Preliminary comparative genomics analysis among Corynebacterium kroppenstedtii complex necessitates a reassessment of precise species associated with mastitis.

AIMS: This study aimed to characterize the first complete genome of Corynebacterium parakroppenstedtii and clarify the evolutionary relationship in the Corynebacterium kroppenstedtii complex (CKC) by using comparative genomics analysis. METHODS AND RESULTS: The genome of isolate yu01 from a breast specimen was sequenced, and 35 CKC genomes were collected. Analysis of 16S rRNA, rpoB, and fusA suggested ambiguous identification, whereas ANI analysis assigned isolate yu01 as Coryne. parakroppenstedtii. The fourth genospecies "Corynebacterium aliikroppenstedtii" was identified in CKC. Comparative genomics analysis suggested that the genomic arrangement in CKC was highly conserved. A total of 43 potential virulence genes and 79 species-specific genes were detected. Most genome-based phylogenetic analysis were incapable of resolving the interspecific evolutionary relationships among CKCs. A total of 20 core genes were found to be distinguishable in CKC. CONCLUSIONS: This study suggested the limited divergence and unavailability of normal single gene-based identification in CKC and questioned the precise species of strains associated with mastitis, identified as Coryne. kroppenstedtii in previous studies. The 20 genes showed potential to enhance the methods for the identification and epidemiological investigation of CKC.

Predictive Risk Factors for Childbirth-Associated Breast Infections in the United States: A 10-Year Perspective.

Infectious mastitis is a common condition that affects up to 33% of lactating women. Several risk factors have been suggested to be strongly associated with breast abscess, nipple infection, and non-purulent mastitis associated with childbirth. In this retrospective cohort study, we gathered data from the National Inpatient Sample (NIS) between 2005 and 2014 and utilized data stratification and backward linear regression to analyze the predictive factors associated with patients hospitalized with breast infection after childbirth, with special consideration of risk factors affecting hospital length of stay (LOS). In the ten-year period, 4614 women were hospitalized with a primary diagnosis of breast abscess, nipple infection, or non-purulent mastitis associated with childbirth. Mean (SD) age was 26.75 (6) years. The highest frequency distribution of cases was observed in patients aged 22-30 years (49.82%). Mean (SD) LOS was 2.83 (1.95) days. Mean (SD) LOS in patients with procedure was 3.53 (2.47) days, which was significantly longer than that in those with no procedure (2.39 (1.36) days, p < 0.001). Primary diagnosis of breast abscess and occurrence of a hospital procedure were most significantly associated with prolonged LOS. Factors such as age, socioeconomic position, severity of functional loss, as well as comorbidities were also contributing risk factors to the development of breast infection and increased hospital LOS. Further studies should examine these findings, as they relate to breastfeeding practices and concentrate on establishing best practices for risk reduction and prevention of childbirth-associated breast and nipple infections and hospitalizations.

Diabetic Fibrous Mastopathy: Imaging Features With Histopathologic Correlation.

Diabetic fibrous mastopathy (DFM) is a rare benign fibrotic disease of the breast that develops in patients with longstanding and often uncontrolled diabetes mellitus. Clinically, patients may present with an irregular, firm, palpable mass, which may be solitary or multiple, occurring in one or both breasts. Diabetic fibrous mastopathy occurs most often in premenopausal women with heterogeneously or extremely dense breasts; mammography may show focal asymmetry or, less often, a noncalcified mass with indistinct or obscured margins, but there are usually no discrete findings. On US, DFM may have marked hypoechogenicity and posterior shadowing secondary to extensive fibrosis. Diabetic fibrous mastopathy features on contrast-enhanced MRI are also nonspecific, with gradual persistent nonmass enhancement reported. Because the clinical presentation and US features of DFM overlap with those of breast cancer, histopathologic correlation is needed to confirm diagnosis and exclude malignancy. These findings include collagenous stroma often with keloidal features and chronic perilobular and perivascular inflammation. Histopathologic findings of lymphocytic lobulitis and perivascular inflammation are common to other autoimmune conditions.

