Biodistribution and intracellular localization of hyaluronan and its nanogels. A strategy to target intracellular S. aureus in persistent skin infections

Intracellular pathogens are a critical challenge for antimicrobial therapies. Staphylococcus aureus (S. aureus) causes approximately 85% of all skin and soft tissue infections in humans worldwide and more than 30% of patients develop chronic or recurrent infections within three months, even after appropriate antibacterial therapies. S. aureus is also one of the most common bacteria found in chronic wounds. Recent evidences suggest that S. aureus is able to persist within phagolysosomes of skin cells (i.e. keratinocytes, phagocytic cells), being protected from both the immune system and a number of antimicrobials. To overcome these limits, nano-formulations that enable targeted therapies against intracellular S. aureus might be developed. Herein, the biodistribution and intracellular localisation of hyaluronan (HA) and HA-based nanoparticles (nanogels, NHs) are investigated, both after intravenous (i.v.) injections (in mice) and topical administrations (in ex vivo human skin). Results indicate HA and NHs accumulate especially in skin and liver of mice after i.v. injection. After topical application on human skin explants, no penetration of both HA and NHs was detected in skin with intact stratum corneum. By contrast, in barrier-disrupted human skin (with partial removal and loosening of stratum corneum), HA and NHs penetrate to the viable epidermis and are taken up by keratinocytes. In mechanically produced wounds (skin without epidermis) they accumulate in wound tissue and are taken up by dermis cells, e.g. fibroblasts and phagocytic cells. Interestingly, in all cases, the cellular uptake is CD44-mediated. In vitro studies confirmed that after CD44-mediated uptake, both HA and NHs accumulate in lysosomes of dermal fibroblasts and macrophages, as previously reported for keratinocytes. Finally, the colocalisation between intracellular S. aureus and HA or NHs is demonstrated, in macrophages. Altogether, for the first time, these results strongly suggest that HA and HA-based NHs can provide a targeted therapy to intracellular S. aureus, in persistent skin or wound infections.

Surveillance of healthcare acquired infections by "alert microorganisms": preliminary results

BACKGROUND

We evaluated the trend of four years (2015 - 2018) of "alert organisms" surveillance carried out at the 450 bed teaching hospital S. Andrea in Rome.

METHODS

All patients with an "Alert organism" isolation were screened. In accordance with definitions used by the Centers for Disease Control patients with an "alert organism" isolation were evaluated for infection or colonization, by an infection control team (ICT).

RESULTS

Between April 2015 and December 2018 a total 4,762 specimens with "Alert organism" isolation were screened and 1,601 patients were surveyed and included in the study. Overall 780 (48.8%) patients developed an healthcare acquired infection (HAI) at our institution, whereas 311 (19.4%) entered with a community acquired infection, 254 (15.8%) with an infection acquired in another healthcare setting and 256 (16.0%) resulted simply colonized. The 780 patients who developed an HAI at our institution presented 878 infectious episodes and the isolation of 931 microorganisms. C. difficile infections were the most common (27.2%), followed by 21.3% respiratory tract infections, 16.9% urinary tract infections, 15.5% surgical site infections, 12.5% bloodstream infections, 3.6% ulcers and 3.0% others. Among HAI group Gram negatives (54.1%) were more frequent than Gram positives (45.9%), whereas in patients entering in the hospital already with a community infection Gram positives overpassed Gram negatives (58.7% vs. 41.3%; p<0.001). Most common pathogens responsible for HAI were C. difficile (25.6%), Klebsiella spp. (25.5%), MRSA (19.6%) and Acinetobacter spp. (15.3%). Notably 30.0% HAI at other institutions were represented by C. difficile. Impressively, >40% of community acquired infections were related to MRSA.

CONCLUSIONS

The present study provided some useful insight into the major multi-resistant pathogens epidemiology at our institution. The Authors succeeded in organizing a multidisciplinary ICT that created a partnership feeling with the hospital personnel.

Risk factors for recurrence in patients with Clostridium difficile infection due to 027 and non-027 ribotypes

OBJECTIVES

Our objective was to evaluate factors associated with recurrence in patients with 027+ and 027- Clostridium difficile infection (CDI).

