Presence of human mycoplasma DNA in gastric tissue samples from Korean chronic gastritis patients

The complete genome sequence of unculturable Mycoplasma faucium obtained through clinical metagenomic next-generation sequencing

Introduction

Diagnosing Mycoplasma faucium poses challenges, and it's unclear if its rare isolation is due to infrequent occurrence or its fastidious nutritional requirements.

Methods

This study analyzes the complete genome sequence of M. faucium, obtained directly from the pus of a sternum infection in a lung transplant patient using metagenomic sequencing.

Results

Genome analysis revealed limited therapeutic options for the M. faucium infection, primarily susceptibility to tetracyclines. Three classes of mobile genetic elements were identified: two new insertion sequences, a new prophage (phiUMCG-1), and a species-specific variant of a mycoplasma integrative and conjugative element (MICE). Additionally, a Type I Restriction-Modification system was identified, featuring 5'-terminally truncated hsdS pseudogenes with overlapping repeats, indicating the potential for forming alternative hsdS variants through recombination.

Conclusion

This study represents the first-ever acquisition of a complete circularized bacterial genome directly from a patient sample obtained from invasive infection of a primary sterile site using culture-independent, PCR-free clinical metagenomics.

Evaluating the presence of Mycoplasma hyorhinis, Fusobacterium nucleatum, and Helicobacter pylori in biopsies of patients with gastric cancer

BACKGROUND

Gastric cancer is the third leading cause of cancer-related deaths worldwide and has been associated with infections that may promote tumour progression. Accordingly, we analysed the presence of Mollicutes, Mycoplasma hyorhinis, Fusobacterium nucleatum and Helicobacter pylori in gastric cancer tissues and evaluated their correlation with clinicopathological factors.

METHODS

Using a commercial kit, DNA were extracted from 120 gastric samples embedded in paraffin: 80 from patients with gastric cancer and 40 from cancer free patients, dating from 2006 to 2016. Mollicutes and H. pylori were detected by PCR; F. nucleatum and M. hyorhinis were detected by qPCR, together with immunohistochemistry for the latter bacteria.

RESULTS

Mollicutes were detected in the case and control groups (12% and 2.5%) and correlated with the papillary histologic pattern (P = 0.003), likely due to cell transformation promoted by Mollicutes. M. hyorhinis was detected in the case and control group but was not considered a cancer risk factor. H. pylori was detected at higher loads in the case compared to the control group (8% and 22%, P = 0.008) and correlated with metastasis (P = 0.024), lymphatic invasion (P = 0.033), tumour of diffused type (P = 0.028), and histopathological grading G1/G2 (P = 0.008). F. nucleatum was the most abundant bacteria in the case group, but was also detected in the control group (26% and 2.5%). It increased the cancer risk factor (P = 0.045, OR = 10.562, CI95% = 1.057-105.521), and correlated with old age (P = 0.030) and tumour size (P = 0.053). Bacterial abundance was significantly different between groups (P = 0.001).

CONCLUSION

Our findings could improve the control and promote our understanding of opportunistic bacteria and their relevance to malignant phenotypes.

[Clinical implications of the genus Mycoplasma]

Dentro del género Mycoplasma, las especies que tradicionalmente se han relacionado con cuadros infecciosos han sido principalmente M. pneumoniae, M. genitalium, M. hominis o U. urealyticum. Sin embargo, existen otras muchas que están implicadas y, que muchas veces, son desconocidas para los profesionales sanitarios. El objetivo de esta revisión es identificar todas las especies del género Mycoplasma que se han aislado en el hombre y determinar su participación en la patología infecciosa humana.

Frequency of different human mollicutes species in the mucosa of the oropharynx, conjunctiva, and genitalia of free-ranging and captive capuchin monkeys (Cebus spp.)

This study is the first to evaluate the occurrence of several Mollicutes species in Brazilian capuchin monkeys (Cebus spp.). Mollicutes were detected by culture and polymerase chain reaction (PCR) in samples of the oropharyngeal, conjuctiva, and genital mucosae of 58 monkeys. In the oropharynx, Mollicutes in general (generic PCR to the Class), and those of the genus Ureaplasma (genus PCR), were detected in 72.4% and 43.0% of the samples, respectively. The identified species in this site included: Mycoplasma arginini (43.1%), M. salivarium (41.4%), and M. pneumoniae (19.0%). Both Ureaplasma and Mycoplasma are genera of the order Mycoplasmatales. In the preputial/vaginal mucosa, PCR detected Mollicutes in general in 27.58% of the samples, the genus Ureaplasma in 32.7%, the species M. arginini in 8.6%, and Acholeplasma laidlawii of the order Acholeplasmatales in 1.7% In the conjunctiva, Mollicutes in general were detected in 29.3% of the samples, with 1.7% being identified as A. laidlawii. Culturing was difficult due to contamination, but two isolates were successfully obtained. The Mollicutes species of this study provided new insights into these bacteria in Brazilian Cebus. Studies are lacking of the actual risk of Mollicutes infection or the frequency at which primates serve as permanent or temporary reservoirs for Mollicutes. In the present study, the samples were collected from monkeys without clinical signs of infection. The mere presence of Mollicutes, particularly those also found in humans, nevertheless signals a need for studies to evaluate the impact of these microorganisms on the health of non-human primates (NHPs) and the possibility of cross-species transmission between NHPs and humans.

Role of bacteria in oncogenesis

Although scientific knowledge in viral oncology has exploded in the 20th century, the role of bacteria as mediators of oncogenesis has been less well elucidated. Understanding bacterial carcinogenesis has become increasingly important as a possible means of cancer prevention. This review summarizes clinical, epidemiological, and experimental evidence as well as possible mechanisms of bacterial induction of or protection from malignancy.

Mycoplasma salivarium detected in a microbial community with Candida glabrata in the biofilm of an occluded biliary stent

Mycoplasma salivarium, preferentially an inhabitant of the human oral cavity, has rarely been found in other locations associated with disease. We describe here, for what is believed to be the first time, the detection of M. salivarium, together with Candida glabrata, in an occluded biliary stent of an icteric, cholestatic patient.

Helicobacter hypothesis for idiopathic parkinsonism: before and beyond

We challenge the concept of idiopathic parkinsonism (IP) as inevitably progressive neurodegeneration, proposing a natural history of sequential microbial insults with predisposing host response. Proof-of-principle that infection can contribute to IP was provided by case studies and a placebo-controlled efficacy study of Helicobacter eradication. "Malignant" IP appears converted to "benign", but marked deterioration accompanies failure. Similar benefit on brady/hypokinesia from eradicating "low-density" infection favors autoimmunity. Although a minority of UK probands are urea breath test positive for Helicobacter, the predicted probability of having the parkinsonian label depends on the serum H. pylori antibody profile, with clinically relevant gradients between this "discriminant index" and disease burden and progression. In IP, H. pylori antibodies discriminate for persistently abnormal bowel function, and specific abnormal duodenal enterocyte mitochondrial morphology is described in relation to H. pylori infection. Slow intestinal transit manifests as constipation from the prodrome. Diarrhea may flag secondary small-intestinal bacterial overgrowth. This, coupled with genetically determined intense inflammatory response, might explain evolution from brady/hypokinetic to rigidity-predominant parkinsonism.

Toll-like receptor-9 expression is inversely correlated with estrogen receptor status in breast cancer

Toll-like receptor 9 (TLR9) recognizes microbial and vertebrate DNA. We previously demonstrated TLR9 expression in human breast cancer cell lines and showed that TLR9 ligands stimulate their in vitro invasion. The aim of this study was to characterize TLR9 expression in clinical breast cancer specimens. Immunohistochemical staining intensity was compared with known baseline prognostic factors and distant metastasis-free survival. TLR9 expression was detected in 98% of the tumors studied (n = 141). The mean TLR9 staining intensity was higher in ER- than in the highly ER+ breast cancers (p = 0.039). High-grade tumors had significantly increased TLR9 expression (p = 0.027) compared with lower-grade tumors. The highest TLR9 expression was detected in the mucinous and the lowest in the tubular breast cancers (p = 0.034). Distant metastasis-free survival was higher in the lower TLR9-expressing half of the cohort than in the higher TLR9-expressing group (p = 0.118). TLR9 expression did not correlate with menopausal, PgR or Her2 status, patient age, tumor proliferative or invasive characteristics.

Mycoplasma host specificity: Fact or fiction?

Bacteria of the genus Mycoplasma are the smallest organisms known to be capable of self-replication. They only occur in association with animal host cells on which they are dependant for many pre-formed nutrients since they lack many of the metabolic pathways associated with energy production and the synthesis of cell components found in other species of bacteria. It is generally thought that most species of Mycoplasma are very host specific but there are many reports of mycoplasmas in hosts that are not perceived as their normal habitat. Sometimes these "crossings" may have a pathological impact particularly where there may be predisposing conditions such as immunodeficiency. These are often reported in humans but may also occur in animals whose immune or physiological status is not known. This review brings together some of these reported incidents and speculates on their potential impact for laboratory diagnosis.

Role of chronic infection and inflammation in the gastrointestinal tract in the etiology and pathogenesis of idiopathic parkinsonism. Part 3: predicted probability and gradients of severity of idiopathic parkinsonism based on H. pylori antibody profile

BACKGROUND

Eradicating Helicobacter may convert rapidly progressive idiopathic parkinsonism to quieter disease, however only a minority of probands have evidence of current infection.

AIM

To explore the cross-sectional fit of parkinsonism as an extra-alimentary consequence of Helicobacter pylori, using the serum antibody profile.

METHODS

A discriminant index for parkinsonism was based on the Western Blot pattern of IgG antibodies against electrophoretically separated H. pylori antigens in 124 subjects with idiopathic parkinsonism, 196 without. In parkinsonism, association was assessed between index and 1, anthropometric measures; 2, current and 3, increase over 4 years in hypokinetic and psychomotor/psychometric disability; and 4, a global score of current severity.

RESULTS

Predicted probability of being labeled parkinsonian was greatest with cytotoxin-associated-gene-product (CagA) positivity and vacuolating-toxin negativity (p = .03 and .004, respectively, for antibody-age interactions), and urease-B negativity (p = .03, irrespective of age). In this circumstance, the odds for parkinsonism increased fivefold by age 80 years (p = .001). Helicobacter status, according to anti-urease enzyme-linked immunosorbent assay (ELISA), did not complement the model. Gradients, of clinically relevant size, were found between index and disease burden, despite the potentially confounding effect of antiparkinsonian medication. The higher the index 1, the worse was posture, as gauged by forward displacement of occiput (p = .04), 2, the shorter mean stride-length (p = .003), longer reaction time (= .002) and lesser cognitive efficiency (= .03), 3, the greater their deterioration (p = .006, .002, and .03 respectively), and 4, the greater the overall severity of parkinsonism (< .001).

CONCLUSION

The apparent importance of H. pylori in the etiology/pathogenesis of idiopathic parkinsonism is not confined to those with evidence of current infection.