Aims: The current study aimed to isolate and characterize bacterial strains associated diarrhea with the focus on Enterobacter species strains and test for susceptibility to antibiotics. Methodology and results: A total of 400 stool samples from inpatients suffering from diarrhea in Al-Qasim Hospital at Al-Hilla City of Iraq were screened form January 2018 to January 2019. Phenotypic, molecular, and biochemical methods were used to identify the isolated bacteria. A new strain of Enterobacter hormaechei was obtained from two stool samples of inpatients suffering from diarrhea for more than two weeks. This strain is Gram negative, rod shaped, and facultative anaerobic. Multiple sequence alignment analysis and phylogenetic tree construction of the sequenced 16S rRNA gene of the isolated strain suggested that this strain can be identified as E. hormaechei subsp. xiangfangensis, named as E. hormaechei subsp. xiangfangensis strain AA1. This strain was resistant to augmentin, ampicillin, cephalothin, cefoxitin, ceftazidime, cefixime, ticracillin/clavulanic acid, cefotaxime, streptomycin, erythromycin, amikacin, ciprofloxacin, and chloramphenicol, while it was susceptible to meropenem along with imipenem. Conclusion, significance and impact of study In the present study, E. hormaechei subsp xiangfangensis was isolated for the first time in Iraq and was resistant to most of the tested antibiotics, making it an etiologic agent that is not easy to be treated.
Diarrhea--microbiology