Journal Description
Microorganisms
Microorganisms
is a scientific, peer-reviewed, open access journal of microbiology, published monthly online by MDPI. The Hellenic Society Mikrobiokosmos (MBK), the Spanish Society for Nitrogen Fixation (SEFIN) and the Society for Microbial Ecology and Disease (SOMED) are affiliated with the Microorganisms, and their members receive a discount on the article processing charges.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), PubMed, PMC, PubAg, CAPlus / SciFinder, AGRIS, and other databases.
- Journal Rank: JCR - Q2 (Microbiology) / CiteScore - Q2 (Microbiology (medical))
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 15.1 days after submission; acceptance to publication is undertaken in 2.8 days (median values for papers published in this journal in the second half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
- Testimonials: See what our editors and authors say about the Microorganisms.
- Companion journal: Applied Microbiology.
Impact Factor:
4.5 (2022);
5-Year Impact Factor:
4.8 (2022)
Latest Articles
Facial Skin Microbiome Composition and Functional Shift with Aging
Microorganisms 2024, 12(5), 1021; https://doi.org/10.3390/microorganisms12051021 (registering DOI) - 18 May 2024
Abstract
The change in the skin microbiome as individuals age is only partially known. To provide a better understanding of the impact of aging, whole-genome sequencing analysis was performed on facial skin swabs of 100 healthy female Caucasian volunteers grouped by age and wrinkle
[...] Read more.
The change in the skin microbiome as individuals age is only partially known. To provide a better understanding of the impact of aging, whole-genome sequencing analysis was performed on facial skin swabs of 100 healthy female Caucasian volunteers grouped by age and wrinkle grade. Volunteers’ metadata were collected through questionnaires and non-invasive biophysical measurements. A simple model and a biological statistical model were used to show the difference in skin microbiota composition between the two age groups. Taxonomic and non-metric multidimensional scaling analysis showed that the skin microbiome was more diverse in the older group (≥55 yo). There was also a significant decrease in Actinobacteria, namely in Cutibacterium acnes, and an increase in Corynebacterium kroppenstedtii. Some Streptococcus and Staphylococcus species belonging to the Firmicutes phylum and species belonging to the Proteobacteria phylum increased. In the 18–35 yo younger group, the microbiome was characterized by a significantly higher proportion of Cutibacterium acnes and Lactobacillus, most strikingly, Lactobacillus crispatus. The functional analysis using GO terms revealed that the young group has a higher significant expression of genes involved in biological and metabolic processes and in innate skin microbiome protection. The better comprehension of age-related impacts observed will later support the investigation of skin microbiome implications in antiaging protection.
Full article
(This article belongs to the Special Issue Microbiota in Human Health and Disease)
►
Show Figures
Open AccessArticle
Role of Probiotics in Gut Microbiome and Metabolome in Non-Alcoholic Fatty Liver Disease Mouse Model: A Comparative Study
by
Tian Wu, Zheng Zeng and Yanyan Yu
Microorganisms 2024, 12(5), 1020; https://doi.org/10.3390/microorganisms12051020 (registering DOI) - 17 May 2024
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide. Numerous studies conducted recently have demonstrated a connection between the dysbiosis of the development of NAFLD and gut microbiota. Rebuilding a healthy gut ecology has been proposed as a strategy
[...] Read more.
Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide. Numerous studies conducted recently have demonstrated a connection between the dysbiosis of the development of NAFLD and gut microbiota. Rebuilding a healthy gut ecology has been proposed as a strategy involving the use of probiotics. The purpose of this work is to investigate and compare the function of probiotics Akkermansia muciniphila (A. muciniphila) and VSL#3 in NAFLD mice. Rodent NAFLD was modeled using a methionine choline-deficient diet (MCD) with/without oral probiotic delivery. Subsequently, qPCR, histological staining, and liver function tests were conducted. Mass spectrometry-based analysis and 16S rDNA gene sequencing were used to investigate the liver metabolome and gut microbiota. We found that while both A. muciniphila and VSL#3 reduced hepatic fat content, A. muciniphila outperformed VSL#3. Furthermore, probiotic treatment restored the β diversity of the gut flora and A. muciniphila decreased the abundance of pathogenic bacteria such as Ileibacterium valens. These probiotics altered the metabolism in MCD mice, especially the glycerophospholipid metabolism. In conclusion, our findings distinguished the role of A. muciniphila and VSL#3 in NAFLD and indicated that oral-gavage probiotics remodel gut microbiota and improve metabolism, raising the possibility of using probiotics in the cure of NAFLD.
Full article
(This article belongs to the Special Issue Probiotics, Prebiotics, and Gut Microbes)
Open AccessArticle
Efficiency of Virucidal Disinfectants on Wood Surfaces in Animal Husbandry
by
Martin J. Oettler, Franz J. Conraths, Uwe Roesler, Sven Reiche, Timo Homeier-Bachmann and Nicolai Denzin
Microorganisms 2024, 12(5), 1019; https://doi.org/10.3390/microorganisms12051019 - 17 May 2024
Abstract
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests
[...] Read more.
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (Picea abies), pine (Pinus sylvestris), poplar (Populus sp.), beech (Fagus sylvatica) and Douglas fir (Pseudotsuga menziesii), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of −10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions.
