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Biomedical subjects

M Cinco

Publications and source records attributed to M Cinco.

At least 19 recordsLinked to original sources

Serological evidence of Rickettsia infections in forestry rangers in north-eastern Italy.

The prevalence of antibodies to Rickettsiae and other tick-borne microrganisms in the sera of 181 forestry rangers from Friuli-Venezia-Giulia, Italy, was examined. Seven (3.9%) sera were positive for Rickettsia conorii and Rickettsia helvetica, as single or dual infections; four of these sera had been found previously to be positive for Borrelia burgdorferi. Antibodies to Coxiella burnetii were detected in five (2.8%) sera, four of which were also positive for B. burgdorferi. These findings indicate that patients in this north-eastern Italian region with fever subsequent to tick-bite should be investigated for Rickettsia and Coxiella infections.

Animals↗

Guidelines for the diagnosis of tick-borne bacterial diseases in Europe.

Ticks are obligate haematophagous acarines that parasitise every class of vertebrate (including man) and have a worldwide distribution. An increasing awareness of tick-borne diseases among clinicians and scientific researchers has led to the recent description of a number of emerging tick-borne bacterial diseases. Since the identification of Borrelia burgdorferi as the agent of Lyme disease in 1982, 11 tick-borne human bacterial pathogens have been described in Europe. Aetiological diagnosis of tick-transmitted diseases is often difficult and relies on specialised laboratories using very specific tools. Interpretation of laboratory data is very important in order to establish the diagnosis. These guidelines aim to help clinicians and microbiologists in diagnosing infection transmitted by tick bites and to provide the scientific and medical community with a better understanding of these infectious diseases.

Animals↗

Seroprevalence of tick-borne infections in forestry rangers from northeastern Italy.

The aim of this study was to estimate the seroprevalence of antibodies to Borrelia burgdorferi, Anaplasma phagocitophilum and tick-borne encephalitis (TBE) virus, and risk factors, in forestry rangers from the Friuli-Venezia-Giulia region in northeastern Italy. Sera from 181 forestry rangers were examined with two-tiered serological tests for TBE, Lyme borreliosis and ehrlichiosis. Information about risk factors such as job location, residence, number of tick bites and outdoor leisure activities was collected with a questionnaire. Seropositivity was 0.6% for TBE virus, 23.2% for Lyme borreliosis and 0.6% for ehrlichiosis. Lyme borreliosis positivity, as determined by Western blot, was associated with working in the foothills, with gardening in the northeastern part of the region, and with a history of yearly tick bites. Risk factors were similar when a case of Lyme borreliosis was defined either by Western blot positivity or by clinical history.

Adult↗

Induction of cystic forms by different stress conditions in Borrelia burgdorferi.

Cystic forms of Borrelia burgdorferi might represent a low metabolic activity state or phase of B. burgdorferi cells that allows the spirochete to survive in a hostile environment until conditions are favourable to multiply again. In this study we evaluated the rate of cyst formation induced by oxidative stress, pH variations, and heating, reconversion of cysts to vegetative forms, and some aspects of their metabolic activity. We observed cyst formation in the presence of extreme pH values, and at high temperature, but the best production of cystic forms was observed in the presence of H2O2. When transferred to BSK II medium, the cystic forms reconverted to spirochetes in relation to their age and type of induction treatment. Furthermore, we demonstrated a low metabolic activity of cystic forms by measuring amino acid incorporation. Overall, these data suggest that the phenomenon of conversion to cysts by B. burgdorferi provides a limited survival potential. This short-term survival, however, gives borreliae an additional chance to overcome unfavourable environmental conditions.

Amino Acids↗

Acarological risk of exposure to agents of tick-borne zoonoses in the first recognized Italian focus of Lyme borreliosis.

