Cronobacter(Enterobacter sakazakii): An Opportunistic Foodborne Pathogen

Abstract

Cronobacter spp. (Enterobacter sakazakii) are a recently described genus that is comprised of six genomospecies. The classification of these organisms was revised based on a detailed polyphasic taxonomic study. Cronobacter spp. are regarded as ubiquitous organisms having been isolated from a wide variety of foods. These bacteria are opportunistic pathogens and are linked with life-threatening infections in neonates. Clinical symptoms of Cronobacter infection include necrotizing enterocolitis, bacteremia, and meningitis, with case fatality rates of 50-80% being reported. Contaminated powdered infant formula has been epidemiologically linked with infections. Recently, infections among immunocompromised adults, mainly the elderly, have also been reported. A high tolerance to osmotic stress and elevated temperatures contribute to the survival of Cronobacter spp. in dried foods such as powdered infant formula. Controlling the organism in the production environment, thereby reducing dissemination, necessitates the provision of suitable diagnostic tools. Studies demonstrated that a high degree of variability exists amongst the phenotypic-based methods used to identify Cronobacter spp. However, advances in molecular detection and subtyping techniques have significantly improved the identification and characterization of Cronobacter spp. The dose required to induce infection has yet to be determined. In vitro virulence studies have shown that Cronobacter spp. may survive in macrophage cells and efficiently attach to and invade epithelial cell lines. The production of exopolysaccharide may contribute to the formation of biofilm and active efflux pumps promote resistance to antimicrobial agents such as bile salts and disinfectants. A holistic approach combining techniques such as comparative genome analysis, proteomics, and in vivo challenges could help unravel the complex interactions between this pathogen and its host. These data would help identify those properties in Cronobacter spp. which enable the bacterium to survive in the production environment and infect vulnerable neonates via the food chain.

Chemical Composition and Antibacterial Potential of Artemisia arborescens L. Essential Oil

“…The inhibitory spectrum was evaluated against bacterial species (Enterobacteria, L. monocytogenes and salmonellas) responsible for human outbreaks commonly associated with food matrices [9,22,44]. All Gram-negative species (Salmonella spp.…”

Antibacterial activity of Borago officinalis and Brassica juncea aqueous extracts evaluated in vitro and in situ using different food model systems

“…The spectrum of inhibition was evaluated against Enterobacter spp. (38 strains), L. monocytogenes (42 strains), S. aureus (35 strains) and S. enterica (18 strains) which are bacterial species reported to be responsible for human diseases and are commonly associated with the consumption of contaminated food items (Crum-Cianflone, 2008;Healy et al, 2010;Swaminathan & Gerner-Smidt, 2007;Wilson et al, 2000). Both AEs showed a negligible inhibition of L. monocytogenes strains and, with a few exceptions, salmonellae, but the activity towards staphylococci and enterobacteria was found to be interesting.…”

“…Enterobacter spp. are also often responsible for human sporadic and epidemic cases associated with food matrices (Healy, Cooney, O'Brien, Iversen & Whyte, 2010). Moreover, Staphylococcus aureus that is responsible for the most frequent foodborne intoxication, is acquiring a new epidemiological dimension through the putative role of some foods, in particular chicken and pork, as a vehicle of livestock-associated methicillin resistant (MRSA) strains (Harrison et al 2013).…”

Cronobacter spp. – opportunistic food-borne pathogens. A review of their virulence and environmental-adaptive traits

“…Historically, Cronobacter have been implicated in newborn and infant infections, causing meningitis, necrotizing enterocolitis (NEC) and bacteraemia or sepsis (Healy et al, 2010). However, not all Cronobacter spp.…”

“…Infections in elderly and immunocompromised adults have also been reported (Healy et al, 2010), and the epidemiology of these cases suggests that other potential sources of contamination exist, such as the home environment (Kandhai et al, 2004;Kilonzo-Nthenge et al, 2008), retail foods (e.g. dried milk powder, dried meats, legumes, nuts, dried flours and spices) (Friedemann, 2007;Hochel et al, 2012) or drinking water (Lui et al, 2013).…”