The biological diversity of Klebsiella pneumoniae (K. pneumoniae) has widely been reported to be associated with pathological progress in severe nosocomial and community-acquired infections. 250 clinical specimens included sputum, urine and swabs from wound and burns samples were collected from Al-Batool Teaching Hospital (38.4%), Baqubah Teaching Hospital (61.6%) and private laboratories in Baqubah and Diyala, Iraq. Positive rates of nosocomial acquired infection were sputum 98%, urine 96%, and swabs from wound and burns 94%, while positive rates of community acquired infection were sputum 60%, urine 60%, and swabs wound and burns 30%. Positive rates of nosocomial and community acquired infections were 96% and 48%, respectively. The distribution of pathogenic bacteria of E. coli was 19.2% and 8.8%, and those of K. pneumoniae were 23.2% and 12% of nosocomial and community acquired infections respectively, which is a higher percentage than other pathogenic bacteria of nosocomial and community acquired infections. The nosocomial-acquired K. pneumoniae isolates were less susceptible than community-acquired K. pneumoniae isolates. Multi-drug resistant (MDR) and extensively drug resistant (XDR) are commonly caused by -lactam/ -lactamase inhibitor combinations: Ticarcillin clavulanate, carbapenems and meropenem 100%; cephalosporines and ceftazidime 96%. Phylogenetic analysis of the 16S rRNA gene showed the presence of six nucleic acid variations in various samples. This variance might exhibit a clear tendency to be localized in the community acquired K. pneumoniae isolates. Fifteen ribosomal sequences were deposited at GenBank in accession numbers starts from OM992298 to OM992312.
