Microbiology
Zahra Yousefpour; Fateme Davarzani; Parviz Owlia
Abstract
Background & Objective: The ability of Pseudomonas aeruginosa to form biofilm has an important role in establishment of chronic phase of infections. Biofilm formation can be affected by antibiotics sub-MIC concentrations. The principal aim of the present study was to evaluate the effect of gentamicin ...
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Background & Objective: The ability of Pseudomonas aeruginosa to form biofilm has an important role in establishment of chronic phase of infections. Biofilm formation can be affected by antibiotics sub-MIC concentrations. The principal aim of the present study was to evaluate the effect of gentamicin at sub-MIC concentrations on biofilm formation in 100 Pseudomonas aeruginosa clinical isolates.Methods: Determination of minimal inhibitory concentration of gentamicin for clinical isolates was done using micro broth dilution method. The amount of biofilm formation in the treated and untreated isolates with gentamicin sub-MIC (1/2&1/4MIC) concentrations was evaluated using microtitre plate assay. pelA and pslA genes were detected in clinical isolates by PCR method.Results: 99% of clinical isolates were biofilm producer. Different changes in amountof biofilm formation were observed in the treated clinical isolates with sub-MIC concentrations of gentamicin. Two dominant changes were observed in 80% of clinical isolates. These concentrations had inhibitory effect on biofilm formation in 46.4% of isolates and caused a significant decrease in its amount. While in 31.3% of the isolates, the biofilm formation was significantly increased. The frequency of pelA and pslA genes among clinical isolates was 100%. Conclusion: gentamicin sub-MIC concentrations cause different changes on biofilm formation of Pseudomonas aeruginosa clinical isolates. Therefore, further studies are needed for discovering new treatment strategies and using sub-MIC concentrations of the antibiotic in prevention and treatment of Pseudomonas aeruginosa infections.
Microbiology
Ehsan Kazemi Moghaddam; Parviz Owlia; Abolfazl Jahangiri; Iraj Rasooli; Mohammad Reza Rahbar; Marjan Aghajani
Abstract
Background & Objectives: Due to the importance of Pseudomonas aeruginosa in severe inpatient infections and high mortality, the need for an efficient vaccine against these bacteria is increasing. In this regard, the general outer membrane porin of the most problematic microorganism P. aeruginosa, ...
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Background & Objectives: Due to the importance of Pseudomonas aeruginosa in severe inpatient infections and high mortality, the need for an efficient vaccine against these bacteria is increasing. In this regard, the general outer membrane porin of the most problematic microorganism P. aeruginosa, outer membrane protein F (OprF), is a good vaccine candidate. Methods:The databank of NCBI was used to retrieve protein sequences recorded for OprF in P. aeruginosa.The current study aimed at investigating the conservation of the OprF in 150 reference sequences, clinical, and environmental strains of P. aeruginosa from different countries via bioinformatic tools.T-COFFEE and PRALINE software were used for alignment. Results: Of these, 134 strains were isolated from clinical specimens and other strains from environmental samples. Evaluation of alignment by the mentioned software clearly showed that this protein was conserved. Antigenicity and grand average of hydropathicity were favorable. Conclusion: Conservation of OprF in all pathogenic and environmental strains of P. aeruginosa indicated that it can be considered as a good immunogen; however, the protectivity of OprF should be validated experimentally.
Microbiology
Shadi Shahsavan; Parviz Owlia; Abdolaziz Rastegar Lari; Bita Bakhshi; Maliheh Nobakht
Abstract
Background: Shigella spp. are gram negative bacteria, which are of global public health importance. The growing of multidrug-resistant Shigella isolates are a major problemaround the world. Methods: Overall, 50 isolates of Shigella spp. from children diarrheic stools were studied. ...
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Background: Shigella spp. are gram negative bacteria, which are of global public health importance. The growing of multidrug-resistant Shigella isolates are a major problemaround 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 were12% 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.
