title: Corynebacterium species causing breast abscesses among patients attending a tertiary care hospital in Chennai, South India.
abstract: BACKGROUND
  Corynebacterium species other than Corynebacterium diphtheriae were mostly considered contaminants in the past, but there are reports of their association with wide variety of human infections lately. In this study, we look into Corynebacterium species isolated from breast abscess patients and assess their antimicrobial susceptibility pattern and treatment outcomes.
  
  
  METHODS
  Pus samples from suspected breast abscess cases were examined from October 2014 to September 2015. Growth of Gram-positive bacilli morphologically resembling Corynebacterium species were identified by matrix-assisted laser desorption/ionization- time of flight mass spectrometry identifications generated by the Vitek MS system (bioMérieux, France) (MALDI-TOF Vitek MS system) and antimicrobial susceptibility was done.
  
  
  RESULTS
  Corynebacterium species were isolated from 10 female breast abscess patients with median age of 36 years (range 25-59 years). Out of the 10 isolates four isolates were identified as C. kroppenstedtii; one isolate as C. striatum and five isolates were identified as C. amycolatum/C.xerosis. Out of four isolates of C .kroppenstedtii, two isolates were resistant to cotrimoxazole and one C. striatum isolate was resistant to penicillin, ampicillin, cotrimoxazole and clindamycin. Of the five isolates identified as C amycolatum/C xerosis, all were sensitive to vancomycin and linezolid but resistant to clindamycin. All the patients were treated with incision, drainage and antibiotics based on the sensitivity pattern; eight were cured and two patients did not come for follow-up.
  
  
  CONCLUSIONS
  Corynebacterium species should be considered one of the causative agents of breast abscess and a varied susceptibility profile amongst the different species makes susceptibility testing important. Identification by MALDI-TOF Vitek MS system may not differentiate between C. amycolatum and C. xerosis.
authors.affiliation: a Department of Microbiology , Apollo Cancer Institute , Chennai , India.
authors.forename: Indira
authors.initials: I
authors.lastname: Poojary
authors.affiliation: b Department of Histopathology , Apollo Cancer Institute , Chennai , India.
authors.forename: Ann
authors.initials: A
authors.lastname: Kurian
authors.affiliation: a Department of Microbiology , Apollo Cancer Institute , Chennai , India.
authors.forename: Jayalekshmi
authors.initials: J
authors.lastname: V A
authors.affiliation: a Department of Microbiology , Apollo Cancer Institute , Chennai , India.
authors.forename: Debora
authors.initials: D
authors.lastname: Devapriya J
authors.affiliation: a Department of Microbiology , Apollo Cancer Institute , Chennai , India.
authors.forename: Thirunarayan
authors.initials: T
authors.lastname: M A
mesh_terms: D000038:Abscess / Q000188:drug therapy / Q000382:microbiology* / Q000601:surgery; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D001940:Breast / Q000473:pathology; D001941:Breast Diseases / Q000188:drug therapy / Q000382:microbiology* / Q000601:surgery; D003352:Corynebacterium / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*; D003354:Corynebacterium Infections / Q000188:drug therapy / Q000382:microbiology* / Q000601:surgery; D004322:Drainage; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007194:India; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D062606:Tertiary Care Centers; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: Breast abscess; Corynebacterium species; MALDI-TOF Vitek MS system; Pus