Abstract

Background and Objective: Neonatal sepsis is a remarkable factor in mortality, morbidity, neonatal and perinatal complications. Group B Streptococcus (GBS) is the primary cause of invasive disease in infants and pregnant women. This study aimed to determine the relationship between antimicrobial resistance of the bacteria colonized in the vagina and rectum of pregnant women and early neonatal infection.

Material and Methods: In this prospective study conducted on 282 pregnant women, bacterial sensitivity to ampicillin, cefazolin, erythromycin, vancomycin, gentamicin, amikacin was measured. Furthermore, the relationship between rectal and vaginal colonization of mothers and early neonatal sepsis was evaluated.

Results: Of 98 positive rectal cultures, 49 (50%) were Gram-positive cocci and 49 (50%) E.coli. of 143 positive vaginal cultures, 136 (95.1%) were Gram-positive cocci, 7 (4.9%) were E.coli and two were positive GBS.  We could find definitive neonatal sepsis. Significant correlation was found between a history of urinary tract infection and the mother's positive rectal culture (P =0. 03).

Conclusion: Clinical sepsis in neonates is correlated with positive rectal culture (P =0. 001) and the positive E.coli vaginal cultures is associated with suspected neonatal sepsis (P =0.007). Gram-positive cocci were resistance to ampicillin and gentamicin, and E.coli was resistant to ampicillin, erythromycin and vancomycin. Because of resistance to ampicillin, we recommend cefazolin due to its sensitivity to organisms and safety in pregnancy.

Keywords: Antibacterial Agents, Escherichia Coli, Gram-Positive Cocci, Newborn, Sepsis

Abstract

Background and Objective: The aim of this study was to evaluate chemical composition, antibacterial and antifungal effect and antioxidant property of Salvia officinalis, Mentha piperita and Mentha Longifolia.

Material and Methods: At first, chemical analysis of essential oils was determined using GC/MS. Then the antibacterial and antifungal effect of tested essential oils on L. monocytogenes, S. aureus, S. typhimurium and E. coli and two fungal strains including A. niger and A. flavus were determined using disk diffusion agar and broth microdilution methods.  The antioxidant property of essential oils was evaluated using DPPH assay.

Results: Linalool (14.38%), l. menthone (19.03%) and δ-terpinene (21.78%) were the major components of Salvia officinalis, Mentha piperita and Mentha Longifolia, respectively. all tested essential oils had antibacterial effect on foodborne pathogens, which was comparable with tetracycline’s effect. In addition, all essences had appropriate antioxidant potential compared with BHT.

Conclusion: based on the results, Salvia officinalis, Mentha piperita and Mentha Longifolia can be introduced as appropriate natural preservatives.

Keywords: Salvia officinalis; Mentha piperita; Mentha Longifolia, Antibacterial Agents.

Abstract

      Background and Objectives: Antibiotic resistance in bacteria has actuated researchers toward evaluating many new antibacterial compounds of which are the thiazoles. In this research the inhibitory effects of novel thiazole derivatives were unraveled on Staphylococcus aureus, Streptococcus agalactiae, Pseudomonas aeruginosa and Klebsiella pneumoniae and oxothiazole liver toxicity effects were assessed on mice.

       Methods: The antibacterial effect of thiazole derivatives was evaluated by measuring the halo zone with disk diffusion method and dilution procedure in microplate in order to discriminate the minimum inhibitory concentration (MIC) and the liver toxicity of oxothiazole, also, was discerned by injecting 160 mg/kg, 265 mg/ kg and 350 mg/kg doses to mice as well as scrutinizing the liver histopathology.

      Results: Derivatives utilized in experiment had no inhibitory effect on Pseudomonas aeruginosa and Klebsiella pneumoniae, though their inhibitory effect was observed on Staphylococcus aureus and Streptococcus agalactiae. For Staphylococcus aureus and Streptococcus agalactiae the diameters of growth inhibition zone were 8.9-22.3 mm and 16.1-25.6 mm, respectively and MIC of 50-200 and 25-100 µg/ml by order. Additionally, by increasing the injection dose of oxothiazole with 160 mg/ml, 265 mg/ml and 350 mg/ml doses, the hepatitis lesions and liver necrosis were observed in experimental mice.

       Discussion: The thiazole derivatives possessed more inhibitory trace on gram positive bacteria than gram negative ones. Furthermore, the likely presence of oxygen link to thiazole ring in tested compounds results in the enhancement of inhibitory potency of these substances. Besides, our results suggest that high doses of oxothiazole cause severe liver damage and rapid death less than 24 hours.

