RESUMO

We have been trying to find a miRNA that can specifically regulate the function of mycobacterial host cells to achieve the purpose of eliminating Mycobacterium tuberculosis. The purpose of this study is to investigate the regulation of mmu-let-7a-5p on macrophages apoptosis and its effect on intracellular BCG clearance. After a series of in vitro experiments, we found that mmu-let-7a-5p could negatively regulate the apoptosis of macrophages by targeting Caspase-3. The extrinsic apoptosis signal axis TNFR1/FADD/Caspase-8/Caspase-3 was inhibited after BCG infection. Up-regulated the expression level of mmu-let-7a-5p increase the cell proliferation viability and inhibit apoptosis rate of macrophages, but down-regulated its level could apparently reduce the bacterial load of intracellular Mycobacteria and accelerate the clearance of residual Mycobacteria effectively. Mmu-let-7a-5p has great potential to be utilized as an optimal candidate exosomal loaded miRNA for anti-tuberculosis immunotherapy in our subsequent research.

Assuntos

Apoptose , Carga Bacteriana , Caspase 3 , Macrófagos , MicroRNAs , Animais , Camundongos , Caspase 3/metabolismo , Proliferação de Células , Macrófagos/microbiologia , Macrófagos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Mycobacterium bovis/fisiologia , Mycobacterium tuberculosis , Células RAW 264.7

RESUMO

BACKGROUND: Different organic and inorganic bedding materials can be used in dairy farms. Among organic materials, there is an increasing interest in alternative substrates based on recycled manure solids (RMS). Microbiological analyses are crucial to monitor the microbial load and evaluate the presence of pathogens impacting animal welfare and health. However, logistic factors may hamper the possibility of immediately sending fresh samples to the laboratory, requiring storage in cooled conditions before analysis. METHODS: We assessed the impact of sample refrigeration and freezing of different organic and inorganic bedding substrates including separated raw manure solids (SRMS), anaerobically digested manure solids (ADMS), and new sand (NS), on the total bacterial count (TBC) and on different microbial classes. RESULTS: The TBC was higher in fresh NS and ADMS than in refrigerated and frozen samples of the same substrates; in addition, the TBC of ADMS was higher in refrigerated than frozen samples. The TBC of SRMS did not change significantly with refrigeration and freezing. Freezing reduced the total Gram-negative bacterial count more than refrigeration in all substrates. In fresh NS, Gram-negatives were higher than in both refrigerated and frozen NS. Escherichia coli counts were significantly lower in frozen than in refrigerated SRMS. However, both refrigeration and freezing of ADMS resulted in no E. coli growth. The coliform counts were also lower in frozen than refrigerated NS and SRMS. Frozen NS and ADMS showed lower counts compared to refrigeration for Gram-negative bacteria other than E. coli and coliforms. On the other hand, cold storage did not significantly impact the streptococci and streptococcus-like organisms (SSLO) count of all evaluated bedding substrates. CONCLUSION: Refrigeration and freezing affect the bacteriological results of bedding substrates, with freezing generally leading to lower counts than refrigeration. Whenever possible, preference should be given to analyzing fresh bedding samples, however, when necessary, refrigeration would be recommended over freezing, while acknowledging that the measured bacterial load might underestimate the actual microbial content.

Assuntos

Carga Bacteriana , Indústria de Laticínios , Congelamento , Esterco , Refrigeração , Animais , Bovinos , Esterco/microbiologia , Feminino , Abrigo para Animais , Bactérias/isolamento & purificação , Bactérias/classificação

RESUMO

BACKGROUND: Nocardia, a rare but potentially fatal pathogen, can induce systemic infections with diverse manifestations. This study aimed to investigate the tissue and organ damage caused by Nocardia farcinica (N. farcinica) in mice via different infection routes, evaluate the resulting host immune responses, and assess its invasiveness in brain tissue. METHODS: BALB/c mice were infected with N. farcinica through intranasal, intraperitoneal, and intravenous routes (doses: 1 × 10^8, 1 × 10^7, 1 × 10^7 CFU in 50 µl PBS). Over a 7-day period, body temperature, weight, and mortality were monitored, and samples were collected for histopathological analysis and bacterial load assessment. Serum was isolated for cytokine detection via ELISA. For RNA-seq analysis, mice were infected with 1 × 107 CFU through three infection routes, after which brain tissue was harvested. RESULTS: Intraperitoneal and intravenous N. farcinica infections caused significant clinical symptoms, mortality, and neural disruption in mice, resulting in severe systemic infection. Conversely, intranasal infection primarily affected the lungs without causing significant damage to other organs. Intraperitoneal and intravenous infections significantly increased serum cytokines, particularly TNF-α and IFN-γ. RNA-seq analysis of brains from intravenously infected mice revealed significant differential gene expression, whereas the intranasal and intraperitoneal routes showed limited differences (only three genes). The enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in the intravenous group were primarily related to immune processes. CONCLUSION: The study demonstrated that intravenous N. farcinica infection induces significant clinical symptoms, triggers an inflammatory response, damages multiple organs, and leads to systemic infections.

