Seroprevalence of anti-Chlamydia trachomatis IgG in outpatients attending a sexually transmitted disease clinic in Italy

Prevalence of anti-Chlamydia trachomatis specific IgG antibodies was evaluated in a sexually transmitted disease outpatient population composed of 741 heterosexuals, 470 males and 271 females, and of 147 homosexual-bisexual men. The prevalence rates were 60.0% in heterosexual males, 50.6% in females and 73.5% in homosexuals-bisexuals. A positive association between age and antibody prevalence was found in males. Among heterosexuals there is an increasing trend of seropositivity with number of partners during the previous year. A significant association between anti-chlamydial and anti-herpes simplex, type 2, antibodies has been demonstrated.     

肠道黏膜、肠道免疫和微生物群在肠源性白念珠菌感染中的作用

肠源性白念珠菌感染是指肠道内定植的白念珠菌在一定条件下发生易位,突破肠道,造成组织感染,甚至引发侵袭性白念珠菌感染。肠道黏膜作为念珠菌第一接触位点,是抵抗白念珠菌定植或侵入的第一道防线,常通过物理屏障和激活宿主免疫抑制感染。作为另一种防御机制,肠道内微生物群则通过调节pH, 分泌抗菌肽和竞争黏附点共同抵抗白念珠菌侵袭感染。本综述总结肠道黏膜、肠道免疫和微生物群这三个关键因素在肠源性白念珠菌感染中的作用, 为肠道定植引发侵袭性白念珠菌病的科学研究提供新思路。     

Surveillance of nosocomial transmission of Candida albicans in an intensive care unit by DNA fingerprinting

The frequency of nosocomial transmission of the opportunistic fungal pathogen Candida albicans in an intensive care unit was tested by DNA fingerprinting of 91 isolates from 32 hospitalized patients with the mid-repetitive Ca3 DNA probe. This showed that serial isolates of C. albicans from individual patients belonged to genetically distinct strains. In comparison with nosocomial bacterial pathogens, the transmission of C. albicans in an intensive care unit occurred at a much lower frequency. In conclusion, the threat of C. albicans infection does not lie within the hospital, but in commensal isolates. These findings are relevant for infection control practices.     

NDV-3 protects mice from vulvovaginal candidiasis through T- and B-cell immune response

We have previously reported that vaccination with rAls3p-N protein of Candida albicans, formulated with alum adjuvant (also designated as NDV-3) protects immunocompetent mice from, lethal disseminated candidiasis and mucosal oropharyngeal candidiasis. NDV-3 vaccine was recently, tested in a Phase 1 clinical trial and found to be safe, well-tolerated, and induced robust humoral and, cellular immune responses with increased interferon (IFN)-gamma and interleukin (IL)-17 secretion. In preparation for a Phase 2 clinical trial against vulvovaginal candidiasis (VVC), we evaluated NDV-3, efficacy in a murine VVC model. Here, NDV-3 induced a strong immune response characterized by high, anti-rAls3p-N serum IgG and vaginal IgA titers. Furthermore, moderate doses of the vaccine (a range of 1–30 μg given subcutaneously [SQ] or 0.3–10 μg given intramuscularly [IM]) elicited a 10–1000 fold, decrease in vaginal fungal burden vs. control (mice injected with alum adjuvant alone) in both inbred, and outbred mice infected with different clinical C. albicans isolates. Additionally, NDV-3 required both, T and B lymphocytes for efficacy in reducing C. albicans tissue burden, which is followed by a reduction, in neutrophil influx to the affected site. Finally, anti-rAls3p-N antibodies enhanced the ex vivo killing, of C. albicans by neutrophils primed with IFN-gamma. These data indicate that NDV-3 protects mice, from VVC by a mechanism that involves the concerted priming of both humoral and adaptive immune, responses.     

Fungal cell adhesion molecules in Candida albicans

Adherence of Candida albicans to host tissues is considered a crucial step in the pathogenesis of candidiasis. Using in vitro assays, it was demonstrated that the yeast — mycelium transition was an important phenomenon in the acquisition of adhesive properties. Proteins with MWs of 60, 68, 200 and > 200 kDa seemed to be involved in germ tube adherence to plastic surfaces. Likewise, recent investigations have revealed that C. albicans expresses on its surface receptors which interact with a wide variety of host proteins, particularly some extracellular matrix components like fibronectin, laminin and collagen. Plasmatic components, such as fibrinogen, iC3b and C3d, have also been proposed as mediators of adherence of C. albicans. Thus, by their reaction with laminin, fibrinogen and C3d, the mannoproteins of 68 and 60 kDa demonstrated multiple biological activities. Proteins of similar MWs were detected as C3d and iC3b receptors, the latter showing similarities with the neutrophil CR3. Based upon the antigenic, structural and functional homologies between the candidal receptors and mammalian integrins, it was postulated that these fungal cell adhesion molecules (F-CAM) are members of the integrin family. Interactions with host proteins and molecular mimicry of mammalian adhesion molecules may be a fertile area for further research.Corresponding author.     

