Case report: detection of rotavirus RNA in the cerebrospinal fluid of a child with rotavirus gastroenteritis and meningism

Although case reports have described detection of rotavirus (RV) in extraintestinal sites such as the liver, kidney, and central nervous system (CNS) of children with RV gastroenteritis, CNS localization in RV infection seems to be rare. RT-PCR and nucleotide sequencing detected a G1P[8] strain in the stool and cerebrospinal fluid (CSF) samples of a patient with concurrent RV-associated enteritis and CNS signs. Upon sequence analysis, the viruses detected in the CSF was identical to the virus detected in the stools. In the VP7- and VP4-based phylogenetic dendograms the strain clustered within the G1-Ic sub-lineage and the P[8]-III lineage. This study supports the hypothesis that RV infection was able to spread from the intestinal tract to the CNS, and likely played a role in the onset of neurological disease.

Similar diagnostic performances of antigen detection and nucleic acid detection of Cryptosporidium spp. in a low-prevalence setting

The diagnostic value of a real-time PCR assay for the detection of Cryptosporidium spp. in fecal samples was assessed as compared to the combination of the immunocromatographic assay (IC) and immunofluorescence assay (IF) currently performed in our laboratory for the diagnosis of cryptosporidiosis. On a total of 1040 samples collected from 2006 to 2010 and belonging to 533 patients suspected of having an intestinal parasitosis, Cryptosporidium spp. was detected in 31 samples (belonging to 12 patients) by IC and IF; the real-time PCR assay revealed Cryptosporidium spp. DNA in 5 additional samples for a total of 36 samples (13 patients). The real-time PCR assay exhibited higher sensitivity than IC and IF; however, its application to the diagnosis of cryptosporidiosis should be evaluated by every single laboratory, depending on the availability of trained personnel, financial resources, and the cost/effectiveness related to the prevalence of cryptosporidiosis.

Cell-cycle-dependent localization of human cytomegalovirus UL83 phosphoprotein in the nucleolus and modulation of viral gene expression in human embryo fibroblasts in vitro

The nucleolus is a multifunctional nuclear compartment widely known to be involved in several cellular processes, including mRNA maturation and shuttling to cytoplasmic sites, control of the cell cycle, cell proliferation, and apoptosis; thus, it is logical that many viruses, including herpesvirus, target the nucleolus in order to exploit at least one of the above-mentioned functions. Recent studies from our group demonstrated the early accumulation of the incoming ppUL83 (pp65), the major tegument protein of human cytomegalovirus (HCMV), in the nucleolus. The obtained results also suggested that a functional relationship might exist between the nucleolar localization of pp65, rRNA synthesis, and the development of the lytic program of viral gene expression. Here we present new data which support the hypothesis of a potentially relevant role of HCMV pp65 and its nucleolar localization for the control of the cell cycle by HCMV (arrest of cell proliferation in G1-G1/S), and for the promotion of viral infection. We demonstrated that, although the incoming pp65 amount in the infected cells appears to be constant irrespective of the cell-cycle phase, its nucleolar accumulation is prominent in G1 and G1/S, but very poor in S or G2/M. This correlates with the observation that only cells in G1 and G1/S support an efficient development of the HCMV lytic cycle. We propose that HCMV pp65 might be involved in regulatory/signaling pathways related to nucleolar functions, such as the cell-cycle control. Co-immunoprecipitation experiments have permitted to identify nucleolin as one of the nucleolar partners of pp65.

Hepatitis C virus core antigen: analytical performances, correlation with viremia and potential applications of a quantitative, automated immunoassay

BACKGROUND

Testing for hepatitis C virus core antigen (HCV Ag) may represent a complementary tool to anti-HCV and HCV-RNA in the diagnosis and monitoring of HCV infection.

OBJECTIVE

To evaluate the performance characteristics of the automated Abbott ARCHITECT HCV Ag assay.

STUDY DESIGN

Five sites analyzed over 3000 routine serum samples from populations at different risk, comparing HCV Ag results with anti-HCV screening and supplemental assay results and with HCV-RNA.

