Clinical and epidemiological aspects of sporotrichosis: an overview of the cases reported in Europe and in Italy

Sporotrichosis is a fungal infection occurring worldwide, especially in tropical and sub-tropical areas. We present a brief review of clinical and epidemiological aspects of sporotrichosis, as well as its treatment. Sporotrichosis is rarely reported in Europe and the European Centre of Disease Control does not track its infection rate. To fill this gap, we report a survey of clinical cases described over the past forty years in Europe and in Italy.

Infection caused by Sporothrix schenckii: an autochthonous case in Bari, Southern Italy

An autochthonous case of lymphocutaneous sporotrichosis caused by Sporothrix schenckii is reported. The patient developed skin lesions localized along the lymphatics that appeared after he suffered an injury while collecting wicker canes in marshy water. The fungus was identified as Sporothrix schenckii by MALDI-TOF and sequencing. Phylogenetic analysis was also performed. Low MIC values were detected for all tested echinocandins and azoles except for fluconazole. The patient was treated with itraconazole without significant improvement. A regression of lesions was observed after 3 months of therapy with voriconazole. Few cases of sporotrichosis have been reported in Europe. However, several cases of sporotrichosis have been described in Italy. The incidence of sporotrichosis in Italy may be underestimated and microbiologists, and clinicians must be aware of this fungal infection.

Evaluation of Antibiotic Resistance of Helicobacter pylori Strains Isolated in Bari, Southern Italy, in 2017-2018 by Phenotypic and Genotyping Methods

Objective: Helicobacter pylori antibiotic resistance is a constantly evolving process and local surveillance is warranted to guide clinicians in the choice of therapy. Materials and Methods: Antibiotic susceptibility testing was performed by E-test on 92 H. pylori strains, and resistance to clarithromycin and levofloxacin was also evaluated using a commercially available genotyping method. Results: In naïve patients the resistance to clarithromycin, levofloxacin, and metronidazole was 37.7%, 26.2%, and 16.4%, respectively, significantly lower than the percentage found in treated patients. Concomitant resistance to ≥2 antibiotics was also observed in naïve patients. The A2143G mutation of the 23S-rRNA gene was the most frequently detected, also in naïve patients. The highest minimum inhibitory concentration (MIC)₅₀ value (256 mg/L) was associated with A2142 mutations in all the patients carrying them. For levofloxacin resistance a mutation in codon 87 was detected in 63.9% and in codon 91 in 36.1% of the H. pylori strains, without significant differences in the patients groups. A mutation in codon 87 was associated with the highest MIC₅₀ value (32 mg/L). Conclusions: In our area, a high prevalence of H. pylori primary resistance was detected; these rates were higher in patients who had experienced failure of several courses of therapy. A better knowledge of the local epidemiology of resistance, and the genotypes responsible, will improve the H. pylori eradication rates.

A case report of esophageal actinomycosis in an immunocompetent patient and review of the literature

Actinomycosis is a rare, chronic and slowly progressive granulomatous disease caused by Actinomyces spp., a Gram-positive anaerobic bacterium that rarely affects the esophagus. Although this infection is uncommon, it has been reported in both immunocompromised and immunocompetent individuals. The infection is often misdiagnosed because it can mimic other pathological conditions (like neoplasms and candidiasis), and Actinomyces is difficult to isolate because it requires specific growth conditions. However, actinomycosis has a favorable course if the microbiological diagnosis is timely. We report a case of esophageal actinomycosis in an immunocompetent 23-year-old man. The patient was admitted with symptoms of gastro-esophageal reflux disease (GERD), that had subsequently worsened. Histological and microbiological investigations revealed the presence of Actinomyces spp. A review of the literature regarding the clinical features, diagnosis, and management of this infection is also discussed.

Paecilomyces lilacinus Keratitis in a Soft Contact Lens Wearer

We describe a case of keratitis caused by Paecilomyces lilacinus in a contact lens wearer with a history of diabetes.

Isolation and molecular characterization of free-living amoebae from different water sources in Italy

Free-living amoebae (FLA) are protozoa ubiquitous in Nature, isolated from a variety of environments worldwide. In addition to their natural distribution, some species have been found to be pathogenic to humans. In the present study a survey was conducted in order to evaluate the presence and to characterize at molecular level the isolates of amoebic organisms collected from different water sources in Italy. A total of 160 water samples were analyzed by culture and microscopic examination. FLA were found in 46 (28.7%) of the investigated water samples. Groundwater, well waters, and ornamental fountain waters were the sources with higher prevalence rates (85.7%, 50.0%, and 45.9%, respectively). Identification of FLA species/genotypes, based on the 18S rDNA regions, allowed to identify 18 (39.1%) Acanthamoeba isolates (genotypes T4 and T15) and 21 (45.6%) Vermamoeba vermiformis isolates. Other FLA species, including Vahlkampfia sp. and Naegleria spp., previously reported in Italy, were not recovered. The occurrence of potentially pathogenic free-living amoebae in habitats related to human population, as reported in the present study, supports the relevance of FLA as a potential health threat to humans.

