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Maureen Laroche, Jean-Michel Berenger, Oleg Mediannikov, Didier Raoult, Philippe Parola
BACKGROUND: Among the Reduviidae family, triatomines are giant blood-sucking bugs. They are well known in Central and South America where they transmit Trypanosoma cruzi to mammals, including humans, through their feces. This parasitic protozoan is the causative agent of Chagas disease, a major public health issue in endemic areas. Because of the medical and economic impact of Chagas disease, the presence of other arthropod-borne pathogens in triatomines was rarely investigated. METHODOLOGY/PRINCIPAL FINDINGS: In this study, seven triatomines species involved in the transmission of T...
January 17, 2017: PLoS Neglected Tropical Diseases
Hui Xia, Yang Zheng, Bing Zhao, Susan van den Hof, Frank Cobelens, YanLin Zhao
OBJECTIVE: To evaluate the performance of the Sensitire MYCOTB MIC Plate (MYCOTB) which could measure the twelve anti-tuberculosis drugs susceptibility on one 96-wells plate. METHODS: A total of 140 MDR-TB strains and 60 non-MDR strains were sub-cultured and 193 strains were finally tested for drug resistance using MYCOTB and agar proportion method (APM) and another 7 strains failed of subculture. The drugs included ofloxacin (Ofx), moxifloxacin (Mfx), rifampin (RFP), amikacin (Am), rifabutin (Rfb), para-aminosalicylic acid (PAS), ethionamide (Eth), isoniazid (INH), kanamycin (Km), ethambutol (EMB), streptomycin (Sm), and cycloserine(Cs)...
2017: PloS One
Bright Varghese, Mushira Enani, Mohammed Shoukri, Sahar AlThawadi, Sameera AlJohani, Sahal Al-Hajoj
BACKGROUND: Clinical relevance of nontuberculous mycobacteria (NTM) is increasing worldwide including in Saudi Arabia. A high species diversity of NTM's has been noticed in a recent study. However, the identification in diagnostic laboratories is mostly limited to common species. The impact of NTM species diversity on clinical outcome is so far neglected in most of the clinical settings. METHODOLOGY/PRINCIPAL FINDINGS: During April 2014 to September 2015, a nationwide collection of suspected NTM clinical isolates with clinical and demographical data were carried out...
January 11, 2017: PLoS Neglected Tropical Diseases
Prabha Desikan, Atul Kharate, Nikita Panwalkar, Jyoti Khurana, Shaina Beg Mirza, Aparna Chaturvedi, Reeta Varathe, Manju Chourey, Pradeep Kumar, Nitin Doshi, Manoj Pandey
BACKGROUND: The spread of drug-resistant tuberculosis has challenged tuberculosis control strategies globally. The present study aims to analyze the frequency of mutations in rpoB, katG and inhA genes in strains of M. tuberculosis complex (MTBC) circulating in Central India. It is anticipated that the findings may provide a starting point to understand the evolutionary success of drug-resistant strains of MTBC in this region. METHODS: Line probe assay was carried out on 720 consecutive sputum samples of MDR suspects from June 2012 to May 2013...
December 2016: Germs
D Ricaboni, M Mailhe, J-C Lagier, C Michelle, N Armstrong, F Bittar, V Vitton, A Benezech, D Raoult, M Million
Strain Marseille-P2915(T), a Gram-positive, facultative anaerobic and nonmotile coccus, was isolated from the gastric lavage of a patient with severe anaemia. The 16S rRNA and rpoB gene comparison exhibited a sequence identity of 98.7 and 92.6% with Streptococcus infantis strain JCM 10157(T), respectively, collocating it within the 'Streptococcus mitis' group. On the basis of phenotypic and genomic analysis, we propose the validation of the type strain Streptococcus timonensis sp. nov. Marseille-P2915T (= DSM 103349 = CSUR P2915)...
January 2017: New Microbes and New Infections
Parissa Farnia, Donya Malekshahian, Payam Tabarsi, Shima Seif, Ali Akbar Velayati
OBJECTIVE BACKGROUND: Mycobacterium simiae has been identified as the most prevalent slow growing mycobacteria that has been isolated among Iranian patients. Due to an importance of molecular approaches in the treatment of nontuberculosis mycobacteria, this study aimed to evaluate molecular drug susceptibility testing against the first-line (rifampin and isoniazid) and second-line (ciprofloxacin-amikacin and kanamycin) treatment in different subtypes of M. simiae. METHODS: The study involved all patients presenting to our referral tuberculosis center from March 2014 to August 2016, with confirmation of M...
December 2016: International Journal of Mycobacteriology
Hasnain Javed, Nazia Jamil, Tomasz Jagielski, Zofia Bakuła, Zarfishan Tahir
BACKGROUND: GenoType MTBDRplus is a molecular assay for detection of Mycobacterium tuberculosis resistance to isoniazid (INH) and rifampicin (RMP), the two major anti-tuberculosis (TB) drugs. Identification of INH resistance is largely based on the occurrence of mutations in the katG gene, coding for the catalase-peroxidase, or in the promoter region of the inhA gene, coding for the NADH-dependent enoyl-ACP reductase. For testing the RMP resistance, mutations in the rpoB gene, coding for the RNA polymerase β subunit, particularly in the RMP resistance determining region (RRDR) of the gene are investigated...
