Aerobic Bacteria in Infected Breast of Turkish Woman: Prevalence and Antimicrobial Resistance Evaluated in Cases with Lactational Mastitis, Periductal Mastititis and Granulomatous Mastitis

Background: Mastitis is a disease causing serious psychological and physical difficulties in women. We report the aerobic bacteria isolated from infected breasts of 44 women diagnosed with lactational mastitis (LM), 10 with periductal mastitis (PM) and 46 diagnosed with granulomatous mastitis (GM). Methods & Materials: Between November2015-June 2015, pus specimens of 100 women diagnosed with mastitis were Gram stained and aerobic cultures were performed. The isolated bacteria were identified by standart microbiological methods and by Phoenix microbiology analyzer (BD Phoenix™). From 1 LM patient and 19 GM patient's pus samples which showed bacteria on their Gram-stained smears but had sterile cultures, bacterial DNA was isolated. After extraction, the DNA was purified and PCR amplification procedures were performed. 1446–1515nt amplicons were sequenced using the BigDye Terminator v3.1 kit (Applied Biosystems, USA). DNA sequences were examined and edited using MEGA software. Antimicrobial sensitivities of bacteria isolated from cultures were determined by the disc diffusion method. The results were evaluated according to EUCAST 2015 documents. Results: Aerobic bacteria were isolated from 31(70,4%) LM, 6(60%) PM and 19(41,3%) GM patient's samples, S.aureus was found as the most prevalent bacteria (43,1%, 60% respectively) in LM and PM patients. However C.kroppenstedtii was found as the most prevalent bacteria (15,2%) in GM patient's samples. Furthermore, 2 S.aureus, 3 S.epidermidis, 1 S.capitis, 1 Streptococcus spp. 1 S.mitis, 1 L.lactis, 1 K.pneumoniae, 3 C.kroppenstedtii, 1 C.pseudotuberculosis, 1 C.urealyticum DNA were determined from 19(28%) GM patient samples. A statistically significant relation was found between Gram positive bacteria and GM (p<0.05). The most effective antibiotics were trimethoprim-sulfamethoxazole, gentamicin, ciprofloxacin, vancomycin, linezolid for Gram(+)diplococci, ceftazidime, amoxicillin/clavulanic acid, imipenem and gentamicin for Gram(-)bacilli and penicillin, gentamicin, vancomycin, linezolid for Gram(+)bacilli. Conclusion: As a result, for the first time, the bacteria that until now appeared only in animal mastitis (S.saprophyticus, S.capitis, L.lactis) were determined on human granulomateous mastitis. We believe that, the addition of antibiotics penetrating strongly to the adipose tissue and effective on the most common isolated bacteria would be beneficial for the treatment of patients with mastitis.