ABSTRACT
This review is devoted to the mechanisms of antibiotic resistance in mollicutes (class Bacilli, subclass Mollicutes), the smallest self-replicating bacteria, that can cause diseases in plants, animals and humans, and also contaminate cell cultures and vaccine preparations. Research in this area has been mainly based on the ubiquitous mollicute and the main contaminant of cell cultures, Acholeplasma laidlawii. The omics technologies applied to this and other bacteria have yielded a complex picture of responses to antimicrobials, including their removal from the cell, the acquisition of antibiotic resistance genes and mutations that potentially allow global reprogramming of many cellular processes. This review provides a brief summary of well-known resistance mechanisms that have been demonstrated in several mollicutes species and, in more detail, novel mechanisms revealed in A. laidlawii, including the least explored vesicle-mediated transfer of short RNAs with a regulatory potency. We hope that this review highlights new avenues for further studies on antimicrobial resistance in these bacteria for both a basic science and an application perspective of infection control and management in clinical and research/production settings.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Tenericutes/drug effects , Biomedical Research/trendsABSTRACT
Acholeplasma laidlawii is a well-suited model for studying the molecular basis for adapting mollicutes to environmental conditions. Here, we present the whole-genome sequences of two strains of A. laidlawii with increased resistance to tetracycline and melittin.
ABSTRACT
Acholeplasma laidlawii is a well-suited model for study of the molecular basis of the adaptation of mollicutes to environmental conditions. Here we present the whole-genome sequences of four strains of A. laidlawii with differential sensitivity to ciprofloxacin.
ABSTRACT
Mycoplasmas (class Mollicutes), the smallest prokaryotes capable of self-replication, as well as Archaea, Gram-positive and Gram-negative bacteria constitutively produce extracellular vesicles (EVs). However, little is known regarding the content and functions of mycoplasma vesicles. Here, we present for the first time a proteomics-based characterisation of extracellular membrane vesicles from Acholeplasma laidlawii PG8. The ubiquitous mycoplasma is widespread in nature, found in humans, animals and plants, and is the causative agent of phytomycoplasmoses and the predominant contaminant of cell cultures. Taking a proteomics approach using LC-ESI-MS/MS, we identified 97 proteins. Analysis of the identified proteins indicated that A. laidlawii-derived EVs are enriched in virulence proteins that may play critical roles in mycoplasma-induced pathogenesis. Our data will help to elucidate the functions of mycoplasma-derived EVs and to develop effective methods to control infections and contaminations of cell cultures by mycoplasmas. In the present study, we have documented for the first time the proteins in EVs secreted by mycoplasma vesicular proteins identified in this study are likely involved in the adaptation of bacteria to stressors, survival in microbial communities and pathogen-host interactions. These findings suggest that the secretion of EVs is an evolutionally conserved and universal process that occurs in organisms from the simplest wall-less bacteria to complex organisms and indicate the necessity of developing new approaches to control infects.
Subject(s)
Acholeplasma laidlawii/metabolism , Bacterial Proteins/chemistry , Proteome/chemistry , Transport Vesicles/metabolism , Virulence Factors/chemistry , Amino Acid Sequence , Extracellular Fluid/metabolism , Molecular Sequence Data , MycoplasmaABSTRACT
This study demonstrated that extracellular membrane vesicles are involved with the development of resistance to fluoroquinolones by mycoplasmas (class Mollicutes). This study assessed the differences in susceptibility to ciprofloxacin among strains of Acholeplasma laidlawii PG8. The mechanisms of mycoplasma resistance to antibiotics may be associated with a mutation in a gene related to the target of quinolones, which could modulate the vesiculation level. A. laidlawii extracellular vesicles mediated the export of the nucleotide sequences of the antibiotic target gene as well as the traffic of ciprofloxacin. These results may facilitate the development of effective approaches to control mycoplasma infections, as well as the contamination of cell cultures and vaccine preparations.
Subject(s)
Acholeplasma laidlawii/drug effects , Adaptation, Physiological , Anti-Bacterial Agents/pharmacology , Ciprofloxacin/pharmacology , Genes, Bacterial , Mutation , Acholeplasma laidlawii/genetics , Acholeplasma laidlawii/physiology , Amino Acid Sequence , Anti-Bacterial Agents/pharmacokinetics , Base Sequence , Biological Transport , Ciprofloxacin/pharmacokinetics , DNA Topoisomerase IV/chemistry , DNA Topoisomerase IV/genetics , DNA, Bacterial , Microbial Sensitivity Tests , Microscopy, Atomic Force , Microscopy, Electron, Transmission , Molecular Sequence Data , Sequence Homology, Amino Acid , Sequence Homology, Nucleic AcidABSTRACT
The Mycoplasma hominis vaa gene encodes a highly variable surface antigen involved in adhesion to host cells. We studied 15 clinical isolates of Mycoplasma hominis with three types of the vaa gene. These vaa versions determine various forms of Vaa protein, which are characterized by different quantity and structure of homologous replaceable cassettes. Each cassette contains heptad repeats and sites for adherence. The differences on single nucleotides were observed in the primary sequences of the homologous modules of the vaa gene. A high frequency of nucleotide replacements in V module of the vaa gene (first and/or second position in codon) was determined. This region with various clusters of direct and indirect repeats of nucleotide sequences is incorporated into the area of the vaa gene. Amino-acid sequences corresponding to the hyper-variable region of the vaa gene are associated with the sections of coiled-coils and loops of Vaa. These bacterial regions involved in interaction with the host cell membranes could yield useful indications for more insights into the mechanism of mycoplasma persistence in humans.