SEARCH · PubMed Health

Results for “Pathogen detection”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources

PubMed2005

A fast, simple, and reliable high-yielding method for DNA extraction from different plant species.

Genetic studies and pathogen detection in plants using molecular methods require the isolation of DNA from a large number of samples in a short time span. A rapid and versatile protocol for extracting high-quality DNA from different plant species is described. This method yields from 1 to 2 mg of DNA per gram of tissue. The absorbance ratios (A260/A280) obtained ranged from 1.6 to 2.0. A minimal presence of contaminating metabolites (as polymerase chain reaction [PCR] inhibitors) in samples and a considerable savings in reagents are characteristics of this protocol, as well as the low cost of the analysis per sample. The quality of the DNA was suitable for PCR amplification.

DNA, Plant↗

PubMed2001

Effect of a single-use sterile catheter for each void on the frequency of bacteriuria in children with neurogenic bladder on intermittent catheterization for bladder emptying.

OBJECTIVE: The frequency of bacteriuria is high in children with neurogenic bladder on intermittent catheterization for bladder emptying. In an effort to decrease bacteriuria, we examined whether the method of catheter care was responsible for the high rate of bacteriuria. For this, the frequency of bacteriuria was examined in the same patient on single-use sterile catheters and on reused clean catheters. METHODS: A prospective, randomized, crossover trial was conducted with 10 patients who were randomized to 4 months of a new, sterile catheter for intermittent catheterization and 4 months of reuse of a clean catheter for intermittent catheterization. Each week, a urine sample was collected and symptoms of infection and medication use were recorded. RESULTS: A total of 158 urine samples were collected during 164 patient-weeks on the new catheter method for each void; 115 (73%) were positive for a pathogen. Of the 161 samples collected during 169 patient-weeks on the standard, reuse method for voiding, 123 (76%) were positive (115 [73%] of 158 vs 123 [76%] of 161). Escherichia coli was the most common pathogen detected during both method periods. CONCLUSION: A new, sterile catheter for each void did not decrease the high frequency of bacteriuria in patients with neurogenic bladder on intermittent catheterization.

Adolescent↗

PubMed2006

Genetics of complex diseases.

Approaches to the study of the genetic basis of common complex diseases and their clinical applications are considered. Monogenic Mendelian inheritance in such conditions is infrequent but its elucidation may help to detect pathogenic mechanisms in the more common variety of complex diseases. Involvement by multiple genes in complex diseases usually occurs but the isolation and identification of specific genes so far has been exceptional. The role of common polymorphisms as indicators of disease risk in various studies is discussed.

Genetic Diseases, Inborn↗

PubMed2005

Nanotechnology and animal health.

Nanotechnology, as a new enabling technology, has the potential to revolutionise agriculture and food systems in the United States of America and throughout the world. Examples of potential applications of nanotechnology in the science and engineering of agriculture and food systems include disease treatment delivery systems, new tools for molecular and cellular biology, the security of agricultural and food systems, new materials for pathogen detection, and protection of the environment. Existing research has clearly demonstrated the feasibility of introducing nanoshells and nanotubes into animal systems to seek out and destroy targeted cells. Nanoparticles smaller than one micron have been used to deliver drugs and genes into cells. Thus, some building blocks do exist in isolation and are expected to be integrated into systems over the next 10 to 15 years. It is reasonable to presume over the next couple of decades that nanobiotechnology industries and unique developments will revolutionise animal health and medicine.

Animal Welfare↗

PubMed2002

Solid-phase PCR in microwells: effects of linker length and composition on tethering, hybridization, and extension.

During the solid-phase PCR (SP-PCR), DNA oligonucleotides complementary to a soluble template and immobilized on a surface are extended in situ. Although primarily used for pathogen detection, SP-PCR has the potential for much broader application, including disease diagnostics, genotyping, and expression studies. Current protocols for SP-PCR in microwells are suitable for enzymatic detection of immobilized products, but yields are generally insufficient for direct detection of products using conventional fluorescent probes. Here, we quantitatively measure the outcome of tethering, hybridization, and solid-phase extension, and examine the effect of composition and length of the spacer at the 5' end of tethered oligonucleotides. Our results indicate that steric hindrance primarily affects polymerase activity rather than the efficiency of hybridization between the template and the tethered oligonucleotide. SP-PCR yields are significantly higher for a five-unit hexaethyleneglycol (HEG) spacer than for the more commonly used 10-residue deoxythymidine spacer. The optimal 5' HEG spacer resulted in a 60-fold increase in extension efficiency relative to a previously reported value for SP-PCR on a glass surface. Thus, optimized spacers should allow direct quantification of SP-PCR products, providing a simple, quantitative, and cost effective means of sample analysis for a variety of applications.

