Journal of The Academy of Clinical Microbiologists

: 2019  |  Volume : 21  |  Issue : 2  |  Page : 70--73

Bacteriological profile and antimicrobial susceptibility pattern of non-lactational breast abscess

Bimoch Projna Paty, Sasmita Hotta, Abhishek Padhi, Sanghamitra Padhi, Banojini Parida 
 Department of Microbiology, MKCG Medical College, Berhampur, Odisha, India

Correspondence Address:
Dr. Sasmita Hotta
Department of Microbiology, MKCG Medical College, Berhampur, Odisha


BACKGROUND: Breast abscess is a common condition among OPD female patients. It has been reported that 4.6 % and 11% of the women in developed and developing countries are affected by breast abscess. AIMS AND OBJECTIVES: To detect the pathogens causing non lactational breast abscess and to determine their antibiotic sensitivity pattern. MATERIALS AND METHODS: 50 pus samples with diagnosis of non lactational breast abscess were obtained by incision and drainage or by aspiration. Specimens were processed for Gram stain and cultured in both aerobic and anaerobic media. For aerobic blood agar (BA) and Mac-Conkey agar were inoculated. For anaerobic isolation Brucella blood agar (BBA) with 5% sheep blood agar, hemin and vit-k were inoculated and Metronidazole disc was placed in primary streaking line. Plates were incubated in Mark-II Anaerobic system. Isolates were identified by Gram stain, biochemical tests and sensitivities to identification discs like Vancomycin, Kanamycin, Colistin and SPS. Sensitivity patterns of the aerobic isolates were determined by Kirby-Bauer disc diffusion method. RESULTS: Maximum no of cases belongs to age group of 36-45 years (42%). Out of the 50 pus samples 36(72%) were found to be culture positive from which 42 number of bacteria were isolated. Aerobes and facultative anaerobes predominated 30(71%) over the anaerobes 12 (29%). Staphylococcus aureus 11(36%) was found to be the predominant organism. Clostridium perfringens 6(50%) was the commonest anaerobe isolated. Gram positive isolates were sensitive to Clindamycin, Linezolid and Vancomycin and gram negative bacteria were sensitive to Imipenem and Piperacillin-Tazobactam. Percentage of MRSA was 43% .Amongst the gram negative bacteria ESBL production was seen in 55% of isolates. CONCLUSION: Breast abscess is a fairly common surgical problem among both lactational and non-lactational females. Besides aerobes non-lactating breast abscesses also showed the presence of anaerobic bacteria. As minimally invasive management of breast abscesses, such as ultrasound guided drainage with systemic antibiotic drug therapy is the treatment of choice it is essential to provide the appropriate empirical antibiotic therapy in this drug resistance era.

How to cite this article:
Paty BP, Hotta S, Padhi A, Padhi S, Parida B. Bacteriological profile and antimicrobial susceptibility pattern of non-lactational breast abscess.J Acad Clin Microbiol 2019;21:70-73

How to cite this URL:
Paty BP, Hotta S, Padhi A, Padhi S, Parida B. Bacteriological profile and antimicrobial susceptibility pattern of non-lactational breast abscess. J Acad Clin Microbiol [serial online] 2019 [cited 2020 Jul 10 ];21:70-73
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Breast abscess is a potential buildup of pus in the breast caused by an infection. It mainly affects women who are breastfeeding, less commonly non-lactating women in the reproductive age group and very rarely menopausal women. In lactational breast abscess, bacteria from the baby's mouth enter and cause infection. Non-lactational abscesses are predominantly seen in the age group of perimenopausal women.[1] These can be divided into central or peripheral lesions. Central or periareolar abscess is due to the inflammation of non-dilated subareolar ducts. Peripheral abscesses are seen to be associated with conditions such as diabetes, treatment with steroids, trauma and granulomatous lobular mastitis.[2],[3],[4] These non-lactational abscesses sometimes also coexist with malignancy.[5] Usually, organisms present in the milk sinuses are trapped inside and proliferate causing abscess formation.[6]

S. aureus is the most common causative organism in lactational breast abscess.[7] In non-lactational infection other than the common agents, rare causes such as Actinomycetes, Nocardia asteroides and Paragonimus are seen.[8],[9],[10] Mycobacterium tuberculosis is a cause of non-lactational breast abscess in developing countries which commonly occur unilaterally and can be diagnosed by histopathology.[11]

The combination of drainage of the abscess along with antimicrobial therapy basing on the isolated organism and its sensitivity pattern is the mainstay of treatment.

