[Emergence of novel plasmid-mediated beta-lactamase in klebsiella pneumonia]

Antibiotic resistance is a major threat for human health that affects hospitalized patients worldwide; Hence, The World Health Organization [WHO] has chosen antibacterial resistance as its theme in 2011. Klebsiella pneumoniae is a gram-negative opportunistic pathogen and a common cause of nosocomial infections. These bacteria -especially in infants- are the cause of pneumonia, sepsis, meningitis, diarrhea and bacteremia. Increasing emergence of multidrug resistance [MDR] among Klebsiella pneumoniae nosocomial isolates has limited the appropriate therapeutic options for the treatment of infections caused by this pathogen. Beta-Lactamases are major defenses of gram-negative bacteria against antibiotics. Recently, the emergence of new beta-lactamases such as NDM-1 [New Delhi metallo-beta-lactamase-1], OXA-48 [Oxacillinase-48], OXA-181 [oxacillinase-181], KPC [Klebsiella pneumoniae carbapenemase], CTX-M-15 [Cefotaxime-M-15] confer resistance to the most antibiotics such as penicillins, carbapenems, cephalosporins, macrolides, aminoglycosides and sulfamethoxazole. Resistant genes are located on plasmids with different sizes and can be readily transferred between bacteria, from one human to another human, and even from one country to another. In 2011, it has been evaluated that the importance of some of these genes like NDM-1, KPCs is as AIDS, malaria and tuberculosis. These enzymes have emerged as an important threat for hospitalized patients. Some pathogens containing both KPC and NDM-1 may be mistakenly diagnosed as susceptible by conventional laboratory methods and hence they could have an important role in the emergence and spread of more resistant pathogens due to administration of ineffective drugs to patients. No vaccines have been found yet that prevent infections caused by carbapenemase-producing bacteria. Also, there is not enough information about frequency of these plasmid genes and their genetic profiles in Iran. Therefore, it is important to diagnose the Klebsiella pneumoniae strains producing resistant enzymes, especially NDM-1, for better treatment of patients and prevention of the spread of these genes to other bacteria via exact phenotypic and genotypic methods

[Study of antimicrobial effects of organic and aqueous extracts of grains of Triticum sativum Lam. on gram - positive and gram-negative bacteria]

Bacterial diseases are common in human life and antibiotics are commonly used to treat bacterial diseases. However, antibiotic therapy has the disadvantage of being faced with bacterial resistance. Fortunately experience shows that products prepared from medicinal plants can be used safely and successfully to treat bacterial diseases without presenting the disadvantages of side effects and bacterial resistance. Triticum sativum of Poaceae family has been used in Iranian traditional cure for many years ago. Then, the aim of this study was to determine antibacterial activity of wheat against some bacteria. Then, The aim of this study was to determine antibacterial activity of wheat against some bacteria. The extracts were prepared by the method of maceration using water, methanol, chloroform and petroleum ether as extraction solvents. The effect of the zone of inhibition of different concentrations [25, 50, 75, 100 mg/ml] of the prepared extracts on the above - mentioned bacteria was determined using Kirby- Bauer method and using the disk diffusion technique against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa. The water extract of all concentrations [25, 50, 75, 100 mg/ml] showed no antibacterial effects. The methanol extract had a significant effect on Streptococcus pyogenes but a weak effect on Staphylococcus aureus. The chloroform extract had a weak effect on both Streptococcus pyogenes and Staphylococcus aureus. The petroleum ether extract had a significant effect on Streptococcus pyogenes but Weak effects on both Staphylococcus aureus and Escherichia coli. None of the tested extracts had any effects on Pseudomonas aeruginosa. It is concluded that organic extracts of wheat had antibacterial activity against some of the gram positive and gram negative bacteria

Study of isolation and determination of antibiotic resistance, plasmid profiles, protein bands and phenotypic virulence of Shigella flexneri strains

Shigellosis is an acute gastroenteritis caused by Shigella species, including S. dysenteriae, S. flexneri, S. boydi and S. sonnei.The purpose of this study was to isolate and to determine antibiotic resistance, plasmid profile and protein b and s by SDS-PAGE, and also phenotypic virulence by Congo red dye among S. flexneri strains. The isolated bacteria were identified by use of st and ard bacterial and biochemical methods. Antibiotic susceptibility tests were performed according to kirby-Bauer method. Plasmids were isolated by alkaline lysis method. Serological reactions were detected by slide agglutination tests with both polyclonal and monoclonal antisera kits. Virulent strains were isolated on a TSA plate containing Congo red dye. From 350 isolated Shigella spp. 142 [40.57%] were S. flexneri. Of 350 patients 41% were female and 59% male. In 100 S. flexneri isolates, resistance rates to tetracycline, ampicillin, trimethoprim-sulfometoxazol and cephalexin were 95%, 91.3%, 85.6% and 70.3% respectively. All of isolates were sensitive to ciprofloxacin. Most isolates contained multiple plasmid b and s [1-5 plasmid's b and s]. A total of 11 distinct plasmid profile patterns were identified. The results of our study showed that serotype 2 was the most common isolated serotype of S. flexeneri [39%]. In this study, 46% of S. flexneri were Congo red positive and haemolysin positive on blood agar plates. A 120 KDa protein b and was detected on electrophoresis gel. These data showed, pathogenicities of all S. flexneri isolates are not similar. Health care can prevent bacterial diarrhea due to shigella. Therefore laboratories are recommended to be more concerned about isolation of these bacteria. Congo red dye binding test is cheap, simple and rapid, so, it can be used to determine the virulence properties of S. flexneri. Antibiogram tests are recommended to prevent antibiotic resistance

Plasmid profile, antibiotic resistance, and phenotypic virulent strains of S. flexneri

Shigellosis is an acute gastroenteritis caused by Shigella species. The purpose of this study was to determine plasmid profile, antibiotic resistance and phenotypic virulent by Congo red between S. flexneri strains. The isolated bacteria were identified by standard bacterial and biochemical methods. Plasmids were isolated by alkaline lysis method. Antibiotic susceptibility test was performed according to "kirby-Bauer" method. Serological reactions were carried by slide agglutination tests with both polyclonal and monoclonal antiserum kits. Virulent strains were isolated on a TSA plate contained Congo red dye concentration. From 350 isolated Shigella species, 142 [40.57%] were S. flexneri. Eleven distinct plasmid profile patterns were identified. Of S. flexneri isolates, 95% were resistant to tetracycline, 85.6% to SXT and 75.3% to ampicillin. All the isolates were sensitive to ciprofloxacin. Our results showed that 39% were serotype II. 45.56% of S. flexneri were Congo red positive. Antibiotic resistant determination in each case may prevent drug resistance increase. Since Congo red binding test is cheap and simple it can be used to determine virulence properties of S. flexneri