The relationship between intervertebral disc degeneration and chronic infection by Propionibacterium acnes is controversial with contradictory evidence available in the literature. Previous studies ...investigating these relationships were under-powered and fraught with methodical differences; moreover, they have not taken into consideration P. acnes' ability to form biofilms or attempted to quantitate the bioburden with regard to determining bacterial counts/genome equivalents as criteria to differentiate true infection from contamination. The aim of this prospective cross-sectional study was to determine the prevalence of P. acnes in patients undergoing lumbar disc microdiscectomy.
The sample consisted of 290 adult patients undergoing lumbar microdiscectomy for symptomatic lumbar disc herniation. An intraoperative biopsy and pre-operative clinical data were taken in all cases. One biopsy fragment was homogenized and used for quantitative anaerobic culture and a second was frozen and used for real-time PCR-based quantification of P. acnes genomes. P. acnes was identified in 115 cases (40%), coagulase-negative staphylococci in 31 cases (11%) and alpha-hemolytic streptococci in 8 cases (3%). P. acnes counts ranged from 100 to 9000 CFU/ml with a median of 400 CFU/ml. The prevalence of intervertebral discs with abundant P. acnes (≥ 1x103 CFU/ml) was 11% (39 cases). There was significant correlation between the bacterial counts obtained by culture and the number of P. acnes genomes detected by real-time PCR (r = 0.4363, p<0.0001).
In a large series of patients, the prevalence of discs with abundant P. acnes was 11%. We believe, disc tissue homogenization releases P. acnes from the biofilm so that they can then potentially be cultured, reducing the rate of false-negative cultures. Further, quantification study revealing significant bioburden based on both culture and real-time PCR minimize the likelihood that observed findings are due to contamination and supports the hypothesis P. acnes acts as a pathogen in these cases of degenerative disc disease.
Bacterial biofilms resist oxidising agents due to the presence of organic matter Jaglic, Z., Vyzkumny Ustav Veterinarniho Lekarstvi, Brno (Czech Republic); Cervinkova, D., Vyzkumny Ustav Veterinarniho Lekarstvi, Brno (Czech Republic); Vlkova, H., Vyzkumny Ustav Veterinarniho Lekarstvi, Brno (Czech Republic) ...
Czech Journal of Food Sciences,
01/2012, Letnik:
30, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This study evaluated the susceptibility of planktonic and biofilm cells of Staphylococcus spp. (n = 87), Klebsiella spp. (n = 30), and Escherichia coli (n = 74) isolates originating from food contact ...surfaces of milk and meat processing plants to benzalkonium chloride (BAC), sodium hypochlorite (NaClO), chloramine B (CAB), and peracetic acid (PAA). Bacterial growth and reduction of viable cells in the presence of disinfectants were determined in tryptone soya broth (TSB) and water, respectively. Biofilm positive isolates (n = 73) were tested for the presence of selected qac genes. Unlike BAC, chlorine-based disinfectants and PAA were poorly efficient in TSB, especially in the case of biofilms. However, when tested in water, the efficacy of NaClO, CAB and PAA substantially increased, which was particularly evident in biofilms. In water, staphylococcal biofilms were even more susceptible to CAB than planktonic cells. A part (23.3%) of the biofilm positive staphylococci carried the qac genes but did not express an increased resistance to BAC. This study showed that bacterial biofilms protected with organic matter could be one of the main reasons for disinfection failure.
The aim of this work was to isolate new DNA markers linked to the Silene latifolia Y chromosome. To do this we created a chromosome-specific plasmid library after DOP-PCR amplification of ...laser-microdissected Y-chromosomes. The library screening led to the isolation of several clones yielding mostly to exclusive male specific hybridization signals. Subsequent PCR confirmed the Y-unique linkage for one of the sequences. This DNA sequence called MK17 has no homology to any known DNA sequence and it is not expressed. Based on PCR and Southern analyses, MK17 is present only in dioecious species of the Elisanthe section of the genus Silene (S. latifolia, S. dioica, and S. diclinis) and it is absent in related gynodioecious and hermaphroditic species. The mapping analysis using a panel of deletion mutants showed that MK17 is closely linked to the region controlling suppression of gynoecium development. Hence MK17 represents a valuable marker to isolate genes controlling the gynoecium development suppression on the Y chromosome of S. latifolia.
