Distribution of spoligotyping defined genotypic lineages among drug-resistant Mycobacterium tuberculosis complex clinical isolates in Ankara, Turkey

Background

Investigation of genetic heterogeneity and spoligotype-defined lineages of drug-resistant Mycobacterium tuberculosis clinical isolates collected during a three-year period in two university hospitals and National Tuberculosis Reference and Research Laboratory in Ankara, Turkey.

Methods and Findings

A total of 95 drug-resistant M. tuberculosis isolates collected from three different centers were included in this study. Susceptibility testing of the isolates to four major antituberculous drugs was performed using proportion method on Löwenstein–Jensen medium and BACTEC 460-TB system. All clinical isolates were typed by using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) methods. Seventy-three of the 95 (76.8%) drug resistant M. tuberculosis isolates were isoniazid-resistant, 45 (47.4%) were rifampicin-resistant, 32 (33.7%) were streptomycin-resistant and 31 (32.6%) were ethambutol-resistant. The proportion of multidrug-resistant isolates (MDR) was 42.1%. By using spoligotyping, 35 distinct patterns were observed; 75 clinical isolates were grouped in 15 clusters (clustering rate of 79%) and 20 isolates displayed unique patterns. Five of these 20 unique patterns corresponded to orphan patterns in the SITVIT2 database, while 4 shared types containing 8 isolates were newly created. The most prevalent M. tuberculosis lineages were: Haarlem (23/95, 24.2%), ill-defined T superfamily (22/95, 23.2%), the Turkey family (19/95, 20%; previously designated as LAM7-TUR), Beijing (6/95, 6.3%), and Latin-America & Mediterranean (LAM, 5/95 or 5.3%), followed by Manu (3/95, 3.2%) and S (1/95, 1%) lineages. Four of the six Beijing family isolates (66.7%) were MDR. A combination of IS6110-RFLP and spoligotyping reduced the clustering rate from 79% to 11.5% among the drug resistant isolates.

Conclusions

The results obtained showed that ill-defined T, Haarlem, the Turkey family (previously designated as LAM7-TUR family with high phylogeographical specifity for Turkey), Beijing and LAM were predominant lineages observed in almost 80% of the drug-Resistant M. tuberculosis complex clinical isolates in Ankara, Turkey.     

A collaborative study to establish an International Standard Rabies immunoglobulin of human origin

Because the supply of the International Standard for Anti-rabies Serum was very low, the WHO initiated a search for a replacement product. The US Food and Drug Administration agreed to undertake a collaborative study using a human rabies immunoglobulin previously purchased for use as a US standard. The potency of this product was determined, in International Units (IU) per millilitre using the rapid fluorescent focus inhibition test for measuring rabies antibody. The mean potency value was found to be 59 IU per ampoule. In June 1984 this preparation was accepted by WHO as the International Standard for Rabies Immunoglobulin.     

Statistical optimization of medium composition for bacterial cellulose production by Gluconacetobacter hansenii UAC09 using coffee cherry husk extract--an agro-industry waste

During the production of grape wine, the formation of thick leathery pellicle/bacterial cellulose (BC) at the airliquid interface was due to the bacterium, which was isolated and identified as Gluconacetobacter hansenii UAC09. Cultural conditions for bacterial cellulose production from G. hansenii UAC09 were optimized by central composite rotatable experimental design. To economize the BC production, coffee cherry husk (CCH) extract and corn steep liquor (CSL) were used as less expensive sources of carbon and nitrogen, respectively. CCH and CSL are byproducts from the coffee processing and starch processing industry, respectively. The interactions between pH (4.5- 8.5), CSL (2-10%), alcohol (0.5-2%), acetic acid (0.5- 2%), and water dilution rate to CCH ratio (1:1 to 1:5) were studied using response surface methodology. The optimum conditions for maximum BC production were pH (6.64), CSL (10%), alcohol (0.5%), acetic acid (1.13%), and water to CCH ratio (1:1). After 2 weeks of fermentation, the amount of BC produced was 6.24 g/l. This yield was comparable to the predicted value of 6.09 g/l. This is the first report on the optimization of the fermentation medium by RSM using CCH extract as the carbon source for BC production by G. hansenii UAC09.     

Biological activity of some steroidal compounds in the adult and larval frogs.

Four steroids were tested for their biological activity, using the sex-steroid-dependent redevelopment of the secondary sex characteristics in adult frogs and gonadal sex differentiation in larval frogs as end points. In adult frogs, 19-norprogesterone and 6-chloro-17alpha-hydroxy-4, 6-pregnadiene-3,20-dione had antiandrogenic and antiestrogenic effects. 2alpha, 17alpha-Dimethyl-DHT and 2alpha-methyl-DHT were potent androgens and effective antiestrogens. In the larval frogs, all four compounds had a masculinizing effect upon the undifferentiated gonads.     

Effect of seat belts on injuries to front and rear seat passengers.

Data on 2520 occupants of cars involved in accidents were analysed in relation to injury and the severity of the crash to investigate the effect of rear seat passengers on injury to restrained and unrestrained front seat occupants and vice versa. Unrestrained front seat occupants showed a higher incidence of serious injury when there were rear seat passengers. The presence of a rear seat passenger did not affect significantly the overall incidence of injury among restrained front seat occupants within the range of crash severity considered. Unrestrained rear seat passengers behind unrestrained front seat occupants showed a higher incidence of moderate injury and a lower incidence of no injury than those behind restrained front seat occupants. It is concluded that legislation on seat belts has not greatly increased the risk of person to person injury.     

Detection of reactive oxygen species (ROS) by the oxidant-sensing probe 2′,7′-dichlorodihydrofluorescein diacetate in the cyanobacterium Anabaena variabilis PCC 7937

The generation of reactive oxygen species (ROS) under simulated solar radiation (UV-B: 0.30 Wm⁻², UV-A: 25.70 Wm⁻² and PAR: 118.06 Wm⁻²) was studied in the cyanobacterium Anabaena variabilis PCC 7937 using the oxidant-sensing fluorescent probe 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA). DCFH-DA is a nonpolar dye, converted into the polar derivative DCFH by cellular esterases that are nonfluorescent but switched to highly fluorescent DCF when oxidized by intracellular ROS and other peroxides. The images obtained from the fluorescence microscope after 12 h of irradiation showed green fluorescence from cells covered with 295, 320 or 395 nm cut-off filters, indicating the generation of ROS in all treatments. However, the green/red fluorescence ratio obtained from fluorescence microscopic analysis showed the highest generation of ROS after UV-B radiation in comparison to PAR or UV-A radiation. Production of ROS was also measured by a spectrofluorophotometer and results obtained supported the results of fluorescence microscopy. Low levels of ROS were detected at the start (0 h) of the experiment showing that they are generated even during normal metabolism. This study also showed that UV-B radiation causes the fragmentation of the cyanobacterial filaments which could be due to the observed oxidative stress. This is the first report for the detection of intracellular ROS in a cyanobacterium by fluorescence microscopy using DCFH-DA and thereby suggesting the applicability of this method in the study of in vivo generation of ROS.     

Terpenoids from Cedrus deodara

A new novel type of phenolic sesquiterpene, himasecolone, has been isolated in addition to isopimaric acid from the chloroform-soluble fraction extract