In Vitro Antimicrobial Activity of Thymus vulgaris Essential Oil Against Major Oral Pathogens.

The objective of present investigation was to determine antimicrobial activity of Thymus vulgaris oil on some oral pathogens. Thymus vulgaris oil was prepared by hydrodistillation and tested against 30 clinical isolates of each of Streptococcus pyogenes, Streptococcus mutans, Candida albicans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans, prepared from related oral infections using agar disk diffusion and broth microdilution methods. Thymus vulgaris oil at concentrations of 16 to 256 µg/mL exhibited strong inhibitory activity on all clinical isolates producing inhibition zones of 7.5 to 42 mm as measured by agar disk diffusion method. Streptococcus pyogenes and Streptococcus mutans were the most sensitive isolates with minimum inhibitory concentrations of 1.9 and 3.6 µg/mL, respectively. The minimum inhibitory concentration values for C albicans, A actinomycetemcomitans, and P gingivalis were 16.3, 32, and 32 µg/mL, respectively.

Rocket and Two Dimensional Immunoelectrophoresis in Diagnosis of Caprine Brucellosis.

BACKGROUND: Brucellosis is a major bacterial zoonosis of global importance with the causative organisms of Gram-negative facultative intracellular pathogens. The aims of this study were to standardize two immunoelectrophoretic techniques, rocket and cross immunoelectrophoresis, and compare their results with other conventional serodiagnostic tests. METHODS: Sera from 15 sheep, without any history of brucellosis vaccination, infected with Brucella melitensis M16 subcutaneously, were employed in a comparison of culture, precipitating, and immunoelectrophoretic tests. A 125 days serologic follow-up was performed after the infection was started. As a reference, these tests also done in the five healthy sheep. RESULTS: The results obtained with the rocket immunoelectrophoresis test correlated very well with those of the cross immunoelectrophoresis, whereas results of other tests such as culture, Rose Bengal, standard tube agglutination and 2-mercaptoethanol seruagglutination tests were inferior. CONCLUSION: As agglutination test shows cross reaction and a prozone phenomenon, and in blood culture, the bacteria is not always detectable, so they are time consuming rocket and cross immunoelectrophoresis are recommended because their results can be obtained in a shorter time.

Inhibitory activity of Myrtus communis oil on some clinically isolated oral pathogens.

OBJECTIVES: To determine the antimicrobial activities of Myrtus communis oil (MCO) on some oral pathogens. MATERIAL AND METHODS: Thirty strains of Streptococcus mutans, Aggregatibacteractinomycetemcomitans, Porphyromonas gingivalis and 20 strains of Streptococcus pyogenes and Candida albicans isolated from patients with dental caries, periodontal diseases, pharyngitis and oral lesions associated with artificial dentures were used for the antimicrobial activity of MCO. The oil was prepared by hydrodistillation procedures using a Clevenger apparatus. Agar disk diffusion and broth microdilution methods were performed on various concentrations of MCO (3.9-1,000 µg/ml) using all the pathogens isolated. RESULTS: All isolates were sensitive to MCO at 125-1,000 µg/ml by agar disk diffusion producing inhibition zones of 8.1-41.25 mm in diameter. All of the S. pyogenes, S. mutans and C. albicans strains were sensitive to 62.5 µg/ml while 70% (21/30) of A. actinomycetemcomitans and 66.6% (20/30) of P. gingivalis were resistant to these concentrations. All S. pyogenes and S. mutans strains were sensitive to 31.25 µg/ml. All S. pyogenes strains were sensitive to 15.6 and 7.8 µg/ml of MCO. None of the clinical isolates in this study were sensitive to 3.9 µg/ml or to a lower concentration of oil. The minimum inhibitory concentrations of MCO for S. pyogenes, S. mutans, C. albicans, A.actinomycetemcomitans and P. gingivalis were 29.68 ± 4.8, 31.25 ± 0, 46.9 ± 16, 62.5 ± 0 and 62.5 ± 0 µg/ml, respectively. CONCLUSIONS: Data obtained in this study revealed a strong antimicrobial activity of MCO on the tested oral pathogens, and MCO could therefore be useful in the prevention of the related oral infections.

Inhibitory activity of green tea (Camellia sinensis) extract on some clinically isolated cariogenic and periodontopathic bacteria.

