Mycoplasma infections are frequent in humans, as well as in a broad range of animals. However, antimicrobial treatment options are limited, partly due to the lack of a cell wall in these peculiar ...bacteria. Both veterinary and human medicines are facing increasing resistance prevalence for the most commonly used drugs, despite different usage practices. To date, very few reviews have integrated knowledge on resistance to antimicrobials in humans and animals, the latest dating back to 2014. To fill this gap, we examined, in parallel, antimicrobial usage, resistance mechanisms and either phenotype or genotype-based methods for antimicrobial susceptibility testing, as well as epidemiology of resistance of the most clinically relevant human and animal mycoplasma species. This review unveiled common features and differences that need to be taken into consideration in a "One Health" perspective. Lastly, two examples of critical cases of multiple drug resistance are highlighted, namely, the human
and the animal
species, both of which can lead to the threat of untreatable infections.
Mycoplasma genitalium is a sexually transmitted organism commonly treated with azithromycin. However, macrolide resistance has been reported and is associated with point mutations in the 23S rRNA ...gene. To evaluate the prevalence of macrolide resistance in M. genitalium isolates from clinical specimens from France, we first used a previously reported high-resolution melting assay. Because susceptible and resistant M. genitalium isolates were hardly discriminated in M. genitalium-positive clinical specimens, we developed a new molecular assay for the rapid detection of macrolide resistance. An assay using real-time PCR based on fluorescence resonance energy transfer (FRET) coupled with melting curve analysis was designed. The assay was first validated on characterized macrolide-resistant M. genitalium isolates and then applied to 202 urogenital M. genitalium-positive specimens collected from 178 patients from France in 2011 and 2012. Resistant genotypes were confirmed by 23S rRNA gene sequencing. Among the 202 M. genitalium-positive specimens, 155 were amplified, demonstrating a sensitivity of 76.7%. A substitution in the 23S rRNA gene was found in 14.2% of the patient samples. Nine and six patients had M. genitalium isolates with a substitution at positions 2059 and 2058, respectively. In four cases, a mixed population of wild-type and mutated M. genitalium isolates was observed. The prevalence of M. genitalium macrolide resistance has been stable in France since its detection in 2006. Our FRET PCR assay is able to discriminate between wild-type and resistant genotypes directly from clinical specimens. This assay will allow clinicians to shorten the time to the initiation of effective disease treatment.
Inflammasomes are intracellular multiprotein signaling complexes that activate Caspase-1, leading to the cleavage and secretion of IL-1β and IL-18, and ultimately host cell death. Inflammasome ...activation is a common cellular response to infection; however, the consequences of inflammasome activation during acute infection and in the development of long-term protective immunity is not well understood. To investigate the role of the inflammasome in vivo, we engineered a strain of Listeria monocytogenes that ectopically expresses Legionella pneumophila flagellin, a potent activator of the Nlrc4 inflammasome. Compared with wild-type L. monocytogenes, strains that ectopically secreted flagellin induced robust host cell death and IL-1β secretion. These strains were highly attenuated both in bone marrow-derived macrophages and in vivo compared with wild-type L. monocytogenes. Attenuation in vivo was dependent on Nlrc4, but independent of IL-1β/IL-18 or neutrophil activity. L. monocytogenes strains that activated the inflammasome generated significantly less protective immunity, a phenotype that correlated with decreased induction of antigen-specific T cells. Our data suggest that avoidance of inflammasome activation is a critical virulence strategy for intracellular pathogens, and that activation of the inflammasome leads to decreased long-term protective immunity and diminished T-cell responses.
We report 5 cases of vascular Q fever complicated by polymicrobial superinfection in patients who had no risk factors for acute Q fever. Q fever was diagnosed by serologic and molecular assays for ...Coxiella burnetii. We confirmed additional infections using conventional graft cultures.
The human respiratory tract pathogen M. pneumoniae is one of the best characterized minimal bacterium. Until now, two main groups of clinical isolates of this bacterium have been described (types 1 ...and 2), differing in the sequence of the P1 adhesin gene. Here, we have sequenced the genomes of 23 clinical isolates of M. pneumoniae. Studying SNPs, non-synonymous mutations, indels and genome rearrangements of these 23 strains and 4 previously sequenced ones, has revealed new subclasses in the two main groups, some of them being associated with the country of isolation. Integrative analysis of in vitro gene essentiality and mutation rates enabled the identification of several putative virulence factors and antigenic proteins; revealing recombination machinery, glycerol metabolism and peroxide production as possible factors in the genetics and physiology of these pathogenic strains. Additionally, the transcriptomes and proteomes of two representative strains, one from each of the two main groups, have been characterized to evaluate the impact of mutations on RNA and proteins levels. This study has revealed that type 2 strains show higher expression levels of CARDS toxin, a protein recently shown to be one of the major factors of inflammation. Thus, we propose that type 2 strains could be more toxigenic than type 1 strains of M. pneumoniae.
