Bacteriological characteristics of primary breast abscesses in patients from the community in the era of microbial resistance.

Objective: The aim of this study is to evaluate the etiological profile and antimicrobial resistance in breast abscess cultures from patients from the community, treated at a public hospital located in Porto Alegre, Brazil. Methods: This is an retrospective cross-sectional study that evaluated the medical records of patients with bacterial isolates in breast abscess secretion cultures and their antibiograms, from January 2010 to August 2022. Results: Based on 129 positive cultures from women from the community diagnosed with breast abscesses and treated at Fêmina Hospital, 99 (76.7%) of the patients had positive cultures for Staphylococcus sp, 91 (92%) of which were cases of Staphylococcus aureus. Regarding the resistance profile of S. aureus, 32% of the strains were resistant to clindamycin, 26% to oxacillin and 5% to trimethoprim-sulfamethoxazole. The antimicrobials vancomycin, linezolid and tigecycline did not show resistance for S. aureus. Conclusion: Staphylococcus aureus was the most common pathogen found in the breast abscess isolates during the study period. Oxacillin remains a good option for hospitalized patients. The use of sulfamethoxazole plus trimethoprim should be considered as a good option for use at home, due to its low bacterial resistance, effectiveness and low cost.

Breast Tuberculosis in Iran: A Comprehensive Review.

ABSTRACT: Tuberculosis (TB) remains a significant global health concern and kills millions of people every year. While TB can affect any organ in the body, breast TB is relatively uncommon. This study presents a comprehensive review of literature spanning 23 years, with a focus on cases of breast TB in Iran. Among the 96 cases found, the majority (89.6%) fell within the age range of 20-60, with a striking prevalence among women (98.9%). Common symptoms included pain and palpable mass, each presenting in approximately 60.4% of cases. Notably, only a quarter of patients had a confirmed history of exposure to a known TB case. Left breast involvement was more prevalent (58.3%), with ipsilateral lymph node enlargement observed in 40.6% of cases. Given the clinical presentation of breast TB, which often leads to misdiagnosis, a significant proportion of cases (68.7%) were diagnosed through excisional biopsy. Following a standard 6-month regimen of anti-TB drugs, relapse occurred in only 4.2% of cases. This study highlights the need for heightened awareness and vigilance in diagnosing breast TB, especially in regions with a high burden. Although breast TB poses diagnostic challenges, with prompt identification and treatment, the prognosis is generally favorable, with a low incidence of relapse.

LsrR, the effector of AI-2 quorum sensing, is vital for the H2O2 stress response in mammary pathogenic Escherichia coli.

Mammary pathogenic Escherichia coli (MPEC) is an important causative agent of mastitis in dairy cows that results in reduced milk quality and production, and is responsible for severe economic losses in the dairy industry worldwide. Oxidative stress, as an imbalance between reactive oxygen species (ROS) and antioxidants, is a stress factor that is common in most bacterial habitats. The presence of ROS can damage cellular sites, including iron-sulfur clusters, cysteine and methionine protein residues, and DNA, and may cause bacterial cell death. Previous studies have reported that Autoinducer 2 (AI-2) can regulate E. coli antibiotic resistance and pathogenicity by mediating the intracellular receptor protein LsrR. This study explored the regulatory mechanism of LsrR on the H2O2 stress response in MPEC, showing that the transcript levels of lsrR significantly decreased under H2O2 stress conditions. The survival cell count of lsrR mutant XW10/pSTV28 was increased about 3080-fold when compared with that of the wild-type WT/pSTV28 in the presence of H2O2 and overexpression of lsrR (XW10/pUClsrR) resulted in a decrease in bacterial survival rates under these conditions. The ß-galactosidase reporter assays showed that mutation of lsrR led to a remarkable increase in expression of the promoters of ahpCF, katG and oxyR, while lsrR-overexpressing significantly reduced the expression of ahpCF and katG. The electrophoretic mobility shift assays confirmed that LsrR could directly bind to the promoter regions of ahpCF and katG. These results revealed the important role played by LsrR in the oxidative stress response of MPEC.

Mycoplasma bovis subverts autophagy to promote intracellular replication in bovine mammary epithelial cells cultured in vitro.

