Production of a novel biomacromolecule for nanoelectronic devices and artificial retinas utilizing textile wastewater as carbon source: Optimization by Taguchi experimental design

In this study, the ability of Haloarcula sp. IRU1 isolated from Urmia lake, Iran, for production of cruxrhodopsin as a biomacromolecule with nanofunction from textile wastewater was evaluated and optimized by Taguchi experimental design. According to Taguchi method, the optimum conditions at which high cruxrhodopsin production could be achieved were observed to be in the presence of textile wastewater at 0.25 (volume/volume), yeast extract at 0.025 (weight/volume) and KH2PO4 at 0.005 (weight/volume). In conclusion, Haloarcula sp. IRU1 is capable of cruxrhodopsin production from textile wastewater in different conditions

Prevalence of high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium in an Iranian hospital

This study was designed to determine the molecular characteristics and antimicrobial resistance of enterococcal strains isolated from patients admitted to an Iranian Hospital. Enterococcal strains were isolated from the burn patients. All strains were screened for genes encoding resistance to aminoglycoside aac(6')-Ie-aph(2'')-Ia, aph (3'), ant (4'), resistance to vancomycin (vanA, vanB), resistance to tetracycline (tetK, tetL, tetM, tetO), and resistance to erythromycin (ermA, ermB, ermC) by PCR and multiplex PCR-based methods. Genetic diversity was evaluated via Random Amplified Polymorphic DNA (RAPD)-PCR. All enterococcal isolates showed complete sensitivity to vancomycin with MIC � 0.5μg/ml. Resistance to gentamicin, tetracycline, erythromycin, ciprofloxacin or quinopristin-dalfopristin was detected, whilst more than 96.2% of isolates were high-level gentamicinresistant (HLGR) and multiple drug resistant. The most prevalent aminoglycoside resistance gene was aac(6')-Ie-aph(2'')-Ia, that was found in 96.2% (26/27) of the isolates. The most prevalent tetracycline resistance genes were tetM, found in 85.1% (23/27) followed by tetL and tetO found in 7.4% (2/27) of the isolates. The ermA and ermB genes were detected in 33.3% (9/27) and 44.4% (12/27) of the isolates respectively. RAPD-PCR analysis yielded 17 distinct profiles among 27 investigated isolates. One cluster of isolates shared the same RAPD pattern, while 16 isolates had unique RAPD pattern. Our study showed that during the examination time period one RAPD genotype was the common type and was disseminated among patients in the burn unit. Interestingly, most of these strains had an identical or very similar antibiotic and gene resistance pattern

Phenotypic and genotypic characteristics of tetracycline resistant Acinetobacter baumannii isolates from nosocomial infections at Tehran hospitals

Objective(s): To date, the most important genes responsible for tetracycline resistance among Acinetobacter baumannii isolates have been identified as tet A and tet B. This study was carried out to determine the rate of resistance to tetracycline and related antibiotics, and mechanisms of resistance. Materials and Methods: During the years 2010 and 2011, a total of 100 A. baumannii isolates were recovered from patients in different hospitals of Tehran, Iran. Antimicrobial susceptibility to tetracycline, minocycline, doxicycline and tigecycline was evaluated by E-test. Polymerase chain reaction (PCR) of the tet A and tet B genes was performed using specific primers, after which the isolates were subjected to Repetitive Extragenic Palindromic-PCR (PCR) to identify the major genotypes. Results: Of all isolates, 89 were resistant to tetracycline (MIC50 = 32 mu g/ml, MIC90 = 512 mu g/ml). Minocycline with the resistant rate of 35 (MIC50 = 16 mu g/ml, MIC90 = 32 mu g/ml) and doxicycline with the resistant rate of 25 (MIC50 = 16 mu g/ml, MIC90= 32 mu g/ml) have a good activity against A. baumannii isolates. All isolates were sensitive to tigecycline. Frequencies of tet B and tet A genes and coexistence of tet A and tet B among the isolates resistant to tetracycline, were 87.6, 2.2 and 1.1, respectively. Distribution of REP-types among A. baumannii isolates was types A (40), B (30), C (10), D (5) and E (5). Conclusion: It seems that tet A and tet B genes play an important role in the induction of resistance towards tetracyclines used in this study. It is suggested that further studies focus on other antimicrobial drugs and combinations in order to achieve a successful therapy against multi drug resistance (MDR) A. baumannii strains in Iran

Phenotypic and genotypic evaluation of fluoroquinolone resistance in clinical isolates of Staphylococcus aureus in Tehran