Arabidopsis↗

PubMed1988

Treatment of angular cheilitis. The significance of microbial analysis, antimicrobial treatment, and interfering factors.

This prospective study evaluated the significance of microbial analysis and antimicrobial treatment for the cure of angular cheilitis. Furthermore, various etiologic factors were investigated for their relative effect on the healing process. The study included 1) an open trial with 50 patients infected by Candida albicans and/or Staphylococcus aureus, and 2) an intraindividual comparison of eight patients with bilateral lesions infected by Candida albicans as the only detected pathogen. After a base-line examination the patients received ointments containing nystatin and/or fusidic acid, on the basis of the outcome of an initial microbial analysis. The patients were evaluated clinically, photographed, and examined for microorganisms at different time intervals. Ninety-six per cent of the patients who participated in the open trial had no sign of infection after 42 days of treatment. Lesions in the double-blind study, treated with nystatin, were healed after 28 days, whereas lesions that received placebo persisted throughout the treatment period. Increasing age, dry skin, and extended skinfolds at the corner of the mouth were factors closely related to the length of the healing process.

Adult↗

PubMed1991

Diarrheal disease due to Clostridium difficile in general practice.

A total of 288 stool samples from patients attending their general practitioners was examined for the presence of Clostridium difficile. C. difficile or its cytotoxin was found in 16 patients (5.5%) and was the most common enteric pathogen detected. Most patients had only mild to moderate diarrhea but in the majority of patients the diarrhea was protracted. Eleven of the 16 patients had received antimicrobial agents in the 3 mths preceding onset of diarrhea and there was good circumstantial evidence that 2 other patients had also been exposed. None of the patients had a history of any inflammatory bowel disease or possible occupational exposure. The prescribing habits of general practitioners with regard to antimicrobial agents were monitored for a 1 yr period. Tetracyclines and amoxycillin accounted for approximately 25% each of all prescriptions dispensed. Ten of the 16 patients were treated with antimicrobials (mainly metronidazole) and in most cases the diarrhea resolved. We conclude that C. difficile may be a significant cause of community-acquired diarrhea.

Adult↗

PubMed1987

Multiple infusions of cloxacillin for treatment of mastitis during the dry period.

Efficacy of multiple and single intramammary infusions of benzathine cloxacillin (500 mg/quarter) were compared for treatment of mastitis during the dry period. Treatments were three infusions, one each at 0, 7, and 14 d into the dry period; one infusion at drying off; and no infusions. Cows were grouped (30/treatment) based on previous mastitis history, mean monthly SCC, mature equivalent milk production, and pathogen detected pretreatment. Infected quarters/cow at parturition, posttreatment were 1.26, 1.6, and 2.35 for multiple, single, and no infusion groups, respectively. Milk production and somatic cell count posttreatment were not affected by treatment. Across all genera of microorganism, 75.5, 73.6, and 52.8% of infections were eliminated in the multiple, single, and no infusion groups, respectively. Primary effect of multiple infusions with cloxacillin in the dry period was to prevent new streptococcal infections. Sensitivity tests on staphylococcal isolates indicated that cloxacillin was still an effective dry cow treatment after 7 yr of use in the herd. Resistance to cloxacillin in approximately half the posttreatment staphylococcal isolates appeared to be nonenzyme (penicillinase) dependent. Multiple dry cow treatments with cloxacillin do not offer any advantage over a single treatment.

Animals↗

PubMed2000

Monitoring Piscirickettsia salmonis by denaturant gel electrophoresis and competitive PCR.

Reported strains of Piscirickettsia salmonis, a pathogen of salmonid fishes, were analyzed by amplifying part of the internal transcribed spacer (ITS) of the ribosomal RNA (rRNA) operon followed by denaturing gradient gel electrophoresis (DGGE) of the amplicons. All amplified fragments differing in sequence were distinguished by migration during DGGE. A simpler format, constant denaturant gel electrophoresis (CDGE), allowed the same diagnostic distinctions among strains. Sampling during 1997 and 1998 of salmonids from 5 different sites on and near Chiloé Island in southern Chile displaying piscirickettsiosis revealed only P. salmonis resembling LF-89, the type strain first isolated in 1989. These observations are encouraging for control strategies, which might otherwise be compromised by unpredictable shifts of P. salmonis types in salmon farms. A competitive PCR assay offered insight about the power of PCR for quantification and about specific tissue invasiveness by this intracellular pathogen. This approach revealed that the PCR could amplify approximately 1 to 10 P. salmonis genome equivalents against a background of > 99.9% salmonid DNA. It also raised the possibility that the salmonid brain is an important site for P. salmonis survival, with its bacterial load in 1 individual having been about 100 times the loads observed in liver and kidney. Pathogen detection by competitive PCR in a surface seawater sample from a netpen in use indicated a density of about 3000 to 4000 P. salmonis cells (or their DNA remnants) 1(-1). Such quantitative estimates should aid decisions about disease prevention and management as, for example, choice of netpen sites following fallow periods and certification of ova, which are known conduits of infection.