Environmental contamination by dog’s faeces: a public health problem?

The risk to public health from the large number of dog stools present on streets of urban areas is cause for concern. Dog faeces may be a serious hazard because they may contain microorganisms that are both pathogenic to humans and resistant to several classes of antibiotics. The aim of this study was to evaluate the potential for zoonotic infections and for the presence of antibiotic resistant bacteria in canine faeces which contaminates the urban environment. A total of 418 canine faecal samples were collected from streets in seven areas of Bari, Southern Italy. We have isolated multi-drug resistant Enterococci and meticillin-resistant Staphylococcus aureus from these dog faecal samples. The presence of the resistant bacteria in an urban environment may represent a public health hazard which requires control measures by competent authorities. No Salmonella, Yersinia or Campylobacter species were isolated. Giardia cysts were detected in 1.9% of the samples. The predominant Enterococcus species were E. faecium (61.6%), E. gallinarum (23.3%) and E. casseliflavus (5.5%). Other species, including E. faecalis were also isolated. These strains were resistant to clindamycin (86.3%), tetracycline (65.7%), erythromycin (60.27%) and ampicillin (47.9%). High-level aminoglycoside resistance (HLAR) was found in 65.7% of enterococci. Resistance to three or more antibiotics and six or more antibiotics were observed in 67.12% and 38.4% of Enterococcus spp., respectively. Resistance to vancomycin and teicoplanin was not detected in any of the Enterococcus spp. isolated. Methicillin-resistant Staphylococcus aureus was isolated in 0.7% of the faecal samples. Canine faeces left on the streets may represent a risk factor for transmission of microorganisms and a reservoir of multidrug- resistant bacteria thus contributing to the spread of resistance genes into an urban area.

Relation of C. pneumoniae antibodies to inflammation and atherosclerosclerosis in dialysis patients

AIM

the aim of this study was to investigate the association between the presence of antibodies to C. pneumoniae, some markers of inflammation and the presence of preclinical atherosclerotic lesions in hemodyalisis (HD) patients treated with different dialytic membranes.

METHODS

C. pneumoniae antibodies were measured by microimmunofluorescence in blood samples of 68 chronic HD patients and in 120 healthy blood donors. Intima-media thickness (IMT) of carotid and of femoral arteries, eco-color doppler of sovraortic trunk and lower limb vessels were evaluated. Plasma levels of C-reactive protein (CRP) and terminal complement (C) complex, C5b-9, were measured.

RESULTS

HD patients treated by cellulosic membranes have significantly higher plasma levels of C5b-9 and of CRP compared to those treated by synthetic membranes. A significantly higher prevalence of IgG antibodies to C. pneumoniae and also at higher titre was observed in HD patients in comparison to the controls (66% vs. 28%). The carotid artery mean wall thickness was significantly lower in C. pneumoniae seronegative patients than C. pneumoniae seropositive patients. Similar results were obtained for limb arteries. The use of cellulosic membranes, but not synthetic membranes, was associated with higher carotid IMT and this was independent of the C. pneumoniae serology status.

CONCLUSION

in addition to known risk factors, the type of dialytic membrane used may contribute to the progression of atherosclerosis lesions in HD patients. Our data strengthen the evidences that C. pneumoniae infection under high inflammatory status might be a further risk factor for progression of atherosclerosis in HD patients, particularly in those treated with cellulosic membranes.

Seroprevalence of Chlamydophila pneumoniae in ischaemic heart disease

We investigated the presence of Chlamydophila pneumoniae antibodies in 125 patients with cardiovascular disease and in 128 controls. C. pneumoniae antibodies were measured by microimmunofluorescence assay. A significantly high prevalence of IgG C. pneumoniae antibodies at titre > or = 8 was found in patients (84%) in comparison to controls (47.6%). Considering as cut-off the IgG titre > or = 32, 52% of patients with coronaropathies and 18.75% of controls resulted positive (p < 0.0001). IgA C. pneumoniae antibodies were found in patients and controls without statistically significant differences. High C. pneumoniae antibodies (titre > or = 256) were found in 11% of patients with acute myocardial infarction (AMI) and in none of the controls. In patients, the percentage of IgG and IgA seropositivity increased with age and decreased in patients aged > 70 years. Only patients with AMI are at risk of having antibodies against C. pneumoniae (OR = 6.69). None of the known risk factors for cardiovascular disease was significantly associated with C. pneumoniae seropositivity IgG. This is the first report in our area on the possible association of C. pneumoniae IgG seropositivity and acute ischemic events.

