Mardaneh Jalal, Soltan-Dallal Mohammad-Mehdi
Prof Alborzi Clinical Microbiology Research Center, Namazee Hospital, Shiraz University of Medical Sciences, Shiraz.
Department of Bactriology, Department of Pathobiology and Microbiology, School of Public Health ; Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Iran J Pediatr. 2014 Jun;24(3):261-6.
Enterobacter cowanii is a genus of common gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacterium of the Enterobacteriaceae family. This organism can be potentially a powdered infant milk formula-borne opportunistic pathogen. The aim of this study was to isolate and identify E. cowanii from consumed powdered infant formula milk (PIF) in intensive care units (NICU) and to determine antimicrobial susceptibility patterns of this bacterium.
E. cowanii was isolated according to FDA method in 125 samples of PIF milk purchased from drug stores between Jun 2011 and March 2012. For final confirmation, biochemical tests embedded in API-20E system were used. The drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations. Findings : Out of the 125 PIF samples investigated, 4 (3.2%) samples were positive for E. cowanii. All four isolates from PIF samples were uniformly susceptible to imipenem, meropenem, ceftazidime, ciprofloxacin, and colistin. Fifty percent of isolates were resistant to ampicillin, amoxicillin, and cotrimoxazole Conclusion: Analysis of the results indicated that complementary studies are necessary to clarify the possible role of E. cowanii as a food contaminant, in common NICU infections and high risk groups including persons with underlying disease and immunocompromised individuals.
考氏肠杆菌是肠杆菌科常见的革兰氏阴性、兼性厌氧、杆状、无芽孢形成的细菌属。这种微生物可能是一种通过婴儿配方奶粉传播的机会致病菌。本研究的目的是从新生儿重症监护病房（NICU）食用的婴儿配方奶粉（PIF）中分离和鉴定考氏肠杆菌，并确定该细菌的抗菌药敏模式。
根据FDA方法，从2011年6月至2012年3月期间从药店购买的125份PIF奶粉样本中分离考氏肠杆菌。为进行最终确认，使用了API-20E系统中的生化试验。根据CLSI建议，采用纸片扩散法进行药敏试验。结果：在调查的125份PIF样本中，有4份（3.2%）考氏肠杆菌检测呈阳性。来自PIF样本的所有4株分离菌对亚胺培南、美罗培南、头孢他啶、环丙沙星和黏菌素均敏感。50%的分离菌对氨苄西林、阿莫西林和复方新诺明耐药。结论：结果分析表明，有必要进行补充研究，以阐明考氏肠杆菌作为食品污染物在常见的NICU感染以及包括患有基础疾病者和免疫功能低下者在内的高危人群中可能发挥的作用。
