Antimicrobial Resistance Pattern of Salmonella enterica Serotypes Typhi and Paratyphi in blood samples received from Laboratories across Pakistan from January –December 2021

Results:The AMR genes found among the GBS strains were: tet (tetO n = 61, 39%; tetM n = 37, 24%), erm (ermB n = 41, 26%; ermA n = 20, 13%), ant(6)-Ia (n = 18, 11%) and lnuC (n = 1, 1%).Nineteen (12%) GBS strains were multidrug resistant.SAU strains harbored the following AMR genes: norA (n = 86, 64%), tet (tet38 n = 85, 63%; tetK n = 19, 14%; tetL n = 2, 1%), blaZ (n = 79, 59%), fosB1 (n = 44, 32%), ermC (n = 4, 3%), msrA (n = 2, 1%) and mecA (n = 1, <1%).mecA encodes an alternative penicillin-binding protein (PBP2a) that confers high-level resistance to methicillin (methicillin-resistant S. aureus, MRSA).Among all SAU strains, 71% (n = 96) were multidrug resistant.Over the years, AMR rates increased in SAU and GBS strains.Conclusion: Most GBS and S. aureus strains are resistant to antibiotics commonly used for treatment (human and veterinary medicine) and growth promotion in Brazil, highlighting the detection of MRSA and clindamycin-resistant GBS strains which are recognized as global public health threats.Thus, long-term surveillance of drug-resistant GBS and SAU strains is needed to guide local farmers and policymakers on CBM control practices, including antibiotic choice.