Breast milk causing neonatal sepsis and death

Microbiological Screening of Donor Human Milk

Mother's own milk is recognized as the optimal feeding not only for term but also for preterm infants. In addition to risk reduction for sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and retinopathy of prematurity in the early infancy, feeding preterm infants with mother's own milk is also associated with a better neurodevelopmental outcome; lower rates of otitis media, gastroenteritis, and respiratory infections; and a reduced risk of cardiovascular disease, obesity, and diabetes later in life. Donor human milk is the best alternative if mother's own milk is not available or with short supply. There is growing evidence that the benefits of human milk are mediated by the human milk microbiota and by human milk oligosaccharides through their influence on the infant's gut microbiota. Unfortunately, although human milk contains beneficial bacteria, it may also contain pathogenic bacteria. The antimicrobial properties of human milk protect those infants fed with their own mother's raw milk. In donor human milk, however, the antimicrobial activity is diminished due to storage and in particular by pasteurization, hereby lowering the resistance against bacterial infections. Subsequently, microbiological screening of donor human milk might enhance its safety for preterm infants. Up to date, a consensus on recommendations for the microbiological testing of donor human milk is lacking. Existing local and national guidelines for the microbiological screening vary significantly in terms of timing and frequency of testing as well as their specific acceptance and discard criteria. We reviewed the literature about microbiological testing of donor human milk to provide evidence-based recommendations for donor human milk.

Late-Onset Sepsis in a Premature Infant Mediated by Breast Milk: Mother-to-Infant Transmission of Group B Streptococcus Detected by Whole-Genome Sequencing

Background

Late-onset group B Streptococcus (LOGBS) sepsis is a cause of infection and death in infants. Infected breast milk has been considered a source of neonatal GBS infection and invasive infection. However, mother-to-infant transmission of GBS detected by the high-resolution diagnostic method is rarely reported.

Methods

This study describes a low-weight premature infant who developed late-onset GBS septicemia 21 days after birth. GBS strains isolated from the mother’s cervical secretion, the mother’s milk, and the baby’s blood were cultured to identify the source of GBS infection. We further confirmed the GBS isolates through matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Finally, we performed whole-genome sequencing (WGS) and phylogenetic analyses on the GBS strains recovered.

Results

GBS isolates were cultured from the bloodstream of the premature infant and the mother’s milk, respectively. Subsequently, WGS and phylogenetic analyses on three GBS isolates demonstrated that the GBS strain from the infant’s bloodstream was 100% homologous to that from the mother’s breast milk, which had some different gene fragments from the GBS strain from the mother’s cervical secretion. It provided evidence that this infant’s late-onset GBS septicemia originated from his mother’s breast milk instead of the vertical mother-to-infant transmission.

Conclusion

Through WGS and phylogenetic analysis of the GBS strains, we proved in this study that the late-onset GBS sepsis in a premature infant was derived from his mother’s breast milk. It indicated that WGS diagnosis is an effective tool for infection tracing. Furthermore, this report provides direction for preventing late-onset GBS infection.

Inoculation of mother's own milk could personalize pasteurized donor human milk used for feeding preterm infants

BACKGROUND

Human milk is a vehicle for bioactive compounds and beneficial bacteria which promote the establishment of a healthy gut microbiome of newborns, especially of preterm infants. Pasteurized donor human milk (PDHM) is the second-best option when preterm mother's own milk is unavailable. Since pasteurization affect the microbiological quality of donor milk, PDHM was inoculated with different preterm milk samples and then incubated, in order to evaluate the effect in terms of bacterial growth, human milk microbiome and proteolytic phenomena.

METHODS

In an in-vitro study PDHM was inoculated at 10% v/v using ten preterm milk samples. Microbiological, metataxonomic and peptidomic analyses, on preterm milk samples at the baseline (T0), on PDHM and on inoculated milk (IM) samples at T0, after 2 h (T1) and 4 h (T2) of incubation at 37 °C, were conducted.