The Dietary Inflammatory Index Is Associated with Subclinical Mastitis in Lactating European Women.

Subclinical mastitis (SCM) is an inflammatory state of the lactating mammary gland, which is asymptomatic and may have negative consequences for child growth. The objectives of this study were to: (1) test the association between the dietary inflammatory index (DII®) and SCM and (2) assess the differences in nutrient intakes between women without SCM and those with SCM. One hundred and seventy-seven women with available data on human milk (HM) sodium potassium ratio (Na:K) and dietary intake data were included for analysis. Multivariable logistic regression was used to examine the association between nutrient intake and the DII score in relation to SCM. Women without SCM had a lower median DII score (0.60) than women with moderate (1.12) or severe (1.74) SCM (p < 0.01). A one-unit increase in DII was associated with about 41% increased odds of having SCM, adjusting for country and mode of delivery, p = 0.001. Women with SCM had lower mean intakes of several anti-inflammatory nutrients. We show for the first time exploratory evidence that SCM may be associated with a pro-inflammatory diet and women with SCM have lower intakes of several antioxidant and anti-inflammatory nutrients.

Management of Common Complications of Lactation: The Breast Surgeon's Role in Examining the Science and Debunking Old Myths.

Breast surgeons are well poised to promote evidence-based recommendations for lactation-related breast disorders and clarify existing misconceptions in traditional care. Surgeons can resolve lactational fluid collections and avoid milk fistula development during drainage and/or other procedures on the breast. Using principles of surgical wound management, they can provide effective care of nipple trauma. They can distinguish between inflammatory and infectious mastitis and promote delicate tissue handling to prevent breast injury and phlegmon. Finally, breast surgeons can debunk the myth of fungal infections occurring on the highly vascularized nipple and recognize common presentations of conditions such as dermatitis.

Commensal cow Roseburia reduces gut-dysbiosis-induced mastitis through inhibiting bacterial translocation by producing butyrate in mice.

The precise mechanism by which gut dysbiosis contributes to the pathogenesis of extraintestinal diseases and how commensal microbes mediate these processes remain unclear. Here, we show that cows with mastitis had marked gut dysbiosis, characterized by the enrichment of opportunistic pathogenic Escherichia_Shigella and the depletion of commensal Roseburia. Fecal microbiota transplantation from donor cows with mastitis (M-FMT) to recipient mice significantly caused mastitis and changed the gut and mammary microbiota in mice. Notably, M-FMT facilitated the translocation of pathobiont from the gut into the mammary gland, and the depletion of Enterobacteriaceae alleviated M-FMT-induced mastitis in mice. In contrast, commensal Roseburia intestinalis improved M-FMT-induced mastitis and microbial dysbiosis in the gut and mammary gland and limited bacterial translocation by producing butyrate, which was associated with inflammatory signaling inhibition and barrier repair. Our research suggests that commensal Roseburia alleviates gut-dysbiosis-induced mastitis, although further studies in dairy cows and humans are needed.

Negative pressure wound therapy promotes healing and reduced pain in patients with acute suppurative mastitis.

