Medical Laboratory Journal
Volume:11 Issue: 1, Jan-Feb- 2017

Due to their antimicrobial, anticancer and antioxidant properties (due to the presence of free radical scavengers), essential oils and extracts of medicinal plants are of great importance as natural medicinal compounds in public health, treatment of diseases, and protection of raw and processed foods.

Chemical composition and content of essential oil of Thymus kotschyanus was determined by gas chromatography–mass spectrometry. The amount of phenolic and flavonoid compounds in the essential oil was determined by spectrophotometry using gallic acid and quercetin as standards. The antioxidant properties of the essential oil were evaluated by the DPPH method.

The analysis of essential oil with gas chromatography–mass spectrometry showed that thymol (51.1%), p-cymene (13.78%) and α-pinene (7.42%) are the main components. The amount of phenolic compounds was 82 ± 6.43 μg gallic acid/ml essential oil, while the flavonoid content was 30.79 ± 0.5 μg quercetin/ml essential oil. In terms of antioxidant activity, the IC50 value of T. kotschyanus essential oil was determined as 32.35 μg/ml, which is weaker than synthetic antioxidant butylated hydroxytoluen.

The results indicate that the essential oil of T. kotschyanus has good antioxidant activity and can be used in combination with other preservatives to protect food against a variety of oxidative systems.
Keywords:

The unfavorable lipid profile in obese individuals is associated with high incidence of various diseases including cardiovascular disease, hypertension, etc. Dieting for weight loss and physical activity are among the most important factors affecting the serum lipid profile. The aim of this study was to compare the effect of diet with and without physical activity on body mass index and serum lipid profile of obese women.

This clinical trial was performed in 2011 on 39 obese women referred to a weight loss and nutrition counseling center. Subjects were randomly divided into an active group (diet and exercise) and inactive group (diet without exercise). Blood sampling was done before the intervention and two months after the intervention. Data was analyzed using SPSS-16 and t-test.

Mean level of triglyceride reduced significantly in both groups. Mean level of cholesterol and low-density lipoprotein decreased significantly only in the active group. The Mean level of high-density lipoprotein in the two groups had no significant difference.
The results indicate that dieting for weight loss along with short-term physical activity improves serum levels of cholesterol and low-density lipoprotein, but does not affect serum HDL level.

Diagnosis of hepatitis E virus (HEV) infection could be missed in some cases if serological tests are used solely. Molecular characterization of HEV is essential for diagnosis of acute and chronic HEV infections, and evaluating the chronic HEV infection status in immunocompromised patients. The aim of this study was to prepare a suitable HEV positive control, determine the limit of detection (LOD) of HEV RNA for a specific molecular test, and evaluate the efficiency and precision of the test.

Genomic region of HEV NCBI reference sequence was constructed. LOD, intra-assay precision, and inter-assay precision were calculated to evaluate the efficiency and precision of the test. Then, tenfold serial dilutions of the HEV positive control were prepared. Real time PCR was performed three times for each dilution. Mean, standard deviation, and coefficient of variation of cycle thresholds obtained in three independent and simultaneous tests were calculated, and the results were analyzed.

The LOD of this test was determined as 1.4×104 copy/ml or 42 copy/reaction or 14 copy/µl. Intra-assay precision and inter-assay precision for all assays were lower than 2.5% and 10%, respectively.

We propose that the real time PCR assay targeting the ORF2/3 overlapping conserved region is suitable for detection of a wide range of different HEV genotypes found in acute and chronic HEV infections. However, the precision of the test should be improved for detecting HEV RNA lower than 103 copy/ml.

Biofilm is a population of bacteria growing on a surface and enclosed in an exopolysaccharides matrix, which increases resistance to antimicrobial agents and immune response. Uropathogenic Escherichia coli (UPEC) are biofilm-forming bacteria and the most common cause of urinary tract infections (UTIs). This study evaluated the effect of different concentrations of glucose, NaCl, blood, serum and urine on biofilm formation and antigen 43 (Ag43) gene expression, as a main gene involved in biofilm formation.

Among E. coli isolates from patients with UTI, four extended-spectrum beta-lactamase (ESBL) and non-ESBL strains, and a standard UPEC strain were selected. Biofilm formation of the strains in brain heart infusion (BHI) broth with different concentrations of glucose, NaCl, sheep blood, serum and human urine was evaluated using microplate method and crystal violet staining. Ag43 gene expression was investigated using Real-Time polymerase chain reaction, SYBR Green dye, and specific primers.

Presence of glucose at all concentrations reduced biofilm formation. Presence of 1% NaCl, 1% sheep blood, 10% bovine serum, and 5% urine significantly increased biofilm formation. Expression of Ag43 by the strains grown under 1% glucose, 1% NaCl, 1% sheep blood, 10% bovine serum and 5% urine decreased.

All environmental factors other than glucose may increase biofilm formation of E. coli at different concentrations. This is not affected by factors such as isolation from inpatient or outpatients and type of strains (ESBL or non-ESBL). Contrary to our expectations, Ag43 expression is independent of environmental factors and decreases even under the most suitable concentrations.

