Detecting Phenotypic and Genotypic of the Antibiotic Resistant Salmonella enterica Serotype Paratyphi Isolated from Blood Samples in Najaf Province /Iraq

Background & Objectives: Salmonella Paratyphi is a leading cause of human paratyphoid fever in developing countries, causing deaths in humans worldwide. There are several paths for catching paratyphoid fever, but the close contact between patients and healthy humans is so far the most frequent cause of human infections. No study is found about the antibiotic resistance (phenotypic and genetic) of S. Paratyphi isolated from patients in Al-Najaf Province/Iraq, to the researcher’s best knowledge. Hence, this study aimed to determine the prevalence of S. Paratyphi isolates from blood specimens and the antibiotic resistance determinants of them, as well as the genetic relationship among isolates. Methods and Results: Blood specimens from 1743 patients with suspected enteric fever were cultured for the identification of Salmonella enterica during the period from first April to the end of October 2017. 107 (6.14%) S. enterica isolates were recovered and only two (1.87%) of isolates were S. enterica serovar Paratyphi B. These two isolates (ST39 and ST89) were tested against 23 antibiotics using the disc diffusion method on Muller-Hinton agar and the genotypic antibiotic resistance determinants by PCR. ST39 isolate was sensitive to all antibiotics while ST89 isolate was resistant to only cefepime, piperacillin and tobramycin. ST39 isolate did not carry integrons (1 or 2) and any resistance determinants, while ST89 isolate carried integron class1 as well as blaTEM, blaCTX-M and aac(6')-lb genes. Conclusions: The findings of S. Paratyphi isolates with integron 1 and resistant antibiotic genes indicating public health risks.