RESULTS

The HCV Ag assay showed a specificity of 100%, a good precision (CV<10%) and excellent dilution linearity (r>0.999). The sensitivity (3 fmol/L) corresponds to 700-1100 IU/mL of HCV-RNA. A non-linear correlation with HCV-RNA was found: r=0.713 vs. Siemens bDNA (523 specimens), r=0.736 vs. Roche Cobas TaqMan (356 specimens) and r=0.870 vs. Abbott Real-Time PCR (273 specimens). HCV Ag quantitation was equally effective on different HCV genoypes (239 for genotype 1/1a/1b/1c, 108 for genotype 2/2a/2c, 86 for genotype 3/3a, 50 for genotype 4/4a/4c/4d). Testing of subjects at high risk for HCV and with potential or actual impairment of the immune system identified 2 cases negative for anti-HCV and positive for HCV Ag on 361 hemodialyzed (0.6%) and 7 cases on 97 (7.2%) among transplant recipients. HCV Ag positivity anticipated anti-HCV seroconversion in all three cases of acute hepatitis C.

CONCLUSIONS

HCV Ag may be used as reflex testing on anti-HCV positive individuals to confirm or exclude an active infection, and on subjects with acute hepatitis or belonging to high risk groups.

Presence of anti-Borrelia burgdorferi antibodies and Borrelia burgdorferi sensu lato DNA in samples of subjects in an area of the Northern Italy in the period 2002-2008

Lyme borreliosis (LB) is a multisystemic disease caused by Borrelia burgdorferi sensu lato complex transmitted to humans by Ixodes ticks and whose epidemiology is poorly investigated in Europe. In this study an epidemiologic survey on the prevalence of the causative agent of such infectious disease was performed in the area of Parma (Northern Italy) during 2002-2008. Serum samples belonging to 2336 patients and cerebrospinal fluid samples (belonging to 42 of the same patients) were analyzed for serologic diagnosis of LB. Direct laboratory assays [polymerase chain reaction (PCR) and cultivation] were performed on samples belonging to patients with the clinical suspicion of LB. The seroprevalence was 0.55% considering the subjects with both anti-B. burgdorferi IgG and IgM. The samples tested by culture and PCR were all negative except for a tick removed from the skin of a healthy man. The results suggest that infection by B. burgdorferi in this area quite rarely occurs.

Differential infectious entry of human influenza A/NWS/33 virus (H1N1) in mammalian kidney cells

In this report we focused our interest on the early events of the replication cycle of NWS/33 human influenza A (NWS) virus in MDCK (canine), LLC-MK2 (simian), and NSK (swine) kidney cells, with different susceptibility upon infection. We have previously demonstrated that actin organization induces restriction to viral replication during the early stages of NWS virus infection in simian kidney cells. To explore how cell endocytic mechanisms are hijacked by NWS virus and may modulate the outcome of viral infection, the effect of drugs affecting selectively the entry via clathrin-coated pits, caveolar/raft-dependent endocytosis and macropinocytosis was analyzed. Results point to critical differences in terms of internalization pathways exploited by NWS virus to enter the examined cell models. Moreover, we show that some ways of entry do not allow an effective virus internalization, depending on the cell type. Understanding how specific cell functions/components may regulate early phases of viral replication allows us to deepen our knowledge on influenza virus infection and provides new insights for anti-viral researches.

Evaluation of a real-time polymerase chain reaction assay for the detection of Dientamoeba fragilis

The diagnostic value of a real-time polymerase chain reaction (PCR) assay targeting the 5.8S rDNA of Dientamoeba fragilis was investigated as compared with conventional parasitologic methods including cultivation testing 959 fecal samples from 491 patients attending a tertiary-care hospital and suspected of having an intestinal parasitosis. The real-time PCR assay revealed 117 additional D. fragilis-positive samples as compared with conventional methods, showing 100% sensitivity and specificity in our experience. On the whole, D. fragilis infection was detected in 186 samples from 105 patients (21.4%, third in frequency among the diagnosed intestinal parasitoses). The evaluated real-time PCR assay represents an effective tool to obtain both an accurate diagnosis and a reliable epidemiologic picture of dientamoebiasis.

Pancreatic pseudocyst-inferior vena cava fistula causing caval stenosis, left renal vein thrombosis, subcutaneous fat necrosis, arthritis and dysfibrinogenemia

AIM

We describe the case of a 38 year old man, with a story of alcohol abuse, who developed a very painful nodular subcutaneous fat necrosis, fever and polyarthritis, denying any abdominal symptoms due to a pancreatic pseudocyst-inferior vena cava fistula.

MATERIAL OF STUDY

The authors discuss the unusual and protracted course with intermittent hyperamylasemia and hyperlipasemia related to clinical manifestations such as subcutaneous fat necrosis, polyarthritis, pleural effusion and dysfibrinogenemia, and vascular complications as inferior vena cava stenosis and left renal vein thrombosis without abdominal symptomatology.

