Archives of Clinical Infectious Diseases
Volume:4 Issue: 2, Apr 2009

Escherichia coli (E. coli) species are able to produce extended-spectrum β-lactamases (ESBLs) that cause high resistance to the beta-lactam antibiotics. Therefore, determining the antibiotic susceptibility patterns in resistant organisms is necessary for suitable therapeutic approaches.Patients and Totally, 260 clinical isolates of E. coli were collected from hospitals in Tehran during April- 2006 to April 2007. All suspected isolates were screened by disk diffusion method and the production of ESBL genes was investigated by phenotypic confirmatory tests. Microbroth dilution method was applied to determine the MIC of ceftazidime. Subsequently, isolates showing MICCAZ≥2μg/ml were subjected to PCR targeting blaTEM and blaSHV genes. Forty-nine percent of isolates contained ESBLs, among which 73.6% and 85.6% were ceftazidime- and cefotaxime-resistant, respectively. Molecular analysis showed 11.2% and 46.4% of ESBL producing isolates contain blaSHV and blaTEM genes, respectively. Results revealed high percentage of ESBL genes among the clinical isolates of E. coli. Since the ESBL genes were detected in resistant isolates, it''s necessary to test all isolates showing reduced susceptibility to thirdgeneration cephalosporins. The isolation of patients infected with ESBL producing isolates can be useful in controlling associated outbreaks.

Antibiotic prophylaxis would benefit all cesarean section patients and may decrease morbidity and length of hospital stay. The present study was conducted to determine whether the administration of cefazolin prior to skin incision was superior to administration at the time of umbilical cord clamping for prevention of post cesarean maternalneonatal infections morbidity.Patients and This was a randomized, double-blinded clinical trial. During the study period, 287 cesarean sections for singleton term pregnancies with intact membranes or passed less than 18 hours from rupture of membrane were entered. A total of 196 patients received 2gr cefazolin before incision and 91 patients received 2gr cefazolin after ord clamping. The occurrence of surgical site opening, total infectious morbidity and neonatal complications were ompared between these groups. Two groups were demographically identical. Rate of IV line need (RR=1.87, 95 I:0.21-17.02), neonatal epsis (RR=1.39, 95%CI:0.14-13.64) and NICU admission (RR=0.19, 95%CI: 0.21-17.02) were not significantly iffered between groups. We suggest the standard cefazolin prophylaxis (after cord clamping) for elective cesarean section and efazolin before incision for non elective cesarean section. Therefore, administration of prophylactic cefazolin prior to ncision will not increase the rate of neonatal sepsis.

Urinary tract infection (UTI) is a frequently diagnosed renal and urologic disease. Escherichia coli is byfar the most common etiologic agent of this disease. This study was aimed to type the E.coli strains isolated from thepatients with urinary tract infection using sero-grouping. Detection of pap adhesion-encoding operon was also targeted.Patients and A total of 130 E. coli strains isolated from patients with UTI were investigated for O-serotyping. The presence of pap adhesion-encoding operon was detected using polymerase chain reaction (PCR). In serogrouping with 13 antisera, 86 strains (66.14%) were O-serogroupable and belonging to O1, O6, O15, O18 & O20 serogroups, while 44 strains (33.86%) were O-non typeable. Predominant serogroups were O6 and O18. The PCR results showed that 61% of strains exhibited the pap genotype. Serogroups O1, O6, O15 and O18 possessed pap operon. There was an obvious correlation between the pap operon and the O-serogroups of the strains. Our results showed that obtained protein patterns of the isolated strains were more reliable than serotyping results for typing purposes. Our findings indicated that pap adhesion–encoding operon has an important role in the development and severity of UTI. Many cases of serious urogenital diseases are caused by a limited number of uropathogenic E.coli strains that generally possess special virulence factors such as pap operon

Nosocomial infections (NI) are major concerns in the management of patients in hospitals and are growing problem in developing and developed countries because of increased mortality and morbidity rates and corresponding costs.Patients and This cross sectional study was carried out on all patients hospitalized for more than 48 hours in pediatric intensive care unit (PICU) of Rasul Akram hospital in Tehran. Nosocomial infection was defined according to the criteria of National Nosocomial Infections Surveillance (NNIS) system. During the study period, 102 patients were hospitalized of whom 15 (14.7%) proved to have NI. The mean duration of PICU stay was 16.1 days for NI group and 8.9 days for non-NI group (p<0.05). Mortality rate was significantly higher among NI group (40%) when compared with non-NI group (11.5%) (OR=5.13, 95%CI:1.29-20.60,p<0.05). Age under 2 years was a risk factor for NI (OR=4.44, 95%CI:1.23-16.67). The most common causative organisms for nosocomial infections in PICU were coagulase-negative staphylococci (CONS), followed by Klebsiella and Pseudomonas aeruginosa. Pneumonia was the most common nosocomial infection, followed by urinary tract infection and sepsis. The calculated NI rate in our study (14.7%) is higher than usual rates reported from PICU in other societies. Meanwhile, long stay in PICU and age less than 2 years are the main risk factor for NI and subjects with NI are 5.13 times more likely to die.