       Keywords: Thiazole derivatives, Antibacterial effects, Oxothiazole, Liver toxicity.

Abstract

      Background and Objective: Probiotics are living microorganisms that have beneficial effects on the health of digestive system. The aim of this study was to evaluate the antimicrobial ability of acidic and neutral supernatants (culture supernatant) of lactic acid bacteria against common bacterial pathogens.

       Methods: Four species of lactic acid bacteria (Lactobacillus plantarum PTCC1745, Lactobacillus PTCC1608, Lactobacillus Saki PTCC1712 and Lactobacillus Lactis PTCC1336) were obtained from the microbial collection of Iranian Research Organization for Science and Technology in Lyophilized form. The antimicrobial activity of neutral and acidic supernatants against bacterial pathogens was investigated using the Disk and Well Diffusion Agar methods.

      Results: Lactic acid bacteria showed good antimicrobial ability against six pathogenic bacteria with the highest inhibitory effect observed in Lactococcus lactis against E. coli PTCC1399 through well method with an average diameter of 14 mm inhibition zone. In this study, the well diffusion method was far more sensitive compared to the disk method and acidic supernatants showed higher antimicrobial efficiency compared to neutral types.

      Conclusion:  the Metabolites produced by lactic acid bacteria are able to inhibit the growth of pathogenic bacteria that can be an important and practical solution for the prevention and treatment of infections and ultimately improve human health.

Abstract

      Background and Objective: The spread of drug resistance in bacteria have prompted researchers to seek suitable alternative for antimicrobial drugs among various medicinal plants and nanoparticles. The aim of this study was to evaluate the effect of silver nanoparticles alone and in combination with methanol extract of Zataria multiflora on five Gram-positive and Gram-negative bacteria.

     Methods: Different concentrations of the nanoparticles and extract alone or in combination with each other were tested against the bacteria, using well diffusion method. Three concentration levels (lowest, average and highest) were prepared form the nanoparticles and the extract for the combination, and finally nine different combinations were prepared.

      Results: The extract and nanoparticles showed inhibitory effects against all the tested bacteria. The maximum diameter of growth inhibition zone in the presence of the extract and nanoparticles were observed in Streptococcus pyogenes (35.6mm) and methicillin-resistant Staphylococcus aureus (20.6mm), respectively. The maximum diameter of growth inhibition zone for the combination was measured in S. pyogenes (31mm).

      Conclusion: The combination of low concentrations of the plant extract and nanoparticles are more effective against bacteria, but the combination of their high concentrations reduce the antibacterial effects in some cases.

     

Abstract

      Background and Objective: The aim of this study was to determine the chemical composition, antibacterial and antifungal effects of Thymus vulgaris and Cuminum Cyminum essential oils against foodborne pathogens and Candida species in vitro.

      Methods: The essential oils were extracted from the aerial parts of Thymus vulgaris and dried Cuminum Cyminum seeds using a Clevenger apparatus for 3 hours. Analysis of the essential oils’ constituents was performed using gas chromatography-mass spectrophotometry. The antibacterial activity of Cuminum Cyminum essential oil and essential oil of Thymus vulgaris against Bacillus cereus, Listeria monocytogenes, Escherichia coli and Salmonella typhimurium were evaluated in agar culture medium. The minimum inhibitory concentration (MIC) of these essential oils against fungal strains of Candida albicans, C. tropicalis, C. parapsilosis and C. dubliniensis was measured.

      Results: Thymol (64.45%) and cuminaldehyde (29.02%) were the main components of the essential oil of Thymus vulgaris and Cuminum Cyminum, respectively. The largest inhibition zone diameter in the essential oils of Thymus vulgaris and Cuminum Cyminum in the agar disk diffusion method was related to B. cereus with 30 and 21 mm diameter, respectively. The largest growth inhibition zone diameter by the essential oil of Thymus vulgaris in the well diffusion method was 21 mm and against B. cereus. The MIC of essential oil of Thymus vulgaris in the microdilution method was 0.09% against all the four Candida strains. The MIC of Cuminum Cyminum essential oil against strains of C. albicans and C. tropicalis was 0.39%, while it was found as 0.19% against C. parapsilosis and C. dubliniensis.

