Analysis of multiply antibiotic-resistant Acinetobacter baumannii belonging to Global Clone 1

Analysis of multiply antibiotic-resistant Acinetobacter baumannii belonging to Global Clone 1. A. baumannii resistant to multiple antibiotics challenges the treatment of infections caused by this organism. Multiply-antibiotic resistant isolates mainly belong to two major global clones GC1 and GC2. The objective of this study was to analyze the antibiotic resistance in Australian GC1s. Twenty six MAR GC1 isolates were recovered from Australian hospitals and examined to determine the genetic basis of their resistance. The results showed the variety of mobile elements, genomic islands, plasmids, transposons and insertion sequences that incorporate antibiotic resistance genes. AbaR islands were found to carry genes conferring resistance to multiple antibiotics. IS26-mediated deletions and homologous recombination between Tn6018 copies in the AbaR islands were shown to be responsible for generating new variants. AbaR0, the ancestor of AbaRs was found and all of the variants seen so far could be derived from it. Carbapenem resistance was rare but three strains carried the oxa23 carbapenem resistance gene in an AbaR4 island, which includes a backbone related to that of AbaR islands. In one isolate, AbaR4 was found where AbaR-type islands are usually found indicating that transposon backbone of AbaR4 can target the same position as AbaR0/AbaR3. The other two strains carried AbaR4 in a conjugative plasmid that can potentially disseminate the oxa23 gene into strains of different types. The small plasmid pRAY* was responsible for introducing the tobramycin resistance gene aadB into GC1s. Hence, this study shows the significance of plasmids incorporating additional determinants in GC1s. The most unexpected finding was horizontal transfer of DNA segments that contain ISAba1-ampC generating resistance to third generation cephalosporins. Overall, Australian GC1 isolates included a diverse collection. However, two outbreak GC1 strains were identified in a single ward of one of the Sydney hospitals. Outbreak strains persisted for a period of time and were then replaced by a GC2 strain

Analysis of multiply antibiotic-resistant Acinetobacter baumannii belonging to Global Clone 1

Analysis of multiply antibiotic-resistant Acinetobacter baumannii belonging to Global Clone 1. A. baumannii resistant to multiple antibiotics challenges the treatment of infections caused by this organism. Multiply-antibiotic resistant isolates mainly belong to two major global clones GC1 and GC2. The objective of this study was to analyze the antibiotic resistance in Australian GC1s. Twenty six MAR GC1 isolates were recovered from Australian hospitals and examined to determine the genetic basis of their resistance. The results showed the variety of mobile elements, genomic islands, plasmids, transposons and insertion sequences that incorporate antibiotic resistance genes. AbaR islands were found to carry genes conferring resistance to multiple antibiotics. IS26-mediated deletions and homologous recombination between Tn6018 copies in the AbaR islands were shown to be responsible for generating new variants. AbaR0, the ancestor of AbaRs was found and all of the variants seen so far could be derived from it. Carbapenem resistance was rare but three strains carried the oxa23 carbapenem resistance gene in an AbaR4 island, which includes a backbone related to that of AbaR islands. In one isolate, AbaR4 was found where AbaR-type islands are usually found indicating that transposon backbone of AbaR4 can target the same position as AbaR0/AbaR3. The other two strains carried AbaR4 in a conjugative plasmid that can potentially disseminate the oxa23 gene into strains of different types. The small plasmid pRAY* was responsible for introducing the tobramycin resistance gene aadB into GC1s. Hence, this study shows the significance of plasmids incorporating additional determinants in GC1s. The most unexpected finding was horizontal transfer of DNA segments that contain ISAba1-ampC generating resistance to third generation cephalosporins. Overall, Australian GC1 isolates included a diverse collection. However, two outbreak GC1 strains were identified in a single ward of one of the Sydney hospitals. Outbreak strains persisted for a period of time and were then replaced by a GC2 strain

A large conjugative Acinetobacter baumannii plasmid carrying the sul2 sulphonamide and strAB streptomycin resistance genes