Animals↗

PubMed2000

A dual infection of infectious salmon anaemia (ISA) virus and a togavirus-like virus in ISA of Atlantic salmon Salmo salar in New Brunswick, Canada.

Two viruses, infectious salmon anaemia (ISA) virus and a novel togavirus-like virus, were isolated from ISA disease outbreaks that were first reported as a new syndrome, haemorrhagic kidney syndrome (HKS) affecting farmed Atlantic salmon Salmo salar L. on the East coast of Canada. Laboratory confirmation of ISA diagnosis was initially complicated by isolation of only the togavirus-like agent using the CHSE-214 cell line. Here we demonstrate that a clinical sample from a disease outbreak of ISA contained a mixture of ISA virus and togavirus-like virus. Reverse transcriptase-polymerase chain reaction (RT-PCR) confirmed the presence of both viruses during serial passage of cultures in SHK-1 and CHSE-214 cells. Virus harvested at passage level 3 in both cell lines caused high mortalities and severe gross pathology consistent with ISA virus infection in experimentally inoculated Atlantic salmon parr (approximately 35 g) in freshwater, beginning 12 d post inoculation. ISA virus was detected by virus isolation from kidney and liver tissues of all dead or moribund fish tested. A comparison of virus isolation, 1-step procedure RT-PCR and RNA dot-blot hybridization for detection of ISA virus (ISAV) in fish tissues showed virus isolation to have 100% sensitivity, followed by RT-PCR (66 and 28% sensitivity in kidney and liver, respectively), with RNA dot-blot hybridization as the least sensitive method (20 and 10% sensitivity in kidney and liver, respectively). No togavirus-like virus was detected in these samples by virus isolation. Moreover, another togavirus-like virus isolate grown in CHSE-214 cells in the absence of any other detectable pathogen was non-pathogenic in experimentally inoculated fish. This study confirms that the original ISA outbreaks in New Brunswick, Canada, were caused solely by ISAV.

Animals↗

PubMed2026

Whole-Genome Sequencing Reveals Co-Infection with Bovine Viral Diarrhea Virus, Bovine Enterovirus, and Caprine Parainfluenza Virus Type 3 in a Calf from a Cattle Herd in Xizang, China.

Although mixed viral infections are increasingly recognized as contributors to bovine diarrhea syndrome, diagnosing such co-infections remains challenging, particularly in high-altitude regions where surveillance is limited. In July 2024, a calf presenting with severe diarrhea and respiratory distress was identified on a cattle farm in Linzhi, Xizang, China. Using unbiased whole-genome sequencing (WGS) of the fecal sample, we assembled near-complete genomes of three distinct RNA viruses: two bovine viral diarrhea virus type 1 (BVDV-1) strains (subtypes 1v and 1q, designated BVDV-1/XZ87 and XZ87), one bovine enterovirus (genotype EV-E, designated BEV/XZ87), and one caprine parainfluenza virus type 3 (CPIV3/XZ87). The CPIV3/XZ87 genome exhibited 99.9% nucleotide identity to the goat-derived GS2017-2 strain from Jiangsu, China, raising the possibility of viral spread through livestock trade. Quantitative real-time PCR (RT-qPCR) confirmed the presence of all three pathogens (Ct values: 24.78 for BEV, 25.98 for CPIV3, and 31.28 for BVDV). This study provides the genomic evidence of a triple co-infection involving BVDV-1, BEV, and CPIV3 in Xizang. It illustrates the potential of WGS for unbiased pathogen detection in complex clinical specimens. The near-complete genomes generated here fill critical gaps in the virological surveillance of this epidemiologically under-sampled high-altitude region.

bovine enterovirus↗

PubMed2001

[A case of pediatric recurrent acute mastoiditis caused by penicillin-resistant Streptococcus pneumonia complicated by primary immunodeficiency].

