Comparison of cyp141 and IS6110 for detection of mycobacterium tuberculosis from clinical specimens by PCR

Tuberculosis is a major public health problem throughout the world. TB's worldwide patterns of prevalence coupled with the increase in incidence of HIV infection threaten the health and lives of humans worldwide. Rapid detection of TB and the rapidly initiation of the administration of medication are important strategies for stopping the transmission of this disease transmission and its resistance to anti-TB drugs. Molecular methods are advantageous relative to conventional techniques due to their greater speed and sensitivity in the detection of TB. In this study, we targeted the cyp141 gene for the detection of Mycobacterium tuberculosis from clinical specimens [n = 123] by PCR and compared the sensitivity and specificity of this new target with those of IS6110 gene. Targeting of the cyp141 gene is more sensitive [97.1% for cultured isolates and 85.7% for direct specimens] than the targeting of the commonly used IS6110 gene [95.1% for cultured isolates and 42.9% for direct specimens], and the specificities of these two target genes were equal [100%]. The cyp141 gene can be used as a new target for the direct detection of Mycobacterium tuberculosis that seems to be superior to IS6110

Drug resistance pattern of Mycobacterium tuberculosis isolates from patients of five provinces of Iran

OBJECTIVE@#To determine the patterns of resistance to first line anti-tuberculosis (TB) drugs among a collection of Mycobacterium tuberculosis (MTB) isolates from 5 provinces of Iran.@*METHODS@#A total of the 6 426 clinical specimens from patients suspected of active TB were collected from March 2010 to June 2012. All specimens were subjected for microscopy and culture tests in the TB centers of studies provinces. Drug susceptibility testing to the first line anti-TB drugs for culture positive MTB was performed on Löwenstein-Jensen (LJ) medium using proportion method.@*RESULTS@#Of 6 426 clinical specimens, 261 were culture positive for mycobacteria, of which 252 were MTB and 9 were MOTT (mycobacteria other than tuberculosis). Of 252 MTB isolates, 211 (83.7%) were pan-susceptible and 41 (16.3%) were resistant to at least one drug. Resistance was most common to streptomycin, 30 isolates (12.0%), followed by isoniazid, 20 isolates (8.0%), rifampin, 15 isolates (6.0%) and ethambutol, 14 isolates (5.5%). Sixteen (6.3%) MTB isolates were MDR. A clear evidence of heterogeneity amongst the 5 provinces in the proportions with resistance to one or more drugs was observed [χ(2); = 12.209 (4 degrees of freedom), P values = 0.015 9].@*CONCLUSIONS@#The prevalence of drug resistance in this study area underscoring the need for further enforcement of TB control strategies in the Iran. Drug susceptibility testing for all TB cases to provide optimal treatment, establishing advanced diagnostic facilities for rapid detection of MDR-TB and continuous monitoring of drug resistance are recommended for prevention and control of drug-resistant TB.

prevalence of ESBL isolates of acinetobacter baumannii using pulsed-field gel electrophoresis

Antibiotics such as fluoroquinolones are used for treating infections caused by Gram-negative bacteria, including Acinetobacter baumannii strains some time have extended-spectrum beta-lactamase [ESBL], but ESBL production is rather rare. Resistance to fluoroquinolones antibiotics is mediated by lactamases and other mechanisms of resistance. The aim of the present study was to investigate of the prevalence of ESBL production and clonal relatedness of A. baumannii in Iran. A. baumannii isolates identified from patients at hospitals in Kermanshah, Iran, were studied. The double disk method was used for detection of ESBL production. The susceptibility to different antibiotics was determined by the disk diffusion method [CLSI]. Clonal relatedness was determined by pulsed-field gel electrophoresis [PFGE] and processed by Bionumerics 7.0 software. Statistical analyses were performed using SPSS-16.0. This study showed high prevalence of resistance to ampicillin and cefpodoxim [98.1 and 92.3%]. Fifty-two of the 84 isolates were identified as ESBL producers. Only colistin and tigecycline remained active against all isolates tested. The PFGE identified eight distinct pulsotypes: A [N=9], B [N=10], C [N=2], D [N=5], E [N=9], F [N=15], G [N=1] and H [N=1]. The PFGE profiles A, B and F were believed to be endemic [specially clone F that was dominant across different wards of the hospitals and appeared to be endemic] in the ICU, emergency, pediatric and infection area throughout the years. Early and timely detection of ESBL-producing A. baumannii clones is useful for preventing their spread within the hospital. PFGE analysis is helpful for detection of common strains in different wards and prevention of further spread of these pulsotypes to other hospital environment

Heterogeneity of Iranian clinical isolates of Mycobacterium fortuitum

The increase of infections caused by nontuberculous mycobacteria [NTM] is receiving increasing attention worldwide. Mycobacterium fortuitum is encountered with increasing frequency in clinical laboratories of Iran. Sequence variation of 48 M. fortuitum clinical isolates, were investigated by sequence analysis of the 16S-23S Internal Transcribed Spacer. Twelve different sequence types [sequevar] were identified by sequence analysis of ITS region. Seven previously described sequevar including MfoA, MfoB, MfoC, MfoD, MfoE, MfoF and MfoG identified. Five novel sequevar namely MfoH, MfoI, MfoJ, MfoK and MfoL that were distinctly different from the previously described sequevar were detected among different clinical strains of M. fortuitum, from Iran. This study showed that the ITS region possesses high discriminatory power between the clinical isolates up to the clonal level. The results also suggest the possibility of the existence of predominant clone of M. fortuitum in affected patients in Iran. The data also point to the conclusion that a large variety of M. fortuitum clone can produce disease although certain clones seem to be predominant

