Human milk is a source of lactic acid bacteria for the infant gut

OBJECTIVES

To investigate whether human breast milk contains potentially probiotic lactic acid bacteria, and therefore, whether it can be considered a synbiotic food. Study design Lactic acid bacteria were isolated from milk, mammary areola, and breast skin of eight healthy mothers and oral swabs and feces of their respective breast-fed infants. Some isolates (178 from each mother and newborn pair) were randomly selected and submitted to randomly amplified polymorphic DNA (RAPD) polymerase chain reaction analysis, and those that displayed identical RAPD patterns were identified by 16S rDNA sequencing.

RESULTS

Within each mother and newborn pair, some rod-shaped lactic acid bacteria isolated from mammary areola, breast milk, and infant oral swabs and feces displayed identical RAPD profiles. All of them, independently from the mother and child pair, were identified as Lactobacillus gasseri. Similarly, among coccoid lactic acid bacteria from these different sources, some shared an identical RAPD pattern and were identified as Enterococcus faecium. In contrast, none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with lactic acid bacteria of the other sources.

CONCLUSIONS

Breast-feeding can be a significant source of lactic acid bacteria to the infant gut. Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin.

Microbial dysbiosis is associated with human breast cancer

Breast cancer affects one in eight women in their lifetime. Though diet, age and genetic predisposition are established risk factors, the majority of breast cancers have unknown etiology. The human microbiota refers to the collection of microbes inhabiting the human body. Imbalance in microbial communities, or microbial dysbiosis, has been implicated in various human diseases including obesity, diabetes, and colon cancer. Therefore, we investigated the potential role of microbiota in breast cancer by next-generation sequencing using breast tumor tissue and paired normal adjacent tissue from the same patient. In a qualitative survey of the breast microbiota DNA, we found that the bacterium Methylobacterium radiotolerans is relatively enriched in tumor tissue, while the bacterium Sphingomonas yanoikuyae is relatively enriched in paired normal tissue. The relative abundances of these two bacterial species were inversely correlated in paired normal breast tissue but not in tumor tissue, indicating that dysbiosis is associated with breast cancer. Furthermore, the total bacterial DNA load was reduced in tumor versus paired normal and healthy breast tissue as determined by quantitative PCR. Interestingly, bacterial DNA load correlated inversely with advanced disease, a finding that could have broad implications in diagnosis and staging of breast cancer. Lastly, we observed lower basal levels of antibacterial response gene expression in tumor versus healthy breast tissue. Taken together, these data indicate that microbial DNA is present in the breast and that bacteria or their components may influence the local immune microenvironment. Our findings suggest a previously unrecognized link between dysbiosis and breast cancer which has potential diagnostic and therapeutic implications.

Two syngeneic cell lines from human breast tissue: the aneuploid mammary epithelial (Hs578T) and the diploid myoepithelial (Hs578Bst) cell lines

We characterized two human cell lines (Hs578T and Hs578Bst), which provide several unique features that should be useful in the study of breast disease. Hs578T, derived from a carcinosarcoma, is epithelial in origin. Hs578Bst, established from normal tissue peripheral to the tumor, is myoepithelial in origin. This is the first report of companion cell lines, one malignant and one normal, established from the same organ.

Skin bacteria and skin disinfection reconsidered

Large discrepancies in the available data on skin microbiology stimulated investigations of the number, interactions, and location of commensals and the true efficiency of disinfection by using skin biopsy, culture of frozen sections, and other methods.Most current procedures were less than 0.5% as sensitive as the biopsy method described. This gave mean bacterial counts ranging from 4,400/cm(2) on the breast to 400,000/cm(2) in the axillae. An iodine preparation removed 95% of accessible organisms, but about 20% of bacteria were protected by follicles, crevices, and lipids. Commensals in over 20% of people produced antibiotics against a wide range of pathogens. Conversely, "satellitism" was demonstrable in 12% of people.