Assuntos

Encéfalo , Citocinas , Camundongos Endogâmicos BALB C , Nocardiose , Nocardia , Animais , Nocardia/genética , Nocardiose/microbiologia , Nocardiose/imunologia , Camundongos , Citocinas/sangue , Feminino , Encéfalo/microbiologia , Encéfalo/patologia , Pulmão/microbiologia , Pulmão/patologia , Modelos Animais de Doenças , Carga Bacteriana

RESUMO

OBJECTIVE: This study aims to analyse the association between the baseline microbial load of selected periodontopathogenic bacteria collected from gingival crevicular fluid (GCF) and the primary outcome of steps I and II therapy. MATERIALS AND METHODS: 222 patients with stage III periodontitis were included into this retrospective analysis that received steps 1 and 2 periodontal therapy without adjunctive systemic antibiotics. Baseline GCF samples were quantitatively analysed using ELISA-based kits for levels of periodontopathogens (Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Treponema denticola (Td), and Tannerella forsythia (Tf)) and associated with the primary therapy outcome using a "treat-to-target" therapy endpoint (TE) defined as ≤ 4 sites with PD ≥ 5 mm six months after therapy. RESULTS: 38.2% of the patients achieved TE. Patients failing to achieve TE revealed significantly increased levels of Pg, Fn, and Tf at baseline (Pg: p = 0.010, Fn: p = 0.008 Tf: p = 0.004). Multivariate binary logistic regression adjusted for sex, mean probing depth, diabetes, and current smoking status showed an independent relationship between Tf and the TE (aOR 2.570, p = 0.023). CONCLUSION: Increased microbial load is associated with decreased responsiveness to therapy. The findings suggest that specifically baseline Tf levels are associated with poorer treatment outcomes and might improve the accuracy of periodontal diagnosis. CLINICAL RELEVANCE: The findings of this study support the concept of a critical biomass that is sufficient to induce and maintain an immune response within the periodontal pocket, which ultimately leads to irreversible tissue destruction. However, calculating this level in advance may serve as an early indicator for intervention. KEY FINDING: Baseline Tannerella forsythia levels are associated with poorer treatment outcome.

Assuntos

Biomarcadores , Líquido do Sulco Gengival , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Líquido do Sulco Gengival/microbiologia , Líquido do Sulco Gengival/química , Resultado do Tratamento , Biomarcadores/análise , Ensaio de Imunoadsorção Enzimática , Carga Bacteriana , Adulto , Treponema denticola/isolamento & purificação , Porphyromonas gingivalis/isolamento & purificação , Fusobacterium nucleatum/isolamento & purificação , Tannerella forsythia/isolamento & purificação , Periodontite/microbiologia , Periodontite/terapia , Aggregatibacter actinomycetemcomitans/isolamento & purificação , Prevotella intermedia/isolamento & purificação

RESUMO

BACKGROUND: Biofilm formation is an essential virulence factor that creates a highly protected growth mode for Staphylococcus aureus (S. aureus) to survive in any hostile environment. Antibiotic sub-minimal inhibitory concentration (sub-MIC) may modulate the biofilm formation ability of bacterial pathogens, thereby affecting bacterial pathogenesis and infection outcomes. Intense antimicrobial therapy to treat biofilm-associated infections can control the pathogenic infection aggravation but cannot guarantee its complete eradication. OBJECTIVE: This study aimed to assess the sub-MICs effect of 5 different antimicrobial classes on biofilm-forming capacity among Staphylococcus aureus clinical isolates using three different biofilm quantitation techniques. METHODS: In this study, the effects of 5 different antimicrobial agents, namely, azithromycin, gentamicin, ciprofloxacin, doxycycline, and imipenem, at sub-MICs of 12.5%, 25%, and 50% were tested on 5 different clinical isolates of S. aureus. The biofilms formed in the absence and presence of different antimicrobial sub-MICs were then assessed using the following three different techniques: the crystal violet (CV) staining method, the quantitative PCR (qPCR) method, and the spread plate method (SPM). RESULTS: Biofilm formation was significantly induced in 64% of the tested conditions using the CV technique. On the other hand, the qPCR quantifying the total bacterial count and the SPM quantifying the viable bacterial count showed significant induction only in 24% and 17.3%, respectively (Fig. 1). The difference between CV and the other techniques indicates an increase in biofilm biomass without an increase in bacterial growth. As expected, sub-MICs did not reduce the viable cell count, as shown by the SPM. The CV staining method revealed that sub-MICs of imipenem and ciprofloxacin had the highest significance rate (80%) showing an inductive effect on the biofilm development. On the other hand, doxycycline, azithromycin, and gentamicin displayed lower significance rates of 73%, 53%, and 47%, respectively. CONCLUSION: Exposure to sub-MIC doses of antimicrobial agents induces the biofilm-forming capacity of S. aureus via increasing the total biomass without significantly affecting the bacterial growth of viable count.

