Detection of VIM- and IMP-type metallo-beta-lactamase genes in acinetobacter baumannii isolates from patients in two hospitals in Tehran

Background: acinetobacter baumannii, is an opportunistic pathogen and is responsible for numerous nosocomial infections. In recent years, this microorganism has been resistant to a wide range of antibiotics. One of the most important mechanisms of resistance in this microorganism is production of metallo-beta-lactamases [MBLs]

Objectives: The aim of this study was to detect VIM- and IMP-type metallo-beta-lactamase genes in Acinetobacter baumanniiisolates from patients in two Hospitals in Tehran

Materials and Methods: 104 isolates were tested using the PCR method for the identification of VIM- and IMP-type Genes

Results: vim1, vim2, imp1and imp2 genes were detected in 6.7%, 41.7%, 50% and 1.7% of the isolates from Tehran Heart Center, and in 29.5%, 38.6%, 4.5% and 4.5% of the isolates from Shahid Mutahhari Hospital respectively

Discussion: our analysis revealed that the majority of the isolates had at least one of these genes, indicating that MBLs production is an important resistance mechanism in Acinetobacter baumannii

Acceleration of skin wound healing with tragacanth [Astragalus] preparation: an experimental pilot study in rats

Gum tragacanth is a natural complex mixture of polysaccharides and alkaline minerals extracted from species of Astragalus plant, which is found widely in arid regions of the Middle East. In a pilot experimental study we examined the effects of its topical application on wound healing in ten albino adult male rats. Two similar parasagittal elliptical full-thickness wounds [control vs. test samples] were created on the dorsum of each animal. Test group samples were fully covered by a thin layer of gum tragacanth daily. The extent of wound healing was evaluated by planimetric analysis on multiple occasions during the 10-day study period. On the 7[th] day of the study, the percent of wound closure was significantly higher in gum tragacanth-treated specimens compared to the control samples [87% +/- 2% vs. 70% +/- 4%, P<0.001]. The majority of wounds in the test group were completely closed by the 10[th] day of the study. The difference in wound healing index measured by histological examination on day 10 of the study was also statistically meaningful between the two groups [0.624 +/- 0.097 vs. 0.255 +/- 0.063, P<0.05]. The results of this study clearly showed the useful effects of topical application of gum tragacanth in acceleration of skin wound contraction and healing. More studies are encouraged to identify the implicating agents and precisely understand the mechanism by which they exert their wound healing effects

Plasma vitamin D status and its correlation with risk factors of thrombosis, P-selectin and hs-CRP level in patients with venous thromboembolism; the first study of iranian population

Low plasma level of vitamin D is linked to the increased risk of cardiovascular diseases such as hypertension, diabetes, dyslipidemia and peripheral vascular diseases. Vitamin D deficiency is a worldwide problem that involves Iranian population. To the best of our knowledge, this was the first investigation on venous thromboembolism [VTE] subjects that assessed the correlation of vitamin D level with plasma P-selectin, hs-CRP, and risk factors of thrombosis. In this prospective study, patients with diagnosis of acute deep vein thrombosis and or pulmonary eboembolism were enrolled. All patients' clinical data, demographics and risk factors of thrombosis were evaluated. Plasma level of P-selectin and hs-CRP were measured by ELISA method. Radio immune assay method was used to determine plasma level of 25-hydroxy vitamin D. In this study, 60 subjects were included. The mean +/- SD plasma 25-hydroxy vitamin D level [25[OH] D] of participants was 21.4 +/- 14.6 ng/mL. The vitamin D deficiency was reported in 60% of patients. No significant relation was found between the plasma 25[OH]D level and P-selectin and hs-CRP. In multiple regression analysis, there was a significant relationship between the level of 25[OH]D and the patients' age [beta = 0.452; p = 0.001], diabetes [beta = 0.280; p = 0.036] and positive family history of cardiovascular diseases [beta = 0.373; p = 0.003]. Vitamin D deficiency is a frequent problem in Iranian VTE patients. Moreover, Plasma level of vitamin D is not associated with increase level of P-selectin and hs-CRP in VTE patients

Can a new antiseptic agent reduce the bacterial colonization rate of central venous lines in post-cardiac surgery patients?

