Association of diverse bacterial communities in human bile samples with biliary tract disorders: a survey using culture and polymerase chain reaction-denaturing gradient gel electrophoresis methods

Bacterial infection is considered a predisposing factor for disorders of the biliary tract. This study aimed to determine the diversity of bacterial communities in bile samples and their involvement in the occurrence of biliary tract diseases. A total of 102 bile samples were collected during endoscopic retrograde cholangiopancreatography (ERCP). Characterization of bacteria was done using culture and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) methods. Antimicrobial susceptibility of the isolates was determined based on the Clinical and Laboratory Standards Institute (CLSI) guidelines and identity of the nucleotide sequences of differentiated bands from the DGGE gels was determined based on GenBank data. In total, 41.2 (42/102) of the patients showed bacterial infection in their bile samples. This infection was detected in 21 (4/19), 45.4 (5/11), 53.5 (15/28), and 54.5 (24/44) of patients with common bile duct stone, microlithiasis, malignancy, and gallbladder stone, respectively. Escherichia coli showed a significant association with gallstones. Polymicrobial infection was detected in 48 of the patients. While results of the culture method established coexistence of biofilm-forming bacteria (Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, Enterococcus spp., and Acinetobacter spp.) in different combinations, the presence of Capnocytophaga spp., Lactococcus spp., Bacillus spp., Staphylococcus haemolyticus, Enterobacter or Citrobacter spp., Morganella spp., Salmonella spp., and Helicobacter pylori was also characterized in these samples by the PCR-DGGE method. Multidrug resistance phenotypes (87.5 ) and resistance to third- and fourth-generation cephalosporins and quinolones were common in these strains, which could evolve through their selection by bile components. Ability for biofilm formation seems to be a need for polymicrobial infection in this organ. © 2016 Springer-Verlag Berlin Heidelber

Evaluation of virulence factors and plasmid-related transmissibility among different isolates of Enterococci

The incidence of virulence factors among 114 Enterococcus faecalis and 35 Enterococcus faecium strains from different clinical specimens were compared with those isolated from control groups. A few of the isolates expressed two or more of the following traits simultaneously: hemolysin, aggregation substance, gelatinase, DNase, hemagglutinin and antibiotic resistance. The frequencies of hemolysin, aggregation substance, and gelatinase production in E. faecalis were much higher than those in E. faecium. However, no statistically significant differences were detected in the other traits. Two of the isolates showed total resistance to all of the antibiotics tested, and others displayed varied degrees of resistance pattern. The frequency of plasmid transfer was shown to be 10 -4- 10 -7 per donor among the isolated strains. The plasmid profile of the bacteria indicated that most of the isolates contained one or more plasmids with molecular weight ranging in 2 to 42 Mda regions. Resistance to gentamicin and tetracycline was the most observed antibiotic resistance pattern, and had the property of efficient inter-enterococcal spp. transfer by mating

Features of childhood acute myeloid leukemia in Iran: A report from double center study

Acute Myeloblastic Leukemia is one of the important malignancies in children. For better managing the prognosis of this disease, there should be enough information about common features of this malignancy. The aim of this study was to evaluate these common features in children with Acute Myeloblastic Leukemia. A total of 104 eligible children less than 15-year-old have been referred from 2007-2011 to two referral centers for childhood malignancies. Basic epidemiological information recorded in checklists for each individual. Analyzes have been done by SPSS version 22. Out of patients, 57 cases were males (54.8). The male/female ratio was 1.2. The mean age of patients was 6.5 ± 4.3 years. The majority subtypes of patients were M3, M4, non-M3, and M2, respectively. The common molecular abnormalities were t (15;17) and inv (16). Of patients, 19.2 had an early relapse. The mean age of relapse in patients was 6.7 ± 3.9 years. Sixty patients (57.7) were alive, and 44 cases (42.3) died during or after therapy. The three years overall survival rate of patients was 42 in this study. According to our data, AML has the same frequency as compared with data from developing countries. But different epidemiological characteristic was a lower rate of three years overall survival in patients. These data may serve the health authorities for more effective environmental and preventive measurements, purposeful allocation of resources for facilitating upto-date diagnostic and treatment modalities, psychological support programs for respective family members and educational purposes. © 2015 Tehran University of Medical Sciences. All rights reserved

Preparation of immunotoxin herceptin-botulinum and killing effects on two breast cancer cell lines

Background: Worldwide, breast cancer is the most common cancer diagnosed among women and a leading cause of cancer deaths. The age of onset in Iran has become reduced by a decade for unknown reasons. Herceptin, a humanized monoclonal antibody, is a target therapy for breast cancer cells with over expression of HER2-neu receptors, but it is an expensive drug with only 20 beneficial rate of survival. This study introduces a novel approach to enhance the efficacy of this drug through immunoconjugation of the antibody to botulinum toxin. Decreasing the cost and adverse effects of the antibody were secondary goals of this study. Materials and Methods: Botulinum toxin was conjugated with Herceptin using heterobifunctional cross linkers, succinimidyl acetylthiopropionate (SATP) and sulfo-succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) according to the supplier's guidelines and tested on two breast cancer cell lines: SK-BR-3 and BT-474. Toxin and Herceptin were also used separately as controls. The cytotoxicity assay was also performed using the new bioconjugate on cultured cells with Alamar blue and a fluorescence plate reader. Results: Herceptin-Toxin bioconjugation significantly improved Herceptin efficacy on both breast cancer cell lines when compared to the control group. Conclusions: Toxin-Herceptin bioconjugation can be a potential candidate with increased efficiency for treating breast cancer patients with over expression of the HER2 receptor