Infantile myofibromatosis belongs to a family of soft tissue tumors. The majority of these tumors have benign behavior but resistant and malignant courses are known, namely in tumors with visceral ...involvement. The standard of care is surgical resection. Observations suggest that low dose chemotherapy is beneficial. The treatment of resistant or relapsed patients with multifocal disease remains challenging. Patients that harbor an actionable mutation in the kinase domain are potential subjects for targeted tyrosine kinase inhibitor therapy.
An infant boy with inborn generalized infantile myofibromatosis that included bone, intracranial, soft tissue and visceral involvement was treated according to recent recommendations with low dose chemotherapy. The presence of a partial but temporary response led to a second line of treatment with six cycles of chemotherapy, which achieved a partial response again but was followed by severe toxicity. The generalized progression of the disease was observed later. Genetic analyses were performed and revealed a PDGFRB gene c.1681C>A missense heterozygous germline mutation, high PDGFRβ phosphokinase activity within the tumor and the heterozygous germline Slavic Nijmegen breakage syndrome 657del5 mutation in the NBN gene. Targeted treatment with sunitinib, the PDGFRβ inhibitor, plus low dose vinblastine led to an unexpected and durable response without toxicities or limitations to daily life activities. The presence of the Slavic NBN gene mutation limited standard chemotherapy dosing due to severe toxicities. Sister of the patient suffred from skull base tumor with same genotype and histology. The same targeted therapy led to similar quick and durable response.
Progressive and resistant incurable infantile myofibromatosis can be successfully treated with the new approach described herein. Detailed insights into the biology of the patient's tumor and genome are necessary to understand the mechanisms of activity of less toxic and effective drugs except for up to date population-based chemotherapy regimens.
In previous studies, Propionibacterium acnes was cultured from intervertebral disc tissue of ~25% of patients undergoing microdiscectomy, suggesting a possible link between chronic bacterial ...infection and disc degeneration. However, given the prominence of P. acnes as a skin commensal, such analyses often struggled to exclude the alternate possibility that these organisms represent perioperative microbiologic contamination. This investigation seeks to validate P. acnes prevalence in resected disc cultures, while providing microscopic evidence of P. acnes biofilm in the intervertebral discs.
Specimens from 368 patients undergoing microdiscectomy for disc herniation were divided into several fragments, one being homogenized, subjected to quantitative anaerobic culture, and assessed for bacterial growth, and a second fragment frozen for additional analyses. Colonies were identified by MALDI-TOF mass spectrometry and P. acnes phylotyping was conducted by multiplex PCR. For a sub-set of specimens, bacteria localization within the disc was assessed by microscopy using confocal laser scanning and FISH.
Bacteria were cultured from 162 discs (44%), including 119 cases (32.3%) with P. acnes. In 89 cases, P. acnes was cultured exclusively; in 30 cases, it was isolated in combination with other bacteria (primarily coagulase-negative Staphylococcus spp.) Among positive specimens, the median P. acnes bacterial burden was 350 CFU/g (12 - ~20,000 CFU/g). Thirty-eight P. acnes isolates were subjected to molecular sub-typing, identifying 4 of 6 defined phylogroups: IA1, IB, IC, and II. Eight culture-positive specimens were evaluated by fluorescence microscopy and revealed P. acnes in situ. Notably, these bacteria demonstrated a biofilm distribution within the disc matrix. P. acnes bacteria were more prevalent in males than females (39% vs. 23%, p = 0.0013).
This study confirms that P. acnes is prevalent in herniated disc tissue. Moreover, it provides the first visual evidence of P. acnes biofilms within such specimens, consistent with infection rather than microbiologic contamination.
Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is the most common drug-resistant epilepsy. Despite major advances in epilepsy research, the epileptogenesis of the MTLE-HS is not ...well understood. The altered neuroimmune response is one of the pathomechanisms linked to progressive epileptogenesis in MTLE-HS, and understanding its role may help design future cures for pharmaco-resistant MTLE-HS. Here, the neuroimmune function was evaluated by the assessment of cytokine-chemokine profiles in brain samples from the hippocampus of patients with MTLE-HS.
Brain samples from patients with MTLE-HS collected during epileptosurgical resection (n = 21) were compared to those obtained from autopsy controls (n = 13). The typing of HS was performed according to ILAE consensus classification, and patients were additionally sorted into subgroups based on the severity of neuronal depletion (Wyler grading system). Differences between patients with MTLE-HS with and without a history of febrile seizures were also assessed. RNA was isolated from native samples, and real-time gene expression analysis of cytokine-chemokine profiles, i.e., levels of IL-1β, IL-6, IL-10, IL-18, CCL2, CCL3, CCL4, and STAT3, was carried out by qRT-PCR methodology.
Upregulation of IL-1β (p = 0.001), IL-18 (p = 0.0018), CCL2 (p = 0,0377), CCL3 (p < 0.001), and CCL4 (p < 0.001) in MTLE-HS patients was detected when compared to the post-mortem hippocampal samples collected from autopsy controls. The STAT3 expression was higher in more severe neuronal loss and glial scaring determined by different Wyler grades in HS patients. Furthermore, cytokine-chemokine profiles were not different in MTLE-HS patients with or without febrile seizures.
The upregulation of specific cytokines and chemokines in MTLE-HS provides evidence that the neuroinflammatory process contributes to MTLE epileptogenesis. History of febrile seizures did not alter the immune profiles. Specific immune mediators and related immune pathways represent potential therapeutic targets for seizure control and pharmacoresistancy prevention in MTLE associated with hippocampal sclerosis.
•Cytokine and chemokine signaling contributes to MTLE epileptogenesis.•Specific cytokine-chemokine profiles are upregulated in hippocampal sclerosis.•The expression of cytokines and chemokines was independent of the presence of febrile seizures in MTLE-HS patients.•The STAT3 expression was higher in more severe neuronal loss & glial scaring determined by the different Wyler grades in HS.•Specific cytokine-chemokine profiles may be targeted by future treatments to control seizures or prevent pharmacoresistancy.
Staphylococcus epidermidis may form biofilms in milk processing plants and secondarily contaminate milk products. In this study, the ability of
S. epidermidis to form a biofilm in milk and the ...influence of glucose and NaCl on biofilm formation were analysed. Biofilm production on stainless steel was investigated at 30
°C in pasteurized milk and in milk containing glucose, NaCl or both glucose and NaCl. Biofilm formation was evaluated by monitoring of colony-forming units (cfu) on stainless chips and by real-time quantitative PCR analysis of the
icaA and
σ
B transcripts. An increase in cfu and
icaA transcription was observed after 20
h incubation, especially in milk containing glucose and NaCl. NaCl alone was shown to present a greater risk of biofilm development in milk than glucose alone, but the NaCl/glucose combination represented the highest risk. The
σ
B factor did not seem to be involved in biofilm formation under the conditions of this study.
We established a new auxiliary phylogenetic approach based on genomic in situ hybridization technique (GISH). We used an interspecific hybrid Silene latifolia x Silene viscosa to compare two ...different genomes simultaneously on one slide. By using GISH with genomic DNA from another closely related species as a probe, we directly compared the level of relatedness between the genomes of the studied species and parental species. This experimental design enabled us to approximately estimate evolutionary relationships between the genome of tested plant species and genomes of both parental species of the hybrid by using the ratio of intensities of fluorescence signals. We tested this technique in various Silene species and the results were in accordance with the topology of the phylogenetic tree we constructed based on rDNA sequences. The results were also well correlated with phylogenetic distances between species that we estimated from an rDNA-based phylogenetic tree. Our experimental approach could help to improve tree topology and serve as a useful complementary tool in molecular phylogenetic studies in related species.
This review is a short introduction to phylogenetic analysis. Phylogenetic analysis allows comprehensive understanding of the origin and evolution of species. Generally, it is possible to construct ...the phylogenetic trees according to different features and characters (e.g. morphological and anatomical characters, RAPD patterns, FISH patterns, sequences of DNA/RNA and amino acid sequences). The DNA sequences are preferable for phylogenetic analyses of closely related species. On the other hand, the amino acid sequences are used for phylogenetic analyses of more distant relationships. The sequences can be analysed using many computer programs. The methods most often used for phylogenetic analyses are neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference.
The adherence of microorganisms to surfaces is a critical precondition for biofilm development. In this study, we evaluated the adherence (in amounts capable of biofilm formation) of Staphylococcus ...epidermidis in milk to stainless steel. During a 6-h time frame, the effect of milk temperature and laminar flow on adherence was analysed. In amounts capable of biofilm formation, the cells adhered within 0.5 h; however, at the milk temperatures promoting cell growth (25 and 28 °C), the cells proceeded to detach from the surface when bacteria started to grow (after 2 h), but only during the milk flow. When the temperatures were below the growth limit (6 and 22 °C) or under static conditions, the cells remained attached during the whole monitoring period. This study showed that temperatures which are suboptimal for growth and static conditions support the adhesion S. epidermidis in amounts capable of biofilm formation. On the contrary, at temperatures allowing the growth, adhered cells of S. epidermidis can easily be washed away from the stainless steel surface when bacteria begin to grow.
PDF
