sakazakii; however, nothing is known about its antigenicity. Besides, little is known about OMPs from other Cronobacter species [8–10]. In contrast, the virulence and antigenic properties of OMPs of closely related Enterobacter species including E. Baf-A1 cell line aerogenes [11] and E. cloacae [12, 13] were studied well. Prematurely born infants with low birth weights and infants in neonatal intensive care units are highly susceptible to Cronobacter infections with the pathogen being transmitted primarily from contaminated environments to the infant formula during the preparation [14–20].

In rare cases, nosocomial infections can happen in adults especially in immunocompromised ones [21]. In check details 2004, a joint FDA/WHO workshop raised an alert concerning the presence of Cronobacter in powdered infant formula (PIF) and recommended applying higher microbiological standards during its manufacturing [22]. This warning culminated into increased research efforts to study Cronobacter including the development of improved isolation and identification methods, and understanding of the growth and survival characteristics. Antibodies are the www.selleckchem.com/products/sbe-b-cd.html most frequently used tools to study bacterial antigenic determinants; however, little is known about the production of monoclonal antibodies that

recognize Cronobacter antigenic determinants. In this paper we describe the production and characterization of 5 MAbs that recognize outer membrane proteins of Cronobacter. In addition, antigenic properties, identification, distribution and cell surface localization of the MAbs- recognized OMPs were examined using electron microscopy and MALDI-TOF spectrometry. To our knowledge, this is the first report on using monoclonal antibodies to study the surface antigens of this pathogen. Methods Materials Alkaline phosphatase-conjugated goat anti-mouse immunoglobulin, complete

Freund’s adjuvant, incomplete Freund’s adjuvant, sarkosyl, DMSO, pancreatic RNase and DNase and a mouse subisotyping kit were from Sigma-Aldrich, USA. Gold-conjugated (18 nm) anti-mouse IgG was obtained from Jackson Immunochemicals, USA. Polyethelyene medroxyprogesterone glycol 4000 was from Fluka, USA. Micro test plates, tissue culture plates and flasks were from Griener, Germany. Coommassie Brilliant blue G-250 was from BDH chemicals, Ireland and BSA was from Biobasic, Canada; Proteinase K was from Promega, USA. Goat anti-mouse-conjugated to horse radish peroxidase (HRP) was from Santa Cruz, USA. Penicillin, streptomycin and amphotercin B were from PAA Laboratories GMBH, Austria. Recovery cell culture freezing media was from Gibco, USA. Myeloma SP2 cells were a gift from Dr. Khalid Qaoud, Yarmouk University, Jordan. All other chemicals and reagents were of analytical grade. Bacteria and growth conditions Stock cultures were maintained through out this study on Trypticase Soy Agar (TSA) (Oxoid, UK) or nutrient agar plates (HiMedia, India) at 4°C until use. The type strain C.