Investigation in Central Italy of the possible association between Cryptococcus neoformans var. Gattii and Eucalyptus camaldulensis

The authors present a worldwide review of isolations of Cryptococcus neoformans, var. neoformans and C. neoformans var. gattii from animals and vegetation, referring in particular to the already well-known association of the former variety with Eucalyptus camaldulensis. They then review the Italian situation relative to this association and their studies carried out in Central Italy: in Latina (Lazio), Pisa, Viareggio and Lake Massaciuccoli (Tuscany). From the 256 E. camaldulensis trees examined C. neoformans var. gattii was not isolated. An E. camaldulensis tree situated in the nature reserve on Lake Massaciuccoli proved to be positive for C. neoformans var. neoformans. This variety was isolated from the leaves, flowers, bark and the debris at the foot of the tree, suggesting that it had colonized the entire tree and that it was capable of developing not only on its usual habitat (bird guano, soil rich with guano) but also on Eucalyptus trees. The identity of the isolates was confirmed by their genomic profiles obtained by random amplification polymorphic DNA (RAPD) with the primer (GACA)₄. The presence of a single genotype indicates a sole source of contamination, perhaps brought by a bird coming from a contaminated environment.     

唾液富组蛋白5——治疗白念珠菌感染的一种新策略

白念珠菌是一种机会性病原体,可引起不同部位的真菌感染。目前,白念珠菌治疗药物单一,且随着临床药物的不合理使用,白念珠菌耐药问题日益加剧。富组蛋白5(Hst-5)是口腔唾液中分泌最丰富的抗菌肽,作为宿主第一道防御线,对白念珠菌具有很强的抗菌活性。其作用机制与传统抗真菌药物和其他抗菌肽不同,其中涉及白念珠菌表面的多种转运蛋白、MAPK途径、体外多种金属离子等,且随着对Hst-5的深入研究,发现Hst-5的多种衍生肽(K11R-K17R、P-113Tri等),在抗菌效力上能发挥更大杀伤力。因此,对Hst-5及其衍生肽在白念珠菌中的抗菌机制进行研究尤为重要,将为目前临床治疗真菌感染提供新策略。     

Prevalence of anti-Toxoplasma gondii antibodies in the population of the area of Parma (Italy)

Between 1987 and 1991, the prevalence of IgG antibodies toToxoplasma gondii was determined by ELISA in 28,247 serum samples belonging to 19,432 subjects of the area of Parma (Italy). The overall prevalence was 48.5%. The correlation of infection with age, performed on 420 sera, showed a significant increase of positivity until 30–40 approximately years. In consecutive sera obtained from 172 subjects, the IgG and IgM production was analyzed for about 8 months, and four different patterns were delineated which were comprehensive of the wide range of immunological responses toToxoplasma gondii exposure observed. Among pregnant females the prevalence ofanti-Toxoplasma gondii antibodies was 48.7%, and 5 cases of seroconversion during the pregnancy were observed (0.27%) from which two cases of congenital toxoplasmosis originated.     

Sequential changes in antibody levels to the ENV and GAG Antigens in human immunodeficiency virus infected subjects

Sera from 51 HTLV-III (human immunodeficiency virus, HIV)-antibody positive subjects consisting of 21 asymptomatic individuals and 15 ARC and 15 AIDS patients were analyzed for their serological profiles toward the viral antigens. One of the asymptomatic subjects only showed a p24 reactivity in the immunoblot, but antibodies to the env antigens were clearly identified by immunoprecipitation of viral antigens (RIP) followed by SDS-polyacrylamide gel electrophoresis. RIP patterns of different subjects and even different bleeds from the same subjects showed a varying reactivity to the gag antigens whereas the reactivity towards the env antigens appeared to be generally stable. RIP analysis of sequential sera of virus-infected individuals indicated a pattern consistent with an initial steady rise of antibody reactivities to the gag antigens relative to the reactivities to the envelope antigens. These reactivities reached a plateau and then slowly declined. While all sera tested had antibodies to the envelope antigens gp160, gp120 and gp4l, 86% of the asymptomatic subjects, 67% of the ARC patients and only 33% of the AIDS patients had antibodies to the gag proteins p24 and pr53gag.Corresponding author.     

