HISTOPATHOLOGICAL STUDIES WITH ELECTRON MICROSCOPY (SEM & TEM) OF ALTERNARIA ALTERNATA, CAUSAL AGENT OF BROWN SPOT AND BLACK ROT DISEASES (AS POSTHARVEST DISEASES) ON CITRUS IN THE NORTH OF IRAN

The tangerine pathotype of Alternaria alternata produces a host-selective toxin (HST), known as ACT-toxin, and causes Alternaria brown spot disease of citrus. The structure of ACT-toxin is closely related to AK- and AF-toxins, which are HSTs produced by the Japanese pear and strawberry pathotypes of A. alternata, respectively. AC-, AK-, and AF-toxins are chemically similar and share a 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid moiety. Two genes controlling AK-toxin biosynthesis (AKT1 and AKT2) were recently cloned from the Japanese pear pathotype of A. alternata. Portions of these genes were used as heterologous probes in Southern blots, that detected homologs in 13 isolates of A. alternata tangerine pathotype from Minneola tangelo in Florida. Partial sequencing of the homologs in one of these isolates demonstrated high sequence similarity to AKT1 (89.8%) and to AKT2 (90.7%). AKT homologs were not detected in nine isolates of A. alternata from rough lemon, six isolates of nonpathogenic A. alternata, and one isolate of A. citri that causes citrus black rot. The presence of homologs in the Minneola isolates and not in the rough lemon isolates, nonpathogens or black rot isolates, correlates perfectly to pathogenicity on Iyo tangerine and ACT-toxin production. Functionality of the homologs was demonstrated by detection of transcripts using reverse transcription-polymerase chain reaction (RT-PCR) in total RNA of the tangerine pathotype of A. alternata. The high sequence similarity of AKT and AKT homologs in the tangerine patho-type, combined with the structural similarity of AK-toxin and ACT-toxin, may indicate that these homologs are involved in the biosynthesis of the decatrienoic acid moiety of ACT-toxin.

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Endopolygalacturonase Is Essential for Citrus Black Rot Caused by Alternaria citri but Not Brown Spot Caused by Alternaria alternata

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2001.14.6.749 ◽

2001 ◽

Vol 14 (6) ◽

pp. 749-757 ◽

Cited By ~ 143

Author(s):

Atsunori Isshiki ◽

Kazuya Akimitsu ◽

Mikihiro Yamamoto ◽

Hiroyuki Yamamoto

Keyword(s):

Cell Wall ◽

Alternaria Alternata ◽

Biochemical Properties ◽

Brown Spot ◽

Black Rot ◽

Citrus Peel ◽

Degrading Enzyme ◽

Cell Wall Degrading Enzyme ◽

A Cell

Alternaria citri, the cause of Alternaria black rot, and Alternaria alternata rough lemon pathotype, the cause of Alternaria brown spot, are morphologically indistinguishable pathogens of citrus: one causes rot by macerating tissues and the other causes necrotic spots by producing a host-selective toxin. To evaluate the role of endopolygalacturonase (endoPG) in pathogenicity of these two Alternaria spp. pathogens, their genes for endoPG were mutated by gene targeting. The endoPGs produced by these fungi have similar biochemical properties, and the genes are highly similar (99.6% nucleotide identity). The phenotypes of the mutants, however, are completely different. An endoPG mutant of A. citri was significantly reduced in its ability to cause black rot symptoms on citrus as well as in the maceration of potato tissue and could not colonize citrus peel segments. In contrast, an endoPG mutant of A. alternata was unchanged in pathogenicity. The results indicate that a cell wall-degrading enzyme can play different roles in the pathogenicity of fungal pathogens. The role of a cell wall-degrading enzyme depends upon the type of disease but not the taxonomy of the fungus.

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Evaluation of in vitro antifungal potential of several fungicides against Alternaria alternata (Fr.) Keissler, the causal agent of potato brown spot in Afghanistan

Novel Research in Microbiology Journal ◽

10.21608/nrmj.2021.149383 ◽

2021 ◽

Vol 5 (1) ◽

pp. 1106-1117

Author(s):

Abdul Madadi ◽

Hadia Rauf ◽

Mohammad H. Falahzadah ◽

Ahsanullah Yousufzai ◽

Abdul S. Jamily ◽

...

