Production of Monoclonal Antibodies in a Mouse Model via Lipopolysaccharide Conjugates with Synthetic Polymers Specific to Salmonella Enteritidis O Antigen Ayse Nalbantsoy, 1 Ismail Karaboz, 2 and Ismet Deliloglu Gurhan 1 Abstract Monoclonal antibodies (Mabs) specific for lipopolysaccharide (LPS) of Salmonella Enteritidis were evaluated in a model of LPS conjugated synthetic polymer immunization of Balb=c mice by conventional hybridoma method. Nine hybridoma cell lines were determined as antibody positive against LPS. The clone 5A8 secreting the highest antibody was selected for further characterization. Evaluated results indicate that the synthetic polymer can be used as an effective adjuvant in immunization with LPS, because the 5A8 Mab were obtained using synthetic polymer as an adjuvant. 5A8 Mab was classified as IgG2a isotype by antibody capture enzyme-linked immuno- sorbent assay. The reactivity of the Mab against lipid A and different LPS of Salmonella were investigated using an indirect enzyme-linked immunosorbent assay. Mab presented a wide spectrum of reactivity, coupling with antigens against Salmonella. The hybridoma 5A8 determined in this study has a great potential to be used in the development of diagnostic, prophylactic, and therapeutic agents specific for Salmonella Enteritidis and Salmonella LPS. Introduction S almonella is one of the most dangerous bacterial path- ogens in foods representing a serious risk for public health (Peter et al., 1999; Iankov et al., 2004; Schneid et al., 2005; Okamura et al., 2007). Moreover, Salmonella enterica, with >2500 serovars, is responsible for considerable economic losses worldwide (Karasova et al., 2009). Salmonella En- teritidis, however, only rose to its predominant position in human and poultry in the mid-1980s as a result of vertical and horizontal transmission within and between large poultry organizations in many parts of the world (Davies et al., 1997; Hochel et al., 2001). Poultry products are known to be a sig- nificant reservoir for Salmonella and the most important source of Salmonella Enteritidis infection in humans (Ochoa- Reparaz et al., 2005). Both Salmonella Enteritidis and Salmonella Typhimurium are capable of infecting a range of hosts. Sys- temic infection with these serovars is more transient, with the exception of newly hatched chicks, causing slight clinical disease. In contrast, Salmonella enterica serovar Gallinarum and serovar Pullorum cause systemic disease only restricted in place of avian species (Chappell et al., 2009). Salmonellae are antigenically complex, and serovars have been differentiated by somatic lipopolysaccharide (LPS) or flagellar protein antigens. On this basis, they have been con- sidered as possible candidates for vaccines and diagnostic reagents (Malik et al., 2002) . Conventional methodology for identifying Salmonella is both labor intensive and time con- suming, which requires several enrichment and selective platings followed by biochemical and serological identifica- tion. Salmonella identification can takes 7 to 11 days depending on the methods used (Mayer et al., 1985; Humbert et al., 1990; Keller et al., 1993; Adams and Moss, 1995; Solano et al., 2000; Schneid et al., 2005). Several more rapid serological assays to be used in screening Salmonella Enteritidis have been described; these include agglutination tests and enzyme-linked immu- nosorbent assay (ELISA) (Swaminathan et al., 1985; Wyatt et al., 1993) using different antigens such as LPS, flagellin, and so on (Kerr et al., 1992; Zijderveld et al., 1992; Solano et al., 2000). LPS is, therefore, a good antigen of choice for use in an immuno- chemical assay for the serological detection of antibodies (Luk and Lindberg, 1991; Jaoho et al., 2000; Brooks et al., 2008). On the other hand, monoclonal antibodies (Mabs) have greater number potential for identifying, isolating, and puri- fying bacterial antigens and also in defining the role of specific antigens in diagnosis, classification, and immunity to infec- tion. They may also facilitate serotyping and strain differen- tiation (Torensma et al., 1992; Malik et al., 2002). Development of the novel reagents such as diagnostics Mabs has become economically important for detection of Salmonella Enteritidis. The objective of this study was the production of Mab against Salmonella Enteritidis LPS via the immunization of 1 Department of Bioengineering, Faculty of Engineering, Ege University, Izmir, Turkey. 2 Basic and Industrial Microbiology Section, Department of Biology, Faculty of Science, Ege University, Izmir, Turkey. FOODBORNE PATHOGENS AND DISEASE Volume 7, Number 12, 2010 ª Mary Ann Liebert, Inc. DOI: 10.1089=fpd.2010.0612 1521