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PloS One 2024The skin microbiome maintains healthy human skin, and disruption of the microbiome balance leads to inflammatory skin diseases such as folliculitis and atopic...
The skin microbiome maintains healthy human skin, and disruption of the microbiome balance leads to inflammatory skin diseases such as folliculitis and atopic dermatitis. Staphylococcus aureus and Cutibacterium acnes are pathogenic bacteria that simultaneously inhabit the skin and cause inflammatory diseases of the skin through the activation of innate immune responses. Silkworms are useful invertebrate animal models for evaluating innate immune responses. In silkworms, phenoloxidase generates melanin as an indicator of innate immune activation upon the recognition of bacterial or fungal components. We hypothesized that S. aureus and C. acnes interact to increase the innate immunity-activating properties of S. aureus. In the present study, we showed that acidification is involved in the activation of silkworm hemolymph melanization by S. aureus. Autoclaved-killed S. aureus (S. aureus [AC]) alone does not greatly activate silkworm hemolymph melanization. On the other hand, applying S. aureus [AC] treated with C. acnes culture supernatant increased the silkworm hemolymph melanization. Adding C. acnes culture supernatant to the medium decreased the pH. S. aureus [AC] treated with propionic acid, acetic acid, or lactic acid induced higher silkworm hemolymph melanization activity than untreated S. aureus [AC]. S. aureus [AC] treated with hydrochloric acid also induced silkworm hemolymph melanization. The silkworm hemolymph melanization activity of S. aureus [AC] treated with hydrochloric acid was inhibited by protease treatment of S. aureus [AC]. These results suggest that acid treatment of S. aureus induces innate immune activation in silkworms and that S. aureus proteins are involved in the induction of innate immunity in silkworms.
Topics: Animals; Hemolymph; Bombyx; Staphylococcus aureus; Melanins; Immunity, Innate; Hydrogen-Ion Concentration; Monophenol Monooxygenase
PubMed: 38814922
DOI: 10.1371/journal.pone.0298502 -
Food Chemistry: X Jun 2024Microbial composition plays an important role in the quality and flavor of bacon. The aims of this study were to detect bacterial community succession using...
Microbial composition plays an important role in the quality and flavor of bacon. The aims of this study were to detect bacterial community succession using high-throughput sequencing (HTS) and volatile flavor compound changes using gas chromatography-ion mobility spectrometry (GC-IMS) during the production of Zhenba bacon. The results showed that a total of 70 volatile compounds were detected. Among them, ketones, hydrocarbons, aldehydes, esters and alcohols were the main substances in the curing and smoking stages. In addition, the fungal abundance was greater than the bacterial abundance, and there was obvious succession of the microbial community with changes in fermentation time and processing technology. The main functional bacterial genera in the curing and smoking stages were , and , and the main fungal genera were and . Through correlation analysis, we found that pyrrole, 2-pentanol, methyl isobutyl ketone (MIBK) and ethyl acetate (EA) were significantly correlated with , , and ( < 0.01), and it is speculated that they contribute significantly to flavor formation. The results of this study are helpful for understanding the microbial dynamics and characteristic volatile flavor compounds in Zhenba bacon, and provide new insights into the relationship between microorganisms and flavor through potential correlations.
PubMed: 38813459
DOI: 10.1016/j.fochx.2024.101478 -
Frontiers in Medicine 2024The emergence of community-acquired methicillin-resistant (CA-MRSA) infections at the end of the 20th century represents a significant shift in the epidemiology of...