Microbiology
Tahereh Tahmasebi; Rahim Nosrati; Hamed Zare; Horieh Saderi; Reyhaneh Moradi; Parviz Owlia
Volume 11, Issue 4 , October 2016, , Pages 354-362
Abstract
Background: Glutathione (GSH) is a non-protein thiol compound, which plays an important role in the response to oxidative stress and nutritional stress. The aim of this study was to isolate indigenous S. cerevisiae strains capable of effectively produce GSH. Methods: One hundred-twenty sweet fruit samples ...
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Background: Glutathione (GSH) is a non-protein thiol compound, which plays an important role in the response to oxidative stress and nutritional stress. The aim of this study was to isolate indigenous S. cerevisiae strains capable of effectively produce GSH. Methods: One hundred-twenty sweet fruit samples were collected. The strains were isolated on yeast glucose chloramphenicol (YGC) agar medium and identified. The isolates were evaluated for GSH producing on yeast malt (YM) medium. Concentration of glutathione was investigated by recording absorbance of all samples at wavelength 412 nm (Ellman’s method). In addition, optimization of glucose and peptone concentration in culture medium and the effects of various environmental conditions such as temperature (20–35 °C), agitation rate (150–250 rpm), and initial pH (4.0–6.0) were assessed on producing of GSH. Results: From 120 samples, 80 isolates were identified by morphological, biochemical and molecular tests as S. cerevisiae. Five isolates were capable to produce effectively GSH. The optimal culture conditions were agitation rate, 200 rpm; temperature, 30 °C; initial pH, 6; glucose, 30 g/l; and peptone concentration, 5 g/l. In optimal conditions, the amount of derived glutathione was improved compared to YM basal medium and highest GSH concentration (296.8 mg/l) was obtained after cultivation with shaking for 72 h. Conclusion: The possibility of obtaining S. cerevisiae cells with a high GSH intracellular content can be considered an interesting opportunity of furthering the range of application and utilization of this molecule.
Microbiology
Horieh Saderi; Parviz Owlia
Abstract
Background: This study was done to detect multidrug resistant (MDR) and extremely drug resistant (XDR) of Pseudomonas aeruginosa among strains isolated from patients in Tehran, Iran, due to importance of these phenotypes in treatment of human infections. Methods: Eighty eightP. aeruginosa were isolated ...
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Background: This study was done to detect multidrug resistant (MDR) and extremely drug resistant (XDR) of Pseudomonas aeruginosa among strains isolated from patients in Tehran, Iran, due to importance of these phenotypes in treatment of human infections. Methods: Eighty eightP. aeruginosa were isolated from patients in Tehran, Iran, and identified by routine methods and PCR for oprL gene. Their antimicrobial susceptibility to 16 antimicrobial agents from 7 antimicrobial categories (aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, penicillins/ß-lactamase inhibitors, monobactams, polymyxins) were determined by disk diffusion method, according to recommendation of Clinical and Laboratory Standards Institute. Characterization of P. aeruginosa isolates as MDR and XDR was done according to standardized international terminology presented by European Centre for Disease Prevention and Control as well as the Centers for Disease Control and Prevention in 2011. MDR was defined as acquired non-susceptibility to at least one agent in ≥3 antimicrobial categories and XDR was defined as non-susceptibility to at least one agent in ≥6 antimicrobial categories. Results: The rates of susceptibility to antimicrobials were as follows: gentamicin 27.3%, tobramycin 54.5%, amikacin 56.8%, netilmicin 36.4%, imipenem 55.7%, meropenem 55.7%, doripenem 60.2%, ceftazidime 63.6%, cefepime 56.8%, ciprofloxacin 59.1%, levofloxacin 60.2%, ticarcillin-clavulanic acid 37.5%, piperacillin-tazobactam 63.6%, aztreonam 43.2%, colistin 90.9%, polymyxin 95.5%. Altogether, 48 (54.5%) and 29 (33%) isolates were characterized as MDR and XDR, respectively. Discussion:The high frequency of antibiotic resistance in clinical isolates of P. aeruginosa in Iran makes epidemiological surveillance of susceptibility of this bacterium more essential for the best selection of empirical antibiotics.
