Contamination of hay and haylage with enteric bacteria and selected antibiotic resistance genes following fertilization with dairy manure or biosolids
Canadian Journal of Microbiology, Ahead of Print. The present study evaluated if enteric bacteria or antibiotic resistance genes carried in fecal amendments contaminate the hay at harvest, representing a potential route of exposure to ruminants that consume the hay. In the field experiments, dairy manure was applied to a hay field for three successive growing seasons, and biosolids were applied to a hay field for one growing season. Various enteric bacteria in the amendments were enumerated by viable plate count, and selected gene targets were quantified by qPCR. Key findings include the following: at harvest, hay receivin...
Source: Canadian Journal of Microbiology - January 12, 2022 Category: Microbiology Authors: Andrew Scott Roger Murray Yuan-Ching Tien Edward Topp Source Type: research
Aerobic polychlorinated biphenyl-degrading bacteria isolated from the Tohoku region of Japan are not regionally endemic
In this study, 78 environmental samples were collected from the Tohoku region and 56 aerobic PCB-degrading bacterial strains were isolated. They belonged to the genera Achromobacter, Rhodococcus, Pseudomonas, Stenotrophomonas, Comamonas, Pigmentiphaga, Xenophilus, Acinetobacter, and Pandoraea. Previously reported aerobic PCB-degrading bacterial strains isolated in Japan belonged to the same genera, except that the genera Acidovorax and Bacillus were not identified in the present study. In particular, the isolated Comamonas testosteroni strains YAZ2 and YU14-111 had high PCB-degrading abilities. Analysis of the sequences of...
Source: Canadian Journal of Microbiology - January 12, 2022 Category: Microbiology Authors: Tomijiro Hara Yumiko Takatsuka Source Type: research
Deep tillage reduces the dependence of tobacco (Nicotiana tabacum L.) on arbuscular mycorrhizal fungi and promotes the growth of tabacco in dryland farming
Canadian Journal of Microbiology, Ahead of Print. The traditional shallow tillage method reduces soil quality and affects the efficiency of agricultural production. Using conventional rotary tillage (12 cm) as the control, Yunyan 87 as the test variety, and paddy soil as the test site, we studied the effects of deep tillage (subsoiling 30 cm) on soil nutrients, arbuscular mycorrhizal fungi (AMF), and tobacco (Nicotiana tabacum L.) growth. The results showed that deep tillage increased the content of organic carbon, available phosphorus (AP), and available potassium (AK) in the 20 –40 cm soil layer. The AMF community was ...
Source: Canadian Journal of Microbiology - January 10, 2022 Category: Microbiology Authors: Jialei Gong Zhongyi Zheng Bufan Zheng Yongjun Liu Ruiwen Hu Jia Gong Sichun Li Lijun Tian Xiangshen Tian Juan Li Zhongwen Rang Source Type: research
Unraveling aerobic cultivable cellulolytic microorganisms within the gastrointestinal tract of sheep (Ovis aries) and their evaluation for cellulose biodegradation
This study expands our knowledge of aerobic cellulolytic isolates from the GT of sheep and highlights their potential application as a microbial additive in the aerobic process of cellulose bioconversion. (Source: Canadian Journal of Microbiology)
Source: Canadian Journal of Microbiology - January 7, 2022 Category: Microbiology Authors: Jie Yang Jie Zhao Bobo Wang Zhisheng Yu Source Type: research
Bradyrhizobium japonicum FN1 produces an inhibitory substance that affects competition for nodule occupancy
In this study, Bradyrhizobium japonicum FN1, along with other Bradyrhizobia in our culture collection, was screened for bacteriocin-like activity. Five distinct inhibitory effects were observed. FN1 genes putatively involved in bacteriocin production were computationally identified. These genes were mutagenized, and the subsequent strains were screened for loss of inhibitory activity. Mutant strain BRJ-48, with an insert in bjfn1_01204, displayed a loss of ability to inhibit an indicator strain. This loss can be complemented by the introduction of a plasmid expressing bjfn1_01204 in trans. The strain carrying the mutation ...
