scholarly journals Nontuberculous Mycobacteria in Guadeloupe, Martinique, and French Guiana from 1994 to 2012

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Elisabeth Streit ◽  
Julie Millet ◽  
Nalin Rastogi
Keyword(s):  
French Guiana ◽  
Nontuberculous Mycobacteria ◽  
Clinical Specimen ◽  
Distribution Patterns ◽  
Drug Susceptibility ◽  
Geographical Variations ◽  
Common Group ◽  
Human Infections ◽  
Changes Over Time

Nontuberculous mycobacteria (NTM) are ubiquitous environmental organisms able to cause severe opportunistic human infections. Their distribution patterns are subject to geographical variations. This study describes their isolation frequencies from clinical specimen in the three French overseas departments of the Americas, namely, Guadeloupe, Martinique, and French Guiana during 1994–2012. A total of 651 strains from as many patients (one isolate per species per patient) were analysed regarding regional isolation patterns and potential pattern changes over time. TheMycobacterium aviumcomplex was the most common group of NTM in Guadeloupe and French Guiana. In Martinique it was the second most common after the rapidly growing mycobacteria.M. fortuitumwas the most commonly isolated species in all three departments. Some species (M. kansasii,M. xenopi, andM. terraecomplex) displayed a clear regional preference. Furthermore a change in isolation frequency was observed forM. intracellulare(increase) andM. kansasii(decrease) in Guadeloupe. In conclusion, marked regional differences in isolation frequencies of NTM species were observed in the study area. Results are discussed in context of variables such as study populations, risk factors, methodology employed, isolation from pulmonary versus sterile isolation sites (blood, urine, and CSF), and in vitro drug-susceptibility patterns.

scholarly journals Drug Susceptibility Distributions of Mycobacterium chimaera and Other Nontuberculous Mycobacteria

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Bettina Schulthess ◽  
Daniel Schäfle ◽  
Nicole Kälin ◽  
Tamara Widmer ◽  
Peter Sander
Keyword(s):  
Antibiotic Susceptibility ◽  
Nontuberculous Mycobacteria ◽  
Drug Susceptibility ◽  
Species Differentiation ◽  
Content Type ◽  
Susceptibility Data ◽  
Clinical Breakpoints ◽  
Antibiotic Susceptibility Patterns ◽  
Definition Of

ABSTRACT Recent outbreaks of cardiac surgery-associated Mycobacterium chimaera infections have highlighted the importance of species differentiation within the Mycobacterium avium complex and pointed to a lack of antibiotic susceptibility data for M. chimaera. Using the MGIT 960/EpiCenter TB eXiST platform, we have determined antibiotic susceptibility patterns of 48 clinical M. chimaera isolates and 139 other nontuberculous mycobacteria, including 119 members of the M. avium complex and 20 Mycobacterium kansasii isolates toward clofazimine and other drugs used to treat infections with slow-growing nontuberculous mycobacteria (NTM). MIC50, MIC90, and tentative epidemiological cutoff (ECOFF) values for clofazimine were 0.5 mg/liter, 1 mg/liter, and 2 mg/liter, respectively, for M. chimaera. Comparable values were observed for other M. avium complex members, whereas lower MIC50 (≤0.25 mg/liter), MIC90 (0.5 mg/liter), and ECOFF (1 mg/liter) values were found for M. kansasii. Susceptibility to clarithromycin, ethambutol, rifampin, rifabutin, amikacin, moxifloxacin, and linezolid was in general similar for M. chimaera and other members of the M. avium complex, but increased for M. kansasii. The herein determined MIC distributions, MIC90, and ECOFF values of clofazimine for M. chimaera and other NTM provide the basis for the definition of clinical breakpoints. Further studies are needed to establish correlation of in vitro susceptibility and clinical outcome.

scholarly journals In Vitro Monitoring of Plasmodium falciparum Drug Resistance in French Guiana: a Synopsis of Continuous Assessment from 1994 to 2005

2007 ◽  
Vol 52 (1) ◽  
pp. 288-298 ◽  
Author(s):  
Eric Legrand ◽  
Béatrice Volney ◽  
Jean-Baptiste Meynard ◽  
Odile Mercereau-Puijalon ◽  
Philippe Esterre
Keyword(s):  
Plasmodium Falciparum ◽  
French Guiana ◽  
Control Program ◽  
Drug Susceptibility ◽  
Warning Signs ◽  
Strongly Correlated ◽  
First Line ◽  
Drug Pressure ◽  
Line Drug