METHODS

Patients with CDI observed between January and December 2014 in six hospitals were consecutively included in the study. The 027 ribotype was deduced by the presence of tcdB, tcdB, cdt genes and the deletion Δ117 in tcdC (Xpert® C. difficile/Epi). Recurrence was defined as a positive laboratory test result for C. difficile more than 14 days but within 8 weeks after the initial diagnosis date with reappearance of symptoms. To identify factors associated with recurrence in 027+ and 027- CDI, a multivariate analysis was performed in each patient group. Subdistributional hazard ratios (sHRs) and 95% confidence intervals (95%CIs) were calculated.

RESULTS

Overall, 238 patients with 027+ CDI and 267 with 027- CDI were analysed. On multivariate analysis metronidazole monotherapy (sHR 2.380, 95%CI 1.549-3.60, p <0.001) and immunosuppressive treatment (sHR 3.116, 95%CI 1.906-5.090, p <0.001) were factors associated with recurrence in patients with 027+ CDI. In this patient group, metronidazole monotherapy was independently associated with recurrence in both mild/moderate (sHR 1.894, 95%CI 1.051-3.410, p 0.033) and severe CDI (sHR 2.476, 95%CI 1.281-4.790, p 0.007). Conversely, non-severe disease (sHR 3.704, 95%CI 1.437-9.524, p 0.007) and absence of chronic renal failure (sHR 16.129, 95%CI 2.155-125.000, p 0.007) were associated with recurrence in 027- CDI.

CONCLUSIONS

Compared to vancomycin, metronidazole monotherapy appears less effective in curing CDI without relapse in the 027+ patient group, independently of disease severity.

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.

Cervicovaginal bacteria and fungi in pregnant diabetic and non-diabetic women: a multicenter observational cohort study

OBJECTIVE

We evaluated the prevalence of cervicovaginal Bacteria, group B Streptococcus (GBS), Gardnerella vaginalis (GV), Candida spp., Chlamydia trachomatis (CT), Mycoplasma hominis (MH) and Ureaplasma urealyticum (UU) in pregnant women with and without diabetes mellitus (DM).

PATIENTS AND METHODS

Cervicovaginal swabs were gathered from 473 pregnant patients divided into 127 diabetic and 346 non-diabetic. The results were correlated to gestational age, parity and glycemic control.

RESULTS

A higher prevalence of MH/UU (p=0.012) was found in the diabetic patients. After the 28th week of pregnancy, the prevalence for all investigated microorganisms appeared similar except for MH/UU (p=0.014). In multigravida, there were statistical differences between two groups in testing for Bacteria (p=0.015) and for MH/UU (p=0.037). The diabetic condition correlated to the state of multigravida in cases positive for Candida spp. (p=0.049) and in those testing positive for at least one microorganism (p=0.043). Pregnant with a blood glucose > 92 have twice the risk of being positive to a single microbiological test than those with better glycemic control.

CONCLUSIONS

The higher prevalence of MH/UU after the 28th weeks can be explained with the physiologically reduced insulin tolerance characteristic of this gestational period. Among the diabetic testing positive to Candida spp. the statistically significant association was observed only in multigravida condition. These data suggest that diabetic multigravida women are at increased risk for Candida spp. infection in relation to the improper glycemic control.

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.

Lyme Borreliosis Infection in Europe

Lyme borreliosis is the most common tick-borne disease in the United States and Europe. It is caused by spirochetes of the Borrelia burgdorferi species complex which are transmitted by ticks of the genus Ixodes. This paper presents a review of the studies published about Lyme borreliosis in Europe and in Italy. Seroepidemiologic studies have been conducted in various European countries concerning patients, groups at risk and general population. The distribution of LB in Europe is very variable and the risk is associated with occupational and recreational activities in forested areas and with residence in rural area. Taking the limitations of seroprevalence methods into account, it is evident that the prevalence of Lyme borreliosis varies considerably in different European countries, with an overall increasing prevalence from west to east in central-eastern Europe, a gradient of decreasing incidence in Spain and Greece and from north to south in Italy.

