Application of Bacteriophages

The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibiotics takes mankind back to the ‘pre-antibiotic era' and search for alternative treatments. Bacteriophages have been one of promising alternative agents which can be utilised for medicinal and biological control purposes in agriculture and related fields. The idea to treat bacterial infections with phages came out of the pioneering work of Félix d‘Hérelle but this was overshadowed by the success of antibiotics. Recent renewed interest in phage therapy is dictated by its advantages most importantly by their specificity against the bacterial targets. This prevents complications such as antibiotic-induced dysbiosis and secondary infections. This article is compiled by the participants of the Expert Round Table conference ‘Bacteriophages as tools for therapy, prophylaxis and diagnostics' (19-21 October 2015) at the Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi, Georgia. The first paper from the Round Table was published in the Biotechnology Journal. This InFocus articleexpandsfromthispaperandincludes recent developments reported since then by the Expert Round Table participants, including the implementation of the Nagoya Protocol for the applications of bacteriophages

Assessment of the Role of Local Strawberry Rhizosphere—Associated Streptomycetes on the Bacterially—Induced Growth and Botrytis cinerea Infection Resistance of the Fruit

The future need for sustainable agriculture will be met in part by wider use of biological control of plant pathogens over conventional fungicides hazardous to the environment and to public health. Control strategies involving both (i) direct use of microorganisms antagonistic to the phytopathogen, and (ii) use of bioactive compounds (secondary metabolites/antibiotic compounds) from microorganisms on the phytopathogen were both adapted in order to investigate the ability of streptomycetes isolated from the rhizosphere of strawberry plants to promote the growth of the fruit and suppress Botrytis cinerea causing strawberry rot on the Sunshine Coast, Queensland, Australia. In vitro studies showed that 25/39 streptomycetes isolated from strawberry field soils inhibited B. cinerea growth by antifungal activity, ranging from antibiosis to volatile compound production. However, when non-volatile antifungal compounds were extracted and applied aerially to the actively growing strawberry fruits infected with B. cinerea, a significant disease reduction was not recorded. On the other hand, plant and fruit growth was promoted by the presence of actively growing streptomycetes in container media. Findings might indicate that live streptomycete inoculum can be used as growth promoting agent in container media for this economically important crop

The effects of Vermicomposting on Population and Community Structure of Enterococci in a Residential Community

The effects that vermiculture (VC) treatment had on population and community structure of enterococci in domestic biosolids in a residential resort in southeast Queensland were investigated by enumerating and typing enterococci with a biochemical fingerprinting method. Vermiculture beds with a substrate consisting of non-amended biosolids from an activated sludge sewage treatment plant were established. Various treatments (earthworms added and earthworms excluded) beds were sampled on 3 occasions. Enterococci numbers were significantly lower in the earthworm treatments than those without. Of the 300 isolates biochemically fingerprinted, 106 different biochemical phenotypes (BPTs) were identified. The overall mean diversity of enterococci in all beds was high (0.87 ± 0.13; maximum is 1), indicating a diverse enterococci population. The overall mean population similarity (Sp) value amongst beds was quite low (0.16 ± 0.10) also indicating a diverse population. Antibiotic resistance patterns (ARPs) of the 106 BPTs revealed that 83.6% were resistant to rifampicin, 59.6% were resistant to erythromycin, 21.9% were resistant to tetracycline, 7.7% were resistant to ampicillin and 2.9% were resistant to gentamicin and vancomycin. The results indicate that the current VC methods used in the residential resort to create worm castings for potting mixture may not satisfactorily pasteurize the biosolids and significant number of pathogenic microorganisms could be present. There remains a potential health risk to workers and guests and routine monitoring of pathogens is recommended for improved management of stockpiled biosolids