ABSTRACT Implemented as one arm of the malaria control program in French Guiana in the early 1990s, our laboratory has since established in vitro profiles for parasite drug susceptibility to a panel of eight antimalarials for more than 1,000 Plasmodium falciparum isolates from infected patients. The quinine-doxycycline combination was introduced in 1995 as the first-line drug treatment against uncomplicated P. falciparum malaria, replacing chloroquine, and the first-line drug combination was changed to the artemether-lumefantrine combination in 2002. Resistance to chloroquine declined 5 years after it was dropped in 1995 as the first-line drug, but unlike similar situations in Africa, there was a rapid halt to this decline. Doxycycline susceptibility substantially decreased from 2002 to 2005, suggesting parasite selection under quinine-doxycycline drug pressure. Susceptibility to mefloquine decreased from 1997 onward. Throughout the period from 1994 to 2005, most isolates were sensitive in vitro to quinine, amodiaquine, and atovaquone. Susceptibility to amodiaquine was strongly correlated with that to chloroquine and to a lesser extent with that to mefloquine and halofantrine. Susceptibilities to mefloquine and to halofantrine were also strongly correlated. There were two alerts issued for in vitro artemether resistance in the period from 2002 to 2003 and again in 2005, both of which could be associated with the presence of an S769N polymorphism in the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA)-type P. falciparum ATPase6 (PfATPase6) gene. Analysis of susceptibility to lumefantrine, conducted for the first time in 2005, indicates an alarming rate of elevated 50% inhibitory concentrations. In vitro monitoring of parasite drug susceptibility should be pursued to further document the consequences of specific drug policies on the local parasite population and, in particular, to establish profiles of susceptibility to individual components of drug combinations to provide early warning signs of emerging parasite resistance.

scholarly journals Discordant Temporal Evolution ofPfcrtandPfmdr1Genotypes and Plasmodium falciparum In Vitro Drug Susceptibility to 4-Aminoquinolines after Drug Policy Change in French Guiana

2012 ◽  
Vol 56 (3) ◽  
pp. 1382-1389 ◽  
Author(s):  
Eric Legrand ◽  
Joséphine Yrinesi ◽  
Marie-Thérèse Ekala ◽  
Julie Péneau ◽  
Béatrice Volney ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Drug Policy ◽  
French Guiana ◽  
Target Genes ◽  
Gene Copy Number ◽  
Drug Susceptibility ◽  
Gene Copy ◽  
Poor Correlation ◽  
Content Type

ABSTRACTAnalysis of the evolution of drug target genes under changing drug policy is needed to assist monitoring ofPlasmodium falciparumdrug resistance in the field. Here we genotypePfcrtandPfdmr1of 700 isolates collected in French Guiana from 2000 (5 years after withdrawal of chloroquine) to 2008, i.e., the period when the artemether-lumefantrine combination was progressively introduced and mefloquine was abandoned. Gene sequencing showed fixation of the 7G8-typePfcrtSMVNT resistance haplotype and near fixation of the NYCDYPfdmr1haplotype.Pfdmr1gene copy number correlated with 50% inhibitory concentrations of mefloquine and halofantrine (r= 0.64 and 0.47, respectively,n= 547); its temporal changes paralleled changes inin vitromefloquine susceptibility. However, the molecular parameters studied did not account for the regainedin vitrosusceptibility to chloroquine and showed a poor correlation with susceptibility to artemether, lumefantrine, or quinine. Identification of novel markers of resistance to these antimalarials is needed in this South American area.

scholarly journals A Bacterially-Expressed Recombinant Envelope Protein from Usutu Virus Induces Neutralizing Antibodies in Rabbits

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 157
Author(s):  
Kinga Böszörményi ◽  
Janet Hirsch ◽  
Gwendoline Kiemenyi Kayere ◽  
Zahra Fagrouch ◽  
Nicole Heijmans ◽  
...  
Keyword(s):  
Envelope Protein ◽  
Neutralizing Antibodies ◽  
Size Exclusion ◽  
Vitro Assay ◽  
Usutu Virus ◽  
Transmission Electron ◽  
Exclusion Chromatography ◽  
Efficacious Vaccine ◽  
Human Infections