Acarological risk was calculated as the probability of encountering at least one host-seeking Ixodes ricinus tick infected by the pathogen Borrelia burgdorferi sensu lato, in 100 m transects in the province of Genoa, Italy. The seasonal pattern of I. ricinus was studied using generalized estimating equations (GEE) with negative binomial error, to consider overdispersion of tick counts and repeated sampling of the same dragging sites from April 1998 to March 1999. Prevalence of infection by B. burgdorferi s.l. was evaluated by PCR and hybridization with genospecies-specific probes. Acarological risk (R) peaked in April (R = 0.2, 95% CI 0.13-0.26) and November (R = 0.29, 95% CI 0.10-0.46). Borrelia garinii and B. valaisiana were the most common genospecies at our study site suggesting a major role of birds as reservoirs. DNA from Anaplasma phagocytophilum, the agent of granulocytic ehrlichiosis in humans and animals, was amplified from an adult I. ricinus.

Anaplasma↗

Conversion of Borrelia garinii cystic forms to motile spirochetes in vivo.

Cystic forms (also called spheroplasts or starvation forms) and their ability to reconvert into normal motile spirochetes have already been demonstrated in the Borrelia burgdorferi sensu lato complex. The aim of this study was to determine whether motile B. garinii could develop from cystic forms, not only in vitro but also in vivo, in cyst-inoculated mice. The cysts prepared in distilled water were able to reconvert into normal motile spirochetes at any time during in vitro experiments, lasting one month, even after freeze-thawing of the cysts. Motile spirochetes were successfully isolated from 2 out of 15 mice inoculated intraperitoneally with cystic forms, showing the infectivity of the cysts. The demonstrated capacity of the cysts to reconvert into motile spirochetes in vivo and their surprising resistance to adverse environmental conditions should lead to further studies on the role and function of these forms in Lyme disease.

Animals↗

Evidence of involvement of the mannose receptor in adhesion of Borrelia burgdorferi to monocyte/macrophages.

The mannose receptor (MR) plays an important role in the recognition of some pathogens in nonopsonic phagocytosis and in antigen presentation to T cells. We found that Borrelia burgdorferi, the agent of Lyme borreliosis, adheres to monocyte-derived macrophages and to rat MR-transfected cells but not to untransfected cells. Antibodies to MR and sugars such as mannose, mannan, fucose, and some lectins significantly lowered the adhesion, confirming participation of the MR in the binding.

Bacterial Adhesion↗

Isolation and characterization of Borrelia burgdorferi sensu lato strains in an area of Italy where Lyme borreliosis is endemic.

Between 1993 and 1998, we isolated Borrelia burgdorferi sensu lato from 55 of the 119 patients with clinically diagnosed Lyme borreliosis who were admitted to "San Martino" Hospital in Belluno, Veneto, an Adriatic region in northeastern Italy where Lyme borreliosis is endemic. Upon hospitalization, all patients presented erythema migrans. Isolates were typed using ribosomal DNA PCR-restriction fragment length polymorphism (RFLP) analysis of the rrfA-rrlB intergenic spacer. Of the 41 isolates typed, 37 belonged to Borrelia afzelii, 2 to Borrelia garinii, and 2 to B. burgdorferi sensu stricto. Pulsed-field gel electrophoresis, performed on 21 strains (13 new isolates and 8 controls), revealed different RFLP patterns within the B. garinii and B. afzelii strains; among the five B. garinii strains and the 12 B. afzelii strains, three or two different RFLP patterns were identified, according to the restriction enzyme used. The protein patterns of the new isolates confirmed their genotypic classification and revealed the level of expression of some immunodominant proteins like OspA and other characteristic Osps. These findings constitute the first report of such a high recovery rate of B. burgdorferi from patients in a very restricted area in Italy; they also indicate the predominance of the genospecies B. afzelii in the study area and the heterogeneity of the circulating strains.

Adult↗

Sensitivity of Borrelia and Leptospira to Quinupristin-dalfopristin (Synercid) in vitro.

In vitro activity of Quinupristin-dalfopristin (Synercid) against seventeen isolates of Borrelia burgdorferi and two representatives of Leptospira spp. was investigated. MICs ranged from 0.03 to 0.125 for B. burgdorferi and 0.125-0.25 microg/ml for Leptospires. Time killing studies carried out with 2 MIC demonstrated U 3 log(10)-unit killing after 72 h, showing a significant activity against spirochetes, though at a lower level than other antibiotics in use in the therapy of Lyme disease and leptospirosis.

