Georgios Gouvras, head of DG SANCO's health threats unit.
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Epidemiology↗
Biomedical subjects
P Guglielmetti
Publications and source records attributed to P Guglielmetti.
Role of extracorporeal photochemotherapy in patients with refractory chronic graft-versus-host disease.
Recent studies suggest that extracorporeal photochemotherapy (ECP) may be beneficial in patients with steroid-refractory chronic graft-versus-host disease (cGvHD). However, it is not yet clear whether certain conditions, such as age, mode of onset of cGvHD etc., influence clinical response and whether certain affected organs are more sensitive to ECP than others. We analysed the main clinical and laboratory parameters related to evolution of the disease in 32 steroid-refractory cGvHD patients, to identify any useful response predictors to ECP. ECP affected the course of the disease positively in 78% (25/32) of our cases.
Adult↗
Risk factors for acquiring Helicobacter pylori infection in a group of Tuscan teenagers.
Risk factors for acquiring Helicobacter pylori infection include hygienic, social, and environmental conditions. Some of these conditions usually change over time. We therefore investigated the existence of risk factors in a group of teenagers living in a place with the same environmental characteristics, in which hygienic and crowding conditions have not changed significantly in the last 20 years. A group of 164 students, mostly borne in 1977, attending four different schools, were examined serologically for H. pylori infection and CagA status. The importance of the risk factors for the transmission of the infection were evaluated by the chi2 test. P values <0.05 were considered significant. Twenty-two students (13.4%) were H. pylori seropositive. Students attending teachers' college and high school of arts were infected significantly more often than those attending high school (P = 0.011 and P = 0.012, respectively). Students who smoked and students whose parents had a manual job had an increased risk of acquiring the infection (P = 0.002, and P = 0.036, respectively). Crowding conditions and the presence of domestic animals were close to being statistically significant. Other factors, such as gender, number of bathrooms and bedrooms, sharing the bed with adults as a child, presence of a sexual partner, and a family history of peptic ulcer and gastric cancer, did not increase the risk of infection. The prevalence of seropositivity for CagA was similar in the various risk groups. Manual job of parents and smoking were the most important factors for acquiring H. pylori infection.
Adolescent↗
Molecular typing of Candida spp. by random amplification of polymorphic DNA and analysis of restriction fragment length polymorphism of ribosomal DNA repeats.
Random amplification of polymorphic DNA (RAPD) using an arbitrary oligonucleotide primer (5'-CGGTGCGACG) and analysis of restriction fragment length polymorphism of ribosomal DNA (rDNA-RFLP) after digestion of genomic DNA with restriction endonuclease EcoRI were investigated as tools for genotypic delineation beyond the species level of 91 Candida clinical isolates and four reference strains including 33 Candida albicans, 19 Candida tropicalis, 22 Candida krusei and 21 Candida (Torulopsis) glabrata. Results indicated that both techniques can be useful for typing isolates of the above species, although showing a variable discriminative potential with different species. As compared to RAPD fingerprinting, the discriminative potential of rDNA-RFLP appeared to be highest for C. albicans and lowest for C. glabrata, being overall similar for C. krusei and identical for C. tropicalis. A comparative analysis of the results obtained with the two typing techniques showed that, except for C. tropicalis, they were able to provide non-redundant information, and that their use in combination could enhance the discriminative potential for delineation among C. glabrata and C. krusei isolates.
Candida↗
Patterns of antimicrobial use and antimicrobial resistance among healthy children in Bolivia.
OBJECTIVE: To determine the incidence of antimicrobial-resistant, nonpathogenic Escherichia coli among healthy children aged 6-72 months in Camiri town and a rural village, Javillo, in south-eastern Bolivia. METHOD: A community-based survey: stool samples were obtained from 296 healthy children selected by modified cluster sampling in Camiri and all 25 eligible children in Javillo. E. coli isolates were tested for antimicrobial susceptibility according to the standard disc diffusion method. By a questionnaire survey of 12 pharmacies and by using simulated patients, we investigated the antimicrobial availability and the usage patterns in Camiri town. RESULTS: In Camiri, over 90%, and in Javillo over 70% of children carried E. coli resistant to ampicillin, trimethoprim-sulphamethoxazole (TMP/SMX) or tetracycline. Overall, 63% of children carried E. coli with multiple resistance to ampicillin, TMP/SMX, tetracycline and chloramphenicol. In the simulated patients study, antimicrobials were dispensed inappropriately for 92% of adults and 40% of children with watery diarrhoea, and were under-prescribed for males with urethral discharge (67%) or females with fever and dysuria (58%). The dose and/or duration of antimicrobials dispensed was almost always too low. CONCLUSION: Our study showed a disturbingly high prevalence of carriage of nonpathogenic E. coli resistant to antimicrobials. The prevalence of resistance to ampicillin and TMP/SMX was higher than that previously reported in developing countries. The existence of a large reservoir of resistance genes in healthy individuals in developing countries represents a threat to the success of antimicrobial therapy throughout the world. Programmes to improve rational and effective drug use in developing countries are urgently needed.
