Moulds and mycotoxins in herb tea and medicinal plants

The level of toxigenic moulds and mycotoxins were analyzed in 62 samples of medicinal plant material and 11 herbal tea samples. The most predominant fungi detected were: Aspergillus, Penicillium, Mucor, Rhizopus, Absidia, Alternaria, Cladosporium and Trichoderma. Aspergillus flavus, a known producer of the aflatoxin mycotoxin, was present in 11 or 18% of the 62 medicinal plant samples and in 1 or 9% of the herbal tea samples. The medicinal plant samples, contaminated with A. flavus were also analyzed for the mycotoxins aflatoxin, ochratoxin and zearalenone; ochratoxin was found in one of the 7 samples analyzed. This study suggests that medicinal plant material and possibly herbal teas, if stored improperly allowing for mould growth, should be analyzed for mould and mycotoxin prior to use.     

植物乳杆菌ATCC8014对寄生曲霉NRRL 2999孢子形态及生长与产毒影响的研究

为探讨植物乳杆菌ATCC 80 1 4对寄生曲霉NRRL 2 999生长与产毒的影响 ,将植物乳杆菌与寄生曲霉同时接种到MRS肉汤和预先厌氧培养植物乳杆菌后再接种寄生曲霉孢子 ,2 8℃培养 1 5天。在培养的第3、6、9、1 2和 1 5天测定培养液中的pH值、黄曲霉毒素B1 和菌丝体重量。结果显示 :植物乳杆菌可显著抑制寄生曲霉生长 (P <0 0 1 ) ,抑制的机制在于孢子灭活 ,使其不能发育成菌丝 ,故也不能产生黄曲霉毒素B1 ,在电子显微镜下可观察到寄生曲霉孢子充水肿胀死亡 ,而植物乳杆菌的细胞形态也由长杆状变为椭圆形 ;当植物乳杆菌ATCC 80 1 4接种到已经培养了 3天的寄生曲霉NRRL 2 999培养液中时 ,则植物乳杆菌对其生长与产毒无显著影响。在以乳酸调整的pH4 5MRS肉汤中 ,乳酸对寄生曲霉生长有显著的抑制作用 (P <0 0 1 ) ,但并不影响黄曲霉毒素B1 的合成     

Microbial contamination of seven major weaning foods in Nigeria

Five million children aged less than five years die annually due to diarrhoea. The aim of the study was to identify some possible contributing factors for persistent diarrhoea. Seven weaning foods, including a locally-made food, were evaluated by estimating the microbial load using the most probable number method and aflatoxin levels (AFM1, AFG1, AFG2, and AFB2) by immunoaffinity column extraction and high-performance liquid chromatography (HPLC) with detection of fluorescence. The results showed that the locally-made weaning food had the highest microbial count (2,000 cfu/g) and faecal streptococcal count (25 cfu/g). Moulds isolated were mainly Aspergillus niger, A. flavus, A. glaucus, Cladosporium sp., and Penicillium sp. The home-made weaning food recorded the highest fungal count (6,500 cfu/g). AFM1 of the weaning foods was 4.6-530 ng/mL. One weaning food had AFB1 level of 4,806 ng/g. Aflatoxin metabolites, apart from AFM1 and AFB1 present in the weaning foods, were AFG1 and AFG2. There were low microbial counts in commercial weaning foods but had high levels of aflatoxins (AFM1, AFG1, AFG2, AFB1, and AFB2). Growth and development of the infant is rapid, and it is, thus, possible that exposure to aflatoxins in weaning foods might have significant health effects.     

Indoor exposure to mould allergens

Humid indoor environments may be colonised by allergenic filamentous microfungi (moulds), Aspergillus spp., Penicillium spp., Cladosporium spp., and Alternaria spp. in particular. Mould-induced respiratory diseases are a worldwide problem. In the last two decades, mould allergens and glucans have been used as markers of indoor exposure to moulds. Recently, mould allergens Alt a 1 (Alternaria alternata) and Asp f 1 (Aspergillus fumigatus) have been analysed in various environments (residential and occupational) with enzyme-linked immunosorbent assays, which use monoclonal or polyclonal antibodies. Household Alt a 1 and Asp f 1 levels were usually under the limit of the method detection. By contrast, higher levels of mould allergens were found in environments with high levels of bioaerosols such as poultry farms and sawmills. Data on allergen Alt a 1 and Asp f 1 levels in agricultural settings may provide information on possible colonisation of respective moulds and point out to mould-related diseases in occupants.     