DNA relatedness,karyotyping and gene probing of Candida tropicalis,Candida albicans and its synonyms Candida stellatoidea and Candida Claussenii

Isolates of Candida albicans with varied phenotypes, including sucrose-negative variants (C. stellatoidea, serotypes A and B) and avirulent germ tube-negative forms (C. claussenii) showed significant (> 90%) DNA relatedness to classical C. albicans, but insignificant relatedness to C. tropicalis and sucrose-negative C. tropicalis. A transverse alternating-field gel electrophoresis procedure (TAFE) showed discrete karyotype patterns among the phenotypic variants of C. albicans including the sucrose-negative C. stellatoidea. The number of chromosome-sized DNA bands for C. tropicalis (7 bands) were within the range of bands observed for C. albicans (5 to 10 bands). The general DNA-migration pattern for C. albicans appeared distinct from that of C. tropicalis. An aspartyl proteinase (PrA) gene probe from C. albicans hybridized with chromosomal DNA from C. albicans, C. claussenii and C. stellatoidea but not with that from C. tropicalis.     

Fluorescence analysis detects gp60 subtype diversity in Cryptosporidium infections

Ninety percent of human cryptosporidiosis infections are attributed to two species; the anthroponotic Cryptosporidium hominis and the zoonotic Cryptosporidium parvum. Sequence analysis of the hypervariable gp60 gene, which is used to classify Cryptosporidium to the subtype level, has highlighted extensive intra-species diversity within both C. hominis and C. parvum. The gp60 has also facilitated contamination source tracking and increased understanding of the epidemiology of cryptosporidiosis. Two surface glycoproteins, the gp40 and gp15 are encoded in the gp60 gene; both are exposed to the hosts’ immune system and play a pivotal role in the disease initiation process. The extent of genetic diversity observed within the gp60 would support the hypotheses of significant selection pressure placed on the gp40 and gp15. This study used a dual fluorescent terminal-restriction fragment length polymorphism (T-RFLP) analysis to investigate the genetic diversity of Cryptosporidium subtype populations in a single host infection. Terminal-RFLP showed subtype variation within one human Cryptosporidium sample and mouse samples from seven consecutive passages with C. parvum. Furthermore, this was the first study to show that differences in the ratio of subtype populations occur between infections. T-RFLP has provided a novel platform to study infection populations and to begin to investigate the impact of the hosts’ immune system on the gp60 gene.     

Study of C. burnetii human and animal seroprevalence in a rural population in Madrid community

A pilot study on human seroprevalence of antibodies to C. burnetii in the Madrid region, initiated in a small rural population, shows a 15.4% positivity by the indirect immunofluorescence test. An urban sample shows an 8.8% positivity. Animal seroprevalence in livestock located in the village under study is 76.6% in caprine and 17.7% in bovine. A high risk epidemiological situation is detected.Presented at the 4th European Congress of Clinical Microbiology, Nice, 17–20 April, 1989.     

Clinical and mycological evaluation of fluconazole in the secondary prophylaxis of esophageal candidiasis in AIDS patients

A prospective, multicenter, open study of fluconazole prophylaxis was performed in AIDS patients to evaluate the efficacy and toxicity of the drug in preventing relapses of esophageal candidiasis. To this aim, 99 AIDS patients who presented a first episode of clinically and microbiologically confirmed esophageal candidiasis were enrolled in eleven clinical centers scattered throughout the Italian territory. After resolution of this initial esophagitis, all subjects were given fluconazole, 100 mg/die, and followed up for a 6 month period. Only 7 out of the 99 patients enrolled had a relapse ofCandida esophagitis, during a mean follow-up period of 138.5 days. All relapsing patients had CD4⁺ cell number <100/µl at baseline. Mild side effects were reported in only eight patients. However, 14 of the 27 subjects from whom serial serum samples were available became (12) or remained (2) antigenemic during fluconazole prophylaxis, independently from relapse, suggesting the persistence of tissue-invasive, proliferatingCandida cells. Overall, the data of this study suggest a beneficial effect of prophylactic maintenance therapy with fluconazole againstCandida esophagitis, particularly in the population with >100 CD4⁺/µl. However, the data onCandida antigenemia in these patients invite the consideration of a relative inefficiency of the drug to eradicate the microrganism from the esophageal tissue.     