RESULTS

After ultrasonograms and CT Scans showing a 3-4 cm cyst at the pancreatic head with a solid bud protruding into the pseudocystic cavity, and an ERCP showing a communication between the pancreatic duct and the pseudocyst but failing in demonstrating the vascular fistula, the patient underwent a Roux-en-y pseudocyst-jejunostomy and suture of the caval communication leading to complete recovery with normalization of laboratory findings.

DISCUSSION

In our case, the locally sclerosing activity of the enzymes in the endothelium led to a communication between the inferior vena cava and the pseudocyst and to a complete thrombosis of the left renal vein and to a stenosis of the inferior vena cava itself The fluctuance of the symptomatology severity was probably due to an intermittent opening of the passage between pseudocyst and vena cava. Such a clinical case, to the author knowledge, has never been reported.

CONCLUSION

When in presence of very high levels of amylasemia and lipasemia in spite of the paucity of abdominal symptomatology, and the onset of unusual complications such as panniculitis, pleural effusion, arthritis and coagulative disorders, a pancreatic pseudocyst-inferior vena cava fistula should be kept in consideration during diagnosis.

Norovirus RNA in the blood of a child with gastroenteritis and convulsions--A case report

Potential extra-intestinal spread is an important issue in understanding the pathogenesis of NoV disease. A previously healthy 14-month-old boy was admitted to the Pediatric Emergency Department of the University-Hospital of Parma, Italy, for afebrile convulsions in a gastroenteritis episode. Bacterial culture and microscopic examination on cerebrospinal fluid (CSF) yielded negative results as well as PCRs and reverse-transcription PCRs (RT-PCRs) for neurotropic viruses performed either on CSF or plasma. Stools were subjected to electron microscopy and conventional cell culture, yielding negative results. NoV was found in stools and plasma by nested RT-PCR targeting the NoV polymerase gene. The nucleotide sequences obtained from the two specimens showed 100% identity, demonstrating that the strain invading the blood stream was from the intestine, and, in comparison with GenBank sequences, they belonged to NoV genotype GII.4, "2006b" variant. The child had no abnormal electrolyte balance and no fever that could justify seizures, encouraging the hypothesis that NoV could be the cause of the neurologic disorder. These findings further induce to review the current concept of human NoV focused on intestinal infection.

Modulatory effect of rRNA synthesis and ppUL83 nucleolar compartmentalization on human cytomegalovirus gene expression in vitro

The nucleolus is a nuclear domain involved in the biogenesis of ribosomes, as well as in many other important cellular regulatory activities, such as cell cycle control and mRNA processing. Many viruses, including herpesviruses, are known to exploit the nucleolar compartment during their replication cycle. In a previous study, we demonstrated the preferential targeting and accumulation of the human cytomegalovirus (HCMV) UL83 phosphoprotein (pp65) to the nucleolar compartment and, in particular, to the nucleolar matrix of lytically infected fibroblasts; such targeting was already evident at very early times after infection. Here we have investigated the possible effects of rRNA synthesis inhibition upon the development of HCMV lytic infection, by using either actinomycin D or cisplatin at low concentrations, that are known to selectively inhibit RNA polymerase I activity, whilst leaving RNA polymerase II function unaffected. Following the inhibition of rRNA synthesis by either of the agents used, we observed a significant redistribution of nucleolar proteins within the nucleoplasm and a simultaneous depletion of viral pp65 from the nucleolus; this effect was highly evident in both unextracted cells and in nuclear matrices in situ. Of particular interest, even a brief suppression of rRNA synthesis resulted in a very strong inhibition of the progression of HCMV infection, as was concluded from the absence of accumulation of HCMV major immediate‐early proteins within the nucleus of infected cells. These data suggest that a functional relationship might exist between rRNA synthesis, pp65 localization to the nucleolar matrix and the normal development of HCMV lytic infection. J. Cell. Biochem. 108: 415–423, 2009. © 2009 Wiley‐Liss, Inc.

Evaluation of a real-time polymerase chain reaction assay for the laboratory diagnosis of giardiasis

A real-time polymerase chain reaction (PCR) assay was evaluated in comparison with the combination of conventional methods (microscopic examination and antigen detection assay) during the period 2006 to 2008 on 771 fecal samples belonging to 386 patients to assess its usefulness for an accurate laboratory diagnosis of giardiasis. The real-time PCR assay detected Giardia intestinalis DNA in 195 samples (106 patients), including 26 samples (21 patients) negative by the conventional assays. Among the 21 patients, in 8 cases, giardiasis was previously diagnosed also by conventional methods in additional samples of the same patients, whereas in 13, it would have been undiagnosed if real-time PCR assay was not used. The real-time PCR assay demonstrated a detection limit of 2 cysts per reaction and 100% specificity and sensitivity compared to conventional methods. A genotype analysis targeting the beta-giardin gene allowed to identify 53 samples (23 patients) containing genotype A and 59 samples (45 patients) containing genotype B.