Molecular Epidemiology of Cryptosporidiosis in Iranian Children, Tehran, Iran

Background: Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determina­tion of subtypes of Cryptosporidium among children with diarrhea in Tehran by se­quence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene.Methods: Fecal samples were collected from 794 diarrheic children. Initial identification of Crypto­spo­ridium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly."nResults: Out of 794 collected samples, 19 (2.40 %) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47 %) of the positive isolates were Crypto­spori­dium parvum and 2 (10.52 %) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the chil­dren."nConclusion: The predominancy of C. parvum species (specially, IId A20G1a sub­type) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran

Antimicrobial susceptibility patterns of the gram-negative bacteria isolated from septicemia in Children?s Medical Center, Tehran, Iran

Introduction. The choice of antimicrobial treatment for septicemia is often empirical and based on the knowledge of local antimicrobial activity patterns of the most common bacteria causing such bloodstream infections. The current study aimed to study the prevalence of bacterial pathogens causing septicemia and their antimicrobial resistant profiles in hospital admitted patients. Methods. This cross sectional study done at Children?s Medical Center, Tehran, Iran. We examined 168 bacterial strains isolated from 186 clinically diagnosed septicemia cases refereed at Children?s Medical Center, Tehran, Iran Over a period of twelve months from July 2010 to 2011 July. 11446 blood samples from patients of clinically suggestive septicemia were evaluated. Results. Bacterial strains were isolated from 910 (7.95%) of blood cultures. Gram-negative bacteria identified were Pseudomonas species (20.5%), Pseudomonas aeruginosa (1.86%), Salmonella spp (1.09%), Acinetobacter naumannii (8.13%), Escherichia coli (4.06%), Klebsiella spp (5.16%). Gram-negative pathogens were more than gram positive in bloodstream infections. Antimicrobial susceptibility testing was done according to Clinical and Labo- ratory Standards Institute (CLSI, USA) guidelines against: amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, gentamicin. Resistanc to different antibiotics in the most important isolated bacteria were: 32.1 %, 10.8%, 87.8%, 96%, 39.1%, 35.2, 49.4%, 69%, 80.02%, 22%, 59%, 30.1% respectively, for Pseudomonas spp, 32%, 3.7%, 84.2 %, 83.2%, 80.1%, 75.4%, 44.8%, 45.2%, 33.3%, 19%, 34.1, 11.5% respectively for Acinetobacter species. Discussion. Resistant to majority of the antimicrobial agents for several pathogens implicated in bloodstream infections, particularly in Gram-negative bacteria, can make complication in treatment of infection cause by them

The role of the intensive care unit environment and health-care workers in the transmission of bacteria associated with hospital acquired infections

The goal of this study was to attempt to determine the rate of contamination of health-care workers' (HCWs) hands and environmental surfaces in intensive care units (ICU) by the main bacteria associated with hospital acquired infections (HAIs) in Tehran, Iran. A total of 605 and 762 swab samples were obtained from six ICU environments and HCWs' hands. Identification of the bacterial isolates was performed according to standard biochemical methods, and their antimicrobial susceptibility was determined based on the guidelines recommended by clinical and laboratory standards institute (CLSI). The homology of the resistance patterns was assessed by the NTSYSsp software. The most frequent bacteria on the HCWs' hands and in the environmental samples were Acinetobacter baumannii (1.4 and 16.5, respectively), Staphylococcus aureus (5.9 and 8.1, respectively), S. epidermidis (20.9 and 18.7, respectively), and Enterococcus spp. (1 and 1.3, respectively). Patients' oxygen masks, ventilators, and bed linens were the most contaminated sites. Nurses' aides and housekeepers were the most contaminated staff. Imipenem resistant A. baumannii (94 and 54.5), methicillin-resistant S. aureus (MRSAs, 59.6 and 67.3), and vancomycin resistant Enterococci (VREs, 0 and 25) were detected on the hands of ICU staff and the environmental samples, respectively. Different isolates of S. aureus and Enterococcus spp. showed significant homology in these samples. These results showed contamination of the ICU environments and HCWs with important bacterial pathogens that are the main risk factors for HAIs in the studied hospitals. © 2015 King Saud Bin Abdulaziz University for Health Sciences

Nitazoxanide and doxycycline sensitivity among metronidazole resistant helicobacter pylori isolates from patients with gastritis

Background: Antibiotic therapy should be done based on resistance characteristics of Helicobacter pylori strains to commonly prescribed antibiotics in areas with higher resistance rates. Objectives: This study examined antibacterial activity of nitazoxanide and doxycycline against clinical H. pylori isolates showing different metronidazole resistance levels. Methods: A total of 122 patients, who underwent endoscopy were enrolled in this study from 3 hospitals of Tehran, during November 2014 to July 2015. Helicobacter pylori isolates were obtained from gastric biopsies of the patients after culture in specific culture medium and characterization by both biochemical and molecular methods. Antimicrobial susceptibility to metronidazole was detected using the agar dilution method and minimum inhibitory concentrations of nitazoxanide and doxycycline were determined for metronidazole resistant strains. Results: From a total of 122 gastric biopsy specimens, 55 H. pylori strains were recovered (45). Thirty-three of these strains (60.0) were resistance to metronidazole. MIC50 and MIC90 values for metronidazole were 32 and 64 µg/mL, respectively. MIC50 and MIC90 values for doxycycline and nitazoxanide were measured as 4 and �8 µg/mL, and 8 and �32 µg/mL, respectively. Conclusions: Dominance of high level metronidazole resistance H. pylori strains among the studied patients questioned its usefulness for first-line therapy in Iran. Nitazoxanide and doxycycline showed superior activity against H. pylori strains in comparison to metronidazole, which should be considered for alternative therapies. © 2018, Kowsar Medical Publishing Company. All rights reserved