Santino I

Prevalence of Chlamydia pneumoniae in peripheral blood mononuclear cells in Italian patients with acute ischaemic heart disease.

Chlamydia pneumoniae infection generally starts in the respiratory tract and probably disseminates systemically in the blood stream within alveolar macrophages. We investigated the prevalence of C. pneumoniae DNA in peripheral blood mononuclear cells (PBMC) in patients with acute ischaemic heart disease. Samples of blood were obtained from 93 consecutive patients with acute ischaemic heart disease and from 42 healthy subjects, for detection of C. pneumoniae DNA in PBMC by polymerase chain reaction (PCR) and for serology. C. pneumoniae DNA in PBMC was detected in 25.8% (24/93) of the patients with acute ischaemic heart disease and in 4.8% (2/42) of the healthy subjects (P=0.008). C. pneumoniae IgG was found in 76.3% of patients and in 45.2% of healthy subjects (P=0.0008) while C. pneumoniae IgA was found in 59.1% and in 33.3%, respectively (P=0.01). No correlation was found between anti-C. pneumoniae antibody titers and positive PCR results. The detection of C. pneumoniae DNA in PBMC may aid in selecting patients who may benefit from antibiotic treatment; however, to support this contention, longitudinal studies on patients treated with antibiotics would also be necessary.

Chlamydia pneumoniae infection and atherosclerotic coronary disease

BACKGROUND Previous works have suggested an association between Chlamydia pneumoniae infection and coronary heart disease. We evaluated the prevalence of C. pneumoniae infection in patients with acute myocardial infarction (AMI) and coronary heart disease (CHD). METHODS AND RESULTS Ninety-eight patients with AMI, 80 patients with CHD, and 50 control subjects matched for age and sex were investigated. Immunoglobulin (Ig)M, IgG, and IgA antibodies to C pneumoniae were measured by the microimmunofluorescence test. IgM antibodies were not found; IgG positivity was found in 58.2% of the AMI group, 60.0% of the CHD group, and 38% of the control group, whereas for IgA, positivity was found in 33.7%, 43.7%, and 22% of cases in AMI, CHD, and control groups, respectively. Titers indicating reinfection were found in AMI and CHD groups in 6.1% and 10%, respectively, whereas titers indicating chronic infection were found in 14% of the AMI group and 25% of the CHD group. A significant correlation was found between chronic C pneumoniae infection and dyslipidemias in the AMI and CHD groups (P =.003; P =. 0006). CONCLUSIONS The results suggest that chronic C pneumoniae infection may be associated with the development of atherosclerotic coronary disease. In our next step, we will test whether antichlamydial antibiotics may help to reduce the risk of atherosclerotic disease.

Chlamydia pneumoniae and atherosclerosis: current state and future prospectives.

Chlamydia pneumoniae, an intracellular bacterial pathogen, is known as a leading cause of human respiratory tract infections worldwide. Over the last decade, several reports in the literature have suggested that infection with C. pneumoniae may contribute to the pathogenesis of atherosclerosis. In order to play a causative role in chronic disease, C. pneumoniae would need to persist within infected tissue for extended periods of time, thereby stimulating a chronic inflammatory response. C. pneumoniae has been shown to disseminate systemically from the lungs through infected peripheral blood mononuclear cells and to localize in arteries where it may infect endothelial cells, vascular smooth muscle cells, monocytes/macrophages and promote inflammatory atherogenous process. The involvement of C. pneumoniae in atherosclerosis was investigated by seroepidemiological and pathological studies, in vivo and in vitro studies, and in clinical antibiotic treatment trials. This review will provide an update on the role of C. pneumoniae in atherosclerosis focusing on the recent insights and suggesting areas for future research.

Multicentric study of seroprevalence of Borrelia burgdorferi and Anaplasma phagocytophila in high-risk groups in regions of central and southern Italy.

