Effects of aloe vera and chitosan nanoparticle thin-film membranes on wound healing in full thickness infected wounds with methicillin resistant Staphylococcus Aureus

Objective: To assess effect of Aleo vera with chitosan nanoparticle biofilm on wound healing in full thickness infected wounds with antibiotic resistant gram positive bacteria

Method: Thirty rats were randomized into five groups of six rats each. Group I: Animals with uninfected wounds treated with 0.9% saline solution. Group II: Animals with infected wounds treated with saline. Group III: Animals with infected wounds were dressed with chitosan nanoparticle thin-film membranes. Group IV: Animals with infected wounds were treated topically with Aloe vera and Group V: Animals with infected wounds were treated topically with Aloe vera and dressed with chitosan nanoparticle thin-film membranes. Wound size was measured on 6, 9, 12, 15, 18 and 21days after surgery

Results: Microbiology, reduction in wound area and hydroxyproline contents indicated that there was significant difference [p<0.05] between group V and other groups. Quantitative histological studies and mean rank of the qualitative studies demonstrated that there was significant difference [p<0.05] between group V and other groups

Conclusion: The Aloe vera with chitosan nanoparticle thin-film membranes had a reproducible wound healing potential and hereby justified its use in practice

Detection of common clones of Salmonella enterica serotype Infantis from human sources in Tehran hospitals

Aim: The aims of this study were to investigate antibiotic resistance pattern and molecular characterization of Salmonella Infantis strains, isolated from human sources in Tehran hospitals from 2008 to 2010

Background: Infection caused by Salmonella is one of the major public health problems. Despite the clinical importance of Salmonella enteric subsp. enteric serovar Infantis in humans, there is no information available about the common clones of Salmonella Infantis in clinical isolates in Iran

Methods: S. Infantis strains were identified by conventional microbiological and serological testing. The antimicrobial susceptibility of the S.Infantis isolates was determined using the disk diffusion method. The genetic relatedness and the dominant clones of S. Infantis strains were detected by the Multi Locus Sequence Typing [MLST] and pulsed-field gel electrophoresis [PFGE] techniques

Results: More than 80% of the S. Infantis isolates represented multidrug-resistant patterns. PFGE revealed high genetic similarity among S. Infantis strains. While, MLST indicated high-clonal similarity among strains, where all S. Infantis strains were assigned to the ST32 sequence type

Conclusion: This is the first study in Iran conducted to determine the sequence types of S. Infantis in clinical isolates using MLST. The genetically closed MDR S. Infantis clones were responsible for the apparent endemic occurrence of salmonellosis, caused by this Salmonella serovar, in Tehran

Profiling of Virulence-associated Factors in Shigella Species Isolated from Acute Pediatric Diarrheal Samples in Tehran, Iran

OBJECTIVES: The genus Shigella comprises the most infectious and diarrheagenic bacteria causing severe diseases, mostly in children under five years of age. This study aimed to detect nine virulence genes (ipaBCD, VirA, sen, set1A, set1B, ial, ipaH, stx, and sat) in Shigella species (spp.) using multiplex polymerase chain reaction (MPCR) and to determine the relation of Shigella spp. from pediatric diarrheal samples with hospitalization and bloody diarrhea in Tehran, Iran. METHODS: Shigella spp. were isolated and identified using standard microbiological and serological methods. The virulence genes were detected using MPCR. RESULTS: Seventy-five Shigella spp. (40 S. sonnei, 33 S. flexneri, 1 S. dysenteriae, and 1 S. boydii) were isolated in this study. The prevalence of ial, sen, sat, set1A, and set1B was 74.7%, 45.4%, 28%, 24%, and 24%, respectively. All S. flexneri isolates, while no S. sonnei, S. dysenteriae, or S. boydii isolates, contained sat, set1A, and set1B. All isolates were positive for ipaH, ipaBCD, and virA, while one (1.4%) of the isolates contained stx. The highest prevalence of virulence determinants was found in S. flexneri serotype IIa. Nineteen (57.6%) of 33 S. flexneri isolates were positive for ipaBCD, ipaH, virA, ial, and sat. The sen determinants were found to be statistically significantly associated with hospitalization and bloody diarrhea (p = 0.001). CONCLUSION: This study revealed a high prevalence of enterotoxin genes in S. flexneri, especially in serotype 2a, and has presented relations between a few clinical features of shigellosis and numerous virulence determinants of clinical isolates of Shigella spp.