Central venous [CV] catheters play an essential role in the management of critically ill patients in the Intensive Care Unit [ICU].CV lines are, however, allied to catheter-associated blood stream infections. Bacterial colonization of CV lines is deemed the main cause of catheter-associated infection. The purpose of our study was to compare bacterial colony counts in the catheter site before CV line insertion in two groups of post-cardiac surgery patients: a group receiving Sanosil [an antiseptic agent composed of H[2]O[2] and silver] and a control group. This interventional prospective double-blinded clinical trial recruited the patients in three post-cardiac surgery ICUs of a heart center. The participants were divided into interventional [113 patients] and control [136 patients] groups. Sanosil was added to the routine preparation procedure [Chlorhexidine bath one day before and scrub with Povidone-Iodine just before the CV line insertion]. After the removal of the CV lines, the catheters tips were sent for culture and evaluation of colony counts. Catheter colonization occurred in 55 [22.1%] patients: 26 [23%] patients in the Sanosil group and 29 [21.3%] in the control group; there was no significant statistical difference between the two groups [p value = 0.75, RR = 1.05, 95%CI: 0.76-1.45]. The most common organism having colonized in the cultures of the catheter tips was staphylococcus epidermis: 20 cases in the control group and 16 cases in the intervention group. Catheter colonization frequently occurs in post-cardiac surgery patients. However, our results did not indicate the effectiveness of adding Sanosil to the routine preparation procedure with respect to reducing catheter bacterial colonization

Angiotensin- converting enzyme insertion/deletion polymorphism and its association with coronary artery disease in an Iranian population

The study of the association between genotype and phenotype is of great importance for the prediction of many diseases and pathophysiological conditions. The relationship between angiotensin-converting enzyme [ACE] gene insertion/ deletion [I/D] polymorphism and pathological processes such as coronary artery disease [CAD] has been investigated previously with discordant results. This study was designed to determine the association between ACE gene I/D polymorphism and CAD in an Iranian population. A total of 1050 individuals who were referred to Tehran Heart Center for coronary angiography were recruited. Six hundred seventy-six CAD-positive patients [documented by coronary angiography and Gensini scores higher than 6] and 374 CAD-negative patients were evaluated for ACE gene I/D polymorphism via the Polymerase Chain Reaction Amplification method. The patients' age, sex, smoking status and its duration as well as familial history of CAD, hypertension, and diabetes mellitus were recorded. Five hundred four [74.6%] of the CAD-positive patients were male, and the mean age of this group was 60 [60 +/- 10]. In the CAD-negative individuals, the mean age was 56 [56 +/- 10] and 196 of them were male [52.4%]. After the analysis of all the groups and gender subgroups, neither genotype nor allele frequency was significantly different between the CAD-positive and CAD-negative groups [p values for genotypes and allele frequencies were 0.494 and 0.397, respectively]. ACE gene I/D polymorphism was not associated with an increased risk of CAD in an Iranian population

[Synthesis of silver nanoparticles through chemical reduction and biosynthesis methods and evaluation of their antibacterial effects]

Silver nanoparticles have wide applications in medicine and treatment of bacterial infections due to their disinfection properties. Chemical synthesis, biosynthesis and antibacterial properties of silver nanoparticles have been studied previously, but regarding the high costs of chemical synthesis and the increase of antibiotic-resistance phenomenon among bacteria, assessment of the biosynthesis of silver nanoparticles and their effects on different clinical and standard bacterial strains is of great importance. Silver nanoparticles were synthesized through chemical and biosynthesis methods and their size and size distribution was assessed Transmission Electron Microscope. Chemically synthesized nanoparticles were added to tubes containing TSB medium and different bacterial strains for their antibacterial effects and their minimum inhibitory concentration was calculated Chemically synthesized silver nanoparticles had high monodispersity, but biosynthesized nanoparticles had higher polydispersity. Smaller silver nanoparticles had better antibacterial effects on Gram-negative and Gram-positive bacteria, in such a manner that they inhibited the bacterial growth at 0.2 mM concentration, but larger nanoparticles had lesser effects. Biosynthesis through bacterial supernatant is cost effective, but it produces polydisperse nanoparticles. Silver nanoparticles can replace antibiotics due to their suitable antibacterial effects, but it should be mentioned that clinical strains are more resistant than standard strains and bacterial resistance to these nanoparticles should be checked before their prescription

comparative study of recombinant human basic fibroblast growth factor [bFGF] and erythropoietin [EPO] in prevention of skin flap ischemic necrosis in rats

Impaired wound healing in ischemic tissues such as skin flaps resulting from inefficient perfusion is one major cause of complications in plastic surgery. In present experimental study, we investigated the effects of fibroblast growth factor-2 [FGF-2 or bFGF] and erythropoietin [EPO] in prevention of skin flap necrosis in rats. 30 adult albino rats were randomized into 3 groups: in control group, normal saline solution; in EPO group, erythropoietin [100U/ kg/day]: and in FGF-2 group, fibroblast growth factor-2 [2,5 microg/day] were injected subcutaneously in 3 daily consecutive doses in the designated flap areas before creating 4:1 random pattern skin flaps on the dorsum of animals. Areas of ischemic [S] and necrotic [S[N]] zones were measured and compared in all groups one week after the flap creations. The necrotic zone [S[N]], as well as the ratio of the necrotic zone to the total discolored zone [S[N]/[S[I]+S[N]]] were substantially larger in the control group [41% +/- 7%, 90% +/- 6%] compared to the EPO [20% +/- 2%,42% +/- 4%] and the FGF-2 [8% +/- 2%,19% +/- 3%] groups [p < 0.001]. The differences in these values were also meaningful between the EPO and FGF-2 groups [p < 0.001].Vascular density in ischemic area of the control group was less than those in the EPO and the FGF-2 groups; however, the differences were not statistically significant between any of the groups [p > 0.05]. Local administration of erythropoietin or fibroblast growth factor-2 in skin flaps could remarkably increase tissue viability and accelerate the wound healing process. However, the therapeutic effect of fibroblast growth factor-2 in preventing the necrotic event in, ischemic zones of skin flaps is much more considerable than that of erythropoietin

Detection of vim- and ipm-type metallo-beta-lactamases in Pseu-domonas aeruginosa clinical isolates

Pseudomonas aeruginosa is the most important bacterium isolated from burn wounds, and its resistance to imipenem due to metallo-beta-lactamases is increasing. This study was designed to detect vim1, vim2, Ipm1 and ipm2 metallo-beta-lactamases genes between Pseudomonas aeruginosa isolates isolated from Shahid Motahari Burns Hospital, Iran. To that end, we isolated 483 nonduplicate consecutive isolates of P aeruginosa from burn infections; and after biochemical confirmation, we examined the imipenem susceptibility via the Kirby-Bauer method. All the imipenem-resistant and imipenem-intermediate isolates were screened for vim1, vim2, ipm1 and ipm2 genes through the FOR method. From the 483 isolates, 272 [56%] and 63 [13%] isolates had resistant and intermediate zones in their imipenem antibiogram pattern, respectively. Fifty-four [16.1%], 7[2.1%], 22[6.6%], and 11[3.3%] of the resistant and intermediate isolates had vim1, vim2, ipm1 and ipm2 genes in their PCR results, respectively. MBL-mediated imipenem resistance in P aeruginosa is a cause for concern in the treatment of infective burn patients. The rate of imipenem resistance due to MBL was increased dramatically and newer versions of MBL families were detected for the first time. These results suggest that an effective method should be provided to fight MBL production in clinical isolates

Association between androgenic hormone levels and left ventricular ejection fraction

Androgens have been shown to have diverse effects on the cardiovascular system. The aim of this study was to compare androgenic hormone levels in patients with different left ventricular ejection fractions [EF]. The study population consisted of 515 consecutive men who were referred for angiographic studies and whose results of echocardiography and coronary angiography were available. The patients were classified into four groups: EF < 35%, EF=35-45%, EF=45-54%, and EF >/= 55% to evaluate the trends of baseline characteristics and serum androgens, including free testosterone [fT], total testosterone [tT], and dehydroepiandrosterone sulfate [DHEAS]. To better elucidate the difference in the patients with severe heart failure, the patients were divided into two groups according to their EF level, and comparisons were repeated between those with EF < 35% and the ones with EF >/= 35%. There were statistically significant trends in some characteristics in the patients with different levels of EF. The subjects with higher EF levels were less likely to have diabetes [p value < 0.001], coronary artery lesion [p value < 0.001], or high levels of C-reactive protein [CRP] [p value < 0.001]. As regards the patients with severe heart failure, our regression analysis revealed that the fT level was significantly lower in those with EF < 35% than in the ones with EF >/= 35% [5.82 +/- 2.73 pg/mL vs. 6.88 +/- 3.34 pg/mL, p value < 0.05]. A significant association was found between the level of fT and EF < 35%. There is a need for further controlled prospective studies to delineate any possible causal relationship accurately

Ultrasonographic screening of the carotid artery in coronary artery bypass surgery