Keyword(s):

Alternaria Alternata ◽

Causal Agent ◽

Brown Spot ◽

Antifungal Potential

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Susceptibility of citrus species to Alternaria alternata, the causal agent of the Alternaria brown spot

Scientia Horticulturae ◽

10.1016/j.scienta.2007.04.005 ◽

2007 ◽

Vol 113 (4) ◽

pp. 336-342 ◽

Cited By ~ 18

Author(s):

R.F. Reis ◽

T.F. de Almeida ◽

E.S. Stuchi ◽

A. de Goes

Keyword(s):

Alternaria Alternata ◽

Causal Agent ◽

Brown Spot ◽

Citrus Species ◽

Alternaria Brown Spot

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Phenotypic Analysis of Alternaria alternata, the Causal Agent of Tobacco Brown Spot

Plant Pathology Journal ◽

10.3923/ppj.2015.79.85 ◽

2015 ◽

Vol 14 (2) ◽

pp. 79-85 ◽

Cited By ~ 4

Author(s):

Hancheng Wang ◽

Yanfei Huang ◽

Haiqian Xia ◽

Jin Wang ◽

Maosheng Wang ◽

...

Keyword(s):

Alternaria Alternata ◽

Causal Agent ◽

Brown Spot ◽

Phenotypic Analysis

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Citrus Black Rot is Caused by Phylogenetically Distinct Lineages of Alternaria alternata

Phytopathology ◽

10.1094/phyto-95-0512 ◽

2005 ◽

Vol 95 (5) ◽

pp. 512-518 ◽

Cited By ~ 29

Author(s):

T. L. Peever ◽

L. Carpenter-Boggs ◽

L. W. Timmer ◽

L. M. Carris ◽

A. Bhatia

Keyword(s):

Phylogenetic Analysis ◽

Alternaria Alternata ◽

Sequence Data ◽

Brown Spot ◽

Ecological Niches ◽

Black Rot ◽

Data Set ◽

Dna Sequence Data ◽

Rough Lemon ◽

Combined Data

Phylogenetic analysis revealed that isolates of Alternaria alternata causing black rot of citrus were associated with six well-supported evolutionary lineages. Isolates recovered from brown spot lesions on Minneola tangelo, leaf spot lesions on rough lemon, and healthy citrus tissue and noncitrus hosts were related closely to isolates from black-rotted fruit. Phylogenies estimated independently from DNA sequence data from an endopolygalacturonase gene (endoPG) and two anonymous regions of the genome (OPA1-3 and OPA2-1) had similar topologies, and phylogenetic analysis was performed on the combined data set. In the combined phylogeny, isolates from diverse ecological niches on citrus and noncitrus hosts were distributed in eight clades. Isolates from all lineages, regardless of ecological or host association, caused black rot in fruit inoculation assays, demonstrating that small-spored Alternaria isolates associated with different ecological niches on citrus and other plant hosts are potential black rot pathogens. These data also indicated that the fungi associated with black-rotted fruit do not form a natural evolutionary group distinct from other Alternaria pathogens and saprophytes associated with citrus. The use of the name A. citri to describe fungi associated with citrus black rot is not justified and it is proposed that citrus black rot fungi be referred to as A. alternata.

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Analysis of babA, cagE and cagA Genes in Helicobacter pylori from Upper Gastric Patients in the North of Iran

Infectious Disorders - Drug Targets ◽

10.2174/1871526518666180515113218 ◽

2019 ◽

Vol 19 (3) ◽

pp. 274-278 ◽

Cited By ~ 1

Author(s):

Saba Fakhrieh Asl ◽

Mehrnaz Pourvahedi ◽

Ali Mojtahedi ◽

Mohammad Shenagari

Keyword(s):

Helicobacter Pylori ◽

Gastric Diseases ◽

Specific Primers ◽

The North ◽

Different Types ◽

North Of Iran ◽

Gastric Biopsies ◽

Pcr Method ◽

Non Ulcer Dyspepsia ◽

H Pylori

Objective:Helicobacter pylori is a Gram-negative bacterium which has a serious effect on up to half of the world’s population and has been related to different gastric diseases. The goal of this study was to assess the frequency of babA, cagE and cagA genotypes among H. pylori strains isolated from gastric biopsies of endoscopic patients in the north of Iran.Methods:The present study was performed on 90 strains of H. pylori isolated from patients with gastric diseases (Gastric ulcer (GU), Duodenal ulcer (DU), Gastritis (G), Non-ulcer dyspepsia (NUD) and Gastric adenocarcinoma (GC)). DNA was extracted from all isolated strains and PCR method was performed to detect the prevalence of babA2, cagE and cagA genes using specific primers.Results:Among 90 samples of H. pylori, babA2, cagE, and cagA genes were detected in 42.2%, 30% and 82.2% of strains respectively. The statistical analysis showed that the prevalence of cagA gene in GU, G, DU, and NUD was significantly higher than other genes. Moreover, cagA, and babA2 genes were significantly more prevalent in GC patients compared to cagE gene. Our isolates exhibited 8 distinct arrangements of virulence patterns. The occurrence of cagA (35.6%) was the most prevalent pattern followed by cagA/babA2 (20%) and cagA/babA2/cagE (14.4%).Conclusion:In summary, as first report from Guilan province in the north of Iran, we showed significant association between the presence of babA2, cagE, and cagA genes in different types of gastric disorders.