Aspergillus flavus and aflatoxin B1 in flour production

This paper discusses the results of investigations of contamination with aflatoxin — producing fungi and aflatoxin B₁ affecting 545 samples of wheat grains, 475 samples of intermediate products of wheat grain being milled to flour (like middlings) and 238 samples of flour. A significant contamination with moulds was detected in analyzed samples. AlthoughAspergillus (34.87%) and Penicillium (32.37%) dominated, other types were also present, e.g.,Cladosporium, Fusarium, Mucor, Alternaria, Rhizopus, Absidia andTrichoderma (listed in order of frequency). The presence ofAspergillus flavus, the known aflatoxin producer, was detected in 9.94% of analyzed samples. Isolates of A.Flavus were capable of producing aflatoxin B₁ under favourable conditions. Aflatoxin B₁ was found in 76.8% of samples contaminated withA. flavus. The highest contamination with aflatoxin B₁ was detected in wheat grain samples (mean value of 16.3 µg/kg) and in intermediate products of wheat grain being milled to flour (mean value of 11.13 µg/kg). Contamination was lower in flour samples (mean value of 4.13 µg/kg). With regard to proposed standards given by the FAO and WHO, under which the content of aflatoxin should not exceed 30 µg/kg in food products, only two of 96 samples did not meet these criteria.     

黄曲霉毒素B_1抗原的构建

黄曲毒素Ｂ１是只有反应原性而无免疫原性的半抗原，不能直接刺激动物抗体，只有和牛血清蛋白（ＢＳＡ）、卵清白蛋白（ＯＶ）等载体蛋白连接后才能刺激动物产生分泌抗体，黄曲霉毒素Ｂ１抗原的构建是黄曲霉毒素Ｂ１免疫学检测研究的第一步。本文首先研究了回流温度和时间对黄曲霉毒素Ｂ１肟产生的影响，通过统计分析得到８５℃，回流２ｈ时黄曲霉毒素Ｂ１肟的产率最高，产率高达８９％。在此基础上进一步研究了黄曲霉毒素Ｂ１肟与载体蛋白—牛血清白蛋白反应的起始摩尔比对产物摩尔比的影响，随着反应起始摩尔比的增加，产物的摩尔比也稍有增加，但是增加幅度不显著，而黄曲霉毒素Ｂ１肟的利用率则随着起始摩尔比的增加而减少，选择３０∶１为黄曲霉毒素Ｂ１肟与牛血清白蛋白的反应起始摩尔比得到摩尔比为６．５∶１的黄曲霉毒素Ｂ１肟与牛血清蛋白的连接物。     

Seasonal variability of culturable fungal genera in the house dust of inner-city residences

House dust samples were collected up to six times over a 1-year period to explore seasonal variability of individual fungal genera in inner-city households in Minneapolis, Minnesota. General linear mixed-effects models were used to explore the variability of 13 fungal genera (Cladosporium, yeasts, Aureobasidium, Alternaria, Penicillium, Epicoccum, Mucor, Rhodotorula, Aspergillus, sterile fungi, Phoma, Pithomyces, and Fusarium) found in more than 20% of total dust samples. The five most common fungi (% of samples detected) were Cladosporium (81%), yeasts (63%), Aureobasidium (57%), Alternaria (56%), and Penicillium (55%), with the remaining genera found in 20-50% of the samples. When expressed as frequency of occurrence (%), genus fraction of total fungal concentration (%), or concentration of individual genera (CFU/g), these five genera also varied substantially by season. In contrast, Aureobasidium, Fusarium, and Mucor levels remained relatively constant throughout the year. The observed concentrations of the five most common fungal genera were higher than levels associated with increased respiratory symptoms reported in previous studies. Our results indicate that seasonal variability in common fungal genera is large: within-home to between-home variance ratios of Penicillium (4.1), Alternaria (4.9), Cladosporium (7.1), and yeasts (20.3) were substantially larger than that observed for total fungi (2.5). These results suggest that future studies attempting to link individual fungal genera to health effects need to characterize and control for this seasonal variability.     