The emergence of community-acquired methicillin-resistant (CA-MRSA) infections at the end of the 20th century represents a significant shift in the epidemiology of staphylococcal infections and, consequently, their clinical management. There are diverse CA-MRSA clones that are widely spread worldwide, showing differences in their regional dissemination, which has been dynamically changing over time. Although the first CA-MRSA description occurred about 30 years ago, its epidemiology in certain regions, such as South America, has been poorly explored, resulting in a gap in the understanding of the epidemiology of CA-MRSA in under-represented countries/regions. This report describes the first four clinical cases of invasive infections caused by CA-MRSA in a tertiary hospital in the central-southern region of Chile. It also associates the clinical characteristics of the infections with the microbiological and molecular features of the isolates. The four isolates belong to sequence type 8, which has been widely described as a cause of community-acquired infections. All of them presented a wide resistome and virulome. Additionally, in two of them, it was possible to reconstruct the COMER genetic element, present in the USA300-Latin American variant clone. Considering these findings, it is crucial to prepare for a potential increase in invasive CA-MRSA infections in Chile. This would involve enhancing current surveillance systems and maintaining a low threshold of suspicion for these infections among clinicians.
PubMed: 38813384
DOI: 10.3389/fmed.2024.1365756 -
Heliyon May 2024Since the clock of antimicrobial resistance was set, modern medicine has shed light on a new cornerstone in technology to overcome the worldwide dread of the...
Since the clock of antimicrobial resistance was set, modern medicine has shed light on a new cornerstone in technology to overcome the worldwide dread of the post-antimicrobial era. Research organizations are exploring the use of nanotechnology to modify metallic crystals from macro to nanoscale size, demonstrating significant interest in the field of antimicrobials. Herein, the antimicrobial activities of aluminum oxide (AlO), cobalt aluminum oxide (CoAlO), and aluminum doped zinc oxide (ZnAlO) nanoparticles were examined against some nosocomial pathogens. The study confirmed the formation and characterization of AlO, CoAlO, and ZnAlO nanoparticles using various techniques, revealing the generation of pure nanoscale nanoparticles. With inhibition zones ranging from 9 to 14 mm and minimum inhibitory concentrations varying from 4 mg/mL to 16 mg/mL, the produced nanoparticles showed strong antibacterial activity against , , , and . Meanwhile, the bactericidal concentrations ranged from 8 mg/mL to 40 mg/mL. In culture, ZnAlO NPs demonstrated a unique ability to inhibit the development of nosocomial infections with high bactericidal activity (8 mg/mL). Transmission electron microscope images revealed changes in cell shape, bacterial cell wall morphology, cytoplasmic membrane, and protoplasm due to the introduction of tested nanoparticles. These results pave the way for the use of these easily bacterial wall-piercing nanoparticles in combination with potent antibiotics to overcome the majority of bacterial strains' resistance.
PubMed: 38813232
DOI: 10.1016/j.heliyon.2024.e31462 -
Heliyon May 2024The demand for cowhide (ponmo) is currently very high, particularly in Nigeria, due to rising commodity prices, including animal proteins, which has forced a larger...
The demand for cowhide (ponmo) is currently very high, particularly in Nigeria, due to rising commodity prices, including animal proteins, which has forced a larger percentage of the population who cannot afford meat, chicken, turkey or eggs to rely on other meat products such as "ponmo," "kundi," and "tinko" as an alternative source of protein. This research aims to identify microorganisms associated with ponmo, determine the antibiogram of the isolates, and assess the nutritional value of ponmo marketed in Ilishan-Remo central market. Six ponmo vendors were sampled for Dry White Ponmo (DWP), Wet White Ponmo (WWP), Wet Brown Ponmo (WBP) and Brown Ponmo Water (BPW) and transported in sterile containers to the Laboratory for analysis to determine the microbial load, sensitivity, and proximate analysis using standardized methods. For microbiological analysis, samples were tested in triplicate. All samples analyzed had a high microbial load count (from 1.1 x 10 to 1.4 x 10). The organisms isolated were (34.21 %) (26.31 %) spp. (18.42 %) spp. (13.15 %) and Coagulase-negative staphylococci (7.89 %). All the isolates were multidrug-resistant (MDR). Septrin had the highest resistivity (86.84 %) while gentamicin had the lowest resistance (7.89 %). Pefloxacin sensitivity was observed in 37 of the 38 isolates (97.37 % sensitivity). Ciprofloxacin and gentamicin came second and third (84.2 % and 73.68 % sensitivity) respectively. According to the proximate analysis, the WWP has more protein, fat, and fiber, whereas the WBP has more moisture. Food handlers should follow Good Hygiene Practices and take a Food Handlers Test regularly.