OBJECTIVE: To determine the in vitro inhibitory activity of green tea extract on some clinically isolated cariogenic and periodontopathic bacteria. MATERIALS AND METHODS: Twenty strains of each of Streptococcusmutans, Aggregatibacteractinomycetemcomitans, Porphyromonasgingivalis, and Prevotellaintermedia were isolated from carious teeth and periodontal pockets of patients with dental caries and periodontal diseases. Green tea extract was prepared by aqueous extraction method and diluted from 50 to 1.56 mg/ml. Standard techniques of agar disk diffusion and broth microdilution assays were applied for qualitative and quantitative determinations of antibacterial activity of green tea extract on each isolates. RESULTS: All clinical isolates of S. mutans (100%) were sensitive to green tea extract at concentrations 6.25, 12.5, 25, and 50 mg/ml producing inhibition zones ranging from 10 to 38 mm. All periodontopathic isolates (A. actinomycetemcomitans, n = 20, P. intermedia, n = 20, and P. gingivalis, n = 20) (100%) tested were sensitive to 12.5, 25, and 50 mg/ml of this extract. The minimal inhibitory concentration of green tea extract for S. mutans was 3.28 ± 0.7 mg/ml and for A. actinomycetemcomitans 6.25, for P. gingivalis and P. intermedia 12.5 mg/ml. CONCLUSIONS: Our findings showed that green tea extract exhibited strong antibacterial activity on S. mutans,A. actinomycetemcomitans,P. gingivalis and P. intermedia and therefore may be used in mouthwashes or dentifrices for prevention of dental caries and periodontal diseases.

Inhibitory activity of Aloe vera gel on some clinically isolated cariogenic and periodontopathic bacteria.

Aloe vera is a medicinal plant with anti-inflammatory, antimicrobial, antidiabetic and immune-boosting properties. In the present study we investigated the inhibitory activities of Aloe vera gel on some cariogenic (Streptococcus mutans), periodontopathic (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and an opportunistic periodontopathogen (Bacteroides fragilis) isolated from patients with dental caries and periodontal diseases. Twenty isolates of each of these bacteria were investigated for their sensitivity to Aloe vera gel using the disk diffusion and microdilution methods. S. mutans was the species most sensitive to Aloe vera gel with a MIC of 12.5 µg/ml, while A. actinomycetemcomitans, P. gingivalis, and B. fragilis were less sensitive, with a MIC of 25-50 µg/ml (P < 0.01). Based on our present findings it is concluded that Aloe vera gel at optimum concentration could be used as an antiseptic for prevention of dental caries and periodontal diseases.

Active immunization using exotoxin A confers protection against Pseudomonas aeruginosa infection in a mouse burn model.

BACKGROUND: Pseudomonas aeruginosa is an important cause of nosocomial infection and may lead to septicemia and death. We evaluated the immunogenicity of semi-purified exotoxin A from the bacterium in a mouse burn model. METHODS: The toxoid was prepared from exotoxin A taken from toxigenic strains of P. aeruginosa (PA 103). 50 mice were immunized with the toxoid, burned with hot metal and infected with 1 x 10(8) CFU of toxigenic strains of P. aeruginosa (experimental group); 25 non-immunized mice were also burned and infected (control group). The mortality rate and presence of any exotoxin and P. aeruginosa in the sera, liver and spleen were determined. RESULTS: In the experimental group, 2 mice died before the burns were administered and were excluded from the study. The remainder (48 mice) were challenged with a lethal dose of P. aeruginosa and followed for 70 days. 3 of these mice died. Neither P. aeruginosa nor exotoxin A was not detected in the liver, spleen or sera of the surviving mice. The protective efficacy of toxoid vaccination was therefore 93.8%. In the control group, all mice died from bacteremia and septicemia, most (80%) within 6 days, and P. aeruginosa and exotoxin A were isolated from sera, spleen and liver. CONCLUSION: Active immunization of mice using a semi-purified exotoxin A derived from P. aeruginosa was 93.8% effective at protecting mice from subsequent P. aeruginosa infections in a mouse burn model.

Comparison between Alpha and silver sulfadiazine ointments in treatment of Pseudomonas infections in 3rd degree burns.

The goal of this study was to evaluate the efficacy of Alpha ointment in the treatment of burn wounds and compare its results with silver sulfadiazine (SS). Similar burn ulcers were produced on anterior surface of thigh of 60 rats. The wounds were infected with Pseudomonas aeruginosa and dressing and debridement was performed daily. The first group of rats received topical SS, the second group received Alpha ointment and the third (control group) received no medication. Wound healing, contraction, culture, and scar formation were evaluated at the end of the second and 10th week. Alpha ointment was equally effective as SS, considering wound healing and contraction. Wound infection was significantly less common in Alpha ointment group compared to the other two groups (p<0.05). Alpha ointment is a less expensive drug with an acceptable result compared to SS. Therefore, we recommend it as an alternative to SS, especially in patients with low economical backgrounds or in those who show adverse reactions to SS.

