Study of Cronobacter sakazakii Strains Isolated from Powdered Milk Infant Formula by Phenotypic and Molecular Methods in Iran

Abstract

Background: Cronobacter is a genus within the family Enterobacteriaceae and was previously known as Enterobacter sakazakii. Cronobacter sakazakii is an opportunistic ubiquitous bacterium and is identified throughout the world as an emerging food-borne pathogen. This pathogen causes meningitis, necrotizing enterocolitis (NEC), and sepsis (septicemia) in patients hospitalized in neonatal intensive care units and has a high mortality and morbidity rate. Contamination of powdered infant milk formula occurs more easily because it is a nonsterilized product. Objectives: The aims of the present study were as follows: Isolation of Cronobacter sakazakii from powdered infant formula milk (PIF), confirmation of isolates by biochemical tests and polymerase chain reaction (PCR) molecular method, and characterization of an antibiotic susceptibility profile. Methods: A cross-sectional study was performed on 125 powdered infant formula milk (PIF) samples purchased from hospital drug stores between June 2014 and March 2015. Cronobacter sakazakii was recovered according to FDA protocol. For the final confirmation of isolates, different biochemical tests embedded in the API-20E kit system and manual biochemical tests were used according to the directions of the manufacturer. Antibiotic susceptibility testing was performed on Mueller-Hinton agar by disk diffusion method according to CLSI recommendations. For molecular confirmation of isolates confirmed by biochemical tests, PCR was performed on 16S rRNA gene specific for Cronobacter sakazakii. Results: Out of the 125 PIF samples investigated, nine (7.2%) of the samples were positive for Cronobacter sakazakii. All C. sakazakii strains isolated from PIF samples were uniformly susceptible to ticarcillin, chloramphenicol, levofloxacin, ciprofloxacin, moxifloxacin, cefepime, piperacillin-tazobactam, and colistin. All isolates were confirmed by PCR. Conclusions: Results showed that PIF that is being consumed in Iran is contaminated with this pathogen and can cause disease in infants; especially those hospitalized in neonatal intensive care units (NICUs) and fed PIF. The number of reported cases of Cronobacter infections is very low, but nevertheless there has been a slight increase recently. While the reported cases worldwide are few, it needs to be noted that the number of infections may be underestimated since not all clinical analysis laboratories carry out research on other bacterial pathogens, and not all countries have a system for reporting diseases.

Prevalence, phenotypic and genotypic characterization, virulence potential and antimicrobial resistance of Cronobacter species from ready-to-eat foods

“…As prescribed for the treatment, in our study, more than 90% of the Cronobacter isolates were also susceptibility to piperacillintazobactam, gentamicin, amikacin, imipenem, meropenem, tetracycline, trimethoprim/sulfamethoxazole, ciprofloxacin, and chloramphenicol. Susceptibility to these antimicrobials has been reported in many countries: Brazil [30], China [9], and Iran [56]. In the current study, the multidrug resistance to at least three or more antimicrobial agents was detected in the 12 (18.8%) of Cronobacter isolates.…”

“…Previous reports revealed the occurrence of resistance to the antimicrobial agents in Cronobacter spp. isolated from different sources [31,32,56]. Increasing resistance of Cronobacter against a range of cephalosporins and penicillins due to the production of β-lactamases has been reported [11,29,30].…”

Prevalence and Antibiotic Susceptibility Patterns of Salmonella and Shigella Species Isolated from Pediatric Diarrhea in Tehran

“…High rates of antibiotic resistance may result from the uncontrolled or inappropriate use of antibiotics. This can cause antibiotic-resistant bacteria to spread easily between hospital wards, leading to protracted outbreaks with high mortality and morbidity rates (35). The epidemiological information and monitoring system are, therefore, necessary to control Salmonella and Shigella infections in public health sectors.…”

A novel primer targeted gyrB gene for the identification of Cronobacter sakazakii in powdered infant formulas (PIF) and baby foods in Iran

“…Comparing the results with other studies in Iran, our findings showed a decrease in contamination rate of PIFs. According to Mardaneh and Dallal study in 2017 on 125 samples of PIFs, the contamination rate was reported 7.2% (Mardaneh & Dallal, ). On the other hand, contamination of baby foods in our study showed a higher contamination rate than some other studies, such as Abdel‐Galil et al, who reported only one contaminated sample (1.6%) (Abdel‐Galil et al, ) and lower contamination rate than (Aigbekaen & Oshoma, ; Iversen & Forsythe, ) studies who reported 27.1% (Aigbekaen & Oshoma, ) and 24%, respectively (Iversen & Forsythe, ).…”

“…This bacterium has been identified in various food sources, although its relevance to powdered infant formula (PIF) and baby food are major sources of concern (Biering et al, 1989;Teramoto et al, 2010;Yan et al, 2012). Raw materials of different origin or heatsensitive materials that are added to the PIF heating, extrinsic contamination of opened cans and carrier humans can be potential sources of bacteria (Abdel-Galil, Abdel-Latif, Ammar, & Serry, 2015;Jaradat, Al Mousa, Elbetieha, Al Nabulsi, & Tall, 2014;Mardaneh & Dallal, 2017).…”