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Topic Review
Candida and Candidiasis
One of the most important questions in microbiology nowadays is how apparently harmless, commensal yeasts such as Candida spp. can cause a rising number of infections. The occurrence of the disease requires firstly the attachment to the host cells, followed by the invasion of the tissue. The adaptability translates into a rapid ability to respond to stress factors, to take up nutrients or to multiply under different conditions. By forming complex intracellular networks such as biofilms, Candida spp. become not only more refractive to antifungal therapies but also more prone to cause disease. The inter-microbial interactions can enhance the virulence of a strain. In vivo, the fungal cells face a multitude of challenges and, as a result, they develop complex strategies serving one ultimate goal: survival. This review presents the virulence factors of the most important Candida spp., contributing to a better understanding of the onset of candidiasis and raising awareness of the highly complex interspecies interactions that can change the outcome of the disease.
  • 1.7K
  • 27 Oct 2020
Topic Review
Heavy Metals Bioremediation
Cadmium (Cd), chromium (Cr) and lead (Pb) are heavy metals that have been classified as priority pollutants in aqueous environment while methane-oxidizing bacteria as a biofilter arguably consume up to 90% of the produced methane in the same aqueous environment before it escapes into the atmosphere. However, the underlying kinetics and active methane oxidizers are poorly understood for the hotspot of epipelon that provides a unique micro-ecosystem containing diversified guild of microorganisms including methane oxidizers for potential bioremediation of heavy metals. In the present study, the Pb2+, Cd2+and Cr6+ bioremediation potential of epipelon biofilm was assessed under both high (120,000 ppm) and near-atmospheric (6 ppm) methane concentrations. Epipelon biofilm demonstrated a high methane oxidation activity following microcosm incubation amended with a high concentration of methane, accompanied by the complete removal of 50 mg L−1 Pb2+ and 50 mg L−1 Cd2+ (14 days) and partial (20%) removal of 50 mg L−1 Cr6+ after 20 days. High methane dose stimulated a faster (144 h earlier) heavy metal removal rate compared to near-atmospheric methane concentrations. DNA-based stable isotope probing (DNA-SIP) following 13CH4 microcosm incubation revealed the growth and activity of different phylotypes of methanotrophs during the methane oxidation and heavy metal removal process. High throughput sequencing of 13C-labelled particulate methane monooxygenase gene pmoA and 16S rRNA genes revealed that the prevalent active methane oxidizers were type I affiliated methanotrophs, i.e., Methylobacter. Type II methanotrophs including Methylosinus and Methylocystis were also labeled only under high methane concentrations. These results suggest that epipelon biofilm can serve as an important micro-environment to alleviate both methane emission and the heavy metal contamination in aqueous ecosystems with constant high methane fluxes.
  • 1.6K
  • 27 Oct 2020
Topic Review
Drug Resistance in Cedecea neteri
Cedecea, a genus in the Enterobacteriaceae family, includes several opportunistic pathogens reported to cause an array of sporadic acute infections, most notably of the lung and bloodstream. One species, Cedecea neteri, is associated with cases of bacteremia in immunocompromised hosts and has documented resistance to different antibiotics, including β-lactams and colistin. Despite the potential to inflict serious infections, knowledge about drug resistance determinants in Cedecea is limited.
  • 1.6K
  • 31 Aug 2021
Topic Review
The Gut Microbiome in NAFLD
Non-alcoholic fatty liver disease (NAFLD) is a multifactorial disease in which environmental and genetic factors are involved. Although the molecular mechanisms involved in NAFLD onset and progression are not completely understood, the gut microbiome (GM) is thought to play a key role in the process, influencing multiple physiological functions. 
  • 1.6K
  • 30 Oct 2020
Topic Review
Occurrence of Triclosan in the Water Environment
Triclosan (TCS), a kind of pharmaceuticals and personal care products (PPCPs), is widely used and has had a large production over years. It is an emerging pollutant in the water environment that has attracted global attention due to its toxic effects on organisms and aquatic ecosystems, and its concentrations in the water environment are expected to increase since the COVID-19 pandemic outbreak.
  • 1.6K
  • 09 Sep 2022
Topic Review
YdfD
ydfD is a lytic gene from the Qin cryptic prophage that encodes a 63-amino-acid protein, the ectopic expression of which in Escherichia coli can cause nearly complete cell lysis rapidly. The bacterial 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway is responsible for synthesizing the isoprenoids uniquely required for sustaining bacterial growth.
  • 1.6K
  • 21 Mar 2022
Topic Review
Streptobacillus Moniliformis
Streptobacillus moniliformis is a non-motile, Gram-negative rod-shaped bacterium that is a member of the family Leptotrichiaceae. The genome of S. moniliformis is one of two completed sequences of the order Fusobacteriales. Its name comes from the Greek word streptos for "curved" or "twisted", and the Latin words bacillus meaning "small rod" and moniliformis for "necklace". S. moniliformis is microaerophilic, requiring less oxygen than is present in the atmosphere for its growth.