Penicillin-resistant Streptococcus pneumoniae in Iran.

OBJECTIVE: To determine the prevalence of penicillin-resistant Streptococcus pneumoniae isolated from patients with community-acquired pneumococcal infections. MATERIALS AND METHODS: A broth dilution method was used to determine the minimum inhibitory concentration (MIC) of penicillin and other commonly used antibiotics. 115 heavy growth or pure culture of S. pneumoniae strains were isolated from: blood 10, cerebrospinal fluid (CSF) 15, ear 5, eye 12, purulent rhinosinusitis 48, sputum 22, and pleural fluid 3. RESULTS: Of the 115 pneumococcoal isolates, 76 (66.1%) were sensitive to penicillin while the remaining 39 (33.9%) were nonsusceptible (15.6% resistant and 18.3% intermediately resistant). Among the 25 pneumococcal isolates from sterile sites (blood 15, CSF 10), 15 (60%) were penicillin-resistant whereas among the 90 isolates from nonsterile sites, 24 (26.7%) were resistant to penicillin (<0.004). The MIC values of antibiotics tested for S. pneumoniae were: penicillin 0.008-4 microg/ml, chloramphenicol 0.25-32 microg/ml, erythromycin 0.008-128 microg/ml, tetracycline 0.06-64 microg/ml, vancomycin 0.03-0.5 microg/ml, azithromycin 0.016-128 microg/ml, ciprofloxacin 0.006-8 microg/ml, cefotaxime 0.007-2 microg/ml, and ceftriaxone 0.016-12 microg/ml. CONCLUSION: Approximately one third of S. pneumoniae isolated from the clinical specimens were nonsusceptible to penicillin in this region.

Comparison of biotyping and antibiotyping of Pseudomonas aeruginosa isolated from patients with burn wound infection and nosocomial pneumonia in Shiraz, Iran.

The objective of present study was to compare and determine the prevalence ofantibiotypes and biotypes of Pseudomonas aeruginosa isolated from patients with burn infection and nosocomial pneumonia in Shiraz, Iran. Thirty isolates from each group of patients were used. Antibiotyping (antibiotic sensitivity profiles) was performed by disk diffusion of Bauer-Kirby method using eleven antibiotics and biotyping (biochemical profiles) was done by standard biochemical procedures. High rate of multi-drug resistant isolates were observed by both groups of patients. P. aeruginosa isolated from burn infection were found more resistant (26.7%) to the all antibiotics used than those from nosocomial pneumonia (6.7%) p < or = 0.04. All P. aeruginosa (100%) isolates from burn infection were resistant to gentamycin, carbenicillin, cephtazidime and cephalothin. The lowest resistance rate was observed with meropenem. Antibiotic susceptibility profiles revealed 11 and 15 different antibiotypes among P. aeruginosa isolates from patients with burn infection and nosocomial pneumonia, respectively. The biochemical profiles consisting of 21 biochemical tests grouped P. aeruginosa into 8 different biotypes. Biotypes BVIII 15(50%) and BIII 11(36.7%) were the most prevalent isolates from burn infection and nosocomial pneumonia, respectively p < or = 0.04. Data obtained in this study revealed that different types of Pseudomonas aeruginosa are involved in burn wound infection and nosocomial pneumonia in this region.

Cross-reaction of sera from patients with various infectious diseases with Leishmania infantum.

OBJECTIVE: To compare and evaluate the application of indirect fluorescent antibody (IFA) and counterimmunoelectrophoresis (CIEP) for laboratory identification of visceral leishmaniasis. MATERIALS AND METHODS: Serum samples from patients with malaria (Plasmodium vivax, n = 86; Plasmodium falciparum, n = 38), brucellosis (n = 26), tuberculosis (n = 31) and typhoid fever (n = 35) were examined for the presence of antibody to Leishmaniainfantum antigen using IFA and CIEP tests. RESULTS: Using IFA, false-positive results were malaria (P. vivax 19.8%, P. falciparum 13.2%), tuberculosis (6.4%), brucellosis (3.8%), and typhoid fever (2.8%). Using CIEP, a lower percentage of false-positives was observed only among malaria patients (P. vivax 2.3%, P. falciparum 2.6%). Serum samples from patients with other infectious diseases were negative in the CIEP test. CONCLUSION: Based on the results of this study, the CIEP technique is recommended for immunodiagnosis of visceral leishmaniasis, especially in regions where malaria, brucellosis and tuberculosis are prevalent.