ABSTRACT
Background and Aim: Quaternary ammonium compounds can be used for growth control of fungi in hospitals and algae in swimming pools. The aim of this study was to evaluate antifungal and antialgal effect of new quaternary ammonium compounds
Material and Methods: In this experimental study, eight tetravalent ammonium salts with different positions in R1 and R2 were synthesized. These compounds were synthesized from 4,4 - Amino methyl biphenyls compounds and were different from each other in biphenyls and amine groups. To determine their effects on molds, they were cultured in potato-dextrose-agar [PDA] medium containing nistatin on the basis of Medallion method. The diameter of inhibitory growth zones for mold in the test cultures were compared with those of the control cultures. The effect of the new compounds on algae strains Clorella vulgaris 157 was evaluated by using glucose solid medium exposed to suitable light at room temperature for 5-3 days. Zones of inhibition were detected
Results: Antifungal effect of compound 149 on the molds was 100%, similar to the effect of Nistatin. This effect was from 68% to 100% for compounds 188 and 178 respectively and lasted for a long time in the culture medium, even after 3 to 7 days no growth was observed. By increasing the concentration of the compounds, compound No. 188 showed a higher inhibitory growth rate for algae in comparison to compounds No. 149 and NO. 178. Three times increase in the concentrations of the compounds resulted in 2.1, 1.45 and 1.38 times increase in the diameters of the zones of inhibition for the compounds No. 188, No. 149 and NO.178 respectively
Conclusion: Compounds used in this study had similar inhibitory effects on eukaryotic cells and their antifungal and anti-algae effects were similar. Increase in antifungal effects led to increased anti algae effect. Use of these compounds is recommended in the industry
ABSTRACT
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
ABSTRACT
Objective: To study genetic bases and morphology of pili in Mycobacterium tuberculosis (M. tuberculosis). Methods: PCR and sequencing were used to investigate two related pili, Mtp and Flp genes in clinical isolates of M. tuberculosis. The primers were designed and PCR program were set for whole genes amplification. PCR products of the two genes from all isolates were sequenced by an applied biosystems apparatus and the results were analysed by online software. In the other hands, harvested cells from fresh cultures of isolates were undergoing specific sample preparation for sectional and negative staining for transmission electron microscopy. Results: Electrophoresis revealed two specific bonds of 361 bp for Mtp and 150 bp for Flp genes and confirmed primer and PCR conditions designing. There were not any mutations in sequencing results of Mtp and Flp in comparison with reference sequence. Transmission electron microscopy examination revealed two distinct types of pili in the isolates as a bundle-forming pilus and rope-like pilus. From total investigated cells, 10% harbored pili in their structure. Conclusions: Two genes of pili in all clinical isolates of M. tuberculosis were conserved and two morphological types of pili were detected. We proposed that by targeting pili proteins by a suitable inhibitor, it could affect the pathogenesis especially in resistant forms.
ABSTRACT
Objective: To investigate the biosorption potential of isolated bacteria as an alternative biosorbent material for the removal of zinc and nickel from aqueous solution in a bubble column bioreactor. Methords: In this study from four points of waste water treatment plant, some Gram-positive and Gram-negative bacteria under heavy metal stress conditions were isolated by microbiological methods. Biosorption experiments were conducted in a bubble column containing waste water in high concentrations of nickel and zinc inoculated by isolated bacteria. A kinetic study was done to investigate the fitting of either pseudo first-order or second order equations. Results: The 96% removal of zinc and 54% removal of nickel were achieved by biosorption column experiment by the isolated bacteria. A comparison between a non-aerated and aerated column shows a higher removal percentage with the same contact time. The study of contact time in the experiments also confirmed that with more contact time, while the removal efficiency increases the capacity of microorganisms to absorb the metal ions decreases. Results of kinetic study showed pseudo-second-order equation with a coefficient of determination of 0.9648 and 0.9992 for zinc and nickel, and the pseudo-first-order equation with 0.2410 and 0.4794, respectively. Conclusions: It was be concluded that biosorbtion method is a suitable alternative method to remove metal ions for further study in large scale.
