scholarly journals In Vitro Antimicrobial Susceptibility of Clinical Isolates of Borrelia miyamotoi

2018 ◽  
Vol 62 (7) ◽  
pp. e00419-18 ◽  
Author(s):  
Joris Koetsveld ◽  
Annemijn Manger ◽  
Dieuwertje Hoornstra ◽  
Ronald O. Draga ◽  
Anneke Oei ◽  
...  

ABSTRACT Borrelia miyamotoi is an emerging relapsing fever (RF) Borrelia species that is reported to cause human disease in regions in which Lyme borreliosis is endemic. We recently showed that B. miyamotoi tick isolates are resistant to amoxicillin in vitro; however, clinical isolates have not been studied. Therefore, our aim was to show the antimicrobial susceptibility of recently obtained clinical isolates of B. miyamotoi. A dilution series of various antibiotics was made in modified Kelly-Pettenkofer medium with 10% fetal calf serum. The susceptibilities of different B. miyamotoi clinical, B. miyamotoi tick, RF Borrelia, and Borrelia burgdorferi sensu lato isolates were tested by measuring MICs through colorimetric changes and by counting motile spirochetes by dark-field microscopy after 72 h of incubation. The ceftriaxone and azithromycin MIC ranges of the six B. miyamotoi clinical isolates tested were 0.03 to 0.06 mg/liter and 0.0016 to 0.0032 mg/liter, respectively. These values are similar to MICs for RF Borrelia strains and B. miyamotoi tick isolates. All tested RF Borrelia strains were susceptible to doxycycline (microscopic MIC range, 0.0625 to 0.25 mg/liter). In contrast to the MICs of the tested B. burgdorferi sensu lato strains and in line with our previous findings, the amoxicillin MICs (range, 8 to 32 mg/liter) of all RF Borrelia strains, including B. miyamotoi clinical isolates, were above the clinical breakpoint for resistance (≤4 mg/liter). Clinical isolates of B. miyamotoi are highly susceptible to doxycycline, azithromycin, and ceftriaxone in vitro. Interestingly, as described previously for tick isolates, amoxicillin shows poor in vitro activity against B. miyamotoi clinical isolates.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam J. Replogle ◽  
Christopher Sexton ◽  
John Young ◽  
Luke C. Kingry ◽  
Martin E. Schriefer ◽  
...  

AbstractBorrelia spirochetes are the causative agents of Lyme borreliosis (LB) and relapsing fever (RF). Despite the steady rise in infections and the identification of new species causing human illness over the last decade, isolation of borreliae in culture has become increasingly rare. A modified Barbour-Stoenner-Kelly (BSK) media formulation, BSK-R, was developed for isolation of the emerging RF pathogen, Borrelia miyamotoi. BSK-R is a diluted BSK-II derivative supplemented with Lebovitz’s L-15, mouse and fetal calf serum. Decreasing the concentration of CMRL 1066 and other components was essential for growth of North American B. miyamotoi. Sixteen B. miyamotoi isolates, originating from Ixodes scapularis ticks, rodent and human blood collected in the eastern and upper midwestern United States, were isolated and propagated to densities > 108 spirochetes/mL. Growth of five other RF and ten different LB borreliae readily occurred in BSK-R. Additionally, primary culture recovery of 20 isolates of Borrelia hermsii, Borrelia turicatae, Borrelia burgdorferi and Borrelia mayonii was achieved in BSK-R using whole blood from infected patients. These data indicate this broadly encompassing borreliae media can aid in in vitro culture recovery of RF and LB spirochetes, including the direct isolation of new and emerging human pathogens.


2018 ◽  
Vol 56 (4) ◽  
pp. e01892-17
Author(s):  
Meredith A. Hackel ◽  
Joseph P. Iaconis ◽  
James A. Karlowsky ◽  
Daniel F. Sahm