December 2016: International Journal of Mycobacteriology
Ernest A Ochang, Ubong A Udoh, Ubleni E Emanghe, Gerald O Tiku, Jonah B Offor, Micheal Odo, Emmanuel Nkombe, Oju E Owuna, Sunday M Obeten, Martin M Meremikwu
OBJECTIVE/BACKGROUND: World Health Organization tuberculosis (TB) indices from 2014 to 2016 showed that Nigeria had the 6th highest prevalence, 4th highest incidence, and the highest mortality rate globally. In efforts to improve TB care, the XpertMTB/Rif (GeneXpert) technology, Cepheid, Sunnyvale, California, USA, which has revolutionized TB detection with concomitant rifampicin-resistance molecular detection, was introduced in Cross River State, South-South Nigeria, in 2014. The GeneXpert uses molecular beacons to detect five overlapping 81-bp regions in the rpoB gene known as the Rifampicin Resistant Determinant Region (RRDR)...
December 2016: International Journal of Mycobacteriology
Anand K Maurya, Vijaya L Nag, Surya Kant, Ramawadh S Kushwaha, Tapan N Dhole
OBJECTIVE/BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is a major public health problem. The diagnosis of MDR-TB is of paramount importance in establishing appropriate clinical management and infection control measures. Rapid detection of MDR-TB allows the establishment of an effective treatment regimen, minimizes the risk of further resistance, and limits the spread of drug-resistant strains. The aim of this study is to determine the genotypic characterization of MDR-TB isolates from extra pulmonary tuberculosis (EPTB) cases in tertiary care centers in Northern India...
December 2016: International Journal of Mycobacteriology
Amit Singh, Anil Kumar Gupta, Krishnamoorthy Gopinath, Divakar Sharma, Prashant Sharma, Deepa Bisht, Pawan Sharma, Sarman Singh
AIM & OBJECTIVE: In India, tuberculosis (TB) is a foremost health problem, and the emergence of multidrug-resistant (MDR) and extensively drug resistant (XDR) strains of Mycobacterium tuberculosis (M. tuberculosis) has further complicated the situation. Although various mechanisms have been proposed to elucidate the emergence of resistance, our knowledge remains insufficient. The formation of a very complex network and drugs of proteins are countered by their efflux/modification or target over-expression/modification...
December 2016: International Journal of Mycobacteriology
M Cameron, H W Barkema, J De Buck, S De Vliegher, M Chaffer, J Lewis, G P Keefe
This study evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) for the identification of bovine-associated coagulase-negative staphylococci (CNS), a heterogeneous group of different species. Additionally, we aimed to expand the MALDI-ToF MS database with new reference spectra as required to fill the gaps within the existing commercial spectral library. A total of 258 isolates of CNS were used in the study, covering 16 different CNS species. The majority of the isolates were previously identified by rpoB gene sequencing (n = 219), and the remainder were identified by sequencing of 16S rRNA, hsp60, or both rpoB and hsp60...
December 29, 2016: Journal of Dairy Science
Ana L Diéguez, Sabela Balboa, Thorolf Magnesen, Jesús L Romalde
Nine isolates obtained from a great scallop hatchery in Norway were characterized using a polyphasic approach. Strains were Gram-negative, aerobic and motile rods with oxidative metabolism. Phylogenetic analysis based on the sequences of 16S rRNA and rpoB genes showed that these strains formed two different groups associated with members of the genus Neptuniibacter. DNA-DNA hybridization (DDH) and Average Nucleotide Identity (ANI) demonstrated that the isolates constituted two novel species of this genus, which can be phenotypically differentiated from their closest relatives...
December 21, 2016: Systematic and Applied Microbiology
Shaoxing Chen, Yao Xu, Li-Xia Ke
A novel extremely halophilic archaeon, strain Y73T was isolated from a salt mine in Yunnan, China. Colonies formed on solid medium were circular (2-3 mm in diameter) with smooth, orange, glistening and convex (~1 mm in elevation). Cells were Gram-stain-negative, non-motile and pleomorphic. Mg2+ was required for growth (optimum at 0.05 M). Optimal growth was observed at 20 % (w/v) NaCl, 42-45 °C and pH 7.5-8.5 in aerobic conditions. The result of sequence similarity searching of 16S rRNA gene showed that strain Y73T was closely related to Halorubrum halophilum B8T (identity: 98...
December 29, 2016: International Journal of Systematic and Evolutionary Microbiology
Vadim Molodtsov, Nathan T Scharf, Maxwell A Stefan, George A Garcia, Katsuhiko S Murakami
Since 1967, Rifamaycin (RIF) has been used as a first line antibiotic treatment for tuberculosis (TB), and it remains the cornerstone of current short-term TB treatment. Increased occurrence of RIF-resistant (RIF(R) ) TB, ∼41% of which results from the RpoB S531L mutation in RNA polymerase (RNAP), has become a growing problem worldwide. In this study, we determined the X-ray crystal structures of the Escherichia coli RNAPs containing the most clinically important S531L mutation and two other frequently observed RIF(R) mutants, RpoB D516V and RpoB H526Y...