BACKGROUND: The purpose of this study was to compare the outcomes of vacuum sealing drainage (VSD) and conventional incision and drainage (I&D) for treating acute suppurative mastitis. METHODS: Hospital medical records were searched for patients 20-50 years of age who were diagnosed with acute suppurative mastitis from January 2014 to December 2018, and treated with traditional I&D or VSD. Patients were divided into those treated with VSD and I&D, and outcomes including pain, healing time, length of hospital stay, and length of antibiotic course were compared between the groups. Pain was evaluated with a numeric rating scale from 0 (no pain) to 10 (most severe pain). Subgroup analysis of lactating women was also performed. RESULTS: There were 110 women who received traditional I&D, and 105 women that received VSD included. The 2 groups were similar with respect to age (31.1 ± 4.8 vs. 29.9 ± 4.4, p = 0.058), and disease characteristics. The median pain score of women who received VSD (5 [IQR 5-6]) was significantly less than that of women who received I&D (8 [IQR 7-8]) (p < 0.001). The time for healing was significantly less in women who received VSD (40 days [IQR 30-45 days]) compared to I&D (60 days [IQR 45-70 days]) (p < 0.001). The length of hospital say and the length of antibiotic treatment were similar between the 2 groups. Results were similar for lactating women. CONCLUSIONS: VSD is effective for treating acute suppurative mastitis with reduced pain and shortening healing time.

Acute Quadriplegia in a Lactating Woman With Mastitis and Breast Abscess.

BACKGROUND: Puerperal mastitis, as well as breast abscess, are common complications that can arise during the breastfeeding period. Acute-onset quadriplegia has been described as a complication of bacterial or viral infections. Here we report a case of puerperal breast abscess with transient acute-onset staphylococcal mediated quadriplegia. MAIN ISSUE: A 28-year-old lactating Caucasian woman presented at our tertiary perinatal center 31 days postpartum with weakness of all four limbs, the signs and symptoms of mastitis in her left breast and a possible breast abscess with redness, a painful breast lump, and fever. A few hours after admission, the participant developed a proximal quadriplegia. MANAGEMENT: The participant was admitted to the intensive care unit for monitoring. The neurologists treated her as a possible case of Guillain-Barré syndrome and administered intravenous immunoglobulin therapy for 5 days. The breast abscess was diagnosed via ultrasound and treated by regular aspiration of pus and intravenous antibiotic therapy with ampicillin and sulbactam as Staphylococcus aureus was isolated from breast abscess fluid. Fifteen days after the first symptoms the participant recovered completely and could breastfeed her son exclusively, even though she developed a galactocele on the affected side. CONCLUSION: We report a possible association between mastitis and abscess formation, common breastfeeding issues, and transient acute onset staphylococcal mediated quadriplegia. To the best of our knowledge this is the only case in the medical literature. Independent of the systemic complications, antibiotic treatment and regular abscess aspirations have proven to be a key strategy to the resolution of puerperal mastitis and breast abscess.

Bacterial factors of mastitis in lactating women and its effect on the physical properties and chemical composition of breast milk.

Mastitis is a complication seen in some breastfeeding mothers and is the most common inflammatory lesion of the breast in breastfeeding mothers. In this complication, breast milk undergoes chemical and physical changes. It can lead to a drop in breastfeeding, weight loss, and, consequently, stunted growth of infants. Bacteria are the main cause of breast inflammation. Therefore, in this study, bacterial factors of mastitis were evaluated in lactating women. Also, their effects were considered on the physical properties and chemical composition of mothers' breast milk. For this purpose, 210 breastfeeding mothers referred to health centers were randomly selected, and their milk samples were collected. In addition to collecting mothers' demographic information by a questionnaire, the chemical composition (sugar, protein, and fat) and the physical properties (pH, density, and freezing temperature) of milk were measured. Bacterial evaluations were performed on the milk of these mothers by catalase test, coagulase test, and mannitol salt agar. Data were analyzed by SPSS software, Chi-square, Mann-Whitney U test, and T-test. The results showed that 56 mothers had mastitis, and Staphylococcus aureus and coagulase-negative staphylococci were the main bacteria in the milk of these mastitis mothers. These bacteria caused physical and chemical changes in breast milk so that mothers with Staphylococcus aureus mastitis had less sugar in their milk, and mothers with coagulase-negative staphylococci had less protein in their milk. Therefore, Staphylococcus aureus may reduce milk sugar by consuming milk sugar, and coagulase-negative staphylococci may also target milk protein. But to confirm these results, a larger population of mothers with mastitis is needed. Further studies are also needed to prove this result.

