Microbiome-immune interactions in tuberculosis

Tuberculosis (TB) remains an infectious disease of global significance and a leading cause of death in low- and middle-income countries. Significant effort has been directed towards understanding Mycobacterium tuberculosis genomics, virulence, and pathophysiology within the framework of Koch postulates. More recently, the advent of “-omics” approaches has broadened our appreciation of how “commensal” microbes have coevolved with their host and have a central role in shaping health and susceptibility to disease. It is now clear that there is a diverse repertoire of interactions between the microbiota and host immune responses that can either sustain or disrupt homeostasis. In the context of the global efforts to combatting TB, such findings and knowledge have raised important questions: Does microbiome composition indicate or determine susceptibility or resistance to M. tuberculosis infection? Is the development of active disease or latent infection upon M. tuberculosis exposure influenced by the microbiome? Does microbiome composition influence TB therapy outcome and risk of reinfection with M. tuberculosis? Can the microbiome be actively managed to reduce risk of M. tuberculosis infection or recurrence of TB? Here, we explore these questions with a particular focus on microbiome-immune interactions that may affect TB susceptibility, manifestation and progression, the long-term implications of anti-TB therapy, as well as the potential of the host microbiome as target for clinical manipulation.

Description of the Demicyclic life Cycle of Puccinia Sherardiana in Sphaeralcea Angustifolia in Mexico.

During 2017-2019, leaves and stems with dark brown lesions containing hypophyllous telia surrounded by chlorotic halos were collected from Sphaeralcea angustifolia plants located in Axapusco, State of Mexico. Based on the morphological characteristics of pycnia, aecia and telia observed by light microscopy and scanning electron microscopy, the fungus Puccinia sherardiana was identified. Uredial stage was not present during the observation period. Identity verification was carried out by phylogenetic analysis with sequences of part of the 28S gene from ribosomal DNA. In addition, pathogenicity tests were done on S. angustifolia leaves by inoculating teliospores. The inoculated plants developed symptoms 15 days after inoculation, the signs beginning with the presence of aecia in the epidermis of the host and later telia were formed, completing the Koch Postulates. Puccinia sherardiana was previously described as a rust with a microcyclic life cycle on species of the genera Alcea, Malvastrum, Sidalcea and Sphaeralcea , belonging to the Malvaceae family, however, this study revealed that this plant pathogenic fungus has a demicyclic life cycle.

Pomegranate (Punica granata L.) Inner Decay Caused by Gluconobacter oxydans Bacterium

During the autumn of 2018, inner fruit decay symptoms were observed in pomegranate fruits collected from markets in different localities and farms from Giza, Minia and Assuit Governorates, Egypt. Similar symptoms were observed in each location. The symptoms appeared as creamy bright growth of bacteria in the mesocarp layer, decayed both arils and seeds. Bacteria were isolated from these decayed fruits. The pathogenicity test for isolated bacteria was done. Also, the expressed symptom was compared with the original observed symptoms as followed in Koch postulates. Based on morphological characteristics, analysis of 16S rDNA Genes sequences, and pathogenicity test on pomegranate fruits, the causal agent was identified as Gluconobacter oxydans. Possible control attempts were implemented included applying of essential oils. The results revealed that essential oils of Marjoram, followed by Chamomile expressed the most effective against infection with the bacterium when compared with the control.

Pathogen identification and control of sooty spot caused by Cladosporium ramotenellum, appearing on fresh easy peeler mandarins from Perú

During the 2018 season, superficial dry and firm black spots, where sometimes an aerial mycelium developed, appeared on the rind of easy peeler mandarins causing high economic losses in fresh citrus exports from Perú. In this work, we have identified the causal agent, a species of Cladosporium not previously reported as a citrus pathogen. The pathogen was isolated from rind lesions of affected fruit and was identified by sequencing as Cladosporium ramotenellum; and fulfilment of Koch postulates was proven. This species was present on the surface of immature fruit in the groves, indicating that the infection is likely initiated before harvest. Cladosporium ramotenellum is resistant to the postharvest fungicides imazalil, pyrimethanil, and thiabendazole, but sensitive to propiconazole, prochloraz, and ortho-phenylphenol. We designed a postharvest industrial treatment to decrease the Cladosporium sp. load on the fruit surface that limited the incidence of infection and reduced the postharvest losses caused by the fungus. Although this species is quite ubiquitous, this is the first description of C. ramotenellum causing decay of citrus fruit, being the symptoms of this disease similar to the ones described previously and caused by Cladosporium cladosporoides in cv. Satsuma mandarins from Japan.