We report a disseminated infection caused by Spiroplasma apis, a honeybee pathogen, in a patient in France who had X-linked agammaglobulinemia. Identification was challenging because initial ...bacterial cultures and direct examination by Gram staining were negative. Unexplained sepsis in patients with agammaglobulinemia warrants specific investigation to identify fastidious bacteria such as Spiroplasma spp.
ABSTRACT
The pathogenicity of
Mycoplasma hominis
is poorly understood, mainly due to the absence of efficient genetic tools. A polyethylene glycol-mediated transformation protocol was recently ...developed for the
M. hominis
reference strain M132 using the pMT85-Tet plasmid. The transformation efficiency remained low, hampering generation of a large mutant library. In this study, we improved transformation efficiency by designing
M. hominis
-specific pMT85 derivatives. Using the Gibson Assembly, the
Enterococcus
-derived
tet
(M) gene of the pMT85-Tet plasmid was replaced by that of a
M. hominis
clinical isolate. Next, the
Spiroplasma
-derived spiralin gene promoter driving
tet
(M) expression was substituted by one of three putative regulatory regions (RRs): the
M. hominis
arginine deiminase RR, the
M. hominis
elongation factor Tu RR, or the 68 bp SynMyco synthetic RR. SynMyco-based construction led to a 100-fold increase in transformation efficiency in
M. hominis
M132. This construct was also transformed into the
M. hominis
PG21 reference strain and three other clinical isolates. The transposon insertion locus was determined for 128 M132-transformants. The majority of the impacted coding sequences encoded lipoproteins and proteins involved in DNA repair or in gene transfer. One transposon integration site was in the mycoplasma immunoglobulin protease gene. Phenotypic characterization of the mutant showed complete disruption of the human antibody cleavage ability of the transformant. These results demonstrate that our
M. hominis
-optimized plasmid can be used to generate large random transposon insertion libraries, enabling future studies of the pathogenicity of
M. hominis
.
IMPORTANCE
Mycoplasma hominis
is an opportunistic human pathogen, whose physiopathology is poorly understood and for which genetic tools for transposition mutagenesis have been unavailable for years. A PEG-mediated transformation protocol was developed using the pMT85-Tet plasmid, but the transformation efficiency remained low. We designed a modified pMT85-Tet plasmid suitable for
M. hominis
. The use of a synthetic regulatory region upstream of the antibiotic resistance marker led to a 100-fold increase in the transformation efficiency. The generation and characterization of large transposon mutagenesis mutant libraries will provide insight into
M. hominis
pathogenesis. We selected a transformant in which the transposon was integrated in the locus encoding the immunoglobulin cleavage system MIB–MIP. Phenotypic characterization showed that the wild-type strain has a functional MIB–MIP system, whereas the mutant strain had lost the ability to cleave human immunoglobulins.
Mycoplasma hominis
is an opportunistic human pathogen, whose physiopathology is poorly understood and for which genetic tools for transposition mutagenesis have been unavailable for years. A PEG-mediated transformation protocol was developed using the pMT85-Tet plasmid, but the transformation efficiency remained low. We designed a modified pMT85-Tet plasmid suitable for
M. hominis
. The use of a synthetic regulatory region upstream of the antibiotic resistance marker led to a 100-fold increase in the transformation efficiency. The generation and characterization of large transposon mutagenesis mutant libraries will provide insight into
M. hominis
pathogenesis. We selected a transformant in which the transposon was integrated in the locus encoding the immunoglobulin cleavage system MIB–MIP. Phenotypic characterization showed that the wild-type strain has a functional MIB–MIP system, whereas the mutant strain had lost the ability to cleave human immunoglobulins.
•Non-urogenital infections are unusual in immunocompetent adults.•We report the first Ureaplasma parvum meningitis in an immunocompetent patient.•This case should alert about potential post-operative ...Ureaplasma infections in immunocompetent patients.
We report the case of a Ureaplasma parvum meningitis in an immunocompetent patient, 17 days after surgical ablation of a craniopharyngioma. Presence of U. parvum in the cerebrospinal fluid was assessed by 16S rDNA sequencing and U. parvum specific PCR. This article details a surprising complication in an adult of a transphenoidal surgery for ablation of a craniopharyngioma. This is the first case, to our knowledge, of U. parvum meningitis in an adult patient.
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