Neonatal Mastitis and Concurrent Serious Bacterial Infection.

OBJECTIVES: Describe the clinical presentation, prevalence, and outcomes of concurrent serious bacterial infection (SBI) among infants with mastitis. METHODS: Within the Pediatric Emergency Medicine Collaborative Research Committee, 28 sites reviewed records of infants aged ≤90 days with mastitis who were seen in the emergency department between January 1, 2008, and December 31, 2017. Demographic, clinical, laboratory, treatment, and outcome data were summarized. RESULTS: Among 657 infants (median age 21 days), 641 (98%) were well appearing, 138 (21%) had history of fever at home or in the emergency department, and 63 (10%) had reported fussiness or poor feeding. Blood, urine, and cerebrospinal fluid cultures were collected in 581 (88%), 274 (42%), and 216 (33%) infants, respectively. Pathogens grew in 0.3% (95% confidence interval [CI] 0.04-1.2) of blood, 1.1% (95% CI 0.2-3.2) of urine, and 0.4% (95% CI 0.01-2.5) of cerebrospinal fluid cultures. Cultures from the site of infection were obtained in 335 (51%) infants, with 77% (95% CI 72-81) growing a pathogen, most commonly methicillin-resistant Staphylococcus aureus (54%), followed by methicillin-susceptible S aureus (29%), and unspecified S aureus (8%). A total of 591 (90%) infants were admitted to the hospital, with 22 (3.7%) admitted to an ICU. Overall, 10 (1.5% [95% CI 0.7-2.8]) had sepsis or shock, and 2 (0.3% [95% CI 0.04-1.1]) had severe cellulitis or necrotizing soft tissue infection. None received vasopressors or endotracheal intubation. There were no deaths. CONCLUSIONS: In this multicenter cohort, mild localized disease was typical of neonatal mastitis. SBI and adverse outcomes were rare. Evaluation for SBI is likely unnecessary in most afebrile, well-appearing infants with mastitis.

Influence of Previous COVID-19 and Mastitis Infections on the Secretion of Brain-Derived Neurotrophic Factor and Nerve Growth Factor in Human Milk.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) play a critical role in neurodevelopment, where breast milk is a significant dietary source. The impact of previous COVID-19 infection and mastitis on the concentration of BDNF and NGF in human milk was investigated. METHODS: Concentrations of BDNF and NGF were measured via ELISA in human milk samples collected from 12 mothers with a confirmed COVID-19 PCR, 13 mothers with viral symptoms suggestive of COVID-19, and 22 unexposed mothers (pre-pandemic Ctl-2018). These neurotrophins were also determined in 12 mothers with previous mastitis and 18 mothers without mastitis. RESULTS: The NGF concentration in human milk was lower in the COVID-19 PCR and viral symptoms groups than in the unexposed group, but BDNF did not differ significantly. Within the COVID-19 group, BDNF was higher in mothers who reported headaches or loss of smell/taste when compared with mothers without the respective symptom. BDNF was lower in mothers with mastitis than in mothers without mastitis. CONCLUSIONS: Previous COVID-19 and mastitis infections changed differently the secretion of NGF and BDNF in human milk. Whether the changes in NGF and BDNF levels in milk from mothers with infection influence their infant's development remains to be investigated.

[Breast abscess: epidemiological, diagnostic and therapeutic features in patients hospitalized in the Main Hospital in Dakar]. / Abcès du sein: aspects épidémiologiques, diagnostiques et thérapeutiques à l'Hôpital Principal de Dakar.