Assuntos

Antibacterianos , Biofilmes , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas , Staphylococcus aureus , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Antibacterianos/farmacologia , Humanos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Carga Bacteriana , Ciprofloxacina/farmacologia , Gentamicinas/farmacologia

RESUMO

In scenarios where yeast and bacterial cells coexist, it is of interest to simultaneously quantify the concentrations of both cell types, since traditional methods used to determine these concentrations individually take more time and resources. Here, we compared different methods for quantifying the fuel ethanol Saccharomyces cerevisiae PE-2 yeast strain and cells from the probiotic Lactiplantibacillus plantarum strain in microbial suspensions. Individual suspensions were prepared, mixed in 1:1 or 100:1 yeast-to-bacteria ratios, covering the range typically encountered in sugarcane biorefineries, and analyzed using bright field microscopy, manual and automatic Spread-plate and Drop-plate counting, flow cytometry (at 1:1 and 100:1 ratios), and a Coulter Counter (at 1:1 and 100:1 ratios). We observed that for yeast cell counts in the mixture (1:1 and 100:1 ratios), flow cytometry, the Coulter Counter, and both Spread-plate options (manual and automatic CFU counting) yielded statistically similar results, while the Drop-plate and microscopy-based methods gave statistically different results. For bacterial cell quantification, the microscopy-based method, Drop-plate, and both Spread-plate plating options and flow cytometry (1:1 ratio) produced no significantly different results (p > .05). In contrast, the Coulter Counter (1:1 ratio) and flow cytometry (100:1 ratio) presented results statistically different (p < .05). Additionally, quantifying bacterial cells in a mixed suspension at a 100:1 ratio wasn't possible due to an overlap between yeast cell debris and bacterial cells. We conclude that each method has limitations, advantages, and disadvantages. ONE-SENTENCE SUMMARY: This study compares methods for simultaneously quantifying yeast and bacterial cells in a mixed sample, highlighting that in different cell proportions, some methods cannot quantify both cell types and present distinct advantages and limitations regarding time, cost, and precision.

Assuntos

Microbiologia Industrial , Saccharomyces cerevisiae , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/citologia , Microbiologia Industrial/métodos , Citometria de Fluxo/métodos , Contagem de Colônia Microbiana/métodos , Carga Bacteriana/métodos , Saccharum/microbiologia , Microscopia/métodos

RESUMO

Milk is an essential part of the human diet and is a nutrient-rich food that improves nutrition and food security. The aim of this study was to determine the presence and concentration of aflatoxin M1 (AFM1), adulterants, microbial loads, and physicochemical properties of raw cow's milk (CM) in Nekemte City, Ethiopia. A total of 12 samples of fresh CM were purposefully collected from four kebeles in the city (Bake Jama, Burka Jato, Cheleleki, and Bakanisa Kese) based on the potential of each milk production and distributor site. The AFM1 concentration was determined by high-performance liquid chromatography (HPLC) with a Sigma-Aldrich standard (St. Louis, MO, USA). The concentrations of AFM1 in Bake Jama, Burka Jato, Cheleleki, and Bakanisa Kese were found to be 0.01-0.03 g/L, 0.31-0.35 g/L, 0.19-0.21 g/L, and 0.04-0.07 g/L, respectively. The concentrations of AFM1 in the present study varied significantly (p < 0.05) and ranged from 0.01 g/L to 0.35 g/L. These results show that of the 12 samples tested, all were positive for AFM1 and contaminated to varying degrees. The results of this study also revealed that the concentration of AFM1 in 7 (58%) of the 12 milk samples was above the European Union's (EU) maximum tolerance limit (0.05 g/L). The present study also revealed that of the investigated adulterants, only the addition of water had positive effects on three milk samples, while the remaining adulterants were not detected in any of the milk samples. The total bacterial count (TBC) and total coliform count (TCC) were significantly (p < 0.05) different and ranged from 5.53 to 6.82 log10cfumL-1 and from 4.21 to 4.74 log10cfumL-1, respectively. The physicochemical properties of the milk samples in the present study were significantly (p < 0.05) different and ranged from 2.8% to 5.75% fat, 7.03% to 9.75% solid-not-fat (SNF), 2.35% to 3.61% protein, 3.33% to 5.15% lactose, 11.54% to 13.69% total solid, 0.16% to 0.18% titratable acid, 26.7 to 32.1°C, 6.35 to 6.55 pH, and 1.027 to 1.030 specific gravity. The physicochemical parameters of the raw milk in the study area met the required quality standards. Hence, further studies are required to determine the extent of the problem and the factors associated with high levels of AFM1 in raw milk in the study areas, including the detection of aflatoxin B1 (AFB1) in animal feed.

Assuntos

Aflatoxina M1 , Contaminação de Alimentos , Leite , Etiópia , Aflatoxina M1/análise , Leite/química , Leite/microbiologia , Animais , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Bovinos , Cromatografia Líquida de Alta Pressão , Carga Bacteriana

RESUMO

Objective: Antimicrobial resistance is an emerging problem and multi-drug resistant (MDR) Klebsiella pneumoniae (K. pneumoniae) represents an enormous risk of failing therapy in hospital-acquired pneumonia. The current study aimed to determine the immunomodulatory effect of topical flagellin in addition to antibiotic treatment during respiratory infection evoked by hypervirulent antibiotic-susceptible and antibiotic-resistant K. pneumoniae in mice. Methods: C57BL6 mice were inoculated intranasally with hypervirulent K. pneumoniae (K2:O1) which was either antibiotic-susceptible or multi-drug resistant. Six hours after infection, mice were treated with antibiotics intraperitoneally and flagellin or vehicle intranasally. Mice were sacrificed 24 hours after infection. Samples were analyzed for bacterial loads and for inflammatory and coagulation markers. Results: Flagellin therapy induced neutrophil influx in the lung during antibiotic-treated pneumonia evoked by either antibiotic-susceptible or -resistant K. pneumoniae. The pulmonary neutrophil response was matched by elevated levels of neutrophil-attracting chemokines, neutrophil degranulation products, and local coagulation activation. The combined therapy of effective antibiotics and flagellin did not impact K. pneumoniae outgrowth in the lung, but decreased bacterial counts in distant organs. Neutrophil depletion abrogated the flagellin-mediated effect on bacterial dissemination and local coagulation responses. Conclusion: Topical flagellin administration as an adjunctive to antibiotic treatment augments neutrophil responses during pneumonia evoked by MDR-K. pneumoniae, thereby reducing bacterial dissemination to distant organs.