Full article
(This article belongs to the Special Issue Disinfection and Sterilization of Microorganisms)
Open AccessArticle
Rapid Identification of Brucella Genus and Species In Silico and On-Site Using Novel Probes with CRISPR/Cas12a
by
Yan Zhang, Yufei Lyu, Dongshu Wang, Meijie Feng, Sicheng Shen, Li Zhu, Chao Pan, Xiaodong Zai, Shuyi Wang, Yan Guo, Shujuan Yu, Xiaowei Gong, Qiwei Chen, Hengliang Wang, Yuanzhi Wang and Xiankai Liu
Microorganisms 2024, 12(5), 1018; https://doi.org/10.3390/microorganisms12051018 - 17 May 2024
Abstract
Human brucellosis caused by Brucella is a widespread zoonosis that is prevalent in many countries globally. The high homology between members of the Brucella genus and Ochrobactrum spp. often complicates the determination of disease etiology in patients. The efficient and reliable identification and
[...] Read more.
Human brucellosis caused by Brucella is a widespread zoonosis that is prevalent in many countries globally. The high homology between members of the Brucella genus and Ochrobactrum spp. often complicates the determination of disease etiology in patients. The efficient and reliable identification and distinction of Brucella are of primary interest for both medical surveillance and outbreak purposes. A large amount of genomic data for the Brucella genus was analyzed to uncover novel probes containing single-nucleotide polymorphisms (SNPs). GAMOSCE v1.0 software was developed based on the above novel eProbes. In conjunction with clinical requirements, an RPA-Cas12a detection method was developed for the on-site determination of B. abortus and B. melitensis by fluorescence and lateral flow dipsticks (LFDs). We demonstrated the potential of these probes for rapid and accurate detection of the Brucella genus and five significant Brucella species in silico using GAMOSCE. GAMOSCE was validated on different Brucella datasets and correctly identified all Brucella strains, demonstrating a strong discrimination ability. The RPA-Cas12a detection method showed good performance in detection in clinical blood samples and veterinary isolates. We provide both in silico and on-site methods that are convenient and reliable for use in local hospitals and public health programs for the detection of brucellosis.
Full article
(This article belongs to the Section Microbial Biotechnology)
Open AccessArticle
Sodium Polyoxotungstate Inhibits the Replication of Influenza Virus by Blocking the Nuclear Import of vRNP
by
Zhuogang Li, Yuanyuan Duan, Yang Yu, Yue Su, Mingxin Zhang, Yarou Gao, Lefang Jiang, Haonan Zhang, Xiaoqin Lian, Xingjian Zhu, Jiaxin Ke, Qun Peng and Xulin Chen
Microorganisms 2024, 12(5), 1017; https://doi.org/10.3390/microorganisms12051017 - 17 May 2024
Abstract
Both pandemic and seasonal influenza are major health concerns, causing significant mortality and morbidity. Current influenza drugs primarily target viral neuraminidase and RNA polymerase, which are prone to drug resistance. Polyoxometalates (POMs) are metal cation clusters bridged by oxide anions. They have exhibited
[...] Read more.
Both pandemic and seasonal influenza are major health concerns, causing significant mortality and morbidity. Current influenza drugs primarily target viral neuraminidase and RNA polymerase, which are prone to drug resistance. Polyoxometalates (POMs) are metal cation clusters bridged by oxide anions. They have exhibited potent anti-tumor, antiviral, and antibacterial effects. They have remarkable activity against various DNA and RNA viruses, including human immunodeficiency virus, herpes simplex virus, hepatitis B and C viruses, dengue virus, and influenza virus. In this study, we have identified sodium polyoxotungstate (POM-1) from an ion channel inhibitor library. In vitro, POM-1 has been demonstrated to have potent antiviral activity against H1N1, H3N2, and oseltamivir-resistant H1N1 strains. POM-1 can cause virion aggregation during adsorption, as well as endocytosis. However, the aggregation is reversible; it does not interfere with virus adsorption and endocytosis. Our results suggest that POM-1 exerts its antiviral activity by inhibiting the nuclear import of viral ribonucleoprotein (vRNP). This distinct mechanism of action, combined with its wide range of efficacy, positions POM-1 as a promising therapeutic candidate for influenza treatment and warrants further investigation.
Full article
(This article belongs to the Section Antimicrobial Agents and Resistance)
►▼
Show Figures
Figure 1
Open AccessArticle
Divergence within the Taxon ‘Candidatus Phytoplasma asteris’ Confirmed by Comparative Genome Analysis of Carrot Strains
by
Rafael Toth, Anna-Marie Ilic, Bruno Huettel, Bojan Duduk and Michael Kube
Microorganisms 2024, 12(5), 1016; https://doi.org/10.3390/microorganisms12051016 - 17 May 2024
Abstract
Phytoplasmas are linked to diseases in hundreds of economically important crops, including carrots. In carrots, phytoplasmosis is associated with leaf chlorosis and necrosis, coupled with inhibited root system development, ultimately leading to significant economic losses. During a field study conducted in Baden-Württemberg (Germany),
[...] Read more.
