## 1 Introduction  
_Cronobacter sakazakii_ is a Gram-negative xerotolerant bacterium, non-spore-forming, facultatively anaerobic, and opportunistic enteric pathogen predominately affecting those with compromised immune systems [1]. It belongs to the genus _Cronobacter_ which consists of seven species, including the most pathogenic _C. sakazakii_, _C. malonaticus_, and _C. turicensis_[2]. Although the original reservoir of _C. sakazakii_ has not been definitively identified, it has been isolated from water, soil, factory equipment, and foods such as milk, meat, and cereals [3]. It has also been observed that _C. sakazakii_ can strongly adhere to abiotic surfaces such as silicone, latex, stainless steel, and glass for several months or even years [4, 5], forming biofilms, while other studies have reported its resistance to a number of stresses like heating, cooling, osmotic stress, and drying, as well as natural antibiotics [6, 7]. However,it should be noted that one of the most common routes of _C. sakazakii_ contamination is powdered infant formulae (PIFs), as well as the equipment and utensils used for their reconstitution [8; 9; 10]. Several epidemiological studies have linked the consumption of contaminated reconstituted infant formulae (RIFs) to serious health problems in newborns, particularly due to their immature immune system [11; 12]. These infections have a high death rate (40-80%) and can cause serious diseases like newborn meningitis, bacteremia, necrotizing colitis, and meningoencephalitis, while surviving infants often suffer from neurological sequelae like hydrocephalus, quadriplegia, and delayed brain development [13]. The infection _C. sakazakii_ though the consumption of infant formulae is an ongoing public health issue. In the USA, the National Advisory Committee on Microbiological Criteria for Foods (NACMCF) has reported a relatively high prevalence rate, ranging between 2-15%, of _Cronobacter_ spp. contamination occurred in PIFs, and, in late 2021 and early 2022, a series of _Cronobacter_ spp. illnesses among infants in the U.S. was associated with PIF feeding [14]. For all these reasons _C. sakazakii_ has attracted scientific interest in exploring ways to address the problem, over the years. One of the most effective approaches is to prevent contamination at the source during PIF production. The USA's regulations mandate infant formula manufacturers to set up production lines and in-process controls, encompassing all processing stages, to prevent _Cronobacter_ spp. from contaminating PIFs [15]. Another approach for avoiding _C. sakazakii_ infections is to prevent its growth if it is present in PIFs. To this end, several biological ways have been proposed including the use of natural substances with antimicrobial properties like polyphenols [16], bacterioxins [17], organic acids [18], hydrogen peroxide [19], phages [20], etc., while others focus on enhancing the host's defense [21], interfering with its intestinal system [22; 23], as well as quorum sensing mechanisms [24]. More details on _C. sakazakii_ biocontrol strategies can be found in recent reviews [25; 26; 27; 28]. It is undeniable that human milk is the \"golden standard\" for infant nutrition, but breastfeeding is often not possible for various reasons, leading to infant feeding based on specially designed formulae. The main constituents of infant formulae (IF), powder or liquid, are proteins, carbohydrates, fats, vitamins, and minerals. They are also often enriched with bioactive compounds and probiotics. Their composition varies according on the infants needs and can be categorized as follows: (a) cow's milk-based formulae where the proteins are mainly either caseins or whey proteins, with lactose being the main source of carbohydrate; (b) formulae with hydrolyzed proteins digested into peptides for infants allergic to cow's milk caseins; (c) formulae with proteins of vegetable origin, mainly soya, for infants with lactose intolerance; and (d) special formulations for cases of premature infants with metabolic diseases.