Microbiological quality of indoor and outdoor swimming pools in Greece: investigation of the antibiotic resistance of the bacterial isolates

During 1997-2005, the microbiological quality and susceptibility of bacterial isolates of swimming pool waters were investigated. A total of 462 water samples were collected from three indoor swimming pools (a teaching pool, a competition public pool, a hydrotherapy pool) and two outdoor swimming pools (a hotel semi-public and a residential private pool) in Northwestern Greece. All water samples were analyzed for the presence of bacteria, protozoa and fungi and susceptibility tests were performed for the bacterial isolates. Sixty-seven percent of the examined water samples conformed to the microbiological standards and 32.9% exceeded at least one of the indicated limits. Out of 107 bacterial isolates, 38 (35.5%) resistant strains were detected. Multi-resistant Pseudomonas alcaligenes, Leuconostoc, and Staphylococcus aureus (isolated from the teaching pool), Staphylococcus wernerii, Chryseobacterium indologenes and Ochrobactrum anthropi (isolated from the competition pool), Pseudomonas aeruginosa, P. fluorescens, Aeromonas hydrophila, Enterobacter cloacae, Klebsiella pneumoniae and S. aureus (isolated from the hydrotherapy pool) and A. hydrophila (isolated from the hotel pool) were detected. The swimming pool with the poorest microbiological quality (THC 500 cfu/ml in 12.1% of the samples, P. aeruginosa counts 1500 cfu/100 ml in 6% of the samples) and the highest prevalence of multi-resistant isolates (73.6%) was the hydrotherapy pool. No Cryptosporidium or Giardia cysts and no Legionella, Mycobacteria and Salmonella were detected, but there were isolations of Candida albicans, Aspergillus spp., Mucor spp., Alternaria spp., Rhizopus spp., Trichophyton spp., and Penicillium spp.     

Environmental and clinical epidemiology of Aspergillus terreus: data from a prospective surveillance study

Aspergillus terreus may be resistant to amphotericin B and is associated with significant morbidity and mortality in immunocompromised patients. Local incidence is influenced by the density of airborne Aspergillus spp. spores which may in turn depend on meteorological factors. Once-weekly environmental samples were collected prospectively inside and outside the University Hospital of Cologne, Germany (UHC) and haematological patients were screened for nasal Aspergillus spp. colonisation and monitored for invasive fungal disease (IFD). RAPD (rapid amplification of polymorphic DNA)-polymerase chain reaction (PCR) and amphotericin B susceptibility testing were performed on all A. terreus isolates. A total of 4919 colony-forming units (cfu) were isolated (2212 indoors, 2707 outdoors). Further identification revealed A. fumigatus (73.5%), A. niger (4.3%), A. flavus (1.7%), A. terreus (0.2%) and non-Aspergillus fungi (20.3%). RAPD-PCR did not reveal clonal relationships between the A. terreus isolates. All A. terreus isolates displayed complete resistance to amphotericin. The B. Aspergillus spp. conidia exposure was lowest in June and highest in November inside and outside UHC. Conidia load correlated with the season and the relative humidity, with increasing spore counts during dry periods. One out of 855 nasal swabs was positive for A. niger. The patient did not develop IFD. A. terreus is unlikely to be a relevant pathogen at the UHC. Results from RAPD-PCR suggested a wide epidemiological variety of strains rather than a common source of contamination. Nasal swab surveillance cultures for early detection of Aspergillus spp. colonisation were not useful in identifying patients who may develop IFD. The risk of IFD at the UHC may increase in autumn and during dry periods.     

