Identification And Clinical Significance Of Corynebacterium From Abscess In Granulomatous Mastitis

BackgroundGranulomatous mastitis(GM)is a rare benign disease that often affects child-bearing age women.The main clinical manifestations [1.2] are painful mass and erythema in the breast,draining sinuses and skin ulceration could be common if it is not precisely treated.The condition could be recurrent or persisted in a long time.So far,the causes for this disease are not very clear.Recently,the incidence of GM has gradually increased,therefore more and more women suffer from it.In recent decades,a growing literature has suggested that corynebacterium infection is closely related to the pathogenesis of GM [3.4].Interestingly,a present study[5] by our department shown corynebacterium was the main bacteria of microbiota in breast pus using examinedusing metagenomic sequencing and a bioinformatic analysis.The finding shed more light on the role of corynebacterium in the development of GM and may facilitate a precise treatment for this disease entity.There is no consensus on the optimal treatment strategy for GM,steroids and sequential surgery is the common recommendation by domestic and foreign experts[6.8].But steroids don't always work well for GM patients with concurrent corynebacterium infection.However,because the rate of bacterial culture by plate with 5% sheep blood agar was very low,the detection of corynebacterium is seldomly performed in clinical treatment.Previous studies has shown that media containing Tween 80 was critical for the culture of corynebacteria[9].Besides,the method of Polymerase chain reaction(PCR)could improve the sensitivity of corynebacterium detection.In this study,we tried to improve detecting rate of corynebacterium by using PCR and remodifying the media supplemented with Tween 80(high lipid)and compared with common culture media,aiming at finding out which method has the highest accuracy as well as the role of antibiotics therapy for patients with corynebacterium infection.Objectives1?To compare the detection rate of corynebacterium by different methods: media containing 5% sleep blood agar,media containing Tween 80 and PCR.2?To investigate the relationship between corynebacterium and pathogenesis of GM,finding out the role of corynebacterium in the development of GM.3?To explore the role of antibiotics therapy for patients with corynebacterium infection and facilitate a precise treatment for this disease entity.Methods1?PCR and remodifying the media supplemented with Tween 80 were used to improve detecting rate of corynebacterium and compared with common culture media.2?According to the detecting result of PCR,patients suffered in different treatment to find out the role of antibiotics therapy for patients with corynebacterium infection.Results1?Study on the Detection Method of corynebacterium in Granulomatous Mastitis:1)24 cases of pus samples were divided into two replicates: the positive rate of media with 5% sheep blood agar and Tween 80 was 16.7%,50.0% respectively.The last one was significantly increased by 33.3%.Difference between the two methods was statistically significant,P = 0.014.2)44 cases of pus samples were divided into two replicates: the positive rate of corynebacterium and C.kroppenstedtii culured by lipid-supplemented media were 36.4%,31.2% respectively.The positive rate of PCR were 50.0% of corynebacterium and 45.5% of C.kroppenstedtii.Difference between the two methods was not statistically significant,P = 0.197.2?The guidance of therapy after detecting corynebacterium in GM:1)86 cases of pus samples were detected by PCR: the positive rate of corynebacterium was 59.3% and the negative was 40.7%.The positive rate of C.kroppenstedtii was 54.7% and the negative was 45.3 %.2)GM patients with abscess should recommend antibiotics therapy,including short-acting levofloxacin and long-term anti-mycobacteria drugs.3)Following-up of 42 patients,the positive result by PCR of corynebacterium was 21 cases and recurrence rate was 23.5%.Differences between the three different treatments were statistically significant,P = 0.036.4)Following-up of 42 patients,the negative result by PCR of corynebacterium was 21 cases and recurrence rate was 16.7%.Differences between the three different treatments were not statistically significant,P = 0.719.ConclusionsLipid-supplemented media and PCR detection method are also reliable and rapid methods for the detection of corynebacterium from abscess in granulomatous mastitis.Antibiotics therapy for patients with corynebacterium infection could improve prognosis.It's meaningful for GM patients with early detection of Corynebacterium infection to clinical guidance for application with lipophilic antibiotics.