Background:Pseudomonas aeruginosa is one of the most common causes of nosocomial infections. Resistance of P. aeruginosa to β-lactam antibiotics may be the result of acquired resistance through mutation and over production of various antibiotic inactivating enzymes. This research aimed to determine the prevalence of extended-spectrum β-lactamases (ESBL) and metallo β-lactamase (MBL) production as well as the presence of their related genes among AmpC β-lactamase producing P. aeruginosa isolated from burns.Objectives:The current study aimed to determine the prevalence of class A ESBL and MBL production in relation to the presence of their related genes among AmpC β-lactamase producing P. aeruginosa isolated from burns.Materials and Methods:The antimicrobial susceptibility of 51 P. aeruginosa isolates from patients with burns was examined against 13 antibiotics by the disc diffusion method. Minimum inhibitory concentrations (MIC) for imipenem and ceftazidime were measured by the microdilution method. AmpC production was detected by AmpC disc and the modified three-dimensional extract tests. ESBL phenotype was confirmed by the double disc synergy test (DDST). Presence of β-lactamase genes was detected by specific primers and polymerase chain reaction (PCR).Results:All isolates were multidrug resistant. AmpC, ESBL and MBL production were observed in 35 (68.6%), 20 (39.2%) and 19 (37.3%) isolates, respectively. Overall, 43 isolates (84.3%) carried β-lactamase genes, out of which 31 (60.8%) harbored blaAmpC, 20 (39.2%) had blaTEM and 11 (21.6%) carried blaPER-1 genes. Among the AmpC producers, two isolates (6.5%) carried blaAmpC + blaESBL, 13 (41.9%) had blaAmpC + blaMBL and six (19.4%) produced the three enzymes.Conclusions:A high prevalence of multiple β-lactamase production was observed among the AmpC producers (60%), of which the majority co-produced AmpC and MBL. The current study results showed correlation between β-lactamase production and the presence of antibiotic resistance genes in the isolates.

A TiO 2 nanostructure coating has shown to significantly improve the thermal and electrical properties of steel plates and increase their resistance to oxidation, corrosion, and wear, especially in high temperature applications. In this research, the corrosion resistance properties of a mild steel substrate by applying TiO 2 nanostructure coating using the sol-gel method were investigated. The quality of the coating, however, is notably affected by such process parameters as the dip-coating rate, drying time, heat-treatment rate, and the number of coating layers. Moreover, this article presents an integrated approach to the optimal parameter setting for the above process. Using experimental data from a coating process by the sol-gel method, an artificial neural network is trained to map the vector of process parameters onto a measure of corrosion resistance. An evolutionary search algorithm is then employed to find the optimum set(s) of process parameters. The efficiency of the proposed approach is demonstrated using a case study involving a 316L stainless steel substrate.

Laryngotracheoesophageal clefts (LTEC) are rare malformations which involve the upper respiratory and digestive tract. Surgical repair should be undertaken promptly to maintain a secure airway and prevent serious pulmonary aspiration. This paper reports the first case of LTEC type 3 with severe laryngotracheomalacia that was brought to Mofid children's hospital in late infancy with a poor health status. Delayed defect correction was our team strategy for the patient when she had achieved good weight gain. At the age of 22 months in collaboration with the pediatric surgical and otolaryngologist team, the repair of the laryngeal cleft was done with lateral open approach method. She was discharged with tracheostomy and gastrostomy. In the next six months follow up after the surgery tracheostomy decannulation and gastrostomy tube removal were done and the infant is now in regular follow-up.