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ANALESRANFwww.analesranf.comOn the other hand we could observe amarked MLS (macrolides, lincosamides andstreptogramins) type resistance. Threemechanisms are mainly responsible foracquiring resistance to MLS antibiotics instaphylococci: (1) target site modifications bymethylation or mutation; (2) active efflux ofantibiotics; or (3) inactivation of antibiotics.The first mechanism includes target sitemodifications by a methylase encoded by oneor more of the erm genes, methylating 23SrRNA and thereby altering binding sites for MLSantibiotics (23). In S. aureus is due to theaction of efflux pumps, encoded by the mrsAand mrsB genes responsible for pumpingmacrolide and streptogramin B antibiotics outof the bacteria (MSB resistance phenotype)(24), MLSB phenotype can be expressed intoforms of constitutive (cMLSB) or inducible(iMLSB) (25).In a study conducted by Ortiz andcollaborators in 2020 in a hospital in Mexico,they found 100% MLS-type resistance in S.aureus isolates (26).In our previous study, strains of S. aureuswith an MLS-type resistance of 44% and highresistance to fluoroquinolones wereidentified, this in a tertiary hospital withhospital conversion during the covid 19pandemic, in 2020.The isolated strains havethe classification of MDR and XDR according tothe resistance patterns shown (27).In the statistical an%u00e1lisis the results showedthat there is no significant correlationbetween oxacillin resistance and glycemiccontrol (Rho = -0.043, p = 0.736),erythromycin resistance (Rho = 0.102, p =0.421), HBP (Rho = -0.096 , p = 0.445) norgender (Rho = 0.171, p = 0.172).These findings suggest that oxacillinresistance is not influenced by glycemiccontrol, erythromycin resistance, HTN orgender in the sample studied. The lack ofsignificant correlation could be due to themultifactorial nature of antibiotic resistance,indicating the need to consider other clinicaland microbiological factors in future studies.agents was a protective factor againstStaphylococcus colonization in the nasalpassages, but it is not described whether thesame occurred in diabetic foot lesions (9).However, in our study, glycemic control byboth oral hypoglycemic agents and insulindoes not show a correlation that indicatesprotection against methicillin-resistantStaphylococcus, which is sensitive tomethicillin.In a further study carried out by 250samples, 48 strains of S. aureus were isolated.Of which 22 presented resistance tomethicillin with 45.83%, a percentage similarto that obtained in our study and whichsuggests the specific prevalence of resistanceto methicillin in patients with diabetic foot(19). An important difference is that 100% ofthe isolates of both coagulase-positive andnegative Staphylococcus showed 100%sensitivity to linezolid, a second-line drugwhen vancomycin also loses effectiveness. Inour study, although it is a very lowpercentage, 1.5% already exists. methicillinresistant strains with resistance also tolinezolid.In a study in Mexico in 2015 conducted byEstrella and collaborators, in the search forMRSA and its prevalence, in a sample of 100patients diagnosed with diabetes mellitus,they found a 42% prevalence of S. aureus andof this the 34% showed resistance tomethicillin (20). Mario Sanchez in 2017demonstrated the prevalence of MRSA inpatients with diabetic foot infection with atotal S. aureus isolate of 67 strains, of which55% showed resistance to methicillin (21).Another study conducted in Latin Americaby Gabriela Carro in 2020 showed a prevalenceof S. aureus of 19% of the total isolates, ofwhich 53.8% showed resistance tomethicillin,(22) results very similar to thosewe obtained in our study. The difference isthat the methicillin resistance that we presentis only from one region of the State of Mexicoin Mexico.Identification of Staphylococcus aureus andprevalence of Staphylococcus aureusresistant to methicillinJorge Almeida et al.495 An. R. Acad. Farm.Vol. 90. n%u00ba 4 (2024) %u00b7 pp. 489-498