Nizami Duran

Antimicrobial Activity of Some Thiourea Derivatives and Their Nickel and Copper Complexes

Five thiourea derivative ligands and their Ni2+ and Cu2+ complexes have been synthesized. The compounds were screened for their in vitro anti-bacterial activity using Gram-positive bacteria (two different standard strains of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes, Bacillus cereus) and Gram-negative bacteria (Esherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, Proteus vulgaris, Enterobacter aerogenes) and in vitro anti-yeast activity (Candida albicans, Candida krusei, Candida glabrata, Candida tropicalis, Candida parapsilosis). The minimum inhibitory concentration was determined for all ligands and their complexes. In vitro anti-yeast activity of both ligands and their metal complexes is greater than their in vitro anti-bacterial activity. The effect of the structure of the investigated compounds on the antimicrobial activity is discussed.

Synthesis, characterization and antimicrobial activities of transition metal complexes of N,N -dialkyl- N′ -(2-chlorobenzoyl)thiourea derivatives

N,N-di-n-propyl-N′-(2-chlorobenzoyl)thiourea (HL1) (1), N,N-diphenyl-N′-(2-chlorobenzoyl)thiourea (HL2) (2), and their NiII, CoII, CuII, ZnII, PtII, CdII and PdII complexes have been synthesized and characterized. HL1 and its copper complex were characterized by single-crystal X-ray diffraction methods. The ligands coordinate as bidentates yielding essentially neutral complexes of the type [ML2]. The complexes were screened for their in vitro antibacterial, antifungal activities and toxicity. All compounds showed antimicrobial activity, but antibacterial efficacy is greater than antifungal activity.

High prevalence of Staphylococcus aureus cultivation and superantigen production in patients with psoriasis

The aim of this study was to evaluate the association of Staphylococcal enterotoxins (se) a through e, exfoliative toxin (et) a and b, toxin and toxic shock syndrome toxin (tst) and mecA with psoriasis. We also investigated the distribution of Staphylococcus aureus (S. aureus) in the skin and nares. Fifty consecutive patients with chronic plaque-type psoriasis and 50 sex- and age-matched healthy controls were included in this study. There was a statistical difference in cultivation of S. aureus between lesional (64%) and non-lesional skin (14%) in patients with psoriasis (p = 0.037). S. aureus was cultivated from the nares in 25 (50%) of 50 patients with psoriasis and in 17 (34%) of 50 healthy controls (p > 0.05). In psoriasis patients, 31 (96.8%) out of the 32 strains isolated from the lesional skin and 3 (42.3%) out of the 7 strains isolated from the non-lesional skin were toxigenic (p = 0.01). Isolated strains from the nares were toxigenic in 96% (24/25) for patients with psoriasis and in 41.2% (7/17) for healthy controls, respectively (p = 0.006). Patients with cultivation-positive in lesional skin had a significantly higher PASI score than patients who were cultivation-negative in lesional skin (8.28 +/- 3.97 vs. 5.89 +/- 2.98, p = 0.031). Our results confirm that S. aureus colonization and its toxigenic-strains are associated with psoriasis. According to our findings, non-classical superantigens such as methicillin resistance gene (mecA), see and etb may also be associated with psoriasis.

Short-term Effect of Mastic Gum on Salivary Concentrations of Cariogenic Bacteria in Orthodontic Patients

OBJECTIVE To determine antibacterial activity of chewing mastic gum against the salivary levels of Streptococcus mutans, the total number of viable bacteria, and lactobacilli in patients undergoing therapy with fixed orthodontic appliances. MATERIALS AND METHODS In this study, the levels of S mutans, lactobacilli, and total cultivated bacteria were measured before and after chewing mastic gum. The antibacterial effects of chewing mastic gum against these microorganisms in saliva were compared with a placebo gum. The counts for orthodontically treated patients were evaluated before chewing gum; just after chewing gum; and after 45, 75, 105, and 135 minutes. Saliva samples taken from the patients were inoculated onto trypticase-yeast-cystine-bacitracin agar for mutans streptococci and onto Rogosa agar for lactobacilli. The agar plates were incubated for 48 hours anaerobically at 37 degrees C. The total number of viable bacteria was then counted. RESULTS Just after chewing the mastic gum for 15 minutes, a significant decrease of total bacteria and S mutans was observed (P < .001). The reduction in lactobacilli was not significant at later first stage (P > .05). However, at the end of 135 minutes, there were significantly fewer S mutans (P < .001), total viable bacteria (P < .001), and lactobacilli (P < .001) in the oral cavity after chewing mastic gum than after chewing paraffin (P < .001). The results show that chewing mastic gum decreased the total viable bacteria, S mutans, and lactobacilli in saliva in orthodontically treated patients with fixed appliances. CONCLUSION Chewing mastic gum might be useful in preventing caries lesions.