Penicillin-resistant Streptococcus pneumoniae (PRSP) is a frequently detected pathogen of intractable acute otitis media and is associated with prolonged or recurrent infection. The use of antibiotics has made the incidence of secondary acute mastoiditis following acute otitis media relatively rare, but when it does occur, its severe complications may be life-threatening. We report a case of pediatric recurrent acute mastoiditis caused by PRSP in a 6-year-old boy suffering from PRSP acute mastoiditis on 4 occasions, twice undergoing simple mastoidectomy. Although we initially suspected PRSP to be the chief factor in iterative infection, immunological analysis demonstrated significantly decreased IgG and IgA antibodies in serum and the patient was diagnosed as having common variable immunodeficiency (CVID). As the first middle ear infection occurred at the age of 6 and there was no history of upper respiratory tract infection, CVID may be the main pathological factor of recurrent mastoiditis, although infection occurred, only in the ear and did not involve other organs. This suggests that recurrent mastoiditis in the present case involved the coexistence of PRSP and CVID.

Acute Disease↗

PubMed2026

Discarding Bedside Cart Paper-Packaged Supplies Between Patients: What Evidence Is Required?

BACKGROUND: Discarding paper-packaged sterile supplies from bedside supply carts between patients in pediatric intensive care units (PICUs) is a potential practice to target for environmental stewardship. OBJECTIVES: To determine opinions about this practice, including what evidence should be required to implement and what evidence would be adequate to abandon it. METHODS: A survey was distributed to all pediatric intensivists engaged in multicenter research in Canada and to all PICU nurses at one institution in Canada. RESULTS: The response rate was 75 of 254 (30%). The practice occurred in 54 (72%) of the respondents' units. Ten respondents (13%) agreed the practice was effective in preventing nosocomial infections. Most respondents agreed the practice should be based on empirical evidence, including a combination of improved patient outcomes (n = 57, 76%), rate of contamination of supplies within the supply carts (n = 55, 73%), and survivability of pathogens inoculated onto paper (n = 56, 75%). Most respondents agreed they would be comfortable with a randomized controlled trial (n = 52, 69%) and would support action based on the results (n = 54, 72%). The potential trial outcome most highly ranked was next-patient nosocomial infection with pathogen from the previous patient (n = 23, 31%); this was ranked more often by intensivists (P = .005). Other outcomes highly ranked included next-patient colonization with pathogen from the previous patient (n = 44, 59%) and pathogen detection on supplies within the supply cart (n = 43, 57%). CONCLUSIONS: Most respondents agreed that the practice was not based on empirical evidence, agreed the practice should be based on empirical evidence, and would agree to a randomized trial with patient-important outcomes.

Humans↗

PubMed2003

The Toll-like receptor 5 stimulus bacterial flagellin induces maturation and chemokine production in human dendritic cells.

Toll-like receptors (TLRs) are pattern recognition receptors that serve an important function in detecting pathogens and initiating inflammatory responses. Upon encounter with foreign Ag, dendritic cells (DCs) go through a maturation process characterized by an increase in surface expression of MHC class II and costimulatory molecules, which leads to initiation of an effective immune response in naive T cells. The innate immune response to bacterial flagellin is mediated by TLR5, which is expressed on human DCs. Therefore, we sought to investigate whether flagellin could induce DC maturation. Immature DCs were cultured in the absence or presence of flagellin and monitored for expression of cell surface maturation markers. Stimulation with flagellin induced increased surface expression of CD83, CD80, CD86, MHC class II, and the lymph node-homing chemokine receptor CCR7. Flagellin stimulated the expression of chemokines active on neutrophils (IL-8/CXC chemokine ligand (CXCL)8, GRO-alpha/CXCL1, GRO-beta/CXCL2, GRO-gamma/CXCL3), monocytes (monocyte chemoattractant protein-1/CC chemokine ligand (CCL)2), and immature DCs (macrophage-inflammatory protein-1 alpha/CCL3, macrophage-inflammatory protein-1 beta/CCL4), but not chemokines active on effector T cells (IFN-inducible protein-10 kDa/CXCL10, monokine induced by IFN-gamma/CXCL9, IFN-inducible T cell alpha chemoattractant/CXCL11). However, stimulating DCs with both flagellin and IFN-inducible protein-10 kDa, monokine induced by IFN-gamma, and IFN-inducible T cell alpha chemoattractant expression, whereas stimulation with IFN-beta or flagellin alone failed to induce these chemokines. In functional assays, flagellin-matured DCs displayed enhanced T cell stimulatory activity with a concomitant decrease in endocytic activity. Finally, DCs isolated from mouse spleens or bone marrows were shown to not express TLR5 and were not responsive to flagellin stimulation. These results demonstrate that flagellin can directly stimulate human but not murine DC maturation, providing an additional mechanism by which motile bacteria can initiate an acquired immune response.

