Multiple-locus variable number of tandem repeats (VNTR) fingerprinting (MLVF) and antibacterial resistance profiles of extended spectrum beta lactamase (ESBL) producing Pseudomonas aeruginosa among burnt patients in Tehran

Extended spectrum p-lactamase (ESBL)-producing trait was present in 48 out of the 112 (42.8) Pseudomonas aeruginosa isolates collected from burn wound infections during a 12-month period. The presence of oxa-10, per-1, veb-1 and ges genes and the multiple-locus variable number of tandem repeats (VNTR) fingerprinting (MLVF) of 112 P. aeruginosa strains were determined by PCR and multiplex PCR. Disk diffusion methods were used to determine the susceptibility of the isolates to antimicrobial agents as instructed by CLSI. All ESBL isolates were resistant to aztreonam, cefepime, cefotaxime, cefpodoxime, ceftazidime, ceftriaxone and ofloxacin. Fewer than 60 of ESBL isolates were resistant to imipenem, meropenem, and piperacillin-tazobactam but more than 90 were resistant to amikacin, ciprofloxacin, levofloxacin, ticarcillin and tobramycin. The most prevalent ESBL genes included oxa-10 (70) and per-1 (50) followed by veb-1 (31.3). The gene encodes GES enzyme did not detect in any isolates. A total of 100 P. aeruginosa strains were typed by MLVF typing method. MLVF produced 42 different DNA banding patterns. These data indicate that different MLVF types infect burn wounds in patients at a hospital in Tehran and also suggest an alarming rate of ESBL-producing isolates in this test location. (C) 2011 Elsevier Ltd and ISBI. All rights reserved

Congenital dislocation of knee: results of the treatment in 29 cases between 1970 and 2010 years at Shafa Yahyaian Hospital in Tehran

Background: There are not many reports regarding the treatment approaches of congenital dislocation of the knee in the literature. Therefore, the preferred method of treatment of this rare congenital disease is still controversial. Hereby, we report the treatment outcome of 29 patients admitted in Shafa Yahyaian Hospital during 40 years. Methods: In this retrospective study done in Shafa Yahyaian Hospital in Tehran, Iran during 2010, we retrospectively reviewed the medical records of 29 patients treated conservatively or surgically for congenital dislocation of the knee. Patients had been evaluated for an average follow-up of 8.5 years. Results: Overall, 54 knee dislocations had been treated surgically (58%) or conservatively (42%). Range of knee motion, persistent recurvatum, instability, valgus deformity after treatment and limping were the more important factors reported in the two surgically or conservatively treated groups. Knee function was satisfactory in patients with conservative treatment. Despite 80% of instability in the operated knees, patients could ambulate with or without braces and had a range of motion equal to 80 degrees. Knee function was also good after quadricepsplasty with transarticular pins in selected cases. Conclusion: We recommend a conservative approach to the disease, regardless of the patient's age at the time of treatment and subsequent surgery in patients with dissatisfactory recovery. Quadricepsplasty with transarticular fixation is recommended as a good option in treating these patients. Posterior capsulorrhaphy for patients with CDK and ligamentous laxity is also recommended

Optimal online charging of plug-in electric vehicles considering voltage unbalance factor

© 2017 IEEE. The worldwide application and grid-to-vehicle charging of plug-in electric vehicles (PEVs) are expected to tremendously grow within the next few years. Uncoordinated PEV charging in low voltage (LV) distribution networks can lead to local grid problems such as overloading of transformers and voltage unbalances. A potential solution and key challenge for PEV integration is the smart shifting of charging activities to off-peak periods. This paper investigates the impacts of single-phase PEV charging at residential houses on the three-phase distribution network. It proposes online coordinated PEV charging using a genetic algorithm (GA) to minimize the overall voltage unbalance factor (VUF) by controlling the time of charging considering voltage constraints. The impacts of uncoordinated and GA coordinated PEV charging on VUF and voltage profiles will be simulated for a real Western Australian distribution network in the Perth solar city

Rooftop PV with battery storage solar smoother

© 2014 IEEE. Utilities are becoming concern about the increasing number of solar panels feeding unstable power into generator-based mini-grids particularly in rural locations. When the mini-grid experiences large changes in the injection of solar power, for example on cloudy days, the generators have to work hard to keep up. This paper recommends inclusion of battery storage (BS) solar smoother across terminals of existing rooftop PVs to compensate fluctuations in active output power due to environmental factors such as passing clouds and variations in solar radiation. A BS energy management strategy (BS-EMS) will be implemented to control the solar smoother and regulate the voltage at point of common coupling (PCC) while providing the grid with constant output power profile during daylight. A simple approach is also introduced and implemented to estimate battery rating based on typical measured PV characteristics

Impact of battery rating on performance of rooftop PV supporting household loads, regulating PCC voltage and providing constant output power to grid

The dependency rooftop photovoltaic generation system (rooftop PV) output power to environmental factors (sun radiation, panel temperature, passing clouds, etc.) and loading level (operating point on v-i characteristics) may result in sudden output power variations particularly during cloudy periods. This paper will first implement a rooftop PV with a battery storage energy management strategy (BS-EMS) to support the household loads and regulate the voltage at point of common coupling (PCC) while providing the grid with a constant output power during daylight. System operation is based on the power balance between rooftop PV, BS and grid which is achieved by dynamic control of the BS converter to assure constant output power to the grid during daylight. Then, the impact of battery rating on the performance of BS-EMS will be investigated for typical sunny and cloudy days in summer and winter

Investigation of biofilm formation ability, antimicrobial resistance and the staphylococcal cassette chromosome mec patterns of methicillin resistant Staphylococcus epidermidis with different sequence types isolated from children