  • 1.6K
  • 03 Nov 2022
Topic Review
Targeting Gut Microbial Biofilms
Colorectal cancer (CRC) is a global public health issue which poses a substantial humanistic and economic burden on patients, healthcare systems and society. In recent years, intestinal dysbiosis has been suggested to be involved in the pathogenesis of CRC, with specific pathogens exhibiting oncogenic potentials such as Fusobacterium nucleatum, Escherichia coli and enterotoxigenic Bacteroides fragilis having been found to contribute to CRC development. More recently, it has been shown that initiation of CRC development by these microorganisms requires the formation of biofilms. Gut microbial biofilm forms in the inner colonic mucus layer and is composed of polymicrobial communities. Biofilm results in the redistribution of colonic epithelial cell E-cadherin, increases permeability of the gut and causes a loss of function of the intestinal barrier, all of which enhance intestinal dysbiosis. This literature review aims to compile the various strategies that target these pathogenic biofilms and could potentially play a role in the prevention of CRC. We explore the potential use of natural products, silver nanoparticles, upconverting nanoparticles, thiosalicylate complexes, anti-rheumatic agent (Auranofin), probiotics and quorum-sensing inhibitors as strategies to hinder colon carcinogenesis via targeting colon-associated biofilms.
  • 1.6K
  • 22 Oct 2020
Topic Review
Campylobacter Fetus
Campylobacter fetus is a rod-shaped, gram-negative species of bacteria within the genus Campylobacter of phylum Proteobacteria. Identification of C. fetus species in infected animals or people is routinely performed by culture on blood or cefoperazone deoxycholate agar. Subspecies of C. fetus commonly causes reproductive disease in ruminants and gastrointestinal disease in humans. Transmission of C. fetus subspecies venerealis occurs mainly through venereal contact while transmission of C. fetus subspecies fetus occurs mainly through ingestion of bacteria in a contaminated environment. Infertility in cattle and abortion in sheep are common outcomes of infection associated with C. fetus subspecies venerealis and C. fetus subspecies fetus, respectively. Disease in humans occurs through zoonotic transmission of C. fetus mainly via ingestion of contaminated food or water sources. C. fetus can be diagnosed with polymerase chain reaction assays, enzyme linked immunosorbent assays and vaginal mucus agglutination testing. As vaccines are typically not efficient in preventing future spread, infected bulls are often culled. Human infections may be treated with erythromycin as antimicrobial resistance has been emerging for the fluoroquinolones.
  • 1.6K
  • 11 Oct 2022
Topic Review
Elite Rhizobia Strains in Africa
Grain legumes play a significant role in smallholder farming systems in Africa because of their contribution to nutrition and income security and their role in fixing nitrogen. Biological Nitrogen Fixation (BNF) serves a critical role in improving soil fertility for legumes. Dinitrogen can be reduced to ammonium (NH3) through the Haber–Bosch process or via biological nitrogen fixation (BNF) utilizing some soil bacteria or archaea (diazotrophs). Rhizobia belong to Alphaproteobacteria and Betaproteobacteria, a group of Gram-negative bacteria that forms nodules on roots (sometimes stems) of leguminous plants to fix nitrogen in a symbiotic relationship with their host plants. The rhizobia–legume symbiosis is the most studied plant–microbial mutualism because of the importance of nitrogen fixation for almost all agricultural systems.
  • 1.6K
  • 21 Jul 2022
Topic Review
ESKAPE Bacteria in the Dog
ESKAPE bacteria (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are a group of common opportunistic pathogens associated mainly with nosocomial infections.
  • 1.6K
  • 30 Oct 2020
Topic Review
Biotechnological Importance of Torulaspora delbrueckii
Torulaspora delbrueckii has attracted interest in recent years, especially due to its biotechnological potential, arising from its flavor- and aroma-enhancing properties when used in wine, beer or bread dough fermentation, as well as from its remarkable resistance to osmotic and freezing stresses.    
  • 1.6K
  • 23 Sep 2021
Topic Review
Respiratory System and its Microbiome
Several studies suggest the importance of preserving the micro-ecosystem of commensal, symbiotic and pathogenic microbes of the respiratory system, and, more recently, its relationship with the intestinal microbiome. However, recent studies investigate how it leads to the maintenance of human health, also in relation to some factors such as the effect of age, diet and others, making its composition and stability better understood.  
  • 1.6K
  • 09 Nov 2020
Topic Review
Nanocellulose Functional Material
Nanocellulose is generally defined as cellulose particles or fibers with dimensions in the nanometer range. It can be derived from different cellulose sources, such as wood pulp, agricultural residues, or bacterial cultures, using various methods including mechanical treatment, enzymatic hydrolysis, or chemical processes.
  • 1.6K
  • 28 Jul 2023
Topic Review
Outer Membrane Porins in Gram-Negative Bacteria
Gram-negative bacteria depend on their cell membranes for survival and environmental adaptation. They contain two membranes, one of which is the outer membrane (OM), which is home to several different outer membrane proteins (Omps). One class of important Omps is porins, which mediate the inflow of nutrients and several antimicrobial drugs. The microorganism’s sensitivity to antibiotics, which are predominantly targeted at internal sites, is greatly influenced by the permeability characteristics of porins.
