Three-year cumulative antibiogram of breast-associated secretion and drainage specimens in female patients in Syria (2022-2024): microbiologic spectrum, antimicrobial susceptibility, and annual MSSA trends.

backgroundBreast discharge and breast abscesses are common clinical presentations with heterogeneous etiologies. When infection is suspected, culture with antimicrobial susceptibility testing (AST) is essential to guide targeted therapy, particularly in settings where antimicrobial resistance and antibiotic misuse may influence empirical choices. We aimed to characterize the microbiologic spectrum and cumulative susceptibility patterns of breast-associated secretion and drainage specimens submitted for culture in a private central microbiology laboratory in Damascus, Syria, and to assess annual MSSA susceptibility trends.

methodsWe performed a retrospective, laboratory-based analysis of breast-associated secretion and drainage specimens from female patients processed between 1 January 2022 and 31 December 2024. To minimize duplicate-sampling bias, only the first culture per patient per calendar year was included, and annual cohorts represented unique patients. Organisms were categorized as Gram-positive or Gram-negative. Susceptibility was summarized as S/I/R with explicit reporting of numbers tested per antibiotic. An annual MSSA trend analysis across 2022–2024 was conducted for selected clinically relevant agents using Pearson’s chi-square test.

resultsWe included 122 cultures (2022: 42; 2023: 35; 2024: 45; mean age 37.4 years). Gram-positive organisms predominated (74.6%). All Staphylococcus aureus isolates were phenotypically methicillin susceptible by direct MIC-based testing, making MSSA the most common isolate (84/122, 68.9%), followed by E. coli (14/122, 11.5%). MSSA showed universal susceptibility to methicillin and vancomycin and high susceptibility to linezolid, with lower susceptibility to fluoroquinolones, TMP-SMX, and fusidic acid. E. coli and pooled Enterobacterales showed highest activity to carbapenems and amikacin, with variable fluoroquinolone activity and low cephalosporin activity. These Gram-negative findings should be interpreted cautiously because of the small organism-specific and pooled denominators. MSSA minocycline susceptibility increased significantly over time (Pearson’s chi-square test, p = 0.006); other agents showed no significant annual change.

conclusionThis three-year cumulative antibiogram provides locally relevant susceptibility data for breast-associated secretion and drainage specimens submitted for culture in Syria, supporting context-specific empiric therapy, culture-guided refinement, early de-escalation, and stewardship, with careful interpretation of low-denominator estimates.