MRSA, which was previously considered as health care associated pathogen is seen highly distributed in the surroundings. Of the total 26,930 samples collected 4219 (15.7%) were S. aureus positive. According to the publications when these S.aureus isolates were tested for Methicillin resistance, 1695(40%) were found to be MRSA. The pooled prevalence of MRSA was 6.45% in the total samples and 41% among the S.aureus isolates. The review also determined that the prevalence of the strain in samples collected from human was 6.5% per total sample size and 38% in S.aureus isolates. The result was less than the report of Eshetie et al (Eshetie et al., 2016) and Sarrafzadeh et al (Sarrafzadeh et al., 2021) who reported the pooled prevalence of MRSA in total sample size collected from human to be 32.5% in Ethiopia and 42% in Iran respectively. Our result is also less than the analysis of Deyno et al (Deyno, Fekadu, et al., 2017) which reported the pooled prevalence of MRSA among S.auresu in Ethiopia as 47%. However, it is coincided with the report of Khanala et al. (Khanal et al., 2021) who reported the pooled prevalence of MRSA among S.aureus as (38.2%). According to the assessment of WHO (Morrison & Zembower, 2020), the resistance rate of S.auresus to methicillin exceeds 50% in the community and hospitals in WHO regions and ranged between. The document of WHO also indicated that the prevalence of MARSA in Ethiopia was reported as 31.6%. A meta-analysis with aim of determining the prevalence of MRSA among the S. areus in Africa reported that the overall pooled prevalence of the strain in Ethiopia was estimated to be 55% (Falagas et al., 2013).
The review found that the health status of the individual was found as factor associate with the prevalence of MRSA that the strain is significantly prevalent in the patients than in apparently health individuals. The pooled prevalence of MRSA in the apparently normal person was estimated to be 15% whereas; it was 38% in isolates from patients. With similar pace, Hassoun et al (Hassoun et al., 2017) determined that the pooled prevalence of MRSA in S.aureus isolated from patients (1.8%),was higher than that of apparently health individuals(0.76%).
In the current review 15% (95%CI:1–38%) of S. aureus isolates from food animals were MRSA. MRSA in food animals isolates was less prevalent than in environmental samples and human. In agreement with the findings of Samutela et al. (Samutela et al., 2021) which reported MRSA pooled prevalence among the S.aureus isolates from African pigs as ranged from 10 to 100%, the current finding lied in the range. However, it is higher than the previous report by Lozano et al. (Lozano et al., 2016) who reported the prevalence of animal associated MRSA among S. aureus in different African countries including Ethiopia as ranged between 0 and 3%. It is expected that the Livestock Associated Methicillin-resistant S. aureus (LA-MRSA) is highly associated with usage of antibiotics in animal feed as growth promoter and as prophylaxis. The clonal complex 398 (LA-MRSA CC 398) has been considered to be zoonotically important because of its capacity to colonize a wide range of hosts and can jump between hosts. These species may act as carriers of MRSA originating from humans (so called “humanosis”). Moreover, bovine and human MRSA strains are indistinguishable by phenotyping and genotyping methods providing evidence for MRSA transmission between human and cattle(Hata et al., 2010). However, in most of the cases the LA-MRSA remained non pathogenic in human and even when occur they cause less sever infections than HA- and CA-MRSA (Crespo-Piazuelo & Lawlor, 2021).
Apart from its ability to resist antibiotics, the concern of S.aureus to be burden in public, and animal health arise from its adaptation to diversity of environmental conditions (Pournajaf et al., 2014). The environmental isolates of S.aureus were found highly resistant to Methicillin than human and food animals isolates that about 54% (95%CI: 34–73%) of the isolates were MRSA. The isolates were recovered from samples collected from different materials in and around health settings including floor, stethoscope, surface of drug ruminants, air and west waters from hospitals, and other public services such as buses. This might be from the reason that majority of the samples were collected from health care settings which might have exposed to the drug.
Staphylococcus aureus has long been mentioned as food-born pathogen as enterotoxin producer and is one of the public health problematics worldwide. The extraordinarily use of antibiotics in food animals might result in the spread of the resistant microorganisms in foods(Abebe et al., 2020). The spread of MRSA strains in food, therefore, adds other difficulty in control of the diseases in food industry particularly from the view point of enterotoxogenicity nature of the bacterium. In the current review, the researches collected samples from raw milk and processed milk, meat and cockroach contacting with the food materials. MRSA isolates from food samples (77% (95% CI: 29–100%)) were the most prevalent of all other sample categories. The presence of S. aureus in food materials for human consumption is indicative for the spoilage of the food and the suspicious of food intoxication.
More over 22 of the studies have determined the multidrug resistance ability of MRSA to different antimicrobial agents. Accordingly, the isolates were found highly resistant (more than 80% pooled resistance proportion) to cefuroxime (100%), Tobramycin (100%), Neomycin (99%) and Penicillin (92%), Pipracilin (91%), Erythromycin (88%), Bacitracin(84%) and Amoxacilin-clavulanicacid (80%). According to the review, the drug of relatively better effective against MRSA were Clindamycin, chloramphenicol, Amikacin, vancomycin, Knamycin and Ceftriaxone with resistance rates of 21%, 22%, 27%, 20%, 25% and 30% respectively.
Similarly, the previous systematic reviews conducted by Eshetie et al (Eshetie et al., 2016) and Gebremariam et al. (Gebremariam & Zelelow, 2014) have also documented that MRSA strains were found to be too highly resistant to most of the above mentioned antibiotics. It is obvious that MRSA strains are able to express beta-lactam hydrolyzing enzymes so called betalactamases or capable of modifying penicillin binding proteins (Tenover, 2006) so that MRSA strains are capable of inactivating the beta-lactam agents such as penicillin, ampicillin, cephalosporins, and carbapenems. Even more, MRSA has a tendency to resist non-beta- lectam antibiotics due largely to co-existence of other resistance gene along with mecA or mecC gen. Most importantly, vancomycin is considerably the most effective and considered as the last resort treatment for resistant infections of MRSA. The emergence of vancomycin resistant MRSA has, therefore, disadvantaged the usefulness of this drug (Enright et al., 2002). In this meta-analysis 14.31% (95% CI:4.87–35.29) of MRSA was found vancomycin resistant indicating huge blow, especially for the future.