Anti-Mycoplasma Activity of Daptomycin and Its Use for Mycoplasma Elimination in Cell Cultures of Rickettsiae

Wiwit Tantibhedhyangkul,Jintapa Sueasuay,Naharuthai Inthasin,Ekkarat Wongsawat,Sutthicha Matamnan,Yupin Suputtamongkol

doi:10.3390/antibiotics8030123

Wiwit Tantibhedhyangkul, Jintapa Sueasuay + Show 4 more

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https://doi.org/10.3390/antibiotics8030123

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Journal: Antibiotics	Publication Date: Aug 21, 2019
Citations: 3	License type: CC BY 4.0

Affiliation: Siriraj Hospital, Mahidol University

Abstract

Mycoplasma contamination detrimentally affects cellular functions and the growth of intracellular pathogens in cell cultures. Although several mycoplasmacidal agents are commercially available for sterile cell cultures, they are not applicable to rickettsia-infected cells. In our attempt to find an anti-mycoplasma drug for contaminated rickettsial cultures, we determined the susceptibilities of three common Mycoplasma species to daptomycin. Mycoplasma orale and M. arginini showed low-level resistance to daptomycin (minimum inhibitory concentration, MIC = 2 mg/L), whereas M. hyorhinis was high-level resistant (MIC = 32 mg/L). However, some Mycoplasma isolates developed higher resistance to daptomycin after failed treatments with inadequate doses or durations. An aminoglycoside (gentamicin) was still active against M. hyorhinis and could be used in Orientia cultures. For complete eradication of mycoplasmas in Rickettsia cultures, we recommend a 3-week treatment with daptomycin at 256 mg/L. In contaminated Orientia cultures, daptomycin at 32 mg/L was effective in eradicating M. orale, whereas either gentamicin or amikacin (100 mg/L) was effective in eradicating M. hyorhinis. Unlike each drug alone, the combinations of daptomycin plus clindamycin and/or quinupristin/dalfopristin proved effective in eradicating M. hyorhinis. In summary, our study demonstrated the in vitro anti-mycoplasma activity of daptomycin and its application as a new mycoplasma decontamination method for Rickettsia and Orientia cultures.

Highlights

Mycoplasma organisms are a serious threat during cell culture because they grow well extracellularly in vitro, contaminate cell lines for a long time without being recognized, and spread to other cell lines
Mycoplasma contamination may not affect the growth of cell lines, but it usually interferes with the cellular response [1] and inhibits the growth of intracellular pathogens, including Rickettsia and Orientia [4]
We summarized the antimicrobial susceptibilities of common mycoplasma species to other antibiotics that may be used for mycoplasma decontamination

Summary

Introduction

Mycoplasma organisms are a serious threat during cell culture because they grow well extracellularly in vitro, contaminate cell lines for a long time without being recognized, and spread to other cell lines. It has been reported that approximately 15–35% of continuous cell lines are contaminated by mycoplasmas [1]. The common Mollicutes species causing cell culture contamination include M. orale, M. arginini, M. hyorhinis, M. hominis, M. fermentans, and Acholeplasma laidlawii [3]. Mycoplasma contamination may not affect the growth of cell lines, but it usually interferes with the cellular response [1] and inhibits the growth of intracellular pathogens, including Rickettsia and Orientia [4]. Mycoplasma organisms are the smallest bacteria with the smallest genomes [2]. More than 100 Mycoplasma species have been identified, some of which are pathogenic in humans or animals [5]. The best-known pathogenic mycoplasmas in humans are M. pneumoniae and M. genitalium

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