Phytoplasmas are linked to diseases in hundreds of economically important crops, including carrots. In carrots, phytoplasmosis is associated with leaf chlorosis and necrosis, coupled with inhibited root system development, ultimately leading to significant economic losses. During a field study conducted in Baden-Württemberg (Germany), two strains of the provisional taxon ‘Candidatus Phytoplasma asteris’ were identified within a carrot plot. For further analysis, strains M8 and M33 underwent shotgun sequencing, utilising single-molecule-real-time (SMRT) long-read sequencing and sequencing-by-synthesis (SBS) paired-end short-read sequencing techniques. Hybrid assemblies resulted in complete de novo assemblies of two genomes harboring circular chromosomes and two plasmids. Analyses, including average nucleotide identity and sequence comparisons of established marker genes, confirmed the phylogenetic divergence of ‘Ca. P. asteris’ and a different assignment of strains to the 16S rRNA subgroup I-A for M33 and I-B for M8. These groups exhibited unique features, encompassing virulence factors and genes, associated with the mobilome. In contrast, pan-genome analysis revealed a highly conserved gene set related to metabolism across these strains. This analysis of the Aster Yellows (AY) group reaffirms the perception of phytoplasmas as bacteria that have undergone extensive genome reduction during their co-evolution with the host and an increase of genome size by mobilome.
Full article
(This article belongs to the Special Issue Phloem Localized Insect Transmitted Bacteria Associated with Plant Diseases)
►▼
Show Figures
Figure 1
Open AccessArticle
Exploring Gut Microbiota Alterations with Trimethoprim-Sulfamethoxazole and Dexamethasone in a Humanized Microbiome Mouse Model
by
George B. H. Green, Alexis N. Cox-Holmes, Olivia Backan, Olivia Valbak, Anna Claire E. Potier, Dongquan Chen, Casey D. Morrow, Christopher D. Willey and Braden C. McFarland
Microorganisms 2024, 12(5), 1015; https://doi.org/10.3390/microorganisms12051015 - 17 May 2024
Abstract
Along with the standard therapies for glioblastoma, patients are commonly prescribed trimethoprim-sulfamethoxazole (TMP-SMX) and dexamethasone for preventing infections and reducing cerebral edema, respectively. Because the gut microbiota impacts the efficacy of cancer therapies, it is important to understand how these medications impact the
[...] Read more.
Along with the standard therapies for glioblastoma, patients are commonly prescribed trimethoprim-sulfamethoxazole (TMP-SMX) and dexamethasone for preventing infections and reducing cerebral edema, respectively. Because the gut microbiota impacts the efficacy of cancer therapies, it is important to understand how these medications impact the gut microbiota of patients. Using mice that have been colonized with human microbiota, this study sought to examine how TMP-SMX and dexamethasone affect the gut microbiome. Two lines of humanized microbiota (HuM) Rag1−/− mice, HuM1Rag and HuM2Rag, were treated with either TMP-SMX or dexamethasone via oral gavage once a day for a week. Fecal samples were collected pre-treatment (pre-txt), one week after treatment initiation (1 wk post txt), and three weeks post-treatment (3 wk post txt), and bacterial DNA was analyzed using 16S rRNA-sequencing. The HuM1Rag mice treated with TMP-SMX had significant shifts in alpha diversity, beta diversity, and functional pathways at all time points, whereas in the HuM2Rag mice, it resulted in minimal changes in the microbiome. Likewise, dexamethasone treatment resulted in significant changes in the microbiome of the HuM1Rag mice, whereas the microbiome of the HuM2Rag mice was mostly unaffected. The results of our study show that routine medications used during glioblastoma treatment can perturb gut microbiota, with some microbiome compositions being more sensitive than others, and these treatments could potentially affect the overall efficacy of standard-of-care therapy.
Full article
(This article belongs to the Special Issue Gut Microbiota and Precise Modulation)
►▼
Show Figures
Figure 1
Open AccessReview
Probiotics in the New Era of Human Milk Oligosaccharides (HMOs): HMO Utilization and Beneficial Effects of Bifidobacterium longum subsp. infantis M-63 on Infant Health
by
Chyn Boon Wong, Huidong Huang, Yibing Ning and Jinzhong Xiao
Microorganisms 2024, 12(5), 1014; https://doi.org/10.3390/microorganisms12051014 - 17 May 2024
Abstract
A healthy gut microbiome is crucial for the immune system and overall development of infants. Bifidobacterium has been known to be a predominant species in the infant gut; however, an emerging concern is the apparent loss of this genus, in particular, Bifidobacterium longum
[...] Read more.
A healthy gut microbiome is crucial for the immune system and overall development of infants. Bifidobacterium has been known to be a predominant species in the infant gut; however, an emerging concern is the apparent loss of this genus, in particular, Bifidobacterium longum subsp. infantis (B. infantis) in the gut microbiome of infants in industrialized nations, underscoring the importance of restoring this beneficial bacterium. With the growing understanding of the gut microbiome, probiotics, especially infant-type human-residential bifidobacteria (HRB) strains like B. infantis, are gaining prominence for their unique ability to utilize HMOs and positively influence infant health. This article delves into the physiology of a probiotic strain, B. infantis M-63, its symbiotic relationship with HMOs, and its potential in improving gastrointestinal and allergic conditions in infants and children. Moreover, this article critically assesses the role of HMOs and the emerging trend of supplementing infant formulas with the prebiotic HMOs, which serve as fuel for beneficial gut bacteria, thereby emulating the protective effects of breastfeeding. The review highlights the potential of combining B. infantis M-63 with HMOs as a feasible strategy to improve health outcomes in infants and children, acknowledging the complexities and requirements for further research in this area.