An 8-year survey on the occurrence of imported malaria in a nonendemic area by microscopy and molecular assays

Our study aimed to describe the occurrence of imported malaria in a nonendemic area (Parma, Italy) during the period 2000 to 2007, comparing the data obtained by microscopy and molecular assays targeting plasmodial 18S subunit rRNA gene. The prevalence of imported malaria in Parma was 21.8% by microscopy and 22.7% by polymerase chain reaction (PCR). Plasmodium falciparum accounted for 81.1% of the cases, followed by Plasmodium ovale (8.8%), Plasmodium vivax (3.8%), and Plasmodium malariae (1.9%). Mixed infections accounted for 4.4% of the cases. In this study, PCRs proved to be more sensitive and specific than microscopy and changed the picture of malaria epidemiology in Parma, detecting additional cases of malaria undiagnosed by microscopy and allowing speciation of plasmodia in cases misidentified by microscopy. Generally, imported malaria cases reflect the number of immigrants who visit their native countries, in particular, West Africa, explaining the increased prevalence of P. ovale cases among non-P. falciparum infections in Parma.

Myiasis of the scalp due to Dermatobia hominis in a traveler returning from Brazil

This article describes a case of myiasis by Dermatobia hominis diagnosed in a young Italian man returning from a vacation through Brazil. Considering the increasing number of travels to tropical and subtropical areas, clinicians in nonendemic areas must think about the possibility of imported unusual infestations during their daily practice.

Mycobacterium avium subspecies paratuberculosis infection in cases of irritable bowel syndrome and comparison with Crohn's disease and Johne's disease: common neural and immune pathogenicities

Mycobacterium avium subsp. paratuberculosis causes Johne's disease, a systemic infection and chronic inflammation of the intestine that affects many species, including primates. Infection is widespread in livestock, and human populations are exposed. Johne's disease is associated with immune dysregulation, with involvement of the enteric nervous system overlapping with features of irritable bowel syndrome in humans. The present study was designed to look for an association between Mycobacterium avium subsp. paratuberculosis infection and irritable bowel syndrome. Mucosal biopsy specimens from the ileum and the ascending and descending colon were obtained from patients with irritable bowel syndrome attending the University of Sassari, Sassari, Sardinia, Italy. Crohn's disease and healthy control groups were also included. Mycobacterium avium subsp. paratuberculosis was detected by IS900 PCR with amplicon sequencing. Data on the potential risk factors for human exposure to these pathogens and on isolates from Sardinian dairy sheep were also obtained. Mycobacterium avium subsp. paratuberculosis was detected in 15 of 20 (75%) patients with irritable bowel syndrome, 3 of 20 (15%) healthy controls, and 20 of 23 (87%) people with Crohn's disease (P = 0.0003 for irritable bowel syndrome patients versus healthy controls and P = 0.0000 for Crohn's disease patients versus healthy controls). One subject in each group had a conserved single-nucleotide polymorphism at position 247 of IS900 that was also found in isolates from seven of eight dairy sheep. There was a significant association (P = 0.0018) between Mycobacterium avium subsp. paratuberculosis infection and the consumption of hand-made cheese. Mycobacterium avium subsp. paratuberculosis is a candidate pathogen in the causation of a proportion of cases of irritable bowel syndrome as well as in Crohn's disease.

Prevalence of imported malaria in Parma during 2005-2006

BACKGROUND AND AIM OF THE WORK

Malaria is a protozoan infection caused by parasites of the genus Plasmodium (P. falciparum, P. ovale, P. vivax, P. malariae) that is transmitted from one human to another by female Anopheles mosquitoes. It can be considered a reemerging imported disease in our area because of increasing of movements from endemic countries, and nowadays it is the most common imported infection in Italy. This study describes the occurrence of imported malaria in our area between January 2005 and May 2006.

METHODS

During 17 months we analysed 170 blood samples belonging to 139 patients (95 foreigners and 44 Italians) with the clinical suspect of malaria. Samples were used to prepare orange acridine and Giemsa stained thin blood films for microscopic observation and to perform an immunochromatographic assay for the detection of specific plasmodia antigens. Molecular assays (nested-PCR and Real-time PCR) were also performed in order to confirm the diagnosis.

