Mycoplasma pneumoniae and Chlamydia pneumoniae in calcified nodules of aortic stenotic valves

Janibacter species with evidence of genomic polymorphism isolated from resected heart valve in a patient with aortic stenosis

The authors report isolation and identification of two strains of bacteria belonging to the genus Janibacter from a human patient with aortic stenosis from a rural area of the country of Georgia. The microorganisms were isolated from aortic heart valve. Two isolates with slightly distinct colony morphologies were harvested after sub-culturing from an original agar plate. Preliminary identification of the isolates is based on amplification and sequencing of a fragment of 16SrRNA. Whole genome sequencing was performed using the Illumina MiSeq instrument. Both isolates were identified as undistinguished strains of the genus Janibacter. Characterization of whole genome sequences of each culture has revealed a 15% difference in gene profile between the cultures and confirmed that both strains belong to the genus Janibacter with the closest match to J. terrae. Genomic comparison of cultures of Janibacter obtained from human cases and from environmental sources presents a promising direction for evaluating a role of these bacteria as human pathogens.

Inflammation and Mechanical Stress Stimulate Osteogenic Differentiation of Human Aortic Valve Interstitial Cells

Background: Aortic valve calcification is an active proliferative process, where interstitial cells of the valve transform into either myofibroblasts or osteoblast-like cells causing valve deformation, thickening of cusps and finally stenosis. This process may be triggered by several factors including inflammation, mechanical stress or interaction of cells with certain components of extracellular matrix. The matrix is different on the two sides of the valve leaflets. We hypothesize that inflammation and mechanical stress stimulate osteogenic differentiation of human aortic valve interstitial cells (VICs) and this may depend on the side of the leaflet. Methods: Interstitial cells isolated from healthy and calcified human aortic valves were cultured on collagen or elastin coated plates with flexible bottoms, simulating the matrix on the aortic and ventricular side of the valve leaflets, respectively. The cells were subjected to 10% stretch at 1 Hz (FlexCell bioreactor) or treated with 0.1 μg/ml lipopolysaccharide, or both during 24 h. Gene expression of myofibroblast- and osteoblast-specific genes was analyzed by qPCR. VICs cultured in presence of osteogenic medium together with lipopolysaccharide, 10% stretch or both for 14 days were stained for calcification using Alizarin Red. Results: Treatment with lipopolysaccharide increased expression of osteogenic gene bone morphogenetic protein 2 (BMP2) (5-fold increase from control; p = 0.02) and decreased expression of mRNA of myofibroblastic markers: α-smooth muscle actin (ACTA2) (50% reduction from control; p = 0.0006) and calponin (CNN1) (80% reduction from control; p = 0.0001) when cells from calcified valves were cultured on collagen, but not on elastin. Mechanical stretch of VICs cultured on collagen augmented the effect of lipopolysaccharide. Expression of periostin (POSTN) was inhibited in cells from calcified donors after treatment with lipopolysaccharide on collagen (70% reduction from control, p = 0.001), but not on elastin. Lipopolysaccharide and stretch both enhanced the pro-calcific effect of osteogenic medium, further increasing the effect when combined for cells cultured on collagen, but not on elastin. Conclusion: Inflammation and mechanical stress trigger expression of osteogenic genes in VICs in a side-specific manner, while inhibiting the myofibroblastic pathway. Stretch and lipopolysaccharide synergistically increase calcification.

Mycoplasma pneumoniae and Chlamydia pneumoniae seropositivity in patients with age-related macular degeneration

Background

To determine a possible relation between Mycoplasma pneumoniae (MP) or Chlamidia pneumoniae (CP) seropositivity and age-related macular degeneration (AMD).

Methods

Sixty patients (20 wet AMD, 20 dry AMD and 20 non-AMD controls) were included in the study. Serum samples were collected for analysis of IgM and IgG antibody seropositivity for CP and MP by enzyme-linked immunosorbent assay (ELISA). Comparison of the distribution of seropositivity of these antibodies among patients with wet and dry AMD, and controls was performed. A prospective comparative clinical trial was applied.

Results

There was no major difference in the distribution of IgM and IgG seropositivity to CP and MP in patients with wet and dry AMD, and in controls (p > 0.05).

Conclusions

We found no significant association between MP as well as CP antibody titers and AMD. It seems that MP or CP infection is not a risk factor for AMD.

Keywords

Mycoplasma pneumoniae; Chlamydia pneumoniae; Age-related macular degeneration; Serology

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms.

