MicrobiologyOpen

Antimicrobial resistance is a global concern requiring a one-health approach. Given wild animals can harbor antimicrobial-resistant bacteria (ARB), we investigated their presence in 11 fecal samples from wild animals using deoxycholate hydrogen sulfide lactose agar with or without cefotaxime (CTX, 1 mg/L). Thus, we isolated CTX-resistant Escherichia coli from two Japanese red fox fecal samples. One strain was O83:H42-ST1485-fimH58 CTX-M-55-producing E. coli carrying the genes aph(3″)-Ib, aph(3')-Ia, aph(6)-Id, mdf(A), sitABCD, sul2, tet(A), and tet(B), whereas the other was O25:H4-ST131-fimH30 CTX-M-14-producing E...

Salt tolerant organisms are increasingly being used for the industrial production of high-value biomolecules due to their better adaptability compared to mesophiles. Chromohalobacter canadensis is one of the early halophiles to show promising biotechnology potential, which has not been explored to date. Advanced high throughput technologies such as whole-genome sequencing allow in-depth insight into the potential of organisms while at the frontiers of systems biology. At the same time, genome-scale metabolic models (GEMs) enable phenotype predictions through a mechanistic representation of metabolism...

As continued growth in gut microbiota studies in captive and model animals elucidates the importance of their role in host biology, further pursuit of how to retain a wild-like microbial community is becoming increasingly important to obtain representative results from captive animals. In this study, we assessed how the gut microbiota of two wild-caught small mammals, namely Crocidura russula (Eulipotyphla, insectivore) and Apodemus sylvaticus (Rodentia, omnivore), changed when bringing them into captivity...

The Gram-negative bacteria Brucella ceti and Brucella pinnipedialis circulate in marine environments primarily infecting marine mammals, where they cause an often-fatal disease named brucellosis. The increase of brucellosis among several species of cetaceans and pinnipeds, together with the report of sporadic human infections, raises concerns about the zoonotic potential of these pathogens on a large scale and may pose a threat to coastal communities worldwide. Therefore, the characterization of the B. ceti and B...

Five yeast fungi strains (i.e., two Cryptococcus albidus, one Candida guillermondii, and two Candida tropicalis) were isolated from sugarcane and tested for their use of lignin as sole carbon source and their potential to grow in the presence of phenol and phenol derivatives (i.e., pentachlorophenol and p-nitrophenol). The full set of isolated yeasts showed ligninolytic activity, achieving at least 36% lignin degradation after 25 days. The C. albidus JS-B1 strain had the highest ligninolytic activity, achieving 27% lignin degradation within 4 days...

Recent research demonstrated that some Listeria monocytogenes plasmids contribute to stress survival. However, only a few studies have analyzed gene expression patterns of L. monocytogenes plasmids. In this study, we identified four previously published stress-response-associated transcriptomic data sets which studied plasmid-harboring L. monocytogenes strains but did not include an analysis of the plasmid transcriptomes. The four transcriptome data sets encompass three distinct plasmids from three different L...

Antibiotic resistance is becoming increasingly prevalent amongst bacterial pathogens and there is an urgent need to develop new types of antibiotics with novel modes of action. One promising strategy is to develop resistance-breaker compounds, which inhibit resistance mechanisms and thus resensitize bacteria to existing antibiotics. In the current study, we identify bacterial DNA double-strand break repair as a promising target for the development of resistance-breaking co-therapies. We examined genetic variants of Escherichia coli that combined antibiotic-resistance determinants with DNA repair defects...

Spores are an infectious form of the zoonotic bacterial pathogen, Bacillus anthracis. The outermost spore layer is the exosporium, comprised of a basal layer and an external glycoprotein nap layer. The major structural proteins of the inner basal layer are CotY (at the mother cell central pole or bottlecap) and ExsY around the rest of the spore. The basis for the cap or noncap specificity of the CotY and ExsY proteins is currently unknown. We investigated the role of sequence differences between these proteins in localization during exosporium assembly...

BACKGROUND: Surface raw water used as a source for drinking water production is a critical resource, sensitive to contamination. We conducted a study on Swedish raw water sources, aiming to identify mutually co-occurring metacommunities of bacteria, and environmental factors driving such patterns. METHODS: The water sources were different regarding nutrient composition, water quality, and climate characteristics, and displayed various degrees of anthropogenic impact...