RESULTS

IM samples at T2 showed a Total Bacterial Count not significantly different (p > 0.01) compared to preterm milk samples. At T2 lactic acid bacteria level was restored in all IM. After inoculation, metataxonomic analysis in IM samples showed that Proteobacteria remained the predominant phylum while Firmicutes moved from 3% at T1 to 9.4% at T2. Peptidomic profile of IM resembled that of PDHM, incubated for the same time, in terms of number and type of peptides.

CONCLUSION

The study demonstrated that inoculation of PDHM with mother's own milk could restore bacterial growth and personalize human milk microbiome in PDHM. This effect could be beneficial because of the presence of maternal probiotic bacteria which make PDHM more similar to mother's own milk.

Hypervirulent Streptococcus agalactiae septicemia in twin ex-premature infants transmitted by breast milk: report of source detection and isolate characterization using commonly available molecular diagnostic methods

Background

Group B Streptococcus (GBS) infections caused by Streptococcus agalactiae is a leading cause of meningitis and sepsis in neonates, with early-onset GBS symptoms emerging during the first week of life and late-onset occurring thereafter. Perinatal transmission of GBS to the neonate through the birth canal is the main factor associated with early-onset neonate infections, while less is understood about the source of late-onset infections.

Methods

In this report we describe a case of twin ex-premature infants who presented one month after birth with GBS septicemia. The mother had been appropriately screened at gestational age 35–37 weeks and laboratory methods failed to detect GBS colonization by culture or clinical molecular methods. In attempts to identify and isolate the source of GBS infection, additional surveillance swabs were collected from the mother at the time of neonate admission. Culture and a commercially available, FDA-cleared molecular PCR assay were performed.

Results

No GBS was detected from swabs collected from the perianal, thigh/groin or axillary areas. However, expressed breast milk and swabs from the breastmilk pump were positive by both methods. Since simultaneous culture and molecular methods which used breastmilk as a source were performed, investigators ascertained the limit of detection for GBS in breastmilk. The limit of detection was determined to be tenfold lower than that of LIM-broth enriched cultures—the FDA-approved source. Subsequent whole genome sequencing (WGS) analysis of isolates recovered from breastmilk and blood cultures from the infants demonstrated all strains were related and characterized as ST-452. Both infants responded very well to treatment and continued to have no related events or concerns at the two-year follow up appointment.

Conclusions

Strain type 452 (capsular type IV) has recently emerged as a hypervirulent strain and has previously been documented as causing GBS infections in elderly populations. Antibiotic therapy resolved both mother and infant infections. Subsequent testing for the presence of GBS in breastmilk samples also showed an absence of bacteria. This is the first report of infant twins late-onset GBS infections caused by the hypervirulent S. agalactiae ST-452 with breastmilk as the source.

Understanding the Elements of Maternal Protection from Systemic Bacterial Infections during Early Life

Late-onset sepsis (LOS) and other systemic bloodstream infections are notable causes of neonatal mortality, particularly in prematurely born very low birth weight infants. Breastfeeding in early life has numerous health benefits, impacting the health of the newborn in both the short-term and in the long-term. Though the known benefits of an exclusive mother's own milk diet in early life have been well recognized and described, it is less understood how breastfed infants enjoy a potential reduction in risk of LOS and other systemic infections. Here we review how gut residing pathogens within the intestinal microbiota of infants can cause a subset of sepsis cases and the components of breastmilk that may prevent the dissemination of pathogens from the intestine.