地下空间空气中微生物调查

目的通过对51个地下空间空气中微生物检测,了解地下空间空气中微生物污染状况.方法1992-2004年对华北地区51个地下空间,按通风状况分为密闭型(12个)、通风型(21个)、半密闭型(18个).用撞击法和沉降法检测空气中细菌总数、真菌数、链球菌及厌氧菌.分离出的黄曲霉菌用ELISA方法检测黄曲霉毒素B1.结果地下空间空气中细菌总数符合GJB 3768-1999《屯兵坑道环境卫生学要求》,半密闭型地下空间房间和通道空气中细菌总数、真菌数的监测结果均高于相应对照(P＜0.01).鉴定出的2 845株真菌中,青霉属及曲霉属为优势菌,分别占41.5%及19.1%.73株黄曲霉菌中黄曲霉毒素B1阳性者9株,占12.3%.通风型、密闭型地下空间通道和房间空气中厌氧菌高于相应对照组(P＜0.01或P＜0.05),链球菌与相应对照组相比,差异无统计学意义.密闭型通道空气中厌氧菌分别是半密闭型及通风型通道的4.2倍及3.8倍.结论地下空间房间和通道空气中含有大量真菌和厌氧菌,对进驻人员健康有一定危害.     

Incidence of aflatoxin-potential contamination in Spanish sausages

525 strains of moulds were isolated from 8 samples of red pepper (Capsicum annuum) and from 3 samples of black pepper (Piper nigrum). These spices were commonly added to the various kinds of spanish sausages, specially to the spanish "chorizo". Of these 525 isolated moulds, 100 belonged to the Aspergillus flavus group. 69 were isolated from red pepper and 31 from black pepper. Of these strains, 28 strains isolated from red pepper were found positive in producing aflatoxin B1 while only 8 of the strains isolated from black pepper produced aflatoxin B1. 16 of the strains isolated from red pepper also produced aflatoxin G1. After experimental contamination by these aflatoxicogenic strains of moulds of various kinds of spanish sausages, and after drying them under similar storage conditions used in the sausage industry, the presence of aflatoxin were detected only on the skin but not in the meat of the sausage.     

Effects of carotenoids on aflatoxin B1-induced mutagenesis in S. typhimurium TA 100 and TA 98

The effects of beta-carotene, canthaxanthin, and extracts of tomato paste (containing lycopene) and orange juice (containing cryptoxanthin) on aflatoxin B1 (AFB1)-induced mutagenesis in S. typhimurium TA 100 and TA 98 were investigated. Inhibition of mutagenesis was studied during and following completion of AFB1 metabolism (i.e., after the addition of menadione), thereby permitting separate examination of the metabolic activation and phenotypic expression phases. Each experimental carotenoid, except lycopene, inhibited AFB1-induced mutagenesis in both tester strains. Cryptoxanthin was the most potent inhibitor, being at least an order of magnitude more potent than the other carotenoids. Inhibition by beta-carotene and canthaxanthin was more prominent during the activation phase, whereas cryptoxanthin was more effective during the subsequent phenotypic expression phase. These inhibitory effects were not dependent on conversion to retinol.     

Protective effect of soybean saponins and major antioxidants against aflatoxin B1-induced mutagenicity and DNA-adduct formation

Saponins from various plant sources have been suggested as possible anticarcinogens. Major dietary sources of saponins include legumes such as soybeans. This study was performed to determine the effect of soybean saponins on aflatoxin B(1)(AFB(1))-induced mutagenicity and AFB(1)-DNA adduct formation using Salmonella typhimurium and human liver hepatoma (HepG2) cells, respectively. Major antioxidants including L-ascorbic acid, alpha-tocopherol, all-trans-retinol, and butylated hydroxytoluene (BHT), previously reported to possess antimutagenic activity, were used as test materials to evaluate the relative effectiveness of saponins. Results indicated antimutagenicity was in the order of BHT > saponins > alpha-tocopherol > L-ascorbic acid. Soybean saponins exerted a significant effect, inhibiting the mutagenicity of AFB(1) by 52%, 64%, and 81% at concentrations of 600, 900, and 1,200 microg per plate, respectively. The amount of tritiated AFB(1) metabolites-DNA adducts formed in HepG2 cells was significantly reduced when cells were preincubated with 10 or 30 microg/ml of test materials. Soybean saponins inhibited AFB(1)-DNA adduct formation by 50.1% at a concentration of 30 microg/ml, whereas L-ascorbic acid and BHT reduced adduct formation by 38.4% and 32.6%, respectively, at the same concentrations. These results indicate that soybean saponins possess not only a significant antimutagenic activity but a strong inhibitory action against carcinogen-induced DNA damages. Soybean saponins possibly block the initiation stage of carcinogenesis, and further studies are required to elucidate the mechanisms of action.     