In Vitro Susceptibility of Isolates of Borrelia Burgdorferi S.L. to Antimicrobial Agents

In the present study, we investigate the in vitro antimicrobial activity of macrolides, β-lactams and tetracycline against Borrelia burgdorferi s.l. clinical and tick isolates. Minimal inhibitory concentrations (MICs) were determined in normal growth condition and after pre-exposure of the strains to sub-MIC of the founder of each drug family. All the classes of tested antibiotics showed good antibacterial activity against all the borreliae isolates and there were no significant susceptibility differences among clinical and tick isolates. After pre-exposure of the strains to sub-MIC of erythromycin, cefoxitin and tetracycline, we observed that some strains of B. burgdorferi s.l. showed higher MIC values to both the pre-exposed drug and drugs of the same family. The less susceptibility of borreliae, in the last growth condition in vitro, could be one of the justifications of clinical results indicating the limited efficacy of these antibiotics in treatment of B. burgdoferi infections.

Saccharomyces cerevisiae fungemia, a possible consequence of the treatment of Clostridium difficile colitis with a probioticum

The yeast Saccharomyces boulardii is a biotherapeutic agent used for the prevention and treatment of several gastrointestinal diseases, such as diarrhoea caused by Clostridium difficile, in addition to the antibiotic therapy. In this study we report a case of Saccharomyces cerevisiae fungemia in a patient with Clostridium difficile-associated diarrhoea (CDAD) treated orally with S. boulardii in association with vancomycin. The identification of the S. cerevisiae was confirmed by molecular technique. Fungemia is a rare, but a serious complication to treatment with probiotics. We believe it is important to remind the clinicians of this risk when prescribing probiotics, especially to immunocompromised patients.

Microbiological and molecular characterization of extreme drug-resistant carbapenemase-producing Klebsiella pneumoniae isolates

Fifteen Klebsiella pneumoniae clinical isolates showing non-susceptibility to carbapenems and resistant to colistin were collected in an Italian hospital. All isolates resulted negative to AmpC, MBL and ESBL production but positive to modified Hodge test, therefore were evaluated as KPC producers. The presence of blaKPC genes was verified by polymerase chain reaction (PCR) and sequencing. Furthermore, molecular typing was performed by multilocus sequence typing (MLST). PCR analysis and nucleotide sequencing revealed that all 15 isolates carried the blaKPC-3 gene. MLST analysis attributed the isolates from all patients to belong to the sequence type ST512. All isolates showed extensively drug-resistant (XDR) phenotype. The emergence of colistin-resistant K. pneumoniae underscores the implementation of strict control measures to prevent the dissemination of these organisms in hospitals.

A Case of Pericarditis Due to Roseomonas Gilardii in a Patient with Angiosarcoma of the Pericardium

Roseomonas gilardii is a Gram-negative slow growing coccobacillus that has been recognized as an opportunistic pathogen which can lead to infections, especially in immunocompromised and chronically ill patients. The organism is generally susceptible to carbapenems and aminoglycosides, but resistant to most of the cephalosporins. We report what we believe is the first case of a 72-year-old oncologic woman who developed a pericarditis caused by R. gilardii in Italy.

Clinical and Serological Features of Patients with Suspected Lyme Borreliosis

Serology is currently the method of choice for the laboratory diagnosis of Lyme borreliosis, but it must be interpreted with caution. A total of 954 patients with suspected Lyme borreliosis were evaluated on the basis of clinical and serological data. The seroprevalence of Borrelia burgdorferi antibodies was 4.4% (42 of the 954 serum samples). The most frequent clinical manifestation was erythema migrans which occurred in 50% of the seropositive patients, followed by neuroborreliosis (16.6%) and arthritis (11.9%). Carditis was rare. Our findings suggest that for the diagnosis of Lyme borreliosis, serologic tests need to be combined with clinical signs and symptoms.

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.

Detection of Different Borrelia Burgdorferi Genospecies in Serum of People with Different Occupational Risks: Short Report

This study is aimed at applying a previously described PCR-based method to detect B. burgdorferi sensu lato and different Borrelia genospecies in total DNA preparations of serum samples collected from people with different occupational risks for tick bite and with serological evidence of borreliosis. Among the seropositive samples, the PCR for B. burgdorferi confirmed the positivity in 65% of the forestry workers and in 60% of the subjects living in the same area. None of the seronegative subjects belonging to the control group showed the presence of B. burgdorferi sensu lato DNA. Results on genospecies distribution show that B. afzelii was the predominant species, followed by B. garinii and finally by B. valaisiana.