Application of Bacteriophages

The emergence of antibiotic-resistant bacteria and decrease in the discovery rate of novel antibiotics takes mankind back to the ‘pre-antibiotic era’ and search for alternative treatments. Bacteriophages have been one of promising alternative agents which can be utilised for medicinal and biological control purposes in agriculture and related fields. The idea to treat bacterial infections with phages came out of the pioneering work of Félix d‘Hérelle but this was overshadowed by the success of antibiotics. Recent renewed interest in phage therapy is dictated by its advantages most importantly by their specificity against the bacterial targets. This prevents complications such as antibiotic-induced dysbiosis and secondary infections. This article is compiled by the participants of the Expert Round Table conference ‘Bacteriophages as tools for therapy, prophylaxis and diagnostics’ (19–21 October 2015) at the Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi, Georgia. The first paper from the Round Table was published in the Biotechnology Journal1. This In Focus article expands from this paper and includes recent developments reported since then by the Expert Round Table participants, including the implementation of the Nagoya Protocol for the applications of bacteriophages

Fusarium and Sarocladium species associated with rice sheath rot disease in sub-saharan Africa

Sarocladium and Fusarium species are commonly identified as causal agents of rice sheath rot disease worldwide. However, limited knowledge exists about their genetic, pathogenic, and toxigenic diversity in sub-Saharan African (SSA) countries, where an increasing incidence of this disease has been observed. In this study, seventy fungal isolates were obtained from rice plants displaying disease symptoms in rice research programs and farmer fields in Mali, Nigeria, and Rwanda. Thus, an extensive comparative analysis was conducted to assess their genetic, pathogenic, and toxigenic diversity. The Fusarium spp. were characterized using the translation elongation factor (EF-1 alpha) region, while a concatenation of Internal Transcribed Spacer (ITS) and Actin-encoding regions were used to resolve Sarocladium species. Phylogenetic analysis revealed four Fusarium species complexes. The dominant complex in Nigeria was the Fusarium incarnatum-equiseti species complex (FIESC), comprising F. hainanense, F. sulawesiense, F. pernambucatum, and F. tanahbumbuense, while F. incarnatum was found in Rwanda. The Fusarium fujikuroi species complex (FFSC) was predominant in Rwanda and Mali, with species such as F. andiyazi, F. madaense, and F. casha in Rwanda and F. annulatum and F. nygamai in Mali. F. marum was found in Nigeria. Furthermore, Fusarium oxysporum species complex (FOSC) members, F. callistephi and F. triseptatum, were found in Rwanda and Mali, respectively. Two isolates of F. acasiae-mearnsii, belonging to the Fusarium sambucinum species complex (FSAMSC), were obtained in Rwanda. Isolates of Sarocladium, which were previously classified into three phylogenetic groups, were resolved into three species, which are attenuatum, oryzae, and sparsum. S. attenuatum was dominant in Rwanda, while S. oryzae and S. sparsum were found in Nigeria. Also, the susceptibility of FARO44, a rice cultivar released by Africa Rice Centre (AfricaRice), was tested against isolates from the four Fusarium species complexes and the three Sarocladium species. All isolates evaluated could induce typical sheath rot symptoms, albeit with varying disease development levels. In addition, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine variation in the in vitro mycotoxins of the Fusarium species. Regional differences were observed in the in vitro mycotoxins profiling. Out of the forty-six isolates tested, nineteen were able to produce one to four mycotoxins. Notably, very high zearalenone (ZEN) production was specific to the two F. hainanense isolates from Ibadan, Nigeria, while Fusarium nygamai isolates from Mali produced high amounts of fumonisins. To the best of our knowledge, it seems that this study is the first to elucidate the genetic, pathogenic, and toxigenic diversity of Fusarium species associated with the rice sheath rot disease complex in selected countries in SSA

Bacterial Viruses Subcommittee and Archaeal Viruses Subcommittee of the ICTV : update of taxonomy changes in 2021

In this article, we - the Bacterial Viruses Subcommittee and the Archaeal Viruses Subcommittee of the International Committee on Taxonomy of Viruses (ICTV) - summarise the results of our activities for the period March 2020 - March 2021. We report the division of the former Bacterial and Archaeal Viruses Subcommittee in two separate Subcommittees, welcome new members, a new Subcommittee Chair and Vice Chair, and give an overview of the new taxa that were proposed in 2020, approved by the Executive Committee and ratified by vote in 2021. In particular, a new realm, three orders, 15 families, 31 subfamilies, 734 genera and 1845 species were newly created or redefined (moved/promoted).Non peer reviewe

Abolishment of morphology-based taxa and change to binomial species names: 2022 taxonomy update of the ICTV bacterial viruses subcommittee

Peer reviewe