Acinetobacter baumannii is an important nosocomial pathogen that often complicates treatment because of its high level of resistance to antibiotics. Though plasmids can potentially introduce various genes into bacterial strains, compared to other Gram-negative bacteria, information about the unique A. baumannii plasmid repertoire is limited. Here, whole genome sequence data was used to determine the plasmid content of strain A297 (RUH875), the reference strain for the globally disseminated multiply resistant A. baumannii clone, global clone 1(GC1). A297 contains three plasmids. Two known plasmids were present; one, pA297-1 (pRAY*), carries the aadB gentamicin, kanamycin and tobramycin resistance gene and another is an 8.7kb cryptic plasmid often found in GC1 isolates. The third plasmid, pA297-3, is 200kb and carries the sul2 sulphonamide resistance gene and strAB streptomycin resistance gene within Tn6172 and a mer mercuric ion resistance module elsewhere. pA297-3 transferred sulphonamide, streptomycin and mercuric ion resistance at high frequency to a susceptible A. baumannii recipient, and contains several genes potentially involved in conjugative transfer. However, a relaxase gene was not found. It also includes several genes encoding proteins involved in DNA metabolism such as partitioning. However, a gene encoding a replication initiation protein could not be found. pA297-3 includes two copies of a Miniature Inverted-Repeat Transposable Element (MITE), named MITE-297, bracketing a 77.5kb fragment, which contains several IS and the mer module. Several plasmids related to but smaller than pA297-3 were found in the GenBank nucleotide database. They were found in different A. baumannii clones and are wide spread. They all contain either Tn6172 or a variant in the same position in the backbone as Tn6172 in pA297-3. Some related plasmids have lost the segment between the MITE-297 copies and retain only one MITE-297. Others have segments of various lengths between two MITE-297 copies, and these can be derived from the region in pA297-3 via a deletion adjacent to IS related to IS26 such as IS1007 or IS1007-like. pA297-3 and its relatives represent a third type of conjugative Acinetobacter plasmid that contributes to the dissemination of antibiotic resistance in this species.NHMR

Fauna and the distribution of mosquitoes (Diptera: Culicidae) in Chahar Mahal and Bakhtiari province, 2011-2012

زمینه و هدف: پشه‌ها خانواده‌ی بزرگی از دوبالان را شامل می‌شوند که به لحاظ توانایی انتقال انواع عوامل بیماری‌زا در پزشکی و بهداشت اهمیت فراوانی دارند. این مطالعه به منظور تکمیل اطلاعات موجود در زمینه‌ی تنوع گونه‌ای و انتشار پشه‌های بومی استان چهارمحال و بختیاری انجام گرفته است. روش بررسی: این پژوهش توصیفی و مقطعی در طول تابستان 1390 و 1391 در تمامی شهرستان‌های استان چهارمحال و بختیاری انجام گردید. نمونه‌ها به روش ملاقه زنی جمع آوری و با استفاده از کلیدهای معتبر شناسایی شدند. داده‌های تعیین هویت و مختصات جغرافیایی نقاط نمونه برداری در نرم افزار ArcGIS 10 وارد گردید تا نقشه‌ی پراکندگی هر یک از گونه‌ها به دست آید. یافته ها: در این مطالعه، 8335 لارو از 92 زیستگاه لاروی جمع آوری گردید که به 18 گونه شامل کولیستا لانجی آرئولاتا، کولیستا ساب اوکریا، اوکلروتاتوس کاسپیوس سنسولاتو، کولکس تیلری، کولکس تریتانس، کولکس هورتنزیس، کولکس پیپینس، کولکس پرگزیگوس، کولکس میمتیکوس، کولکس ترای تنیورینکوس، کولکس اربیینی، کولکس لاتیسینکتوس، آنوفل ماکولیپنیس سنسولاتو، آنوفل سوپرپیکتوس، آنوفل دتالی، آنوفل مارتری، آنوفل کلاویژر و آنوفل تورکودی تعلق داشتند. کولکس تریتانس به عنوان یک گونه‌ی جدید برای استان چهارمحال و بختیاری گزارش می‌گردد. کولکس تیلری و آنوفل سوپرپیکتوس بیش ترین فراوانی و گسترده ترین انتشار را در استان نشان دادند. نتیجه گیری: این مطالعه نشان می‌دهد که برخی از مهم ترین پشه‌های ناقل بیماری‌ها در سطح استان چهارمحال و بختیاری از تنوع و پراکندگی وسیعی برخوردار هستند. برای تعیین توانایی پشه‌های بومی در انتقال عوامل بیماری زا در استان به مطالعات بیشتری نیاز است

Vertical Distribution, Biodiversity, and Some Selective Aspects of the Physicochemical Characteristics of the Larval Habitats of Mosquitoes (Diptera: Culicidae) in Chaharmahal and Bakhtiari Province, Iran