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High Parasitic Contamination of Soil Samples in the North of Iran: a Potential Risk of Parasitic Infection for Tourists

Infectious Disorders - Drug Targets ◽

10.2174/1871526520666200602150446 ◽

2020 ◽

Vol 20 ◽

Author(s):

Beheshteh Haghparast-kenari ◽

Tooran Nayeri ◽

Shahabeddin Sarvi ◽

Mohammad Taghi Rahimi ◽

Ehsan Ahmadpour ◽

...

Keyword(s):

Contaminated Soil ◽

Urban Areas ◽

Intestinal Parasites ◽

Parasitic Infection ◽

Animal Husbandry ◽

Soil Samples ◽

Human Society ◽

Public Parks ◽

The North ◽

North Of Iran

Background: Soil-transmitted parasites (STPs) are significant intestinal parasites that infect humans and animals and impose considerable burdens on human society and animal husbandry industries. Therefore, the present study aimed to determine the prevalence of parasitic elements of soil samples collected from the north of Iran. Methods: A total of 256 soil samples were collected from public parks, public places, vegetable gardens, sand heaps, and shadow areas near houses in the north of Iran and examined using the sucrose flotation method. Results: Out of 256 examined samples, 131 (51.2%) ones showed parasitic contamination including larvae (43%), oocysts (14.1%), and different eggs (6.6%). According to the results, the most and least common parasites observed in the samples were larvae (43%), as well as Toxascaris leonina, and Trichuris trichiura (0.4%), respectively. Moreover, the most and least contaminated locations were sand heaps (62.5%) and shadow areas near houses (45.6%), respectively. Regarding cities, Behshahr (68.3%) and Sari (67.5%) had the highest contaminated soil samples, whereas Chalus (37.5%) showed the lowest contamination. On the other hand, rural samples showed more contamination, compared to urban areas (P< 0.05). Conclusion: The findings of the present study indicate that the overall prevalence of STPs in examined areas and highly contaminated soil samples can be considered as a potential source of human contamination particularly tourists with STPs.

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Identification and Characterization of the Most Common Genetic Variant Responsible for Acephalic Spermatozoa Syndrome in Men Originating from North Africa

International Journal of Molecular Sciences ◽

10.3390/ijms22042187 ◽

2021 ◽

Vol 22 (4) ◽

pp. 2187

Author(s):

Caroline Cazin ◽

Yasmine Boumerdassi ◽

Guillaume Martinez ◽

Selima Fourati Ben Mustapha ◽

Marjorie Whitfield ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

North Africa ◽

Posterior Part ◽

North African ◽

The North ◽

Transmission Electron ◽

Variant Filtering ◽

North African Population ◽

Sperm Nuclei

Acephalic spermatozoa syndrome (ASS) is a rare but extremely severe type of teratozoospermia, defined by the presence of a majority of headless flagella and a minority of tail-less sperm heads in the ejaculate. Like the other severe monomorphic teratozoospermias, ASS has a strong genetic basis and is most often caused by bi-allelic variants in SUN5 (Sad1 and UNC84 domain-containing 5). Using whole exome sequencing (WES), we investigated a cohort of nine infertile subjects displaying ASS. These subjects were recruited in three centers located in France and Tunisia, but all originated from North Africa. Sperm from subjects carrying candidate genetic variants were subjected to immunofluorescence analysis and transmission electron microscopy. Moreover, fluorescent in situ hybridization (FISH) was performed on sperm nuclei to assess their chromosomal content. Variant filtering permitted us to identify the same SUN5 homozygous frameshift variant (c.211+1_211+2dup) in 7/9 individuals (78%). SUN5 encodes a protein localized on the posterior part of the nuclear envelope that is necessary for the attachment of the tail to the sperm head. Immunofluorescence assays performed on sperm cells from three mutated subjects revealed a total absence of SUN5, thus demonstrating the deleterious impact of the identified variant on protein expression. Transmission electron microscopy showed a conserved flagellar structure and a slightly decondensed chromatin. FISH did not highlight a higher rate of chromosome aneuploidy in spermatozoa from SUN5 patients compared to controls, indicating that intra-cytoplasmic sperm injection (ICSI) can be proposed for patients carrying the c.211+1_211+2dup variant. These results suggest that the identified SUN5 variant is the main cause of ASS in the North African population. Consequently, a simple and inexpensive genotyping of the 211+1_211+2dup variant could be beneficial for affected men of North African origin before resorting to more exhaustive genetic analyses.

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