Anisakis pegreffi etiological agent of gastric infections in two Italian women

Two cases of gastric anisakiasis have been documented in two Italian women who had consumed raw anchovies (Engraulis encrasicolus). The first patient was a 49-year-old woman presenting with epigastric pain and bloody vomiting after ingestion of marinated (vinegar) raw anchovies. During the esophagogastroduodenoscopy (EGDS) a white color worm was detected and extracted from cardia by means of biopsy forceps. The second patient was a 59-year-old woman with irritable bowel syndrome and gastritis, who underwent to periodical EGDSs. In the course of the last EGDS, a white color round worm on antrum and a small polyp on the fundus of the stomach were observed. The two nematodes have been identified as L3 larvae of the genus Anisakis by a light microscope, and as Anisakis pegreffi by polymerase chain reaction-restriction fragment length polymorphism. The molecular identification of the etiological agent at the species level allows to identify what Anisakidae species play a zoonotic role and which are the fish host species.

The source of Helicobacter pylori infection in the neonatal period

AIMS

To investigate the transmission of Helicobacter pylori in the perinatal period.

METHODS

H. pylori status of 180 women was preliminarily screened by serology and stool antigen test (SAT) within the fourth day after delivery and a positive value was confirmed by (13)C-urea breath test. Infants were analyzed by SAT at 1, 6, 12 and 18 months of age. H. pylori status was also investigated in the medical and paramedical staff of the Neonatology Unit.

RESULTS

H. pylori infection was found in 34.4% of the women. At the 1(st) month of age, 5 out of 172 newborns (2.9%) were H. pylori positive by SAT. Three out of the five positive infants were born to H. pylori non-infected mothers. Formula feeding (P=0.02) and admission in intermediate-risk neonatal unit (P=0.01) were significantly related to a positive H. pylori result. Medical and paramedical staff of the neonatology unit was found H. pylori positive in 34.8% of cases. All five H. pylori positive children spontaneously cleared the infection.

CONCLUSIONS

Perinatal H. pylori SAT positive status is low in our area, and it may be found both in infants from infected or non-infected mothers. Formula feeding and admission in intermediate-risk neonatal unit appear to be related with H. pylori infection.

Recombinant K39 immunochromatographic test for diagnosis of human leishmaniasis

A new recombinant K39 immunochromatographic test (ICT) was compared with the immunofluorescent antibody assay (IFA) for the rapid serological diagnosis of visceral leishmaniasis (VL) in Apulia, Southern Italy. A total of 264 individuals were tested, including 19 patients with VL (three of which were HIV positive), 67 individuals with suspected VL, 40 healthy controls and 138 patients with other diseases. The ICT was positive in all 19 patients with VL and negative in sera from the remaining individuals. Both the sensitivity and specificity of ICT was 100%. The ICT also worked well in HIV–Leishmania co-infected patients. Antibodies to Leishmania detected by the IFA and ICT remained at detectable levels for up to 12–24 months. A positive reaction by the ICT was detectable at a serum dilution of up to 1:20,480, indicating that a strong immunoresponse is mounted against the recombinant K39 antigen. In conclusion, the ICT is highly sensitive, specific, rapid, noninvasive and cost effective (€8.43 for ICT and €12 for IFA) in the diagnosis of VL in areas of low VL endemicity.

Seroprevalence of Q fever, brucellosis and leptospirosis in farmers and agricultural workers in Bari, Southern Italy

To establish the seroprevalence of antibodies to C. burnetii, Leptospira and Brucella in subjects at risk of exposure, 128 workers exposed to farm animals and 280 healthy blood donors were studied. Antibodies to C. burnetii, Leptospira and Brucella were determined by indirect immunofluorescence assay, by microagglutination test (MAT) and by standard tube agglutination test, respectively. Of subjects exposed to farm animals 73.4 % were positive for anti C. burnetii IgG (titer > or = 20) compared to 13.6 % of control subjects (p < 0.0001). The seroprevalence was found mainly among the veterinarians (100 %) and the animal breeding workers (84 %). The trend of percentage of positivity to antibodies to C. burnetii is significant only in the group of workers > or = 70 years, when adjusted for sex and occupation. None of the subjects examined had antibodies to Leptospira and Brucella. Further improvements in the occupational hygiene of the work environment is advisable.