A pilot study on nutrients, antimicrobial proteins, and bacteria in commerce-free models for exchanging expressed human milk in the USA

Expressed human milk can be donated or sold through a variety of channels, including human milk banks, corporations or individuals, or peer-to-peer milk sharing. There is a paucity of research regarding the nutrient and bioactive profiles of expressed human milk exchanged through commerce-free scenarios, including peer-to-peer milk sharing. The study objective was to evaluate the macronutrient, antimicrobial protein, and bacteria composition in expressed human milk acquired via commerce-free arrangements. Expressed human milk samples were collected from the following commerce-free scenarios: milk expressed for a mother's or parent's own infant (MOM; N = 30); unpasteurized milk donated to a non-profit milk bank (BANKED; N = 30); milk expressed for peer-to-peer milk sharing (SHARED; N = 31); and health professional-facilitated milk sharing where donors are serologically screened and milk is dispensed raw (SCREENED; N = 30). Analyses were conducted for total protein, lactose, percent fat and water, lysozyme activity, immunoglobulin A (IgA) activity, total aerobic bacteria, coliform, and Staphylococcus aureus. No bacterial growth was observed in 52/121 samples, and 15/121 had growth greater than 5.0 log colony-forming units/mL. There was no evidence of differences by groups (p > .05) in lactose, fat, water, lysozyme activity, sIgA activity, aerobic bacteria, coliforms, and S. aureus. Mean protein values (95% confidence interval) were 1.5 g/dL (1.4, 1.6) for BANKED, 1.4 g/dL (1.3, 1.5) for MOM, 1.6 g/dL (1.5, 1.7) for SCREENED, and 1.5 g/dL (1.4, 1.6) for SHARED, which was not significantly different (p = .081). This research contributes to growing literature on the risks and benefits of uncompensated, peer-to-peer milk sharing.

Current Trends in Research on Human Milk Exchange for Infant Feeding

Breastfeeding is critical for the healthy growth and development of infants. A diverse range of infant-feeding methods are used around the world today. Many methods involve feeding infants with expressed human milk obtained through human milk exchange. Human milk exchange includes human milk banking, human milk sharing, and markets in which human milk may be purchased or sold by individuals or commercial entities. In this review, we examine peer-reviewed scholarly literature pertaining to human milk exchange in the social sciences and basic human milk sciences. We also examine current position and policy statements for human milk sharing. Our review highlights areas in need of future research. This review is a valuable resource for healthcare professionals and others who provide evidence-based care to families about infant feeding.

Staphylococcus pseudintermedius septicemia in puppies after elective cesarean section: confirmed transmission via dam's milk

Background

In humans, transmission of bacteria causing fatal sepsis in the neonates through mother’s milk has been reported. In dogs, it is believed that bacteria from canine milk are not the primary cause of neonatal infections. Staphylococcus pseudintermedius is colonizing the skin and mucocutaneous junctions in adult dogs and can act as an opportunistic pathogen. This bacterium was previously isolated from the canine milk and, although, its transmission from the dam’s milk to the newborn puppies causing a neonatal sepsis was suggested, this hypothesis has not been confirmed.

Case presentation

A 4.5-year-old healthy Boston terrier dam had an elective cesarean section, delivering five normal puppies and one dead runt. Next day, two puppies developed pustules on their legs and around the muzzle. After two more days, strings of blood were noticed in the stool of the biggest puppy that suddenly died later that night. The same day, blood became visible in the feces of all other puppies. Necropsy of the dead puppy revealed a distended abdomen, catarrhal gastroenteritis with lymphadenopathy, dark red and slightly firm lung, mild dilatation of the right heart chamber and congestion of the liver, spleen, pancreas and meninges. The thoracic cavity contained white-yellow slightly opaque exudate, and there was transudate in the abdominal cavity. Histopathology revealed an acute interstitial pneumonia and multifocal myocardial necrosis with mineralization. Bacteriology of the internal organs, body cavity effusions of the dead puppy and dam’s milk revealed a diffuse growth of S. pseudintermedius in pure culture. Whole genome sequencing (WGS) revealed that all isolates belonged to the sequence type 241 and differed in 2–5 single nucleotide polymorphisms; thus, the epidemiological link between the outbreak-associated isolates was confirmed.