RESULTS

Thirty-six cases of malaria were diagnosed: 35 in foreigners coming from Africa and only one in an Italian who lived in Chad. Thirty-three patients were infected by P. falciparum, 1 by P. ovale, 1 by P. vivax, and a mixed infection by P. falciparum, P. ovale and P. malariae was also found.

CONCLUSIONS

Malaria is usually associated with travels within areas where the infection is endemic and our data demonstrated that imported malaria in our area has a prevalence of 25.89%.

The mesenteric and antimesenteric site of the tumor as possible prognostic factor in colorectal cancer: 5-year survival analysis

INTRODUCTION

Colorectal cancer is still one of the many factors of death both in males and in females. To date, the most important prognostic factors are mainly related to the pathological stage of the disease.

AIM OF THE STUDY

The purpose of this study was to analyze the possible role of tumor circumferential localization on the colonic wall (mesenteric (M) or antimesenteric (AM)) as a possible prognostic factor. In this study, we compare the localization of the tumor with patient's survival. The hypothesis of this study is that M tumors, closer to blood and lymphatic vessels, should be more aggressive in terms of hematogenous and lymphatic spread compared to the AM tumors.

PATIENTS AND METHODS

All patients undergoing curative resection for colorectal cancer were enrolled in this study; there was no statistical difference for age, sex and co-morbidity. The histopathological examination was carried out in the standard manner. Next, we have taken care to survival of neoplastic patients by examining of our 5-year follow-up archive: we divided patients in different groups concerning the different tumor stage and we compare these results with the different localizations of tumor at the operation.

RESULTS

In 45% of cases, we were able to distinguish the different localizations M (160 patients) or AM (47 patients) and this difference is statistically significant (P<0.0001, Pearson Chi-Square-test (PCS-t)). The number of metastatic nodes is statistically higher in the M group compared to the AM group one (P=0.003949). Medium time of follow-up was 36.54 months; AM and M patients have a rather similar survival, only at the end the two curves seem to change but not in a significant manner. Only if we consider the difference between the two groups comparing T3 tumor can we observe a statistically significant difference (P<0.005).

CONCLUSIONS

In conclusion, the localization of M or AM colorectal cancer is feasible in 45% of cases. M tumors have significantly more lymph nodes metastases but a better 5-year survival than AM tumors. A possible explanation for such results might be the different pattern of diffusion of cancer cells.

Infective colitis associated with human intestinal spirochetosis

AIM

Our study reports the detection and identification of intestinal spirochetosis in patients with colonic diseases in a tertiary-care hospital over a 12-year period, and includes a description of all cases we diagnosed.

METHODS

Our patients (8323) underwent colonoscopy and histopathological examinations including transmission electron microscopy (TEM) and light microscopy. Specimens from patients suspected of intestinal spirochetosis at histopathology (17 patients) underwent microbiological investigation performed by culture and molecular methods (16S restriction fragment length polymorphism-polymerase chain reaction [RFLP-PCR], nox RFLP-PCR assays).

RESULTS

Seventeen cases were diagnosed: seven patients were infected by B. aalborgi, one by B. pilosicoli, two by both species and four by Brachyspira spp. diagnosed both histopathology and microbiology (culture and molecular methods: 16S RFLP-PCR and nox RFLP-PCR assays). Three cases were referred to as Brachyspira spp. infections using only histopathology, including TEM.

CONCLUSIONS

Our results demonstrated that intestinal spirochetosis, although rarely occurring, might play a role in chronic diarrhea and suggested a pathogenetic mechanism of intestinal spirochetosis based on the destruction of colonic microvilli and colitis histologically documented, providing additional clinical and pathological information on this entity. This study suggests that metronidazole seems to be the drug of choice for the eradication of intestinal spirochetosis.

Occurrence of human intestinal spirochetosis in comparison with infections by other enteropathogenic agents in an area of the Northern Italy

The aim of this study was to investigate the occurrence of human intestinal spirochetosis (IS) by a 16S rRNA restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) in a selected group (234) of patients with gastrointestinal complaints and/or potential risk factors for IS in comparison with the occurrence of infections by other enteropathogenic agents. By using 16S rRNA RFLP-PCR, 16 patients (6.8%) with IS were found (11 infected by Brachyspira aalborgi, 3 by Brachyspira pilosicoli, and 2 by both species); moreover, 10 patients with gastroenteric viruses (4.2%), 13 with enteropathogenic bacteria other than intestinal spirochetes (5.5%), and 24 with intestinal parasites (10.2%) were found. This study provides an enhancement of the knowledge about the distribution of IS, suggesting that it may be more frequent than suspected and that clinicians should consider IS when patients present with long-standing diarrhea. Moreover, 16S rRNA RFLP-PCR might be a powerful tool not only for diagnostic purpose but also to investigate the occurrence of IS just on fecal samples, not requiring invasive diagnostic techniques.