December 23, 2016: Molecular Microbiology
Virginia Post, Llinos Harris, Mario Morgenstern, R Geoff Richards, Samuel K Sheppard, Fintan Moriarty
Nasal colonization with methicillin-resistant Staphylococcus aureus is poorly described for surgeons, despite the increased exposure to nosocomial pathogens and at-risk patients. This study investigated the molecular epidemiology and antimicrobial resistance of 26 MRSA isolates cultured from the nares of an international cross-sectional study of 1,166 human and 60 veterinary surgeons. All isolates were subjected to agr-, spa- and MLST typing and the presence of 22 virulence factors were screened for by PCR...
December 21, 2016: Journal of Medical Microbiology
Huagang Peng, Qiwen Hu, Weilong Shang, Jizhen Yuan, Xiaopeng Zhang, Hui Liu, Ying Zheng, Zhen Hu, Yi Yang, Li Tan, Shu Li, Xiaomei Hu, Ming Li, Xiancai Rao
OBJECTIVES: Vancomycin-intermediate Staphylococcus aureus (VISA) strains have spread globally. We previously isolated an ST239 VISA (XN108) with a vancomycin MIC of 12 mg/L. The mechanism for XN108 resistance to vancomycin was investigated in this study. METHODS: Genome comparison was performed to characterize mutations that might contribute to the XN108 resistance phenotype. The novel mutation WalK(S221P) was identified and investigated using allelic replacement experiments...
December 20, 2016: Journal of Antimicrobial Chemotherapy
Anna Rominski, Anna Roditscheff, Petra Selchow, Erik C Böttger, Peter Sander
OBJECTIVES: Rifampicin, a potent first-line TB drug of the rifamycin group, shows only little activity against the emerging pathogen Mycobacterium abscessus. Reportedly, bacterial resistance to rifampicin is associated with polymorphisms in the target gene rpoB or the presence of enzymes that modify and thereby inactivate rifampicin. The aim of this study was to investigate the role of the MAB_0591 (arrMab)-encoded rifampicin ADP-ribosyltransferase (Arr_Mab) in innate high-level rifampicin resistance in M...
December 20, 2016: Journal of Antimicrobial Chemotherapy
Emmanuel Andre, Léonie Goeminne, Alexandre Colmant, Patrick Beckert, Stefan Niemann, Michel Delmee
OBJECTIVES: Neither the liquid medium-based Bactec MGIT, nor commercial molecular assays such as the Xpert MTB/RIF and the MTBDRplus V2.0 assays are capable of detecting up to 30% of rifampicin-resistant Mycobacterium tuberculosis (MTB) strains in Swaziland due to the large proportion of the rpoB Ile491Phe mutation. In other countries, the frequency of this mutation is thought to be low. METHODS: We designed a real-time multiplex allele-specific (MAS) PCR assays to identify the rpoB Ile491Phe mutation responsible for these undetected resistant MTB strains...
December 17, 2016: Clinical Microbiology and Infection
Marina V Efimova, Radomira Vankova, Victor V Kusnetsov, Raisa P Litvinovskaya, Ilya E Zlobin, Petre Dobrev, Nina P Vedenicheva, Alina L Savchuk, Raisa A Karnachuk, Natalia V Kudryakova, Vladimir V Kuznetsov
In order to evaluate whether brassinosteroids (BS) and green light regulate the transcription of plastid genes in a cross-talk with cytokinins (CKs), transcription rates of 12 plastid genes (ndhF, rrn23, rpoB, psaA, psaB, rrn16, psbA, psbD, psbK, rbcL, atpB, and trnE/trnY) as well as the accumulation of transcripts of some photoreceptors (PHYA, CRY2, CRY1A, and CRY1B) and signaling (SERK and CAS) genes were followed in detached etiolated barley leaves exposed to darkness, green or white light ±1μm 24-epibrassinolide (EBL)...
December 18, 2016: Steroids
Ivy Rukasha, Halima M Said, Shaheed V Omar, Hendrik Koornhof, Andries W Dreyer, Alfred Musekiwa, Harry Moultrie, Anwar A Hoosen, Gilla Kaplan, Dorothy Fallows, Nazir Ismail
Treatment of tuberculosis (TB) and HIV co-infections is often complicated by drug-to-drug interactions between anti-mycobacterial and anti-retroviral agents. Rifabutin (RFB) is an alternative to rifampin (RIF) for TB regimens and is recommended for HIV patients concurrently receiving protease inhibitors because of reduced induction of CYP3A4. This study sought to determine the proportion of RFB susceptible isolates among RIF-resistant strains in a high HIV prevalence setting in South Africa. In addition, the study explored the association between rpoB mutations and minimum inhibitory concentrations (MIC) of RIF and RFB...
2016: Frontiers in Microbiology
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