  • 1.6K
  • 14 Jul 2023
Topic Review
Plasmids Mediating Quinolone Resistance
Plasmid-mediated quinolone resistance (PMQR) remains one of the main mechanisms of bacterial quinolone resistance and plays an important role in the transmission of antibiotic resistance genes (ARGs). The two novel plasmids, p3M-2A and p3M-2B, which mediate quinolone resistance in Proteus vulgaris strain 3M (P3M) were identified. Of these, only p3M-2B appeared to be a qnrD-carrying plasmid. Both p3M-2A and p3M-2B could be transferred into Escherichia coli, and the latter caused a twofold change in ciprofloxacin resistance, according to the measured minimum inhibitory concentration (MIC). Plasmid curing/complementation and qRT-PCR results showed that p3M-2A can directly regulate the expression of qnrD in p3M-2B under treatment with ciprofloxacin, in which process, ORF1 was found to play an important role. Sequence alignments and phylogenetic analysis revealed the evolutionary relationships of all reported qnrD-carrying plasmids and showed that ORF1–4 in p3M-2B is the most conserved backbone for the normal function of qnrD-carrying plasmids. The identified direct repeats (DR) suggested that, from an evolutionary perspective, p3M-2B may have originated from the 2683-bp qnrD-carrying plasmid and may increase the possibility of plasmid recombination and then of qnrD transfer. To the best of our knowledge, this is the first identification of a novel qnrD-carrying plasmid isolated from a P. vulgaris strain of shrimp origin and a plasmid that plays a regulatory role in qnrD expression. This study also sheds new light on plasmid evolution and on the mechanism of horizontal transfer of ARGs encoded by plasmids.
  • 1.6K
  • 27 Oct 2020
Topic Review
Antimicrobial Resistance Assessment in Aquacultures
Aquaculture is a new food production sector that has been increasing dramatically over the last two decades due to the high demand for a healthy protein source. The aquaculture production figures indicate a substantial increase in the relative contribution of aquaculture to total fish consumption from 5% in 1962 to 49% in 2002. The use of antimicrobials in aquaculture, even at subinhibitory concentrations, has been promoting antimicrobial resistance in bacteria from the aquatic environment. New omics tools and approaches pave the way for the assessment of antimicrobial resistance in these environments.
  • 1.6K
  • 19 Jul 2021
Topic Review
Honeybee Microbiota
Numerous honeybee (Apis mellifera) products, such as honey, propolis, and bee venom, are used in traditional medicine to prevent illness and promote healing. Therefore, this insect has a huge impact on humans’ way of life and the environment. While the population of A. mellifera is large, there is concern that widespread commercialization of beekeeping, combined with environmental pollution and the action of bee pathogens, has caused significant problems for the health of honeybee populations. One of the strategies to preserve the welfare of honeybees is to better understand and protect their natural microbiota. 
  • 1.6K
  • 05 Sep 2021
Topic Review Peer Reviewed
Morphometric Characterization of Bacteria Associated with Bacteremia
Among the leading causes of bacteremia are Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. E. coli and K. pneumoniae are increasingly exhibiting resistance to last-resort antibiotics, such as carbapenems. Rapid and accurate identification of these pathogens is critical for timely treatment and infection control. This paper aimed to develop a computer-aided bacterial morphometric technique for identifying and classifying wild-type E. coli, K. pneumoniae, and S. aureus in a field guide fashion. A 3D laser scanning confocal microscope was used to gather key parameters of each organism: length (L, µm), circular diameter (CD, µm), volume (V, µm3), surface area-to-cross-sectional area ratio (SA/CSA, unitless), surface uniformity ratio (Str), and surface texture ratio (Sdr). Microscope images and measurement results showed that S. aureus was spherical with the shortest length (1.08 µm) and smallest volume (0.52 µm3). E. coli and K. pneumoniae were rod-shaped with lengths >2.0 µm and volumes >1.0 µm3. Carbapenem-resistant (CR) strains exhibited larger volumes than their wild-type counterparts. Surface parameters further differentiated strains: wild-type E. coli had a greater surface texture or a less smooth surface (larger Sdr) than K. pneumoniae (lower Sdr) did. CR E. coli had more surface uniformity (lower Str) than CR K. pneumoniae did. A dichotomous key based on shape, circular diameter, volume, length, and surface characteristics was developed to classify the species using a series of paired, contrasting features. This morphometric analysis can aid researchers in quickly identifying bacteria, leading to faster diagnosis of life-threatening diseases and improved treatment decisions.
  • 1.6K
  • 28 Aug 2025
Topic Review
Essential Oil from Cistus ladanifer L.
In Oulmes (Middle Atlas, Morocco), the local population uses C. ladanifer traditionally to treat various diseases and health issues due to its antioxidant, gastric, anti-inflammatory, antitumor, antimicrobial, and antiviral properties. This plant is usually harvested in May in this area (flowering time). The leaves of all Cistus species secrete essential oils. Essential oils from different species of medicinal plants have been documented to possess antimicrobial propriety with strong activity against Gram-negative and Gram-positive bacteria and also fungi.
  • 1.6K
  • 25 Oct 2021
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