Mycoplasma species are the smallest prokaryotes capable of self-replication. To investigate Mycoplasma induced autophagy in mammalian cells, Mycoplasma bovis (M. bovis) and bovine mammary epithelial cells (bMEC) were used in an in vitro infection model. Initially, intracellular M. bovis was enclosed within a membrane-like structure in bMEC, as viewed with transmission electron microscopy. In infected bMEC, increased LC3II was verified by Western blotting, RT-PCR and laser confocal microscopy, confirming autophagy at 1, 3 and 6 h post-infection (hpi), with a peak at 6 hpi. However, the M. bovis-induced autophagy flux was subsequently blocked. P62 degradation in infected bMEC was inhibited at 3, 6, 12 and 24 hpi, based on Western blotting and RT-PCR. Beclin1 expression decreased at 12 and 24 hpi. Furthermore, autophagosome maturation was subverted by M. bovis. Autophagosome acidification was inhibited by M. bovis infection, based on detection of mCherry-GFP-LC3 labeled autophagosomes; the decreases in protein levels of Lamp-2a indicate that the lysosomes were impaired by infection. In contrast, activation of autophagy (with rapamycin or HBSS) overcame the M. bovis-induced blockade in phagosome maturation by increasing delivery of M. bovis to the lysosome, with a concurrent decrease in intracellular M. bovis replication. In conclusion, although M. bovis infection induced autophagy in bMEC, the autophagy flux was subsequently impaired by inhibiting autophagosome maturation. Therefore, we conclude that M. bovis subverted autophagy to promote its intracellular replication in bMEC. These findings are the impetus for future studies to further characterize interactions between M. bovis and mammalian host cells.

Associations of fecal microbial profiles with breast cancer and nonmalignant breast disease in the Ghana Breast Health Study.

The gut microbiota may play a role in breast cancer etiology by regulating hormonal, metabolic and immunologic pathways. We investigated associations of fecal bacteria with breast cancer and nonmalignant breast disease in a case-control study conducted in Ghana, a country with rising breast cancer incidence and mortality. To do this, we sequenced the V4 region of the 16S rRNA gene to characterize bacteria in fecal samples collected at the time of breast biopsy (N = 379 breast cancer cases, N = 102 nonmalignant breast disease cases, N = 414 population-based controls). We estimated associations of alpha diversity (observed amplicon sequence variants [ASVs], Shannon index, and Faith's phylogenetic diversity), beta diversity (Bray-Curtis and unweighted/weighted UniFrac distance), and the presence and relative abundance of select taxa with breast cancer and nonmalignant breast disease using multivariable unconditional polytomous logistic regression. All alpha diversity metrics were strongly, inversely associated with odds of breast cancer and for those in the highest relative to lowest tertile of observed ASVs, the odds ratio (95% confidence interval) was 0.21 (0.13-0.36; Ptrend < .001). Alpha diversity associations were similar for nonmalignant breast disease and breast cancer grade/molecular subtype. All beta diversity distance matrices and multiple taxa with possible estrogen-conjugating and immune-related functions were strongly associated with breast cancer (all Ps < .001). There were no statistically significant differences between breast cancer and nonmalignant breast disease cases in any microbiota metric. In conclusion, fecal bacterial characteristics were strongly and similarly associated with breast cancer and nonmalignant breast disease. Our findings provide novel insight into potential microbially-mediated mechanisms of breast disease.

Characterization of Pediatric Breast Abscesses and Optimal Treatment: A Retrospective Analysis.

BACKGROUND: Literature on pediatric breast abscesses is sparse; therefore, treatment is based on adult literature which has shifted from incision and drainage (I&D) to needle aspiration. However, children may require different treatment due to different risk factors and the presence of a developing breast bud. We sought to characterize pediatric breast abscesses and compare outcomes. MATERIALS AND METHODS: A retrospective review of patients presenting with a primary breast abscess from January 2008 to December 2018 was conducted. Primary outcome was persistent disease. Antibiotic utilization, treatment required, and risk factors for abscess and recurrence were also assessed. A follow-up survey regarding scarring, deformity, and further procedures was administered. Fisher's exact and Kruskal-Wallis tests for group comparisons and multivariable regression to determine associations with recurrence were performed. RESULTS: Ninety-six patients were included. The median age was 12.8 y [IQR 4.9, 14.3], 81% were women, and 51% were African-American. Most commonly, patients were treated with antibiotics alone (47%), followed by I&D (27%), and aspiration (26%). Twelve patients (13%) had persistent disease. There was no difference in demographic or clinical characteristics between those with persistent disease and those who responded to initial treatment. The success rates of primary treatment were 80% with antibiotics alone, 90% with aspiration, and 96% with I&D (P = 0.35). The median time to follow-up survey was 6.5 y [IQR 4.4, 8.5]. Four patients who underwent I&D initially reported significant scarring. CONCLUSIONS: Treatment modality was not associated with persistent disease. A trial of antibiotics alone may be considered to minimize the risk of breast bud damage and adverse cosmetic outcomes with invasive intervention.