Assuntos

Farmacorresistência Bacteriana Múltipla , Flagelina , Infecções por Klebsiella , Klebsiella pneumoniae , Camundongos Endogâmicos C57BL , Neutrófilos , Animais , Flagelina/imunologia , Flagelina/administração & dosagem , Neutrófilos/imunologia , Neutrófilos/efeitos dos fármacos , Infecções por Klebsiella/imunologia , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Camundongos , Pulmão/imunologia , Pulmão/microbiologia , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Administração Tópica , Modelos Animais de Doenças , Infiltração de Neutrófilos/efeitos dos fármacos , Carga Bacteriana/efeitos dos fármacos

RESUMO

BACKGROUND: Environmental bacteria in animal healthcare facilities may constitute a risk for healthcare-associated infections (HAI). Knowledge of the bacterial microflora composition and factors influencing the environmental bacterial load can support tailored interventions to lower the risk for HAI. The aims of this study were to: (1) quantify and identify environmental bacteria in one operating room (OR) and one ultrasound room (UR) in a small animal hospital, (2) compare the bacterial load to threshold values suggested for use in human healthcare facilities, (3) characterise the genetic relationship between selected bacterial species to assess clonal dissemination, and (4) investigate factors associated with bacterial load during surgery. Settle plates were used for passive air sampling and dip slides for surface sampling. Bacteria were identified by Matrix Assisted Laser Desorption-Time Of Flight. Antimicrobial susceptibility was determined by broth microdilution. Single nucleotide polymorphism-analysis was performed to identify genetically related isolates. Linear regression was performed to analyse associations between observed explanatory factors and bacterial load. RESULTS: The bacterial load on settle plates and dip slides were low both in the OR and the UR, most of the samples were below threshold values suggested for use in human healthcare facilities. All settle plates sampled during surgery were below the threshold values suggested for use in human clean surgical procedures. Staphylococcus spp. and Micrococcus spp. were the dominating species. There was no indication of clonal relationship among the sequenced isolates. Bacteria carrying genes conveying resistance to disinfectants were revealed. Air change and compliance with hygiene routines were sufficient in the OR. No other factors possibly associated with the bacterial load were identified. CONCLUSIONS: This study presents a generally low bacterial load in the studied OR and UR, indicating a low risk of transmission of infectious agents from the clinical environment. The results show that it is possible to achieve bacterial loads below threshold values suggested for use in human healthcare facilities in ORs in small animal hospitals and thus posing a reduced risk of HAI. Bacteria carrying genes conveying resistance to disinfectants indicates that resistant bacteria can persist in the clinical environment, with increased risk for HAI.

Assuntos

Carga Bacteriana , Hospitais Veterinários , Animais , Suécia , Carga Bacteriana/veterinária , Bactérias/isolamento & purificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/classificação , Ultrassonografia/veterinária , Infecção Hospitalar/veterinária , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/microbiologia , Salas Cirúrgicas , Antibacterianos/farmacologia

RESUMO

PURPOSE: To evaluate the antimicrobial effect of a new active oxygen fluid (Blue®m) as a root canal irrigant against Enterococcus faecalis compared to sodium hypochlorite (NaOCl). MATERIAL AND METHODS: Forty-five extracted single-canaled human teeth were selected, received root canal preparation, autoclaved, and contaminated with Enterococcus faecalis. The specimens were randomly allocated into three groups: Group (A) served as the negative control, receiving irrigation with saline (n = 15); Group (B) was irrigated with 5.25% NaOCl (n = 15); and Group (C) was irrigated with 10 mL of Blue®m (n = 15). Microbial sampling from the root canals was performed before and after irrigation. The difference between the pre-irrigation and post-irrigation colony-forming units (CFU/mL) was calculated. The data was analysed using a one-way ANOVA followed by post-hoc Tukey tests. The significance level was set at 5%. RESULTS: Blue®m statistically significantly reduced the bacterial load compared to saline (p = 0.009), but NaOCl was most effective, outperforming both (p 0.0001). CONCLUSION: Irrigation with Blue®m demonstrated antibacterial efficacy against Enterococcus faecalis, but it was not as effective as NaOCl.

Assuntos

Cavidade Pulpar , Enterococcus faecalis , Irrigantes do Canal Radicular , Hipoclorito de Sódio , Enterococcus faecalis/efeitos dos fármacos , Humanos , Irrigantes do Canal Radicular/farmacologia , Hipoclorito de Sódio/farmacologia , Cavidade Pulpar/microbiologia , Carga Bacteriana/efeitos dos fármacos , Preparo de Canal Radicular/métodos , Teste de Materiais , Contagem de Colônia Microbiana