PubMed: 38813194
DOI: 10.1016/j.heliyon.2024.e30882 -
Chinese Journal of Traumatology =... May 2024We carried out the study aiming to explore and analyze the risk factors, the distribution of pathogenic bacteria, and their antibiotic-resistance characteristics...
PURPOSE
We carried out the study aiming to explore and analyze the risk factors, the distribution of pathogenic bacteria, and their antibiotic-resistance characteristics influencing the occurrence of surgical site infection (SSI), to provide valuable assistance for reducing the incidence of SSI after traumatic fracture surgery.
METHODS
A retrospective case-control study enrolling 3978 participants from January 2015 to December 2019 receiving surgical treatment for traumatic fractures was conducted at Tangdu Hospital of Air Force Medical University. Baseline data, demographic characteristics, lifestyles, variables related to surgical treatment, and pathogen culture were harvested and analyzed. Univariate analyses and multivariate logistic regression analyses were used to reveal the independent risk factors of SSI. A bacterial distribution histogram and drug-sensitive heat map were drawn to describe the pathogenic characteristics.
RESULTS
Included 3978 patients 138 of them developed SSI with an incidence rate of 3.47% postoperatively. By logistic regression analysis, we found that variables such as gender (males) (odds ratio (OR) = 2.012, 95% confidence interval (CI): 1.235 - 3.278, p = 0.005), diabetes mellitus (OR = 5.848, 95% CI: 3.513 - 9.736, p < 0.001), hypoproteinemia (OR = 3.400, 95% CI: 1.280 - 9.031, p = 0.014), underlying disease (OR = 5.398, 95% CI: 2.343 - 12.438, p < 0.001), hormonotherapy (OR = 11.718, 95% CI: 6.269 - 21.903, p < 0.001), open fracture (OR = 29.377, 95% CI: 9.944 - 86.784, p < 0.001), and intraoperative transfusion (OR = 2.664, 95% CI: 1.572 - 4.515, p < 0.001) were independent risk factors for SSI, while, aged over 59 years (OR = 0.132, 95% CI: 0.059 - 0.296, p < 0.001), prophylactic antibiotics use (OR = 0.082, 95% CI: 0.042 - 0.164, p < 0.001) and vacuum sealing drainage use (OR = 0.036, 95% CI: 0.010 - 0.129, p < 0.001) were protective factors. Pathogens results showed that 301 strains of 38 species of bacteria were harvested, among which 178 (59.1%) strains were Gram-positive bacteria, and 123 (40.9%) strains were Gram-negative bacteria. Staphylococcus aureus (108, 60.7%) and Enterobacter cloacae (38, 30.9%) accounted for the largest proportion. The susceptibility of Gram-positive bacteria to Vancomycin and Linezolid was almost 100%. The susceptibility of Gram-negative bacteria to Imipenem, Amikacin, and Meropenem exceeded 73%.
CONCLUSION
Orthopedic surgeons need to develop appropriate surgical plans based on the risk factors and protective factors associated with postoperative SSI to reduce its occurrence. Meanwhile, it is recommended to strengthen blood glucose control in the early stage of admission and for surgeons to be cautious and scientific when choosing antibiotic therapy in clinical practice.
PubMed: 38811319
DOI: 10.1016/j.cjtee.2024.04.007 -
PloS One 2024The use of plants in the biological production of silver nanoparticles for antibacterial applications is a growing field of research. In the current work, we formulated...