Conclusions

This is the first report of a confirmed transmission of S. pseudintermedius through dam’s milk causing a neonatal sepsis in a puppy after an elective cesarean section. The epidemiological link between S. pseudintermedius isolates obtained from dam’s milk and internal organs of the affected puppy was confirmed by WGS. Our findings indicate that milk of healthy dams can serve as a reservoir of bacteria that can cause fatal sepsis in the newborn puppies.

High-Temperature Short-Time Pasteurization System for Donor Milk in a Human Milk Bank Setting

Donor milk is the best alternative for the feeding of preterm newborns when mother's own milk is unavailable. For safety reasons, it is usually pasteurized by the Holder method (62.5°C for 30 min). Holder pasteurization results in a microbiological safe product but impairs the activity of many biologically active compounds such as immunoglobulins, enzymes, cytokines, growth factors, hormones or oxidative stress markers. High-temperature short-time (HTST) pasteurization has been proposed as an alternative for a better preservation of some of the biological components of human milk although, at present, there is no equipment available to perform this treatment under the current conditions of a human milk bank. In this work, the specific needs of a human milk bank setting were considered to design an HTST equipment for the continuous and adaptable (time-temperature combination) processing of donor milk. Microbiological quality, activity of indicator enzymes and indices for thermal damage of milk were evaluated before and after HTST treatment of 14 batches of donor milk using different temperature and time combinations and compared to the results obtained after Holder pasteurization. The HTST system has accurate and simple operation, allows the pasteurization of variable amounts of donor milk and reduces processing time and labor force. HTST processing at 72°C for, at least, 10 s efficiently destroyed all vegetative forms of microorganisms present initially in raw donor milk although sporulated Bacillus sp. survived this treatment. Alkaline phosphatase was completely destroyed after HTST processing at 72 and 75°C, but γ-glutamil transpeptidase showed higher thermoresistance. Furosine concentrations in HTST-treated donor milk were lower than after Holder pasteurization and lactulose content for HTST-treated donor milk was below the detection limit of analytical method (10 mg/L). In conclusion, processing of donor milk at 72°C for at least 10 s in this HTST system allows to achieve the microbiological safety objectives established in the milk bank while having a lower impact regarding the heat damage of the milk.

Handling of Breast Milk by Neonatal Units: Large Differences in Current Practices and Beliefs

Background: Breast milk (BM) for premature infants is subjected to multiple steps of processing, storage and distribution. These steps may influence the quality and safety of BM. Guidelines concerning the use of mother's own milk are either not available or limited to specific aspects of BM handling and are based on evidence of variable strength. This may result in diverse BM handling routines by health care professionals. Objective: We surveyed neonatal units to increase the knowledge about the current practice of BM handling routines of mother's own milk and to identify controversial aspects that could give directions for future research. Methods: An online-based questionnaire was sent to 307 different neonatal departments providing level III to level I neonatal care within Germany, Austria and Switzerland. Practices concerning screening for cytomegalovirus and BM bacteria, pasteurization, fortification, storage, workforce and the incidence of BM administration errors were surveyed. Results: A total of 152 units, 56% of contacted level III units and 51% of level II units, participated in the survey (Germany 53%, Switzerland 71%, and Austria 56%). We found differences concerning indication and method of CMV inactivation (performed by 58%), bacterial count screening (48%) and bacterial count reduction (17%) within participating units. Thirty different thresholds for bacterial BM counts were reported by 65 units, resulting in pasteurization or discarding of BM. The use of nutrient analysis (12%) and fortification regimens in addition to standard multicomponent fortifiers (58%) using either individual (93%), targeted (3%), or adjusted (4%) fortification protocols varied profoundly. There is a high variability in staff and available facilities for BM handling. 73% of units report about BM administration errors. Conclusion: There is a wide variability in most aspects of BM handling in the participating units. Despite limited evidence labor and cost intensive procedures are applied which may have an impact on BM quality.