Background: Recently, an emerging flavivirus, Usutu virus (USUV), has caused an epidemic among birds in Europe, resulting in a massive die-off in Eurasian blackbirds. Currently found only in Europe and Africa, it can be envisioned that Usutu virus will follow the path of other flaviviruses, like West Nile virus and Zika virus, and will spread via its mosquito vectors and bird hosts to other parts of the world. Several cases of human infections by Usutu virus have already been published. Anticipating this spread, development of an efficacious vaccine would be highly desirable. Method: This study describes the production in E. coli, purification, and refolding of a partial USUV envelope protein. Prior to immunization, the protein was characterized using size exclusion chromatography, transmission electron microscopy and dynamic light scattering, showing the limited presence of virus-like structures, indicating that the protein solution is probably a mixture of mono and multimeric envelope proteins. Results: Immunizations of two rabbits with the refolded E-protein fraction, mixed with a strong adjuvant, resulted in the generation of neutralizing antibodies, as evidenced in an in vitro assay. Discussion: The way forward towards a subunit vaccine against Usutu virus infection is discussed.

Bacteriophage-host depth distribution patterns in soil are maintained after nutrient stimulation in vitro

2021 ◽  
Vol 787 ◽  
pp. 147589
Author(s):  
Xiaolong Liang ◽  
Yusong Wang ◽  
Ying Zhang ◽  
Bingxue Li ◽  
Mark Radosevich
Keyword(s):  
Depth Distribution ◽  
Distribution Patterns

scholarly journals Assessment of the Drug Susceptibility of Plasmodium falciparum Clinical Isolates from Africa by Using a Plasmodium Lactate Dehydrogenase Immunodetection Assay and an Inhibitory Maximum Effect Model for Precise Measurement of the 50-Percent Inhibitory Concentration

2006 ◽  
Vol 50 (10) ◽  
pp. 3343-3349 ◽  
Author(s):  
Halima Kaddouri ◽  
Serge Nakache ◽  
Sandrine Houzé ◽  
France Mentré ◽  
Jacques Le Bras
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Lactate Dehydrogenase ◽  
Active Metabolite ◽  
Inhibitory Concentration ◽  
Drug Susceptibility ◽  
Maximum Effect ◽  
Malaria Parasites ◽  
Effect Model

ABSTRACT The extension of drug resistance among malaria-causing Plasmodium falciparum parasites in Africa necessitates implementation of new combined therapeutic strategies. Drug susceptibility phenotyping requires precise measurements. Until recently, schizont maturation and isotopic in vitro assays were the only methods available, but their use was limited by technical constraints. This explains the revived interest in the development of replacement methods, such as the Plasmodium lactate dehydrogenase (pLDH) immunodetection assay. We evaluated a commercially controlled pLDH enzyme-linked immunosorbent assay (ELISA; the ELISA-Malaria antigen test; DiaMed AG, Cressier s/Morat, Switzerland) to assess drug susceptibility in a standard in vitro assay using fairly basic laboratory equipment to study the in vitro resistance of malaria parasites to major antimalarials. Five Plasmodium falciparum clones and 121 clinical African isolates collected during 2003 and 2004 were studied by the pLDH ELISA and the [8-3H]hypoxanthine isotopic assay as a reference with four antimalarials. Nonlinear regression with a maximum effect model was used to estimate the 50% inhibitory concentration (IC50) and its confidence intervals. The two methods were observed to have similar reproducibilities, but the pLDH ELISA demonstrated a higher sensitivity. The high correlation (r = 0.98) and the high phenotypic agreement (κ = 0.88) between the two methods allowed comparison by determination of the IC50s. Recently collected Plasmodium falciparum African isolates were tested by pLDH ELISA and showed drug resistance or decreased susceptibilities of 62% to chloroquine and 11.5% to the active metabolite of amodiaquine. No decreased susceptibility to lumefantrine or the active metabolite of artemisinin was detected. The availability of this simple and highly sensitive pLDH immunodetection assay will provide an easier method for drug susceptibility testing of malaria parasites.

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