Bacteriology of pediatric breast abscesses beyond the neonatal period.

BACKGROUND: Limited data exist regarding the presentation and bacteriology of nonneonatal pediatric breast abscess. OBJECTIVE: To determine the bacteriology and characteristic presentation of pediatric breast abscesses in a tertiary care center. METHODS: Cross-sectional study of patients age 1 month to 21 years admitted to a pediatric Emergency Department (ED) between 1996 and 2018 with a breast abscess. Patients with pre-existing conditions were excluded. Records were reviewed to determine demographics, history, physical exam findings, wound culture results, imaging and ED disposition. We used descriptive statistics to describe prevalence of different bacteria. RESULTS: We identified 210 patients who met study criteria. Median age was 13.6 years [IQR 6.6, 17.4], and 91% (191/210) were females. Ninety-two patients (43.8%) were 'pre-treated' with antibiotics prior to ED visit, and 33/210 (16%) were febrile. Ultrasound was obtained in 85 patients (40.5%), 69 patients had a single abscess and 16 had multiple abscesses. Most patients were treated with antibiotics and 100 had a surgical intervention, of these 89 had I&D and 11 a needle aspiration. Admission rate was 45%. Culture results were available for 75 (75%). Thirty-three (44%) had a negative culture, or grew non-aureus staphylococci or other skin flora. Culture were positive for MSSA 21 (28%), MRSA 13 (17%), Proteus mirabilis 2 (2.6%), Serratia 1 (1.3%). Other organisms include Gram-negative bacilli, group A Streptococcus and enterococcus. CONCLUSIONS: Non-neonatal pediatric breast abscess bacteriology is no different than data published on other skin abscesses. MRSA coverage should be considered based on local prevalence in skin infections.

Burkholderia vietnamiensis causing a non-lactational breast abscess in a non-cystic fibrosis patient in Tamil Nadu, India.

Burkholderia cepacia complex is a Gram-negative opportunistic pathogen usually found in people with an immunocompromised condition such as cystic fibrosis (CF). In a tropical country like India, this organism has been associated with a number of hospital-acquired infections including sepsis. We present here a report of a case of Burkholderia vietnamiensis causing a non-lactational breast abscess in a non-CF patient. The pathogen was identified as B. cepacia using Vitek system and matrix-assisted laser desorption ionisation-time of flight. This was confirmed by polymerase chain reaction (PCR) using recA genus-specific gene and sequencing of the PCR amplicons. recA-restriction fragment length polymorphism and recA gene sequencing revealed that the isolate is B. vietnamiensis. This is the first description of B. vietnamiensis isolated from a clinical case from India.

[Primary breast tuberculosis in a man: a case report]. / Tuberculose mammaire primitive chez un sujet de sexe masculin : à propos d'un cas.

The breast tuberculosis accounts for 0.06 to 0.1% of extra-pulmonary localizations. Frequent in women, it remains exceptional in men. We report a rare case of primary breast tuberculosis occurring in a male patient. A 33-years-old patient presented with a chronic and fistulized non-inflammatory-right breast swelling with an atrophic cutaneous ulceration. The thoracic CT was in favor of a right breast abscess with a thick wall. The patient had received non-specific antibiotics (amoxicillin-clavulanate and metronidazole) for 10 days coupled with a surgical drainage before consulting us for persisting symptoms. The culture of the pus was sterile, the GeneXpert and the search for acid-fast bacilli (AFB) both performed on the swab of the ulceration were negative. Histopathological analysis of the lesion was in favor of a granulomatous mastitis. Given the chronic and atrophic nature of the ulceration, the histological aspect of granulomatous mastitis and the persisting symptoms despite the non-specific antibiotic therapy, we made a presumptive diagnostic of breast tuberculosis. The evolution was favorable with oral anti-tuberculosis treatment.

Imaging and clinical features of breast tuberculosis: a review series of 62 cases.