Hence, the present study was conducted on fifty female patients with a provisional diagnosis of non-lactational breast abscess.

Aim of the study

The study aimed to detect the various pathogens causing non-lactational breast abscess and to determine their antibiotic sensitivity pattern.

 Materials and Methods

The present study was conducted from December 2015 to October 2017 on fifty patients visiting the General Surgery Outpatient Department (OPD) of MKCG Medical College and hospital, Berhampur, Odisha, India, having provisional diagnosis of non-lactational breast abscess. Of them, 34 (68%) patients were homemakers and 16 (32%) patients were working women. Patients having any benign and malignant disease of the breast were excluded from the study. Patient's demographic details, brief clinical history, predisposing factors, history of economic status and menopausal status and investigation reports (if any) were obtained.

Pus samples were obtained using the sterile technique from the abscess in the operation theatre either by needle aspiration or by incision and drainage. Samples were immediately transported to the department of microbiology in sterile labelled containers. To maximise the yield of anaerobic bacteria, the aspirated pus was transported in Robertson cooked meat broth or in air-free capped syringes. Gram-stain preparations were made of all specimens. For aerobic culture, samples were inoculated onto blood agar, chocolate agar and MacConkey agar plates and incubated. Isolated colonies were identified using standard methods.[12] Antimicrobial susceptibility test was performed for all the aerobic isolates with positive cultures according to the Kirby Bauer's disc-diffusion method. For Methicillin-resistant S. aureus (MRSA), a zone diameter of ≤21 mm was taken as a marker for Methicillin resistance using a Cefoxitin (30 μg) disc. For phenotypic confirmation of extended-spectrum beta-lactamases (ESBL) production by Gram-negative isolates, antibiotic discs such as Ceftazidime (30 μg), Ceftazidime/Clavulanic acid (30/10 μg), Cefotaxime (30 μg) and Cefotaxime/Clavulanic acid (30/10 μg) discs were used. If the inhibition zone around the cephalosporin disc is extended on the side nearest the clavulanic acid discs, then the presence of ESBL is confirmed.[13] For anaerobic culture, aspirated sample transported in Robertson cooked meat broth was inoculated onto the pre-reduced freshly prepared Brucella Blood Agar (BBA) medium with 5% sheep blood supplemented with Vitamin K and hemin, and a Metronidazole disc (5U) was placed in primary streaking line and incubated in a Mark II Hi Gas Pak jar of 3.5 L. The colonies that showed a definite zone of inhibition to metronidazole were presumptively identified as anaerobes. All colony morphotypes from the non-selective anaerobic BBA were characterised by colony morphology, pigmentation, haemolysis and Gram-stain. Colonies were subcultured onto chocolate agar and BBA for aerotolerance test.

The confirmed obligatory anaerobes were subjected to further identification by Gram-stain of each morphotype and by placing specific differential discs such as Colistin (CL) (10 μg), Vancomycin (5 μg) and Kanamycin (1 mg) for Gram-negative isolates, and sodium polyanethol sulphonate (5%) disc was placed near the CL disk for rapid presumptive identification of Peptostreptococcus anaerobius if Gram-positive cocci are seen. For definitive identification, biochemical reactions such as catalase (15% Hydrogen Peroxide) were done.[14]


A total of fifty patients with non-lactational breast abscess were included in the study. The maximum number of cases belong to the age group of 36–45 years (42%), 26% belong to the age group 46–55 years and 12% were in the age group of 26–35 years. Non-lactating breast abscess was more commonly observed in homemakers (68%) than in working women (32%). Of the 50 pus samples, 36 (72%) were found to be culture positive from which 42 no. of bacteria were isolated. Of all the culture-positive samples, 31 (86%) showed monomicrobial growth and 5 (14%) showed polymicrobial growth. Aerobes and facultative anaerobes predominated 30 (71%) over the anaerobes 12 (29%). Of all the samples that showed mixed growth (5), majority (4) showed the growth of one aerobe and one anerobe. S. aureus 11 (36%) was found to be the predominant organism followed by Pseudomonas aeruginosa 6 (20%), Escherichia coli, Enterococcus, Klebsiella spp and Streptococcus pyogenes among aerobic isolates. Among the anaerobes, Clostridium perfringens 6 (50%) was the most common organism followed by Bacteroides fragilis 3 (25%), P. anaerobius and Prevotella melaninogenic [Table 1].{Table 1}

All the Gram-positive isolates were found to be sensitive to Clindamycin, Linezolid and Vancomycin. Maximum resistance was seen to the drugs such as Tetracyclin (53%) and Levofloxacin (61%). Gram-negative bacteria were found to be sensitive to Imipenem and Piperacillin-Tazobactam. The percentage of MRSA is 43%. Among the Gram-negative bacteria, ESBL production was observed in 55% of isolates [Table 2].{Table 2}


Acute bacterial mastitis may lead to pyogenic abscess formation or may resolve with antibiotics. It is a common condition reported in female patients attending surgical OPD. This can be supported by the fact that 4.6% and 11% of the women in developed and developing countries are affected by breast abscess. The gold standard for the treatment is surgical drainage and antibiotic therapy.[15],[16]

Sonographically guided aspiration of pus along with antibiotic therapy is a new method which can prevent scar formation and also increase the cure rate.[17],[18]

In our study, the maximum number of patients belong to the age group of 35–45 (42%) years followed by 46–55 (26%) years, i.e., women in perimenopausal age group. This coincides with the findings of other studies.[19] Diseases were seen to be more common in case of homemakers (68%) than that of working women (32%) in this study. Homemakers from the rural background may be less careful about their own health and less aware about the healthcare availability in their area.[20]

Eighty-six per cent (86%) of our culture-positive samples are monomicrobial, whereas only 14% are polymicrobial, in which the combination of one aerobe and one anaerobe is more (4%). This finding was similar to the study of Sandhu et al.[20] Polymicrobial aerobic–anaerobic infection is due to microbial synergy in which factors such as protection from phagocytosis and intracellular killing, essential growth factor production and lowering of oxidation-reduction potential in host tissue play key role.[21],[22],[23]

Aerobic isolates 30 (71%) predominated in our study over the anaerobes 12 (29%). In other studies, anaerobes were isolated in higher percentage (44%).[24] S. aureus was the predominant organism (26%) from all 42 isolates. Similar finding as S. aureus as the most common aerobic isolate was observed by Sandhu et al. In our study, C. perfringens was the predominant anaerobic organism (50%) of all anaerobic isolates followed by Bacteroides fragillis (25%), whereas in other studies, Bacteroidesand Peptostreptococcus were the predominant organisms.[20],[24]

Although surgical removal of pus is a must for an abscess, antimicrobial therapy is helpful to control the infection. In our study, ESBL production was seen in 55% of Gram-negative isolates. Hence, in such organisms, antibiotics that are resistant to degradation by beta-lactamases are necessary. Most of the Gram-positive isolates, Percentage of MRSA was, were found to be sensitive to oral drugs such as Clindamycin and Linezolid, so the treatment is easier.


Hence, to conclude, breast abscess is a fairly common surgical problem among both lactational and non-lactational females. Non-lactating breast abscesses besides aerobes also showed the presence of anaerobic bacteria. With minimally invasive management of breast abscesses, such as ultrasound-guided drainage plus systemic antibiotic drug therapy, understanding the current bacteriological profile of these abscesses is essential to determine the correct choice of empirical antibiotic therapy in this drug resistance era.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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