Breast abscesses are neoformed collections of purulent matter occupying the mammary gland and the periglandular tissue. They can occur both in lactating or non-lactating women. The purpose of our study was to describe the epidemiological, diagnostic and therapeutic features of breast abscesses in patients hospitalized in the Division of General Surgery at the main hospital in Dakar. We conducted a retrospective, descriptive study involving all patients treated for breast abscess over a 4-year period. We collected data from 41 medical records of female patients. The average age of patients was 31 years. The main risk factor was mastitis during lactation (27%). The average time of progression was 12 days, ranging from 1 to 30 days. Left abscesses were reported in 61% of cases and mostly manifested as an inflammatory swelling (88%). Upper quadrants were mainly involved (43.9%). Breast ultrasound was performed in 51.2% of female patients. Surgical drainage under general anesthesia was performed in all female patients. The mean quantity of pus was 119 cc. Staphylococcus aureuswas the most commonly isolated germ (79.5%). The average length of stay in hospital was 7 days and operative morbidity was 31.7%. Mortality was zero. Prevention of abscesses during lactation is based on improving breastfeeding practices and on early antibiotic treatment in patients with mastitis.

Risk of Breast Cancer in Women with Mastitis: A Retrospective Population-Based Cohort Study.

Background and objectives: Breast cancer is a common cancer in women and has been the fourth leading cause of death in Taiwanese women. Risk factors for breast cancer include family history of breast cancer, genetic factors, and not breastfeeding. Several studies have reported an association between repeated inflammation at a young age, especially among lactating women, and cancer; however, the number of studies about the association of mastitis and breast cancer in nonlactating women is still limited. Therefore, the aim of this study was to determine the relationship between mastitis in women aged ≥40 years and breast cancer. Materials and Methods: This was a retrospective cohort study design. The data source was the Longitudinal Health Insurance Database 2010 (LHID 2010), comprising data collected by Taiwan's National Health Insurance program. Cases of newly diagnosed mastitis in women aged ≥40 years (ICD-9-CM code = 611.0) were selected from the years 2010 to 2012. Women not diagnosed with mastitis were selected as the control group, and their data for the years 2009 to 2013 were obtained through the database. In addition, the non-mastitis group was matched 1:10 by age. Results: A total of 8634 participants were selected from the LHID 2010, which included 734 cases with mastitis and 7900 cases without mastitis. After adjustment for age, hypertension, hyperlipidemia, diabetes, hypothyroidism, and autoimmune diseases, the Cox proportional hazard model showed that patients with mastitis had a higher risk of breast cancer (aHR = 3.71, 95% CI = 1.9-7.02) compared with the non-mastitis group. The Kaplan-Meier curve also showed that women with mastitis had a higher risk of developing breast cancer. Conclusions: This study confirmed that women with mastitis have a higher risk of developing breast cancer. Therefore, women aged ≥40 years could reduce breast cancer risk by taking precautions to prevent mammary gland infection and mastitis.

Tres casos de complicación por inyecciones de silicona líquida en mamas / Three cases of complication for liquid silicone injections in breasts

INTRODUCCIÓN Y OBJETIVO: Desde que se popularizó en 1960 el uso de inyecciones de silicona líquida para aumento mamario, su uso continúa como práctica clandestina a pesar de las complicaciones ampliamente documentadas y de que nunca se aprobó como material de relleno con fines estéticos. Analizamos 3 casos documentados con el fin de compartir el tratamiento quirúrgico usado en nuestro Servicio. MATERIAL Y MÉTODO: Presentamos 3 casos clínicos severos de mastitis por silicona líquida en la Cátedra de Cirugía Plástica, Reparadora y Estética del Hospital de Clínicas en Montevideo, Uruguay. Revisamos las historias clínicas y seguimiento posoperatorio y llevamos a cabo una revisión bibliográfica consultando PubMed y SciELO en enero de 2020. RESULTADOS: El tiempo promedio de aparición de las complicaciones mayores fue de 17 años. Los síntomas comunes incluyeron mastitis de repetición, dolor intenso, nódulos palpables y deformidad en las mamas. En todos los casos se hizo reconstrucción mamaria con material aloplástico; en una paciente se asoció reconstrucción con colgajo tóracodorsal de Holmström. Los resultados estéticos fueron aceptables, con disminución de la deformidad y remisión del dolor. De la búsqueda bibliográfica seleccionamos un total de 24 artículos. CONCLUSIONES: Las complicaciones por inyección de silicona líquida en las mamas frecuentemente aparecen después de años. El tratamiento quirúrgico ideal es la resección de la mayor cantidad posible de tejido infiltrado por la silicona para evitar recidivas. Tanto la reconstrucción mamaria con materiales aloplásticos como con tejidos autólogos son opciones reconstructivas válidas a considerar de acuerdo a cada caso clínico. Finalmente planteamos el algoritmo de tratamiento para estos casos usado en nuestro Servicio

