Adeel Arsalan et al. Int. Res. J. Pharm. 2013, 4 (4) Page 17 INTERNATIONAL RESEARCH JOURNAL OF PHARMACY www.irjponline.com ISSN 2230 – 8407 Review Article CRONOBACTER SAKAZAKII: AN EMERGING CONTAMINANT IN PEDIATRIC INFANT MILK FORMULA Adeel Arsalan*, Zubair Anwar, Iqbal Ahmad, Zufi Shad, Sadia Ahmed Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, Pakistan Email: adeelarsalan@hotmail.com Article Received on: 20/02/13 Revised on: 01/03/13 Approved for publication: 21/04/13 DOI: 10.7897/2230-8407.04403 IRJP is an official publication of Moksha Publishing House. Website: www.mokshaph.com © All rights reserved. ABSTRACT Cronobacter sakazakii (C. sakazakii) previously known as Enterobacter sakazakii is a motile, Gram-negative, non-sporing yellow pigmented rod, which belongs to lethal Enterobacteriaceae family. C. sakazakii is ubiquitously found in air, soil, floor drains, and dry product processing environment. It has been isolated from hospitals, clinical materials, and cutting fluids and is also present in cerebrospinal fluid (CSF), blood, sputum, throat, nose, stool, gut, skin, wounds, bone marrow, eye, ear and breast abscesses. C. sakazakii is a virulent pathogen and can adhere to silicon, latex, polycarbonate, and stainless steel. Therefore, Feeding-bottles or utensils used to prepare pediatric infant formula (PIF) should be thoroughly cleaned to diminish the development of biofilms, which could be the source of infections. Due to its virulence, C. sakazakii causes life threatening infections such as septicemia, necrotizing enterocolitis, bacteriamia and meningitis. Hence, the regulatory authorities such as Food and Drug Administration (FDA), Food and Agriculture Organization/World Health Organization (FAO/WHO), Centers for Disease Control and Prevention (CDC) and Health Canada strongly recommend breast-feeding over the bottle-feed to minimize the risk of infections caused by C. sakazakii. Keywords: Cronobacter sakazakii; Pediatric infant formula; Contamination; Necrotizing enterocolitis; Meningitis INTRODUCTION Cronobacter sakazakii (C. sakazakii) is an emerging food- borne, motile, peritrichous, Gram-negative rods, non-spore- forming bacterium belonging to the Enterobacteriaceae family. It is an opportunistic human and food-borne pathogen previously known as yellow pigmented Enterobacter sakazakii. Farmer et al. mentioned the first used of the name E. sakazakii 1 after the Japanese bacteriologist Riichi Sakazakii. Several genera and species of Enterobacteriaceae have been isolated from the reconstituted pediatric infant formula (PIF). C. sakazakii’s physiological traits aid in its environmental survival, and give the ability to produce a yellow pigment that protects the cell against UV rays in sunlight. It also provides capsular and film barrier formation to assist in adherence to surfaces including other cell types, and its ability to resist desiccation during long dry periods 2 . C. sakazakii has been of much concern in life-threatening bacterial infections especially in low birth-weight neonates and infants. The clinical isolates of the bacterium produce only slightly yellow pigmentation when cultured on nutrient agar at 37 o C, but produce a non-diffusible yellow-gold pigment when incubated at room temperature. Pangalos in 1929 was the first to report that septicemia in an infant was caused by a yellow-pigmented coliform in tryptone soy agar TSA 3 . Willis and Robinson reported 40-80% mortality rates among infected infants 4 . Neonatal infections have been associated with C. sakazakii colonization of the food preparation equipment such as brushes, blenders, and spoons 5,6 . Its contamination from the samples of commercially available dry PIF has been reported 7-9 . C. sakazakii is an opportunistic pathogen most commonly affecting immunocompromised patients and neonates 4,10 . Neonatal infections have been reported to be on rise via contact with C. sakazakii in the birth canal or through post- birth environmental sources 11-13 . Detection of Cronobacter sakazakii Steigerwalt and his co-workers have observed that the presence or absence of yellow pigmentation can distinguish between the two strains of Enterobacteriaceae family (Enterobacter cloacae and C. sakazakii) when these strains are cultured on tryptone soy agar (TSA) 14 . It was further reported that fermentation of D-sorbitol helps in the differentiation among different strains 15 . C. sakazakii can be identified by some traditional biochemical methods, but there is a need of isolation in pure culture from mixed contamination in PIF before identification can be carried out 16 . Biochemical tests for the identification of C. sakazakii are shown in Table 1. Currently, molecular detection methods such as polymerase chain reaction (PCR), real-time PCR, and immunoassays are commonly employed for its identification 17 . Sometimes even more advanced methods such as DNA microarray-based assays have been used for the detection of C. sakazakii 18 . In the investigation of PIF contamination, a combination of methods such as antibiograms, ribotyping, plasmid analysis, multilocus enzyme electrophoresis, and chromosomal restriction fragment analysis have been used 19 . Sources of contamination C. sakazakii has been isolated from floor drains, air, vacuum canister, broom bristles, room heater, electrical control box, transition socks, a clean-inplace valve, floor, and condensate in a dry product processing plant 4 . Van Os et al. have isolated C. sakazakii from grass silage in The Netherlands 20 . It has also been isolated from hospital air 21 , clinical materials 22,23 , rats 24 , soil 25 , rhizosphere 26 , sediment and wetlands 27 , crude oil 28 and cutting fluids 29 . Clinical Sources Farmer et al. have reported that most of the C. sakazakii isolates from infected patients originate from CSF, blood, sputum, throat, nose, stool, gut, skin, wounds, bone marrow, eye, ear and breast abscess 1 . Although C. sakazakii infections in vaginally born newborns have been suspected to originate from mother’s birth canal, the presence of its infection in neonates born through caesarian section has questioned this hypothesis 8,30,31 . Moreover, often the fecal, vaginal, and