Helicobacter pylori seroprevalence in selected groups of Albanian volunteers

BACKGROUND

Albania is a Mediterranean, South-East European developing country where epidemiological data on infectious diseases are scarce. In this study, the seroprevalence of Helicobacter pylori infection in 1,088 Albanian healthy volunteers (472 females followed-up to a prenatal clinic, 173 recruits, 443 health care workers) was evaluated.

MATERIALS AND METHODS

Sera were tested for immunoglobulin-G (IgG) antibodies against H. pylori using a quantitative enzyme immunosorbent assay.

RESULTS

The overall H. pylori seroprevalence was 70.7%. The H. pylori seroprevalence increased by age, from 60.4% in individuals younger than 20 years to 81% among those > or = 50 years of age with a significant trend of increase by age. The overall seroprevalence was 73.9% for females and 59.5% for males. In addition the seroprevalence was 55.3% for people living in rural areas and 72.3% for people living in urban areas. No significant differences were found according to level of education except for individuals with elementary level of education. Nurses and hospital auxiliaries have significantly higher H. pylori seroprevalence when compared to other health care workers (physicians and office workers). When each variable (age, gender, area of residence, occupation, and education level) was adjusted for the confounding effect of the other variables by stepwise logistic analysis, we observed that age greater than 40 years and female gender remain the only variables independently associated with the presence of H. pylori IgG antibodies.

CONCLUSIONS

H. pylori is highly prevalent among the Albanian population. Improving living conditions, education in hygiene, and the supply of running water are measures to prevent the transmission of H. pylori infection and other infections spread by the fecal-oral route in Albania.

Amebic liver abscess: report of three cases

Amebic abscess is a common manifestation of extraintestinal amebiasis and it is associated with relatively high morbidity and mortality. We present three cases seen in Bari, Southern Italy, one of which was autochthonous and the other two were not. Diagnosis was performed by elevated antibody titre for E. histolytica through immunofluorescence assay and positive antigen determination by ELISA in stools and in abscess aspirate. Fever often accompanied by chills, abdominal pain, weight loss and hepatomegaly were present. Laboratory findings also revealed leukocytosis with neutrophilia. Pleural effusion was observed in two patients. In all our patients multiple abscesses were observed. All the patients were treated with metronidazole and two of them also underwent the aspiration of the amoebic abscess. In all of them there was improvement of the clinical picture, as demonstrated by computerized tomography.

Amoebic hepatic abscesses in an HIV-positive patient

Herein we report the case of hepatic amoebic abscesses in an HIV-positive Italian seaman with a history of promiscuous heterosexual intercourse. In October 2004, the patient was hospitalized because of fever and recurring abdominal pain. Abdominal ultrasonography revealed six hepatic hypoechoid oval lesions with hyperechoid margins. Stool samples were negative for parasites and bacteria, and serology for Entamoeba histolytica was also negative. Therapy with meropenem plus levofloxacin was initiated. After a partial resolution of clinical symptoms and reduction of three hepatic lesions, the patient was again hospitalized in December 2004, because of recurring intense pain at the right hypochondrium and fever. At this time, one hepatic lesion at the sixth segment was enlarged, two lesions were unchanged, and the remaining three smaller abscesses were resolved. Serum antibodies for E. histolytica and amoebic antigens on the largest abscess drainage were positive; moreover, E. histolytica was also identified on drainage fluid with polymerase chain reaction (PCR). Therapy with metronidazole followed by paromomycin improved both symptoms and radiographic images. This case report suggests that in HIV-infected patients, invasive amoebiasis should be considered and atypical aspects, such as multiple hepatic lesions, delayed positivity of serology for E. histolytica, and possible bacterial superinfection should be evaluated.

Role of chlamydia infection in the pathogenesis of atherosclerotic plaques in HIV-1-positive patients

BACKGROUND

Various authors have hypothesized a role of Chlamydia pneumoniae infection in the pathogenesis of atherosclerosis. To better understand the possible role of this infection in the pathogenesis of epi-aortic lesions in HIV-1-positive patients, the presence of anti-Chlamydia pneumoniae antibodies was evaluated in a group of individuals subjected to ultrasonography of the epi-aortic vessels.

PATIENTS AND METHODS

The presence of specific antibodies in 129 subjects was determined; 59 patients were HIV-1-positive, of whom 30 had carotid plaques and 29 were without lesions. The control group was composed of 70 subjects. All were subjected to ultrasonography of the epi-aortic vessels. IgG, IgM and IgA anti-C. pneumoniae antibodies were measured with micro-immunofluorescence and positive sera were tested for C. trachomatis and C. psittaci.

