Suppurative corneal ulceration in Bangladesh

Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary, Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season.     

深部病原真菌菌种4453株分析

目的 分析深部病原真菌菌种分布。方法 收集1991-2003年我院门诊及住院病人6533例，对其标本按真菌培养分离鉴定步骤进行鉴定。结果 分离出白念珠菌3555株(85．44％)，克柔念珠菌309株(7．43％)，高里念珠菌239株(5．74％)；呼吸系统分离出真菌3004株(68．35％)；消化系统真菌1291株(29．37％)；泌尿生殖系统87株(1．98％)；神经系统8株(0．18％)；血液5株(0．11％)。结论 念珠菌属尤其白念珠菌是我院近13年间系统性真菌感染的重要致病菌；合理应用抗生素及早期诊断尤为重要。     

河北磁县食管癌胃癌高发人群口腔真菌分布的调查

应用常规方法随机研究食管癌、胃癌高发的磁县人群５４７例的口腔真菌。结果：１．口腔真菌阳性率为６８．４％，食管真菌阳性率为４７．３％，前者显著高于后者（Ｐ＜０．００１）。２．口腔真菌以念珠菌、曲霉菌和青霉菌为主，食管真菌以曲霉菌、青霉菌和念珠菌占多数。３．口腔与食管内的产毒真菌差异无显著性意义（Ｐ＞０．０５）。本结果为进一步研究口腔真菌与上消化道癌及肿瘤的一级预防提供了依据。     

Autonomously replicating plasmids carrying theAMA1 region inPenicillium chrysogenum

Plasmid vectors containing theAMA1 sequence transformed with high efficiency and replicated autonomously inPenicillium chrysogenum. The efficiency of transformation ofP. chrysogenum was related to the length of theAMA1 fragment used for constructing the different autonomously replicating plasmids. One of the two palindromic inverted repeats ofAMA1 (the 2.2-kbSalI-HindIII fragment) is sufficient to confer autonomous replication and a high transformation efficiency. Deletion of the 0.6-kb central fragment located between the inverted repeats did not affect either the ability of the plasmids to replicate autonomously or the efficiency of transformation, but did alter the mitotic stability and the plasmid copy number. Deletion of any fragment of the 2.2-kb repeat caused the loss of the ability to replicate autonomously and reduced the transformation efficiency. Most of the transformants retained the original plasmid configuration, as multimers and without reorganization, after several rounds of autonomous replication. TheAMA1 region works as an origin of replication inP. chrysogenum andA. nidulans but not apparently inAcremonium chrysogenum.     

Antigenic and immunogenic mimicry of the HER2/neu oncoprotein by phage-displayed peptides

To recover peptides that antigenically and immunogenically mimic the p185^HER2 oncoprotein, we selected the phage-peptide libraries pVIII-9aa and pVIII-9aa. Cys using murine monoclonal antibodies (mAb) MGr2 and MGr6, directed against two distinct epitopes of the p185^HER2 extracellular domain. Phagedisplayed peptides containing consensus amino acid motifs were recovered and shown to compete specifically for mAb binding on tumor cells that overexpress p185^HER2. The deduced amino acid sequence of the peptides suggests that both epitopes defined by the mAb on p185^HER2 are discontinuous and that hydrophobic interactions are involved in binding with the mAb. A phage clone displaying the GPLDSLFAQ peptide elicited a specific immune response against the p185^HER2 in BALB/c mice, demonstrating that this phage-displayed peptide represents an immunological equivalent of the MGr2 epitope on p185^HER2 and might be used as a substitute for this oncoprotein in in vitro and in vivo immunological studies.     

Development of a quantitative monoclonal antibody‐based immunoassay for humicola ianuginosa on rice grains and comparison with conventional assays

A sensitive, specific, quantitative enzyme‐linked immunosorbent assay (ELISA) has been developed that can be used to determine the extent of mycelial growth of a sporulating thermophilic fungus, Humicola lanuginosa on the surface of rice grains. The assay employs a monoclonal antibody EC6, developed in a previous study, which does not recognize spores of the fungus. Using antigen‐coated wells, a direct linear relationship was established between dilutions of extracts from freeze‐dried mycelium (0.5 to 3 μg/ml) and absorbance values but to eliminate day‐to‐day variations it was found to be necessary to run a dilution series, prepared from stock freeze‐dried mycelium, with every test sample. The ELISA method was compared with conventional quantitative methods. Estimates of total mycelial length in freeze‐dried material by ELISA were found to be in the same order of magnitude as those determined by ergosterol and a theoretical calculation. The ELISA method also compared favourably with direct linear measurements (by photomicrography) of live mycelium present in aliquots from homogenates of a 1 cm² plug taken from a plate but estimates of the latter by the dilution plate count method were much lower. In assays with inoculated rice grains, the quantitative ELISA method proved more sensitive than either the ergosterol method or direct plating of surface‐sterilized grains. The ELISA method also has the advantage of being highly specific and quick to conduct.     