Adjuvants, Immunologic↗

PubMed2005

Cutting edge: MyD88 controls phagocyte NADPH oxidase function and killing of gram-negative bacteria.

MyD88 is an adaptor protein for the TLR family of proteins that has been implicated as a critical mediator of innate immune responses to pathogen detection. In this study, we report that MyD88 plays a crucial role in killing Gram-negative bacteria by primary macrophages via influencing NADPH oxidase function. Peritoneal macrophages from MyD88-/- mice exhibited a marked inability to kill Escherichia coli (F18) or an attenuated strain of Salmonella typhimurium (sseB) in vitro. This defect in killing was due to diminished NADPH oxidase-mediated production of superoxide anion in response to bacteria by MyD88-/- phagocytes as a consequence of defective NADPH oxidase assembly. Defective oxidase assembly in MyD88-deficient macrophages resulted from impaired p38 MAPK activation and subsequent phosphorylation of p47phox. Together these data demonstrate a pivotal role for MyD88 in killing Gram-negative bacteria via modulation of NADPH oxidase activity in phagocytic cells.

Adaptor Proteins, Signal Transducing↗

PubMed1997

Cryptosporidium parvum in children with diarrhea in Zulia State, Venezuela.

The prevalence and importance of Cryptosporidium parvum as a causal agent of acute diarrhea among pediatric patients from Zulia State, Venezuela was assessed. Single stool specimens were collected from 310 children 0-60 months of age with acute diarrheal disease who were admitted to three public hospitals and from 150 comparable control children without gastrointestinal symptoms who were seen as outpatients. Cryptosporidium parvum oocysts were identified in 35 (11.2%) of 310 children with diarrhea and the coccidium was the single detectable pathogen in only 12 (34.2%). Other potential pathogenic parasites were present in most of the patients shedding oocysts (23 of 35, 65%). In nondiarrheal control children, oocysts were identified in nine (6%) of 150. The data suggest that C. parvum is relatively highly endemic in children 0-60 months of age in Zulia State and that although C. parvum may be an important pathogen associated with diarrhea, it may be a cause of only a small proportion of diarrheal episodes.

Acute Disease↗

PubMed2000

Growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes in egg products held at different temperatures.

Growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes in steamed eggs and scrambled eggs held at different temperatures (5, 18, 22, 37, 55, and 60 degrees C) were investigated in the present study. Among the holding temperatures tested, both pathogens multiplied best at 37 degrees C followed by 22, 18, and 5 degrees C. In general, E. coli O157:H7 grew better in the egg products than L. monocytogenes did at all the storage temperatures tested except at 5 degrees C. E. coli O157:H7 did not grow in steamed eggs and scrambled eggs held at 5 degrees C. L. monocytogenes showed a slight population increase of approximately 0.6 to 0.9 log CFU/g in these egg products at the end of the 36-h storage period at 5 degrees C. The population of both pathogens detected in the egg products was affected by the initial population, holding temperature, and length of the holding period. It was also noted that L. monocytogenes was more susceptible than E. coli O157:H7 in steamed eggs held at 60 degrees C. After holding at 60 degrees C for 1 h, no detectable viable cells of L. monocytogenes with a population reduction of 5.4 log CFU/g was observed in steamed eggs, whereas a lower population reduction of only approximately 0.5 log CFU/ml was noted for E. coli O157:H7.

Animals↗

PubMed1999

[Reasons for the application of medical ozone in the treatment of chronic purulent mesotympanitis].

Ozone-oxygen mixture (ozone concentration 600 microg/l) was used in irrigations of the tympanic cavity in 52 patients with chronic purulent mesotympanitis (CPM). The course of the treatment consisted of 5-7 procedures. 18 CPM controls received standard treatment without the irrigations. The course of the ozone-oxygen irrigations produced good results: ear discharge and tympanic mucosa inflammation stopped in 81% of the irrigated patients, levels of myeloperoxidase which marks inflammation reduced significantly, bactericidal effects of the mixture were observed for all the detected pathogens, antibiotic sensitivity of the bacteria rose. Fast antiinflammatory result of ozone therapy was due not only to its bactericidal effect but also via its antihypoxic and immunomodulating mechanisms.

Chronic Disease↗