Anti-Bacterial Agents↗

Antigenic conservation of an immunodominant invariable region of the VlsE lipoprotein among European pathogenic genospecies of Borrelia burgdorferi SL.

Lyme disease is caused by genetically divergent spirochetes, including 3 pathogenic genospecies: Borrelia burgdorferi sensu stricto, B. garinii, and B. afzelii. Serodiagnosis is complicated by this genetic diversity. A synthetic peptide (C(6)), based on the 26-mer invariable region (IR(6)) of the variable surface antigen of B. burgdorferi (VlsE), was used as ELISA antigen, to test serum samples collected from mice experimentally infected with the 3 genospecies and from European patients with Lyme disease. Regardless of the infecting strains, mice produced a strong antibody response to C(6), which indicates that IR(6) is antigenically conserved among the pathogenic genospecies. Twenty of 23 patients with culture-confirmed erythema migrans had a detectable antibody response to C(6). A sensitivity of 95.2% was achieved, with serum samples collected from patients with well-defined acrodermatitis chronica atrophicans. Fourteen of 20 patients with symptoms of late Lyme disease also had a positive anti-IR(6) ELISA. Thus, it is possible that C(6) may be used to serodiagnose Lyme disease universally.

Amino Acid Sequence↗

Evidence of Dbps (decorin binding proteins) among European strains of Borrelia burgdorferi sensu lato and in the immune response of LB patient sera.

Decorin binding proteins DbpA and DbpB act as Borrelia burgdorferi (B. burgdorferi) adhesins to decorin, and are able to elicit a persistent antibody response in the mouse; accordingly DbpA protein would seem to be promising in immunoprofilaxis of Lyme borreliosis (LB). This study examines the distribution of Dbp epitopes in European strains of B. burgdorferi, of different genospecies and the presence of antibodies to Dbps in human sera from patients suffering from early and late LB, as revealed by immunoblotting. Different levels of expression of Dbp epitopes were found both among and within genospecies; data from human sera indicate that Dbps are expressed during infection though not as strongly as in the mouse infection.

Adhesins, Bacterial↗

Epidemiological trend of human leptospirosis in Italy between 1994 and 1996.

In the three-year period 1994 1996, 222 reports on human cases of leptospirosis were received by the Italian Ministry of Health. The average annual number of reports was 29.2% lower than in the preceding eight years. In all cases but two the infections were thought to have been acquired in Italy. As in previous years, the majority of cases was observed in the northern regions of the country (83.8%), mostly in males (88.9%). Cases occurred in all age groups, but were more common in the working-age population (15-64 years). There was no common-source outbreaks. The typical leptospiral seasonal course, with a peak in August, was observed. During 1994, leptospirosis was the reported cause of death in 19 patients. Mortality was higher among males than females. The overall fatality rate was 22.6%. During the study period, a total of 126 cases of leptospirosis were confirmed by the National Centre for Leptospirosis or one of the 12 Regional Leptospira Laboratories. Of the 103 patients for whom information on place of residence, contact with animals, occupational and recreational activities was available, 98 (95.1%) were people who live in rural areas or devote themselves to occupational or recreational activities at risk. The likely source of infection and the mode of exposure were known for 55 patients. Forty-five patients (81.8%) were likely infected by contaminating water (43 cases) or soil (2 cases), ten (18.2%) by direct contact with animals or animal urine. Both running (51.2%) and stagnant water (27.9%) have been reported as a source of infection. Rodents were implicated in 50.0% of the 10 cases involving animals. In comparison with the preceding eight-year period, the risk of contracting leptospirosis was found to have increased for recreational activities (from 34.7 to 38.2%) and decreased for occupational activities (from 45.8 to 32.7%). A large number of infections, however, was ascribed to accidental events (25.5%). As in the previous period, besides fever, the involvement of the liver was the most frequent clinical manifestation (70.8%). Influenza-like symptoms were the only signs of illness in 15.1% of cases. Infections by 9 different serogroups were detected. The most frequent antibodies were those against serovars icterohaemorrhagiae, poi, copenhageni and brattislava. The presence of co-agglutinins against serovars belonging to different serogroups prevented the identification of the presumptive infecting serogroup in 19.8% of subjects.