      Conclusion: In this study, Cuminum Cyminum essential oil and essential oil of Thymus vulgaris show suitable inhibitory effects against the growth of bacteria using well and disk diffusion methods. Regarding the antifungal effects, the MIC of essential oil of Thymus vulgaris is lower than the Cuminum Cyminum essential oil, which indicates the higher antifungal activity of the essential oil of Thymus vulgaris. This study has raised the possibility of using these essential oils as suitable antimicrobial compounds and alternatives for chemical preservatives in the food industry.

ABSTRACT

         Background and Objective: Hospital clothing and textiles have a great role in providing medical services to patients. Hospital services would not be possible without using these textiles. The aim of this study was to prepare non-woven polyester for use in medical textiles.

         Methods: In this study, most important expected properties of hospital clothing were created on polyester fabrics via various stages of finishing using chemicals such as calcium chloride, sodium alginate, chitosan and nanoparticles of silver nitrate and aluminum oxide. Antibacterial (activity against Staphylococcus aureus), deodorizing and wicking properties of samples were evaluated using nano-biomaterials via standard tests.

          Results: The water absorption rate of nonwoven samples that were finished with chitosan significantly improved. The results also showed favorable level of antimicrobial activity caused by silver nitrate and chitosan. In addition, deodorizing activity was observed in all samples. However, silver nitrate-finished samples had higher deodorizing activity. The capillary action of all samples reduced after completion of all finishing procedures.

          Conclusion: The results show that the use of chitosan and alginate along with nanoparticles of silver nitrate and aluminum oxide can be effective in achieving the desired properties of medical textiles.

        Keywords: Medical textiles, antibacterial substances, chitosan, silver nitrate.

Background and Objective: Nowadays, incidence of antibiotic-resistance among pathogenic bacteria has increased due to indiscriminate use of antimicrobial drugs for treatment of diseases, especially urinary tract infections. Medicinal plants are also of great importance as antibacterial agents. Therefore, the aim of this study was to determine the antibacterial effect of ethanolic extract of nettle (Urtica dioica L.) leaves using two methods of disk diffusion and well diffusion.

         Methods: Ethanolic extract of nettle leaves was prepared by the percolation method. Effect of different concentrations of the extract on Escherichia coli (PTCC1399), Staphylococcus aureus (PTCC 1431), Staphylococcus epidermidis (PTCC 1435) and Staphylococcus saprophyticus (PTCC1440) was evaluated using the disk diffusion and well diffusion methods by measuring diameter of growth inhibition zone. Gentamicin and propylene glycol were used as positive and negative control, respectively.

        Results: In both methods, especially in the well diffusion, the ethanolic extract of nettle leaves had favorable inhibitory effect on the growth of S. aureus, S. epidermidis and S. saprophyticus. In the well diffusion method, the highest rate of susceptibility to the extract (89%) was related to S. saprophyticus and S. epidermidis.

         Conclusion: The ethanolic extract of nettle leaf has good inhibitory effect on the growth of S. aureus (especially in the well diffusion method), which confirms the traditional use of this plant for the treatment of urinary tract infections.

          Keywords: Antibacterial Effect, Staphylococcus, E. Coli, Ethanolic Extract, Nettle (Urtica dioica L.).

ABSTRACT

         Background and Objective: Although antibiotics are commonly used for treatment of infectious diseases, these treatments are often associated with several problems such as unwanted side effects and resistance to antibiotics. The aim of this study was to evaluate the antibacterial effect of aqueous and alcoholic extracts of Nasturtium officinale on Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes.

          Methods: All experiments were performed using the well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the aqueous and alcoholic extracts of N. officinale against the pathogenic bacteria studied were determined by microdilution method.

         Results: In the well diffusion method, S. aureus and L. monocytogenes were the most sensitive bacteria with MIC of 8 μg/ml, while E. coli and S. typhimurium were the most resistant bacteria to the aqueous and alcoholic extracts. In addition, the inhibitory activity of the alcoholic and aqueous extracts of N. officinale was higher against gram-positive bacteria compared to gram-negatives. The lowest MIC (6.25 μg/ml) and MBC (12.5 μg/ml) of the plant extract were against S. aureus.

          Conclusion: The aqueous and alcoholic extracts of N. officinale affect the growth of gram-positive bacteria (S. aureus and L. monocytogenes) but not the gram-negatives (S. typhimurium and E. coli). These extract could be used for treatment of infections.

        Keywords: Nasturtium Officinale, Aqueous Extract, Alcoholic Extract, Antibacterial Effect.

