مریم باقرنژاد

A major concern about S. pneumoniae is the emergence of resistance to antibiotics, especially to penicillin. The aim of this study was to assess the role of PBPs gene in penicillin resistance of S. pneumoniae strains isolated from two intensive care units (ICUs).. This cross-sectional study was carried out on 62 samples suspected to S. pneumoniae isolated from patients who were admitted to ICUs of Namazi and Shahid Faghihi Hospitals, Shiraz, Iran, in 2010-2011. At first suspected colonies were identified by phenotypic and chemical tests. Organisms were confirmed to be S. pneumoniae on the basis of the presence of lytA gene by polymerase chain reaction (PCR) method. Antibiotic resistance was evaluated according to Clinical and Laboratory Standards Institute (CLSI). Molecular analyses of penicillin resistance were carried out using specific primers for pbp1a, pbp2b and pbp2x genes. Of total samples, 50 (80.64%) isolates were confirmed to be S. pneumoniae by PCR assay. Of these isolates, 20 (40%), 10 (20%), and 20 (40%) strains were sensitive, moderately sensitive, and resistant to penicillin, respectively. Out of resistant and moderately sensitive strains, 6 (20%) and 1 (3.33%) strains harbored pbp1a and pbp2x genes, respectively. However, pbp2b was not identified in any samples. Monitoring other kinds of resistance mechanisms is recommended due to the low frequency of pbps genes.

Macrolide Streptococcus pneumoniae is generally mediated by two mechanisms: 23SrRNA methylation and efflux. The aim of this study was to assess the molecular mechanism of resistance in S.pneumoniae strains isolated from intensive care units in Shiraz. This was a cross – sectional study. 50 strains of S.pneumoniae were obtained from the patients admitted to intensive care units (ICU) of Nemazee and Shahid-Faghihi Hospitals, from 2010 to 2011. Suspected colonies were identified by phenotypical and biochemical tests. Organisms were confirmed to be Streptococcus pneumoniae on the basis of the presence of lytA gene by PCR method. Antibiotic resistance was evaluated according to Standard Clinical and Laboratory Standards Institute (CLSI). Macrolide resistance genes were identified by use of ermB and mefA specific primers. Using SPSS software, statistical analysis was performed by means of chi- square test. Resistance to erythromycin, clarithromycin and azithromycin levofloxacin were 18%, 48% and 44% respectively. In this study, 25 strains (50%) had mefA and 21 (42%) had ermB genes. Erythromycin resistance had significant relationships with mefA and ermB genes. The results of our study showed that the predominant mechanism of macrolide resistance was due to mefA gene in this area. Increased macrolide resistance calls for attention to the pattern of resistance in the therapeutic regimens.

Helicobactr pylori (H.pylori) infection is related to chronic gastritis, peptic ulcer and duodenal ulcer. Thus, identification and treatment of the infection has a considerable importance. The aim of this study was to compare three methods of polymerase chain reaction (PCR), culture and rapid urease test (RUT) in identification of Helicobactr pylori in gastric biopsy specimens.

263 patients (157 woman and 106 man) who suffering from digestive complaints and referred to the endoscopy department of Hajar Hospital in Sharkord (2007, Iran) were participated in the study. Three gastric biopsy samples were collected from each patient. Samples were examined by standard RUT and culture methods for diagnosis of H. pylori. PCR was used for diagnosis of ureC gene.

Out of 263 patients, 36.49%, 9.50%, 13.30%, 9.48% and 5.50% had criteria gastritis, gastric ulcer, duodenal ulcer, esophagitis and gastric cancer, respectively. H.pylori infection was diagnosed in 54.37%, 31.94% and 84.79% of the patients by RUT, culture and PCR method, respectively.

Findings of this study indicated that PCR has a greater sensitivity rather than rapid urease test and culture methods for diagnosis of H.pylori.

