Occurrence and Characterization of Penicillium Species Isolated from Post-Harvest Apples in Lebanon

The apple is one of the most important fruit tree crops in the Mediterranean region. Lebanon, in particular, is among the top apple producer countries in the Middle East; however, recently, several types of damage, particularly rot symptoms, have been detected on fruits in cold storage. This study aims to identify the causal agents of apple decay in Lebanese post-harvest facilities and characterize a set of 39 representative strains of the toxigenic fungus Penicillium. The results demonstrated that blue mould was the most frequent fungal disease associated with apples showing symptoms of decay after 3–4 months of storage at 0 °C, with an average frequency of 76.5% and 80.6% on cv. Red and cv. Golden Delicious apples, respectively. The morphological identification and phylogenetic analysis of benA gene showed that most Penicillium strains (87.2%) belong to P. expansum species whereas the remaining strains (12.8%) belong to P. solitum. Furthermore, 67.7% of P. expansum strains produced patulin when grown on apple puree for 14 days at 25 °C with values ranging from 10.7 mg kg⁻¹ to 125.9 mg kg⁻¹, whereas all P. solitum did not produce the mycotoxin. This study highlights the presence of Penicillium spp. and their related mycotoxin risk during apple storage and calls for the implementation of proper measures to decrease the risk of mycotoxin contamination of apple fruit products.     

Phylogeny and Mycotoxin Profile of Pathogenic Fusarium Species Isolated from Sudden Decline Syndrome and Leaf Wilt Symptoms on Date Palms (Phoenix dactylifera) in Tunisia

In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.     

Mycotoxin Production in Liquid Culture and on Plants Infected with Alternaria spp. Isolated from Rocket and Cabbage

Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.     

Natural Occurrence of Alternaria Fungi and Associated Mycotoxins in Small-Grain Cereals from The Urals and West Siberia Regions of Russia

Alternaria fungi dominate the grain microbiota in many regions of the world; therefore, the detection of species that are able to produce mycotoxins has received much attention. A total of 178 grain samples of wheat, barley and oat obtained from the Urals and West Siberia regions of Russia in 2017–2019 were included in the study. Grain contamination with Alternaria fungi belonging to sections Alternaria and Infectoriae was analysed using qPCR with specific primers. The occurrence of four mycotoxins produced by Alternaria, AOH, AME, TEN, and TeA, was defined by HPLC-MS/MS. Alternaria DNA was found in all analysed grain samples. The prevalence of DNA of Alternaria sect. Alternaria fungi (range 53 × 10⁻⁴–21,731 × 10⁻⁴ pg/ng) over the DNA of Alternaria sect. Infectoriae (range 11 × 10⁻⁴‒4237 × 10⁻⁴ pg/ng) in the grain samples was revealed. Sixty-two percent of grain samples were contaminated by at least two Alternaria mycotoxins. The combination of TEN and TeA was found most often. Eight percent of grain samples were contaminated by all four mycotoxins, and only 3% of samples were free from the analysed secondary toxic metabolites. The amounts varied in a range of 2–53 µg/kg for AOH, 3–56 µg/kg for AME, 3–131 µg/kg for TEN and 9–15,000 µg/kg for TeA. To our knowledge, a new global maximum level of natural contamination of wheat grain with TeA was detected. A positive correlation between the amount of DNA from Alternaria sect. Alternaria and TeA was observed. The significant effects of cereal species and geographic origin of samples on the amounts of DNA and mycotoxins of Alternaria spp. in grain were revealed. Barley was the most heavily contaminated with fungi belonging to both sections. The content of AOH in oat grain was, on average, higher than that found in wheat and barley. The content of TEN in the grain of barley was lower than that in wheat and similar to that in oat. The content of TeA did not depend on the cereal crop. The effect of weather conditions (summer temperature and rainfall) on the final fungal and mycotoxin contamination of grain was discussed. The frequent co-occurrence of different Alternaria fungi and their mycotoxins in grain indicates the need for further studies investigating this issue.     

4株产抗肿瘤活性物质喜树内生真菌的鉴定及其主要代谢产物HPLC初步比较

采用MTT法测定了4株喜树内生真菌发酵产物的体外抗肿瘤活性,4菌株发酵产物分别对HL-60、HeLa和HepG2肿瘤细胞株增殖有一定抑制作用。通过PDA培养基上菌落、菌丝和孢子形态观察以及ITS区(包括5.8S r DNA)核酸序列分析,4株喜树内生真菌被鉴定为链格孢属(Alternaria spp.)真菌。HPLC分析显示4菌株主要代谢产物存在差异,说明植物内生真菌遗传代谢的多样性。内生真菌代谢产物是天然产物的丰富来源。     

Phylogeny and Toxin Profile of Freshwater Pufferfish (Genus Pao) Collected from 2 Different Regions in Cambodia

The species classification of Cambodian freshwater pufferfish is incomplete and confusing, and scientific information on their toxicity and toxin profile is limited. In the present study, to accumulate information on the phylogeny and toxin profile of freshwater pufferfish, and to contribute to food safety in Cambodia, we conducted simultaneous genetic-based phylogenetic and toxin analyses using freshwater pufferfish individuals collected from Phnom Penh and Kratie (designated PNH and KTI, respectively). Phylogenetic analysis of partial sequences of three mitochondrial genes (cytochrome b, 16S rRNA, and cytochrome c oxidase subunit I) determined for each fish revealed that PNH and KTI are different species in the genus Pao (designated Pao sp. A and Pao sp. B, respectively). A partial sequence of the nuclear tributyltin-binding protein type 2 (TBT-bp2) gene differentiated the species at the amino acid level. Instrumental analysis of the toxin profile revealed that both Pao sp. A and Pao sp. B possess saxitoxins (STXs), comprising STX as the main component. In Pao sp. A, the toxin concentration in each tissue was extremely high, far exceeding the regulatory limit for STXs set by the Codex Committee, whereas in Pao sp. B, only the skin contained high toxin concentrations. The difference in the STX accumulation ability between the two species with different TBT-bp2 sequences suggests that TBT-bp2 is involved in STX accumulation in freshwater pufferfish.     

