The use of bacterial interference to prevent infection.

For decades, bacterial strains of low virulence were occasionally used in man to replace or to block colonization by the more virulent organisms and thereby prevent bacterial infection. This paper reviews the topic and presents recent information on the implantation of strain 215 alpha-hemolytic streptococcus (alpha-strep) in the nasopharynx of neonates in the intensive care unit. A single inoculation of strain 215 can change abnormal colonization of the pharynx to "normal" (alpha-strep predominant) in 48-72 h in most neonates.

Abnormal colonization of neonates in an ICU: conversion to normal colonization by pharyngeal implantation of alpha hemolytic streptococcus strain 215.

Normal bacterial flora provide a natural defense mechanism against infection. Our experience indicates that "normal" flora for the ICU neonate contains alpha hemolytic (alpha-) streptococci as the predominant organism. The purpose of the current investigation is to study the feasibility of implanting a carefully selected, naturally occurring strain of alpha-streptococcus in the nasopharynx of neonates considered to be at high risk of infection because of the abnormal colonization of their pharynx with potential pathogens.

Abnormal colonization of neonates in an intensive care unit: means of identifying neonates at risk of infection.

The current investigation was designed to select infants in the neonatal intensive care unit (ICU) at highest risk of infection. The data, derived from a prospective study of 223 neonates, indicate that neonates in an ICU develop their initial aerobic pharyngeal flora according to one of the three patterns shown in Table 1, one of which (low titer or no growth) is dependent on antibiotic therapy. Of particular importance is the finding that infants with normal flora (alpha-streptococci predominating) or cultures showing low titers (less than 10(4) colony-forming units (cfu)/ml) or no growth did not become infected.

Neonatal osteomyelitis.

To evaluate current conservative therapy and document the existence of a recent shift in etiologic agents, we reviewed the records of 45 infants who developed osteomyelitis within the first ten weeks of life and who were admitted to Babies Hospital (New York) from 1951 through 1976. Emphasis was placed on characteristics and course of the disease, etiologic agents, therapy, and outcome. Illness was diagnosed within the first two weeks of life in 34 of the 45 infants (73%).