Chlamydia Pneumoniae and Chronic Diseases with a Great Impact on Public Health

Chlamydia pneumoniae is recognised as a common cause of respiratory tract infections and has recently been implicated in several extrapulmonary chronic diseases, with great impact on public health, such as atherosclerosis, multiple sclerosis and Alzheimer's disease. The involvement of C. pneumoniae in such diseases may be correlated to characteristic features of this pathogen, including intracellular growth and ability to induce persistent forms. C. pneumoniae persistent forms are inherently more suited to evade the host immune response and are more difficult to eradicate by antibiotics. Our preliminary experimental findings show that interaction of C. pneumoniae with macrophages and/or T cells characterized by interference with TNF-α production, and redox state, culminates in the induction of T cell apoptosis and survival of infected macrophages. Based on our evidence, the poor cooperation between T cells and macrophages could lead to an inappropriate immune response against C. pneumoniae that may therefore promote the development of extrapulmonary chronic diseases.

No evidence of involvement of Chlamydia pneumoniae in lung cancer by means of quantitative real-time polymerase chain reaction

Chlamydia pneumoniae, an obligate intracellular pathogen, is well-known as etiological agent of acute respiratory infections; the repeated or prolonged exposure to chlamydial antigens may promote the persistence of C. pneumoniae in the respiratory tract leading to chronic diseases, such as chronic obstructive pulmonary disease and asthma. The predilection of C. pneumoniae to cause respiratory tract infections combined with its persistent nature suggest that it might play a role in lung cancer. The aim of our study is to evaluate the involvement of C. pneumoniae in pathogenesis of lung cancer. We therefore investigated the presence of C. pneumoniae DNA in tumor lung tissues by using real-time PCR assay. Simultaneously, tumor and healthy tissues from the same patient with primary carcinoma lung were analyzed. C. pneumoniae DNA was not detected in a single lung tumor tissue by means of an highly sensitive, and specific real-time PCR assay based on FRET hybridization probes. In conclusion, this study does not support the involvement of C. pneumoniae in the pathogenesis of lung cancer, suggesting that further investigations are needed to clarify other potential causative factors for the development of this malignancy.

Evaluation by Real-Time PCR of the Expression of S. Flexneri Virulence-Associated Genes ospB and phoN2 under Different Genetical Backgrounds

Under conditions of activated type III secretion Shigella flexneri up-regulates the expression of numerous genes, including the virulence plasmid (pINV)-encoded ospB and phoN2 genes. ospB and phoN2 are virulence-associated genes which are part of a bicistronic transcriptional unit encoding OspB, a protein (effector) of unknown function secreted by the type III secretion (TTS) apparatus, and PhoN2 (apyrase or ATP-diphosphohydrolase), a periplasmic protein involved in polar IcsA localization on the surface of S. flexneri. In this work we used real-time PCR to measure transcription of ospB and phoN2 of wild-type S. flexneri strain M90T as well as of derivative mutants impaired in definite virulence traits. The results obtained confirmed and extended previous reports indicating that the expression of ospB and phoN2 genes is modulated in a virB-dependent, mxiE-independent manner under conditions of non-activated secretion, while their expression is considerably induced in a mxiE-dependent manner under conditions of activated secretion. That the expression of the ospB-phoN2 operon is up-regulated in condition of activated secretion, indicates that probably the expression of these two genes might be important, especially during the later stages of infection of S. flexneri.

Genotype and phenotype relationship in MLSb resistance in Streptococcus pyogenes and Streptococcus agalactiae isolated in central Italy

The aim of this work is to study a correlation between phenotype and genotype in clinical isolates of erythromycin-resistant Streptococcus spp. Among the 25 erythromycin-resistant S. pyogenes, we detected six strains with iMLSB, nine with cMLSB and two with M phenotypes. Among 14 erythromycin-resistant S. agalactiae, we detected five strains with iMLSB, seven with cMLSB and none with an M phenotype. Moreover, 8 S. pyogenes and 2 S. agalactiae showed a phenotype not matching the known ones described in literature, defining an unknown phenotype. Upon examination, the genetic profiles, erm(A), erm(B) and mef(A), of the clinical isolates did not easily correlate with a specific phenotype. Our findings highlighted that the whole matter of phenotypic diversity in macrolide-resistant S. pyogenes and S. agalactiae strains and the correlation with their genetic profiles should be submitted to a more careful analysis of phenotypic and genotypic characterization.