Seyedeh Maryam Sharafi; Iraj Rasooli; Ali Dehghan Kashani; Parviz Owlia; Mohammad Bagher Rezaee; Shakiba Darvish Alipoor Astaneh
Volume 5, Issue 4 , September 2010, , Pages 184-193
Abstract
Background and Objectives: There is a profound inclination among people toward consumption of herbs and herbal products. Some of these products are harmful while health-promoting potentials of some others should be discovered. In the present study the antibacterial, antioxidant, acute and subchronic ...
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Background and Objectives: There is a profound inclination among people toward consumption of herbs and herbal products. Some of these products are harmful while health-promoting potentials of some others should be discovered. In the present study the antibacterial, antioxidant, acute and subchronic and cancer cell toxicity of methanolic and aqueous extracts of Rosa damascena Mill. was studied. Materials and Methods: Antimicrobial activities were determined by agar disc diffusion method. Total phenol content was estimated. Antioxidative properties of the extracts were determined by bleaching of beta carotene or 2,20-diphenylpicrylhydrazyl (DPPH). The Ferric-Reducing Antioxidant Power (FRAP) was expressed as gallic acid equivalents or known Fe (II) concentration for rose extracts and blood sera respectively. Acute and subchronic toxicity and cytotoxicity of the extracts were tested using animal model or Hela cells. Hematology and clinical chemistry parameters were noted. Results: Staphylococcus aureus was found susceptible. The total phenol contents of the methanolic and aqueous extracts were 132.67±3.51 and 117.33±6.81 μg Gallic acid equivalent/mg sample, respectively. Antioxidative effects were higher than those of the synthetic antioxidants were. A dose dependent levels of FRAP was noted in blood sera of rats gavaged with the extracts. Decrease in cholesterol/HDL and LDL/HDL ratios, fasting glucose, blood urea nitrogen, creatinine and uric acid is suggestive of promising therapeutic potentials of the extract. Inhibitory concentration of 50% (IC50) of 4.5 µg/ml was determined for cytotoxicity of the extract against Hela cell line. Conclusion: The results suggest application of rose extract as a natural antioxidant and health-promoting agent.
Parviz Owlia; Zakaria Bameri; Mohsen Chitsaz
Volume 5, Issue 3 , June 2010, , Pages 137-142
Abstract
Background and Objective: Organisms producing CTX-M β-lactamases are emerging as a source of resistance to oxyiminocefalosporins such as ceftriaxone and ceftazidime. However, the laboratory detection of these strains is not well defined. In this study, phenotypic assay for screening of extended-spectrum ...
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Background and Objective: Organisms producing CTX-M β-lactamases are emerging as a source of resistance to oxyiminocefalosporins such as ceftriaxone and ceftazidime. However, the laboratory detection of these strains is not well defined. In this study, phenotypic assay for screening of extended-spectrum β-lactamases producing strains and molecular assay for the identification of CTX-M β-lactamases genes was developed and used to investigate the prevalence of these enzymes among clinical isolates of Klebsiella pneumoniae in three general hospitals of Tehran, Iran. Materials and Methods: Phenotypic detection was used for screening of isolates by agar dilution method. A decrease of ≥3 doubling dilution in an MIC for either ceftriaxone or ceftazidime tested in combination with 4 mg/l clavulanic acid (prepared from Glasco Smith company) versus its MIC when tested alone, confirmed an ESBL-producing organism. The PCR assay consisted of four primer sets. Results: In initial screening test, 117 (69%) from 168 clinical isolates were positive and 51 isolates (31%) were negative. From the positive isolates, 96 isolates were positive in phenotypic confirmatory test. Using molecular assay, 117 strains potentially producing extended-spectrum-β-lactamases were examined for the presence of CTX-M enzymes: 88 strains (75.2%) were positive for blactx-m group І genes, 1 strain (0.85%) was positive for blactx-m group ІІІ genes , and 2 strains (1.7%) were positive for blactx-m group ІV. Conclusion: The prevalence of extended-spectrum β-lactamases (ESBLs) are increasing significantly in hospitals of Tehran. In other side, we found that the CTX-M І group had the most prevalence than other CTX-M groups.
Mohsen Mirzaee; Parviz Owlia; Mohammad Reza Mehrabi; Amir Gharib
Volume 4, Issue 4 , September 2009, , Pages 151-156
Abstract
Background and Objectives: The most common problems limiting the medical use of aminoglycosides have been the nephro- and oto-toxicities as well as the increasing bacterial resistance. Encapsulation of drugs into liposomes enhances their efficacy while reducing their toxicities. The aim of this ...
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Background and Objectives: The most common problems limiting the medical use of aminoglycosides have been the nephro- and oto-toxicities as well as the increasing bacterial resistance. Encapsulation of drugs into liposomes enhances their efficacy while reducing their toxicities. The aim of this study was to evaluate the antimicrobial activity of free and liposomal amikacin. Material and Methods: Encapsulated amikacin into liposome was prepared by sonication. The drug contained in the liposome was measured by HPLC after lysis of vesicles by 0.2% Triton X-100. The amikacin kinetic released from liposomes in the presence of normal human pooled plasma was also evaluated. The MICs of this drug for Pseudomonas. aeruginosa (ATCC 27853), Escherichia. coli (ATCC 25922), Streptococcus. faecalis (ATCC 29212) and Staphylococcus. aureuse (ATCC 29213) were determined and compared to those of the respective free drug using a broth dilution method. Results: In the presence of plasma, liposomal retention of amikacin was 80.25 ± 0.55% (P ≤ 0.05) after 1 h of incubation and then remained nearly constant over a 24 h period of the study. The encapsulation efficiency of liposomal preparation was 24.36% ± 0.14 (P ≤ 0.05) of the initial amount of the drug in solution. The MICs of liposomal amikacin against all bacterial strains tested were lower than MICs of free amikacin. Conclusion: The amikacin appears a promising approach in the management of bacterial infections and should be further evaluated in vivo experiments.
Horieh Saderi; Parviz Owlia; Maryam Eslami
Volume 4, Issue 4 , September 2009, , Pages 161-166
Abstract
Background and Objectives: Staphylococcus aureus is an important cause of nosocomial and community-acquired infections in every region of the world. Clindamycin is one of the alternative agents used to treat S. aureus infections and accurate identification of clindamycin resistance is important to prevent ...
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Background and Objectives: Staphylococcus aureus is an important cause of nosocomial and community-acquired infections in every region of the world. Clindamycin is one of the alternative agents used to treat S. aureus infections and accurate identification of clindamycin resistance is important to prevent therapeutic failure. Unfortunately, inducible clindamycin resistance is not detected by standard susceptibility tests. This study aimed to determine the prevalence of the macrolides-lincosamides-streptogramins B (MLSB) resistance in S. aureus isolated in four university hospitals in Tehran, Iran. Material & Methods: Two hundreds and forty-four non-duplicate clinical isolates of S. aureus (133 methicillin resistant S. aureus (MRSA) and 111 methicillin susceptible (MSSA) S. aureus) were collected in 2008. Antimicrobial susceptibilities were determined by the D-test. Results: Altogether, 68% and 61.1% of isolates were resistant to erythromycin and clindamycin, respectively; with higher resistance in MRSA isolates compared to MSSA isolates. The constitutive MLSB (cMLSB) resistance phenotype was recognized in 61.1%, while 5.3% had shown inducible MLSB (iMLSB) resistance phenotype. Constitutive MLSB resistance phenotype predominated over inducible MLSB resistance phenotype and susceptible phenotype (83.9, 9.3 and 6.8%, respectively) among the MRSA isolates, whereas susceptible phenotype predominated over constitutive MLSB resistance phenotype and inducible MLSB resistance phenotype (62.6, 31.3 and 2%, respectively) among the MSSA isolates. Conclusion:Considering the higher prevalence of clindamycin resistance in MRSA isolates compared MSSA isolates, routine D-test of MRSA isolates is strongly recommended to prevent treatment failure.
Horieh Saderi; Parviz Owlia; Zohreh Maleki; Mehri Habibi; Nayere Rahmati
Volume 3, Issue 3 , June 2008, , Pages 161-167
Abstract
Background and Objective: Vancomycin is frequently the antibiotic of choice for the treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). For the last years, the incidence of vancomycin-intermediate S. aureus (VISA) and vancomycin-resistant S. aureus (VRSA) has ...
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Background and Objective: Vancomycin is frequently the antibiotic of choice for the treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). For the last years, the incidence of vancomycin-intermediate S. aureus (VISA) and vancomycin-resistant S. aureus (VRSA) has been increased in various parts of the world. The present study was carried out to determine the presence of VISA and VRSA in Tehran. Materials and Methods: A total of 164 S. aureus strains were isolated from clinical specimens in four university-affiliated hospitals in Tehran from November 2006 to June 2007. Minimum inhibitory concentration (MIC) of vancomycin of isolates was determined by agar dilution method. Vancomycin (6 mg/l) screen agar plate method and E-test were used to confirm presence of resistance to vancomycin. Disc diffusion agar test was also used to detect resistance to other antimicrobial agents. Results: Only one VRSA(MIC 256 mg/l) was detected and three strains with MIC 4 mg/l considered VISA according to recent CLSI breakpoints for vancomycin. Only VRSA strain had shown growth on vancomycin screen agar plate and was also resistant to several antimicrobial agents but susceptible to quinupristin/dalfopristin, linezolid, chloramphenicol, mupirocin and cotrimoxazole. Isolated VISA were also multi-resistant but showed susceptibility to quinupristin/dalfopristin, linezolid, chloramphenicol and mupirocin. Conclusion: Detection of vancomycin resistance in Iranian S. aureus isolates emphasizes the challenges confronted by the infection control specialists in hospitals in Iran as well as causing problems in the treatment of patients with S. aureus infections.
Horieh Saderi; Mehri Habibi; Parviz Owlia; Mohammadreza Asadi Karam
Volume 3, Issue 1 , January 2008, , Pages 11-14
Abstract
Background and Objective: Methicillin resistance in Staphylococcus aureus is an increasingly important clinical problem. A chromosomal gene, mecA, mediates resistance to penicillinase-resistant penicillins such as methicillin and oxacillin in Staphylococcus aureus. We evaluated the validity of ...
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Background and Objective: Methicillin resistance in Staphylococcus aureus is an increasingly important clinical problem. A chromosomal gene, mecA, mediates resistance to penicillinase-resistant penicillins such as methicillin and oxacillin in Staphylococcus aureus. We evaluated the validity of disk diffusion test by using oxacillin, methicillin and cefoxitin disks with consideration of the presence of mecA gene as the reference method for detection of methicillin resistant Staphylococcus aureus (MRSA). Materials and Methods: The susceptibility testing of 222 S. aureus clinical isolates to oxacillin (1 µg), cefoxitin (30 µg) and methicillin (5 µg) was carried out by the disk diffusion method according to the Clinical Laboratory Standards Institute guidelines. Detection of mecA gene was performed using PCR method. Results: An amplified mecA gene of 310 bp was detected in 55% of examined strains by PCR, thus 55% strains were considered MRSA. Sensitivity of oxacillin, methicillin and cefoxitin disks were determined 100%, 99.1% and 98.3% respectively. All MRSA strains in PCR had shown resistance to penicillinase-resistant penicillins by oxacillin disk, but two and one strains were sensitive by cefoxitin and methicillin disk respectively. Thus, oxacillin was the most appropriate disk for detecting MRSA. Conclusion: The prevalence of MRSA in this study is comparable to that found in United States, Canada, Europe and Iran, but the percentage of MRSA isolates is almost twice of percentage reported from Japan.
Parviz Owlia; Horieh Saderi; Zohreh Karimi; Seyed Mohammad Bagher Akhavi Rad; Mohammad Ali Bahar
Volume 3, Issue 1 , January 2008, , Pages 20-25
Abstract
Background and Objective: Metallo-beta-lactamase (MBL)-mediated resistance is an emerging threat in hospital isolates of Pseudomonas aeruginosa. There is not enough information from Iran regarding the prevalence and the screening methods for such enzymes. The present study was undertaken to detect ...
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Background and Objective: Metallo-beta-lactamase (MBL)-mediated resistance is an emerging threat in hospital isolates of Pseudomonas aeruginosa. There is not enough information from Iran regarding the prevalence and the screening methods for such enzymes. The present study was undertaken to detect Metallo betalactamase in strains of P. aeruginosa isolated from burned patientusingphenotypic method. Materials and Methods: For this purpose, 128 consecutive P. aeruginosa isolates obtained from hospitalized patients were subjected to susceptibility testing to antipseudomonal drugs by disc diffusion and minimal inhibitory concentration (MIC) for ceftazidime was determined. The production of MBL was detected by the zone size enhancement with EDTA impregnated ceftazidime disc. Results: It was found out that 94 (73.44%) of the isolates were resistant to ceftazidime. These isolates screened as ESBLs producing strains and introduced for detection of MBL production. Out of the 94 P. aeruginosa that were resistant to ceftazidime, 50 (53.2%) isolates were MBL positive. This result indicated that 39.06% of all isolates were MBL positive. Conclusion: MBL-mediated ceftazidime resistance in P. aeruginosa is a cause for concern in the therapy of critically ill patients. The MBL producing P. aeruginosa isolates were more resistant to various antimicrobial agents. This result suggests that MBL producing isolates in hospitals may cause serious infections that illustrated when these strains were responsible for a nosocomial outbreak.
Parviz Owlia; Effat Souri; Qurban Behzadian-Nejad
Volume 2, Issue 3 , June 2007, , Pages 104-108
Abstract
Background and Objective: The opportunistic pathogen Pseudomonas aeruginosa secrets a capsule-like polysaccharide called alginate which is important for evasion of host defenses, especially in patients with suppressed immunity. Method of alginate determination has an important role in the study of microbial ...
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Background and Objective: The opportunistic pathogen Pseudomonas aeruginosa secrets a capsule-like polysaccharide called alginate which is important for evasion of host defenses, especially in patients with suppressed immunity. Method of alginate determination has an important role in the study of microbial alginate. In this study, a novel method for alginate determination by highperformance liquid chromatography (HPLC) was introduced. Materials and Methods: Standard alginate was used for construction of standard curve and standard mucoid and non-mucoid strains of Pseudomonas aeruginosa were used as positive and negative samples respectively. The method of Toyoda was modified for determination of microbial alginate. HPLC determination was performed using a Resolve C18 column (3.9 × 150 mm, Waters, Milford, MA) and acetonitrile-water-butyl acetate (55: 42: 3) as the mobile phase at a flow rate of 0.6 ml/min and detection at 565 nm. Results: The obtained data indicated that minimal detectable concentration of alginate by this method is 20 μg/ml. The method was linear over the range of 1-1000 μg/ml of alginate. The retention time was about 10 min. Conclusion: The proposed method was used for determination of alginate in standard mucoid and non-mucoid strains of Pseudomonas aeruginosa. The results of this study showed that the proposed method is a simple and valid method for bacterial alginate assay.
Horieh Saderi; Parviz Owlia; Mohammad Reza Jalali Nadoushan; Farid Zaeri; Elaheh Zandieh
Volume 1, Issue 3 , June 2006, , Pages 99-104
Abstract
Background and Objectives: This study was designed as a retrospective study on urine samples during three years in Shaheed Mostafa Khomeini Hospital to determine demographic characteristics of patients with urinary tract infection (UTI), microbial etiology, and susceptibility of isolated bacteria to ...
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Background and Objectives: This study was designed as a retrospective study on urine samples during three years in Shaheed Mostafa Khomeini Hospital to determine demographic characteristics of patients with urinary tract infection (UTI), microbial etiology, and susceptibility of isolated bacteria to antibiotics. Materials and Methods: All urines fulfilling the criteria for significant bacteriuria (>104 colonyforming units/ml of urine) were included in the study. Isolation and identification of bacteria was performed by standard method and susceptibility testing was determined by disk diffusion method according to NCCLS guideline. A total of 909 patients with urinary tract infection were enrolled in this study. Results: Mean age of the patients was 53.2 years. In addition, females were affected more often than males (female/male sex ratio was 2.22). Meanwhile, considering all strains, 79.5% were Gram-negative bacilli and 67.7% were Enterobacteriaceae. Furthermore, E.coli and Klebsiella spp represented the most common Gram-negative and Enterococci and S. aureus represented the most frequent Gram-positive isolates. The four most frequently isolated bacteria were E. coli (52.1%), Enterococci (10.5%), klebsiella spp. (10.3%), and pseudomonas spp. (9.4%). In addition, E. coli was significantly more common in females (56.6%) than in males (42.2%) and in outpatients (57.4%) than in inpatients (47.4%). The proportion of pseudomonas spp. was significantly higher in males (17.7%) than in females (5.6%). Enterococci were significantly more common in inpatients (12.5%) than in outpatients (8.4%). Altogether, the rate of susceptibility of all UTI pathogens was very low to ampicillin (6.9%) and high to cefotaxime (83.6%) and ciprofloxacin (78.2%). Urinary pathogens isolated from female patients and outpatients were more susceptible to most of examined antibiotics than those isolated from males and inpatients. Conclusion: It was found out that degrees for antibiotic resistance of urinary pathogens are alarming and show the necessity of keeping up the monitoring of antibiotics susceptibility in UTI isolates and restricting antibiotic consumption in our population.
Parviz Owlia; Horieh Saderi; Sadegh Mansouri; Sirus Salemi; Hossein Ameli
Volume 1, Issue 2 , April 2006, , Pages 61-64
Abstract
Background and Objectives: Infection is the most common problem following burn injury. Selection and dissemination of intrinsic and acquired resistance mechanisms increase the probability of burn wound colonization by resistant species including Pseudomonas aeruginosa. Multi-drug resistant Pseudomonas ...
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Background and Objectives: Infection is the most common problem following burn injury. Selection and dissemination of intrinsic and acquired resistance mechanisms increase the probability of burn wound colonization by resistant species including Pseudomonas aeruginosa. Multi-drug resistant Pseudomonas aeruginosa has frequently been reported as the cause of nosocomial outbreaks of infection in burn wards or as colonizers of the wound of burned patients. Therefore, this research study was conducted to compare the activity of various antibiotics and disinfectants against clinically important strains of P. aeruginosa. Materials and Methods: One hundred strains of P. aeruginosa were obtained as clinical isolates from burn wound infections. The antimicrobial activity of antibiotics was tested by disk diffusion method of Kirby-Baur. For disinfectants, 30 μl of each of them was placed on sterile blank disk and studied by disk diffusion method. Results: The frequency of resistant strains to kanamycin, tobramycin, amikacin, cefotaxime, carbenicillin, ceftazidime, ceftizoxime, cefixim, ciprofloxacin, cefazolin, cephalexine, and ceftriaxone was 100, 93, 95, 81, 84, 95, 94, 100, 99, 100, 100, and 92 respectively. The averaged diameter of inhibition zone for chlorhexidine (0.2%), povidione iodine (10%), cetrimide-C (3.5%), dekosept, hypochlorite (10%), micro 10+ (2%), deconex 53+ (2%), and ethanol (70%) was 14.4 ± 1.9 mm, 10.6 ± 1.3 mm, 9.1 ± 2.6 mm, 8.6 ± 2.2 mm, 26.9 ± 5.2 mm, 6.58 ± 1.5 mm, 8.3 ± 2.2 mm, and 6 ± 0.0 mm respectively.