Phytophthora cathayensis sp. nov., a new species pathogenic to Chinese Hickory (Carya cathayensis) in southeast China

Crown decline and mortality associated with collar lesions were observed on Carya cathayensis (Chinese hickory) trees in a plantation in Zhejiang province, China. Examination of active lesions resulted in the isolation of a homothallic, papillate Phytophthora sp. Detailed morphological and physiological studies and phylogenetic analysis, using ITS, beta-tubulin, cytochrome oxidase I, and heat shock protein 90 gene regions, revealed that all isolates belonged to an undescribed species residing in phylogenetic Clade 4, which is described here as Phytophthora cathayensis sp. nov. Inoculation trials were conducted under greenhouse conditions on C. cathayensis and C. illinoensis (pecan) plants to fulfill Koch postulates and hypothesize a possible pathway of the incursion. An existing report of a Phytophthora species with the same ITS sequence was reported on C. illinoensis from the USA in 2009. The difference in susceptibility of the two inoculated Carya species, and the report from the USA, suggest a possible introduction with plant material from the USA to China.

Isolation, Characterization and Pathogenicity of Edwardsiella tarda a Causative Disease on Freshwater Fish in Yogyakarta

Edwarsiella tarda is a cosmopolitan bacterium and is a cause of Edwardsiellosis in various fish species. The bacterial infection causes large losses on aquaculture in Asia, especially Japan. This study was conducted to isolate and characterize E. tarda as causative disease in freshwater fishes, and to determine its pathogenicity to catfish (Pangasius sp.). Bacteria were isolated from kidney of diseased fishes on Tryptone Soya Agar medium. Identification was conducted based on morphological colonies, morphological cells and biochemical tests. Fulfillment of Koch Postulates was done by injecting bacteria intraperitoneally on 7-9 cm fishes at dose of 107 cfu/fish. Pathogenicity test was carried out by intraperitoneal injection at 104, 105, 106, and 107 cfu/fish to 7-9 cm-catfish (Pangasius sp.) and followed by observation of disease signs and mortality every six hours for 7 days. Pathogenicity was determined as Lethal Dosage (LD50) using Dragstedt Behrens method. In this research we have isolated three isolates E. tarda causing disease in fishes. The clinical signs of this disease were lose of pigmentation over the lession, swollen of stomach, haemorhage on fins , small cutaneous lesions, and necrotic on fins area. The LD50 of E. tarda isolate L2, L3, and N3 were 4.64 ± 0.35x105, 1.54 ± 0.07x105, and 1.13 ± 0.13x106 cfu/fish, respectively.

An update on the detection methods of Parachlamydia acanthamoebae, an atypical agent of pneumonia

Parachlamydia acanthamoebae (P. acanthamoebae) has been recognized as an emerging agent of pneumonia as it has been identified in human samples via culture-based, molecular and serological techniques. Additionally, studies on animal models have shown that it fulfills the third and fourth Koch postulates to be assigned a pathogenic role. Due to the threat posed by it, multiple tools have been employed in the search for P. acanthamoebae. The methods utilized for its detection would be cell culture based approaches which involve both animal and amoebal cell culture and also molecular techniques that encompasses polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH) and in situ hybridization (ISH). Additionally, immunohistochemistry (IHC) and serology based techniques such as direct and indirect immunofluorescence are also employed with the usage of Western blotting or immunoblotting as confirmatory procedures. This review attempts to describe the variety of techniques that are present in literature for the isolation and identification of P. acanthamoebae.

Pathogenity Test Bacteria Pasteurella multocida Local Isolate Using Postulate Koch

The study aimed to find out whether <em>Pasteurella multocida</em> bacteria isolated from buffalo in HSU (Hulu Sungai Utara) is the cause of SE (<em>Septicema epizootica</em>) disease in swamp buffaloes using Koch Postulates. Total of 10 Balb-C mice aged 2 weeks were infected with 100 μl culture containing 4 x 108 CFU (1.5 McFarland Scale) <em>P. multocida</em> subcutaneously in the neck , and observed every 4 hours until the animal died. Samples were taken from the spleen, lungs, and heart with different times of death within 15 hours, 35 hours, and 59 hours with sterile swab cotton. Samples were grown on a nutrient broth medium (NB), inoculated on a soy trypticase agar (TSA), and incubated for 24 hours at 37 ° C. Separate colonies were stained with Gram and spore staining. The colonies were tested by catalase, biochemical, indol motility (SIM) sulfite, confectionary, and planted on Mac Conkey Agar media. <em>P. multocida</em> was identified following Carter's method of showing lung, spleen, and positively infected <em>P. multocida</em> samples. It was concluded that <em>P. multocida</em> bacteria isolated from buffalo in HSU are pathogenic and can cause SE disease.