RESULTS

No subjects were positive for IgM. Both the IgA and IgG levels did not differ significantly in the three groups. The only highly significant variable was the use of protease inhibitors.

CONCLUSION

Our data suggest that the damage to the carotid wall in HIV-1 patients was not due to C. pneumoniae.

Detection of human papilloma virus in women attending the IRCCS, Ospedale oncologico Bari, Southern Italy: preliminary data

We investigated the diffusion of HPV genotypes using molecular methods. HPV DNA was detected in 30.4% of women examined. The genotype HPV 16 was the most common followed by HPV 31, HPV 51 and HPV 58. Mixed infections were observed in 30.4% of HPV positive women. The 66.7% of the lower age group (< 35 years) was HPV positive. HPV infection was associated with the presence of morphological abnormalities in 13.7% of the women examined. The presence of HPV DNA in women younger than 35 years is an indication for the implementation of sexually transmitted disease education in our area to prevent potentially dangerous infections.

Quantitative kinetics of damage and recovery of cytoskeletal structure by means of image analysis

The cytoskeleton is a network of proteins which structurally and dynamically organise the cytoplasm of living cells. Microtubules are among its constituents. Morphological alterations of microtubules are related to functional impairment. Therefore cytoskeletal morphology is a valuable indicator of cell injury and functionality. This paper focuses on the comparison between normal and altered cytoskeletal microtubules by means of image analysis and classification with the aim of replacing visual assessment. Morphology has been quantified by the extraction of some descriptors yielded by spatial differentiation, fractal analysis and Fourier analysis followed by non-linear filtering. The principal component analysis of these descriptors has led to image recognition and has been applied to hepatocytes and fibroblasts exposed to some xenobiotics. In the case of hepatocytes, images have been ranked according to the severity of cytoskeletal damage, a dose-response relation has been derived from the regression of the first principal component and the percentage of structural recovery after exposure has been estimated.

Reduced expression of the chemokine receptor CCR1 in human macrophages and U-937 cells in vitro infected with Leishmania infantum

Chemokines exert their actions through G-proteinlinked receptors, which are expressed to variable extents by different cell types. In accordance with the chemokine classification, these receptors are designated as CXC, CC, XC, and CX(3)C, followed by R and a number. The purpose of this investigation was to evaluate CCR1 expression in human peripheral blood-derived macrophages and the human monocytic U-937 cell line. Cells in vitro were infected with live Leishmania infantum promastigotes (zymodeme MON1); cell lysates were then subjected to SDS-PAGE and immunoblotting, by using an anti-CCR1 affinity purified polyclonal antibody. The expression of the CCR1 gene was analyzed by RT-PCR, using specific human primers. The results of both immunoblotting and RT-PCR showed that CCR1 expression in Leishmania-infected cells was lower than in uninfected control cells. These results indicate that Leishmania infantum infection causes a down-regulation of the CCR1 gene and protein expression, suggesting that reduced phagocyte recruitment at the inflammation sites could favor parasite progression and the spread of Leishmania infection.

In vitro assays for evaluation of drug activity against Leishmania spp

Leishmania is a parasitic protozoan which causes severe disease in humans and dogs. Screening of new compounds against leishmaniasis is particularly needed to determine the toxicity of some existing drugs and the appearance of drug-resistant strains. Reliable and simple in vitro models are required for large-scale initial screenings. In this review different methods for in vitro evaluation of drug activity against Leishmania spp. are summarized.

Chlamydia pneumoniae in community-acquired pneumonia: seven years of experience

OBJECTIVES

To determine the prevalence of Chlamydia pneumoniae in community-acquired pneumonia during a period of seven years.

METHODS

Serum samples from 311 patients with pneumonia were evaluated using microimmunofluorescence assay to detect C. pneumoniae -specific IgG and IgM antibodies.

RESULTS

Thirty nine patients (12.5%) complied with the diagnostic criteria of acute C. pneumoniae infection (a four-fold rise in the titer of IgG antibody, or a single IgG titer > or = 1:512, or a single IgM titer > or = 1:16). All patients were diagnosed as having pneumonia. Co-infection with other respiratory tract pathogens was found in four patients.

CONCLUSIONS

C. pneumoniae is an important cause of pneumonia also in our area. Pneumonia due to this bacterium occurs in the cold months and in early spring; in addition we have observed periods of increased incidence of one years duration and periods of low incidence lasting one-two years. Therapy with macrolides and levofloxacin was effective in all patients with C. pneumoniae infection.