Characterization of inter-genogroup reassortant rotavirus strains detected in hospitalized children in Italy

Analysis of archival stool collections provides an invaluable source of virus strains and genetic material that may be exploited for molecular, epidemiological, and biological studies. The aim of this study was the molecular characterization of unusual human rotavirus (HRV) strains displaying atypical combinations of electropherotype (e-type) and VP4 and/or VP7 genotypes. Analysis of a panel of archival stools collected in northern Italy revealed continual circulation of P[8]G1 HRVs during 1987-1990 and the onset of P[6] + P[8]G1 strains after 1989. Interestingly, nine G1 strains, associated with either P[8], P[4] + P[8], P[6] + P[8], or untypeable VP4 genes, and two P[4]G1 + G2 strains, displayed short RNA e-type. The genetic constellation of the unusual strains was investigated by analysis of the VP4, VP6, VP7, and NSP4 genes. All the G1 strains with short e-type were subgroup (SG)II or SGI + SGII, and possessed a NSP4 of genogroup B or A + B. Conversely, the P[4]G1 + G2 strains were SGI and possessed a genogroup A NSP4. Sequence analysis of the VP7 and VP4 genes revealed that the unusual P[8]G1 and P[4]G1 + G2 viruses emerged by reassortment of strains circulating locally, rather than by introduction of new strains.

Human intestinal spirochaetosis in Parma: a focus on a selected population during 2002-2005

BACKGROUND AND AIM OF THE WORK

Human intestinal spirochaetosis (HIS) is a large bowel infection characterised by the colonization of the intestinal mucosa by spirochaetes belonging to the genus Brachyspira. The causative agents of HIS are Brachyspira aalborgi and Brachyspirapilosicoli. Symptoms of the infection, even if not specific, are long standing diarrhoea, abdominal pain, meteorism and rectal bleeding and sometimes they can suggest the clinical suspect of inflammatory bowel diseases or rectal carcinoma. Since poor data were available on the prevalence of this infection, the aim of our study was to describe the occurrence of this infection in our area in the period 2002-2005.

METHODS

During a period of 4 years we analysed 297 faecal samples from 99 patients selected by potential risk factors and symptomatology suspected for HIS. The diagnosis of HIS was performed by isolation and a molecular assay based on 16S rDNA restriction fragment length polymorphism (RFLP)-polymerase chain reaction (PCR).

RESULTS

From 2002 to 2005 we detected 12 cases of intestinal spirochaetosis, 7 caused by Brachyspira aalborgi, 4 by Brachyspirapilosicoli and one by both spirochaetes, which represented the first case of a mixed infection by 2 intestinal spirochaetes in our area.

CONCLUSIONS

Despite the fact that HIS seems to be a low prevalence infection in our area, in a strongly selected population we found 12 cases of this infection (12.12%). These results stimulate us to extend the research of intestinal spirochaetosis in the general population, when long standing gastrointestinal disorders and potential risk factors are present.

Genetic polymorphisms influence Plasmodium ovale PCR detection accuracy

Detection of Plasmodium ovale by use of a nested PCR assay with a novel Plasmodium ovale primer set was superior to detection of Plasmodium ovale by real-time PCR assays. Nested PCR was also better at detecting P. malariae. The detection of P. ovale in many patients first admitted >2 months following their return to Italy indicated that P. ovale relapses are common.

Colonic amoebiasis and spirochetosis: morphological, ultrastructural and microbiological evaluation

BACKGROUND

The present study reports on a prompt diagnosis of colonic amoebiasis with colonic spirochetosis by Brachyspira aalborgi and B. pilosicoli; such diagnosis allowed exclusion of other diseases and resolution of the case after specific treatment.