Organosulfur compounds of garlic modulate mutagenesis, metabolism, and DNA binding of aflatoxin B1

The effects of two organosulfur compounds of garlic (ajoene and diallyl sulfide) and a crude garlic extract on aflatoxin B1 (AFB1)-induced mutagenesis were determined using rat liver 9,000 g supernatant (S-9) as the activation system and Salmonella typhimurium TA-100 as the tester strain. The effects of these compounds on AFB1 binding to calf thymus DNA were also measured. Metabolites of AFB1 were isolated and analyzed by reverse-phase high-performance liquid chromatography. All these compounds inhibited S-9-dependent mutagenesis induced by AFB1. They also inhibited AFB1 binding to DNA. A significant decrease in organo-soluble metabolites of AFB1 was observed with ajoene and garlic extract. An increase of glucuronide and glutathione conjugates was obtained with garlic extract. The results indicate that garlic compounds tested in this study are antimutagenic and, potentially, anticarcinogenic.     

Contamination of chlorhexidine cream used to prevent ascending urinary tract infections.

Chlorhexidine-containing cream is often used as an antimicrobial barrier to ascending urinary tract infection in patients with indwelling urethral catheters. The cream is dispensed in small tubes for personal use but repeated use of a tube still entails a potential infection hazard. The extent of cream contamination was analysed by emulsifying it in 1% peptone broth with 1% Tween-80 added as a wetting agent, and culturing quantitatively for bacteria and fungi by membrane filtration. Twenty-three per cent of cream samples and 35% of swabs taken from outside the tube beneath the screw cap demonstrated microbial contamination. Isolates included potential pathogens such as enterococci, staphylococci, Proteus mirabilis, Pseudomonas aeruginosa, opportunists like Moraxella spp. and diphtheroids, and contaminants such as Bacillus spp., micrococci, and a mould of the genus Cladosporium. Contamination of cream with a particular bacterial strain was found to precede urinary tract infection with the same microbe. We recommend that chlorhexidine cream for this use be dispensed in single dose units to ensure sterility.     

伏马菌素与黄曲霉毒素对SD大鼠联合毒性的研究

目的探讨伏马菌素 B_1(fumonisin B_1,FB_1)和黄曲霉毒素 B_1(aflatoxin B_1,AFB_1)对SD 大鼠的联合毒性作用。方法雄性 SD 大鼠按体重分为5组,每组12只,分别灌胃给予受试物(100μg/kg bw FB_1、100μg/kg bw AFB_1、100μg/kg bw FB_1+100μg/kg bw AFB_1、50μg/kg bw FB_1+50μg/kg bw AFB_1、蒸馏水),连续灌胃30d,观察动物的生长发育、食物利用情况、血液学、血生化指标及脏器组织病理学的改变情况。结果实验结束时100μg/kg bw FB_1+100μg/kg bw AFB_1组体重增重为(164.9±19.8)g,食物利用率为(25.3±1.6)%,低于实验对照组体重增重为(203.7±17.1)g,食物利用率为(28.1±1.2)%,也低于其余各实验组(P<0.05),而其余各染毒组与实验对照组间的差异无统计学意义(P>0.05);各实验组动物肝功能指标血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、γ-谷氨酰胺转移酶(γ-GT)水平升高,且 FB_1+AFB_1组的升高程度较单独给予 FB_1和 AFB_1严重;同时 FB_1+AFB_1高剂量组动物肝脏、肾脏重量降低,肝脏出现明显病理变化,血清中超氧化物歧化酶(SOD)活力降低,丙二醛(MDA)水平升高等。结论两种真菌毒素存在联合毒性作用。本研究结果为进一步探讨两种真菌毒素同时暴露对人群健康的危害与联合作用。     

A potent sperm motility-inhibiting activity of bioflavonoids from an ethnomedicine of Onge, Alstonia macrophylla Wall ex A. DC, leaf extract