RESUMO

Tuberculosis (TB) has been and still is a global emergency for centuries. Prevention of disease through vaccination would have a major impact on disease prevalence, but the only available current vaccine, BCG, has insufficient impact. In this article, a novel subunit vaccine against TB was developed, using the Ag85B-ESAT6-Rv2034 fusion antigen, two adjuvants - CpG and MPLA, and a cationic pH-sensitive liposome as a delivery system, representing a new TB vaccine delivery strategy not previously reported for TB. In vitro in human dendritic cells (DCs), the adjuvanted formulation induced a significant increase in the production of (innate) cytokines and chemokines compared to the liposome without additional adjuvants. In vivo, the new vaccine administrated subcutaneously significantly reduced Mycobacterium tuberculosis (Mtb) bacterial load in the lungs and spleens of mice, significantly outperforming results from mice vaccinated with the antigen mixed with adjuvants without liposomes. In-depth analysis underpinned the vaccine's effectiveness in terms of its capacity to induce polyfunctional CD4+ and CD8+ T-cell responses, both considered essential for controlling Mtb infection. Also noteworthy was the differential abundance of various CD69+ B-cell subpopulations, which included IL17-A-producing B-cells. The vaccine stimulated robust antigen-specific antibody titers, further extending its potential as a novel protective agent against TB.

Assuntos

Adjuvantes Imunológicos , Lipossomos , Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose , Vacinas de Subunidades Antigênicas , Animais , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Mycobacterium tuberculosis/imunologia , Camundongos , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Humanos , Feminino , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Concentração de Íons de Hidrogênio , Tuberculose/prevenção & controle , Tuberculose/imunologia , Camundongos Endogâmicos C57BL , Células Dendríticas/imunologia , Cátions , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/administração & dosagem , Citocinas/metabolismo , Linfócitos T CD8-Positivos/imunologia , Pulmão/imunologia , Pulmão/microbiologia , Linfócitos T CD4-Positivos/imunologia , Carga Bacteriana

RESUMO

Epidemiological studies report the impact of co-infection with pneumococcus and respiratory viruses upon disease rates and outcomes, but their effect on pneumococcal carriage acquisition and bacterial load is scarcely described. Here, we assess this by combining natural viral infection with controlled human pneumococcal infection in 581 healthy adults screened for upper respiratory tract viral infection before intranasal pneumococcal challenge. Across all adults, respiratory syncytial virus (RSV) and rhinovirus asymptomatic infection confer a substantial increase in secondary infection with pneumococcus. RSV also has a major impact on pneumococcal density up to 9 days post challenge. We also study rates and kinetics of bacterial shedding through the nose and oral route in a subset. High levels of pneumococcal colonization density and nasal inflammation are strongly correlated with increased odds of nasal shedding as opposed to cough shedding. Protection against respiratory viral infections and control of pneumococcal density may contribute to preventing pneumococcal disease and reducing bacterial spread.

Assuntos

Derrame de Bactérias , Portador Sadio , Coinfecção , Infecções por Picornaviridae , Infecções Pneumocócicas , Infecções por Vírus Respiratório Sincicial , Rhinovirus , Streptococcus pneumoniae , Humanos , Rhinovirus/fisiologia , Adulto , Infecções Pneumocócicas/microbiologia , Infecções por Picornaviridae/virologia , Infecções por Picornaviridae/microbiologia , Portador Sadio/microbiologia , Masculino , Feminino , Infecções por Vírus Respiratório Sincicial/virologia , Coinfecção/microbiologia , Coinfecção/virologia , Adulto Jovem , Carga Bacteriana , Pessoa de Meia-Idade , Inflamação , Vírus Sinciciais Respiratórios/fisiologia , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Adolescente , Nasofaringe/microbiologia , Nasofaringe/virologia

RESUMO

OBJECTIVES: Pharmacodynamic parameters evaluated under conditions that simulate an infection site volume and microbial load might reveal hidden risks of resistance selection and subsequent treatment failure. The study aimed to investigate the predictive potential of MICs determined at various conditions on the antimicrobial effect and emergence of resistance. METHODS: We assessed meropenem MICs (microdilution: 0.2 mL, 5 × 105 cfu/mL; macrodilution: 2 mL, 5 × 105 cfu/mL), MICHVs (220 mL, 5 × 105 cfu/mL), MICHIs (0.2 mL, 5 × 107 cfu/mL) and MICHVIs (220 mL, 5 × 107 cfu/mL) for five Klebsiella pneumoniae strains and analysed these values alongside the results of experiments in a dynamic in vitro model. A clinically relevant meropenem dosing regimen was simulated and the starting bacterial inocula were 106 and 108 cfu/mL. RESULTS: The effectiveness of meropenem agreed with MICHVs for the 106 cfu/mL inoculum and with MICHIs or MICHVIs for the 108 cfu/mL inoculum. Strains characterized as resistant according to these values grew during meropenem exposure, and resistant mutants were selected. CONCLUSIONS: Our results suggest that MICHV-based parameters may be suitable for predicting antibacterial effects and the risk of resistance development when the inoculum is 106 cfu/mL, while MICHI- or MICHVI-based parameters are suitable for these purposes when the inoculum is 108 cfu/mL. Also, the correlation between resistance selection and the MICHI-based parameter was as high as one that corresponds with a mutant prevention concentration (MPC)-based parameter; this suggests that the MPC can be replaced by the more easily determined alternative parameter MICHI.