METHODS AND RESULTS

A 37-year-old Italian man with a history of several months' mucosal diarrhea travelled to Greece, Romania and Tunisia. After his last trip he presented with an increase of up to 3-5 discharges daily, associated with bloody diarrhea, supporting the clinical suspect of inflammatory bowel disease. Colonoscopy revealed erosions from the cecum to the rectum, and ulcers both in the descending and sigmoid colon. Structures resembling amoebic trophozoites and sinusoidal microorganisms were observed in the colonic biopsies at histopathology and electron microscopy. Entamoeba histolytica DNA was detected by small-subunit rDNA polymerase chain reaction (PCR) from feces, rectal biopsies and isolated trophozoites. Spirochetes were identified from feces, colonic biopsies and cultures using a 16S rDNA restriction fragment length polymorphism-PCR specific for the detection of B. aalborgi and B. pilosicoli. After therapy, the patient was restored to health.

CONCLUSIONS

The rapid identification of E. histolytica, B. aalborgi and B. pilosicoli using traditional and specific and sensitive molecular methods permitted an accurate diagnosis and a specific therapy. It is suggested that mixed infection by parasites and spirochetes might occur more frequently than expected: it would be of extreme interest and importance to intensify clinical findings, and one infection should not prompt the pathologist/clinician to stop looking.

Prevalence of intestinal parasites in the area of Parma during the year 2005

BACKGROUND AND AIM OF THE WORK

Intestinal parasitosis represent a relevant clinical problem, especially in developing countries, where they are responsible for morbidity and mortality in adults and children and many epidemiological data are available for these areas. The actual situation of intestinal parasitosis in Europe is not yet well investigated since they are usually not notified. We describe the occurrence of intestinal parasitosis in our laboratory from January to December 2005.

METHODS

We considered all patients (1117) whose stool samples were sent to our laboratory with the suspect of intestinal parasitosis during the year 2005. Each specimen was subjected to macroscopic and microscopic examination to demonstrate the presence of worm eggs, larvae, protozoan trophozoites or cysts and to an immunochromatographic assay to detect Giardia intestinalis and Cryptosporidium spp. specific antigens. Cultures for protozoa and helminths were carried out and a PCR specific for Entamoeba histolytica/Entamoeba dispar was also performed.

RESULTS

Our results indicated that 148 patients (13.24%) were affected by intestinal parasitosis. Among the 951 Italians, 96 (10%) were infected, while out of a total of 166 foreigners 52 had intestinal parasitosis (31%). Moreover, we found that 113 infections were caused by only one parasite while 35 were mixed infections.

CONCLUSIONS

Intestinal parasitosis represent a remarkable cause of gastrointestinal disease and our study demonstrates that these infections are quite common in our area, affecting both Italians and non European citizens from developing countries.

Comparative evaluation of molecular assays for the identification of intestinal spirochaetes from diseased pigs

Rapid identification of porcine Brachyspira species is required in order to differentiate pathogenic from non-pathogenic species. The aim of our study was to compare a recently described genetic method based on polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), nox RFLP-PCR assay, and three species-specific PCRs described previously in the literature with a 16S rRNA gene RFLP-PCR discriminatory reference assay (16S RFLP-PCR) for the identification of Brachyspira spp. of swine origin. In this study, 20 porcine spirochaetal strains were identified and compared to 33 reference strains by 16S RFLP-PCR and nox RFLP-PCR and three species-specific PCRs. RFLP-PCR methods showed concordant results for 47 strains and discordances for 6 strains (2 differently identified and 4 not revealed by nox RFLP-PCR). In our hands species-specific PCRs showed concordant results with 16S and nox RFLP-PCR for 43 strains and discordances for 10 strains (2 differently identified and 8 not amplified). The same results observed testing the 20 field-isolated spirochaetes were obtained for the corresponding porcine faecal samples. The detection limit was 10(2) -10(3) cells/g of faeces for 16S rRNA gene PCR and 10(4) cells/g of faeces for nox PCR. In our experience nox RFLP-PCR appeared successful for the speciation of B. hyodysenteriae reserving 16S RFLP-PCR for all other pathogenic and non-pathogenic Brachyspira species. Among the species-specific PCR assays tested only that for B. pilosicoli was useful in our hands.