The aim of this study was to evaluate the seroprevalence of B. burgdorferi and A. phagocytophila in populations of workers from 4 Italian regions, known to be exposed to tick bites. A total of 712 serum samples collected were divided as follows: 387 samples were obtained from workers at risk for tick bites and 325 from individuals that were not considered to be at risk of ticks bites and served as the control group. Antibodies against B. burgdorferi were found in 29 (7.5%) of the 387 risk workers and in 4 (1.2%) of the 325 control group. Antibodies reactive with the HGE agent were found in 22 (5.7%) of the 387 risk workers and in 3 (0.9%) of the 325 control group. Antibodies to both B. burgdorferi and A. phagocytophila were found in 1.6% of the forestry workers confirming the possibility of coinfection or concurrent infection. The present finding show significant differences between seroprevalence of the risk workers and that of the people with no risk for tick exposure.

Detection of Chlamydia pneumoniae in atherosclerotic coronary arteries.

Chlamydia pneumoniae has recently been associated with the development of coronary heart diseases by sero-epidemiological studies and by direct detection of the organism in atherosclerotic tissues. The aim of our study was to employ a semi-nested PCR approach to investigate the presence of C. pneumoniae in both normal and atherosclerotic coronary arteries of humans obtained at autopsy. Moreover, we have evaluated the role of infection with C. pneumoniae in relation to the extent of coronary atherosclerosis. One hundred and eighty coronary artery specimens were collected at autopsy from 60 consecutive subjects (three arterial segments from each subject). Atherosclerosis in each arterial segment was graded histologically by the Stary classification. Thirty normal coronary arteries were also taken at autopsy as control. PCR results evidenced the presence of C. pneumoniae DNA in atherosclerotic coronary arteries in 19 (31.7%) of 60 subjects examined, while none of the 30 subjects with non-atherosclerotic tissues was positive (p=0.001). Moreover, of the 180 atherosclerotic specimens examined, C. pneumoniae DNA was detected in 3.4% (2/59) of mild atherosclerotic lesions, and in 14.0% (17/121) of advanced atherosclerotic lesions (p=0.05). Our results demonstrate that the presence of C. pneumoniae DNA may be associated with the severity of coronary atherosclerosis.

Chlamydia pneumoniae in asymptomatic carotid atherosclerosis.

We evaluated, in 415 patients with asymptomatic carotid atherosclerosis: (i) the prevalence of C. pneumoniae DNA in atherosclerotic carotid plaques and peripheral blood mononuclear cells (PBMC); (ii) the distribution of C. pneumoniae in atherosclerotic carotid plaques and PBMC from the same patients; (iii) the correlation between circulating anti-chlamydial antibodies and the presence of C. pneumoniae DNA. Overall, 160 atherosclerotic carotid plaques and 174 PBMC specimens from patients with asymptomatic carotid atherosclerosis were examined by ompA nested touchdown PCR for presence of C. pneumoniae. In addition, C. pneumoniae DNA was detected in 81 specimens of atherosclerotic carotid plaque and PBMC obtained from the same patients. C. pneumoniae DNA was found in 36.9% of atherosclerotic carotid plaques and in 40.2% of PBMC specimens examined (P=NS). With regard to 81 patients, C. pneumoniae DNA was detected in 27.2% of atherosclerotic carotid plaques and in 44.4% of PBMC specimens(P=0.05). In 18 patients, the presence of C. pneumoniae DNA in PBMC specimens and atherosclerotic carotid plaques coincided (P=0.005). No statistically significant association was found between anti-C. pneumoniae antibodies (IgG and IgA) and positive PCR results. In conclusion, our results suggest that the detection of C. pneumoniae DNA in PBMC specimens seems to be a first-choice method to identify the patients at risk for endovascular chlamydial infection.

Imaging bacteria with radiolabelled quinolones, cephalosporins and siderophores for imaging infection: a systematic review

Bacterial infections are still one of the main causes of patient morbidity and mortality worldwide. Nowadays, many imaging techniques, like computed tomography or magnetic resonance imaging, are used to identify inflammatory processes, but, although they recognize anatomical modifications, they cannot easily distinguish bacterial infective foci from non bacterial infections. In nuclear medicine, many efforts have been made to develop specific radiopharmaceuticals to discriminate infection from sterile inflammation. Several compounds (antimicrobial peptides, leukocytes, cytokines, antibiotics…) have been radiolabelled and tested in vitro and in vivo, but none proved to be highly specific for bacteria. Indeed factors, including the number and strain of bacteria, the infection site, and the host condition may affect the specificity of tested radiopharmaceuticals. Ciprofloxacin has been proposed and intensively studied because of its easy radiolabelling method, broad spectrum, and low cost, but at the same time it presents some problems such as low stability or the risk of antibiotic resistance. Therefore, in the present review studies with ciprofloxacin and other radiolabelled antibiotics as possible substitutes of ciprofloxacin are reported. Among them we can distinguish different classes, such as cephalosporins, fluoroquinolones, inhibitors of nucleic acid synthesis, inhibitors of bacterial cell wall synthesis and inhibitors of protein synthesis; then also others, like siderophores or maltodextrin-based probes, have been discussed as bacterial infection imaging agents. A systematic analysis was performed to report the main characteristics and differences of each antibiotic to provide an overview about the state of the art of imaging infection with radiolabelled antibiotics.

Detection of Borrelia burgdorferi sensu lato DNA by PCR in serum of patients with clinical symptoms of Lyme borreliosis

Lyme borreliosis is a disease caused by spirochaetes belonging to the genospecies complex Borrelia burgdorferi sensu lato (s.l.) transmitted by Ixodes ticks. At present, serology remains the main diagnostic tool for laboratory diagnosis of Lyme borreliosis. Recently, the PCR technique has been applied for diagnosis of B. burgdorferi s.l., but, until now, a reliable, easy-to-perform and sensitive method has not been described. Here we present a new PCR-based method for the detection of both B. burgdorferi s.l. and Borrelia genospecies DNAs in serum samples collected from patients showing Lyme disease symptoms. Of 265 serum samples of patients included in this study, 7.5% were positive, 1.9% was borderline and 90.6% were negative for antibodies against B. burgdorferi by enzyme-linked immunosorbent assay and Western blotting. The B. burgdorferi s.l. 16S rRNA gene was detected by PCR in all serum-positive and in two borderline samples. None of the serum-negative samples nor serum samples collected from healthy subjects gave positive PCR reactions. Of PCR-positive serum samples, 50% gave a positive reaction for Borrelia afzelii, 18% for Borrelia garinii and 23% for two Borrelia species. Two samples (9%) were not identified to species level. The new protocol could be considered to be reliable as neither false-positive nor false-negative reactions were recorded, and to be sensitive as it detects DNA from one bacterial cell.

Detection of four Borrelia burgdorferi genospecies and first report of human granulocytic ehrlichiosis agent in Ixodes ricinus ticks collected in central Italy

The presence of Borrelia burgdorferi s.l. and of Ehrlichia phagocytophila group was sought by PCR in Ixodes ricinus collected in a protected area of central Italy. Nymphs (n = 1475, gathered in 295 pools of 5 nymphs each) and adult ticks (n = 28) were examined. B. burgdorferi s.l. was detected in 13.8% of the nymph pools; of these, 63.4% were infected by B. valaisiana, 26.8% by B. afzelii, 7.3% by B. garinii, and 2.5% by B. burgdorferi s.s. Only a single adult male tick proved to host B. afzelii. The agent of human granulocytic ehrlichiosis (HGE) was detected in 2.7% of the nymph pools. Two HGE agent-positive nymph pools were also found to be positive for B. garinii and for B. afzelii, respectively. This is the first report from central Italy of the finding of the HGE agent in ticks.

Kodamaea ohmeri isolate from two immunocompromised patients: first report in Italy

Kodamaea ohmeri is an unusual yeast‐form fungus that has recently been identified as an important aetiological agent of fungaemia, endocarditis, cellulitis, funguria and peritonitis in immunocompromised patients. We present two new isolated of K. ohmeri. The microorganisms were identified by CHROMagar Candida medium, VitekII system and API ID32C. Biochemical identification of the two yeast isolates was confirmed by sequence analysis of the 26S ribosomal DNA. Antifungal susceptibility testing done by Sensititre YeastOne showed that the isolates were susceptible to amphotericin B, voriconazole and itraconazole. This work is the first report of isolation of K. ohmeri in immunocompromised patients in Italy.