High-throughput sequencing approaches, which target a taxonomically discriminant locus, allow for in-depth insight into microbial communities' compositions. Although microorganisms are historically investigated by cultivation on artificial culture media, this method presents strong limitations, since only a limited proportion of microorganisms can be grown in vitro. This pitfall appears even more limiting in enological and winemaking processes, during which a wide range of molds, yeasts, and bacteria are observed at the different stages of the fermentation course...

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has become a staple in clinical microbiology laboratories. Protein-profiling of bacteria using this technique has accelerated the identification of pathogens in diagnostic workflows. Recently, lipid profiling has emerged as a way to complement bacterial identification where protein-based methods fail to provide accurate results. This study aimed to address the challenge of rapid discrimination between Escherichia coli and Shigella spp...

The formate-specific anion channel FocA of Escherichia coli belongs to the superfamily of homopentameric formate-nitrite transporters (FNT). Minimally nine amino acid residues are conserved in the formate translocation pore of each protomer of the pentamer, including a histidine (H209) and a threonine (T91), both of which are crucial for bidirectional formate translocation through the pore. Information regarding in vivo functional or structural roles for the other seven conserved residues is limited, or nonexistent...

Bacterial swimming is mediated by the rotation of a flagellar filament. Many bacteria are now known to be able to O-glycosylate their flagellins, the proteins that make up the flagellar filament. For bacteria that use nonulosonic acid sugars such as pseudaminic acid, this glycosylation process is essential for the formation of a functional flagellum. However, the specific role of glycosylation remains elusive. Aeromonas caviae is a model for this process as it has a genetically simple glycosylation system. Here, we investigated the localization of the glycans on the A...

While contemporary changes in feeding preferences have been documented in phytophagous insects, the mechanisms behind these processes remain to be fully clarified. In this context, the insect gut microbiome plays a central role in adaptation to novel host plants. The cucurbit frugivorous fruit fly Zeugodacus cucurbitae (Diptera, Tephritidae) has occasionally been reported on "unconventional" host plants from different families, including Solanaceae. In this study, we focus on wild parental (F0 ) adults and semiwild first filial (F1 ) larvae of Z...

The global increase in antibiotic resistance of pathogenic microorganisms requires the identification and characterization of novel antimicrobials. Bacterial biosensors expressing fluorescent proteins such as pHluorin variants are suitable for high-throughput screenings. Here, we present Listeria spp. pH-sensitive biosensors with improved fluorescence for single-cell analysis of antimicrobials by flow cytometry.

Bacteriophages infecting dairy starter bacteria are a leading cause of milk fermentation failure and strategies to reduce the risk of phage infection in dairy settings are demanded. Along with dairy starters, bacteriocin producers (protective cultures) or the direct addition of bacteriocins as biopreservatives may be applied in food to extend shelf-life. In this work, we have studied the progress of infection of Lactococcus cremoris MG1363 by the phage sk1, in the presence of three bacteriocins with different modes of action: nisin, lactococcin A (LcnA), and lactococcin 972 (Lcn972)...

Extremes of pH present a challenge to microbial life and our understanding of survival strategies for microbial consortia, particularly at high pH, remains limited. The utilization of extracellular polymeric substances within complex biofilms allows micro-organisms to obtain a greater level of control over their immediate environment. This manipulation of the immediate environment may confer a survival advantage in adverse conditions to biofilms. Within the present study alkaliphilic biofilms were created at pH 11...

Biofilms are intricate communities of microorganisms encapsulated within a self-produced matrix of extra-polymeric substances (EPS), creating complex three-dimensional structures allowing for liquid and nutrient transport through them. These aggregations offer constituent microorganisms enhanced protection from environmental stimuli-like fluid flow-and are also associated with higher resistance to antimicrobial compounds, providing a persistent cause of concern in numerous sectors like the marine (biofouling and aquaculture), medical (infections and antimicrobial resistance), dentistry (plaque on teeth), food safety, as well as causing energy loss and corrosion...

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The growth and tolerance of Kluyveromyces marxianus at high temperatures decreased significantly in the synthetic medium (SM), which is commonly used in industrial fermentations. After 100 days of adaptive laboratory evolution, a strain named KM234 exhibited excellent tolerance at a high temperature, without loss of its growth ability at a moderate temperature. Transcriptomic analysis revealed that the KM234 strain decreased the expression of the ammonium (NH4 + ) transporter gene MEP3 and increased the synthesis of the amino acid carbon backbone, which may contribute greatly to the high-temperature growth phenotype...