Source: Canadian Journal of Microbiology - January 6, 2022 Category: Microbiology Authors: MacLean G. Kohlmeier Harry Yudistira Amanat Ali Ivan J. Oresnik Source Type: research
Positive regulation of the MarR-type regulator slnO and improvement of salinomycin production by Streptomyces albus by multiple transcriptional regulation
Canadian Journal of Microbiology, Ahead of Print. The purpose of this study was to explore the function of the MarR family regulator slnO. Additionally, a high-yield strain of salinomycin was constructed using combined regulation strategies. First, the slnO gene overexpression strain (GO) was constructed in Streptomyces albus. Compared to the wild-type (WT) strain, salinomycin production in the GO strain increased by approximately 28%. Electrophoretic mobility gel shift assays (EMSAs) confirmed that the SlnO protein can bind specifically to the intergenic regions of slnN-slnO, slnQ-slnA1, and slnF-slnT. qRT-PCR experiments...
Source: Canadian Journal of Microbiology - January 4, 2022 Category: Microbiology Authors: Hongrui Zhang Weiwei Chen Xinyi Wang Yongquan Li Zhenhong Zhu Source Type: research
Note of appreciation
Canadian Journal of Microbiology,Volume 68, Issue 1, Page iii-iii, January 2022. (Source: Canadian Journal of Microbiology)
Source: Canadian Journal of Microbiology - January 4, 2022 Category: Microbiology Source Type: research
LuxS modulates motility and secretion of extracellular protease in fish pathogen Vibrio harveyi
In this study, an in-frame deletion of the luxS gene was constructed to reveal the role of LuxS in the physiology and virulence of V. harveyi. Statistical analysis showed no significant differences in the growth ability, biofilm formation, antibiotic susceptibility, virulence by intraperitoneal injection, and ability of V. harveyi to colonize the spleen and liver of the pearl gentian grouper between the wild-type (WT) and luxS mutant. However, deletion of luxS decreased the secretion of extracellular protease, while increasing swimming and swarming abilities. Simultaneously, a luxS-deleted mutant showed overproduction of l...
Source: Canadian Journal of Microbiology - December 2, 2021 Category: Microbiology Authors: Ya-Qiu Zhang Yi-Qin Deng Juan Feng Jian-Mei Hu Hao-Xiang Chen Zhi-Xun Guo You-Lu Su Source Type: research
Diversity and function of microbial communities in the sand sheath of Agropyron cristatum by metagenomic analysis
Canadian Journal of Microbiology, Ahead of Print. The roots of most gramineous plants are surrounded by a variety of microorganisms; however, few studies have focused on the rhizosheath of psammophytes. Therefore, in this study, we used Illumina HiSeq high-throughput sequencing technology to analyse the composition and functional diversity of microbial communities in the rhizosheath of sand-grown Agropyron cristatum (L.) Gaertn. We found that the number of species and functions of microbial communities gradually decreased from the rhizosheath to the bulk soil. Thus, the microbial composition of the rhizosheath was richer a...
Source: Canadian Journal of Microbiology - November 22, 2021 Category: Microbiology Authors: Yuehua Wang Meixiao Wu Yijing Wang Xuefei Wang Ming Yu Guixia Liu Hui Tang Source Type: research
Loop-mediated isothermal amplification (LAMP) assay for rapid detection of viable but non-culturable Vibrio cholerae O1
Canadian Journal of Microbiology, Ahead of Print. Vibrio cholerae, an important waterborne pathogen, is a rod-shaped bacterium that naturally exists in aquatic environments. When conditions are unfavorable for growth, the bacterium can undergo morphological and physiological changes to assume a coccoid morphology. This stage in its life cycle is referred to as viable but non-culturable (VBNC) because VBNC cells do not grow on conventional bacteriological culture media. The current study compared polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) to detect and identify VBNC V. cholerae. Becaus...
Source: Canadian Journal of Microbiology - November 18, 2021 Category: Microbiology Authors: Parastoo Chamanrokh Rita R. Colwell Anwar Huq Source Type: research
Identification of plasmids from Brazilian Chromobacterium violaceum strains
Canadian Journal of Microbiology, Ahead of Print. Chromobacterium violaceum is an opportunistic pathogen found in tropical and subtropical regions worldwide. Chromobacterium violaceum infections are difficult to treat, and many strains are resistant to antibiotics. Recently, a novel plasmid (pChV1) was discovered in the type strain ATCC 12472, suggesting that other C. violaceum strains may harbor extra-chromosomal DNA. The aim of the present study was to detect and compare new plasmids in Brazilian strains of C. violaceum using next-generation sequencing techniques. We obtained draft genomes of six plasmids from strains is...