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.

Could Chlamydia Pneumoniae Be Considered an Infectious Risk Factor for Inflammatory Diseases Such as Atherosclerosis ?

Chlamydia pneumoniae, a Gram-negative intracellular obligate bacteria, is recognised as a common cause of upper respiratory tract infections, and accounts for ∼10% of community-acquired pneumonia. In recent years, chronic and persistent infection with C. pneumoniae has been implicated in the pathogenesis of atherosclerosis. Atherosclerosis is regarded as a chronic inflammatory disease that results from complex interactions between a variety of cell types such as endothelial cells, vascular smooth muscle cells, monocytes/macrophages and inflammatory mediators. Involvement of C. pneumoniae in the pathogenesis of atherosclerosis has been supported by findings from seroepidemiologic studies, direct detection of chlamydial DNA, experimental animal and in vitro studies, and antibiotic intervention trials. The spectrum of cell biological, animal, and human clinical data suggests that C. pneumoniae may be considered an infectious risk factor for atherosclerosis but further studies are needed to clarify the etiopathogenetic role of C. pneumoniae in atherosclerotic vessel walls.

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.

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.

Prevalence of Borrelia Burgdorferi sensu lato genomospecies and of the human granulocytic ehrlichiosis (HGE) agent in Ixodes ricinus ticks collected in the area of Monti Lepini, Italy

Ticks are obligate hematophagous arthropods that are parasites in every class of vertebrates in most regions of the world. They are also considered to be important vectors for the transmission of human infectious diseases. In the present study we used polymer chain reaction (PCR) amplification analysis to determine the prevalence of Borrelia burgdorferi and Ehrlichia phagocytophila, the agents of, respectively, Lyme borreliosis and human granulocytic ehrlichiosis, among ticks inhabiting the area of Monti Lepini, a wild area located in the Latium Region of Italy. A total of 141 I. ricinus ticks (125 nymphs and 16 adults) were collected in the studied area. Total DNAs were extracted from I. ricinus nymphs (pooled in groups of five) and from individual adults. The DNA samples were examined for the presence of B. burgdorferi sensu lato and E. phagocytophila by PCR using two specific pairs of oligonucleotides that specifically amplify distinct DNA regions of the 16S rRNA genes of the two species. The prevalence of vectors infected with B. burgdorferi s. l. was 16% in pooled nymphs samples, and 12.5% in adult ticks, while E. phagocytophila was found only in pooled nymphs samples (8%). Three genomospecies were identified, namely Borrelia afzelii, Borrelia garinii, and Borrelia valaisiana, in samples found positive for B. burgdorferi s. l. No sample was found positive for Borrelia burgdorferi sensu stricto.

Prevalence of IgG antibodies against Borrelia Burgdorferi s.l. and Ehrlichia Phagocytophila in sera of patients presenting symptoms of Lyme disease in a central region of Italy

The aim of this study was to evaluate the prevalence (seroprevalence) of antibodies against Borrelia burgdorferi and Ehrlichia phagocytophila among patients resident in Lazio, a region of central Italy. Of a sample of 1,050 patients, which presented clinical manifestations related to Lyme disease, 34 (3.2%) were Borrelia-seropositive (Lyme index value >/= 1.2). The sera of 25 out of the 34 patients that were Borrelia-positive were also analysed for the presence of antibodies against E. phagocytophila and 3 (12%) were found Ehrlichia-positive (titres >1:64). No Ehrlichia positive samples were found among sera of 250 Borrelia-negative patients. Since both B. burgdorferi s.l. and Ehrlichia species share the same tick vector (Ixodes ricinus), our results indicate that concurrent transmission of these microbial pathogens might have been occurred among the patients included in this study.

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.