BACKGRAUND AND OBJECTIVE: Since it became popular in 1960, the use of liquid silicone injections for breast augmentation has continued as a clandestine practice, despite widely documented complications and that it was never approved as filler for cosmetic purposes. We report 3 clinical cases in order to share the surgical treatment used in our Service. METHODS: We present 3 severe clinical cases of liquid silicone mastitis in the Chair of Plastic, Reconstructive and Aesthetic Surgery of the Hospital de Clínicas in Montevideo, Uruguay. Reviews of the medical records and controls in polyclinic were performed and a bibliographic review was carried out consulting PubMed and SciELO in January 2020. RESULTS: The average time of onset of complications was 17 years. Common symptoms include recurrent mastitis, severe pain, palpable nodules and breast deformity. In all cases, breast reconstructions were performed with alloplastic materials; in one patient the use of reconstruction with the Holmström thoracodorsal flap technique was associated. Acceptable aesthetic results, decreased deformity and remission of pain were obtained. From the results obtained in the bibliographic search, a total of 24 articles were selected. CONCLUSIONS: Complications from liquid silicone injection into the breast often appear after years. The ideal surgical treatment consists of the resection of the largest number of tissues infiltrated with silicone to avoid recurrences. Both breast reconstruction with alloplastic materials and autologous tissues are valid as reconstructive options that should be considered according to each clinical case

Lactational phlegmon: A distinct clinical entity affecting breastfeeding women within the mastitis-abscess spectrum.

We aimed to describe the presentation and treatment of lactational phlegmon, a unique complication of mastitis in breastfeeding women that may require surgical management. We retrospectively analyzed medical charts of breastfeeding women treated by a single breast surgeon for lactational phlegmon or the related conditions of abscess or uncomplicated mastitis (UM) from July 2016 to October 2018. Demographic variables and treatment details were analyzed using ANOVA and Pearson's Chi-square test. Ten women with lactational phlegmon (19.2%), 15 women with abscess (28.8%), and 27 women with UM (51.9%) were identified. Phlegmon presented as a tender, erythematous, and nonfluctuant mass in a ductal distribution. Ultrasonography demonstrated an ill-defined, complex fluid collection. Epidemiologically, women with phlegmon were similar to patients with abscess and UM. Women with phlegmon reported more intense deep breast massage than patients in the other two groups, but significantly lower rates of breast pump use than women with abscess (30.0% vs 80.0%, P < .05). Relative to women with UM, patients with complicated mastitis (CM, defined as phlegmon or abscess) reported greater utilization of nipple shields (36.0% vs 11.1%, P < .05). Treatment of phlegmon entailed effective milk removal, antibiotics (range 10-30 days), and close follow-up until both clinical and radiographic resolution (range 8 days to >3 months), with biopsy of persistent masses. Antibiotic duration was significantly longer for patients with phlegmon compared to those with UM (mean 15.0 days vs 9.7 days, P < .05). Two phlegmons coalesced into abscesses within 1 week of diagnosis. Lactational phlegmon is a complication of mastitis in breastfeeding women that is distinct from abscess and UM. Optimal treatment consists of an extended course of antibiotics and close follow-up to monitor for coalescence into a drainable fluid collection and/or persistence of mass requiring biopsy.