The methanol extract (ME) and the n-butanol fractions of methanolic extract of Alstonia macrophylla Wall ex A. DC leaves were investigated on the forward motility (FM) of mammalian (goat and human) spermatozoa. The ME at 600 microg mL-1 as well as fraction B at 100 microg mL-1 concentrations showed marked inhibition of sperm FM in both goat and human species when tested by microscopic and spectrophotometric methods. Approximately 60-80% of the goat spermatozoa lost their FM when treated with 600 microg mL-1 of ME and 100 microg mL-1 of fraction B. At 100 microg mL-1 concentration, fraction B showed 90% loss of FM in human spermatozoa, while fraction B at 400 microg mL-1 concentration showed complete inhibition of sperm FM at 0 min. The inhibitory activity of fraction B increases with increasing concentration in a dose-dependent manner. Phytochemical study of the extract revealed that the leaf contains tannins, flavonoids, sterols, triterpenes, alkaloids and reducing sugars. Further fractionation and purification of the bioactive n-butanol part of ME showed the presence of ursolic acid (fraction B), beta-sitosterol (fraction A), beta-sitosterol glucoside and a mixture of minor compounds (fraction C, detected on thin-layer chromatography). The results reveal that fraction B (ursolic acid), a pentacyclic triterpene, has the potential of sperm motility inhibition and can serve as a topical vaginal contraceptive.     

人体血清中黄曲霉毒素-白蛋白加合物的测定及应用

黄曲霉毒素B1 (AFB1 )是人类原发性肝癌 (HCC)的主要病因之一 ,发展和应用AFB1 及其体内分子生物标记物敏感、特异的检测方法对肝癌高危人群的筛检具有重要意义。人体血清中黄曲霉毒素 白蛋白加合物 (AFB ALB)的测定已应用于人体黄曲霉毒素暴露水平与肝癌的研究 ,本研究旨在建立敏感特异的AFB ALB的测定方法。该方法选择使用Microcon 5 0微型浓缩器使白蛋白快速分离 ,改变了用沉淀和其他分离白蛋白的方法 ,同时由于在同一装置内加入蛋白分解酶消化 ,从而减少了转移操作步骤 ,增加了白蛋白的回收率 ,对消化样品采用竞争性放射免疫测定 (RIA)法进行AFB ALB的测定 ,提高了测定的敏感性及特异性。应用改进的方法对我国江苏启东和广西扶绥两肝癌高发区居民的血样进行了测定 ,表明该地区人群黄曲霉毒素暴露较普遍 ,血清AFB ALB阳性率高。     

The assessment of the sensitivity of environmental fungi to urea phosphate

In this paper the authors presented the influence of various urea phosphate doses, 1-12%, on the environmental fungi growth depending on its intensity and the type of created spore e.g. (Penicillium italicum, Aspergillusfumigatus, Aspergillus niger, Cladosporium resinae, Mucor hiemalis i Rhizopus nigricans). The result of urea phosphate effect on fungi was estimated by static culture method using dry mass increase change [g. dry mass/ldm3]. The control was created by the growth of the above mentioned fungi on the basis of urea phosphate free soil. The obtained results were worked out by a statistic method using Duncan's test. The tested fungi showed different sensitivity to the various urea phosphate doses. In the presence of 1% urea phosphate the fungi sensitivity depended on their growth intensity (Aspergillus niger, Mucor hiemalis i Rhizopus nigricans). Additionally, the stimulation of fungi growth with rapid vegetative structure progress was observed. Independently of their physiological properties, significant inhibition of dry mass increase in the range of 3-12% concentration urea phosphate was observed. The result of the use of 3% urea phosphate was the reduction of dry mass growth of all tested fungi.     

黄曲霉强产毒菌株的产毒规律研究

目的：为研究２株黄曲霉菌株的黄曲霉毒素的产毒规律。方法：接种后，每２或３ｄ用薄层层析法检测黄曲霉毒素产量。结果：产毒培养基中黄曲霉毒素产量迅速增长，在培养第５ｄ时达到高峰，菌株１８－１产生黄曲霉毒素Ｂ１７．５０ｇ／ｋｇ和Ｇ１３３．３３ｇ／ＫＧ。菌株３０－２产生黄曲霉毒素Ｂ１０．９０ｇ／ｋｇ。之后，毒素含量逐渐降低。