ABSTRACT Ceftaroline fosamil was approved by the United States Food and Drug Administration in 2010 and by the European Medicines Agency in 2012. As of April 2017, only one commercial antimicrobial susceptibility testing device offered a Gram-negative panel that included ceftaroline. This circumstance is unfortunate, as many clinical microbiology laboratories rely solely on commercial devices to generate in vitro antimicrobial susceptibility testing results for common bacterial pathogens. In lieu of device-based testing of clinical isolates of Enterobacteriaceae, laboratories wishing to test ceftaroline must either opt for disk diffusion testing or use a gradient strip; however, both alternatives interrupt laboratory workflow and require additional labor and expense. Identification of a reliable surrogate β-lactam to predict in vitro susceptibility to ceftaroline may offer another interim solution as laboratories await availability of ceftaroline for testing on their commercial devices. We tested six β-lactams (aztreonam, ceftazidime, ceftriaxone, cefotaxime, cefoxitin, and cefpodoxime) as potential surrogates for ceftaroline against a collection of 543 clinical isolates of Enterobacteriaceae selected to approximate the distribution of ceftaroline MICs observed in AWARE global surveillance studies conducted in 2013. All six potential surrogates generated very major error rates of 16.3% to 56.6%, far exceeding the accepted limit of 1.5% set by the Clinical and Laboratory Standards Institute (CLSI) and the United States Food and Drug Administration (FDA) Center for Devices and Radiological Health. Failure to identify a reliable surrogate to predict in vitro susceptibility and resistance to ceftaroline for clinical isolates of Enterobacteriaceae underscores the need for expedited addition of newer antimicrobial agents to commercial antimicrobial susceptibility testing devices.


2017 ◽  
Vol 55 (4) ◽  
pp. 1025-1031 ◽  
Author(s):  
Kunatum Prasidthrathsint ◽  
Mark A. Fisher

ABSTRACTAntimicrobial susceptibility patterns from 599A. defectiva,G. adiacens, andG. elegansclinical isolates were determined by broth microdilution. We observed significant differences in susceptibility across species, particularly to penicillin and ceftriaxone, and across geographical regions.A. defectivawas the least susceptible species overall to penicillin. All isolates were susceptible to vancomycin and >90% were susceptible to levofloxacin.


2011 ◽  
Vol 75 (3) ◽  
pp. 429-433 ◽  
Author(s):  
F.G. Leivas ◽  
D.S. Brum ◽  
S.S. Fialho ◽  
W.P. Saliba ◽  
M.T.T. Alvim ◽  
...  

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Jana Holmar ◽  
Heidi Noels ◽  
Joachim Jankowski ◽  
Setareh Orth-Alampour

Abstract Background and Aims Vascular calcification (VC) is one major complication in patients with chronic kidney disease whereas a misbalance in calcium and phosphate metabolism plays a crucial role. The mechanisms underlying VC have not been entirely revealed to date. Therefore are the studies aiming at the identification and characterization of the mediators/uremic toxins involved in VC ongoing and highly relevant. However, currently many different protocols being used in the studies of vascular calcification processes. This complicates the comparison of study outcomes, composing systematic reviews, and meta-analyses. Moreover, the reproducibility of data is hampered, and the efficiency in calcification research through the lack of a standardized protocol is reduced. In this study, we developed a standardized operating protocol for in vitro and ex vivo approaches to aiming at the comparability of these studies. Method We analysed in vitro and ex vivo experimental conditions to study VC. Vascular smooth muscle cells (HAoSMCs) were used for in vitro experiments and aortas from Wistar rats were used for ex vivo experiments. The influence of the following conditions was studied in detail: • Phosphate and calcium concentrations in calcifying media. • Incubation time. • Fetal calf serum (FCS) concentration. The degree of calcification was estimated by quantification of calcium concentrations that were normalized to protein content (in vitro) or to the dry weight of the aortic ring (ex vivo). Additionally, the aortic rings were stained using the von Kossa method. Optimal conditions for investigating medial vascular calcification were detected and summarized in the step-by-step protocol. Results We were able to demonstrate that the degree and the location of VC in vascular smooth muscle cells and aortic rings were highly dependent on the phosphate and CaCl2 concentration in the medium as well as the incubation time. Furthermore, the VC was reduced upon increasing fetal calf serum concentration in the medium. An optimized protocol for studying vascular calcification in vitro and ex vivo was developed and validated. The final protocol (Figure 1) presented will help to standardize in vitro and ex vivo approaches to investigate the processes of vascular calcification. Conclusion In the current study, we developed and validated a standardized operating protocol for systematic in vitro and ex vivo analyses of medial calcification, which is essential for the comparability of the results of future studies.


2014 ◽  
Vol 58 (12) ◽  
pp. 7398-7404 ◽  
Author(s):  
Tamirat Gebru ◽  
Benjamin Mordmüller ◽  
Jana Held