Current therapeutic regimens used for eradication of H.pylori consist of two antibiotics with proton pump inhibitors and bismuth compounds. Clarithromycin is the most important antibiotic used for treatment of H.pylori infection in Iran. The aim of this study was to identify clarithromycin resistance in H.pylori strains and evaluate role of A2143G, A2142G and A2142C of 23SrRNA point mutations in producing resistance to this drug. This was a cross-sectional study which included 263 patients who had referred to endoscopy department of Hajar hospital, in Shahrekord city, in 2007. Biopsy samples were cultured on brucella agar medium and incubated. For identification of H.pylori gram stain, urease, catalase, oxidase tests were used and PCR method was used to identify Urec gene. Standard method of NCLSI (National Clinical and Laboratory Standards Institute) was used for assessment of clarithromycin resistance. Specific primers and restriction enzymes BsaI and MboII were used to detect A2143G and A2142G mutations by PCR-RFLP method. Also for determination of A2142C mutation, specific primers and PCR method were used. Isolation of 84 strains of H.pylori (31.94%) was confirmed by means of PCR method. Among 19 (22.62%) of clarithromycin resistant strains, 13 (68.40%), 3 (15.78%) and 2 (10.52%) had A2143G, A2142G, A2142C mutations respectively and one unknown mutation was detected in 23SrRNA gene. Because of considerable resistance to clarithromycin, precise diagnosis of this mutation by molecular approach in other parts of the country seems necessary.

Metronidazole is one of the most important antibiotics in Helicobacter pylori (H.pylori) eradication regimens. This study was designed to determine metronidazole resistance H.pylori isolates from patients referred to Hajar hospital, Shahrekord, Iran. In this cross-sectional study, 263 patients who referred to endoscopy department of Hajar hospital, Shahrekord in 2007 were randomly selected. Gastric biopsy samples were cultured on selective Brucella agar containing 10% blood and incubated under microerophilic condition at 370C between 3 and 7 days. Gram stain, urease, catalase and oxidase tests were used to detect H.pylori isolates, and PCR (polymerase chain reaction) to determine ureC gene. H.pylori identified. Standard CLSI (Clinical and Laboratory Standard Institute) was used to evaluate metronidazole resistance. Rapid urease test (RUT), culture and PCR detect H.pylori infection in 54.37%, 84% and 84.79%, respectively. Of isolated strains, 49 (58.33%) metronidazole resistance and 7 (8.33%) semi-sensitive were recognized. Of 49 metronidazole resistant patients, 32.65%, 20.40%, 12.24%, 6.10%, 4.80% and 24.48% had gastritis, gastric ulcer, duodenal ulcer, esophagitis, gastric cancer and normal endoscopy, respectively. Fisher, exact test shows that there are relation between metronidazole resistance and women. Regarding high metronidazole resistance among studied patients, alternative antibiotics with less resistance is recommended in Helicobacter pylori (H.pylori) eradication regimens.

Various Helicobacter species causes contamination of birds, human and other mammals. H.hepaticus infection associated with intestinal, biliary and hepatic disorders such as liver, gall bladder and pancreas cancers. Mus musculus is the most common host of this bacteria that play an important role in transmission of zoonotic infection. The aim of this study was determination of the rate of H.hepaticus in Mus musculuses of Esfahan province by PCR. This was a cross-sectional study, which was done on 261 Mus musculuses isolated in Esfahan in 2009. Following the description of mice in steril condition hepatic samples isolated. Then for identification Helicobacter genus and H.hepaticus, general and specific primers were used respectively. Helicobacter genus identified in 72% of tatal samples. Out of all Helicobacter genus 42% was be H.hepaticus. According high rate of Helicobacter species infection, it sounds that the widespread surveillance of Mus musculuses in studied area was be necessary.

Metronidazole is a key component for treatment of peptic ulcer caused by Helicobacter pylori infection. The aim of this study was to determine the role of rdxA gene in metronidazole resistance in H.pylori strains isolated from Hajar hospital of Shahrekord, Iran. This cross-sectional study was done on 263 patient who referred to endoscopy department of Hajar hospital of Shahrekord on summer 2007. H.pylori was identified using gram stain,urease, catalase, oxidase tests and PCR method. Metronidazole Resistance was evaluated according to Standard Clinical and Laboratory Standards Institute (CLSI). Specific primers were used for detection of 200bp deletion in sensitive, semi-sensitive and resistance strains. Out of 84 isolated strains, 49 (58.33%) and 7 (%8.33) were resistant and semi-sensitive to metronidazole respectively. However 200bp deletion in rdxA gene was observed in only 2 strains. Statistical analysis indicated that there was no relation between metronidazole resistance, clinical criteria and rdxA gene deletion. Regarding to low frequency of rdxA gene mutation observed in our survey, the study of other possible molecular mechanisms involved in resistance to metronidazole is recommended.