Superoxide dismutase (SOD) of Corynebacterium glutamicum was purified and characterized. The enzyme had a native molecular weight of about 80kDa, whereas a monomer with molecular weight of 24kDa was found on SDS-PAGE suggesting it to be homotetramer. The native SOD activity stained gel revealed a unique cytosolic enzyme. Supplementing growth media with manganese increased the specific activity significantly, while adding iron did not result in significant difference. No growth perturbation was observed with the supplemented media. In vitro metal removal and replacement studies revealed conservation of about 85% of the specific activity by substitution with manganese, while substitution with copper, iron, nickel or zinc did not restore any significant specific activity. Manganese was identified by atomic absorption spectrometer, while no signals corresponding to fixing other metallic elements were detected. Thus, C. glutamicum SOD could be considered a strict (non-cambialistic) manganese superoxide dismutase (MnSOD).

Graft copolymerization of acrylic acid/acrylonitrile (AAc/AN) comonomer onto low-density poly(ethylene) (LDPE) and poly(ethylene terephthalate) (PET) films using direct radiation grafting technique has been investigated. The effect of different reaction conditions on the grafting yield was studied. The structure of the grafted films at different compositions was characterized by FTIR, TGA, SEM, and XRD. Biodegradation of grafted LDPE and PET was investigated by burial method in two types of Egyptian soils (agricultural and desert soils). The bacteria responsible for biodegradation were isolated and characterized, and the capacities for the growth on these polymers as substrates were compared. The isolates from agricultural soil were characterized as Pseudomonas, Alcaligenes, Bacillus, Proteus, and Enterobacter, whereas the isolates from desert soil were characterized as Alcaligenes, Bacillus, and Pseudomonas. The highest degradation rate was found to be achieved using agricultural soil. It is found that the isolated strains belonging to the genus Pseudomonas were mainly responsible for the degradation of both polymers. It has also been found that the increase of AAc ratio in the composition increases the hydrophilicity of the films and the degradation rate. PET polymer is generally found to be more resistant to the biodegradation than LDPE in the two types of soils tested.

Although, nosocomial infections (NIs) are considered to be an important cause of mortality and prolonged stay in hospitals, there are only a few studies that are concerned with their prevention and reduction in rehabilitation units. This could be because most NI surveys have been carried out mainly in acute and long-stay in hospitals. As a result, limited information is available on prevention and reduction of NIs in rehabilitation units. The present study is a systematic review that draws attention to the significance of setting up specific means for infection control in hospital units concerned with critical cases, and stresses on the need to adapt to new infection control policies, training of healthcare professionals, educating patients regarding safety measures and fighting nosocomial infections. Furthermore, this study aims to show the obligations of following certain considerations while prescribing antimicrobial therapy so as to maximize the efficacy and reduce the adverse effects of conventional antibiotics. Systematic review survey methods were adopted throughout the study. Results of the study were debatable concerning the question of predominance of Gram positive or negative microorganisms as nosocomial etiological agents. Infection control measures such as continuous surveillance protocols, suitable prevention methods and appropriate therapeutic treatment strategies such as de-escalation and rotational antibiotic therapies might help reduce nosocomial infections. Much attention should be given in hospitals to the environmental conditions including quality of water and air. Patients with a suppressed immune system during their stay in hospitals are susceptible to levels of microorganisms that are considered safe for a healthy community. Hence, this study suggests that special safety levels should be set up regarding the levels of microorganisms in hospitals and these should be much lower than those used for a healthy community.

Escherichia coli is a Gram-negative bacteria that causes various diseases, including pneumonia, urinary tract infections, and diarrhoea. The present work is an effort to study antimicrobial resistance pattern in this bacteria. Clinical samples (6840) were collected from King Fahd Hospital in Madinah, Saudi Arabia and screened for E. coli strains. Of all positive samples obtained from different clinical sources, about 3% isolates represented E. coli and 71.6% of these were collected from clinical samples of male patients. E. coli isolates were recovered from sputum (20.58%), wound (55.88%), and catheters tips (9.31%) representing about 86% of all clinical specimens. Antimicrobial susceptibility pattern of the E. coli isolates to twelve different antimicrobials revealed that all the isolates (100%) were susceptible to imipenem, amikacin, and aztreonam. Cefoxitin, ceftazidime and ciprofloxacin showed a sensitivity of 98.7%. This was followed by gentamycin (98.6%), piperacillin (95.7%), cotrimoxazole (92.3%), cephalothin (91.4%), and Augmentin (91.1%). Ampicillin showed the least susceptibility of 87.5%. Hence, cotrimoxazole, Augmentin, and ampicillin should be prescribed with care in order to avoid increasing resistance patterns in E. coli. Results also demonstrate that frequency of E. coli infections was highest during summer and winter seasons representing about 30% each. Autumn season, which coincided with the season of pilgrimage, recorded about 22% of infections while spring season had the least recorded percentage with only 17% of infections. This study is therefore a step towards the generation of national data on the prevalence of antimicrobial resistance patterns of E. coli.

Nucleotide and amino acid sequences of Corynebacterium glutamicum recA genes, from GenBank, were compared in silico. On the basis of the identity found between sequences, two degenerate primers were designed on the two sides of the deduced open reading frame (ORF) of the recA gene. PCR experiments, for amplifying the recA ORF region, were done. pGEM Ò -T Easy vector was selected to be used for cloning PCR products. Then recA ORF was placed under the control of Escherichia coli hybrid trc promoter, in pKK388-1 vector. pKK388-1 vector, containing recA ORF, was transformed to E. coli DH5a DrecA (recombinant deficient strain), in an attempt to phenotypically complement it. Ultraviolet (u.v.) exposure experiments of the transformed and non-transformed E. coli DH5a DrecA cells revealed tolerance of transformed cells up to dose 0.24 J/cm 2 , while non-transformed cells tolerated only up to dose 0.08 J/cm 2 . It is concluded that phenotypic complementation of E. coli DH5a DrecA with recA ORF of C. glutamicum, could be achieved and RecA activity could be restored.