by assessing the number of samples identified as positive for MRSA isolation from coagulase positive staphylococci isolates.

| Prevalence of coagulase positive staphylococci (CPS)
In pursuit of understanding the microbial landscape within dairy pro- A univariate logistic regression analysis was conducted on distinct risk factors using independent samples.The results indicated significant associations (p < .05) between coagulase positive staphylococci contamination risk and various factors, including the dairy farm's management system, the breeds of dairy cattle (Holstein Friesian (HF) cross and Jersey), and the production system, as depicted in the following results (Table 2).

| Risk factor analysis
In this study, various factors were analyzed using multivariable logistic regression to assess their impact on the risk of coagulase positive staphylococci contamination.The factors included sanitation, breed, production system, management system, farm hygiene, farm size, and food safety training.Among these, food safety training, farm size, management, farm hygiene, and production system were found to be statistically significant (p < .05) in their association with the risk of coagulase positive staphylococci contamination.
However, breed and sanitation did not show a statistically significant association with the risk of coagulase positive staphylococci contamination.
Specifically, food safety training had a highly significant impact on the risk of S. aureus contamination in dairy cows, with a p-value of .001.This study indicated a substantial protective effect associ- The management system also had a significant association with the risk of coagulase positive staphylococci contamination in dairy cows, with a p-value of .001.Dairy farms with poor management systems had a 7.34 times higher risk of coagulase positive staphylococci contamination compared to those with good management systems.Similarly, dairy farms with medium management systems had a 5.1 times higher risk of contamination compared to those with good management systems.contamination compared to those under semi-intensive production systems.
Farm hygiene also had a significant impact on the risk of S. aureus contamination, with a p-value of .001.Dairy farms with poor hygiene status had a 2.88 times higher risk of coagulase positive staphylococci contamination compared to those with moderate farm hygiene (Table 3).

| Antimicrobial susceptibility test
An antimicrobial susceptibility test was done on all S. aureus isolates.The results indicated that all MRSA isolates demonstrated resistance to Penicillin (100%).Additionally, S. aureus isolates exhibited a high resistance rate to mostly used antimicrobial drugs in both veterinary and human health.Specifically, S. aureus displayed significant "in vitro resistance" to antibiotics, such as Cefoxin (95%), Tetracycline (95%), Penicillin (100%), and Ciprofloxacin (62.5%).
Table 4 provides details on the number of isolates sensitive to various antibiotics.A majority of MRSA isolates were sensitive to Sulfamethoxazole-trimethoprim (95%) and Gentamycin (92.5%), followed by Erythromycin (90%) and Chloramphenicol (92.5%), while Ciprofloxacin exhibited a sensitivity of 62.5%.Notably, Tetracycline demonstrated the lowest sensitivity at 25% (Table 4).Based on this investigation, 75% of Methicillin-resistant Staphylococcus aureus (MRSA) isolates were found to concern the profile of multidrug resistance (MDR).This finding underscores the complex and difficult nature of the antimicrobial challenges posed by a significant majority of the MRSA strains examined in the study (Table 5).

| Questionnaire survey
In this study, 50 participants took part.Among them, 56% and 52% of individuals responsible for milking were engaged in udder washing and drying activities before milking, respectively.Notably, 96% did not employ separate drying towels for the udder.Conversely, 80% did not adhere to the practice of washing their hands between milking sessions, although 98% consistently washed their hands before milking.It is noteworthy that all individuals involved in milking followed the practice of cleaning milking equipment with detergents before the milking process.