The protective role of topical propolis on experimental keratitis via nitric oxide levels in rabbits

The aim of this study was to investigate antioxidant, anti-inflammatory, and antibacterial properties of propolis in the treatment of experimental Staphylococcus aureus keratitis. Twenty young New Zealand white rabbits were used in this experiment. Staphylococcus aureus were given by intrastromal injection to 16 rabbits and 4 rabbits were used as control group (Group 1). Group 2 was treated with phosphate-buffered solution drops; Group 3 was administered ethanolic extract of propolis drops; Group 4 received topical ciprofloxacin drops; Group 5 was treated with topical ciprofloxacin drops along with ethanolic extract of propolis drops. The eyes were examined by slit lamp to assess corneal opacity. And then, corneas were removed to determine nitric oxide (NO) levels and count bacteria. Corneas were also evaluated histologically. Corneal NO concentration in gruop 5, treated with a combination of propolis and ciprofloxacin was determined significantly lower (10.0± 1.8 μmol/g wet tissue) than in Group 4, treated with ciprofloxacin (24.0± 3.1 μmol/g wet tissue), from Group 3, treated with propolis (15.6± 1.8 μmol/g wet tissue), and treated with PBS (44.7± 7.8 μmol/g wet tissue). There were significantly fewer bacteria in eyes that received propolis plus ciprofloxacin than in eyes treated with ciprofloxacin (p = 0.0001) or propolis (p = 0.0001) or eyes treated with PBS (p = 0.0001). The light microscopic examination revealed that the control group showed normal corneal morphology. In the nontreated group, sections of the stromal infiltration revealed the presence of inflammatory cells, which were diffusely distributed (p < 0.05). Administrations of ciprofloxacin plus propolis resulted in a significantly reduced histological damage with fewer bacterial inoculation of the corneal stroma in comparison with the other groups (p < 0.05). Based on these findings, we suggest that ethanolic extract of propolis has antioxidant, anti-inflammatory, and antibacterial properties for S. aureus keratitis in rabbits.

Synthesis and anti-proliferative activity of fluoro-substituted chalcones.

A series of novel fluoro-substituted chalcone derivatives have been synthesized. All synthesized compounds were characterized by (1)H nuclear magnetic resonance (NMR), (13)C NMR, and elemental analysis. Their anti-proliferative activities were evaluated against five cancer cells lines, namely, A549, A498, HeLa, A375, and HepG2 using the MTT method. Most of the compounds showed moderate to high activity with IC50 values in the range of 0.029-0.729μM. Of all the synthesized compounds, 10 and 19 exhibited the most potent anti-proliferative activities against cancer cells, and 10 was identified as the most promising compound.

Cutaneous infection caused by Aspergillus terreus

Aspergillus species are widely distributed in nature, and more than 30 species have been reported to be involved in human and animal infection. Cutaneous infections due to Aspergillus terreus are particularly rare. In this report, we describe a case of cutaneous infection caused by A. terreus in a paediatric patient who underwent surgical treatment for an open tibial fracture secondary to an agricultural accident.