The use of plants in the biological production of silver nanoparticles for antibacterial applications is a growing field of research. In the current work, we formulated Ocimum kilimandscharicum extracts using silver nanoparticles, and evaluated its potential antibacterial activity. Aqueous and methanol plant extracts were used to reduce silver nitrate at different time intervals (30 to 150 minutes) and pH (2 to 11). The UV-visible absorption spectrum recorded for methanol and aqueous extracts revealed a successful synthesis of AgNPs for methanol and aqueous extracts. The antimicrobial activity of the AgNPs was evaluated against Escherichia coli ATCC 25922, Salmonella choleraesuius ATCC 10708, and Staphylococcus aureus ATCC 25923 The best inhibition zone for the methanol and aqueous-mediated AgNPs, ranging from 12 ± 1 to 16 ± 1mm. Additionally, the methanol and aqueous extract silver nanoparticles had the same Minimum Inhibitory Concentration (6.25 ± 0.00 mg/ml), whereas the Minimum Bactericidal Concentrations were 12.5 ± 0.00 and 25 ± 0.00 mg/ml, respectively. The highest inhibition zone of 16 ± 1 mm was observed against Salmonella choleraesuius with 50 ± 0.00 mg/ml aqueous silver nanoparticles. The results show that the silver nanoparticles made with Ocimum kilimandscharicum have antibacterial action against those microorganisms.
Topics: Plant Extracts; Anti-Bacterial Agents; Silver; Metal Nanoparticles; Ocimum; Plant Leaves; Microbial Sensitivity Tests; Staphylococcus aureus; Escherichia coli; Bacteria
PubMed: 38809950
DOI: 10.1371/journal.pone.0295463 -
PloS One 2024Biofilms make it difficult to eradicate bacterial infections through antibiotic treatments and lead to numerous complications. Previously, two periprosthetic... (Comparative Study)
Comparative Study
Biofilms make it difficult to eradicate bacterial infections through antibiotic treatments and lead to numerous complications. Previously, two periprosthetic infection-related pathogens, Enterococcus faecalis and Staphylococcus lugdunensis were reported to have relatively contrasting biofilm-forming abilities. In this study, we examined the proteomics of the two microorganisms' biofilms using LC-MS/MS. The results showed that each microbe exhibited an overall different profile for differential gene expressions between biofilm and planktonic cells as well as between each other. Of a total of 929 proteins identified in the biofilms of E. faecalis, 870 proteins were shared in biofilm and planktonic cells, and 59 proteins were found only in the biofilm. In S. lugdunensis, a total of 1125 proteins were identified, of which 1072 proteins were found in common in the biofilm and planktonic cells, and 53 proteins were present only in the biofilms. The functional analysis for the proteins identified only in the biofilms using UniProt keywords demonstrated that they were mostly assigned to membrane, transmembrane, and transmembrane helix in both microorganisms, while hydrolase and transferase were found only in E. faecalis. Protein-protein interaction analysis using STRING-db indicated that the resulting networks did not have significantly more interactions than expected. GO term analysis exhibited that the highest number of proteins were assigned to cellular process, catalytic activity, and cellular anatomical entity. KEGG pathway analysis revealed that microbial metabolism in diverse environments was notable for both microorganisms. Taken together, proteomics data discovered in this study present a unique set of biofilm-embedded proteins of each microorganism, providing useful information for diagnostic purposes and the establishment of appropriately tailored treatment strategies. Furthermore, this study has significance in discovering the target candidate molecules to control the biofilm-associated infections of E. faecalis and S. lugdunensis.
Topics: Biofilms; Enterococcus faecalis; Proteomics; Staphylococcus lugdunensis; Plankton; Bacterial Proteins; Tandem Mass Spectrometry; Chromatography, Liquid
PubMed: 38809833
DOI: 10.1371/journal.pone.0298283 -
Microbiology Spectrum May 2024Surveillance schemes for methicillin-resistant (MRSA) are widely established at the national and international levels. Due to the simple standardization of the...
Surveillance schemes for methicillin-resistant (MRSA) are widely established at the national and international levels. Due to the simple standardization of the protocol, mainly isolates from bloodstream infections are used. However, the limitations of this simple surveillance system are well described. We conducted a comprehensive analysis of MRSA isolates in a large Slovenian region over 5 years to identify the optimal sample group for assessing the overall MRSA diversity. At the same time, this study provides to date non-available molecular characterization of Slovenian MRSA isolates. A total of 306 MRSA isolates from various sources were sequenced and phenotypically tested for resistance. The isolates exhibited significant molecular diversity, encompassing 30 multi locus sequence type (MLST) sequence types (STs), 39 ST-SCC genetic lineages, 49 types, and 29 antibiotic resistance profiles. Furthermore, the isolate pool comprised 57 resistance genes, representing 22 resistance mechanisms, and 96 virulence genes. While bloodstream isolates, commonly used in surveillance, provided insights into frequently detected clones, they overlooked majority of clones and important virulence and resistance genes. Blood culture isolates detected 21.3% types, 24.1% resistance phenotypes, and 28.2% MLST-SCC profiles. In contrast, strains from soft tissues demonstrated superior genomic diversity capture, with 65.3% types, 58.6% resistance phenotypes, and 71.8% MLST-SCC profiles. These strains also encompassed 100.0% of virulence and 82.5% of resistance genes, making them better candidates for inclusion in surveillance programs. This study highlights the limitations of relying solely on bloodstream isolates in MRSA surveillance and suggests incorporating strains from soft tissues to obtain a more comprehensive understanding of the epidemiology of MRSA.IMPORTANCEIn this study, we investigated the diversity of methicillin-resistant (MRSA), a bacterium that can cause infections that are difficult to treat due to its resistance to antimicrobial agents. Currently, surveillance programs for MRSA mainly rely on isolates from bloodstream infections, employing a standardized protocol. However, this study highlights the limitations of this approach and introduces a more comprehensive method. The main goal was to determine which group of samples is best suited to understand the overall diversity of MRSA and to provide, for the first time, molecular characterization of Slovenian MRSA isolates. Our results suggest that including MRSA strains from soft tissue infections rather than just blood infections provides a more accurate and comprehensive view of bacterial diversity and characteristics. This insight is valuable for improving the effectiveness of surveillance programs and for developing strategies to better manage MRSA infections.
PubMed: 38809050
DOI: 10.1128/spectrum.00140-24 -
Anais Da Academia Brasileira de Ciencias 2024The present study aimed to suggest the replacement of animal blood with human blood in culture media, involving alternative methods and ethical considerations, such as...
The present study aimed to suggest the replacement of animal blood with human blood in culture media, involving alternative methods and ethical considerations, such as animal welfare, in addition to potential laboratory cost reduction. Characteristics of growth and hemolysis development were compared in different culture media, using both sheep blood and human blood. Blood types from the ABO blood group system were tested, and commercially acquired sheep blood agar was used for comparison. Bacteria of the genus Streptococcus spp., Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli were tested. It was observed that growth in media with type A and O positive blood showed closer similarities to those performed in agar with sheep blood. Depending on the bacterial species, the results were either more positive or not, with faster-growing and less demanding bacteria showing better results than, for example, S. pneumoniae, which demonstrated difficulty in the growth process and hemolysis generation in human blood agar. The research suggests that in some situations, sheep blood could be replaced, especially when the goal is growth and isolation, but may not be as suitable when the objective is to analyze hemolysis or when the studied species is demanding.
Topics: Humans; Animals; Sheep; Culture Media; Feasibility Studies; Staphylococcus aureus; Blood; Hemolysis; Escherichia coli
PubMed: 38808880
DOI: 10.1590/0001-3765202420231168