The incidence of stroke after coronary artery bypass grafting [CABG] is between 0.9% and 6.7%, which significantly increases in-hospital and out-hospital costs. This study was designed to evaluate the prevalence of significant carotid stenosis and its risk factors in CABG. In total, 2044 consecutive patients undergoing elective CABG were investigated through a pre-operative duplex scanning of the carotid arteries. The relation of age, sex, smoking, hypertension diabetes, dyslipidemia, and coronary disease with carotid stenosis was evaluated. The prevalence of carotid stenosis was 7.6%. The multivariate analysis showed that age over 55 and left main coronary disease were significant independent risk factors for carotid stenosis. Female gender, smoking hypertension, and diabetes were the risk factors in the univariate logistic regression model. Carotid stenosis is prevalent in CABG candidates. It seems that age >/= 55 years and left main coronary disease are the independent risk factors for carotid stenosis in CABG patients

Left-sided endocarditis associated with multi-drug resistance acinetobacter Lwofii

Acinetobacter lwoffii, and important nosocomial pathogen, is a gram-negative aerobic bacillus that is a component of the normal flora on the skin, oropharynx, and perineum of about 20-25% of healthy individuals. We herein present a case of a 66-year-old man with combined mitral and aortic valve endocarditis associated with multi-drug resistance acinetobacter lowffii bacteremia

Serum levels of lipoprotein [A] and homocysteine in patients on hemodialysis who take hydroxymethylglutaryl-CoA reductase inhibitors, vitamin B6, and folic acid

High serum levels of lipoprotein [a] and homocysteine are risk factors of cardiovascular disease which are prevalent in patients on hemodialysis. Controversy exists about the effects of hydroxymethylglutaryl-CoA reductase inhibitors on serum lipoprotein [a] levels in patients on hemodialysis. Also, deficiency of some water soluble vitamins and administration of statins may raise serum levels of homocysteine in these patients. This study was designed to investigate serum levels of lipoprotein [a] and homocysteine in patients on hemodialysis who were taking a statin, vitamin B6, and folic acid. We investigated on 152 patients with maintenance hemodialysis who were taking atorvastatin or lovastatin, vitamin B6, and folic acid for at least 6 months. Their serum levels were obtained to measure lipoprotein [a] and homocysteine levels, as well as triglyceride, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. The mean serum values of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol and triglyceride were significantly less than the maximum reference values [P < .001]. The mean serum level of lipoprotein [a] was also less than the reference value [P = .009], but homocysteine level was 33% higher on average than the reference value [P < 001]. Our study demonstrated that in our patients on hemodialysis, the mean serum level of homocysteine was about 30% higher than the reference value although they were receiving vitamin B6 and folic acid. Hence, they were still exposed to the risk of cardiovascular disease

Do C-reactive protein and lipoprotein [a] have different impacts on the severity of coronary artery disease in diabetic and non-diabetic patients?

The potential role of lipoprotein [a] changes and also inflammation in coronary artery disease [CAD] have rendered these processes one of the most interesting objects of study in patients affected by type 2 diabetes mellitus. The aim of the current study was to evaluate lipoprotein [a] and other lipid profiles and also C-reactive protein [CRP] as the predictors of cardiovascular disease severity in non-insulin dependent diabetic subjects in comparison with non-diabetic CAD patients. Between June and September 2004, 372 patients with CAD were enrolled at Tehran Heart Center. Non-insulin dependent diabetics accounted for 102 of the cases, and the remaining 270 were non-diabetics. The severity of CAD was evaluated using the Gensini score, and the effect of patient variables such as serum lipid concentrations and CRP on CAD severity in the diabetics was investigated and compared with that of the non-diabetics. The mean of the Gensini score, CRP, and serum concentrations of all the lipid profiles were similar between the diabetic and non-diabetic patients. In the diabetic group, a high CRP concentration [?=0.200, Rs= 0.040; P=0.046] was effective on the Gensini score, whereas lipoprotein [a] and lipid profiles did not influence CAD severity. In the non-diabetics, no significant relationships were found between the Gensini score and all the studied laboratory indices. A high CRP level is an important predictor of the severity of CAD in diabetic patients with CAD

