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The Journal of Antimicrobial... Jul 2024The measurement of VOCs release in the headspace of a bacterial culture represents a new approach to rapidly assess antimicrobial susceptibility. Herein, we evaluated...
OBJECTIVES
The measurement of VOCs release in the headspace of a bacterial culture represents a new approach to rapidly assess antimicrobial susceptibility. Herein, we evaluated the diagnostic performance of the VITEK® REVEAL™ system directly from a collection of Gram-negative positive blood cultures.
MATERIALS AND METHODS
One hundred and twenty-eight positive blood cultures were included in the analysis (Enterobacterales, n = 95; Pseudomonas aeruginosa, n = 21; Acinetobacter baumannii complex, n = 12). Samples were processed using VITEK® REVEAL™ according to the manufacturer's recommendations, and MICs of 22 antimicrobials were compared with those obtained using reference methods. Categorical agreement (CA), essential agreement (EA) and categorical errors were calculated.
RESULTS
Overall, 2220 strain/antibiotic pair combinations were analysed. Of these, most were classified as resistant by reference antimicrobial susceptibility testing (1091/2220; 48.7%). The overall CA and EA were 97.6% and 97.7%, respectively. CA ranged from 97.5% in Enterobacterales to 97.9% in both P. aeruginosa and A. baumannii complex. The overall number of categorical discrepancies were: 18 very major errors (1.6%), 13 major errors (1.2%) and 22 minor errors (2.4%). EA ranged from 95.2% in P. aeruginosa to 98.1% in Enterobacterales. Screening test for ESBL phenotype was positive, indeterminate and negative in 13.7%, 32.6% and 27.4% of Enterobacterales isolates tested by both VITEK® REVEAL™ and the reference method, showing 100% CA.
CONCLUSIONS
VITEK® REVEAL™ represents a reliable tool to obtain antimicrobial susceptibility results of the main Gram-negative species directly from positive blood cultures with time to results of less than 8 h.
PubMed: 38958300
DOI: 10.1093/jac/dkae219 -
Revista Brasileira de Parasitologia... 2024Diseases such as those caused by feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) represent health problems for cats. Feline leishmaniasis (FL) has...
Diseases such as those caused by feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) represent health problems for cats. Feline leishmaniasis (FL) has been reported in several cities across the country. The objective was to carry out a clinical-epidemiological and laboratory study of FIV, FeLV and FL in cats from shelters in Dourados, Mato Grosso do Sul, Brazil. Blood samples and swabs from the conjunctival and nasal mucosa were obtained from 75 cats, from four animal shelters. Serology for FIV and FeLV was performed. For Leishmania, polymerase chain reaction (PCR) was performed on blood, conjunctiva and nasal mucosa. In the immunochromatographic serological test, seven cats tested positive for FIV and none for FeLV. No samples was positive in PCR for Leishmania. The study showed that despite the presence of human and canine leishmaniasis in the studied region, Leishmania spp. were absent in the cats studied. To avoid an increase in contagion in shelters, it is essential isolate cats with FIV.
Topics: Animals; Cats; Brazil; Immunodeficiency Virus, Feline; Leukemia Virus, Feline; Cat Diseases; Prevalence; Male; Leishmaniasis; Female; Leishmania
PubMed: 38958295
DOI: 10.1590/S1984-29612024035 -
Revista Brasileira de Parasitologia... 2024The Amblyomma genus (Arachnida: Ixodidae) is widely distributed in South America, with 34 species occurring in Brazil. Amblyomma nodosum Neumann 1889 is a species that...
