Efficiency of BclI restriction fragment length polymorphism for detection of hemophilia A carriers in Sistan and Baluchestan province, Southeast of Iran

Background: Indirect genetic diagnosis using polymorphic DNA markers can detect carriers of hemophilia A. This technique is preferable in developing countries because of its simplicity and cost effectiveness compared to direct mutation analysis. In the present study, we examined usefulness of intragenic marker BclI restriction fragment length polymorphism (RFLP) at intron 18, for carrier detection. How this marker is informative was tested in 102 members of 16 hemophiliac families from Sistan and Baluchestan province, Southeast of Iran. Methods: Blood samples were obtained from 29 hemophilia A patients and 73 of their relatives, after taking informed consents. DNA was extracted using proteinase K digestion followed by DNA precipitation. Factor VIII gene polymorphism was identified by the polymerase chain reaction/RFLP which is both sensitive and economical. Results: Our results showed that almost 69.8 of Xchromosomes had restriction site for BclI enzyme. The heterozygosity rate for BclI polymorphism in tested women was 61.4, signifying the usefulness of this marker in carrier detection. The informative rate respecting this polymorphism was 43.7 meaning that a remarkable percent of families from the target population could be diagnosed using this marker alone. Conclusion: In Sistan and Baluchestan province where there is limited access to sophisticated facilities of molecular diagnosis, use of PCR-based analysis of DNA polymorphism in the BclI locus can be used to identify a remarkable percentage of the carriers and even for prenatal diagnosis. Meanwhile, it is necessary to evaluate the effectiveness of other polymorphic DNA markers to enhance the informative rate

Multi-locus sequence type analysis of Shigellas pp. Isolates from Tehran, Iran

Background and Objectives: Strains of Shigella spp. can cause shigellosis, or bacillary dysentery. That is a public health problem worldwide. The aim of this study was to describe the population structure and genetic relatedness of multidrug resistant S. sonnei and S. flexneri isolated during a one year period from children with diarrhea in Tehran, Iran. Materials and Methods: A total of 70 Shigella spp. were detected during the study period. Twenty MDR isolates of Shigella spp. were randomly selected and used in this study. Bacterial identification was performed by conventional biochemical and serological and confirmed by molecular method. After antimicrobial susceptibility testing, we used Multilocus sequence typing (MLST) for subtyping isolates. Results: We found 14 Shigella sonnei and 6 Shigella flexneri isolates. Results of MLST showed five sequence types (ST) (145, 152, 241, 245, 1502) and BURST analysis revealed the largest number of single locus variant (SLV) and highest frequency (FREQ) for ST152. ST 152 with nine members was predicted as the founder by BURST. Frequency for ST 1502 and ST 245 was four isolates and the least frequency was seen for ST 241 and 145 with one and two members, respectively. ST 145 and ST 245 were described as singletons in BURST. All isolates with ST145 and ST245 were identified as Shigella flexneri. Conclusion: Annual Multi locus sequence typing of MDR Shigella would help us in better understanding of dominant species and comparing our results with the same studies in other countries especially our neighbor countries in source tracking purposes. © Tehran University of Medical Science. All rights reserved

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

Acinetobacter baumannii clonal lineages I and II harboring different carbapenem-hydrolyzing-β-lactamase genes are widespread among hospitalized burn patients in Tehran

The aim of this study was to analyze antimicrobial resistance patterns and their encoding genes and genotypic diversity of Acinetobacter baumannii isolated from burn patients in Tehran, Iran. The presence of extended-spectrum beta-lactamase- and blaOXA-encoding genes among 37 multidrug resistant (MDR) A. baumannii strains isolated from patients hospitalized in a teaching hospital in Tehran was evaluated. Susceptibility to 7 antibiotics was tested by disk agar diffusion and to polymyxin B and colistin was tested by E-test, according to CLSI guidelines. All isolates were then analyzed by PCR for the presence of blaIMP, blaVIM, blaSIM blaOXA-23, blaOXA-24, and blaOXA-58-like carbapenemase genes, and blaOXA-51-like, blaTEM, blaSHV, blaPER, blaVEB, and blaGIM genes. Genotyping of A. baumannii strains was performed by repetitive sequence-based (REP)-PCR and cluster analysis of REP-PCR profiles. A. baumannii isolates were assigned to international clones by multiplex PCR sequence group analysis. Twenty-five A. baumannii isolates were classified as MDR, and 12 were classified as extensively drug resistant. All isolates were susceptible to colistin and polymyxin B. Eighty-one percent of the isolates was resistant to imipenem or meropenem and harbored at least one or both of the blaOXA-23-like or blaOXA-24-like carbapenemase genes. Co-existence of different resistance genes was found among carbapenem-resistant isolates. Multiplex PCR sequence group analysis most commonly assigned A. baumannii isolates to international clones I (18/37; 48.6) and II (18/37; 48.6). An alarming increase in resistance to carbapenems and the spread of blaOXA-23-like and/or blaOXA-24-like carbapenemase genes was observed among A. baumannii strains belonging to clonal lineages I and II, isolated from burn patients in Tehran. © 2015 King Saud Bin Abdulaziz University for Health Sciences

PFGE genotyping and molecular characterization of Campylobacter spp. isolated from chicken meat

A total of 70 samples were collected from chicken meat obtained from 10 markets in Tehran, Iran from which 39 Campylobacter coli were isolated. Among 10 antibiotics used, maximum resistance was seen to trimethoprim-sulphamethoxazole (SXT) (97.36), nalidixic acid (94.8), ciprofloxacin (87.7), streptomycin (89.72), and tetracycline (97.4). No resistance was to gentamycin was observed. None of the Campylobacter strains under study harbored integron, suggesting the involvement of other resistance mechanisms in emergence of multi drug resistance (MDR) phenotype among the isolates. Two major types (A and B) and 15 subtypes (A1-A8 and B1-B7) were identified. Pulsed-field gel electrophoresis (PFGE) analysis demonstrated a high degree of homogeneity while the majority of the isolates shared identical or very similar PFGE genotypes. Isolates with identical genotypes differed in their resistance profile, although all of them assigned to MDR phenotype. To our knowledge, this is the first molecular survey from Iran characterizing Campylobacter isolates from poultry, which adds to our knowledge the epidemiological linkage of Campylobacter isolates with MDR properties from different sources and emphasizes the need for cautious use of antimicrobials in different fields of food production chain

PAGINA TIPO

SUMMARY. To the best of our knowledge, this is the first report of Klebsiella, Acinetobacter and Pseudomonas-producing Klebsiella pneumoniae Carbapenemase (KPC) among burn infants in Iran. The objective of this study was to determine the phenotypic detection of these KPC among isolated Psedomonas aeruginosa, Acinetobacter baumannii and Klebsiella spp. A cross-sectional study was performed (February to September 2011) at a tertiary burn hospital in Tehran, Iran. Sixty-four strains were isolated from 20 patients. Strain and genus of isolates were confirmed, antibiotic susceptibility testing was implemented, and KPC determined by Modified Hodge Test. Fifteen of 36 strains (six Pseudomonas aeruginosa, six Acinetobacter baumannii, and three Klebsiella pneumoniae) were resistant to imipenem. Ten strains of 36 Gram negative isolates were resistant to all tested antibiotics except for Colistin. Thirteen of 15 resistant imipenem strains were confirmed as KPC-producer bacteria that isolated from nine patients. Six of 36 isolated strains were extended-spectrum β-lactamase (ESBL)-producing bacteria, of which four strains were both KPC and ESBL. A high percentage of multidrug resistant (MDR) strains in our centre with positive KPC have created a major challenge in terms of mortality and morbidity. The findings of this study highlight the importance of implementing an effective infection control strategy to prevent and decrease the prevalence of KPC-producing organisms

Investigation of efflux-mediated tetracycline resistance in Shigella isolates using the inhibitor and real time polymerase chain reaction method

Background: Shigella spp. are gram negative bacteria, which are of global public health importance. The growing of multidrug-resistant Shigella isolates are a major problem around the world. Methods: Overall, 50 isolates of Shigella spp. from children diarrheic stools were studied. The isolates were identified and confirmed using biochemical, serological and molecular methods (ipaH, wbgZ and rfc genes). Antimicrobial susceptibility test was done according to the Clinical and Laboratory Standards Institute (CLSI) guidelines against minocycline, tetracycline, doxycycline, ampicillin, streptomycin, trimethoprim-sulfamethoxazole, nalidixic acid, norfloxacin, ciprofloxacin and levofloxacin. Also, the role of efflux pump in defense of Shigella against tetracycline was investigated by Minimum Inhibitory Concentration (MIC) with and without an efflux pump inhibitor. Detection of tetA, tetB, tetC and tetD genes in Shigella was evaluated by conventional Polymerase Chain Reaction (PCR) and real time PCR. Results: Molecular identification revealed a prevalence of 14 for Shigella flexneri and 86 for Shigella sonnei. Minimum Inhibitory Concentration (MIC) of 90 of resistant isolates was changed in the presence CCCP. Results of conventional PCR exhibited that 66 of isolates were positive for tetA, while according to real time PCR method, 90 of isolates carried tetA. Positive results for tetB were 12 and 18 by conventional and real time PCR methods, respectively. No positive results were detected for tetC and tetD. Also, tetB was detected only in S. flexneri while tetA was detected in both S. flexneri and S. sonnei. Conclusion: It seems that efflux-mediated tetracycline resistance to tetracycline in S. flexneri can be related to tetB, however resistance in S. sonnei can be related to the expression of tetA. © 2016, IRANIAN JOURNAL OF PATHOLOGY