Full article
(This article belongs to the Special Issue Probiotics, Prebiotics, and Gut Microbes)
►▼
Show Figures
Graphical abstract
Open AccessReview
A Review: Microbes and Their Effect on Growth Performance of Litopenaeus vannamei (White Leg Shrimps) during Culture in Biofloc Technology System
by
Bilal Raza, Zhongming Zheng, Jinyong Zhu and Wen Yang
Microorganisms 2024, 12(5), 1013; https://doi.org/10.3390/microorganisms12051013 - 17 May 2024
Abstract
In the modern era of Aquaculture, biofloc technology (BFT) systems have attained crucial attention. This technology is used to reduce water renewal with the removal of nitrogen and to provide additional feed. In BFT, microorganisms play a crucial role due to their complex
[...] Read more.
In the modern era of Aquaculture, biofloc technology (BFT) systems have attained crucial attention. This technology is used to reduce water renewal with the removal of nitrogen and to provide additional feed. In BFT, microorganisms play a crucial role due to their complex metabolic properties. Pathogens can be controlled through multiple mechanisms using probiotics, which can promote host development and enhance the quality of the culture environment. During culturing in a biofloc technology system, the supplementation of microalgae and its accompanying bacteria plays a beneficial role in reducing nitrogenous compounds. This enhances water quality and creates favorable environmental conditions for specific bacterial groups, while simultaneously reducing the dependency on carbon sources with higher content. The fluctuations in the bacterial communities of the intestine are closely associated with the severity of diseases related to shrimp and are used to evaluate the health status of shrimp. Overall, we will review the microbes associated with shrimp culture in BFT and their effects on shrimp growth. We will also examine the microbial impacts on the growth performance of L. vannamei in BFT, as well as the close relationship between probiotics and the intestinal microbes of L. vannamei.
Full article
(This article belongs to the Special Issue Microbial Ecology and Sustainable Aquaculture)
Open AccessArticle
Bacillus siamensis Improves the Immune Status and Intestinal Health of Weaned Piglets by Improving Their Intestinal Microbiota
by
Huawei Liu, Xinyu Liu, Haiyang Liu, Jiaqi Tang, Wei He, Tianqi Xu, Baojing Cheng, Baoming Shi and Jianchun Han
Microorganisms 2024, 12(5), 1012; https://doi.org/10.3390/microorganisms12051012 - 17 May 2024
Abstract
Previous studies on the early interference of gut microbiota by Bacillus siamensis (B. siamensis) in weaned piglets are rarely reported, and the present trial is a preliminary study. This experiment was conducted to investigate the effects of B. siamensis supplementation on
[...] Read more.
Previous studies on the early interference of gut microbiota by Bacillus siamensis (B. siamensis) in weaned piglets are rarely reported, and the present trial is a preliminary study. This experiment was conducted to investigate the effects of B. siamensis supplementation on the growth performance, serum biochemistry, immune response, fecal short-chain fatty acids and microbiota of weaned piglets. Sixty weaned piglets were randomly divided into a control group (CON) and a B. siamensis group (BS), which were fed a basal diet and the basal diet supplemented with 5 × 1010 CFU B. siamensis per kg, respectively. Each group had 3 replicates and 10 piglets per replicate. The trial lasted for 28 days. The results showed that B. siamensis significantly increased the serum growth hormone (GH) and insulin-like growth factor (IGF) in piglets. Compared with the CON group, the levels of serum immunoglobulin and inflammatory factors in the BS group were significantly improved. In addition, the serum concentrations of zonulin and endotoxin (ET) in the BS group were lower. The dietary addition of B. siamensis significantly increased fecal short-chain fatty acid (SCFA) levels in piglets. Notably, B. siamensis improved the microbial composition by increasing beneficial genera, including Weissella, Lachnospiraceae_NK4A136_group and Bifidobacterium, and decreasing pathogenic genera, including Pantoea, Fusobacterium and Gemella, in piglet feces. Correlation analysis showed that the benefits of dietary B. siamensis supplementation were closely related to its improved microbial composition. In summary, the addition of B. siamensis can improve the immunity function, inflammatory response, gut permeability and SCFA levels of weaned piglets, which may be achieved through the improvement of their microbiota.
Full article
(This article belongs to the Section Gut Microbiota)
►▼
Show Figures
Figure 1
Open AccessArticle
In-Host Flat-like Quasispecies: Characterization Methods and Clinical Implications
by
Josep Gregori, Sergi Colomer-Castell, Marta Ibañez-Lligoña, Damir Garcia-Cehic, Carolina Campos, Maria Buti, Mar Riveiro-Barciela, Cristina Andrés, Maria Piñana, Alejandra González-Sánchez, Francisco Rodriguez-Frias, Maria Francesca Cortese, David Tabernero, Ariadna Rando-Segura, Tomás Pumarola, Juan Ignacio Esteban, Andrés Antón and Josep Quer
Microorganisms 2024, 12(5), 1011; https://doi.org/10.3390/microorganisms12051011 - 17 May 2024
Abstract
The repeated failure to treat patients chronically infected with hepatitis E (HEV) and C (HCV) viruses, despite the absence of resistance-associated substitutions (RAS), particularly in response to prolonged treatments with the mutagenic agents of HEV, suggests that quasispecies structure may play a crucial
[...] Read more.
