Background: Global increase in the prevalence of virulent extended-spectrum betalactamase (ESBL)-producing uropathogenic Escherichia coli (UPEC), which is also multidrug resistant (MDR), leads to increase in severity of urinary tract infections (UTIs), decrease in the efficacy of the first-line antibiotics, and therefore increase in the morbidity and mortality rates. Methods: We investigated the distribution of ESBL-producing UPEC in 78 E. coli isolates from community-acquired UTI patients in southern Iran. The prevalence of three major ESBL genes, antimicrobial resistance patterns against 15 conventional antibiotic disks, and the presence of 11 important virulence genes that involve in the development and progression of UTIs were evaluated in these isolates. Results: Of the UPECs, 34.6% were ESBL-positive and 96.3% of the ESBL-producers were MDR. Among the ESBL-producers, 100% harbored bla CTX-M , 63% harbored bla SHV , and 11.1% harbored bla TEM genes. ESBL-producers showed a higher level of resistance to the tested cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, and tetracycline than non-ESBL producers. All isolates were resistant to the tested penicillins. Prevalence of resistance to about two-third of the tested antibiotics was higher than 50% and 93.6% of the isolates were MDR. High prevalence of virulence factors particularly the adhesins (82.1% csgA, 73.1% fimH genes) and siderophore (73.1% sitA gene) was seen in the UPECs. But fortunately in MDR isolates, the virulence score and prevalence of hemagglutinin (tsh), hemolysin toxin (hlyD) and invasin (ibeA) genes were lower than in non-MDR UPECs. Shockingly, among the 15 common antibiotics, only nitrofurantoin (<20% resistance) could be recommended as an appropriate drug for the treatment of UTIs due to our ESBL-producer UPECs. Conclusion: The alarming level of virulent MDR ESBL-producer E. coli strains in this study necessitates the performing of an antibiotic stewardship program, regional screening of ESBL-producers and their virulence properties to select appropriate antibiotic, or designing new therapeutic methods for UTIs by inactivation of the essential virulence factors of UPECs.

Background: Klebsiella pneumoniae is an important cause of healthcare-associated infection. Carbapenemases have increasingly been reported in Enterobacteriaceae, especially in K. pneumoniae. Propose: The objective of this study was to determine antibiotic resistance patterns, and the molecular epidemiology of multidrug resistant K. pneumoniae isolates, obtained from hospitalized patients in Shiraz, Iran. Methods: In this study, 60 K. pneumoniaeisolates were collected from Nemazee and Faghihi referral hospitals. Antibiotic susceptibility testing and MIC were performed by disk diffusion test and Epsilometer (E)-test strips, respectively. Carbapenemase genes were identified by polymerase chain reaction and sequencing. Then, clonal relationships were analyzed, using PFGE. Results: Thirty-three out of 60 K. pneumoniae isolates were resistant to carbapenems. Among the isolates, 86.6% were multidrug resistant (MDR). Polymyxin B (18.3%) and tigecycline (23.3%) were shown to be the most active agents against K. pneumoniae isolates. In our study, the high prevalence of bla NDM (45%) and bla OXA-48 (10%) was detected. Conclusion: The results of this study revealed the widespread carbapenemase gene between different wards in hospitals as a risk factor for treatment options. PFGE analysis showed 11 clusters and 3 singletons based on an 80% similarity level. Also, PFGE analysis showed that there were similar genetic patterns among K. pneumoniae isolates and these patterns were responsible for the distribution of infection in hospitals.

Objectives: Antibiotic resistance, phylogenetic groups and Pulsed-Field Gel Electrophoresis (PFGE) patterns were evaluated in urinary tract infection (UTI) Escherichia coli (E. coli) isolates from outpatients and inpatients. Methods: In this study, antibiotic resistance of 153 outpatients and 147 inpatients E. coli isolated from non-hospitalized and hospitalized patients were evaluated in Shiraz County, Iran. Phylogenetic groups and Pulse Field Gel Electrophoresis (PFGE) patterns of 143 ESBLs producing E. coli were also assessed. Results: The incidence of ESBL-producing E. coli was shown to be 46.4% and 49% in outpatient and inpatient UTI E. coli isolates, respectively. Most ESBL producers were detected on patients hospitalized in clinical surgery units (66.7%) and intensive-Care units (62.5%). Phylogenetic groups D were the dominant group in both outpatient and inpatient isolates (67.6% and 61.1%, respectively) and also in internal, clinical surgery and ICU units. PFGE results showed more relatedness (>80% similarity) among inpatient isolates. PFGE analysis of 49 ESBL-producing inpatient E.coli in hospital units revealed 17 different pulsotypes, consisting of 11 clones and 6 single patterns. There were no clonal patterns in outpatient isolates, and similarity among outpatient isolates and also between inpatient and outpatient isolates were less than 80% (75% and 66%, respectively). Conclusions: The results showed extreme genomic diversity among the ESBL-producing E. coli isolated from community and multiclonal dissemination of ESBL-producing E. coli isolated from hospital units.

Background: We aimed to investigate antimicrobial resistance and clonal relationships among poultry Escherichia coli isolates from different broiler farms and their relationships with Extended-Spectrum Beta-Lactamase (ESBL) producing urinary pathogenic E. coli (UPEC) isolates from the same geographical area. Methods: Twenty four E. coli isolates from six broiler farms with colibacillosis and 97 ESBL producing human UPEC isolates were investigated for resistance to critically important antimicrobials in human medicine in Shiraz, central Iran in 2015-16. In addition, clonal relationships of these isolates were investigated with Pulse Field Gel Electrophoresis (PFGE). Results: As expected, cephalosporins and imipenem resistance were significantly higher in ESBL producing human E. coli isolates in comparison with non-ESBL avian pathogenic E. coli (APEC) isolates. In addition, significantly higher percentages of gentamycin and trimethoprim-sulfamethoxazole resistance were seen in human isolates. In contrast, nitrofurantoin resistance was significantly higher in APEC isolates. Based on PFGE patterns, five clusters were identified in APEC isolates. Isolates from each farm were closely related to each other by PFGE patterns. However, different PFGE restriction profiles were seen among the E. coli isolates from different broiler farms. Comparison of PFGE patterns among APEC and UPEC isolates showed two closely related PFGE patterns. Conclusion: There were clonally related E. coli isolates caused the outbreaks of colibacillosis within broiler farms. Some of these isolates had closely related PFGE patterns with human UPEC isolates which suggest avian pathogenic E. coli strains as a potential zoonosis.