Microbiological indoor air quality in healthy buildings

There is a growing interest in indoor air quality for a better quality environment both at home and at work because many people spend at least 80% of their time indoors. The aim of our study was to evaluate the indoor concentration of airborne bacteria and fungi in a University auditorium, in an office of public buildings and in an apartment in the presence and in absence of building's occupants, building materials and furnishings. The concentrations of airborne bacteria and fungi were determined using a Surface Air System (SAS). In presence of people and furnishings the average air concentrations of bacteria (University auditorium: 925-1225 CFU m(-3); office: 493 CFU m(-3); apartment: 92-182 CFU m(-3)) were higher than in absence (respectively: 190-315 CFU m(-3); 126 CFU m(-3); 66-80 CFU m(-3)). The average air concentrations fungal were higher in presence of people and furnishings (University auditorium: 1256-1769 CFU m(-3); office: 858 CFU m(-3); apartment: 147-297 CFU m(-3)) than in absence (respectively: 301-431 CFU m(-3); 224 CFU m(-3); 102-132 CFU m(-3)). The obtained data can be considered as a step to identify acceptable levels for bioaerosols in common indoor environments.

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.

Lyme borreliosis in central Italy (1995-1998)

From January 1995 to July 1998, 340 serum samples collected in Central Italy from patients clinically suspected of having Lyme borreliosis were investigated. All samples were tested for the presence of antibodies to B. burgdorferi by Elisa. The Elisa positive samples were subjected to further tests by Western Blot for confirmation. Out of 340 patients, 13 (3.8%) proved to be B. burgdorferi positive, while 9 (2.6%) were found to have Lyme disease with seroprevalence being higher in these latter than that of blood donors from Central Italy. Our results indicate that Lyme borreliosis is present in Central Italy. A comparison between Italian and European studies reveals that Lyme disease is still underestimated in Italy, the main reason being that a monitoring system for the study of Lyme borreliosis was only established in 1990.

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.

Borrelia burgdorferi s.l. and Ehrlichia chaffeensis in the National Park of Abruzzo

The aims of the present study were (a) to determine the presence of Ixodes ricinus in three different areas of the National Park of Abruzzo; (b) to search for the presence of Borrelia burgdorferi in the collected sample of Ixodes; (c) to determine the seroprevalence of B. burgdorferi antibodies and E. chaffeensis antibodies in inhabitants of the park and in park workers. The presence of B. burgdorferi in Ixodes was checked by PCR. For the detection of antibodies to B. burgdorferi all sera were assayed by ELISA as screening test and by Western blot as confirmatory test. For the detection of antibodies to E. chaffeensis all sera were assayed by IFA. Antibodies to B. burgdorferi were present in 9.1% of the park workers, 4.5% were confirmed positive by the IgG Western blot test. None of the inhabitants of the park was positive. Antibodies against E. chaffeensis were found in 4.5% of the park workers and 8% of the inhabitants of the park. The results obtained in the collecting of the ticks seem to show that the presence of I. ricinus in the park territory is rather discontinuous and small in number, therefore it is not epidemiologically significant for the transmission of B. burgdorferi sensu lato. Serological study for Ehrlichia revealed a high frequency of E. chaffeensis antibodies in the park inhabitants and a lower prevalence in the park workers.

Geographical incidence of infection with Borrelia burgdorferi in Europe

During recent years many seroepidemiological studies have been published about Lyme borreliosis in various European countries. This paper presents a review of these studies to clarify the geographical incidence of the infection by B. burgdorferi in Europe and particularly in Italy. Data of Lyme disease seroprevalence has been established in European patients or at-risk populations and in blood donors or control subjects. In Northern Europe the sero-prevalence of antibodies to B. burgdorferi in patients or in at-risk subjects is higher in Sweden, 19% and lower in Estonia, 2.7%. In Central Europe the incidence of antibodies to B. burgdorferi in patients or in at-risk subjects is higher in The Netherlands, 28% and Switzerland, about 26%, and lower in Poland, 15%. The range of antibodies to B. burgdorferi in blood donors or control subjects shows the highest spikes in Ireland 15% and the lowest in Austria 7.7% and in Germany 5.5%. In Southern Europe we have the highest incidence in Croatia, 43%, while we have the lowest incidence in Greece, 1.1%. In Italy the seroprevalence of antibodies to B. burgdorferi in patients or in at-risk subjects seems to vary, in Northern Italy, from the lowest incidence in Lombardia 3.2% to the highest in Friuli 22.3%; in Central Italy, from the lowest incidence in Emilia (Parma) 0.2% to the highest in Toscana 18.3%. The range of antibodies to B. burgdorferi in blood donors or control subjects shows the lowest spikes in Lazio 1.5%, while the highest are in Sicilia 10.9%. Although the amount of works on infection diffusion by B. burgdorferi is increasing, the statistical evaluations, comparisons and the drawing of acceptable conclusions continue to be difficult. In fact data, obtained from various European laboratories, are often not directly comparable, because of different serological tests used to detect antibodies to B. burgdorferi. Consequently it seems very important the work that could be performed by a multicenter study on the standardization of the criteria to be used in WB interpretation, presently in progress among several different European laboratories, and the necessary consequent efforts to elaborate a common panel of criteria about the comparison of the data.