The repeated failure to treat patients chronically infected with hepatitis E (HEV) and C (HCV) viruses, despite the absence of resistance-associated substitutions (RAS), particularly in response to prolonged treatments with the mutagenic agents of HEV, suggests that quasispecies structure may play a crucial role beyond single point mutations. Quasispecies structured in a flat-like manner (referred to as flat-like) are considered to possess high average fitness, occupy a significant fraction of the functional genetic space of the virus, and exhibit a high capacity to evade specific or mutagenic treatments. In this paper, we studied HEV and HCV samples using high-depth next-generation sequencing (NGS), with indices scoring the different properties describing flat-like quasispecies. The significance of these indices was demonstrated by comparing the values obtained from these samples with those from acute infections caused by respiratory viruses (betacoronaviruses, enterovirus, respiratory syncytial viruses, and metapneumovirus). Our results revealed that flat-like quasispecies in HEV and HCV chronic infections without RAS are characterized by numerous low-frequency haplotypes with no dominant one. Surprisingly, these low-frequency haplotypes (at the nucleotide level) exhibited a high level of synonymity, resulting in much lower diversity at the phenotypic level. Currently, clinical approaches for managing flat-like quasispecies are lacking. Here, we propose methods to identifying flat-like quasispecies, which represents an essential initial step towards exploring alternative treatment protocols for viruses resistant to conventional therapies.
Full article
(This article belongs to the Special Issue Microbial Genome Analysis and Interpretation Using Computational Approaches—Second Edition)
►▼
Show Figures
Figure 1
Open AccessArticle
Use of Lactoperoxidase Inhibitory Effects to Extend the Shelf Life of Meat and Meat Products
by
Filip Beňo, Adéla Velková, Filip Hruška and Rudolf Ševčík
Microorganisms 2024, 12(5), 1010; https://doi.org/10.3390/microorganisms12051010 - 17 May 2024
Abstract
Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of bacteria, especially Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas spp.
[...] Read more.
Lactoperoxidase (LP) is an important enzyme of the salivary and mammary glands. It has been proven to increase the shelf life of raw milk by inhibiting the growth of bacteria, especially Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas spp. The aim of this work was to verify the use of LP to extend the shelf life of meat products. In vitro experiments showed inhibitory effects on the selected bacteria (Listeria innocua (ATCC 33090), Staphylococcus saprophyticus (CP054440.1), and Pseudomonas fluorescens (ATCC 13525) due to a prolongation of the lag phase of growth curves. A lower increase in viable counts (p < 0.05) was also found by testing pork cubes’ surface treated with LP solution (5%) + L. innocua and stored for 7 days at 15 °C. LP has also been studied at concentrations of 0.25 and 0.50% in meat products (pork ham and pâté) during refrigerated storage (4 °C for 28 days). Lower viable counts were observed throughout the storage experiment, especially for 0.50% LP (p < 0.05). Meat products containing LP also showed lower levels of oxidation (MAD) (p < 0.05). According to these results, LP could extend the shelf life of a wider range of products.
Full article
(This article belongs to the Section Food Microbiology)
►▼
Show Figures
Figure 1
Open AccessReview
Residents or Tourists: Is the Lactating Mammary Gland Colonized by Residential Microbiota?
by
Ruomei Xu, Grace McLoughlin, Mark Nicol, Donna Geddes and Lisa Stinson
Microorganisms 2024, 12(5), 1009; https://doi.org/10.3390/microorganisms12051009 - 17 May 2024
Abstract
The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that
[...] Read more.
The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that the lactating mammary gland houses a warm and nutrient-rich environment and is in contact with the external environment, it may be expected that the lactating mammary gland would contain a high biomass microbiome. This discrepancy raises the question of whether the bacteria in milk come from true microbial colonization in the mammary gland (“residents”) or are merely the result of constant influx from other bacterial sources (“tourists”). By drawing together data from animal, in vitro, and human studies, this review will examine the question of whether the lactating mammary gland is colonized by a residential microbiome.
Full article
(This article belongs to the Section Microbiomes)
►▼
Show Figures
Figure 1
Open AccessArticle
Epidemiological Study of Pathogens in Spontaneous Bacterial Peritonitis in 2017–2024—A Preliminary Report of the University Hospital in South-Eastern Poland
by
Jolanta Gruszecka and Rafał Filip
Microorganisms 2024, 12(5), 1008; https://doi.org/10.3390/microorganisms12051008 - 17 May 2024
Abstract
Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral
[...] Read more.
Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral center in south-eastern Poland. Microbiological analysis of the ascitic fluids was performed in all patients. The presence of microorganisms was found in samples from 17 patients, and 21 pathogens were isolated, including 15 Gram-positive bacteria and 6 Gram-negative bacteria. Staphylococcus epidermidis, MRCNS (methicillin-resistant coagulase-negative staphylococci, resistant to all beta-lactam antibiotics: penicillins, penicillins with beta-lactamase inhibitor, cephalosporins and carbapenems) was the main pathogen detected (19.05%, 4/21), followed by Enterococcus faecalis (9.52%, 2/21), Enterococcus faecium (9.52%, 2/21), Staphylococcus haemolyticus, MRCNS (4.76%, 1/21), Streptococcus mitis (9.52%, 2/21), Streptococcus parasanguinis (9.52%, 2/21), Micrococcus luteus (4.76%, 1/21) and Bacillus spp. (4.76%, 1/21). The following Gram-negative bacteria were also found in the specimens examined: Escherichia coli, ESBL (extended-spectrum β-lactamase producing E. coli) (4.76%, 1/21), Escherichia coli (4.76%, 1/21), Pseudomonas aeruginosa (4.76%, 1/21), Klebsiella oxytoca (9.52%, 2/21) and Sphingomonas paucimobilis (4.76%, 1/21). Gram-positive bacteria caused nosocomial infections in nine patients with SBP, Gram-negative bacteria caused nosocomial infections in two patients. In six patients with SBP, community-acquired infections caused by Gram-negative bacteria were found in three cases, Gram-positive bacteria in two cases, and in one case, community-acquired infection was caused by mixed Gram-positive and Gram-negative. Bacteria isolated from patients with hospital-acquired SBP showed higher drug resistance than those found in patients with non-hospital SBP. Bacterial infections in cirrhotic patients with complications may be responsible for their deteriorating health. Prompt intervention is critical to reducing mortality.