Gastrointestinal carriage rate of Clostridium difficile in elderly, chronic care hospital patients

The carriage rate of Clostridium difficile in patients at a chronic care hospital was determined by two point prevalence surveys at 6-monthly intervals. In the first survey C. difficile or its toxin was present in stool samples from five symptomless patients on three of the four wards studied. All of these colonized patients had been in hospital for at least 2 months, but there was no relationship between carriage of the organism and antibiotic use. When the survey was repeated 6 months later, no symptomless carriers were found but one symptomatic patient had C. difficile and its toxin present in the stool. The results suggest that C. difficile should always be considered as a possible cause of diarrhoea in long-stay hospitalized patients.     

Comparison of seven phenotyping methods forCandida albicans

Seven different phenotyping methods for strain differentiation ofCandida albicans (auxono-typing, enzymotyping, resistotyping, Phongpaichit's morphotyping, Hunter's morphotyping and Odds and Abbott's biotyping method — 1980 and 1983 versions) were compared on a single population of 94 strains. 77.6% of the strains belonged to auxono-typing 1, 59.6% to enzymotyping A, 34% to resistotyping B and 30.8% to BC, 40.4% to Phongpaichit's morphotyping 000,000 and 40.4% to Hunter's morphotyping No fringe/Smooth surface. Using biotyping systems (1980 and 1983 versions), the most frequent biotypes were 145 (29.8%) and 147 (31.9%) respectively. The Discriminatory Index of Hunter and Gaston was employed to carry out comparisons among the different systems. The best discriminatory results, although far from ideal, were found using Phongpaichit's morphotyping (DI=0.827) and Odds and Abbott's method (DI=0.815 and 0.831 — 1980 and 1983 versions). A good discriminatory result was also found using Hunter's morphotyping method together with the biotyping of Odds and Abbott (1983 version). These approximated the ideal (DI=0.950) and showed minimal difficulty in interpretation. The proposed combined method revealed high discrimination among the vulvovaginal strains, and suggested the absence of transmissible pathogenic strains.     

Identification of antigens reacting with anti-Candida albicans germ tube antibodies

Anti-Candida albicans germ tube antibodies can be induced in rabbits immunized with different C. albicans extracts. Antigens responsible for the induction of those antibodies have molecular weights of approximately 230–250, 62, 43 and 41 kDa. These antigens are present in the cell wall of both C. albicans morphological forms, although their location seems to be different.     

Recent advances in chlamydia trachomatis

Chlamydia trachomatis is an obligate intracellular energy parasitic bacterium with a genome of 660 × 10⁶ daltons, possessing a plasmid and unique life cycle which includes the differentiation of the infective elementary body to a replicative reticulate body. C. trachomatis is the etiological agent of trachoma, which affects approximately 500 million people in developing countries. Recently it became evident that in industrialised Western nations certain strains of C. trachomatis are the most common cause of sexually transmitted infections such as non-gonoccocal urethritis, cervicitis, endometritis, salpingitis and subsequent ectopic pregnancies or infertility, perihepatitis, neonatal conjunctivitis and pneumonia, adult conjunctivitis and epididymitis. Since C. trachomatis infections are often asymptomatic, widespread screening of sexually active young people is needed in order to initiate early antibiotic treatment which may prevent serious complications such as ectopic pregnancies and infertility. Development of sensitive and simple techniques for mass screening for detection of Chlamydia in excretions as well as techniques for detection of specific markers of chronic internal infections (such as Chlainydia specific IgA antibodies) is of great importance.     

我国犬种菌布鲁氏菌病的调查研究

本文报告了全国23个省区市检查的12 949只犬、1 676人、15种动物2 255只,都发现有不同程度的犬种布氏菌感染存在(0.3%~42.7%)。南方省区犬的感染率高于北方省区。犬种布氏菌对母犬的感染率高于雄犬(2:1)。1岁龄以下犬的感染率低于年长犬。2岁龄以上犬的感染率无明显区别。解剖644只犬,主要从脾、淋巴结和肝中分到166株犬种布氏菌。根据犬种布氏菌对两种染料的敏感性分为两个型:对硫堇有抗性,对复红敏感;对两种染料都有抗性。8种血清学方法对比表明,R-SAT与R-RBPT吻合率最高,以≥1:80为标准,分离菌的阳性率近于50%,以≥1:320为标准,分菌率近于80%。