Adult↗
Seroprevalence of Toxocara canis-IgG antibodies in two rural Bolivian communities.
A survey on toxocara canis-IgG seroprevalence was carried out in two Bolivian communities (Mora and Zanja Honda) living in the Cordillera Province, Department of Santa Cruz. Two hundred and sixteen people, both males and females, 2 to 85 years old were sampled. Altogether, 73 people were positive (34%). The seroprevalence was 27% in Mora and 42% in Zanja Honda (p = 0.022). No statistical correlations were found with sex and age. High prevalences were also found for intestinal helminths (hookworms, Trichuris trichiura, Ascaris lumbricoides, Hymenolepis nana and Strongyloides stercoralis). Positive association between T. canis seropositivity and presence of T. trichiura and between T. trichiura and hookworms were found. T. canis egg prevalence in dog population was found consistently higher in Zanja Honda than in Mora (40% vs 27%).
Adolescent↗
Unusual species of campylobacters isolated in the Siena Tuscany area, Italy.
From January 1989 to December 1990, stool samples from 288 children with enteritis were examined for the presence of unusual campylobacters which represented about 20% of all campylobacteria isolated when the filtration technique was used. The isolation percentage was the following: C. jejuni ss. jejuni 6.9%; C. coli 2%; C. jejuni ss. doylei, C. upsaliensis and C. concisus each 0.7%. The atypical Campylobacter isolates were examined for their virulence characteristics. Toxin profiles based on cytotonic, cytotoxic and cytolethal distending factors were determined after analysis responses in Vero, CHO and HeLa cells. Adhesivity and invasivity tests were performed on Intestine 407 cells. No strain was cytotoxic. C. jejuni ss. doylei and C. concisus induced an elongation of CHO cells (a cytotonic-like effect). C. upsaliensis strains provoked a cytolethal distending effect. No strain adhered to cells in vitro. Our results suggest that the filtration technique is excellent for the isolation of atypical campylobacters and indicate that the unusual Campylobacter isolates could be potentially virulent.
Animals↗
Serologic survey for antibodies to Borrelia burgdorferi in sheep, goats and dogs in Cordillera Province, Bolivia.
A serosurvey for antibodies to Borrelia burgdorferi using an enzyme-linked immunosorbent assay (ELISA) was conducted on sheep, goat and dog serum samples collected in Cordillera Province, Bolivia, in 1992 Sera from 98 sheep, 218 goats and 43 dogs were tested. The observed seroprevalence in sheep and dogs was 0.0%, whereas the seropositivity rate for goat serum samples was 5.0%. Upon analysing 10 positive sera by Western immunoblotting, five reacted against the specific protein antigens and all of them met the criteria for positivity on the basis of immunoglobulin G (IgG) bands, indicating that goats in Cordillera Province were exposed to B. burgdorferi. These findings, which are further proof of the existence of B. burgdorferi infection in Bolivia, indicate the serologic analysis of goats as a suitable tool for Lyme borreliosis surveillance.
Animals↗
Serological survey of leptospiral infections in sheep, goats and dogs in Cordillera province, Bolivta.
A serological survey for antibodies to Leptospira spp. was conducted on sheep, goat and dog serum samples collected in three localities in Cordillera province in the southern part of the Santa Cruz Department (Bolivia) in 1992. A total of 98 sheep, 218 goats and 43 dogs were tested against 29 leptospiral serovars using the microscopic agglutination test. At the time of blood collection all of the examined animals appeared healthy and presented no clinical sign suggestive of leptospirosis. Antibody prevalences, as determined by positive results at a 1:100 dilution or higher, was 14.3% in sheep, 19.7% in goats, and 14.0% in dogs. Agglutinins against six serovars (poi. shermani, pomona, canicola, javanica, djasiman) were found in positive animals. The highest serological prevalence in sheep and goats was recorded for serovar poi, followed by pomona in sheep and shermani in goats. Titres to shermani were the commonest in dogs. The results of this survey indicate that leptospiral infection is common in south-east Bolivia and that serovars of several serogroups concur in the etiology.
