We aimed to evaluate whether two commonly used PCR primers are effective to identify
P. endodontalis
and discriminate from other prevalent black-pigmented bacteria in apical periodontitis (AP). ...Endodontic canal samples from patients with asymptomatic AP (n = 20) were collected and cultured in anaerobiosis. Two primer sets to detect
P. endodontalis
were selected from the literature and first analyzed for their specificity
in silico
; and then tested on clinical isolates
in vitro
and finally, in apical exudates
ex vivo
. The identity
of P. endodontalis
was verified by PCR and Sanger sequencing with universal primers for bacterial V3–V6 regions 16S rDNA. Only one primer set showed specificity only for
P. endodontalis
clones in silico and also was specific for
P. endodontalis
in vitro
and
ex vivo
.
Background. Pneumocystis without obvious accompanying pathology is occasionally reported in autopsied infant lungs. Its prevalence and significance are unknown. Interestingly, this mild infection ...induces a strong activation of mucus secretion—related genes in young immunocompetent rodents that has not been explored in infants. Excess mucus is induced by multiple airway offenders through nonspecific pathways and would explain a cofactor role of Pneumocystis in respiratory disease. We undertook characterization of the prevalence of Pneumocystis and associated mucus in infant lungs. Methods. Samples from 128 infants (mean age, 101 days) who died suddenly and unexpectedly in Santiago during 1999–2004 were examined for Pneumocystis using nested polymerase chain reaction (nPCR) amplification of the P. jirovecii mtLSU ribosomal RNA gene and immunofluorescence microscopy (IF). Pneumocystis-negative infants 28 days and older and their age-closest positives were studied for MUC5AC expression and Pneumocystis burden by Western blot and quantitative PCR, respectively. Results. Pneumocystis DNA was detected by nPCR in 105 of the 128 infants (82.0%) and Pneumocystis organisms were visualized by IF in 99 (94.3%) of the DNA-positive infants. The infection was commonest at 3–4 months with 40 of 41 (97.6%) infants of that age testing positive. MUC5AC was significantly increased in Pneumocystis-positive tissue specimens (P = .013). Death was unexplained in 113 (88.3%) infants; Pneumocystis was detected in 95 (84.0%) of them vs 10 of 15 (66.7%) with explained death (P = .28). Conclusions. A highly focal Pneumocystis infection associated to increased mucus expression is almost universally present in the lungs of infants dying unexpectedly in the community regardless of autopsy diagnosis.
Salmonellosis is globally recognized as one of the leading causes of acute human bacterial gastroenteritis resulting from the consumption of animal-derived products, particularly those derived from ...the poultry and pig industry.
spp. is generally associated with self-limiting gastrointestinal symptoms, lasting between 2 and 7 days, which can vary from mild to severe. The bacteria can also spread in the bloodstream, causing sepsis and requiring effective antimicrobial therapy; however, sepsis rarely occurs. Salmonellosis control strategies are based on two fundamental aspects: (a) the reduction of prevalence levels in animals by means of health, biosecurity, or food strategies and (b) protection against infection in humans. At the food chain level, the prevention of salmonellosis requires a comprehensive approach at farm, manufacturing, distribution, and consumer levels. Proper handling of food, avoiding cross-contamination, and thorough cooking can reduce the risk and ensure the safety of food. Efforts to reduce transmission of
by food and other routes must be implemented using a One Health approach. Therefore, in this review we provide an update on
, one of the main zoonotic pathogens, emphasizing its relationship with animal and public health. We carry out a review on different topics about
and salmonellosis, with a special emphasis on epidemiology and public health, microbial behavior along the food chain, predictive microbiology principles, antimicrobial resistance, and control strategies.
Tetracyclines have a high resistance percentage in
spp. of both human and animal origin. Essential oils, such as cinnamon (
), clove (
), oregano (
), and red thyme (
), have shown bactericidal ...activity against this bacterium. However, in many cases, the minimum inhibitory concentration (MIC) exceeds the cytotoxicity limits. The objective of this study was to assess the in vitro efficacy of combining oxytetracycline with essential these oils against field multidrug-resistant (MDR)
strains. The MIC of each product was determined using the broth microdilution method. The interaction was evaluated using the checkerboard method, by means of the fractional inhibitory concentration index (FIC
) determination. The results showed a positive interaction (synergy and additivity) between oxytetracycline and the four oils tested, resulting in a reduction in both products' MICs by 2 to 4 times their initial value, in the case of oils, and by 2 to 1024 times in the case of the antibiotic. The combination of oxytetracycline and cinnamon achieved the best results (FIC
0.5), with a decrease in the antibiotic effective concentration to below the sensitivity threshold (MIC of the combined oxytetracycline 0.5 µg/mL). There was no antagonistic effect in any case, although differences in response were observed depending on the bacterial strain. The results of this study suggest that combining oxytetracycline with cinnamon oil could be an effective alternative for controlling tetracycline-resistant strains of
. However, its individual use should be further evaluated through in vitro susceptibility tests.
Tuberculosis-like lesions (TBL) in pigs have been associated with microorganisms other than mycobacteria. In this work a histopathological and microbiological evaluation of TBL in pigs is shown. A ...total of 352 samples belonging to 171 pigs totally condemned at slaughterhouse due to generalized TBL were sampled and selected for analysis. Pyogranulomatous (56.2%) and granulomatous lesions (20.2%) were observed in all analysed organs. Most of the granulomas observed in both lymph nodes and lungs belonged to more advanced stages of development (stages III and IV) whereas in the liver and the spleen most of lesions belonged to intermediate stages (stages II and III). Different microorganisms were simultaneously detected from TBL in the 42.7% of the animals. Mycobacterium tuberculosis complex (MTC) (38%), coryneform bacteria (40.3%) and streptococci (28.1%) were the main groups of microorganisms detected after bacteriological analysis, with Trueperella pyogenes and Streptococcus suis as the most frequently isolated species. Mycobacteria belonging to MTC were the most frequently detected pathogens in granulomatous and pyogranulomatous lesions in submandibular lymph nodes (32.7%) and coryneform bacteria were the microorganisms more frequently isolated from lungs (25.9%) and spleen samples (37.2%). These results may provide new insights into the pathogenesis and diagnosis of this pathology. The importance of coryneform bacteria and streptococci in such processes must be evaluated in future studies.
Aim
To determine the methylation pattern of TLR2 gene promoter and its association with the transcriptional regulation of periapical inflammatory and angiogenic responses in symptomatic and ...asymptomatic forms of apical periodontitis.
Methodology
In this cross‐sectional study, apical lesions were obtained from volunteers with asymptomatic apical periodontitis (AAP) (n = 17) and symptomatic apical periodontitis (SAP) (n = 17) scheduled for tooth extraction, and both total RNA and DNA were extracted. DNA was bisulfite‐treated, a region of CpG island within the TLR2 gene was amplified by qPCR and the products were sequenced. Additionally, the mRNA expression of TLR2, TLR4, IL‐6, IL‐12, TNFalpha, IL‐23, IL‐10, TGFbeta, VEGFA and CDH5 was analysed by qPCR. The data were analysed with chi‐square tests, Mann–Whitney or unpaired t‐tests, and Spearman´s correlation; variable adjustments were performed using multiple linear regression (P < 0.05).
Results
TLR2 depicted a hypomethylated DNA profile at the CpG island in SAP when compared with AAP, along with upregulated expression of TLR2, with pro‐inflammatory cytokines IL‐6 and IL‐23, and the angiogenesis marker CDH5 (P < 0.05). TLR2 methylation percentage negatively correlated with mRNA levels of IL‐23 and CDH5 in apical periodontitis. Lower methylation frequencies of single CpG dinucleotides −8 and −10 localized in close proximity to nuclear factor κB (NFκB) binding within the TLR2 promoter were identified in SAP versus AAP (P < 0.05). Finally, unmethylated −10 and −8 single sites demonstrated up‐regulation of IL‐23, IL‐10 and CDH5 transcripts compared to their methylated counterparts (P < 0.05).
Conclusions
TLR2 gene promoter hypomethylation was linked to transcriptional activity of pro‐inflammatory cytokines and angiogenic markers in exacerbated periapical inflammation. Moreover, unmethylated single sites in close proximity to NFκB binding were involved in active transcription of IL‐23, IL‐10 and CDH5.
This paper presents a discrete-time output feedback controller to regulate the output voltage of a DC-DC buck converter. The proposal’s main feature is the application of a discrete-time equivalent ...of the robust exact filtering differentiator. First, the document exposes a theoretical analysis of the closed-loop system, where it is considered the problem of implementing a real-time differentiator with a good relationship between exactness and noise filtration performance. Hence, secondly, the controller in a laboratory setup is presented. The first experimental results suggest that the proposed controller exhibits good robustness against noise and maintains the asymptotic accuracy, even with saturated control inputs, as in the case of the DC-DC buck converter. Consequently, aiming to verify the features of the proposed method, the controller is validated through multiple experiments, showing satisfactory voltage tracking accuracy, good suppression of instantaneous load and supply voltage disturbances, and robustness against bounded measurement noise.
The Human Immunodeficiency Virus (HIV) Viral Infectivity Factor (Vif) is a 192-amino acid accessory protein essential to viral replication which counteracts host APOBEC3 proteins. APOBEC3 proteins ...interfere with the replication of HIV, hepatitis C virus, hepatitis B virus and retrotransposons. Vif is a recent candidate target for therapeutic and preventative interventions in HIV/AIDS yet little is known about its clinical relevance. We describe the results of applying different machine learning algorithms (Apriori, Multifactor Dimensionality Reductor, C4.5, Artificial Neural Networks and ID3) to the search of associations between HIV-1 Vif protein attributes and clinical endpoints. Final iterations showed that the presence of mutations in BC Boxes, APOBEC motifs and Cullin5 binding motifs were together associated with higher initial CD4 T cells while mutations of specific APOBEC motifs coupled with the conservation of other APOBEC motifs were associated with lower historic CD4 T cells. Conservation of specific APOBEC motifs and BC boxes were linked to lower initial viral loads while different combinations of mutations in the Nuclear Localisation Inhibition Signal and BC Boxes were associated with higher historic viral loads. Further scrutiny of these combinations through traditional statistical methods revealed striking differences in both CD4 T cells and viral loads in patients stratified into those having the previous combinations. While artificial intelligence algorithms do not phase out traditional statistical methods, our Artificial Intelligence (AI)-based approach highlights their use at reducing the dimensionality of large and complex datasets and at proposing novel, unimaginable, associations of biological patterns with functional relevance or clinical roles.
To determine Toll-like receptors (TLR)2 and TLR4 expression levels and associate them with matrix metalloproteinases (MMPs) in asymptomatic apical periodontitis (AAP), symptomatic apical ...periodontitis (SAP), and healthy controls. Apical tissue/lesion samples were obtained from chronic AAP (
n
= 35) and SAP (
n
= 29), and healthy periodontal ligament (HPL,
n
= 10) with indication of tooth extraction, respectively. mRNA expression levels of TLR2, TLR4, MMP-1, MMP-2, MMP-8, and MMP-13 were determined by real-time reverse-transcription polymerase chain reaction. The data were analyzed with Kruskal-Wallis and Dunn’s pot hoc test (
p
< 0.05). The correlation coefficient was obtained using the Spearman correlation (
p
< 0.05). TLR2, MMP-1, MMP-2, and MMP-13 mRNA levels were the highest in SAP followed by AAP and controls (
p
< 0.05). TLR4 and MMP-8 were over expressed in AAP and SAP compared to HPL (
p
< 0.05). TLR2 positively correlated with TLR4, MMP-1, MMP-8, and MMP-13 in SAP (
p
< 0.05). TLR2 and TLR4 are overexpressed in apical lesions versus healthy periodontal ligament and correlate with collagenolytic MMPs. Particularly, TLR2 is overexpressed in SAP in association with MMP-1, MMP-8, and MMP-13. Our results suggest that the activation of TLR2 along with MMP overexpression might contribute to SAP clinical presentation and progression. TLRs, MMPs, and their interaction can explain the clinical presentations and evolution of apical periodontitis and might represent key targets for new diagnostic and treatment approaches.
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