Antiviral Activity of Hatay Propolis Against Replication of Herpes Simplex Virus Type 1 and Type 2

Background Propolis is a bee product widely used in folk medicine and possessing many pharmacological properties. In this study we aimed to investigate: i) the antiviral activities of Hatay propolis samples against HSV-1 and HSV-2 in HEp-2 cell line, and ii) the presence of the synergistic effects of propolis with acyclovir against these viruses. Material/Methods All experiments were carried out in HEp-2 cell cultures. Proliferation assays were performed in 24-well flat bottom microplates. We inoculated 1×105 cells per ml and RPMI 1640 medium with 10% fetal calf serum into each well. Studies to determine cytotoxic effect were performed. To investigate the presence of antiviral activity of propolis samples, different concentrations of propolis (3200, 1600, 800, 400, 200, 100, 75, 50, and 25 μg/mL) were added into the culture medium. The amplifications of HSV-1 and HSV-2 DNA were performed by real-time PCR method. Acyclovir (Sigma, USA) was chosen as a positive control. Cell morphology was evaluated by scanning electron microscopy (SEM). Results The replication of HSV-1 and HSV-2 was significantly suppressed in the presence of 25, 50, and 100 μg/mL of Hatay propolis. We found that propolis began to inhibit HSV-1 replication after 24 h of incubation and propolis activity against HSV-2 was found to start at 48 h following incubation. The activity of propolis against both HSV-1 and HSV-2 was confirmed by a significant decrease in the number of viral copies. Conclusions We determined that Hatay propolis samples have important antiviral effects compared with acyclovir. In particular, the synergy produced by antiviral activity of propolis and acyclovir combined had a stronger effect against HSV-1 and HSV-2 than acyclovir alone.

Efflux pump genes and antimicrobial resistance of Pseudomonas aeruginosa strains isolated from lower respiratory tract infections acquired in an intensive care unit

The aim of this study was to determine the antimicrobial resistance rates and the resistance genes associated with efflux pumps of Pseudomonas aeruginosa strains isolated from the patients who acquired lower respiratory tract infection (LRTI) in intensive care unit (ICU). Fifty P. aeruginosa strains isolated from the lower respiratory tract specimens of the patients who acquired LRTIs in ICU were included in this study. P. aeruginosa strains were isolated from tracheal aspirate (27), bronchoalveolar lavage (14) and sputum (9). The susceptibilities of the isolates were investigated by the disk diffusion method. Multiplex PCR assay was carried out for the detection of 13 antibiotic-resistance genes. Antimicrobial resistance rates of the isolates were found high and the highest resistance rate of the isolates studied was determined against to mezlocillin (50%) followed by norfloxacin (48%), ciprofloxacin (46%), meropenem (40%). Fourty-three isolates (86%) were determined to carry one and more resistance genes. NfxB gene was most often determined in the genes that were investigated. The significant relation between the resistance to cefepime, piperacilline/tazobactam and the mexC gene, that between the resistance to mezlocillin, piperacilline/tazobactam, ceftazidime, cefepime and ampC genes, and that between the resistance to ciprofloxacin, norfloxacin and oprJ, oprN and nfxB genes was identified. Resistance caused by genes for carbapenemases, aminoglycoside-modifying enzymes and other mechanisms were not identified in this study. Understanding the prevalence and mechanism of antimicrobial resistance in P. aeruginosa may help to select empirical therapy for nosocomial LRTIs due to P. aeruginosa in our ICU.

Evaluation of nosocomial infections and risk factors in critically ill patients

Summary Background Nosocomial infections are one of the most serious complications in intensive care unit patients because they lead to high morbidity, mortality, length of stay and cost. The aim of this study was to determine the nosocomial infections, risk factors, pathogens and the antimicrobial susceptibilities of them in intensive care unit of a university hospital. Material/Methods The patients were observed prospectively by the unit-directed active surveillance method based on patient and the laboratory. Results 20.1% of the patients developed a total of 40 intensive care unit-acquired infections for a total of 988 patient-days. The infection sites were the lower respiratory tract, urinary tract, bloodstream, wound, and the central nervous system. The respiratory deficiency, diabetes mellitus, usage of steroid and antibiotics were found as the risk factors. The most common pathogens were Enterobacteriaceae, Staphylococcus aureus, Candida species. No vancomycin resistance was determined in Gram positive bacteria. Imipenem and meropenem were found to be the most effective antibiotics to Enterobacteriaceae. Conclusions Hospital infection rate in intensive care unit is not very high. The diabetes mellitus, length of stay, usage of steroids, urinary catheter and central venous catheter were determined as the risk factors by the final logistic regression analysis. These data, which were collected from a newly established intensive care unit of a university hospital, are important in order to predict the infections and the antimicrobial resistance profile that will develop in the future.