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

Abstract

The genus Cronobacter consists of a diverse group of Gram-negative bacilli and comprises seven species: Cronobacter sakazakii, Cronobacter malonaticus, Cronobacter muytjensii, Cronobacter turicensis, Cronobacter dublinensis, Cronobacter universalis and Cronobacter condimenti. Cronobacter are regarded as opportunistic pathogens, and have been implicated in newborn and infant infections, causing meningitis, necrotizing enterocolitis and bacteraemia or sepsis. Cronobacter virulence is believed to be due to multiple factors. Some strains were found to produce diarrhoea or cause significant fluid accumulation in suckling mice. Two iron acquisition systems (eitCBAD and iucABCD/iutA), Cronobacter plasminogen activator gene (cpa), a 17 kb type VI secretion system (T6SS), and a 27 kb filamentous haemagglutinin gene (fhaBC) and associated putative adhesins locus are harboured on a family of RepFIB-related plasmids (pESA3 and pCTU1), suggesting that these are common virulence plasmids; 98 % of 229 tested Cronobacter strains possessed these plasmids. Even though pESA3 and pCTU1 share a common backbone composed of the repA gene and eitCBAD and iucABCD/iutA gene clusters, the presence of cpa, T6SS and FHA loci depended on species, demonstrating a strong correlation with the presence of virulence traits, plasmid type and species. Other factors were observed, in that Cronobacter form biofilms, and show unusual resistance to heat, dry and acid stress growth conditions. The outer-membrane protein A is probably one of the bestcharacterized virulence markers of Cronobacter. Furthermore, it was reported that Cronobacter employ phosphatidylinositide 3-kinase/Akt signalling, which activates protein kinase C-a and impairs the host cell's mitogen-activated protein kinase pathway, in order to invade cells. Cronobacter can also use immature dendritic cells and macrophages to escape the immune response. This review addresses the various virulence and environmental-adaptive characteristics possessed by members of the genus Cronobacter.

Cronobacterspp. in Common Breast Milk Substitutes, Bogotá, Colombia

“…For Cronobacter spp., the international standard is a total absence in IMF ( 13 ). The most recovered species in the samples we tested was C. sakazakii , which is the species associated with the highest number of disease cases reported in neonates and whose sequence type 4 is already known to be associated with severe cases of meningitis ( 14 ). The PCR method we used enabled greater coverage compared with the traditional method because the identification of the species is confirmed in a single analytical run, thus speeding up the subsequent public health response and providing valuable information for epidemiologic surveillance.…”

Immunological detection of Cronobacter and Salmonella in powdered infant formula by plasmonic label-free assay

“…pointed out this bacterium genus as a foodborne pathogen of interest due to its high mortality rate, estimated between 40 and 80% (Jaradat et al . ). The Cronobacter genus, formerly described as Enterobacter sakazakii (Farmer et al .…”

Inhibitory effect of camel milk on Cronobacter sakazakii

“…C. sakazakii has been isolated from wide range of dairy products (Ye, Li, Wu, Zhang, & Lu, ). Moreover, powder infant formula has been epidemiologically linked to Cronobacter infections in infants (Healy et al, ; Jaradat et al, ). Researchers in globe initiated numerous research project to investigate presence of C. sakazakii in baby foods.…”