Assuntos

Antibacterianos , Klebsiella pneumoniae , Meropeném , Testes de Sensibilidade Microbiana , Meropeném/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Antibacterianos/farmacologia , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/tratamento farmacológico , Tienamicinas/farmacologia , Farmacorresistência Bacteriana , Carga Bacteriana

RESUMO

BACKGROUND: Studying long-term treatment outcomes of TB is time-consuming and impractical. Early and reliable biomarkers reflecting treatment response and capable of predicting long-term outcomes are urgently needed. OBJECTIVES: To develop a pharmacometric multistate model to evaluate the link between potential predictors and long-term outcomes. METHODS: Data were obtained from two Phase II clinical trials (TMC207-C208 and TMC207-C209) with bedaquiline on top of a multidrug background regimen. Patients were typically followed throughout a 24 week investigational treatment period plus a 96 week follow-up period. A five-state multistate model (active TB, converted, recurrent TB, dropout, and death) was developed to describe observed transitions. Evaluated predictors included patient characteristics, baseline TB disease severity and on-treatment biomarkers. RESULTS: A fast bacterial clearance in the first 2 weeks and low TB bacterial burden at baseline increased probability to achieve conversion, whereas patients with XDR-TB were less likely to reach conversion. Higher estimated mycobacterial load at the end of 24 week treatment increased the probability of recurrence. At 120 weeks, the model predicted 55% (95% prediction interval, 50%-60%), 6.5% (4.2%-9.0%) and 7.5% (5.2%-10%) of patients in converted, recurrent TB and death states, respectively. Simulations predicted a substantial increase of recurrence after 24 weeks in patients with slow bacterial clearance regardless of baseline bacterial burden. CONCLUSIONS: The developed multistate model successfully described TB treatment outcomes. The multistate modelling framework enables prediction of several outcomes simultaneously, and allows mechanistically sound investigation of novel promising predictors. This may help support future biomarker evaluation, clinical trial design and analysis.

Assuntos

Antituberculosos , Diarilquinolinas , Tuberculose Pulmonar , Humanos , Antituberculosos/uso terapêutico , Antituberculosos/farmacocinética , Resultado do Tratamento , Feminino , Diarilquinolinas/uso terapêutico , Masculino , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/mortalidade , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Mycobacterium tuberculosis/efeitos dos fármacos , Carga Bacteriana , Modelos Estatísticos , Idoso , Recidiva

RESUMO

OBJECTIVES: The aim of this study was to quantitatively and comprehensively investigate the combined effects of arginine and fluoride on the suppression of pathogenicity using an in situ biofilm model and next-generation sequencing (NGS). METHODS: Using the in situ model, dental biofilms were formed and the viable bacterial counts and arginine activity in the arginine- and fluoride-containing dentifrice and control groups were measured. We also compared their effects on the bacterial microbiota and predictive functional factors in the control, arginine (arg), and arginine + fluoride (argF) groups using NGS analysis. RESULTS: Compared to the control treatment, the use of 8 % arginine and 1450 ppm fluoride toothpaste resulted in significantly high oral NH4+ concentrations without affecting the number of viable bacteria (P < 0.05). NGS analysis revealed that the oral microbiota of the control, arg, and argF groups were significantly different. Heat map analysis of the predicted functional factors revealed that the arg group had different properties from the other groups and activated specific substrate metabolic pathways; contrastingly, argF treatment inhibited the activity of these pathways and prevented an increase in the abundance of bacterial genera that utilize substrates such as sucrose, suggesting the synergistic effect of arginine and fluoride. CONCLUSIONS: This study indicates that the combination of arginine and fluoride has a synergistic effect on the bacterial microbiota and pathogenicity of dental biofilms compared with arginine alone. CLINICAL SIGNIFICANCE: Our findings suggest that the combination of arginine and fluoride could be used as an effective prebiotic and may inhibit the growth of bacteria associated with dental diseases.

Assuntos

Arginina , Biofilmes , Cariostáticos , Fluoretos , Cremes Dentais , Arginina/farmacologia , Biofilmes/efeitos dos fármacos , Humanos , Fluoretos/farmacologia , Cremes Dentais/farmacologia , Cariostáticos/farmacologia , Sinergismo Farmacológico , Dentifrícios/farmacologia , Carga Bacteriana/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Bactérias/classificação , Microbiota/efeitos dos fármacos , Placa Dentária/microbiologia , Adulto , Masculino , Adulto Jovem , Sequenciamento de Nucleotídeos em Larga Escala , Saliva/microbiologia

RESUMO

Salmonella enteretidis (SE) has a great propensity to translocate from the cecum into internal organs such as the spleen and liver. However, a major concern is the ability of SE to colonize the ovaries. This study aimed to evaluate the efficacy of cell walls from Saccharomyces cerevisiae to control the Salmonella load in the ceca and ovaries of commercial layer pullets. Ten-week-old layer pullets were divided into 2 groups: one group was fed a control diet with commercial feed without additives, and another group was fed the same diet supplemented with 0.5 kg/metric ton of yeast cell walls (YCWs). At 16 wk of age, the birds in both groups were challenged with 3.0 × 109 CFU/mL SE by oral gavage. The birds were euthanized on d 7 and 14 postchallenge to collect the ceca and ovaries for Salmonella load determination. The results demonstrated that there were no statistical differences in ovary SE infection rates. The trend in the prevalence of SE positivity in the ovaries was similar at 14 d, with 2.1% (YCW pullets) to 4.2% positive for the ovaries of the nontreated pullets. There was also no significant difference in the SE log10 MPN/gram between the YCW and the control groups. In the ceca, the high level of SE (3.0 × 109 cfu/pullet), which results in ovarian transmission, causes high intestinal tract inflammation. There was a significant difference in the prevalence of SE in the ceca at 7 d postchallenge but not at 14 d postchallenge. In conclusion, the reduction in Salmonella load observed in the ceca on d 7 in this study shows the potential of YCW supplementation for reducing Salmonella colonization in poultry.