Genetic structure change in harvard vaccine strain of clostridium tetani for the period of 1990 to 2010 by pulsed-field gel electrophoresis

PFGE facilitates the differential migration of large DNA fragments through agarose gel by constantly changing the direction of the electrical field during electrophoresis. Possibility of high difference between strains and repeatability make PFGE one of the strong molecular methods in study of bacterial strains in epidemiology. To identifying and DNA fingerprinting of vaccine strain of Clostridium tetani by PFGE technique. Also, possibility of genotyping profile changes in frequency of vaccine strain of C. tetani during the period of 1990 to 2011. The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute in Karaj. The seeds were inoculated into Columbia blood agar and grown for 72 h. The cultures were incubated at 35[degree]C in anaerobic conditions. The PFGE analyses were performed using genomic DNA digested with the restriction enzyme SmaI. The electrophoresis analyses were carried out on a CHEF DR III apparatus [Bio Rad] and band patterns obtained were then analyzed. The PFGE profile obtained from vaccine strain during a period of more than two decades revealed no remarkable genetic changes and mutations. This type of analysis provides detailed data useful for surveillance of vaccine strains and isolates as well as for the selection of certain predominant profiles for further investigation. This study showed no considerable change in chromosomal genome of Harvard, the vaccine strain. It is therefore concluded that the vaccine produced by Razi Institute had evidently no alteration or modification in accordance to PFGE profile analysis during a period of more than two decades

Increase in prevalence of vancomycin resistant isolates of Enterococcous faecium at Labbafinejad hospital

Vancomycin resistant isolates of Enterococcous faecium [VRE] have previously been reported from Tehran Hospitals. However, little data were available on the genetic heterogeneity of VRE isolates among the Iranian population. Therefore the emergence of infections with the new clones of VRE needs to be investigated. The drug resistance surveillance program at Labbafinejad hospital has to be continued. Overall, 103 non-replicative isolates of enterococci grown from urine samples in the first quarter of 2005 were screened for their susceptibilities to different antibiotics. Ribotyping was then used to genetically characterize the isolates of VRE. Using disk diffusion method, all isolates were found susceptible to linezolid. Resistance to high level concentration of gentamicin was detected in 65.7% of isolates. All isolates of F. faecalis [n=86] were susceptible to vaneomycin. Conversely, over 70% of E. faecium isolates [n=12] showed resistance to this glycopeptide. The VRE isolates recovered from patients in 2005 were heterogeneous comparing with those of 2000. Conventional bacteriology confirmed the increase in the rate of VRE. It appears that a variety of new VRE clones have arisen recently at different wards of this hospital as determined by ribotyping

Antibiotic resistance patterns and genetic analysis of klebsiella pneumoniae isolates from the respiratory tract

Klebsiella pneumoniae is a pathogenic bacterium causing nosocomial infections in particular severe respiratory tract infections. Little information is available on the antibiotic susceptibility of pulmonary isolates of Klebsiella spp. The aims of this study were to determine the antibiotic resistance patterns and prevalence of extended-spectrum Beta-lactamase [ESBLs] producing Kleb. Among the respiratory isolates and to detect the possible clonal outbreaks associated with them. The respiratory isolates of K. pneumoniae [n=33] received from two Tehran hospitals during 2002-2005 were evaluated. Disk diffusion was used to determine the susceptibility of isolates to 14 antibiotics. Phenotypic confirmatory and double disk synergy methods were used to detect extended spectrum ?-lactamase producing isolates [ESBLs]. Respiratory isolates were then analyzed by multilocus enzyme electrophoresis [MLEE]. ESBL phenotype was detected in 75.75% of the isolates. The most effective antibiotic was imipenem followed by tazobactam/piperacillin. MLEE analysis revealed 13 electrophoretic types [ETs]. The locus leucine-tyrosine peptidase showed the highest genetic diversity [0.733]. These 33 respiratory isolates consisted of 16.5% Klebsiella pneumoniae. This rate is lower than the neighboring country, Turkey [35%]. However, ESBL-producing strains belonging to different genetic lineages are serious concerns at Tehran hospitals. Carbapenem is still considered one of the most effective antibiotics against multi-drug resistant isolates

Bactericidal effects of essential oils from clove, lavender and geranium on multi-drug resistant isolates of Pseudomonas aeruginosa

The inhibitory effects of essential oils including clove, lavender and geranium extracted from Eugenia caryophyllata, Lavandula officinalis and Pelargonium graveolens on multi-drug resistant isolates of Pseudomonas aeruginosa were investigated. The main constituents of clove, lavander and geranium oil were eugenol [80-90%], 1,8-cineol [13%] and citronellol [45%] respectively. Clove had the most effective essential oil against P. aeruginosa. A combination consisting of clove, lavender and geranium oils at a ratio of 3:1:1 showed the most inhibitory effect [32-64 microg/ml] and strong synergy with gentamicin. The essential oils from clove, lavender and geranium exhibited bactericidal activity against multi-drug resistant strains of P. aeruginosa and may be alternatives compounds against these strains in the future