Molecular detection and antimicrobial resistance of Klebsiella pneumoniae from house flies [Musca domestica] in kitchens, farms, hospitals and slaughterhouses

Identifying disease vectors and pathogens is one of the key steps in controlling vector-borne diseases. This study investigated the possible role of house flies [Musca domestica] as vectors in the transmission ofKlebsiella pneumoniae in Chaharmahal VA Bakhtiari and Isfahan provinces of Iran. House flies were captured from household kitchens, cattle farms, chicken farms, animal hospitals, human hospitals and slaughterhouses. Isolation of K. pneumoniae from external surfaces and guts of the flies was performed using MacConkey agar [MA] and thioglycollate broth [TGB]. Identification of the isolates was performed with phenotypic techniques and polymerase chain reaction [PCR]. A total of 600 house flies were sampled during the study period from different locations in four different seasons. Overall, 11.3% of the captured house flies were positive for K. pneumoniae. In Chaharmahal VA Bakhtiari province, the prevalence was 12.7%, while in Isfahan province, 10.0% of the sampled house flies were infected with K. pneumoniae. Season-wise, the highest prevalence of infections among the house flies was in summer. The organisms were highly resistant to ampicillin, amoxicillin, cefotaxime and piperacillin. A lowest level of resistance was observed for imipenem/cilastatin. The findings of this study demonstrated that house flies are potential vectors of antibiotic-resistant K. pneumoniae in Isfahan and Chaharmahal provinces, Iran. Control efforts for infections caused by this particular bacterium should takeM. domestica into account

Genetic characterization of cryptosporidium spp. among patients with gastrointestinal complaints

Aim: This study investigated subtypes of Cryptosporidium in patients with gastrointestinal complaints in Tehran, Iran

Background: Cryptosporidium, an intracellular protozean parasite, is among the major causative agents of gastroenteritisdisorders in humans. It also causes water-borne and food-borne outbreaks of diarrheal diseases

Patients and methods: A total of 1685 fecal samples were collected from patients with gastrointestinal complaints whohad been referred to clinical laboratories Tehran, Iran. The primary diagnosis was established by the detection of oocystsusing the modified Ziehl-Neelsen staining method and following that, the positive microscopically samples wereselected for sequence analysis of the partial 60 kDa glycoprotein [gp60] gene

Results: Out of 1685 collected samples, 7 [0.4 %] were positive for Cryptosporidium oocysts. Sequence analysis of gp60gene in seven Cryptosporidium isolates revealed that two subtype families were identified, IIa and IId. Five [of 7] isolatesbelonged to the subtype family IIa and the remaining two isolates belonged to IId. Two sub-types were recognized within thesubtype family II,a including IIaA16G2R1 [3/5], IIaA17G1R1 [2/5], while IIdA17G1d was the only subtype within IIdsubtype family

Conclusion: The predominance of zoonotic subtype families of C. parvum species [IIa, IId] in this study highlights theimportance of zoonotic transmission of cryptosporidiosis in the country

Molecular detection of fluoroquinolone resistance-associated gyrA mutations in ofloxacin-resistant clinical isolates of Mycobacterium tuberculosis from Iran and Belarus

Objective/background: Detection of mutations in the quinolone resistance-determining region [QRDR] of the gyrA gene could determine resistance to fluoroquinolone antitubercu-losis drugs. The aim of this study was to detect mutations in QRDRs

Methods: From 184 clinical isolates of Mycobacterium tuberculosis, ofloxacin resistance was proven in 42 isolates using the proportion method

The molecular basis of resistance to ofloxacin were investigated by the determination of mutations in the QRDR region of the gyrA gene. Extracted DNA fragments of 194 bp from the gyrA gene were amplified and an automatic DNA sequencer was used for the sequencing process

Results: Molecular genetic analysis of 42 resistant M. tuberculosis strains demonstrated that they belong to Principal Genetic Group [PGG] 1 in 19 cases [45.2 +/- 10.9%], to PGG2 in 15 cases [35.7 +/- 10.5%], and to PGG3 in eight cases [19.0 +/- 8.4%]

