Detection of Serum Resistance Genes (lppA and omK36) in Enterobacteriaceae Species Isolated from Extraintestinal Infections

The study was aimed to genetically detection of genes encode outer membrane proteins related with human serum resistance: lipoprotein A (lppA) and outer membrane protein (ompk36) in 26 isolates of Enterobacteriaceae family isolated from intestinal and extra-intestinal infections. lppA and ompK36 genes were amplifed from genomic DNA using conventional PCR of all isolates of Enterobacteriaceae, it was found that 20(76.9%) of Enterobacteriaceae isolates gave positive result for lppA gene at 456 bp while only 15(57.6%) of isolates gave positive result for ompK36 gene at 305 bp. The highest prevalence of lppA gene was 100% and 80% observed among blood and UTI isolates, respectively, while the percent of lppA gene among intestinal isolates was (70%) and the lowest incidence of a lppA gene was detected in respiratory tract isolates which was 50%. The ompK36 was distributed among 70% of intestinal strains and among 50% while only 25% of blood isolates were having ompK36. The highest frequency of the lppA was observed in 100% of E.coli and Salmonella typhi strains which gave positive result at 456 bp, The prevalence of the lppA gene in Shigella dysentery, P. vulgaris and Serratia marcescens isolates were 80, 75 and 50%, respectively.