ABSTRACT

         Background and Objectives:  Many species of  Ziziphora have been used in traditional medicine in the Azarbaijan region, northwest of Iran. This study aimed to determine antibacterial activity of essential oil and methanol extract of Ziziphora tenuior on some pathogenic bacteria isolated from urogenital tract infections.

         Methods: The essential oil and methanol extract of Z. tenuior were obtained by Clevenger and maceration methods. Under sterile conditions, the required amount of urine was taken from patients referred to a number of clinics in Tabriz during 2014. After identification of the isolates using standard microbiological methods, antimicrobial effects of the essential oil and methanol extract of the plant on the isolates were evaluated by determining minimum inhibitory concentration (MIC), minimum bactericidal concentration, and antibiogram test.

          Results: The MIC for essential oil of Z. tenuior was 250µg/mL for most Gram-negative bacteria except Pseudomonas aeruginosa. Moreover, the MIC for Staphylococcus aureus was 250µg/mL and 500µg/mL for other strains of Staphylococcus.

           Conclusion: Comparison of the inhibitory and bactericidal effects of the essential oil and methanol extract of Z. tenuior showed that the essential oil is able to inhibit growth of the bacteria tested even in low concentrations. Further studies are required in this regard using animal models.

         Keywords: Antibacterial Agents, Ziziphora tenuior, Plant Extracts, Urinary Tract Infection. 

ABSTRACT
        Background and objectives: Synthesis and characterization of several metal complexes (metal ions: Co2+, Ti4+ and Ce3+) of macroacyclic Schiff base ligand have been reported. The Schiff base ligand is prepared from the condensation reaction of 1, 4-di-(4-fluoro-2-aminophenoxy) butane with salicylaldehyde in ethanol. In addition, antibacterial activity of metal ions, Schiff base ligand and their complexes have been investigated. Recent studies show that many Schiff base complexes have antibacterial activity against Gram-positive and Gram-negative bacteria. Therefore, we aimed to synthesize new Schiff base complexes and evaluate their antibacterial activity against a number of Gram-positive and Gram-negative bacteria.
         Methods: Schiff base ligand and their complexes were characterized by mass spectrometry and IR, H-NMR and C-NMR spectroscopy. The in vitro antibacterial activity of the Schiff base ligand, metal ions and their complexes were evaluated against some Gram-positive and Gram-negative bacteria by disk diffusion method and determining minimum inhibitory concentration.
          Results: In this study, the Schiff base complexes had good antibacterial activity, but the Schiff base ligand and metal ions did not show any antibacterial effect. In some cases, the antibacterial effect of the complexes was higher than that of the standard antibiotics tetracycline and gentamycin. The titanium complex showed the highest antibacterial activity in both methods. This complex created the largest growth inhibition zone (diameter: 100mm) against Staphylococcus aureus, and had the lowest minimum inhibitory concentration against Bacillus subtilis (6.75 mg/ml).
          Conclusion: The compounds synthesized in our study have strong antibacterial activity.
          Keywords: Schiff base complex, Schiff base ligand, antibacterial activity, Staphylococcus aureus, Bacillus subtilis.

ABSTRACT
       Background and Objective: Anaerobic bacteria are the main cause of periodontitis. It has been shown that green tea and black tea have antibacterial effect. The aim of this study was to determine he antibacterial effect of Iranian green tea and black tea against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia.
        Methods: Aqueous and methanolic extracts of Iranian green tea and black tea at concentrations ranging from 10 to 500 mg/ml were tested against standard strains of A. actinomycetemcomitans  (ATCC 33384), P. gingivalis (ATCC 33227) and P. intermedia (ATCC 25671) using agar disk diffusion, broth microdilution and determination of minimum inhibitory concentration.
         Results: P. gingivalis, A. actinomycetemcomitans and P. intermedia were sensitive to the methanolic extract of Iranian green tea at concentrations of 100-500 mg/ml, 10-500 mg/ml and 50-500mg/ml, respectively. P. gingivalis, A. actinomycetemcomitans and P. intermedia were sensitive to the methanolic extract of Iranian black tea at concentrations of 200-500 mg/ml, 20-500 mg/ml and 200-500 mg/ml, respectively. In addition, P. gingivalis, A. actinomycetemcomitans and P. intermedia were sensitive to the aquatic extract of Iranian green tea at concentrations of 200-500mg/ml, 100-500 mg/ml and 200-500 mg/ml, respectively.
        Conclusion: The aquatic and alcoholic extracts of Iranian green tea and black tea have antibacterial activity against A. actinomycetemcomitans, P. intermedia and P. gingivalis. Therefore, incorporation of Iranian black tea as an effective native herb could be beneficial for prevention of oral cavity diseases.
          Keywords: Tea, Green Tea, Antibacterial Agents, Anaerobic Bacteria. 