Adolescent↗

Interaction with Borrelia burgdorferi causes increased expression of the CR3 integrin and increased binding affinity to fibronectin via CR3.

We have previously demonstrated that the alphaMbeta2 integrin (known as CR3 or Mac-1) expressed on neutrophils (PMNs) and/or on CHO Mac-1 transfected cells,in the presence of serum complement binds B. burgdorferi and promotes an increased non -opsonic adhesion, in the presence of serum complement. In this study we demonstrate that: 1) living motile B. burgdorferiand recombinant lipidated OspA and OspC, up-regulate CR3 expression on PMNs; 2) in the absence of serum, B. burgdorferi induces increased adhesion of CHO cells expressing CR3 to fibronectin, an extracellular matrix protein. Both the I-domain and the lectin-like domain of CR3 are involved in the binding recognition and activation because mAb anti I-domain and N-acetyl-glucosamine inhibit cell adhesion to fibronectin. These data indicate that B. burgdorferi whole cells, but not Osps, activate CR3 integrin; since this receptor plays a key role in priming neutrophils to important inflammatory events, the interaction of B. burgdorferi with neutrophils via the CR3 may enhance their role both in defence and in disease.

Animals↗

Identification of Leptospira biflexa by real-time homogeneous detection of rapid cycle PCR product.

Sequence analysis of 16S rRNA genes extracted from nucleic acids databases enabled the identification of a Leptospira biflexa (L. biflexa) signature sequence, against which a reverse primer designated L613, was designed. This primer, when used in conjunction with a universal bacterial specific forward primer designated Fd1, enabled the development of a LightCycler-based PCR protocol in which fluorescence emission due to binding of SYBR Green I dye to amplified products could be detected and monitored. A melting temperature (Tm), determined from the melting curve of the amplified product immediately following the termination of thermal cycling, confirmed that the product was that of L. biflexa. Agarose gel electrophoresis therefore was not necessary for identification of PCR products. The PCR protocol was very rapid, and consisted of 30 cycles with a duration of 20 s for each cycle with the monitoring of the melting curve requiring an additional 3 min. The whole protocol was completed in less than 20 min. The PCR protocol was also specific and enabled the identification of 18 strains of L. biflexa, whilst excluding 14 strains of L. interrogans and Leptonema illini. Two examples of its utility in improving work flow of a Leptospira reference laboratory are presented in this article. The use of a simple boiling method for extraction of DNA from all the members of the Leptospiraceae family DNA further simplifies the procedure and makes its use conducive to diagnostic laboratories.

Base Sequence↗

Comparative bacteriostatic and bactericidal activities of cefodizime against Borrelia burgdorferi sensu lato.

The MIC and MSC (minimum spirocheticidal concentration) and killing rate for Borrelia burgdorferi, the etiological agent of Lyme disease, were assessed for cefodizime in comparison with ceftriaxone, minocycline, azithromycin, roxithromycin, and ciprofloxacin. The range of cefodizime MICs was greater than those of azithromycin and roxithromycin but comparable to those of ceftriaxone and minocycline. The MSCs were 1 to 2 dilutions higher than the MICs of all of the tested compounds. The killing curves of cefodizime and ceftriaxone showed parallel courses. In conclusion, cefodizime exerted an activity comparable to that of ceftriaxone against B. burgdorferi.

Borrelia burgdorferi Group↗

Surface receptors of neutrophils towards B. burgdorferi.