Many aromatic plants from the genus Satureja have been used in traditional medicine in north of Iran. This study aimed to determine the ecological requirements for the growth of Satureja mutica Fisch. & C.A. Mey, and evaluate antioxidant and antibacterial activity of ethanolic extract of S. mutica collected from North Khorasan Province, Iran.

Aerial parts of S. mutica were collected in blooming stage. Ecological requirements and the traditional uses of the plant were recorded. Ethanol extract of the plant was prepared by maceration. Antioxidant capacity of the extract was measured by three methods of total antioxidant capacity, reducing power and 2,2-Diphenyl-1-picrylhydrazyl, and then compared with standard antioxidants (butylated hydroxyanisole and butylated hydroxytoluene). Antibacterial activity of the extract was studied against nine Gram-positive and Gram-negative bacteria by agar dilution method and determining the minimum inhibitory concentrations (MICs).

S. mutica is the most common wild aromatic annual herb in north slob and sunny areas around mountains of Bojnord (1020-1300 m). The ecological features of this region are as follows: annual rainfall 308 mm, average temperature 11.5 oC, semi dry cold climate in the sandy clay loam soil, Ec=0.7 desizimence, and pH= 7.30. Ethnopharmacological data showed that this plant has been widely used by rural people as an anti-infective, antispasm and sedative agent that could treat rheumatic pain, migraine, toothache and diarrhea. The ethanol extract of S.mutica had relatively high antioxidant activity with IC50 value of 11.2 mg/ml. The extract also had high antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus and Enterococcus faecalis, with inhibition zone diameters ranging between 15.1±0.5 and 27.7±0.8 mm and MIC values of 60, 68, 53 and 83 mg/ml, respectively.

It can be concluded that the extract of S. mutica has favorable antibacterial and antioxidant activity, which could be used as natural anti-microbial agent for treatment of some infection diseases.

Cellulose is a major component of plant biomass, which can be converted into biofuels and valuable chemicals. The key step in utilization of this organic material is its hydrolysis into soluble sugars. This study evaluated cellulase production by Trichoderma harzianum under different pH values, temperatures and incubation periods with the aim to increase enzyme production and decrease its costs.
The amount of protein production and the hydrolytic activity of cellulase enzymes including exoglucanase, endoglucanase and β-glucosidase produced by T. harzianum were evaluated using various substrates such as avicel, carboxymethyl cellulose, cellobiose, Whatman grade 1 filter paper under different pH values (4, 4.8, 5.5 and 6.5), temperatures (25, 28 and 34 °C) and incubation times (48, 72, 96 and 120 h).
The optimum condition for cellulase production by T. harzianum is 120 hours of incubation at 25 °C and pH of 6.5.
T. harzianum can be used for the production of all three classes of cellulase. This fungus is suitable for the efficient production of cellulolytic enzymes and reducing the cost of consumables.

Q fever is a zoonotic disease caused by an obligate gram-negative intracellular pathogen called Coxiella burnetii. The aim of this study was to determine the seroprevalence of anti-C. burnetii antibodies in bulk tank milk (BTM) samples of dairy cattle in west and northwest of Iran.

Overall, 71 BTM samples (covering nearly 700 dairy cattle) were collected in autumn 2013. A commercial Q fever antibody ELISA Test Kit (Liebefeld-Bern, Switzerland) was used to identify the presence of antibodies against inactivated phase 1 and phase 2 C. burnetii antigens.

The results of ELISA test showed that 17 BTM samples (23.9%) were positive for the presence of anti-C. burnetii antibodies.

This study is the first to evaluate presence of anti-C. burnetii antibodies in BTM samples from dairy cattle herds in west and northwest of Iran. The high prevalence of this pathogen highlights the need for pasteurization of raw milk and raising awareness in consumers of dairy products in these regions.

Klebsiella pneumoniae is one of the most important nosocomial pathogens. Its capsular polysaccharide is considered as the first and most important virulence factor of this bacterium. This study aimed to investigate the presence of capsular serotypes K1 and K2 in K. pneumoniae isolates to examine the virulence potency of the isolates.

Overall, 65 capsulated K. pneumoniae isolates were collected from patients with urinary tract infections in Rasht, Iran. The isolates were examined using biochemical tests and CPS gene amplification using PCR. Mucoid phenotype of the isolates was determined by the string test. The presence of K1 and K2 genes was evaluated by PCR using specific primers for the genes.

Of 65 K. pneumoniae isolates, seven (10.77%) were positive for the presence of the K1 gene and four (6.15%) were positive for the presence of the K2 gene. In addition, six serotype K1 isolates (27.27%), four serotype K2 isolates (18.18%), and 12 non-K1/K2 serotype isolates (54.54%) had hypermucoviscosity phenotypes.

Our results confirm the presence of the capsular serotypes in K. pneumoniae isolates, with a relatively high prevalence for the capsular serotype K1. This study clarifies the importance of rapid diagnosis and suitable treatment of infections caused by K. pneumoniae in prevention of complicated infections.