impact of low serum triglyceride on LDL-cholesterol estimation

Most clinical laboratories directly measure serum triglyceride, total cholesterol, and high- density lipoprotein cholesterol. They indirectly calculate low-density lipoprotein cholesterol value using the Friedewald equation. Although high serum triglyceride [>400 mg/dL or 4.52 mmol/L] devaluates low- density lipoprotein cholesterol calculation by using this formula, effects of low serum triglyceride [<100 mg/dL or 1.13 mmol/L] on its accuracy is less defined. Two hundred thirty serum samples were assayed during a one-year period. In 115 samples, the triglyceride level was below 100 mg/dL and in 115 samples from age- and sex-matched patients the triglyceride level was 150 - 350 mg/dL [1.69 - 3.95 mmol/L]. In both groups total cholesterol was above 250 mg/dL [6.46 mmol/L]. On each sample, total cholesterol, high-density lipoprotein cholesterol, and triglyceride were directly measured in duplicate and low-density lipoprotein cholesterol measured directly and calculated with Friedewald equation as well. Statistical analysis showed that when triglyceride is <100 mg/dL, calculated low- density lipoprotein cholesterol is significantly overestimated [average :12.17 mg/dL or 0.31 mmol/L], where as when triglyceride is between 150 and 300 mg/dL no significant difference between calculated and measured low-density lipoprotein cholesterol is observed. In patients with low serum triglyceride and undesirably high total cholesterol levels, Friedewald equation may overestimate low-density lipoprotein cholesterol concentration and it should be either directly assayed or be calculated by a modified Friedewald equation. Using linear regression modeling, we propose a modified equation

Role of Carotid Artery Screening Before Coronary Artery Bypass Graft Surgery

The incidence of stroke is 2.1-5.2% in bypass surgery patients with a mortality of 0-38%. This study was designed to evaluate the incidence of significant carotid artery stenosis and its related risk factors in c and idates for coronary artery bypass graft [CABG] surgery. 1045 consecutive c and idates for CABG underwent carotid artery Doppler examination in a prospective study. The relation of age, sex, smoking and diabetes as well as lipid profile and carotid stenosis was evaluated In 1045 CABG c and idates with the mean age of 60 years, the prevalence of significant carotid stenosis [>60%] was 6.9%. In the patients who aged 65 years and older, significant stenosis was 12.5%. Age of 50 years and above, female gender hypercholesterolemia and diabetes mellitus are independent risk factors for significant carotid stenosis. Significant carotid stenosis has an earlier beginning in our study. Cost effectiveness studies are recommended for revising the previous screening protocols

Induced Myocardial Infarction Using Ligation of the Left Anterior Descending Coronary Artery Major Diagonal Branch: Development of an Ovine Model

We report experimental myocardial infarction by occluding coronary arteries in ovine models. Twelve ewes were included in the study. After the chest was opened by left lateral thoracotomy incision, the second diagonal branch of the left anterior descending coronary artery was ligated at a point approximately 40% distant from its base. Prophylactic antiarrhythmics were administered. Animals were mechanically ventilated during surgery and stayed in the ICU for 24h afterwards. Experiments were then evaluated by echocardiographic, electrocardiographic, hemodynamic, serologic and morphologic investigations. Echocardiographic measurements were repeated after two months and animals were then sacrificed for postmortem cardiac examinations. All animals survived the surgical procedure. Cyanotic discoloration and hypokinesia in the cardiac tissue in an area of 3x4 cm plus ST-segment elevations was detected immediately after vessel ligation. More over, there were pathologic Q-waves 2 months later. Echocardiographic evaluations revealed an average of 22% relative decrease in cardiac ejection fraction. Wall motion analysis demonstrated anteroapical hypokinesia and akinesia in all animals one day and two months after operation. Thin walled infarcted areas with tissue fibrosis were evident in pathologic investigations two months after surgery. In conclusion, we developed a practical and safe method of producing myocardial infarction in large animal models

Asymptomatic bacteriuria in type 2 diabetic women in Iran

This study was performed to evaluate the prevalence and risk factors of asymptomatic bacteriuria [ASB] in women with type 2 diabetes mellitus in Iranian population. Between March 2003 and December 2003, 202 nonpregnant women with diabetes type 2 who were between 31 to 78 years old and had no abnormalities of the urinary tract system were included. We defined ASB as the presence of at least 105 colony-forming units/ml of 1 or 2 bacterial species, in two separated cultures of clean-voided midstream urine. All the participants were free from any symptoms of urinary tract infection [UTI]. Risk factors for developing bacteriuria was assessed and compared in participants with and without bacteriuria. In this study, the prevalence of ASB was 10.9% among diabetic women. E.coli was the most prevalent microorganism responsible for positive urine culture. Most of the isolated microorganisms were resistant to Co-trimoxazole, Nalidixic acid and Ciprofloxacin. Pyuria [P<0.001] and glucosuria [P<0.05] had meaningful relation with bacteriuria but no association was evident between age [P<0.45], duration of diabetes [P<0.09], macroalbuminuria [P<0.10] and HbA1c level [P<0.75], and the presence of ASB. The prevalence of ASB is more prevalent in women with type 2 diabetes, which pyuria and glucosuria can be considered as risk factors in this regard. Routine urine culture can be recommended for diabetic women even when there is not any urinary symptom