Isolates from PGG1 were dominant among resistant isolates [P < .05]. It was found that 24 [57%] resistant isolates carried mutations at codon 94 with five different amino acid changes: D94A [n = 11], D94G [n = 3], D94T [n = 4], D94A [n = 4], and D94Y [n = 2]. The remaining 18 [43%] isolates had mutations in codon A90V [GCG -> GTG] and S91P [TCG -> CCG]

Five isolates had two mutations in codons 90 and 94. There was no difference between mutations at these two codons in resistant isolates of the two countries [P < .001]. There was no polymorphii observed in codon 95 in any of the ofloxacin-susceptible isolates

Conclusion: It was concluded that the determination of nucleotide sequences of QRE can be used as a molecular test for the rapid detection of ofloxacin resistance. Furthermc frequencies in gyrA codons in Belarus and Iran were similar, therefore it is not of geograj ical concern for the two countries

Multilocus variable-number tandem-repeat analysis for genotyping of Shigella sonnei strains isolated from pediatric patients

The aims of this study were to characterize Iranian Shigella sonnei strains isolated from pediatric cases and evaluate the utility of multilocus variable-number tandem-repeat [VNTR] analysis [MLVA] for genotyping of local S. sonnei strains. S. sonnei has become the dominant species in certain parts of Iran. Although PFGE is still a gold standard for genotyping and source tracking of food-borne pathogens, it is laborious, expensive, time-consuming, and often difficult to interpret. However, MLVA is a PCR-based method, which is rapid, relatively inexpensive and easy to perform. A total of 47 S. sonnei isolates were obtained from sporadic cases of pediatric shigellosis in Tehran, Iran, during the years 2002-2003 [n=10] and 2008-2010 [n=37]. The patients suffered from acute diarrhea and had evidence of more than three episodes of watery, loose, or bloody stools per day. A MLVA scheme based on 7 VNTR loci was established to assess the diversity of 47 S. sonnei isolates. Based on the results, it was clear that the S. sonnei isolates were heterogeneous. Overall, 47 S. sonnei isolates were discriminated into 21 different genotypes. Analysis of the MLVA profiles using a minimum spanning tree [MST] algorithm showed the usefulness of the MLVA assay in discriminating S. sonnei isolates collected over different time periods. However, no correlation was found between the MLVA genotypes and age, gender or clinical symptoms of the patients. It is assumed that our S. sonnei isolates are derived from a limited number of clones that undergo minor genetic changes in the course of time. The present study has provided some valuable insights into the genetic relatedness of S. sonnei in Tehran, Iran

Expression of Vascular Endothelial Growth Factor [VEGF] and Epidermal Growth Factor Receptor [EGFR] in patients with serous Ovarian Carcinoma and their clinical significance

Background: Vascular endothelial growth factor [VEGF] has an essential role in tumor metastasis by inducing the construction of abnormal blood vessels. Epidermal growth factor receptor [EGFR] is involved in different parts of cancer growth such as tumor initiation, angiogenesis and metastasis

Objectives: The aim of this study was to evaluate the expression of VEGF and EGFR in ovarian cancer in southern Iran and to assess the correlation between expression of these two markers and patients' age, tumor stage, and grade

Patients and Methods: In this cross-sectional study, 50 paraffin blocks of serous ovarian adenocarcinomas and 50 paraffin-embedded specimens from control individuals operated for reasons other than malignancy were immunohistochemically stained using anti-human VEGF and EGFR antibodies

Results: A significant difference in the frequency of positive expression of VEGF was observed in ovarian cancer patients [25.0%] compared with the control group [8.0%] [P = 0.023]. A significant difference between EGFR expression in patients [56.8%] and controls [24.0%] was also obtained [P = 0.001]. No significant correlation between VEGF and EGFR expression and patients' age, tumor grade and stage were detected [P > 0.05]

Conclusions: The significant increase in both VEGF and EGFR in the patients with ovarian cancer compared to healthy individuals could have prognostic value. Identifying these markers may be useful for chemopreventive and chemotherapeutic strategies for patients with serous ovarian cancer

effects of essential oil of galbanum on caffeine induced-cleft palate in rat embryos

