Characterization of uropathogenic E. coli O25b-B2-ST131, O15:K52:H1, and CGA: Neutrophils apoptosis, serum bactericidal assay, biofilm formation, and virulence typing.

Pathogenic and drug-resistant strains of Escherichia coli (E. coli) O25b-B2-ST131, O15:H1-D-ST393, and CGA (clonal group A) clonal groups have spread worldwide. This study aimed at determining E. coli epidemic clonal groups, their virulence factors, biofilm formation, neutrophils apoptosis, and antimicrobial resistance pattern of uropathogenic E. coli. A total of 95 CTX-M-1-producing E. coli clinical isolates were enrolled. E. coli O25b-B2-ST131, CGA, and O15:K52:H1 were identified by serotyping and phylogrouping and allele-specific polymerase chain reaction-based assay. Antibiotic susceptibility, biofilm formation, hemolysis, and human serum bactericidal assay were performed. Neutrophil apoptosis was assayed by flow cytometry. Nine E. coli clonal groups including six O25b-B2-ST131 strains, two CGA, and one O15:K52:H1-D-ST393 strains were detected. One O25b-B2-ST131 isolate was a strong biofilm-producer. Three ST131 isolates had type I fimbriae. Furthermore, all the CGA and O15:K52:H1 and three of ST131 isolates harbored the P fimbriae. The virulence genes ompT, fimH, and traT were detected among all the clonal groups. The apoptosis was induced by O25b-B2-ST131, CGA, and O15:K52:H1 E. coli. There was no significant difference regarding apoptosis induction among clonal groups. Furthermore, the presence of the cdt, usp, and vat genes was significantly associated with the apoptosis of neutrophils by O25b-B2-ST131, CGA, and O15:K52:H1-D-ST393 clonal groups.

First case of Helicobacter pylori infection resistant to seven antibiotics in Iran.

Treatment of Helicobacter pylori infection with common antibiotics is typically recommended for several digestive conditions, including peptic ulcers. However, reports of resistant H. pylori isolates are increasing, and unfortunately, these do not respond to currently available therapeutic regimens. We report the case of a 31-year-old woman with two peptic ulcers in the duodenal antrum. An H. pylori strain was isolated, and tested for antibiotic resistance using agar dilution and disk diffusion. The isolated strain was found to be resistant to all seven antibiotics that were tested. Therefore, constant monitoring for antibiotic resistance should be performed prior to initiating antibiotic therapy.

Primary resistance of Helicobacter pylori to levofloxacin and moxifloxacine in Iran.

The increase in the prevalence of antibiotic resistance in Helicobacter pylori had a drastic effect on successful treatment. Up-to-date information on H. pylori antibiotic therapy in Iran is still limited. In this study, we aim to determine the prevalence of antibiotic resistance among the H. pylori strains. Furthermore, the possibility of using fluoroquinolones for antibiotic treatment was investigated. Antral biopsy specimens obtained from dyspeptic patients were investigated for H. pylori. Bacterial culture and susceptibility tests were done based on standard methods. H. pylori ATCC 43504 was used as a quality control. In the current study, 30 H. pylori strains were selected randomly and retested to confirm our susceptibility tests. Of 170 patients, 150 were identified as positive for H. pylori (88.2%). In this study, 150 single colonies of H. pylori strains [81 women (54%), 69 men (46%); mean age 38.6; aged 21-70 years] were collected. Primary resistance of H. pylori isolates were clarithromycin (34%), metronidazole (78.6%), tetracycline (9.3%), amoxicillin (10%), levofloxacin (5.3%) and moxifloxacine (4.6%). In conclusion, our results show that we are confronting a new generation of resistant strains of H. pylori in Iran. This alarming finding indicates an urgent need for introduction of new effective antibiotics in our country. Since the majority of clinicians prefer to continue with the ineffective antibiotics as therapeutic regimens, they must also be prepared to deal with treatment failures.

Frequency of antibiotic resistance in Helicobacter pylori strains isolated from the northern population of Iran.

The purpose of this study was to evaluate the primary resistance rates of recent clinical Helicobacter pylori isolates to the most commonly used antibiotics in Iran. Two hundreds and ten patients presenting with gastric maladies between January and July of 2009 were enrolled in this study. Endoscopy was performed, and biopsy specimens were collected from each patient for subsequent bacterial culture of H. pylori. Single colony isolates from each patient were then used for antimicrobial susceptibility testing. The disk diffusion method was used to determine susceptibility patterns. One hundred and ninety-seven of the patients were H. pylori positive (93.8%). The rates of resistance to tetracycline, amoxicillin, ciprofloxacin, metronidazole, clarithromycin, and furizoladone were 37.1%, 23.9%, 34.5%, 65.5%, 45.2%, and 61.4%, respectively. A significant association between amoxicillin resistance and disease state (P<0.05) was identified. Furthermore, some double, triple, quadruple, and quintuple combinations of antibiotic resistance were found to be associated with disease state. This study evaluated the prevalence of H. pylori resistance to the most commonly prescribed antibiotics used in Iran and showed that resistance rates were generally higher than previously reported. This data adds to the growing body of evidence that suggests there is increasing antibiotic resistance among H. pylori isolates, which likely is responsible for the decreasing efficacy of anti-H. pylori therapy at the local and global level. Hence, there is a need for continued monitoring of resistance patterns, especially at the local level, and for incorporation of that information into treatment regimens for H. pylori infections.

First case of Helicobacter pylori infection resistant to seven antibiotics in Iran

Treatment of Helicobacter pylori infection with common antibiotics is typically recommended for several digestive conditions, including peptic ulcers. However, reports of resistant H. pylori isolates are increasing, and unfortunately, these do not respond to currently available therapeutic regimens. We report the case of a 31-year-old woman with two peptic ulcers in the duodenal antrum. An H. pylori strain was isolated, and tested for antibiotic resistance using agar dilution and disk diffusion. The isolated strain was found to be resistant to all seven antibiotics that were tested. Therefore, constant monitoring for antibiotic resistance should be performed prior to initiating antibiotic therapy.