Bacterial profile of the oropharynx in infants: an assessment of the confounding factors for colonization

Microbial profile and characterization of blue bulb manual suction devices used to promote airway clearance in newborns in intrapartum and postpartum units

BACKGROUND

Newborns are suctioned with a blue bulb manual suction device to remove naso-oropharyngeal secretions and promote airway clearance. This study identifies and discusses the microbial profile and characterization of the bulb used in newborns on intrapartum and postpartum units.

METHODS

This was a descriptive study with convenience sampling of a total of 50 bulbs used in cesarean births, vaginal births, and on the postpartum unit. The bulbs were tested for microbial growth, and the percentages of contaminated bulbs were calculated. The χ² test was used to compare the proportion of bulbs with microbial growth by route of birth among bulbs sampled from the intrapartum unit.

RESULTS

Microbial profile and characterization identified a total of 57 different gram-positive cocci and rods and gram-negative rods. Among 50 bulbs cultured, bacterial growth was present in 42% of the bulbs, and Escherichia coli was identified in 55% of the gram-negative rod isolates. The χ² test comparing vaginal and cesarean bulbs showed a statistically significant difference in the percentages of contaminated bulbs for any growth (P = .023) and for any Staphylococcus spp (P = .050).

CONCLUSIONS

New empirical evidence confirms the bulb is a potential bacterial reservoir and poses a potential health risk for nosocomial infections for newborns. Further studies are needed to identify bacterial transmission, newborn outcomes, bactericidal bulb cleaning methods, and quality and safe suction practices.

The aetiology of diarrhoea, pneumonia and respiratory colonization of HIV-exposed infants randomized to breast- or formula-feeding

BACKGROUND

Diarrhoea and pneumonia are common causes of childhood death in sub-Saharan Africa but there are few studies describing specific pathogens.

OBJECTIVES

The study aimed to describe the pathogens associated with diarrhoea, pneumonia and oropharyngeal colonization in children born to HIV-infected women (HIV-exposed infants).

METHODS

The Mashi Study randomized 1200 HIV-infected women and their infants to breastfeed for 6 months with ZDV prophylaxis or formula-feed with 4 weeks of ZDV. Children were tested for HIV by PCR at 1, 4, 7, 9 and 12 months and by ELISA at 18 months. Pre-defined subsets of children were sampled during episodes of diarrhoea (n = 300) and pneumonia (n = 85). Stool was tested for bacterial pathogens, rotavirus and parasites. Children with pneumonia underwent bacterial blood culture, and testing of nasopharyngeal aspirates for viral pathogens by PCR. Oropharyngeal swabs were collected from a consecutive subset of 561 infants at the routine 3-month visit for bacterial culture.

RESULTS

The median age (range) at sampling was 181 days for diarrhoea (0-730) and 140 days for pneumonia (2-551). Pathogens were identified in 55 (18%) children with diarrhoea and 32 (38%) with pneumonia. No differences in pathogens by child HIV status (HIV-infected vs HIV-uninfected) or feeding strategy were identified. Campylobacter was the most common diarrhoeal pathogen (7%). Adenovirus (22%) and other viruses (19%) were the primary pathogens isolated during pneumonias. More formula-fed infants had oropharyngeal colonization by pathogenic Gram-negative bacteria (16.8% vs 6.2%, P = 0.003), which was associated with a non-significant increased risk of pneumonia (OR 2.2, 95% CI 0.8-5.7).

CONCLUSION

A trend toward oropharyngeal bacterial colonization was observed in formula-fed infants. Although viruses were most commonly detected during pneumonia, respiratory colonization by Gram-negative bacteria may have contributed to pneumonia in formula-fed infants.

The respiratory microbiota during health and disease: a paediatric perspective

Recent studies investigating the relationship between the microbiota and disease are demonstrating novel concepts that could significantly alter the way we treat disease and promote health in the future. It is suggested that the microbiota acquired during childhood may shape the microbial community and affect immunological responses for later life, and could therefore be important in the susceptibility towards disease. Several diseases, including asthma, pneumonia, and otitis media, are associated with changes in composition and diversity of the respiratory microbiota. This review summarises current literature, focusing on the composition and development of the respiratory microbiota in children and its relationship with respiratory diseases.