Background and aims: Mosquitoes (Diptera: Culicidae) are still a focus of research because of their role in the transmission of diseases and annoying biting behavior. Source reduction is an effective measure to control mosquito populations, which is based on good knowledge of larval habitats. This study was conducted to obtain that basic knowledge in Chaharmahal and Bakhtiari province. Methods: This study was carried out in 2011 and 2012. Geographical coordinates, altitude, pH, temperature, and the dissolved oxygen level of larval habitats were recorded by relevant devices, followed by documenting physical attributes by direct observation. In addition, the indices of biodiversity were calculated to analyze the vertical biodiversity of species. Finally, the affinity index was calculated to elucidate species co-occurrence. Results: Eighteen species were recovered from 92 larval habitats. Low- (≤ 1400 m), mid- (1401–2000 m), and high- (≥ 2001 m) altitudes lodged 7, 17, and 14 species, respectively. Further, the indices of the species richness and biodiversity for these altitudinal categories were 0.93, 1.94, and 1.58, as well as 1.54, 2.13, and 1.96, respectively. Larval habitats were mostly natural, temporary, with standing but clear water, muddy substrate, sunlit, and with vegetation. Other physicochemical characteristics and affinity of species were described and discussed as well. Conclusion: To the best of our knowledge, this is the first report of vertical distribution and biodiversity of mosquito larvae in Iran. The relative uniformity of physicochemical characteristics of larval habitats was attributed to prevailing water resources in the studied area and sampling design. The oviposition site selection of gravid mosquitoes is still an unresolved problem which needs further investigations. Keywords:Elevation diversity gradient Breeding place Oviposition sit

Evaluating the Performance of Forecasting Models for Portfolio Allocation Purposes with Generalized GRACH Method

Portfolio theory assumes that investors accept risk. This means thatin the equal rate of return on the two assets, the assets were chosenthat have a lower risk level. Modern portfolio theory is accepted byinvestors who believe that they are not cope with the market. Sothey keep many different types of securities in order to access theoptimum efficiency rate that is close to the rate of return on market.One way to control investment risk is establishing the portfolioshares. There are many ways to choose the optimal portfolioshares. Among these methods in this study we use loss functions.For this, we choose all firms from the year2011to the end of 2015that had been a member in the Tehran Stock Exchange. The resultsof this research show that the likelihood functions have the bestperformance in Forecasting the optimal portfolio allocationprob-lem

Forecasting the Profitability in the Firms Listed in Tehran Stock Exchange Using Data Envelopment Analysis and Artificial Neural Network

Profitability as the most important factor in decision-making, has always been considered by stake­holders in the company's profitability. Also can be a basis for evaluating the performance of the managers. The ability to predict the profitability can be very useful to help decision-makers. That's why one of the most important issues is the expected profitability. The importance of these forecasts depends on the amount of misalignment with reality. The amount of deviation is less than the forecast of higher accuracy. Although there are various methods for predicting but the use of artificial intelligence techniques is increasing due to fewer restriction. The aim of this study is to evaluate the predictive power of profitability using DEA and neutral network, to enhance the decision-making users of 2012 to 2015of 7 premier financial ratios were used as independent variables. Test results show that both of ANN and DEA have ability to forecast profitability and given that neutral network prediction accuracy is higher than the DEA, the model predict better the profitability of companies

Five decades of genome evolution in the globally distributed, extensively antibiotic-resistant Acinetobacter baumannii global clone 1.

The majority of Acinetobacter baumannii isolates that are multiply, extensively and pan-antibiotic resistant belong to two globally disseminated clones, GC1 and GC2, that were first noticed in the 1970s. Here, we investigated microevolution and phylodynamics within GC1 via analysis of 45 whole-genome sequences, including 23 sequenced for this study. The most recent common ancestor of GC1 arose around 1960 and later diverged into two phylogenetically distinct lineages. In the 1970s, the main lineage acquired the AbaR resistance island, conferring resistance to older antibiotics, via a horizontal gene transfer event. We estimate a mutation rate of ∼5 SNPs genome- 1 year- 1 and detected extensive recombination within GC1 genomes, introducing nucleotide diversity into the population at >20 times the substitution rate (the ratio of SNPs introduced by recombination compared with mutation was 22). The recombination events were non-randomly distributed in the genome and created significant diversity within loci encoding outer surface molecules (including the capsular polysaccharide, the outer core lipooligosaccharide and the outer membrane protein CarO), and spread antimicrobial resistance-conferring mutations affecting the gyrA and parC genes and insertion sequence insertions activating the ampC gene. Both GC1 lineages accumulated resistance to newer antibiotics through various genetic mechanisms, including the acquisition of plasmids and transposons or mutations in chromosomal genes. Our data show that GC1 has diversified into multiple successful extensively antibiotic-resistant subclones that differ in their surface structures. This has important implications for all avenues of control, including epidemiological tracking, antimicrobial therapy and vaccination

Genome Sequence of Acinetobacter baumannii Strain D36, an Antibiotic-Resistant Isolate from Lineage 2 of Global Clone 1.

Multiply antibiotic-resistant Acinetobacter baumannii isolate D36 was recovered in Australia in 2008 and belongs to a distinct lineage of global clone 1 (GC1). Here, we present the complete 4.13 Mbp genome sequence (chromosome plus 4 plasmids), generated via long read sequencing (PacBio)