Assuntos

Ração Animal , Ceco , Parede Celular , Galinhas , Dieta , Suplementos Nutricionais , Ovário , Doenças das Aves Domésticas , Saccharomyces cerevisiae , Salmonelose Animal , Animais , Feminino , Ração Animal/análise , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Ovário/microbiologia , Salmonelose Animal/microbiologia , Salmonelose Animal/prevenção & controle , Ceco/microbiologia , Parede Celular/química , Dieta/veterinária , Saccharomyces cerevisiae/fisiologia , Suplementos Nutricionais/análise , Carga Bacteriana/veterinária

RESUMO

We report here on the characterisation in mice of a noninvasive bacille Calmette-Guérin (BCG) skin challenge model for assessing tuberculosis (TB) vaccine efficacy. Controlled human infection models (CHIMs) are valuable tools for assessing the relevant biological activity of vaccine candidates, with the potential to accelerate TB vaccine development into the clinic. TB infection poses significant constraints on the design of a CHIM using the causative agent Mycobacterium tuberculosis (Mtb). A safer alternative is a challenge model using the attenuated vaccine agent Mycobacterium bovis BCG as a surrogate for Mtb, and intradermal (skin) challenge as an alternative to pulmonary infection. We have developed a unique noninvasive imaging system based on fluorescent reporters (FluorBCG) to quantitatively measure bacterial load over time, thereby determining a relevant biological vaccine effect. We assessed the utility of this model to measure the effectiveness of 2 TB vaccines: the currently licenced BCG and a novel subunit vaccine candidate. To assess the efficacy of the skin challenge model, a nonlinear mixed-effects models was built describing the decline of fluorescence over time. The model-based analysis identified that BCG vaccination reduced the fluorescence readout of both fluorophores compared to unvaccinated mice (p < 0.001). However, vaccination with the novel subunit candidate did not alter the fluorescence decline compared to unvaccinated mice (p > 0.05). BCG-vaccinated mice that showed the reduced fluorescent readout also had a reduced bacterial burden in the lungs when challenged with Mtb. This supports the fluorescence activity in the skin as a reflection of vaccine induced functional pulmonary immune responses. This novel noninvasive approach allows for repeated measurements from the challenge site, providing a dynamic readout of vaccine induced responses over time. This BCG skin challenge model represents an important contribution to the ongoing development of controlled challenge models for TB.

Assuntos

Vacina BCG , Modelos Animais de Doenças , Mycobacterium tuberculosis , Pele , Animais , Vacina BCG/imunologia , Camundongos , Mycobacterium tuberculosis/imunologia , Feminino , Pele/microbiologia , Pele/imunologia , Tuberculose/prevenção & controle , Tuberculose/imunologia , Tuberculose/microbiologia , Eficácia de Vacinas , Camundongos Endogâmicos C57BL , Carga Bacteriana , Vacinas contra a Tuberculose/imunologia , Vacinação/métodos , Mycobacterium bovis/imunologia , Humanos

RESUMO

Despite the high mortality rate, sepsis lacks specific and effective treatment options. Conventional antibiotics, such as TIENAM (TIE; imipenem and cilastatin sodium for injection), face challenges owing to the emergence of bacterial resistance, which reduces their effectiveness and causes adverse effects. Addressing resistance and judicious drug use is crucial. Our research revealed that aloin (Alo) significantly boosts survival rates and reduces inflammation and bacterial load in mice with sepsis, demonstrating strong antimicrobial activity. Using a synergistic Alo + TIE regimen in a cecal ligation and puncture (CLP)-induced sepsis model, we observed a remarkable increase in survival rates from 10 % to 75 % within 72 h compared with the CLP group alone. This combination therapy also modulated inflammatory markers interleukin (IL)-6, IL-1ß, and tumor necrosis factor (TNF)-α, mitigated tissue damage, regulated immune cells by lowering NK, activated CD8+ and CD4+ T cells while increasing peritoneal macrophages, and decreased the bacterial load in the peritoneal cavity. We noted a significant shift in the abdominal cavity microbiota composition post-treatment, with a decrease in harmful bacteria, such as Lachnospiraceae_NK4A136_group, Klebsiella, Bacillus, and Escherichia, and an increase in beneficial bacteria, such as Lactobacillus and Mucispirillum. Our study emphasizes the efficacy of combining Alo with TIE to combat sepsis, and paves the way for further investigations and potential clinical applications aiming to overcome the limitations of TIE and enhance the therapeutic prospects of Alo.