我院住院患者痰培养病原菌菌谱和耐药性研究

目的:研究我院住院患者痰培养病原菌菌谱和耐药性。方法:对来自我院2005年1月～2007年7月住院患者6052份合格痰标本中培养的2255株病原菌药敏试验进行回顾性分析。结果:2255株病原菌中,革兰阴性杆菌1210株,占53.7%,主要为铜绿假单胞菌、鲍曼不动杆菌、肺炎克雷伯菌、大肠埃希菌,分别占19.5%、13.9%、8.2%、6.4%;革兰阳性球菌429株,占19.0%,主要为凝固酶阴性葡萄球菌、金黄色葡萄球菌;真菌519株,占23.0%,主要为白色念珠菌。结论:革兰阴性杆菌及革兰阳性球菌对相当多数的抗生素耐药率较高。     

某院2015-2019年肺炎克雷伯菌的耐药性及耐药基因分析

摘要：目的 分析某院临床分离的肺炎克雷伯菌(Klebsiella pneumoniae,KP)耐药情况及耐药基因,指导临床规范使用抗菌药物。方法 收集该院2015-2019年临床分离的2416株肺炎克雷伯菌,使用VITEK-2 Compact系统对临床分离株进行细菌鉴定,药敏试验采用MIC法和K-B纸片扩散法,采用WHONET 5.6软件对菌株的标本来源、科室分布、检出率及耐药率进行统计,采用SPSS 26.0软件对5年期间菌株的检出率、耐药率进行比较及趋势分析,选取2019年内科重症监护病房(Intensive care unit,ICU)的19株耐碳青霉烯肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumoniae,CR-KP),通过二代测序平台对其进行全基因组测序(whole genome sequencing, WGS),运用丹麦技术大学(DTU)基因组流行病学中心(CGE)(https://cge.cbs.dtu.dk/services/ResFinder/)的ResFinder 4.0工具进行耐药基因筛查,运用MORPHEUS(https://software.broadinstitute.org/morpheus/)在线制作耐药基因热图。结果 2015-2019年临床标本共分离出2416株KP,主要来自痰液、尿液,分别占51.7%(1249/2416)、11.3%(273/2416),科室主要分布于内科ICU、外科ICU,分别占23.2%(561/2416)、19.1%(461/2416)。每年KP的分离率呈上升趋势(χ2趋势=18.190,P＜0.001),其对常用抗菌药物的耐药率呈逐年升高趋势,除对替加环素的耐药率无法统计外,对其他各类抗菌药物的耐药率差异均有统计学意义(P＜0.001),对亚胺培南、美罗培南耐药率分别从2015年的2.9%、3.0%上升至2019年的16.0%、13.7%。5年间共检出354株CR-KP,主要来自痰液、尿液,分别占43.8%(155/354)、10.7%(38/354),分布较高的科室为外科ICU、内科ICU,分别占14.4%(51/354)、10.2%(36/354),每年的检出率呈上升趋势(χ2趋势=46.176,P＜0.001),其对各类抗菌药物的耐药率呈逐年升高趋势,除对庆大霉素的耐药率差异无统计学意义(P=0.105)、对替加环素的耐药率差异无法统计外,对其他各类抗菌药物的耐药率差异均有统计学意义(P＜0.05)。采用WGS技术对19株CR-KP进行分析,共筛查出15种耐药基因,主要包括β-内酰胺酶耐药基因(blaKPC-2)、喹诺酮类耐药基因(qnrS1)、磷霉素耐药基因(fosA)、四环素耐药基因(tetA)、氯霉素耐药基因(catA2)以及氨基糖苷类耐药基因(aadA2b、rmtB)等。结论 该院KP、CR-KP的耐药情况日趋严重,CR-KP同时携带多种耐药基因,耐药表型多样化。运用WGS结合生物信息学分析技术研究细菌耐药机制,有助于耐药菌防控措施的精准实施,未来将成为耐药菌研究的主流技术之一。     

Variation in Pharmacognostic Characters and Polyphenolic Contents among Four Species of Medicinal Plants from the Genus Spermacoce (Rubiaceae)

Spermacoce hispida L. is one of the important medicinal plants used in traditional systems of medicine. It is observed that, several times it is difficult to differentiate the plant from the other allied species from the same genus, Spermacoce, especially, when they are in drug form. Therefore, the present study aims to document the differences in the pharmacognostic characters, preliminary phytochemical analysis and polyphenolic contents from the leaves of four species belonging to the genus Spermacoce, viz. S. hispida L., S. mauritiana O. Gideon, S. stricta L. and S. ocymoides Burm. Transverse section passing through the midrib with lamina on either sides, epidermal characters, leaf constants, organoleptic characters, physicochemical analysis, extractive values and preliminary phytochemical analysis were carried out for all these species. Total phenolic content by Folin-Ciocalteu method and total flavonoids by AlCl₃ method were also estimated from the leaves of all these species. The results indicated that S. hispida can be clearly differentiated from the other selected species on the basis of size and number of epidermal cells, size of trichomes, leaf constants, physicochemical analysis and extractive values. However, it is also found that S. hispida possess total phenolic content at 6.88±0.34 mg CAE/g and 9.17±0.46 mg TAE/g. Total flavonoids was at 5.98±0.30 mg QE/g. The study will provide information with respect to identification and differentiation amongst selected species of genus Spermacoce.