Unusual presentation of leishmaniasis as an adrenal cystic mass

An unusual presentation of leishmaniasis that occurred in an Italian immunocompetent woman is described. The patient had a long history of coagulopathy due to factor VIII deficiency and pain in the right lumbar region. Computed axial tomography demonstrated a cystic mass in the right adrenal gland. Histological examination of the surgically removed cyst showed the presence of histiocytes containing Leishmania amastigotes. Serodiagnosis for leishmaniasis performed through immunofluorescent antibody testing and the rK39 enzyme immunoassay was positive, whereas a bone marrow aspirate did not reveal any parasite. The patient was not treated for leishmaniasis and recovered well after surgery. Serological testing was still positive 2 years after surgery, but clinical follow-up did not reveal the signs typical of visceral leishmaniasis.

Evaluation of a rapid immunochromatographic test for serodiagnosis of visceral leishmaniasis

The purpose of this study was to compare the performance of a rapid immunochromatographic dipstick test for the qualitative detection of circulating antibodies to the leishmanial recombinant antigen K39 with that of a classical immunofluorescent antibody test for serodiagnosis of visceral leishmaniasis. Sera from 143 Italian subjects, including 69 patients with clinically suspected visceral leishmaniasis, 23 patients with hypergammaglobulinemia and 51 healthy controls, were tested. The immunochromatographic test was performed according to the manufacturer's instructions, using antigen-impregnated nitrocellulose paper strips. The immunofluorescent antibody test was performed according to an established method, using promastigotes of Leishmania infantum zymodeme Montpellier 1 as antigen. In 11 patients, diagnosis of active Leishmania infection was established by microscopic examination of biopsy samples and/or clinical response to meglumine antimoniate. Results of the two tests correlated for all but two sera examined. In two patients, one with proven infectious mononucleosis and one with bacterial pneumonia, the immunofluorescent antibody test was positive and the dipstick test was negative. In the restricted sample of patients in whom a definitive diagnosis was established, the immunochromatographic test was positive in 11 of 11 patients with confirmed Leishmania infection and negative in 103 of 103 subjects who either had other documented diseases or were healthy controls, showing 100% sensitivity and 100% specificity.

Nitric oxide production by Leishmania-infected macrophages and modulation by cytokines and prostaglandins

Nitric oxide (NO) produced by an inducible nitric oxide synthase (iNOS or NOS2) plays a major microbicidal role in murine macrophages and its importance is now emerging also in the dog and human models. In dogs we demonstrated that macrophages in vitro infected with Leishmania infantum produced NO, after stimulation with cytokine-enriched peripheral blood mononuclear cell supernatants. In addition, parasite killing was reduced by the NOS inhibitor L-NG monomethylarginine. On the contrary, canine blood monocytes before macrophage differentiation did not release NO, and their leishmanicidal activity was instead correlated with superoxide anion and interferon (IFN)-gamma production. In human macrophage cultures, after infection with Leishmania infantum, we showed both iNOS expression by immunofluorescence and western blotting and NO release by the Griess reaction for nitrites. Various cytokines and prostaglandins can differently modulate NO synthesis. In our experiments, stimulation by recombinant human IFN-gamma and bacterial lipopolysaccharide greatly enhanced iNOS expression and NO production in human macrophages. In addition, the prostaglandin E2 increased NO release in activated, Leishmania-infected human macrophages. These results are interesting in the light of a possible immunological or pharmacological regulation of NO synthesis and microbicidal functions of macrophages.

Inducible nitric oxide synthase expression in Leishmania-infected dog macrophages

Nitric oxide (NO) production by the inducible NO synthase (iNOS or NOS2) represents one of the main microbicidal mechanisms of murine macrophages, but its role in other animal models is poorly investigated. Therefore, the aim of this work was to evaluate NOS2 expression in dog macrophages infected with Leishmania infantum. Macrophages obtained from peripheral blood of healthy dogs were activated with recombinant human interferon (rhIFN)-gamma and bacterial lipopolysaccharide (LPS) and then infected with L. infantum promastigotes. zymodeme MONI. For the immunofluorescence assay fixed macrophages were incubated with polyclonal rabbit anti-NOS2 and then with rhodamine F(ab')2 goat anti-rabbit IgG. For immunoblotting, cell lysates were submitted to SDS-PAGE and blots were incubated with polyclonal rabbit anti-NOS2 and then with horseradish peroxidase-conjugated goat anti-rabbit IgG. Results demonstrated that L. infantum-infected cells, after stimulation with rhIFN-gamma and LPS, displayed high levels of fluorescence for the NOS2 in their cytoplasm, unlike unstimulated uninfected macrophages. In western blotting, polyclonal anti-NOS2 reacted specifically with a protein band corresponding to 130 kDa. The signal produced in Leishmania-infected cells stimulated with rhIFN-gamma and LPS was higher than that produced in Leishmania-infected unstimulated cells. No band was detected in cellular lysates from uninfected unstimulated cells. These results indicate that dog macrophages can express NOS2, and suggest a role for IFN-gamma and LPS in NOS2 induction also in this animal model.