Determination of antibodies to Borrelia burgdorferi in the serum of patients living in Calabria, southern Italy

The aim of our work was to determine the sero-prevalence of antibodies to B. burgdorferi in 300 patients living in Calabria, a region of southern Italy. The research of antibodies to B. burgdorferi was conducted by ELISA as a screening method and Western Blot as a confirmatory test. Out of the 300 patients we found a rate of positivity of 7.3% with ELISA and 4.5% with Western Blot. This data allows us to classify Calabria, among the regions where Lyme borreliosis is non-endemic and where sero-epidemiological research has been carried out on patients, as having a degree of positivity second to that of Campania (9.1%) and higher than Lombardy (3.2%) and Umbria (2.8%). Considering all the demographic and clinical data, only that of the higher IgG positivity of males over females is statistically significant.

Lyme disease seroprevalence in a region of central Italy

The present study reports the seroprevalence of IgG antibodies to B. burgdorferi by testing sera from volunteer blood donors in Latium, a region of Central Italy. All samples were tested by ELISA and the positive samples were assayed by Western blotting as a confirmatory test. A positivity rate of 4.3% was recorded by ELISA, while after the confirmatory test by Western blotting the positivity rate decreased to 1.5%. The presence of significant antibody titers to B. burgdorferi in the sera of healthy subjects shows that further investigations are necessary to clarify the real prevalence of Lyme disease in our region.

Epidemiology of urogenital infections caused by Chlamydia trachomatis and outline of characteristic features of patients at risk

A study of Chlamydia trachomatis infection was conducted in two stages on 15,656 subjects at urogenital clinics of the Faculty of Medicine and Surgery at La Sapienza University in Rome, the S. Anna Hospital in Turin, and the Niguarda Hospital in Milan. The overall incidence of the disease was 6.4% in patients examined throughout the whole study period. The rate of positive cases was 5.8% for the 5270 patients examined up to 1990, and 6.7% for the 10,386 patients examined from 1990 to 1992, showing an increasing trend. There was a much higher positivity rate in men (9.8%) than in women (6.0%); the difference was statistically significant. Of all patients, 60%, were asymptomatic. In symptomatic patients, C. trachomatis was present in 18.5% of cases of non-gonococcal urethritis and in 12.8% of cases of salpingitis. The highest incidence of C. trachomatis infection was in women who had begun sexual activity at an early age, (under 25 years in age), had several sexual partners and used intra-uterine contraceptive devices or spermicides or both.

Rate of occurrence of Helicobacter pylori in patients with gastroduodenal pathology: pilot research

In an attempt to establish the etiologic role of Helicobacter pylori (H. pylori) in gastric and/or duodenal pathology, 169 patients were tested and compared with a control group of 25 healthy subjects, for a total of 194 subjects. Data on sex, age, familiarity, smoking, coffee and alcohol habits were collected and each patient underwent histological, microbiological and immunological tests. 80 (41.2%) subjects were found positive to H. pylori. This bacterium was detected in 53.3% of patients with gastric ulcer while IgG were found in 86.7%; in 50% of patients with chronic atrophic gastritis while IgG were detected in 80%; in 48.5% of patients with duodenal ulcer while IgG were found in 87.9%; in 41.8% of patients with superficial chronic gastritis while IgG were detected in 80.2%. In the control group of healthy patients H. pylori was found in 28% of patients while IgG were detected in 62.5%. The results do not confirm a direct clear-cut correlation between this microorganism and the pathologies studied.

TWAR: a new chlamydial species?