ABSTRACTPlasmodium falciparumgametocytes are not associated with clinical symptoms, but they are responsible for transmitting the pathogen to mosquitoes. Therefore, gametocytocidal interventions are important for malaria control and resistance containment. Currently available drugs and vaccines are not well suited for that purpose. Several dyes have potent antimicrobial activity, but their use against gametocytes has not been investigated systematically. The gametocytocidal activity of nine synthetic dyes and four control compounds was tested against stage V gametocytes of the laboratory strain 3D7 and three clinical isolates ofP. falciparumwith a bioluminescence assay. Five of the fluorescent dyes had submicromolar 50% inhibitory concentration (IC50) values against mature gametocytes. Three mitochondrial dyes, MitoRed, dihexyloxacarbocyanine iodide (DiOC6), and rhodamine B, were highly active (IC50s < 200 nM). MitoRed showed the highest activity against gametocytes, with IC50s of 70 nM against 3D7 and 120 to 210 nM against clinical isolates. All compounds were more active against the laboratory strain 3D7 than against clinical isolates. In particular, the endoperoxides artesunate and dihydroartemisinin showed a 10-fold higher activity against 3D7 than against clinical isolates. In contrast to all clinically used antimalarials, several fluorescent dyes had surprisingly highin vitroactivity against late-stage gametocytes. Since they also act against asexual blood stages, they shall be considered starting points for the development of new antimalarial lead compounds.


2005 ◽  
Vol 17 (8) ◽  
pp. 751 ◽  
Author(s):  
Mona E. Pedersen ◽  
Øzen Banu Øzdas ◽  
Wenche Farstad ◽  
Aage Tverdal ◽  
Ingrid Olsaker

In this study the synthetic oviduct fluid (SOF) system with bovine oviduct epithelial cell (BOEC) co-culture is compared with an SOF system with common protein supplements. One thousand six hundred bovine embryos were cultured in SOF media supplemented with BOEC, fetal calf serum (FCS) and bovine serum albumin (BSA). Eight different culture groups were assigned according to the different supplementation factors. Developmental competence and the expression levels of five genes, namely glucose transporter-1 (Glut-1), heat shock protein 70 (HSP), connexin43 (Cx43), β-actin (ACTB) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), analysed as mRNA by using reverse transcription–polymerase chain reaction, were measured on bovine embryos cultured for 9 days. Gene expression of these in vitro-produced embryos was compared with the gene expression of in vivo-produced embryos. There was no significant difference found in embryo developmental competence between the Day 9 embryos in BOEC co-culture, FCS and BSA supplements in SOF media. However, differences in gene expression were observed. With respect to gene expression in in vivo and in vitro embryos, BOEC co-culture affected the same genes as did supplementation with FCS and BSA. HSP was the only gene that differed significantly between in vitro and in vivo embryos. When the different in vitro groups were compared, a significant difference between the BOEC co-culture and the FCS supplementation groups due to Glut-1 expression was observed.


2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Dae Hun Kim ◽  
Su-Young Kim ◽  
Hee Jae Huh ◽  
Nam Yong Lee ◽  
Won-Jung Koh ◽  
...  

ABSTRACT We evaluated the in vitro activity of rifamycin derivatives, including rifampin, rifapentine, rifaximin, and rifabutin, against clinical nontuberculous mycobacteria (NTM) isolates. Of the rifamycin derivatives, rifabutin showed the lowest MICs against all NTM species, including Mycobacterium avium complex, M. abscessus, and M. kansasii. Rifabutin also had effective in vitro activity against macrolide- and aminoglycoside-resistant NTM isolates. Rifabutin could be worth considering as a therapeutic option for NTM disease, particularly drug-resistant disease.


2021 ◽  
Vol 70 (7) ◽  
Author(s):  
Souad Belkacemi ◽  
Maryam Tidjani Alou ◽  
Saber Khelaifia ◽  
Didier Raoult

To date, the axenic culture of Treponema pallidum remains a challenge in the field of microbiology despite countless attempts. Here, we conducted a comprehensive bibliographic analysis using several databases and search engines, namely Pubmed, Google scholar, Google, Web of Science and Scopus. Numerous unsuccessful empiric studies have been conducted and evaluated using as criteria dark-field microscopic observation of motile spiral shaped cells in the culture and virulence of the culture through rabbit infectivity. All of these studies failed to induce rabbit infectivity, even when deemed positive after microscopic observation leading to the misnomer of avirulent T. pallidum . In fact, this criterion was improperly chosen because not all spiral shaped cells are T. pallidum . However, these studies led to the formulation of culture media particularly favourable to the growth of several species of Treponema, including Oral Microbiology and Immunology, Zürich medium (OMIZ), Oral Treponeme Enrichment Broth (OTEB) and T-Raoult, thus allowing the increase in the number of cultivable strains of Treponema . The predicted metabolic capacities of T. pallidum show limited metabolism, also exhibited by other non-cultured and pathogenic Treponema species, in contrast to cultured Treponema species. The advent of next generation sequencing represents a turning point in this field, as the knowledge inferred from the genome can finally lead to the axenic culture of T. pallidum .


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