Two-center collaborative evaluation of performance of the BD phoenix automated microbiology system for identification and antimicrobial susceptibility testing of gram-negative bacteria

The performance of the BD Phoenix Automated Microbiology System (BD Diagnostic Systems, Sparks, MD) was assessed for identification (ID) and antimicrobial susceptibility testing (AST) of the majority of clinically encountered bacterial isolates in a European collaborative two-center trial. A total of 494 bacterial isolates including various species of the Enterobacteriaceae and 110 nonfermentative gram-negative bacteria were investigated: of these, 385 were single patient isolates, and 109 were challenge strains tested at one center. The performance of the Phoenix extended-spectrum beta-lactamase (ESBL) test was also evaluated for 203 strains of Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca included in the study. Forty-two antimicrobial drugs were tested, including members of the following drug classes: aminoglycosides, beta-lactam antibiotics, beta-lactam/beta-lactamase inhibitors, carbapenems, cephems, monobactams, folate antagonists, quinolones, and others. Phoenix system ID results were compared to those of the laboratories' routine ID systems (API 20E and API CHE, ATB ID32E, ID32GN, and VITEK 2 [bioMérieux, Marcy l'Etoile, France]); Phoenix AST results were compared to those of frozen standard broth microdilution (SBM) panels according to NCCLS (now CLSI) guidelines (NCCLS document M100-S9, approved standard M7-A4). Discrepant results were repeated in duplicate. Concordant IDs of 98.4 and 99.1% were observed for the Enterobacteriaceae and the nonfermentative group, respectively. For AST results, the overall essential agreement was 94.2%; the category agreement was 97.3%; and the very major error rate, major error rate, and minor error rate were 1.6, 0.6, and 1.9%, respectively. In terms of ESBL detection, Phoenix results were 98.5% concordant with those of the reference system, with 98.0% sensitivity and 98.7% specificity. In conclusion, the Phoenix ID results showed high agreement with results of the systems to which they were being compared: the AST performance was highly equivalent to that of the SBM reference method, and the system proved to be very accurate for the detection of ESBL producers.

Comparison between two real-time PCR assays and a nested-PCR for the detection of Toxoplasma gondii

BACKGROUND AND AIM OF THE WORK

In recent years, the diagnosis of toxoplasmosis has been improved by Real-time PCR assays. In this study we compared the performances of two Real-time PCRs (FRET and TaqMan protocols) already described in the literature, and one nested-PCR, currently used in our laboratory for the molecular diagnosis of toxoplasmosis.

METHODS

We evaluated the sensitivity and the specificity of a FRET- and a TaqMan-based Real-time PCRs targeting a 529 bp repeat region and the 18S RNA gene, respectively, and a nested-PCR, targeting the B1-gene of Toxoplasma gondii. We also tested, through nested-PCR, 46 biological samples obtained during a period of 29 months from pregnant women or immunocompromised patients with suspected T. gondii infection.

RESULTS

The analytical sensitivity of nested and TaqMan PCRs was approximately 10(3) tachyzoites/ml. FRET assay showed a sensitivity of 102 tachyzoites/ml. Three out of 46 biological samples were nested-PCR-positive and these results were also confirmed by both Real-time PCRs.

CONCLUSIONS

Nested- and real-time PCRs evaluated in this study resulted very sensitive and specific; in particular FRET PCR resulted more sensitive than the other assays, probably because of the greater copy number of the target sequence. Real-time PCR assays are easy-to-use, producing results faster than conventional PCR systems and reducing contamination risks.

Molecular epidemiology of norovirus infections in sporadic cases of viral gastroenteritis among children in Northern Italy

Surveillance of norovirus infections in sporadic cases of pediatric gastroenteritis admitted to a main hospital in Northern Italy during a full-year period (2002) showed that noroviruses (10.4%) were the second most common causative viral agent, following rotaviruses (21.1%), and noroviruses (81%) were mostly implicated in mixed infections. The epidemic period of norovirus was September-December, with September and November as months of major prevalence (33.3 and 38.5%, respectively). Six distinct norovirus genotypes were detected (GI.7, GII.1, GII.2, GII.4, GII.7, GII, not assigned named GIIb), and the predominant genotype was GII.4. A "new GII.4 2002 variant" accounted for 82.9% of total strains. Since the severity of norovirus symptoms does not usually require admission to hospital, the burden of norovirus disease in the general children population may be much higher than that suggested by the present hospital-based investigation.

HBV genotypes and antiviral-resistant variants in HBV infected subjects in Northern Italy

HBV genotypes were investigated in sera/plasma from 97 HBV positive subjects. Genotype D was revealed in 80.4% followed by E in 6.2%. Genotypes A, B, and C were also found, as well as for the first time a new combination of HBV D and G genotypes. In a cohort of subjects of this population, the relationship with lamivudine and/or famciclovir-resistant HBV mutants was also investigated. Among 12 untreated subjects, 25% carried HBV drug-resistant strains suggesting that drug-resistant variants naturally exist in untreated Italian HBV chronically infected subjects.