In 1986 Grayston and coworkers termed TWAR (or Taiwan Acute Respiratory) a new strain of Chlamydia which has still not received an exact taxonomic classification. In fact, whereas initially the TWAR strain was classified as C. psittaci because of its oval-shaped, glycogen free, dense inclusions, recent studies on the immunological analysis, DNA analysis and ultrastructural morphology, would seem to indicate that TWAR is a new Chlamydial species, whose proposed name as C. pneumonia. TWAR is mainly responsible for respiratory syndrome varying in gravity from a slight form to pneumonia, and is liable to give rise to epidemic forms; in addition, more recently, certain Authors have postulated its involvement in the pathogenesis of ischemic cardiopathy.

[Bacterial anti-Ig activity]

The production of the five classes of immunoglobulins represents the highest grade of the various system of defence the man puts in act against the microbial attack. So bacteria fight in several levels across the different stages of human antibodies synthesis processes and action, trying for cancelling the effect. Therefore, a more exact definition of the mechanisms of bacterial actions against human immunoglobulins would permit us to intervene in a more efficacious way in favour of defence powers of the human organism. In this way we could improve the knowledge of the bacterial damage process, increase the means of human immunization, and our therapy attempts. We analyzed therefore in this study the different defence mechanisms that bacteria use against human immunoglobulins. Bacteria can avoid "a priori" or divert antibodies formation, by synthesis of surface structural identical to components of the host. Bacteria can stop or hinder transmission of antigenic message working against the phagocytosis mechanisms. Bacteria can stop or lessen antibodies synthesis process. Bacteria can avoid specific contact with antibodies, especially, by masking the microbial surface. Bacteria can change their superficial structures to avoid antibodies action. Bacteria can destroy antibodies by synthesis of protease activity capable of hydrolyzing globulins.

[Chlamydiae. 2. Chlamydia trachomatis]

The Chlamydia trachomatis (C.t.) causes trachoma, inclusion conjunctivitis, lymphogranuloma venereum and it is the more frequent responsible of sexually transmitted infections; in fact, only in the United States, 3-4 million of people suffer from these infections each year. Besides, there are many secondary infections that may cause sterility in man and woman. Risk factors, for venereal infections owed to C.t., are related to the number of sexual partners, age, socioeconomics status and sexual preference. More frequently, the C.t. infects persons that begin sexual activity earlier, those who have many sexual partners and an higher level of education. The direct diagnosis for detecting C.t. can be performed with the citologic test, cell culture, direct immunofluorescence and enzyme immuno-assay. Although, the cell culture is the technique of choice, at present the immunofluorescence and enzyme immuno-assay are the methods preferred because of rapidity and esecution. The indirect diagnosis can be achieved by the complement fixation, indirect immunofluorescence and enzyme immuno-assay tests. In this case, excluding the complement fixation test not more reliable, the method of choice depends, above all, upon the kind of infection in progress. Tetracycline, erythromycin, rifampicin and cloramphenicol are considered the treatment of choice.

[Chlamydiae. 1]

Throughout the animal kingdom the Chlamydiae are among the most common and ancient pathogens, but only in the 1966 they were classified by Page in the same genus because of different nosological pictures that they cause, while more recently were identified as bacteria. Chlamydiae have been divided into two species: C. trachomatis and C. psittaci. In 1986 Grayston et al. proved the etiological role of a "new chlamydial strain", named TWAR (Taiwan-Acute Respiratory), in human pneumonia and bronchitis; TWAR is distinguishable from other Chlamydiae and possibly represents a new entity. The Chlamydiae are non-motile, metabolically poor bacteria, completely lacking of any enzimatic system for energy production (ATP) and for this reason are obligate intracellular parasites; they poses group-specific, species-specific and type-specific antigens. Four series of surface proteins were identified as responsible for their pathogenic properties, while many Authors consider a particular lipopolysaccharidical acid, group antigen, as a real LPS. These bacteria poses an unique developmental cycle with production of two type of particles different for metabolic and infecting characters: elementary body and reticulate body. The Chlamydiae have a broad spectrum of host. They cause persistent or chronic infections and their survival is insured by the elementary body. The Chlamydiae stimulate the humoral and the cellular-mediate immunity system and are capable of survival in the monocytes and macrophages.