This study investigated the molecular characterizations of 80 methicillin resistant Staphylococcus epidermidis (MRSE) collected during 2012-2013 in Tehran Children's Medical Center, Iran. About 90 of MRSE isolates were multi-drug resistant (MDR) and the highest resistance was observed to cotrimoxazole and they were quite sensitive to quinupristin-dalfopristin and linezolid. Though vanA gene was not detected, the majority of isolates showed intermediate resistance to vancomycin (MIC90 16 mu g/ml). Resistance to mupirocin was observed in 18 isolates. Staphylococcal cassette chromosome mec (SCCmec) types V, III, IV and II were detected in 23.75, 7.5, 6.25 and 5 of isolates respectively, in some of which the additional parts of mec or ccr complexes were observed. In 57.5 MRSE isolates SCCmec types were not classified. 41.2 of MRSE isolates were carrying intercellular adhesion (ica) operon and 40 had strong or intermediate biofilm. The types of arginine catabolic mobile element (ACME) were limited to type I and II. Nine sequence types (STs) were seen in mupirocin resistant MRSE isolates. The common STs were ST2, ST5 and ST22 with 27.7 (5/18), 22.2 (4/18) and 16.6 (3/18) frequencies, respectively. ST23, ST54 and ST179 plus three novels STs 580, 581,588 were also observed. The majority of STs, 83.3 (15/18) belonged to clonal complex 2 (CC2). The spread of antibiotic resistance and virulence factors among MRSE species is an alarming sign in Children's Hospitals. The combination of these two issues leads to increase the chance of successfully establishing of common STs in hospital environments, and promotes the device-related infections and bacteremia. (C) 2016 Elsevier Ltd. All rights reserved

A high prevalence of mupirocin and macrolide resistance determinant among Staphylococcus aureus strains isolated from burnt patients

Infections due to Staphylococcus aureus have become increasingly common among burn patients. The antibiotic resistance profile of S. aureus isolates and inducible resistance against clindamycin were investigated in this study. The presence of mecA gene, mupA gene and macrolide resistance genes were detected using PCR and multiplex-PCR. The resistance rate to methicillin, erythromycin and mupirocin were 58.5, 58 and 40, respectively. The prevalence of constitutive and inducible resistance among macrolide resistant isolates was 75 and 25, respectively. Ninety five percent of the isolates were positive for one or more erm genes. The most common genes were ermA (75), ermC (72) and ermB (69), respectively. The ermA gene predominated in the strains with the inducible phenotype, while ermC was more common in the isolates with the constitutive phenotype. The msrA gene was only found in one MRSA isolate with the constitutive phenotype. A total of 27 isolates (25) carried the mupA gene. All the mupirocin resistant isolates and almost all the erythromycin resistant isolates were also resistant against methicillin which may indicate an outbreak of MRSA isolates with high-level mupirocin and erythromycin resistance in the burn unit assessed. (C) 2011 Elsevier Ltd and ISBI. All rights reserved

DISTRIBUTION OF BACTERIAL CONTAMINATION IN A TEACHING HOSPITAL IN TEHRAN - A SPECIAL FOCUS ON STAPHYLOCOCCUS AUREUS

There are documents that confirm the cycle of bacterial transmission between patients, staff, and the inanimate environment. The environment may have more effect on intensive care units (ICUs), because the patients who require intensive care have unstable clinical conditions and are more sensitive to infections. The aim of this study was to determine the prevalence of bacteria in air and inanimate surface in the ICUs and to compare the microbial levels to standard levels. Air and inanimate surface in the four ICUs of a teaching hospital underwent weekly surveillance by means of air sampler and swabs for a period of six-month. Total bacterial counts were evaluated onto trypticase soy agar and mannitol salt agar (MSA). A total of 725 samples air (168) and inanimate surfaces (557) were collected. The total mean +/- SD CFU/m(3) of airborne bacteria in all of the ICUs were 115.93 +/- 48.04. The most common bacteria in air of the ICUs were Gram-positive cocci (84.2%). The total mean +/- SD airborne of Staphylococcus aureus was 12.10+/-8.11 CFU/m(3). The highest levels of S. aureus contamination were found in ventilators and bed ledges. More suitable disinfection of hospital environments and monthly rotation in utilization of the various disinfectant agents are needed for the prevention of airborne and inanimate transmission of S. aureus

Phenotypic and Genotypic Evaluation of Aminoglycoside Resistance in Clinical Isolates of Staphylococci in Tehran, Iran

Aminoglycosides play an important role in the treatment of staphylococcal infections, despite the emerging widespread resistance among Staphylococcus. To determine the prevalence of aminoglycoside resistance and aminoglycoside modifying enzyme (AME) genes among infected patients at a teaching hospital in Tehran, Iran, we tested 585 Staphylococcus isolates, of which 322 were Staphylococcus aureus and 263 were coagulase-negative staphylococci, as determined by the disk diffusion method and multiplex PCR. The minimum inhibitory concentration of gentamicin for each isolate was determined by microbroth dilution. All methicillin-resistant staphylococci were mecA-positive by PCR. Of the 585 isolates, 27.6 were susceptible to gentamicin and kanamicin, 27.1 to tobramicin and amikacin, and 21.3 to netilmicin. The most prevalent AME genes included aac(6')-Ie-aph(2 '') (93.7) followed by aph(3')-IIIa (84.3) and ant (4')-Ia (28.1). More than 90 of aminoglycoside-resistant staphylococci contained at least one AME gene. The coexistence of two or three AME genes was detected in most gentamicin-resistant isolates. These results suggest an alarming rate of aminoglycoside resistance in this test location in Tehran, Iran. Continued surveillance at the genotypic and phenotypic levels, and adherence to well-designed antibiotic and infection-control policies are necessary to limit the spread of antimicrobial resistance