| DISCUSS ION
In this investigation, 22.19% (93 out of 419) of the coagulase positive staphylococci were identified from a total of 419 samples collected from both small-and large-scale dairy farms in Wolaita Sodo Town.
In this investigation, 57.5% (23 out of 40) of the isolates were identified as MRSA from various origins.These findings agree with those of Elemo et al. (2017) The high prevalence of MRSA in dairy cattle could be attributed to the extensive use of antibiotics for managing bacterial contaminations, such as bovine mastitis.Indiscriminate antibiotic use may contribute to the existence of multidrug-resistant bacterial strains and an increased likelihood of drug residues in milk (Aklilu & Chia, 2020).The substantial presence of these bacteria in milk and its products may be linked to inadequate hygienic practices, including unclean hands of milkers and unhygienic milking equipment and environments.Milk collected directly from farms or markets is susceptible to contamination under unsanitary conditions.
In a more recent study from Malaysia by Aklilu and Chia (2020), 38% of the 44 S. aureus isolates were confirmed as MRSA using the cefoxitin disk diffusion test and mecA detection.This prevalence is lower than that observed in the present study.The variance in prevalence outlined by these authors may be attributed to the use of the PCR (polymerase chain reaction) method for MRSA detection, which has higher sensitivity and specificity, resulting in a lower detection rate of S. aureus compared to the culture method (Khakpoor et al., 2011).
Regarding the proportion of S. aureus, our study found rates of 16.9%, 2.1%, and 3.1% in raw milk, pooled from the farm, and pooled milk from the collection center, respectively.These results are consistent with the findings of Regasa et al. (2019) and Mekuria et al. (2013) in the Oromia region.However, they differ from the findings in South-West Uganda, Iran, and Annand, Gujarat, where varied rates were reported for raw milk, pooled from the farm, and pooled milk from the collection center.
Examining the prevalence of MRSA in milk can be used as a valuable tool for evaluating both the hygienic condition in dairy herds and the potential risks to human health exposed to antibiotic-resistant strains.Detecting antimicrobial-resistant bacteria in raw milk is crucial for public health due to the potential spread of these bacteria through the dairy food chain.While MRSA is relatively uncommon in food, dairy milk could be a pos- Contrary to the findings of Regasa et al. (2019), breed and sanitation were not statistically significantly associated with the risk of S. aureus contamination, aligning with the reports of Mekuria et al. (2013).Food safety training emerged as highly significant for the risk of S. aureus contamination in dairy cows (p = .001).The risk of S. aureus contamination in dairy farm owners and milkers was 5.303 times higher than that of those who did not undergo food safety training.
The management system also showed a significant association with the risk of S. aureus contamination in dairy cows (p = .001).Dairy farms under poor management had a 7.34 times higher risk compared to those under good management, while those under medium management had a 5.1 times higher risk.The prevalence of S. aureus in poorly managed dairy farms was 48.7%, lower than that reported by Seyoum et al. (2018) but higher than the 10.5% reported by Mekuria et al. (2013).This could be attributed to inadequate practices such as unsanitary conditions and the use of a single towel for teat cleaning, providing opportunities for udder and milk contamination.
The study found a significant association between the production system and S. aureus contamination risk in dairy cows (p = .032).
Dairy cows under less intensive, extensive production systems had only 3.2% of the risk compared to those under semi-intensive production systems.This finding aligns with the findings of Abunna et al. (2016), suggesting that the prevalence of S. aureus contamination is linked to overcrowding in semi-intensive systems, increasing the contact rate between dairy cows and the potential for disease transmission.
Focusing on this specific topic may offer insights into improving management strategies for dairy cow production systems to reduce the risk of S. aureus contamination.This could lead to cost savings by decreasing the occurrence of contaminations and, consequently, lowering associated treatment expenses.Understanding the specific link between the production system and S. aureus prevention may empower employers to make informed decisions that benefit both the economy and the ethical treatment of animals, providing them with the best possible environment based on their needs.
The level of farm hygiene was found to be significantly linked to the risk of S. aureus contamination in dairy cows (p = .001).Dairy farms with poor hygiene were 2.88 times more likely to be at risk of S. aureus contamination compared to those with moderate hygiene.This observation aligns with the findings of Megersa (2015), who noted a high association between poor hygiene and S. aureus In the current study, it was observed that 98% of workers did not wash their hands before milking.This contrasts with the findings of Elmonir et al. (2019), where approximately 47.8% of workers did not wash their hands, and also differs significantly from the situation reported in Ethiopia by Ayele et al. (2017), where all workers (100%) were reported to wash their hands.The lack of handwashing among workers, coupled with other unhygienic practices such as raw milk consumption and the absence of personal protective equipment (PPE) use, may pose a zoonotic threat to occupational health on dairy farms (Asiimwe et al., 2017).
Additionally, the study suggests that the workers' lack of awareness and willingness to work while ill could contribute significantly to the dissemination of S. aureus contamination in the examined farms (Elmonir et al., 2019).
Examining specific practices, the study found that 56% of milking personnel practiced udder washing before milking.This contrasts with the findings of Regasa et al. (2019), where 76.5% practiced udder washing and only 8% of respondents in this study practiced udder washing.Moreover, 96% of individuals did not use separate drying towels for the udder, aligning with the findings of Abate et al. (2015), who reported that all interviewees did not use separate towels for drying the udder after washing.However, a unanimous 100% reported the practice of washing milking equipment and storage containers with detergents before milking, in contrast to Regasa et al. (2019), where 58.8% practiced this pre-milking hygiene measure.

| CON CLUS ION AND RECOMMENDATIONS
This 2. Improving personal and environmental hygiene, including milking utensils, may reduce the prevalence of S. aureus in milk.
3. Gentamycin and Sulfamethoxazole-trimethoprim should be considered the drugs of choice for treatment against S. aureus contaminations.