Background: Fluoroquinolones are broad-spectrum antibiotics widely used in the treatment of bacterial infections such as Staphylococcus aureus isolates. Resistance to these antibiotics is increasing. Material/Methods: The occurrence of mutations in the grlA and gyrA loci were evaluated in 69 fluoroquinolone-resistant S. aureus isolates from 2 teaching hospitals of Tehran University of Medical Sciences. Results: Out of the 165 S. aureus isolates, 87 (52.7) were resistant to methicillin and 69 (41.8) were resistant to fluoroquinolone. Fluoroquinolone-resistant S. atoms isolates had a mutation at codon 80 in the grlA gene and different mutational combinations in the gyrA gene. These mutational combinations included 45 isolates at codons 84 and 86,23 isolates at codons 84,86 and 106 and 1 isolate at codons 84, 86 and 90. Fluoroquinolone-resistant S. aureus isolates were clustered into 33 PFGE types. Conclusions: The findings of this study show that the fluoroquinolone-resistant S. aureus strains isolated in the teaching hospitals in Tehran had multiple mutations in the QRDRs region of both grlA and gyrA genes

The synergistic effect of hydroalcoholic extracts of Origanum vulgare, Hypericum perforatum and their active components carvacrol and hypericin against Staphylococcus aureus

Aim: This study was designed to evaluate the synergistic activities of hydroalcoholic extracts of medicinal plants Origanum vulgare and Hypericum perforatum and their active components, carvacrol and hypericin against Staphylococcus aureus. Methods: The synergistic effects of the plants, as well as carvacrol and hypericin, were examined using a checkered method against S. aureus (ATCC 12600). Results: A fractional inhibitory concentration of 0.5 was obtained for combination of O. vulgare and H. perforatum and 0.49 for combination of the active ingredients carvacrol and hypericin, both of which indicated a synergistic effect. Conclusion: This preliminary evaluation demonstrated a synergistic property of O. vulgare and H. perforatum extracts in treating S. aureus infection. This study indicates that combination of the plants, as well as combination of carvacrol and hypericin, might be used as a new antibacterial strategy against S. aureus. We studied and evaluated the synergistic activities of hydroalcoholic extracts of oregano and St John's wort and their active components, carvacrol and hypericin, against Staphylococcus aureus. The results suggest that a combination of oregano and St John's wort extracts, as well as a combination of hypericin and carvacrol, have potential for use as natural and effective combinations against S. aureus infection

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

Echinococcosis/Hydatidosis in Ilam Province, Western Iran

Background: Hydatidosis is a zoonotic disease of global prevalence. It causes considerable health problems and economic losses throughout the world, including Iran. The objective of this study was to assess the current status of echinococcosis/hydatidosis in the province of Ilam (western Iran). Methods: From April to September 2011, 65 stray dogs were collected from urban and rural areas of Ilam City. Parasites were isolated from the dogs and stained with carmine. A taxonomic study was carried out by measuring different parts of helminths. Meat inspection documents from slaughterhouses in Ilam were used to assess the prevalence of hydatidosis during a 3-year period in sheep, cattle, and goats. ELISA test was used to detect the presence of antibodies to hydatidosis in human sera. Clinical records from 2000 to 2010 of either treated or diagnosed patients from public hospitals of this province were reviewed. Results: The prevalence of Echinococcus granulosus infection in stray dogs was 9. A total of 81,726 animals were assessed for hydatidosis; 2.94 (2403 cases) had liver hydatidosis and 2.34 (1918 cases) had lung hydatidosis. Within a 10-year period, 140 patients (91 females and 49 males) were treated for hydatidosis. Of 1200 human sera, 2.25 (27 patients) were seropositive for hydatidosis. Conclusion: Hydatidosis is endemic in Ilam Province especially in rural area. The health and economic losses caused by the disease are significant; thus, our efforts need to be focused on the control of this disease

Comparison of virulence factors and biofilm formation among Staphylococcus aureus strains isolated from human and bovine infections

The aim of this study was to find different prevalence of genes involved in the biofilm formation process and to assess the phenotypic and genotypic markers of biofilm formation among Staphylococcus aureus strains isolated from human and bovine infections. In this study, 215 S. aureus strains were collected from human and dairy cow's infections. The biofilm forming capacity of the strains was evaluated using a colorimetric microtiter plate assay. The genes encoding microbial surface components, recognizing adhesive matrix molecules (MSCRAMMs) (ebpS, eno, fib, fnbA, fnbB, cna and bap), and the intracellular adhesion (ica) genes (icaA, and icaD) were targeted by polymerase chain reaction (PCR)-based method. Approximately 70 of the isolates produced biofilm. Among these, 59.3 were producers of weakly adherent biofilms while 34.8 and 5.8 produced moderate and strong biofilms, respectively. The most prevalent gene was icaD found in 88.4 of the isolates, followed by icaA, fib and eno found in 87.9, 75.8 and 75.3 of the isolates, respectively. The bap gene was not detected in any of the isolates. The prevalence of ebpS and fnbA genes among bovine isolates were significantly higher than those in human isolates, whilst the prevalence of cm gene was significantly higher in the human isolates. In this study, a high prevalence of biofilm production was found among S. aureus strains isolated from human and bovine infections. Most biofilm producing isolates were positive for MSCRAMM, icaA, and icaD genes. (C) 2015 Elsevier Ltd. All rights reserved