Human breast microbiome correlates with prognostic features and immunological signatures in breast cancer

BACKGROUND

Currently, over half of breast cancer cases are unrelated to known risk factors, highlighting the importance of discovering other cancer-promoting factors. Since crosstalk between gut microbes and host immunity contributes to many diseases, we hypothesized that similar interactions could occur between the recently described breast microbiome and local immune responses to influence breast cancer pathogenesis.

METHODS

Using 16S rRNA gene sequencing, we characterized the microbiome of human breast tissue in a total of 221 patients with breast cancer, 18 individuals predisposed to breast cancer, and 69 controls. We performed bioinformatic analyses using a DADA2-based pipeline and applied linear models with White's t or Kruskal-Wallis H-tests with Benjamini-Hochberg multiple testing correction to identify taxonomic groups associated with prognostic clinicopathologic features. We then used network analysis based on Spearman coefficients to correlate specific bacterial taxa with immunological data from NanoString gene expression and 65-plex cytokine assays.

RESULTS

Multiple bacterial genera exhibited significant differences in relative abundance when stratifying by breast tissue type (tumor, tumor adjacent normal, high-risk, healthy control), cancer stage, grade, histologic subtype, receptor status, lymphovascular invasion, or node-positive status, even after adjusting for confounding variables. Microbiome-immune networks within the breast tended to be bacteria-centric, with sparse structure in tumors and more interconnected structure in benign tissues. Notably, Anaerococcus, Caulobacter, and Streptococcus, which were major bacterial hubs in benign tissue networks, were absent from cancer-associated tissue networks. In addition, Propionibacterium and Staphylococcus, which were depleted in tumors, showed negative associations with oncogenic immune features; Streptococcus and Propionibacterium also correlated positively with T-cell activation-related genes.

CONCLUSIONS

This study, the largest to date comparing healthy versus cancer-associated breast microbiomes using fresh-frozen surgical specimens and immune correlates, provides insight into microbial profiles that correspond with prognostic clinicopathologic features in breast cancer. It additionally presents evidence for local microbial-immune interplay in breast cancer that merits further investigation and has preventative, diagnostic, and therapeutic potential.

Loss of p53 protein in human papillomavirus type 16 E6-immortalized human mammary epithelial cells

We have shown previously that introduction of the human papillomavirus type 16 (HPV16) or HPV18 genome into human mammary epithelial cells induces their immortalization. These immortalized cells have reduced growth factor requirements. We report here that transfection with a single HPV16 gene E6 is sufficient to immortalize these cells and reduce their growth factor requirements. The RB protein is normal in these cells, but the p53 protein is sharply reduced, as shown by immunoprecipitation with anti-p53 antibody (pAB 421). We infer that the E6 protein reduces the p53 protein perhaps by signalling its destruction by the ubiquitin system. The HPV-transforming gene E7 was unable to immortalize human mammary epithelial cells. Thus, cell-specific factors may determine which viral oncogene plays a major role in oncogenesis.

Genetic dissimilarity of commensal strains of Candida spp. carried in different anatomical locations of the same healthy women

Candida spp. carriage and strain relatedness were assessed in 52 healthy women at 17 anatomical locations by using an isolation procedure which assesses carriage intensity and by using a computer-assisted DNA fingerprinting system which computes genetic similarity between strains on the basis of the patterns of Southern blots probed with the moderately repetitive sequence Ca3. Candida spp. were cultured from 73% of the test individuals, most frequently from the oral (56%), vulvovaginal (40%), and anorectal (24%) regions. Half of the test individuals with Candida spp. carried the organism simultaneously in more than one of the three general areas of carriage. Isolates from different body locations of the same individual were either completely unrelated, identical, or highly similar but nonidentical. In 11 cases in which Candida spp. were simultaneously isolated from the oral cavity and vaginal canal, seven pairs of isolates were genetically unrelated and four pairs were similar but nonidentical. In the latter cases, the isolate pairs each appear to have arisen by genetic divergence from a single progenitor. A comparison of the genetic relatedness of isolates from different individuals further uncovered a single strain which was vaginospecific in the Iowa City, Iowa area and reduced genetic diversity among vulvovaginal strains compared with those isolated from other body locations. These results suggest that strains adapt to different anatomical locations and, conversely, that in a healthy individual there is anatomical selection of vaginotropic, anotropic and orotropic strains of Candida spp.