Caffeine at high doses is a known rodent teratogen and induces limb malformations along with cleft palate in various strains of rats and mice. The teratogenic effects of some drugs can be prevented by the application of antioxidant drugs and stimulation of the maternal immune system. Also, there is some evidence that galbanum is antioxidant. Therefore, in this study, the prophylactic effect of galbanum on teratogenic effects of caffeine was evaluated. This experimental study was performed on 28 pregnant rats that were divided into four groups. Control group received normal saline and test groups received caffeine [80 mg/kg], caffeine [80 mg/kg] plus galbanum [200 mg/kg] and galbanum [200 mg/kg], intraperitonealy at 9-11th days of gestation, respectively. Fetuses were collected at 20th day of gestation and after determination of weight and length; they were stained by Alizarin red - Alcian blue method. Cleft palate incidence was 33.3%, in caffeine group and decreased to 8.3% by galbanum. The mean of weight and length of fetuses from rat that received galbanum were significantly greater than those received only caffeine. It is concluded that galbanum decreased cleft palate induced by caffeine; but its mechanism needs more details evaluation

effects of quercetin and retinoic acid on skeletal system of rat embryos in prenatal period

Prenatal rat embryo exposure to retinoid induces some malformations in various organs, the most active and teratogenic metablolite is all-trans-retinoic acid [atRA]. The teratogenic effects of some drugs can be prevented by the application of antioxidant drugs and stimulation of the maternal immune system. Also, quercetin, a naturally occurring flavonoid has excellent antioxidant properties. Therefore, in this study, the prophylactic effect of quercetin on teratogenic effects of atRA was evaluated. In this experimental study, 40 pregnant rats were divided into 7 groups. Control group received normal saline and test groups received dimethylsulfoxide [DMSO], quercetin [75 mg/kg], quercetin [200 mg/kg], atRA [25 mg/kg], atRA [25 mg/kg] plus quercetin [75 mg/kg] and atRA [25 mg/kg] plus quercetin [200 mg/kg], intraperitoneally at 8-10th days of gestation. Fetuses were collected at 20th day of gestation and after determination of weight and length; they were stained by Alizarin red-Alcian blue method. Cleft palate, exencephaly and spina bifida incidence were 30.76, 61.53 and 30.76% range in group which received only atRA. Cleft palate, exencephaly and spina bifida incidence were 11.11, 16.66 and 5.55% in group which received atRA plus quercetin [75 mg/kg]. However, cleft palate, exencephaly and spina bifida incidence were 10.52, 10.52 and 0% in group which received atRA plus quercetin [200 mg/kg]. The means of weight and length of fetuses from rat that received atRA plus quercetin [75 mg/kg] were significantly greater than those received only atRA. It is concluded that quercetin decreased teratogenicity induced by atRA, but this subject needs more detailed evaluation

Mutation detection in activin A receptor, type I [ACVR1] gene in fibrodysplasia ossificans progressiva in an iranian family

Fibrodysplasia Ossificans Progressiva [FOP, MIM 135100] is a rare genetic disease that is often inherited sporadically in an autosomal dominant pattern. The disease manifests in early life with malformed great toes and, its episodic and progressive bone formation in skeletal muscle after trauma is led to extra-articular ankylosis. In this study, a 17 year-old affected girl born to a father with chemical injury due to exposure to Mustard gas during the Iran-Iraq war, and her first degree relatives were examined to find the genetic cause of the disease. The mutation c.617G>A in the Activin A receptor, type I [ACVR1] gene was found in all previously reported patients with FOP. Therefore, peripheral blood samples were taken from the patient and her first-degree relatives. DNA was extracted and PCR amplification for ACVR1 was performed. The sequencing of ACVR1 showed the existence of the heterozygous c.617G>A mutation in the patient and the lack of it in her relatives. Normal result of genetic evaluation in relatives of the patient, ruled out the possibility of the mutation being inherited from parents. Therefore, the mutation causing disease in the child, whether is a new mutation with no relation to the father's exposure to chemical gas, or in case of somatic mutation due to exposure to chemical gas, the mutant cells were created in father's germ cells and were not detectable in his blood sample

Antibiotic sensitivity patterns and molecular typing of Shigella sonnei strains using ERIC-PCR