Full article
(This article belongs to the Special Issue New Obstacles in Bacterial, Fungal and Viral Infections: Antimicrobial Resistance and Emerging Pathogens)
►▼
Show Figures
Figure 1
Open AccessArticle
Abundance, Characterization and Diversity of Culturable Anoxygenic Phototrophic Bacteria in Manitoban Marshlands
by
Katia Messner and Vladimir Yurkov
Microorganisms 2024, 12(5), 1007; https://doi.org/10.3390/microorganisms12051007 - 17 May 2024
Abstract
Marshes are an important ecosystem, acting as a biodiversity hotspot, a carbon sink and a bioremediation site, breaking down anthropogenic waste such as antibiotics, metals and fertilizers. Due to their participation in these metabolic activities and their capability to contribute to primary productivity,
[...] Read more.
Marshes are an important ecosystem, acting as a biodiversity hotspot, a carbon sink and a bioremediation site, breaking down anthropogenic waste such as antibiotics, metals and fertilizers. Due to their participation in these metabolic activities and their capability to contribute to primary productivity, the microorganisms in such habitats have become of interest to investigate. Since Proteobacteria were previously found to be abundant and the waters are well aerated and organic-rich, this study on the presence of anoxygenic phototrophic bacteria, purple non-sulfur bacteria and aerobic anoxygenic phototrophs in marshes was initiated. One sample was collected at each of the seven Manitoban sites, and anoxygenic phototrophs were cultivated and enumerated. A group of 14 strains, which represented the phylogenetic diversity of the isolates, was physiologically investigated further. Aerobic anoxygenic phototrophs and purple non-sulfur bacteria were present at each location, and they belonged to the α- and β-Proteobacteria subphyla. Some were closely related to known heavy metal reducers (Brevundimonas) and xenobiotic decomposers (Novosphingobium and Sphingomonas). All were able to synthesize the photosynthetic complexes aerobically. This research highlights the diversity of and the potential contributions that anoxygenic phototrophs make to the essential functions taking place in wetlands.
Full article
(This article belongs to the Section Environmental Microbiology)
►▼
Show Figures
Figure 1
Open AccessArticle
Ticks and Tick-Borne Pathogens Circulating in Peri-Domestic Areas in Mainland Portugal
by
Leonardo Moerbeck, Ricardo Parreira, Magdalena Szczotko, Gonçalo Seixas, Rita Velez, Małgorzata Dmitryjuk, Ana Sofia Santos, Ana Domingos and Sandra Antunes
Microorganisms 2024, 12(5), 1006; https://doi.org/10.3390/microorganisms12051006 - 16 May 2024
Abstract
Over the years, tick-borne pathogens (TBPs) have garnered significant interest due to their medical, veterinary and economic importance. Additionally, TBPs have drawn attention to how these microorganisms interact with their own vectors, increasing the risk to human and animal infection of emerging and
[...] Read more.
Over the years, tick-borne pathogens (TBPs) have garnered significant interest due to their medical, veterinary and economic importance. Additionally, TBPs have drawn attention to how these microorganisms interact with their own vectors, increasing the risk to human and animal infection of emerging and reemerging zoonoses. In this sense, ticks, which are obligate hematophagous ectoparasites, have a key role in maintaining and transmitting TBPs among humans and animals. The aim of this study was to assess the prevalence of neglected TBPs in mainland Portugal, namely Anaplasma spp., Babesia spp., Ehrlichia spp. and Neoehrlichia mikurensis. DNA fragments were detected in questing ticks collected from five different ecological areas under investigation. To the best of the authors’ knowledge, this study reports new worldwide findings, including B. bigemina infecting Ixodes frontalis, Ixodes ricinus and Rhipicephalus sanguineus sensu lato. Additionally, it presents new findings in Portugal of N. mikurensis infecting I. ricinus and of presumably Wolbachia endosymbionts being detected in I. ricinus. Overall, there were 208 tick samples that were negative for all screened TBPs. The results herein obtained raise concerns about the circulation of neglected TBPs in mainland Portugal, especially in anthropophilic ticks, highlighting the importance of adopting a One Health perspective.
Full article
(This article belongs to the Special Issue The One Health Challenge: Zoonotic Parasites)
►▼
Show Figures
Figure 1
Open AccessArticle
Pre-Bleaching Coral Microbiome Is Enriched in Beneficial Taxa and Functions
by
Laís F. O. Lima, Amanda T. Alker, Megan M. Morris, Robert A. Edwards, Samantha J. de Putron and Elizabeth A. Dinsdale
Microorganisms 2024, 12(5), 1005; https://doi.org/10.3390/microorganisms12051005 - 16 May 2024
Abstract
Coral reef health is tightly connected to the coral holobiont, which is the association between the coral animal and a diverse microbiome functioning as a unit. The coral holobiont depends on key services such as nitrogen and sulfur cycling mediated by the associated
[...] Read more.
Coral reef health is tightly connected to the coral holobiont, which is the association between the coral animal and a diverse microbiome functioning as a unit. The coral holobiont depends on key services such as nitrogen and sulfur cycling mediated by the associated bacteria. However, these microbial services may be impaired in response to environmental changes, such as thermal stress. A perturbed microbiome may lead to coral bleaching and disease outbreaks, which have caused an unprecedented loss in coral cover worldwide, particularly correlated to a warming ocean. The response mechanisms of the coral holobiont under high temperatures are not completely understood, but the associated microbial community is a potential source of acquired heat-tolerance. Here we investigate the effects of increased temperature on the taxonomic and functional profiles of coral surface mucous layer (SML) microbiomes in relationship to coral–algal physiology. We used shotgun metagenomics in an experimental setting to understand the dynamics of microbial taxa and genes in the SML microbiome of the coral Pseudodiploria strigosa under heat treatment. The metagenomes of corals exposed to heat showed high similarity at the level of bacterial genera and functional genes related to nitrogen and sulfur metabolism and stress response. The coral SML microbiome responded to heat with an increase in the relative abundance of taxa with probiotic potential, and functional genes for nitrogen and sulfur acquisition. Coral–algal physiology significantly explained the variation in the microbiome at taxonomic and functional levels. These consistent and specific microbial taxa and gene functions that significantly increased in proportional abundance in corals exposed to heat are potentially beneficial to coral health and thermal resistance.
Full article
(This article belongs to the Special Issue Marine Microbial Diversity: Focus on Corals)
►▼
Show Figures
Figure 1
Open AccessReview
Exploring the Toxin-Mediated Mechanisms in Clostridioides difficile Infection
by
Evdokia Pourliotopoulou, Theodoros Karampatakis and Melania Kachrimanidou
Microorganisms 2024, 12(5), 1004; https://doi.org/10.3390/microorganisms12051004 - 16 May 2024
Abstract
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains
[...] Read more.
Clostridioides difficile infection (CDI) is the leading cause of nosocomial antibiotic-associated diarrhea, and colitis, with increasing incidence and healthcare costs. Its pathogenesis is primarily driven by toxins produced by the bacterium C. difficile, Toxin A (TcdA) and Toxin B (TcdB). Certain strains produce an additional toxin, the C. difficile transferase (CDT), which further enhances the virulence and pathogenicity of C. difficile. These toxins disrupt colonic epithelial barrier integrity, and induce inflammation and cellular damage, leading to CDI symptoms. Significant progress has been made in the past decade in elucidating the molecular mechanisms of TcdA, TcdB, and CDT, which provide insights into the management of CDI and the future development of novel treatment strategies based on anti-toxin therapies. While antibiotics are common treatments, high recurrence rates necessitate alternative therapies. Bezlotoxumab, targeting TcdB, is the only available anti-toxin, yet limitations persist, prompting ongoing research. This review highlights the current knowledge of the structure and mechanism of action of C. difficile toxins and their role in disease. By comprehensively describing the toxin-mediated mechanisms, this review provides insights for the future development of novel treatment strategies and the management of CDI.
Full article
(This article belongs to the Special Issue Recent Advances in Clostridioides difficile Infection)
►▼
Show Figures
Figure 1
Open AccessArticle
Whole Genome Sequence Analysis of Listeria monocytogenes Isolates Obtained from the Beef Production Chain in Gauteng Province, South Africa
by
James Gana, Nomakorinte Gcebe, Rian Edward Pierneef, Yi Chen, Rebone Moerane and Abiodun Adewale Adesiyun
Microorganisms 2024, 12(5), 1003; https://doi.org/10.3390/microorganisms12051003 - 16 May 2024
Abstract
The study used whole-genome sequencing (WGS) and bioinformatics analysis for the genomic characterization of 60 isolates of Listeria monocytogenes obtained from the beef production chain (cattle farms, abattoirs, and retail outlets) in Gauteng province, South Africa. The sequence types (STs), clonal complexes (CCs),
[...] Read more.
The study used whole-genome sequencing (WGS) and bioinformatics analysis for the genomic characterization of 60 isolates of Listeria monocytogenes obtained from the beef production chain (cattle farms, abattoirs, and retail outlets) in Gauteng province, South Africa. The sequence types (STs), clonal complexes (CCs), and the lineages of the isolates were determined using in silico multilocus sequence typing (MLST). We used BLAST-based analyses to identify virulence and antimicrobial genes, plasmids, proviruses/prophages, and the CRISPR-Cas system. The study investigated any association of the detected genes to the origin in the beef production chain of the L. monocytogenes isolates. Overall, in 60 isolates of Listeria monocytogenes, there were seven STs, six CCs, forty-four putative virulence factors, two resistance genes, one plasmid with AMR genes, and three with conjugative genes, one CRISPR gene, and all 60 isolates were positive for proviruses/prophages. Among the seven STs detected, ST204 (46.7%) and ST2 (21.7%) were the most prominent, with ST frequency varying significantly (p < 0.001). The predominant CC detected were CC2 (21.7%) and CC204 (46.7%) in lineages I and II, respectively. Of the 44 virulence factors detected, 26 (across Listeria Pathogenicity Islands, LIPIs) were present in all the isolates. The difference in the detection frequency varied significantly (p < 0.001). The two AMR genes (fosX and vga(G)) detected were present in all 60 (100%) isolates of L. monocytogenes. The only plasmid, NF033156, was present in three (5%) isolates. A CRISPR-Cas system was detected in six (10%), and all the isolates carried proviruses/prophages. The source and sample type significantly affected the frequencies of STs and virulence factors in the isolates of L. monocytogenes. The presence of fosX and vga(G) genes in all L. monocytogenes isolates obtained from the three industries of the beef production chain can potentially cause therapeutic implications. Our study, which characterized L. monocytogenes recovered from the three levels in the beef production chain, is the first time genomics was performed on this type of data set in the country, and this provides insights into the health implications of Listeria.
Full article
(This article belongs to the Special Issue Foodborne Pathogens: Detection Methods, Food Safety, and Public Health 2.0)
►▼
Show Figures
Figure 1
Open AccessArticle
Real-Time PCR (qtPCR) to Discover the Fate of Plant Growth-Promoting Rhizobacteria (PGPR) in Agricultural Soils
by
Ilenia Iosa, Caterina Agrimonti and Nelson Marmiroli
Microorganisms 2024, 12(5), 1002; https://doi.org/10.3390/microorganisms12051002 - 16 May 2024
Abstract
To optimize the application of plant growth-promoting rhizobacteria (PGPR) in field trials, tracking methods are needed to assess their shelf life and to determine the elements affecting their effectiveness and their interactions with plants and native soil microbiota. This work developed a real-time
[...] Read more.
To optimize the application of plant growth-promoting rhizobacteria (PGPR) in field trials, tracking methods are needed to assess their shelf life and to determine the elements affecting their effectiveness and their interactions with plants and native soil microbiota. This work developed a real-time PCR (qtPCR) method which traces and quantifies bacteria when added as microbial consortia, including five PGPR species: Burkholderia ambifaria, Bacillus amyloliquefaciens, Azotobacter chroococcum, Pseudomonas fluorescens, and Rahnella aquatilis. Through a literature search and in silico sequence analyses, a set of primer pairs which selectively tag three bacterial species (B. ambifaria, B. amyloliquefaciens and R. aquatilis) was retrieved. The primers were used to trace these microbial species in a field trial in which the consortium was tested as a biostimulant on two wheat varieties, in combination with biochar and the mycorrhizal fungus Rhizophagus intraradices. The qtPCR assay demonstrated that the targeted bacteria had colonized and grown into the soil, reaching a maximum of growth between 15 and 20 days after inoculum. The results also showed biochar had a positive effect on PGPR growth. In conclusion, qtPCR was once more an effective method to trace the fate of supplied bacterial species in the consortium when used as a cargo system for their delivery.
Full article
(This article belongs to the Special Issue Microbial Ecology of Soil Microorganisms, Networks with Plants and Ecosystem Services)
►▼
Show Figures
Figure 1
Journal Menu
► ▼ Journal Menu-
- Microorganisms Home
- Aims & Scope
- Editorial Board
- Reviewer Board
- Topical Advisory Panel
- Instructions for Authors
- Special Issues
- Topics
- Sections & Collections
- Article Processing Charge
- Indexing & Archiving
- Editor’s Choice Articles
- Most Cited & Viewed
- Journal Statistics
- Journal History
- Journal Awards
- Society Collaborations
- Editorial Office
Journal Browser
► ▼ Journal BrowserHighly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Aquaculture Journal, Fishes, Microorganisms, Water
Women in Aquaculture Research
Topic Editors: Camino Ordás, Patrícia Díaz-RosalesDeadline: 30 June 2024
Topic in
Agronomy, Environments, Microorganisms, Pollutants, Sustainability, Water
Soil and Water Pollution Process and Remediation Technologies, 2nd Volume
Topic Editors: Hongbiao Cui, Ru Wang, Yu Shi, Haiying Lu, Lin ChenDeadline: 15 July 2024
Topic in
Antibiotics, Antioxidants, JoF, Microbiology Research, Microorganisms
Redox in Microorganisms, 2nd Edition
Topic Editors: Michal Letek, Volker BehrendsDeadline: 31 July 2024
Topic in
Molecules, Pharmaceutics, Antibiotics, Microorganisms, Biomolecules, Marine Drugs, Polymers, IJMS
Antimicrobial Agents and Nanomaterials
Topic Editors: Sandra Pinto, Vasco D. B. BonifácioDeadline: 30 September 2024
Conferences
Special Issues
Special Issue in
Microorganisms
Role of Oral Microbiota in Oral and General Health in Adults and Children
Guest Editors: Alessandra Amato, Federica Di SpiritoDeadline: 20 May 2024
Special Issue in
Microorganisms
The Urban Microbiome
Guest Editors: Haruo Suzuki, Soojin JangDeadline: 31 May 2024
Special Issue in
Microorganisms
Emerging Pathogens Causing Acute Hepatitis
Guest Editors: Sayed F. Abdelwahab, Ibrahim M. Sayed, Ahmed El-ShamyDeadline: 15 June 2024
Special Issue in
Microorganisms
Monkeypox—Current Knowledge and Future Perspectives
Guest Editors: Jakab Ferenc, Krisztián BányaiDeadline: 30 June 2024
Topical Collections
Topical Collection in
Microorganisms
Trends in Yeast Biochemistry and Biotechnology
Collection Editors: Seiji Shibasaki, Mitsuyoshi Ueda
Topical Collection in
Microorganisms
Epidemiology and Pathogenicity of Animal-Adapted Streptococci
Collection Editors: Peter Valentin-Weigand, Marcus Fulde
Topical Collection in
Microorganisms
Biodegradation and Environmental Microbiomes
Collection Editors: Shuangjiang Liu, Hongzhi Tang, Jiandong Jiang, Xiaolei Wu