Background: Antimicrobial resistance is a growing problem in many bacterial pathogens and is of particular concern for hospital-acquired nosocomial infections. Klebsiella pneumonia is an important cause of nosocomial infections has rapidly become the most common extended spectrum beta-lactamases (ESBLs) producing organism. ESBL are defined as the enzymes capable of hydrolyzing oxyimino-cephalosporins. The aim of this study was to compare phenotypic detection of ESBL using two phenotypically method among the clinical isolates of Klebsiella pneumoniae.Methods: In this cross-sectional study a total of 144 isolates from clinical samples Urine, sputum, wound, blood, throat and body fluids isolated and identified as K. pneumoniae in a teaching hospitals in Shiraz within a six months period from December 2012 to May 2013. Antibacterial susceptibility test performed to 14 antibiotics by the disk diffusion method according to CLSI guideline and then isolates that were resistant to at least one of the beta-lactam antibiotics evaluated for the production of betalactamase enzymes by using E-test ESBL and combined disk method.Results: Totally 38 (26.3%) isolates produced ESBLs. All ESBL producing isolates were susceptible to imipenem and meropenem and resistant to aztreonam. The highest antibiotic resistance was observed for amoxicilin (100%) and the lowest antibiotic resistance was observed for meropenem (9.7%). The number of 38 (100%) isolates were identified as ESBL producer by using E-test ESBL ceftazidime. It was while using the combined disks; ceftazidime/clavulanic acid, cefotaxime/clavulanic acid and cefpodoxime/ clavulanic acid, respectively 35 (92.1%), 34 (89.4%) and 31 (81.5%) of isolates identified as beta-lactamase producing isolates.Conclusion: Considering the high prevalence of bacteria producing ESBL, screening for infections caused by ESBL-producing isolates may be lead to the most effective antibiotics therapies.

A tribological investigation, in terms of the coefficient of friction and wear resistance of refined, bleached and deodorized palm olefin, was conducted using a pin-on-disk tribotester. Palm oil was selected as a candidate due to its superior tribological properties and its large production, which can lead to the mass production of bio-lubricant. The material of the pin and the disk is Titanium (Ti6Al4V). The experiments were conducted following the ASTM G99. The normal load was 9.8 N and the observation time was 1 hour. The sliding speeds were 0.25 m/s and 1 m/s. In this research, only 5 ml of the test lubricant was applied at the beginning of the experiment to investigate the capability of the lubricant to maintain its function. To make sure the lubricant does not subside due to the centrifugal force from the rotating disk, a groove was crafted on the disk. In this research, the coefficient of friction and wear rate were calculated. From the analyses, the coefficient of friction calculated for palm olefin was the lowest for both sliding speed conditions, while the wear rate obtained showed that it was efficient lubricating oil at low speed, with a high wear rate at high speed.

Background: Nanocoating of biomedical materials has emerged as a crucial emerging discipline, to enhance tribological behaviors, durability, and performance of materials.Objective: This study aimed to investigate the tribological characteristics of substrates coated with Hydroxyapatite (HAp) and Silica glass (SiO2).Material and Methods: In this experimental study, the substrates were Ti-6Al-4V, a widely used titanium alloy for osseointegration implants. The substrates were coated with 90% HAp and 10% SiO2 via the plasma cold spray technique. The friction examination was analyzed at room temperature and under the Simulated Body Fluid (SBF) condition using the pin-on-disc technique.Results: The microstructural analysis confirmed the coated technique in producing a nano-sized layer. While the pin-on-disc test indicates that nanocoated Ti-6Al-4V specimens have a significantly higher average coefficient of friction than uncoated specimens, surface roughness is the primary contributor. Conclusion: Through microstructure properties and tribological behavior, the coated alloy may provide a benefit in circumstances, in which lubrication availability is restricted or undesirable, such as when the implant comes into contact with the bone interface.

The stretch bending test is one of the methods for forming metals, especially sheets. In this method, a piece of a metal sheet simultaneously undergoes compressive and tensile forces, thereby being converted into a curved piece with a great curvature. In the present research, springback was studied using a U-form die in a stretch bending test, and the experiments were performed on st12 steels through a laboratory set-up. Moreover, various parameters were investigated, including die radius, pin diameters, blank holding force (BHF), and distance between pins. The stretching depth was 10 mm. Not to mention, springback is affected by technical and geometric parameters. For example, the results of the present study revealed that increasing the pin spacing led to the reduction of springback and for more spacing, the springback tends to spring-go, additionally, it was observed that a rise in the die radius, pin diameters, and blank holder force resulted in the reduction of springback.

AbstractBackground: Carbapenemase-resistant Enterobacteriaceae is a major threat to public health. These microorganisms are resistant to all types of beta-lactam antibiotics.Methods: This cross-sectional study was conducted on 51 Enterobacteriaceae isolates from clinical samples in Sina Hospital and Tehran Heart Center in Iran from 2016 to 2018. Antibiotic susceptibility test was performed by disk diffusion method. Carbapenem-resistant isolates were identified by the Modified Hodge Test (MHT) and Polymerase Chain Reaction (PCR) for surveying the presence of VIM, NDM, IMMP, and OXA-48 genes.Results: Out of 51 clinical samples, 38 isolates were positive for both MHT and PCR tests, and 5 isolates were negative in both tests. The results of both tests are similar in 84.3% of the isolates.Conclusion: The MHT is an appropriate and easy method for approving carbapenemase production. Also, a laboratory can detect the carbapenemase production by identification of the KPC genes.

Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community acquired infections. Detection of MRSA in laboratories is very important for treatment and appropriate infection control. The aim of this study was to evaluate cefoxitin disk diffusion method for detection of MRSA and comparison of this method with other conventional methods. Methods: A total of 175 clinical isolates of S. aureus isolated from clinical specimens were studied. The isolates were identified by conventional laboratory methods. In this respect, E-test MIC, cefoxitin and oxacillin disk diffusion methods, and MAST ID Methicillin strips were used for detection of MRSA. All disk diffusion methods were performed as recommended by NCCL and manufacturers’ guidelines. Results: Using E-test MIC, 53 out of 175 strains of S. aureus were resistant to methicillin. In addition, disk diffusion method using oxacillin disk showed that 52 strains are resistant to methicillin. In this respect, 8 strains had intermediate resistance to methicillin. For cefoxitin disk diffusion method, 52 strains were resistant to methicillin. This method had a good correlation with E-test MIC method. Meanwhile, MAST ID methicillin strips detected 47 strains that were resistant to mehicillin. Sensitivity and specificity for both cefoxitin and oxacillin disk diffusion methods were 98%and 100% respectively. However cefoxitin was better than oxacillin for detecting intermediate resistant strains of S. aureus. Sensitivity and specificity for MAST ID methicillin strips were 91% and 100% respectively. Conclusion: This study revealed that cefoxitin disk diffusion method is a good alternative for oxacillin disk diffusion method for detection of MRSA. This method is more reliable for identification of intermediate resistant strains of S. aureus.