Antibacterial Activity of CdTe/ZnS Quantum Dot-ß Lactum Antibiotic Conjugates.

ß-Lactum antibiotics are broad class of antibiotics which kills bacteria by inhibiting the formation of peptidoglycan that constitutes the bacterial cell wall. The resistance that develops in bacteria for antibiotics led the scientific world to think about the future aspects for modifying the way through which antibiotics are acted on the bacteria and become lethal for them. In this consequence, the potential of latest marketed antibiotics e.g. Amoxiciline (I), ceftazidim (II) have been evaluated after being conjugated with quantum dots. The surface of quantum dots has been conjugated with antibiotics by carbodiimide coupling with the help of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as conjugating agent between antibiotic and functionalized quantum dots. The antibacterial properties of QD-conjugated antibiotics have been determined by disc diffusion assay. The potency of QD-conjugated antibiotics has been estimated by determining their MIC50 for the selected strain of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Minimum inhibitory concentration study, minimum bactericidal concentration and growth pattern analysis revealed that QD-antibiotic conjugates showed slightly more prospective than pure native antibiotics against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.

Antibacterial properties of amino acid functionalized silver nanoparticles decorated on graphene oxide sheets.

Graphene oxide (GO) sheets decorated with amino acid L-cysteine (L-cys) functionalized silver nanoparticles (GO-L-cys-Ag) was synthesized by AgNO3, trisodium citrate, and NaBH4. GO-L-cys-Ag nanocomposite was characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, ultraviolet-visible (UV-vis) absorption spectra, which demonstrated that a diameter of L-cys-AgNPs compactly deposited on GO. Antibacterial activity tests of GO-L-cys-Ag nanocomposite were carried out using Escherichia coli MTCC 1687 and Staphylococcus aureus MTCC 3160 as model strains of Gram-negative and Gram-positive bacteria, respectively. The effect of bactericide dosage on antibacterial activity of GO-L-cys-Ag nanocomposite was examined by plate count, well diffusion and broth dilution methods. Morphological observation of bacterial cells by scanning electron microscope (SEM) showed that GO-L-cys-Ag nanocomposite was more destructive to cell membrane of Escherichia coli than that of Staphylococcus aureus. The above technique establish that the bactericidal property of GO-L-cys-Ag nanocomposite with wide range of applications in biomedical science.

Production of Biohydrogen from Wastewater by Klebsiella oxytoca ATCC 13182.

Production of biohydrogen from distillery effluent was carried out by using Klebsiella oxytoca ATCC 13182. The work focuses on optimization of pH, temperature, and state of bacteria, which are the various affecting factors for fermentative biohydrogen production. Results indicates that at 35 °C for suspended cultures, the production was at its maximum (i.e., 91.33 ± 0.88 mL) when compared with other temperatures. At 35 °C and at pH 5 and 6, maximum productions of 117.67 ± 1.45 and 111.67 ± 2.72 mL were observed with no significant difference. When immobilized, Klebsiella oxytoca ATCC 13182 was used for biohydrogen production at optimized conditions, production was 186.33 ± 3.17 mL. Hence, immobilized cells were found to be more advantageous for biological hydrogen production over suspended form. Physicochemical analysis of the effluent was conducted before and after fermentation and the values suggested that the fermentative process is an efficient method for biological treatment of wastewater.

Recurrent malignant proliferating trichilemmal tumor with lymph node metastasis in a young woman.

Malignant proliferating trichilemmal tumor (MPTT) is a rare cutaneous tumor predominantly affecting the scalp, eyelids, neck and face of elderly women. It is a large, solitary, multilobulated lesion that may arise within a pilar cyst. These tumors are largely benign, often cystic, and are characterized by trichilemmal keratinization. However, at times, the tumor has an aggressive clinical course and a propensity for nodal and distant metastases. Wide local excision with a 1 cm margin of normal tissue is the treatment of choice. Adjuvant chemotherapy and radiotherapy have been occasionally used to prevent recurrence in MPTT. This is a case report of a recurrent malignant trichilemmal tumor over scalp in a young female patient with nodal metastasis.