The ribosomal DNA of the Zygomycete Mucor miehei

The ribosomal DNA from the Zygomycete Mucor miehei has been characterised. The complete rDNA unit was cloned by heterologous PCR using primers whose sequence matched conserved regions of the rDNA from related fungal species. The sequence of the overlapping PCR products revealed the existence of a repeated unit of 9574 bp. The genes encoding the different rRNA species were identified by their homology to the corresponding sequences from other fungi. We estimate that the rDNA unit is present in the genome of M. miehei in about 100 copies. This estimation was made by comparing the intensity of its hybridisation signal in a Southern blot with that of the mmp gene coding for aspartyl protease, which was assumed to be contained in single copy. The size and structure of the M. miehei rDNA unit was similar to that of other fungi. The genes encoding the 25S, 18S and 5.8S RNAs are closely linked within the repeated unit which also contains the 5S gene. This latter gene appears to be transcribed in the opposite direction. The 25S, 18S and 5.8S genes showed 70–80% homology to the corresponding genes from other fungi, whereas the degree of homology for the 5S gene was much lower. The highest homology (about 80%) corresponded to the few available sequences from other Mucor species. Homology to genes from other Zygomycota was no higher than that observed for genes from the Ascomycota or Basidiomycota fungi. Received: 21 December 1999 / 1 March 2000     

Unusual aspects of allergic bronchopulmonary fungal disease: Report of two cases due to Curularia organisms associated with allergic fungal sinusitis

We report two cases of allergic bronchopulmonary fungal disease (ABPFD) caused by Curvularia sp and associated with allergic fungal sinusitis (AFS). Curvularia lunata was cultured in one case and Curvularia senegalensis was cultured in the other. Based on these cases and a review of the literature, we discuss unusual clinical and pathologic features that can occur in ABPFD. Unusual clinical aspects of ABPFD include associated AFS, absence of asthma, progression to Churg-Strauss angiitis and granulomatosis, concomitant hypersensitivity pneumonitis, and underlying cystic fibrosis. Atypical pathologic features that may occur in ABPFD include follicular bronchiolitis, xanthomatous bronchiolitis, limited tissue invasion, fungus balls, and association with unusual fungi. Prominent follicular bronchiolitis and xanthomatous bronchiolitis were misleading histologic features in one of our cases and led to a delay in recognition of the diagnosis. Both patients presented primarily with AFS; ABPFD was detected subsequently. This suggests that a small subset of patients with AFS may be at risk for ABPFD. The goal of this review is to increase awareness of unusual clinical and pathologic manifestations of ABPFD. It is hoped that this will result in accurate diagnosis and proper therapy, especially for patients who present with atypical features. Unusual fungal species should be considered in patients who have clinical findings compatible with ABPFD but who do not demonstrate immunologic reactivity to Aspergillus sp, especially Aspergillus fumigatus. In addition, ABPFD should be considered in patients with AFS who develop new pulmonary lesions.     

Integrative and replicative genetic transformation of Aureobasidium pullulans

A hybrid selectable marker for transformation was constructed by placing the promoter (TEF1p) from the gene encoding the Aureobasidium pullulans translation elongation factor 1- (TEF1) adjacent to the 5 end of the Escherichia coli hygromycin B phosphotransferase gene (HPT). Plasmids containing this hybrid gene (TEF1p/HPT) transformed A. pullulans strain R106 to a hygromycin B-resistant (HmB^R) phenotype. A PCR-generated DNA fragment consisting of the TEF1p/HPT resistance marker flanked by 41 bp of homologous DNA has also been shown to transform A. pullulans to HmB^R. Linearized plasmid DNA consistently produced more transformants than circular plasmid DNA. Analyses of 23 HmB^R transformants revealed integration of the plasmid in only eight of these transformants. In two transformants, integration into the largest chromosome (VIII) resulted in an alteration of the molecular karyotype. In four other transformants, integration occurred in chromosome VI (the chromosome containing TEF1) but only one was the result of homologous recombination with the genomic copy of the TEF1 promoter. The remainder of the transformants contained replicative plasmids that could be visualized on an agarose gel by ethidium bromide staining. These plasmids were generally 7–8 kb in size. One transformant appeared to contain four plasmids ranging in size from 4 to 8 kb, suggesting rearrangement of the transforming DNA. One plasmid obtained from a HmB^R A. pullulans transformant was able to transform E. coli to ampicillin resistance. However, after recovery from E. coli, this plasmid (approximately 4 kb) was unable to transform A. pullulans to HmB^R.