Assuntos

Ceco , Emodina , Camundongos Endogâmicos C57BL , Sepse , Animais , Sepse/tratamento farmacológico , Sepse/imunologia , Sepse/microbiologia , Emodina/farmacologia , Emodina/uso terapêutico , Emodina/análogos & derivados , Ceco/cirurgia , Ceco/microbiologia , Camundongos , Masculino , Ligadura , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Punções , Modelos Animais de Doenças , Imipenem/uso terapêutico , Imipenem/farmacologia , Citocinas/metabolismo , Quimioterapia Combinada , Microbioma Gastrointestinal/efeitos dos fármacos , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Microbiota/efeitos dos fármacos , Carga Bacteriana/efeitos dos fármacos

RESUMO

BACKGROUND: Tuberculosis (TB) and intestinal helminths are diseases that pose a dual burden on public health in low-income countries. Previous studies have shown that helminths can affect the shedding of bacteria or the bacterial load in the sputum of active TB patients. However, there is limited information on bacterial load in TB patients with helminth infections. OBJECTIVE: This study aimed to compare bacterial load in helminths-infected and non-infected pulmonary tuberculosis patients at selected public health facilities in Jimma zone, Oromia, Ethiopia. METHODS: The study was conducted in Jimma Zone, Oromia, Ethiopia. A facility-based comparative cross-sectional study was employed from August 01, 2020, to January 2021. A total of 124 (55 intestinal helminths-infected and 69 non-infected) newly diagnosed smear-positive pulmonary tuberculosis (PTB) patients were included in the study. A convenience sampling technique was employed to recruit study participants, and a semi-structured questionnaire was used to collect data regarding socio-demographic characteristics and possible risk factors for intestinal helminths co-infection. Stool examination was performed using both wet mount and Kato Katz technique. Additionally, weight and height measurements, sputum, and blood samples were taken to determine body mass index, bacilli load, and diabetic mellitus, respectively. Data were entered into Epi-Data software version 3.1 and analyzed using Statistical Packages for Social Sciences (SPSS) Version 25. A statistically significant difference was defined as a P-value of less than 0.05. RESULTS: Intestinal helminths reduced bacilli load 3 times more than intestinal helminths non-infected PTB (AOR = 3.44; 95% CI; 1.52, 7.79; P = 0.003) However, diabetes mellitus, HIV, drinking alcohol and cigarette smoking were not associated with bacilli load. The rate of co-infection TB with intestinal helminths was 44%. The three most prevalent parasites detected were Trichuris trichiura 29 (66%), hookworm 19 (43%), and Ascaris lumbricoides 11(25%)). Among co-infected patients about 36 (81.8%) had a single parasite infection, and 19 (43.2%) had multiple infections. A body mass index < 18.5 (AOR = 3.26; 95% CI; 1.25, 8.56;P = 0.016) and untrimmed fingernail status (AOR = 3.63; 95%CI;1.32,9.93;P = 0.012) were significantly associated with PTB- intestinal helminth -co-infection. CONCLUSION: Helminth infection was associated with a lower bacilli load compared to helmenths non-infected PTB. The rate of co-infection TB with intestinal helminths was 44%. Trichuris trichiura was the most prevalent helminth. Untrimmed fingernail and a body mass index were associated with PTB-intestinal helminth co-infection.

Assuntos

Coinfecção , Helmintíase , Enteropatias Parasitárias , Tuberculose Pulmonar , Humanos , Etiópia/epidemiologia , Estudos Transversais , Feminino , Masculino , Helmintíase/epidemiologia , Helmintíase/complicações , Helmintíase/parasitologia , Adulto , Coinfecção/epidemiologia , Coinfecção/parasitologia , Coinfecção/microbiologia , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/complicações , Enteropatias Parasitárias/parasitologia , Pessoa de Meia-Idade , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/complicações , Carga Bacteriana , Adulto Jovem , Helmintos/isolamento & purificação , Animais , Fezes/parasitologia , Fezes/microbiologia , Mycobacterium tuberculosis/isolamento & purificação , Escarro/microbiologia , Escarro/parasitologia , Adolescente , Instalações de Saúde/estatística & dados numéricos , Fatores de Risco , Saúde Pública

RESUMO

BACKGROUND: The spread of Carbapenemase-producing Organisms (CPO) remains a major threat globally. Within clinical settings, the existing method of determining gene load involves traditional culture to determine bacterial load and polymerase-chain-reaction-based Xpert Carba-R Assay to determine carbapenemase gene type. However, there is a need for a fast and accurate method of quantifying CPO colonisation to study the risk of persistent CPO carriage. OBJECTIVE: This study evaluated the accuracy of Xpert Carba-R Ct value in estimating carbapenamase producing bacterial loads in stool samples. METHODS: Stool samples were obtained from an ongoing study investigating the household transmission of CPO in Singapore. Stool samples lacking carbapenemase producing organisms were spiked with organism carrying a single carbapenemase gene (blaKPC, blaNDM, blaVIM, blaOXA-48(-like) or blaIMP-1) and serially diluted before being subjected to Xpert Carba-R assay and traditional culture. Standard curves with regression lines showing correlation between Ct values and plate counts were generated. The standard curves were validated with stool samples collected from patients. RESULTS: The limit of detection of blaNDM, blaKPC, and blaOXA-48 was approximately 103 cfu/mL, while that of blaIMP-1 and blaVIM was approximately 104 cfu/mL. Validation of the blaNDM and blaOXA-48 curves revealed average delta values of 0.56 log(cfu/mL) (95% CI 0.24-0.88) and 0.80 log(cfu/mL) (95% CI 0.53-1.07), respectively. CONCLUSIONS: Our validation data for stool positive for blaNDM and blaOXA-48-type suggests that bacterial loads can be estimated within a reasonable range of error.

Assuntos

Carga Bacteriana , Proteínas de Bactérias , Fezes , beta-Lactamases , beta-Lactamases/genética , Fezes/microbiologia , Humanos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo