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Microorganisms Apr 2024Carbapenems are last-resort antibiotics used to treat multidrug-resistant bacterial infections. Resistance to carbapenems has been designated as an urgent threat and is...
Carbapenems are last-resort antibiotics used to treat multidrug-resistant bacterial infections. Resistance to carbapenems has been designated as an urgent threat and is increasing in healthcare settings. However, little is still known about the distribution and characteristics of carbapenem-resistant bacteria (CRB) outside of healthcare settings. Here, we surveyed the distribution of CRB in ten diverse freshwater and seawater environments in California, U.S., ranging from San Luis Obispo County to San Bernardino County, combining both direct isolation and enrichment approaches to increase the diversity of isolated CRB. From the locations surveyed, we selected 30 CRB for further characterization. These isolates were identified as members of the genera , , , , , , and . These isolates were resistant to carbapenems, other β-lactams, and often to other antibiotics (tetracycline, gentamicin, or ciprofloxacin). We also found that nine isolates belonging to the genera , (), and () produced carbapenemases. Overall, our findings indicate that sampling different types of aquatic environments and combining different isolation approaches increase the diversity of the environmental CRB obtained. Moreover, our study supports the increasingly recognized role of natural water systems as an underappreciated reservoir of bacteria resistant to carbapenems and other antibiotics, including bacteria carrying carbapenemase genes.
PubMed: 38674746
DOI: 10.3390/microorganisms12040802 -
Microorganisms Apr 2024and related genera are among the most important contaminants in the pharmaceutical production environment, and the identification of these microorganisms at the species...
and related genera are among the most important contaminants in the pharmaceutical production environment, and the identification of these microorganisms at the species level assists in the investigation of sources of contamination and in preventive and corrective decision making. The aim of this study was to evaluate three methodologies for the characterization of endospore-forming aerobic bacterial strains isolated from a pharmaceutical unit in Rio de Janeiro, Brazil. MALDI-TOF MS was performed using MALDI Biotyper and VITEK MS RUO systems, and complete 16S rRNA gene sequencing was performed using the Sanger methodology. The results showed the prevalence of the genera (n = 9; 36.0%), (n = 5; 20.0%), and (n = 4; 16.0%). Three (20.0%) strains showed <98.7% of DNA sequencing similarity on the EzBioCloud Database, indicating possible new species. In addition, the reclassification of to the genus as sp. nov. is proposed. In conclusion, 16S rRNA and MALDI TOF/MS were not sufficient to identify all strains at the species level, and complementary analyses were necessary.
PubMed: 38674668
DOI: 10.3390/microorganisms12040724 -
International Journal of Molecular... Apr 2024The potato dry rot disease caused by spp. seriously reduces potato yield and threatens human health. However, potential biocontrol agents cannot guarantee the stability...
The potato dry rot disease caused by spp. seriously reduces potato yield and threatens human health. However, potential biocontrol agents cannot guarantee the stability and activity of biocontrol. Here, 18 synthetic microbial communities of different scales were constructed, and the synthetic microbial communities with the best biocontrol effect on potato dry rot disease were screened through in vitro and in vivo experiments. The results show that the synthetic community composed of , , , , and has the best biocontrol activity. Metabolomics results show that interacts with other member strains to produce caproic acid and reduce the disease index to 38.01%. Furthermore, the mycelial growth inhibition after treatment with caproic acid was 77.54%, and flow cytometry analysis showed that the living conidia rate after treatment with caproic acid was 11.2%. This study provides potential value for the application of synthetic microbial communities in potatoes, as well as the interaction mechanisms between member strains of synthetic microbial communities.
Topics: Solanum tuberosum; Plant Diseases; Biological Control Agents; Fusarium; Microbial Interactions; Bacteria; Microbial Consortia
PubMed: 38674022
DOI: 10.3390/ijms25084437 -
Foods (Basel, Switzerland) Apr 2024Enumeration of endospores of butyric acid-forming clostridia in cheese milk is an essential part of milk quality monitoring for cheese producers to avoid late blowing,...
Enumeration of endospores of butyric acid-forming clostridia in cheese milk is an essential part of milk quality monitoring for cheese producers to avoid late blowing, severe spoilage caused by clostridia during ripening. However, due to the lack of an internationally standardized method, different methods are used and it is important to consider how the choice of method affects the results. This is particularly relevant when clostridial spore counts in milk are considered for quality payments. The aim of this study was to evaluate the specificity of the AMP-6000 method for the enumeration of endospores of cheese spoiling clostridia in milk. First, to assess the prevalence of diversity and to determine potential non-target species, we identified isolates from positive reactions of the AMP-6000 method used to quantify clostridial endospores in raw milk and teat skin samples by MALDI-TOF MS. Based on these results, a strain library was designed to evaluate method inclusivity and exclusivity using pure cultures of target and non-target strains according to ISO 16140-2:2016. Most target strains, as well as all tested and strains were inclusive. However, may be underestimated as only some strains gave positive results. All non-target strains of bacilli and lysinibacilli, but not all paenibacilli, were confirmed to be exclusive. This study provides performance data to better understand the results of microbiological enumeration of butyric acid-forming clostridia in milk and serves as a basis for future methodological considerations and improvements.
PubMed: 38672865
DOI: 10.3390/foods13081192 -
Insects Apr 2024American foulbrood is an infectious disease of the honeybee brood that causes multiple types of damage to beekeeping. The causative agent of the disease is the bacterium...
American foulbrood is an infectious disease of the honeybee brood that causes multiple types of damage to beekeeping. The causative agent of the disease is the bacterium , which forms resistant infective spores and is viable for decades. After the eradication measures have been implemented, in cases of clinically visible disease, it is necessary to conduct effective final disinfections of equipment and tools. This study aimed to determine the effect of ten commercially available and commonly used disinfectants on certified strains of under laboratory conditions, as well as to compare the obtained results among individual genotypes of . Selected products were tested by determining the zone of inhibition using an agar diffusion test, a suspension test for viable bacteria, a surface disinfectant test, and a sporicidal effect in the suspension test. Incidin OxyFoam S and Sekusept Aktiv are both effective against all examined genotypes of . Despadac and Despadac Secure have a bactericidal effect, but their sporocidal effect is not as satisfactory as that of Genox. Genoll does not exhibit a sporicidal effect, and Ecocide S at 1%, Bee protect H forte, and Bee protect F did not exhibit a satisfactory sporocidal effect. Additionally, EM PROBIOTIC FOR BEES did not exhibit any bactericidal effect. The effective application of control measures and proper application of final disinfection can reduce the reoccurrence of visible clinical signs of disease, whereas methods of early diagnosis can significantly reduce the incidence of the disease.
PubMed: 38667398
DOI: 10.3390/insects15040268 -
Revista Argentina de Microbiologia Apr 2024Phytopathogenic fungi Alternaria alternata and Colletotrichum gloeosporioides cause diseases in plant tissues as well as significant postharvest losses. The use of...
Phytopathogenic fungi Alternaria alternata and Colletotrichum gloeosporioides cause diseases in plant tissues as well as significant postharvest losses. The use of chemical fungicides for their control has negative effects on health and the environment. Secondary metabolites from halophilic bacteria are a promising alternative for new antifungal compounds. In the present study, halophilic bacteria were isolated and characterized from two sites with saline soils called branquizales in Campeche, Mexico. A total of 64 bacteria were isolated. Agrobacterium, Bacillus, Inquilinus, Gracilibacillus, Metabacillus, Neobacillus, Paenibacillus, Priestia, Staphylococcus, Streptomyces and Virgibacillus were among the identified genera. The antifungal potential of the culture supernatant (CS) of 39 halophilic bacteria was investigated against C. gloeosporioides and A. alternata. The bacteria showing the greatest inhibition of mycelial growth corresponded to Bacillus subtilis CPO 4292, Metabacillus sp. CPO 4266, Bacillus sp. CPO 4295 and Bacillus sp. CPO 4279. The CS of Bacillus sp. CPO 4279 exhibited the highest activity and its ethyl acetate extract (AcOEt) inhibited the germination of C. gloeosporioides, with IC values of 8,630μg/ml and IC of 10,720μg/ml. The organic partition of the AcOEt extract led to three fractions, with acetonitrile (FAcB9) showing the highest antifungal activity, with values exceeding 66%. Halophilic bacteria from 'blanquizales' soils of the genus Bacillus sp. produce metabolites with antifungal properties that inhibit the phytopathogenic fungus C. gloeosporioides.
PubMed: 38614909
DOI: 10.1016/j.ram.2024.02.004 -
Frontiers in Bioengineering and... 2024The demand for highly robust and metabolically versatile microbes is of utmost importance for replacing fossil-based processes with biotechnological ones. Such an...
The demand for highly robust and metabolically versatile microbes is of utmost importance for replacing fossil-based processes with biotechnological ones. Such an example is the implementation of DSM 365 as a novel platform organism for the production of value-added products such as 2,3-butanediol or exopolysaccharides. For this, a complete genome sequence is the first requirement towards further developing this host towards a microbial chassis. A genome sequencing project has just been reported for DSM 365 showing a size of 5,788,318 bp with a total of 47 contigs. Herein, we report the first complete genome sequence of DSM 365, which consists of 5,889,536 bp with 45 RNAs, 106 tRNAs, 5,370 coding sequences and an average GC content of 45.6%, resulting in a closed genome of 365. The additional nucleotide data revealed a novel NRPS synthetase that may contribute to the production of tridecaptin. Building on these findings, we initiated the top-down construction of a chassis variant of . In the first stage, single knock-out mutants of non-essential genomic regions were created and evaluated for their biological fitness. As a result, two out of 18 variants showed impaired growth. The remaining deletion mutants were combined in two genome-reduced variants which either lack the production of endogenous biosynthetic gene clusters (GR1) or non-essential genomic regions including the insertion sequence IS (GR2), with a decrease of the native genome of 3.0% and 0.6%, respectively. Both variants, GR1 and GR2, showed identical growth characteristics to the wild-type. Endpoint titers of 2,3-butanediol and EPS production were also unaffected, validating these genome-reduced strains as suitable for further genetic engineering.
PubMed: 38605990
DOI: 10.3389/fbioe.2024.1378873 -
ACS Chemical Biology May 2024The prevalence of multidrug-resistant (MDR) pathogens combined with a decline in antibiotic discovery presents a major challenge for health care. To refill the discovery...
The prevalence of multidrug-resistant (MDR) pathogens combined with a decline in antibiotic discovery presents a major challenge for health care. To refill the discovery pipeline, we need to find new ways to uncover new chemical entities. Here, we report the global genome mining-guided discovery of new lipopeptide antibiotics tridecaptin A and tridecaptin D, which exhibit unusual bioactivities within their class. The change in the antibacterial spectrum of Oct-TriA was explained solely by a Phe to Trp substitution as compared to Oct-TriA, while Oct-TriD contained 6 substitutions. Metabolomic analysis of producer sp. JJ-21 validated the predicted amino acid sequence of tridecaptin A. Screening of tridecaptin analogues substituted at position 9 identified Oct-His9 as a potent congener with exceptional efficacy against and reduced hemolytic and cytotoxic properties. Our work highlights the promise of tridecaptin analogues to combat MDR pathogens.
Topics: Anti-Bacterial Agents; Pseudomonas aeruginosa; Humans; Microbial Sensitivity Tests; Host Specificity; Drug Discovery; Lipopeptides; Peptides
PubMed: 38602492
DOI: 10.1021/acschembio.4c00034 -
Frontiers in Microbiology 2024is a delicious and nutritious ectomycorrhizal fungus. However, its cultivation is hindered owing to limited studies on its symbiotic relationships. The symbiotic...
is a delicious and nutritious ectomycorrhizal fungus. However, its cultivation is hindered owing to limited studies on its symbiotic relationships. The symbiotic relationship between and its host is closely related to the shiro, a complex network composed of mycelium, mycorrhizal roots, and surrounding soil. To explore the symbiotic relationship between and its host, soil samples were collected from shiro (Tb) and corresponding rhizosphere (CK) in four cities in Liaoning Province, China. The physicochemical properties of all the soil samples were then analyzed, along with the composition and function of the fungal and bacterial communities. The results revealed a significant increase in total potassium, available nitrogen, and sand in Tb soil compared to those in CK soil, while there was a significant decrease in pH, total nitrogen, total phosphorus, available phosphorus, and silt. The fungal community diversity in shiro was diminished, and altered the community structure of its shiro by suppressing other fungi, such as (ectomycorrhizal fungus) and (phytopathogenic fungus). The bacterial community diversity in shiro increased, with the aggregation of mycorrhizal-helper bacteria, such as and , and plant growth-promoting bacteria, such as and , facilitated by . Microbial functional predictions revealed a significant increase in pathways associated with sugar and fat catabolism within the fungal and bacterial communities of shiro. The relative genetic abundance of carboxylesterase and gibberellin 2-beta-dioxygenase in the fungal community was significantly increased, which suggested a potential symbiotic relationship between and . These findings elucidate the microbial community and relevant symbiotic environment to better understand the relationship between and .
PubMed: 38601932
DOI: 10.3389/fmicb.2024.1361117 -
Scientific Reports Apr 2024Vulvar lichen sclerosus (VLS) is a chronic and progressive dermatologic condition that can cause physical dysfunction, disfigurement, and impaired quality of life....
Vulvar lichen sclerosus (VLS) is a chronic and progressive dermatologic condition that can cause physical dysfunction, disfigurement, and impaired quality of life. However, the etiology of VLS remains unknown. The vulvar skin, intestinal and vaginal microbiomes have been postulated to play important roles in the pathogenesis of this disease. The aim of this study was to compare the compositional characteristics of the vulvar skin, vagina, and gut microbiota between perimenopausal or postmenopausal VLS patients and healthy controls. The study involved six perimenopausal or postmenopausal VLS patients which were based on characteristic clinical manifestations and histologic confirmation and five healthy controls. The pruritus severity of each patient was evaluated using the NRS scale, and the dermatology-specific health-related quality of life was assessed using the Skindex-16. Metagenomic sequencing was performed, and the results were analyzed for alpha and beta diversity. LEfSe analysis were used to investigate the microbial alterations in vulvar skin, gut and vagina. KEGG databases were used to analyze differences in functional abundance. The study found significant differences in alpha diversity between the two groups in stool and vaginal samples (P < 0.05). Patients with VLS had a higher abundance of Enterobacter cloacae, Flavobacterium_branchiophilum, Mediterranea_sp._An20, Parabacteroides_johnsoniiand Streptococcus_bovimastitidis on the vulvar skin, while Corynebacterium_sp._zg-913 was less abundant compared to the control group. The relative abundance of Sphingomonas_sp._SCN_67_18, Sphingobium_sp._Ant17, and Pontibacter_sp_BT213 was significantly higher in the gut samples of patients with VLS.Paenibacillus_popilliae,Gemella_asaccharolytica, and Coriobacteriales_bacterium_DNF00809 compared to the control group. Additionally, the vaginal samples of patients with VLS exhibited a significantly lower relative abundance of Bacteroidales_bacterium_43_8, Bacteroides_sp._CAG:20, Blautia_sp._AM28-10, Fibrobacter_sp._UWB16, Lachnospiraceae_bacterium_AM25-39, Holdemania_filiformis, Lachnospiraceae_bacterium_GAM79, and Tolumonas_sp. Additionally, the butyrate-producing bacterium SS3/4 showed a significant difference compared to the controls. The study found a negative relationship between Sphingobium_sp._Ant17 in stool and Skindex-16 (P < 0.05), while Mediterranea_sp._An20 had a positive correlation with Skindex-16 (P < 0.05) in the skin. Additionally, our functional analysis revealed alterations in Aminoacyl_tRNA_biosynthesis, Glutathione_metabolism, the pentose phosphate pathway, and Alanine__aspartate_and_glutamate_metabolism in the VLS patient group. The study suggests that perimenopausal or postmenopausal patients with VLS have a modified microbiome in the vulvar skin, gut, and vagina. This modification is linked to abnormal energy metabolism, increased oxidative stress, and abnormal amino acid metabolism.
Topics: Female; Humans; Vulvar Lichen Sclerosus; Postmenopause; Perimenopause; Quality of Life; Microbiota; Arrhythmias, Cardiac; Vagina
PubMed: 38600101
DOI: 10.1038/s41598-024-58983-y