The Amblyomma genus (Arachnida: Ixodidae) is widely distributed in South America, with 34 species occurring in Brazil. Amblyomma nodosum Neumann 1889 is a species that predominantly feeds on Passeriformes during immature stages (larvae and nymphs) and anteaters (Myrmecophagidae) during adult stages. The aim of the present study is to report, for the first time, an unusual case of parasitism by adults of A. nodosum on a yellow cururu toad (Rhinella icterica) captured in the city of Nossa Senhora da Glória, Sergipe state (Northeastern Brazil) in the Caatinga biome, and also investigate the presence of DNA of Rickettsia in the collected material. DNA was extracted from all specimens collected (N=8) and subjected to PCR assays based on the tick 16S rRNA endogenous gene and gltA gene for Rickettsia sp. All samples (8/8; 100%) were positive for the 16S rRNA endogenous gene and two amplicons (obtained from one male and one female) were purified and sequenced. The BLASTn analysis of the sequences revealed a high degree of similarity (95-100%) with A. nodosum sequences previously deposited on GenBank, while the phylogenetic analysis clustered the sequences obtained in the same clade as A. nodosum sequences from Brazil.
Topics: Animals; Brazil; Amblyomma; Tick Infestations; Male; Female; Rickettsia; Bufonidae
PubMed: 38958294
DOI: 10.1590/S1984-29612024031 -
American Journal of Reproductive... Jul 2024Vulvovaginal candidiasis (VVC) is a common mucosal fungal infection, and Candida albicans is the main causative agent. The NLRP3 inflammasome plays an important role in...
PROBLEM
Vulvovaginal candidiasis (VVC) is a common mucosal fungal infection, and Candida albicans is the main causative agent. The NLRP3 inflammasome plays an important role in VVC, but the underlying mechanism is unknown.
METHOD OF STUDY
Vaginal epithelial cells were divided into three groups: control, C. albicans strain SC5314 (wild-type, WT), and WT+ Matt Cooper Compound 950 (MCC950, a specific NLRP3 inhibitor). After human vaginal epithelial cells were pretreated with 1 µmol/L MCC950 for 2 h, C. albicans (MOI = 1) was cocultured with the human vaginal epithelial cells for 12 h. The cell supernatants were collected, LDH was detected, and the IL-1β and IL-18 levels were determined by ELISA. The expression of the pyroptosis-related proteins NLRP3, Caspase-1 p20 and GSDMD was measured by Western blotting analysis. The protein expression of the pyroptosis-related N-terminus of GSDMD (GSDMD-N) was detected by immunofluorescence.
RESULTS
In this study, we showed that the WT C. albicans strain induced pyroptosis in vaginal epithelial cells, as indicated by the LDH and proinflammatory cytokine levels and the upregulated levels of the pyroptosis-related proteins NLRP3, Caspase-1 p20, and GSDMD-N. MCC950 reversed the changes in the expression of these proteins and proinflammatory cytokines in vaginal epithelial cells.
CONCLUSION
C. albicans activated the NLRP3 inflammasome to induce vaginal epithelial cell pyroptosis. MCC950 inhibited the NLRP3 inflammasome, reduced vaginal epithelial cell pyroptosis, and decreased the release of inflammatory cytokines.
Topics: Female; Humans; NLR Family, Pyrin Domain-Containing 3 Protein; Candidiasis, Vulvovaginal; Epithelial Cells; Inflammasomes; Candida albicans; Pyroptosis; Vagina; Interleukin-18; Interleukin-1beta; Indenes; Furans; Caspase 1; Heterocyclic Compounds, 4 or More Rings; Phosphate-Binding Proteins; Cells, Cultured; Sulfonamides
PubMed: 38958245
DOI: 10.1111/aji.13893 -
Journal of Medical Microbiology Jul 2024Anti-fungal agents are increasingly becoming less effective due to the development of resistance. In addition, it is difficult to treat organisms that form biofilms...