Bloodstream infection (BSI) is an important cause of mortality and morbidity and among the most common health-care associated infections. In this study we described the frequency of occurrence and antimicrobial susceptibility patterns of nosocomial and community-acquired BSI isolates from a teaching hospital in Tehran, Iran.Patients and This cross-sectional study was conducted in 850-bed Rasul Akram university hospital from April 2006 to April 2007. All patients with a positive blood culture were enrolled. Antimicrobial susceptibility testing was performed with disk diffusion and E-test MIC. During the study period, 456 isolates were obtained from blood cultures, from a total of 8818 collected sets, among which 291were felt to represent true bacteremia and 98 were nosocomial. Acinetobacter spp. were the most frequently isolated agents in the hospital and community acquired BSIs (32%), followed by Escherichia coli (13.7%) and Klebsiella spp. (12%). The most effective antibiotics for gram-negative and gram-positive bacteria were ciprofloxacin (13% resistance rate) and vancomycin and oxacillin (with 13% resistance rate), respectively. Analysis of antibiotic resistance pattern showed that 20.43% of Acinetobacter spp. and 15.4% of Pseudomonas aeruginosa were multi drug resistant (MDR), while 48.7% of Klebsiella spp were ESBL-producing isolates and 15% of Staphylococcus aureus were oxacillin-resistant. We did not observe any vancomycin-resistant strains among isolates of S. aureus. Rifampin and ciprofloxacin showed good activity against most of gram-positive and gram-negative organisms, respectively. Carbapenems (imipenem and meropenem) were highly active against strains of Enterobacteriaceae (E. coli, Klebsiella)that showed resistance to third generation of cephalosporines.

Escherichia coli O157:H7, Vibrio cholerae, and Salmonella typhimurium are pathogenic bacteria found in contaminated water and food. No assay method is currently available on simultaneous detection or identification of all the three pathogens. Our aim was to develop a rapid and reliable method for this purpose. A protocol for sample collection, and a PCR procedure was designed specifically for the assay. Selected fragments of 239 bp, 432 bp, and 360 bp for E. coli O157 lipopolysaccharide (LPS) gene (rfbE), V. cholerae toxin gene (ctx), and Salmonella typhimurium putative cytoplasmic protein gene (STM4497), respectively, were amplified from the extracted bacterial DNA samples in a single tube by multiplex PCR. The multiplex PCR products were analyzed by gel electrophoresis. All unknown samples were verifiably identified. The assay was sensitive enough to detect and identify as few as 100 cells of E. coli O157:H7, V. cholerae and Salmonella typhimurium. The presence of other bacteria did not interfere with the analysis. This assay is a specific and reliable tool which allows cost-effective detection of all three bacterial pathogens in one reaction tube.

Nucleic acid based detection of Mycobacterium tuberculosis has the potential to improve the analysis of the tuberculosis epidemiology and patient care by increasing the specificity and sensitivity of diagnosis. Patients and Fifty suspected cases were screened for M. tuberculosis by using a new primer sequence andcomparing its results with the primer (IS6110) most widely used for tuberculosis diagnosis. The mean age of cases was 33.6±14.3 years. Twenty one cases (42%) were positive for M. tuberculosis. Maximum positivity was found in sputum (10/19) followed by menstrual blood (4/8), blood (5/15), ascitic fluid (1/2), and pleural fluid (1/5). The new designed primer was reproducible and in complete concordance with the PCR-results obtained by the standard method using IS 6110 insertion sequence in all 50 cases in which both methods were used

Cholera is a bacterial infection that causes both local outbreaks and worldwide pandemics. There was a cholera epidemic in Iran in summer 2005, during which 1118 individuals were infected and 11 died. The present study was conducted to determine the impact of educational activities of Iranian Ministry of Health on the people''s knowledge and attitude towards the disease.Patients and This cross sectional study was carried out on 240 subjects. Samples were selected by cluster sampling in Yazd, Iran. Data were collected by a prepared questionnaire and analyzed by student t- test and chi square, when appropriate. Mean scores of subject''s awareness before and after outbreak were 4.5 and 10.5, respectively (p<0.05). Only 33% of subjects knew cholera as a transmittable disease, however, following the intervention, the respected percentage reached up to 99.5%. Our study showed that few people were aware of cholera, however, their awareness improved significantly following the education. Therefore, effective continuous educations should be attempted, especially through mass media, in order to reduce the health and economic impacts of endemic diseases.