AIM: To outline the disease burden of breast tuberculosis (TB) as a quantitative analysis amongst three tertiary hospitals in South Africa, with correlation to their clinical, demographic, and imaging features. MATERIALS AND METHODS: A retrospective analysis was undertaken over an 18-month period (01/01/2017-30/06/2018) of all patients undergoing laboratory investigations for breast disease at the mammography departments of these three tertiary centres. RESULTS: The prevalence of breast TB was 2.5% (n=62) of 2,516 patients. The median age of presentation was 38.5 years (interquartile range [IQR] 33-45). HIV status was known in 45 patients, of whom 36 were HIV infected (80%, 95% CI: 0.65-0.90, p<0.0001). Based on the ultrasound and/or mammogram findings, the patients were classified into five categories: TB breast abscess (40.3%), inflammatory/disseminated (24.2%), isolated TB lymphadenitis (22.6%), nodular (11.3%), and sclerosing form (1.6%). Histology demonstrated necrotising granulomatous inflammation in 57 cases (92%). Acid-fast bacilli (AFB) were positive in 8.1% (n=5) of the cytology and 16.1% (n=10) of the histology specimens. Culture for Mycobacterium tuberculosis was positive in 27% (17 cases), and in 12.9% (n=8). AFB were detected histologically using polymerase chain reaction (PCR) testing. CONCLUSION: Knowledge of the varied clinical and radiological features is necessary to maintain a high degree of suspicion to prevent misdiagnoses, inappropriate management, and complications. Ultrasound-guided core biopsy rather than fine-needle aspiration (FNA) is advocated as the first-line intervention in diagnosing or excluding this disease, as it yields a better tissue sample and more often a positive diagnosis.

Fecal non-aureus Staphylococci are a potential cause of bovine intramammary infection.

The presence of non-aureus staphylococci (NAS) in bovine rectal feces has recently been described. Similar to other mastitis causing pathogens, shedding of NAS in the environment could result in intramammary infection. The objective of this study was to investigate whether NAS strains present in feces can cause intramammary infection, likely via teat apex colonization. During a cross-sectional study in 5 dairy herds, samples were collected from the habitats quarter milk, teat apices, and rectal feces from 25%, 10%, and 25% of the lactating cows, respectively, with a cow serving as the source of one type of sample only. Samples from clinical mastitis cases were continuously collected during the 1-year study period as well. The 6 most prevalent NAS species, Staphylococcus (S.) chromogenes, S. cohnii, S. devriesei, S. equorum, S. haemolyticus, and S. hominis, were further subtyped by random amplification of polymorphic deoxyribonucleic acid polymerase chain reaction (RAPD-PCR), when the same NAS species was present in the same herd in the three habitats. For S. chromogenes, S. cohnii, S. devriesei, and S. haemolyticus, the same RAPD type was found in rectal feces, teat apices, and quarter milk, indicating that fecal NAS can infect the mammary gland. For S. hominis and S. equorum, we were unable to confirm the presence of the same RAPD types in the three habitats.

Differences in virulence between the two more prevalent Staphylococcus aureus clonal complexes in rabbitries (CC121 and CC96) using an experimental model of mammary gland infection.

Staphylococcal mastitis is a major health problem in humans and livestock that leads to economic loss running in millions. This process is currently one of the main reasons for culling adult rabbit does. Surprisingly, the two most prevalent S. aureus lineages isolated from non-differentiable natural clinical mastitis in rabbits (ST121 and ST96) generate different immune responses. This study aimed to genetically compare both types of strains to search for possible dissimilarities to explain differences in immune response, and to check whether they showed similar virulence in in vitro tests as in experimental intramammary in vivo infection. The main differences were observed in the enterotoxin gene cluster (egc) and the immune-evasion-cluster (IEC) genes. While isolate ST121 harboured all six egc cluster members (seg, sei, selm, seln, selo, selu), isolate ST96 lacked the egc cluster. Strain ST96 carried a phage integrase Sa3 (Sa3int), compatible with a phage integrated into the hlb gene (ß-haemolysin-converting bacteriophages) with IEC type F, while isolate ST121 lacked IEC genes and the hlb gene was intact. Moreover, the in vitro tests confirmed a different virulence capacity between strains as ST121 showed greater cytotoxicity for erythrocytes, polymorphonuclear leukocytes and macrophages than strain ST96. Differences were also found 7 days after experimental intramammary infection with 100 colony-forming units. The animals inoculated with strain ST121 developed more severe gross and histological mastitis, higher counts of macrophages in tissue and of all the cell populations in peripheral blood, and a significantly larger total number of bacteria than those infected by strain ST96.

Tuberculosis of the breast: analysis of 17 cases.

Tuberculosis constitutes a major public health problem in the world. Certain extra-pulmonary locations of tuberculosis disease are very exceptional. Amongst these, tuberculosis of the breast is rare even in countries where this infection is endemic. This form of tuberculosis is characterized by clinical and radiological polymorphisms and might mimic other diseases, especially breast cancer. This retrospective study is entailing seventeen patients treated in the Onco-Gynecology Department of the Mohammed VI Cancer Treatment Center, in the Ibn Rochd University Hospital of Casablanca, for breast tuberculosis, over a period of three years. We report the epidemiological, clinical and paraclinical aspects and we specify the treatment and evolution of the patients.

Primary actinomycosis of the breast in postmenopausal women.