ABSTRACT
             Background and objectives: Utilization of essential oils instead of chemical preservatives has received significant attention in recent years. The present study aims to evaluate chemical composition and antibacterial and antioxidant properties of essential oils of Zataria multiflora, Artemisia deracunculus and Mentha piperita.
             Methods: Chemical profile of the essential oils was analyzed by gas chromatography/mass spectrometry. The microwell dilution and agar disk diffusion methods were used to evaluate the antibacterial properties of the essential oils. Total phenolic content, β-carotene-linoleic acid bleaching test and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays were carried out to determine the antioxidant properties.
             Results: Menthol (39.18%) and mentone (21.64%) were the main components of the essential oil of M. piperita, while estragol (34.75%) and limonene (15.72%) were the major components of the essential oil of A. dracunculus. The main components of the essential oil of Z. multiflora were carvacrol (36.81%) and thymol (33.04%). The essential oils of M. piperita and Z. multiflora showed greater antimicrobial effects. Moreover, Z. multiflora showed the greatest antioxidant activity among the essential oils. The total phenolic content of Z. multiflora was 228.14±0.45 mg gallic acid equivalent/g.
             Conclusion: Given their favorable antioxidant and antimicrobial properties, the essential oils of Z. multiflora, A. deracunculus and M. piperita can be used as natural food preservatives.
             Keywords: Zataria multiflora, Artemisia deracunculus, Mentha piperita, antibacterial effect, antioxidant effect.   

ABSTRACT
            Background and Objectives: Nowadays, infections with antibiotic-resistant bacteria are among the most important causes of mortality worldwide. This has attracted the attention of researchers to seek suitable alternatives for antibiotics. The venom of many toxic species such as arthropods has antibacterial properties. In this study, we investigated antibacterial effects of crude venom of Latrodectus dahli on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis.
            Methods: Lyophilized crude venom of L. dahli was dissolved in 50 mM Tris-HCl buffer. Protein concentration was determined by the Bradford assay. Then, the bacteria were exposed to different concentrations (31.25-250 ng/mL) of the crude venom. Inhibitory activity of the venom against the bacteria was determined by MTT assay and determining minimum inhibitory concentration (MIC).
            Results: Results of the MTT assay showed that the crude venom significantly inhibited the growth of E. coli (31.25 and 62.5 ng/mL), S. aureus (at 250 ng/mL) and B. subtilis (at 125 and 250 ng/mL). In the MIC experiment, the crude venom significantly inhibited the growth of E. coli (at concentrations of 31.25 and 62.5ng/mL), S. aureus (at concentrations of 31.25-250 ng/mL) and B. subtilis (at concentrations of 31.25-250ng/mL).
            Conclusion: The crude venom of L. dahli and its components showed relatively strong antibacterial effects.
            Keywords: Spider venoms, Black Widow Spider, Antibacterial agent, Drug-resistance.

ABSTRACT
            Background and Objectives: Schiff base ligands are prepared via the condensation reaction of 1, 10- dimethyl–phenantroline aldehyde derivative with some nitrogen donor ligands, such as benzene ring that have different functional groups (-OH, -SH, -OCH₃,-CH₂OH, -Br) in acetonitrile. Recent studies suggest that Schiff bases might have antibacterial activity. Therefore, we aimed to synthesize new Schiff base complexes and evaluate their antibacterial activity against a number of Gram-positive and Gram-negative bacteria.
            Methods: Schiff base ligands and their complexes were characterized by mass spectrometry, infrared spectroscopy and nuclear magnetic resonance spectroscopy. The in vitro antibacterial activity of the Schiff base ligands and metal ions against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa was evaluated by determining minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using the broth dilution method.
            Results: All synthesized Schiff bases exhibited favorable antibacterial activity against the tested microorganism, but the antibacterial effect of compounds 3OH and 3SH was more significant than that of other compounds.
            Conclusion: Compound 3EOH has favorable antibacterial activity against the tested bacteria.
            Keywords: Schiff bases, antibacterial effect, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa.