The Spread of Insertion Sequences Element and Transposons in Carbapenem Resistant Acinetobacter baumannii in a Hospital Setting in Southwestern Iran / 감염과화학요법

Background@#Acinetobacter baumannii is one of the most important hospital pathogenic bacteria that cause infectious diseases. The present study aimed to determine the frequency of carbapenem resistance genes in association with transposable elements and molecular typing of carbapenem-resistant A. baumannii bacteria collected from patients in Shiraz, Iran. @*Materials and Methods@#A total of 170 carbapenem-resistant A. baumannii isolates were obtained from different clinical specimens in two hospitals. The minimum inhibitory concentrations (MIC) of imipenem were determined and the prevalence of OXA Carbapenemases, Metalloβ-lactamases genes, insertion sequences (IS) elements, and transposons were evaluated by the polymerase chain reaction (PCR) method. Finally, molecular typing of the isolates was performed by the Enterobacterial Repetitive Intergenic Consensus-PCR method. @*Results@#The MICs ranged from 16 to 1,024 µg/mL for imipenem-resistant A. baumannii isolates. Out of the 170 carbapenem resistant A. baumannii isolates, bla OXA-24-like (94, 55.3%) followed by bla OXA-23-like (71, 41.7%) were predominant. In addition, A. baumannii isolates carried bla VIM (71, 41.7%), bla GES (32, 18.8%), bla SPM (4, 2.3%), and bla KPC (1, 0.6%). Moreover, ISAba1 (94.2%) and Tn2009 (39.2%) were the most frequent transposable elements. Furthermore, (71, 44.0%) and (161, 94.7%) of the ISAba1 of the isolates were associated with bla OXA-23 and bla OXA-51 genes, respectively. Besides (3, 1.7%), (1, 0.6%) and (5, 2.9%) of bla OXA-23 were associated with IS18, ISAba4, and ISAba2, respectively. Considering an 80.0% cut off, clusters and four singletons were detected. @*Conclusion@#According to the results, transposable elements played an important role in the development of resistance genes and resistance to carbapenems. The results also indicated carbapenem-resistant A. baumannii bacteria as a public health concern.

Possible molecular mechanisms for paramecium learning

Learning is a cornerstone of intelligent behavior in animals. This behavior has been mostly studied in organisms with a fairly complex nervous system. However, recent reports of learning in unicellular organisms suggested the existence of associative learning in unicellular organisms. In particular, the capability to associate different light intensities with cathodal stimulation in paramecium is of special interest. We have investigated the previous reports on this phenomenon and proposed a molecular mechanism for learning behavior in paramecium. Specifically, we have used the existing evolutionary evidence in order to find the possible molecular pathways that may play a role in Paramecium's learning. Moreover, previous studies have been reviewed in order to propose new experiments that can verify the plausibility of the present hypothesis

Molecular identification of giardia duodenalis isolates from Fars province, Iran

Giardia duodenalis is one of the most common human intestinal protozoan parasites worldwide and is endemic throughout the world with a vast range of mammalian hosts. The present study aimed to identify the prevalence of G. duodenalis isolates and determine the most common of its assemblages in the patients referring to health centers and hospitals in Fars province, Iran that will be subjected to further molecular investigation. We collected 1000 human fecal samples from health centers and hospitals in Shiraz, Iran in a one year period from September 2009 to August 2010. Microscopic examination for the presence of G. duodenalis cysts and trophozoites was performed by direct wet mount before and after the concentration techniques. Extraction of DNA was performed by Phenol-Chloroform-Isoamylalcohol [PCI]. G. duodenalis-Positive, specimens were analyzed by PCR. A fragment of the SSU-rDNA [292 bp] gene was amplified by PCR using the forward primer RH11 and the reverse primer RH4. Genotyping was performed using sequence analysis of G. duodenalis glutamate dehydrogenase gene using primers GDHeF, GDHiF, and GDHiR. The prevalence of Giardia infection was 10.7% [107/1000] examined based on microscopic examination. PCR identified 80% [40/50] of the samples as positive for G. duodenalis based on SSU-rDNA amplification on sucrose gradient samples. Besides, genotyping results indicated 32 isolates [80%] as assemblage All and 8 isolates [20%] as assemblage Bill and BIV based on the DNA sequence analysis of the glutamate dehydrogenase locus of G. duodenalis. The findings of this study emphasize that Iran [Fars Province] is a favorable area for giardiasis with an anthroponotic infection route

Performance of latex agglutination test [KAtex] in diagnosis of visceral leishmaniasis in Iran

Visceral leishmaniasis [VL] is an endemic disease in some parts of Iran. Many techniques have been used for diagnosis of VL, among which the urine based latex agglutination test [KAtex] is a promising one. To compare three diagnostic tests of VL including KAtex, ELISA and Direct Agglutination Test [DAT] in VL patients and healthy controls in the south west of Iran. Serum [n = 29] and urine samples [n = 31] were collected from parasitologically confirmed VL patients. Control samples were obtained from healthy individuals [n = 61] and also from patients with infectious diseases other than VL. The collected serum samples were tested by DAT and ELISA using crude antigen from promastigotes of Leishmania infantum and the urine samples were tested by KAtex. Sensitivity and specificity of KAtex for diagnosis of VL was found to be 83.9% and 100%, respectively. Sensitivities of DAT and ELISA were 93.1% and 86.2% and their specificities were 100% and 90.5%, respectively. KAtex yielded a satisfactory sensitivity and specificity in diagnosis of VL in Iran and can be recommended as a rapid, field applicable and reliable test for diagnosis of VL in this region

[Application of superior enzymatic systems for characterization of causative agents of visceral leishmaniasis [kala-azar] in Iran using isoenzyme electrophoresis]

Visceral leishmaniasis [Kala-azar] is one of the parasitic zoonotic diseases which is caused by Leishmania donovani complex parasites. Thus, the aim of this study is the application of different enzymatic systems for discrimination species and strains visceral leishmaniasis agent. In this experimental study, reference strains of Leishmania infatum, Leishmania major, Leishmania tropica in addition, the leishmania parasites isolated from bone marrow of subjects and internal organs of dogs infected to visceral leishmaiasis [VL] were inoculated on RPMI + FBS 10% medium for mass cultivation. Then, using electrophoresis on polyacrilamid gel, six enzymatic systems including GPI, PGM, MDH, G6PD, 6PGD and NH2 were examined in order that identification of species and strains of the isolates and thus finding the appropriate enzymatic systems for discrimination of these compared with reference strains. Isoenzymatic profile of six enzymatic systems mentioned above for these isolates were compared with reference strains and also relative migration were calculated. Finally, the results were showed that only five enzymatic systems, except 6PGD, had discriminated ability of different species. In the present study, GPI and G6PD enzymes had the most heterogeneity while NH2 enzyme had the most homogeneity. Moreover, PGM, GPI and MDH were highly active enzymes

Comparison of serological methods [ELISA, DAT and IFA] for diagnosis of visceral leishmaniasis utilizing an endemic strain

The causative agent of visceral leishmaniasis [VL] in Iran is Leishmania infantum [L. infantum] [Mediterranean type] and its major reservoir host is the dog. To compare the serological methods including direct agglutination test [DAT], indirect immunofluorescent-antibody test [IFA] and enzyme-linked immunosorbent assay [ELISA] for serodiagnosis of endemic strain of L. infantum. 61 blood samples from VL patients referred to Shiraz hospitals and 49 blood samples from control group were collected. Native strain of the parasite isolated from a VL patient from the region was cultured and characterized. Antigens from this L. infantum parasite were used in ELISA and IFA system. Anti-Leishmania antibody was detected in 43 [70.5%], 49 [80.3%] and 51 [83.6%] cases using DAT, IFA and ELISA, respectively. Based on these results, sensitivity and specificity of DAT was found to be 70.5% and 100%, respectively. Sensitivities of IFA and ELISA in diagnosis of VL were 80.3% and 83.6% and their specificity was 90.5%. Results of this study showed that DAT and ELISA have the highest specificity and sensitivity in diagnosis of VL. DAT is a simple, cost-effective and field applicable test. Thus, it can be recommended for early and accurate diagnosis of VL, especially in regions where malaria, brucellosis and tuberculosis are prevalent