INTRODUCTION: Actinomycosis is a chronic infection caused by actinomyces species characterized by an abscess formation, tissue fibrosis, and draining sinuses. Primary actinomycosis of the breast is rare. PATIENTS AND METHODS: In this paper we present a 64-year-old postmenopausal woman. For the diagnosis of primary actinomycosis of the breast, mammography, ultrasonography, MRI, and histopathologic examinations are required. Microbiological culture and histopathology are of the most importance during the process of diagnosis. In our case, at the intersection of the sternum and the lower inner quadrant of the right breast, there was a 1 cm wide fistula opening, and an abscess. A. israelii has been isolated from the microbiological culture taken from the lesion RESULTS: An optimal surgical resection of infected tissues has been performed as the treatment with the wound left open for tertiary healing The patient was given sulbactam 4*1 gr/day intravenously for 4 weeks post-op.. Recurrence was not detected during the yearly follow up procedures CONCLUSIONS: Actinomycosis should be considered when differentially diagnosing clinical instances of suppurative or granulomatous infections of the breast and mass regions that can't be ruled out as malignancies. Early diagnosis will save the patient from unnecessary surgical operations and ineffective antibiotic treatments. KEY WORDS: Actinomycosis, Breast abscess, Breast diseases.

An uncommon cause for a breast abscess: Actinomyces turicensis with Peptoniphilus harei.

Our case report describes a patient with a common presenting complaint yet an uncommon infection. Our patient presented with a fluctuant breast mass diagnosed as a breast abscess. An aspirate sample was sent for culture and sensitivities, which revealed the presence of Actinomyces turicensis and the anaerobe Peptoniphilus harei She was therefore prescribed several weeks of amoxicillin and metronidazole, and made a full recovery. There are only three case reports describing A. turicensis as a causative organism for breast abscess, one of which had also occurred in our department. One case also showed the additional presence of P. harei Our findings reveal a growing need for increasing clinician awareness of A. turicensis and the importance of aspirate sample culture and sensitivity.

Post-traumatic necrotising fasciitis of the breast: a case study with literature review.

Necrotising fasciitis is a rare infection of the skin and underlying soft tissue. It primarily involves the extremities and rarely the breast. Primary necrotising fasciitis of the breast in a non-lactating, healthy female is rarer still. The authors present the case report of a patient presenting with primary necrotising fasciitis of the breast after sustaining a penetrating injury. The patient was managed successfully with serial debridement and negative pressure wound therapy (NPWT). To our knowledge only 19 such cases have been reported in the indexed literature so far. This is also the eighth case globally of primary necrotising fasciitis of the breast in a non-lactating female without any associated immunosuppression, which is the basis of reporting this case.

The microbiome and breast cancer: a review.

The human microbiome plays an integral role in physiology, with most microbes considered benign or beneficial. However, some microbes are known to be detrimental to human health, including organisms linked to cancers and other diseases characterized by aberrant inflammation. Dysbiosis, a state of microbial imbalance with harmful bacteria species outcompeting benign bacteria, can lead to maladies including cancer. The microbial composition varies across body sites, with the gut, urogenital, and skin microbiomes particularly well characterized. However, the microbiome associated with normal breast tissue and breast diseases is poorly understood. Collectively, studies have shown that breast tissue has a distinct microbiome with particular species enriched in the breast tissue itself, as well as the nipple aspirate and gut bacteria of women with breast cancer. More importantly, the breast and associated microbiomes may modulate therapeutic response and serve as potential biomarkers for diagnosing and staging breast cancer.

Fulminant gas-forming breast abscess associated with synergistic Veillonella infection.

We present a rare case of a rapidly fulminant and destructive breast abscess with gas production by the synergistic infection of Veillonella and Streptococcus species. To our knowledge, this is the first reported case of Veillonella infection in the breast. Early recognition, empiric antibiotic cover, aggressive surgical debridement, and drainage are necessary to avoid systemic septicemia. Staged reconstructive breast surgery allows for correction any resultant breast deformity.

Pilonidal abscess of the breast.

Pilonidal disease is a common condition, typically occurring in the natal cleft of adult males. Other sites of pilonidal sinus are rarely reported. We report a case of periareolar pilonidal abscess in the breast of a 52-year-old woman who presented via the breast clinic complaining of nipple inversion and pain. Clinical examination and imaging revealed an underlying abscess which recurred despite antibiotic therapy and needle aspiration; the patient therefore underwent surgical excision of the abscess cavity. Subsequent histology diagnosed pilonidal abscess, an important differential to consider in the case of breast abscess, particularly in cases that are slow to resolve or recur post-treatment.