B cells are essential for murine mammary tumor virus transmission, but not for presentation of endogenous superantigens

Murine mammary tumor viruses (MMTVs) are retroviruses that encode superantigens capable of stimulating T cells via superantigen-reactive T cell receptor V beta chains. MMTVs are transmitted to the suckling offspring through milk. Here we show that B cell-deficient mice foster nursed by virus-secreting mice do not transfer infectious MMTVs to their offspring. No MMTV proviruses could be detected in the spleen and mammary tissue of these mice, and no deletion of MMTV superantigen-reactive T cells occurred. By contrast, T cell deletion and positive selection due to endogenous MMTV superantigens occurred in B cell-deficient mice. We conclude that B cells are essential for the completion of the viral life cycle in vivo, but that endogenous MMTV superantigens can be presented by cell types other than B cells.

The breast: a clean-contaminated surgical site

BACKGROUND

Capsular contracture is one of the most common complications associated with breast implants. While the cause of this process has not yet been elucidated, subclinical infection is a likely culprit.

OBJECTIVES

The authors assess the hypothesis that a probable source of contamination is endogenous breast bacteria, likely originating in the ducts themselves and most concentrated near the nipple.

METHODS

Twenty-five healthy patients presenting for routine reduction mammaplasty were recruited as study participants. Tissue samples were taken intraoperatively from the periareolar, inframammary, and axillary regions of each sampled breast. Specimens were then processed in the microbiology laboratory, and quantitative bacterial counts were obtained.

RESULTS

Of the 50 breasts sampled, 19 yielded positive culture results, for a rate of 38%. There was a significant difference in the positive culture rate among all three sites, with increasing quantitative bacterial counts in the axillary, inframammary, and periareolar regions, respectively. The most commonly-identified organisms in this study included various species of Staphylococcus and Propionibacterium acnes, with S. epidermidis being the most common.

CONCLUSIONS

The breast harbors significant endogenous bacteria that can become the source of spontaneous or postoperative infection. Positive intraoperative cultures with high quantitative counts suggest that breast tissue harbors more bacteria than normal skin flora. Routine perioperative antibiotic prophylaxis may be suboptimal for the prevention of foreign body seeding in this setting. Furthermore, bacterial concentrations are highest in areas with the most ductal tissue, namely the periareolar region. These findings may be helpful when considering which incision site to select for augmentation mammaplasty.

Association of breast and gut microbiota dysbiosis and the risk of breast cancer: a case-control clinical study

BACKGROUND

Breast cancer ranks first in women, and is the second cause of death in this gender. In addition to genetics, the environment contributes to the development of the disease, although the factors involved are not well known. Among the latter is the influence of microorganisms and, therefore, attention is recently being paid to the mammary microbiota. We hypothesize that the risk of breast cancer could be associated with the composition and functionality of the mammary/gut microbiota, and that exposure to environmental contaminants (endocrine disruptors, EDCs) might contribute to alter these microbiota.

METHODS

We describe a case-control clinical study that will be performed in women between 25 and 70 years of age. Cases will be women diagnosed and surgically intervened of breast cancer (stages I and II). Women with antecedents of cancer or advanced tumor stage (metastasis), or who have received antibiotic treatment within a period of 3 months prior to recruitment, or any neoadjuvant therapy, will be excluded. Controls will be women surgically intervened of breast augmentation or reduction. Women with oncological, gynecological or endocrine history, and those who have received antibiotic treatment within a period of 3 months prior to recruitment will also be excluded. Blood, urine, breast tissue and stool samples will be collected. Data regarding anthropometric, sociodemographic, reproductive history, tumor features and dietary habits will be gathered. Metabolomic studies will be carried out in stool and breast tissue samples. Metagenomic studies will also be performed in stool and breast tissue samples to ascertain the viral, fungal, bacterial and archaea populations of the microbiota. Quantitation of estrogens, estrogen metabolites and EDCs in samples of serum, urine and breast tissue will also be performed.

DISCUSSION

This is the first time that the contribution of bacteria, archaea, viruses and fungi together with their alteration by environmental contaminants to the risk of breast cancer will be evaluated in the same study. Results obtained could contribute to elucidate risk factors, improve the prognosis, as well as to propose novel intervention studies in this disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03885648 , 03/25/2019. Retrospectively registered.

Risk of breast implant bacterial contamination from endogenous breast flora, prevention with nipple shields, and implications for biofilm formation

BACKGROUND

Capsular contracture (CC) is a common complication of breast augmentation that is thought to arise from bacterial contamination and subsequent biofilm formation on the implant. Endogenous breast flora expressed through the nipple may contaminate the sterile field during breast augmentation, acting as a possible source for initiation of biofilm formation.

OBJECTIVES

The authors investigate the incidence of nipple bacterial contamination with endogenous breast flora after standard chest wall sterilization during breast augmentation.

METHODS

Bacterial contamination of nipples and nipple shields was assessed in a series of 32 consecutive patients presenting for breast augmentation (63 breasts: 31 bilateral procedures and 1 unilateral procedure). After standard sterilization of the chest wall, occlusive nipple shields were applied and breast augmentation was performed. At the conclusion of breast augmentation, the nipple shields were removed and, using the same swab, both the nipple/areolar area and occlusive dressings were cultured.

RESULTS

Data from 63 cultured nipples and nipple shields revealed that 22 nipples/nipple shields (34.9%) were positive for bacterial contamination. Three patients, all of whom had negative cultures, developed CC after augmentation.

CONCLUSIONS

The exposed nipple is a potential source of implant contamination during breast augmentation. An improved understanding of biofilms and related risk factors for CC can provide surgeons with insights for addressing this common complication. Meticulous hemostasis, use of nipple shields, and submuscular device placement may contribute to a lower incidence of CC.

Characterization of microbial presence at the surface of silicone mammary implants

The purpose of this project was to examine the incidence of microbial presence on the surface of mammary implants and its correlation with clinical presentation. The significance of microbial presence without signs of overt infection is questioned. Several issues are raised, including whether the presence of micro-organisms may immunize the host, trigger autoimmune reactions, or locally change the course of healing (resulting in capsular contracture). A total of 150 explanted silicone mammary implants from 87 patients were cultured. Cultures of 81 devices were positive (54%); the predominant isolate was Staphylococcus epidermidis (found on 68 implants, or 84%). Bacteria were detected on 76% (62 of 82) of implants surrounded by contracted capsules and on 28% (19 of 68) of those without capsular contracture (p < 0.05). Among 40 patients (46%) who had no general health problems, 11 (28%) had positive cultures of explanted devices (15 of 62 explants, or 24%). In the remaining 47 patients (54%) who complained of myalgia (77%), arthralgia (68%), chronic fatigue (38%), skin rashes (21%), cognitive problems (19%), dry mucosal membranes (19%), episodes of low-grade fever (17%), and hair loss (13%), 38 (81%) had positive cultures (66 of 88 explants, or 75%) (p < 0.05). The hypothesis that capsular contracture or problems that might be related to chronic infection and immunization are associated with subclinical infection is supported by this study.

Clinical relevance of positive breast periprosthetic cultures without overt infection

The true incidence of positive breast periprosthetic cultures in the absence of overt infection is not clearly established. We retrospectively reviewed data from 389 implants that were removed for reasons other than clinical infection. Many of these patients presented with a variety of musculoskeletal ailments. Others had symptomatic capsular contracture as the presenting complaint. In a few a known implant rupture was the reason for explantation. We identified a positive culture rate of 23.5 percent from capsule tissue. Most of these organisms were coagulase-negative staphylococci and anaerobic diphtheroids, but fungi and other organisms (generally felt to be more pathogenic than the less virulent coagulase-negative staphylococci) also were cultured. In an attempt to identify the clinical relevance of these positive cultures, we statistically evaluated the culture results for associations with capsular contracture, implant rupture, type of implant, and location of implant. Of these, the only statistically significant correlation was between positive culture result and symptomatic capsular contracture (Baker class IV).

Analysis of proviral integration in human mammary epithelial cell lines immortalized by retroviral infection with a temperature-sensitive SV40 T-antigen construct

A panel of eight conditionally immortal lines derived by infection of human breast epithelial cells with an amphotropic retrovirus transducing a ts mutant of SV40 large T-antigen was analyzed with respect to individual retroviral integration patterns. Each line contained multiple integration sites which were clonal and stable over extended passage. Similar integration patterns were observed between individual lines arising separately from the same stock of pre-immortal cells, suggesting a common progenitor. Retroviral integration analysis of pre-immortal cells at different stages of pre-crisis growth showed changes indicative of a progressive transition from polyclonality to clonality as the cells approached crisis. Each of the immortal lines contained a sub-set of the integration sites of their pre-immortal progenitors, with individual combinations and copy numbers of sites. Since all the cell lines appeared to originate from single foci in separate flasks, it is likely that each set arose from a common clone of pre-immortal cells as the result of separate genetic events. There was no evidence from this analysis to suggest that specific integration sites played any part either in the selection of pre-crisis clones or in the subsequent establishment of immortal lines.

Epithelial HBL-100 cell line derived from milk of an apparently healthy woman harbours SV40 genetic information

The epithelial HBL-100 cell line was established in vitro from milk of an apparently healthy woman. It exhibits characteristics of transformation from the very beginning and evolves during in vitro maintenance, until becoming tumorigenic in nude mice. This immortal cell line represents a useful model for studying the progression of human epithelial cells toward malignancy. In the course of our investigations we detected a 94K protein in HBL-100 cells obtained from four different sources. This protein is shown to be indistinguishable from the SV40 large T-antigen on the basis of: Recognition by polyclonal and different monoclonal antibodies. Partial peptide map analysis. Specific binding capacity to the SV40 DNA origin of replication. The presence of a tandemly integrated SV40 genome is demonstrated by Southern blotting. Successful rescue of SV40 DNA by fusion with permissive COS-7, but not CV-1 cells, indicates that the SV40 T-antigen from HBL-100 cells is defective in a function(s) essential to the replication of the viral DNA. The possible origin of the SV40 genetic information that we have detected in HBL-100 cells and the implications of this finding on studies involving this cell line are discussed.

Studies on the endogenous flora of the human breast

Identification of the endogenous microbiological flora of the human breast and its role in breast infections following subglandular augmentation or reduction mammaplasty was undertaken. A total of 231 cultures were performed on 59 breasts in 30 patients. Patients were followed for 12 months. No fungus was cultured from any specimen. Of the breasts cultured 53% were positive for coagulase-negative staphylococcus. Other aerobes found included diphtheroids, lactobacillus, D-enterococcus, micrococcus, and alpha-hemolytic streptococcus. Propionibacterium acne was the most frequent anaerobic bacteria cultured. Other anaerobes included peptococcus and clostridium sporogenes. There was no correlation with respect to the type of bacterium and the depth within the breast where the culture specimens were taken. Postoperative wound infections developed in 2 of 19 patients undergoing reduction mammaplasty. Bacteria identical to those cultured at the time of surgery were again cultured from the wound. Twenty subglandular augmentation mammaplasties were performed with a 25% capsular rate at one year. Two capsules were associated with no bacterial growth at the time of mammaplasty surgery, whereas three were associated with coagulase-negative staphylococcus, Propionibacterium acne, and diphtheroids, respectively. Of the 15 breasts with no capsular contracture after one year, operative culture revealed coagulase-negative staphylococcus in 8 and no bacterial growth in 7. Even breast tissue located deep within the gland away from the nipple contains a flora that is similar to that of normal skin. Cases of infection in which the endogenous bacteria were correlated with later infection was documented.

A microbiological and clinical review on Corynebacterium kroppenstedtii

The genus Corynebacterium represents a taxon of Gram-positive bacteria with a high G+C content in the genomic DNA. Corynebacterium kroppenstedtii is an unusual member of this taxon as it lacks the characteristic mycolic acids in the cell envelope. Genome sequence analysis of the C. kroppenstedtii type strain has revealed a lipophilic (lipid-requiring) lifestyle and a remarkable repertoire of carbohydrate uptake and utilization systems. Clinical isolates of C. kroppenstedtii have been obtained almost exclusively from female patients and mainly from breast abscesses and cases of granulomatous mastitis. However, the role of C. kroppenstedtii in breast pathologies remains unclear. This review provides a comprehensive overview of the taxonomy, microbiology, and microbiological identification of C. kroppenstedtii, including polyphasic phenotypic approaches, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and the use of 16S rRNA gene sequencing. A clinical review presents reported cases, various antimicrobial treatments, antibiotic susceptibility assays, and antibiotic resistance genes detected during genome sequencing. C. kroppenstedtii must be considered a potential opportunistic human pathogen and should be identified accurately in clinical laboratories.

Contamination in smooth gel breast implant placement: testing a funnel versus digital insertion technique in a cadaver model

BACKGROUND

Overt infection and biofilm formation resulting from breast augmentation are rare but serious problems that can lead to contracture and a need for revision surgery. The Keller Funnel is a medical device composed of a rip-stop nylon sleeve with a hydrophilic inner coating. One claim of the funnel is that it facilitates a "no touch" technique, thereby limiting contamination. To date, there are no data to support this claim.

OBJECTIVES

The authors evaluate skin and breast parenchyma contamination with standard implantation techniques and the Keller funnel.

METHODS

Insertion techniques were tested in two fresh cadavers. Smooth, round, moderate-plus silicone gel implants were placed for each experiment. To quantify the amount of skin contamination, a 2% w/v fluorescein paste was painted onto the cadaver thorax. After implantation, the implants were soaked in 250 mL of sterile water, and the fluorescence emission of the resulting solution was measured with an ultraviolet-visible spectrophotometer. To qualify the potential contamination from breast parenchyma, the cadaver breast tissue was swabbed with methicillin-sensitive Staphylococcus aureus, and the implant surfaces were cultured postimplantation.

RESULTS

The funnel resulted in a 27-fold decrease in skin contact for all smooth gel implants (P = .00059). The amount of skin contact and potential contamination increased incrementally with increasing implant volume when either the funnel or digital implantation techniques were used. Bacterial contamination from breast parenchyma was two times more likely with the standard digital insertion technique (P = .06).

CONCLUSIONS

The Keller funnel appears to significantly reduce the amount of skin contact and potential parenchyma contamination.

Early pathogenesis and inflammatory response in experimental bovine mastitis due to Streptococcus uberis

A generally similar clinical response was observed in six lactating Holstein-Friesian cows after intramammary inoculation with approximately 10(7) colony-forming units of Streptococcus uberis. Increased concentrations of serum amyloid A (SAA) were measured in both milk and serum taken 6 and 11h after inoculation, respectively. In contrast, increased concentrations of haptoglobin were detected after 10h of infection, in milk only. In the blood, tumour necrosis factor-alpha (TFN-alpha) was detected (0.503 ng/ml) in only one animal, at the time of euthanasia (10h after infection). Interferon-gamma (IFN-gamma), like haptoglobin, was not detected in blood. Parallel to the development of inflammation and influx of inflammatory cells into the udder tissue, a marked decrease in the number of monocytes and neutrophils in blood was observed. Bacteria were found both intracellularly (macrophages and neutrophils) and within the lumen of ducts and alveoli. Lesions developed progressively in an ascending manner and became widespread throughout the mammary gland in less than 8h. The parallel development of inflammation and increased concentrations of SAA and haptoglobin in milk points to these acute phase proteins as potential diagnostic markers for the early detection of S. uberis -associated mastitis.

Review of a hospital experience of breast abscesses

A retrospective review of breast abscesses during a 10-year period was performed. Only 8.5 per cent (6/72) of patients were in the puerperium. Peripherally sited abscesses were predominantly staphylococcal in origin, incision and drainage was effective treatment in all. By contrast, a subareolar abscess yielded a higher proportion of anaerobic bacteria and 46 per cent (13/28) of these patients had duct ectasia. We conclude that in present day practice a breast abscess is more likely to be related to duct ectasia than to the puerperium, and that patients with anaerobic infection or subareolar abscesses should be assumed to have duct ectasia and may require excision of the major duct system (Hadfield's procedure).

Staphylococcus aureus associated with mammary glands of cows: genotyping to distinguish different strains among herds

The hypothesis that strains of Staphylococcus aureus are more likely to be unique to a herd than common to several herds was tested. Herds (n=28) from nine geographic areas of Korea, with elevated milk somatic cell counts (>500000 cells/ml) were enrolled in this study. Mammary quarter milk samples were aseptically collected from all lactating cows (n=616) with at least three functional quarters. Milk was cultured and S. aureus isolates were typed using pulse field gel electrophoresis of DNA SmaI digests. A total of 181 cows were identified as having S. aureus intramammary infections. A total of 52 different types of S. aureus were identified and 34 (65.4%) were associated with a single herd. A total of 18 types of S. aureus were found in multiple herds; 14 types were found in two herds, and four types were found in three herds. Herds with 1, 2, 3, and more than 3 types, were: four (14.3%); eight (28.6%); nine (32.1%); and seven (25.0%). The data indicate that the majority of strains were found in one herd only, and more than 90% were found in two or less herds, suggesting that strains of S. aureus are more likely to be restricted to a single herd, than found in multiple herds.

Mammary candidiasis: A medical condition without scientific evidence?

Many physicians, midwives and lactation consultants still believe that yeasts (particularly Candida spp.) play an important role as an agent of nipple and breast pain despite the absolute absence of scientific proofs to establish such association. In this context, the objective of this study was to investigate the microorganisms involved in sore nipples and/or painful "shooting" breastfeeding by using a variety of microscopy techniques, as well as culture-dependent and-independent identification methods. Initially, 60 women (30 diagnosed as suffering "mammary candidiasis" and 30 with no painful breastfeeding) were recruited to elucidate the role of their pumps on the milk microbial profiles. After realizing the bias introduced by using such devices, manual expression was selected as the collection method for the microbiological analysis of milk samples provided by 529 women with symptoms compatible with "mammary candidiasis". Nipple swabs and nipple biopsy samples were also collected from the participating women. Results showed that the role played by yeasts in breast and nipple pain is, if any, marginal. In contrast, our results strongly support that coagulase-negative staphylococci and streptococci (mainly from the mitis and salivarius groups) are the agents responsible for such cases. As a consequence, and following the recommendations of the US Library of Medicine for the nomenclature of infectious diseases, the term "mammary candidiasis" or "nipple thrush" should be avoided when referring to such condition and replaced by "subacute mastitis".

The nonpuerperal breast infection: aerobic and anaerobic microbial recovery from acute and chronic disease

Sixty breast culture specimens were obtained by needle aspiration from 54 women and 2 men. A total of 221 microbial isolates were obtained from 52 culture-positive samples. Aerobes alone were recovered from 11 patients while 5 were culture-positive for anaerobes only. Thirty-six patients harbored mixed aerobic and anaerobic microbial flora, and the anaerobic gram-positive cocci were the predominant isolates recovered. The mean microbial recovery for patients with an acute abscess was 2.9 isolates, while in patients with chronic infections the mean microbial recovery was 5. The anaerobic populations outnumbered facultative isolates by two to one, and 34% of anaerobic isolates were recovered from subculture. These findings demonstrate that, contrary to previous reports, nonpuerperal breast infections involve a mixed infection that is primarily anaerobic.

Mastitis in children from birth to 17 years

Twenty-two cases of mastitis were evaluated between 1995 and 2003. Nine of the children were younger than 2 months of age, and 12 were older than 8 years of age. Girls accounted for 82% of the cases. Seven of the infections were true abscesses. Pathogens included Staphylococcus aureus in 5, Gram-negative bacilli in 3, group A Streptococcus in 1 and enterococcus in 1. These data suggest that mastitis in children occurs in 2 distinct age groups, neonates and pubescent/postpubescent; however, the clinical disease is similar in both populations.