Source: Canadian Journal of Microbiology - November 15, 2021 Category: Microbiology Authors: Daniel Chaves de Lima In ácio Gomes Medeiros Rita de C ássia Silva-Portela Francisco Carlos da Silva Junior Lucymara Fassarela Agnez-Lima Jorge Estefano Santana de Souza Silvia R. Batistuzzo de Medeiros Source Type: research
Seasonal changes in the abundance and activity of bacterial and fungal denitrifying communities associated with different compost amendments
Canadian Journal of Microbiology, Ahead of Print. Composts can be efficient organic amendments in potato culture as they can supply carbon and nutrients to the soil. However, more information is required on the effects of composts on denitrification and nitrous oxide emissions (N2O) and emission-producing denitrifying communities. The effects of three compost amendments (municipal source separated organic waste compost (SSOC), forestry waste mixed with poultry manure compost (FPMC), and forestry residues compost (FRC)) on fungal and bacterial denitrifying communities and activity was examined in an agricultural field cropp...
Source: Canadian Journal of Microbiology - November 11, 2021 Category: Microbiology Authors: Amy Novinscak Claudia Goyer Carolyn Wilson Bernie J. Zebarth David L. Burton Martin H. Chantigny Martin Filion Source Type: research
Effect of sub-inhibitory concentrations of cefepime on biofilm formation by Pseudomonas aeruginosa
This study investigated the effect of cefepime at sub-minimum inhibitory concentrations (sub-MICs) on in vitro biofilm formation (BF) by clinical isolates of Pseudomonas aeruginosa. The effect of cefepime at sub-MIC levels (½–1/256 MIC) on in vitro BF by six clinical isolates of P. aeruginosa was phenotypically assessed following 24 and 48 h of challenge using the tissue culture plate (TCP) assay. Quantitative real-time polymeric chain reaction (qRT-PCR) was employed to observe the change in expression of three biofilm-related genes, namely, a protease-encoding gene (lasA), fimbrial protein-encoding gene (cupA1), an...
Source: Canadian Journal of Microbiology - November 3, 2021 Category: Microbiology Authors: Soheir A.A. Hagras Alaa El-Dien M.S. Hosny Omneya M. Helmy Mounir M. Salem-Bekhit Faiyaz Shakeel Hala A. Farrag Source Type: research
Metallo-beta-lactamase-producing Escherichia coli in the sewage of Mexico City: where do they come from?
Canadian Journal of Microbiology, Ahead of Print. While monitoring the presence of antibiotic resistance in municipal wastewater bacteria from Mexico City, five Escherichia coli isolates were found to be resistant to carbapenems, antibiotics of “last resort” used mostly in hospitals. Further analysis revealed that these carbapenem-resistant isolates carried the gene encoding a metallo-beta-lactamase, NDM-5. The gene was found to be beared by a large, ∼145 kb conjugative plasmid, which also carries putative genes encoding resistance t o sulfonamides, trimethoprim, tetracycline, ciprofloxacin, and chloramphenicol (alth...
Source: Canadian Journal of Microbiology - October 18, 2021 Category: Microbiology Authors: Kathia L üneberg Carlos F. Am ábile-Cuevas Eduardo Mucito-Varela Leticia Mart ínez Eva Salinas Yolanda L ópez-Vidal Christina Siebe Irma Rosas Source Type: research
Microbiology of barrier component analogues of a deep geological repository
This study explored the abundance, viability, and composition of microorganisms in several ancient natural analogues using a combination of cultivation and cultivation-independent approaches. Samples were obtained from the Tsukinuno bentonite deposit (Japan) that formed ∼10 mya, t he Opalinus Clay formation (Switzerland) that formed ∼174 mya, and Canadian shield crystalline rock from Northern Ontario that formed ∼2.7 bya. Analysis of 16S rRNA gene amplicons revealed that three of the ten Tsukinuno bentonite samples analyzed were dominated by putative aerobic heterotrophs and fermenting bacteria from the phylum Actino...
Source: Canadian Journal of Microbiology - October 14, 2021 Category: Microbiology Authors: Rachel C. Beaver Katja Engel W. Jeffrey Binns Josh D. Neufeld Source Type: research
