Comparative study about some salmonella isolation techniques from cases of enterica

Typhoid fever remains an important public health problem in many parts of the world. Rapid and sensitive laboratory methods for Salmonella isolation in diagnosis of typhoid fever are essential for prompt and effective antibiotic therapy. This study was designed to compare Some techniques for Salmonella isolation from blood and stool to find the most rapid, sensitive and specific one to detect their antibiotic sensitivity pattern suitable for antibiotic therapy and epidemiological surveillance. For this purpose 312 patients [262 typhoid study cases - 50 none typhoid control cases] admitted to Abbassia Fever Hospital from April 1996 to April 1999 were examined 191 cases out of 312 cases proved to be enterica by conventional techniques like [WBCs count, ESR, Widal test, ordinary stool and blood isolation culture,]. Yielded 104 Salmonella Strains by conventional techniques but when bi-examined in 5 groups for isolation of salmonella by one of the following culture techniques in comparison to ordinary B. C: [1- Isoslate culture, 2- Monocyte culture, 3- Clot culture, 4- Stool culture, and 5- Bone marrow culture.] they yielded [127,] salmonella isolates. The results of conventional and non conventional isolation techniques were evaluated and compared as regards specificity, sensitivity, rate of isolation, performance and costs. From this study it was found that [1-The mononuclear culture was the most sensitive blood culture technique in isolating Salmonella strains with 63% sensitivity and average time 1.1 days if compared to conventional blood culture [2.8 days]. It was found that the indirect mononuclear technique took the same time as conventional blood culture [2. 7 days- 2.8 days]. The test was easy but hazardous to laboratory workers, 2- The lysis isoslate culture was the most rapid blood culture technique by direct method [one day] but it was less sensitive than conventional one [43% - 55%]. The test showed also simple and no difference between direct and indirect technique as regard average isolation time, 3- The clot culture technique was the simplest one and showed the same sensitivity as conventional blood culture [58- 55%] with average time 2.6 days nearly equal to conventional techniques [2.8 days]. the test was selective for salmonella species and inhibited the growth of skin contaminants. The separated serum could be used for serological diagnosis of typhoid fever. 4- The stool culture technique had a limited value in diagnosis of acute typhoid fever with very low sensitivity 13% compared to ordinary blood culture technique which is less sensitive and takes more average time [2.8 days] 5- The bone marrow culture although highly specific and sensitive; it can not be used as a routine technique except in case of [F. U. O] to exclude the infection in some typhoid cases finder specific therapy. 6- The highest isolation rate of salmonella strains from, blood [47%] was obtained by using both ordinary blood culture and isostate blood culture together. It has the chance of isolation when there is low number of bacteria