Cronobacter sakazakii

Cronobacter sakazakii is a Gram-negative, non-spore-forming, facultatively anaerobic rod that belongs to the Enterobacteriaceae family. It is a pathogen known to cause severe infections such as neonatal meningitis, sepsis, and necrotizing enterocolitis in newborns, with a high mortality rate. The organism can also cause illness in the elderly or those with compromised immune systems, though infections in these groups are less common.

Epidemiology

Cronobacter sakazakii is ubiquitous in the environment and has been isolated from a variety of sources including water, soil, and food. However, it is most notoriously associated with powdered infant formula, through which it has been linked to outbreaks of neonatal infections. The bacterium can survive in dry conditions, making powdered products an ideal environment for its persistence.

Pathogenesis

The pathogenesis of Cronobacter sakazakii involves the bacterium entering the host, surviving, and proliferating in the host's tissues. It can cross the intestinal barrier, enter the bloodstream, and then breach the blood-brain barrier to cause meningitis. The exact mechanisms by which Cronobacter sakazakii causes disease are not fully understood, but it is known to possess virulence factors such as adhesins, invasins, and endotoxins that facilitate its pathogenicity.

Clinical Manifestations

Infections with Cronobacter sakazakii can lead to a range of clinical manifestations, from mild gastrointestinal illness to severe, life-threatening conditions. The most severe infections, such as meningitis and sepsis, are primarily seen in neonates, particularly preterm infants or those with weakened immune systems. Symptoms of meningitis may include fever, irritability, poor feeding, and lethargy. Sepsis symptoms can be more varied and may include fever, rapid breathing, and changes in heart rate.

Diagnosis

Diagnosis of Cronobacter sakazakii infection involves the isolation and identification of the bacterium from sterile sites such as cerebrospinal fluid (CSF) or blood. Laboratory tests include culture, biochemical tests, and PCR assays to confirm the presence of the bacterium.

Treatment

Treatment of Cronobacter sakazakii infections typically involves the use of antibiotics. Empirical antibiotic therapy may be initiated before the results of susceptibility testing are available, especially in cases of neonatal meningitis or sepsis. The choice of antibiotics should be guided by the results of antimicrobial susceptibility testing due to the potential for antibiotic resistance.

Prevention

Prevention of Cronobacter sakazakii infection is primarily focused on minimizing the risk of contamination in powdered infant formula. Recommendations include strict adherence to hygiene practices in the preparation of formula, using boiled water to reconstitute the formula, and minimizing the time between preparation and consumption. Additionally, healthcare facilities should follow infection control practices to prevent nosocomial infections.

See Also

• Enterobacteriaceae
• Neonatal meningitis
• Sepsis
• Necrotizing enterocolitis