Agglutination Tests↗
Species, biotype and serogroup of Campylobacter spp. isolated from children with diarrhoea over a ten-year period.
From 1981 to 1990, stool samples from 6403 gastroenteritis cases were examined for the presence of campylobacters as well as Salmonella, Shigella, Aeromonas species and Yersinia enterocolitica. The percentages of isolation were the following: campylobacters 10.8 (86.1% of isolates were C. jejuni and 13.9% were C. coli), Salmonella spp. 8.4, Aeromonas spp 1.4, Yersinia enterocolitica 0.3. Shigella spp. were isolated only occasionally. Predominant biotypes of campylobacters were C. jejuni I (69.5%), C. jejuni II (29.5%) and C. coli I (92.7%). The six most common LIO serogroups-36; 4; 1; 28.53; 11; 2-accounted for 50% ca. of typable strains. Campylobacters are the most common etiological agent of bacterial enteritis in children living in this area of Tuscany. The species and serogroup determination can be useful from an epidemiological point of view.
Aeromonas↗
Detection of a vacuolating cytotoxin in stools from children with diarrhea.
A cytotoxin inducing vacuolation in HEp-2 cells was detected in 19 (3.1%) of 618 stool specimens from children with diarrhea but in none of 135 from control children. Common enteric pathogens were found in only two (10.5%) of the 19 cytotoxin-positive stool specimens. The vacuoles induced by stool filtrates resembled those induced by the vacuolating toxin (VacA) of Helicobacter pylori. The vacuolating toxin was heat-labile and protease-sensitive, and it had an apparent molecular weight of > 100,000 but was not neutralized by an antiserum to H. pylori VacA. Although proper prospective case-control studies are needed to definitely assess the etiologic association between the new vacuolating cytotoxin and diarrhea, the present study suggests that microorganisms of the gastrointestinal tract produce a Helicobacter-like vacuolating toxin and may be responsible for cases of childhood diarrhea whose etiology is currently considered unknown.
Bacterial Proteins↗
Enteropathogens associated with childhood diarrhea in Italy. The Italian Study Group on Gastrointestinal Infections.
BACKGROUND: Infectious diarrheal diseases remain an important cause of childhood morbidity in industrialized countries. The knowledge of the etiology and epidemiology of childhood diarrhea in a given area is needed to plan any measure designed to prevent or ameliorate diarrheal illness and to develop practice guidelines for the most appropriate stool examination procedures. METHODS: We evaluated 618 children with diarrhea and 135 controls prospectively for viral, bacterial and parasitic enteric pathogens. Diarrheagenic Escherichia coli was identified by gene probes specific to different virulence factors. Stool filtrates were examined for the presence of free bacterial toxins by a cell culture cytotoxicity assay. Clinical and epidemiologic data were recorded and analyzed in relation to microbiologic findings. RESULTS: Enteropathogens were identified in 59% of children with diarrhea and in 10.4% of asymptomatic controls. The agents mainly associated with disease were rotavirus (23.6%), Salmonella (19.2%) and Campylobacter (7.9%). Rotavirus was significantly more frequent among children observed as inpatients whereas Campylobacter was significantly more common in outpatients. Infections with diarrheagenic E. coli, Shigella flexneri, yersinia enterocolitica, Cryptosporidium and Giardia were observed in a limited number of patients. The clinical presentation of children was not sufficiently characteristic to permit presumptive diagnosis of a specific pathogen. conversely the presence of blood and/or leukocytes in stools had a high positive predictive value for Salmonella or Campylobacter infection. CONCLUSION: The results of this study will be useful for planning strategies to prevent and control diarrheal diseases in our country.
Child↗
Distribution of cphA or related carbapenemase-encoding genes and production of carbapenemase activity in members of the genus Aeromonas.
The prevalence of the cphA gene or related carbapenemase-encoding genes was investigated in 114 Aeromonas strains belonging to the six species of major clinical interest. A species-related distribution of cphA-related sequences was observed. Similar sequences were found in A. hydrophila, A. veronii bv. sobria, A. veronii bv. veronii, and A. jandaei, but not in A. caviae, A. trota, or A. schubertii. However, a single A. caviae strain (of 62 tested) was found carrying cphA-related sequences, suggesting the possibility of the horizontal transfer of this gene to species which normally do not carry it. Production of carbapenemase activity was detectable in 83% of the hybridization-positive strains but in none of the hybridization-negative ones. When it was present, carbapenemase activity was always inhibitable by EDTA. Either carbapenemase-producing or not, Aeromonas strains appeared to be susceptible to imipenem when in vitro susceptibility testing was performed with inocula of conventional size (10(5) CFU), for which MICs were always < or = 1 microgram/ml. With a larger inoculum (10(8) CFU), the MICs for carbapenemase-negative strains always remained < or = 1 microgram/ml, while those for carbapenemase-producing strains were always > or = 4 micrograms/ml, being usually higher than the breakpoint for susceptibility. The present results indicate that the production of metallocarbapenemase activity, apparently encoded by cphA homologs, is widespread among some of the Aeromonas species of clinical interest (A. hydrophila, A. veronii bv. sobria, A. veronii bv. veronii, and A. jandaei) and that imipenem MICs for carbapenemase-producing strains are subjected to a relevant inoculum size effect.