Nitric oxide production by Leishmania-infected macrophages and modulation by prostaglandin E2

Nitric oxide (NO), produced by the nitric oxide synthase (iNOS) enzyme, is the most-important molecule responsible for the killing of Leishmania parasites by macrophages. In previous work we have demonstrated that, after activation with recombinant human interferon-gamma and/or bacterial lipopolysaccharide, human macrophages infected with Leishmania infantum are able to produce nitric oxide and to express nitric oxide synthase. The arachidonate derivative prostaglandin E2 has been shown to modulate various macrophage activities, and in particular nitric oxide production, sometimes with opposite effects, related to experimental conditions. In this work we have evaluated nitric oxide release and parasite killing by peripheral blood-derived L. infantum-infected human macrophages in vitro stimulated with lipopolysaccharide and simultaneously treated with prostaglandin E2. Experiments were also performed in the presence of the nitric oxide synthase inhibitor L-NGmonomethylarginine (L-NMMA) and of the cyclooxygenase inhibitor indomethacin. Nitric oxide release in supernatants of macrophage cultures was measured by the Griess reaction for nitrites. Parasite killing was microscopically evaluated by fluorescent dyes. Results demonstrated that macrophages stimulated with lipopolysaccharide and treated with prostaglandin E2 exhibited increased nitric oxide production and parasite killing, which were significantly reduced by either L-NMMA or indomethacin. In indomethacin-treated macrophages, nitric oxide production and leishmanicidal ability were partially restored by the addition of exogenous prostaglandin E2. Taken together, these results indicate that prostaglandin E2 may be involved in nitric oxide production, and possibly in the host-protective immune response against Leishmania. Moreover, the demonstration of a stimulatory role of prostaglandin E2 on nitric oxide production induced by intracellular pathogens in humans is interesting in the light of a possible pharmacological regulation of nitric oxide by modulation of prostaglandin E2 synthesis.

Interactions between Leishmania parasites and host cells

Several species of protozoa belonging to the genus Leishmania are pathogenic for humans, causing visceral and cutaneous diseases. They are transmitted by phlebotomine sandflies as flagellated promastigotes to mammals hosts, where they live as aflagellated amastigotes mainly within macrophages. Studies performed on mice infected with Leishmania major demonstrated that host defence against this infection depends on the interleukin-12-driven expansion of the T helper 1 cell subset, with production of cytokines such as interferon-gamma, which activate macrophages for parasite killing through the release of nitric oxide. The parasitocidal role of this radical is now emerging also in the human and canine model. Healing or progression of the infection is related to the genetic and immune status of the host, and to the virulence of different species and strains of Leishmania. The parasite survival ultimately depends on the ability to evade the host immune response by several mechanisms. Among them, inhibition of the signal transduction pathway of the host cells is particularly important. In fact, promastigotes inhibit protein kinase C activation, cause Ca++ influx into the host cell and decrease the levels of myristoylated alanine-rich C kinase substrate-related proteins, which are substrates for PKC. In addition, Leishmania infection blocks IFN-gamma-induced tyrosine kinase phosphorylation, with consequent impairment of signalling for IL-12 and nitric oxide production. Finally, Leishmania activates protein phosphotyrosine phosphatases, which down-regulate mitogen-activated protein kinase signalling and c-fos and nitric oxide synthase expression. New pharmacological applications, including protein tyrosine phosphatase and protein farnesyltransferase inhibitors, are being evaluated against leishmaniosis in vitro and in vivo in the murine model.

Detection of Bartonella henselae and Afipia felis DNA by polymerase chain reaction in specimens from patients with cat scratch disease

Polymerase chain reaction (PCR) amplification and colorimetric identification of amplicons were performed to detect Bartonella henselae and Afipia felis DNA in specimens from patients who were clinically and histologically suspected of having cat scratch disease. PCR products were revealed using 2% ethidium bromide agarose-gel electrophoresis and identified with specific probes in a commercial colorimetric hybridization assay (DEIA) (GEN-ETI-K; DiaSorin, Italy). Six paraffin-embedded lymph node biopsies from 18 patients as well as 18 samples of peripheral whole blood and 18 sera were investigated. Bartonella henselae DNA was recovered from the whole blood of four patients, and Bartonella henselae and Afipia felis DNA were detected in one patient's lymph node biopsy. This study suggests that PCR-DEIA is sufficiently sensitive to be considered feasible for the molecular diagnosis of cat scratch disease.