2. 6
| Questionnaire survey Information on potential sources of coagulase positive staphylococci (CPS) contamination in milk was gathered through personal observation and a structured questionnaire.The study examined various factors contributing to contamination, including the cleanliness of the utensils and milking conditions, the health status and cleanness of milking cows' udders, the cleanliness of milk handlers, and the hygiene of milking utensils.Special attention was given to the practices and utensils used for milking.Additionally, the overall hygiene of the housing facilities was evaluated.Face-to-face interviews were conducted with one representative milker from each of the 34 dairy farms to complete the questionnaire.2.7 | Laboratory examination2.7.1 | Culturing and biochemical testsA loopful of milk was streaked onto 5% sheep blood agar loops and incubated at 37°C for 24 h.Colonies were characterized based on Gram staining, cellular morphology, and hemolytic patterns.Selected colonies were cultured on mannitol salt agar, followed by subculturing on nutrient broth and agar plates at 37°C for 24-48 h to obtain pure cultures.Pure isolates were preserved at 4°C for subsequent biochemical tests based onQuinn et al. (2002) protocols.Identification of coagulase positive staphylococci involved catalase and tube coagulase tests.Colonies exhibiting hemolysis-positive, Gram-positive, catalase-positive, and coagulase-positive traits were recognized as coagulase positive staphylococci.
ated with food safety training among dairy farm owners and milkers.Those who took food safety training were identified to be at a remarkable 5.303 times lower risk of Staphylococcus aureus (S. aureus) contamination compared to their counterparts who did not receive such training.This compelling finding prompts a deeper exploration into the potential mechanisms underlying the observed difference.Those individuals with food safety training could exhibit enhanced awareness and adherence to hygienic practices, thereby reducing the likelihood of coagulase positive staphylococci contamination.The training might empower dairy farm owners and milkers to implement more effective preventive measures, such as stringent sanitation protocols and proper handling procedures.
and Joshi et al. (2014), who reported 24.1% of coagulase positive staphylococci in Shashemene, Ethiopia, and 23% of S. aureus in Pokhara, Nepal, respectively.However, they differ from the results ofRiva et al. (2015), who observed 9.1% of coagulase positive staphylococci from bovine raw milk in Italy.Furthermore, they surpass the findings ofSuleiman et al. (2012) in Nigeria and MekonnenHailemariam et al. (2005) in Ethiopia, both of whom isolated 8% of coagulase positive staphylococci from bovine raw milk.The difference in the prevalence of coagulase positive staphylococci across different studies may be attributed to variations in environmental conditions, management systems, sample sizes, and hygienic practices employed in farms and milk collection centers.Additionally, differences in animal production systems among countries could contribute to these variations.It is worth noting that coagulase positive staphylococci are likely communicable pathogens that can be transmitted among cows or from individual to individual through contact with animals during unclean milking activities, as contamination in dairy cows.The potential cause of this correlation may be attributed to the critical role of personal hygiene among milkers and the sanitation of milking equipment, serving as crucial avenues for the transmission of S. aureus between cows and from barns to milk, as highlighted byLee et al. (2012).Similarly,Elmonir et al. (2019) in Egypt detected MRSA isolates in cows, workers, and milking equipment on dairy farms, with the initial contamination occurring on the milker's hand due to inadequate hand washing, followed by subsequent contaminations from the milking bucket at the farm level.
investigation unveiled the presence of Methicillin-resistant Staphylococcus aureus (MRSA) in dairy farms found in Wolaita Sodo Town.The identification of MRSA in milk poses an elevated risk to consumers in Wolaita Sodo Town, as it may exacerbate antimicrobial resistance across various bacterial strains.Notably, all MRSA isolates demonstrated resistance to Penicillin, with Gentamycin and Sulfamethoxazole-trimethoprim emerging as recommended drugs for addressing MRSA contaminations.Of concern, a staggering 75% of the MRSA isolates exhibited multidrug resistance to three or more classes of antibiotics, highlighting the widespread distribution of multidrug-resistant MRSA strains originating from raw cow's milk.Therefore, based on the above conclusions, the following points are forwarded:-1.Experts should regularly follow the development of drug resistance.
(CLSI, 2018)cation of isolates as susceptible, intermediate, or resistant for each antibiotic followed the guidelines of the Clinical Laboratory Standards Institute (CLSI).This classification was determined by measuring the zone of inhibition around the antibiotic disk, and the diameter of this zone was measured in millimeters using a ruler(CLSI, 2018), by the manufacturer's duction, the study investigation aimed to analyze 419 milk samples collected from 34 diverse dairy farms.With a focus on assessing the prevalence of S. aureus, our study set out to explore potential contamination in various types of milk, including raw milk, pooled milk from the farm, and bulk tank milk from collection centers.Out of the Prevalence of coagulase positive staphylococci. in different milk samples.Association of potential risk factors with S. aureus contamination.
The production system was significantly associated with the risk of coagulase positive staphylococci contamination in dairy cows, with a p-value of .032.Dairy cows kept under extensive production systems had a 3.2% lower risk of coagulase positive staphylococci TA B L E 1 Association coagulase positive staphylococci.contamination with potential risk factors.Antibiotic susceptibility pattern of MRSA isolates (n = 40).
TA B L E 3 TA B L E 4 Daka et al.'s (2012)ilar prevalence of 58.1% in and around Asella, Ethiopia.Additionally, it is consistent withDaka et al.'s (2012)discovery of 60.3% MRSA among S. au- Hygienic practices by milking personnel.