ABSTRACT
OBJECTIVE@#To investigate the biosorption potential of isolated bacteria as an alternative biosorbent material for the removal of zinc and nickel from aqueous solution in a bubble column bioreactor.@*METHORDS@#In this study from four points of waste water treatment plant, some Gram-positive and Gram-negative bacteria under heavy metal stress conditions were isolated by microbiological methods. Biosorption experiments were conducted in a bubble column containing waste water in high concentrations of nickel and zinc inoculated by isolated bacteria. A kinetic study was done to investigate the fitting of either pseudo first-order or second order equations.@*RESULTS@#The 96% removal of zinc and 54% removal of nickel were achieved by biosorption column experiment by the isolated bacteria. A comparison between a non-aerated and aerated column shows a higher removal percentage with the same contact time. The study of contact time in the experiments also confirmed that with more contact time, while the removal efficiency increases the capacity of microorganisms to absorb the metal ions decreases. Results of kinetic study showed pseudo-second-order equation with a coefficient of determination of 0.9648 and 0.9992 for zinc and nickel, and the pseudo-first-order equation with 0.2410 and 0.4794, respectively.@*CONCLUSIONS@#It was be concluded that biosorbtion method is a suitable alternative method to remove metal ions for further study in large scale.
ABSTRACT
OBJECTIVE@#To study genetic bases and morphology of pili in Mycobacterium tuberculosis (M. tuberculosis).@*METHODS@#PCR and sequencing were used to investigate two related pili, Mtp and Flp genes in clinical isolates of M. tuberculosis. The primers were designed and PCR program were set for whole genes amplification. PCR products of the two genes from all isolates were sequenced by an applied biosystems apparatus and the results were analysed by online software. In the other hands, harvested cells from fresh cultures of isolates were undergoing specific sample preparation for sectional and negative staining for transmission electron microscopy.@*RESULTS@#Electrophoresis revealed two specific bonds of 361 bp for Mtp and 150 bp for Flp genes and confirmed primer and PCR conditions designing. There were not any mutations in sequencing results of Mtp and Flp in comparison with reference sequence. Transmission electron microscopy examination revealed two distinct types of pili in the isolates as a bundle-forming pilus and rope-like pilus. From total investigated cells, 10% harbored pili in their structure.@*CONCLUSIONS@#Two genes of pili in all clinical isolates of M. tuberculosis were conserved and two morphological types of pili were detected. We proposed that by targeting pili proteins by a suitable inhibitor, it could affect the pathogenesis especially in resistant forms.
ABSTRACT
Objective:To analyse molecular detection of coliforms and shorten the time of PCR. Methods:Rapid detection of coliforms by amplification of lacZ and uidA genes in a multiplex PCR reaction was designed and performed in comparison with most probably number (MPN) method for 16 artificial and 101 field samples. The molecular method was also conducted on isolated coliforms from positive MPN samples; standard sample for verification of microbial method certificated reference material; isolated strains from certificated reference material and standard bacteria. The PCR and electrophoresis parameters were changed for reducing the operation time. Results:Results of PCR for lacZ and uidA genes were similar in all of standard, operational and artificial samples and showed the 876 bp and 147 bp bands of lacZ and uidA genes by multiplex PCR. PCR results were confirmed by MPN culture method by sensitivity 86%(95%CI:0.71-0.93). Also the total execution time, with a successful change of factors, was reduced to less than two and a half hour. Conclusions:Multiplex PCR method with shortened operation time was used for the simultaneous detection of total coliforms and Escherichia coli in distribution system of Arak city. It’s recommended to be used at least as an initial screening test, and then the positive samples could be randomly tested by MPN.
ABSTRACT
Iran is one of the endemic regions with high prevalence of brucellosis. Several serological markers for diagnosis and response to treatment are available. Serum level of Soluble Interleukin-2 Receptor alpha [SIL-2R alpha] is a new marker to assess response to therapy and clinical relapse of brucellosis. This study intends to investigate the serum levels of SIL-2R alpha before and after treatment, to evaluate this marker for patients responding to treatment of brucellosis. This study is an analytical cross-sectional study. Forty patients who had clinical signs of brucellosis and serological tests confirmed the disease have been treated with standard antibiotics for 6 weeks. 2ME and SIL-2R alpha levels were measured before and after treatment and these values were compared. Among the 40 patients, 27 patients [67.5%] had improvement in symptoms and 13 patients [32.5%] had no symptoms after treatment. In Comparing serum levels of SIL-2R alpha and 2ME before and after treatment, decreasing of both markers after treatment was significant [p<0.001]. In patients with false positive for 2ME, SIL-2R alpha in 57% of patients had a reduction, but in patients with false negative for 2ME, SIL-2R alpha in only 28% of patients increased. Not only is Serum level of SIL-2R alpha useful for predicting response to treatment of brucellosis, but also in cases of false positive of 2ME can be helpful.
ABSTRACT
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