MATERIALS AND METHODS

eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies.

RESULTS

MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.

No evidence for a direct role of Helicobacter pylori and Mycoplasma pneumoniae in carotid artery atherosclerosis

BACKGROUND

That infections with certain pathogens, by initiating an inflammatory response, may contribute to the development of atherosclerosis is suggested by clinical and experimental evidence.

AIM

To analyse atherosclerotic plaques of the carotid artery, samples of apparently healthy greater saphenous veins and circulating leucocytes from the same individual patients for the presence of Helicobacter pylori and Mycoplasma pneumoniae.

METHODS

Samples from 36 patients undergoing carotid endarterectomy for symptomatic carotid artery stenosis were analysed by polymerase chain reaction for the presence of DNA specific for H. pylori and M. pneumoniae. IgG antibody titres against H. pylori and M pneumoniae and plasma levels of soluble E-selectin, soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1 were determined.

RESULTS

M. pneumoniae-specific DNA was detected in the atherosclerotic plaques of 13 of 36 (36.1%) patients, in the saphenous veins of 9 of 36 (25%) patients and in the leucocytes of 27 of 36 (75%) patients. No salient association was observed between the presence of M. pneumoniae-specific DNA in leucocytes and atherosclerotic plaques or veins. A marked correlation between the presence of M. pneumoniae in the respective specimens and the studied inflammatory markers or the presence of anti-M. pneumoniae antibodies was not observed. H. pylori-specific DNA could not be detected in the specimens tested.

CONCLUSIONS

The absence of H. pylori and the random distribution of M. pneumoniae in tissue samples obtained from patients with symptomatic carotid artery stenosis do not support a role for these pathogens in the development of atherosclerosis due to a direct interaction of the bacteria with the vasculature.

Chlamydia pneumoniae in foci of "early" calcification of the tunica media in arteriosclerotic arteries: an incidental presence?

Only a few previous works investigated the involvement of Chlamydia pneumoniae (Chlamydophila pneumoniae) in arterial calcification. The present study investigated a possible association between C. pneumoniae and medial calcification. Carotid artery segments obtained by endarterectomy from 60 patients were examined by PCR and immunohistochemistry to identify the presence of C. pneumoniae. Arterial specimens showing double-positive (n = 17), double-negative (n = 22), and single-positive results (n = 21) were further analyzed by a combination of histology, immunohistochemistry, and electron microscopy. Medial calcification occurred in 10 of 17 (58.8%) C. pneumoniae double-positive arterial specimens, but no medial calcification was observed in any of 22 C. pneumoniae double-negative arterial specimens. Electron microscopy indicated C. pneumoniae in smooth muscle cells (SMCs) in foci of medial calcification. Medial SMCs showing damage to the cytoplasm and basement membrane contained the structures with the appearance of elementary, reticulate, and aberrant bodies of C. pneumoniae. The presence of C. pneumoniae in SMCs was confirmed by electron-microscopic immunocytochemistry. In the extracellular matrix, calcification was observed in C. pneumoniae aberrant bodies that exited the SMCs. The findings offer a new hypothesis of arterial calcification: they suggest that C. pneumoniae infection of medial SMCs may be associated with the pathophysiological events of arteriosclerotic calcification of the tunica media.

Trypanosoma cruzi trans-sialidase as a new therapeutic tool in the treatment of chronic inflammatory diseases: possible action against mycoplasma and chlamydia

The present paper proposes a new therapy using Trypanosoma cruzi trans-sialidase to treat diseases with unclear pathogenesis that present in common chronic inflammation and fibrosis. This hypothesis is based on recent findings that co-infection with mycoplasma and chlamydia is present in many of these diseases and that this enzyme was capable to eliminate or decrease the co-infection from the host. We identified that mycoplasmas and chlamydias are present in atherosclerosis, aortic valve stenosis, dilated cardiomyopathy, chronic chagasic myocarditis and cancer. We hypothetized that mycoplasmal infection may induce immunodepression in the host, favoring proliferation of pre-existent chlamydial infection and that elimination of mycoplasma would lead to improvement of the immune system resistance and the control of chlamydial proliferation. Mycoplasma has a particular parasitic relationship with host cells, involving strong adherence of their membranes, making it extremely difficult to eradicate mycoplasmal infection from the host. A new therapeutic approach is suggested using one or more agents that prevent or inhibit the adherence of mycoplasma to host cell membranes by removing sialic acid residues and preventing oxidation of the cells. The use of a neuraminidase enzyme, particularly the T. cruzi trans-sialidase enzyme, associated with treatment using anti-oxidating agents is proposed. Preliminary experimental animal and laboratory tests showed good results. The proposal that trans-sialidase from T. cruzi is efficient in combating co-infection of mycoplasma and chlamydia is based, at least in part, on the observation that chagasic patients suffering from T. cruzi infection present less mycoplasma and chlamydia infection in their tissues. Also, a lower incidence of the diseases above described to be related to mycoplasma infection is observed in chagasic patients. It is also hypothesized that co-infection with mycoplasma and chlamydia may induce oxidation of the host cells. Anti-oxidants such as those present in plant extracts may also be used in the treatment. Other diseases such as chronic hepatitis, glomerulonephritis, Multiple Sclerosis, Alzheimer's Syndrome and idiopathic encephalitis are other examples of chronic diseases where mycoplasma and chlamydia might be present, as they have the characteristics of unknown etiology, persistent chronic inflammation and fibrosis.

Cytokines in Mycoplasma pneumoniae infections

Mycoplasma pneumoniae (M. pneumoniae) is one of the smallest free-living bacteria known. Along with other unique characteristics of this genus, it lacks the typical peptidoglycan cell wall of most eubacteria. Best known for causing tracheobronchitis and atypical pneumonia in humans, this pathogen also causes a number of extrapulmonary syndromes such as meningitis/encephalitis and arthritis. Recent studies also suggest that infection may be associated with chronic conditions such as asthma. Although the mechanisms of M. pneumoniae pathogenesis remain to be elucidated, one important component of M. pneumoniae infections is the induction of proinflammatory and other cytokines in both acute and chronic conditions. In this review, we survey the induction of cytokines by M. pneumoniae in different model systems, and we discuss the possible role of induced cytokines in M. pneumoniae pathogenesis.

Mycoplasma pneumoniae and its role as a human pathogen

Mycoplasma pneumoniae is a unique bacterium that does not always receive the attention it merits considering the number of illnesses it causes and the degree of morbidity associated with it in both children and adults. Serious infections requiring hospitalization, while rare, occur in both adults and children and may involve multiple organ systems. The severity of disease appears to be related to the degree to which the host immune response reacts to the infection. Extrapulmonary complications involving all of the major organ systems can occur in association with M. pneumoniae infection as a result of direct invasion and/or autoimmune response. The extrapulmonary manifestations are sometimes of greater severity and clinical importance than the primary respiratory infection. Evidence for this organism's contributory role in chronic lung conditions such as asthma is accumulating. Effective management of M. pneumoniae infections can usually be achieved with macrolides, tetracyclines, or fluoroquinolones. As more is learned about the pathogenesis and immune response elicited by M. pneumoniae, improvement in methods for diagnosis and prevention of disease due to this organism may occur.

Chronic infection and coronary artery disease

On a variety of fronts, chronic infection has been found to be significantly associated with the development of atherosclerosis and the clinical complications of unstable angina, myocardial infarction, and stroke. For the most part, these relationships are still just associations. Failure to confirm initial reports of serologic associations also has been common. Specific causative relationships on par with that determined between H pylori and peptic ulcer disease have not yet been established. Potential mechanisms whereby chronic infections may play a role in atherogenesis are myriad. In the case of C pneumoniae, the effect may result from direct vessel wall colonization that may damage the vessel either directly or indirectly by initiating immunologic responses. In other cases the effect may simply be that of enhancing the pre-existing chronic inflammatory response of the body to standard risk factors such as hyperlipidemia. Even though the infectious agent may not directly infect the vessel wall, it may perform its critical role from afar. Chronic infection might also influence pre-existing plaque by enhancing T-cell activation or other inflammatory responses that may participate in the destabilization of the intimal cap. Hence chronic infection may play a role either in the initiation, progression, or the destabilization of atherosclerotic plaques. The infectious agents with the most evidence to support an etiologic role in atherosclerosis include C pneumoniae and cytomegalovirus. Evidence is mounting for a variety of other potential agents including other herpes viruses, influenza, other specific bacteria (such as M pneumoniae), and chronic infections with common bacterial agents (periodontal disease, chronic bronchitis, and chronic urinary tract infection, among others) [191]. Future studies are expected to elucidate further the pathophysiologic relationship between chronic infection and atherosclerosis and to evaluate further the potential of a variety of treatment approaches, including antibiotics.