Aeromonas↗
Detection of the Vibrio cholerae heat-stable enterotoxin gene by polymerase chain reaction.
A polymerase chain reaction assay was developed for detection of the Vibrio cholerae heat-stable enterotoxin gene (sto). The assay is based on two oligonucleotide primers suitable for amplification of the entire sto open reading frame. Reaction conditions were defined to obtain optimal results in terms of specificity and sensitivity. Under these conditions the assay was highly sensitive and enabled good results to be obtained using, as a template, crude DNA preparations from single bacterial colonies. A rapid protocol for direct sequence analysis of the amplification product, which may be used in combination with the PCR assay to confirm the product identity and analyse sequence polymorphisms within the sto gene, was also developed. Twenty-two V. cholerae non-O1 isolates from sporadic cases of V. cholerae non-O1-associated gastroenteritis from Cuba were analysed by this PCR assay. Four strains (18.2%) were found to carry the sto gene. The prevalence of V. cholerae non-O1 strains carrying the sto gene among clinical isolates is higher than that reported for other geographical areas, except in the case of epidemics.
Amino Acid Sequence↗
Prevalence of measles antibodies before and after vaccination in previously unvaccinated children of the Cordillera Province (Santa Cruz Department, Bolivia).
A study was carried out in the Cordillera Health District (Santa Cruz Department, Bolivia) from October 1988 to April 1989 to determine the seroprevalence of measles antibodies and the seroconversion rates among a group of previously unvaccinated children (9-36 months of age) from the urban and rural area of the province, before and after immunization with a standard dose of Schwarz measles vaccine. Among 265 previously unvaccinated children, 77 (29%) had measles IgG antibodies prior to immunization; 141 out of 147 (96%) seronegative children at the time of vaccination seroconverted. No difference in seroprevalence and in seroconversion rates was found between the urban and rural groups.
Age Factors↗
Prevalence of antibodies to Borrelia burgdorferi, Borrelia parkeri and Borrelia turicatae in human settlements of the Cordillera Province, Bolivia.
A seroepidemiological study to determine the prevalence of human Lyme borreliosis and tick-borne relapsing fever was carried out in three communities (Camiri, Boyuibe and Gutierrez) of the Cordillera Province, Santa Cruz Department, south-eastern Bolivia. Anti-B. burgdorferi, anti-B. turicatae and anti-B. parkeri antibodies, tested by the indirect immunofluorescent assay (IFA), were detected in 10.8, 16.1 and 8.2% of the serum samples tested, and confirmed by IFA-ABS in 1.3, 1.3 and 1.0%, respectively. This is the first report of the presence of Lyme borreliosis and tick-borne relapsing fever in Bolivia. For Lyme borreliosis these findings represent a further datum to support its existence in South America.
Adolescent↗
Two cases of Campylobacter mucosalis enteritis in children.
Two cases of Campylobacter mucosalis enteritis in children are reported. The patients recovered without antimicrobial therapy. Strains were isolated only by the feces filtration technique. In one child, bactericidal antibodies to the homologous strain were detected in a convalescent-phase serum sample. C. mucosalis should be considered a primary intestinal pathogen.
Antibodies, Bacterial↗
El fenómeno suicida en cepas de Aeromonas mesófilas aisladas de muestras clínicas [The suicide phenomenon in strains of mesophilic Aeromonas isolated from clinical specimens].
A study was carried out to determine the occurrence of the suicide phenomenon in Aeromonas spp strains, isolated from clinical samples, and to establish its relationship with the clinical manifestations of diarrheal diseases. 23 strains were studied: 10, of Aeromonas sobria; 7, of Aeromonas hydrophila; and 6, of Aeromonas caviae. All suicidal strains were isolated from patients with acute diarrheal disease. 3 out of 8, isolated from non-diarrheic feces, showed an intermediate phenotypic profile. Various growth patterns associated to the suicide phenomenon were reported.
Acute Disease↗