Shigella sonnei is considered as a major cause of diarrheal disease in both developing and developed countries. Iran is one of the endemic areas of shigellosis. The present study was undertaken to investigate the antibiotic susceptibility and genetic relatedness of S. sonnei strains isolated from pediatric patients in Tehran, Iran. The study included all S. sonnei strains isolated from pediatric patients with diarrhea admitted to several hospitals in Tehran, Iran, during 2008-2010. Shigella spp. strains were recovered from patients using standard microbiological methods. S. sonnei strains were further studied by antimicrobial susceptibility testing and Enterobacterial Repetitive Intergenic Consensus [ERIC] - PCR analysis. Eighty nine Shigella isolates were isolated. S. sonnei was the most prevalent Shigella species [60.7%] followed by, S. flexneri [31.5%]. Eleven antimicrobial resistance patterns [R[1]-R[11]] were identified among S. sonnei isolates. The majority of the strains were resistant to trimethoprim-sulfamethoxazole, tetracycline and streptomycin. All isolates were susceptible to ciprofloxacin, ceftizoxime and chloramphenicol. All strains were typable by ERIC-PCR. Five ERIC-PCR patterns [E[1]-E[5]] were found among S. sonnei isolates; however the half of the isolates was clustered in E4 pattern. The antibiotic resistance rates are increasing among S. sonnei strains. Moreover, a predominant clone or limited clones of S. sonnei were responsible for shigellosis caused by this Shigella species in pediatric patients in Tehran, Iran

Effect of erythromycin on albendazole-induced teratogenicity in pregnant rats

Albendazole is utilized as an anthelmentic agent. One its side effect is teratogenicity. This effect apparently is related to its metabolites especially albendazole sulfoxid. The aim of present study was evaluation effect of erythromycin [as enzyme inhibitor in biotransformation] on albendazole biotransformation and consequently fetal malformation. Four groups of female pregnant wistar rats [8 rats each group] were used. First group received normal saline [as control group]. A single oral dose 30 mg/kg of albendazole was administered to rats on day 10 of gestation in group 2. Rats in group 3 received albendazole similar group 2 and erythromycin at dose 60 mg/kg. Rats in group 4 received only erythromycin on day 10 of gestation. The rats were euthanatized on day 20 of gestation. The skeletal malformation of fetus was studied by stereomicroscope after staining by Alizarin red-Alcian blue. The length and weight of fetuses were significantly decreased by albendazole but erythromycin did not prevent this effect. In group that received only erythromycin, the length and weight of fetuses was similar to control group. Erythromycin decreased albendazole effect on weight of placenta. There was an increase in resorption by erythromycin when co-administrated with albendazole. The incidence of skeletal malformations [mostly of the limbs, vertebrae and palate] decreased significantly by erythromycin when co-administrated with albendazole. Thus, erythromycin may inhibit albendazole biotransformation and decrease teratogenicity of it metabolites; but this subject needs more detailed evaluation

Genetic structure change in harvard vaccine strain of clostridium tetani for the period of 1990 to 2010 by pulsed-field gel electrophoresis

PFGE facilitates the differential migration of large DNA fragments through agarose gel by constantly changing the direction of the electrical field during electrophoresis. Possibility of high difference between strains and repeatability make PFGE one of the strong molecular methods in study of bacterial strains in epidemiology. To identifying and DNA fingerprinting of vaccine strain of Clostridium tetani by PFGE technique. Also, possibility of genotyping profile changes in frequency of vaccine strain of C. tetani during the period of 1990 to 2011. The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute in Karaj. The seeds were inoculated into Columbia blood agar and grown for 72 h. The cultures were incubated at 35[degree]C in anaerobic conditions. The PFGE analyses were performed using genomic DNA digested with the restriction enzyme SmaI. The electrophoresis analyses were carried out on a CHEF DR III apparatus [Bio Rad] and band patterns obtained were then analyzed. The PFGE profile obtained from vaccine strain during a period of more than two decades revealed no remarkable genetic changes and mutations. This type of analysis provides detailed data useful for surveillance of vaccine strains and isolates as well as for the selection of certain predominant profiles for further investigation. This study showed no considerable change in chromosomal genome of Harvard, the vaccine strain. It is therefore concluded that the vaccine produced by Razi Institute had evidently no alteration or modification in accordance to PFGE profile analysis during a period of more than two decades

Microbial susceptibility, virulence factors, and plasmid profiles of uropathogenic Escherichia coli strains isolated from children in Jahrom, Iran

Background: Urinary tract infections [UTIs], including cystitis and pyelonephritis, are the most common infectious diseases in childhood. Escherichia coli [E. coli] accounts for as much as 90% of the community-acquired and 50% of nosocomial UTIs. Therefore, identification of E. coli strains is important for both clinical and epidemiological implications. Understanding antibiotic resistance patterns and molecular characterization of plasmids and other genetic elements is also epidemiologically useful

Methods: To characterize uropathogenic strains of E. coli, we studied 96 E. coli strains recovered from urine samples of children aged 1 month to 14 years with community-acquired UTIs in Jahrom, Iran. We assessed virulence factors [VFs], drug sensitivities, and plasmid profiles

Results: Drug sensitivities of the isolates were: 19.8% [ampicillin], 24% [trimethoprim-sulfamethoxazole], 29.2% [tetracycline], 75.5% [nalidixic acid], 80.4% [cefixime], 84.6% [gentamicin], 91.4% [ciproAoxacin], 96.8% [nitrofurantoin], 96.8% [amikacin] and 100% [imipenem]. Totally, 76 isolates harbored plasmids with an average of 5.5 plasmids [range: 1-10] in each strain. Plasmid profiling distinguished 22 different E. coli genotypes in all isolates that ranged in similarity from 50% to 100%. PCR showed that the prevalence of virulence genes ranged from 15.62% forhly to 30.2% for pap

Conclusion: These data mandate local monitoring of drug resistance and its consideration in empirical therapy of E. coli infections. Plasmid analysis of representative E. coli isolates also demonstrates the presence of a wide range of plasmid sizes, with no consistent relationship between plasmid profiles and resistance phenotypes. Plasmid profiles distinguished more strains than did the antimicrobial susceptibility pattern

Antimicrobial susceptibility, plasmid profiles, and RAPD-PCR typing of Acinetobacter bacteria

Background: Multiple-drug resistant Acinetobacter have widely spread in the last decades imposing a serious nosocomial source of infection. Nevertheless, little knowledge was gaimed on tracing the development of antibiotic resistance in Acinetobacter species.Objectives: Explore Acinetobacter spp. via antimicrobial susceptibility, plasmid profiles, and random amplified polymorphism DNA polymerase chain reaction (RAPD-PCR) typing.Methods: One hundred twelve Acinetobacter isolates (including 66 A. baumannii and 46 non-Acinetobacter baumannii strains) were obtained from three university hospitals. The source of infection of these isolates included blood, urine, wound, and respiratory tract. Their susceptibilities to 17 antibiotics were tested and then allAcinetobacter isolates were typed by plasmid analysis and RAPD-PCR method.Results: A. baumannii isolates revealed nine different patterns of antibiotic resistance. Of those, non-A. baumannii, were associated with plasmid and RAPD-PCR typings (p 0.05).Conclusion: There is a wide spread of multi-drug resistant Acinetobacter spp., particularly A. baumannii, in the Middle East region that can be traced efficiently by plasmid and genotyping typing of Acinetobacter. More care should be taken for tracing the development of antimicrobial resistance of Acinetobacter using precisemolecular typing techniques.Keywords: Acinetobacter baumannii, antimicrobial susceptibility, molecular typing, plasmid profiles RAPD-PCR

cholera outbreak associated with drinking contaminated well water

Cholera has been a significant public health challenge in many communities. An outbreak of acute diarrheal illness occurred among participants in a wedding ceremony in a village in Qazvin, Iran, in 2008. We conducted an epidemiological, environmental and microbiological investigation to determine the causative agent, source and extent of this outbreak. Clinical and environmental samples were collected and analyzed for the presence of diarrhea-causing bacterial organisms, which included Vibrio cholera. The relationship between the strains was determined using enterobacterial repetitive intergenic consensus poly-merase chain reaction [ERIC-PCR]. The attack rate was 21.8%. Clinical and environmental samples were positive for V. cholerae serotype Inaba. All tested isolates had a similar ERIC-PCR pattern, which indicated that a single clone of V. cholerae was responsible for this outbreak. Our findings demonstrated that well water was the source of this outbreak

Characterization of Pseudomonas aeruginosa strains isolated from burned patients hospitalized in a major burn center in Tehran, Iran

Pseudomonas aeruginosa is an important life-threatening nosocomial pathogen and plays a prominent role in serious infections in burned patients. The current study was undertaken to characterize P. aeruginosa strains isolated from burned patients in Tehran, Iran. The study was conducted in a major burn center in Tehran, Iran in 2007. A total of seventy specimens obtained from different clinical origin with positive culture results for P. aeruginosa were included in the study. Antimicrobial susceptibility test was performed according to the standard CLSI guideline. The relationship between the strains was also determined using antimicrobial drug resistance pattern analysis and plasmid profiling. All strains were multi drug resistant. The percentage of resistance to tested antibiotics was: imipenem 97.5%, amikacin 90%, piperacillin 87.5%, ceftizoxime 72.7%, gentamicin 67.5%, ciprofloxacin 65%, ceftriaxone 60%, and ceftazidime 57.5%. Thirteen resistant phenotypes were recognized, R3 [TET, IPM, AMK, CIP, PIP, GM, CAZ, CRO, CT] was the predominant resistance pattern seen in 27.5% of isolates. Results obtained from Etest showed that 100% of P. aeruginosa strains were resistant to cefoxitin, 97% to cefotetan, 93% to ticarcillin, 89% to ticarcillin/clav, 76% to gentamicin and imipenem, 63% to piperacillin, 49% to tetracycline, and 20% to meropenem. Nine different plasmid profiles were observed among the strains. The current study showed an increase rate of resistance for some antibiotics tested among P. aeruginosa strains isolated from burned patients in Tehran. A combination of antibiotic susceptibility testing and profile plasmid analysis, which are relatively cheap and available methods, showed to be useful to characterize the clinical strains of P. aeruginosa isolated from burned patients in Iran

Detecting rare triple heteroplasmic substitutions in the mitochondrial DNA control region: a potential concern for forensic DNA studies

Mitochondrial DNA [mtDNA] is a useful tool for population studies, identification of humans and forensic DNA studies. The existence of several hundreds copies of mtDNA per cell permit its extraction from minute or degraded samples. In addition, the level of polymorphism in the hypervariable [HV] region is high enough to permit its use in human identity testing. However, the presence of several heteroplasmy might lead to ambiguous results. This study was an experiental study. This study evaluated heteroplasmy in the HV region of mtDNA in blood samples of 30 Iranians who belonged to ten unrelated families from three sequential generations [grandmother, mother and daughter]. There were no heteroplasmic substitutions in the HV1 region, but analysis of HV2 showed heteroplasmic substitutions in two out ten families. In the first family the grandmother showed heteroplasmy [T/C] in nucleotide positions 146 and 151, however it was not detected in the mother and daughter. In second family, a triple heteroplasmy [T/C] was detected in the daughter in nucleotide positions 146, 151 and 295, but these heteroplasmic substitutions were not obvious in the grandmother and mother. Heteroplasmy in mtDNA is not a rare phenomenon and probably exists in everyone, but a triple heteroplasmy in one family member is a novel finding. Our results demonstrate that one or two sequence differences between samples in mtDNA do not warrant exclusion. In our study, the average nucleotide difference between unrelated persons in the HV2 region was 2.8 nucleotides, whereas there was a triple heteroplasmy in one person which was not obvious in her family

Occurrence of class 2 integrons among multi-drug resistant Shigella sonnei isolated from Tehran, Iran in 2005

Shigellosis is one of the major causes of morbidity in children with diarrhea in Iran. Integrons play an important role in the evolution and dissemination of multidrug resistance in gram-negative bacteria. The occurrence of integrons among Shigella spp. is frequently reported throughout the world. The aim of this study was to assess the occurrence of class 2 integrons among the multi drug resistant S. sonnei isolated from Iranian children in 2005. The study was conducted in two major pediatric hospitals in Tehran, Iran. Fecal specimens and rectal swab collected from patients were cultured and identified as Shigella by the conventional methods. Antimicrobial susceptibility test was performed according to the standard CLSI guideline. Multi-drug resistant isolates of S. sonnei were further examined for the presence of class 2 integron by PCR using specific primers. Amplicons were confirmed by restriction endonuclease analysis. A total of 83 multi-drug resistant S. sonnei strains were isolated. Of these, 45 [54%] exhibited a class 2 integron of 2.1 kbp, and 34 [41%] a class 2 integron of 1.3 kbp. Class 2 integrons were not detected in four isolates. The results showed an increased occurrence of class 2 integron carrying S. sonnei isolated from children in Tehran in 2005