Risk of breast cancer in women with non-lactational mastitis.

Little is known regarding the association of non-lactational mastitis women with breast cancer risk. This population-based cohort study examined the breast cancer risk in women with non-lactational mastitis. We identified 3,091 women with non-lactational mastitis between 2000 and 2011 using the Taiwan National Health Insurance Research Database. We performed 1:4 propensity score matching by age, socioeconomic status and comorbidities and identified 12,364 women without non-lactational mastitis. The mean age of women with non-lactational mastitis was 37.9 years; these women had a higher breast cancer risk than the comparison group (adjusted hazard ratio = 1.94, 95% confidence interval: 1.30-2.90). The incidence rates of breast cancer in women with non-lactational mastitis and the comparison group were 14.79 and 7.57 per 10,000 person-years, respectively. Furthermore, non-lactational mastitis was a risk factor for breast cancer in women aged <50 years, women with lower socioeconomic status and women with hormonal medication (p < 0.05). Women who had more episodes of non-lactational mastitis had a higher risk of developing a breast cancer. Thus, the risk of breast cancer in women with non-lactational mastitis is significantly higher than those without non-lactational mastitis.

Surgical drainage of lactational breast abscess with ultrasound-guided Encor vacuum-assisted breast biopsy system.

Lactational breast abscess is a serious complication of mastitis and commonly diagnosed in breast-feeding women. The traditional drainage of breast abscess was often performed with incisive technique which may result in prolonged healing time, regular dressings, dressing pain, interfering with breastfeeding and unsatisfactory cosmetic outcome. As minimal invasive alternatives to incisive drainage, needle aspiration or percutaneous catheter placement cannot completely replace incisive drainage for the inability to treat large, multiloculated or chronic abscess. Vacuum-assisted breast biopsy system (VABB) has been successfully applied in the treatment of benign breast diseases with satisfactory cosmetic outcomes. Among VABB devices, EnCor system has some distinctive features that make it an appropriate candidate for the treatment of lactational breast abscesses. In this study, for the first time, we investigated the feasibility, efficacy, and cosmetic results of surgical drainage of lactational breast abscess with US-guided Encor VABB system. Our data suggests this procedure could serve as a promising alternative for women with lactational breast abscess who require incisive intervention with high cure rate, relatively short healing time, low recurrence rate, few complications, satisfactory cosmetics outcome and without interfering with breastfeeding.

Histopathological and microbiological findings in buffalo chronic mastitis: evidence of tertiary lymphoid structures.

Buffalo mastitis is an important economic problem in southern Italy, causing qualitative/quantitative alterations in milk and resulting in economic losses due to the sub-clinical course and chronic evolution. We investigated 50 udders of slaughtered buffaloes and subjected them to effectual microbiological screening to evaluate macro and microscopic mammary gland changes, immune-characterize the cell infiltrates, and compare the degree of tissue inflammation with somatic cell counts. Numerous Gram-positive and Gram-negative bacteria were isolated from all samples, majority of which were environmental mastitis pathogens. Histological features referable to chronic mastitis were observed in 92% udders. Lymphocytes, plasma cells and macrophages were found to evolve into aggregates in 48% udders, which often organized to form tertiary lymphoid structures (TLSs). A predominance of interstitial CD8+ over CD4+ lymphocytes and, in TLSs, scattered CD8+ lymphocytes in the mantle cells and CD79+ lymphocytes in germinal centers, were evidenced. Environmental pathogens are known to persist and cause chronic inflammatory changes in buffaloes, where CD8+ lymphocytes play an important role by controlling the local immune response. Moreover, the TLSs evidenced here for the first time in buffalo mastitis, could play a role in maintaining immune responses against persistent antigens, thereby contributing in determining the chronic course of mastitis.