The spirochetal agent of Lyme borreliosis, Borrelia burgdorferi, is able to induce an infection which develops in three stages: an early, localized infection, disseminated infection and a third stage, chronic infection, which probably indicates that a protected niche has been established in one or more tissues, where the spirochetes persist even if a specific immune response has been initiated. During the first stage, immediately after their entry into the host tissue, B. burgdorferi meet the motile phagocytic cells, neutrophils and monocytes; this is followed by consequent phagocytosis and killing. Although the rate and mechanism of this killing is not entirely clear, there is evidence that phagocytosis by both neutrophils and monocytes proceeds even in the absence of specific antibodies. We have demonstrated in both neutrophils and CHO Mac-1 (CR3 integrin) transfected cells, that one phagocyte receptor which is involved in B. burgdorferi adhesion in non osponic phagocytosis is the CR3 complement receptor known as integrin alpha m beta 2. Both recognition domains of the integrin, the iC3b site and the COOH terminal lectin site, bind to B. burgdorferi. Data presented here show that inhibition of adhesion on CR3 Mac-1 transfected cells and neutrophils is induced by mannose as well as by N-acetyl-D-glucosamine, sugars known to be specific inhibitors of the COOH terminal lectin-site of the integrin CR3. The inhibitory effect was serum complement independent. On the contrary, monoclonal antibody VIM12 directed towards the lectin domain not only failed to inhibit but improved adhesion, suggesting that, as a consequence of the binding, the integrin becomes more receptive to B. burgdorferi attachment at the I domain. Pretreatment of the borrelias with NalO4 eliminated adhesion, suggesting that the sugar residue/s recognized by CR3 is located on the bacteria.

Animals↗

Detection of HGE agent-like Ehrlichia in Ixodes ricinus ticks in northern Italy by PCR.

Little is known about the distribution of Human Granulocytic Ehrlichiosis (HGE) in Europe and even less is known in Italy, where no case of clinically documented HGE has been reported. In a previous study we reported the presence of Ehrlichia DNA in Ixodes ricinus ticks from Central Italy. By the use of an Ehrlichia-specific PCR we found that 24% of the ticks were positive. Furthermore, we demonstrated a simultaneous coinfection of the same tick by both, Borrelia burgdorferi and Ehrlichia phagocytophila. Since the Friuli-Venezia Giulia region (North-east of Italy) is endemic for Lyme borreliosis (LB) and the geographic distribution of HGE usually overlaps that of LB, we decided to carry out a survey concerning the presence of Ehrlichia spp. in a recreational area near Trieste where the presence of Lyme borreliosis and Borrelia burgdorferi sensu lato in ticks is well demonstrated. Ticks were analyzed in pools (because a low infection rate was expected): eleven samples out of 93 were found positive by Ehrlichia-PCR. Subsequent sequence analysis of some of the positive PCR products revealed a high homology with the HGE agent Ehrlichia (only one base substitution in almost 450 bp sequenced). These findings add new and interesting data on the Ehrlichia epidemiology in Italy. By now we have demonstrated the presence of two distinct granulocytic ehrlichiae in Italiyn ticks by the aid of a PCR-based analysis: Ehrlichia phagocytophila in Central Italy and an HGE-like Ehrlichia in the north-eastern Italy, in a region close to Slovenia where the first reported case of HGE in Europe occurred.

Animals↗

Real-time homogeneous assay of rapid cycle polymerase chain reaction product for identification of Leptonema illini.

Partial 16S rDNA sequences of eight Leptospira-like field isolates that reacted weakly or not at all to microscope agglutination test were found to be similar to the 16S rDNA sequence of the nonpathogen Leptonema illini-type strain 3055. Comparison of these sequences with those of Leptospira 16S rDNA sequences revealed a Leptonema species signature sequence for which a forward amplification primer was designed. This primer was used in conjunction with a bacterial-specific 16S rDNA universal reverse primer for developing a LightCycler-based rapid PCR protocol in which fluorescence emission due to the binding of SYBR green I dye to the amplified products was continuously monitored. A melting temperature (T(m)) determined from the melting curve of the amplified product immediately after PCR confirmed that the product was of Leptonema. The protocol for 24 samples consisting of 30 PCR cycles and melting curve acquisitions required 30 min to complete and agarose gel electrophoresis of the PCR products was not necessary. The method was specific as PCR products were detected from the seven Leptonema reference strains and the eight field isolates that had been previously verified as Leptonema by 16S rDNA sequencing, but not from the two representative strains from each of the eight Leptospira genospecies tested.

Base Sequence↗