Anti-fungal agents are increasingly becoming less effective due to the development of resistance. In addition, it is difficult to treat organisms that form biofilms due to a lack of ability of drugs to penetrate the biofilms. We are attempting to assess the effect of a new therapeutic agent, -acetylcysteine (NAC), on adhesion and biofilm formation in clinical strains. Meanwhile, to detect the transcription level changes of adhesion and biofilm formation-associated genes ( and ) when administrated with NAC in strains, furthermore, to explore the mechanism of drug interference on biofilms. N-acetylcysteine (NAC) exhibits certain inhibitory effects on adhesion and biofilm formation in C. parapsilosis clinical strains from CRBSIs through: (1) down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections (CRBSIs), (2) regulating the metabolism and biofilm -forming factors of cell structure. To determine whether non-antifungal agents can exhibit inhibitory effects on adhesion, amounts of total biofilm formation and metabolic activities of isolates from candidemia patients, NAC was added to the yeast suspensions at different concentrations, respectively. Reverse transcription was used to detect the transcriptional levels of adhesion-related genes ( and ) and biofilm formation-related factors ( and ) in the knockout strain, CP7 and CP5 clinical strains in the presence of NAC. To further explore the mechanism of NAC on the biofilms of , RNA sequencing was used to calculate gene expression, comparing the differences among samples. Gene Ontology (GO) enrichment analysis helps to illustrate the difference between two particular samples on functional levels. A high concentration of NAC reduces the total amount of biofilm formation in . Following co-incubation with NAC, the expression of in both CP7 and CP5 clinical strains decreased, while there were no significant changes in the transcriptional levels of compared with the untreated strain. GO enrichment analysis showed that the metabolism and biofilm-forming factors of cell structure were all regulated after NAC intervention. The non-antifungal agent NAC exhibits certain inhibitory effects on clinical isolate biofilm formation by down-regulating the expression of the gene, making it a highly potential candidate for the treatment of catheter-related bloodstream infections.
Topics: Biofilms; Acetylcysteine; Humans; Candida parapsilosis; Catheter-Related Infections; Candidemia; Fungal Proteins; Antifungal Agents
PubMed: 38958241
DOI: 10.1099/jmm.0.001848 -
Clinical Chemistry Jul 2024
PubMed: 38958122
DOI: 10.1093/clinchem/hvae091 -
Journal of Medicinal Chemistry Jul 2024(Mtb), the infectious agent of tuberculosis (TB), causes over 1.5 million deaths globally every year. Host-directed therapies (HDT) for TB are desirable for their...
(Mtb), the infectious agent of tuberculosis (TB), causes over 1.5 million deaths globally every year. Host-directed therapies (HDT) for TB are desirable for their potential to shorten treatment and reduce the development of antibiotic resistance. Previously, we described a modular biomimetic strategy to identify , targeting PPM1A (IC = 1.19 μM), a metal-dependent phosphatase exploited by Mtb to survive intracellularly. restricted the survival of Mtb in macrophages and lungs of infected mice. Herein, we redesigned to create , which is a more potent inhibitor for PPM1A (IC = 180 nM). efficiently increased the level of phosphorylation of S403-p62 and the expression of LC3B-II to activate autophagy, resulting in the dose-dependent clearance of Mtb in infected macrophages. possesses a good pharmacokinetic profile and oral bioavailability ( = 74%). In vivo, is well tolerated up to 50 mg/kg and significantly reduces the bacteria burden in the spleens of infected mice.
PubMed: 38958057
DOI: 10.1021/acs.jmedchem.4c00513 -
Gut Microbes 2024The juxtaposition of well-oxygenated intestinal colonic tissue with an anerobic luminal environment supports a fundamentally important relationship that is altered in...
The juxtaposition of well-oxygenated intestinal colonic tissue with an anerobic luminal environment supports a fundamentally important relationship that is altered in the setting of intestinal injury, a process likely to be relevant to diseases such as inflammatory bowel disease. Herein, using two-color phosphorometry to non-invasively quantify both intestinal tissue and luminal oxygenation in real time, we show that intestinal injury induced by DSS colitis reduces intestinal tissue oxygenation in a spatially defined manner and increases the flux of oxygen from the tissue into the gut lumen. By characterizing the composition of the microbiome in both DSS colitis-affected gut and in a bioreactor containing a stable human fecal community exposed to microaerobic conditions, we provide evidence that the increased flux of oxygen into the gut lumen augments glycan degrading bacterial taxa rich in glycoside hydrolases which are known to inhabit gut mucosal surface. Continued disruption of the intestinal mucus barrier through such a mechanism may play a role in the perpetuation of the intestinal inflammatory process.
Topics: Gastrointestinal Microbiome; Colitis; Animals; Humans; Oxygen; Bacteria; Mice; Intestinal Mucosa; Feces; Mice, Inbred C57BL; Dextran Sulfate; Colon; Male
PubMed: 38958039
DOI: 10.1080/19490976.2024.2361493 -
Journal of Materials Chemistry. B Jul 2024Surgical site infection (SSI) caused by pathogenic bacteria leads to delayed wound healing and extended hospitalization. Inappropriate uses of antibiotics have caused a...
Surgical site infection (SSI) caused by pathogenic bacteria leads to delayed wound healing and extended hospitalization. Inappropriate uses of antibiotics have caused a surge in SSI and common antibiotics are proving to be ineffective against SSI. Antimicrobial peptides (AMPs) can be a potential solution to prevent SSI because of their broad spectrum of antimicrobial activities. In this study, naturally sourced AMPs were studied along with microfibers, fabricated by a novel wet-spinning method using sodium alginate and polycaprolactone. Afterward, fibers were functionalized by the catechol groups of dopamine immobilizing nucleophilic AMPs on the surface. Conjugation between PCL and alginate resulted in fibers with smooth surfaces improving their mechanical strength hydrogen bonds. Having an average diameter of 220 μm, the mechanical properties of the fiber complied with USP standards for suture size 3-0. Engineered microfibers were able to hinder the growth of spp., a pathogenic bacterium for at least 60 hours whereas antibiotic ceftazidime failed. When subjected to a linear incisional wound model study, accelerated healing was observed when the wound was closed using the engineered fiber compared to Vicryl. The microfibers promoted faster re-epithelialization compared to Vicryl proving their higher wound healing capacity.
PubMed: 38958038
DOI: 10.1039/d4tb00889h -
Surgical Infections Jul 2024Post-partum infection is a major contributor to maternal mortality and is responsible for approximately 10% of maternal fatalities worldwide. The risk of infection is...
Post-partum infection is a major contributor to maternal mortality and is responsible for approximately 10% of maternal fatalities worldwide. The risk of infection is substantially higher in cesarean section procedures. Approximately 8% of women who undergo cesarean sections are susceptible to infection. Although the body of evidence supporting the regular pre-operative utilization of prophylactic antibiotic treatment is steadily expanding, its usefulness in cesarean sections has not yet been standardized, and post-partum infection is still a serious medical challenge. We aimed to retrospectively assess the prophylactic effectiveness of cefazolin in combination with other antibiotic agents in cesarean sections. Both uni-variable and multi-variable analyses were conducted to identify factors that may affect cefazolin pre-operative antibiotic prophylaxis in elective cesarean section operations. The uni-variable analysis included timing of administration, operation duration, body mass index (BMI), and wound type. A multi-variable logistic regression model was then created to determine which variables provide independent information in the context of other variables. Time of administration did not affect prophylactic cefazolin efficacy. However, prophylactic cefazolin was 1.43 and 1.77 times more effective when the operation lasted for 45 minutes or more, compared with operations that were shorter than 45 minutes. Patients with a BMI ranging from 18 to 29 kg/m showed increased efficacy of prophylactic cefazolin compared with obese patients with a BMI exceeding 30 kg/m. The effectiveness of prophylactic cefazolin decreased by 95% in patients with clean-contaminated surgical incisions compared with those with clean surgical incisions. Our findings demonstrate that administering pre-operative prophylactic antibiotic agents to women undergoing cesarean section resulted in a reduction in post-partum infections, thereby reducing maternal mortality. Furthermore, optimal timing of administration, re-dosing if necessary, length of prophylactic medication, and dosing adjustments for obese patients are crucial factors in preventing surgical site infections and promoting antimicrobial stewardship.
PubMed: 38957977
DOI: 10.1089/sur.2024.048