Giardia and Cryptosporidium in water: evaluation of two concentration methods and occurrence in wastewater

Giardia and Cryptosporidium are important agents of water-borne parasitic diseases. In this work we have examined the recovery efficiency of two methods for concentrating Giardia cysts and Cryptosporidium oocysts from water: a membrane filtration method and a crossflow filtration method. Results demonstrated a higher recovery efficiency for crossflow filtration method in comparison to the membrane filtration method. In addition, Giardia cysts and Cryptosporidium oocysts concentration was evaluated in wastewater samples submitted to chemical flocculation or chemical flocculation followed by slow sand filtration. Results showed that slow sand filtration was capable of reducing the number of Giardia cysts, but not of Cryptosporidium oocysts in wastewater.

Polymerase chain reaction detection of Bartonella henselae bacteraemia in an immunocompetent child with cat-scratch disease

A case of Bartonella henselae bacteraemia is reported in an immunocompetent 8-year-old boy with cat-scratch disease. Serology to B. henselae, diagnosed by polymerase chain reaction, was positive. DNA was extracted from peripheral whole blood and amplified with specific primers targeting the htrA gene of B. henselae. A non-isotopic hybridization assay with a species-specific oligonucleotide probe was used to detect the amplified product.

CONCLUSION

The polymerase chain reaction can be used for the rapid laboratory diagnosis of bacteraemia in cat-scratch disease.

Prevalence of antibodies to Bartonella henselae in patients with suspected cat scratch disease (CSD) in Italy

Cat scratch disease (CSD) is a relatively new diagnosed illness with clinical signs of self-limiting regional lymphadenopathy accompanied by symptoms of fever and malaise, to encephalopathy and neuropathy, occurring after a cat scratch or flea bite. Bartonella henselae is now accepted as the etiologic agent of CSD. From January 1994 to September 1998, 412 patients were evaluated for suspect CSD in Italy. Sera were tested for antibodies to B. henselae by a commercially available indirect immunofluorescent assay (IFA), based on B. henselae-infected Vero-cells as the antigen substrate. Of the 412 patients, 26 (6.3%) were considered positive having titers of immunoglobulin G (IgG) to B. henselae of 64 or higher. In these patients CSD was indeed confirmed by either histopathologic examination of lymph nodes biopsy or fourfold raise in antibody titers. Nevertheless, sera were tested by IFA for Afipia felis and one showed a double reactivity to B. henselae and A. felis. Finally, three sera, negative to B. henselae serology, were positive to A. felis. Three hundred and eighty-six patients received alternative diagnoses. One hundred and twenty-five serum samples from control subjects were negative by IFA for either B. henselae or A. felis. Moreover, a cross-reactivity with sera from patients affected by other diseases was not observed. Our study shows that the ascertained cases of CSD are etiologically determined by B. henselae, IFA assay is confirmed as a useful tool in the laboratory diagnosis and, over a 5 years period of study, the incidence of CSD in Italy has been low.

Gastrospirillum hominis and human chronic gastritis

Gastrospirillum hominis, a new spiral bacterium, was found in the gastric mucosa of two patients with antral chronic gastritis. These 2 cases originated from a series of 2781 consecutive gastric biopsies observed over a period of five years, with a prevalence of 0.072%. Dogs and cats may be responsible for transmission to humans but in our experience no contact with pets was documented. Detection of these organisms might provide new insight into the pathogenesis of human gastritis.

[The treatment of bacterial infections of the lower respiratory tract in childhood. An open comparative study of sulbactam/ampicillin vs. ceftazidime]

Sixty children suffering from lower respiratory tract infections have been included into this study, respectively 30 (18 M + 12 F) in the sulbactam/ampicillin (S/A) group and 30 (20 M + 10 F) in the ceftazidime (CFT) group. Average age was 42.9 months +/- 34.4 in S/A group (range 6-120) and 48.7 +/- 42.1 (range 6-144) in CFT group. Both groups were similar as to sex, age, type and duration of the infection. Posology was 150 mg/kg/die for S/A and 50 mg/kg/die for CFT. The duration of treatment was 7.2 days +/- 2.2 (range 5-12) for S/A group and 6.4 days +/- 1.6 (range 5-12) for CFT group. At the end of the therapy clinical recovery has been obtained in all cases. A rapid defervescence and remission of symptoms at an identical rate has been recorded in both treatment groups. General and local tolerability was excellent in both treatment groups.